KR102138325B1 - Piezoelectric vibration module and piezoelectric vibration actuator with piezoelectric vibration module - Google Patents

Abstract

The piezoelectric vibration module according to the present invention includes a vibration plate having a corrugation portion near both ends; A piezoelectric element disposed on one surface of the vibrating plate and repeating expansion and contraction deformation according to application of an external power source to generate vibration force; And a base plate which is spaced apart by fixing both ends of the vibration plate.
In particular, the present invention relates to a piezoelectric vibration actuator employing the piezoelectric vibration module described above.

Description

Piezoelectric vibration module and piezoelectric vibration actuator with piezoelectric vibration module

The present invention relates to a piezoelectric vibration module and a piezoelectric vibration actuator provided with the piezoelectric vibration module.

In general, in portable electronic devices such as mobile phones, E-book terminals, game machines, and PMPs, the vibration function is used for various purposes.

In particular, the vibration generating device for generating such a vibration is mainly mounted on a portable electronic device and is used as an alarm function that is a silent incoming signal.

In accordance with the multi-functionality of such portable electronic devices, the vibration generating device is currently in demand not only for miniaturization but also for integration and various high-functionality.

Moreover, recently, a touch-type device for touching and inputting a portable electronic device is generally adopted according to a user's request to easily use the portable electronic device.

Currently used haptic devices include not only the concept of touching and inputting, but also a concept that reflects the intuitive experience of the interface user and further diversifies feedback on the touch. Such a haptic device is published in Patent Document 1.

The actuator module, haptic feedback device, and electronic device disclosed in Patent Document 1 are equipped with at least one piezoelectric element and a vibration plate that mounts the piezoelectric element and transmits vibration generated in the piezoelectric element, as is well known.

The actuator module is configured to vibrate the vibrating plate up and down through a piezoelectric element that is in contact with a surface of the vibrating plate in the longitudinal direction to change the volume according to an electrical signal.

As described above, the actuator module according to Patent Document 1 is mounted on one surface of the vibration plate along the longitudinal direction, for example, two piezoelectric elements are arranged in parallel along the longitudinal direction of the vibration plate.

In order for two piezoelectric elements arranged in parallel (that is, arranged in parallel) to be mounted on a conventional vibrating plate, the width of the vibrating plate must inevitably be increased, thereby increasing the space occupied by the portable electronic device. . This violates the piezoelectric actuator module, which increasingly requires miniaturization and integration.

In addition to this, the piezoelectric element is formed in a bar shape having a length longer than that of the width, and thus has to be structurally vulnerable. Since it continuously undergoes expansion and contraction repeatedly, it is easily damaged and has a problem of deteriorating reliability. .

Republic of Korea Patent Publication No. 10-2011-0118079

The present invention has been created to solve the above-mentioned disadvantages, and provides a piezoelectric vibration module and a piezoelectric vibration actuator equipped with the piezoelectric vibration module capable of generating vertical and horizontal translational motion through a longitudinally divided piezoelectric element.

In order to achieve the above object, the piezoelectric vibration module according to the present invention includes a vibration plate having a corrugation portion near both ends; A piezoelectric element disposed on one surface of the vibrating plate and repeating expansion and contraction deformation according to application of an external power source to generate vibration force; And a base plate which is spaced apart by fixing both ends of the vibration plate.

In the present invention, the corrugation portion protrudes downward from the other surface of the vibration plate.

The piezoelectric element of the present invention is disposed on the corrugation unit.

Preferably, the central portion of the piezoelectric element is positioned on the corrugation, particularly the concave portion of the corrugation.

The base plate can be supported by forming a stepped portion at both ends of the base plate while maintaining a gap with the vibration plate.

To be selectable, the corrugation unit is composed of two corrugation units.

The two corrugation units may be arranged symmetrically with respect to the center of the vibration plate.

The piezoelectric vibration actuator according to the present invention adopts the above-described piezoelectric vibration module, and a piezoelectric element that repeatedly generates expansion and contraction according to the application of an external power source to generate vibration force, and the piezoelectric element is disposed on one surface and a coreror on the other A piezoelectric vibration module having a vibration plate that forms a gating portion, and drives in the vertical direction, and a base plate that is coupled to both ends of the vibration plate so as to be spaced apart from the vibration plate; An upper case opening the lower portion and forming an inner space so that the piezoelectric vibration module vibrates linearly; And a weight body disposed on the piezoelectric vibration module to increase the vibration force of the piezoelectric vibration module.

In the present invention, the weight body is mounted with a bracket extending vertically upward from the vibrating plate.

The upper case may be shielded with the base plate of the piezoelectric vibration module.

The weight body is spaced apart from the upper inner surface of the upper case at a predetermined distance while being arranged apart from the vibrating plate.

Preferably, the piezoelectric element is disposed in the corrugation portion of the vibration plate.

The base plate may form a stepped portion protruding upward at both ends thereof.

Here, the height of the stepped portion is formed to be higher than the height of the corrugation protrusion of the vibration plate.

Features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

Prior to this, the terms or words used in the specification and claims should not be interpreted in a conventional and lexical sense, and the inventor may appropriately define the concept of terms in order to best describe his or her invention. Based on the principle that it should be interpreted as meanings and concepts consistent with the technical idea of the present invention.

As described above, according to the description of the present invention, the present invention proposes a piezoelectric vibration module capable of preventing peeling between the piezoelectric element and the vibration plate, thereby improving the durability of the piezoelectric vibration module.

Specifically, the present invention arranges the piezoelectric elements symmetrically on one surface of the vibrating plate and provides a corrugated corrugated portion at the bonding portion between the vibrating plate and the piezoelectric element, corresponding to repeated expansion and contraction deformation of the piezoelectric element. The vibration plate can be contracted and relaxed to prevent peeling of the piezoelectric element.

In the present invention, a maximum warpage occurs in the center of the piezoelectric element, and the generation of cracks in the center of the piezoelectric element can be minimized by reducing the length of the piezoelectric element.

The present invention has an effect of reducing the resonance frequency by extending the length of the vibration plate in a limited internal space through the corrugation portion formed on the vibration plate.

1 is a view schematically showing a piezoelectric vibration module according to the present invention.
2A to 2B are views illustrating a driving process of the piezoelectric vibration module shown in FIG. 1.
3 is a perspective view of a piezoelectric vibration actuator according to the present invention.
4 is an exploded perspective view of the piezoelectric vibration actuator shown in FIG. 3.
5 is a front view of the piezoelectric vibration actuator according to the present invention except the upper case.

Now, the piezoelectric vibration module according to the present invention and the piezoelectric vibration actuator equipped with the piezoelectric vibration module will be described in detail with reference to the accompanying drawings.

Advantages, features, and methods of achieving the advantages of the present invention will become apparent through embodiments described below along with the accompanying drawings. In addition to the reference numerals to the components of each drawing in this specification, the same reference numerals throughout the specification refer to the same or similar components. In addition, when a detailed description of known technologies related to the present specification obscures the gist of the present invention, the detailed description is omitted.

The present invention relates to a piezoelectric vibration module 100 capable of transmitting the vibration force of the piezoelectric element to external components through repeated expansion and contraction deformation.

Referring to FIG. 1, the piezoelectric vibration module 100 according to the present invention includes a piezoelectric element 110, a vibration plate 120 and a base plate 130, and the piezoelectric vibration module 100 is, for example, a touch screen panel It can be used as a means to generate vibration force (touch screen panel; not shown).

The vibration plate 120 transmits the vibration force of the piezoelectric element 110 to external components by repeating expansion and contraction deformation integrally with the piezoelectric element 110, and is generally made of an elongated plate. As illustrated, one surface of the vibration plate 120 is mounted with the piezoelectric element 110, and the other surface of the vibration plate 120 forms a corrugation unit 121 (corrugation). Alternatively, the corrugation 121 may be formed on one surface of the vibration plate 120 and the piezoelectric element 110 on the other surface of the vibration plate 120.

The vibration plate 120 may include a PCB (not shown) that applies power to drive the piezoelectric element 110.

As is well known, each piezoelectric element 110 may be configured by being stacked in a single layer type or a multi-layer type. The multilayered piezoelectric element can secure an electric field required for driving the piezoelectric element even at a low external voltage. Accordingly, since it is possible to cause an effect of lowering the driving voltage of the piezoelectric vibration module 100 according to the present invention, it will be preferable to employ a multilayer piezoelectric element in the present invention.

In addition, the vibrating plate 120 is made of a metallic material having elastic force, for example, SUS, so that it can be integrally deformed with the piezoelectric element 110 that repeats expansion and contraction deformation upon application of an external power source. In addition, the piezoelectric element 110 and the vibration plate 120 are materials similar to the thermal expansion coefficient of the piezoelectric element to prevent the bending phenomenon that may occur due to the curing of the adhesive member when coupled to each other in a bonding manner. It can also be made of invar.

As described above, the vibration plate 120 is formed of an invar material having a coefficient of thermal expansion similar to that of the piezoelectric element 110, so that the piezoelectric element 110 is operated under a high temperature external environment or thermal stress generated during thermal shock. Since the stress) is reduced, it has an effect of preventing the piezoelectric deterioration phenomenon that the electrical characteristics are lowered.

The piezoelectric vibration module 100 according to the present invention includes a vibration plate 120 having two corrugation units 121, but is not limited thereto, and the vibration plate 120 forms one or more corrugation units 121. You may. The two corrugations 121 are disposed adjacent to both ends of the vibration plate 120, respectively. Specifically, the two correlation units 121 are provided to be symmetrical along the longitudinal direction with respect to the center of the vibration plate 120.

The piezoelectric elements 110 are joined on the corrugation part 121 of the vibration plate 120, and are arranged in a row in a state spaced apart from each other along a longitudinal direction on one surface of the vibration plate 120 as described above. Preferably, the corrugation part 121 protruding outward from the vibration plate 120 is joined to an opposite surface on which the vibration plate 120 is not formed, that is, one surface of the vibration plate 120.

In particular, the central portion C of the piezoelectric element 110 is placed on the vibration plate 120 so as to be disposed on the concave shape of the corrugation portion 121. In other words, the central portion C of the piezoelectric element 110 is not joined to the vibration plate 120 due to the geometric shape of the corrugation portion 121 protruding downward. The contact surface of the piezoelectric element 110 except for the central portion C is coupled to the vibration plate 120 to reliably position the piezoelectric element 110 to transmit vibration force to the vibration plate 120.

The present invention can reduce the size of a device in a mobile phone or other portable device employing a haptic device while maintaining the same frequency as that of a conventional haptic device. Generally, a frequency capable of providing a haptic feeling is 300 Hz or less, The preferred positive frequency is approximately 150-250 Hz, more preferably 200 Hz.

In the present invention, as described above, the correlation between the length of the vibration plate 120 and a frequency capable of providing a haptic feeling can be inferred from the following equation.

Here, F _n represents the resonance frequency, k is the stiffness of the driving unit, and m is the mass of the driving unit. The term driving unit is a component member that translates upward and downward due to the application of power from the piezoelectric vibration module of the present invention to induce vibrational force, and refers to the vibration plate 120 and the weight body 300 (see FIG. 5 ).

Here, k is the stiffness of the driving part, C is a constant, E is a Young's modulus, I is a moment of inertia, and L is an effective length.

Based on Equation 2 above, the stiffness (k) of the driving unit becomes smaller as the length of the vibration plate 120 increases. By substituting these results into Equation 1, it can be seen that the resonance frequency F _n decreases as the stiffness (k) of the driving unit decreases.

As a result, as the length of the vibration plate 120 increases, the resonance frequency (F _n ) decreases, and the length of the vibration plate 120 is a factor that greatly affects the resonance frequency used. In order to make the resonance frequency low, the length of the piezoelectric vibrating module 100 may be made long, but the mountability of the module 100 is reduced and the occupied space is increased.

The piezoelectric vibration module 100 according to the present invention can extend the vibration plate 120 to the maximum length in the same internal space according to the degree of bending of the corrugation unit 121, thereby providing a resonance frequency of 150 to 250 Hz. .

The vibration plate 120 is spaced in parallel with the base plate 130 at a predetermined distance, and the base plate 130 is formed of a plate having an elongated and flat shape as shown overall, and a piezoelectric vibration actuator (FIG. 4) It is formed in a size to close the open lower surface of the upper case of (see).

The base plate 130 forms a step portion 131 at both ends thereof, and the vibration plate 120 is fixed to the step portion 131 of the base plate 130. The step portion 131 provides a space between the vibration plate 120 and the base plate 130.

When power is applied to each of the piezoelectric elements 110, the piezoelectric elements 110 are attached on one surface of the vibration plate 120 so that the moment is in the center of the vibration plate 120 through the expansion and/or contraction process. Will occur. As described above, since the moment occurs while the vibration plate 120 is fixed to the step portion 131 provided at both ends of the base plate 130, the center of the vibration plate 120 is deformed in the vertical direction. Will happen.

Therefore, the height of the stepped portion 131 is greater than the height of the protruding corrugation portion 121 and has a size that will not collide with the base plate 130 when moving up and down of the vibrating plate 120.

2A to 2B are diagrams showing a driving process of the piezoelectric vibration module 100 shown in FIG. 1, and the piezoelectric vibration module 100 according to the present invention is coupled to an image display unit such as a touch screen panel or LCD. It transmits power to the outside. For reference, the piezoelectric vibration module 100 of FIG. 1 shows a state before external power is applied.

2A is a front view of the piezoelectric vibration module 100 in which the length of the piezoelectric element 110 expands when power is applied, and when the length of the piezoelectric element 110 increases, the vibration plate 120 has a relatively small strain and a vibration plate ( Since both ends of the 120) are fixed to the base plate 130, the vibration plate 120 is bent in a downward direction to be driven. As the piezoelectric element 110 expands, the piezoelectric element 110 relaxes in the longitudinal direction. At this time, the vibration plate 120 is also coupled to the piezoelectric element 110 so that it extends along the relaxation direction. Since the elongation rate of the piezoelectric element 110 is greater than the strain rate of the vibration plate 120, the piezoelectric element 110 is peeled or broken from the vibration plate 120. However, the present invention provides a non-bonding portion between the vibration plate 120 and the piezoelectric element 110 through the corrugation unit 121, and the piezoelectric element 110 through the bending of the corrugation unit 121 It is possible to alleviate the difference in deformation of the vibration plate 120. That is, when the piezoelectric element 110 expands, the corrugation part 121 uncoupled with the piezoelectric element 110 opens to prevent peeling and/or damage of the piezoelectric element 110.

2B is a front view of the piezoelectric vibration module 100 in which the length of the piezoelectric element 110 contracts when power is applied, and when the length of the piezoelectric element 110 decreases, the vibration plate 120 is bent upward and driven. As the piezoelectric element 110 contracts, the corrugation unit 121 uncoupled with the piezoelectric element 110 is narrowed to prevent peeling and/or damage of the piezoelectric element 110.

As illustrated, a user of a haptic device having a piezoelectric element 110 divided into two by vibrations in the up and down directions can sense vibration feedback.

3 to 5 are views showing the piezoelectric vibration actuator 1 equipped with the piezoelectric vibration module 100 shown in FIG. 1.

As shown, the piezoelectric vibrating actuator 1 of the present invention is a piezoelectric vibrating module 100 and an upper case 200 and a weight body 300 that cause a vibration force by moving in a vertical direction due to the application of power. Is done.

The upper case 200 is formed in a box shape with one side open, and accommodates the piezoelectric vibration module 100 equipped with the piezoelectric element 110 in its inner space. The open surface of the upper case 200 may be closed with the base plate 130 of the piezoelectric vibration module 100. The upper case 200 and the base plate 130 may be combined in various ways such as caulking, welding, or bonding, which are already well known to those skilled in the art.

The piezoelectric vibration module 100 mounts the weight 300 on one surface of the vibration plate 120. The weight body 300 is coupled to the brackets 310 arranged vertically on both sides of the vibration plate 120 and disposed on the piezoelectric vibration module 100. The bracket 310 is coupled to the center of the vibration plate 120. The bracket 310 and the vibration plate 120 may be formed of a single unitary component, or alternatively, may be fixedly coupled by various bonding methods.

The bracket 310 may arrange the weight 300 to be spaced apart from one surface of the vibration plate 120. The weight body 300 is a medium that increases the vibration force to the maximum, and is formed to be inclined upward toward both ends from the center portion of the weight body 300 to prevent contact with the vibration plate 120.

Here, the weight body 300 may be made of a metal material, and is preferably made of a tungsten material having a relatively high density in the same volume.

In the piezoelectric vibration actuator 1 of the present invention, the upper case 200 is formed so as to be spaced apart from the upper portion of the weight body 300 when the vibration plate 120 of the piezoelectric vibration module 100 is driven to bend upward to displace Edo does not contact or collide with the upper inner surface of the weight body 300 and the upper case 200.

Although the present invention has been described in detail through specific embodiments, the present invention is specifically described, and the piezoelectric vibration module according to the present invention and the piezoelectric vibration actuator provided with the piezoelectric vibration module are not limited thereto. It is clear that the modification or improvement is possible by a person having ordinary knowledge in the field within the technical idea of.

All simple modifications or changes of the present invention belong to the scope of the present invention, and the specific protection scope of the present invention will be clarified by the appended claims.

1 ----- Piezoelectric Vibration Actuator
100 ----- Piezoelectric vibration module
110 ----- Piezoelectric element
120 ----- vibrating plate
130 ----- base plate
200 ----- upper case
300 ----- Weight
310 ----- Bracket

Claims (14)

A vibration plate having a corrugation portion near both ends;
A piezoelectric element disposed on one surface of the vibration plate and repeatedly generating expansion and contraction deformation according to application of an external power source to generate vibration force; And
A base plate coupled to both ends of the vibration plate so as to be spaced apart from the vibration plate;
Including,
Steps are formed at both ends of the base plate, and both ends of the vibration plate are coupled to the steps,
The corrugation unit is formed in two symmetrically symmetrical relative to the center of the vibration plate,
The piezoelectric element is characterized in that the length in the width direction is longer than the longitudinal direction of the vibration plate, the piezoelectric vibration module.
The method according to claim 1,
The corrugation portion is a piezoelectric vibration module protruding downward from the other surface of the vibration plate.
The method according to claim 1,
The piezoelectric element is a piezoelectric vibration module disposed in the corrugation unit.
The method according to claim 1,
A piezoelectric vibration module in which the central portion of the piezoelectric element is disposed in the correlation.
delete delete delete A piezoelectric element that generates vibration force by repeatedly expanding and contracting according to the application of an external power source, a piezoelectric element disposed on one surface, a corrugation portion formed on the other surface, and a vibration plate driving in the vertical direction, and the vibration plate A piezoelectric vibration module having a base plate coupled to both ends of the vibration plate so as to be arranged spaced apart;
An upper case opening the lower portion and forming an inner space so that the piezoelectric vibration module vibrates linearly; And
A weight body disposed on the piezoelectric vibration module to increase the vibration force of the piezoelectric vibration module;
Including,
Steps are formed at both ends of the base plate, and both ends of the vibration plate are coupled to the steps,
The corrugation portion is formed to be symmetrical to the left and right relative to the center of the vibration plate,
The piezoelectric element is characterized in that the length in the width direction is longer than the longitudinal direction of the vibration plate, the piezoelectric vibration actuator.
The method according to claim 8,
The weight body is a piezoelectric vibration actuator mounted in a bracket extending vertically upward from the vibration plate.
The method according to claim 8,
The upper case is a piezoelectric vibration actuator that is shielded by a base plate of the piezoelectric vibration module.
The method according to claim 8,
The weight body is a piezoelectric vibration actuator spaced apart at a predetermined distance from the upper inner surface of the upper case.
delete delete The method according to claim 8,
The height of the step portion is a piezoelectric vibration actuator formed higher than the height of the corrugation protrusion of the vibration plate.

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