Base distortion generator and base distortion sensitivity measurement system

Abstract

To provide a base strain generating device for detecting base sensitivity of a sensor to be measured.SOLUTION: A base strain generating device installs a clamp assembly and clamps a center part of a strain beam to fix a position of an attachment structure. Consequently, a sensor to be measured installed on the attachment structure does not generate additional acceleration components through vibration of the strain beam. Meanwhile, two magnetic circuit devices are installed, and the magnetic circuit devices provide sine wave excitation to both ends of the strain beam to swing both ends of the strain beam back and forth. Vibration with a stable amplitude can be generated by controlling a magnitude and a frequency of the sine wave excitation, so that base strain sensitivity under different frequencies or different base strains can be measured. This eliminates displacement at the installation position of the sensor to be measured and generation of additional acceleration output in the sensor to be measured, and improves accuracy of measuring the base strain sensitivity.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of sensor measurement technology, and in particular to a base strain generator and a base strain sensitivity measurement system. [Background technology]

[0002] A piezoelectric acceleration sensor is an inertial sensor that uses the piezoelectric effect of a piezoelectric sensing element. Its main components are a base, a piezoelectric sensing element, and a mass block (weight), and its structure can be divided into compression type and shear type.

[0003] Piezoelectric acceleration sensors must be fixed to the object being measured, which is subject to vibration during operation, and the mass block applies alternating stress to the piezoelectric sensitive element. During measurement, the sensitive part of the compression vibration sensor is placed directly on the sensor base, and the two are in surface contact, so the influence of deformation of the base due to strain is relatively large.

[0004] If the mounting surface of a piezoelectric acceleration sensor is curved, distortion occurs in the base of the piezoelectric acceleration sensor, stress is applied to the internal piezoelectric element, polarization occurs, and an erroneous output occurs. This causes an erroneous response to the base distortion, and the ratio of the acceleration value output due to this erroneous response to the base distortion is called the base distortion sensitivity.

[0005] In accordance with the Chinese national standard "GB / T13823.6-1992 Calibration Method for Vibration and Shock Sensors - Base Strain Sensitivity Measurement," a 1500mm x 76mm x 12.5mm steel beam is used, with one end fixed, to form a strain beam. A vibration measurement sensor is installed 40mm from the fixed end of the strain beam, with the centerline of the vibration measurement sensor perpendicular to the surface of the strain beam. When a certain force is applied to the free end of the strain beam to bend it, a certain amount of bending stress ε is generated in the base of the acceleration sensor to be measured. The strain beam is then released, causing it to vibrate at its natural frequency. The acceleration sensor generates an output acceleration α. ​​The acceleration sensor is then rotated around the mounting axis, and the maximum output α generated is calculated. maxis obtained, and the base distortion sensitivity is defined as follows:

number

[0006] The currently used methods for measuring base strain sensitivity are to fix one end of a strain beam, apply a force to the free end to generate a specified base strain at the location where the sensor to be measured is attached, and then release the strain beam to vibrate at its natural frequency, or to apply a steady-state excitation to the free end of the strain beam to bend it. However, in both of these methods, the measurement sensor is installed 40 mm away from the fixed end of the strain beam, which generates an additional acceleration component in the sensitive axis of the measurement sensor during vibration, which reduces the accuracy of the base strain measurement. Summary of the Invention

[0007] Therefore, conventionally, the sensor to be measured was installed 40 mm away from the fixed end of the strain beam, which caused an additional acceleration component to be generated in the sensitive axis of the sensor to be measured during vibration, resulting in a problem that affected the measurement accuracy of the base strain sensitivity.To solve this problem, it is necessary to provide a base strain generator and a base strain sensitivity test device.

[0008] First, the present invention provides a base distortion generator for detecting the base sensitivity of a sensor to be measured, the base distortion generator comprising the following components: base, a strain beam having a mounting structure at its center for fixing and mounting a sensor to be measured;

[0009] a clamp assembly, the clamp assembly being a clamping fixture comprised of an assembly, the clamp assembly being fixedly connected to the base and used to fix the position of the mounting structure at the center of the strain beam; Two sets of magnetic circuit devices are fixedly connected to a base, one set of magnetic circuit devices is provided at each end of a strain beam, and the magnetic circuit devices apply sinusoidal excitation to both ends of the strain beam, causing both ends of the strain beam to move back and forth, and the direction of the sinusoidal excitation is parallel to the direction of the sensitive axis of the sensor to be measured.

[0010] On the other hand, the present invention also provides a base distortion sensitivity measurement system including the following configuration.

[0011] the base strain generator includes a base, a strain beam, a clamp assembly, and two sets of magnetic circuit devices; The sensor to be measured is fixedly mounted to a mounting structure at the center of the strain beam.

[0012] At least two strain gauges are fixedly mounted in the center of the strain beam and are used to measure strain values ​​within a set range of the mounting structure.

[0013] Two displacement sensors, one fixed to each magnetic circuit device, are used to measure the initial positions of both ends of the strain beam when the strain beam is stationary. After the initial positions of both ends of the strain beam are set as the zero displacement points, feedback control is used to maintain both ends of the strain beam vibrating with equal amplitude on both sides of the zero displacement point during movement.

[0014] A control device is connected to each of the magnetic circuit device, the sensor to be measured, the strain gauge, and the displacement sensor, and controls at least the magnitude and frequency of the sinusoidal excitation by the magnetic circuit device, and obtains the strain value output by the strain gauge, the displacement value output by the displacement sensor, and the acceleration value output by the sensor to be measured.

[0015] This application relates to a base strain generator and a base strain sensitivity measurement system. By providing a clamp assembly, the base strain generator is fastened to the center of the strain beam, fixing the position of the mounting structure. The sensor to be measured mounted on the mounting structure does not generate additional acceleration components due to the vibration of the strain beam. At the same time, two sets of magnetic circuit devices apply sinusoidal excitation to both ends of the strain beam, causing them to move back and forth. By controlling the magnitude and frequency of the sinusoidal excitation, vibrations of stable amplitude can be generated, allowing the measurement of base strain sensitivity at different frequencies and different base strains. This solution prevents displacement of the mounting position of the sensor to be measured and prevents additional acceleration output from the sensor to be measured, improving the measurement accuracy of the base strain sensitivity. [Brief explanation of the drawings]

[0016] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and to make other features, objects, and advantages of the application apparent. The drawings of the schematic embodiments of the application and the description thereof are used to explain the application and are not intended to unduly limit the application.

[0017] [Figure 1] 1 is a schematic diagram of a base distortion generator according to an embodiment of the present invention; [Figure 2] 2 is a schematic structural diagram of a clamp assembly of the base strain generator provided in the embodiment shown in FIG. 1; [Figure 3] 2 is a schematic structural diagram of a clamping assembly and a strain beam in a clamped state of the base strain generator provided in the embodiment shown in FIG. 1; [Figure 4] FIG. 1 is a schematic structural diagram of a base distortion generator provided by another embodiment of the present application; [Figure 5] FIG. 5 is a schematic structural view of the embodiment shown in FIG. 4 after the closing plate of the base strain generator is removed. [Figure 6]5 is a schematic diagram illustrating the positional relationship between the clamp assembly, groove, and support bead of the base strain generator provided by the embodiment shown in FIG. 4. [Figure 7] 4. FIG. 5 is a perspective view (enlarged view of B in FIG. 4) of one of the magnetic circuit arrangements of the base distortion generator provided by the embodiment shown in FIGS. [Figure 8] 1 and 4. FIG. 5 is a perspective view (enlarged view of B in FIG. 4) of one magnetic circuit device of the base strain generator provided by the embodiment shown in FIG. 1 and FIG. 4 after removing a sealing plate. [Figure 9] 4. FIG. 5 is a perspective view (enlarged view of B in FIG. 4) of one of the magnetic circuit arrangements of the base distortion generator provided by the embodiment shown in FIGS. [Figure 10] 1 and 4. FIG. 5 is a perspective view (enlarged view of B in FIG. 4) of one magnetic circuit device of the base distortion generator provided by the embodiment shown in FIGS. [Figure 11] 1 and 4. FIG. 5 is a schematic diagram (enlarged view of B in FIG. 4) showing the installation position of a displacement sensor mounting hole in one magnetic circuit device of the base strain generator provided by the embodiment shown in FIGS. [Figure 12] 1. FIG. 5 is a schematic diagram (enlarged view of B in FIG. 4) showing the installation position of a measurement object in one magnetic circuit device of the base distortion generator provided by the embodiment shown in FIGS. [Figure 13] 1 and 4 (enlarged view of part B in FIG. 4). FIG. [Figure 14] 5 is an explanatory diagram of magnetic field lines of a magnetic circuit device of the base distortion generator provided by the embodiment shown in FIGS. 1 and 4. FIG. [Figure 15] 1 is a schematic diagram of a frame structure of a base strain sensitivity testing system provided by an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0018] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described in more detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present invention, and are not used to limit the present invention.

[0019] The present application provides a base strain generator 100 for measuring the base strain sensitivity of a sensor 300 under test.

[0020] As shown in FIGS. 1 and 4, in one embodiment of the present application, the base strain generator 100 includes a base 110 , a strain beam 120 , a clamp assembly 130 , and a magnetic circuit device 140 .

[0021] A mounting structure 121 is provided at the center of the strain beam 120 to fix and install the sensor 300 to be measured. A clamp assembly 130 is fixedly connected to the base 110 and is used to clamp the center of the strain beam 120 to fix the position of the mounting structure 121. Two sets of magnetic circuit devices 140 are provided, each fixedly connected to the base 110, one set at each end of the strain beam 120. The ends of the strain beam 120 provide sinusoidal excitation to oscillate both ends of the strain beam 120, and the direction of the sinusoidal excitation is parallel to the direction of the sensitive axis of the sensor 300 to be measured.

[0022] Specifically, the sensor to be measured 300 may be a piezoelectric acceleration sensor.

[0023] In this embodiment, the clamp assembly 130 is installed to clamp the central portion of the strain beam 120, thereby fixing the position of the mounting structure 121. Furthermore, the sensor 300 to be measured, which is placed on the mounting structure 121, does not generate additional acceleration components due to the vibration of the strain beam 120. At the same time, two magnetic circuit devices 140 apply sinusoidal excitation to both ends of the strain beam 120, causing the ends of the strain beam 120 to reciprocate. Furthermore, by controlling the magnitude and frequency of the sinusoidal excitation, vibrations of stable amplitude can be generated, allowing the base strain sensitivity to be measured at different frequencies and different base strains. This eliminates misalignment of the installation position of the sensor 300 to prevent additional acceleration output from the sensor 300, improving the measurement accuracy of the base strain sensitivity.

[0024] As shown in FIGS. 1 and 2, in one embodiment of the present invention, the distances between the two sets of magnetic circuit devices 140 and the mounting structure 121 are equal in the longitudinal direction of the strain beam 120.

[0025] In this embodiment, by arranging two sets of magnetic circuit devices 140 and simultaneously applying the same sinusoidal excitation to both ends of the strain beam 120, a uniform bending force is applied to both sides of the base of the measured sensor 300, which generates a uniform strain in the base and improves measurement accuracy.

[0026] As shown in Figures 2 and 6, in one embodiment of the present invention, the clamp assembly 130 and the middle portion of the strain beam 120 are clamped together in a line contact manner.

[0027] In this embodiment, the purpose of providing the line contact is to clamp the strain beam 120 without affecting the bending change in the center of the strain beam 120 .

[0028] 2, in one embodiment of the present application, the mounting structure 121 has a mounting hole. The mounting hole penetrates the strain beam 120. The central axis of the mounting hole is parallel to the sinusoidal excitation direction. When the measured sensor 300 is fixed in the mounting hole, the sensitive axis of the measured sensor 300 coincides with the central axis of the mounting hole.

[0029] In this embodiment, the sensor to be measured 300 is fixed using a mounting hole, and the screw holes of the sensor to be measured 300 are aligned with the mounting holes of the strain beam 120 and attached with a fixing screw, so the mounting structure is simple and does not affect the deformation of the strain beam 120. Furthermore, since the base of the sensor to be measured 300 is in direct contact with the strain beam 120, the deformation of the strain beam 120 is more effectively transmitted to the base of the sensor to be measured 300, improving the accuracy of the base strain measurement of the sensor to be measured 300.

[0030] Of course, the specific form of the mounting structure 121 is not limited, and a clamp or bayonet rotation may be used so that the base of the sensor under test 300 is in full contact with the strain beam 120 .

[0031] In one embodiment of the present application, multiple mounting structures 121 are provided perpendicular to the extension direction of the strain beam 120, so that multiple sensors to be measured 300 can be detected simultaneously.

[0032] As shown in FIG. 2, in one embodiment of the present application, the clamp assembly 130 includes a frame 131, a fixed rod 132, and a movable screw 134.

[0033] The frame 131 includes a bottom plate 131a and a cantilever arm 131b, and the bottom plate 131a is fixed to the base 110. The fixed rod 132 is fixedly installed on the bottom plate 131a. The upper surface of the fixed rod 132 faces the lower surface of the strain beam 120, and there is a gap between the upper surface of the fixed rod 132 and the lower surface of the strain beam 120.

[0034] The movable screw 134 is threadedly engaged with the cantilever arm 131b, and is aligned with the central axis of the fixed rod 132 and intersects perpendicularly with the central axis of the mounting hole. The lower surface of the movable screw 134 and the upper surface of the strain beam 120 are arranged opposite each other, and a gap is present between the lower surface of the movable screw 134 and the upper surface of the strain beam 120.

[0035] When the movable screw 134 rotates, the movable screw 134 and the fixed rod 132 move closer together, and the strain beam 120 is sandwiched between the movable screw 134 and the fixed rod 132 .

[0036] In this embodiment, the fixed rod 132 and the movable screw 134 are provided to limit the positions of both sides of the strain beam 120, respectively, and by determining the relative positions of the central axes of the movable screw 134 and the fixed rod 132 and the mounting hole, the position of the mounting hole is not displaced by the influence of vibrations at both ends of the strain beam 120, so no additional acceleration components are generated in the sensitive axis of the measured sensor 300.

[0037] 3 , in one embodiment of the present invention, a first positioning groove 122 is provided on the top surface of the strain beam 120, and the movable screw 134 has a first conical portion 134a at its end closer to the strain beam 120. The minimum diameter of the first conical portion 134a is smaller than the inner diameter of the first positioning groove 122, and the maximum diameter of the first conical portion 134a is larger than the inner diameter of the first positioning groove 122. When the strain beam 120 is clamped, at least a portion of the first conical portion 134a is inserted into the first positioning groove 122.

[0038] A second positioning groove 123 is provided on the underside of the strain beam 120, and a second conical portion 132a is provided at the end of the fixed rod 132 closer to the strain beam 120. The minimum diameter of the second conical portion 132a is smaller than the inner diameter of the second positioning groove 123, and the maximum diameter of the second conical portion 132a is larger than the inner diameter of the second positioning groove 123. When the strain beam 120 is clamped, at least a portion of the second conical portion 132a is inserted into the second positioning groove 123.

[0039] In this embodiment, the movable screw 134, the fixed rod 132, and the strain beam 120 are interconnected by the cooperation of the first conical portion 134a with the first positioning groove 122 and the cooperation of the second conical portion 132a with the second positioning groove 123. The line contact can minimize the influence of the clamp assembly 130 on the bending of the strain beam 120.

[0040] As shown in Figures 4 and 6, in one embodiment of the present application, the clamp assembly 130 includes a first T-shaped steel 135, a second T-shaped steel 136, a plurality of first arc pieces 138b, a plurality of second arc pieces 138c, and a support block 138d.

[0041] The first T-beam 135 includes a first horizontal portion 136a and a first vertical portion 136b fixedly connected to one another.

[0042] The second T-shaped steel 136 includes a second horizontal portion 137a and a second vertical portion 137b that are fixedly connected to each other. The first horizontal portion 136a and the second horizontal portion 137a are disposed opposite each other, with a gap between the first horizontal portion 136a and the second horizontal portion 137a. The first vertical portion 136b and the second vertical portion 137b are disposed opposite each other, with a gap between the first vertical portion 136b and the second vertical portion 137b.

[0043] The closure plate 138a covers the upper surface of the first vertical portion 136b and the upper surface of the second vertical portion 137b, and the closure plate 138a is fixedly connected to the upper surface of the first vertical portion 136b and the upper surface of the second vertical portion 137b, respectively.

[0044] A plurality of first arcuate pieces 138b are fixedly connected to the surface of the first vertical portion 136b closer to the second vertical portion 137b. A plurality of second arcuate pieces 138c are fixedly connected to the surface of the second vertical portion 137b closer to the first vertical portion 136b. Each of the first arcuate pieces 138b has a second arcuate piece 138c arranged opposite it, and the first arcuate pieces 138b and the second arcuate pieces 138c arranged opposite them are located on the same horizontal plane.

[0045] The support block 138d is provided between the first T-shaped steel 135 and the second T-shaped steel 136. A first distance is provided between the first horizontal portion 136a and the support block 138d, and a second distance is provided between the second horizontal portion 137a and the support block 138d.

[0046] During use of the clamp assembly, a central portion of strain beam 120 is clamped between first arcuate piece 138b and second arcuate piece 138c, and the bottom of strain beam 120 contacts the top surface of support block 138d. Support block 138d provides support to strain beam 120.

[0047] Specifically, the first T-shaped steel 135 may be No. 45 steel, and the second T-shaped steel 136 may be No. 45 steel. No. 45 steel is a medium-carbon steel with a carbon content of 0.4% or more, and is a high-quality carbon structural steel that has low hardness and is easy to process.

[0048] When the clamp assembly 130 is in use, the four arc pieces make line contact with the strain beam 120. The arc pieces are configured as sheet-like structures with arcuate edges, but the arc pieces may also be shaped as half of a circle, i.e., semicircular pieces.

[0049] In this embodiment, the arc piece is installed as a sheet-like structure with arcuate edges rather than a cylinder or other shape, because it is easier to reach inside the clamp assembly 130 and remove the measured sensor 300 located at the center of the strain beam 120.

[0050] It is worth noting that the first distance may be equal to the second distance, however, during actual use of the base strain generator, when the clamp assembly 130 and the strain beam 120 are clamped, the position of the second T-shaped steel 136 is finely adjusted, so that the second distance is not equal to the second distance from a microscopic point of view, although the difference between the first distance and the second distance is not that great, the difference being on the order of millimeters.

[0051] As shown in FIG. 6, in one embodiment of the present invention, the clamp assembly further includes a groove 139a and a support bead 139b.

[0052] Groove 139a is provided on the upper surface of support block 138d. Support bead 139b is embedded in groove 139a. The groove surface of groove 139a matches the shape of support bead 139b.

[0053] When the clamp assembly 130 is in use, point contact is formed between the top of the support bead 139b and the bottom surface of the strain beam 120, and surface contact is formed between the bottom of the support bead 139b and the groove surface of the groove 139a, and the support block 138d supports the strain beam 120.

[0054] In this embodiment, by installing the groove 139a and the support bead 139b, when the central portion of the strain beam 120 is clamped, the strain beam 120 is supported by the cooperative action of the support bead 139b and the support block 138d, and does not affect the bending change of the central portion of the strain beam 120 itself.

[0055] As shown in FIG. 5, in one embodiment of the present application, the clamp assembly further includes a tightening assist mechanism 139c.

[0056] The tightening assist mechanism 139c is provided on the side of the second vertical portion 137b farther away from the first vertical portion 136b.

[0057] When the first T-shaped steel 135 is fastened and fixed onto the base 110 and the central portion of the strain beam 120 is positioned between the first arc-shaped piece 138b and the second arc-shaped piece 138c, the tightening assist mechanism 139c moves toward the second T-shaped steel 136 and tightens it, pressing the tightening assist mechanism 139c against the second vertical portion 137b. As a result, the second arc-shaped piece 138c is pressed against the central portion of the strain beam 120, and the first arc-shaped piece 138b and the second arc-shaped piece 138c sandwich the central portion of the strain beam 120.

[0058] Specifically, the tightening assist mechanism 139c has a plate-like structure.

[0059] A plurality of circular through holes are provided in the first horizontal portion 136a of the first T-shaped steel 135, and the first T-shaped steel 135 is bolted to the base via these circular through holes.

[0060] The support block 138d has a plurality of circular through-holes, and the support block 138d is fixed to the base by bolts via these circular through-holes.

[0061] A plurality of bolt adjustment through holes 137c are provided in the second T-shaped steel 136. The bolt adjustment through holes 137c are strip-shaped, and can be adjusted by sliding them along the length of the bolt adjustment through holes 137c within the length of the bolt adjustment through holes 137c, thereby allowing fine adjustment of the installation position of the second T-shaped steel 136. The length direction of the bolt adjustment through holes 137c is the same as the direction in which the second T-shaped steel 136 approaches or moves away from the support block 138d.

[0062] The tightening assist mechanism 139c has a plurality of circular through-holes, and the clamp assembly further includes a plurality of screws for use in combination with the tightening assist mechanism 139c. Each screw is inserted into a circular through-hole in the tightening assist mechanism 139c, and tightening the screws causes the tightening assist mechanism 139c to gradually approach the second T-shaped steel 136 until the end of the screw is pressed against the surface of the second vertical portion 137b. This presses the tightening assist mechanism 139c against the second horizontal portion 137a, causing the second T-shaped steel 136 and the second arc-shaped piece 138c to approach the strain beam 120, and the second arc-shaped piece 138c is pressed against the strain beam 120, sandwiching the strain beam 120 between the first arc-shaped piece 138b and the second arc-shaped piece 138c.

[0063] When installed, the support block 138d is bolted to the base 110 to fix its position.

[0064] The detailed operational steps for clamping the clamp assembly 130 and strain beam 120 in this embodiment are as follows:

[0065] In S100, the relative position of the first T-shaped steel 135 and the support block 138d is determined, and after the determination, the bolts of the first T-shaped steel 135 are tightened to fix the first T-shaped steel 135 to the base 110. Then, the bolts of the support block 138d are tightened to fix the first T-shaped steel 135 to the base 110. Fixing the first T-shaped steel 135 and the support block 138d provides a position reference as a reference for subsequent fine adjustment of the position of the second T-shaped steel 136.

[0066] In S200, the bolt is inserted into the bolt adjustment through-hole 137c of the second T-shaped steel 136, but is not tightened.

[0067] In S300, the strain beam 120 is disposed between the first arc piece 138b and the second arc piece 138c, and the central position is adjusted so that the central portion of the strain beam 120 is located between the first arc piece 138b and the second arc piece 138c, and the lower surface of the strain beam 120 abuts on the top of the support bead 139b. Optionally, the first arc piece 138b is two pieces, and the second arc piece 138c is two pieces.

[0068] In S400, the screw of the tightening assist mechanism 139c is tightened in a direction approaching the second T-shaped steel 136 so that the tightening assist mechanism 139c is pressed against the second vertical portion 137b of the second T-shaped steel 136. By pressing the tightening assist mechanism 139c against the second vertical portion 137b of the second T-shaped steel 136, the second arc-shaped piece 138c on the second T-shaped steel 136 is pressed against the strain beam 120, and the strain beam 120 is sandwiched between the first arc-shaped piece 138b and the second arc-shaped piece 138c. At this time, the position of the second T-shaped steel 136 is finely adjusted in the A direction.

[0069] In S500, the bolt in the bolt adjustment through hole 137c of the second T-shaped steel 136 is tightened to fix the position of the second T-shaped steel 136.

[0070] As shown in FIGS. 7, 8, 9 and 10, in one embodiment of the present application, the magnetic circuit module includes a first magnet 143 a, a second magnet 143 b, a coil bobbin 145 a, a magnetic yoke 144 and a drive coil 146 .

[0071] Second magnet 143b is disposed parallel to and facing first magnet 143a. A gap is provided between first magnet 143a and second magnet 143b. Coil bobbin 145a is disposed in the gap between first magnet 143a and second magnet 143b and is configured in the shape of a rectangular frame with a hollow portion.

[0072] The magnetic yoke 144 is disposed in a hollow portion of the coil bobbin 145a. A drive coil 146 is wound around the coil bobbin 145a.

[0073] Both the first magnet 143a and the second magnet 143b are magnetic, and the magnetic yoke 144 is made of a magnetically permeable material. When the magnetic circuit device 140 is in use, a sinusoidal current is supplied to the drive coil 146, a first air-gap magnetic field is formed between the first magnet 143a and the magnetic yoke 144, and a second air-gap magnetic field is formed between the second magnet 143b and the magnetic yoke 144, and the drive coil 146 is subjected to an ampere force perpendicular to the direction of the magnetic field.

[0074] Specifically, the drive coil 146 is driven by an ampere force perpendicular to the direction of the magnetic field, and the coil bobbin 145a therefore moves horizontally in a direction perpendicular to the magnetic field lines.

[0075] 13, in one embodiment of the present invention, the coil bobbin 145a includes an outer frame and an inner frame. The outer frame of the coil bobbin 145a is provided with a coil winding groove 145b. The coil winding groove 145b is used to accommodate the drive coil 146.

[0076] Specifically, the coil winding groove 145b accommodates the drive coil 146, and when energized, the drive coil 146 is connected to a regularly changing, steady-state sinusoidal current, and the current flowing through the drive coil 146 is a sinusoidal current. Taking the present embodiment shown in FIG. 14 as an example, the direction of the magnetic field lines is horizontal, i.e., along the X-axis (the direction of the magnetic field lines is shown in FIG. 14), so the drive coil 146 is subjected to a steady-state sinusoidal ampere force perpendicular to the magnetic field lines. That is, the ampere force is in the Y-axis direction (the direction of the ampere force is shown in FIG. 10), which allows the coil bobbin 145 and the drive coil 146 to move back and forth.

[0077] 14, in one embodiment of the present invention, the side of first magnet 143a closest to magnetic yoke 144 is the north pole, and the side of first magnet 143a farther from yoke 144 is the south pole. The side of second magnet 143b closest to magnetic yoke 144 is the north pole, and the side of second magnet 143b farther from magnetic yoke 144 is the south pole.

[0078] Specifically, the magnetic field lines 2 on the left side flow from the north pole of the magnet to the magnetic yoke 144 and then return to the south pole of the magnet, forming a counterclockwise closed loop. The magnetic field lines 3 on the right side flow from the north pole of the magnet to the magnetic yoke 144 and then return to the south pole of the magnet, forming a clockwise closed loop.

[0079] As shown in FIGS. 9 and 10, in one embodiment of the present application, the magnetic circuit module further includes a T-shaped fixed block 150.

[0080] A T-shaped fixture block 150 is disposed between the coil bobbin 145 a and the free end of the strain beam 120 .

[0081] The T-shaped fixing block 150 includes a horizontal connecting plate and a vertical connecting plate that are arranged perpendicular to each other.

[0082] The vertical connecting plate and the free end of the strain beam 120 are connected by bolts. The lower surface of the horizontal connecting plate is fixedly connected to the coil bobbin 145a.

[0083] Specifically, the free ends of the strain beam 120 are both ends of the strain beam 120, and are the ends where the strain beam 120 and the magnetic circuit device 140 are connected.

[0084] The T-shaped fixing block 150 and the strain beam 120 are connected by bolts.

[0085] As shown in FIG. 7, in one embodiment of the present invention, the magnetic circuit module includes a pressure plate 147, a first side magnetic conductive plate 141a, a second side magnetic conductive plate 141b, a first protective plate 140a, a second protective plate 140b, and a sealing plate 149d.

[0086] The magnetic circuit device 140 is configured by the pressure plate 147, the first magnetic conductive plate 141a, the second magnetic conductive plate 141b, the first protective plate 140a, the second protective plate 140b, and the sealing plate 149d.

[0087] Specifically, the first-side magnetic conductive plate 141a and the second-side magnetic conductive plate 141b are arranged parallel to each other, and the first-side magnetic conductive plate 141a and the second-side magnetic conductive plate 141b are both perpendicular to the pressure plate 147 and fixedly connected to it. The first-side magnetic conductive plate 141a and the second-side magnetic conductive plate 141b are both perpendicular to the sealing plate 149d and fixedly connected to it. The first protective plate 140a and the second protective plate 140b are arranged parallel to each other, and the first protective plate 140a and the second protective plate 140b are both perpendicular to the pressure plate 147 and fixedly connected to it. The first protective plate 140a and the second protective plate 140b are both perpendicular to the sealing plate 149d and fixedly connected to it.

[0088] The device further includes a limiting plate 148b, which is located above the magnetic yoke 144 and disposed on top of the protective box 5. A first side of the limiting plate 148b is fixedly connected to the first-side magnetic conductive plate 141a, and a second side of the limiting plate 148b is fixedly connected to the second-side magnetic conductive plate 141b. When energized, the coil bobbin 145a drives the free end of the strain beam 120 to oscillate. The frequency and magnitude of the sinusoidal current are controlled to cause the strain beam 120 to oscillate at different frequencies, and the limiting plate 148b is used to limit the range of oscillation, thereby protecting the device from damage due to excessive stress caused by excessive oscillation.

[0089] 9, in one embodiment of the present invention, the distortion generator further includes a first convex base 149a and a second convex base 149b. The first convex base 149a is plate-shaped. The second convex base 149b is plate-shaped.

[0090] The first convex base 149a and the second convex base 149b are parallel to each other, with a gap provided between the first convex base 149a and the second convex base 149b, the first convex base 149a being fixedly connected to the first side magnetic conductive plate 141a, and the second convex base 149b being positively connected to the second side magnetic conductive plate 141b.

[0091] Specifically, the height of first protruding base 149a is lower than the height of first-side magnetic conductive plate 141a, and the height of second protruding base 149b is lower than the height of second-side magnetic conductive plate 141b. First protruding base 149a is plate-shaped and is disposed in close contact with and parallel to first-side magnetic conductive plate 141a, while second protruding base 149b is plate-shaped and is disposed in close contact with and parallel to second-side magnetic conductive plate 141b.

[0092] The height here refers to the length in the height direction, and the height direction refers to the direction in which the sealing plate 149d faces the T-shaped fixing block 150.

[0093] The coil bobbin 145a is located between the first magnet 143a and the second magnet 143b. A magnetic yoke 144 is provided inside the coil bobbin 145a. A constant magnetic gap 1 exists between the coil bobbin 145a and the first magnet 143a. As shown in FIG. 14, a constant magnetic gap 1 exists between the coil bobbin 145a and the second magnet 143b. There is a constant magnetic gap 1 between the magnetic yoke 144 and the base, and the first magnet 143a and the second magnet 143b are parallel to each other. 9, the first magnet 143a is disposed adjacent to the first protruding base 149a and abuts against the inner surface of the first magnetic conductive plate 141a, the second magnet 143b is disposed adjacent to the second protruding base 149b and abuts against the inner surface of the second magnetic conductive plate 141b, the coil bobbin 145a is located between the first magnet 143a and the second magnet 143b, and the magnetic yoke 144 is installed in the hollow of the coil bobbin 145a. The magnetic yoke 144 is made of a magnetic conductive material.

[0094] Specifically, the coil bobbin 145a is configured as a rectangular frame with a hollow portion. Both the first magnet 143a and the second magnet 143b are magnetic, and the magnetic yoke 144 is nonmagnetic and made of a magnetically conductive material. When current is applied, the center of the magnetic yoke 144 can conduct magnetism and form a magnetic field. A first air gap magnetic field is formed between the first magnet 143a and the magnetic yoke 144, and a second air gap magnetic field is formed between the second magnet 143b and the magnetic yoke 144. The coil bobbin 145a is located between the first air gap magnetic field and the second air gap magnetic field. Therefore, there are gaps between the coil bobbin 145a and the pressure plate 147, between the coil bobbin 145a and the first magnet 143a, between the coil bobbin 145a and the second magnet 143b, and between the coil bobbin 145a and the magnetic yoke 144.

[0095] Also, as shown in Figure 14, due to the action of the sinusoidal current, an ampere force is generated between the first magnet 143a and the coil bobbin 145a, and between the second magnet 143b and the coil bobbin 145a, and a left magnetic field line 2 exists between the first magnet and the magnetic yoke, and a right magnetic field line 3 exists between the second magnet 143b and the magnetic yoke.

[0096] In one embodiment of the present application, the inner surface of the first-side magnetic conductive plate 141a is set as a convex surface, and the inner surface of the second-side magnetic conductive plate 141b is set as a convex surface.

[0097] Specifically, the first magnet 143a is attracted to the inner surface of the first magnetic conductive plate 141a, and the second magnet 143b is attracted to the inner surface of the second magnetic conductive plate 141b.

[0098] Specifically, a gap is set in advance between the first magnet 143a, the second magnet 143b and the magnetic yoke 144, and the first magnet 143a is fixed to the inner surface of the first side magnetic conductive plate 141a, and the second magnet 143b is fixed to the inner surface of the second side magnetic conductive plate 141b.

[0099] As shown in FIG. 7, in one embodiment of the present invention, the distortion generator further includes a cover plate 148a.

[0100] The cover plate 148 a is fixedly connected to a T-shaped fixing block 150 .

[0101] Specifically, the cover plate 148a forms an airtight space inside the magnetic circuit device 140, covers the magnetic circuit device 140, and is used to prevent foreign objects from falling into the magnetic circuit device 140.

[0102] The T-shaped fixed block 150 is embedded in the cover plate 148a, and the horizontal connecting plate of the T-shaped fixed block 150 is fixedly connected to the cover plate 148a. Therefore, when the strain beam 120 swings, the cover plate 148a and the T-shaped fixed block 150 also move in conjunction with the swing of the strain beam 120.

[0103] As shown in FIG. 10, in one embodiment of the present invention, the distortion generator further includes a first magnetic yoke fixing plate 142a and a second magnetic yoke fixing plate 142b.

[0104] The first magnetic yoke fixing plate 142a and the second magnetic yoke fixing plate 142b are parallel to each other.

[0105] The first magnetic yoke fixing plate 142a is fixedly connected to the inner surface of the first protective plate 140a with bolts, and the second magnetic yoke fixing plate 142b is fixedly connected to the inner surface of the second protective plate 140b with bolts, thereby fixing the attachment position of the magnetic yoke 144.

[0106] Specifically, the first protective plate 140a covers the outer surface of the first magnetic yoke fixing plate 142a, but is not directly connected to the first magnetic yoke fixing plate 142a. One side of the first protective plate 140a is fixedly connected to the first magnetic conductive plate 141a with a bolt, and the other side of the first protective plate 140a is fixedly connected to the second magnetic conductive plate 141b with a bolt. One side of the first magnetic yoke fixing plate 142a is fixedly connected to the first magnetic conductive plate 141a with a bolt, and the other side of the first magnetic yoke fixing plate 142a is fixedly connected to the second magnetic conductive plate 141b with a bolt. One side of the second magnetic yoke fixing plate 142b is fixedly connected to the first magnetic conductive plate 141a with a bolt, and the other side of the second magnetic yoke fixing plate 142b is fixedly connected to the second magnetic conductive plate 141b with a bolt.

[0107] The same is true for the second protective plate 140b. The second protective plate 140b is not directly connected to the second magnetic yoke fixing plate 142b. One side of the second protective plate 140b is fixedly connected to the first magnetic conductive plate 141a by a bolt, and the other side of the second protective plate 140b is fixedly connected to the second magnetic conductive plate 141b by a bolt.

[0108] The first magnetic yoke fixing plate 142a and the second magnetic yoke fixing plate 142b are both made of a magnetic conductive material and have magnetic conductivity.

[0109] In this embodiment, when an AC current is supplied to the drive coil 146, the coil bobbin 145 drives both ends of the strain beam 120 to swing. Power is transmitted by placing a connecting plate between the coil bobbin and the strain beam 120. Both ends of the strain beam 120 are inserted into T-shaped fixing blocks 150, and the T-shaped fixing blocks 150 apply power only to the ends of the strain beam 120.

[0110] This application also provides a base strain sensitivity test system 10.

[0111] 15 , in one embodiment of the present application, the base strain sensitivity testing system 10 includes the above-described base strain generator 100, a sensor to be measured 300, at least two strain gauges 400, two displacement sensors 500, and a control device 200. The base strain generator includes a base 110, a strain beam 120, a clamp assembly 130, and two magnetic circuit devices 140.

[0112] The sensor under test 300 is fixedly mounted on a mounting structure in the center of the strain beam 120 .

[0113] At least two strain gauges 400 are fixedly installed at the center of the strain beam 120. The strain gauges 400 are used to measure strain values ​​within a set range of the mounting structure 121.

[0114] A displacement sensor 500 is fixedly installed on each magnetic circuit device 140. The displacement sensor 500 is used to measure the initial positions of both ends of the strain beam 120 when the strain beam 120 is stationary, and the initial positions of both ends of the strain beam 120 are set as the zero points of displacement at both ends of the strain beam 120. Then, by using feedback control, both ends of the strain beam 120 always oscillate with a constant amplitude on both sides of the zero displacement point.

[0115] The control device 200 is connected to the magnetic circuit device 140, the measured sensor 300, the strain gauge 400, and the displacement sensor 500. The control device 200 is used to at least control the magnitude and frequency of the sinusoidal excitation output by the magnetic circuit device 140, acquire strain values ​​by the strain gauge 400, acquire displacement values ​​by the displacement sensor 500, and acquire acceleration values ​​output by the measured sensor 300.

[0116] Specifically, a sealing plate 149d of the magnetic circuit device 140 is provided with a displacement sensor mounting hole 149e for mounting a displacement sensor 500. The displacement sensor 500 is an eddy current sensor capable of non-contact measurement. A measuring body 149c used in conjunction with the displacement sensor 500 is attached to the coil bobbin 145a. A displacement sensor 500 is provided at each end of the strain beam 120. The displacement sensor 500 measures the initial positions of both ends of the strain beam 120 when the strain beam 120 is stationary. Feedback control is used to make the amplitude of the oscillation of the strain beam 120 equal on both sides of the zero displacement point. Specifically, the displacement sensor 500 detects the distance between the probe of the displacement sensor 500 and the measuring body 149c.

[0117] There can be two or four strain gauges 400, two of which form a half-bridge circuit, and four of which form a full-bridge circuit. When the strain gauge 400 is installed at the center of the strain beam 120, the strain gauge 400 is positioned near the sensor to be measured 300. Optionally, when there are two strain gauges 400, the two strain gauges 400 are positioned symmetrically around the sensor to be measured 300 at the center of the strain beam 120.

[0118] The technical features of the above-described embodiments can be combined in any manner, and the order of execution of each method step is not limited, but for the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope of this specification.

[0119] The above-mentioned embodiments only represent some embodiments of the present application, and although the descriptions thereof are relatively specific and detailed, they should not be construed as limiting the patent scope of the present application. It should be noted that those skilled in the art can make some modifications and improvements without departing from the concept of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application should be determined by the appended claims. [Explanation of symbols]

[0120] 100, base distortion generator; 110, base, 120, strain beam, 121 , mounting structure, 122, first positioning groove; 123, second positioning groove; 130 , clamp assembly; 131, frame, 131a, bottom plate; 131b, cantilever arm; 132, fixed rod, 132a, second cone; 134, movable screw, 134a, first cone; 135, first T-section steel, 136a, first horizontal portion; 136b, first vertical portion; 136, second T-section steel, 137a, second horizontal section; 137b, second vertical section; 137c, bolt adjustment through-hole; 138a, closing plate; 138b, first arc piece; 138c, second arc piece; 138d, supporting block; 139a, groove; 139b, support bead; 139c, tightening assist mechanism; 140 , magnetic circuit device, 140a, first protective plate; 140b, second protective plate; 141a, first side magnetic conductive plate; 141b, second side magnetic conductive plate; 142a, first magnetic yoke fixing plate; 142b, second magnetic yoke fixing plate; 143a, first magnet; 143b, second magnet; 144, magnetic yoke, 145a, coil bobbin, 145b, coil winding groove; 146, drive coil, 147, pressure plate, 148a, cover plate; 148b, limiting board, 149a, first convex base; 149b, second convex base; 149c, measuring body, 149d, sealing plate; 149e, displacement sensor mounting hole; 150, T-shaped fixed block, 1. Magnetic gap, 2, left magnetic field lines, 3, right side magnetic field line, 10, base distortion sensitivity test system, 200, control device, 300, the sensor to be measured; 400, strain gauge, 500, displacement sensor

Claims

1. A base distortion generator used to measure the base sensitivity of a sensor under test, comprising: a base, a strain beam, a clamp assembly, and two sets of magnetic circuit devices fixedly connected to the base; The strain beam has a mounting structure at its center for fixing and mounting the sensor to be measured, the clamp assembly is fixedly connected to the base and is used to fix the position of the mounting structure at the center of the strain beam; a pair of the magnetic circuit devices are provided at each end of the strain beam, and the magnetic circuit devices apply sinusoidal excitation to both ends of the strain beam, causing the both ends of the strain beam to reciprocate, and the direction of the sinusoidal excitation is parallel to the direction of the sensitive axis of the sensor to be measured; A base distortion generator characterized by:

2. 2. The base strain generator according to claim 1, wherein the clamp assembly and the central portion of the strain beam are clamped by line contact.

3. The base strain generator of claim 2, characterized in that the mounting structure is provided with a mounting hole, the mounting hole penetrates the strain beam, the central axis of the mounting hole is parallel to the direction of the sinusoidal excitation, and when the sensor to be measured is fixedly mounted in the mounting hole, the sensitive axis of the sensor to be measured coincides with the central axis of the mounting hole.

4. The clamp assembly includes a frame, a fixed rod, and a movable screw; The frame includes a bottom plate and a cantilever arm, the bottom plate being fixed to a base; the fixed rod is fixedly disposed on the bottom plate, the upper surface of the fixed rod faces the lower surface of the strain beam, and there is a gap between the upper surface of the fixed rod and the lower surface of the strain beam; the movable screw is fixed to the cantilever arm with a bolt, the mounting direction of the movable screw coincides with the central axis of the fixed rod and intersects perpendicularly with the central axis of the mounting hole, the bottom surface of the movable screw and the upper surface of the strain beam are arranged opposite to each other, and there is a gap between the bottom surface of the movable screw and the upper surface of the strain beam; When the movable screw is rotated, the movable screw and the fixed rod approach each other, and the strain beam is sandwiched between the movable screw and the fixed rod.

4. The base distortion generator according to claim 3.

5. The base strain generator of claim 4, characterized in that a first positioning groove is provided on the upper surface of the strain beam, and the movable screw has a first conical portion at its end closer to the strain beam, the minimum diameter of the first conical portion being smaller than the inner diameter of the first positioning groove and the maximum diameter of the first conical portion being larger than the inner diameter of the first positioning groove, and when the strain beam is clamped, at least a portion of the first conical portion is inserted into the first positioning groove.

6. The base strain generator of claim 5, characterized in that a second positioning groove is provided on the underside of the strain beam, and the fixed rod has a second conical portion at its end closer to the strain beam, the minimum diameter of the second conical portion being smaller than the inner diameter of the second positioning groove and the maximum diameter of the second conical portion being larger than the inner diameter of the second positioning groove, and when the strain beam is clamped, at least a portion of the second conical portion is inserted into the second positioning groove.

7. the clamp assembly includes a first T-shaped steel, a second T-shaped steel, a closure plate, a plurality of first arc pieces, a plurality of second arc pieces, and a support block; the first T-beam includes a first horizontal portion and a first vertical portion fixedly connected to one another; the second T-shaped steel includes a second horizontal portion and a second vertical portion fixedly connected to each other, the first horizontal portion and the second horizontal portion being disposed opposite each other with a gap therebetween, the first vertical portion and the second vertical portion being disposed opposite each other with a gap therebetween, the closure plates cover an upper surface of the first vertical portion and an upper surface of the second vertical portion and are fixedly connected to the upper surface of the first vertical portion and the upper surface of the second vertical portion, respectively; the first arcuate piece is fixedly connected to a surface of the first vertical portion near the second vertical portion; the second arc piece is fixedly connected to a surface of the second vertical portion near the first vertical portion, each first arc piece having the second arc piece on its opposite side, the first arc piece and the second arc piece being located on the same horizontal plane; the support block is installed between the first T-shaped steel and the second T-shaped steel, a first distance is provided between the first horizontal portion and the support block, and a second distance is provided between the second horizontal portion and the support block; When the clamp assembly is in use, a central portion of the strain beam is clamped between the first arc piece and the second arc piece, a bottom portion of the strain beam is pressed against an upper surface of the support block, and the strain beam is supported by the support block.

4. The base distortion generator according to claim 3.

8. The clamp assembly further includes a groove and a support bead. the groove is provided on the upper surface of the support block, the support bead is embedded in the groove, and the surface of the groove conforms to the shape of the support bead; When the clamp assembly is in use, point contact is formed between the top of the support bead and the bottom surface of the strain beam, and surface contact is formed between the bottom of the support bead and the surface of the groove, thereby supporting the strain beam by the support block.

8. The base distortion generator according to claim 7.

9. the clamp assembly further includes a tightening assist mechanism; the tightening assist mechanism is provided on a side of the second vertical portion farther away from the first vertical portion, When the first T-shaped steel is screwed and fixed onto the base and the central portion of the strain beam is located between the first arc piece and the second arc piece, the clamping assist mechanism is moved in a direction approaching the second T-shaped steel and clamped, and the clamping assist mechanism presses against the second vertical portion, thereby pressing the second arc piece against the central portion of the strain beam, and the first arc piece and the second arc piece clamp the central portion of the strain beam.

9. The base distortion generator according to claim 8.

10. A base strain sensitivity measurement system, comprising: a base strain generator according to any one of claims 1 to 9; a sensor to be measured; at least two strain gauges; two displacement sensors; and a control device; the base strain generator includes a base, a strain beam, a clamp assembly, and two sets of magnetic circuit devices; The sensor to be measured is fixed and installed by a mounting structure at the center of the strain beam, The strain gauge is fixedly installed at the center of the strain beam and is used to measure strain values ​​within a set range of the mounting structure; The displacement sensor is installed in each magnetic circuit device, and the displacement sensor is used to measure the initial positions of both ends of the strain beam when the strain beam is stationary, and after the initial positions of both ends of the strain beam are set as zero displacement points, the both ends of the strain beam are maintained to always oscillate with the same amplitude on both sides of the zero displacement point through feedback control; the control device is connected to the magnetic circuit device, the measured sensor, the strain gauge, and the displacement sensor, respectively, and controls at least the magnitude and frequency of the sinusoidal excitation by the magnetic circuit device, acquires the strain value output by the strain gauge, acquires the displacement value output by the displacement sensor, and acquires the acceleration value output by the measured sensor; A base strain sensitivity measurement system.

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