JP2016162060A - Piezoelectric actuator and tactile sense presentation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric actuator improved in heat radiation properties, and a tactile sense presentation device presenting the feeling of vibration stimulation operation.SOLUTION: A piezoelectric actuator 1 comprises: a piezoelectric element 2; and a heat radiation member 5 attached to the piezoelectric element 2 and radiating heat of the piezoelectric element 2. A notch groove 5c-1 is formed on a surface of the heat radiation member 5. The piezoelectric actuator 1 is included in a driving source of a tactile sense presentation device 100.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a piezoelectric actuator and a tactile presentation device, and more particularly to a piezoelectric actuator that generates ultrasonic vibration and a tactile presentation device including the piezoelectric actuator.

  A portable electronic device including a piezoelectric actuator that provides tactile feedback has been proposed (see, for example, Patent Document 1).

  The portable electronic device described in Patent Document 1 includes a touch-sensitive display that gives a tactile feedback of vibration to an operator. The touch-sensitive display is supported so as to be pressed down toward the base of the housing. A piezoelectric actuator having a curved deformable substrate is supported at both ends at the base of the housing.

  Circular piezoelectric elements are bonded to the corners of the substrate of the piezoelectric actuator. The piezoelectric element is contracted in the diameter direction by an operation signal generated by pressing the touch-sensitive display, so that the substrate is curved. A stop portion made of a compressible silicone material is provided on the surface of the piezoelectric element, and the stop portion functions as a buffer for the piezoelectric element.

JP 2010-152889 A

  Since the piezoelectric actuator used in the portable electronic device described in Patent Document 1 requires a high driving voltage to vibrate at a frequency in the ultrasonic region, the piezoelectric actuator generates a large amount of heat. In particular, when the piezoelectric actuator is driven for a long time in a high-temperature atmosphere, there is a problem that the vibration stimulation operation feeling is lowered unless the heat radiation from the piezoelectric actuator is obtained. However, the portable electronic device described in Patent Document 1 does not provide heat dissipation from the piezoelectric actuator.

  Accordingly, it is an object of the present invention to provide a piezoelectric actuator with improved heat dissipation and a tactile sensation presentation device that presents a stable vibration stimulation operation feeling.

[1] The present invention includes a piezoelectric element and a heat radiating member attached to the piezoelectric element and radiating heat of the piezoelectric element, and a notch groove portion is formed on a surface of the heat radiating member. It is in the piezoelectric actuator.

[2] The notch groove described in [1] is characterized in that it includes a recess or a slit.

[3] The piezoelectric element according to [1] or [2] is attached to a diaphragm.

[4] The present invention further provides a tactile sensation presentation apparatus comprising the piezoelectric actuator according to any one of [1] to [3] as a drive source.

[5] The tactile sense presentation device according to [4] provides a vibration feedback force that presents a sense of stimulation operation to an operator who inputs an operation member to which vibration of the piezoelectric element is transmitted. Features.

[6] The operation member according to [5] is a touch panel or a switch button.

  According to the present invention, it is possible to improve heat dissipation of the piezoelectric actuator, reduce vibration loss of the tactile sense presentation device, and obtain a good vibration stimulation operation feeling.

It is a top view for demonstrating the piezoelectric actuator which concerns on 1st Embodiment suitable for this invention. It is sectional drawing for demonstrating the piezoelectric actuator which concerns on 1st Embodiment. (A) is a top view for demonstrating the heat radiating member applied to the piezoelectric actuator which concerns on 1st Embodiment, (b) is a side view of a heat radiating member. It is sectional drawing for demonstrating the piezoelectric actuator which concerns on 2nd Embodiment. (A) is a top view for demonstrating the modification of the heat radiating member applied to a piezoelectric actuator, (b) is a side view of a heat radiating member. (A) And (b) is a side view which shows typically the displacement at the time of the drive of the piezoelectric actuator shown in FIG. (A)-(c) is a top view for demonstrating the other modification of the thermal radiation member applied to a piezoelectric actuator. It is a functional block diagram of the tactile sense presentation device concerning a 3rd embodiment.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

[First Embodiment]
(Configuration of piezoelectric actuator)
1 and 2, reference numeral 1 schematically illustrates a piezoelectric actuator applied to a tactile sense presentation device.

  The piezoelectric actuator 1 is used as a drive source of a tactile sensation presentation device that applies a vibration feedback force that presents a stimulation operation feeling to an operator's finger that performs an input operation on an operation surface of an operation member such as a touch panel or switch button. It is done.

  The piezoelectric actuator 1 includes a piezoelectric element 2 having a rectangular shape in plan view that generates ultrasonic vibrations by a driving voltage applied to the electrodes. The piezoelectric element 2 is formed with an electrode (not shown) by, for example, sputtering or vapor deposition.

  As the piezoelectric actuator 1, for example, a monomorph piezoelectric actuator constituted by a single piezoelectric element 2 or a laminated monomorph piezoelectric actuator constituted by laminating a plurality of piezoelectric elements 2 is used. The monomorph type expands and contracts when a driving voltage is applied to the piezoelectric element 2.

  As the piezoelectric actuator 1, for example, a bimorph type piezoelectric actuator configured by bonding the piezoelectric elements 2 to both surfaces of an elastic plate may be used. The bimorph type is curved in an arch shape when a driving voltage is applied to the piezoelectric element 2.

  As the piezoelectric element 2, for example, a ceramic material such as lead zirconate titanate (PZT) or barium titanate is used. As the electrode, for example, a metal material such as gold, silver, or copper is used.

  The piezoelectric element 2 according to the illustrated example is attached with a diaphragm 3 having a square shape in plan view through a fixing member such as a thermosetting double-sided tape or an adhesive. The piezoelectric elements 2 are arranged side by side at four corners of the diaphragm 3. As the diaphragm 3, for example, a material such as resin or metal is used. Note that the piezoelectric element 2 can be formed by forming a piezoelectric material layer on the surface of the vibration plate 3 by using a film forming technique.

  The diaphragm 3 is supported by a support portion 4 formed on a part of a housing made of, for example, metal or resin. The support 4 allows the diaphragm 3 to be deformed when the piezoelectric element 2 expands and contracts according to the drive voltage applied to the electrodes.

  The diaphragm 3 is attached to the back of the operation surface of an operation member formed by a touch panel or a switch button that receives an operation input by an operator. Further, the support portion 4 is not limited to being formed as a part of the casing, and may be formed on an operation member different from the casing, for example.

(Configuration of heat dissipation member)
By the way, since the heat generated in the piezoelectric actuator 1 is easily accumulated, the temperature of the piezoelectric actuator 1 becomes high. For this reason, when the piezoelectric actuator 1 is driven for a long time in a high voltage, high frequency, high temperature atmosphere, the output is lowered due to the temperature characteristics of the piezoelectric actuator 1.

  As a heat dissipation means of the piezoelectric actuator 1, for example, by providing a heat dissipation member such as a heat pipe inside the housing to release the heat from the piezoelectric actuator 1 to the outside of the housing, the cost and weight of the product are increased. This leads to an increase in

  The main part of the piezoelectric actuator 1 according to the first embodiment is that a piezoelectric element 2 of the piezoelectric actuator 1 is attached with a heat radiating member 5 made of an elastic material having a high thermal conductivity (thermal emissivity), so that the piezoelectric actuator 1 1 is to improve the heat radiation effect.

  As a material of the heat radiating member 5, for example, a thermosetting resin-based elastomer such as silicone or urethane is suitable, and a heat conductive filler is blended and dispersed in the thermosetting resin-based elastomer. There may be. As the fixing member for attaching the heat radiating member 5 to the piezoelectric element 2, a flexible adhesive having a high thermal conductivity is suitable, and various thermosetting adhesives such as silicone and urethane are used.

  In addition, as the heat radiating member 5, it is preferable to keep the inhibition of vibration of the diaphragm 3 to a minimum, and it is preferable to reduce the resistance to bending deformation by forming a thin thickness. The heat radiating member 5 may have a function of improving the heat radiating effect in the piezoelectric actuator 1 and may also have a function as a member for relaxing external force transmitted to the piezoelectric element 2. You may combine the function as a member which reduces a deformation | transformation.

(Configuration of the surface of the heat dissipation member)
The piezoelectric actuator 1 is preferably provided with a structure for allowing the heat dissipation member 5 to be deformed along with expansion and contraction of the piezoelectric element 2 and further improving the heat dissipation effect of the heat dissipation member 5.

  3 (a) and 3 (b), a plurality of rectangular heat radiation fins 5a are integrally formed on the surface of the heat radiation member 5 at a predetermined interval. By forming radiating fins 5a scattered in a matrix on the surface of the radiating member 5, the recessed portions 5a-1 that are notched grooves are formed in a lattice shape. The recessed portion 5a-1 has a recessed surface 5a-2 continuously on one plane.

(Effects of the first embodiment)
According to the piezoelectric actuator 1 according to the first embodiment, the following effects are obtained in addition to the above effects.

  By forming the recessed portion 5 a-1 on the surface of the heat radiating member 5, deformation of the heat radiating member 5 accompanying expansion and contraction of the piezoelectric element 2 is not hindered. In addition, the heat radiation area of the heat radiating member 5 can be increased, and heat radiation can be promoted.

[Second Embodiment]
FIG. 4 shows a piezoelectric actuator according to the second embodiment. In FIG. 4, the same member names and symbols are used for members that are substantially the same as those in the first embodiment, and a detailed description of these members is omitted.

  In the first embodiment, the heat dissipation member 5 is attached to the surface of the piezoelectric element 2 of the piezoelectric actuator 1, and this second embodiment includes the surface and side surfaces of the piezoelectric element 2. The difference is that the heat dissipating member 5 is attached to the entire exposed portion.

  In FIG. 4, a concave heat radiating member 5 is fixed to the entire surface of the piezoelectric element 2 of the piezoelectric actuator 1 via a silicone-based adhesive or the like. The heat radiating member 5 is covered on the entire surface of the piezoelectric element 2, and the heat radiating area of the heat radiating member 5 is expanded. By forming the recessed portion 5a-1 shown in FIG. 3A and FIG. 3B on the surface of the heat dissipation member 5, it is possible to further promote heat dissipation.

(Effect of the second embodiment)
According to the piezoelectric actuator 1 according to the second embodiment, in addition to the effects in the first embodiment, the following effects are obtained.

  By covering and attaching the entire surface of the piezoelectric element 2 using the heat radiating member 5 made of an elastomer having a high thermal emissivity, the heat radiating area of the heat radiating member 5 can be expanded, and the heat radiating effect can be further improved. It becomes possible.

  Since the entire surface of the piezoelectric element 2 is covered with the heat radiating member 5, an effect of reducing vibration noise can be obtained.

  As another example of the heat radiating member 5, as shown in FIGS. 5A and 5B, there is a heat radiating member 5 in which a plurality of trapezoidal radiating fins 5b are integrally formed. In the heat dissipating fins 5b, a plurality of recessed portions 5b-1 having triangular grooves are arranged in a straight line along one opposing side of the heat dissipating member 5 with a predetermined interval. The recessed portion 5b-1 is formed on one plane.

  6 (a) and 6 (b) show the displacement during driving of the piezoelectric actuator 1 shown in FIG. 5 (b).

  As shown in FIGS. 6A and 6B, the piezoelectric actuator 1 is cooled by utilizing expansion and contraction of the piezoelectric element 2. When a driving voltage is applied to the piezoelectric element 2, the heat radiating member 5 is curved and deformed in an arch shape as the piezoelectric element 2 expands and contracts. With the deformation of the heat radiating member 5 during expansion and contraction of the piezoelectric element 2, the air A in the recessed portion 5b-1 of the heat radiating member 5 is replaced.

  By processing the recessed portions 5b-1 which are a plurality of notched grooves having triangular grooves on the surface of the heat radiating member 5, it is difficult to inhibit expansion and contraction of the piezoelectric element 2, and cooling of the piezoelectric actuator 1 can be promoted.

  FIG. 7A to FIG. 7C show still another modified example of the heat radiating member 5. Various heat radiating members 5 having a configuration in which the air A in the heat radiating member 5 is replaced by utilizing the vibration of the piezoelectric actuator 1 can be employed.

  In FIG. 7A, a plurality of heat radiating fins 5 c are arranged along one opposing side of the heat radiating member 5. The radiating fin 5c is formed by cutting a plurality of slit-shaped notch grooves 5c-1 into a rectangular frame shape. This notch groove 5c-1 is formed continuously on one plane.

  In FIG. 7B, a plurality of heat radiating fins 5 d are arranged in parallel at four locations on the heat radiating member 5. The heat dissipating fin 5d has a plurality of slit-shaped notch grooves 5d-1 formed in a lattice shape. This notch groove 5d-1 is continuously formed on one plane.

  In FIG. 7 (c), a circular heat radiating member 5 is attached to the piezoelectric element 2. The heat radiating member 5 is formed by notching slit-shaped groove portions 5e-1 radially extending at equal intervals by dividing the radial direction into eight, and fan-shaped radiating fins 5e are arranged. . This notch groove 5e-1 is formed continuously on one plane.

  In the above modification, the radiating fins 5a to 5e are on the same plane as the surface of the radiating member 5 and all have the same height. However, the present invention is not limited to this. For example, the radiating member 5 The heat dissipating fins 5a to 5e may have different heights from the surface. Even in the recesses 5a-1, 5b-1 and the notch grooves 5c-1, 5d-1, 5e-1, they may be set to different depths.

  In addition, the piezoelectric actuator 1 according to the above-described embodiment, modified example, and illustrated example includes, for example, the shape, size, arrangement number, and arrangement of the piezoelectric element 2 and the heat radiating member 5 according to the shape and size of the symmetrical object used. What is necessary is just to select a position, arrangement | positioning shape, etc. suitably, and the initial objective of this invention can be achieved.

[Third Embodiment]
(Configuration of tactile presentation device)
The piezoelectric actuator 1 configured as described above constitutes a drive source of the tactile sense presentation device. Here, referring to FIG. 8, an example of a functional block diagram of the tactile sense presentation device 100 according to the third embodiment is shown.

  In the first embodiment, the configuration in which the diaphragm 3 is fixed to the piezoelectric element 2 is exemplified, but the present invention is not limited to this. The piezoelectric actuator 1 may be arranged directly on the back surface of the operation surface of the operation member 101 using the operation member 101 formed by a touch panel or a switch button that receives an operation input from an operator as a vibration plate. When the piezoelectric actuator 1 is disposed on the back surface of the operation surface of the operation member 101, the piezoelectric actuator 1 may be disposed on the back surface of the operation surface with a predetermined distance.

  The tactile sense presentation device 100 includes the piezoelectric actuator 1, the detection unit 102, and the control unit 103. The detection unit 102 includes a capacitance type sensor, a force sensor, or the like, and detects an operation input when the operation surface of the operation member 101 receives an operation input from the operator. The control unit 103 is a microcomputer that controls the piezoelectric actuator 1.

  The control unit 103 is realized by an arbitrary combination of hardware and software, centering on a control program that realizes various components such as a CPU, ROM, and RAM, a storage unit that stores the control program, and an external connection interface. . Of course, various known methods and apparatuses can be used as the method and apparatus.

  The controller 103 applies a predetermined driving voltage to the piezoelectric actuator 1 by inputting a detection signal from the detector 102. When the control unit 103 applies a drive voltage to the piezoelectric actuator 1, the piezoelectric actuator 1 expands and contracts.

  The operation member 101 to which the piezoelectric actuator 1 is attached is deformed in accordance with the expansion and contraction of the piezoelectric actuator 1, and the operation surface that receives an operation input by the operator vibrates. This vibration is transmitted to the operator who contacts the operation member 101.

(Effect of the third embodiment)
According to the tactile sense presentation device 100 configured as described above, the following effects can be obtained.

(1) Since the heat dissipation characteristics of the piezoelectric actuator 1 can be improved, it is possible to obtain a good operation feeling and vibration stimulation operation feeling.
(2) Since it is not necessary to provide a special heat dissipation mechanism such as a heat pipe inside the housing, the structure can be simplified. As a result, the cost reduction effect and weight reduction by reducing the number of components can be obtained.

  In addition, the tactile sense presentation device 100 can be attached to various interior components such as an instrument panel, a steering wheel, and a center console of a vehicle.

  In addition, the tactile sensation providing apparatus 100 can be used as an input device for remotely operating an in-vehicle device, and as an input device for various portable information terminal devices such as a mobile phone and a camera.

  As is apparent from the above description, typical embodiments, modifications, and illustrations according to the present invention have been illustrated. However, the above-described embodiments, modifications, and illustrations are within the scope of the claims. It does not limit the invention concerned. Therefore, it should be noted that not all the combinations of features described in the above embodiments, modifications, and illustrated examples are necessarily essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric actuator, 2 ... Piezoelectric element, 3 ... Diaphragm, 4 ... Support part, 5 ... Radiation member, 5a-5e ... Radiation fin, 5a-1, 5b-1 ... Recessed part (notch groove part), 5a-2 ... concave surface, 5c-1, 5d-1, 5e-1 ... notch groove part, 100 ... tactile sensation presentation device, 101 ... operation member, 102 ... detection part, 103 ... control part, A ... air

Claims (6)

A piezoelectric element;
A heat dissipating member attached to the piezoelectric element and dissipating heat of the piezoelectric element;
A piezoelectric actuator characterized in that a notch groove is formed on a surface of the heat radiating member.   The piezoelectric actuator according to claim 1, wherein the notch groove portion is a recess or a slit.   The piezoelectric actuator according to claim 1, wherein the piezoelectric element is attached to a diaphragm.   A tactile sense presentation device comprising the piezoelectric actuator according to claim 1 as a drive source.   5. The tactile sensation according to claim 4, wherein the tactile sensation providing apparatus gives a vibration feedback force that presents a sense of stimulation operation to an operator who inputs an operation member to which vibration of the piezoelectric element is transmitted. Presentation device.   The tactile sensation providing apparatus according to claim 5, wherein the operation member is a touch panel or a switch button.

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