Quartz flexible accelerometer torquer stator assembly magnetic measurement clamp and magnetic measurement method

Abstract

The invention provides a quartz flexible accelerometer torquer stator assembly magnetic measurement clamp and a magnetic measurement method, and solves various influences caused by taking open-circuit flux density of a center point of a torquer as a torquer stator assembly selection basis in the prior art. According to the invention, the characteristic that a Hall chip is sensitive to a magnetic field and can be converted into magnetic induction intensity is utilized, and the characteristic of an inner cavity structure of a torquer stator assembly of a quartz flexible accelerometer is combined, so that a magnetic measurement clamp capable of carrying out a multi-point closed flux density test at a working air gap between a torquer stator and magnetic steel is designed; the step core shaft on the magnetic measurement clamp can be perfectly and adaptively inserted into the working air gap, so that the Hall chip embedded on the step core shaft is located in the working air gap, and the conversion from the open-circuit magnetic flux density test of the end face of the magnetic steel assembly to the closed magnetic flux density test of the working air gap is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a magnetic measuring fixture and a magnetic measuring method for a stator assembly of a quartz flexible accelerometer torquer. Background Art

[0002] The quartz flexible accelerometer was first developed by Senstan Corporation in the United States in the 1970s. The specific structure is as follows: Figure 3 As shown, it is the most widely used accelerometer in domestic navigation and guidance, positioning and orientation systems.

[0003] As the core component of the quartz flexible accelerometer, the torquer stator assembly mainly includes the torquer stator and the magnetic steel assembly. The torquer stator has an inner cavity, and the magnetic steel assembly is located in the inner cavity of the torquer stator, and a working air gap is formed between the circumference of the magnetic steel assembly and the torquer stator. The installation of the torquer stator assembly is a key link in the production of quartz flexible accelerometers. The torquer stator assembly adopts a permanent magnet moving coil type and a top-to-top layout. Its two magnetic circuits are independent of each other, forming a push-pull structure. In addition, the selection of the torquer stator assembly before installation is also the key to affecting the performance of the quartz flexible accelerometer.

[0004] The existing quartz flexible accelerometer torquer stator assembly magnetic density test method usually adopts a traditional handheld probe magnetic measuring fixture. The probe of the magnetic measuring fixture is relatively large and can only measure the open-circuit magnetic density of the center point of the end face of the magnetic steel assembly. It is impossible to measure in a small and complex space (such as a working air gap). Therefore, when this method is used to select the upper and lower torquer stator assemblies of the quartz flexible accelerometer, there may be a large magnetic density error, resulting in asymmetric magnetic density of the upper and lower torquer stator assemblies after assembly, and the symmetry accuracy of the quartz flexible accelerometer scale factor is reduced, which leads to the problem of large changes in the product scale factor.

[0005] Therefore, it is necessary to develop a new magnetic measuring fixture and magnetic measuring method for the torquer stator assembly. Summary of the invention

[0006] The purpose of the present invention is to solve the various influences brought about by the existing open-circuit magnetic density at the center point of the torquer as the basis for selecting the torquer stator assembly, and to provide a quartz flexible accelerometer torquer stator assembly magnetic measurement fixture and magnetic measurement method, aiming to improve the repeatability, stability and accuracy of the quartz flexible accelerometer.

[0007] To achieve the above purpose, the technical solution provided by the present invention is:

[0008] A magnetic measurement fixture for a stator assembly of a quartz flexible accelerometer torquer, which is special in that it comprises a fixture body, a cover and a cover plate;

[0009] The interior of the clamp body is a cavity, one end of which is coaxially provided with a stepped core shaft, and the other end is provided with the cover, and the body (i.e., the circumference) of the clamp body is provided with a through hole;

[0010] The step mandrel is a circular ring shaft, which can be inserted into the working air gap of the stator assembly of the torquer to be measured, and a notch is arranged along the axial direction of the mandrel for embedding the Hall chip of the magnetic measuring instrument;

[0011] The length of the step mandrel should satisfy the following requirement: when the step mandrel is inserted into the working air gap of the torquer stator assembly to be measured, the Hall chip embedded in the gap is at the same height as the magnetic steel of the torquer stator assembly;

[0012] A mounting position for mounting a cover plate is axially arranged at the position corresponding to the notch of the fixture body; the cover plate shields the Hall chip embedded on the step mandrel, and is used to ensure that the magnetic circuit is closed when the step mandrel is inserted into the working air gap of the stator assembly of the torquer to be measured, that is, to ensure magnetic measurement under a closed circuit, and the cover plate can slide back and forth axially at the mounting position;

[0013] The fixture body, step mandrel, cover and cover plate are all made of non-magnetic and magnetic-isolating materials.

[0014] Further, the fixture body is a hollow shaft, one end of which is coaxially connected to the step core shaft through a step surface;

[0015] A notch is provided on the step surface at a position corresponding to the notch, the notch being connected to the mounting position.

[0016] Furthermore, the cover plate is slidably installed at the installation position of the clamp body through a guide rail and guide groove structure, and its length is smaller than the length of the installation position. The end of the cover plate that contacts the clamp body is semicircular.

[0017] Furthermore, the cover is a screw, which is screwed onto the other end of the clamp body, namely the tail end.

[0018] Meanwhile, the present invention provides a quartz flexible accelerometer torquer stator assembly magnetic measurement tool, which is special in that it comprises a Tesla meter and the above-mentioned quartz flexible accelerometer torquer stator assembly magnetic measurement fixture;

[0019] The Hall chip of the Tesla meter is embedded in the notch of the step mandrel; the sensor leads of the Hall chip pass through the inside of the fixture body and the through holes of the body in sequence and are led out.

[0020] Furthermore, in order to facilitate the operation of the operator and improve the rotation angle accuracy, it also includes an electric indexing plate and a clamping tool; the clamping tool is used to install the magnetic measuring fixture on the electric indexing plate;

[0021] The electric dividing plate is used to drive the magnetic measuring fixture to rotate a required angle.

[0022] In addition, the present invention provides a magnetic measurement method using the above-mentioned quartz flexible accelerometer torquer stator assembly magnetic measurement tool, which is special in that the steps are as follows:

[0023] 1) Insert the stepped mandrel of the magnetic measuring fixture into the working air gap of the torque generator stator assembly to be measured, so that the Hall chip embedded on the stepped mandrel is at the same height as the magnetic steel;

[0024] 2) Rotate the magnetic measuring fixture as required, and use the Hall chip to measure the magnetic induction intensity at the corresponding point of the working air gap.

[0025] Furthermore, the magnetic measuring fixture is mounted on the electric dividing plate by means of a clamping fixture, and the electric dividing plate is used to rotate the magnetic measuring fixture.

[0026] And, a method for selecting a stator assembly of a quartz flexible accelerometer torquer, characterized in that:

[0027] 1) According to the above-mentioned magnetic measurement method, the magnetic induction intensity of at least three points corresponding to the working air gap in the stator assembly of the upper torquer to be selected and the stator assembly of the lower torquer to be selected is measured respectively;

[0028] 2) According to the magnetic induction intensity measured in step 1), select the upper torquer stator assembly and the lower torquer stator assembly for assembly. The selection requirements are:

[0029] ① The difference between the magnetic induction intensity of the measured point on the stator assembly of the upper torquer to be selected and the magnetic induction intensity of the measured point on the stator assembly of the lower torquer to be selected is ≤200GS;

[0030] ② The absolute value of the difference in magnetic induction intensity between the corresponding measuring points of the upper torque converter stator assembly to be selected and the lower torque converter stator assembly to be selected is ≤200GS;

[0031] ③ The difference in magnetic induction intensity between the corresponding measuring points of the upper torque converter stator assembly and the lower torque converter stator assembly to be selected is the smallest.

[0032] Concept and principle of the present invention:

[0033] In view of the drawbacks of traditional handheld probe magnetic measurement fixtures and magnetic density testing methods, the present invention abandons the idea of ​​open-circuit magnetic density testing at the center point of the end face of the magnetic steel component, utilizes the characteristics of the Hall chip that is sensitive to the magnetic field and can be converted into magnetic induction intensity, and combines the characteristics of the inner cavity structure of the quartz flexible accelerometer torquer stator assembly to perform multi-point closed magnetic density testing at the working air gap between the torquer stator and the magnetic steel. For this purpose, the present invention designs a special magnetic measuring fixture, on which the step core shaft can be perfectly inserted into the working air gap (that is, the inner circumference of the step core shaft is tangent to the outer cylindrical surface of the magnetic steel, and the outer circumference of the step core shaft is tangent to the inner hole of the torquer stator, so as to achieve a sliding fit between the step core shaft and the working air gap), so that the Hall chip embedded in the step core shaft is in the working air gap, thereby realizing the conversion from the open-circuit magnetic density testing at the center point of the end face of the magnetic steel component to the closed magnetic density testing of the working air gap.

[0034] The advantages of the present invention are:

[0035] 1. The present invention designs a special magnetic density test fixture and embeds a Hall chip so that the special magnetic density test fixture and the working air gap of the torquer stator assembly are slidably matched, which can realize the technical research from magnetic measurement of the end face of the magnetic steel assembly to magnetic measurement of the working air gap, and can accurately provide a basis for the selection of subsequent torquer stator assemblies, realize the precise selection of upper and lower torquer stator assemblies, and improve the symmetry accuracy index of the product scale factor.

[0036] 2. The present invention can reduce the possibility of large magnetic density measurement errors when selecting the open-circuit magnetic density at the center point of the end face of the magnetic steel component, thereby reducing the magnetic density asymmetry of the upper and lower torquer stator assemblies after assembly, avoiding the decrease in the symmetry accuracy of the scale factor of the quartz flexible accelerometer, thereby reducing the impact of magnetic field changes on the quartz flexible accelerometer, and further improving the repeatability and stability accuracy of the quartz flexible accelerometer.

[0037] 3. After the present invention completes the design and manufacture of the special magnetic density test fixture, the magnetic measurement process is optimized, and according to the working air gap magnetic density of the four symmetrical points of the upper and lower torquer stator assemblies, the one with the smallest symmetrical magnetic density difference is selected to form a pair, thereby achieving accurate matching of the upper and lower torquer stator assemblies and production of high-precision quartz flexible accelerometers, improving the symmetry accuracy index of the product scale factor, reducing the unqualified assembly phenomenon of the quartz flexible accelerometer caused by the torquer matching problem, and reducing the resulting decomposition and associated scrapping.

[0038] 4. The present invention converts the open-circuit magnetic density measurement of the end face of the magnetic steel assembly into the closed-circuit magnetic density measurement of the upper and lower torquer stator assemblies. Since the upper and lower torquer stator assemblies are assembled into a torquer stator assembly (see Figure 4), the main distribution position of the magnetic density lines is in the gap between the magnetic steel and the upper and lower torquer stator assemblies, that is, the working gap where the pendulum assembly is located. The entire structure is roughly symmetrically arranged. The torquer coil is wound on the skeleton and then assembled with the pendulum frame to form a pendulum assembly. The magnetic steel is a permanent magnet, which generates an axial constant top magnetic field inside the watch core. When the product is in working condition, it moves in the air gap between the upper and lower torquer stator assemblies and the skeleton assembly. Therefore, in order to enable the product to obtain good magnetic pairing, it is necessary to measure and select the working air gap magnetic density of the symmetrical points of the upper and lower torquers in a closed loop. If measures can be taken to measure the working gap magnetic density of several points evenly distributed in the closed loop of the torquer stator assembly, more accurate matching of the upper and lower torquer stator assemblies can be achieved, and the accuracy of the degree factor symmetry index can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 : It is a structural diagram of each component of the magnetic density test fixture of the present invention; wherein a is a schematic diagram of the overall structure, b is a schematic diagram of the screw structure, and c is a schematic diagram of the cover plate structure;

[0040] Figure 2 It is an assembly diagram of the magnetic density testing tool of the present invention;

[0041] In the figure: 1- fixture body; 2- step mandrel; 3- screw; 4- Hall chip; 5- cover plate; 6- through hole; 7- mounting position; 8- sensor lead; 9- Tesla meter; 10- step surface;

[0042] Figure 3 It is a schematic diagram of the structure of an existing general-purpose quartz flexible accelerometer;

[0043] In the figure: 01- pendulum assembly, 02- torquer stator assembly, 03- servo circuit;

[0044] Figure 4 The figure is a schematic diagram of the points for measuring the upper and lower torquer stator assemblies using the magnetic measuring tool of the present invention. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0046] like Figure 1As shown, the magnetic measuring fixture of the stator assembly of the quartz flexible accelerometer torquer includes a fixture body, a cover and a cover plate. The fixture body is a hollow shaft, and a step core shaft is coaxially arranged on one end face thereof (specifically, a step surface is extended inward from the inner wall surface of this end of the fixture body, and is connected to the step core shaft coaxially arranged with the fixture body, and the end face of the fixture body is higher than the step surface); a cover is installed on the other end (in this embodiment, a screw is selected as the cover, and after each component is installed in place, it is screwed into the other end of the fixture body), and a through hole is arranged on the body of the fixture body (i.e. on the circumference); the step core shaft is a circular shaft, which can be adapted to be inserted into the working air gap of the stator assembly of the torquer to be measured, and a notch is arranged on its body along the axial direction for embedding the Hall chip of the magnetic measuring instrument; the length of the step core shaft should meet the following requirements: when the step core shaft is inserted into the working air gap of the stator assembly of the torquer to be measured , the Hall chip embedded in its notch is at the same height as the magnetic steel of the torquer stator assembly; a mounting position for installing a cover plate is axially arranged at the notch corresponding to the fixture body; the length of the cover plate is less than the length of the mounting position, and the end of the cover plate in contact with the fixture body is semicircular, which blocks the Hall chip embedded in the step core shaft, and is used to ensure that the magnetic circuit is closed when the step core shaft is inserted into the working air gap of the torquer stator assembly to be measured, that is, to ensure magnetic measurement under a closed loop, and the cover plate can slide back and forth axially at the mounting position (the cover plate can be slidably installed at the mounting position of the fixture body through a guide rail and guide groove structure); a notch that connects the notch and the mounting position is arranged at the position of the step surface corresponding to the notch; the fixture body, step core shaft, cover and cover plate are all made of non-magnetic and magnetic-isolating materials.

[0047] like Figure 2 As shown, the quartz flexible accelerometer torquer stator assembly magnetic measurement tool includes a Tesla meter and the above-mentioned quartz flexible accelerometer torquer stator assembly magnetic measurement fixture; wherein, the Hall chip of the Tesla meter is embedded in the notch of the step mandrel; the sensor leads of the Hall chip are successively passed through the inside of the fixture body and the through holes of the body and connected to the Tesla meter body. Of course, in order to facilitate the operation of the operator and improve the rotation angle accuracy, it also includes an electric dividing plate and a clamping fixture; the clamping fixture is used to install the magnetic measurement fixture on the electric dividing plate; the electric dividing plate is used to drive the magnetic measurement fixture to rotate the required angle.

[0048] The magnetic measurement method using the above-mentioned quartz flexible accelerometer torquer stator assembly magnetic measurement tool has the following steps:

[0049] 1) Install the magnetic measuring fixture on the electric indexing plate through the clamping fixture, keeping the end face of the step mandrel on the magnetic measuring fixture facing vertically downward;

[0050] 2) Move the clamping fixture, align the notch of the magnetic measuring fixture with the side mark of the outer cylindrical surface of the torquer stator, and vertically insert the step core shaft of the magnetic measuring fixture downward into the working air gap of the torquer stator assembly to be measured until the bottom of the torquer stator. At this time, the Hall chip embedded in the step core shaft is at the same height as the bonded magnetic steel assembly, the inner circumference of the step core shaft is tangent to the outer cylindrical surface of the magnetic steel assembly, and the outer circumference is tangent to the inner cylindrical surface of the torquer stator. The cover plate covers the Hall chip to ensure that the magnetic density measurement is performed in a closed loop. After completion, fix and keep the fixture position unchanged;

[0051] 3) Carry out magnetic density measurement at the first point before starting the electric dividing plate, then control the electric dividing plate to rotate 90 degrees clockwise and stop, carry out magnetic density measurement at the second point, and then continue to rotate 90 degrees clockwise to carry out magnetic density measurement at the third point, and then continue to rotate 90 degrees to carry out magnetic density measurement at the fourth point, thus completing the magnetic density measurement at any point of 0°, 180°, 270°, and 360°.

[0052] For the same torquer stator assembly, the magnetic induction intensity range of the center point of the magnetic steel assembly measured by a traditional handheld probe magnetic measuring fixture is (1050~1300) GS, and the magnetic induction intensity range of the 0°, 180°, 270°, and 360° points measured by the magnetic measuring tool of the present invention is (4200~4600) GS.

[0053] Of course, according to actual needs, an electric dividing plate can be used to drive the measuring fixture to rotate and stop, so that the Hall chip can measure the magnetic induction intensity at any point in the working air gap.

[0054] Using the above magnetic measuring tools and the principle of magnetic measuring method, the stator assembly of the quartz flexible accelerometer torquer can be selected, such as Figure 4 As shown, the magnetic induction intensity of the three positions A, B, and C of the lower torquer stator assembly to be selected, and the magnetic induction intensity of the three positions I, II, and III of the upper torquer stator assembly to be selected are measured respectively, and then the magnetic induction intensity of each point is compared, and the magnetic density test difference between the lower torquer stator assembly A, B, and C and the upper torquer stator assembly I, II, and III is selected to be ≤200GS, and the absolute value of the magnetic density difference between I and C, II and B, and III and A is ≤200GS, and the upper and lower torquer stator assemblies with the smallest magnetic induction intensity difference between the corresponding measuring points are assembled as a pair.

[0055] In summary, the quartz flexible accelerometer torquer stator assembly magnetic measuring fixture and magnetic measuring method designed by the present invention can perform multi-point closed magnetic density measurement, and the upper and lower torquer stator assemblies of the quartz flexible accelerometer are selected in this way to reduce the magnetic density error of the selected torquer stator assembly, reduce the magnetic density asymmetry of the upper and lower torquer stator assemblies after assembly, and avoid the decrease in the symmetry accuracy of the scale factor of the quartz flexible accelerometer, thereby reducing the influence of magnetic field changes on the quartz flexible accelerometer, and further improving the repeatability and stability accuracy of the quartz flexible accelerometer.

[0056] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A magnetic measuring fixture for a stator assembly of a quartz flexible accelerometer torquer, characterized in that: It includes a fixture body, a cover and a cover plate; The interior of the clamp body is a cavity, one end of which is coaxially provided with a stepped core shaft, and the other end is provided with the cover, and the body of the clamp body is provided with a through hole; The step mandrel is a circular ring shaft, which can be inserted into the working air gap of the stator assembly of the torquer to be measured, and a notch is arranged along the axial direction of the mandrel for embedding the Hall chip of the magnetic measuring instrument; The length of the step mandrel should satisfy the following requirement: when the step mandrel is inserted into the working air gap of the torquer stator assembly to be measured, the Hall chip embedded in the gap is at the same height as the magnetic steel of the torquer stator assembly; A mounting position for mounting a cover plate is axially arranged at the position corresponding to the notch of the fixture body; the cover plate is used to ensure that the magnetic circuit is closed when the step mandrel is inserted into the working air gap of the stator assembly of the torquer to be measured, and the cover plate can slide back and forth axially at the mounting position; The fixture body, step mandrel, cover and cover plate are all made of non-magnetic and magnetic-isolating materials.

2. According to claim 1, the magnetic measuring fixture for the stator assembly of the quartz flexible accelerometer torquer is characterized in that: The clamp body is a hollow shaft, one end of which is coaxially connected to the step core shaft through a step surface; A notch is provided on the step surface at a position corresponding to the notch, the notch being connected to the mounting position.

3. The magnetic measuring fixture for stator assembly of quartz flexible accelerometer torquer according to claim 1 or 2, characterized in that: The cover plate is slidably mounted on the mounting position of the fixture body through a guide rail and guide groove structure, and its length is smaller than the length of the mounting position. The end of the cover plate that contacts the fixture body is semicircular.

4. According to claim 3, the magnetic measuring fixture for the stator assembly of the quartz flexible accelerometer torquer is characterized in that: The cover is a screw.

5. A quartz flexible accelerometer torquer stator assembly magnetic measurement tool, characterized in that: A magnetic measuring fixture comprising a Tesla meter and a quartz flexible accelerometer torquer stator assembly as described in any one of claims 1 to 4; The Hall chip of the Tesla meter is embedded in the notch of the step mandrel; the sensor leads of the Hall chip pass through the inside of the fixture body and the through hole in sequence and are led out.

6. The quartz flexible accelerometer torquer stator assembly magnetic measurement tool according to claim 5, characterized in that: It also includes an electric indexing table and clamping fixtures; The clamping fixture is used to install the magnetic measuring fixture on the electric dividing plate; The electric dividing plate is used to drive the magnetic measuring fixture to rotate a required angle.

7. A method for measuring magnetism using the quartz flexible accelerometer torquer stator assembly magnetism measuring tool of claim 5, characterized in that: Here are the steps: 1) Insert the stepped mandrel of the magnetic measuring fixture into the working air gap of the torque generator stator assembly to be measured, so that the Hall chip embedded on the stepped mandrel is at the same height as the magnetic steel; 2) Rotate the magnetic measuring fixture as required, and use the Hall chip to measure the magnetic induction intensity at the corresponding point of the working air gap.

8. The magnetic measurement method according to claim 7, characterized in that: The magnetic measuring fixture is mounted on the electric dividing plate through a clamping fixture, and the electric dividing plate is used to rotate the magnetic measuring fixture.

9. A method for selecting a stator assembly of a quartz flexible accelerometer torquer, characterized in that: 1) According to the magnetic measurement method of claim 7 or 8, the magnetic induction intensity of at least three points corresponding to the working air gap in the stator assembly of the upper torquer to be selected and the stator assembly of the lower torquer to be selected is measured respectively; 2) According to the magnetic induction intensity measured in step 1), select the upper torquer stator assembly and the lower torquer stator assembly for assembly. The selection requirements are: ① The difference between the magnetic induction intensity of the measured point on the stator assembly of the upper torquer to be selected and the magnetic induction intensity of the measured point on the stator assembly of the lower torquer to be selected is ≤200GS; ② The absolute value of the difference in magnetic induction intensity between the corresponding measuring points of the upper torque converter stator assembly to be selected and the lower torque converter stator assembly to be selected is ≤200GS; ③ The difference in magnetic induction intensity between the corresponding measuring points of the upper torque converter stator assembly and the lower torque converter stator assembly to be selected is the smallest.

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