JPS62222917A - Piezoelectric driven type feeding device - Google Patents

Abstract

PURPOSE:To increase a feeding speed, by connecting an elastic plate of a vibrating member through an elastic connecting member to a feeding member, and forming a low-rigid portion at a connecting part of the connecting member to be connected to the feeding member which low-rigid portion has a rigidity lower than that of the other part of the connecting member. CONSTITUTION:For use with a linear parts feeder, a bimorph 22 as a vibrating member is mounted at its lower end by a screw 25 to a base 20 having plural mount seats 21 on the upper surface thereof. The bimorph 22 comprises an elastic member 23 such as a leaf spring and piezoelectric elements 24 bonded on both surfaces of the elastic member 23. The bimorph 22 is so mounted as to be vertically inclined. The upper end of the bimorph 22 is connected through a connecting member 27 such as a leaf spring to a trough 26 as a feeding member. The connecting member 27 comprises an upper portion 29 and a lower portion 30 bent from the former. A fixing part 27a of the upper portion 29 to be fixed to the trough 26 and a lower part of a bent portion 27b are formed with low-rigid portions 32 and 33 having a rigidity lower than that of the other parts.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to conveying relatively small articles such as electronic parts or mechanical parts by means of vibration, and in particular uses a piezoelectric element as the vibration source. The present invention relates to the piezoelectric drive type conveyance device used.

(Prior art) As an example of a conventional piezoelectric drive type conveyor device, the Utility Model Application No. 52-6
There is a linear parts feeder disclosed in Japanese Utility Model Publication No. 1087 or Japanese Utility Model Application Publication No. 57-46517, and the principle of construction thereof is shown in FIG. In FIG. 4, 1 is a base, 2 is a lower frame fixed to the upper surface of the base 1, and an upper frame 4 is attached to both ends of this via two elastic plates 3.3 that stand up at an angle. supported horizontally. Reference numeral 5 denotes a trough serving as a conveying body fixed on the upper frame 4, on which the conveyed object 6 is placed. Reference numeral 7 denotes a piezoelectric element attached to each elastic plate 3, to which an alternating current voltage applied to terminals 8 and 9 is applied via lead wires 8a and 9a. In this case, the elastic plate 3 and both piezoelectric elements 7,
7 constitutes a bimorph 10 which is a vibrating body, and when an alternating current voltage is applied to both piezoelectric cords 7, 7 so that the polarization direction is opposite, one piezoelectric cord 7, for example, in a positive half cycle.
The bimorph 10 is deflected and vibrates in the direction of the arrow 11 by repeating the stretching motion in which the piezoelectric cord 7 is extended and the other piezoelectric cord 7 is contracted, and conversely, one is contracted and the other is extended in a negative half cycle. This deflection vibration causes the trough 5 to vibrate diagonally up and down in the direction shown by arrow 12, and by repeating the operation of jumping up the conveyed object 6 diagonally upward, it is moved along the trough 5 in the direction of arrow 13. In this case, the conveyance speed of the conveyed object 6 is proportional to the vibration amplitude of the trough 5.

This type of piezoelectric drive type parts feeder has a smaller and simpler structure than electromagnetic drive feeders or electric vibration feeders, so it is easier to handle and repair, and it is also economical because there are fewer consumable crabs. , has many features such as no concerns about noise problems, but there is still a problem in terms of conveyance speed, and the reason for this will be described below.

That is, it is known that if an alternating current voltage with the same frequency as the natural frequency of the bimorph 10 is applied, the vibration amplitude will increase by ten times or more even with the same voltage due to a resonance phenomenon. However, even during resonance, if a large load is applied to the bimorph 10 in its vibration direction, the vibration amplitude will drop rapidly, so the elastic plate 3
It is necessary to minimize the load applied to the vibration direction.

As shown in FIG. 4, since the two bimorphs 10 have the same length and are parallel to each other, the trough 5 always remains horizontal and moves diagonally up and down against vibrations of the bimorphs 10 in the direction of the arrow 11. It will vibrate in the direction of arrow 12. However, in the conventional device described above, since the angle of the connecting portion 4a of the upper frame 4 is always kept constant even during vibration, the angle formed between the upper end of the elastic plate 3 and the trough 5 as shown in FIG. The elastic plate 3 vibrates in such a way that θ is always kept constant, and this causes an excessive bending external force to be applied to the two ends of the elastic plate 3 in a direction that prevents the vibration.

Therefore, the vibration amplitude of the bimorph 10 and the trough 5
This had the disadvantage that the vibration amplitude was small, making it impossible to obtain a practical conveyance speed.

Therefore, in order to eliminate such drawbacks, it has been considered to construct the device as shown in FIGS. 6 to 8. That is, the upper end of the elastic plate 3 of the bimorph 1o and the trough 5 are connected by a connecting member 14 made of elastic porcelain, and the bending rigidity of the connecting member 14 is set to a value lower than that of the elastic plate 3. be. As a result, by elastically deforming the connecting member 11 with low bending rigidity during vibration, the elastic plate 3
The angular change between the two ends of the bimorph 10 and the trough 5 is allowed with a relatively small external force, and the load applied in the vibration direction is reduced accordingly, making it possible to expect the vibration amplitude of the bimorph 10 to increase. It is something.

However, even with this configuration, the vibration amplitude of the trough 5 in the vertical direction was still insufficient. That is, since the vibration direction of the bimorph 10 is close to the horizontal direction even in the diagonal vertical direction, even if the vibration amplitude of the bimorph 10 becomes large to some extent, the vertical vibration amplitude Ll (
(see Figure 8) does not become that large. For this reason, the lifting effect of the conveyed object was not so large, and the conveyance speed was still insufficient.

(Problems to be Solved by the Invention) As described above, it has not yet been possible to sufficiently secure the vibration amplitude of the trough 5 in the downward direction, resulting in an inferior conveyance speed.

51 The present invention is intended to solve these drawbacks, and therefore, its purpose is to provide a piezoelectric drive type conveying device that can increase the vibration amplitude in the vertical direction of the conveying body and increase the conveying speed. There is something to do.

[Configuration of the Invention (Means for Solving the Problems) The piezoelectric part i-shaped conveying device of the present invention connects the elastic plate of the vibrating body and the conveying body by an elastic connecting part, The connecting portion is made up of an upper piece fixed to the lower surface of the conveyor body and oriented substantially horizontally, and a lower piece bent from an end of the upper piece and oriented toward the vibrating body. A low-rigidity portion having lower rigidity than other portions is provided between a lower portion of the bent portion of the lower piece and a portion fixed to the carrier and the bent portion of the upper piece. It was formed.

(Function) During vibration, the elastic deformation of the low-rigidity parts of both the two side pieces and the bottom piece of the connecting part reduces the load in the vibration direction applied to the vibrating body, reducing the vibration amplitude of the vibrating body. increase. In this case, since the amount of elastic deformation in the low-rigidity parts of both the upper and lower pieces of the connection part is larger than the other parts, the movement form of the connection part during vibration is mainly caused by the low-rigidity parts on both sides. It becomes a form like a link movement that repeatedly bends the part,
This makes it possible to increase the amplitude in the vertical direction at the portion of the upper piece of the connecting portion that is fixed to the carrier.

(Embodiment) An embodiment in which the present invention is applied to a linear parts feeder will be described below with reference to FIGS. 1 to 3. 20 is a base on which a plurality of mounting seats 21 (only one is shown) are fixed to the upper surface;
22 is a bimorph which is an excitation body, and this bimorph 2
2 is an elastic plate 23 made of, for example, a leaf spring or a plastic plate.
A piezoelectric element 24 is attached to both sides of the plate by adhesion or the like. The lower end of the elastic plate 23 of this bimorph 22 is fixed to the inclined surface portion 21H on the side of the mounting seat 21 with a screw 25.

Although not shown, a plurality of bimorphs 22 are provided,
The bimorphs 22 are oriented obliquely in the vertical direction and are parallel to each other. On the other hand, 26 is a trough which is a conveyor,
This is for placing a conveyed object (not shown) and conveying it linearly by vibration. Now, 27 is almost "flat" with a leaf spring or elastic plastic.
This connecting portion 27 is connected to an upper piece 29 which is oriented substantially horizontally and is fixed to the lower surface side of the trough 26 by a screw 28, and from the right end of this upper piece 29 in the drawing. A lower piece 30 is bent and directed toward the bimorph 22. By fixing this lower piece 30 to the upper end of the elastic plate 23 of the bimorph 22 with a screw 31, the upper end of the elastic plate 23 is fixed. and the trough 26 are connected via a connecting portion 27. Then, the upper piece 29 of the connecting portion 27
Among them, between the fixed part 27a to the trough 26 and the bent part 27b, and in the lower part of the bent part 27b of the lower piece part 30, there are low-rigidity parts 32 and 33 each having lower rigidity than the other parts.
is formed. In this case, the low rigidity portion 32.33 is the second
As shown in the figure, that part is locally made narrower to make it less rigid than other parts. On the other hand, as shown in FIG. 1, a recess 34 is formed in the lower surface of the trough 26 at a portion corresponding to the right side of the upper piece 29 of the connecting portion 27 as shown in the figure. A gap is formed between the upper piece 27 and the trough 26.
The right side portion in the figure can also be deformed toward the trough 26 side (upper side).

Next, the operation of the above configuration will be explained. bimorph 2
When an alternating current voltage is applied to both piezoelectric elements 24 and 24 in such a manner that their polarization directions are opposite, for example, one piezoelectric element 24 expands and the other piezoelectric element 24 contracts in a positive half cycle.
On the other hand, by repeating the stretching movement in which one side contracts and the other side extends in a negative half cycle, the bimorph 22 deflects and vibrates in the direction of arrow 35 in FIG. This deflection vibration causes the trough 26 to vibrate diagonally up and down as shown by arrow 36, and by repeating the operation of jumping up the conveyed object diagonally upward, the object is moved to the left in the figure along the trough 26. In this embodiment, since the low-rigidity parts 32 and 33 are formed in the connecting part 27 made of elastic material that connects the upper end of the elastic plate 23 of the bimorph 22 and the trough 26, this low-rigidity part 32,33 is formed. Since the rigid portions 32 and 33 are elastically deformed relatively easily, changes in the angle between the upper end of the elastic plate 23 and the trough 26 due to vibration can be tolerated with a relatively small external force. Therefore, the load applied to the elastic plate 23 of the bimorph 22 in the vibration direction (arrow 35 direction) is reduced, and the vibration amplitude of the bimorph 22 in the arrow 35 direction is increased. Moreover, since the highly rigid bent portion 27b, which has a substantially “F” shape, is located between the low-rigidity portions 32 and 33, the movement form of the connecting portion 27 during vibration is mainly as shown in FIG. By repeatedly bending the low-rigidity parts 32 and 33 on both sides, a movement form such as a link movement in which the bending part 27b is swung in a direction opposite to the vibration direction of the bimorph 22 is obtained. Therefore, when the bimorph 22 is displaced from the center position shown by the solid line to the left in the figure as shown by the two-dot chain line,
The bent portion 27b is displaced so as to rotate in the clockwise direction in the figure around the low rigidity portion 33 of the lower piece 30, and the end of the bent portion 27b on the trough 26 side is displaced upward. anti-1
- On the other hand, when the bimorph 22 is displaced to the right in the drawing as shown by the dashed line, the bent portion 27b is rotated counterclockwise in the drawing around the low rigidity portion 33 of the lower piece 30. As a result, the end of the bent portion 27b on the trough 26 side is displaced downward. Due to the synergistic effect of the rocking movement of the bending part 27b of the connecting part 27 and the increase in the vibration amplitude of the bimorph 22 described above, the amount of vertical displacement of the end of the bending part 27b on the trough 26 side, and thus the vertical movement of the trough 26. The vibration amplitude L2 in the direction increases, thereby increasing the bouncing effect of the conveyed object and increasing the conveyance speed.

In the present embodiment, the low rigidity portions 32 and 33 are formed by locally narrowing predetermined portions of the 1-side piece 29 and the lower piece 30 of the connecting portion 27. For example, the low-rigidity portion may be formed by locally reducing the plate thickness of predetermined portions of the second side piece and the lower side piece. In addition, in this embodiment, the connecting portion 27 is connected to the bimorph 22.
Although the elastic plate 23 is constructed as a separate part, for example, the connecting portion may be formed integrally with the elastic plate of the bimorph. Furthermore, the vibrating body is not limited to the bimorph 22 in which one piezoelectric element 24 is attached to each side of the elastic plate 23; for example, a piezoelectric element is attached to one side of the elastic plate 23.
You can use only one sheet, or three or more sheets including both sides.

Furthermore, in this embodiment, the four parts 34 are provided so that the bent part 27b of the connecting part 27 does not hit the trough 26 even if it is displaced upward, but the fixing part 27a of the connecting part 27 and the trough 26 are attached to each other by a seat. A similar effect can be obtained by attaching it through the hole, and in this case, the four portions 26 are not necessary. In addition, the present invention can be modified in various ways without departing from the spirit, such as being applicable to a bowl-shaped parts feeder.

[Effects of the Invention] As is clear from the above description, the present invention reduces the load in the vibration direction applied to the vibrator by elastic deformation of the low-rigidity portions of both the upper and lower pieces of the connection part. By doing so, the vibration amplitude of the vibrating body can be increased, and the movement form of the connecting part during vibration can be made into a form such as a link movement that repeatedly bends the low rigidity parts on both sides. The vibration amplitude in the vertical direction at the part fixed to the conveying body among the parts and the vibration amplitude in the vertical direction of the conveying body can be increased, and the conveying speed can be increased, which is an excellent effect.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment in which the present invention is applied to a linear parts feeder, in which Figure 1 is a front view of the main part, Figure 2 is a perspective view of the connecting part, and Figure 3 is a perspective view of the connecting part. is a front view of the connecting portion for explaining the action, and Fig. 4 to Fig. 8 show a conventional example, Fig. 4 is a front view of the whole, Fig. 5 is an action explanatory diagram, and Fig. 6 is a view corresponding to FIG. 1, FIG. 7 is a perspective view of the connecting member, and FIG. 8 is a view corresponding to FIG. 3. In the drawing, 22 is a bimorph (vibrating body), 23 is an elastic plate,
24 is a piezoelectric element, 26 is a trough (carrying body), 27 is a connecting part, 27a is a fixed part, 27b is a bent part, 29 is a two-side piece, 30 is a lower piece, 32 and 33 are low-rigidity parts It is. Figure 3 Figure 2a Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. A carrier is disposed above a vibrating body formed by attaching a piezoelectric element to an elastic plate, and the elastic plate of the vibrating body and the conveying body are connected by an elastic connecting portion, The connecting portion is made up of an upper piece fixed to the lower surface of the conveyor body and oriented substantially horizontally, and a lower piece bent from an end of the upper piece and oriented toward the vibrating body. A low-rigidity portion having lower rigidity than other portions is provided between a lower portion of the bent portion of the lower piece and a portion fixed to the carrier and the bent portion of the upper piece. A piezoelectric drive type conveyor device characterized in that: