Shock-resistant quartz flexible accelerometer swing beam and design method

Abstract

The invention discloses an anti-impact quartz flexible accelerometer swing beam and a design method, relates to the technical field of accelerometer structure design, and solves the problem that the swing beam is easy to break when the existing swing assembly is sensitive to strong impact and high vibration in the directions of a swing shaft and an output shaft. The invention provides a shock-resistant quartz flexible accelerometer pendulum beam which is assembled in a pendulum assembly of a quartz flexible accelerometer comprising a quartz pendulum piece and a coil assembly, the quartz pendulum piece comprises a pendulum beam, a pendulum tongue and a pendulum piece outer ring, and the coil assembly comprises a coil framework and a coil winding. The swing beam comprises a reinforcing boss arranged on the surface of the swing beam.

Description

Technical Field

[0001] The invention relates to the technical field of accelerometer structure design, and in particular to an impact-resistant quartz flexible accelerometer pendulum beam and a design method thereof. Background Art

[0002] Quartz flexible accelerometer is a high-precision inertial sensor widely used in launch vehicles, missiles, satellites, vehicle systems, ships, drilling and other fields. During measurement, especially in the fields of logging while drilling and missile control, the accelerometer may be in a harsh environment of strong vibration and high impact for a long time, which has a great impact on its accuracy, stability, life and reliability. Quartz flexible accelerometer is a typical feedback control sensor, which relies on electromagnetic torque to balance the inertial torque. The pendulum assembly is one of the core components of the accelerometer, which is used to detect and control the sensitive displacement generated by the sensitive inertial torque. Among them, the flexible beam is the link between the pendulum mass and the fixed position. The high flexibility of the ultra-thin flexible beam in the input axis ensures the high resolution of the accelerometer. Therefore, the pendulum beam is the key to the accuracy of the accelerometer. At the same time, the ultra-thin structure requirements and the intrinsic brittleness of the quartz material make the flexible beam the most vulnerable position of the entire quartz accelerometer.

[0003] Taking the Ф25.4 type accelerometer as an example, the existing pendulum beam thickness is between 20μm and 30μm, and the thickness of the rest of the quartz pendulum is 0.76m. When the sensor works in a harsh dynamic environment, the impact and vibration that the pendulum beam can withstand determines the life and reliability of the accelerometer. In addition, the existing quartz pendulum has a displacement constraint of 19μm in the direction of the input axis, and there is a feedback force to control it. That is, the maximum excitation in the direction of the input axis can be regarded as a displacement excitation of 19μm, under which the pendulum beam will not break. The existing quartz pendulum has neither displacement constraints nor feedback control in the direction of the pendulum axis and the output axis, and the degree of freedom control of the pendulum assembly depends entirely on the structural support of the pendulum beam. Therefore, it is necessary to optimize the structure of the pendulum beam to enhance its resistance to strong impact and high vibration in the direction of the pendulum axis and the output axis.

[0004] In summary, the pendulum beam needs to be able to stably control the freedom of the pendulum mass and also needs to have sufficient support for the sensitive mass in harsh mechanical environments. The existing pendulum assembly is prone to breakage when it is sensitive to strong impact and high vibration in the direction of the pendulum shaft and output shaft. Therefore, it is necessary to optimize the structure of the pendulum beam and improve the support for the sensitive mass to make it meet the application conditions in extreme mechanical environments, increase the service life of the sensor, and improve the mechanical environment adaptability of the quartz flexible accelerometer. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a shock-resistant quartz flexible accelerometer pendulum beam and a design method. The method optimizes the structure of the pendulum beam and designs a reinforcing boss on the pendulum beam, thereby increasing the strength of the pendulum beam and the support force of the pendulum beam on the sensitive mass. The feasibility and effectiveness of the structural optimization design are verified by using a mechanical model of the quartz flexible accelerometer, calculating the limit steady-state input, shock resistance, and eigenvalue buckling coefficient of the pendulum beam, and having important engineering application value for improving the mechanical adaptability of the quartz flexible accelerometer.

[0006] According to an embodiment of the present invention, a shock-resistant quartz flexible accelerometer pendulum beam is provided, which is assembled into a pendulum assembly of a quartz flexible accelerometer including a quartz pendulum piece and a coil assembly, wherein the quartz pendulum piece includes a pendulum beam, a pendulum tongue and a pendulum piece outer ring, the coil assembly includes a coil frame and a coil winding, and wherein the pendulum beam includes a reinforcing boss arranged on its surface.

[0007] Optionally, a reinforcing boss is respectively provided on the surfaces of the front and rear sides of the swing beam; the size of the reinforcing boss is a width less than 3.93 mm, a length less than 2.55 mm, and a thickness between 0 μm and 20 μm.

[0008] According to another embodiment of the present invention, a design method for a pendulum beam of a quartz flexible accelerometer based on the shock resistance is provided, comprising the following steps:

[0009] Step S1, establishing a mechanical simulation model of the pendulum assembly of the quartz flexible accelerometer to provide a parameterized modeling platform and a result verification platform for model optimization calculation;

[0010] Step S2, based on the multi-parameter optimization module of the mechanical simulation model, designing the reinforcing boss structure of the pendulum beam to obtain an optimized pendulum assembly model;

[0011] Step S3, based on the verification module of the mechanical simulation model, the optimized pendulum component model is compared and verified. If the verification result meets the design target requirements, the current optimized pendulum component model is saved and output for production application; otherwise, the design parameters are adjusted and the process returns to step S2;

[0012] Wherein, the step S1 specifically includes the following steps:

[0013] Step S1.1, using the geometric model of the pendulum assembly of the quartz flexible accelerometer to be optimized as the original geometric model of the pendulum assembly;

[0014] Step S1.2, meshing the original geometric model of the pendulum assembly to obtain a meshed pendulum assembly model;

[0015] Step S1.3, setting material parameters for the meshed pendulum component model, including setting the density, elastic modulus and Poisson's ratio of the quartz, coil skeleton and coil winding in the pendulum component;

[0016] Step S1.4, setting boundary conditions for the meshed pendulum assembly model and solving the boundary conditions, wherein the boundary conditions include the boss fixing constraint of the outer ring of the pendulum piece and the accelerometer excitation;

[0017] Step S1.5, model post-processing, establishing a multi-parameter optimization module and a verification module, and obtaining a mechanical simulation model of the pendulum assembly.

[0018] Optionally, in the step S1.2, the original geometric model of the pendulum assembly is meshed, including treating the pendulum tongue, the outer ring of the pendulum piece, the coil frame and the coil winding as equivalent to a rigid body.

[0019] Optionally, in step S1.3, setting material parameters for the meshed pendulum assembly model includes setting the density of the quartz pendulum piece in the pendulum assembly to 2.20 g / cm 3 , elastic modulus is 76.7 GPa, Poisson's ratio is 0.17; the density of the coil skeleton in the pendulum assembly is set to 2.78 g / cm 3 , elastic modulus is 73.1 GPa, Poisson's ratio is 0.33; the density of the coil winding in the pendulum assembly is set to 8.93 g / cm 3 , the elastic modulus is 110GPa, and the Poisson's ratio is 0.34.

[0020] Optionally, the step S2 specifically includes the following steps:

[0021] Step S2.1, setting the optimization target of the pendulum assembly based on the multi-parameter optimization module of the mechanical simulation model, wherein the optimization target includes the output shaft anti-shock index;

[0022] Step S2.2, setting the structural parameter range of the reinforcing boss, wherein the width of the reinforcing boss is smaller than the width of the swing beam, the length of the reinforcing boss is smaller than the length of the swing beam, and the position of the reinforcing boss is set within the range of the swing beam;

[0023] Step S2.3, based on the multi-parameter optimization module of the mechanical simulation model, by traversing the structural parameter range of the reinforcing boss, calculating the impact resistance of each group of structures within the structural parameter range, and selecting the optimal reinforcing boss structural parameters that meet the design results from all the impact resistance performance results obtained after the traversal;

[0024] Step S2.4, obtaining an optimized pendulum assembly model, in which the reinforcing boss of the pendulum beam has the optimal reinforcing boss structural parameters.

[0025] Optionally, the step S3 specifically includes the following steps:

[0026] Step S3.1, based on the verification module of the mechanical simulation model, calculating the characteristic buckling coefficient of the pendulum beam of the original pendulum assembly geometric model, and calculating the characteristic buckling coefficient of the pendulum beam of the optimized pendulum assembly model;

[0027] Step S3.2, in the verification module of the mechanical simulation model, applying an impact load in the output shaft direction to the original pendulum assembly geometric model, and calculating the transient response of the pendulum beam under the maximum impact, and applying an impact load in the output shaft direction to the optimized pendulum assembly model, and calculating the transient response of the pendulum beam under the maximum impact, the transient response under the maximum impact is the impact resistance;

[0028] Step S3.3, compare the characteristic buckling coefficient and impact resistance of the pendulum beam of the original pendulum assembly geometric model and the pendulum beam of the optimized pendulum assembly model. If the simulation result of the optimized pendulum assembly model meets the design target requirements, save the current optimized pendulum assembly model and output it for production application, otherwise adjust the design parameters and return to step S2.

[0029] According to yet another embodiment of the present invention, a method for designing a shock-resistant quartz flexible accelerometer pendulum beam is provided, comprising the following steps:

[0030] S1. Establish a mechanical simulation model of the quartz flexible accelerometer pendulum assembly to provide a parametric modeling platform and result verification platform for model optimization calculation:

[0031] The mechanical simulation model established by the present invention has the following two functions. Optimization: Based on the ANSYS WORKBENCH software, the pendulum beam is parametrically modeled, and a mechanical simulation model of the quartz flexible accelerometer pendulum assembly is established. The pendulum beam structural parameters are used as the target input, and the impact resistance of the pendulum beam is improved and the maximum value of the distributed stress on the pendulum beam is less than the bending strength of the quartz material as the optimization target, so that the simulation model can calculate the appropriate optimized structural parameters. Verification: The model can verify the impact resistance and characteristic buckling coefficient of the optimized pendulum assembly, and provide a verification platform for the extreme mechanical environment adaptability of the pendulum assembly.

[0032] S2. Based on the multi-parameter optimization function of the mechanical simulation model, optimize the pendulum beam structure, design a reinforced boss structure, and improve the impact strength of the pendulum beam:

[0033] The existing pendulum beam structure is prone to fracture when it is sensitive to strong impact and high vibration in the direction of the pendulum axis and output shaft. Strengthening the boss can improve the structural strength of the pendulum beam, increase the support of the pendulum beam to the sensitive mass, and improve the impact resistance of the accelerometer. Based on the multi-parameter optimization function of the mechanical simulation model, the optimization target constraints are set, and the boundary conditions of the strengthened boss are set. The structural parameters of the strengthened boss can be obtained through the model.

[0034] S3. Comparative verification based on the mechanical model of quartz flexible accelerometer:

[0035] Based on the mechanical model of the quartz flexible accelerometer pendulum assembly, the impact resistance and eigenvalue buckling coefficient of the original pendulum assembly and the existing pendulum assembly are compared and calculated, the calculation results of the simulation of the existing pendulum beam and the optimized pendulum beam are compared, and the improvement effect of the optimized structure on the pendulum beam's adaptability to the extreme mechanical environment is compared. If the simulation results of the optimized pendulum assembly model do not meet the design target requirements, otherwise return to step S1.

[0036] Compared with the prior art, the shock-resistant quartz flexible accelerometer pendulum beam and design method provided by the embodiments of the present invention have at least the following beneficial effects:

[0037] 1. The new swing beam designed by the present invention has a reinforcing boss structure compared to the swing beam in the prior art. The reinforcing boss enhances the supporting effect of the swing beam on the sensitive mass and increases the structural strength of the swing beam. The simulation results show that the new swing beam designed by the present invention can effectively improve the impact resistance of the quartz flexible accelerometer, enhance the stability of the swing beam, and reduce the occurrence of buckling, which has important engineering application value for improving the mechanical adaptability of the quartz flexible accelerometer.

[0038] 2. The mechanical simulation model of the quartz flexible accelerometer pendulum assembly established in the method of the present invention can obtain the optimal structural parameters of the reinforced boss within the set optimization target and the specified structural boundary conditions. In addition, the model combines transient dynamic analysis and eigenvalue buckling analysis, can effectively calculate the impact resistance and eigenvalue buckling coefficient of the pendulum assembly, and can effectively simulate and verify the mechanical environmental adaptability of the pendulum assembly. The model in the present invention provides an optimization platform and a verification platform for the structure of the pendulum assembly, calculates the structure accurately, saves calculation time, and improves experimental efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. The features and advantages of the present invention can be more clearly understood by referring to the drawings. The drawings are schematic and should not be understood as limiting the present invention in any way. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 It is a schematic diagram of an original geometric model of a pendulum assembly to be optimized used in a design method of a shock-resistant quartz flexible accelerometer pendulum beam provided in accordance with an embodiment of the present invention.

[0041] Figure 2 It is a schematic diagram of a pendulum assembly including a shock-resistant quartz flexible accelerometer pendulum beam provided according to an embodiment of the present invention.

[0042] Figure 3 FIG. 1 is a cross-sectional view of a shock-resistant quartz flexible accelerometer pendulum beam provided according to an embodiment of the present invention.

[0043] Figure 4 Schematic diagram of the instability of the pendulum beam under the excitation of pendulum shaft acceleration.

[0044] Figure 5 The maximum stress response of the pendulum beam under the maximum impact load of the output shaft in the original geometric model of the pendulum assembly used in an example of the design method of the shock-resistant pendulum beam of the quartz flexible accelerometer provided according to the embodiment of the present invention.

[0045] Figure 6 The maximum stress distribution of the pendulum beam under the maximum impact of the output shaft in the original geometric model of the pendulum assembly used in an example of the design method of the shock-resistant pendulum beam of the quartz flexible accelerometer provided in accordance with the embodiment of the present invention.

[0046] Figure 7 The maximum stress response of the swing beam under the maximum impact load of the output shaft is optimized in an example of the design method of the shock-resistant swing beam of the quartz flexible accelerometer provided according to an embodiment of the present invention.

[0047] Figure 8 The maximum stress distribution of the swing beam under the maximum impact of the output shaft is optimized in an example of the design method of the shock-resistant swing beam of the quartz flexible accelerometer provided according to the embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0049] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0050] A shock-resistant quartz flexible accelerometer pendulum beam and a design method according to an embodiment of the present invention are described in detail below with reference to the accompanying drawings.

[0051] like Figure 2As shown, a shock-resistant quartz flexible accelerometer pendulum beam 10 is provided according to an embodiment of the present invention, and is used in a pendulum assembly of a quartz flexible accelerometer including a quartz pendulum piece and a coil assembly, wherein the quartz pendulum piece includes a pendulum beam 10, a pendulum tongue 20 and a pendulum piece outer ring 30, and wherein the coil assembly 40 includes a coil skeleton 42 and a coil winding 44, and the pendulum beam 10 includes a reinforcing boss 12 arranged on its surface. The structure of the existing pendulum beam 10 is prone to buckling or fracture when it is subjected to sensitive strong impacts and high vibrations in the direction of the pendulum shaft and the output shaft. By providing a reinforcing boss 12 on the pendulum beam 10, the structural strength of the pendulum beam 10 can be improved, the supporting effect of the pendulum beam 10 on the sensitive mass can be increased, and the overall shock resistance of the quartz flexible accelerometer can be improved. The structure of the reinforcing boss 12 is shown in FIG. Figure 3 shown.

[0052] like Figure 2 and Figure 3 As shown, optionally, a reinforcing boss 12 may be provided on both the front and rear sides of each pendulum beam 10 of the pendulum assembly. Also optionally, the size range of the reinforcing boss 12 is less than 3.93 mm in width, less than 2.55 mm in length, and between 0 μm and 20 μm in thickness.

[0053] A method for designing a shock-resistant quartz flexible accelerometer pendulum beam provided in accordance with an embodiment of the present invention includes the following steps.

[0054] Step S1, establish a mechanical simulation model of the quartz flexible accelerometer pendulum assembly, import the pendulum assembly geometric model into the mechanical simulation model, which can be used to optimize the mechanical properties of the pendulum assembly, calculate and verify its impact resistance and eigenvalue buckling coefficient, and provide an optimization and result verification platform for the extreme mechanical environmental adaptability of the pendulum assembly. The simulation model can be based on ANSYSWORKBENCH software. Step S1 specifically includes the following steps.

[0055] Step S1.1, importing the geometric model, taking the geometric model of the pendulum assembly of the quartz flexible accelerometer to be optimized as the original geometric model of the pendulum assembly. Figure 1 As shown, the structure of an original geometric model is exemplarily shown, and the pendulum assembly of the quartz flexible accelerometer includes: a quartz pendulum and a coil assembly, wherein the quartz pendulum includes a pendulum beam 10, a pendulum tongue 20 and a pendulum outer ring 30, and wherein the coil assembly 40 includes a coil skeleton 42 and a coil winding 44. For example, taking a Ф25.4 type quartz flexible accelerometer as an example, the size of the pendulum beam to be optimized is: length 2.55mm, width 3.93mm, thickness 25μm.

[0056] Step S1.2, meshing the imported original geometric model of the pendulum assembly to obtain a meshed pendulum assembly model. Since the thickness of the pendulum beam 10 in the quartz pendulum beam is much smaller than the thickness of the pendulum tongue 20, the pendulum tongue 20, the pendulum outer ring 30, the coil frame 42, and the coil winding 44 can be equivalent to a rigid body during meshing.

[0057] Step S1.3, setting material parameters for the meshed pendulum assembly model. The material parameters of the meshed pendulum assembly model are set, and the material parameters include the density, elastic modulus and Poisson's ratio of the quartz, coil skeleton 42 and coil winding 44 in the pendulum assembly. The following Table 1 is an example of setting the material properties of the parts of the pendulum assembly model of the quartz flexible accelerometer.

[0058] Table 1 Material parameters of the parts of the pendulum assembly model

[0059] <![CDATA[Density g / cm 3 > Elastic modulus GPa Poisson's ratio Quartz pendulum 2.20 76.7 0.17 Coil skeleton 2.78 73.1 0.33 Coil Winding 8.93 110 0.34

[0060] Step S1.4, setting boundary conditions for the meshed pendulum assembly model and solving the problem. The boundary conditions of the meshed pendulum assembly model are set, for example, the boss fixing constraint of the outer ring 30 of the pendulum assembly is added thereto, and the accelerometer excitation is set.

[0061] Step S1.5, model post-processing, establishing a multi-parameter optimization module and a verification module, and obtaining a mechanical simulation model of the pendulum assembly. Based on the mechanical simulation model, optimization results or verification results can be obtained according to the set requirements. The multi-parameter optimization module of the mechanical simulation model obtained in step S1 can be used to set the optimization target in step 2 to calculate the structural optimization parameters of the reinforced boss. The verification module of the mechanical simulation model obtained in step S1 can calculate the maximum impact load and buckling coefficient that the pendulum assembly structure before optimization and the optimized pendulum assembly structure can bear, so as to compare the impact resistance and stability of the original pendulum assembly and the optimized pendulum assembly.

[0062] Step S2, based on the multi-parameter optimization module of the mechanical simulation model, optimize the pendulum beam structure in the pendulum assembly, design the reinforcing boss of the pendulum beam, and improve the impact resistance of the pendulum beam. By setting the optimization target of the pendulum assembly, setting the structural parameter selection range of the reinforcing boss, based on the S1 model, traversing the setting range of the boss structural parameters, the optimized pendulum assembly model is obtained, wherein the design of the reinforcing boss includes setting the length, width and thickness of the reinforcing boss. The role of the reinforcing boss of the pendulum beam is to increase the moment of inertia of the section, enhance the strength of the pendulum beam, and improve the impact resistance of the pendulum beam.

[0063] like Figure 4As shown, a schematic diagram of the instability of the pendulum axis direction is shown, taking the calculation of the pendulum axis buckling coefficient as an example. Assuming the PA axis (pendulum axis) as the x-axis and the OA axis (output axis) as the y-axis, the approximate differential equation of the deflection curve is:

[0064]

[0065] Where w″ represents the curvature of the deflection curve, w is the deflection, M is the bending moment, E is the elastic modulus of the material, I is the section moment of inertia, and F cr is the critical force of the pendulum beam.

[0066] Set the boundary conditions of the pendulum beam (one end is fixed and the other end is free) and obtain the critical force F of the pendulum beam cr :

[0067]

[0068] Wherein, l is the length of the swing beam 10, that is, the length of the swing beam 10 in the vertical direction.

[0069] It can be seen from formula (2) that the improved design of the cross-sectional shape is helpful to increase the cross-sectional moment of inertia of the pendulum beam and to improve the motion stability of the quartz pendulum.

[0070] The existing pendulum beam structure is prone to buckling or breaking when subjected to strong impact or high vibration in the direction of the pendulum axis and output shaft. By setting a reinforcing boss on the pendulum beam, the strength of the pendulum beam structure can be improved, the support of the pendulum beam to the sensitive mass can be increased, and the impact resistance of the quartz flexible accelerometer can be improved. Figure 2 and Figure 3 As shown, the width, height and relative position of the boss can be determined by substituting into the mechanical simulation model established in step S1. Step S2 specifically includes the following steps.

[0071] Step S2.1, setting the optimization target of the pendulum assembly. The optimization target is to improve the impact resistance of the pendulum beam and set the maximum tolerable impact, which can be set according to the application scenario. For example, the optimization target may include the output shaft impact resistance index.

[0072] Step S2.2, setting the structural parameter range of the reinforcing boss, wherein the width of the reinforcing boss is smaller than the width of the swing beam, the length of the reinforcing boss is smaller than the length of the swing beam, and the position of the reinforcing boss is set within the range of the swing beam;

[0073] Step S2.3, based on the mechanical simulation model established in step S1, using the multi-parameter optimization function of the mechanical simulation model, by traversing the structural parameter range of the reinforcing boss, calculating the impact resistance of each group of structures within the structural parameter range, and selecting the optimal reinforcing boss structural parameters that meet the design results from all the impact resistance results obtained after the traversal;

[0074] Step S2.4, obtaining an optimized pendulum assembly model, in which the reinforcing boss of the pendulum beam has the optimal reinforcing boss structural parameters.

[0075] In Example 1, the output shaft impact resistance index of 180g, 0.5ms is taken as the optimization target, and the original geometric model of the pendulum assembly including the pendulum beam with a width of 3.93mm, a length of 2.55mm, and a thickness of 25μm is optimized. The original geometric model of the pendulum assembly is imported into the mechanical simulation model, and the structural parameter range of the reinforcing boss is set as: width <3.93mm, length <2.55mm, thickness>0μm, and the relative position is required to be on the pendulum beam. After traversing the structural parameter range of the reinforcing boss, the impact resistance of each group of models within the structural parameter range is calculated to obtain the optimal model of the optimal pendulum beam. In this example, the optimal structural parameters of the reinforcing boss 12 of the pendulum beam calculated based on the simulation model are: length 2.55mm, width 1.8mm, thickness 10μm, and the distance from the upper right edge of the pendulum beam is 0.1mm. The optimized pendulum assembly model is established based on this.

[0076] Step S3, based on the verification module of the mechanical simulation model of the quartz flexible accelerometer pendulum assembly, the optimized pendulum assembly model is compared and verified. The original pendulum assembly geometric model and the optimized pendulum assembly model are imported into the mechanical simulation model for simulation, and the simulation results of the original pendulum assembly geometric model and the optimized pendulum assembly model are obtained through the verification module. The two sets of simulation results include impact resistance and eigenvalue buckling coefficient respectively. This step S3 specifically includes the following steps.

[0077] Step S3.1, in the verification module of the mechanical simulation model, respectively calculate the characteristic buckling coefficients of the pendulum beam of the original pendulum assembly geometric model and the pendulum beam of the optimized pendulum assembly model. For example, the optimized pendulum assembly model and the original geometric model of the pendulum assembly obtained in Example 1 above are calculated, and a compression force of 1N is applied to them in the direction of the pendulum axis and a shear force of 1N is applied to them in the direction of the output axis, and their respective characteristic buckling coefficients are calculated. The calculation results are shown in Table 2.

[0078] Table 2 Comparison of characteristic buckling coefficients of pendulum components

[0079] Original pendulum assembly Optimized rear swing assembly Swing shaft 0.67 1.04 Output shaft 4.22 15.56

[0080] As can be seen from Table 2, the original pendulum assembly does not buckle, and the maximum force it can withstand in the direction of the pendulum axis is 0.67N, and the maximum force it can withstand in the direction of the output shaft is 4.22N. That is, the maximum acceleration that can be borne in the direction of the pendulum axis without buckling is 82.1g, and the maximum acceleration in the direction of the output shaft is 159.7g. The critical force of the optimized pendulum assembly in the direction of the pendulum axis is 1.04N, and the maximum force it can withstand in the direction of the output shaft is 15.56N. That is, the maximum acceleration that can be borne in the direction of the pendulum axis without buckling is 127.4g, and the maximum acceleration in the direction of the output shaft is 588.7g.

[0081] Step S3.2, in the verification module of the mechanical simulation model, impact loads are applied to the original pendulum assembly geometric model and the optimized pendulum assembly model in the output shaft direction, and the transient responses of their respective pendulum beams under the maximum impact are calculated as the impact resistance performance.

[0082] The bending strength of quartz material is 52.4MPa. The transient impact response of the pendulum beam is simulated based on the maximum shear stress theory. The impact load is in the direction of the output shaft, and the action time is 0.5ms of half-wave acceleration excitation.

[0083] Continuing to refer to Example 1 above, the transient impact response of the pendulum assembly before and after optimization in Example 1 is calculated respectively. It can be calculated that the maximum acceleration impact in the output axis direction that the pendulum beam in the original pendulum assembly geometric model can withstand is 129g 0.5ms, and the maximum stress of the pendulum beam changes with time as shown in Figure 5 As shown, the stress distribution is as follows: Figure 6 The maximum acceleration shock that the swing beam in the optimized swing assembly can withstand in the output shaft direction is 180g 0.5ms, and the maximum stress of the swing beam changes with time as shown in Figure 7 As shown, the stress distribution is as follows: Figure 8 shown.

[0084] Step S3.3, compare the characteristic buckling coefficient and impact resistance of the pendulum beam of the original pendulum assembly geometric model and the pendulum beam of the optimized pendulum assembly model. If the simulation result of the optimized pendulum assembly model meets the design target requirements, save the current optimized pendulum assembly model and output it, otherwise adjust the design parameters and return to step S2.

[0085] See also Figures 5 to 8 By comparison, it can be obtained that in the above Example 1, the novel pendulum beam design method proposed by the present invention is applied, and the eigenvalue buckling coefficient in the pendulum axis direction of the optimized pendulum assembly is increased by 55.2%, and the eigenvalue buckling coefficient in the output axis direction is increased by 2.6 times, which effectively increases the stability of the pendulum assembly and makes the pendulum assembly less prone to buckling in extreme mechanical environments.

[0086] The optimization calculation results were verified by transient impact simulation. By comparing the impact resistance of the two pendulum assemblies, it can be concluded that in this embodiment, the new pendulum beam design method proposed by the present invention is applied to increase the maximum impact that the pendulum assembly can withstand in the output shaft direction by 39.5%, and it meets the design requirements. The optimized pendulum assembly model can be output for production applications in specific fields.

[0087] Therefore, the mechanical model of the quartz flexible accelerometer pendulum assembly established by the present invention can effectively calculate the stress response and transient impact response of the pendulum assembly. The above scheme adopted by the present invention can effectively improve the support force of the pendulum beam on the sensitive mass, so that it meets the application conditions in extreme mechanical environments, improve the service life of the sensor, and improve the mechanical environment adaptability of the quartz flexible accelerometer, which plays an important role in the engineering application value of the quartz flexible accelerometer. According to the shock-resistant quartz flexible accelerometer pendulum beam design method provided by the embodiment of the present invention, the structural strength of the pendulum beam can be increased and the supporting effect of the pendulum beam on the sensitive mass can be enhanced by designing a reinforcing boss structure on the pendulum beam. The mechanical simulation model of the quartz flexible accelerometer pendulum assembly established in the method of the present invention can obtain the optimal structural parameters of the reinforcing boss within the set optimization target and the specified structural boundary conditions. In addition, the model integrates transient dynamic analysis and eigenvalue buckling analysis, can effectively calculate the impact resistance and eigenvalue buckling coefficient of the pendulum assembly, and can effectively simulate and verify the mechanical environment adaptability of the pendulum assembly. The mechanical model is simple to establish, the calculation structure is accurate, the calculation time is saved, and the experimental efficiency is improved. The novel pendulum beam structure proposed in the present invention can effectively improve the impact resistance of the quartz flexible accelerometer, enhance the stability of the pendulum beam, and reduce the occurrence of buckling, which has important engineering application value for improving the mechanical adaptability of the quartz flexible accelerometer.

[0088] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0089] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0090] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A shock-resistant quartz flexible accelerometer pendulum beam, characterized in that: Assembled into a pendulum assembly of a quartz flexible accelerometer including a quartz pendulum and a coil assembly, wherein the quartz pendulum includes a pendulum beam, a pendulum tongue and a pendulum outer ring, the coil assembly includes a coil frame and a coil winding, and wherein the pendulum beam includes a reinforcing boss arranged on its surface.

2. The shock-resistant quartz flexible accelerometer pendulum beam according to claim 1, characterized in that: A reinforcing boss is provided on the surfaces of the front and rear sides of the swing beam; The dimensions of the reinforcing boss are: a width less than 3.93 mm, a length less than 2.55 mm, and a thickness between 0 μm and 20 μm.

3. A design method for a shock-resistant quartz flexible accelerometer pendulum beam based on claim 1 or 2, characterized in that: The following steps are involved: Step S1, establishing a mechanical simulation model of the pendulum assembly of the quartz flexible accelerometer to provide a parameterized modeling platform and a result verification platform for model optimization calculation; Step S2, based on the multi-parameter optimization module of the mechanical simulation model, designing the reinforcing boss structure of the pendulum beam to obtain an optimized pendulum assembly model; Step S3, based on the verification module of the mechanical simulation model, the optimized pendulum component model is compared and verified. If the verification result meets the design target requirements, the current optimized pendulum component model is saved and output for production application; otherwise, the design parameters are adjusted and the process returns to step S2; Wherein, the step S1 specifically includes the following steps: Step S1.1, using the geometric model of the pendulum assembly of the quartz flexible accelerometer to be optimized as the original geometric model of the pendulum assembly; Step S1.2, meshing the original geometric model of the pendulum assembly to obtain a meshed pendulum assembly model; Step S1.3, setting material parameters for the meshed pendulum component model, including setting the density, elastic modulus and Poisson's ratio of the quartz, coil skeleton and coil winding in the pendulum component; Step S1.4, setting boundary conditions for the meshed pendulum assembly model and solving the boundary conditions, wherein the boundary conditions include the boss fixing constraint of the outer ring of the pendulum piece and the accelerometer excitation; Step S1.5, model post-processing, establishing a multi-parameter optimization module and a verification module, and obtaining a mechanical simulation model of the pendulum assembly.

4. The design method according to claim 3, characterized in that: In the step S1.2, The original geometric model of the pendulum assembly is meshed, including the pendulum tongue, pendulum outer ring, coil frame and coil winding being equivalent to rigid bodies.

5. The design method according to claim 4, characterized in that: In the step S1.3, setting material parameters for the meshed pendulum component model includes: The density of the quartz pendulum in the pendulum assembly is set to 2.20 g / cm 3 , elastic modulus is 76.7 GPa, Poisson's ratio is 0.17; The density of the coil skeleton in the pendulum assembly is set to 2.78 g / cm 3 , elastic modulus is 73.1 GPa, Poisson's ratio is 0.33; The density of the coil winding in the pendulum assembly is set to 8.93 g / cm 3 , the elastic modulus is 110GPa, and the Poisson's ratio is 0.

34.

6. The design method according to claim 5, characterized in that: The step S2 specifically includes the following steps: Step S2.1, setting the optimization target of the pendulum assembly based on the multi-parameter optimization module of the mechanical simulation model, wherein the optimization target includes the output shaft anti-shock index; Step S2.2, setting the structural parameter range of the reinforcing boss, wherein the width of the reinforcing boss is smaller than the width of the swing beam, the length of the reinforcing boss is smaller than the length of the swing beam, and the position of the reinforcing boss is set within the range of the swing beam; Step S2.3, based on the multi-parameter optimization module of the mechanical simulation model, by traversing the structural parameter range of the reinforcing boss, calculating the impact resistance of each group of structures within the structural parameter range, and selecting the optimal reinforcing boss structural parameters that meet the design results from all the impact resistance performance results obtained after the traversal; Step S2.4, obtaining an optimized pendulum assembly model, in which the reinforcing boss of the pendulum beam has the optimal reinforcing boss structural parameters.

7. The design method according to claim 6, characterized in that: The step S3 specifically comprises the following steps: Step S3.1, based on the verification module of the mechanical simulation model, calculating the characteristic buckling coefficient of the pendulum beam of the original pendulum assembly geometric model, and calculating the characteristic buckling coefficient of the pendulum beam of the optimized pendulum assembly model; Step S3.2, in the verification module of the mechanical simulation model, applying an impact load in the output shaft direction to the original pendulum assembly geometric model, and calculating the transient response of the pendulum beam under the maximum impact, and applying an impact load in the output shaft direction to the optimized pendulum assembly model, and calculating the transient response of the pendulum beam under the maximum impact, the transient response under the maximum impact is the impact resistance; Step S3.3, compare the characteristic buckling coefficient and impact resistance of the pendulum beam of the original pendulum assembly geometric model and the pendulum beam of the optimized pendulum assembly model. If the simulation result of the optimized pendulum assembly model meets the design target requirements, save the current optimized pendulum assembly model and output it for production application, otherwise adjust the design parameters and return to step S2.

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