TWI681188B - Actuator and manufacuring method thereof and acoustic transmitter - Google Patents

Abstract

An actuator and a manufacturing method thereof and an acoustic transmitter are disclosed. The actuator includes an elastic metal element with a ring structure, a multilayer piezoelectric element provided within the ring structure of the elastic metal element, and a plurality of coupling elements provided at two ends of the multilayer piezoelectric element and coupling the multilayer piezoelectric element and the elastic metal element. The elastic metal element is imparted a preload stress. With the coupling elements, which have a size corresponding to the preload stress, are provided between the two ends of the multilayer piezoelectric element in its stacking direction and the elastic metal element, the preload stress can be maintained. The acoustic transmitter includes the actuator and a diaphragm. The actuator vibrates due to a voltage received and the diaphragm vibrates by driven by the actuator to transmit acoustic waves.

Description

Actuator and its manufacturing method and sonic transmitter

The present invention relates to an actuator and its manufacturing method and sonic wave transmitter. Specifically, it relates to an actuator and its manufacturing method using piezoelectric technology, and a low-frequency sonic wave transmitter including the actuator.

Generally speaking, there are many reasons why a water pipe or other pipeline may leak. For example, when the pipeline is subjected to excessive external force, internal pressure or uneven load may cause the pipe body to rupture or break. In addition, the joint between the pipe and the pipe may cause the aging of the plastic gasket material due to long use time. In addition, due to corrosion, vibration displacement and other factors, the joint gap will become larger and leak. In addition, the pipeline may also be corroded due to the influence of water quality or soil quality, so that the strength of the pipe is weakened and the pipe is broken. In addition, incomplete blocking of valves on the pipeline may also cause flow loss.

In the traditional detection of pipeline leakage, a transmitter capable of transmitting a specific frequency can be placed near the pipeline, and then the person can hold the receiver to receive the reflected frequency. In addition, the sound wave can also be injected into the valve, and the sound wave moves on the pipe to let the receiver on the ground know the position of the pipeline.

Generally speaking, the pipeline to be tested is usually hundreds of meters to several kilometers long, so the signal transmitted by the transmitter needs to be transmitted far enough to detect the breach of the pipeline. For such a launch The design of the actuator, which leads to the emission of sound waves, is more critical. Therefore, how to develop a sound source that can transmit sound waves to a distant place to actively detect pipeline leaks is currently an issue that the industry needs to solve.

An embodiment of the present invention discloses an actuator, including: an elastic metal member having a plurality of bending sections and a plurality of connecting sections to form a ring structure having a long axis direction and a short axis direction; a laminated piezoelectric element is provided in the A plurality of piezoelectric elements stacked in the ring structure of the elastic metal member along the long axis direction; and a plurality of coupling members disposed in the ring structure of the elastic metal member so that the laminated piezoelectric member is in the long The two ends in the axial direction are respectively coupled with the connecting sections of the elastic metal part in the long axis direction.

An embodiment of the present invention discloses a method for manufacturing an actuator, which includes: providing a laminated piezoelectric element stacked with a plurality of piezoelectric elements; forming an elastic metal piece integrally, the elastic metal piece formed has a plurality of bending segments and a plurality of The connecting segment forms a ring structure having a long axis direction and a short axis direction; prestresses the elastic metal member; and utilizes a plurality of coupling members having dimensions corresponding to the prestress to stack the laminated piezoelectric member in its stacking direction The two ends of the upper part are respectively coupled with the connecting section of the elastic metal piece in the direction of the long axis to maintain the prestress.

An embodiment of the present invention discloses a sound wave transmitter including: an actuator as described above for receiving voltage and vibrating; a diaphragm disposed on the actuator and attached to the elastic metal member located in the short One of the connecting sections in the axis direction is vibrated by the elastic metal member; and the carrier is provided on the actuator and is attached to another connection of the elastic metal member in the short axis direction To support the actuator and the diaphragm.

1‧‧‧Elastic metal parts

11a, 11b, 11c, 11d bending section

12a, 12b, 12c, 12d ‧‧‧ connection section

2‧‧‧Laminated piezoelectric

21‧‧‧ Piezoelectric unit

221、222‧‧‧electrode

3‧‧‧Coupling

4‧‧‧ diaphragm

5‧‧‧Carrier

6‧‧‧Fixed parts

A‧‧‧Long axis direction

B‧‧‧Short axis direction

2a, 2b, c‧‧‧ length

dx, dy‧‧‧ displacement

S201~S203‧‧‧Step

FIG. 1A is a schematic structural view of an embodiment of the actuator of the present invention.

FIG. 1B is a schematic structural diagram of an embodiment of an electrode of an actuator of the present invention.

FIG. 2 is a schematic structural diagram of an embodiment of the sound wave transmitter of the present invention.

FIG. 3 is a schematic flowchart of an embodiment of the method for manufacturing an actuator of the present invention.

Fig. 4 is a schematic plan view of the elastic metal member of Experimental Example 1 of the actuator of the present invention.

FIG. 5 is a graph showing the ratio of long to short axis vs. stroke of the comparative example and the experimental example of the actuator of the present invention.

Fig. 6 is a frequency-amplitude graph of the comparative example of the actuator of the present invention and the experimental examples of external pull.

Fig. 7 is a frequency-amplitude graph of the comparative example of the actuator of the present invention and the experimental examples of the internal pressure.

The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed herein. The structure, ratio, size, etc. shown in the drawings of this specification are only used to match the contents disclosed in the specification, for those who are familiar with this skill to understand and read, and are not used to limit the limitations of the invention. Therefore, any modifications, changes or adjustments should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and the purpose of the present invention.

Referring to FIG. 1A, the actuator of the present invention includes an elastic metal member 1, a laminated piezoelectric member 2, and a coupling member 3.

The elastic metal piece 1 may have a plurality of bending sections 11a to 11d and a plurality of connecting sections 12a to 12d to form a ring structure having a long-axis direction A and a short-axis direction B, wherein these connected bends The curved sections 11a-11d and the connecting sections 12a-12d are integrally formed into the ring structure, which can be regarded as a series structure mechanically. The integral formation of the loop-shaped structure by the bending sections 11a-11d and the connecting sections 12a-12d is only one embodiment, and is not limited thereto. As shown in FIG. 1A, the connecting sections 12b and 12d are located in the long axis direction A, the connecting sections 12a and 12c are located in the short axis direction B, and the bending section 11a is located between the connecting sections 12d and 12a and is connected to The curved section 11d between the sections 12d and 12c is mirror-symmetric with the long axis direction A, and the curved section 11b is located between the connecting sections 12b and 12a and with the curved section 11c located between the connecting sections 12b and 12c in the long axis direction A Mirror symmetry.

In addition, each of the curved sections 11a to 11d constitutes a partial circumference of the ellipse, and each of the connecting sections 12a to 12d may be a straight section. In addition, in the present invention, the connecting sections 12a and 12c can be omitted and only the connecting sections 12b and 12d can be retained, and the curved sections 11a and 11b can be made to be a continuous elliptical part of the perimeter, and the curved sections 11c and 11d can also be made continuous to make the common Partial perimeters of the same ellipse are such that the perimeter of the ellipse part formed by the curved segments 11a and 11b and the perimeter of the ellipse part formed by the curved segments 11c and 11d can be mirror-symmetrical in the long axis direction A.

The elastic metal part 1 with a ring structure of the present invention can be regarded as an ellipse. The elastic metal part 1 with a ring structure of the present invention may have two connecting sections 12b and 12d in the long axis direction A and symmetrical in the long axis direction A Two bending sections (continuous bending sections 11a and 11b and continuous bending sections 11c and 11d) provided, or may have two connecting sections 12b and 12d in the long axis direction A, two in the short axis direction B Connecting sections 12a and 12c, and four bending sections 11a to 11d (two bending sections 11a and 11d are symmetrical and the bending sections 11b and 11c are symmetrical) arranged symmetrically along the long axis direction A, more depending on the actuator Design more bending sections and connecting sections for the vibration frequency or stroke.

Furthermore, the elastic metal member 1 having a ring structure can be given a prestress, for example, providing external tension or internal pressure in the direction of the long axis to make the elastic metal member 1 have a prestress, which will be described in detail later Of it. In addition, in general, the material of the elastic metal member 1 may be, for example, elastic steel, or an elastic steel alloy, or other metals or alloys having elasticity.

The laminated piezoelectric element 2 may include a plurality of stacked piezoelectric cells 21 and electrodes 221 and 222 formed thereon, wherein the piezoelectric cells 21 may be piezoelectric sheets, as shown in FIG. 1B. The stacked piezoelectric units 21 are arranged in the ring structure of the elastic metal member 1 in such a manner that the stacking direction is parallel to the long axis direction A of the elastic metal member 1. In addition, the electrodes 221 and 222 are arranged as shown in FIG. 1B. Referring to FIG. 1A, the electrode 221 is arranged above and between the piezoelectric cells 21, and the electrode 222 is arranged below and between the piezoelectric cells 21, namely The left and right sides (long axis direction A) of each piezoelectric unit 21 are electrodes 221 and 222, respectively. The upper and lower sides of each piezoelectric unit 21 (short axis direction B) are electrodes 221 and 222, respectively. Grounding and the electrode 221 can apply a voltage, which is electrically parallel to the stacked piezoelectric units 21, so that each piezoelectric unit 21 has a stretching phenomenon in the thickness (long axis direction A), that is, in the long axis direction A A displacement is generated, which in turn drives the displacement of the elastic metal member 1 in the short axis direction B.

In addition, the material of the piezoelectric unit 21 may be a single crystal material such as quartz, a thin film material such as zinc oxide, a polymer material such as polyvinylidene difluoride (PVDF), such as lead zirconate titanate ( Pb(ZrTi)O3; PZT) ceramic materials, or composite piezoelectric materials such as PZT combined with silicon, glass or rubber.

A plurality of coupling members 3 can be disposed in the ring structure of the elastic metal member 1. As shown in FIG. 1A, the two coupling members 3 can be positioned in the long axis direction A to couple the two ends of the laminated piezoelectric member 2 to the connection sections 12b and 12d of the elastic metal 1 member, respectively. The thickness of the coupling member 3 can be determined according to the magnitude of the prestress. For example, when the elastic metal member 1 is given a pre-external tensile force, the coupling member 3 with a larger thickness (long axis direction A) can be used to couple the laminated piezoelectric Part 2 and elastic metal part 1 to maintain the pre-external pulling force; when the elastic metal part is given 1 When pre-internal pressure is used, a coupling member 3 with a small thickness (long axis direction A) may be used to couple the laminated piezoelectric member 2 and the elastic metal member 1.

In addition, the coupling between the laminated piezoelectric member 2, the coupling member 3 and the elastic metal member 1 can be fixed through the fixing member 6. As shown in FIG. 1A, the fixing member 6 may be a locking element such as an iron nail, a rivet, a screw, or a bolt, or may be a connection coated on the laminated piezoelectric member 2, the coupling member 3, and the elastic metal member 1 The adhesive between the segments 12b and 12d can also be a snap-fit design on the connecting segments 12b and 12d of the coupling member 3, the laminated piezoelectric member 2, and the elastic metal member 1, thereby strengthening the maintenance of the prestress In order to prevent the prestress from disappearing due to the loosening of the laminated piezoelectric member 2, the coupling member 3 and the elastic metal member 1 after the actuator vibrates for a period of time.

According to this, the elastic metal member of the present invention can convert the deformation of the laminated piezoelectric member in the stacking direction (ie, the long axis direction of the elastic metal member) into the vibration of the elastic metal member in the short axis direction, so it has a large stroke. In addition, an ellipse-like elastic metal part is formed by providing integrally formed connecting segments between a plurality of bending segments. Compared with an ellipse-like elastic metal part, it has better performance in stroke and frequency. Furthermore, the elastic metal part can be given prestress, and by adjusting the thickness of the coupling member to maintain the pre-external tension or pre-internal pressure, the pre-stressed elastic metal part can enable the actuator to have a relatively high Zhenfu.

Referring to FIG. 2, the sound wave transmitter of the present invention includes an elastic metal member 1, a laminated piezoelectric member 2, a coupling member 3, a diaphragm 4, a bearing member 5, and a fixing member 6. The elastic metal member 1, the laminated piezoelectric member 2, the coupling member 3, and the fixing member 6 are as shown above and in FIG. 1A, so they will not be repeated here.

As shown in FIG. 2, the diaphragm 4 may be provided on the actuator and attached to the connecting section 12 a of the elastic metal member 1 in the short axis direction B to be driven to vibrate by the elastic metal member 1. The carrier 5 may be provided on the actuator and attached to the connecting section 12c of the elastic metal member 1 in the short axis direction B to support The actuator and the diaphragm 4 are supported. In addition, the carrier 5 is only illustrated by a plate in FIG. 2, and may be implemented by a base or a frame during its specific implementation. The transmission frequency of the sound wave transmitter of the present invention is 10 Hz to 500 Hz, and the stroke may be greater than 0.5 mm.

Therefore, the sound wave transmitter of the present invention has a lower frequency, so the sound wave can be transmitted farther, and can be used as a sound source for actively detecting pipeline leakage, thereby detecting whether the pipeline is deteriorated and affecting the formation of standing waves.

Please refer to FIG. 3, which schematically illustrates the manufacturing process of the actuator of the present invention.

As shown in step S201, an elastic metal piece is integrally formed. The formed elastic metal piece has a plurality of bending sections and a plurality of connecting sections to form a ring structure having a long axis direction and a short axis direction. In addition, each curved section may be a partial circumference of an ellipse and each connecting section may be a straight partial section. Furthermore, the plurality of connecting segments may be two connecting segments in the direction of the long axis, and the plurality of bending segments may be two bending segments symmetrical in the direction of the long axis; or, the plurality of connecting segments may be in the direction of the long axis The two connecting sections on the upper side and the other two connecting sections on the short axis direction, and the plurality of bending sections may be four bending sections symmetrical in the long axis direction.

As shown in step S202, the elastic metal piece is prestressed. The elastic metal member may be provided with an external pulling force or an internal pressure in the direction of the long axis to provide the elastic metal member with the prestress.

As shown in step S203, the elastic metal member and the laminated piezoelectric member are coupled using a plurality of coupling members having a size corresponding to the prestress. For the formation of the laminated piezoelectric member, for example, a plurality of piezoelectric cells can be stacked to form a laminated piezoelectric member, and an electrode can be formed on the laminated piezoelectric member. In addition, the method of coupling the laminated piezoelectric member and the elastic metal member is that the coupling member couples both ends of the laminated piezoelectric member in the stacking direction to the connecting sections of the elastic metal member in the long axis direction, To maintain prestress. The size of the coupling member can be determined according to the size of the prestress. When the elastic metal member is given a pre-external pulling force, a thicker coupling member can be used to couple the laminated piezoelectric member and the elastic metal member, thereby maintaining the pre-external pulling force; When given When the elastic metal member is pre-internally pressured, a coupling member with a smaller thickness can be used to couple the laminated piezoelectric member and the elastic metal member. In addition, it may include using a plurality of fixing members to connect the laminated piezoelectric member, a plurality of coupling members, and an elastic metal member in the long axis direction to enhance the maintenance of the prestress.

Next, referring to FIGS. 4-7 and Table 1, comparative examples and experimental examples are provided here to illustrate the vibration performance of the actuator of the present invention.

Experimental example 1 As shown in Figure 4, the elastic metal part of the actuator has a long axis of length 2a, a short axis of length 2b, four connecting segments of length c and four bends between the connecting segments Segment, where two connecting segments are on the long axis and two connecting segments are on the short axis, and each connecting segment is a straight segment and each curved segment belongs to the same elliptical perimeter. The elastic metal piece of Experimental Example 1 is referred to as having For the elastic metal part of the ellipse-like ring structure, Experimental Example 1 has no prestress, and has a displacement dx in the long axis direction and a displacement dy in the short axis direction. In addition, the comparative example adopted by the present invention is: an elliptical elastic metal piece having a long axis length 2a and a short axis length 2b, and the comparative example has no connecting section and no prestress. Secondly, the elastic metal parts of Experimental Examples 2 to 7 are the same in structure as Experimental Example 1, except that the external pull is 0.014mm, 0.035mm, The pre-stress of the external pull 0.35mm, internal pressure 0.014mm, internal pressure 0.035mm, internal pressure 0.35mm, wherein the direction of the external pull or internal pressure is the long axis direction.

In Figure 5, the horizontal axis is the ratio of the long axis to the short axis (a/b), and the vertical axis dy/dx is the stroke of the actuator, that is, the displacement of the elastic metal member in the short axis direction and the displacement in the long axis direction The ratio of the amount. According to FIG. 5, it can be found that Experimental Example 1 has a larger stroke than the Comparative Example. In addition, in the case where a/b is 2.5, Experimental Example 4 and Experimental Example 7 have a larger stroke than the Comparative Example. In addition, the larger the a/b value, the larger the stroke, for example, 1.5 to 10, 1.5 to 8, or 2 to 6. Therefore, it can be seen that actuators using elastic metal parts with an ellipse-like ring structure have a larger stroke than actuators with elastic metal parts having an ellipse. , It has a larger stroke.

Next, please refer to Figures 6 and 7. Figure 6 is the amplitude-frequency curve of Experimental Example 2-4 where the prestress is externally pulled and Experimental Example 1 without prestress, and Figure 7 is the experiment where the prestress is internal pressure The amplitude-frequency curve of Example 5-7 and Experimental Example 1 without prestress. According to Figures 6 and 7, it can be found that at relatively low frequencies, such as 1000 Hz or even below 500 Hz, the elastic metal parts of the pre-stressed experimental example 2-7 have a larger size than the elastic metal parts of the non-pre-stressing experimental example 1. Zhenfu.

In summary, the actuator of the present invention includes an elastic metal member having an ellipse-like ring structure, a laminated piezoelectric member provided with a plurality of piezoelectric units stacked along the long axis direction in the elastic metal member, and provided in a laminate At both ends of the electrical component, a plurality of coupling members coupling the laminated piezoelectric component and the elastic metal component in the long axis direction. The sound wave transmitter of the present invention includes the aforementioned actuator and the diaphragm driven by the actuator. A plurality of coupling members having a size corresponding to the prestress is provided between both ends of the stacked piezoelectric member in the stacking direction and the elastic metal member so as to maintain the prestress given to the elastic metal member. Therefore, the actuator of the present invention has a relatively high vibration in a relatively low frequency range, and the sound wave transmitter of the present invention can transmit sound waves farther because of its lower frequency.

The above-mentioned embodiments are only illustrative of the effects of the present invention, not used to limit the present invention. Anyone who is familiar with this skill can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. . Therefore, the scope of protection of the rights of the present invention should be as listed in the scope of patent application mentioned later.

1‧‧‧Elastic metal parts

11a, 11b, 11c, 11d bending section

12a, 12b, 12c, 12d ‧‧‧ connection section

2‧‧‧Laminated piezoelectric

21‧‧‧ Piezoelectric unit

3‧‧‧Coupling

6‧‧‧Fixed parts

A‧‧‧Long axis direction

B‧‧‧Short axis direction

Claims (17)

An actuator includes an elastic metal piece having a plurality of bending sections and a plurality of connecting sections to form a ring structure having a long axis direction and a short axis direction; a laminated piezoelectric element is provided in the ring structure of the elastic metal piece And has a plurality of piezoelectric units stacked along the long axis direction; and a plurality of coupling members disposed in the ring structure of the elastic metal member, so that both ends of the laminated piezoelectric component in the long axis direction It is respectively coupled with the connecting section of the elastic metal piece in the direction of the long axis. The actuator as described in item 1 of the patent application scope further includes an electrode provided on the laminated piezoelectric element, the electrode is used to receive a voltage to deform the laminated piezoelectric element, thereby driving the elastic metal element in the Vibration in the short axis direction. The actuator according to item 1 of the patent application scope, wherein the elastic metal member has a prestress, and the plurality of coupling members are respectively located between the elastic metal member and the laminated piezoelectric member to maintain the prestress. The actuator as described in item 1 of the scope of the patent application further includes a plurality of fixing members that connect the elastic metal member, the laminated piezoelectric member, and the plurality of coupling members in the long axis direction. The actuator according to item 1 of the scope of the patent application, wherein each of the curved sections is an elliptical partial circumference, and each of the connecting sections is a straight partial line segment. The actuator according to item 1 of the patent application scope, wherein the plurality of connecting segments are two connecting segments in the direction of the long axis, and the plurality of bending segments are two symmetrical segments in the direction of the long axis Curved section. The actuator as described in item 1 of the patent application, wherein the plurality of connecting segments are two connecting segments in the long axis direction and the other two connecting segments in the short axis direction, and the plural Each bending section is four bending sections that are symmetrical about the long axis direction. The actuator according to item 1 of the patent application scope, wherein the ratio of the long axis of the ring structure in the long axis direction to the short axis in the short axis direction is between 1.5 and 10. The actuator according to item 1 of the patent application scope, wherein the ratio of the long axis of the ring structure in the long axis direction to the short axis in the short axis direction is between 1.5 and 8. The actuator according to item 1 of the patent application scope, wherein the ratio of the long axis of the ring structure in the long axis direction to the short axis in the short axis direction is between 2 and 6. The actuator according to item 1 of the patent application scope, wherein the ratio of the long axis of the ring structure in the long axis direction to the short axis in the short axis direction is 2.5. The actuator according to item 1 of the patent application scope, wherein the material of the piezoelectric unit is a single crystal material, a polymer material, a ceramic material, or a composite piezoelectric material. A method for manufacturing an actuator includes: providing a laminated piezoelectric member in which a plurality of piezoelectric units are stacked; an elastic metal member is integrally formed, the elastic metal member formed has a plurality of bending sections and a plurality of connecting sections to form a long A ring structure in the axial direction and the short axis direction; prestressing the elastic metal member; and using a plurality of coupling members having a size corresponding to the prestressing force, the stacked piezoelectric member in the stacking direction are respectively The elastic metal pieces are coupled in the connection section in the direction of the long axis to maintain the prestress. The manufacturing method as described in item 13 of the patent application scope, wherein the forming of the laminated piezoelectric element includes: stacking the plurality of piezoelectric cells to form the laminated piezoelectric element, and forming an electrode on the laminated piezoelectric element. The manufacturing method described in Item 13 of the patent application scope further includes connecting the laminated piezoelectric element, the plurality of coupling elements, and the elastic metal element in the long axis direction with a plurality of fixing elements. A sound wave transmitter, including: the actuator according to any one of the patent application items 1-12, for receiving a voltage and vibrating; a diaphragm, provided on the actuator and attached to the elasticity One of the connecting sections of the metal member in the direction of the short axis is driven to vibrate by the elastic metal member; and the carrier member is provided on the actuator and is attached to the elastic metal member in the short axis Another connecting segment in the direction to support the actuator and the diaphragm. The sound wave transmitter as described in item 16 of the patent application scope has a transmission frequency of 10 Hz to 500 Hz and a stroke greater than 0.5 mm.

Images