Suspended wire pendulum accelerometer

Abstract

The invention discloses a suspended wire pendulum accelerometer, comprising a circuit component, an eddy current sensor component, a suspended wire pendulum component, an eddy current sheet, and a permanent magnet component. The eddy current sensor component comprises an eddy current coil, the suspended wire pendulum component comprises a pendulum frame, an elastically supported suspended wire, a coil winding is wound on the pendulum frame, one side of the pendulum frame is located in a fixed magnetic field, and the eddy current sheet is fixed on the pendulum frame and adapted to the eddy current sensor component. After power is applied, a high-frequency current is generated in the eddy current coil, an eddy current is formed on the surface of the eddy current sheet, and the coil winding is subjected to the magnetic force in the fixed magnetic field. The suspended wire pendulum component is suspended in balance. When subjected to acceleration, the suspended wire pendulum component generates an inertial moment deviating from a balanced position, and the eddy current sheet is displaced relative to the eddy current sensor component, causing the eddy current coil differential inductance to change and be converted into an electrical signal. The eddy current sheet is always in a balanced position through current feedback of a torque balance electrical signal loop, and the feedback current signal is simultaneously used as an output, that is, the magnitude of the acceleration is characterized.

Description

Technical Field

[0001] The invention relates to an instrument for measuring acceleration, in particular to a suspended wire pendulum accelerometer. Background Art

[0002] Acceleration measurement is an important topic raised by engineering technology. When an object has a large acceleration, the object and the instruments and equipment it carries and other objects without relative acceleration are all subjected to a force that can produce the same acceleration, that is, dynamic load. To know the dynamic load, you need to measure the acceleration. Secondly, to know the spatial position of each instantaneous aircraft, rocket and ship, you can continuously measure their acceleration through inertial navigation, and then get the velocity component through integration operation, and then integrate again to get the position coordinate signal in one direction. The instrument measurement results in the three coordinate directions synthesize the motion curve and give the spatial position of each instantaneous spacecraft. The accelerometer that measures aircraft overload is one of the earliest aircraft instruments to be applied. For example, in some control systems, acceleration signals are often required as part of the information required to produce control effects, and the problem of continuously measuring acceleration also arises here.

[0003] An accelerometer is an instrument that measures the linear acceleration of a vehicle. The accelerometer is one of the important components in an inertial navigation system. It is installed on the three measuring axes of the inertial navigation subsystem to measure the linear acceleration of the moving body in the coordinate system and provide the measured acceleration to the computer for the feedback signal of the moving body's stabilization loop and the calculation of navigation parameters. Accelerometers are currently widely used in aviation, aerospace, navigation and weapons and equipment. The mainstream accelerometers used in navigation, guidance and control at home and abroad are quartz accelerometers, suspended wire accelerometers and MEMS (Micro Electro Mechanical System) accelerometers. How to further reduce the size, improve sensitivity and shock and vibration resistance is a direction that needs to be further improved in the field of accelerometers. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a suspended wire pendulum accelerometer with a brand new structure, small size, high sensitivity and strong impact and vibration resistance.

[0005] The technical solution adopted by the present invention is: the present invention includes a mounting seat, an outer cover, a circuit component, an eddy current sensor component, a suspended wire pendulum component, an eddy current sheet, and a permanent magnet component. The outer cover is fixedly and sealedly connected to the mounting seat to form a closed space for accommodating components inside. The eddy current sensor component and the permanent magnet component are both fixedly arranged inside. The permanent magnet component includes two magnetic poles that are relatively arranged and have opposite magnetic properties to form a fixed magnetic field. The eddy current sensor component includes an eddy current coil. The suspended wire pendulum component includes a pendulum frame and two elastically supported suspension wires. A coil winding is wound on the pendulum frame. The circuit component and the coil winding constitute a torque balance electrical signal loop. One side of the pendulum frame is located in the gap between the two magnetic poles. The eddy current sheet is fixed on one side of the pendulum frame and is adapted to the position of the eddy current sensor component. After the circuit component is powered on, the electric High-frequency current is continuously generated in the eddy current coil. Under the action of the eddy current effect, eddy currents are formed on the surface of the eddy current sheet. At the same time, the coil winding is subjected to the magnetic force in the fixed magnetic field, so that the suspended wire pendulum assembly is suspended in a balanced position. When the suspended wire pendulum accelerometer is subjected to acceleration, under the action of the measured acceleration, the suspended wire pendulum assembly generates an inertial torque, deviates from the balanced position relative to the permanent magnet assembly, so that the eddy current sheet on the suspended wire pendulum assembly is displaced relative to the eddy current sensor assembly, thereby causing a change in the differential inductance of the eddy current coil, which is converted into an electrical signal through the servo circuit of the circuit assembly, and then through the current feedback of the torque balance electrical signal circuit. Under the action of the fixed magnetic field, the suspended wire pendulum assembly is excited and the eddy current sheet is always driven to be in a balanced position. The feedback current signal is also used as an output, and this output represents the magnitude of the input acceleration.

[0006] A base plate is provided on the mounting seat, and the two magnetic poles are fixedly connected to the base plate. A first pendulum support, a second pendulum support, and an eddy current sensor support are also provided on the base plate. A wire pendulum adjustment shaft passes through the second pendulum support laterally and can rotate axially. The eddy current sensor assembly is fixedly connected to the eddy current sensor support. The two ends of the coil winding are respectively connected to two wiring disks located on the pendulum frame and are conductive. Two sealing sleeves are fixedly connected to one side of the pendulum frame, and damping oil is filled in the two sealing sleeves. The two elastic support suspension wires respectively pass through one sealing sleeve and are suspended in the damping oil. The two elastic support suspension wires are located on the same axis of the two sealing sleeves. The outer ends of the two elastic support suspension wires are respectively connected to the first pendulum support and the wire pendulum adjustment shaft and are conductive, so that the first pendulum support, the second pendulum support and the circuit assembly are electrically connected to form the torque balance electrical signal circuit, and the pendulum frame is suspended.

[0007] The eddy current sensor assembly also includes an eddy current sensor skeleton, one end of the eddy current sensor skeleton is fixedly connected to the eddy current sensor support through an eddy current sensor mounting screw, and the other end of the eddy current sensor skeleton is divided into two arms. Two eddy current coils are provided, and the two eddy current coils are respectively located on the opposite inner sides of the two arms. There is an induction space between the two arms, and the eddy current sheet extends into the induction space. Lead terminals are respectively provided at the ends of the two arms, which are electrically connected to the circuit assembly to generate high-frequency current in the two eddy current coils through the circuit assembly.

[0008] The suspended wire pendulum accelerometer also includes a pendulum limit screw. A first threaded hole is provided on the base plate at a position corresponding to the lower side of the pendulum frame. The pendulum limit screw is adaptively connected to the first threaded hole, and a front end of the pendulum limit screw extends above the base plate to limit the lower limit position of the pendulum frame to prevent the eddy current sheet from touching the eddy current sensor assembly.

[0009] The first threaded hole is located below the gap between the two magnetic poles, and the front end of the swing limit screw extends into the gap between the two magnetic poles.

[0010] The suspended wire pendulum accelerometer also includes a magnetic field adjustment screw. A second threaded hole is provided on the base plate below the gap between the two magnetic poles. The magnetic field adjustment screw is adaptively connected to the second threaded hole, and the front end of the magnetic field adjustment screw extends into the gap between the two magnetic poles to adjust the size of the magnetic field in which the coil winding is located.

[0011] The bottom plate is provided with two opposite magnetic pole mounting vertical plates, and the two magnetic poles are respectively fixed on the two magnetic pole mounting vertical plates.

[0012] The first pendulum support, the second pendulum support and the eddy current sensor support are respectively located in the mounting holes on the base plate and fixed.

[0013] The mounting seat is provided with a mounting hole.

[0014] The sealing sleeve is a glass tube.

[0015] The elastic supporting suspension wire is made of platinum-silver alloy.

[0016] The bottom plate and the mounting seat are a split connection structure, and the bottom plate is fixed to the mounting seat by bottom plate mounting screws.

[0017] Alternatively, the base plate and the mounting seat are an integrally formed connection structure.

[0018] The circuit assembly comprises a wiring seat, and the wiring seat is sealed and fixed to the bottom of the mounting seat by laser sealing.

[0019] The wiring seat is also provided with a welding wire hole for welding the wires connecting the pendulum assembly, the eddy current sensor assembly and the circuit assembly, and sealing the wires by plugging.

[0020] The outer cover and the mounting seat are sealed and fixed by laser sealing.

[0021] The circuit assembly includes a detection circuit, an amplification circuit, a correction circuit, and a sine wave oscillator. The detection circuit is used to convert the displacement of the eddy current sheet into an electrical signal that is easy to measure. The amplification circuit is used to amplify the weak signal of the sensitive acceleration of the eddy current sensor assembly and provide a suitable amplification factor. The correction circuit is used to provide the necessary feedback current for the rebalancing of the suspended wire pendulum assembly to obtain the rebalancing torque, and provide the necessary correction network to enable the suspended wire pendulum accelerometer to work normally and meet static and dynamic performance indicators. The sine wave oscillator is used to provide a sinusoidal high-frequency oscillation signal of the eddy current sensor assembly.

[0022] The beneficial effects of the present invention are as follows: since the present invention includes a mounting seat, an outer cover, a circuit component, an eddy current sensor component, a suspended wire pendulum component, an eddy current sheet, and a permanent magnet component, the outer cover is fixedly and sealedly connected to the mounting seat to form a closed space for accommodating components inside, the eddy current sensor component and the permanent magnet component are both fixedly arranged inside, the permanent magnet component includes two magnetic poles that are relatively arranged and have opposite magnetic properties to form a fixed magnetic field, the eddy current sensor component includes an eddy current coil, the suspended wire pendulum component includes a pendulum frame, two elastic The pendulum frame is supported by a suspension wire, and a coil winding is wound on the pendulum frame. The circuit assembly and the coil winding constitute a torque balance electrical signal loop. One side of the pendulum frame is located in the gap between the two magnetic poles. The eddy current sheet is fixed on one side of the pendulum frame and is adapted to the position of the eddy current sensor assembly. After the circuit assembly is powered on, a high-frequency current is continuously generated in the eddy current coil. Under the action of the eddy current effect, eddy currents are formed on the surface of the eddy current sheet. At the same time, the coil winding is subjected to the magnetic force in the fixed magnetic field, so that The wire pendulum assembly is suspended in a balanced position. When the wire pendulum accelerometer is subjected to acceleration, the wire pendulum assembly generates an inertial torque under the action of the measured acceleration, deviates from the balanced position relative to the permanent magnet assembly, so that the eddy current sheet on the wire pendulum assembly is displaced relative to the eddy current sensor assembly, thereby causing the change of the differential inductance of the eddy current coil, and is converted into an electrical signal through the servo circuit of the circuit assembly, and then through the current feedback of the torque balance electrical signal loop, under the action of the fixed magnetic field, the wire pendulum assembly is stimulated and the eddy current sheet is always in a balanced position, and the feedback current signal is output at the same time, and this output represents the magnitude of the input acceleration. The present invention overcomes the defects and shortcomings of the prior art and provides a brand-new structural form, which is a single-axis wire-supported pendulum-type, torque rebalancing accelerometer. Compared with other accelerometers, its advantages are: it combines the pendulum assembly and the sensitive mass into one, so that the accelerometer is small in size, light in weight (less than 50 grams), and low in power consumption (0.16 mA / g to 0.32mA / g); it adopts eddy current sensor, which has high sensitivity, wide frequency range, small balance displacement under inertial force, and strong anti-interference ability; it adopts special support structure, which makes it have larger overload capacity (120g) and strong anti-impact and vibration ability (maximum vibration 26g, 20Hz~2000Hz, 2h; maximum impact 1200g, 3ms, 1 / 2sin) compared with other types of accelerometers; it adopts magnetic circuit symmetric compensation method, which makes it able to work in a wide temperature working range (-55℃~+85℃), and has better solutions in large range, strong impact and vibration. The present invention has excellent environmental adaptability, high precision, high reliability and stability, and can be widely used in flight control systems and inertial navigation systems in the fields of aerospace, aviation, navigation, weapons, etc.; therefore, the present invention provides a new structural form, which is small in size, high in sensitivity, strong in anti-impact and vibration ability, and is a suspended wire pendulum accelerometer. . BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the bottom structure of the suspended wire pendulum accelerometer according to the first embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A-A cross-sectional structural schematic diagram shown;

[0025] Figure 3 It is a schematic diagram of the explosion structure of the first embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the exploded structure of another viewing angle of the first embodiment of the present invention;

[0027] Figure 5 It is a schematic diagram of the assembly structure of the mounting base and some parts connected thereto according to the first embodiment of the present invention;

[0028] Figure 6 It is a schematic diagram of the exploded structure of the bottom plate and some parts connected thereto according to the first embodiment of the present invention;

[0029] Figure 7 is a schematic structural diagram of an eddy current sensor assembly according to a first embodiment of the present invention;

[0030] Figure 8 Schematic diagram of the assembly structure of the suspended wire pendulum assembly of the first embodiment of the present invention;

[0031] Fig. 9 yes Figure 8 A schematic diagram of the local enlarged structure at position I shown;

[0032] Fig.10 It is a schematic diagram of the explosion structure of the second embodiment of the present invention;

[0033] Fig.11 is a schematic diagram of the exploded structure of another viewing angle of the second embodiment of the present invention;

[0034] Fig.12 It is a schematic diagram of the overall principle of the circuit components of an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Embodiment 1:

[0036] like Figures 1 to 9 , Fig.12 As shown, the suspended wire pendulum accelerometer of this embodiment includes a mounting base 1, an outer cover 2, a circuit component, an eddy current sensor component 4, a suspended wire pendulum component 5, an eddy current sheet 7, and a permanent magnet component 8. The outer cover 2 is fixedly and sealedly connected to the mounting base 1 to form a closed space for accommodating components inside. The eddy current sensor component 4 and the permanent magnet component 8 are both fixedly arranged inside. The permanent magnet component 8 includes two magnetic poles 81 and 82 that are relatively arranged and have opposite magnetic properties to form a fixed magnetic field. The eddy current sensor component 4 includes an eddy current coil 44, and the suspended wire pendulum component 5 includes A pendulum frame 51 and two elastically supported suspension wires 53 are provided. A coil winding 52 is wound around the pendulum frame 51. The circuit assembly and the coil winding 52 form a torque balance electrical signal loop. One side of the pendulum frame 51 is located in the gap between the two magnetic poles 81 and 82. The eddy current sheet 7 is fixed on one side of the pendulum frame 51 and is adapted to the position of the eddy current sensor assembly 4. After the circuit assembly is powered on, a high-frequency current is continuously generated in the eddy current coil 44. Under the action of the eddy current effect, eddy currents are formed on the surface of the eddy current sheet 7. At the same time, the wire The coil winding 52 is subjected to the magnetic force in the fixed magnetic field, so that the suspended wire pendulum assembly 5 is suspended in a balanced position. When the suspended wire pendulum accelerometer is subjected to acceleration, under the action of the measured acceleration, the suspended wire pendulum assembly 5 generates an inertial moment, deviates from the balanced position relative to the permanent magnet assembly 8, so that the eddy current sheet 7 on the suspended wire pendulum assembly 5 is displaced relative to the eddy current sensor assembly 4, thereby causing the differential inductance of the eddy current coil 44 to change, and is converted into an electrical signal through the servo circuit of the circuit assembly, that is, the eddy current sensor assembly 4 is used to position The accelerometer detects the position and then feeds back the current of the torque balance electrical signal circuit, that is, the feedback current is loaded on the coil winding 52. The coil winding 52 is subjected to electromagnetic force under the action of the fixed magnetic field, which stimulates the suspended wire pendulum assembly 5 and drives the eddy current sheet 7 to always be in a balanced position. The feedback current signal is also used as the output. The output current of the accelerometer is proportional to the acceleration acting on its sensitive axis. This output represents the magnitude of the input acceleration. The output current is converted into a velocity increment pulse sequence by the amplification and transformation subassembly, and the actual measured acceleration value can be obtained by calculation.

[0037] The mounting seat 1 is provided with a bottom plate 6. In this embodiment, the bottom plate 6 and the mounting seat 1 are a split connection structure. The bottom plate 6 is fixed to the mounting seat 1 by bottom plate mounting screws 11, which is more convenient for installing various components. Of course, the bottom plate 6 and the mounting seat 1 can also be an integrally formed connection structure. The two magnetic poles 81 and 82 are fixedly connected to the bottom plate 6. Specifically, two opposite magnetic pole mounting vertical plates 61 and 62 are provided on the bottom plate 6. The two magnetic poles 81 and 82 are respectively fixed on the two magnetic pole mounting vertical plates 61 and 62. The bottom plate 6 is also provided with a first swing support The first pendulum support 63, the second pendulum support 64, and the eddy current sensor support 65 are respectively located in the mounting holes on the base plate 6 and fixed, a wire pendulum adjustment shaft 66 passes through the second pendulum support 64 horizontally and can be axially rotated, the eddy current sensor assembly 4 is fixedly connected to the eddy current sensor support 65, the two ends of the coil winding 52 are respectively connected to the two wiring plates 56 and 57 located on the pendulum frame 51 and are conductive, and two sealing sleeves 54 are fixedly connected to one side of the pendulum frame 51. The two sealing sleeves 54 are filled with damping oil 55, and the two elastic supporting suspension wires 53 respectively pass through one of the sealing sleeves 54 and are suspended in the damping oil 55. The two elastic supporting suspension wires 53 are located on the same axis of the two sealing sleeves 54. By adjusting the suspension wire pendulum adjustment shaft 66, the position of the pendulum frame 51 can be fine-tuned. The outer ends of the two elastic supporting suspension wires 53 are respectively connected to the first pendulum support column 63 and the suspension wire pendulum adjustment shaft 66 and conduct electricity, so that the first pendulum support column 63 and the second pendulum support column 64 are electrically connected to the circuit component to form the torque The electric signal circuit is balanced and the pendulum frame 51 is suspended. In this embodiment, the elastic supporting wire 53 is arranged on a long side of the pendulum frame 51, and the long side of the pendulum frame 51 opposite to the elastic supporting wire 53 is located in the gap between the two magnetic poles 81 and 82, so that the force is balanced and it is conducive to balance. The mounting seat 1 is provided with a mounting hole 10 for easy installation on the object to be measured. The sealing sleeve 54 is a glass tube, and the elastic supporting wire 53 is made of platinum-silver alloy. In this embodiment, the mounting seat 1 is square, the outer cover 2 is circular, and the bottom plate 6 is circular.

[0038] The eddy current sensor assembly 4 also includes an eddy current sensor skeleton 41, one end of the eddy current sensor skeleton 41 is fixedly connected to the eddy current sensor support 65 through an eddy current sensor mounting screw 40, and the other end of the eddy current sensor skeleton 41 is divided into two arms 42 and 43. Two eddy current coils 44 are provided, and the two eddy current coils 44 are respectively located on the opposite inner sides of the two arms 42 and 43. There is an induction space 48 between the two arms 42 and 43, and the eddy current sheet 7 extends into the induction space 48. Lead terminals 45 are respectively provided at the ends of the two arms 42 and 43, which are electrically connected to the circuit assembly to generate a high-frequency current of 12MHz in the two eddy current coils 44 through the circuit assembly.

[0039] The suspended wire pendulum accelerometer further includes a pendulum limit screw 97. A first threaded hole 67 is provided on the base plate 6 at a position corresponding to the lower side of the pendulum frame 51. The pendulum limit screw 97 is adapted to be connected with the first threaded hole 67, and the front end of the pendulum limit screw 97 extends above the base plate 6 to limit the lower limit position of the pendulum frame 51 to prevent the eddy current sheet 7 from touching the eddy current sensor assembly 4. Specifically, in this embodiment, the first threaded hole 67 is located below the gap between the two magnetic poles 81 and 82, and the front end of the pendulum limit screw 97 extends into the gap between the two magnetic poles 81 and 82, so that the space utilization rate is improved.

[0040] The suspended wire pendulum accelerometer further includes a magnetic field adjustment screw 98. A second threaded hole 68 is provided on the bottom plate 6 below the gap between the two magnetic poles 81 and 82. The magnetic field adjustment screw 98 is adapted to be connected with the second threaded hole 68, and the front end of the magnetic field adjustment screw 98 extends to the gap between the two magnetic poles 81 and 82 to adjust the size of the magnetic field where the coil winding 52 is located, thereby improving the space utilization rate. The different upper and lower positions of the magnetic field adjustment screw 98 affect the magnetic field, thereby affecting the current. By manually adjusting the depth of the magnetic field, the output is within the required range when the meter is initially installed.

[0041] The circuit component includes a terminal block 3, and the terminal block 3 is sealed and fixed to the bottom of the mounting base 1 by laser sealing. The terminal block 3 is also provided with a welding wire hole 30 to weld the connection between the suspended wire pendulum component 5, the eddy current sensor component 4 and the circuit component, and is sealed by a plug 31. The outer cover 2 is sealed and fixed to the mounting base 1 by laser sealing.

[0042] The circuit components include a detection circuit, an amplification circuit, a correction circuit, and a sine wave oscillator. The detection circuit is used to convert the displacement of the eddy current sheet 7 into an electrical signal that is easy to measure. The amplification circuit is used to amplify the weak signal of the sensitive acceleration of the eddy current sensor component 4 and provide a suitable amplification factor. The correction circuit is used to provide the necessary feedback current for the rebalancing of the suspended wire pendulum component 5 to obtain the rebalancing torque, and provide the necessary correction network to enable the suspended wire pendulum accelerometer to work normally and meet static and dynamic performance indicators. The sine wave oscillator is used to provide a sinusoidal high-frequency oscillation signal of the eddy current sensor component 4.

[0043] The main functions of the pendulum assembly 5 include: forming the sensitive mass of the accelerometer, serving as the displacement input of the eddy current sensor assembly 4, generating Ampere torque, and ensuring that the accelerometer can withstand strong external mechanical shocks and vibrations.

[0044] The signal sensor part of the present invention is mainly composed of a meter head, an oscillation circuit and a detection circuit, wherein the meter head part is mainly composed of the eddy current sensor skeleton 41, the differential coil, i.e. the eddy current coil 44, and the eddy current sheet 7, and its main function is to convert the displacement of the detection mass into an electrical signal that is easy to measure.

[0045] The torquer part of the present invention is mainly composed of the permanent magnet assembly 8, the pendulum frame 51, and the coil winding 52. Its main function is to generate feedback torque to balance the external inertia torque under the action of the input signal.

[0046] The rebalancing circuit part of the present invention is mainly composed of a preamplifier circuit, a correction current and a power amplifier circuit. Its main functions include: amplifying the weak signal of the sensitive acceleration of the signal sensor; providing the necessary feedback current to the torquer to obtain the rebalancing torque; providing the acceleration system with a suitable amplification factor and necessary correction network to enable the accelerometer system to work normally and meet certain static and dynamic performance indicators.

[0047] Embodiment 2:

[0048] like Fig.10 , Fig.11 As shown, the difference between this embodiment and the first embodiment is that: in this embodiment, the mounting seat 1 is triangular and the bottom plate 6 is irregular, which further reduces the volume.

[0049] The remaining features of this embodiment are the same as those of the first embodiment.

[0050] The present invention overcomes the defects and shortcomings of the prior art and provides a brand-new structural form, which is a single-axis suspension wire-supported pendulum-type, moment rebalancing accelerometer. Compared with other accelerometers, the present invention has the following advantages: it combines the pendulum assembly and the sensitive mass into one, so that the accelerometer is small in size, light in weight (less than 50 grams), and low in power consumption (0.16 mA / g to 0.32 mA / g); it adopts an eddy current sensor with high sensitivity, wide frequency range, small balance displacement under the action of inertial force, and strong anti-interference ability; it adopts a special supporting structure, so that it has a larger overload capacity (120g) and strong anti-impact and vibration resistance compared with other types of accelerometers. Dynamic capacity (maximum vibration 26g, 20Hz~2000Hz, 2h; maximum impact 1200g, 3ms, 1 / 2sin); it adopts the method of symmetrical magnetic circuit compensation, so that it can work in a wide temperature working range (-55℃~+85℃), and has better solutions in large range, strong impact and vibration. The present invention has excellent environmental adaptability, high precision and high reliability and stability, and can be widely used in flight control systems and inertial navigation systems in the fields of aerospace, aviation, navigation, weapons, etc.; therefore, the present invention provides a new structural form with small size, high sensitivity and strong impact and vibration resistance, and is a suspended wire pendulum accelerometer.

[0051] The invention can be widely applied to the field of acceleration measurement.

Claims

1. A suspended wire pendulum accelerometer, characterized in that: The invention comprises a mounting seat (1), an outer cover (2), a circuit component, an eddy current sensor component (4), a pendulum component (5), an eddy current sheet (7), and a permanent magnet component (8); the outer cover (2) is fixedly and hermetically connected to the mounting seat (1) to form a closed space for accommodating components inside; the eddy current sensor component (4) and the permanent magnet component (8) are both fixedly arranged inside; the permanent magnet component (8) comprises two magnetic poles (81, 82) arranged opposite to each other and having opposite magnetic properties to form a fixed magnetic field; and the eddy current sensor component (4) and the permanent magnet component (8) are fixedly arranged inside. The component (4) includes an eddy current coil (44), the suspended wire pendulum component (5) includes a pendulum frame (51) and two elastically supported suspension wires (53), the pendulum frame (51) is wound with a coil winding (52), the circuit component and the coil winding (52) form a torque balance electrical signal circuit, one side of the pendulum frame (51) is located in the gap between the two magnetic poles (81, 82), the eddy current sheet (7) is fixed on one side of the pendulum frame (51) and is located at the position of the eddy current sensor component (4). After the circuit assembly is powered on, a high-frequency current is continuously generated in the eddy current coil (44). Under the action of the eddy current effect, an eddy current is formed on the surface of the eddy current sheet (7). At the same time, the coil winding (52) is acted upon by a magnetic force in the fixed magnetic field, so that the suspended wire pendulum assembly (5) is suspended in the air in a balanced position. When the suspended wire pendulum accelerometer is subjected to acceleration, under the action of the measured acceleration, the suspended wire pendulum assembly (5) generates an inertial moment, deviates from the balanced position relative to the permanent magnet assembly (8), and causes the The eddy current sheet (7) on the suspended wire pendulum assembly (5) is displaced relative to the eddy current sensor assembly (4), thereby causing a change in the differential inductance of the eddy current coil (44), which is converted into an electrical signal through the servo circuit of the circuit assembly, and then fed back through the current of the torque balance electrical signal circuit. Under the action of the fixed magnetic field, the suspended wire pendulum assembly (5) is stimulated and the eddy current sheet (7) is driven to always be in a balanced position, and the feedback current signal is simultaneously used as an output, and this output represents the magnitude of the input acceleration;The mounting seat (1) is provided with a base plate (6), the two magnetic poles (81, 82) are fixedly connected to the base plate (6), the base plate (6) is also provided with a first pendulum support (63), a second pendulum support (64), and an eddy current sensor support (65), a wire pendulum adjustment shaft (66) passes through the second pendulum support (64) transversely and can rotate axially, the eddy current sensor assembly (4) is fixedly connected to the eddy current sensor support (65), the two ends of the coil winding (52) are respectively connected to two wiring plates (56, 57) located on the pendulum frame (51) and are conductive, two sealing sleeves (54) are fixedly connected to one side of the pendulum frame (51), the two sealing sleeves (54) are filled with damping oil (55), the two elastic support suspension wires (53) respectively pass through one of the sealing sleeves (54) and are suspended in the damping oil (55). ), the two elastic support suspension wires (53) are located on the same axis of the two sealing sleeves (54), and the outer ends of the two elastic support suspension wires (53) are respectively connected to the first pendulum support (63) and the pendulum adjustment shaft (66) and conduct electricity, so that the first pendulum support (63), the second pendulum support (64) and the circuit component are electrically connected to form the torque balance electrical signal circuit, and the pendulum frame (51) is suspended; the circuit component includes a wiring seat (3), and the wiring seat (3) and the bottom of the mounting seat (1) are sealed and fixed by laser sealing; the wiring seat (3) is also provided with a welding wire hole (30) to weld the connection between the pendulum assembly (5), the eddy current sensor assembly (4) and the circuit assembly, and seal it through a plug (31); the outer cover (2) and the mounting seat (1) are sealed and fixed by laser sealing. ; 2. The suspended wire pendulum accelerometer according to claim 1, characterized in that: The eddy current sensor assembly (4) further comprises an eddy current sensor skeleton (41), one end of the eddy current sensor skeleton (41) being fixedly connected to the eddy current sensor support (65) via an eddy current sensor mounting screw (40), the other end of the eddy current sensor skeleton (41) being separated into two arms (42, 43), two eddy current coils (44) being provided, the two eddy current coils (44) being respectively located at the opposite inner sides of the two arms (42, 43), an induction space (48) being provided between the two arms (42, 43), the eddy current sheet (7) extending into the induction space (48), the ends of the two arms (42, 43) being respectively provided with lead terminals (45) which are electrically connected to the circuit assembly so as to generate high-frequency currents in the two eddy current coils (44) via the circuit assembly.

3. The suspended wire pendulum accelerometer according to claim 1, characterized in that: The suspended wire pendulum accelerometer further comprises a pendulum limit screw (97); a first threaded hole (67) is provided on the base plate (6) at a position corresponding to the lower side of the pendulum frame (51); the pendulum limit screw (97) is adaptively connected to the first threaded hole (67); and a front end of the pendulum limit screw (97) extends above the base plate (6) to limit the lower limit position of the pendulum frame (51) and prevent the eddy current sheet (7) from contacting the eddy current sensor assembly (4).

4. The suspended wire pendulum accelerometer according to claim 3, characterized in that: The first threaded hole (67) is located below the gap between the two magnetic poles (81, 82), and the front end of the swing limit screw (97) extends into the gap between the two magnetic poles (81, 82).

5. The suspended wire pendulum accelerometer according to claim 1, characterized in that: The suspended wire pendulum accelerometer also includes a magnetic field adjustment screw (98); a second threaded hole (68) is provided on the base plate (6) below the gap between the two magnetic poles (81, 82); the magnetic field adjustment screw (98) is adaptively connected to the second threaded hole (68), and the front end of the magnetic field adjustment screw (98) extends into the gap between the two magnetic poles (81, 82) to adjust the size of the magnetic field in which the coil winding (52) is located.

6. The suspended wire pendulum accelerometer according to claim 1, characterized in that: The bottom plate (6) is provided with two opposite magnetic pole mounting vertical plates (61, 62), and the two magnetic poles (81, 82) are respectively fixed on the two magnetic pole mounting vertical plates (61, 62); the first pendulum support column (63), the second pendulum support column (64), and the eddy current sensor support column (65) are respectively located in the mounting holes on the bottom plate (6) and fixed; the mounting seat (1) is provided with a mounting hole (10); the sealing sleeve (54) is a glass tube; and the elastic support suspension wire (53) is made of platinum-silver alloy.

7. The suspended wire pendulum accelerometer according to claim 1, characterized in that: The base plate (6) and the mounting seat (1) are a split connection structure, and the base plate (6) is fixed to the mounting seat (1) via base plate mounting screws (11); or, the base plate (6) and the mounting seat (1) are an integrally formed connection structure.

8. The suspended wire pendulum accelerometer according to claim 1, characterized in that: The circuit assembly comprises a detection circuit, an amplification circuit, a correction circuit, and a sine wave oscillator. The detection circuit is used to convert the displacement of the eddy current sheet (7) into an electrical signal that is easy to measure. The amplification circuit is used to amplify the weak signal of the sensitive acceleration of the eddy current sensor assembly (4) and provide an amplification factor. The correction circuit is used to provide the necessary feedback current for rebalancing the suspended wire pendulum assembly (5) to obtain a rebalancing torque, and to provide a correction network so that the suspended wire pendulum accelerometer can work normally and meet static and dynamic performance indicators. The sine wave oscillator is used to provide a sine wave high-frequency oscillation signal of the eddy current sensor assembly (4).

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