A kind of automobile wheel hub bearing unit rotary bending fatigue testing machine calibration device and calibration method

Abstract

The application discloses a kind of automobile wheel hub bearing unit rotary bending fatigue testing machine calibration device and calibration method, it is related to wheel hub bearing test field, including test machine mesa etc., test machine loading arm is arranged in the vertical direction above test machine mesa, one side end surface of wheel hub bearing sample is fixed on test machine mesa, the other side end surface of wheel hub bearing sample is fixed in the bottom of test machine loading arm;Support is fixed in the vertical direction on test machine mesa, the loading end of manual hydraulic loading device is rested on the top of test machine loading arm, and force sensor is connected on the loading end;Test machine bending moment sensor is set on test machine loading arm, and calibration bending moment sensor is installed on the end surface of wheel hub bearing sample.The application can carry out the calibration of automobile wheel hub bearing bending fatigue testing machine and test, also can be extended to other automobile parts and so on product stress test and calibration, suitable for wheel hub bearing production research and development enterprise, also suitable for automobile main machine factory.

Description

Technical Field

[0001] This invention relates to the field of wheel hub bearing testing, and more specifically to a calibration device and calibration method for a rotary bending fatigue testing machine for automotive wheel hub bearing units. Background Technology

[0002] Rotary bending fatigue testing is an important method for testing the fatigue performance of materials in the development of many automotive parts (especially wheel bearings). Before conducting rotary bending fatigue tests, the rotary bending fatigue testing machine usually needs to be calibrated.

[0003] Chinese patent document (CN110361286A) discloses a calibration device and method for a rotary bending fatigue testing machine. The device includes a stress standard and a lever mechanism. Strain gauges are mounted on both the upper and lower sides of the stress standard, and both ends are clamped by the inner and outer clamps of the rotary bending fatigue testing machine, respectively. One end of the lever mechanism is connected to the bending load application position of the rotary bending fatigue testing machine via an axially acting rod, and the other end suspends a weight pan. The distance from the bending load application position to the clamping point of the inner clamp is L1, and the distance to the clamping point of the outer clamp is L2. The ratio of the width T1 of the stress standard clamped by the inner clamp to the width T2 of the stress standard clamped by the outer clamp is set to L1 / L2, based on which the real-time strain can be measured using strain gauges. However, this calibration device is only applicable to small cantilever rotary bending fatigue testing machines used in aero-engines and is not suitable for rotary bending fatigue testing machines used in the automotive wheel hub bearing field. Furthermore, this technical solution uses weights and a weight pan to apply the load. When using weights, the load magnitude needs to be changed by adding or removing weights, which is inconvenient and provides a limited load range, failing to achieve stepless load variation. Existing technologies also lack calibration devices for rotary bending fatigue testing machines suitable for wheel hub bearings. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a calibration device and calibration method for a rotating bending fatigue testing machine for automotive wheel hub bearings. It can be used to calibrate the bending fatigue testing machine and test of automotive wheel hub bearings, and can also be extended to stress testing and calibration of other automotive parts and other products. It is suitable for wheel hub bearing manufacturing and R&D enterprises, as well as automotive OEMs.

[0005] The objective of this invention is achieved through the following technical solution: A calibration device for a rotary bending fatigue testing machine of an automotive wheel hub bearing unit includes a bracket, a manual hydraulic loading device, a testing machine loading arm, a wheel hub bearing specimen, and a wheel hub bearing bending fatigue testing machine. The top of the wheel hub bearing bending fatigue testing machine is the testing machine table. The testing machine loading arm is arranged vertically above the testing machine table. One end face of the wheel hub bearing specimen is fixed to the testing machine table, and the other end face of the wheel hub bearing specimen is fixed to the bottom of the testing machine loading arm. The bracket for installing the manual hydraulic loading device is fixed vertically to the testing machine table. The loading end of the manual hydraulic loading device rests on the top of the testing machine loading arm and is used to apply a load to the testing machine loading arm. A force sensor is connected to the loading end for real-time display of the output load magnitude. A testing machine bending moment sensor is installed on the testing machine loading arm to measure and feed back the bending moment of the wheel hub bearing specimen to the wheel hub bearing bending fatigue testing machine. A calibration bending moment sensor is installed on the end face of the wheel hub bearing specimen.

[0006] As a further technical solution, the manual hydraulic loading device is movably mounted on the bracket via a screw mechanism, and the mounting height of the manual hydraulic loading device on the bracket is adjusted by the screw mechanism.

[0007] As a further technical solution, the inner ring of the wheel hub bearing specimen is fixed on the test machine table, and the outer ring of the wheel hub bearing specimen is fixed on the bottom of the loading arm of the test machine; the strain gauge of the calibrating bending moment sensor is attached to the end face of the inner ring of the wheel hub bearing specimen, and the position of the strain gauge is coplanar with the loading end of the manual hydraulic loading device.

[0008] A calibration method using the above-mentioned calibration device for a rotary bending fatigue testing machine for automotive wheel hub bearing units includes the following steps:

[0009] Step 1: Fix the wheel hub bearing specimen between the loading arm of the testing machine and the testing machine table. Install the manual hydraulic loading device on the testing machine table through the bracket, with the loading end resting on the loading arm of the testing machine. Attach the strain gauge of the calibration moment sensor to the inner ring end face of the wheel hub bearing specimen, so that the position of the strain gauge is coplanar with the loading end of the manual hydraulic loading device.

[0010] Step 2: Control the manual hydraulic loading device to output several loads F of different sizes in sequence. Calculate the theoretical bending moment Ma based on the distance L between the loading end and the wheel hub bearing sample. Ma = F * L.

[0011] Step 3: For each load F, record the bending moment Mb measured by the calibrated bending moment sensor;

[0012] Step 4: For each load F, simultaneously record the bending moment Mc measured by the bending moment sensor of the testing machine;

[0013] Step 5: Compare the bending moments Mb and Mc corresponding to each load F. Calculate the calibration error using the formula (Mc-Mb) / Mb*100%. If the absolute value of the obtained calibration error is greater than or equal to 2%, adjust the testing machine parameters and recalibrate. If the absolute value of the obtained calibration error is less than 2%, the calibration is complete.

[0014] As a further technical solution, in the fifth step, before calculating the calibration error, the theoretical value Ma is used as a reference, and the measurement error is calculated according to the formula (Mb-Ma) / Ma*100%. If the absolute value of the obtained measurement error is greater than or equal to 2%, the manual hydraulic loading device is controlled to output loads F of different sizes again, and the bending moment Mb is measured again. If the absolute value of the obtained measurement error is less than 2%, there is no need to remeasure, and the calibration error is calculated again.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. The manual hydraulic loading device enables stepless variation of the calibration load, and can flexibly output multiple sets of loads of different sizes for the testing machine to calibrate;

[0017] 2. The strain gauge of the calibrated bending moment sensor is coplanar with the loading end of the manual hydraulic loading device to ensure that the bending moment measured during calibration is accurate and reliable, thereby improving calibration accuracy;

[0018] 3. During the calibration process, both measurement error and calibration error are calculated simultaneously to ensure that the calibration values ​​are accurate and reliable. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0020] Figure 2 This is a top view of the structure of the present invention.

[0021] Figure 3 for Figure 2 AA sectional view.

[0022] Figure 4 for Figure 3 A magnified view of a portion of region B in the middle.

[0023] Explanation of reference numerals in the attached drawings: 1. Support bracket; 2. Manual hydraulic loading device; 2. Loading end 2-1; 3. Screw device; 4. Loading arm of the testing machine; 5. Calibration bending moment sensor; 6. Wheel hub bearing specimen; 7. Wheel hub bearing bending fatigue testing machine; 8. Testing machine table; 9. Testing machine bending moment sensor; 10. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings:

[0025] Example: As attached Figures 1-4 As shown, this calibration device for a rotating bending fatigue testing machine for automotive wheel hub bearing units includes a bracket 1, a manual hydraulic loading device 2, a loading end 2-1, a force sensor 3, a lead screw device 4, a testing machine loading arm 5, a calibration bending moment sensor 6, a wheel hub bearing sample 7, a wheel hub bearing bending fatigue testing machine 8, a testing machine table 9, and a testing machine bending moment sensor 10.

[0026] Reference Appendix Figure 1 The top of the wheel hub bearing bending fatigue testing machine 8 is the testing machine platform 9. The testing machine loading arm 5 is arranged vertically above the testing machine platform 9. One end face (inner ring flange) of the wheel hub bearing specimen 7 is fixed on the testing machine platform 9, and the other end face (outer ring flange) of the wheel hub bearing specimen 7 is fixed to the bottom of the testing machine loading arm 5. A bracket 1 is fixedly installed vertically on the testing machine platform 9. The bracket 1 is supported by two support legs. The manual hydraulic loading device 2 is installed on the bracket 1 by means of a screw device 4 and can be raised and lowered along the bracket 1. The loading end 2-1 of the manual hydraulic loading device 2 rests on the top of the testing machine loading arm 5. The load is applied to the testing machine loading arm 5 through the loading end 2-1. A force sensor 3 is connected to the loading end 2-1, which can display the output load in real time. A testing machine bending moment sensor 10 is installed on the testing machine loading arm 5 to measure and feed back the bending moment of the wheel hub bearing specimen 7 to the wheel hub bearing bending fatigue testing machine 8. The strain gauge of the calibrated bending moment sensor 6 is attached to the inner ring end face (not the mounting surface) of the wheel hub bearing specimen 7, with an external signal cable leading out and connected to the control terminal. Figure 3 , 4 As shown, the strain gauge is located in the same plane as the loading end 2-1 of the manual hydraulic loading device 2, which ensures that the bending moment measured during calibration is accurate and reliable, and improves the calibration accuracy.

[0027] A calibration method using the above-mentioned calibration device for a rotary bending fatigue testing machine for automotive wheel hub bearing units includes the following steps:

[0028] Step 1: Fix the wheel hub bearing specimen 7 between the loading arm 5 and the test table 9 of the testing machine, such as... Figure 4 As shown, the inner flange of the wheel hub bearing specimen 7 is fixed on the testing machine table 9, and the outer ring of the wheel hub bearing specimen 7 is fixed to the bottom of the loading arm 5 of the testing machine. The manual hydraulic loading device 2 is mounted on the testing machine table 9 via the bracket 1, with the loading end 2-1 resting on the top of the loading arm 5 of the testing machine. The strain gauge of the calibration moment sensor 6 is glued to the non-mounting surface of the inner flange of the wheel hub bearing specimen 7, so that the position of the strain gauge is coplanar with the loading end 2-1 of the manual hydraulic loading device 2.

[0029] Step 2: Control the manual hydraulic loading device 2 to output several loads F of different sizes in sequence (five in this embodiment, corresponding to F1 to F5, F1 = 0.5kN, F2 = 1kN, F3 = 2kN, F4 = 5kN, F5 = 10kN). Based on the distance L between the loading end 2-1 and the wheel hub bearing sample 7, calculate the theoretical bending moment values ​​Ma1 to Ma5, Ma1 = 0.5L (kN·m), Ma2 = 1L (kN·m), Ma3 = 2L (kN·m), Ma4 = 5L (kN·m), Ma5 = 10L (kN·m).

[0030] Step 3: For loads F1 to F5, record the bending moments Mb1 to Mb5 measured by the calibrated bending moment sensor 6;

[0031] Step 4: For loads F1 to F5, simultaneously record the bending moments Mc1 to Mc5 measured by the bending moment sensor 10 of the testing machine;

[0032] Step 5: Using the theoretical value Ma as a reference, calculate the measurement error according to the formula Mb - Ma / Ma*100%. If the absolute value of the obtained measurement error is greater than or equal to 2%, control the manual hydraulic loading device 2 to output loads F of different magnitudes again and measure the bending moment Mb again. If the absolute value of the obtained measurement error is less than 2%, there is no need to remeasure; continue calculating the calibration error. Compare the bending moments Mb and Mc corresponding to each load F, and calculate the calibration error according to the formula Mc - Mb / Mb*100%. If the absolute value of the obtained calibration error is greater than or equal to 2%, adjust the test parameters of the wheel hub bearing bending fatigue testing machine 8 and recalibrate. If the absolute value of the obtained calibration error is less than 2%, the calibration is complete, and the wheel hub bearing bending fatigue test can be carried out.

[0033] This invention relates to the calibration of bending moment parameters in a wheel hub bearing bending fatigue testing machine. The wheel hub bearing bending fatigue testing machine performs rotational bending resonance tests on bearings to assess their fatigue crack strength. The input parameter during testing is the bending moment (torque) M1. To check the accuracy of this parameter, the device and calibration method provided in this invention can be used for calibration and verification.

[0034] During operation, the wheel hub bearing specimen is installed on the wheel hub unit bending fatigue testing machine, and the fixed bracket is placed on the testing machine's table. The force output by the manual hydraulic device presses against the upper end of the loading arm of the testing machine, and the magnitude of the force F is known through the sensor. The distance from the loading point to the wheel hub bearing specimen is L, and the magnitude of the force loading bending moment is Ma = FL. At the same time, the bending moment at the position of the wheel hub bearing is measured in real time through the bending moment sensor strain bridge, which is Mb. At this time, the bending moment displayed by the wheel hub bearing bending fatigue testing machine's own control system is Mc (the bending moment sensor of the equipment itself is on the lever arm). We compare the magnitudes of Mb and Mc (Ma is a reference) to judge whether the bending moment parameters of the testing machine itself are accurate. If the error is large (greater than 2%), the parameters of the testing machine are adjusted until the requirements are met.

[0035] It is understood that, for those skilled in the art, any equivalent substitutions or modifications to the technical solutions and inventive concepts of this invention should fall within the scope of protection of the appended claims.

Claims

1. A calibration device for a rotating bending fatigue tester for automobile wheel hub bearing units, characterized in that: The application relates to a wheel hub bearing bending fatigue test machine, which comprises a support (1), a manual hydraulic loading device (2), a test machine loading arm (5), a wheel hub bearing test sample (7) and a wheel hub bearing bending fatigue test machine (8). The top of the wheel hub bearing bending fatigue test machine (8) is a test machine table (9), the test machine loading arm (5) is arranged above the test machine table (9) in the vertical direction, one side end surface of the wheel hub bearing test sample (7) is fixed on the test machine table (9), and the other side end surface of the wheel hub bearing test sample (7) is fixed on the bottom of the test machine loading arm (5). The support (1) for installing the manual hydraulic loading device (2) is fixed on the test machine table (9) in the vertical direction, the loading end (2-1) of the manual hydraulic loading device (2) is placed on the top of the test machine loading arm (5) and is used for applying a load to the test machine loading arm (5), a force sensor (3) is connected to the loading end (2-1) and is used for displaying the output load size in real time, a test machine bending moment sensor (10) is arranged on the test machine loading arm (5), and a calibration bending moment sensor (6) is installed on the end surface of the wheel hub bearing test sample (7). The inner ring of the wheel hub bearing test sample (7) is fixed on the test machine table (9), and the outer ring of the wheel hub bearing test sample (7) is fixed on the bottom of the test machine loading arm (5); the strain gauges of the calibration bending moment sensor (6) are attached to the end surface of the inner ring of the wheel hub bearing test sample (7), and the positions of the strain gauges are coplanar with the loading end (2-1) of the manual hydraulic loading device (2).

2. The automobile hub bearing unit rotating bending fatigue tester calibration device according to claim 1, characterized by: The manual hydraulic loading device (2) is movably installed on the support (1) through a lead screw device (4), and the installation height of the manual hydraulic loading device (2) on the support (1) is adjusted by the lead screw device (4).

3. A calibration method using the automobile hub bearing unit rotating bending fatigue tester calibration device according to any one of claims 1 to 2, characterized by: The application further discloses a calibration method of the wheel hub bearing bending fatigue test machine. First step: the wheel hub bearing test sample (7) is fixed between the test machine loading arm (5) and the test machine table (9), the manual hydraulic loading device (2) is installed on the test machine table (9) through the support (1) and is placed on the test machine loading arm (5), the strain gauges of the calibration bending moment sensor (6) are attached to the end surface of the inner ring of the wheel hub bearing test sample (7), and the positions of the strain gauges are coplanar with the loading end (2-1) of the manual hydraulic loading device (2); Second step: the manual hydraulic loading device (2) is controlled to output a plurality of loads F in sequence, the bending moment theoretical value Ma is calculated according to the distance L between the loading end (2-1) and the wheel hub bearing test sample (7), and Ma=F*L; Third step: for each load F, the bending moment Mb measured by the calibration bending moment sensor (6) is recorded; Fourth step: for each load F, the bending moment Mc measured by the test machine bending moment sensor (10) is recorded; Fifth step: the bending moments Mb and Mc corresponding to each load F are compared, the calibration error is calculated according to the formula (Mc-Mb) / Mb*100%, if the absolute value of the obtained calibration error is greater than or equal to 2%, the test machine parameters are adjusted, and the calibration is re-performed, and if the absolute value of the obtained calibration error is less than 2%, the calibration is completed.

4. The method of calibration of claim 3, wherein: In the fifth step, before calculating the calibration error, the measurement error is calculated according to the formula (Mb-Ma) / Ma*100% with the theoretical value Ma as the reference. If the absolute value of the obtained measurement error is greater than or equal to 2%, the manual hydraulic loading device (2) is controlled to output a load F of a different size again, and the bending moment Mb is measured again. If the absolute value of the obtained measurement error is less than 2%, it is not necessary to measure again, and the calibration error is continued to be calculated.

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