Base strain generating device and base strain sensitivity measuring 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 utilizes 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 to be measured, which is subject to vibration during operation, and the mass block applies alternating stress to the piezoelectric sensing element. During measurement, the sensing part of the compression type vibration sensor is placed directly on the sensor base, and the two are in surface contact, so the effect of deformation of the base due to distortion 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, causing polarization and generating an erroneous output. 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] According to the Chinese national standard "GB / T13823.6-1992 Calibration method for vibration and shock sensors - Base strain sensitivity measurement", a steel beam of 1500 mm x 76 mm x 12.5 mm is used with one end fixed to form a strain beam. A vibration measuring sensor is installed 40 mm from the fixed end of the strain beam, and the center line of the vibration measuring sensor is 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 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 the base strain sensitivity are to fix one end of a strain beam and apply a force to the free end to produce a prescribed value of base strain at the location where the sensor to be measured is attached, and then release the strain beam to vibrate it at its natural frequency, or to apply a steady-state excitation to the free end of the strain beam to bend it. However, in the above two methods, the measurement sensor is placed 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 measurement accuracy of the base strain. Summary of the Invention

[0007] Therefore, in the past, the measured sensor 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 measured sensor 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 generating device and a base strain sensitivity testing device.

[0008] First, the present invention provides a base distortion generating device for detecting a base sensitivity of a sensor to be measured, the base distortion generating device 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 part, the clamp assembly being fixedly connected to the base and used to fix the position of the mounting structure at the central portion 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 measuring 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; A sensor to be measured is fixedly mounted to a mounting structure in 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, the two ends of the strain beam are maintained to vibrate with equal amplitude on both sides of the zero displacement point during motion through feedback control.

[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 clamped to the center of the strain beam, the position of the mounting structure is fixed, and the measured sensor installed on the mounting structure will not generate additional acceleration components due to the vibration of the strain beam. At the same time, two sets of magnetic circuit devices provide sinusoidal excitation to both ends of the strain beam, causing both ends of the strain beam to move back and forth, and by controlling the magnitude and frequency of the sinusoidal excitation, a stable amplitude vibration can be generated, and the base strain sensitivity at different frequencies and different base strains can be measured. With this solution, the installation position of the measured sensor will not be displaced, and the measured sensor will not generate additional acceleration output, improving the measurement accuracy of the base strain sensitivity. [Brief description 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 generating device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic structural diagram of a clamp assembly of the base strain generator provided in the embodiment shown in FIG. 1 . [Diagram 3] FIG. 2 is a schematic structural diagram of a clamp 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. 2 is a schematic structural diagram of a base distortion generating device provided by another embodiment of the present application; [Diagram 5] FIG. 5 is a schematic structural diagram of the base strain generator in the embodiment shown in FIG. 4 after removing the closing plate. [Figure 6]FIG. 5 is a schematic diagram showing the positional relationship between the clamp assembly, grooves, and support beads of the base strain generator provided by the embodiment shown in FIG. 4. [Figure 7] 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. 1 and 4. [Figure 8] 5 is a perspective view (an enlarged view of B in FIG. 4) of one of the magnetic circuit devices of the base strain generator provided by the embodiment shown in FIG. 1 and FIG. 4 after removing a sealing plate. [Figure 9] 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. 1 and 4. [Figure 10] 5 is a perspective view (enlarged view of B in FIG. 4) of one of the magnetic circuit devices of the base distortion generator provided by the embodiment shown in FIG. 1 and FIG. 4, seen from another angle. [Figure 11] 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. 1 and 4. FIG. [Figure 12] 5 is a schematic diagram (enlarged view of B in FIG. 4) showing the installation position of a measurement body in one magnetic circuit device of the base distortion generator provided by the embodiment shown in FIGS. 1 and 4. FIG. [Figure 13] 5 is a schematic configuration diagram of a coil bobbin and a coil winding groove of a magnetic circuit device of the base strain generator provided by the embodiment shown in FIG. 1 and FIG. 4 (an enlarged view of a part B in FIG. 4). FIG. [Figure 14] FIG. 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. [Figure 15] FIG. 2 is a schematic diagram of a frame structure of a base strain sensitivity test system provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 generating device 100 for measuring the base strain sensitivity of a sensor 300 to be measured.

[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] The strain beam 120 has a mounting structure 121 at its center for fixing and installing the sensor 300 to be measured. The 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 set being fixedly connected to the base 110, and one set being provided at each end of the strain beam 120. The ends of the strain beam 120 provide sinusoidal excitation for oscillating 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, so that the position of the mounting structure 121 is fixed, and the measured sensor 300 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, the two sets of magnetic circuit devices 140 provide sinusoidal excitation to both ends of the strain beam 120, causing both ends of the strain beam 120 to reciprocate. In addition, by controlling the magnitude and frequency of the sinusoidal excitation, a stable amplitude of vibration can be generated, and the base strain sensitivity at different frequencies and different base strains can be measured. This eliminates the misalignment of the installation position of the measured sensor 300, prevents the measured sensor 300 from generating additional acceleration output, and improves 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, thereby generating a uniform strain in the base and improving the 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 the mounting holes, 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 fixing screws, 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 better 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 or the like can be used to ensure 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 may be provided perpendicular to the extension direction of the strain beam 120 to allow multiple measured sensors 300 to 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 screwed into the cantilever arm 131b, and the movable screw 134 coincides 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 disposed opposite to each other, and a gap is provided between the lower surface of the movable screw 134 and the upper surface of the strain beam 120.

[0035] As the movable screw 134 rotates, the movable screw 134 and the fixed rod 132 approach each other, 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 due to the influence of vibrations at both ends of the strain beam 120, so that 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 upper surface of the strain beam 120, and the movable screw 134 has a first conical portion 134a at an 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 on 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 connected to each other 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 reduce the influence of the clamp assembly 130 on the bending of the strain beam 120 as much as possible.

[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, and there is 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, and there is 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 arc pieces 138b are fixedly connected to the surface of the first vertical portion 136b on the side closer to the second vertical portion 137b. A plurality of second arc pieces 138c are fixedly connected to the surface of the second vertical portion 137b on the side closer to the first vertical portion 136b. Each of the first arc pieces 138b has a second arc piece 138c arranged opposite it, and the first arc piece 138b and the second arc piece 138c arranged opposite 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 the strain beam 120 is clamped between the first arcuate piece 138b and the second arcuate piece 138c, and the bottom of the strain beam 120 contacts the top surface of the support block 138d. The support block 138d provides support to the 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 contact and form line contact with the strain beam 120. The arc pieces are configured as sheet-like structures with arcuate edges, although the shape of the arc pieces may also be half of a circle, i.e., a semicircular piece.

[0049] In this embodiment, the arc piece is installed as a sheet-like structure with arc edges, rather than a cylinder or other shape, because it is convenient 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 mentioning that the first interval may be equal to the second interval, however, during the 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 fine-tuned, so that the second interval is not equal to the second interval from the microscopic point of view, but the difference between the first interval and the second interval is not so large, and the difference is in 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] The groove 139a is provided on the upper surface of the support block 138d. A support bead 139b is embedded in the groove 139a. The groove surface of the groove 139a matches the shape of the 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 remote 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 disposed between the first arcuate piece 138b and the second arcuate piece 138c, the fastening assist mechanism 139c moves in a direction approaching the second T-shaped steel 136 and is fastened, and the fastening assist mechanism 139c is pressed against the second vertical portion 137b. As a result, the second arcuate piece 138c is pressed against the central portion of the strain beam 120, and the first arcuate piece 138b and the second arcuate piece 138c sandwich the central portion of the strain beam 120.

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

[0059] The first horizontal portion 136a of the first T-shaped steel 135 is provided with a plurality of circular through holes, 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 bolted to the base 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 rectangular, and the installation position of the second T-shaped steel 136 can be finely adjusted by sliding and adjusting along the length direction of the bolt adjustment through holes 137c within the range of the length of the bolt adjustment through holes 137c. 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 is provided with 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 of the tightening assist mechanism 139c, and by tightening the screws, the tightening assist mechanism 139c gradually approaches the second T-shaped steel 136 until the end of the screw is pressed against the surface of the second vertical portion 137b. This causes the tightening assist mechanism 139c to be pressed against the second horizontal portion 137a, and the second T-shaped steel 136 and the second arc piece 138c to approach the strain beam 120, and the second arc piece 138c is pressed against the strained beam 120, and the strained beam 120 is sandwiched between the first arc piece 138b and the second arc 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 the 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 no tightening work is performed.

[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 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 piece 138b and the second arc 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 143a, a second magnet 143b, a coil bobbin 145a, a magnetic yoke 144, and a driving coil 146.

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

[0072] The magnetic yoke 144 is disposed in a hollow portion of a 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 in a conducting state, the drive coil 146 is connected to a regularly changing steady-state sine wave current, and the current flowing through the drive coil 146 is a sine wave 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 receives a steady-state sine wave 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), and this 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 the first magnet 143a closer to the magnetic yoke 144 is the N pole, and the side of the first magnet 143a farther from the yoke 144 is the S pole. The side of the second magnet 143b closer to the magnetic yoke 144 is the N pole, and the side of the second magnet 143b farther from the magnetic yoke 144 is the S 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, 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, 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 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] In addition, it also includes a limiting plate 148b, which is located above the magnetic yoke 144, and the limiting plate 148b is disposed on the upper part 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. In a current-carrying state, the coil bobbin 145a drives the free end of the strain beam 120 to swing. The frequency and magnitude of the sinusoidal current are controlled to make the strain beam 120 swing at different frequencies, and the limiting plate 148b is used to limit the range of swing, thereby protecting the device from damage caused by excessive stress caused by excessive swing range.

[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 is fixedly connected to the first side magnetic conductive plate 141a, and the second convex base 149b is positively connected to the second side magnetic conductive plate 141b.

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

[0092] Here, the height 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. 9, the first magnet 143a is disposed adjacent to the first protruding base 149a, the first magnet 143a abuts against the inner surface of the first-side magnetic conductive plate 141a, the second magnet 143b is disposed adjacent to the second protruding base 149b, the second magnet 143b abuts against the inner surface of the second-side 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 in a rectangular frame shape having a hollow portion. Both the first magnet 143a and the second magnet 143b are magnetic, and the magnetic yoke 144 is non-magnetic and made of a magnetic conductive material. After energization, the center of the magnetic yoke 144 can conduct magnetism to 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, and therefore there is a gap 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] Furthermore, as shown in FIG. 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 side magnetic conductive plate 141a, and the second magnet 143b is attracted to the inner surface of the second side 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, 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 fixed block 150 .

[0101] Specifically, the cover plate 148a is used to form an enclosed space inside the magnetic circuit device 140, to cover the magnetic circuit device 140, and 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, so that 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 by bolts, and the second magnetic yoke fixing plate 142b is fixedly connected to the inner surface of the second protective plate 140b by 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, and the first protective plate 140a 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 side magnetic conductive plate 141a by a bolt, and the other side of the first protective plate 140a is fixedly connected to the second side magnetic conductive plate 141b by a bolt. One side of the first magnetic yoke fixing plate 142a is fixedly connected to the first side magnetic conductive plate 141a by a bolt, and the other side of the first magnetic yoke fixing plate 142a is fixedly connected to the second side magnetic conductive plate 141b by a bolt. One side of the second magnetic yoke fixing plate 142b is fixedly connected to the first side magnetic conductive plate 141a by a bolt, and the other side of the second magnetic yoke fixing plate 142b is fixedly connected to the second side magnetic conductive plate 141b by 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 side magnetic conductive plate 141a by a bolt, and the other side of the second protective plate 140b is fixedly connected to the second side 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 disposing a connection plate between the coil bobbin and the strain beam 120. Then, 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 distortion sensitivity test system 10.

[0111] 15, in one embodiment of the present application, the base strain sensitivity test system 10 includes the above-mentioned 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 to be measured 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. Using the displacement sensor 500, the initial positions of both ends of the strain beam 120 when the strain beam 120 is stationary are measured, and the initial positions of both ends of the strain beam 120 are set as the zero points of displacement of 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 each of the magnetic circuit device 140, the measured sensor 300, the strain gauge 400, and the displacement sensor 500. The control device 200 is used at least for controlling the magnitude and frequency of the sinusoidal excitation output by the magnetic circuit device 140, acquiring the strain value by the strain gauge 400, acquiring the displacement value by the displacement sensor 500, and acquiring the acceleration value output by the measured sensor 300.

[0116] Specifically, the sealing plate 149d of the magnetic circuit device 140 is provided with a displacement sensor mounting hole 149e for mounting the displacement sensor 500. The displacement sensor 500 is an eddy current sensor and is capable of non-contact measurement. A measuring body 149c used together with the displacement sensor 500 is attached to the coil bobbin 145a. The displacement sensor 500 is provided on 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. What the displacement sensor 500 specifically detects is 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 disposed close to the measured sensor 300. Optionally, when there are two strain gauges 400, the two strain gauges 400 are disposed symmetrically around the measured sensor 300 at the center of the strain beam 120.

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

[0119] The above-mentioned embodiments only represent some embodiments of the present application, and although their descriptions 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 are included in the protection scope of the present application. Therefore, the protection scope 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 portion; 134, movable screw, 134a, first cone portion; 135, first T-beam, 136a, a first horizontal portion; 136b, a first vertical portion; 136, second T-shaped steel, 137a, second horizontal section; 137b, second vertical section; 137c, bolt adjustment through hole, 138a, closing plate, 138b, a first arc piece; 138c, a second arc piece; 138d, support 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, a first magnet; 143b, a second magnet; 144, magnetic yoke, 145a, coil bobbin, 145b, coil winding groove; 146, driving coil, 147, pressure plate, 148a, cover plate; 148b, restriction plate, 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, a 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 to be measured, comprising: a base, a strain beam, a clamp assembly, and two magnetic circuit devices fixedly connected to the base; The strain beam is provided at its center with a mounting structure for fixing and mounting a sensor to be measured, the clamp assembly is fixedly connected to the base and is adapted to fix the position of the mounting structure at the central portion of the strain beam; The magnetic circuit device is provided with a pair at each end of the strain beam, and the magnetic circuit device applies a 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 generating device.

2. 2. The base strain generator of 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 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, an upper surface of the fixed rod faces a 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 generating device 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 are disposed opposite each other and a gap is provided between the first horizontal portion and the second horizontal portion, the first vertical portion and the second vertical portion are disposed opposite each other and a gap is provided between the first vertical portion and the second vertical portion, the closure plate covers an upper surface of the first vertical portion and an upper surface of the second vertical portion and is 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 proximate the second vertical portion; the second arc piece is fixedly connected to a surface of the second vertical portion proximate the first vertical portion, each of the first arc pieces having the second arc piece on an opposite side thereof, 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 a top 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 an upper surface of the support block, the support bead is embedded in the groove, the surface of the groove conforming to the shape of the support bead; in a use state of the clamp assembly, a point contact is formed between an upper portion of the support bead and a bottom surface of the strain beam, and an area contact is formed between a bottom portion of the support bead and a surface of the groove, whereby the strain beam is supported by the support block; 8. A base distortion generator according to claim 7.

9. The clamp assembly further includes a clamping 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 on the base, and the central portion of the strain beam is located between the first arcuate piece and the second arcuate piece, the clamping assistant mechanism is moved in a direction approaching the second T-shaped steel and clamped, and the clamping assistant mechanism presses against the second vertical portion, thereby pressing the second arcuate piece against the central portion of the strain beam, and the first arcuate piece and the second arcuate 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 fixedly 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 distortion sensitivity measurement system.

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