JP2002302232A - Piezoelectric element driving type feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the conveyance capacity of a feeder by increasing the displacement of a blade spring without heightening the blade spring to which a piezoelectric element is adhered in a piezoelectric element driving type feeder provided with a vibration exciting weight. SOLUTION: In the piezoelectric element driving type feeder wherein a trough T is mounted on a base V through a plurality of blade springs for drive, and a vibration exciting weight E is hung held between a pair of front and rear piezoelectric element adhering blade springs B arranged perpendicularly in the bottom face of the trough T, and piezoelectric elements P1 and P2 are adhered to at least one face of a part positioned lower than the changed and bent point Y of the blade springs B, each of the piezoelectric element adhering blade springs B is formed into an L-shape, and the horizontal section B2 is fixed to the bottom face of the trough T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element drive type feeder having a vibrating weight suspended from the bottom of a trough.

[0002]

2. Description of the Related Art Electromagnetic driving systems are widely used as a part feeder driving system. However, the electromagnetic driving system easily generates magnetism and heat, and there are many works that dislike these. Therefore, a driving method using a piezoelectric element that does not generate both magnetism and heat is adopted as an effective method.

FIG. 9 shows a known linear feeder using a vibrating weight among conventional linear feeders driven by a piezoelectric element. This piezoelectric element driving type linear feeder includes a base V, a trough T connected to the base V via a pair of front and rear driving leaf springs A arranged at a predetermined angle (θ), and a vertical arrangement. The vibrating weight E is suspended from the bottom surface of the trough T in such a manner that the front and rear end faces are sandwiched by the pair of front and rear piezoelectric element attaching leaf springs B ′. Piezoelectric elements P ₁ and P ₂ are attached to both surfaces of the pair of piezoelectric element attaching leaf springs (hereinafter sometimes abbreviated as “piezoelectric leaf springs”) B ′, respectively. The polarity of each of the piezoelectric elements P ₁ and P ₂ adhered to both sides of B ′ is determined such that when an AC voltage of the same potential is applied, _{one of} the piezoelectric elements P ₁ and P ₂ expands and the other contracts. That is, the same piezoelectric leaf spring B ′
Each piezoelectric element P ₁ which is stuck on both sides of, the application of the alternating voltages of opposite phases to P _2, the piezoelectric elements P _1, P ₂ is adapted to stretch alternately.

Accordingly, by applying an AC voltage, each of the piezoelectric elements P ₁ and P ₂ adhered to both sides of the pair of piezoelectric leaf springs B ′.
When but expands and contracts alternately, the piezoelectric flexure B 'is resiliently deformed, as a result, pressurized Futsumu E, the piezoelectric plate spring B' vibrates in a horizontal direction D ₁ is the displacement direction of the. The vibration reaction force of the piezoelectric leaf spring B ′ acts on the trough T, and the pair of driving leaf springs A is bent and deformed due to the large inertia of the vibrating weight E, so that the trough T the a vibration direction opposite to the direction of the pressurized Futsumu E, yet vibrates in the vibration direction D ₂ perpendicular to the drive plate spring a. Therefore, the components in the trough T are transported in the direction of arrow Q.

Here, the deformation of the pair of piezoelectric leaf springs B ′ at the time of the vibration conveyance of the linear feeder is as shown in FIG. 10, and the distortion of the front and back surfaces is as shown in FIG. . Note that in FIGS. 10 and 11,
X ₁ and X ₂ indicate ends of the piezoelectric leaf spring B ′ on the trough T side and the vibrating weight E side, respectively. As can be understood from FIG. 10, the distortion changes in the middle part of the piezoelectric leaf spring B ′ (changes from compression to tension or changes from tension to compression).
There is an inflection point Y ′, and the inflection point Y ′ is located substantially at the center of the effective spring length (L ′).

For this reason, if the piezoelectric elements P ₁ and P ₂ are adhered over the entire effective length of the piezoelectric leaf spring B ′, not only the efficiency of generating the vibration force is poor, but also the vicinity of the inflection point Y ′ In this case, an excessive bending force acts on the piezoelectric elements P ₁ and P ₂ , stress concentration occurs, and the life of the elements themselves is shortened.

[0007] Therefore, 'the adhering position of the piezoelectric elements P _1, P ₂ with respect to the inflection point Y' piezoelectric flexure B to avoid, by selecting a lower than this, the problem is solved You. However, if a piezoelectric element having the same length is to be attached to the position, the spring length of the piezoelectric leaf spring B ′ becomes longer, and the height of the entire apparatus becomes higher. Another problem arises:

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a piezoelectric element drive type feeder provided with a vibrating weight, in which the displacement of the leaf spring for attaching the piezoelectric element is increased without increasing the height of the leaf spring. As a result, it is possible to increase the transport capacity of the feeder.

[0009]

According to a first aspect of the present invention, a trough is mounted on a base via a plurality of driving leaf springs, and the trough is vertically disposed on a bottom surface of the trough. In a state sandwiched between the pair of piezoelectric element attaching leaf springs, the vibrating weight is hung, and at least one surface of a portion below the inflection point of the pair of piezoelectric element attaching leaf springs A piezoelectric element drive type feeder having a configuration in which an element is attached, wherein the pair of piezoelectric element attachment leaf springs includes:
Each has an L-shape, and its horizontal plate portion is fixed to the bottom surface of the trough.

According to the first aspect of the present invention, each of the pair of front and rear piezoelectric element attaching leaf springs is formed in an L shape and the horizontal plate portion is fixed to the back surface of the trough. If the lower end is bent in the horizontal direction, the horizontal plate is also bent and deformed, so the inflection point of the vertical plate is
The height of the leaf spring for attaching the piezoelectric element (the length of the vertical plate portion) is shifted upward from the center.

As a result, the piezoelectric element can be attached to a position higher than the center in the height direction of the vertical plate portion of the leaf spring for attaching the piezoelectric element. In addition, since the horizontal plate portion of the plate spring to which the piezoelectric element is attached also bends and deforms, the horizontal plate portion also acts as an effective portion of the plate spring, and the effective length of the plate spring becomes longer. The substantial length of the portion where the element is not attached becomes longer, and the leaf spring for attaching the piezoelectric element is easily deformed. For this reason, when the other conditions are kept constant, the displacement of the lower end portion of (the vertical plate portion of) the piezoelectric element attachment leaf spring can be increased as compared with the conventional flat plate-shaped piezoelectric leaf spring. This means that from the viewpoint of the feeder (device), the amplitude of the trough can be increased without increasing the height of the device.

The invention of claim 2 is based on the premise of the invention of claim 1, and in the case where the length of the vertical plate portion of the leaf spring for attaching the piezoelectric element is constant, the relationship between the vertical plate portion and the surrounding members. The length ratio between the horizontal plate portion and the vertical plate portion is made as large as possible. The larger the ratio, the longer the effective length of the leaf spring for attaching the piezoelectric element, and the smaller its spring constant, so that a large displacement (amplitude of vibration) is obtained when the leaf spring for attaching the piezoelectric element is deformed. It will be easier.

[0013] The invention of claim 3 is the invention of claim 1 or 2.
The spring constant of the pair of piezoelectric element attaching leaf springs is adjusted by adjusting the length of at least one of the trough side and the vibrating weight side spacer and the length of the spring pressing plate. And According to the first or second aspect of the present invention, since the pair of piezoelectric element attaching leaf springs sandwiching the vibrating weight at both front and rear ends are L-shaped, the spring holding plate of the horizontal plate portion on the trough side thereof. By adjusting the length of the leaf spring, the spring constant of the leaf spring can be adjusted.

Further, the invention according to claim 4 is the invention according to claim 1 or 2
The invention is characterized in that the adjustment of the spring constant of the pair of leaf springs for attaching the piezoelectric element is performed by adjusting the mounting position of the vibrating weight with respect to the vertical plate portion. According to the first or second aspect of the invention, since the inflection point of the vertical plate portion is located above the center portion, the piezoelectric element is attached below the inflection point of the leaf spring for attaching the piezoelectric element. Even under the condition of wearing, since there is still room for adjusting the mounting position of the vibrating weight, the above adjustment is possible.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to examples. FIG. 1 is a schematic front view of a piezoelectric element driving type feeder according to the present invention, and FIG. 2 is an exaggerated view of a bent shape of a pair of front and rear piezoelectric element attaching leaf springs B. is a graph showing both sides of each portion of the effective length of the vertical plate portion B ₁ of the piezoelectric element sticking plate spring B F, the surface strain of the R. The same parts as those of the conventional linear feeder using the above-mentioned flat plate-shaped piezoelectric leaf spring B 'are denoted by the same reference numerals, and only the parts unique to the present invention will be described, avoiding redundant description.

In the present invention, an L-shaped piezoelectric leaf spring B is used, and a vibrating weight E is connected to the lower end of the vertical plate B ₁ , and the horizontal plate B ₂ The end is fixed to the bottom of the trough T. Then, by the application of the AC voltage, each of the piezoelectric elements P ₁ and P ₂ attached to both surfaces of the vertical plate portion B ₁ of the pair of piezoelectric leaf springs B alternately expands and contracts, and the piezoelectric leaf spring B The vertical plate portion B ₁ and the horizontal plate portion B ₂ are both bent and deformed, and the vibrating weight E is displaced by the displacement of the lower end of the vertical plate portion B ₁ of the piezoelectric plate spring B connected thereto. vibrates in the horizontal direction D ₁ is the direction. When the vibration reaction force of the piezoelectric leaf spring B acts on the trough T, the driving leaf spring A is vibrated, and the trough T vibrates in a direction D ₂ perpendicular to the driving leaf spring A. Then, the components accommodated therein are transported in the direction of arrow Q.

Here, a pair of piezoelectric leaf springs B suspended on the bottom surface of the trough T with the vibrating weight E sandwiched between the front and rear end faces are L-shaped, and their horizontal plate portions B because ₂ is fixed to the bottom surface of the trough T, as shown in FIG. 2, not only the vertical plate portion B _1, the horizontal plate portion B
_{2 is} also bent and deformed together. Therefore, as shown in FIGS. 2 and 3, the inflection point Y of the vertical plate portion B ₁ of the piezoelectric leaf spring B is shifted upward from the center in the height direction.

As a result, the vertical plate portion B ₁ of the piezoelectric leaf spring B is obtained.
Along with the height can be direction adhering the piezoelectric element P _1, P ₂ to the upper than the central portion of the, for the horizontal plate portion B ₂ also flexural deformation of the piezoelectric plate spring B, also in this horizontal plate portion B ₂ plates In order to act as an effective portion of the spring B, the length of the effective portion of the leaf spring B increases, and the substantial length of a portion of the effective portion where the piezoelectric elements P ₁ and P ₂ are not attached ( (Indicated by “L ₁ ” in FIG. 1)
Becomes longer, and the piezoelectric leaf spring B is easily deformed. Therefore, as compared with the conventional flat plate-shaped piezoelectric plate spring, its able increase the displacement (vertical plate portion B ₁₎ a lower end portion, without increasing the height of the feeder (device), the trough Can be increased, and the component transfer capability as a feeder can be enhanced.

In order to confirm the operation and effect of the present invention, FIG.
(B), as shown in (b), the effective length of the effective length of the vertical plate portion B ₁ and (LB), a flat plate-shaped piezoelectric plate spring B 'of the piezoelectric plate spring B of L-shaped (LB) FIG. 5 shows the change in the deflection of the vibrating weight E when the effective lengths (LP) of the same piezoelectric elements P ₁ and P ₂ adhered to both sides thereof are variously changed by making the same. ing. Each of the piezoelectric elements P ₁ and P ₂ was attached to the lower end of the vertical effective portion of the piezoelectric leaf springs B and B ′, and the applied voltage was constant in all states.

As is apparent from FIG. 5, in the conventional flat plate-shaped leaf spring B ', the maximum deflection is obtained when the ratio of the piezoelectric element length (LP) to its effective length (LB) is about 60%. On the other hand, in the L-shaped leaf spring B according to the present invention, the above ratio is about 7
At 0%, the deflection becomes maximum, and when the L-shaped leaf spring B according to the present invention is used, it is found that the inflection point of the vertical plate portion is shifted upward as compared with the conventional leaf spring. did. In addition, it has been found that the amount of deflection itself is 20 to 40% larger for the L-shaped leaf spring B according to the present invention, and that a large displacement can be obtained efficiently when the height of the apparatus is the same.

Further, the piezoelectric leaf spring constituting the feeder according to the present invention has an L-shape, and not only the vertical plate portion but also the horizontal plate portion functions as an effective length of the spring. The method of adjusting the spring constant is also expanded. The effective portion of the spring is the elastically deformable portion of the spring, and generally,
The spring constant is inversely proportional to the cube of the length of the effective portion. The longer the effective portion, the smaller the spring constant. Conversely, the shorter the effective portion, the larger the spring constant.

As shown in FIG. 6, the vertical plate portion B ₁ of the L-shaped piezoelectric leaf spring B has a spacer 1 disposed between the vertical plate portion B and the end face of the vibrating weight E, and a spring presser provided on the outside thereof. The plates 2 are arranged, and these are fixed to the vibrating weight E by bolts 3.
On the other hand, in the horizontal plate portion B ₂ of the piezoelectric leaf spring B, the spacer 11 is disposed between the horizontal plate portion B ₂ and the bottom surface of the trough T, and the spring pressing plate 12 is disposed outside the horizontal plate portion B _2. It is fixed to the bottom of. Therefore, the piezoelectric leaf spring B
In order to increase the spring constant, as shown in (b), one or both of the spacer 1 and the spring holding plate 12 and / or the spacer 11 and the spring holding plate 12 are lengthened. (In FIG. 6 (b), the length of a spacer or the like is denoted by “′” in its symbol). FIG. 6B shows a case where both of the above are lengthened. Thus, the effective length (L ₁₁ ) of the piezoelectric leaf spring B in FIG. 6A is shortened to the effective length (L ₁₂ ) in FIG. 6B. As described above, since the inflection point Y of the vertical plate portion B ₁ of the L-shaped piezoelectric leaf spring B is shifted upward from the center in the height direction, the inflection point Y is also located on the vibrating weight E side. The above adjustment can be easily performed.

Another example shown in FIGS. 7 and 8 is as follows.
And the lower end of the vertical plate portion B ₁ of the piezoelectric plate spring B of L-shaped left to form a vertical elongated hole 21, the long hole 21, the vertical plate portion B ₁ for pressurizing Futsumu E fixed The position is adjustable. In the example shown in FIGS. 7 and 8, the vertical plate portion B ₁ of the piezoelectric leaf spring B is fixed to the vibrating weight E at the upper end side of the long hole 21.
The effective length (L ₁₃ ) shorter than the effective length (L ₁₁ ) in the case of (a).
And the spring constant increases.

For this reason, the vertical plate portion B ₁ of the piezoelectric leaf spring B is provided.
If the length is constant, the in relation to the respective peripheral members such as the driving plate spring A, when large as possible the ratio of the horizontal plate portion B ₂ and the vertical plate portion length of B _1, the As you did,
In addition to the spring constant is reduced, for deflection of the horizontal plate portion B ₂ is increased, the amplitude of the trough becomes large, and without increasing the height of the feeder, the feeding force is increased.

[0025]

The piezoelectric element drive type feeder according to the present invention can increase the effective length of the leaf spring for attaching the piezoelectric element without increasing the height of the leaf spring, thereby increasing the displacement of the leaf spring.
That is, it is possible to increase the feedability of the feeder without increasing the height of the feeder.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a piezoelectric element drive type feeder according to the present invention.

FIG. 2 is an exaggerated view of a bent shape of a pair of front and rear piezoelectric element attaching leaf springs B;

3 is a graph showing the surface strain of the double-sided F, R at the respective portions of the effective length of the vertical plate portion B ₁ of the piezoelectric element sticking plate spring B.

[4] (a) is attached to the effective length bottom surface pressure Futsumu E of the trough T via the piezoelectric element sticking plate spring B of a pair of L-shaped having a vertical plate portion B ₁ of the (LB) It is a schematic diagram of a state,
(B) is a schematic diagram showing a state in which a vibrating weight E is attached to the bottom surface of the trough T via a plate-shaped piezoelectric element attaching leaf spring B ′ having the same effective length (LB).

FIG. 5 is a graph showing a change in bending of the L-shaped and flat plate-shaped piezoelectric element attaching leaf springs B and B ′ with respect to [piezoelectric element length (LP) / effective spring length (LB)].

FIGS. 6A and 6B are spacers 1 and 11 and a spring holding plate 2 for fixing an L-shaped piezoelectric element attaching leaf spring B to an oscillating weight E and a trough T, respectively. 12 is a diagram illustrating a state in which the length of the spring 12 is changed to change the effective spring length. FIG.

FIG. 7 is a vertical plate portion B of an L-shaped leaf spring B for attaching a piezoelectric element.
Using the long hole 21 formed in ₁ is a front view of a state of changing the spring effective length.

FIG. 8 is a side view of the same.

FIG. 9 is a schematic front view of a conventional piezoelectric element drive type feeder.

FIG. 10 is an exaggerated view of a bent shape of a pair of front and rear piezoelectric element attaching leaf springs B ′ having a flat plate shape.

FIG. 11 is a graph showing the surface distortion of both surfaces F and R in each part forming the effective length of the leaf spring B 'for attaching a piezoelectric element.

[Explanation of symbols]

A: leaf spring for driving B: leaf spring for attaching a piezoelectric element B ₁ : vertical plate section of a leaf spring for attaching a piezoelectric element B ₂ : horizontal plate section of a leaf spring for attaching a piezoelectric element E: vibrating weight P ₁ , P ₂ : Piezoelectric element T: Trough V: Base Y: Inflection point of leaf spring for attaching piezoelectric element 1, 11: Spacing 2, 12: Spring holding plate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuyuki Kimura 100 Takegahana-cho, Ise-shi, Mie Prefecture Shinko Electric Co., Ltd. Ise Office (72) Inventor Kyoji Murashiki 100-Takegahana-cho, Ise-shi, Mie Shinko Electric Co., Ltd. 3F037 BA03 CA14 CA17 CB04 5D107 AA02 BB05 BB06 CC02 CC12 DD02 DD12 FF10

Claims (4)

[Claims] 1. A trough is attached to a base via a plurality of driving leaf springs, and a trough is attached to a bottom surface of the trough between a pair of vertically arranged front and rear piezoelectric element sticking leaf springs. A piezoelectric element-driven feeder having a configuration in which a oscillating weight is suspended and a piezoelectric element is attached to at least one surface of a portion below an inflection point of the pair of piezoelectric element attaching leaf springs, A pair of piezoelectric element attaching leaf springs each have an L-shape, and a horizontal plate portion is fixed to a bottom surface of the trough. 2. In the case where the length of the vertical plate portion of the leaf spring for attaching the piezoelectric element is constant, in relation to the surrounding members,
2. The piezoelectric element drive type feeder according to claim 1, wherein a ratio of each length of the horizontal plate portion and the vertical plate portion is made as large as possible. 3. The adjustment of the spring constant of the pair of piezoelectric element attaching leaf springs is performed by adjusting the length of at least one of the trough side and the vibrating weight side spacer and the length of the spring pressing plate. The piezoelectric element drive type feeder according to claim 1. 4. The piezoelectric device according to claim 1, wherein the adjustment of the spring constant of the pair of leaf springs for attaching a piezoelectric element is performed by adjusting a mounting position of an oscillating weight with respect to the vertical plate portion. Element drive type feeder.