JP2002302231A - Piezoelectric driving type vibrating feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give only a vibration required for conveyance essentially to a trough by making the overall height of a feeder. SOLUTION: In a piezoelectric driving type vibrating feeder, which is provided with a work mass body supported so as to be able to vibrate by a pair of 1st front and rear blade springs on a base table, an opposing mass means to be combined with the work mass body by a pair of 2nd blade springs, and piezoelectric devices, which are adhered to at least one face of each of the second blade springs to convey articles on the work mass body by vibrating the work mass body by giving bending vibration to the 2nd blade springs by applying alternating voltage to the piezoelectric devices, the opposing mass means comprises a single opposing mass body and fixed to each end section of the 2nd blade springs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a piezoelectric drive type vibration feeder.

[0002]

2. Description of the Related Art An apparatus as shown in FIG. 5 is disclosed in Japanese Patent No. 2762211 as a piezoelectric-driven vibration feeder of this type. A carrier (using the terms used in the specification, hereinafter the same) 5 is supported by a carrier support 8 made of a pair of front and rear vertical spring steels, and the lower end is fixed to the base 3. Have been. The base 3 has different heights before and after. That is, it is trapezoidal. Therefore, the length of the carrier supporting member 8 acting as a spring differs between the front and rear. A pair of front and rear vibrators 9 are fixed to the lower surface of the carrier 5, and are formed by attaching the piezoelectric elements 1 to both surfaces of the elastic plate 2. This is a so-called bimorph structure. Mass bodies 7, 7 having different masses are attached to the lower end of the elastic plate 2. I want to transport the transport component 6 in the direction shown by the arrow on the transport body 5. When an AC voltage is applied to the piezoelectric element 1,
The carrier 5 vibrates in an oblique direction due to the expansion and contraction movement of the piezoelectric elements 1 attached to both surfaces of each elastic plate 2, and transports the carrier 6 in the direction of the arrow as is known.

However, in such a piezoelectric driven vibration feeder, since the mass members 7 are fixed to the lower end of the elastic plate 2 and are fixed to the carrier 5 at the root of the elastic plate 2, A rotation is performed around the fixed point as shown by an arrow. This tends to cause the carrier 5 to produce a rotational movement, which will be very complicated. In addition, since a common AC voltage is applied, the masses of the mass members 7 are different, so that the resonance frequencies of the two vibration systems are different even if the elastic constants of the elastic plates 2 are the same. Accordingly, the amplitudes of the masses 7, 7 are different, and the vibration displacement also has a different phase difference from the AC voltage applied thereto. This will further cause the carrier 5 to vibrate in a complicated manner. In this case, it seems that a smooth conveying action cannot be obtained over the entire area of the conveying body 5.

FIG. 6 shows a second conventional piezoelectric-driven vibration feeder, which is disclosed in Japanese Patent No. 1634515. At both ends of a leaf spring mounting block 12 fixed to the lower surface of the trough 11, one end of a pair of inclined front and rear leaf springs 13a and 13b is fixed by bolts b. Block 14
a, 14b lower piezoelectric element mounting leaf spring 15
a, 15b are fixed to the upper end, and the lower end is fixed to the base 17. Piezoelectric elements 16a, 16a 'and 16b, 16b' are attached to both surfaces of the leaf springs 15a, 15b. An AC voltage is applied to these, and leaf springs 15a,
A bending motion of 15b is obtained. The trough 11 amplifies the vibration by the upper leaf springs 13a and 13b. However, even in the conventional example, the vibration isolating structure is not provided, and therefore, the base plate extends from the lower ends of the lower leaf springs 15a and 15b. 17
The reaction force due to the vibration of the trough 11 or the leaf spring 15
The bending reaction forces a and 15b are transmitted directly, thus not only adversely affecting other similar vibrating machines mounted on the common mounting base Q, but also generating noise due to the reaction force transmitted through the floor. To cope with this, an anti-vibration structure as shown in FIG. 7 can be considered. In the figure, parts corresponding to those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. That is, according to the piezoelectric-driven vibration feeder having the vibration-proof structure, the vibration-proof block 18 is mounted below the base 17, and the mounting base 19 and a pair of front and rear vibration-proof springs 20 a having a small constant number , 20b. With this configuration, the vibration reaction force transmitted to the base 17 is hardly transmitted to the installation base 19 due to the deflection of the vibration isolation springs 20a and 20b. However, such a configuration increases the overall height. In this case, there arises a problem that the relationship with other devices arranged in the vicinity and the stability of the present device are lacking.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a function of causing stable vibration over the entire working mass body and reducing the reaction force to the installation table or base to the height of the entire apparatus. It is an object of the present invention to provide a piezoelectrically driven vibration feeder that can prevent the vibration without increasing the size.

[0006]

An object of the present invention is to provide a working mass body supported on a base by a pair of front and rear first leaf springs so as to vibrate, and a work mass body and a pair of front and rear second leaf springs. An opposing mass means to be coupled, and a piezoelectric element attached to at least one surface of each of the second leaf springs, and applying an AC voltage to the piezoelectric element to cause the second leaf spring to perform bending vibration. According to the piezoelectric drive type vibration feeder, in which the working mass body is vibrated to convey an object on the working mass body, the opposed mass means is a single opposed mass body, and the second plate A piezoelectrically driven vibration feeder fixed to each end of a spring, or a working mass supported on a base by torsional vibration by a plurality of first leaf springs arranged at equal angular intervals. Body and the working mass at equal angular intervals. And a piezoelectric element attached to at least one surface of each of the second leaf springs, and applying an AC voltage to the piezoelectric element to form the second In a piezoelectric-driven vibratory feeder in which a leaf spring performs bending vibration to cause the working mass body to torsionally vibrate and convey an object on the working mass body, the opposed mass means is a single opposed mass It is a mass body, and is fixed to each one end of the second leaf spring.

[0007] With the above configuration, it is possible to prevent the reaction force from being transmitted to the base without increasing the overall height of the vibrating feeder, and to reduce the vibration of the trough or the bowl-shaped container as a working mass body. And the transport of the transported object can be performed smoothly.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 1, a piezoelectric drive type vibration feeder 50 is shown.
, The trough 51 is connected to the base 52 by a pair of front and rear inclined plate springs 53a and 53b.
The upper ends of the leaf springs 53a and 53b are fixed to a leaf spring mounting block 54 integrated with the trough 51, through which the trough 51 vibrates in a direction substantially perpendicular to the longitudinal direction of the leaf springs 53a and 53b. Supported as possible.

On the lower surface of the leaf spring mounting block 54,
A pair of substantially inverted L-shaped leaf springs 55a and 55b are fixed by bolts b.
Piezoelectric elements 56a, 56a 'and 56b, 56
b 'is stuck. According to the present invention, the common opposing mass body 57 is fixed to the lower ends of the pair of leaf springs 55a and 55b by the bolts b. Each piezoelectric element 56
a, 56a 'and 56b, 56b' are supplied with an AC voltage from the
° The phase is inverted and applied. Also, the rear leaf spring 53
A proximity sensor 59 is attached to the distal end of the sensor mounting plate 58 so as to face the lower end of the base b, and the lower end is fixed to the base 52 with a leaf spring 53b interposed by a bolt b via a spacer s. Have been. The detection output of the proximity sensor 59 is supplied to the control circuit 60 via the electric line 64, and the output of the amplifier circuit 61 is further supplied to the electric line 63.
Is supplied via

The controller 60 mainly includes a phase detection circuit and a variable frequency power supply as shown in FIG. 10, and the detection output of the proximity sensor 59 is supplied to one input terminal of the phase detection circuit, and the other is supplied to the other input terminal. The input terminal is connected to the amplifier circuit 6
One output is provided. The frequency of the variable frequency power supply is adjusted based on the phase detection output of the phase difference detection circuit,
This output is amplified by the amplifier 61, and the piezoelectric element 56a,
56a 'and 56b, 56b'. As is apparent from vibration engineering, when the phase difference between the vibration displacement and the force, that is, the applied AC voltage becomes 90 °, a resonance state occurs.

The configuration of the embodiment of the present invention has been described above. Next, this operation will be described.

The AC voltage is supplied from the amplifier 61 to the leaf spring 55a,
Piezoelectric elements 56a, 56a 'and 56 attached to 55b
b, 56b '. Thereby, the leaf spring 55a,
55b performs bending vibration and vibrates the common opposing mass body 57 in a direction opposite to the trough 51. The trough 51 has a pair of front and rear leaf springs 53a and 53b that are inclined, and vibrates in a direction substantially perpendicular to the leaf springs 53a and 53b. Is done. The opposing mass body 57 includes leaf springs 55a and 55b.
, And is not fixed to these by the bolts b, so that there is no generation of a force for rotating the trough 51 as in the prior art. The trough 51 is a leaf spring 53a, 53
b is restricted in the inclination direction, and vibrates substantially perpendicularly to the inclination direction over the entire region.

FIG. 8A shows a model of the vibration system according to the embodiment of the present invention, where m ₁ is the mass of the opposed mass body 57 and m ₂
Is (assumed to include the mass of the leaf spring mounting block 54) the weight of the trough 51, k ₁ has a counter mass body 57 trough 51
And k ₂ are the total spring constants of the leaf springs 53 a and 53 b that support the trough 51 on the base 52 so as to vibrate, and c ₁ and c ₂ are the opposing masses. The viscosity coefficient acting between the trough 51 and the trough 51, the viscosity coefficient acting between the trough 51 and the base 52, and F are actuators acting between the opposed mass body 57 and the trough 51, that is, an AC voltage is applied. Piezoelectric elements 56a, 56
a ', 56b, 56b'.

FIG. 8B shows a model of the conventional vibration system shown in FIG. 6, where m ₁ is a trough 11 which is a working mass body.
(Including the leaf spring mounting block 12), m ₂ is the total mass of the leaf spring mounting blocks 14a and 14b, k ₁ is the total spring constant of the auxiliary leaf springs 13a and 13b, and k ₂ is the driving leaf springs 15a and 15b. , C ₁ and C ₂ are the viscosity coefficients between the masses m ₁ and m ₂ and between the mass m ₂ and the base 17, respectively, and F is the leaf spring mounting blocks 14a and 14b.
(Mass m ₂ ) and an actuator working between the base 17 and
That is, the piezoelectric elements 16a, 16 to which the AC voltage is applied
a ', 16b, 16b'. When a differential equation is established by using such a model, the following equations A and B are obtained. A: m ₁ (dx ₁ ² / Dt ² ) + C ₁ (dx ₁ / dt
−dx ₂ / dt) + k ₁ (x ₁ −x ₂ ) = F m ₂ (dx ₂ ² / Dt ² ) + c ₁ (dx ₂ / dt−dx
₁ / dt) + c ₂ (dx ₂ / dt) + k ₁ (x ₂ −
_{x 1) + k 2 x 2} = -F B: m 1 (dx 1 2 / Dt ² ) + C ₁ (dx ₁ / dt
_{-Dx 2 / dt) + k 1} (x 1 -x 2) = 0 m 2 (dx 2 2 / Dt ² ) + C ₁ (dx ₂ / dt−dx
₁ / dt) + c ₂ (dx ₂ / dt) + k ₁ (x ₂ −
x ₁ ) + k ₂ x ₂ = F Further, the reaction force transmitted to the base 52 or 3 for any model, that is, the floor reaction force F _R is as follows. C: F _R = c ₂ (dx ₂ / dt) + k ₂ x _{2 The} results of solving this and simulating are shown in FIGS. 9A and 9B. A indicates the relationship between the trough amplitude (dB) and the frequency Hz (the transfer function from the actuator F to the trough amplitude at each frequency). In the embodiment of the present invention, the value changes as indicated by a and the conventional device ( In FIG. 6), it changes like b. At the drive frequency f, the same trough amplitude is set.
B indicates the relationship between the floor (base) reaction force and the frequency (the transfer function from the actuator F to the floor reaction force at each frequency).
At the same drive frequency f, the embodiment of the present invention is lower by about 30 dB as shown by the graphs a ′ and b ′. Thus, in the embodiment of the present invention, the floor reaction force can be significantly reduced. Further, the total height of the vibration feeder is significantly smaller than that of the conventional example shown in FIG. Therefore, the combination with peripheral devices and stability are far superior. Although the block A is fixed on the upper surface of the opposing mass body 57,
This constitutes a part of the opposing mass m ₁ and increases the weight of the opposing mass 57 as a whole. Thereby, the amplitude of the trough 51 can be made larger than that of the opposed mass body 57. That is, since it is approximated as x ₂ = m ₁ / m ₂ · x ₁ , if m ₁ is increased, the trough amplitude x ₂ can be increased. In the above embodiment, the vibration system is caused to vibrate in a resonance state by the detection output of the proximity sensor 69. However, such control is not performed, and the voltage of the commercial power supply is used as it is, and the additional mass A May be adjusted so as to approach a resonance state.

FIG. 2 shows a piezoelectric drive type vibration feeder according to a second embodiment of the present invention. In this embodiment, a driving leaf spring 66 is vertically arranged in a flat plate shape, and has an upper end portion. Is fixed to a vertical wall of a recess formed in the leaf spring mounting block 54 'by a bolt b. Others are the same as those of the first embodiment, and have similar functions and effects. In the present embodiment, the mounting of the driving leaf spring 66 is simpler than in the first embodiment. Processing of the leaf spring 66 is also easy.

FIG. 3 shows a piezoelectric drive type vibration feeder 70 according to a third embodiment of the present invention. This feeder belongs to the so-called vibrating parts feeder model.
In a bowl-shaped container (also called a bowl) 71, a spiral track is formed as is well known. At the bottom, a leaf spring mounting block 72 is fixed, which is equiangularly spaced from the base 73 (90 ° spaced in the present embodiment).
, A leaf spring 74 (4) having a sufficiently small spring constant
Sheets). This works as an anti-vibration spring. Below the leaf spring mounting block 72, a torsional vibration drive unit 80 according to the present invention is provided. Referring to FIG.
The upper end of the driving leaf spring 81 having a substantially L-shaped cross section is fixed to the leaf spring mounting block 72 by bolts. A cross-shaped opposing mass body 83 is fixed to the lower end of the driving leaf spring 81, and piezoelectric elements 82a and 82b are attached to both surfaces of the driving leaf spring 81, respectively. As in FIG. 1, an AC voltage from the amplifier is applied to these with the phases inverted by 180 ° on both sides. In the present embodiment, when an AC voltage is applied to the piezoelectric elements 82a and 82b, a bending motion is generated in each of the driving leaf springs 81, whereby the torsional vibration in a desired direction is caused by the leaf springs 74 disposed on the outer peripheral side. In the bowl 71. Thus, the conveyed object is smoothly conveyed along the spiral track in the bowl 71.

Also in this embodiment, since the common opposing mass body 83 is fixed to the lower end of the driving leaf spring 81, the work is performed by the rotational movement of the two opposing mass bodies as in the prior art. Rotational motion is not generated in the bowl 71, which is a mass body, in addition to the original torsional vibration, and uniform torsional vibration is performed so that the transport of the conveyed object on the track in the bowl 71 is smooth. Further, the plate spring 74 disposed on the outer peripheral side and having a small number of inclined springs disposed in an inclined manner,
Is prevented from being transmitted to the base 73 side.
The amplitude of the torsional vibration of the bowl 71 of this vibration system and the reaction force to the base 73 are the same as in FIGS. 9A and 9B, and the floor reaction force can be significantly reduced as compared with the related art. In addition, in the case of this vibration system, conventionally, vibration is prevented by disposing several cylindrical rubber bodies below the base 73 or disposing a coil spring. And height can be reduced.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these, and various modifications can be made based on the technical concept of the present invention.

For example, in the first and second embodiments described above, the driving leaf springs 55a and 55b are disposed vertically,
The anti-vibration leaf springs 53a and 53b are arranged in an inclined manner. However, the drive anti-vibration leaf springs may be arranged in an inclined manner and the anti-vibration leaf springs may be vertically disposed.

In the above embodiment, the driving leaf spring 5
Although a piezoelectric element is attached to both surfaces of 5a and 55b, and an AC voltage is applied to them by shifting the phase by 180 °, the piezoelectric element may be attached to only one surface instead. Needless to say, the driving force is larger when they are attached to both sides. Alternatively, a plurality of piezoelectric elements may be attached to one surface.

Further, two or more piezoelectric elements may be attached to this one surface. In this case, an AC voltage having the same phase may be applied to each piezoelectric element.

In the first embodiment, the trough is exemplified as the working mass body. However, as described above, the trough is not only conveyed, but also a screen is stretched in the trough and one end thereof is moved upward. The present invention is also applicable to a working mass body that separates the sieving material supplied from the sieve above and below the sieve while carrying it on the screen.

In the first embodiment, a proximity sensor 59 is provided near one lower end of a pair of front and rear leaf springs 53a and 53b for vibration isolation. However, it may be provided at another position. For example, it may be provided near the front vibration-isolating leaf spring 53a, or may be provided for the driving leaf springs 55a, 55a.
If the proximity sensor is provided close to the b or the trough 51 or the opposing mass body 57, the trough can be resonantly vibrated by the same control circuit if the proximity sensor is installed so that the phase of the sensor output signal is not inverted.

In the vibrating parts feeder according to the third embodiment of the present invention, four inclined leaf springs 74 for vibration isolation are arranged at 90 ° intervals, and the driving leaf spring 81 is also 90
Although four sheets are used at an interval of °, the number is not limited to four, but may be two, or three or five or more. The number of the driving leaf springs 81 may not be the same as the number of the vibration isolating leaf springs 74.
May be larger or smaller than the number.

In the above embodiment, the vibration system is driven at the resonance frequency by the detection output of the proximity sensor. However, the vibration system may be driven by a commercial power supply without using such control. Good. In this case, the additional mass A may be adjusted to substantially resonate.

[0027]

As described above, according to the piezoelectric driven vibration feeder of the present invention, the height of the apparatus is reduced, the floor reaction force is reduced, and the vibration of the working mass body, for example, a trough or a bowl is desired. As a result, the transport of the transported object can be made smooth without causing a rotational motion that causes disturbance.

[Brief description of the drawings]

FIG. 1 is a side view of a piezoelectric drive type vibration feeder according to a first embodiment of the present invention.

FIG. 2 is a side view of a piezoelectric-driven vibration feeder according to a second embodiment of the present invention.

FIG. 3 is a side view of a piezoelectric-driven vibrating parts feeder according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a drive unit of the vibration parts feeder.

FIG. 5 is a side view of a first conventional piezoelectric drive type vibration feeder.

FIG. 6 is a side view of a piezoelectric driven vibration feeder of a second conventional example.

FIG. 7 is a side view of a third conventional piezoelectric drive type vibration feeder.

FIG. 8 shows a model of a vibration system, wherein A shows a model of the vibration system according to the embodiment of the present invention, and B shows a model of the vibration system of the second conventional example.

FIG. 9 is a graph showing a transfer function of each vibration system according to the embodiment of the present invention and a conventional example, where A is a graph showing a transfer function of frequency versus trough amplitude, and B is a graph showing a transfer function of floor reaction force versus frequency. is there.

FIG. 10 shows a block diagram of a control circuit 60 of FIG.

[Explanation of symbols]

 Reference Signs List 50 piezoelectric-driven vibration feeder 51 trough 53 base 53a, 53b driving leaf spring 55a, 55b leaf spring 56a, 56a ', 56b, 56b' piezoelectric element 57 facing mass

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuhiro Saito 100 Takegahana-cho, Ise-city, Mie Prefecture Inside the Ise Office of Shinko Electric Co., Ltd. 72) Inventor Tetsuyuki Kimura 100 Takegahana-cho, Ise-shi, Mie Prefecture Inside the Ise Works of Shinko Electric Co., Ltd. CA14 CB03 CB05

Claims (14)

[Claims] A working mass body supported on a base by a pair of front and rear first leaf springs so as to vibrate; an opposing mass means coupled to the working mass body by a pair of front and rear second leaf springs; A piezoelectric element attached to at least one surface of the second leaf spring;
In a piezoelectric-driven vibratory feeder in which a leaf spring performs bending vibration to vibrate the working mass body and convey an object on the working mass body, the opposed mass means has a single opposed mass. A piezoelectrically driven vibration feeder, which is fixed to each end of the second leaf spring. 2. The spring constant of the first leaf spring is equal to the second spring constant.
2. The piezoelectric drive type vibration feeder according to claim 1, wherein the leaf spring is sufficiently smaller than a total spring constant and functions as an anti-vibration spring. 3. The piezoelectric drive type vibration feeder according to claim 1, wherein the first leaf spring is disposed at a predetermined angle with respect to the horizontal. 4. The piezoelectric driven vibration feeder according to claim 3, wherein the second leaf spring is disposed vertically. 5. The piezoelectric driven vibration feeder according to claim 1, wherein the working mass is a linear trough. 6. A vibration detecting means for detecting any one of vibration displacement, velocity and acceleration of the working mass body or the opposed mass body, and an alternating current applied to the piezoelectric element based on a detection output of the vibration detecting means. The frequency of the voltage is adjusted so that the working mass resonates at a natural frequency determined by the spring constant of the second leaf spring, the mass of the working mass, and the mass of the opposed mass. A piezoelectric drive type vibration feeder according to any one of claims 1 to 5. 7. The vibration detecting means according to claim 1, wherein
7. The piezoelectric-driven vibration feeder according to claim 6, wherein the proximity sensor is disposed close to the leaf spring. 8. A working mass body supported on a base by a plurality of first leaf springs arranged at equal angular intervals so as to be capable of torsional vibration, and a plurality of working mass bodies arranged at equal angular intervals with the working mass body. Opposing mass means coupled by a second leaf spring of each
A piezoelectric element attached to at least one surface of the leaf spring, and applying an AC voltage to the piezoelectric element to cause the second leaf spring to perform bending vibration, thereby causing the working mass body to torsionally vibrate, In the piezoelectric driven vibration feeder configured to convey an object on the working mass body, the opposed mass means is a single opposed mass body, and is fixed to each end of the second leaf spring. A piezoelectric drive type vibration feeder characterized by the following. 9. The piezoelectric drive type according to claim 8, wherein a total spring constant of the plurality of first leaf springs is sufficiently smaller than a total spring constant of the second leaf spring, and functions as an anti-vibration spring. Vibrating feeder. 10. The apparatus according to claim 8, wherein the first leaf spring is disposed at a predetermined angle with respect to the horizontal.
6. The piezoelectric drive type vibration feeder according to 1. 11. The piezoelectric driven vibration feeder according to claim 10, wherein the second leaf spring is disposed vertically. 12. The piezoelectric driven vibration feeder according to claim 8, wherein the working mass is a bowl-shaped container having a spiral track. 13. An alternating current applied to the piezoelectric element based on a detection output of the vibration detecting means, wherein the vibration detecting means detects any of vibration displacement, velocity, and acceleration of the working mass body or the opposed mass body. The frequency of the voltage is adjusted so that the working mass resonates at a natural frequency determined by the spring constant of the second leaf spring, the mass of the working mass, and the mass of the opposed mass. 13. The piezoelectric driven vibration feeder according to any one of 8 to 12. 14. The piezoelectric drive type vibration feeder according to claim 13, wherein said vibration detecting means is a proximity sensor disposed close to said first or second leaf spring.