Accelerometer testing device with magnetic shielding and temperature control function

Abstract

The application relates to the technical field of inertial instrument testing, and particularly discloses an accelerometer testing device with magnetic shielding and temperature control functions, which comprises a base, an upper cover assembly and a lower cover assembly. The measured accelerometer is installed on the upper end connecting platform of the base, and the lower end of the base is provided with four U-shaped holes for fixed connection with a testing table. The upper cover assembly comprises an upper magnetic shielding shell, an upper heating shell, an upper heating sheet and an upper thermistor, and the upper magnetic shielding shell is located outside the upper heating shell. The lower cover assembly comprises a lower magnetic shielding shell, a lower heating shell, a lower heating sheet and a lower thermistor, and the lower magnetic shielding shell is located outside the lower heating shell. The accelerometer testing device can shield the electromagnetic interference signals of the testing environment during the testing process of the high-precision accelerometer, and can provide a stable and adjustable temperature environment for the accelerometer, so that the accelerometer is not disturbed by external magnetic fields and temperature fields, the error caused by the external testing environment is reduced, and the accuracy of the accelerometer testing is ensured.

Description

Technical Field

[0001] This application relates to an accelerometer testing device with magnetic shielding and temperature control functions, which is used to shield electromagnetic interference signals of the test environment during the testing process of a high-precision accelerometer and to provide an adjustable and stable temperature environment for the accelerometer. It belongs to the field of inertial instrument testing technology. Background Technology

[0002] The pendulum integrating gyro accelerometer is a pendulum accelerometer that uses gyro torque to balance inertial torque. It represents the highest precision accelerometer achievable in engineering applications, used for the accurate measurement of missile apparent acceleration, and its performance directly affects the missile's impact point accuracy. This type of accelerometer uses a float assembly supported by high-density floating oil and employs magnetic levitation for precise centering, thereby reducing interference torque in the inner ring and achieving high precision.

[0003] Based on the working principle and structural characteristics of gyro accelerometers, they are highly sensitive to magnetic fields and temperature. External magnetic fields can affect not only the performance of internal electromagnetic components such as magnetic levitation elements and angle sensors, but also magnetize components made of magnetically conductive materials, such as end caps and screws, generating additional interfering torques that affect the instrument's output. Temperature primarily affects the float assembly; uneven internal temperature, large temperature gradients, and fluctuations will cause changes in the float's center of mass and center of buoyancy, thus affecting the instrument's accuracy.

[0004] In the structural design of a gyro accelerometer, a primary temperature control system is incorporated to ensure the instrument operates at a stable temperature. Based on the accelerometer's operational requirements, this operating temperature is generally high, with a temperature difference exceeding 40°C from the ambient temperature of 23°C. For high-precision accelerometers used in inertial measurement systems and during calibration tests in measurement equipment, a secondary temperature control system is required to ensure the temperature stability of the external operating environment, typically kept within 0.5°C. Furthermore, due to structural size limitations, a dedicated magnetic shielding device is generally not designed inside the instrument; instead, electromagnetic protection is implemented in the operating environment.

[0005] In summary, during accuracy calibration or mechanical environment testing of high-precision gyro accelerometers, electromagnetic interference or temperature fluctuations in the external environment will affect the instrument's output, thus causing test errors. Therefore, when testing gyro accelerometers, especially during vibration, shock, or simulated transportation tests on electromagnetic vibration tables, where significant electromagnetic interference and temperature variations exist, it is essential to design an accelerometer testing device with magnetic shielding and temperature control functions to ensure a stable external environment during instrument operation. This helps reduce test errors and achieve the goal of high-precision testing. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide an accelerometer testing device with magnetic shielding and temperature control functions. This device enables the instrument to magnetically shield electromagnetic interference signals from the external environment during calibration testing or environmental testing, and to achieve two-stage temperature control, thereby reducing testing errors and meeting the measurement requirements of high-precision accelerometers.

[0007] The technical solution of this invention is:

[0008] An accelerometer testing device with magnetic shielding and temperature control functions includes a base, an upper cover assembly, and a lower cover assembly; the upper cover assembly is located on the upper part of the base and is connected to the base with four screws, and the lower cover assembly is located on the lower part of the base and is connected to the base with four screws.

[0009] The base has three screw holes at the upper end for mounting the accelerometer for testing, and four U-shaped holes at the lower end for fixed connection with the test bench.

[0010] The upper cover assembly includes an upper magnetic shielding shell, an upper heating plate, an upper heating shell, and an upper thermistor. The upper thermistor is glued to the middle of the top of the upper heating shell, and two upper heating plates are respectively wrapped and pasted around the top and circumference of the upper heating shell. The upper thermistor and the upper heating plates form a temperature control circuit, which can control the temperature inside the upper cover assembly. The upper magnetic shielding shell is located outside the upper heating shell, and the two are connected by four M2 screws, which provide magnetic shielding for the upper end of the accelerometer.

[0011] The lower cover assembly includes a lower magnetic shielding shell, a lower heating plate, a lower heating shell, and a lower thermistor. The lower thermistor is glued to the middle of the bottom of the lower heating shell, and two lower heating plates are respectively wrapped and pasted to the bottom and circumference of the lower heating shell. The lower thermistor and the lower heating plates form a temperature control circuit, which can control the temperature inside the lower cover assembly. The lower magnetic shielding shell is located outside the lower heating shell, and the two are connected by four M2 screws, which provide magnetic shielding for the lower end of the accelerometer.

[0012] The upper magnetic shielding shell, upper heating shell, lower magnetic shielding shell, and lower heating shell are provided with wire outlet grooves for wiring of the upper heating plate, lower heating plate, upper thermistor, and lower thermistor; the base is provided with wire outlet holes for wiring of the accelerometer plug and socket, upper heating plate, lower heating plate, upper thermistor, and lower thermistor.

[0013] The base is made of aluminum, which ensures structural rigidity while being lightweight and will not be magnetized by external magnetic fields.

[0014] The upper and lower magnetic shielding shells are made of 1J50 material and have magnetic shielding function.

[0015] The upper and lower heating shells are made of copper, which has good geothermal conductivity.

[0016] The aforementioned accelerometer testing device can shield high-precision accelerometers from electromagnetic interference signals in the testing environment during testing, and provide the accelerometer with a stable and adjustable external temperature control environment. The temperature adjustment range is from room temperature to +80℃, and the temperature control accuracy reaches 0.5℃, so that the accelerometer is not affected by external magnetic field and temperature field, reducing the error caused by the external testing environment and ensuring the accuracy of the test.

[0017] In summary, this application includes at least the following beneficial technical effects:

[0018] (1) This application discloses an accelerometer testing device, which can be used for high-precision gyro accelerometer calibration testing or environmental testing, so that the accelerometer is not affected by external magnetic field and temperature field, reducing the error caused by external test environment and ensuring the accuracy of the test.

[0019] (2) The accelerometer testing device of this application has a magnetic shielding function, which can be used to shield the electromagnetic interference signal of the test environment during the test of the accelerometer, so as to avoid the external magnetic field from affecting the function of the instrument.

[0020] (3) The accelerometer testing device of this application has a temperature control function, which can provide the accelerometer with a stable and adjustable external working temperature environment. The temperature adjustable range is from room temperature to +80℃, and the temperature control accuracy can reach 0.5℃.

[0021] (4) The accelerometer testing device of this application can set different working environment temperatures for the upper and lower parts of the accelerometer by setting an upper cover assembly and a lower cover assembly, which is beneficial to improving the first-level temperature control accuracy inside the instrument. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an accelerometer testing device with magnetic shielding and temperature control functions according to the present invention.

[0023] Figure 2 This is a schematic diagram of the base structure;

[0024] Figure 3 This is a schematic diagram of the upper cover assembly;

[0025] Figure 4 This is a structural schematic diagram of the lower cover assembly;

[0026] Figure 5 This is a schematic diagram of the upper heating shell structure;

[0027] Figure 6 This is a schematic diagram of the upper magnetic shielding shell;

[0028] Figure 7 This is a schematic diagram of the lower heating shell structure;

[0029] Figure 8 This is a schematic diagram of the lower magnetic shielding shell.

[0030] Explanation of reference numerals in the attached drawings: 1. Base; 2. Upper cover assembly; 3. Accelerometer; 4. Lower cover assembly;

[0031] 201. Upper magnetic shielding shell; 202. Upper heating plate; 203. Upper heating shell; 204. Upper thermistor;

[0032] 401. Lower magnetic shielding shell; 402. Lower heating element; 403. Lower heating shell; 404. Lower thermistor; Detailed Implementation

[0033] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0034] This application discloses an accelerometer testing device with magnetic shielding and temperature control functions, such as... Figure 1 As shown, it includes a base 1, an upper cover assembly 2, and a lower cover assembly 4. The upper cover assembly 2 is located on the upper part of the base 1 and is connected to the base 1 with 4 M2 screws. The lower cover assembly 4 is located on the lower part of the base 1 and is connected to the base 1 with 4 M2 screws. The accelerometer 3 can be installed on the base 1 by removing the upper cover assembly 2 and is fixed by connecting and fixing with 3 M3 screws.

[0035] like Figure 2 As shown, the upper end of the base 1 has 3 M3 screw holes for installing the accelerometer 3 for testing; the lower end of the base 1 has 4 symmetrically distributed U-shaped holes for fixed connection with the test bench; the base 1 can be made of aluminum alloy with high structural strength, which is lightweight while ensuring structural rigidity, making it easy to carry and install, and will not be magnetized by external magnetic fields.

[0036] A downward-facing cavity is formed in the middle of the upper surface of the base 1 to accommodate the accelerometer 3. A connecting platform is formed on the upper surface of the base 1, located at the top of the cavity. The outer diameter of the connecting platform is smaller than the outer diameter of the connecting ring of the accelerometer 3. The lower cover assembly 4 is located inside the cavity. The protruding edge of the lower cover assembly 4 rests on the connecting platform and is connected to it. The connecting ring of the accelerometer 3 rests on the upper surface of the base 1 and is connected to it. The upper cover assembly 2 covers the outside of the accelerometer 3 and is connected to the upper surface of the base 1. The connection platform is designed so that the top of the protruding edge of the lower cover assembly 4 is not higher than the upper surface of the base 1. The accelerometer 3 is rigidly connected to the rigid base 1 only by bolts, which ensures that the vibration transmission is more accurate during the test of the accelerometer 3. The upper and lower parts of the accelerometer 3 are protected by the upper cover assembly 2 and the lower cover assembly 4, which are basically 90% protected. The connection position between the accelerometer 3 and the base 1 that is not protected can also achieve a temperature balance through temperature regulation by the upper heating assembly and the lower heating assembly.

[0037] like Figure 3 As shown, the upper cover assembly 2 includes an upper magnetic shielding shell 201, an upper heating plate 202, an upper heating shell 203, and an upper thermistor 204. The upper thermistor 204 is glued to the middle of the top of the upper heating shell 203, and the lead wire is led out along the lead wire groove of the upper heating shell 203. Two upper heating plates 202 are respectively wrapped and pasted to the top and circumference of the upper heating shell 203, and are fixed externally with pressure-sensitive adhesive insulating tape. The upper thermistor 204 and the upper heating plate 202 form a temperature control circuit, which can control the internal temperature of the upper cover assembly 2 and provide a stable and adjustable temperature environment for the upper part of the accelerometer 3. The upper magnetic shielding shell 201 is located outside the upper heating shell 203, and the two are connected by four M2 screws, which play a magnetic shielding role for the upper part of the accelerometer 3. The upper cover assembly 2 is made into an integral assembly, with four Φ2.2mm through holes symmetrically drilled at the Φ126mm center circle position at the bottom, which facilitates disassembly and assembly from the base 1.

[0038] like Figure 4As shown, the lower cover assembly 4 includes a lower magnetic shielding shell 401, a lower heating plate 402, a lower heating shell 403, and a lower thermistor 404. The lower thermistor 404 is glued to the middle of the bottom end of the lower heating shell 403, and its lead wires are led out along the lead wire groove of the lower heating shell 403. Two lower heating plates 402 are respectively wrapped and pasted to the bottom end and circumference of the lower heating shell 403, and are fixed externally with pressure-sensitive adhesive insulating tape. The lower thermistor 404 and the lower heating plates 402 form a temperature control circuit, which can control the temperature inside the lower cover assembly 4, providing... The lower part of the accelerometer 3 provides a stable and adjustable temperature environment; the lower magnetic shielding shell 401 is located outside the lower heating shell 403, and the two are connected by 4 M2 screws, which provide magnetic shielding for the lower part of the accelerometer 3; at the top Φ79mm center circle position of the lower cover assembly 4, 4 Φ2.2mm through holes are symmetrically drilled, and are connected to the base 1 by 4 M2 screws. The lower cover assembly 4 is generally directly mounted on the base 1. When replacing different accelerometers 3 for testing, the lower cover assembly 4 does not need to be disassembled.

[0039] like Figure 5 As shown, a rectangular groove measuring 6mm in length, 4mm in width, and 2mm in depth is cut in the middle of the top of the upper heating shell 203, where the upper thermistor 204 can be glued. A wiring groove measuring 1mm in width and 1mm in depth is also cut in the top of the upper heating shell 203 for the lead wires of the thermistor to be led out. At the bottom of the upper heating shell 203, at the Φ126mm center circle position, four M2mm threaded holes are symmetrically drilled for installation and fixation with the upper magnetic shielding shell 201.

[0040] like Figure 6 As shown, four Φ2.2mm through holes are symmetrically drilled at the Φ126mm center circle position at the bottom of the upper magnetic shielding shell 201 for installation and fixation with the upper heating shell 203.

[0041] like Figure 7 As shown, a rectangular groove measuring 6mm in length, 4mm in width, and 2mm in depth is cut in the middle of the bottom of the lower heating shell 403 for the lower thermistor 404 to be glued there; a wiring groove measuring 1mm in length, width, and depth is also cut at the bottom of the lower heating shell 403 for the lead wires of the thermistor to be led out; four M2mm threaded holes are symmetrically drilled at the Φ79mm center circle position at the top of the lower heating shell 403 for installation and fixation with the lower magnetic shielding shell 401.

[0042] like Figure 8 As shown, four 2.2mm through holes are symmetrically drilled at the 79mm center circle position on the top of the lower magnetic shielding shell 401 for installation and fixation with the lower heating shell 403.

[0043] The upper magnetic shielding shell 201 and the lower magnetic shielding shell 401 are made of 1J50, which has good magnetic shielding function. The upper heating shell 203 and the lower heating shell 403 are made of copper, which ensures structural rigidity while having good thermal conductivity.

[0044] The upper magnetic shielding shell 201, the upper heating shell 203, the lower magnetic shielding shell 401, and the lower heating shell 403 are provided with wiring grooves for wiring of heating plates (202, 402) and thermistors (204, 404).

[0045] The lead wire of the upper thermistor 204 extends from the wiring groove to the edge of the upper heating shell 203, then extends downward along the axis of the upper heating shell 203, and finally exits through the opening of the upper heating shell 203 to the inside of the upper cover assembly 2. The lead wire of the lower thermistor 404 extends from the wiring groove to the edge of the lower heating shell 403, then extends upward along the axis of the lower thermistor 404, and finally exits through the opening of the lower heating shell 403 to the inside of the lower cover assembly 4.

[0046] A vertically downward-facing cable exit groove is formed on the upper surface of the base 1, extending from the inner wall of the connecting platform to the outer side of the base. The groove is 10mm wide and 4mm deep. Cables exiting from the inner side of the lower cover assembly 4, the inner side of the upper cover assembly 2, and the plug and socket cables of the accelerometer 3 all exit through the cable exit hole to the outer side of the base 1. The cable exit groove in the base 1 is used for routing the cables for the accelerometer 3 plug and socket, heating elements (202, 402), and thermistors (204, 404).

[0047] The accelerometer testing device can shield electromagnetic interference signals from the testing environment and provide an adjustable and stable external temperature control environment for the accelerometer 3. The temperature adjustment range is from room temperature to +80℃, and the temperature control accuracy reaches 0.5℃, so that the accelerometer is not affected by external magnetic field and temperature field, reducing the error caused by the external testing environment and ensuring the accuracy of the test.

[0048] The contents not described in detail in this specification are common knowledge to those skilled in the art.

[0049] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.

Claims

1. An accelerometer testing device with magnetic shielding and temperature control functions, characterized in that: Includes a base (1), an upper cover assembly (2), and a lower cover assembly (4); A downward cavity is provided in the middle of the upper surface of the base (1). The lower cover assembly (4) is located in the cavity of the base (1). The accelerometer (3) for testing is installed on the upper end of the base (1). The accelerometer (3) is located inside the lower cover assembly (4). The upper cover assembly (2) is sleeved on the outside of the accelerometer (3) and connected to the upper part of the base (1). The lower end of the base (1) is used for fixed connection with the test bench; The upper cover assembly (2) includes an upper magnetic shielding shell (201), an upper heating shell (203), and an upper heating assembly located between the upper magnetic shielding shell (201) and the upper heating shell (203). The upper heating assembly is used to control the temperature inside the upper cover assembly (2), and the upper magnetic shielding shell (201) is connected to the outside of the upper heating shell (203). The lower cover assembly (4) includes a lower magnetic shielding shell (401), a lower heating shell (403), and a lower heating assembly located between the lower magnetic shielding shell (401) and the lower heating shell (403). The lower heating assembly is used to control the temperature inside the lower cover assembly (4). The lower magnetic shielding shell (401) is connected to the outside of the lower heating shell (403). The base (1) is made of aluminum alloy with high structural strength; the upper magnetic shielding shell (201) and the lower magnetic shielding shell (401) are made of iron-nickel soft magnetic alloy 1J50, which has the function of magnetic shielding; the upper heating shell (203) and the lower heating shell (403) are made of copper, which has good thermal conductivity.

2. The accelerometer testing device with magnetic shielding and temperature control functions according to claim 1, characterized in that: The upper surface of the base (1) is provided with a connecting platform, which is located at the top of the cavity. The accelerometer (3) to be tested is provided with a connecting ring, which is connected to the upper end of the base (1). The outer diameter of the connecting platform is smaller than the outer diameter of the connecting ring of the accelerometer (3). The top of the lower cover assembly (4) is provided with a protruding edge, which is placed on the connecting platform and connected to the connecting platform.

3. The accelerometer testing device with magnetic shielding and temperature control functions according to claim 1, characterized in that: The upper heating assembly includes an upper heating plate (202) and an upper thermistor (204). The upper thermistor (204) is glued to the middle position of the top of the upper heating shell (203), and the upper heating plate (202) is wrapped and pasted around the top and circumference of the upper heating shell (203).

4. An accelerometer testing device with magnetic shielding and temperature control functions according to claim 1, characterized in that: The lower heating assembly includes a lower heating plate (402) and a lower thermistor (404). The lower thermistor (404) is glued to the middle position of the bottom end of the lower heating shell (403), and the lower heating plate (402) is wrapped and pasted around the bottom end and circumference of the lower heating shell (403).

5. An accelerometer testing device with magnetic shielding and temperature control functions according to claim 1, characterized in that: The top of the upper heating shell (203) is provided with a wiring groove for the lead wire of the upper heating component. The lead wire extends between the upper magnetic shielding shell (201) and the upper heating shell (203) to the bottom of the upper heating shell (203), and then passes through the opening of the upper heating shell (203) to the inside of the upper cover component (2).

6. An accelerometer testing device with magnetic shielding and temperature control functions according to claim 5, characterized in that: The top of the lower heating shell (403) is provided with a wiring groove for the lead wire of the lower heating component. The lead wire extends between the lower magnetic shielding shell (401) and the lower heating shell (403) to the top of the lower heating shell (403), and then passes through the opening of the lower heating shell (403) to the inside of the lower cover assembly (4).

7. An accelerometer testing device with magnetic shielding and temperature control functions according to claim 6, characterized in that: The upper surface of the base (1) is provided with a vertically downward wire outlet groove. The wire outlet groove extends from the inner wall of the connecting platform to the outer side of the base. The leads of the upper heating component, the lower heating component and the accelerometer (3) pass out of the base (1) through the wire outlet groove.

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