JPH0351210A - Piezoelectric drive type carrier device - Google Patents

Abstract

PURPOSE:To increase the mechanical strength of an amplifying spring plate by positioning an exciting body an a carrier transfer medium and also positioning the first and second elastic bodies connected to an weight on both sides of the exciting body in parallel with each other. CONSTITUTION:Junction spring plates 21, exciting spring plates 22, and amplifying spring plates 24 are positioned aslant on a base 1 in that order,in parallel and alternately with each other. With this constitution, the dimensions of the amplifying spring plates 24 and the junction spring plates 21 can be lengthened, and the same frequency as before can be obtained by thickening the plate thickness of the amplifying spring plates 24.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention relates to vibration of a conveyance transmission medium that conveys relatively small parts such as electrical elements or mechanical parts as objects to be conveyed. The present invention relates to a piezoelectrically driven transport device using a piezoelectric element as a source.

(Prior Art) Piezoelectrically driven parts feeders using a piezoelectric element as a vibration source include in-line parts feeders and bowl-shaped parts feeders.

FIG. 3 shows the configuration of a conventional in-line parts feeder. In the figure, reference numeral 1 indicates a base, and reference numeral 2 indicates two joint spring plates 3. The excitation spring plate 4 and the amplification spring plate 5 are connected by bolts 6a, 6b, 6.
A top plate 7 is connected to the amplifying spring plate 5 by bolts 6d and supported horizontally, and 7 is a conveyance medium, such as a trough, on which small parts to be conveyed 8 are placed, and is supported on the top plate 2. ing. 9 is each excitation spring plate 4
The pressure f! attached by adhesive etc. to ! element, in which an alternating voltage applied to terminals 10 and 11 is connected to lead wire 10.
a.

11a. 12 is
This is a weight for suppressing vibration to some extent in order to smoothly transport the conveyed object 8, and is connected together with the vibration spring plate 4 and the joint spring plate 3.

In the device configured in this way, each vibrating leaf spring 4 and the piezoelectric element 9 bonded thereto form a bimorph body which is a vibrating body.
(VERNITRON PIEZO Electric
DIVISION product name) 13, and when an AC voltage is applied to the piezoelectric elements 9 to excite them, each piezoelectric element 9 expands in a positive half cycle and contracts in a negative half cycle. , by shifting the voltage applied to each piezoelectric element 9 by half a cycle, the expansion and contraction motion is converted into a deflection motion due to its bimorph structure, and the amplifying spring plate 5, the trough 7 is vibrated in the direction of arrow 14, and the conveyed object 8 is moved in the direction of arrow 15.

(Problem to be Solved by the Invention) In the conventional piezoelectric drive type parts feeder configured as described above, vibrations excited by the bimorph 13 are transmitted to the amplifying spring plate 5, increasing the amplitude and It will be transmitted to the trough 7 via the plate 2. However, at this time, the amplification spring plate 5, bimorph 13, and top plate 2 are firmly fastened with bolts 6c and 6d.

Therefore, since a considerably large repetitive stress mainly due to bending acts on the amplifying spring plate 5, which has a lower rigidity than the bimorph 13 and the top plate 2, sufficient care must be taken to prevent fatigue failure. Similarly, repeated bending stress acts on the joint spring plate 3, but the amplifying spring plate 5
Since the amplitude is small compared to , the repeated bending stress that occurs is also small. Therefore, in order to prevent fatigue failure, it is necessary to particularly consider the repeated bending stress generated in the amplifying spring plate 5.

It is an object of the present invention to provide a piezoelectric dynamic transfer device that can reduce the stress at the fastening portion of the amplification spring plate provided between the bimorph and the trough and ensure sufficient mechanical strength of the amplification spring plate. The purpose is

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a conveying and transmitting medium on a base via a vibrating body formed by attaching a piezoelectric element to an elastic body, and connects one end of this vibrating body to the conveying and transmitting medium. A piezoelectric interlocking type that is connected by one elastic body, and the other end is connected to a second elastic body and a weight, and the conveyance transmission medium is vibrated by the vibration of the first elastic body to convey the conveyed object. In the conveyance device, a first elastic body and a second elastic body are arranged in parallel on both sides of a vibrating body.

(Function) Since the lengths of the first elastic body and the second elastic body can be increased, the thickness of the plate can be increased to obtain the same frequency as before, which reduces the vibration generated at the fastening part. Stress can be reduced and fatigue failure can be eliminated.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing an in-line parts feeder according to an embodiment of the present invention, and FIG. 2 is a perspective view of FIG. 1.

1 and 2, 1 is the base, 21 is the base 1
A joint spring plate 22, which is partially fixed to a screw hole 1a provided in the base 1 with a bolt 6a, is arranged parallel to the outside of the joint spring plate 2I so as to be inclined relative to the base 1.

A vibrating spring plate 24, which has one end fixed to the other end via a spacer 23 and a bolt 6b, and has piezoelectric elements 9 attached to both sides in the middle by adhesive or the like, is parallel to the outside of this vibrating spring plate 22. A spacer 25. is placed at the other end. It is an amplifying spring plate fixed at one end via a bolt 6c and a nut 6e. The top plate 2 is assembled by screwing bolts 6d into screw holes 2a.

It is attached to the other end of the amplification spring plate 24. Trough 7 is.

It is supported by the upper part of the top plate 2. In addition, the joint spring plate 21. The excitation spring plate 22 and the amplification spring plate 24 are arranged on both sides of the base 1 so that the pair is parallel to each other. Further, an AC voltage is applied to the piezoelectric element 9 via a lead wire (not shown).

As mentioned above, the joint spring plate 21. Since the excitation spring plates 22 and the amplification spring plates 24 are arranged parallel to the base 1 with an inclination, and alternately, the amplification spring plates 24 and the joint springs are arranged in a staggered manner, compared to the conventional configuration in which they are connected in a straight line. The dimensions of the plate 21 can be increased. According to this embodiment, the length of this amplifying spring plate 24 can be made three times or more compared to the conventional one. If the dimensions can be made longer, the joint spring plate 21. Vibration spring plate 22. In order to make the frequency of the system composed of the amplification spring plate 24 and the weight 12 similar to that of the conventional system, the thickness of the amplification spring plate 24 can be increased. If the plate thickness can be increased, the stress generated in the fastening portion of the amplification spring plate 24 can be reduced.

Therefore, the joint spring plate 21. Vibration spring plate 22. The thickness of the amplification spring plate 24 is determined to make the frequency of the system composed of the amplification spring plate 24 and the weight 12 similar to the conventional one. It can be calculated using the first-order equation (■) considering both ends fixed.

However, f is the frequency, Q is the length of the amplification spring plate, λ is a value determined by the boundary conditions, ρ is the weight per unit volume of the amplification spring plate, and A is the cross-sectional area of the amplification spring plate.

E is the longitudinal elastic modulus of the material of the amplification spring plate, and ■ is the moment of inertia of the area of the amplification spring plate D=gf'/12.1 is the plate thickness.

If the length of the amplifying spring plate is tripled and the frequency is the same as the conventional one, the plate thickness can be made approximately 5.2 times thicker using formula (2). Assuming that the amplifying spring plate is fixed at both ends and equally distributed loads are applied, the stress generated in the fastening portion can be calculated using the following equation.

However, σ is the stress of the amplification spring plate, d is the thickness of the amplification spring plate,
P is the load applied to the amplification spring plate, and Q is the length of the amplification spring plate.

Therefore, if the frequency is the same, the length of the amplification spring plate is 3
If the thickness is doubled, the plate thickness can be increased to about 5.2 times, and the stress generated at the fastening part of the amplification spring plate can be reduced to 17
3, and the margin against fatigue failure becomes extremely large.

〔Effect of the invention〕

As explained above, according to the present invention, the length and thickness of the amplifying spring plate can be increased, so the stress generated in the fastening part can be reduced, and a highly reliable piezoelectric device without fatigue failure can be produced. An intermittent conveying device can be provided.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of the present invention, and FIG. 2 is a front view showing one embodiment of the present invention.
FIG. 3 is a perspective view of an embodiment of the present invention shown in FIG. DESCRIPTION OF SYMBOLS 1... Base, 2... Top plate 7... Trough, 9... Piezoelectric element 12.
...Weight, 21... Joint spring plate 22.
...Excitation spring plate, 24...Amplification spring plate (8733) Representative patent attorney Yoshiaki Inomata (and 1 other person) Multi-P 3 Concave

Claims (1)

[Claims] A conveying and transmitting medium is provided on the base via a vibrating body formed by attaching a piezoelectric element to an elastic body, one end of this vibrating body is connected to the conveying and transmitting medium by a first elastic body, and the other end is connected to the vibrating body through a first elastic body. In the piezoelectric drive type conveyance device, which is connected to a second elastic body and a weight, and conveys the conveyed object by vibrating the conveyance transmission medium by the vibration of the first elastic body, the first elastic body 1. A piezoelectric drive type conveyance device, characterized in that a body and a second elastic body are arranged in parallel on both sides of the vibrating body.