JPS6260710A - Piezo drive bowl type parts feeder - Google Patents

Abstract

PURPOSE:To facilitate fixing/adjusting of a vibrating member and to improve the carrying efficiency, in titled parts feeder for electronic elements, by splitting a bowl into a containing section and a carrying section then vibrating independently. CONSTITUTION:A bowl 19 is constructed with a containing section 20 and a carrying section 21 arranged through a slight gap. Upon reciprocal vibration of bimorphs 17, 18 the bimorph 17 will cause reciprocal rotary motion of the carrying section 21 around the containing section 20. Bimorph 18 will cause linear reciprocal motion of the containing section 20 in the direction A and the opposite direction thus to feed the parts in the containing section 20 into the carrying path 21a of carrying section 21. With such arrangement, plural bimorphs 17, 18 may be fixed respectively to the containing section 20 and the carrying section 21 while adjusting the height independently, thereby fixing and adjusting can be facilitated while the carrying efficiency is improved.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention involves storing relatively small articles such as electric elements or mechanical parts in a bowl, and transporting the bowl by reciprocating it using a vibrating body using a piezoelectric element. The present invention relates to a piezoelectrically driven bowl-shaped parts feeder.

[Technical background of the invention]

Conventionally, it has been known to use a bimorph, which is made by pasting piezoelectric elements on both sides of an elastic plate made of a leaf spring or a plastic plate, as a vibrating body of a conveyance device.As a piezoelectric element,
A material such as lead zirconate titanate is used that has been decentralized to have a polarization potential of positive polarity on one surface and negative polarity on the other surface. Therefore, in the conventional bowl-shaped parts feeder using the above-mentioned bimorph as a vibrating body, as shown in FIG. The upper end of each bimorph 2 is connected to the bottom of a pan-shaped bowl 3 by screwing in the same manner, and the bowl 3 is composed of a bowl bottom 4 and a spiral conveyance path 5 provided on its outer periphery.
The elastic roots of the bimorph 2 are attached in a direction that intersects the helical conveyance path 5 at right angles. With this configuration, when the bimorph 2 is energized and vibrated, the bowl 3 rotates back and forth around its center, guiding the conveyed object from the bowl bottom 4 to the spiral conveying path 5 and exiting the bowl 3. 5a direction. When this type of bimorph 2 is used as a vibrator, the structure is smaller and simpler than those using electromagnetic drive or electric drive, so it is easy to handle and repair, and it consumes less power. It has many features such as being economically superior and having no concerns about noise problems.

[Problems with Background Art] By the way, the displacement δ of the upper end of the bimorph 2 when it is deformed by voltage application is expressed by the following equation (1).

where d is the piezoelectric strain constant ■ is the applied voltage t is the thickness of the bimorph; the effective length of the bimorph σ is the thickness of the leaf spring α is the nonlinear coefficient. When an external force is applied, the amount of displacement decreases, and when the external force reaches the restraining load Fb shown in equation (2), the displacement δ becomes zero.

here ω is the width of the bimorph Y is Young's modulus at zero applied voltage.

On the other hand, Bimorph 2 causes a resonance phenomenon when an AC voltage with the same frequency as its natural frequency is applied, and the displacement δ increases by more than 10 times even with the same voltage, and by using it in such a resonant state, the transfer efficiency Although it is known that the restraint load Fb does not change even during resonance,
When the external force reaches the restraining load Fb, the displacement δ becomes zero.

Now, the relationship between the shape of bimorph 2 and the restraint load Fb is (2
) is obtained by substituting equation (1) into equation (3).

In order for the bimorph 2 to be able to withstand a large load according to equation (3), it is necessary to increase the width ω and thickness t of the bimorph 2, and further reduce the effective length. If it is difficult to greatly change the size of the bimorph 2 due to structural constraints, it is conceivable to increase the number of bimorphs 2 and reduce the load acting on each bimorph. However, as the number of bimorphs 2 increases, an imbalance in installation height tends to occur when attaching the bimorphs 2 to the base 1 and the bowl 3, and a biased load is applied to the bimorphs 2, making it difficult to obtain sufficient transport efficiency. There are problems that will go away. That is, as shown in FIG. 7(a), 4
When each bimorph 2 is connected to the bottom of the bowl 3 with the mounting hole of one of the bimorphs 2 at a high position by ΔL and the other mounting hole at a position low by ΔL2, an effect is exerted on the bimorph 2. The load to be applied is as shown in equation (4).

ΔL F=□・Y−A ・・・・・・(4) L′ Here, L′ is the length of the elastic body A is the cross-sectional area of the elastic body. ), a load as shown by the arrow FA acts on the bimorph 2 with low ΔL2, and a load as shown by the arrow Fa in FIG. becomes 2k(+), and the conveyance efficiency becomes extremely low. Therefore, in order to prevent this kind of load from acting, it is necessary to adjust the height of the bimorph 2 very delicately during assembly, and the height of the bimorph 2 If the number is large, the adjustment becomes very troublesome, and the drawback is that the manufacturability becomes very poor.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a piezoelectrically driven bowl-shaped parts feeder that can be easily adjusted when attaching a vibrating body and can obtain high conveyance efficiency.

[Summary of the invention]

In the present invention, the bowl is divided into a storage section and a conveyance section, and each section is vibrated by a separate vibrator consisting of a piezoelectric element attached to an elastic plate. The feature is that the number is reduced and adjustment work at the time of installation can be easily performed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Reference numeral 10 denotes a disc-shaped base, and a plurality of gmils made of an elastic material such as rubber are fixed to the lower surface of this base. Reference numeral 12 denotes four bimorph mounting seats (only three are shown) arranged near the outer periphery of the top surface of the base 10, and these inclined mounting surfaces 12a are arranged in a circle 1 concentric with the outer periphery of the base 10.
3 (indicated by a two-dot chain line in FIG. 1), the directions are set so as to intersect each other at right angles. Reference numeral 14 denotes a spring holder fixed to the center of the 1° base with a screw, and this has a circular convex portion (not shown) into which a spring, which will be described later, is fitted onto the outer periphery.
is formed. Reference numeral 15 denotes three bimorph mounting seats arranged at equal intervals on a circle 16 centered on the seat 14, and these mounting surfaces 15a are all oriented in the direction shown by arrow A in FIG. ing. Reference numerals 17 and 18 designate bimorphs as vibrating bodies, which are formed in substantially the same manner as the bimorph 2, and the lower ends of each of the four bimorphs 17 are fixed to the mounting surface 12a of the bimorph mounting seat 12 with screws. Further, the lower ends of the three bimorphs 18 are similarly fixed to the mounting surface 15a of the bimorph mounting seat 15 with screws. Reference numeral 19 denotes a generally steel-shaped bowl, which has a disc-shaped inner bottom that bulges upward toward the center, and a tapered accommodating portion 20 that is approximately cylindrical and has an inner periphery. The storage section 20 and the transport section 21 each have a spiral stepped transport path 21a formed therein, and a slight gap is provided between the storage section 20 and the transport section 21. 2
Reference numeral 2 denotes a spring bearing seat fixed to the outer bottom surface of the accommodating portion 20 with screws, and a convex portion 22a is provided protruding from the lower surface of the spring bearing seat. 23 is a coil spring, and the lower end of this spring holder is seat 1.
4, and its upper end is fitted to the outer periphery of the protrusion 22a. Reference numeral 24 denotes four bimorph mounting seats fixed at approximately equal intervals to the outer bottom surface of the transport section 21, and the upper ends of the bimorphs 17 are connected to these inclined mounting surfaces 24a by screws. Reference numeral 25 denotes three bimorph mounting seats fixed to the outer bottom surface of the accommodating portion 20, and the upper ends of the bimorphs 18 are connected to these inclined mounting surfaces 25a by screws.

Next, the operation of the above configuration will be explained. When an object to be transported, for example, a small part, is stored in the housing portion 20 of the bowl 19 and an AC power source is applied to the bimorphs 17 and 18, the bimorphs 17 and 18 reciprocate (reciprocating vibration) while resonating with the frequency of the AC power source. )I do. That is, due to the reciprocating motion of the bimorph 17, the transport section 21 performs a reciprocating rotational motion around the housing section 20, and when the bimorph 18 performs a reciprocating motion, the housing section 20 performs a linear reciprocating motion in the direction of the arrow 6 and in the direction opposite to the arrow. conduct. Therefore, along with the linear reciprocating movement of the storage section 20, the transported objects in the storage section 20 are moved in the six directions of the arrows and guided to the transport path 21a of the transport section 21, and the transported objects guided to the transport path 21a. The object is transported along the transport path 21a in the direction of arrow B by the reciprocating rotation of the transport section 21, and finally reaches the exit 21b.
1. : reach.

In the above configuration, the total number of bimorphs 17 and 18 is seven, but since the storage section 20 and the transport section 21 are separate parts, the three bimorphs 18 that drive the storage section 20 and the transport section 21 are driven. The height of each of the four bimorphs 17 needs to be adjusted separately, and the number of heights to be adjusted during adjustment is as small as 4 or 3, so the adjustment work is extremely easy compared to what was conventionally thought of. . In addition, -accommodating section 2
0 receives the weight of the conveyed object acting on the accommodation section 20 by the coil spring 23, so the number of bimorphs 18 can be set as small as three, and the number of bimorphs to be adjusted in height can be reduced. At the same time, since the bimorph 18 that drives the accommodation section 20 only performs reciprocating linear motion and no torsion acts on the elastic plates of the bimorph 18, the equivalent load due to the force in the torsional direction acting on the bimorph 18 is reduced. Therefore, the load applied to the bimorph 18 can be reduced by m, and high transport efficiency can be obtained with a small number of bimorphs. Most of the weight of the stored objects is received by the storage section 20, and the weight of the objects on the transport section 21 does not change, so the load applied to the bimorph 17 does not change. A nearly constant conveyance speed can be obtained.

Furthermore, since the conveying section 21 is annular and so-called hollow, its rigidity is lower than that of a conventional one having an integrated bowl (for this reason, when the bimorph 17 makes a reciprocating movement
Since the torsional force acting on the bimorphs 7 is reduced, the load acting on the bimorphs 17 can also be reduced in this respect, the number of bimorphs 17 can be reduced, and the transport efficiency can also be improved.

FIG. 5 shows another embodiment of the present invention, and the same parts as in FIGS. 1 to 3 are given the same reference numerals and explanations are omitted.
Only the different parts will be explained below. That is, 26 is a bimorph mounting seat fixed to the upper surface of the base 1, to which one end of the bimorph 27 is fixed with a screw so that the bimorph 27 is in a horizontal state, and the other end is attached to an elastic plate. 27a is bent at a right angle to form a low rigidity portion 27b. Reference numeral 28 denotes a protrusion protruding from the outer bottom surface of the accommodating portion 20, to which the other end of the bimorph 27 is fixed with a screw. In addition, in this FIG. 5, the coil spring 2
3. Conveying section 2 for spring seats 14 and 22 and bowl 19
1 and bimorph 17 are omitted. and,
In this configuration, when AC power is supplied to the bimorph 27 and the bimorph 27 is vibrated in the vertical direction, the object to be transported in the storage section 20 is moved in the outer circumferential direction along the slope of the upper surface of the storage section 20 and transported (not shown). It is sent to the department, and has the same effect as the above-mentioned embodiment.

[Effects of the Invention] As is clear from the above description, the present invention divides the bowl into a storage section and a conveyance section, and vibrates each section with a separate vibrator consisting of a piezoelectric element attached to an elastic plate. Therefore, it is possible to reduce the number of vibrating bodies that must be adjusted at the same time when the vibrating bodies are attached, thereby providing a piezoelectrically driven bowl-shaped parts feeder that can facilitate the attachment and adjustment work.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a perspective view of the entire structure, FIG. 2 is a side view, FIG. 3 is a sectional view of the bowl portion, and FIG. 4 is a sectional view of the bowl portion. , FIG. 5 is a side view of the main parts showing another embodiment of the present invention, FIGS. 6 and 7 show the conventional configuration, FIG. 6 is a perspective view, and FIG. 7 is an operational view. It is an explanatory diagram. In the drawing, 10 is a base, 17 and 18 are bimorphs, 19
20 is a bowl, 20 is a storage section, 21 is a conveyance section, 21a is a conveyance path, 23 is a coil spring, and 27 is a bimorph. %+ Figure 3 Figure 4 Figure 5 Figure i6 (a) Section 7

Claims (1)

[Scope of Claims] 1. A bowl-shaped part that transports the object by reciprocating a bowl that accommodates the object and has a transport path on its outer periphery using a vibrator made of a piezoelectric element attached to an elastic plate. A piezoelectrically driven bowl-shaped parts feeder, characterized in that the bowl is divided into a storage section and a conveyance section, each of which is vibrated by a separate vibrating body. 2. The piezoelectrically driven bowl-shaped parts feeder according to claim 1, wherein the storage section is linearly reciprocated by a vibrating body, and the conveyance section is reciprocated by a separate vibrating body. . 3. The piezoelectrically driven bowl-shaped parts feeder according to claim 2, wherein the housing portion is linearly reciprocated in the vertical direction by a vibrator.