JPH07304534A - Paper sheet carrying device - Google Patents

Abstract

PURPOSE:To enable an efficient and smooth carry by obtaining an excellent grip condition by utilizing a deformed degenerative mode of ultrasonic vibrators. CONSTITUTION:First and fourth disk-shaped ultrasonic vibrators 31 to 34 are arranged and installed on a support shaft 2 which is parallel to a surface of a paper sheet 4 to be carried and is orthogonal to the carrying direction. The first vibrator 31 and the second vibrator 32 are arranged in a left end part by making a pair, and the third vibrator 33 and the fourth vibrator 34 are arranged in a right end part by making a pair, and are respectively driven by driving sources 81 to 84 so as to create elliptic motion of a deformed degenerative mode. They are driven so that the elliptic motions of the first and the fourth vibrators 31 and 34 are mutually put in the same phase, and the elliptic motions of the second and the third vibrators 32 and 33 have a phase difference of 180 deg. to these.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper sheet conveying apparatus which uses a disc-shaped ultrasonic vibrator and conveys paper sheets by a frictional force utilizing its standing wave.

[0002]

2. Description of the Related Art Generally, as a paper feeding mechanism for printers and copying machines, a system in which the rotation of a motor is transmitted to a rubber roller through a speed reduction mechanism is used. Recently, instead of this, a transfer technique utilizing a standing wave of an ultrasonic transducer has been proposed. The operating principle is to generate an elliptic motion at a specific point by combining two orthogonal vibrations of an ultrasonic oscillator, and convert the elliptic motion into a frictional force to propel a paper sheet. As a concrete operation method, the same-shaped degenerate mode that synthesizes two bending vibrations, the odd-shaped degenerate mode that synthesizes radial expansion and contraction and in-plane bending (or longitudinal vibration and bending), and two oscillators are arranged orthogonally. There is a composite vibration mode or the like that obtains their combined vibration.

For example, Japanese Patent Laid-Open Publication No. 2-215629 and Japanese Patent Publication No. 5-88676 have been proposed as an ultrasonic wave transporting device utilizing the modified degenerate mode.

[0004]

In the ultrasonic degenerate mode ultrasonic wave transfer using a standing wave, for example, a range of 0 ≦ ωt ≦ π / 2 and 3π / 2 ≦ ωt ≦ 2π during one rotation of the elliptical motion. Only in the case, the mass point of the ultrasonic transducer comes into contact with the paper and the frictional force acts. During other time periods when the frictional force is in the anti-feeding direction, the paper is in a free (non-grip) state and is fed by inertial force. The ultrasonic vibrator is normally pressed to the paper side by a spring, etc., but because the driving frequency of the ultrasonic vibrator is high, the pressing force of the spring cannot follow the elliptical motion of the vibrator and is non-grip in the anti-feed direction. It becomes. For this reason, there are problems that the efficiency of paper feeding is poor and that the amount of feeding varies so that the paper cannot be fed straight.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a paper sheet transporting device that achieves a good grip state by utilizing the deformed degenerate mode of an ultrasonic transducer and enables efficient and smooth transport.

[0006]

According to the present invention, a disc-shaped ultrasonic transducer is AC-driven to be conveyed by synthesizing a radial stretching vibration and an in-plane bending vibration in a direction orthogonal thereto. A device for producing an elliptical motion at a mass point in contact with a paper sheet, converting the elliptical motion into a frictional force to convey the paper sheet,
Support shafts arranged in a direction parallel to the paper surface of the paper sheets to be conveyed and orthogonal to the conveying direction, and arranged on the support shafts, with specific points on the outer periphery as mass points, through the paper sheets. The first, second, third and fourth ultrasonic transducers opposed to each other by the opposing members and the elliptic motions of the first and fourth ultrasonic transducers arranged on both outer sides have the same phase, The second and third ultrasonic transducers arranged inside have a driving means for alternating-current driving these transducers so that the elliptical movements of the second and third ultrasonic transducers have a phase difference of 180 ° with respect to this. .

In the present invention, the first ultrasonic transducer and the second ultrasonic transducer, and the third ultrasonic transducer and the fourth ultrasonic transducer, which are driven in opposite phases to each other, respectively Can be joined together through an insulating vibration absorbing member to form a unit structure, and the two units can be arranged at a predetermined interval. Alternatively, these first to fourth ultrasonic transducers may be arranged at equal intervals. Also, the first to the fourth
The facing member facing the ultrasonic transducer may be a roller, or the facing members arranged to face the first, second, third and fourth ultrasonic transducers, respectively, and facing each other. Alternatively, the fifth, sixth, seventh, and eighth ultrasonic transducers may be AC-driven so that the elliptic motions of the mass points are opposite to each other.

[0008]

According to the present invention, among the four ultrasonic transducers,
The first ultrasonic transducer and the second ultrasonic transducer adjacent to the first ultrasonic transducer have a relation that when one is in a grip state in which a frictional force is applied to a paper sheet, the other is in a non-grip state. It is alternately repeated to obtain an excellent grip state as a whole. 4th ultrasonic transducer and 3rd adjacent to it
The same applies to the ultrasonic transducer of. Therefore, it becomes possible to efficiently convey the paper sheets, and it becomes possible to smoothly convey the paper sheets with little variation.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a sheet conveying device according to an embodiment of the present invention. A support shaft 2 is attached to the frame body 1 so as to be parallel to the surface of the paper 4 to be transported and orthogonal to the transport direction (direction perpendicular to the paper surface of the drawing), and the support shaft 2 has a disk-like shape. The 1st-4th ultrasonic transducers 31-34 are arranged and attached. First ultrasonic transducer 31 and second
Of the ultrasonic transducers 32 are arranged at the left end in the paper width direction of the figure, and the third ultrasonic transducer 33 and the fourth ultrasonic transducer 34 form a pair, and are arranged in the paper width direction of the figure. It is located at the right end.

The first to fourth ultrasonic transducers 31 to 34 are
Each of the driving sources 81 to 84 is AC-driven so as to generate an elliptic motion at a mass point in contact with the sheet 4 by synthesizing a radial stretching vibration and an in-plane bending vibration in a direction orthogonal to the radial stretching vibration. The specific driving method will be described later. 1st to 4th
Of the ultrasonic transducers 31 to 34, the first transducer 31 on the left outer side and the second transducer 32 on the inner side adjacent to the first transducer 31 are integrated with each other through the insulating vibration absorbing member 91. 4 oscillators 3 on the right outside
4 and the inner third vibrator 33 adjacent thereto are integrated via an insulating vibration absorbing member 92 to form another vibrator unit.

These first to fourth ultrasonic transducers 31 to 3
In this embodiment, the rollers 4 and 7 supported by another support shaft 5 attached to the frame 1 are used as the facing members 4 facing each other with the paper 4 in between.
The rollers 6 and 7 are rotatably attached to the support shaft. These rollers 6 and 7 are preferably hard ones, for example, made of metal so as not to absorb the vibrations of the first to fourth ultrasonic transducers 31 to 34 for conveying the paper.

The first to fourth ultrasonic transducers 31 to 34 are
For example, as shown in FIG. 2, a disk-shaped (ring-shaped) piezoelectric ceramic is subjected to polarization treatment in its thickness direction to form fan-shaped four-divided electrodes on both surfaces. A specific point A on the outer circumference of the vibrator is set as a mass point to be brought into contact with the sheet, and two electrodes in the radial direction passing through the mass point A are driven by an alternating signal of, for example, cos ωt, and two electrodes in a direction orthogonal to these are driven.
It drives with alternating current signals of mutually opposite phases of sin ωt and −sin ωt. At this time, stretching vibration ((R, 1) mode vibration) indicated by solid arrows A1 and B1 and broken arrows A2 and B2 occurs in the vibrator in a radial direction including the mass point A, and a direction orthogonal to the stretching vibration is generated. Solid arrows C1 and D2 and dashed arrow C
In-plane bending vibration indicated by 2 and D2 ((1,1) mode vibration)
Occurs. The phase difference between these vibrations is 90 °, which is the same as the phase difference between the drive signals, and the mass A will have an elliptical motion due to the combination of both vibrations.

The concrete driving method of the first to fourth ultrasonic transducers 31 to 34 in this embodiment is as follows. Focusing on the first ultrasonic transducer 31 and the second ultrasonic transducer 32 that form a unit at the left end of FIG. 1, these are driven by AC signals that are 180 ° out of phase with each other by drive sources 81 and 82. To be done. In other words, the elliptic motion generated by the first ultrasonic transducer 31 and the elliptical vibration generated by the second transducer 32 are 180 ° out of phase with each other.

The relationship between the four ultrasonic transducers 84 and the third ultrasonic transducers 83 forming the unit at the right end is similar, and the right outer fourth ultrasonic transducer 34 is the left outer one. Elliptical vibration having the same phase as that of the first ultrasonic transducer 31 is generated, and the third ultrasonic transducer 83 and the second ultrasonic transducer 82 on the inner side generate elliptical vibration having the same phase. Therefore, in practice, among the drive sources 81 to 84 in FIG. 1, the drive sources 82 and 83 can be integrated, and the drive sources 81 and 84 can be integrated.

FIGS. 3 (a) and 3 (b) respectively drive the first and fourth ultrasonic transducers 31 and 34 and the second and third ultrasonic transducers 32 and 33 to the four-divided electrodes. The mutual phase relationship of signals is shown. First and fourth ultrasonic transducers 3
Cos ωt for the two electrodes for stretching vibration of 1,34, and sin ωt, −sin ω for the two electrodes for in-plane bending vibration.
The signal t is given. The cos (ωt−) is applied to the two electrodes for stretching vibration of the second and third ultrasonic transducers 32 and 33.
π), sin (ω) on each of the two electrodes due to in-plane bending vibration.
Signals of t−π) and −sin (ωt−π) are given.

At this time, the first and fourth ultrasonic transducers 3
The mass points A of 1, 34 and the second and third ultrasonic transducers 3
The elliptic motions of the mass points B of 2, 33 are respectively as shown in FIG.
It becomes like (b). As shown, the elliptic motions of the mass points A and B are 180 ° out of phase with each other. Therefore, according to this embodiment, the outer first and fourth ultrasonic transducers 3
While the sheets 1 and 34 are gripping the sheet 4, the inner second and third ultrasonic transducers 32 and 33 are in a non-grip state, and the inner second and third ultrasonic transducers 32 and 33 are While the paper 4 is being gripped, the operation in which the outer first and fourth ultrasonic transducers 31 and 34 are in the non-grip state is repeated.

FIG. 5A shows a transfer velocity waveform by the first and fourth ultrasonic transducers 31 and 34 on the outer side, and FIG.
(B) is the inner second and third ultrasonic transducers 32, 3
3 shows a transport speed waveform according to No. 3. These are cos ωt and cos (ωt, which are obtained by differentiating relatively in-plane bending vibration waveforms represented by sin ωt and sin (ωt−π), respectively.
The waveform is −π). 0 to 2 shown in FIG.
The first and fourth ultrasonic transducers 3 in one cycle of the elliptic motion of π
1, 34 are 0 ≦ ωt ≦ π / 2 and 3π / 2 ≦ ωt ≦ 2
The sheet 4 is conveyed at π, and the second and third ultrasonic transducers 32 and 33 convey the sheet 4 during the remaining period π / 2 ≦ ωt ≦ 3π / 2.

As described above, according to this embodiment, four ultrasonic transducers are used to form two pairs, and each pair is driven so as to alternately grip the paper.
High transport efficiency can be obtained as a whole. Further, variations in conveyance are reduced, and smooth sheet conveyance is possible.

FIG. 6 is data supporting the effect of this embodiment. This is the four ultrasonic transducers 31 shown in FIG.
The results are obtained by variously selecting the phase relationship of the elliptic motion according to ˜34 and varying the drive signal frequency to obtain the transport speed.
When (0,180,180,0) is the phase 0 ° of the elliptic motion of the first and fourth ultrasonic transducers 31 and 34, the elliptical motion of the second and third ultrasonic transducers 32 and 33 is The phase of 180
This is the case corresponding to the above-described embodiment in which the angle is 0 °. A clearly higher transport speed is obtained as compared with the case of setting other phase relationships. For example, compared with the case of (0,0,0,0) in which all ultrasonic transducers are driven in phase, about 20
A feed rate improvement of about 10% is recognized. This is a result of reduced slippage.

The relationship between the conveying speeds of the conventional example and the embodiment will be described with reference to FIG. Here, in the conventional example, for example, in the configuration of FIG. 1, when four ultrasonic transducers 31 to 34 are driven so that their elliptic motions are all in phase, that is, in the data of FIG. 6, (0, 0, 0, 0).

In the conventional example shown in FIG. 7 (a), the action speed can be obtained for the sheet as described above during one cycle of the elliptic motion: 0≤ωt≤π / 2 and 3π / 2≤ωt≤. It is a period of 2π, and the average action speed Vmean1 in these periods is
The maximum action speed Vmax is expressed by the following formula 1.

[0022]

[Formula 1] Vmean1 = 0.637 × Vmax

Since the minimum action speed is Vmin = 0 and the inertial force acts for a non-grip period, the average action speed Vmean2 for one cycle of the elliptic motion is approximately the following expression 2.

[0024]

[Formula 2] Vmean2 = Vmean1 / 2 to Vmax / π

On the other hand, in the case of the embodiment shown in FIG. 7B, the minimum action speed is Vmin = 0, but it is shown by the solid line.
The action speed of cos ωt and the action speed of cos (ωt-π) are alternately compensated, and the average action speed Vmean in one cycle of the elliptic motion is expressed by the following mathematical expression 3.

[0026]

(3) Vmean = 0.637 × Vmax to 2Vmax / π

Now, the velocity fluctuation rate with respect to the average action speed in one cycle of the elliptical motion is defined as the plus side velocity change rate = (maximum action rate-average action rate) / average action rate, and the minus side velocity change rate = ( Minimum action rate-average action rate) / average action rate. Then, in the case of the conventional example of FIG. 7A, the rate of speed variation becomes the following expression 4.

[0028]

## EQU00004 ## Positive speed fluctuation rate = {(Vmax-Vmean2) / Vmean2} * 100 = (. Pi.-1) * 100 = + 214 [%] Negative speed fluctuation rate = {(Vmin-Vmean2) / Vmean2} * 100 = (0-1) × 100 = −100 [%]

On the other hand, in the case of the embodiment shown in FIG. 7B, the speed variation rate is as shown in the following expression 5.

[0030]

## EQU00005 ## Positive side speed fluctuation rate = {(Vmax-Vmean) / Vmean} * 100 = (. Pi./2-1)*100=+57[%] Negative side speed fluctuation rate = {(Vmin-Vmean) / Vmean } × 100 = (0-1) × 100 = −100 [%]

As is clear from the above comparison results, according to this embodiment, the fluctuation rate of the transport speed is also small, and excellent transport performance can be obtained.

FIG. 8 shows a sheet conveying device according to another embodiment of the present invention. The parts corresponding to those in the embodiment of FIG. 1 are designated by the same reference numerals as those in FIG. 1 and their detailed description is omitted. In this embodiment, the first, second, third and fourth ultrasonic transducers 31, 3 are
Instead of the rollers, the fifth, sixth, seventh and eighth ultrasonic transducers 35, 36, 37 and 38 are arranged as members facing 2, 33 and 34, respectively. Fifth
Between the ultrasonic transducer 35 and the sixth ultrasonic transducer 36 and between the seventh ultrasonic transducer 37 and the eighth ultrasonic transducer 38 by insulating vibration absorbing members 93 and 94. They are joined and integrated as a vibrator unit.

The fifth, sixth, seventh and eighth ultrasonic transducers 35, 36, 37 and 38 are opposed to the first and the first ultrasonic transducers 35, 36, 37 and 38, respectively.
The same drive signal as that of the second, third, and fourth ultrasonic transducers 31, 32, 33, and 34 is supplied, and the same conveying force is applied to the sheet 4 from above and below with the sheet 4 interposed therebetween. This state is shown in FIGS. 9 and 10 in correspondence with FIGS.

The mass point A of the first and fourth ultrasonic transducers 31 and 34 and the mass point C of the fifth and eighth ultrasonic transducers 35 and 38 facing the mass point A are ellipses that rotate in opposite directions. A motion is generated and acts on the sheet 4 as a conveying force in the same direction. Similarly, the mass point B of the second and third ultrasonic transducers 32, 33
And the sixth and seventh ultrasonic transducers 36,
With the mass point D of 37, elliptical motions of mutually opposite rotations are generated and act on the sheet 4 as a conveying force in the same direction. This embodiment also enables high-performance transportation.

In the above embodiment, the ultrasonic transducer is 4
Although the split electrode type is used, the present invention is not limited to this. For example, it is possible to use an ultrasonic transducer using a 2-split electrode type shown in FIG. 11A, an 8-split electrode type shown in FIG. 11B, and a 12-split electrode structure shown in FIG. 11C. . Even if these ultrasonic vibrators are used, elliptical vibrations in the deformed degenerate mode can be generated, and therefore, the conveyance performance can be improved by the combination of the AC drives similar to those in the embodiment.

Further, in the embodiment, the first ultrasonic transducer 31
And the second ultrasonic transducer 32 as a pair, the third ultrasonic transducer 33 and the fourth ultrasonic transducer 34 as a pair, and these pairs are integrated as a unit. However, as described in the embodiment, these four ultrasonic transducers have the same elliptical motion by the outer first and fourth ultrasonic transducers 31 and 34, and the inner second and third ultrasonic transducers. It suffices that the elliptical motions of the ultrasonic transducers 32 and 33 have a phase relationship of 180 ° out of phase with respect to this, as shown in FIG.
They may be arranged at equal intervals, as shown in FIG. In FIG. 12, the rollers 61, 6 are opposed to the ultrasonic transducers 31-34.
Although 2, 71 and 72 are arranged, an ultrasonic transducer can be used instead of the roller as in the embodiment of FIG.
Further, the vertical relationship between the ultrasonic transducer and the roller shown in FIGS. 1 and 12 may be reversed.

[0037]

As described above, according to the present invention, when one of the pair of ultrasonic transducers is in the grip state in which a frictional force acts on the paper sheet, the other is in the non-grip state. Providing a transfer device using ultrasonic waves that uses a certain 2 to 4 ultrasonic transducers to obtain an excellent grip state for paper sheets to be transferred and enables high-performance transfer with little variation can do.

[Brief description of drawings]

FIG. 1 shows a schematic configuration of a carrying device according to an embodiment of the present invention.

FIG. 2 shows a configuration of an ultrasonic transducer of the same embodiment.

FIG. 3 shows a state of driving an ultrasonic transducer according to the embodiment.

FIG. 4 shows a state of elliptical motion of the ultrasonic transducer according to the same embodiment.

FIG. 5 shows a transport speed pattern according to the embodiment.

FIG. 6 shows conveyance speed data according to the embodiment in comparison with a conventional example.

FIG. 7 shows an average transport speed according to the embodiment in comparison with a conventional example.

FIG. 8 shows a schematic configuration of a carrying device according to another embodiment of the present invention.

FIG. 9 shows a state of driving an ultrasonic transducer according to the embodiment.

FIG. 10 shows a state of elliptical motion of the ultrasonic transducer according to the same example.

FIG. 11 shows the configuration of another ultrasonic transducer that can be used in the present invention.

FIG. 12 shows a configuration of a carrying device according to still another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Frame body, 2, 5 ... Support shaft, 31 ... 1st ultrasonic transducer, 32 ... 2nd ultrasonic transducer, 33 ... 3rd ultrasonic transducer, 34 ... 4th ultrasonic vibration Child, 4 ... Paper, 6, 7 ...
Rollers, 81, 82, 83, 84 ... Driving source, 35 ... Fifth ultrasonic transducer, 36 ... Sixth ultrasonic transducer, 37 ...
Seventh ultrasonic transducer, 38 ... Eighth ultrasonic transducer.

Claims (4)

[Claims] 1. A disk-shaped ultrasonic transducer is AC-driven to synthesize radial expansion and contraction vibrations and in-plane bending vibrations in a direction orthogonal to the composite vibrations, and thereby a mass point in contact with a paper sheet to be conveyed is obtained. A device for causing an elliptical motion and converting the elliptical motion into a frictional force to convey a paper sheet. The device is arranged in a direction parallel to the paper surface of the paper sheet to be conveyed and orthogonal to the conveyance direction. A support shaft and first, second, third and fourth ultrasonic transducers arranged on the support shaft and facing a facing member via the paper sheet with specific points on the outer circumference as mass points. And the elliptic motions of the first and fourth ultrasonic transducers arranged on both outer sides are in phase with each other, whereas the elliptic motions of the second and third ultrasonic transducers disposed on the inner side are 180 °
And a drive means for alternating-currently driving these vibrators so as to have a phase difference of 1. 2. The first ultrasonic vibrator and the second ultrasonic vibrator, and the third ultrasonic vibrator and the fourth ultrasonic vibrator are insulated by vibration absorption between them. The structure is joined and integrated through a member.
The paper sheet transport device described. 3. The sheet conveying apparatus according to claim 1, wherein the facing member is a roller. 4. The opposing member is the first, second, third
And 5th, 6th, 7th and 8th, which are arranged so as to oppose to each other and the 4th ultrasonic transducer, and are driven by alternating current so that the elliptic motions of the mass points of the opposing ones are opposite to each other.
2. The paper sheet transporting device according to claim 1, which is the ultrasonic transducer.