CN117762249A - Pressure-sensitive vibration feedback element - Google Patents

Abstract

The invention relates to a pressure-sensitive vibration feedback element, which comprises a piezoelectric ceramic body, wherein a base is fixedly arranged below the piezoelectric ceramic body, a piece of elastic sheet is respectively and fixedly arranged in the middle area of the edges of two opposite sides of the piezoelectric ceramic body, and a panel is arranged above the elastic sheet; when the panel is pressed, the panel generates compression force on the elastic sheet, so that the piezoelectric ceramic body is compressed to generate bending vibration and generate voltage through the piezoelectric effect; the spring plate is in a C-shaped spring plate, a U-shaped spring plate or a Z-shaped spring plate; the element is sensitive to pressure, can obtain increased deformation and vibration feeling and higher voltage value under very small pressure, has better structural stability, and can bear larger pressure without being damaged.

Description

Pressure-sensitive vibration feedback element

Technical Field

The invention relates to the technical field of piezoelectric devices, in particular to a pressure-sensitive vibration feedback element.

Background

Mobile terminals are now widely used in daily life. With the mobile terminal, people can use gesture language on the two-dimensional plane to achieve better interactive experience effect. In addition, in order to improve the sense of realism when the user interacts with the terminal, the sense of realism is perceived on the mobile terminal by a haptic feedback technique, for example, vibration perceived by the smart phone user when the user receives a notification, text short message or a light screen is the haptic feedback technique.

With the intensive research of haptic simulation technology, haptic feedback execution of various excitation modes such as piezoelectric mode, electromagnetic mode, pneumatic mode, electric stimulation mode and the like has appeared. Electromagnetic type generally requires a complex mechanism, and has the defects of thicker structure, longer response time and the like; pneumatic type usually requires a complex nozzle array and pneumatic elements, and is difficult to control; the electric stimulation type simulation device is mainly used for simulating pain sense and the like in games, and has huge equipment; the piezoelectric haptic feedback element has low power consumption, fast response and long service life, so that the piezoelectric haptic feedback element is reliable, light and easy to drive in the conventional field.

Implementation principle of piezoelectric type tactile feedback technology: when external force is applied to the ceramic, the ceramic deforms and the internal polarization state changes by utilizing the positive and negative piezoelectric effect of the piezoelectric ceramic, so that charges are generated; when a driving voltage is applied to the ceramic, the ceramic is mechanically deformed, thereby causing vibration. The piezoelectric ceramic actuator has higher reliability and lower energy consumption, and meets the expectations of people on mature electronic products.

In the prior art, for example, CN104101423a discloses a ceramic piezoelectric spring resonant vibration sensor, which is characterized in that a spiral spring with a spiral inner diameter gradually decreasing from top to bottom is arranged on a piezoelectric ceramic, a gravity block is installed at the tail end of the top of the spring, when the gravity block vibrates due to external prying vibration, the gravity block is transferred to a silver plating center point of a piezoelectric ceramic plate through the spring, so that the piezoelectric ceramic also generates corresponding regular vibration, and then a piezoelectric effect is generated, and the sensor is used for anti-theft of an electric vehicle. Such designs typically require external application of large forces to generate the electrical conversion and are not suitable for use in haptic feedback mobile terminals.

Disclosure of Invention

How to achieve better electrical conversion under smaller pressure is a technical problem to be solved by the invention. The invention provides a pressure-sensitive vibration feedback element which is sensitive to pressure, can obtain a higher voltage value under a small pressure, has better structural stability and can bear a larger pressure.

In order to achieve the above purpose, the invention is realized by the following technical scheme:

the pressure-sensitive vibration feedback element comprises a piezoelectric ceramic body, wherein a base is fixedly arranged below the piezoelectric ceramic body, a piece of elastic sheet is respectively and fixedly arranged in the middle area of the two opposite side edges of the piezoelectric ceramic body, and a panel is arranged above the elastic sheet;

when the panel is pressed, the panel generates a compression force on the elastic sheet, so that the piezoelectric ceramic body is compressed to generate bending vibration and generate voltage through the piezoelectric effect.

Further, the configuration of the spring plate is a C-shaped spring plate, a U-shaped spring plate or a Z-shaped spring plate.

Preferably, when the Z-shaped elastic piece is selected, the Z-shaped elastic piece is a Z-shaped elastic piece with an obtuse angle, and the section profile formed by the panel, the elastic piece and the piezoelectric ceramic body is a trapezoid section with a narrow upper part and a wide lower part;

when the C-shaped elastic sheet or the U-shaped elastic sheet is selected, the openings of the two elastic sheets are arranged oppositely.

Further, the piezoelectric ceramic body is formed by alternately laminating a plurality of internal electrodes and a plurality of ceramic plates, each ceramic plate is used for laminating each internal electrode, the number of the internal electrodes is n, n is a double number, and the number of the ceramic plates is n+1;

each internal electrode is arranged in the inner central area of each ceramic plate, and the surface area of each internal electrode is smaller than that of each ceramic plate;

the left side width direction of the inner electrode is provided with a left side extraction part extending to the length edge of the ceramic plate, and the length of the left side extraction part at the edge of the ceramic plate is less than half of the length of the inner electrode;

the right side width direction of the inner electrode is provided with a right side extraction part extending to the length edge of the ceramic plate, and the length of the right side extraction part at the edge of the ceramic plate is less than half of the length of the inner electrode;

defining a structure in which one piece of the internal electrode is laminated on one piece of the ceramic sheet as a layer unit, and assuming that a singular layer unit has a plurality of flush left-side lead-out portions, a double layer unit has a plurality of flush right-side lead-out portions;

assuming that the singular layer-by-layer unit has a plurality of flush right side lead-out portions, the double layer-by-layer unit has a plurality of flush left side lead-out portions;

the number of the left extraction parts is equal to that of the right extraction parts;

providing a left side electrode covering the left side lead-out portion on a side surface having the left side lead-out portion, providing a right side electrode covering the right side lead-out portion on a side surface having the right side lead-out portion, and being free from contact with the right side electrode;

the left side of the upper surface of the piezoelectric ceramic body is provided with a left front electrode, and the left front electrode is connected with the left side surface electrode; the right side of the upper surface of the piezoelectric ceramic body is provided with a right front electrode, the right front electrode is connected with the right side surface electrode, and the left front electrode is not contacted with the right front electrode.

Further, the material of the inner electrode is silver palladium alloy; the ceramic plate is made of PZT piezoelectric ceramic plates; the left side surface electrode, the right side surface electrode, the left front surface electrode and the right front surface electrode are all made of silver; the size of the piezoelectric ceramic body is set according to the requirement, for example, the area size is 12×4mm, and the thickness of the piezoelectric ceramic body is at least 0.05mm, for example, can be 0.5mm; the capacitance loss of the piezoelectric ceramic body is smaller than 0.06, and the insulation resistance is larger than 200MΩ.

Further, the faceplate is sized to cover a surface area of the piezoceramic body; the panel is a touch PCB.

Further, the base is a metal sheet, and the area of the metal sheet is set according to the requirement, for example, the area can be 20×5mm; the thickness of the base is at least 0.1mm, for example may be 0.3mm, preferably the metal sheet is a copper sheet.

Further, the connection mode between the base and the piezoelectric ceramic body is gluing; the elastic sheet is connected with the piezoelectric ceramic body in a cementing way; the elastic sheet and the panel are connected in a splicing or cementing way.

The beneficial technical effects are as follows:

the structure of the pressure-sensitive vibration feedback element is sequentially provided with a metal sheet base, a piezoelectric ceramic body and a panel from bottom to top, wherein a spring piece is arranged between the panel and the piezoelectric ceramic body and is arranged in the middle area of the two opposite side edges of the piezoelectric ceramic body; when the panel is pressed by a finger, the panel compresses the elastic pieces at two sides, the elastic pieces at two sides compress the piezoelectric ceramic body again, so that the piezoelectric ceramic body generates bending vibration, and the force conversion voltage is realized by utilizing the inverse piezoelectric effect of the piezoelectric ceramic body; the element structure is sensitive to pressure, can detect voltage under small pressure, has good mechanical property, has good stability, and can bear pressure of 60N at least to maintain the performance.

Drawings

FIG. 1 is a cross-sectional view of a piezoelectric element of the prior art, wherein a 10-piezoceramic body, a 20-cymbal plate.

FIG. 2 is a schematic cross-sectional structure of a pressure-sensitive vibration feedback element of embodiment 1;

FIG. 3 is a schematic diagram showing the position of the elastic sheet on the piezoelectric ceramic body in the pressure-sensitive vibration feedback element of embodiment 1;

FIG. 4 is a graph comparing the mechanical properties of the example 1 element and the comparative example 1 element;

FIG. 5 is a graph comparing the acceleration of the example 1 element with that of the comparative example 1 element;

FIG. 6 is a schematic diagram showing an exploded structure of a piezoelectric ceramic body in the element of example 1;

FIG. 7 is a schematic diagram of the structure of the internal electrode and the ceramic layer after lamination;

FIG. 8 is a view showing the overall structure of a piezoelectric ceramic body in the element of example 1;

wherein, the piezoelectric ceramic body comprises A1-piezoelectric ceramic body, A2-elastic sheet, a 3-panel, a 4-base, an 11-inner electrode, a 12-ceramic sheet, a 13-left side electrode, a 14-right side electrode, a 15-left front electrode, a 16-right front electrode, a 111-left outlet part, a 112-right outlet part, an A1-singular layer-by-layer unit and an A2-double layer-by-layer unit.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The numerical values set forth in these examples do not limit the scope of the present invention unless specifically stated otherwise. Techniques, methods known to those of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values.

The experimental methods in the following examples, for which specific conditions are not noted, are generally determined according to national standards; if the national standard is not corresponding, the method is carried out according to the general international standard or the standard requirements set by related enterprises.

Example 1

The pressure-sensitive vibration feedback element is shown in the schematic diagrams of fig. 2-3, and comprises a piezoelectric ceramic body 1, wherein a base 4 is fixedly arranged below the piezoelectric ceramic body 1, a piece of elastic sheet 2 is respectively and fixedly arranged in the middle area of the two opposite side edges of the piezoelectric ceramic body 1, and a panel 3 is detachably covered above the elastic sheet 2;

the configuration of the elastic sheet 2 is a Z-shaped elastic sheet with an obtuse angle, and the section surface formed by the panel 3, the elastic sheet 2 and the piezoelectric ceramic body 1 is a trapezoid section with a narrow upper part and a wide lower part;

as shown in fig. 6 to 8, the piezoelectric ceramic body 1 is configured by alternately stacking a plurality of internal electrodes 11 and a plurality of ceramic sheets 12, and the ceramic sheets 12 are stacked with the internal electrodes 11; in this case, the number of the internal electrodes 11, n=28, and the number of the ceramic sheets 12 is n+1=29, and all layers are not shown in fig. 7 after lamination, which is only illustrative;

the inner electrode 11 is arranged in the inner central area of the ceramic sheet 12, and the surface area of the inner electrode 11 is smaller than the surface area of the ceramic sheet 12;

the left side width direction of the inner electrode 11 is provided with a left side extraction part 111 extending to the length edge of the ceramic sheet, and the length of the left side extraction part 111 at the edge of the ceramic sheet 12 is less than half of the length of the inner electrode 11; a right extraction portion 112 extending to the length edge of the ceramic sheet 12 is arranged on the right width direction of the inner electrode 11, and the length of the right extraction portion 112 at the edge of the ceramic sheet 12 is less than half of the length of the inner electrode 11;

defining the structure in which one internal electrode 11 is laminated on one ceramic sheet 12 as a layer unit, in this case, the singular layer unit A1 has a plurality of flush left side lead-out portions 111, then the double layer unit A2 has a plurality of flush right side lead-out portions 112 (of course, in other embodiments, the singular layer unit A1 has a plurality of flush right side lead-out portions 112, then the double layer unit A2 has a plurality of flush left side lead-out portions 111); the number of the left extraction portions 111 is equal to the number of the right extraction portions 112;

as shown in fig. 8, a left side electrode 13 is provided on a side surface having the left extraction portion 111 so as to cover the left extraction portion 111, and a right side electrode 14 is provided on a side surface having the right extraction portion 112 so as to cover the right extraction portion 112, the left side electrode 13 and the right side electrode 14 being not in contact with each other;

a left front electrode 15 is arranged on the left side of the upper surface of the piezoelectric ceramic body 1, and the left front electrode 15 is connected with the left side surface electrode 13; a right front electrode 16 is arranged on the right side of the upper surface of the piezoelectric ceramic body 1, and the right front electrode 16 is connected with the right side surface electrode 14; the left side electrode 13 is not connected to the right front electrode 16;

wherein the material of the inner electrode 11 is silver palladium alloy; the ceramic plate 12 is made of a PZT piezoelectric ceramic plate; the left side surface electrode 13, the right side surface electrode 14, the left front surface electrode 15 and the right front surface electrode 16 are all made of silver; the piezoelectric ceramic body 1 has dimensions (length×width×thickness) of 12×4×0.5mm;

the PZT piezoelectric ceramic sheet is molded by a casting film casting process known to those skilled in the art, and a ceramic sheet with the thickness of about 18 mu m is obtained by cutting a film; preparing 29 ceramic plates, printing inner electrode slurry (silver palladium slurry) on the 28 ceramic plates according to the layered structure of fig. 6, baking and solidifying, laminating according to the structure of fig. 6, and sintering at 950 ℃ to obtain the piezoelectric ceramic body with the structure of fig. 7; according to the structure of fig. 8, silver paste is printed on the surfaces of the left side surface and the right side surface of the piezoelectric ceramic body, which cover the exposed inner electrode, silver paste is printed on the surfaces of the left front surface and the right front surface corresponding to the left side surface and the right side surface, and after baking and curing, sintering is carried out at 950 ℃, and then polarization is carried out, so that the capacitance of the piezoelectric ceramic body is tested to be 450nF, the capacitance is stored to be less than 0.06, and the insulation resistance is greater than 200mΩ;

wherein the faceplate 3 is sized to cover the surface area of the piezoceramic body 6; the panel 3 is a touch control PCB;

wherein the base 4 is a copper sheet, and the size (length, width and thickness) of the copper sheet is 20X 5X 0.3mm;

wherein, the connection mode between the base 4 and the piezoelectric ceramic body 1 is cementing; the elastic sheet 2 is connected with the piezoelectric ceramic body 1 in a cementing way; the elastic sheet 2 and the panel 3 are connected in a gluing way;

when the panel 3 is pressed, the panel 3 generates a compressive force on the spring 2, so that the piezoelectric ceramic body 1 is compressed to generate bending vibration and generate voltage by the inverse piezoelectric effect.

Example 2

The pressure sensitive vibration feedback element has the same structure as that of the embodiment 1, except that the elastic pieces are U-shaped, and the openings of the two elastic pieces are opposite.

Example 3

The pressure-sensitive vibration feedback element has the same structure as that of the embodiment 1, except that the elastic pieces are C-shaped, and the openings of the two elastic pieces are opposite.

Comparative example 1

As shown in fig. 1, a piezoelectric element according to the prior art is constructed by bonding a piezoelectric ceramic body 10 (length×width×thickness=12×4×0.5mm, the same as the piezoelectric ceramic body 1 of example 1) as a unit between two cymbal sheets 20.

Test case

1. Mechanical property test

The piezoelectric elements of example 1 and comparative example 1 were subjected to pressure test using an electronic universal tester at a depressing rate of 40mm/min. As a result, as shown in fig. 4, it is clear from fig. 4 that the pressure-sensitive vibration feedback element of the structure of example 1 of the present invention can withstand at least 60N of pressure, and that example 2 and example 3 can withstand at least 60N of force as well; whereas the piezoelectric element of the structure of comparative example 1 can withstand only 30N of force at maximum. The smaller the pressing bearing force is, the worse the bearable drop test result is, the component of the comparative example 1 breaks in the drop test, and the component of the invention is in good drop test under the same condition.

2. Acceleration test

The piezoelectric elements of example 1 and comparative example 1 were subjected to an acceleration test, and the test method was as follows: the lower surface of the original is adhered to the supporting base plate of the instrument on the acceleration test instrument, the weight block (20 g) of the instrument is adhered to the upper surface of the original, the accelerometer of the instrument is adhered to the weight block, and then the instrument is electrified for testing. The results are shown in FIG. 5, in which the abscissa is time and the ordinate is acceleration (in g), and it is clear from FIG. 5 that the acceleration value of example 1 is larger than that of comparative example 1, and the larger the acceleration value, the better the vibration feeling of the element.

3. Pressure feedback test

The piezoelectric elements of the above example 1 and comparative example 1 were subjected to a pressure feedback test using an electronic universal tester at a depressing rate of 40mm/min, the positive and negative electrodes of the element were connected to an oscilloscope of the instrument, the instrument was deformed by displacement of the instrument when depressed, and the element produced a voltage feedback due to the inverse piezoelectric effect of the piezoelectric ceramic body and displayed a voltage value on the oscilloscope.

The results are shown in Table 1.

TABLE 1 deformation and Voltage relation

As can be seen from table 1, the structural element of the present invention can realize a large deformation amount with a small pressing force, and a large vibration feeling, thereby realizing a large voltage feedback. Example 1 the structure of the present invention can achieve a larger deformation and a larger vibration feeling than comparative example 1 under the same pressing force, and thus a larger feedback voltage. The structure of the invention is superior to the existing structure.

The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.

Claims (8)

1. The pressure-sensitive vibration feedback element is characterized by comprising a piezoelectric ceramic body (1), wherein a base (4) is fixedly arranged below the piezoelectric ceramic body (1), a piece of elastic sheet (2) is respectively and fixedly arranged in middle areas of two opposite side edges of the piezoelectric ceramic body (1), and a panel (3) is arranged above the elastic sheet (2);

when the panel (3) is pressed, the panel (3) generates a compression force on the elastic sheet (2), so that the piezoelectric ceramic body (1) is compressed to generate bending vibration and generate voltage through the piezoelectric effect.

2. A pressure sensitive vibration feedback element according to claim 1, characterized in that the configuration of the spring (2) is a C-spring, a U-spring or a Z-spring.

3. A pressure sensitive vibration feedback element according to claim 2, characterized in that when Z-shaped spring is selected, the Z-shaped spring is a Z-shaped spring having an obtuse angle, and the cross-sectional profile formed by the panel (3), the spring (2) and the piezoelectric ceramic body (1) is a trapezoid cross-section with a narrow top and a wide bottom;

when the C-shaped elastic sheet or the U-shaped elastic sheet is selected, the openings of the two elastic sheets (2) are arranged oppositely.

4. A pressure-sensitive vibration feedback element according to claim 1, wherein the piezoelectric ceramic body (1) is constituted by alternately laminating a plurality of internal electrodes (11) and a plurality of ceramic sheets (12), each of the ceramic sheets (12) laminating each of the internal electrodes (11), the number of the internal electrodes (11) being n and n being a double number, the number of the ceramic sheets (12) being n+1;

each internal electrode (11) is arranged in the inner central area of each ceramic plate (12), and the surface area of the internal electrode (11) is smaller than that of the ceramic plate;

the left side width direction of the inner electrode (11) is provided with a left side extraction part (111) extending to the length edge of the ceramic sheet (12), and the length of the left side extraction part (111) at the edge of the ceramic sheet (12) is less than half of the length of the inner electrode (11);

the right side width direction of the inner electrode (11) is provided with a right side extraction part (112) extending to the length edge of the ceramic sheet (12), and the length of the right side extraction part (112) at the edge of the ceramic sheet (12) is less than half of the length of the inner electrode (11);

defining a structure in which one piece of the internal electrode (11) is laminated on one piece of the ceramic sheet (12) as a layer unit, and assuming that a singular layer-by-layer unit (A1) has a plurality of flush left-side lead-out portions (111), a double layer-by-layer unit (A2) has a plurality of flush right-side lead-out portions (112);

assuming that the singular layer-by-layer unit (A1) has a plurality of flush said right side lead-out portions (112), the double layer-by-layer unit (A2) has a plurality of flush said left side lead-out portions (111);

the number of the left extraction parts (111) is equal to the number of the right extraction parts (112);

a left side electrode (13) covering the left side lead-out portion (111) is provided on a side surface having the left side lead-out portion (111), a right side electrode (14) covering the right side lead-out portion (112) is provided on a side surface having the right side lead-out portion (112), and the left side electrode (13) and the right side electrode (14) are not in contact with each other;

the left side of the upper surface of the piezoelectric ceramic body (5) is provided with a left front electrode (15), and the left front electrode (15) is connected with the left side surface electrode (13); the right side of the upper surface of the piezoelectric ceramic body (1) is provided with a right front electrode (16), the right front electrode (16) is connected with the right side surface electrode (14), and the left front electrode (15) is not contacted with the right front electrode (16).

5. A pressure sensitive vibration feedback element according to claim 1, characterized in that the material of the inner electrode (11) is silver palladium alloy; the ceramic plate (12) is made of a PZT piezoelectric ceramic plate; the left side surface electrode (13), the right side surface electrode (14), the left front surface electrode (15) and the right front surface electrode (16) are all made of silver; the thickness of the piezoelectric ceramic body (1) is at least 0.05mm; the capacitance loss of the piezoelectric ceramic body is smaller than 0.06, and the insulation resistance is larger than 200MΩ.

6. A pressure sensitive vibration feedback element according to claim 1, characterized in that the size of the panel (3) covers the surface area of the piezoceramic body (1); the panel (3) is a touch PCB.

7. A pressure sensitive vibration feedback element according to claim 1, characterized in that the base (4) is a metal sheet, the thickness of the base (4) being at least 0.1mm.

8. A pressure sensitive vibration feedback element according to claim 1, characterized in that the connection between the base (4) and the piezoceramic body (1) is glue; the elastic sheet (2) and the piezoelectric ceramic body (1) are connected in a cementing way; the elastic sheet (2) and the panel (3) are connected in a plugging or cementing way.