Differential bearing inner ring press pressure data acquisition method and system

Abstract

The application relates to the technical field of data processing, in particular to a differential bearing inner ring press pressure data acquisition method and system. The method comprises the following steps: obtaining the vibration acceleration of the pressure head of the press along the pressure assembly direction in the current time period; determining the energy accumulation value of the current time period according to the vibration acceleration and the mass of the pressure head, and determining the first adjustment coefficient; determining the second adjustment coefficient according to the peak value of the vibration acceleration in the current time and the duration greater than the preset acceleration threshold; taking the ratio of the first adjustment coefficient and the second adjustment coefficient as the target adjustment coefficient, obtaining the initial pressure value of the press at the current time obtained by the pressure sensor, and taking the product of the initial pressure value and the target adjustment coefficient as the target pressure value at the current time. Through the above technical scheme, the pressure data of the press in the pressure assembly process can be accurately obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of data processing, and in particular to a differential bearing inner ring pressurizing machine pressure data acquisition method and system. BACKGROUND

[0002] The differential is an important component in the automobile transmission system, which is mainly composed of left and right half axle gears, planetary gears, gear carriers and bearings, etc. The main function of the differential is to enable the left and right drive wheels of the vehicle to rotate at different speeds when the vehicle turns or drives on uneven road surfaces, thereby ensuring that the two sides of the wheels make pure rolling motion and improving driving stability.

[0003] For example, when the vehicle turns, the outer side wheels need a longer driving path and a larger speed, while the inner side wheels need a shorter driving path and a smaller speed. The power of the engine is transmitted to the differential housing through the transmission shaft, which drives the planetary gear to rotate, and then the power is distributed to the left and right half axle gears through the half axle gear. The differential realizes the speed difference of the two sides of the wheels through the cooperation of the planetary gear and the half axle gear.

[0004] The bearing of the differential is used to support the rotating parts and reduce friction. The inner ring of the bearing is usually closely matched with the gear shaft or half shaft of the differential, which fixes the rotating parts and transmits power, and at the same time rotates relative to the outer ring through the rolling body to reduce friction resistance. The inner ring of the bearing can bear radial and axial load, so the assembly process of the inner ring of the bearing will affect the installation effect of the inner ring of the bearing, thereby affecting the stability and safety of the differential.

[0005] At present, in the assembly process of the bearing inner ring and the differential, the bearing inner ring and the differential are mainly pressed by the pressure applied by the press. The pressure applied by the press to the bearing inner ring will affect the pressing effect between the bearing inner ring and the differential, so it is necessary to more accurately obtain the pressure data of the press during the pressing process. SUMMARY

[0006] In order to more accurately obtain the pressure data of the press during the pressing process, the present application provides a differential bearing inner ring pressurizing machine pressure data acquisition method and system.

[0007] According to a first aspect of the embodiment of the present application, a differential bearing inner ring press machine pressure data acquisition method is provided, comprising: in the case that the press machine performs a pressing task on a differential and a bearing inner ring, obtaining a vibration acceleration of a pressing head of the press machine along a pressing direction in a current time period; determining an energy accumulation value of the current time period according to the vibration acceleration and a mass of the pressing head, and determining a dynamic stiffness of the bearing inner ring in the current time period, determining a first adjustment coefficient according to the dynamic stiffness and the energy accumulation value; determining a peak value of the vibration acceleration in the current time and a duration in which the vibration acceleration is greater than a preset acceleration threshold, determining a second adjustment coefficient using the normalized duration and the peak value, and taking a ratio of the first adjustment coefficient and the second adjustment coefficient as a target adjustment coefficient; obtaining an initial pressure value of the press machine at the current time obtained by a pressure sensor, and taking a product of the initial pressure value and the target adjustment coefficient as a target pressure value collected at the current time; the target pressure value is used to monitor the pressing process of the bearing inner ring.

[0008] In this way, the pressure data of the press machine in the pressing process can be more accurately obtained at the current time, and the pressing process of the bearing inner ring and the differential is facilitated.

[0009] Optionally, the energy accumulation value of the current time period is determined according to the vibration acceleration and the mass of the pressing head, comprising: determining a vibration speed of the pressing head at different times in the current time period according to the vibration acceleration of the pressing head at different times in the current time period; determining an energy value of the vibration of the pressing head according to the vibration speed of the pressing head, and taking a sum of the energy values of the pressing head at different times in the current time period as the energy accumulation value.

[0010] Optionally, the dynamic stiffness of the bearing inner ring in the current time period is determined, comprising: in the case that the pressing head of the press machine and the bearing inner ring to be pressed are in a contact state, obtaining a pressure change amount of the bearing inner ring in the current time period, and obtaining a pressing displacement of the pressing head in the current time period; taking a ratio of the pressure change amount and the pressing displacement as the dynamic stiffness.

[0011] In this way, the dynamic stiffness of the bearing inner ring in the current time period can be determined according to the pressure and deformation of the bearing inner ring in the current time period, so as to adaptively adjust the pressure value obtained by the pressure sensor according to the actual situation of the bearing inner ring.

[0012] Optionally, the first adjustment coefficient is determined according to the dynamic stiffness and the energy accumulation value, including: taking the difference between the dynamic stiffness and a reference stiffness as a target difference, and determining a first ratio between the target difference and the maximum dynamic stiffness in the historical time period; the reference stiffness is the stiffness of the bearing inner ring in the pre-contact stage before the pressing; a first product is obtained according to the product of the first preset coefficient, the first ratio and the normalized energy accumulation value, and a first adjustment coefficient is obtained by taking the sum of the first product and a preset positive number; the first adjustment coefficient is used to represent the influence degree of the relative change of the dynamic stiffness and the energy accumulation value on the pressure measurement deviation.

[0013] Optionally, the reference stiffness is determined by: controlling the pressing head of the press to press a plurality of bearing inner rings of the same model in sequence, and determining the stiffness of the bearing inner ring in the pre-contact stage of pressing, and taking the average value of the stiffness of the plurality of bearing inner rings of the same model in the pre-contact stage of pressing as the reference stiffness.

[0014] In this way, the reference stiffness corresponding to the bearing to be pressed can be obtained, and the reference stiffness is used to provide a reference for the dynamic stiffness of the bearing to be pressed in the current time period.

[0015] Optionally, the second adjustment coefficient is determined according to the normalized duration and the peak value, including: multiplying the square root of the normalized duration and the normalized peak value to obtain a second product, and multiplying the second product and a second preset coefficient to obtain a third product; and taking the sum of the third product and a preset positive number as the second adjustment coefficient; the second adjustment coefficient is used to represent the influence degree of the peak value and the duration of the vibration on the pressure measurement deviation.

[0016] Optionally, the method further includes: obtaining temperature information of the pressing head of the press, and adjusting the target pressure value according to the temperature information, and taking the obtained pressure value after adjustment as the target pressure value again.

[0017] Optionally, the method further includes: constructing a to-be-detected pressure feature sequence corresponding to the pressing process of the bearing inner ring and the differential mechanism to be pressed according to the target pressure values at different time points in the pressing process; and comparing the to-be-detected pressure feature sequence with reference pressure feature sequences of different fault types respectively, to determine the fault type corresponding to the pressing process of the bearing inner ring.

[0018] In this way, the fault type corresponding to the pressing process of the bearing inner ring can be determined automatically.

[0019] Optionally, the method further comprises: determining a target pressure range in which the target pressure value at the current time point is located from a plurality of pre-set pressure ranges; different pressure ranges correspond to different regulation modes; and regulating the output power of the press according to the regulation mode corresponding to the target pressure range, so that the pressure value applied to the bearing inner ring is located in the reference pressure range matched by the bearing inner ring to be pressed and the differential.

[0020] In this way, the automatic adjustment of the pressure output by the press can be realized, so that the bearing inner ring to be pressed and the differential obtain the required pressure.

[0021] According to a second aspect of the embodiments of the present application, a differential bearing inner ring press pressure data acquisition system is provided, comprising: a processor and a memory, the memory storing computer program instructions, and the computer program instructions are executed by the processor to implement the steps of the differential bearing inner ring press pressure data acquisition method provided in the first aspect of the present application.

[0022] The technical scheme provided by the embodiments of the present application can have the following beneficial effects: by obtaining the vibration acceleration of the pressing head of the press along the pressing direction when performing the pressing task in the current time period, the first adjustment coefficient and the second adjustment coefficient are determined respectively; the first adjustment coefficient is determined according to the dynamic stiffness of the bearing inner ring and the energy accumulation value, and can reflect the influence degree of the deformation of the bearing inner ring itself in the pressing process on the pressure value obtained by the pressure sensor; the second adjustment coefficient is determined according to the peak value of the vibration acceleration and the duration greater than the pre-set acceleration threshold value, and the second adjustment coefficient can reflect the influence of the vibration on the pressure sensor from the outside; the target pressure value obtained by adjusting the initial pressure value according to the first adjustment coefficient and the second adjustment coefficient can better reflect the actual pressure value of the bearing inner ring in the pressing process, so as to more accurately monitor the pressing process between the differential and the bearing inner ring.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a flow chart of a differential bearing inner ring press pressure data acquisition method according to an exemplary embodiment;

[0025] Figure 2 is a schematic diagram of the change process of the first adjustment coefficient and the second adjustment coefficient in the pressing process of the embodiments of the present application;

[0026] Figure 3 is a schematic diagram of the change process of the target adjustment coefficient in the pressing process of the embodiments of the present application;

[0027] Figure 4 is a comparison diagram of the initial pressure value and the target pressure value of the embodiment of the present application;

[0028] Figure 5 is a structural schematic diagram of a differential bearing inner ring press pressure data acquisition system according to an exemplary embodiment. DETAILED DESCRIPTION

[0029] First, the application scenario of the embodiment of the present application is simply introduced. In the application scenario of the present application, the bearing inner ring and the differential can be pressed and assembled by using the press. The pressure applied by the pressing head of the press will directly affect the pressing and assembling effect of the bearing inner ring and the differential.

[0030] When the pressure applied by the pressing head of the press is insufficient, the interference amount of the bearing inner ring and the differential will be insufficient, the connection strength after pressing and assembling will not be enough, and looseness or relative displacement will easily occur during operation. When the pressure applied by the pressing head of the press is greater than the actual pressure required in the pressing and assembling process, the bearing inner ring will be plastically deformed or have surface indentation due to overload, thereby damaging the inner diameter size and surface precision of the bearing inner ring and affecting the rotation precision and service life of the bearing.

[0031] In order to realize the monitoring of the pressing and assembling process between the bearing inner ring and the differential, the pressure data obtained by the pressure sensor is directly used as the pressure between the bearing inner ring and the differential to be pressed and assembled in the related technology.

[0032] However, in the process of pressing and assembling the bearing inner ring and the differential, the pressure data obtained by the pressure sensor can be affected by other factors besides the actual pressure value. For example, as the bearing inner ring is installed into the differential under the action of the pressure, as the bearing inner ring moves along the pressing and assembling direction, in addition to the actual pressure borne by the bearing inner ring, the bearing inner ring can also be affected by vibration, so that the pressure data collected by the pressure sensor cannot reflect the actual pressure between the bearing inner ring and the differential. Therefore, it is necessary to process the pressure data obtained by the pressure sensor, so that the processed pressure data more accurately reflects the actual pressure value.

[0033] In view of the above technical problems, the embodiment of the present application provides a differential bearing inner ring press pressure data acquisition method and system, Figure 1 is a flowchart of a differential bearing inner ring press pressure data acquisition method according to an exemplary embodiment, as Figure 1 shown, the method comprises the following steps.

[0034] In step S101, in the case that the press performs the pressing and assembling task of the differential and the bearing inner ring, the vibration acceleration of the pressing head of the press along the pressing and assembling direction in the current time period is obtained.

[0035] The distance sensor can be arranged on the side of the pressing head of the press, and when the press is performing the pressing task of the differential and the bearing inner ring, the distance between the end of the pressing head and the bearing inner ring to be pressed is smaller, and the distance between the end of the pressing head and the bearing inner ring to be pressed obtained by the distance sensor can determine whether the press is currently performing the pressing task of the differential and the bearing inner ring.

[0036] Alternatively, an image sensor can be arranged on the side of the pressing head of the press, and when the press is performing the pressing task of the differential and the bearing inner ring, the features of the images collected in the field of view of the camera are different, so that the image data obtained by the image sensor can determine whether the press is currently performing the pressing task of the differential and the bearing inner ring.

[0037] An acceleration sensor, such as a piezoelectric acceleration sensor or a micro-electro-mechanical system acceleration sensor, can be installed on the pressing head of the press; when the press is pressing the differential and the bearing inner ring, if the pressing head of the press is subjected to vibration from the outside or vibration generated during the pressing process, the acceleration sensor can collect and record the vibration acceleration data of the pressing head in real time, so as to determine more accurate pressure data of the pressing head.

[0038] In step S102, the energy accumulation value of the current time period is determined according to the vibration acceleration and the mass of the pressing head, and the dynamic stiffness of the bearing inner ring in the current time period is determined, and the first adjustment coefficient is determined according to the dynamic stiffness and the energy accumulation value.

[0039] The initial pressure value applied by the pressing head to the bearing inner ring and the differential to be pressed can be obtained by using the pressure sensor arranged on the press; the greater the mass of the pressing head, the greater the influence of the vibration of the pressing head on the initial pressure value collected by the pressure sensor.

[0040] According to the direction and size of the vibration acceleration, the vibration speed of the pressing head at different times in the current time period can be determined, and the greater the vibration speed of the pressing head of the same mass, the more intense the vibration of the pressing head; or the greater the influence of the vibration of the pressing head on the initial pressure value collected by the pressure sensor, so that the energy accumulation value of the current time period can be determined according to the vibration acceleration and the mass of the pressing head, and the influence of the vibration acceleration and the pressing head with vibration on the pressure data collected by the pressure sensor can be comprehensively considered by the energy accumulation value.

[0041] In one embodiment, the energy accumulation value of the current time period is determined according to the vibration acceleration and the mass of the pressing head, including: determining the vibration speed of the pressing head at different time points in the current time period according to the vibration acceleration of the pressing head at different time points in the current time period; determining the energy value of the vibration of the pressing head according to the vibration speed of the pressing head, and taking the sum of the energy values of the pressing head at different time points in the current time period as the energy accumulation value.

[0042] According to the vibration acceleration of the pressing head at different time points in the current time period, the vibration speed of the pressing head at different time points can be determined by integrating the vibration acceleration; according to the vibration speed and the mass of the pressing head, the vibration energy value of the pressing head at different time points can be calculated using the kinetic energy formula, and the energy accumulation value of the pressing head can be obtained by summing the energy values at different time points in the current time period.

[0043] Alternatively, the time domain signal of the vibration acceleration can be converted into a frequency domain signal by Fourier transform or wavelet transform; the energy spectrum density of the vibration acceleration signal can be analyzed in the frequency domain, the vibration energy can be determined by integrating the energy spectrum density, and the energy accumulation value can be obtained by accumulating the vibration energy. For details, please refer to the relevant contents of Fourier transform or wavelet transform in the prior art, which are not limited in the embodiments of the present application.

[0044] The current time period can refer to a time period ending at the current time point and having a length equal to a preset length. The vibration of the press in the current time period will affect the accuracy of the pressure data obtained by the pressure sensor at the current time point. Therefore, determining the energy accumulation value of the pressing head in the current time period can facilitate obtaining more accurate pressure data at the current time point.

[0045] In one embodiment, the dynamic stiffness of the bearing inner ring in the current time period is determined, including: in the case that the pressing head of the press and the bearing inner ring to be pressed are in contact, obtaining the pressure change amount of the bearing inner ring in the current time period, and obtaining the pressing displacement of the pressing head in the current time period; taking the ratio of the pressure change amount to the pressing displacement as the dynamic stiffness.

[0046] The dynamic stiffness reflects the resistance of the bearing inner ring to external load during pressing. During the pressing of the bearing inner ring and the differential, the stiffness of the bearing inner ring changes with the pressing state and the pressing pressure, and the dynamic stiffness can reflect the influence of the vibration generated during the pressing process on the initial pressure value obtained by the pressure sensor. Therefore, the ratio of the pressure change amount of the bearing inner ring to the pressing displacement can be taken as the dynamic stiffness of the bearing inner ring in the current time period.

[0047] The pressure change amount of the bearing inner ring in the current time period can refer to the difference between the maximum pressure value and the minimum pressure value of the bearing inner ring in the current time period; the press-fit displacement of the bearing inner ring in the current time period can refer to the distance between the position of the same position of the press head at the starting moment of the current time period and the position of the same position of the press head at the current moment.

[0048] In this way, by determining the dynamic stiffness of the bearing inner ring in the current time period, the dynamic stiffness can reflect the influence of the vibration possibly generated by the press-fitting process on the initial pressure value obtained by the pressure sensor, and therefore the dynamic stiffness can provide better data support for the subsequent pressure value applied by the press.

[0049] In one embodiment, the first adjustment coefficient is determined according to the dynamic stiffness and the energy accumulation value, including: taking the difference between the dynamic stiffness and a reference stiffness as a target difference value, and determining a first ratio between the target difference value and the maximum dynamic stiffness in the historical time period; the reference stiffness is the stiffness of the bearing inner ring in the pre-contact stage before press-fitting; obtaining a first product value according to the product of the first preset coefficient, the first ratio and the normalized energy accumulation value, and taking the sum of a preset positive number and the first product value as the first adjustment coefficient; the first adjustment coefficient is used to represent the influence degree of the relative change of the dynamic stiffness and the energy accumulation value on the pressure measurement deviation.

[0050] The reference stiffness can be collected when the press is not subjected to external vibration, which can provide a reference for the dynamic stiffness of the press-fitting process of the bearing inner ring, and facilitate the non-dimensionalization processing of the dynamic stiffness of the press-fitting process of the bearing inner ring.

[0051] The pre-contact stage refers to the initial time period when the press head of the press contacts the bearing inner ring, and the bearing inner ring and the differential to be press-fitted have not completed press-fitting, and the reference stiffness can better reflect the ability of the bearing inner ring to resist deformation under pressure.

[0052] The target difference value is equal to the difference between the dynamic stiffness and the reference stiffness, and the reference stiffness can be used as a reference for the bearing inner ring, and the target difference value quantifies the degree to which the dynamic stiffness of the bearing inner ring in the current time period deviates from the reference, and the greater the value of the target difference value, the greater the influence degree of the inertial force of the press-fitting process at the current moment; the first ratio between the target difference value and the maximum dynamic stiffness in the historical time period can realize the non-dimensionalization processing of the stiffness.

[0053] A first multiplication value is obtained according to a product of a first preset coefficient, a first ratio and the normalized energy accumulation value; the first preset coefficient can be set according to actual requirements, and the first preset coefficient is used to adjust a weight value or an influence degree of the ratio corresponding to the stiffness and the normalized energy accumulation value on the obtained first adjustment coefficient; for example, the first preset coefficient can be between 0.4 and 0.6.

[0054] A sum value of a preset positive number and the first multiplication value is taken as the first adjustment coefficient; the preset positive number can ensure that the obtained first adjustment coefficient has a basic value, and can ensure that the obtained first adjustment coefficient is at least greater than 0; for example, the preset positive number can be between 1 and 2.

[0055] The first adjustment coefficient is determined according to both the relative change of the dynamic stiffness of the bearing inner ring in the current time period and the energy accumulation value; the greater the influence degree of the vibration generated by the pressing process of the press on the bearing inner ring and the differential mechanism, or the greater the influence degree of the inertial force existing in the pressing process of the press on the pressure measurement result of the pressure sensor, the greater the influence degree of both the relative change of the dynamic stiffness and the energy accumulation value on the pressure measurement deviation.

[0056] In the following, an exemplary calculation formula is taken as an example to more intuitively describe the first adjustment coefficient in the embodiment of the present application, , wherein, is the first adjustment coefficient at the current moment, is a preset positive number, is a first preset coefficient, is the dynamic stiffness of the bearing inner ring to be pressed in the current time period, is the reference stiffness corresponding to the bearing inner ring to be pressed, is the maximum dynamic stiffness in the historical time period, and E is the normalized energy accumulation value in the current time period.

[0057] The maximum dynamic stiffness in the historical time period can refer to the maximum value of the dynamic stiffness of other bearing inner rings of the same type as the bearing inner ring to be pressed in the historical pressing process; the maximum dynamic stiffness in the historical time period can control the absolute value of the target difference in the range greater than 0 and less than 1.

[0058] Normalization can normalize the variable to be normalized to the range of 0 to 1, avoiding the influence of the dimensions or value ranges of different parameter values; for example, normalization of the variable to be normalized can be realized by minimum-maximum standardization, logarithmic transformation, arctangent function and Sigmoid function.

[0059] The greater the difference between the dynamic stiffness of the bearing inner race to be pressed in the current time period and the reference stiffness corresponding to the bearing inner race to be pressed in, The greater the value of the difference, the more sufficient the contact between the pressing head and the bearing inner race to be pressed in becomes, and the rigidity of the overall structure formed by the bearing inner race and the differential is improved.

[0060] The overall structure formed by the bearing inner race and the differential is in the early stage of pressing, the contact between the pressing head and the bearing inner race to be pressed in becomes more sufficient, the pressure loss between the bearing inner race and the differential caused by friction or plastic deformation of the material is smaller, and the pressing efficiency of the pressing head of the press on the bearing inner race and the differential is higher. A larger first adjustment coefficient can be determined.

[0061] The smaller the difference between the dynamic stiffness of the bearing inner race to be pressed in the current time period and the reference stiffness corresponding to the bearing inner race to be pressed in, The smaller the value of the difference, the less the deformation of the bearing inner race under the same force in the current time period, and the effective pressing of the bearing inner race and the differential is formed, so that the pressing efficiency of the pressing head of the press on the bearing inner race and the differential is lower. A smaller first adjustment coefficient can be determined.

[0062] In one embodiment, the reference stiffness is determined by: controlling the pressing head of the press to press a plurality of bearing inner races of the same model that have not been pressed in turn, and determining the stiffness of the bearing inner races in the pre-contact stage of pressing. The average of the stiffness of the plurality of bearing inner races of the same model that have not been pressed in the pre-contact stage of pressing is taken as the reference stiffness.

[0063] By controlling the pressing head of the press to press a plurality of bearing inner races of the same model that have not been pressed in turn, the number of samples for determining the reference stiffness can be expanded, so as to improve the reference value of the determined reference stiffness to the dynamic stiffness.

[0064] The reference stiffness is determined according to the stiffness of the bearing inner race in the pre-contact stage of pressing. In the pre-contact stage of pressing, the vibration, plastic deformation of the material and temperature rise caused by the pressing of the press on the bearing inner race and the differential are less, and the determined reference stiffness can more accurately reflect the inherent properties of the bearing inner race in the initial stage of elastic deformation and the mechanical properties of the initial contact between the bearing inner race and the pressing head.

[0065] The average value of the stiffness of a plurality of non-press-fitted bearing inner rings of the same model in the pre-contact stage of press-fitting is taken as the reference stiffness, compared with directly taking the stiffness of a single bearing inner ring in the pre-contact stage of press-fitting as the reference stiffness, the number of bearing inner rings for determining the reference stiffness is more, the influence of the possible slight differences in the inner diameter, outer diameter and width of the bearing inner rings of the same model can be avoided, and the reference value of the reference stiffness to the dynamic stiffness is improved.

[0066] In step S103, the peak value of the vibration acceleration in the current time and the duration of the vibration acceleration greater than the preset acceleration threshold are determined, the second adjustment coefficient is determined by using the normalized duration and the peak value, and the ratio of the first adjustment coefficient to the second adjustment coefficient is taken as the target adjustment coefficient.

[0067] The greater the peak value of the vibration acceleration in the current time, the more intense the vibration received from the outside in the current time period; the duration of the vibration acceleration greater than the preset acceleration threshold indicates that the pressure machine is subjected to more persistent vibration from the outside; the combination of the peak value and the duration can comprehensively reflect the performance in the two dimensions of the intensity and the persistence of the vibration, so as to avoid the influence of the external vibration on the pressure measurement result of the pressure sensor.

[0068] The preset acceleration threshold can be determined according to the average value of the vibration acceleration of the pressure machine in the historical time period, and can be set according to actual needs, which is not limited in the embodiments of the present application.

[0069] In one embodiment, the second adjustment coefficient is determined by using the normalized duration and the peak value, including: multiplying the square root of the normalized duration and the normalized peak value to obtain a second multiplication value, and multiplying the second multiplication value and a second preset coefficient to obtain a third multiplication value; taking the sum of the third multiplication value and a preset positive number as the second adjustment coefficient; the second adjustment coefficient is used to represent the influence degree of the peak value and the duration of the vibration on the pressure measurement deviation.

[0070] As the peak value of the vibration or the duration of the vibration acceleration greater than the preset acceleration threshold increases, the degree of the existing vibration is higher, and the value of the obtained second adjustment coefficient gradually increases, so that the influence of the pressure value obtained by the vibration can be avoided by using a larger second adjustment coefficient.

[0071] When the duration of the vibration acceleration greater than the preset acceleration threshold is 0, it indicates that there is no large amplitude vibration acceleration in the current time period, and the value of the obtained second adjustment coefficient is equal to the preset positive number, therefore, the preset positive number can ensure that the second adjustment coefficient has a basic value.

[0072] The second preset coefficient can reflect the influence degree of the product of the square root of the normalized duration and the normalized peak value on the value of the second adjustment coefficient; the greater the value of the second preset coefficient, the greater the influence degree of the second product on the value of the second adjustment coefficient; on the contrary, the smaller the value of the second preset coefficient, the smaller the influence degree of the second product on the value of the second adjustment coefficient.

[0073] The second preset coefficient can be calibrated in advance according to the specific value of the product of the square root of the normalized duration and the normalized peak value, for example, the value of the second preset coefficient can be between 0.4 and 0.6.

[0074] With the limitation of the square root of the normalized duration, when the growth rate of the normalized duration gradually increases, the growth rate of the result of the square root is gradually reduced; when the duration takes a larger value, the influence of the growth of the duration on the second adjustment coefficient is attenuated, which can weaken the marginal effect of higher duration, and improve the marginal effect of smaller duration, and the compensation for the pressure value obtained by the sensor is realized as early as possible in the early stage of vibration.

[0075] In the following, an exemplary calculation formula is taken as an example to more intuitively explain the second adjustment coefficient in the embodiment of the application, , wherein, is the second adjustment coefficient at the current moment, is a preset positive number, is the second preset coefficient, is the normalized peak value of the vibration acceleration of the bearing inner ring to be pressed, is the normalized duration.

[0076] The presence of the preset positive number in the calculation formula of the second adjustment coefficient can ensure that the value of the second adjustment coefficient is at least greater than or equal to the preset positive number, and as the normalized peak value or the normalized duration increases, the second adjustment coefficient gradually increases according to the actual situation.

[0077] The second adjustment coefficient is determined according to the peak value and the duration of the vibration, when there is vibration between the differential and the bearing inner ring or the press is subjected to vibration, the pressure data obtained by the pressure sensor will additionally include the inertial force caused by the vibration, so that the pressure data obtained by the pressure sensor is higher than the actual pressure, therefore, the second adjustment coefficient can be used to represent the influence degree of the peak value and the duration of the vibration on the pressure measurement deviation.

[0078] The first adjustment coefficient is used to represent the influence degree of the relative change of the dynamic stiffness and the energy accumulation value on the pressure measurement deviation; the press has different pressure assembly efficiencies on the bearing inner ring and the differential under different dynamic stiffnesses, and the efficiency of the pressure applied by the press to be transmitted on the contact surface of the bearing inner ring and the differential is different, so that the first adjustment coefficient can be used as a numerator item of the target adjustment coefficient for adaptive adjustment of the pressure data obtained by the pressure sensor.

[0079] The second adjustment coefficient is used to represent the influence degree of the peak value and the duration of the vibration on the pressure measurement deviation, and the pressure data obtained by the pressure sensor under the influence of the vibration is higher than the actual pressure, so that the second adjustment coefficient can be used as a denominator item of the target adjustment coefficient to avoid the influence of the vibration on the pressure sensor.

[0080] In the embodiment of the application, the ratio of the first adjustment coefficient to the second adjustment coefficient is used as the target adjustment coefficient, which can consider the influence degree of the relative change of the dynamic stiffness and the energy accumulation value on the pressure measurement deviation, and the influence degree of the peak value and the duration of the vibration on the pressure measurement deviation, so as to obtain more accurate pressure data of the actual pressure value.

[0081] Figure 2 FIG. 1 is a schematic diagram of the change process of the first adjustment coefficient and the second adjustment coefficient in the press assembly process of the embodiment of the application; as the press assembly duration increases, the press assembly stroke of the differential and the bearing inner ring gradually increases, and the determined first adjustment coefficient and the second adjustment coefficient change correspondingly, and according to the obtained first adjustment coefficient and the second adjustment coefficient, the target adjustment coefficient at different time points can be determined to adjust the initial pressure value.

[0082] Figure 3 FIG. 2 is a schematic diagram of the change process of the target adjustment coefficient in the press assembly process of the embodiment of the application, as shown in FIG. 2, the value of the determined target adjustment coefficient can change correspondingly according to the actual situation. Figure 3

[0083] In step S104, the initial pressure value of the press at the current time point obtained by the pressure sensor is obtained, and the product of the initial pressure value and the target adjustment coefficient is used as the target pressure value collected at the current time point.

[0084] The target pressure value can be used to monitor the press assembly process of the bearing inner ring, and compared with the initial pressure value obtained by the pressure sensor, the target pressure value avoids the influence of the vibration and the relative motion between the components on the pressure obtained by the pressure sensor, and the obtained target pressure value can be more matched with the pressure value between the bearing inner ring and the differential in the press assembly process. ​

[0085] Since the target pressure value can be more matched with the pressure value between the bearing inner ring and the differential in the pressing process, the monitoring of the pressing process of the bearing inner ring can be more accurately realized when the pressing process of the bearing inner ring is monitored by using the target pressure value, so that the bearing inner ring and the differential can obtain a matched pressure value in the pressing process.

[0086] Figure 4 is a comparison diagram of the initial pressure value and the target pressure value of the embodiment of the present application, as shown in Figure 4 The initial pressure value obtained by the sensor may be affected by vibration and have a value greater than the actual value. The target pressure value obtained after adjusting the initial pressure value can at least avoid the influence of possible vibration.

[0087] In an embodiment, the temperature information of the pressing head of the press can also be obtained, and the target pressure value is adjusted according to the temperature information, and the pressure value obtained after adjustment is taken as the target pressure value again.

[0088] With the increase of the number of pressing tasks performed by the press, the temperature of the surface of the pressing head of the press will rise, and the temperature will affect the conductivity coefficient of the conductive components such as resistance in the pressure sensor, so that the pressure value obtained by the pressure sensor under the same pressure at different temperatures may be different. Therefore, the target pressure value can be adjusted according to the temperature information to avoid the influence of the temperature rise caused by the increase of the working time of the press on the pressure result.

[0089] Adjusting the target pressure value according to the temperature information can include: obtaining a corresponding relationship curve of the pressure sensor affected by the temperature, the corresponding relationship curve can include an influence coefficient of different temperatures on the pressure sensor; and adjusting the target pressure value according to the temperature information and the corresponding relationship curve.

[0090] In an embodiment, a to-be-detected pressure feature sequence corresponding to the pressing process of the bearing inner ring and the differential to be pressed can also be constructed according to the target pressure values at different moments of the pressing process; and the to-be-detected pressure feature sequence is compared with reference pressure feature sequences of different fault types respectively to determine a fault type corresponding to the pressing process of the bearing inner ring.

[0091] In order to facilitate standardized production, the press usually uses the same length to press different bearing inner rings to be pressed when pressing the bearing inner ring and the differential, and the time sequence of the pressure value when performing the pressing task will be different when the pressing process has different characteristics.

[0092] In order to realize the description of the situation of the press-fitting process, the press-fitting process corresponding to the bearing inner ring and the differential to be press-fitted can be constructed according to the target pressure values at different moments of the press-fitting process to form a to-be-detected pressure feature sequence.

[0093] For example, the elements can be selected at equal intervals from the total sequence of target pressure values at different moments of the press-fitting process according to a preset time interval, and the elements determined in time sequence form a to-be-detected pressure feature sequence.

[0094] Referring to the acquisition method of the to-be-detected pressure feature sequence, reference pressure feature sequences of different fault types can be acquired in advance to determine the fault type corresponding to the to-be-detected pressure feature sequence. The fault types may, for example, include pressure matching, insufficient pressure, and excessive pressure.

[0095] The reference pressure feature sequences obtained under different fault types are different, and the DTW (Dynamic Time Warping) algorithm can be used to compare the to-be-detected pressure feature sequence with the reference pressure feature sequences of different fault types, and the fault type corresponding to the reference pressure feature sequence with the smallest DTW distance is taken as the fault type corresponding to the current press-fitting process.

[0096] In this way, the fault type corresponding to the press-fitting process of the bearing inner ring can be automatically detected, and compared with manual judgment of whether the press-fitting process is abnormal, the labor intensity of personnel monitoring can be reduced.

[0097] In one embodiment, the target pressure range in which the target pressure value at the current moment is located is determined from a plurality of preset pressure ranges; different pressure ranges correspond to different control modes; and the output power of the press machine is controlled according to the control mode corresponding to the target pressure range, so that the pressure value applied to the bearing inner ring is located within the reference pressure range matched by the bearing inner ring and the differential to be press-fitted.

[0098] After adjusting the initial pressure value obtained by the pressure sensor, the target pressure value obtained can better reflect the pressure received by the bearing inner ring and the differential to be press-fitted.

[0099] In order to avoid the vibration of the bearing inner ring to be press-fitted caused by the large adjustment range of the pressure applied by the press machine, and to realize the fine adjustment of the pressure received by the bearing inner ring and the differential, the step-by-step adjustment of the pressure applied by the press machine can be realized according to the pressure range in which the target pressure value at the current moment is located.

[0100] For example, 10 levels can be pre-divided according to the size of the pressure value, different levels correspond to different pressure value ranges, and the interval length of different pressure value ranges can be the same or different; if the required reference pressure range is located in 5 levels in the 10 levels, and the pressure value at the current time is located in level 8, the pressure applied by the press can be adjusted from level 8 to level 7, and gradually transitioned to level 5 through level 6, to realize adaptive adjustment of the pressure applied by the press.

[0101] Figure 5 is a structural schematic diagram of a differential bearing inner ring press pressure data acquisition system 1000 according to an exemplary embodiment. Referring to Figure 5 , the differential bearing inner ring press pressure data acquisition system 1000 comprises a processor 1100 and a memory 1200, the memory 1200 stores computer program instructions, the computer program instructions are executed by the processor 1100 to realize all steps or part of steps of the differential bearing inner ring press pressure data acquisition method in the present application.

[0102] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The application is intended to cover any variations, uses or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice in the art to which the application pertains or can relate to other fields of endeavor within the skill of those in the art and within the scope of the appended claims.

[0103] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof.

Claims

1. A differential bearing inner race press machine pressure data collection method, characterized by, The method comprises the following steps: In the case that the press performs the pressing task on the differential and the bearing inner ring, the vibration acceleration of the pressing head of the press in the current time period along the pressing direction is obtained; The energy accumulation value of the current time period is determined according to the vibration acceleration and the mass of the pressing head, and the dynamic stiffness of the bearing inner ring in the current time period is determined, and the first adjustment coefficient is determined according to the dynamic stiffness and the energy accumulation value, including: taking the difference between the dynamic stiffness and the reference stiffness as the target difference value, and determining the first ratio value between the target difference value and the maximum dynamic stiffness in the historical time period; the reference stiffness is the stiffness of the bearing inner ring in the pre-contact stage before pressing; The first product value is obtained according to the product of the first preset coefficient, the first ratio value and the normalized energy accumulation value, and the sum of the first preset positive number and the first product value is taken as the first adjustment coefficient; the first adjustment coefficient is used to represent the influence degree of the relative change of the dynamic stiffness and the energy accumulation value on the pressure measurement deviation; The peak value of the vibration acceleration in the current time and the duration that the vibration acceleration is greater than the preset acceleration threshold value are determined, and the second adjustment coefficient is determined by using the normalized duration and the peak value, including: the square root of the normalized duration is multiplied by the normalized peak value to obtain a second product value, and the second product value is multiplied by a second preset coefficient to obtain a third product value; the sum of the third product value and a second preset positive number is taken as the second adjustment coefficient; the second adjustment coefficient is used to represent the influence degree of the peak value and the duration of the vibration on the pressure measurement deviation, and the ratio of the first adjustment coefficient to the second adjustment coefficient is taken as the target adjustment coefficient; The initial pressure value of the press at the current time obtained by the pressure sensor is obtained, and the product of the initial pressure value and the target adjustment coefficient is taken as the target pressure value collected at the current time; the target pressure value is used to monitor the pressing process of the bearing inner ring.

2. The differential bearing inner race press force data acquisition method of claim 1, wherein, The energy accumulation value of the current time period is determined according to the vibration acceleration and the mass of the pressing head, including: The vibration speed of the pressing head at different time points in the current time period is determined according to the vibration acceleration of the pressing head at different time points in the current time period; The energy value of the vibration of the pressing head is determined according to the vibration speed of the pressing head, and the sum of the energy values of the pressing head at different time points in the current time period is taken as the energy accumulation value.

3. The differential bearing inner race press force data acquisition method of claim 1, wherein, The dynamic stiffness of the bearing inner ring in the current time period is determined, including: In the case that the pressing head of the press is in contact with the bearing inner ring to be pressed, the pressure change amount of the bearing inner ring in the current time period is obtained, and the pressing displacement of the pressing head in the current time period is obtained; the ratio of the pressure change amount to the pressing displacement is taken as the dynamic stiffness.

4. The differential bearing inner race press force data acquisition method of claim 1, wherein, The reference stiffness is determined by the following method: The pressing head of the press is controlled to press a plurality of unpressed bearing inner rings of the same model in turn, and the stiffness of the bearing inner ring in the pre-contact stage of pressing is determined, and the average value of the stiffness of the plurality of unpressed bearing inner rings of the same model in the pre-contact stage of pressing is taken as the reference stiffness.

5. The differential bearing inner race press force data acquisition method of claim 1, wherein, The method further comprises: Obtain temperature information of a pressing head of the press, and adjust the target pressure value according to the temperature information, and take the adjusted pressure value as a new target pressure value.

6. The differential bearing inner race press force data acquisition method of claim 1, wherein, The method further comprises: According to the target pressure values at different time points of the pressing process, a to-be-detected pressure feature sequence corresponding to the pressing process of the bearing inner ring and the differential is constructed; The to-be-detected pressure feature sequence is compared with reference pressure feature sequences of different fault types respectively, so as to determine the fault type corresponding to the pressing process of the bearing inner ring.

7. The differential bearing inner race press force data acquisition method of claim 1, wherein, The method further comprises: A target pressure range in which the target pressure value at the current time point is located is determined from a plurality of pre-set pressure ranges; different pressure ranges correspond to different regulation modes; According to the regulation mode corresponding to the target pressure range, the output power of the press is regulated, so that the pressure value applied to the bearing inner ring is located in the reference pressure range matched by the to-be-pressed bearing inner ring and the differential.

8. A differential bearing inner race press machine pressure data acquisition system characterized by, Comprise: A processor and a memory, the memory stores computer program instructions, the computer program instructions are executed by the processor to realize the differential bearing inner ring press pressure data acquisition method according to any one of claims 1-7.

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