A miniature strain gauge

Abstract

The present application relates to a micro strain gauge, comprising an elastic component, a housing, a steel string and a signal line; the elastic component is arranged inside the housing; one end of the signal line is connected to the first end of the elastic component through the first end of the housing, and the other end is used to connect to the target acquisition device; the elastic component comprises a first end block, a second end block, a capillary support, a coil, a magnet and an elastic structure; the first end of the capillary support is fixedly connected to the first end block, and the second end of the capillary support is connected to the second end block through the elastic structure; the coil is fixed on the wall of the housing; the magnet is fixed in the through hole in the middle of the coil; the coil is connected to the signal line; the steel string is arranged inside the elastic component along the central axis of the elastic component, the first end is connected to the first end block, and the second end is connected to the second end block. In this way, the size and weight of the micro strain gauge are greatly reduced, the accuracy of the measurement results is guaranteed, and monitoring convenience is provided for more application scenarios.

Description

Technical Field

[0001] The present application relates to the technical field of engineering safety monitoring instruments, and in particular to a micro strain gauge. Background Art

[0002] Vibrating-wire strain gauge is a strain gauge that uses the vibrating-wire principle to measure. Its advantages are simple structure, long-term stable operation, and output signal as a standard frequency signal, which is very convenient for computer processing. Vibrating-wire strain gauge can be used for strain monitoring in scenes such as roads and bridges, water conservancy and hydropower, urban buildings and tunnels.

[0003] In the related technology, the traditional vibrating-wire strain gauge has large dimensions and heavy weight. It is not convenient to install and use when strain monitoring is performed in scenes such as deformation of the arch, deformation of the bottom of the bridge deck, and in narrow spaces. In addition, due to the heavy weight of the vibrating-wire strain gauge, after the arch and the bottom of the bridge deck are bonded, the colloid gap caused by the deadweight becomes larger and larger over time, thus affecting the measurement signal and reducing the accuracy of the measurement result. Summary of the invention

[0004] In view of this, the purpose of the present application is to overcome the deficiencies of the prior art and provide a miniature strain gauge.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] The present application provides a miniature strain gauge, comprising an elastic component, a housing, a steel string and a signal line;

[0007] The elastic component is arranged inside the shell;

[0008] One end of the signal line is connected to the first end of the elastic component through the first end of the housing, and the other end is used to connect to the target acquisition device;

[0009] The elastic component comprises a first end block, a second end block, a capillary support, a coil, a magnet and an elastic structure; the first end of the capillary support is fixedly connected to the first end block, and the second end of the capillary support is connected to the second end block through the elastic structure; the coil is fixed on the wall of the shell; the magnet is fixed in the through hole in the middle of the coil; the coil is connected to the signal line;

[0010] The steel chord is arranged inside the elastic component along the central axis of the elastic component, with a first end connected to the first end block and a second end connected to the second end block;

[0011] When the object under test is deformed, the shell is deformed under force, causing the elastic component to deform. The deformation of the elastic component causes the length of the steel string to change. The change in the length of the steel string causes the vibration frequency signal collected by the coil to change. The coil transmits the collected vibration frequency signal to the target acquisition device through the signal line, so as to realize the strain monitoring of the object under test by the target acquisition device.

[0012] Optionally, the elastic structure includes a fixing component and a spring; the fixing component is fixedly connected to the second end of the capillary support; one end of the spring is connected to the fixing component, and the other end is connected to the second end block.

[0013] Optionally, the fixing assembly includes a threaded tube and a nut.

[0014] Optionally, a threading hole is provided on the second end block, and the lead wire on the coil is connected to the signal wire through the threading hole.

[0015] Optionally, the outer shell includes a first end cover, a second end cover and an outer protective tube; the first end of the outer protective tube is threadedly connected to the first end block; the second end of the outer protective tube is threadedly connected to the second end block; the first end cover is threadedly connected to the first end block; the second end cover is threadedly connected to the second end block, and the first end cover is connected to the first end of the outer protective tube; an expansion joint is arranged between the second end cover and the second end of the outer protective tube.

[0016] Optionally, the housing further comprises a wire outlet seat, which is threadedly connected to the second end cover and is used for connecting the signal line from the outside of the housing to the inside of the housing.

[0017] Optionally, a threaded hole is provided on the first end cover.

[0018] Optionally, a temperature detection element is further included, wherein the temperature detection element is arranged on the capillary support and connected to the signal line, and is used to obtain a temperature signal and output it to the target acquisition device through the signal line.

[0019] Optionally, the coil includes a coil frame and a conducting wire; the conducting wire is wound around the coil frame; and the coil frame is fixed to the inner tube wall of the shell.

[0020] Optionally, the signal line includes a cable.

[0021] The technical solution provided by this application may have the following beneficial effects:

[0022] In the scheme of the present application, a first end block, a second end block, a capillary support, a coil, a magnet and an elastic structure are used to form an elastic component, and a steel string is used to penetrate the elastic component along the central axis of the elastic component, and the first end of the steel string is fixed on the first end block, and the second end is fixed on the second end block. One end of the signal line is connected to the first end of the elastic component, and the other end of the signal line is used to connect the target acquisition device. Based on this, when working, the target acquisition device can be used to power the coil in the elastic component to excite the steel string to vibrate, and the steel string vibration cuts the coil magnetic flux line to generate an induced current, which is then returned to the target acquisition device by the coil. When the object to be measured is deformed, the deformation of the shell of the micro strain gauge will cause the elastic component to deform, and the deformation of the elastic component will cause the length of the steel string running through it to change, which will then cause the vibration frequency of the steel string to change, and the vibration frequency signal sent by the coil to the target acquisition device will change, that is, the induced current collected by the target acquisition device will change, so that the target acquisition device can realize the strain monitoring of the object to be measured. The elastic component is used to replace the original elastic beam structure, avoiding the size limitation of the micro strain gauge caused by the elastic beam structure. A capillary bracket is used and the coil is fixed on the outer shell wall, which greatly reduces the size and weight of the micro strain gauge, ensures the accuracy of the measurement results, and provides monitoring convenience for more application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a schematic diagram of the structure of a micro strain gauge provided in one embodiment of the present application.

[0025] Figure 2 It is a schematic structural diagram of a micro strain gauge provided in another embodiment of the present application.

[0026] Figure 3 It is a schematic structural diagram of a first end cover of a micro strain gauge provided in another embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other implementation methods obtained by ordinary technicians in the field without creative work belong to the scope of protection of the present application.

[0028] See also Figure 1 1 is a schematic diagram of a micro strain gauge provided in an embodiment of the present application. This embodiment provides a micro strain gauge, as shown in the figure, the micro strain gauge may at least include: an elastic component 101, a housing 102, a steel string 103 and a signal line 104.

[0029] The housing 102 includes an elastic component 101 disposed inside.

[0030] One end of the signal line 104 is connected to the first end of the elastic component 101 through the first end of the housing 102 , and the other end is used to connect to the target acquisition device.

[0031] The elastic component 101 includes a first end block 1011, a second end block 1012, a capillary support 1013, a coil 1014, a magnet 1015 and an elastic structure 1016; the first end of the capillary support 1013 is fixedly connected to the first end block 1011, and the second end of the capillary support 1013 is connected to the second end block 1012 through the elastic structure 1016; the coil 1014 is fixed on the inner tube wall of the outer shell 102; the magnet 1015 is fixed in the through hole in the middle of the coil 1014; the coil 1014 is connected to the signal line 104.

[0032] The steel string 103 is disposed inside the elastic component 101 along the central axis of the elastic component 101 , with a first end connected to the first end block 1011 , and a second end connected to the second end block 1012 .

[0033] When the object under test is deformed, the shell 102 is deformed under force, causing the elastic component 101 to deform. The deformation of the elastic component 101 causes the length of the steel string 103 to change. The change in the length of the steel string 103 causes the vibration frequency signal collected by the coil 1014 to change. The coil 1014 transmits the collected vibration frequency signal to the target acquisition device through the signal line 104, so as to realize the strain monitoring of the object under test by the target acquisition device.

[0034] The signal line may be a cable.

[0035] In this embodiment, the elastic component is formed by using the first end block, the second end block, the capillary support, the coil, the magnet and the elastic structure, and the steel string is passed through the elastic component along the central axis of the elastic component, the first end of the steel string is fixed on the first end block, and the second end is fixed on the second end block. One end of the signal line is connected to the first end of the elastic component, and the other end of the signal line is used to connect the target acquisition device. Based on this, when working, the target acquisition device can be used to power the coil in the elastic component to excite the steel string to vibrate, and the steel string vibration cuts the coil magnetic flux line to generate an induced current, which is then returned to the target acquisition device by the coil. When the object to be measured is deformed, the deformation of the shell of the micro strain gauge will cause the elastic component to deform, and the deformation of the elastic component will cause the length of the steel string passing through it to change, which will then cause the vibration frequency of the steel string to change, and the vibration frequency signal sent by the coil to the target acquisition device will change, that is, the induced current collected by the target acquisition device will change, so that the target acquisition device can realize the strain monitoring of the object to be measured. The elastic component is used to replace the original elastic beam structure, avoiding the size limitation of the micro strain gauge caused by the elastic beam structure. A capillary bracket is used and the coil is fixed on the outer shell wall, which greatly reduces the size and weight of the micro strain gauge, ensures the accuracy of the measurement results, and provides monitoring convenience for more application scenarios.

[0036] In a specific implementation, when the steel string 103 is arranged inside the elastic component 101 along the central axis of the elastic component 101, the steel string 103 can be tightened, and the two ends of the steel string 103 can be respectively fixed on the first end block 1011 and the second end block 1012 using set screws, so that the steel string 103 can pass through the middle of the first end block 1011, the capillary support 1013, the elastic component 1014 and the second end block 1012.

[0037] In some embodiments, in order to ensure that when the object under test is deformed, the micro strain gauge can accurately feedback the measurement signal, such as Figure 2 As shown, the elastic structure 1016 of the micro strain gauge may include a fixing component 10161 and a spring 10162. The fixing component 10161 may be fixedly connected to the second end of the capillary support 1013, and the first end of the spring 10162 is connected to the fixing component 10161, and the other end is connected to the second end block 1012.

[0038] After the fixing assembly 10161 is fixed to the second end of the capillary support 1013, the capillary support 1013 and the second end block 1012 are not in direct contact, but are connected by the spring 10162, leaving an elastic gap between them. In this way, when the micro strain gauge is squeezed by an external force, the spring 10162 is also squeezed, causing its length to change, that is, the distance between the capillary support 1013 and the second end block 1012 changes, that is, the length of the steel string 103 running therethrough also changes, thus laying a foundation for the precise measurement of the micro strain gauge.

[0039] When the fixing component 10161 is used to fix the spring 10162 so that an elastic gap is left between the capillary support 1013 and the second end block 1012, the fixing component 10161 can be a threaded tube and a nut.

[0040] In some embodiments, in order to facilitate the connection between the coil and the signal line, such as Figure 2 As shown, a threading hole 10121 may be provided on the second end block 1012, so that a group of lead wires on the coil 1014 can pass through the threading hole 10121 and be connected to the signal line 104. In addition, compared with the traditional micro strain gauge, the threading hole 10121 is used to guide the coil to connect with the signal line 104, eliminating the need to set a terminal, further reducing the size of the micro strain gauge and reducing the weight of the micro strain gauge.

[0041] In some embodiments, the coil may include a coil frame and a wire. The coil frame may be fixed on the inner tube wall of the shell, the magnet may be fixed in the through hole in the middle of the coil frame, and the wire may be wound around the coil frame to form a coil. The coil and the magnet are combined together and connected to the signal line. During operation, the coil may be powered by the target acquisition device. After receiving the power, the coil works together with the two magnets to excite the steel string passing through the coil. The steel string vibrates and cuts the magnetic flux lines to generate an induced current, which is then fed back to the target acquisition device by the coil. In this way, when the length of the steel string changes, the vibration frequency will also change accordingly, thereby affecting the induced current received by the coil. The target acquisition device can monitor the strain of the object under test based on the induced current received from the coil feedback.

[0042] The magnet may be a magnet. During implementation, the magnet may be fixed to the coil frame using a thread.

[0043] In some embodiments, Figure 2As shown, the outer shell 102 may include a first end cover 1021, a second end cover 1022 and an outer protective tube 1023; the first end of the outer protective tube 1023 is threadedly connected to the first end block 1011; the second end of the outer protective tube 1023 is threadedly connected to the second end block 1012; the first end cover 1021 is threadedly connected to the first end block 1011; the second end cover 1022 is threadedly connected to the second end block 1012, and the first end cover 1011 is connected to the first end of the outer protective tube 1023; an expansion joint is provided between the second end cover 1022 and the second end of the outer protective tube 1023.

[0044] When implementing, Figure 2 As shown, the housing 102 may further include a wire outlet seat 1024 , which is threadedly connected to the second end cover 1022 for connecting the signal line 104 from the outside of the housing 102 to the inside of the housing 102 .

[0045] In actual applications, when connecting the various components of the outer shell 102, anaerobic adhesive can be used to seal the various threaded connections of the outer shell 102, rubber plugs can be used to seal the wire outlet seat 1024, and silicone rubber can be used to seal the expansion joint between the second end cover 1022 and the second end of the outer protective tube 1023, so that the outer shell 102 can play a role in waterproofing and preventing mud and sand.

[0046] In some embodiments, Figure 3 As shown, a threaded hole 10211 may also be provided on the first end cover 1021 of the micro strain gauge, so that an external device such as a handle may be used to perform an initial zero point adjustment on the micro strain gauge through the threaded hole 10211 .

[0047] Specifically, the specific implementation method of using the handle to perform initial zero point adjustment through the threaded hole can refer to the existing related technology, which will not be repeated here.

[0048] In some embodiments, Figure 2 As shown, the micro strain gauge may further include a temperature detection element 105 , which may be disposed on the capillary support 1013 and connected to the signal line 104 , so as to obtain a temperature signal and output it to a target acquisition device through the signal line.

[0049] Among them, the temperature detection element can use an intelligent chip thermometer, and connect a group of leads of the intelligent chip thermometer to the signal line through the threading hole, so as to access the target acquisition device through the signal line. In this way, the identification of the object to be measured and the collection of temperature data can be realized.

[0050] In specific implementation, after the micro strain gauge is connected to the target acquisition device through the signal line and starts working, the target acquisition device can collect the chip code and temperature data of the smart chip thermometer in the micro strain gauge, as well as the induced current of the coil, so as to confirm the measured object and the environmental data of the measured object, and realize the strain monitoring of the measured object. Among them, the signal line can be a four-core cable.

[0051] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0052] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0054] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A micro strain gauge, characterized in that: Includes elastic components, housing, steel strings and signal wires; The elastic component is arranged inside the shell; One end of the signal line is connected to the first end of the elastic component through the first end of the housing, and the other end is used to connect to the target acquisition device; The elastic component comprises a first end block, a second end block, a capillary support, a coil, a magnet and an elastic structure; the first end of the capillary support is fixedly connected to the first end block, and the second end of the capillary support is connected to the second end block through the elastic structure; the coil is fixed on the wall of the shell tube; the magnet is fixed in the through hole in the middle of the coil; the coil is connected to the signal line; the elastic structure comprises a fixing component and a spring; the fixing component is fixedly connected to the second end of the capillary support; one end of the spring is connected to the fixing component, and the other end is connected to the second end block; The steel chord is arranged inside the elastic component along the central axis of the elastic component, with a first end connected to the first end block and a second end connected to the second end block; When the object under test is deformed, the shell is deformed under force, causing the elastic component to deform. The deformation of the elastic component causes the length of the steel string to change. The change in the length of the steel string causes the vibration frequency signal collected by the coil to change. The coil transmits the collected vibration frequency signal to the target acquisition device through the signal line, so as to realize the strain monitoring of the object under test by the target acquisition device.

2. The micro strain gauge according to claim 1, characterized in that: The fixing assembly includes a threaded tube and a nut.

3. The micro strain gauge according to claim 1, characterized in that: The second end block is provided with a threading hole, and the lead wire on the coil is connected to the signal wire through the threading hole.

4. The micro strain gauge according to claim 1, characterized in that: The outer shell includes a first end cover, a second end cover and an outer protective tube; the first end of the outer protective tube is threadedly connected to the first end block; the second end of the outer protective tube is threadedly connected to the second end block; the first end cover is threadedly connected to the first end block; the second end cover is threadedly connected to the second end block, and the first end cover is connected to the first end of the outer protective tube; an expansion joint is provided between the second end cover and the second end of the outer protective tube.

5. The micro strain gauge according to claim 4, characterized in that: The housing further comprises a wire outlet seat, which is threadedly connected to the second end cover and is used for connecting the signal line from the outside of the housing to the inside of the housing.

6. The micro strain gauge according to claim 4, characterized in that: The first end cover is provided with a threaded hole.

7. The micro strain gauge according to claim 1, characterized in that: It also includes a temperature detection element, which is arranged on the capillary support and connected to the signal line, and is used to obtain a temperature signal and output it to the target acquisition device through the signal line.

8. The micro strain gauge according to claim 1, characterized in that: The coil comprises a coil frame and a conducting wire; the conducting wire is wound on the coil frame; and the coil frame is fixed on the inner tube wall of the shell.

9. The micro strain gauge according to claim 1, characterized in that: The signal line includes a cable.

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