Micro force value calibration device based on electromagnetic force balance principle

Abstract

The utility model discloses a micro force value calibration device based on an electromagnetic force balance principle. The micro force value calibration device comprises a fixedly arranged base and a cross beam erected above the base through a stand column. A vertically arranged bearing column is arranged below the cross beam, a test space for placing a dynamometer to be calibrated is formed between the bearing column and the cross beam, and a piezoelectric ceramic linear displacement driving module capable of vertically deforming to apply a load is arranged at one vertical end of the test space; the bearing column can be vertically and movably installed on the base through an elastic assembly with the characteristics of a Roburvil structure, the elastic assembly is connected with a balance arm, and the middle of the balance arm is installed on the base through a flexible fulcrum; an electromagnetic force balance sensor assembly is arranged at the end, away from the bearing column, of the balance arm. The force measuring device has the advantages of being ingenious in structural design, capable of measuring micro force values, high in force measuring precision, capable of achieving continuous measurement of the force values and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of measurement technology, especially a micro force value calibration device based on electromagnetic force balance principle. BACKGROUND

[0002] In many disciplines such as new material research and high-end medical equipment processing, micro force value testing technology is widely used. With the rapid development of nanometer measurement and nanometer electromechanical system and other related professions, a large number of micro force values are measured in scientific research and production: such as thin film mechanical property testing, micro hardness testing, etc. In the mechanical property testing of some silicon thin film and composite silicon thin film materials, the range of the load sensor used is only 0~4.5N, and the force value measurement error requirement is within 1%. The test force range of the micro Vickers hardness tester used in micro Vickers hardness testing is 0.09807N~1.961N, and the maximum allowable error of the test force is ±1.5%. The accuracy of the small test force value in these tests directly affects the accuracy of the research results and the quality of the production products.

[0003] However, after using the small force value (range 10N, 5N) standard force gauge to calibrate the force value of the thin film mechanical property testing machine and the micro hardness tester, the accuracy of the entire traceability chain force value is affected due to the difficulty in tracing the source.

[0004] At present, according to the force value measurement instrument calibration range and value transmission method specified in the national verification regulation of our country - JJG 2045-2010 "force value (≤1MN) measurement instrument verification system table", it is impossible to carry out measurement and calibration work on the standard force gauge below 10N and other force gauges, and the reason is that the measurement lower limit of the upper level measurement standard instrument - force standard device is 10N. If the high-grade standard weight is used to trace the force value of the small force value standard force gauge, it will be difficult to place the weight or the uncertainty introduced by the tool will be too large.

[0005] Therefore, it is urgent to develop a force standard device or calibration device that can effectively trace the value of the small force value force gauge. INVENTION CONTENTS

[0006] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the utility model is: how to provide a micro force value calibration device with a clever structure design, capable of measuring micro force value, high force measurement precision and realizing continuous force value measurement.

[0007] In order to solve the above technical problems, the utility model adopts the following technical scheme:

[0008] A micro-force calibration device based on the principle of electromagnetic force balance includes a fixed base and a crossbeam mounted above the base via a column frame. A vertically positioned support column is located below the crossbeam, forming a test space between the support column and the crossbeam for placing a force measuring instrument to be calibrated. A piezoelectric ceramic linear displacement drive module capable of vertically deforming and applying load is located at one end of the test space. The support column is vertically movable on the base via an elastic component with Robeville structure characteristics. A balance arm is connected to the elastic component, and the middle portion of the balance arm is mounted on the base via a flexible fulcrum. An electromagnetic force balance sensor assembly is located at the end of the balance arm furthest from the support column.

[0009] Using the above structure, a balance structure is formed at both ends of the balance arm. The force gauge to be calibrated is placed vertically against the ground in the test space. A vertical load is applied through the piezoelectric ceramic linear displacement drive module, which disrupts the balance of the balance arm. Under the action of the electromagnetic force balance sensor assembly, the balance arm regains balance. At this point, the force detected by the force gauge to be calibrated and the force detected by the electromagnetic force balance sensor assembly are in equilibrium. That is, the force value detected by the electromagnetic force balance sensor assembly can be used to calibrate the force value detected by the force gauge to be calibrated. This structure is ingeniously designed, capable of measuring minute force values, and has high force measurement accuracy and continuous force measurement capability.

[0010] Furthermore, the piezoelectric ceramic linear displacement drive module is located at the top of the support column, and an adjustable-length spiral differential cylinder displacement adjustment device is located below the crossbeam, with the spiral differential cylinder displacement adjustment device facing the support column.

[0011] In this way, the height of the test space can be precisely adjusted using the spiral differential cylinder displacement adjustment device, so that the upper and lower ends of the force measuring instrument to be calibrated form a light contact, so as to enable more accurate calibration.

[0012] Furthermore, the crossbeam is fixed to the column in an adjustable manner.

[0013] In this way, the height of the test space can be quickly adjusted for force gauges of different heights to be calibrated, so as to adapt to the needs of different force gauges.

[0014] Furthermore, the elastic component includes two horizontally arranged and parallel first flexible hinges, the support column is connected to the two first flexible hinges, and one side of the support column is connected to the balance arm through a vertically arranged second flexible hinge. Each of the first and second flexible hinges has two hinge points.

[0015] Furthermore, the flexible fulcrum is a vertically arranged third flexible hinge, and the upper end of the third flexible hinge has a hinge point.

[0016] Furthermore, the electromagnetic force balance sensor assembly includes a single-coil permanent magnet magnetic circuit mechanism and a position detection device. The single-coil permanent magnet magnetic circuit mechanism includes a permanent magnet and a coil. The permanent magnet is fixedly mounted on the base, and the coil is connected to the balance arm.

[0017] Furthermore, a PID control circuit is electrically connected to the coil, and the position detection device includes a light-shielding component disposed on the balance arm. A group of photodiodes is disposed on both sides of the light-shielding component, and the group of photodiodes is electrically connected to the PID control circuit.

[0018] In summary, this utility model has the advantages of ingenious structural design, ability to measure minute force values, high force measurement accuracy, and continuous force measurement capability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the principle structure of this utility model. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the embodiments.

[0021] In practical implementation: such as Figure 1 As shown, a micro-force calibration device based on the principle of electromagnetic force balance includes a fixed base 1 and a crossbeam 2 mounted above the base 1 via a column frame. Below the crossbeam 2, a vertically arranged support column 3 forms a test space 4 between the support column 3 and the crossbeam 2 for placing a force measuring instrument to be calibrated. A piezoelectric ceramic linear displacement drive module 5 capable of vertically deforming and applying loads is installed at one vertical end of the test space 4. The support column 3 is vertically movable on the base 1 via an elastic component 6 with Robeville structural characteristics. A balance arm 7 is connected to the elastic component 6, and the middle part of the balance arm 7 is mounted on the base 1 via a flexible fulcrum 8. An electromagnetic force balance sensor assembly 9 is installed at the end of the balance arm 7 away from the support column 3.

[0022] In this embodiment, the crossbeam 2 is vertically adjustable and fixed to the column. This allows for rapid adjustment of the test space height to accommodate different force gauges at varying heights. Specifically, the column can be configured as a telescopic rod, utilizing its own telescopic function to adjust the crossbeam vertically. Alternatively, one end of the crossbeam 2 can be connected to the column via a vertical through-sleeve, and a locking screw threaded through the side wall of the sleeve can be used to fix the crossbeam 2 at different heights on the column, thus achieving vertical adjustment.

[0023] To ensure the height of the test space is perfectly matched to the height of the force gauge to be calibrated, in this embodiment, the piezoelectric ceramic linear displacement drive module 5 is positioned at the top of the support column 3, and an adjustable-length spiral differential cylinder displacement adjustment device 10 is positioned below the crossbeam 2, directly opposite the support column 3. This allows for precise fine-tuning of the test space height using the spiral differential cylinder displacement adjustment device, ensuring a light contact between the upper and lower ends of the force gauge to be calibrated, thus enabling more accurate calibration.

[0024] like Figure 1 As shown, the elastic component 6 includes two horizontally arranged and parallel first flexible hinges. The support column 3 is connected to the two first flexible hinges. One side of the support column 3 is connected to the balance arm 7 via a vertically arranged second flexible hinge. Both the first and second flexible hinges have two hinge points. The flexible fulcrum 8 is a vertically arranged third flexible hinge, and the upper end of the third flexible hinge has one hinge point.

[0025] In this embodiment, the electromagnetic force balance sensor assembly 9 includes a single-coil permanent magnet magnetic circuit mechanism and a position detection device. The single-coil permanent magnet magnetic circuit mechanism includes a permanent magnet 91 and a coil 92. The permanent magnet 91 is fixedly mounted on the base 1, and the coil 92 is connected to the balance arm 7. A PID adjustment circuit is electrically connected to the coil 92. The position detection device includes a light-shielding component mounted on the balance arm 7. Photodiode groups are arranged on both sides of the light-shielding component, and the photodiode groups are electrically connected to the PID adjustment circuit.

[0026] The micro-force calibration device of this embodiment uses a spiral differential cylinder-type coarse displacement adjustment device to adjust the spatial height position of the standard force gauge under test, so that the force gauge under test and the spiral differential cylinder are just about to make contact. Subsequently, a piezoelectric ceramic with the inverse piezoelectric effect is precisely loaded onto the standard force gauge under test. The piezoelectric ceramic selected in this embodiment has a nominal maximum displacement stroke of 152 and a nominal capacitance of 15. The piezoelectric ceramic drive controller has a nominal output voltage range of -20~120V, and the displacement control accuracy can reach the nanometer level. After the micro-force loading is completed, the initial electromagnetic force equilibrium state is broken, and the movable coil generates displacement. To ensure the response speed of the closed-loop adjustment system, improve the accuracy and stability of the force measurement system, and avoid introducing digital noise, an analog PID control circuit is used. The signal output from the beam position sensor is used as the input of the PID controller, and after PID adjustment, the output is shunted to drive the coil. The torque conversion device controls the beam inside the electromagnetic force balance sensor, restoring the beam to its original equilibrium position. The output current of the current-carrying coil is continuously and dynamically adjusted by an analog PID control circuit, always providing a current proportional to the external force to the coil. Under the influence of the working air gap magnetic field, the energized coil drives the small crossbeam to move towards a new equilibrium position, generating a force against the direction of the external force, ultimately achieving equilibrium with the external force. The device accurately measures the coil current, converts it into a digital signal via analog-to-digital conversion, and feeds it back to the computer control system, thus completing the precise measurement of the minute external force. The electromagnetic force generated by the micro-load F and the current-carrying coil in the magnetic field... They are equal, and their relationship is as follows: ;and . —This refers to the magnetic induction intensity at the working air gap; —The effective length of the coil under magnetic field conditions; —The current intensity through the current-carrying coil.

[0027] When the balance arm regains balance, the force detected by the force gauge to be calibrated and the force detected by the electromagnetic force balance sensor assembly are in equilibrium. This means that the force value detected by the electromagnetic force balance sensor assembly can be used to calibrate the force gauge. This ingenious design enables the measurement of minute force values, providing high accuracy and continuous force measurement.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A micro-force calibration device based on the principle of electromagnetic force balance, characterized in that, The device includes a fixed base (1) and a crossbeam (2) mounted above the base (1) via a column frame; a vertically mounted support column (3) is provided below the crossbeam (2), and a test space (4) for placing the force measuring instrument to be calibrated is formed between the support column (3) and the crossbeam (2); a piezoelectric ceramic linear displacement drive module (5) capable of vertical deformation to apply load is provided at one end of the test space (4); the support column (3) is vertically movable on the base (1) via an elastic component (6) with Robeville structural characteristics; a balance arm (7) is connected to the elastic component (6); the middle part of the balance arm (7) is mounted on the base (1) via a flexible fulcrum (8); an electromagnetic force balance sensor assembly (9) is provided at the end of the balance arm (7) away from the support column (3).

2. The micro-force calibration device based on the principle of electromagnetic force balance as described in claim 1, characterized in that, The piezoelectric ceramic linear displacement drive module (5) is located on the top of the support column (3), and an adjustable length spiral differential cylinder displacement adjustment device (10) is located below the crossbeam (2). The spiral differential cylinder displacement adjustment device (10) is positioned opposite the support column (3).

3. The micro-force calibration device based on the principle of electromagnetic force balance as described in claim 1 or 2, characterized in that, The crossbeam (2) can be adjusted up and down and fixed to the column.

4. The micro-force calibration device based on the principle of electromagnetic force balance as described in claim 1 or 2, characterized in that, The elastic component (6) includes two horizontally arranged and parallel first flexible hinges. The support column (3) is connected to the two first flexible hinges. One side of the support column (3) is connected to the balance arm (7) through a vertically arranged second flexible hinge. Both the first and second flexible hinges have two hinge points.

5. The micro-force calibration device based on the principle of electromagnetic force balance as described in claim 4, characterized in that, The flexible fulcrum (8) is a vertically arranged third flexible hinge, and the upper end of the third flexible hinge has a hinge point.

6. The micro-force calibration device based on the principle of electromagnetic force balance as described in claim 1, characterized in that, The electromagnetic force balance sensor assembly (9) includes a single-coil permanent magnet magnetic circuit mechanism and a position detection device. The single-coil permanent magnet magnetic circuit mechanism includes a permanent magnet (91) and a coil (92). The permanent magnet (91) is fixedly mounted on the base (1), and the coil (92) is connected to the balance arm (7).

7. The micro-force calibration device based on the principle of electromagnetic force balance as described in claim 6, characterized in that, The coil (92) is electrically connected to a PID control circuit. The position detection device includes a light-shielding component disposed on the balance arm (7). A group of photodiodes is disposed on both sides of the light-shielding component. The group of photodiodes is electrically connected to the PID control circuit.

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