KR101393593B1 - Strain gauge sensor, strain gauge sensor structure and manufacturing method thereof - Google Patents

Abstract

A deformation measuring sensor, a structure thereof, and a manufacturing method of the present invention are a plurality of beams formed in parallel to each other and spaced apart from each other and connected to both ends of the beam so as to surround a plurality of beams and have a relatively thicker thickness than a plurality of beams, And a strain gauge attached to the beam for measuring the strain. The strain gauge can accurately measure a strain according to a pressure or a shearing force applied to a plurality of points, Each can be grasped accurately.

Description

Technical Field [0001] The present invention relates to a strain gauge sensor, a strain gauge sensor structure and a manufacturing method thereof,

The present invention relates to a deformation measuring technique, and more particularly to a deformation measuring method and a deformation measuring method in which a deformation at a plurality of points is measured more precisely, , A structure thereof, and a manufacturing method thereof.

A pressure sensor is a device that measures pressure in a specific system, and is widely used for various applications such as industrial measurement, automatic control, medical, automotive engineer, environmental control, and electric appliances. The measurement principle of a pressure sensor is to measure an electrical change due to displacement, deformation, etc., and various types of sensors are put into practical use.

Types of pressure sensors include mechanical pressure sensors using bellows or bellows, pressure resistive electronic pressure sensors using strain gauges, and capacitive electronic pressure sensors measuring the displacement of capacitances between two objects. In particular, piezoresistive sensors using strain gauges are the most popular in terms of performance and price.

Strain refers to the degree of deformation or strain, which is the ratio of the length of an object stretched or shrunk to its original length when stretched or compressed. In the field of dealing with element analysis, it is a term used when a structure or a mechanical element receives external force and deformation occurs. A strain gauge is a gauge attached to the surface of a structure to measure the state and amount of the strain due to such strain. An electric strain gauge measures the strain of the structure by varying the resistance, There are mechanical strain gauges that measure mechanically.

An electric strain gage device uses a metal with a large resistance change. When a metal having a large resistance change is used, resistance is measured by forming a resistance wire in the form of a wire or a foil on an insulator.

Sensors equipped with such strain gauges prevent malfunctions or safety accidents of machines and the like, and enable the user to quickly recognize and respond to an unexpected situation. Also, the smaller the volume of such a sensor, the less influence on other driving parts and the better the space efficiency.

Therefore, a sensor that is small in size and easy to fabricate and capable of precisely detecting deformation due to pressure or the like is required.

It is an object of the present invention to solve the above problems and to provide a method and apparatus for accurately measuring deformation due to a pressure or a shearing force and accurately detecting deformation due to pressure or shearing force at a specific point, A structure and a manufacturing method thereof.

According to an aspect of the present invention, there is provided a deformation measuring sensor including a plurality of beams spaced apart from each other, a plurality of beams connected to both ends of the beam so as to surround the plurality of beams, A frame having an interference preventing groove in the longitudinal direction of the beam; And a strain gauge attached to the beam to measure the strain of the beam.

In the deformation measuring sensor of the present invention, the interference preventing groove may be formed at a portion corresponding to both ends of the beam connected to the frame, or may be formed to be offset from both ends of the beam.

In the deformation measuring sensor of the present invention, the minimum thickness of the portion where the interference preventing groove is located in the frame matches the thickness of the beam.

In the deformation measuring sensor of the present invention, the interference preventing groove may be formed in a U shape, a V shape, or a C shape.

In the strain measuring sensor of the present invention, the interference preventing groove is used as a wiring groove of the strain gage.

In the deformation measuring sensor of the present invention, the beam may be a prismatic column, a cylinder, a pyramid cut at a tip, a column having a thinner thickness than the other portions at both ends, a column having a thicker thickness than the other portions, Characterized in that at least one of the columns has a shape of at least one of the pillars.

In the strain measuring sensor of the present invention, the strain gage is attached to at least one of the upper surface, the lower surface, and both sides of the beam.

The deformation measuring sensor of the present invention is characterized in that the frame or the beam is made of steel, nickel-chrome-molybdenum steel, stainless steel, tool steel, hardened stainless steel, aluminum alloy or duralumin.

The strain measuring sensor of the present invention further includes a signal processing module for processing a signal according to the strain measured by the strain gage.

In the strain measuring sensor of the present invention, the signal processing module may include an amplifier for amplifying a signal transmitted from the strain gauge, a signal processor for digitizing a signal transmitted by the amplifier, and a controller for adjusting the offset of the semiconductor strain gages And an offset adjustment unit.

According to an aspect of the present invention, there is provided a strain gauge sensor structure including a plurality of beams spaced apart from each other to form a strain gauge for strain measurement, and a plurality of beams attached to both ends of the beam, And a frame having a thickness larger than that of the upper beam and having an interference preventing groove in the longitudinal direction of the beam.

In the deformation measuring sensor structure of the present invention, the interference preventing groove may be formed at a portion corresponding to both ends of the beam connected to the frame, or may be formed to be offset from both ends of the beam.

In the deformation measuring sensor structure of the present invention, the minimum thickness of the portion where the interference preventing groove is located in the frame matches the thickness of the beam.

In the deformation measuring sensor structure of the present invention, the interference preventing groove may be formed in a U shape, a V shape, or a C shape.

According to another aspect of the present invention, there is provided a method of manufacturing a strain sensor including a plurality of beams spaced longitudinally apart from each other in a longitudinal direction and spaced apart from each other, Forming a frame having a shape that wraps the plurality of beams and is thicker than the beam, forming an interference preventing groove in the frame in the longitudinal direction of the beam, and forming an upper surface, a lower surface, And attaching a strain gauge to at least one of the sides.

According to the deformation measuring sensor, the structure and the manufacturing method of the present invention, the following effects can be expected.

First, it is possible to precisely measure the strain due to the pressure or shear force applied to a plurality of points, and accurately grasp each point where deformation occurs.

Second, when deformation due to pressure or shear force occurs at a specific point, interference at other points is significantly prevented.

Third, by adopting the support beam type deformation structure, the deformation structure is largely deformed with respect to a relatively small pressure or shearing force. Accordingly, the deformation structure can be made small, thereby reducing the overall size of the sensor.

1 is a perspective view of a strain sensor according to a first embodiment of the present invention.
2 is a bottom perspective view of a strain sensor according to a first embodiment of the present invention.
3 is a plan view of a strain sensor according to a first embodiment of the present invention.
4 is a front view of a strain sensor according to a first embodiment of the present invention.
5 is a configuration diagram of a strain sensor according to a second embodiment of the present invention.
6 is a configuration diagram of a signal processing module according to a second embodiment of the present invention.
7 is a flowchart illustrating a method of manufacturing a deformation measuring sensor according to an embodiment of the present invention.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, and the description of other parts will be omitted so as not to obscure the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a bottom perspective view of a deformation measuring sensor 100 according to a first embodiment of the present invention. FIG. 3 is a perspective view of the deformation measuring sensor 100 according to the first embodiment of the present invention. 4 is a front view of a deformation measuring sensor 100 according to the first embodiment of the present invention. FIG. 4 is a front view of the deformation measuring sensor 100 according to the first embodiment of the present invention.

1 to 4, a strain measurement sensor 100 of the first embodiment includes a frame 110, a plurality of beams 120, and a strain gauge 130. [

The frame 110 has a space penetrating the center of the frame 110 to surround the plurality of beams 120 and is thicker than the plurality of beams 120.

The plurality of beams 120 are formed in a support beam shape with a space 121 opened in a perforated shape of the frame 110 as a deformation structure depending on a pressure or a shearing force. At this time, each of the plurality of beams 120 is spaced apart from one another. The plurality of beams 120 are relatively thinner than the frame 110, so that it is easy to deform due to pressure or shear force.

A strain gauge 130 is attached to the plurality of beams 120 to measure the strain of each of the beams 120.

In the deformation measuring sensor 100 of the first embodiment, the frame 110 has the interference preventing grooves 111 in the longitudinal direction of the beam 120. [ In the deformation measuring sensor 100, the interference preventing groove 111 is located on the bottom surface of the frame 110.

For example, when the deformation measuring sensor 100 is applied with a vertical direction pressure in the Y-axis direction or a horizontal direction shearing force in the X-axis direction, not only the stressed beam 120 but also the other beam 120 is stretched or compressed An interference phenomenon occurs in which a deformation occurs due to the deformation. If a pressure or a shearing force is applied to a plurality of points in the deformation measuring sensor 100, it is difficult to precisely know to which beam 120 the pressure or shearing force is applied due to such interference.

The frame 110 of the first embodiment is provided with an interference preventing groove 111 in the longitudinal direction of the beam 120 so that when pressure or shearing force is applied to the specific beam 120, . This makes it possible to accurately grasp the point where the pressure or shearing force is applied, and to grasp each of a plurality of points when a plurality of pressures or shearing forces are applied.

The interference preventing grooves 111 may be formed in the longitudinal direction of the beam 120 at portions corresponding to both ends of the beam 120 connected to the frame 110 as shown in FIGS. 1 to 4, 120 in the longitudinal direction of the beam 120 so as to be staggered.

1 to 4, the interference preventing groove 111 has a shape of 'C'. The interference preventing groove 111 of the present invention may have a shape such as' U 'shape,' V 'shape or' May be formed in various shapes to minimize the interference due to tension or compression between the back beam 120 and the back beam 120.

At this time, the minimum thickness of the frame 110 in which the interference prevention groove 111 is located may coincide with the thickness of the beam 120. If the interference prevention groove 111 has a U shape, a portion where the thickness of the frame 110 becomes the minimum, such as a central portion of the curved surface, may be equal to the thickness of the beam 120. This also applies to other shapes that the interference prevention groove 111 can take such as a 'V' shape or a 'C' shape. This means that the thickness of the beam 120 of the deformation measuring sensor 100 is relatively thinner than the general thickness of the frame 110, thereby increasing strain due to pressure or shearing force and reducing interference.

In the deformation measuring sensor 100, since both ends of the beam 120 are connected to the frame 110, the strain according to the pressure is greatest at the center thereof. Accordingly, it is preferable that the measurement center of the strain gage 130 is positioned at the center of each beam 120. [

When the strain gauge 130 is located on the upper surface or the lower surface of the beam 120, the strain according to the pressure in the vertical direction in the Y-axis direction is measured. The strain according to the shear force in the horizontal direction which is the X-axis direction is measured.

In the deformation measuring sensor 100, the beam 120 is a prismatic prism, a prismatic prism, a prismatic prism cut at the end, a prismatic pole with a thinner thickness than the other prismatic portion, A pillar having one or more gradient shapes in the longitudinal direction, and the like.

The wiring 131 for transmitting the signal measured by the strain gage 130 is connected to the rear surface or the inside of the substrate through a hole for wiring located in the frame 110 or a rim of the frame 110, Of the conductor circuit. At this time, the interference preventing groove 111 may be used as a wiring groove of the strain gauge 130.

In the deformation measuring sensor 100 of the first embodiment, the plurality of beams 120 are located apart from each other and have both ends connected to the frame 110. As a result, the strain due to the pressure or shear force becomes relatively larger than that in the case where the strain gauge is attached to a conventional planar substrate to measure the strain. Therefore, in the deformation measuring sensor 100, the beam 120, which is a deformation structure depending on the pressure or the shearing force, can be made compact, thereby reducing the overall size of the deformation measuring sensor 100.

When a strain gauge is placed on a planar substrate as in the prior art to measure strain according to pressure, the strain due to pressure is not large as a whole, resulting in poor measurement accuracy. In addition, it is difficult to measure the pressure at a multi-point because it is advantageous to measure the strain at the edge of the substrate while the strain is relatively large at the center of the substrate and the strain gauge is located at the center of the substrate.

In contrast, since the deformation measuring sensor 100 of the first embodiment has a plurality of beams 120, the strain of each beam 120, which is prevented from interference, is compared to determine the pressure or shear force Can be detected. That is, in the deformation measuring sensor 100, the strain according to the pressure applied to a plurality of points or the shear force can be accurately measured, and the strain measuring performance of the strain gage 130 located at the center of each beam 120 is relatively uniform .

In the deformation measuring sensor 100, the frame 110 or the beam 120 may be made of a material such as steel, nickel-chrome-molybdenum steel, stainless steel, tool steel, hardened stainless steel, aluminum alloy or duralumin, It is possible to adopt various materials depending on the material properties.

FIG. 5 is a configuration diagram of a strain measuring sensor 200 according to a second embodiment of the present invention, and FIG. 6 is a configuration diagram of a signal processing module 140 included in the strain measuring sensor 200 of the present invention.

Referring to FIG. 5, the strain measurement sensor 200 includes a frame 110, a plurality of beams 120, a strain gage 130, and a signal processing module 140.

The frame 110 has a space penetrating the center of the frame 110 to surround the plurality of beams 120. At this time, the interference preventing grooves 111 are positioned on the rear surface of the frame 110 in the longitudinal direction of the beam 120 to prevent interference with other beams 120 due to the pressure or shearing force applied to the specific beams 120 do.

In this case, the interference preventing groove 111 may be formed in a U shape, a V shape, a C shape, or the like, and the interference prevention groove 111 may be formed in a shape corresponding to both ends of the beam 120 connected to the frame 110 And may be formed to be staggered with both ends of the beam 120. [

The plurality of beams 120 are formed in the form of a supporting beam in a perforated shape of the frame 110. At this time, each of the plurality of beams 120 is spaced apart from one another. The beam 120 may be, for example, a prismatic column, a prismatic column, a pyramid with a cut end, a column having a thickness thinner than the other column at both ends, a column having a thicker thickness than the other columns at both ends, It is possible to have various shapes that facilitate strain measurement.

At this time, the thickness of the beam 120 may coincide with the minimum thickness of the frame 110 where the interference prevention groove 111 is located.

The frame 110 or the beam 120 may be made of steel, nickel-chromium-molybdenum steel, stainless steel, tool steel, hardened stainless steel, aluminum alloy, or duralumin in consideration of physical properties.

The strain gauge 130 is located in a plurality of beams 120 to measure the strain of each of the beams 120. At this time, the strain gauge 130 is located on at least one of the upper surface, the lower surface, or both sides of the beam 120, and measures the strain according to the pressure or shear force.

The wiring 131 of the strain gauge 130 is connected to the conductor circuit on the backside or inside of the substrate through the wiring hole 132. At this time, the interference prevention groove 111 can function as a passage for the wiring 131 which has passed through the wiring hole 132.

The signal processing module 140 is a structure for processing the signal of the strain gage 130.

The signal processing module 140 in the deformation measuring sensor 200 of the second embodiment is on the same substrate as the deformation measuring sensor 200 and detects the strain measuring signal measured by the strain gage 130 through the conductor circuit of the substrate Receive. The configuration of the deformation measuring sensor 200 located on a single substrate facilitates the fabrication of the deformation measuring sensor 200 including the signal processing module 140.

Referring to FIG. 6, the signal processing module 140 includes an amplification unit 141, a signal processing unit 142, and an offset adjustment unit 143.

The amplifying unit 141 amplifies the signal of the strain gage 130 formed of a thin film semiconductor or the like, thereby amplifying the signal of the strain gage 130 to such an extent that it can properly analyze it. The amplified signal is transmitted to the signal processing unit 142 or the offset adjustment unit 143.

The signal processing unit 142 receives the amplified signal from the amplifying unit 141 and digitizes it. That is, when the strain gauge 130 transmits the sensing information, the signal processing unit 142 may digitize the sensing information to control the pressure generated in the plurality of beams 120 to be numerical values.

The offset adjustment unit 143 is configured to process the sensing information offset of the strain gage 130. [ For example, a strain gage 130 of a thin film semiconductor type may experience deformation in the course of attaching to a plurality of beams 120. Thus, the strain gage 130 performs resistance sensing in the absence of pressure, and the offset adjustment unit supports initialization according to the result of the sensing. This process improves the measurement error when measuring strain due to pressure.

7 is a flowchart illustrating a method of manufacturing a deformation measuring sensor according to an embodiment of the present invention.

Referring to FIG. 7, first, a plurality of beams and a frame forming a structure of the deformation measuring sensor are formed (S10).

In this case, the plurality of beams and frames may be made of steel, nickel-chrome-molybdenum steel, stainless steel, tool steel, hardened stainless steel, aluminum alloy, duralumin or the like in consideration of physical properties.

In step S10, for example, a plurality of beams and a frame, which are divided based on the space, may be formed by piercing the through space spaced apart from the planar material. It is also possible to form a plurality of beams and frames by shaping, wherein the plurality of beams are prisms, cylinders, pyramids with cut ends, columns with thinner thickness at the opposite ends, The shape of at least one of the columns and the columns having one or more gradient shapes in the longitudinal direction can be made to facilitate the strain measurement.

At this time, the plurality of beams are relatively thin in thickness than the frame, so that deformation due to pressure or shear force is relatively easy.

Thereafter, interference preventing grooves formed in the longitudinal direction of the beam are formed in the frame (S20).

For example, the interference preventing groove may be formed together with the frame when the frame is formed, and may be formed by cutting the processed frame.

The interference preventing groove minimizes the occurrence of deformation due to the interference of other beams when a specific beam is applied to a specific beam. The interference preventing groove may be formed at a portion corresponding to both ends of the beam connected to the frame, As shown in FIG.

In this case, the interference preventing groove may be formed in a U shape, a V shape, or a C shape, and the minimum thickness of the portion where the interference preventing groove is located in the frame may match the thickness of the beam .

The strain gage is attached to at least one of the upper surface, the lower surface, or both sides of the beam, which is the deformation structure (S30).

When a strain gauge is attached to the upper or lower surface of the beam, the strain according to the pressure in the vertical direction can be measured. When the strain gauge is attached to the side, the strain according to the shear force in the horizontal direction can be measured.

At this time, the interference preventing groove prevents the other beam from being deformed due to the interference when a pressure or a shearing force is applied to the specific beam.

It should be noted that the embodiments disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100, 200: strain sensor
110: frame
111: interference prevention groove
120: beam
121: Space
130: Strain gauge
131: Wiring
132: wiring hole
140: Signal processing module
141:
142:
143:

Claims (15)

A plurality of beams spaced apart from each other;
A frame connected to both ends of the beam to surround the plurality of beams and thicker than the beam and having an interference preventing groove in the longitudinal direction of the beam; And
A strain gauge attached to the beam to measure a strain of the beam;
Lt; / RTI >
Wherein the interference preventing groove is formed in a portion corresponding to both ends of the beam connected to the frame or is formed so as to be staggered with both ends of the beam. delete The method according to claim 1,
Wherein the minimum thickness of the portion where the interference preventing groove is located in the frame matches the thickness of the beam. The method according to claim 1,
Wherein the interference preventing groove is formed in a U shape, a V shape, or a C shape. The method according to claim 1,
And the interference preventing groove is used as a wiring groove of the strain gage. The method according to claim 1,
Wherein the beam has at least one of a prismatic shape, a cylindrical shape, a prismatic prism with a cut end, a column with a thinner thickness than the other portions at both ends, a thicker column at both ends than the other portions, and a column having at least one gradient shape in the longitudinal direction Features a deformation measuring sensor. The method according to claim 1,
Wherein the strain gauge is attached to at least one of a top surface, a bottom surface, and both sides of the beam. The method according to claim 1,
Wherein the frame or the beam is made of steel, nickel-chrome-molybdenum steel, stainless steel, tool steel, hardened stainless steel, aluminum alloy or duralumin. The method according to claim 1,
A signal processing module for processing a signal according to a strain measured by the strain gauge;
Further comprising a sensor for detecting the deformation of the sensor. 10. The method of claim 9,
The signal processing module
An amplifying unit for amplifying a signal transmitted from the strain gauge;
A signal processing unit for digitizing a signal transmitted by the amplifying unit; And
An offset adjusting unit for adjusting the offset of the semiconductor strain gages;
Wherein the sensor comprises at least one of a sensor and a sensor. A plurality of beams spaced apart from one another so as to form strain gauges for strain measurement; And
A frame attached to both ends of the beam to surround the plurality of beams, thicker than the upper beam, and having a groove for preventing interference in the longitudinal direction of the beam;
/ RTI >
Wherein the interference preventing groove is formed in a portion corresponding to both ends of the beam connected to the frame or is formed to be staggered with both ends of the beam. delete 12. The method of claim 11,
Wherein the minimum thickness of the portion where the interference preventing groove is located in the frame matches the thickness of the beam. 12. The method of claim 11,
Wherein the interference preventing groove is formed in a U shape, a V shape, or a C shape. A plurality of beams spaced apart from each other and spaced apart from each other in a longitudinally spaced apart space in a planar structure and a frame connected to both ends of the beam to surround the plurality of beams and thicker than the beam, ;
Forming an interference preventing groove in the frame in the longitudinal direction of the beam; And
Attaching a strain gauge to at least one of an upper surface, a lower surface and both sides of the beam;
Lt; / RTI >
Wherein the interference preventing groove is formed in a portion corresponding to both ends of the beam connected to the frame or is formed to be offset from both ends of the beam in the step of forming the interference preventing groove.

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