JPH0748573B2 - Piezoelectric element displacement amplification mechanism - Google Patents

Description

The present invention relates to a piezoelectric element displacement amplification mechanism that performs displacement amplification using a piezoelectric element as a drive source.

[Conventional technology]

Conventionally, in this type of piezoelectric element displacement amplification mechanism, as shown in FIG. 5, both ends of the piezoelectric element 13 are connected to one end of the lever arms 15 ₁ and 15 ₂ by _second hinges 14 ₁ and 14 ₂ , respectively. Then, the lever arms 15 ₁ and 15 ₂ use the fulcrum as the first hinge 16 ₁ and 16 ₂
The second hinge 14 ₁ and the lever arm 15 ₁ are supported by a buckling spring 18 serving as a displacement transmitting means so that the buckling spring 18 is connected to the base plate 17 by the other end of the lever arm 15 ₁ , 15 ₂ and is sandwiched by the other ends. Connection of 2nd hinge 14 ₂ and lever arm
The distance of the connection of 15 ₂ is the first hinge 16 ₁ and the lever arm 15
It was configured so as to be equal to the distance of the first hinge 16 ₂ and the lever arm 15 _{and second} connecting portions ₁ of the connection portion.

FIG. 3 shows the piezoelectric element displacement amplification mechanism of FIG. 5 as a beam element.

Connect the connection between the lever arm 15 ₁ , 15 ₂ and the second hinge 14 ₁ , 14 ₂
9 ₁ , 9 ₂ , connect the connection between the lever arms 15 ₁ and 15 ₂ and the first hinges 16 ₁ and 16 ₂ with 10 ₁ and 10 ₂ , and connect the connection between the lever arms 15 ₁ and 15 ₂ and the buckling spring 18. 11 ₁ , 11 ₂ and connection part 9 ₁ to 10 _{1 to} 11 ₁ , 9 ₂
If the angles formed by connecting ~ 10 ₂ ~ 11 ₂ are 12 ₁ and 12 ₂ , respectively, the distance between the connecting portions 9 ₁ and 9 ₂ is equal to the distance between the connecting portions 10 ₁ and 10 ₂ .

As a conventional piezoelectric element displacement amplification mechanism, and the connecting portion 9 ₁
9 ₂ , distance between connections 10 ₁ and 10 ₂ is 13 mm, lever arm 15
The length of ₁ , 15 ₂ is 28 mm, and when a piezoelectric element that generates a force of 21 kgf when a voltage of 150 v (volt) is applied is built in, the center of buckling spring 18 has a displacement of 230 μm and a generated force of 250
The output performance of gf was obtained, and the energy conversion efficiency was only 34%.

[Problems to be Solved by the Invention]

The above-described conventional piezoelectric element displacement amplification mechanism includes the second hinge.
The distance between the connecting portion of the lever 14 ₁ and the lever arm 15 _{1 and} the connecting portion of the second hinge 14 ₂ and the lever arm 15 ₂ is the distance between the connecting portion of the first hinge 16 ₁ and the connecting portion of the lever arm 15 ₁ and the first hinge 16 ₂ . Lever arm
Since a 15 such that equal to the distance of the _second connecting part configuration, when designing the piezoelectric element displacement amplification mechanism, perform energy conversion efficient optimal design each of the distance of the is too long and the limited It has the drawback of being a hindrance to time.

[Means for Solving the Problems]

A piezoelectric element displacement amplification mechanism of the present invention includes a piezoelectric element that contracts according to an applied voltage, a first lever arm having one end connected to one end of the piezoelectric element via a first hinge, and A second lever arm, one end of which is connected to the other end of the piezoelectric element via a second hinge, and one end of the first lever arm, which is provided between the first and second lever arms. A substrate connected to the vicinity of the second lever arm via a third hinge, and further connected to a vicinity of one end of the second lever arm via a fourth hinge, and the other end of the first lever arm to the first lever arm. And a second displacement detecting means for detecting a displacement provided between the second lever arm and the other end of the lever arm, and the displacement of the piezoelectric element is transmitted through the first and second hinges to the first and second levers. It is transmitted to the arm, and the third
And a piezoelectric element displacement amplification mechanism that amplifies and transmits the displacement to the displacement detection means with a fourth hinge as a fulcrum, in the third element rather than the distance between the first hinge and the second hinge. It is characterized in that the distance between the hinge and the fourth hinge is short.

[Work]

The distance between the second hinge that transmits the displacement of the piezoelectric element to the lever arm and the first hinge that functions as a lever fulcrum by connecting the substrate and the lever arm is widened, and the lever arm easily rotates around the fulcrum. That is, the first hinge, which is a fulcrum, does not move and the fulcrum does not move, and the width of the lever arm near the fulcrum becomes wider to increase rigidity, and energy loss in the lever arm decreases. The energy conversion efficiency is greatly improved.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing a first embodiment of the piezoelectric element displacement amplification mechanism of the present invention.

A pair of lever arms 1 ₁ and 1 ₂ are fixed to opposite side surfaces of the substrate 3 via _first hinges 2 ₁ and 2 ₂ , and further, both end surfaces of the piezoelectric element 4 are attached to the lever arms 1 ₁ and 1 _2. Second hinge 5 ₁ , 5 ₂
It is fixed through. The other end of the lever arm 1 _1, 1 _2, buckling spring 6 which is slightly curved is supported. The lever arms 1 ₁ , 1 ₂ , the first hinges 2 ₁ , 2 ₂ , the second hinges 5 ₁ , 5 ₂ , and the substrate 3 are made of 42Ni-Fe alloy material by press punching and wire cutting. The buckling spring 6 was manufactured by processing a stainless steel thin plate. The piezoelectric element 4 is connected to the second hinges 5 ₁ and 5 ₂ with a thermosetting resin,
The lever arm 1 _1, 1 ₂ and buckling spring 6 are connected by crimping with aluminum rivets.

By applying a voltage to the piezoelectric element 4, the displacement 7 of the piezoelectric element 4 is transmitted to the lever arms 1 ₁ , 1 ₂ via the _second hinges 5 ₁ , 5 ₂ , and the first hinge 2 ₁ , The displacement is magnified at the other ends of the lever arms 1 ₁ and 1 _{2 on} the principle of leverage with 2 ₂ as a fulcrum. Further, the buckling spring 6 sandwiched between the lever arms 1 ₁ and 1 ₂
A displacement is transmitted to both ends of the buckling spring 6, and the buckling spring 6 is deformed in a direction perpendicular to the displacement transmitted to the both ends by buckling, and a maximum displacement 8 is generated in the central portion of the buckling spring 6. Then, when the applied voltage is returned to zero volt, the strain of the piezoelectric element 1 returns to the origin, and the displacement of the buckling spring 6 also returns accordingly.

FIG. 2 shows the piezoelectric element displacement amplification mechanism of FIG. 1 as a beam element.

Connect the connecting parts of the lever arms 1 ₁ and 1 ₂ and the second hinges 5 ₁ and 5 ₂ to 9 ₁ and 9
₂ , connect the lever arm 1 ₁ , 1 ₂ and the first hinge 2 ₁ , 2 ₂ to 1
0 ₁ , 10 ₂ and the connecting portions of the lever arms 1 ₁ , 1 ₂ and the buckling spring 6 are 11 ₁ , 11 ₂ , and the connecting portions 9 ₁ 〜 10 ₁ 〜 11 ₁ , 9 ₂ 〜 10 ₂ 〜 11 ₂
The angles formed by tying with and are 12 ₁ and 12 ₂ , respectively. Therefore, as shown in FIG. ₂ , when the distance between the connecting portions 10 ₁ and 10 ₂ is changed and the design of the piezoelectric element displacement amplification mechanism is reviewed so that the energy conversion efficiency is improved, the energy conversion efficiency is improved. Is as shown in Fig. ₂ , the distance between the connecting parts 9 ₁ and 9 ₂ is 13 mm, the distance between the connecting parts 10 ₁ and 10 ₂ is 11 mm, and the angle 12
_1, 12 ₂ was 120 ° (degrees).

The piezoelectric element displacement amplifying mechanism shown in FIG. 1 was also incorporated with a piezoelectric element that generates a force of 21 kgf when the above-mentioned voltage of 150 v (volt) is applied.
An output performance of 320 μm and a generated force of 260 gf was obtained, and the energy conversion efficiency was 51%, an improvement of 17% compared to 34% of the conventional example. The the second hinge 5 _1, 5 ₂ convey the displacement 7 of the piezoelectric element 4 to the lever arm 1 _1, 1 _2, the substrate 3 and the lever arm 1 _1, 1 ₂ by connecting role of the fulcrum of the lever The distance between the hinges _{1 1} and 2 ₂ of _{No. 1} is widened, and the lever arms 1 ₁ and 1 ₂ can easily rotate around the fulcrum. In addition, a first hinge that serves as a fulcrum when a piezoelectric element is displaced, such as a conventional piezoelectric element displacement amplification mechanism.
It is no longer possible for the fulcrum to move due to the expansion of 2 ₁ , 2 ₂ . And the lever arms 1 ₁ , 1 ₂ near the fulcrum
The width of the arm becomes wider and the rigidity increases, and the lever arm 1 ₁ , 1
Energy loss at ₂ decreased. The above has greatly improved the energy conversion efficiency.

FIG. 4 is a front view of the second embodiment of the present invention.

This embodiment, Yes connected to the lever arm 1 _1, 1 ₂ the direction of the buckling spring 6 is changed by 90 ° (degrees) with aluminum rivets, the direction of movement of the buckling spring 6 and the first embodiment changes Other than that, the other operating mechanism is the same.

In the second embodiment, as in the first embodiment, the energy conversion efficiency is 50%.

〔The invention's effect〕

As described above, according to the present invention, the lever arm side of the first hinge connecting the lever arm and the substrate is more than the distance between the lever arm side connecting portions of the second hinge connecting the lever arm and the piezoelectric element. There is an effect that the energy conversion efficiency can be increased to about 50% by making the distance between the connection parts of the two shorter.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of the piezoelectric element displacement amplification mechanism of the present invention, FIG. 2 is a model diagram showing the piezoelectric element displacement amplification mechanism of the first embodiment with beam elements, and FIG. FIG. 4 is a model diagram showing the conventional piezoelectric element displacement amplification mechanism of FIG. 5 with beam elements.
FIG. 5 is a front view of a second embodiment of the present invention, and FIG. 5 is a front view of a conventional piezoelectric element displacement amplification mechanism. 1 ₂ , 1 ₂ , 15 ₁ , 15 ₂ …… Lever arm, 2 ₁ , 2 ₂ , 16 ₁ , 16 ₂ …… First hinge, 5 ₁ , 5 ₂ , 14 ₁ , 14 ₂ …… Second Hinge, 3,17 ... Substrate, 4,13 ... Piezoelectric element, 6,18 ... Buckling spring, 7 ... Piezoelectric element 4 displacement, 8 ... Buckling spring 6 displacement, 9 ₁ , 9 ₂ ...... Second hinge and lever arm connection, 10 ₁ , 10 ₂ ...... First hinge and lever arm connection, 11 ₁ , 11 ₂ ...... Lever arm and buckling spring connection 12 ₁ , 12 ₂ …… Angle formed by the connecting parts 9,10,11.

Claims (1)

[Claims] 1. A piezoelectric element that contracts in response to an applied voltage, a first lever arm whose one end is connected to one end of the piezoelectric element via a first hinge, and the other end of the piezoelectric element. A second end of which one end is connected to the second hinge via a second hinge.
Between the first lever arm and the first and second lever arms, and is connected to one end of the first lever arm near a third hinge via a third hinge.
For detecting displacement provided between a substrate connected to one end of the lever arm via a fourth hinge, and the other end of the first lever arm and the other end of the second lever arm. Displacement detecting means for transmitting the displacement of the piezoelectric element to the first and second lever arms via the first and second hinges, and using the third and fourth hinges as a fulcrum. In a piezoelectric element displacement amplification mechanism that amplifies and transmits a displacement to the displacement detection means, the distance between the third hinge and the fourth hinge is greater than the distance between the first hinge and the second hinge. A piezoelectric element displacement amplification mechanism characterized in that the distance between the two is short.