JPH07257724A - Piezoelectric driving type conveying device - Google Patents

Abstract

PURPOSE:To convey a part to be conveyed at a high speed by arranging a section with high flexural rigidity and a section with low flexural rigidity in a joint member serving as a constitutional part, of a piezoelectrically driving type conveying device and greatly expanding a ratio of flexural rigidity between both sections. CONSTITUTION:In a piezoelectrically driving type conveying device using a shaker body 20 in which a piezoelectric element 21 is adhered on an elastic plate 22, one end of the shaker body 20 is fixed on a base platform 23, while the other end is fixed in one end of a lamination joint member 27 in which two or more of joint members 24 having different length are laminated, and in the lamination joint member 27, the other end of the longest joint member 24 is fixed in a conveying body 25. In this process, the elastic plate 22, in which the ratio of the length to the width is 1 to 0.2-0.5 while the ratio of the length to the thickness is 1 to 0.04-0.08, and the piezoelectric element 21, in which the ratio of the length to the width is 1 to 0.3-0.7 while the ratio of the length to the thickness is l to 0.015-0.06, are used. The ratio of the length, the width, and the thickness of other joint members 24 to the length of the longest joint member 24 are individually set to be 0.5-0.85, 0.3-0.6, and 0.01-0.04 to 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric drive type transfer device for transferring various parts such as electric parts or mechanical parts by vibration.

[0002]

2. Description of the Related Art A conventional piezoelectric drive type conveying device using a piezoelectric element as a drive source is disclosed in Japanese Utility Model Publication Nos. 52-61087 and 57-57.
46517, JP-A-62-4118, JP-A-62-
It has been already known to the public by No. 4119 and the like, and its configuration and transport principle will be described below with reference to FIG.

That is, a structure using two or more vibrating bodies 20 made of so-called bimorphs in which piezoelectric elements 21 are attached to both surfaces of an elastic plate 22, and one end of the vibrating body 20 is obliquely erected and fixed to a base 23. The constitution is such that the other end of the vibrating body 20 is fixed to the carrier 25 via a connecting member 24. An alternating voltage is applied to each piezoelectric element 21 of the piezoelectric drive type transporting device having the above configuration.

By applying the AC voltage, the piezoelectric element 21
Performs a repetitive motion of positively extending in half a cycle and contracting in a negative half cycle. Therefore, in the vibration body 20 made of a bimorph to which the piezoelectric element 21 is attached, the voltage applied to each piezoelectric element 21 is reduced by half. When the cycles are shifted, the expansion / contraction motion is converted into a flexion motion by the cantilever type bimorph structure, and the carrier 25 is vibrated in the direction of the arrow with the connecting portion between the lower end of the elastic plate 22 and the base 23 as a fulcrum. The components are oscillated, and as a result, a unidirectional driving force is applied to the component 26 placed on the carrier.

[0005]

2. Description of the Related Art The connecting member 24 is required to satisfy the following conditions. That is, there are a wide variety of carrier parts 26 placed or put on the carrier 25, and therefore the weight thereof also varies greatly. In consideration of this point, the bending rigidity of the connecting member 24 is at least large enough to support the maximum load of the transport component 26 placed on or input to the transport body 25, and at the same time, the transport driving force of the transport component 26 is applied. Is required to be added.

By the way, in order to support the maximum load of the carrying part 26, the bending rigidity of the connecting member 24 must be a certain magnitude or more. Otherwise, the connecting member 24 cannot bear the load from the carrier 25 including the carrier part 26 and sinks downward together with the carrier 25,
This is because the transport speed of is significantly reduced.

On the other hand, the bending rigidity of the connecting member 24 is adjusted to the connecting member 2
If the size is large enough to support the maximum load of the conveying component 26 over the entire surface of 4, the vibration energy generated by the excitation of the vibrating body 20 is mostly absorbed by the connecting member 24.
As a result, vibration energy that is large enough to transport the transport component 26 at high speed is not transmitted to the transport body 25. Therefore, in order to transport the transport component 26 at high speed, the vibrator 20
It is necessary to reduce the loss of the vibration energy generated by the vibration of the carrier to be transmitted to the carrier 25. This need is achieved by making the bending rigidity of the connecting member 24 not more than the bending rigidity sufficient to support the maximum load. To be done.

In order to satisfy the above conditions and needs regarding the bending rigidity of the connecting member 24, it is necessary to provide a portion having a high bending rigidity and a portion having a low bending rigidity in one connecting member 24, that is, to provide a difference in the bending rigidity ratio. Desired. Conventionally, in order to satisfy the trade-off between these two contradictory conditions and needs, a means such as a notch or a slit is provided in a part of the connecting member. However, even if it is possible to provide a member having a high bending rigidity and a portion having a low bending rigidity in the one connecting member 24 by such means, there is a limit in increasing the ratio of the bending rigidity of the two members, and therefore, there is a limit in the conveying parts. There is a problem that there is a limit to high speed transportation.

[0009]

SUMMARY OF THE INVENTION The present invention is to provide a novel piezoelectric drive type transportation device which solves the problems of the conventional piezoelectric drive type transportation device. That is, specifically, not only the connecting member, which is a component of the piezoelectric drive type transport device, is provided with a member having a high bending rigidity and a member having a low bending rigidity, but also the bending rigidity ratio between these two parts is greatly expanded as compared with the conventional one. It is intended to provide a piezoelectric drive type transfer device which enables high speed transfer of transfer parts.

[0010]

[Means for Solving the Problems] Means for solving the problems will be described below with reference to FIG. In order to solve the above-mentioned problems, the present invention provides a vibrating body 2 which is a so-called unimorph or bimorph in which a piezoelectric element 21 is attached to one surface or both surfaces of an elastic plate 22.
In the piezoelectric drive type transfer device using 0, the vibrating body 2
A structure in which one end of 0 is fixed to the base 23, the other end of the vibrating body 20 is fixed to one end of a laminated connecting member 27 in which two or more connecting members 24 having different lengths are laminated, and the laminated connection. Of the members 27, the other end of the longest connecting member 24 is fixed to the carrier 25 on which the carrier component 26 is placed.

The elastic plate 22 used in the present invention is appropriately selected from stainless steel such as SUS304 having high elasticity and conductivity, spring steel and the like. The reason why the elastic plate 22 is required to have conductivity is that it is possible to apply an AC voltage to the piezoelectric element 21 attached to the elastic plate 22.

The piezoelectric element 21 attached to the elastic plate 22 is selected from suitable piezoelectric elements 21 such as lead zirconate titanate having a high piezoelectric property. Therefore, the piezoelectric element 21 has electrodes formed on both sides thereof by an appropriate means such as silver baking, vacuum deposition or the like, and a direct current voltage is applied to the electrodes for polarization treatment.

The piezoelectric element 21 may be attached to the elastic plate 22 by either unimorph in which the piezoelectric element 21 is attached to only one side of the elastic plate 22 or bimorph in which the piezoelectric element 21 is attached on both sides. This is because in any of these cases, excitation is generated from the vibrating body 20 by applying an AC voltage to the piezoelectric element 21.

One end of the vibrating body 20 having the above-mentioned structure is provided with the base 2.
It is fixed to 3 by suitable means such as screwing or spot welding. However, the fixed portion is a portion where the transport component 26 transports in only one direction when the transport component 26 is placed on the transport body 25. The other end is fixed to one end of the laminated connecting member 27 whose end faces are aligned by screwing, spot welding or other suitable means.

As described above, the connecting member converts the bending rigidity (hereinafter referred to as the former bending rigidity) sufficient to support the load from the carrier 25 including the carrier part 26 and the excitation generated from the vibrating body 20 into a bending motion. , Sufficient flexural rigidity to generate vibration amplitude in the carrier 25 (hereinafter referred to as the latter flexural rigidity)
It is required to have Therefore, the two bending stiffnesses are very different. That is, the flexural rigidity of the former must be at least a flexural rigidity sufficient to support the maximum load from the carrier 25 including the carrier parts 26. On the other hand, the bending rigidity of the latter cannot be conveyed at high speed if the bending rigidity of the former is the same, and therefore the bending rigidity of the former must be made considerably smaller. That is, if the bending rigidity is similar to the former bending rigidity, most of the vibration energy due to the excitation of the vibrating body is absorbed by the connecting member, and the carrier 25 has a vibration amplitude sufficient to carry the carrying component 26 at high speed. This is because it cannot be given.

In the present invention, the former bending rigidity and the latter bending rigidity required for the connecting member are formed in one connecting member by laminating two or more connecting members 24 having different lengths. With such a configuration of the connecting member, the former bending rigidity is ensured by the connecting members at the laminated portions, and the latter bending rigidity is ensured by the connecting members at the portions not laminated. With such a structure of the connecting member, that is, by using the laminated connecting member 27, it is possible to provide a portion having a high bending rigidity and a portion having a low bending rigidity in one laminated connecting member 27. And the latter bending rigidity ratio can be used as the required bending rigidity ratio.

As long as the laminated connecting member 27 has the required bending rigidity ratio and can convey the conveying component 26 in only one direction, the material of each connecting member 24 constituting the laminated connecting member 27. , Width and thickness do not necessarily have to be the same.

Of the other ends of the connecting members 24 constituting the laminated connecting member 27, the other end of the longest connecting member is fixed to the carrier.

[0019]

When an AC voltage is applied to the piezoelectric element 21, which is one of the solid displacement materials, from outside, it expands and contracts in a positive half cycle of the applied voltage, and contracts in a negative half cycle.
The excitation of the vibrating body 20 is brought about. If an AC voltage having the same natural vibration frequency as that of the whole of the vibrating body 20, the laminated connecting member 27 and the carrier 25 is applied, the displacement caused by the vibrating body 20 due to a so-called resonance phenomenon is extremely large. It will be big.

The vibrating body 20 in the piezoelectric drive type conveying apparatus according to the present invention has a so-called cantilever structure because one end thereof is fixed to the base 23. Due to the cantilever structure of the vibrating body 20, the excitation of the vibrating body 20 is converted into a bending motion, and the carrier 25 is transferred via the laminated connecting member 27.
The vibration amplitude in the obliquely vertical direction is generated. This vibration amplitude serves as a driving force that enables the conveyance of the conveyance component 26 placed on the conveyance body 25, and the conveyance speed of the conveyance component 26 is proportional to the vibration amplitude.

Next, specific examples of the present invention will be shown. The elastic plate 22 has a length of 1 to a width of 0.2 to 0.5 and a thickness of 0.0.
A piezoelectric element 21 having a ratio of 4 to 0.08 has a length of 1 and a width of 0.3 to 0.7 and a thickness of 0.015 to 0.0.
The lead zirconate titanate having a ratio of 6 is used to form the laminated connecting member 2
7 is a double-layered connecting member, and the length of the longest connecting member 24 is 0.5 to 0.85 and the width is the longest connecting member 24. 0.3 to 0.6 for 1 and the thickness of each connecting member 2 to be laminated
4 is 0.01 to 1 for the length 1 of the longest connecting member 24.
When the one having the ratio of 0.04 is used, the minimum voltage for starting the transfer is 40V, and the maximum weight of the transfer component 26 capable of high-speed transfer under the drive voltage of 100V (frequency 125HZ) is 15K.
g, the maximum transport speed was 50 mm / sec.

[0022]

The first effect of the present invention is that the material, thickness and number of layers of the connecting member 24 can be appropriately selected, so that one laminated connecting member 27 has high bending rigidity and low bending rigidity. Can be provided, and moreover, the bending rigidity ratio can be made significantly larger than that of the conventional connecting member. Due to this effect, the conveyed article 26 can be conveyed at high speed. This effect is nothing more than the fact that the utilization efficiency of the vibration energy generated from the vibrating body 20 is further improved.

The second effect of the present invention is that the variation of the transport speed of the transport component 26 is extremely small even if the weight of the transport component 26 placed or loaded on the transport member 25 changes. In contrast, in contrast to the variation 1 of the transport speed of the transport component 26 due to the weight change of the transport component 26 in the conventional piezoelectric drive transport device, the transport component under the same condition in the piezoelectric drive transport device according to the present invention. The fluctuation of the transport speed of the carrier 26 is greatly reduced to 0.3 to 0.4, and in addition, the weight of the carrier component 26 that can be placed on or put in the carrier 25 that enables high speed transportation is the conventional piezoelectric drive type. It is possible to make the size about 35% larger than that of the carrier. That is, this effect is nothing but the expansion of the range that enables high-speed transportation of heavy objects.

[Brief description of drawings]

FIG. 1 is a side view of a piezoelectric drive type transfer device according to the present invention.

FIG. 2 is a side view of a conventional piezoelectric drive type transport device.

[Explanation of symbols]

 20. Exciter 21. Piezoelectric element 22. Elastic plate 23. Base 24. Connecting member 25. Carrier 26. Transport parts 27. Laminated connection member

Claims (2)

[Claims] 1. A piezoelectric drive type conveyance device using a vibrating body made of unimorph or bimorph in which a piezoelectric element is adhered to one or both sides of an elastic plate, wherein one end of the vibrating body is fixed to a base. A structure in which the other end of the vibrating body is fixed to one end of a laminated connecting member in which two or more connecting members having different lengths are laminated, and the other end of the longest connecting member among the laminated connecting members is fixed to the carrier. A piezoelectric drive type transport device having the above-mentioned configuration. 2. A piezoelectric drive type conveying device using a vibrating body made of unimorph or bimorph in which a piezoelectric element is attached to one surface or both surfaces of an elastic plate. A piezoelectric element 21 having a ratio of 0.5 and a thickness of 0.04 to 0.08 has a length of 1 to a width of 0.3 to
The lead zirconate titanate having a ratio of 0.7 and a thickness of 0.015 to 0.06 is a two-layer connecting member 24 as the laminated connecting member 27, and the length of the longest connecting member 24 is 1 In contrast, the length of the connecting member 24 that is not the longest is 0.5 to 0.85.
The width is 0.3 to 0.6 with respect to the length 1 of the longest connecting member, and the thickness is 0.01 to 0.04 with respect to the length 1 of the longest connecting member 24 for each of the connecting members 24 to be laminated. Piezoelectric drive type transport device composed of a ratio.