KR102504933B1 - High-sensitivity compression type piezoelectric accelerometer - Google Patents

Abstract

A high sensitivity compression type piezoelectric accelerometer according to an embodiment may include: a base housing having an inner space; a mass body disposed in the inner space while being spaced apart from an inner wall of the inner space; a first sensor unit including a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along the first axis direction; and a control unit configured to measure an acceleration in the first axis direction based on a voltage measured by the pair of piezoelectric sensors of the first sensor unit.

Description

High-sensitivity compression type piezoelectric accelerometer {HIGH-SENSITIVITY COMPRESSION TYPE PIEZOELECTRIC ACCELEROMETER}

The following description relates to a highly sensitive compressive piezoelectric accelerometer.

Generally, accelerometers using PZT-based piezoelectric elements are designed to operate in shear mode to obtain high sensitivity characteristics. In the case of a conventional shear type accelerometer, a cylindrical piezoelectric element is used to measure acceleration in a vertical direction, and a belt-type earthquake-resistant mass is used outside the cylindrical piezoelectric element. At this time, pressure is applied using a band-shaped ring to apply a pre-load to improve the performance of the accelerometer.

In the case of a high-sensitivity compression-type piezoelectric accelerometer like the prior art, it is designed in a form that can apply a preload by adjusting the fastening pressure of the bolt using a bolt penetrating the central axis. In this case, a bolt is installed through the seismic mass and the piezoelectric element so that a uniform preload can be applied. To this end, additional hole processing is required in the piezoelectric element, which may lead to a decrease in output due to a decrease in the volume of the element.

On the other hand, in the case of the prior art in which pre-loading is applied to a single crystal using an earthquake-resistant mass without processing the piezoelectric element, when pressure is applied to the housing or the housing is deformed in a specific direction by resonance, the force caused by the deformation pushes the bolt. There was a problem in that a signal was transmitted to the piezoelectric element through the piezoelectric element.

The above background art is possessed or acquired by the inventor in the process of deriving the present invention, and cannot necessarily be said to be known art disclosed to the general public prior to filing the present invention.

An object according to an embodiment is to provide a highly sensitive compression type piezoelectric accelerometer.

A high-sensitivity compression-type piezoelectric accelerometer according to an embodiment includes a base housing having an inner space; a mass body disposed in the inner space while being spaced apart from an inner wall of the inner space; a first sensor unit including a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along the first axis direction; and a controller configured to measure an acceleration in the first axis direction based on a voltage measured by the pair of piezoelectric sensors of the first sensor unit.

The first sensor unit may include: a first positive piezoelectric sensor connected between the mass body and an inner wall of the base housing at one side with respect to the first axis; and a first reverse piezoelectric sensor connected between the mass body and an inner wall of the base housing at the other side with respect to the first axis, wherein the first forward piezoelectric sensor and the first reverse piezoelectric sensor each have a polling direction. They may be formed in opposite directions relative to each other.

When the base housing is accelerated along the first axial direction, a compressive force is applied to one of the first forward piezoelectric sensor and the first reverse piezoelectric sensor and a tensile force is applied to the other piezoelectric sensor. However, directions of voltages generated by the first forward piezoelectric sensor and the first reverse piezoelectric sensor may be the same.

The first forward piezoelectric sensor and the first reverse piezoelectric sensor may have a hexahedral shape having sides facing along the first axis.

When the base housing is deformed along the first axial direction by an external force, the direction of the force applied to the first forward piezoelectric sensor and the first reverse piezoelectric sensor is the same, but the first forward piezoelectric sensor and the first piezoelectric sensor The directions of the voltages generated in the reverse piezoelectric sensor may be opposite to each other.

The first sensor unit is fastened to press the first forward piezoelectric sensor or the first reverse piezoelectric sensor by screwing to the base housing along the first axial direction in order to apply a preload to the pair of piezoelectric sensors. A first pressure bolt to be; may further include.

The first pressing bolt may be formed of a headless bolt having one side protruding into the inner space of the base housing along the first axial direction and the other side screwed together without a portion protruding from the outside of the base housing.

A high-sensitivity compression-type piezoelectric accelerometer according to an embodiment includes a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along a second axis direction orthogonal to the first axis. 2 sensor units; and a third sensor unit including a pair of piezoelectric sensors installed between the inner wall of the inner space and both sides of the mass body along a third axis direction orthogonal to the first axis and the second axis. wherein each of the first sensor unit, the second sensor unit, and the third sensor unit includes a forward piezoelectric sensor and a reverse piezoelectric sensor disposed symmetrically and in series with respect to the mass body, wherein the first sensor unit , The forward piezoelectric sensor and the reverse piezoelectric sensor of each of the second sensor unit and the third sensor unit may have polling directions opposite to each other.

Each of the first sensor unit, the second sensor unit, and the third sensor unit is screwed to the base housing to press each of the forward piezoelectric sensor or the reverse piezoelectric sensor, and respectively the forward piezoelectric sensor or the reverse piezoelectric sensor. A pressure bolt fastened to press the sensor may be further included.

The center of gravity of each of the first axis, the second axis, and the third axis may be the same.

The mass body and the inner space may have a cube shape including a surface facing each of the first axis, the second axis, and the third axis.

The pair of piezoelectric element sensors along the first axis direction are connected in series to the control unit, and the direction in which each of the pair of piezoelectric element sensors is energized from the control unit is opposite to each other along the first axis direction. can

A high-sensitivity compression-type piezoelectric accelerometer according to an embodiment includes a pair of pairs installed between an inner wall of the inner space and both sides of the mass body along a second axis direction orthogonal to the first axis and connected in series to the control unit. A second sensor unit having a piezoelectric element sensor; and a pair of piezoelectric sensors installed between the inner wall of the inner space and both sides of the mass body along a third axis direction orthogonal to the first axis and the second axis and connected in series to the control unit. And a third sensor unit that does; wherein each of the first sensor unit, the second sensor unit, and the third sensor unit is respectively the pair of sensors along each of the first axis, the second axis, and the third axis. Directions in which each piezoelectric element sensor is energized from the control unit may be opposite to each other.

According to the high-sensitivity compression-type piezoelectric accelerometer according to an embodiment, unlike the design of conventional compression-type piezoelectric accelerometers that are assembled by passing bolts in the axial direction, preloads can be applied in three axial directions using pressure bolts, so that the piezoelectric sensor Manufacturing time and cost can be reduced as there is no need to process separate bolt holes in the element or mass body, and through this, damage to the piezoelectric element can be reduced during assembly and preparation, and greater sensitivity can be obtained compared to sensors of the same volume. .

According to the high-sensitivity compression-type piezoelectric accelerometer according to an embodiment, since piezoelectric sensor elements can be processed into a simple hexahedral shape and used, there is an advantage in that a piezoelectric single crystal material having excellent sensitivity characteristics can be used with minimal processing. Due to the simplification of the sensor, it is possible to reduce cost, reduce delivery time, improve yield and improve assemblability, and gain the advantage of increased sensitivity to volume in terms of sensor performance.

1 is a perspective view illustrating an internal structure of a high-sensitivity compression-type piezoelectric accelerometer according to an exemplary embodiment.
2 is a block diagram of a highly sensitive compression-type piezoelectric accelerometer according to an exemplary embodiment.
3 is a cross-sectional view of a high-sensitivity compression-type piezoelectric accelerometer according to an exemplary embodiment.
4A is a diagram schematically illustrating magnitudes of force and voltage applied and measured from a pair of piezoelectric sensors when a high-sensitivity compression-type piezoelectric accelerometer is accelerated in one direction along a first axis according to an embodiment.
4B is a diagram schematically illustrating magnitudes of force and voltage applied and measured from a pair of piezoelectric sensors when a high-sensitivity compression-type piezoelectric accelerometer is accelerated in another direction of a first axis according to an embodiment.
5 is a diagram showing magnitudes of force and voltage applied and measured from a pair of piezoelectric sensors when a high-sensitivity compression-type piezoelectric accelerometer is compressed and deformed in a first axial direction according to an embodiment.
6 is a diagram showing the structure of a high-sensitivity compression-type piezoelectric accelerometer according to an embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following description is one of several aspects of the embodiments, and the following description forms part of a detailed description of the embodiments.

However, in describing an embodiment, a detailed description of a known function or configuration will be omitted to clarify the gist of the present invention.

In addition, the terms or words used in this specification and claims should not be interpreted in a conventional or dictionary sense, and the inventor may appropriately define the concept of the term in order to explain his or her invention in the best way. Based on the principle that there is, it is a meaning and concept corresponding to the technical idea of a multi-axis high-sensitivity compression type piezoelectric accelerometer according to an embodiment.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one most preferred embodiment of a high-sensitivity compression-type piezoelectric accelerometer according to an embodiment, and all of the technical ideas of the high-sensitivity compression-type piezoelectric accelerometer according to an embodiment are Since it is not a representative, it should be understood that there may be various equivalents and modifications that can replace them at the time of this application.

1 is a perspective view showing an internal structure of a high-sensitivity compression-type piezoelectric accelerometer according to an embodiment, FIG. 2 is a block diagram of the high-sensitivity compression-type piezoelectric accelerometer according to an embodiment, and FIG. Cross-sectional view of a high-sensitivity compression-type piezoelectric accelerometer.

The high-sensitivity compression-type piezoelectric accelerometer 1 according to an embodiment is a compression-type accelerometer that measures a physical quantity of acceleration through an array of piezoelectric elements installed along at least two or more axis directions orthogonal to each other. .

A multi-axis high-sensitivity compression-type piezoelectric accelerometer 1 according to an embodiment measures accelerations excited in each of three axes (eg, x-axis, y-axis, and z-axis) orthogonal to each other using one mass body 12 can do.

From the drawings and the following description, the highly sensitive compression-type piezoelectric accelerometer 1 according to an embodiment will be shown and described as having a configuration for measuring acceleration for each axis along three axis directions orthogonal to each other, but will be described in detail. Technologists will fully understand that the highly sensitive compression-type piezoelectric accelerometer 1 of the present disclosure may be configured in embodiments that measure acceleration in a single axis or two or more axis directions.

A multi-axis high-sensitivity compression type piezoelectric accelerometer 1 according to an embodiment includes a base housing 11, a mass body 12, a first sensor unit 131, a second sensor unit 132, and a third sensor unit 133. and a control unit 14.

The base housing 11 is a case-shaped member to which acceleration is applied according to external force or vibration, and has an internal space 111 accommodating the first to third sensor units 133 as well as the mass body 12 therein can include

The mass body 12 is installed in the inner space 111 of the base housing 11, and is connected through the first to third sensor units 131, 132, and 133 while being spaced apart from the inner wall of the inner space 111. can

For example, each of the first to third sensor units 133 may have a structure installed symmetrically along the first axis, the second axis, or the third axis with respect to the mass body 12, and accordingly Each of the first axis, the second axis, and the third axis may be orthogonal to each other at the position of the mass body 12 .

For example, all of the centers of gravity of the first axis, the second axis, and the third axis of the high-sensitivity compression-type piezoelectric accelerometer 1 may be located on the center of gravity of the mass body 12 .

According to the above structure, the first to third sensor units 133 can be installed to share the same mass body 12, and the housing and sensor configuration of the compression type piezoelectric accelerometer 1 can be designed symmetrically with respect to the center of gravity. Therefore, the advantage of simplification in design or manufacturing can be expected, and a small/lightweight compact design can also be possible.

For example, the mass body 12 may have a hexahedron shape having both sides facing the first axis, the second axis, and the third axis, respectively. Accordingly, the internal space 111 also has the first axis, the second axis, and the second axis. It may have a hexahedron shape having opposite sides facing each of an axis and a third axis.

However, it should be noted that, in addition to the hexahedral shape, the mass body 12 may have a polyhedral or spherical shape having a symmetrical shape with respect to the first axis, the second axis, and the third axis orthogonal to each other.

The first sensor unit 131, the second sensor unit 132, and the third sensor unit 133 are formed along three axes orthogonal to each other, that is, along directions of the first axis, the second axis, and the third axis, respectively, in the base housing. It may have a piezoelectric element sensor structure connected to both ends of the mass body 12 from both inner walls facing each other of (11).

For convenience of description, the first axis corresponds to the x-axis, the second axis corresponds to the y-axis, and the third axis corresponds to the z-axis, but as described above, the number and arrangement of axes It should be noted that differently shaped configurations are also possible.

The first sensor unit 131 includes a first positive piezoelectric sensor 1311 connected between the mass body 12 and the base housing 11 on one side and the mass body 12 and the base on the other side with respect to the first axis. A first reverse piezoelectric sensor 1312 connected between the housing 11 and a first forward piezoelectric sensor 1312 screwed to at least a part of the base housing 11 along the first axial direction to apply a preload to the piezoelectric sensor 1311 or a first pressing bolt 1313 for pressing the first reverse piezoelectric sensor 1312.

The first positive piezoelectric sensor 1311 may include a piezoelectric element in which a voltage is formed according to the magnitude of applied force.

The first reverse piezoelectric sensor 1312 may include a piezoelectric element in which a voltage is formed according to an applied force.

For example, the first forward piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312 are serially connected symmetrically to the mass body 12 along the first axial direction as shown in FIGS. 1 and 3 . Can be installed in mold arrangement.

The first positive piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312 may each have a polling direction opposite to each other. In other words, the first forward piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312 may be formed in opposite directions in which dipoles including molecules or ions constituting the respective internal crystals are aligned. .

Therefore, when compressive force or tensile force in the same direction is applied to each of the first forward piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312, the magnitude of the voltage generated by each of the sensors 1311 and 1312 is The same, but the directions of the voltages may be formed in opposite directions to each other.

The first pressure bolt 1313 is a portion of the base housing 11 that is collinear with the first positive piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312 arranged in series along the first axial direction. It may be a bolt-type member screwed to.

For example, the first pressing bolt 1313 presses either one of the piezoelectric sensors 1311 and 1312 of the first forward piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312 based on the first axial direction. can be installed

For example, the first pressure bolt 1313 may be formed as a headless bolt without a bolt head, and one side protruding into the base housing 11 is the first forward piezoelectric sensor 1311 of the internal space 111. ) or the first reverse piezoelectric sensor 1312 may be pressed, and the other side may be installed to have a recessed position from the outer surface of the base housing 11 so as not to protrude outside the base housing 11.

The second sensor unit 132 includes a first positive piezoelectric sensor 1311 connected between the mass body 12 and the base housing 11 on one side and the mass body 12 and the base on the other side with respect to the second axis. A second reverse piezoelectric sensor 1322 connected between the housing 11 and a second forward piezoelectric sensor screwed to at least a part of the base housing 11 along the second axial direction to apply a preload to the piezoelectric sensor 1321 or a second pressing bolt 1323 for pressing the second reverse piezoelectric sensor 1322.

The second positive piezoelectric sensor 1321 may include a piezoelectric element in which a voltage is formed according to the magnitude of applied force.

The second reverse piezoelectric sensor 1322 may include a piezoelectric element in which a voltage is formed according to an applied force.

For example, the second forward piezoelectric sensor 1321 and the second reverse piezoelectric sensor 1322 are connected in series symmetrically to the mass body 12 along the second axial direction as shown in FIGS. 3 to 4B. Can be installed in mold arrangement.

The second positive piezoelectric sensor 1321 and the second reverse piezoelectric sensor 1322 may each have a polling direction opposite to each other. In other words, the second forward piezoelectric sensor 1321 and the second reverse piezoelectric sensor 1322 may be formed in opposite directions in which dipoles including molecules or ions constituting the respective internal crystals are aligned. .

Therefore, when compressive force or tensile force in the same direction is applied to each of the second forward piezoelectric sensor 1321 and the second reverse piezoelectric sensor 1322, the magnitude of the voltage generated by each of the sensors 1311 and 1312 is The same, but the directions of the voltages may be formed in opposite directions to each other.

The second pressure bolt 1323 is a part of the base housing 11 that is collinear with the second positive piezoelectric sensor 1321 and the second reverse piezoelectric sensor 1322 arranged in series along the second axial direction. It may be a bolt-type member screwed to.

For example, the second pressure bolt 1323 presses one of the piezoelectric sensors 1321 and 1322 of the second positive piezoelectric sensor 1321 and the second reverse piezoelectric sensor 1322 based on the second axial direction. can be installed

For example, the second pressure bolt 1323 may be formed as a headless bolt without a bolt head, and one side protruding into the base housing 11 is the second forward piezoelectric sensor 1321 of the inner space 111. ) or the second reverse piezoelectric sensor 1322 may be pressed, and the other side may be installed to have a recessed position from the outer surface of the base housing 11 so as not to protrude outside the base housing 11.

The third sensor unit 133 includes a third forward piezoelectric sensor 1331 connected between the mass body 12 and the base housing 11 on one side and the mass body 12 and the base on the other side with respect to the third axis. A third reverse piezoelectric sensor 1332 connected between the housing 11 and a third forward piezoelectric sensor screwed to at least a part of the base housing 11 along the third axial direction to apply a preload to the piezoelectric sensor. 1331 or a third pressing bolt 1333 for pressing the third reverse piezoelectric sensor 1332.

The third positive piezoelectric sensor 1331 may include a piezoelectric element in which a voltage is formed according to the magnitude of applied force.

The third reverse piezoelectric sensor 1332 may include a piezoelectric element in which a voltage is formed according to an applied force.

For example, the third forward piezoelectric sensor 1331 and the third reverse piezoelectric sensor 1332 are connected in series symmetrically to the mass body 12 along the third axis direction as shown in FIGS. 3 to 4B. Can be installed in mold arrangement.

The third forward piezoelectric sensor 1331 and the third reverse piezoelectric sensor 1332 may each have a polling direction opposite to each other. In other words, the third forward piezoelectric sensor 1331 and the third reverse piezoelectric sensor 1332 may be formed in opposite directions in which dipoles including molecules or ions constituting the respective internal crystals are aligned. .

Therefore, when compressive force or tensile force in the same direction is applied to each of the third forward piezoelectric sensor 1331 and the third reverse piezoelectric sensor 1332, the magnitude of the voltage generated by each of the sensors 1311 and 1312 is The same, but the directions of the voltages may be formed in opposite directions to each other.

The third pressure bolt 1333 is a portion of the base housing 11 that is collinear with the third positive piezoelectric sensor 1331 and the third reverse piezoelectric sensor 1332 arranged in series along the third axial direction. It may be a bolt-type member screwed to.

For example, the third pressing bolt 1333 presses one of the piezoelectric sensors 1331 and 1332 of the third positive piezoelectric sensor 1331 and the third reverse piezoelectric sensor 1332 based on the third axial direction. can be installed

For example, the third pressure bolt 1333 may be formed as a headless bolt without a bolt head, and one side protruding into the base housing 11 is the third forward piezoelectric sensor 1331 of the internal space 111. ) or the third reverse piezoelectric sensor 1332, and the other side may be installed to have a recessed position from the outer surface of the base housing 11 so as not to protrude outside the base housing 11.

The controller 14 controls the first, second, and third axes based on the voltages measured by each of the first sensor unit 131, the second sensor unit 132, and the third sensor unit 133. Acceleration in a direction can be measured.

A process in which the control unit 14 measures the acceleration through each of the sensor units 131, 132, and 133 will be described below with reference to FIGS. 4A and 4B.

4A and 4B are views schematically showing magnitudes of force and voltage applied and measured from a pair of piezoelectric sensors according to the direction of acceleration applied to a high-sensitivity compression-type piezoelectric accelerometer according to an exemplary embodiment, and FIG. This diagram shows the magnitude of force and voltage applied and measured from a pair of piezoelectric sensors when the highly sensitive compression-type piezoelectric accelerometer according to the example is compressed and deformed in the first axial direction. For convenience of description and understanding, the following description 4A and 4B, the configuration of the first sensor unit 131 installed along the first axis of the three axes will be described as a representative, but those skilled in the art will understand that the following description and the configuration in the drawings It will be appreciated that all are equally applicable to the remaining axes (2nd axis, 3rd axis).

Specifically, FIG. 4A shows the force applied to each of the pair of piezoelectric elements 1311 and 1312 when the high-sensitivity compressive piezoelectric accelerometer 1 is accelerated in one direction of the first axis, and the magnitude and direction of the voltage formed. 4B shows the force applied to each of the pair of piezoelectric elements 1311 and 1312, and the magnitude and direction of the voltage formed when the high-sensitivity compressive piezoelectric accelerometer 1 is accelerated in the other direction of the first axis. .

Referring first to FIG. 4A , when the highly sensitive compressive piezoelectric accelerometer 1 is accelerated in one direction (upward direction in the drawing) based on the first axis direction, a first forward piezoelectric sensor 1311 and a first reverse piezoelectric sensor (1312) It is possible to check the force applied to each and the direction and magnitude of the voltage formed.

As shown in FIG. 4A, when the high-sensitivity compressive piezoelectric accelerometer 1 is accelerated in the upward direction, first, at the time when the base housing 11 is accelerated in the upward direction, the first forward piezoelectric charge is generated by the inertia of the mass body 12. Forces in different directions are applied to the sensor 1311 and the first reverse piezoelectric sensor 1312, respectively.

Specifically, in the case of the first positive piezoelectric sensor 1311 located on the lower side of the mass body 12, the distance between the mass body 12 to maintain a stationary state and the inner wall of the base housing 11 facing downward is reduced. Accordingly, a compressive force is applied to the first forward piezoelectric sensor 1311, while the first reverse piezoelectric sensor 1312 located on the upper side of the mass body 12 faces upwardly to the mass body 12 to maintain a stationary state. As the distance between the inner walls of the viewing base housing 11 increases, a tensile force may be applied to the first reverse piezoelectric sensor 1312 .

Therefore, although forces are applied in opposite directions to each of the first forward piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312, their respective poling directions are opposite to each other, resulting in voltages in the same direction as each other. can form

Referring to FIG. 4B , when the highly sensitive compressive piezoelectric accelerometer 1 is accelerated in another direction (downward direction in the drawing) based on the first axis direction, a first forward piezoelectric sensor 1311 and a first reverse piezoelectric sensor ( 1312) It is possible to check the force applied to each and the direction and magnitude of the voltage formed.

As shown in FIG. 4B, when the high-sensitivity compressive piezoelectric accelerometer 1 is accelerated in the downward direction, first, at the time when the base housing 11 is accelerated in the downward direction, the first forward piezoelectric charge is generated by the inertia of the mass body 12. A tensile force may be applied to the sensor 1311, and a compressive force may be applied to the first reverse piezoelectric sensor 1312.

Specifically, in the case of the first positive piezoelectric sensor 1311 located on the lower side of the mass body 12, the distance between the mass body 12 to maintain a stationary state and the inner wall of the base housing 11 facing downward increases. Accordingly, a tensile force is applied to the first positive piezoelectric sensor 1311, while the first reverse piezoelectric sensor 1312 located on the upper side of the mass body 12 faces upwardly to the mass body 12 to maintain a stationary state. As the distance between the inner walls of the viewing base housing 11 is reduced, a compressive force may be applied to the first reverse piezoelectric sensor 1312 .

As in FIG. 4A , forces in opposite directions are applied to the first forward piezoelectric sensor 1311 and the first reverse piezoelectric sensor 1312, but as their respective poling directions are opposite to each other, consequently in the same direction as each other. of voltage can be formed.

According to the above structure, the magnitude of the voltage measured from the controller 14 by acceleration is amplified by symmetrically connecting the piezoelectric sensors 1311 and 1312 formed in opposite poling directions to the mass body 12 in series along the axial direction. As a result, the sensitivity and resolving power of the highly sensitive compression type piezoelectric accelerometer 1 can be greatly increased.

Meanwhile, when deformation of the base housing 11 occurs, such as compression or tension of the base housing 11, the compression force or tensile force applied to the base housing 11 is applied to the first positive piezoelectric sensor 1311 and the first reverse direction. Although applied in the same direction to each of the piezoelectric sensors 1312, as the directions of the voltages formed from each are opposite to each other, as a result, the signals of the voltages formed in each of the piezoelectric sensors 1311 and 1312 are canceled so that the corresponding base housing The noise signal by the modification of (11) can be effectively attenuated.

As shown in FIG. 5 , when a compressive force in the first axial direction is generated in the base housing 11 and deformation due to compression occurs, the first positive piezoelectric sensor 1311 formed in opposite pole directions to the first piezoelectric sensor 1311 and the first According to the connection structure of the reverse piezoelectric sensor 1312, each of the piezoelectric sensors 1311 and 1312 receives the same compression force, but the directions of the voltage are formed in opposite directions, and as a result, the deformation of the base housing 11 Signals formed by the pair of piezoelectric sensors 1311 and 1312 caused by the signal may cancel each other's signals.

According to the structure described above, in the case of conventional accelerometers, unlike the case of leaving an empty space between the housing and the internal structure to prevent the generation of signals due to deformation of the housing, the design of the highly sensitive compression-type piezoelectric accelerometer 1 according to an embodiment In the case of piezoelectric sensors 131 , 132 , and 133 , it is possible to increase sensitivity through symmetrical arrangement and at the same time reduce a signal caused by deformation of the base housing 11 .

In addition, since the signal according to the deformation of the base housing 11 is canceled, the base housing 11 itself can be used as a base, which requires a wasted space between the base or the base housing and the internal structure. means no

According to the compression-type piezoelectric accelerometer 1 according to an embodiment, the mass body 12 and the piezoelectric sensor elements 1311, 1312, 1321, 1322, 1331, and 1332 can be processed and used in a simple hexahedron shape, so that design and Not only can the manufacturing process be simplified, but the design such as the desired sensitivity and operating frequency band can be easily achieved by simply changing the size of the mass body 12 and the piezoelectric sensor elements 1311, 1312, 1321, 1322, 1331, and 1332. It may also be easy to change the conditions.

According to the high-sensitivity compression-type piezoelectric accelerometer 1 according to an embodiment, unlike the design of a conventional compression-type piezoelectric accelerometer assembled by penetrating bolts in the axial direction, three axial-direction accelerometers are Since the preload can be applied, there is no need to process separate bolt holes in the piezoelectric sensor elements (1311, 1312, 1321, 1322, 1331, 1332) or the mass body 12, thereby reducing manufacturing time and cost, Through this, damage to the piezoelectric element can be reduced during assembly and preparation, and greater sensitivity can be obtained compared to sensors of the same volume.

According to the high-sensitivity compression-type piezoelectric accelerometer 1 according to an embodiment, the piezoelectric sensor elements 1311, 1312, 1321, 1322, 1331, and 1332 can be processed and used in a simple hexahedron shape, so that the piezoelectric sensor has excellent sensitivity characteristics. There is an advantage of using single crystal material with minimal processing, and in addition, cost reduction and delivery time reduction effect due to process simplification, yield improvement and assemblyability improvement are possible, and in terms of sensor performance, there is an advantage of increased sensitivity to volume. You can get it.

According to the highly sensitive compression-type piezoelectric accelerometer 1 according to an embodiment, the mass body 12 corresponding to the seismic mass at the center is measured by using the piezoelectric sensors 131, 132, and 133 along three axial directions, that is, in six directions. Through the supporting design, there is an effect of reducing lateral sensitivity that may occur when the mass body 12 is bent in the vertical direction of the vibration direction.

6 is a diagram showing the structure of a high-sensitivity compression-type piezoelectric accelerometer according to an embodiment.

Referring to FIG. 6 , the configuration of a highly sensitive compressive piezoelectric accelerometer 2 having a connection structure of a piezoelectric sensor different from that of the highly sensitive compressible piezoelectric accelerometer 1 of the exemplary embodiment shown in FIGS. 1 to 5 can be confirmed. The high-sensitivity compression-type piezoelectric accelerometer 2 according to the example may include a base housing 21, a mass body 22, a first sensor unit 23, and a control unit 24.

For example, the high-sensitivity compression-type piezoelectric accelerometer 2 includes a second sensor unit (not shown) to measure accelerations excited from each of three mutually orthogonal axes (eg, x-axis, y-axis, and z-axis); It may include a third sensor unit (not shown), and it is revealed that the configuration of the embodiment for measuring multi-axis acceleration can be achieved by extending/applying the configuration of the first sensor unit 23 to be described later to other axes. put

The first sensor unit 23 according to an embodiment includes a piezoelectric sensor element connected between the mass body 22 and the base housing 21 on one side with respect to a first axis, and the mass body 22 and the base on the other side opposite to the piezoelectric sensor element. It may be a configuration of a pair of piezoelectric sensor elements including a piezoelectric sensor element connected between the housing 21 .

In contrast to the fact that the pair of piezoelectric sensors 1311 and 1312 of the first sensor unit 13 of the exemplary embodiment shown in FIGS. 1 to 5 have opposite polaring directions along the axial direction, the first sensor unit 13 according to the exemplary embodiment The sensor unit 23 is installed to have the same poling direction along the first axis direction, and each of the pair of piezoelectric sensor elements is connected so that the terminal positions of the poles connected to the control unit 22 are opposite to each other can have a configuration.

As shown in FIG. 6, the first sensor unit 23, that is, the piezoelectric sensor element 23 connected to the control unit 22 first relative to the direction of the current among the pair of piezoelectric sensor elements 23 They are connected in series along one direction, and then the other piezoelectric sensor element 23 may have a configuration in which they are connected in series along the other direction opposite to that.

According to the high-sensitivity compression-type piezoelectric accelerometer 2 according to an embodiment, like the high-sensitivity compression-type piezoelectric accelerometer 1 of the embodiment shown in FIGS. 1 to 5, the polaring directions of a pair of facing piezoelectric sensor elements are opposite to each other. Rather than being installed so that each of the pair of piezoelectric sensor elements 23 facing each other is installed so that only the directions of poles that are energized in series to the control unit 22 are opposite to each other, the highly sensitive compression type piezoelectric according to the above-described embodiment. The same characteristics and effects of the accelerometer 1 can be achieved.

As described above, in the embodiments, the embodiments have been described by specific details such as specific components, limited embodiments, and drawings, but these are provided to help overall understanding. In addition, the present invention is not limited to the above-described embodiments, and various modifications and variations can be made from these descriptions by those skilled in the art. Therefore, the spirit of the present invention should not be limited to the above-described embodiments and should not be determined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later belong to the scope of the present invention.

Claims (13)

a base housing having an inner space;
a mass body disposed in the inner space while being spaced apart from an inner wall of the inner space;
a first sensor unit including a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along a first axial direction;
a second sensor unit including a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along a second axis direction orthogonal to the first axis;
a third sensor unit including a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along a third axis direction orthogonal to the first axis and the second axis; and
A control unit for measuring the acceleration in the first axis direction based on the voltage measured by the pair of piezoelectric sensors of the first sensor unit;
Each of the first sensor unit, the second sensor unit, and the third sensor unit includes a forward piezoelectric sensor and a reverse piezoelectric sensor symmetrically arranged in series with respect to the mass body,
The forward piezoelectric sensor and the reverse piezoelectric sensor of each of the first sensor unit, the second sensor unit, and the third sensor unit are highly sensitive compression-type piezoelectric accelerometers, characterized in that their respective poling directions are formed in opposite directions to each other. .
According to claim 1,
The first sensor unit,
a first positive piezoelectric sensor connected between the mass body and an inner wall of the base housing at one side with respect to the first axis; and
A first reverse piezoelectric sensor connected between the mass body and an inner wall of the base housing on the other side with respect to the first axis; includes,
The first forward piezoelectric sensor and the first reverse piezoelectric sensor are each formed with a falling direction opposite to each other, a highly sensitive compressive piezoelectric accelerometer.
According to claim 2,
When the base housing is accelerated along the first axial direction, a compressive force is applied to one of the first forward piezoelectric sensor and the first reverse piezoelectric sensor and a tensile force is applied to the other piezoelectric sensor. However, the direction of the voltage generated by the first forward piezoelectric sensor and the first reverse piezoelectric sensor are the same, characterized in that, a highly sensitive compression type piezoelectric accelerometer.
According to claim 3,
The first forward piezoelectric sensor and the first reverse piezoelectric sensor,
A high-sensitivity compression-type piezoelectric accelerometer, characterized in that it has a hexahedral shape with opposite sides along the first axis.
According to claim 2,
When the base housing is deformed along the first axial direction by an external force, the direction of the force applied to the first forward piezoelectric sensor and the first reverse piezoelectric sensor is the same, but the first forward piezoelectric sensor and the first piezoelectric sensor A highly sensitive compressive piezoelectric accelerometer, characterized in that directions of voltages generated by the reverse piezoelectric sensor are opposite to each other.
a base housing having an inner space;
a mass body disposed in the inner space while being spaced apart from an inner wall of the inner space;
a first sensor unit including a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along a first axial direction; and
A control unit for measuring the acceleration in the first axis direction based on the voltage measured by the pair of piezoelectric sensors of the first sensor unit;
The first sensor unit,
a first positive piezoelectric sensor connected between the mass body and an inner wall of the base housing at one side with respect to the first axis;
a first reverse piezoelectric sensor connected between the mass body and an inner wall of the base housing at the other side with respect to the first axis; and
a first pressing bolt fastened to press the first forward piezoelectric sensor or the first reverse piezoelectric sensor by screwing into the base housing along the first axial direction to apply a preload to the pair of piezoelectric sensors; including,
The first forward piezoelectric sensor and the first reverse piezoelectric sensor are each formed with a falling direction opposite to each other, a highly sensitive compressive piezoelectric accelerometer.
According to claim 6,
The first pressure bolt,
One side protrudes into the inner space of the base housing along the first axis direction, and the other side is formed of a headless bolt screwed together without a protruding part from the outside of the base housing.
delete According to claim 1,
Each of the first sensor unit, the second sensor unit, and the third sensor unit,
A high-sensitivity compression-type piezoelectric accelerometer further comprising a pressure bolt screwed into the base housing to press each of the forward piezoelectric sensor or the reverse piezoelectric sensor to press each of the forward piezoelectric sensor or the reverse piezoelectric sensor. .
According to claim 1,
A highly sensitive compression type piezoelectric accelerometer, characterized in that the center of gravity of each of the first axis, the second axis and the third axis is the same.
According to claim 10,
The mass body and the inner space,
A high-sensitivity compression-type piezoelectric accelerometer, characterized in that it has a regular hexahedral shape composed of surfaces facing each of the first axis, the second axis and the third axis.
delete a base housing having an inner space;
a mass body disposed in the inner space while being spaced apart from an inner wall of the inner space;
a first sensor unit including a pair of piezoelectric sensors installed between an inner wall of the inner space and both sides of the mass body along a first axial direction;
a control unit measuring an acceleration in the first axis direction based on a voltage measured by the pair of piezoelectric sensors of the first sensor unit;
a second sensor unit including a pair of piezoelectric sensors installed between the inner wall of the inner space and both sides of the mass body along a second axis direction orthogonal to the first axis and connected in series to the control unit; and
A pair of piezoelectric sensors installed between the inner wall of the inner space and both sides of the mass body along a third axis direction orthogonal to the first axis and the second axis and connected in series to the controller A third sensor unit; including,
The first sensor unit,
a first positive piezoelectric sensor connected between the mass body and an inner wall of the base housing at one side with respect to the first axis; and
A first reverse piezoelectric sensor connected between the mass body and an inner wall of the base housing on the other side with respect to the first axis; includes,
Each of the first sensor unit, the second sensor unit, and the third sensor unit,
A high-sensitivity compression-type piezoelectric accelerometer, characterized in that directions in which each of the pair of piezoelectric element sensors are energized from the control unit along each of the first axis, the second axis, and the third axis are opposite to each other.

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