A system and method for evaluating the impact durability reliability of a transmission shift hub stop point

Abstract

This invention discloses a system and method for evaluating the impact durability reliability of a transmission shift hub stop. The system includes a shift hub stop strength finite element modeling module, a shift hub upper and lower stop strength finite element calculation module, a one-dimensional simulation load extraction module, a stop material strength evaluation module, and a shift hub stop fatigue calculation module. Based on the shift hub stop strength model, the system simulates the impact operating conditions of the shift hub stop, effectively ensuring the rational design of the shift hub stop's impact operating conditions and improving powertrain development efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of design and simulation of a shifting control mechanism of an automobile transmission, and in particular to a system and method for evaluating the impact durability reliability of a transmission shift hub dead point. Background Art

[0002] The shift hub is an important component of the automobile transmission's gear selection and shifting actuator. As the core component for realizing the gear shifting function, the motor drives the shift hub to rotate, which can drive the shift fork to shift horizontally along the axis, thereby realizing the gear change. The shift hub structure itself needs to bear a certain load in normal working state. The main parts are the shift hub groove, the shift hub stop point, and the shift hub pin shaft.

[0003] Due to the complex shifting logic and the diverse operating conditions and stresses of the shift hub, stringent requirements are placed on the shift hub's structural safety and durability. Failure of the shift hub structure can lead to partial functional loss, significantly impacting the vehicle's lifecycle. Therefore, simulation and optimization of mechanical properties, such as the shift hub's structural strength and durability, are integrated into all levels of testing, from component design to transmission design to vehicle design, and have become an integral part of every design phase.

[0004] The shift hub stop point is the impact-sensitive part of the shift hub. Its durability determines whether the shift hub will fail and its service life. It is also one of the important indicators to ensure that the shift hub does not fail. Therefore, how to predict problems in advance in the design stage to reduce risks and ensure the impact durability reliability of the shift hub stop point has become an urgent need in both traditional and new energy transmission fields. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a system and method for evaluating the impact durability reliability of a transmission shift hub stop point.

[0006] To achieve this purpose, the impact durability reliability evaluation system of the gearbox shift hub stop point designed by the present invention includes a shift hub stop point strength finite element model establishment module, a shift hub upper and lower stop point strength finite element calculation module, a one-dimensional simulation load extraction module, a stop point material strength evaluation module and a shift hub stop point fatigue calculation module; the shift hub stop point strength finite element model establishment module is used to establish a shift hub stop point strength model; the shift hub upper and lower stop point strength finite element calculation module is used to perform finite element strength simulation calculation on the shift hub stop point impact working condition according to the shift hub stop point strength model, and extract the upper and lower stop points under the reference torque. stress value; the one-dimensional simulation load extraction module is used to establish a one-dimensional transmission system model of the shift hub stop point, and extract the impact torque of the upper and lower stop points of the shift hub; the stop point material strength evaluation module is used to judge whether the structural design of each part of the shift hub stop point strength model is qualified according to the impact torque of the upper and lower stop points of the shift hub and the stress values ​​of the upper and lower stop points under the reference torque; the shift hub stop point fatigue calculation module is used to perform fatigue calculation on the upper and lower stop points of the shift hub according to the stress values ​​of the upper and lower stop points under the reference torque, the impact torque of the upper and lower stop points of the shift hub and the material of the shift hub housing, and predict the fatigue life of the upper and lower stop points of the shift hub.

[0007] Furthermore, establishing the shift hub stop point strength model includes establishing a three-dimensional geometric model of the shift hub shell, a three-dimensional geometric model of the shift hub pin shaft, a three-dimensional geometric model of the shift hub bushing, a three-dimensional geometric model of the shift hub double gear, a three-dimensional geometric model of the shift hub connecting bolt, a three-dimensional geometric model of the transmission housing, a three-dimensional geometric model of the shift hub top stop point, a three-dimensional geometric model of the shift hub bottom stop point, and a shift hub stop point strength model formed by assembling the three-dimensional geometric model of the shift hub shell, the three-dimensional geometric model of the shift hub pin shaft, the three-dimensional geometric model of the shift hub bushing, the three-dimensional geometric model of the shift hub double gear, the three-dimensional geometric model of the shift hub connecting bolt, the three-dimensional geometric model of the transmission housing, the three-dimensional geometric model of the shift hub top stop point, and the three-dimensional geometric model of the shift hub bottom stop point.

[0008] Furthermore, establishing the shift hub dead center strength model includes setting the material properties of the shift hub housing, the shift hub pin shaft, the shift hub bushing, the shift hub duplex gear, the shift hub connecting bolts, and the gearbox housing.

[0009] The impact durability reliability evaluation method for the gearbox shift hub stop point based on the impact durability reliability evaluation system for the gearbox shift hub stop point described above is characterized in that: it includes establishing a shift hub stop point strength model; performing finite element strength simulation calculation on the shift hub stop point impact working condition according to the shift hub stop point strength model, and extracting the stress values ​​of the upper and lower stop points under the reference torque; establishing a one-dimensional transmission system model of the shift hub stop point, and extracting the impact torque of the upper and lower stop points of the shift hub; judging whether the structural design of each part of the shift hub stop point strength model is qualified according to the impact torque of the upper and lower stop points of the shift hub and the stress values ​​of the upper and lower stop points under the reference torque; performing fatigue calculation on the upper and lower stop points of the shift hub according to the stress values ​​of the upper and lower stop points under the reference torque, the impact torque of the upper and lower stop points of the shift hub and the material of the shift hub shell, and predicting the fatigue life of the upper and lower stop points of the shift hub.

[0010] Furthermore, the method for establishing the shift hub stop point strength model includes: establishing a three-dimensional geometric model of the shift hub shell, a three-dimensional geometric model of the shift hub pin shaft, a three-dimensional geometric model of the shift hub bushing, a three-dimensional geometric model of the shift hub double gear, a three-dimensional geometric model of the shift hub connecting bolt, a three-dimensional geometric model of the transmission housing, a three-dimensional geometric model of the shift hub top stop point, and a three-dimensional geometric model of the shift hub bottom stop point; according to the constraint relationship between the shift hub shell, the shift hub pin shaft, the shift hub bushing, the shift hub double gear, the shift hub connecting bolt, the transmission housing, the shift hub top stop point, and the shift hub bottom stop point, the three-dimensional geometric model of the shift hub shell, the three-dimensional geometric model of the shift hub pin shaft, the three-dimensional geometric model of the shift hub bushing, the three-dimensional geometric model of the shift hub double gear, the three-dimensional geometric model of the shift hub connecting bolt, the three-dimensional geometric model of the transmission housing, the three-dimensional geometric model of the shift hub top stop point, and the three-dimensional geometric model of the shift hub bottom stop point are assembled to form the shift hub stop point strength model.

[0011] Furthermore, establishing the shift hub stop point strength model includes meshing the shift hub stop point strength model, setting the shift hub housing, shift hub pin shaft, shift hub bushing, shift hub duplex gear, shift hub connecting bolts, and gearbox housing material properties and boundary conditions.

[0012] Furthermore, establishing the shift hub dead point strength model includes setting the load transfer relationship between the shift hub housing, shift hub pin shaft, shift hub bushing, shift hub duplex gear, shift hub connecting bolt, transmission housing, shift hub top dead point and shift hub bottom dead point; and loading torque load on the shift hub duplex gear.

[0013] Furthermore, the method of establishing a one-dimensional transmission system model of the shift hub dead point and extracting the impact torque of the upper and lower dead points of the shift hub includes establishing a one-dimensional transmission system model of the shift hub dead point, and inputting relevant parameters of the shift hub drive motor characteristic curve into the one-dimensional dynamics software; calculating through the simulation results of the shift hub dead point strength model, outputting the torsional stiffness of the power system from the shift hub drive motor to the shift hub dead point, and inputting the torsional stiffness into the one-dimensional transmission system model of the shift hub dead point; inputting the parameters of the transmission gear system of the shift hub dead point into the one-dimensional transmission system model of the shift hub dead point, establishing a complete one-dimensional transmission system model of the shift hub dead point, and extracting the impact torque of the upper and lower dead points of the shift hub.

[0014] Furthermore, the method for judging whether the structural design of each part of the shift hub stop point strength model is qualified based on the impact torque of the upper and lower dead points of the shift hub and the stress values ​​of the upper and lower dead points under the reference torque includes: linearly scaling the stress values ​​of the upper and lower dead points of the shift hub under the reference torque according to the impact torque of the upper and lower dead points of the shift hub to obtain the actual stress values ​​of the upper and lower dead points of the shift hub, and using the actual stress values ​​of the upper and lower dead points of the shift hub as evaluation inputs. If the material strength calculations of the structural designs of each part of the shift hub stop point strength model meet the requirements, the structural design of the shift hub stop point strength model is qualified; otherwise, the structural design of the shift hub stop point strength model is unqualified.

[0015] Furthermore, the method for predicting the fatigue life of the upper and lower dead points of the shift hub by performing fatigue calculation on the upper and lower dead points of the shift hub based on the stress values ​​of the upper and lower dead points of the shift hub under the reference torque, the impact torque of the upper and lower dead points of the shift hub and the material of the shift hub shell includes: linearly scaling the stress values ​​of the upper and lower dead points of the shift hub under the reference torque according to the impact torque of the upper and lower dead points of the shift hub, obtaining the SN curve of the material according to the material of the shift hub shell, superimposing the fatigue damage at each torque level, and predicting the fatigue life of the upper and lower dead points of the shift hub.

[0016] The beneficial effects of the present invention are as follows: based on the shift hub stop point strength model, the present invention simulates the impact working condition of the shift hub stop point, effectively ensures that the impact working condition design of the shift hub stop point is reasonable, and improves the efficiency of powertrain development. When analyzing the impact reliability of the shift hub stop point during the simulation process, the present invention accurately models the shift hub, and combines the actual use working conditions of the whole vehicle, considering the influence of design, assembly process, actual road use, etc. on the impact working condition of the shift hub stop point, and the obtained shift hub stop point impact working condition has high reliability and is not easy to fail. Through a reasonable simplified model, the boundary setting and load distribution setting that conform to the actual situation can not only correctly represent the relationship between the various components when the two-speed transmission shift hub stop point is impacted, but also can realistically simulate the force conditions of the shift hub stop point, thereby improving the accuracy of the finite element strength analysis of the transmission shift hub stop point, improving the analysis efficiency, and further accurately predicting the fatigue life of the shift hub stop point. The disclosure of this calculation method has positive significance for improving the technical level of the transmission shift hub in traditional and new energy industries. When the present invention performs reliability analysis on the impact assembly of the shift hub stop point during the simulation process, the stress distribution of the shift hub shell obtained through simulation can be used to perform all-round and multi-angle iterative optimization of the shift hub shell. The boundary conditions are consistent with the actual working conditions, and the impact force conditions of the shift hub stop point assembly are more in line with reality. The simulation and test results can better meet the reliability requirements of the shift hub stop point in actual use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a module connection diagram of the impact durability reliability evaluation system for the transmission shift hub dead point of the present invention;

[0018] Figure 2 This is a three-dimensional diagram of the connection assembly between the shift hub and the motor in the present invention;

[0019] Figure 3 A three-dimensional diagram of the dead center strength model of the shift hub in the present invention;

[0020] Among them, 301 is a finite element model establishment module for the strength of the shift hub stop point, 302 is a finite element calculation module for the strength of the upper and lower stop points of the shift hub, 303 is a one-dimensional simulation load extraction module, 304 is a stop point material strength evaluation module, and 305 is a shift hub stop point fatigue calculation module;

[0021] 401 - shift hub housing, 402 - shift hub pin, 403 - shift hub drive slider, 404 - shift hub bushing, 405 - shift hub duplex gear, 406 - shift hub connecting bolt, 407 - transmission housing, 408 - shift hub top dead center, 409 - shift hub bottom dead center,

[0022] 501—shift motor, 502—first duplex gear, 503—first duplex gear positioning pin, 504—second duplex gear, 505—second duplex gear positioning pin. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0024] Figure 1 The impact durability reliability evaluation system for the transmission shift hub stop point designed for the present invention includes a shift hub stop point strength finite element model establishment module 301, a shift hub upper and lower stop point strength finite element calculation module 302, a one-dimensional simulation load extraction module 303, a stop point material strength evaluation module 304 and a shift hub stop point fatigue calculation module 305.

[0025] The shift hub stop point strength finite element model establishment module 301 is used to establish the shift hub stop point strength model. The shift hub upper and lower stop point strength finite element calculation module 302 is used to perform finite element strength simulation calculations on the shift hub stop point impact working condition based on the shift hub stop point strength model, extracting the stress values ​​of the upper and lower stop points under a reference torque. The one-dimensional simulation load extraction module 303 is used to establish a one-dimensional transmission system model of the shift hub stop point and extract the impact torque of the shift hub upper and lower stop points. The stop point material strength evaluation module 304 is used to determine the structural design of each component of the shift hub stop point strength model based on the impact torque of the shift hub upper and lower stop points and the stress values ​​of the upper and lower stop points under a reference torque. The shift hub stop point fatigue calculation module 305 is used to perform fatigue calculations on the shift hub upper and lower stop points based on the stress values ​​of the upper and lower stop points under a reference torque, the impact torque of the shift hub upper and lower stop points, and the material of the shift hub housing 401, to predict the fatigue life of the shift hub upper and lower stop points.

[0026] like Figure 2 As shown in FIG3, the method for establishing the shift hub dead center strength model is:

[0027] Carry out structural design on the upper and lower dead points of the shift hub and the upper and lower dead points of the transmission housing.

[0028] A 3D digital model of the shift hub upper and lower dead centers and the housing upper and lower dead centers was designed. Based on the transmission housing 407 and the shift hub dead center strength assembly structure, a simplified 3D geometric model of the shift hub housing 401, shift hub duplex gear 405, shift hub connecting bolt 406, shift hub pin 402, and shift hub bushing 404 was created. Based on actual analysis requirements, the modeling was simplified accordingly. Finally, the shift hub dead center strength assembly analysis model was assembled based on the constraints between the various components in the shift hub dead center strength assembly.

[0029] In the HYPERWORKS software, material parameters, the connection relationship between the subcomponents of the shift hub stop point strength assembly, and the connection relationship between the shift hub stop point strength assembly and the transmission housing 407 are input to establish a finite element analysis model for the shift hub stop point strength analysis.

[0030] The shift hub housing 401, the shift hub double gear 405 and the shift hub connecting bolt 406, the shift hub pin 402, and the shift hub bushing 404 are meshed using 10-node tetrahedral quadratic solid elements. The contact positions of each component need to be mapped to mesh nodes one by one.

[0031] The speed ratio of the gear of the shift motor 501 and the first double gear 502, the second double gear 504, and the shift hub double gear 405 is converted, and the converted torque is loaded on the shift hub double gear 405, and the inner ring of the shift hub bushing 404 and the outer ring of the shift hub pin shaft 402 are set to frictionless contact, and the outer ring of the shift hub bushing 404 and the transmission housing 407 are set to binding contact, simulating the pressed contact state of the shift hub bushing 404 and the transmission housing 407, the bottom of the shift hub connecting bolt 406 is set to binding contact with the shift hub housing 401, the shift hub double gear 405 and the shift hub housing 401 are set to frictionless contact, and the shift hub pin shaft 402 and the shift hub housing 401 are set to binding contact.

[0032] Finite element strength simulation calculation of the shift hub dead center impact working condition is performed based on the shift hub dead center strength model. The method for extracting the stress values ​​of the upper and lower dead centers under the reference torque is as follows:

[0033] The strength iterative calculation of the built shift hub dead center strength finite element model was performed to obtain the stress distribution results under the shift hub top dead center working condition and the shift hub bottom dead center working condition respectively.

[0034] The one-dimensional transmission system model of the shift hub dead center is established, and the method for extracting the impact torque of the upper and lower dead centers of the shift hub is:

[0035] A one-dimensional shift hub control model is built in the one-dimensional dynamics software, and a one-dimensional transmission system model of the shift hub dead point is established to prepare for extracting the upper and lower dead point impact loads corresponding to specific peak torque conditions.

[0036] The parameters related to the shift motor characteristic curve at a specific temperature, ie, the torque-speed characteristic curve of the shift motor 501 , are input into the one-dimensional dynamics software to establish a shift hub dead-point transmission system model including planetary gears or duplex gears.

[0037] The torsional stiffness of the powertrain from the shift motor 501 to the shift hub's stop point is initially calculated using finite element simulation results. The impact torque at the shift hub's stop point is closely related to the torsional stiffness of the shift hub's dual gears 405. Therefore, prior to the one-dimensional dynamics simulation, the torsional stiffness of the system from the shift motor 501 to the shift hub's stop point must be determined through finite element simulation as input for the shift hub's dynamics simulation. Due to the shift hub's drive angle constraints, the two stop points of the shift hub are located at positions 1 and 2, respectively. These two stop points have different torsional stiffnesses, resulting in slightly different impact torques at the corresponding shift hub stops.

[0038] The gear transmission system parameters of the double gear system are obtained, which include the number of gear teeth, the transmission ratio, the rotational inertia of the shift motor, the rotational inertia of the first double gear, the rotational inertia of the second double gear, and the rotational inertia of the shift hub housing.

[0039] The torsional stiffness of the shift hub's end point system and the parameters of the gear transmission system were entered into one-dimensional dynamics software to establish and improve the shift hub end point impact dynamics system model, and the impact loads on the upper and lower end points of the shift hub were extracted. The impact torque of the shift hub end point is closely related to the torsional stiffness of the dual-gear shift system. The shift impact torque varies with the torsional stiffness of the system. Due to the different torsional stiffnesses of shift hub assemblies with different structures, the impact torque input from the shift motor 501 to the shift hub end point varies with the torsional stiffness of the shift hub system. If the end point structures of the shift hub for the same project are not on the same boss, the torsional stiffness may vary. Therefore, the present invention innovatively takes into account the influence of the torsional stiffness of the shift hub assembly on the end point impact torque.

[0040] The method for judging whether the structural design of each part of the shift hub dead center strength model is qualified according to the impact torque of the upper and lower dead centers of the shift hub and the stress values ​​of the upper and lower dead centers under the reference torque is:

[0041] If the initial material of the component is set to linear, the shift hub stop point stress is scaled according to the extracted shift hub impact load to obtain the actual stress values ​​of the upper and lower stop points of the shift hub. The structural strength of the upper and lower stop points of the shift hub is evaluated. If the structural strength results of the stop points meet the requirements, the next step is carried out; otherwise, the local structure of the upper and lower stop points of the shift hub or the transmission case stop points is optimized and improved.

[0042] If the initial component material is set to plastic, the actual stress values ​​at the upper and lower dead points of the shift hub are compared with the material yield strength. If the strength calculation results meet the requirements, the next step is carried out; otherwise, the local structure of the upper and lower dead points of the shift hub or the transmission housing dead points is optimized.

[0043] The fatigue life of the upper and lower dead points of the shift hub is predicted by performing fatigue calculation on the upper and lower dead points according to the stress values ​​of the upper and lower dead points under the reference torque, the impact torque of the upper and lower dead points of the shift hub, and the material of the shift hub housing 401.

[0044] The quasi-static analysis results are combined to form a transient stress history of a fatigue life cycle of the upper and lower dead points of the shift hub under actual driving conditions. The impact torque levels of the dead points under driving conditions and the self-learning test bench conditions, as well as the number of touches at the corresponding dead points, are combined. The stress analysis results are linearly scaled based on the ratio of the impact load of the shift hub dead points to the load from the stress analysis. The SN curve of the material of the shift hub housing 401 is obtained based on the material, and finally, the fatigue damage at each torque level is superimposed. This method can calculate the fatigue life of the shift hub during its working process, i.e., under this load spectrum. The fatigue evaluation of the upper and lower dead points of the shift hub is performed. If the fatigue strength results of the shift hub dead points meet the requirements, the next step is performed; otherwise, the local structure of the upper and lower dead points of the shift hub or the gearbox housing dead points is optimized and improved.

[0045] After completing the above operations, the shift hub stop point durability test is carried out. If the shift hub stop point durability test results meet the requirements, the impact durability reliability of the shift hub stop point is qualified; otherwise, the local structure of the upper and lower stop points of the shift hub or the stop point of the transmission housing is optimized and improved.

[0046] In summary, the present invention simulates the impact working condition of the shift hub stop point based on the shift hub stop point strength model, effectively ensuring that the impact working condition design of the shift hub stop point is reasonable and improving the efficiency of powertrain development. When analyzing the impact reliability of the shift hub stop point during the simulation process, the present invention accurately models the shift hub, combines the actual use working conditions of the whole vehicle, and considers the influence of design, assembly process, actual road use, etc. on the impact working condition of the shift hub stop point. The obtained shift hub stop point impact working condition has high reliability and is not easy to fail. Through a reasonable simplified model, which conforms to the actual boundary setting and load distribution setting, it can not only correctly represent the relationship between the various components when the two-speed transmission shift hub stop point is impacted, but also can realistically simulate the force conditions of the shift hub stop point, thereby improving the accuracy of the finite element strength analysis of the transmission shift hub stop point, improving the analysis efficiency, and further accurately predicting the fatigue life of the shift hub stop point. The disclosure of this calculation method has positive significance for improving the technical level of the transmission shift hub in traditional and new energy industries. When the present invention performs reliability analysis on the impact assembly of the shift hub stop point during the simulation process, the stress distribution of the shift hub obtained through simulation can be used to perform all-round and multi-angle iterative optimization of the shift hub. The boundary conditions are consistent with the actual working conditions, and the impact force conditions of the shift hub stop point assembly are more in line with reality. The simulation and test results can better meet the reliability requirements of the shift hub stop point in actual use.

[0047] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and is susceptible to numerous variations. Any simple modifications, equivalent variations, and modifications to the above embodiments based on the technical essence of the present invention shall be deemed to fall within the scope of protection of the present invention.

Claims

1. A transmission shift hub dead center impact durability reliability evaluation system, characterized by: It includes a shift hub stop point strength finite element model building module (301), a shift hub upper and lower stop point strength finite element calculation module (302), a one-dimensional simulation load extraction module (303), a stop point material strength evaluation module (304) and a shift hub stop point fatigue calculation module (305); The shift hub dead center strength finite element model establishment module (301) is used to establish a shift hub dead center strength model; The shift hub upper and lower dead center strength finite element calculation module (302) is used to perform finite element strength simulation calculation on the shift hub dead center impact working condition according to the shift hub dead center strength model, and extract stress values ​​of the upper and lower dead centers under the reference torque; The one-dimensional simulation load extraction module (303) is used to establish a one-dimensional transmission system model of the shift hub dead point and extract the impact torque of the upper and lower dead points of the shift hub; The stop point material strength evaluation module (304) is used to judge whether the structural design of each part of the shift hub stop point strength model is qualified according to the impact torque of the upper and lower stop points of the shift hub and the stress values ​​of the upper and lower stop points under the reference torque; The shift hub stop point fatigue calculation module (305) is used to perform fatigue calculation on the upper and lower stop points of the shift hub according to the stress values ​​of the upper and lower stop points under the reference torque, the impact torque of the upper and lower stop points of the shift hub and the material of the shift hub housing (401), and predict the fatigue life of the upper and lower stop points of the shift hub.

2. The transmission shift hub dead point impact durability reliability evaluation system according to claim 1, characterized in that: Establishing the shift hub dead center strength model includes establishing a three-dimensional geometric model of the shift hub housing (401), a three-dimensional geometric model of the shift hub pin shaft (402), a three-dimensional geometric model of the shift hub bushing (404), a three-dimensional geometric model of the shift hub double gear (405), a three-dimensional geometric model of the shift hub connecting bolt (406), a three-dimensional geometric model of the transmission housing (407), a three-dimensional geometric model of the shift hub top dead center (408), a three-dimensional geometric model of the shift hub bottom dead center (409), and a three-dimensional geometric model of the gearbox housing (407). A shift hub stop point strength model is formed by assembling a three-dimensional geometric model of the shift hub housing (401), a three-dimensional geometric model of the shift hub pin shaft (402), a three-dimensional geometric model of the shift hub bushing (404), a three-dimensional geometric model of the shift hub double gear (405), a three-dimensional geometric model of the shift hub connecting bolt (406), a three-dimensional geometric model of the transmission housing (407), a three-dimensional geometric model of the shift hub top dead center (408) and a three-dimensional geometric model of the shift hub bottom dead center (409).

3. The impact durability reliability evaluation system for a transmission shift hub dead point according to claim 2, wherein: Establishing the shift hub dead center strength model includes setting the material properties of the shift hub housing (401), the shift hub pin shaft (402), the shift hub bushing (404), the shift hub duplex gear (405), the shift hub connecting bolt (406), the transmission housing (407), the shift hub top dead center (408) and the shift hub bottom dead center (409).

4. A method for evaluating the impact durability reliability of a transmission shift hub stop point based on the transmission shift hub stop point impact durability reliability evaluation system according to any one of claims 1 to 3, characterized in that: It includes establishing a shift hub stop point strength model; performing finite element strength simulation calculation on the shift hub stop point impact working condition according to the shift hub stop point strength model, and extracting the stress values ​​of the upper and lower stop points under a reference torque; establishing a one-dimensional transmission system model of the shift hub stop point, and extracting the impact torque of the upper and lower stop points of the shift hub; judging whether the structural design of each part of the shift hub stop point strength model is qualified according to the impact torque of the upper and lower stop points of the shift hub and the stress values ​​of the upper and lower stop points under a reference torque; performing fatigue calculation on the upper and lower stop points of the shift hub according to the stress values ​​of the upper and lower stop points under the reference torque, the impact torque of the upper and lower stop points of the shift hub and the material of the shift hub shell, and predicting the fatigue life of the upper and lower stop points of the shift hub.

5. The method for evaluating the impact durability reliability of a transmission shift hub stop point according to claim 4, wherein: The method for establishing the shift hub dead point strength model comprises: establishing a three-dimensional geometric model of a shift hub housing (401), a three-dimensional geometric model of a shift hub pin shaft (402), a three-dimensional geometric model of a shift hub bushing (404), a three-dimensional geometric model of a shift hub double gear (405), a three-dimensional geometric model of a shift hub connecting bolt (406), a three-dimensional geometric model of a transmission housing (407), a three-dimensional geometric model of a shift hub top dead point (408), and a three-dimensional geometric model of a shift hub bottom dead point (409); and establishing a three-dimensional geometric model of the shift hub housing (401), the shift hub pin shaft (402), the shift hub bushing (404), the shift hub double gear (405), the three-dimensional geometric model of a transmission housing (407), the three-dimensional geometric model of a shift hub top dead point (408), and the three-dimensional geometric model of a shift hub bottom dead point (409). , the shift hub connecting bolt (406), the transmission housing (407), the shift hub top dead center (408), and the shift hub bottom dead center (409) are constrained by assembling the three-dimensional geometric model of the shift hub housing (401), the three-dimensional geometric model of the shift hub pin shaft (402), the three-dimensional geometric model of the shift hub bushing (404), the three-dimensional geometric model of the shift hub double gear (405), the three-dimensional geometric model of the shift hub connecting bolt (406), the three-dimensional geometric model of the transmission housing (407), the three-dimensional geometric model of the shift hub top dead center (408), and the three-dimensional geometric model of the shift hub bottom dead center (409) to form a shift hub stop point strength model.

6. The method for evaluating the impact durability reliability of a transmission shift hub stop point according to claim 5, wherein: Establishing the shift hub stop point strength model includes meshing the shift hub stop point strength model, setting material properties and boundary conditions of the shift hub housing (401), the shift hub pin shaft (402), the shift hub bushing (404), the shift hub double gear (405), the shift hub connecting bolt (406), the transmission housing (407), the shift hub top stop point (408) and the shift hub bottom stop point (409).

7. The method for evaluating the impact durability reliability of a transmission shift hub dead point according to claim 6, wherein: Establishing the shift hub dead point strength model includes setting the load transfer relationship among the shift hub housing (401), the shift hub pin shaft (402), the shift hub bushing (404), the shift hub duplex gear (405), the shift hub connecting bolt (406), the transmission housing (407), the shift hub top dead point (408) and the shift hub bottom dead point (409); and applying a torque load to the shift hub duplex gear (405).

8. The method for evaluating the impact durability reliability of a transmission shift hub stop point according to claim 4, wherein: The method of establishing a one-dimensional transmission system model of the shift hub dead points and extracting the impact torque of the upper and lower dead points of the shift hub comprises establishing a one-dimensional transmission system model of the shift hub dead points and inputting relevant parameters of the shift hub drive motor characteristic curve into one-dimensional dynamics software; The torsional stiffness of the powertrain from the shift hub drive motor to the shift hub stop is calculated based on the simulation results of the shift hub stop strength model. This stiffness is then input into the one-dimensional transmission system model of the shift hub stop. The parameters of the transmission gear system at the shift hub dead point are input into the one-dimensional transmission system model of the shift hub dead point, a complete one-dimensional transmission system model of the shift hub dead point is established, and the impact torque of the upper and lower dead points of the shift hub is extracted.

9. The method for evaluating the impact durability reliability of a transmission shift hub stop point according to claim 8, wherein: The method for judging whether the structural design of each part of the shift hub stop point strength model is qualified based on the impact torque of the upper and lower dead points of the shift hub and the stress values ​​of the upper and lower dead points under the reference torque includes: linearly scaling the stress values ​​of the upper and lower dead points of the shift hub under the reference torque according to the impact torque of the upper and lower dead points of the shift hub to obtain the actual stress values ​​of the upper and lower dead points of the shift hub, and using the actual stress values ​​of the upper and lower dead points of the shift hub as evaluation inputs. If the material strength calculations of the structural designs of each part of the shift hub stop point strength model meet the requirements, the structural design of the shift hub stop point strength model is qualified; otherwise, the structural design of the shift hub stop point strength model is unqualified.

10. The method for evaluating the impact durability reliability of a transmission shift hub stop point according to claim 9, wherein: The method for predicting the fatigue life of the upper and lower dead points of the shift hub by performing fatigue calculation on the upper and lower dead points of the shift hub according to the stress values ​​of the upper and lower dead points of the shift hub under a reference torque, the impact torque of the upper and lower dead points of the shift hub, and the material of the shift hub housing (401) comprises: linearly scaling the stress values ​​of the upper and lower dead points of the shift hub under a reference torque according to the impact torque of the upper and lower dead points of the shift hub, obtaining the SN curve of the material according to the material of the shift hub housing (401), superimposing the fatigue damage at each torque level, and predicting the fatigue life of the upper and lower dead points of the shift hub.

Images