A durability test method, apparatus, and medium for a camshaft

Abstract

This invention discloses a method, equipment, and medium for testing the durability of camshafts, relating to the field of durability testing technology. It solves the problem of being unable to test the durability of camshafts under different practical application conditions. The method includes collecting initial parameters of the camshaft used in plug-in hybrid electric vehicles, placing the camshaft in a camshaft test bench and conducting a cyclic wear test, collecting characteristic data of the camshaft after the cyclic wear test, conducting a pressure test on the shaft body and cam tip at the cam mounting point under specific temperature conditions, and comprehensively analyzing the durability of the camshaft based on the results of the cyclic wear test and the pressure test. This invention enables durability testing of camshafts under different practical application conditions.

Description

Technical Field

[0001] This invention belongs to the field of durability testing technology, specifically a durability testing method, equipment, and medium for a camshaft. Background Technology

[0002] The camshaft is a component in a piston engine. Its function is to control the opening and closing of the valves. Although the camshaft rotates at half the speed of the crankshaft in a four-stroke engine, its speed is usually still very high and it needs to withstand a lot of torque. Therefore, the design of the camshaft requires high strength and support. Its material is generally high-quality alloy steel or alloy steel. Since the valve movement law is related to the power and operating characteristics of an engine, the camshaft design occupies a very important position in the engine design process.

[0003] In the existing technology, the camshaft lacks durability testing under different actual application conditions. For example, the camshaft's usage under different engine conditions such as cold start, normal operation and overload operation, as well as the pressure resistance of the camshaft body and cam tip at high temperature.

[0004] Therefore, this invention proposes a durability testing method, equipment, and medium for camshafts. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method, equipment and medium for testing the durability of camshafts.

[0006] The technical problem to be solved by this invention is:

[0007] How to conduct durability tests on camshafts under different practical application conditions.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] Firstly, a durability testing method for a camshaft includes:

[0010] Step S1: Collect the initial parameters of the camshaft used in the plug-in hybrid electric vehicle;

[0011] Step S2: Place the camshaft in the camshaft test bench and perform a cyclic wear test on the camshaft;

[0012] Step S3: Collect feature data of the camshaft after the cyclic wear test;

[0013] Step S4: Perform a pressure test on the shaft and cam tip at the cam mounting point of the camshaft under specific temperature conditions;

[0014] Step S5: Based on the results of the cyclic wear test and pressure test, a comprehensive analysis of the camshaft's durability is conducted.

[0015] Furthermore, the data acquisition process in step S1 includes:

[0016] Step S11: Divide the camshaft into a cam and a shaft at the cam mounting point;

[0017] Step S12: Denote the arc end of the cam as the cam base circle, place the cam in a plane rectangular coordinate system, and obtain the coordinates (Xai, Yai) of each point on the cam base circle, i=1,2,...,n, where n is a positive integer and i is the number of each point on the base circle;

[0018] Step S13: Calculate the initial center coordinates (Xc, Yc) and initial radius Rjy of the cam base circle using the least squares method.

[0019] Step S131: Sum the abscissas of all points on the cam base circle, take the average value, and multiply by 2 to obtain the initial abscissa Xc of the cam base circle center.

[0020] Similarly, the initial center ordinate Yc of the cam base circle is obtained by summing the ordinates of all points on the cam base circle, taking the average value, and then multiplying by 2.

[0021] Step S132, using the formula The initial radius Rjy of the cam base circle is calculated.

[0022] Furthermore, the data acquisition process in step S1 also includes:

[0023] Step S14, using the formula The actual distances rsj from each point on the cam base circle to the center of the cam base circle are calculated.

[0024] Step S15: Subtract the radius of the cam base circle from the actual distance from each point on the cam base circle to the center of the cam base circle to obtain the radial deviation of each point on the cam base circle;

[0025] Step S16: Iterate through and compare the radial deviations of all points on the cam base circle to obtain the maximum and minimum values ​​of the radial deviations. Subtract the minimum value of the radial deviation from the maximum value of the radial deviations at each point on the cam base circle to obtain the initial roundness error of the cam base circle.

[0026] Step S17: Obtain the coordinates of each point on the corresponding profile of the cam. Iterate through and compare the ordinates of each point on the cam profile in the first and second quadrants to obtain the maximum value of the ordinate. Record the point corresponding to the maximum value of the ordinate as the cam tip. Obtain the horizontal and vertical coordinates of the cam tip and record them as the initial cam tip coordinates (Xt1, Yt1).

[0027] Step S18: Measure the outer diameter of the camshaft body at the cam mounting point and record it as the initial outer diameter of the camshaft body.

[0028] Furthermore, the experimental process in step S2 includes the following sub-steps:

[0029] Step S21: Connect one end of the camshaft to the rotating module, install the other end of the camshaft in the fixing device, install the test base below the camshaft, and align each cam on the camshaft with the metal block;

[0030] Step S22: Set a first rotational speed, a second rotational speed, and a third rotational speed for the rotating module; wherein the speed of the first rotational speed is lower than the speed of the second rotational speed, and the speed of the second rotational speed is lower than the speed of the third rotational speed;

[0031] Step S23: Perform a cyclic wear test on the camshaft;

[0032] Step S24: Repeat the cyclic wear test on the camshaft a fixed number of times.

[0033] Furthermore, the specific procedure for the cyclic wear test in step S23 is as follows:

[0034] Step S231: Adjust the rotation speed of the rotating module to the first rotation speed, so that the camshaft operates at the first rotation speed for a first fixed time;

[0035] Step S232: After the camshaft has been operating at the first speed for a first fixed time, oil is sprayed onto the surface of the camshaft. At the same time, the speed of the rotating module is adjusted to the second speed, so that the camshaft continues to operate at the second speed for a second fixed time.

[0036] Step S233: After the camshaft has been operating at the second speed for a second fixed time, oil is sprayed onto the surface of the camshaft, and at the same time the speed of the rotating module is adjusted to the third speed, so that the camshaft continues to operate at the third speed for a third fixed time.

[0037] Step S234: After the camshaft has been operating at the third speed for the third fixed time, clean the oil off the camshaft surface and stop the test.

[0038] Among them, the duration of the first fixed duration is less than the duration of the second fixed duration and the duration of the third fixed duration, and the duration of the second fixed duration is greater than the duration of the third fixed duration;

[0039] Step S235, steps S231-S234 are recorded as cyclic wear test.

[0040] Furthermore, the feature data acquisition process in step S3 is as follows:

[0041] Step S31: Obtain the actual coordinates (Xt2, Yt2) of the cam tip after the cyclic wear test, and use the formula... The wear distance JL of the cam tip in the camshaft is calculated;

[0042] Step S32: Compare the wear distance of the cam tip in the camshaft with the wear distance threshold.

[0043] If the wear distance of the cam tip in the camshaft is greater than or equal to the wear distance threshold, the corresponding camshaft will be marked as a product with unqualified durability.

[0044] If the wear distance of the cam tip in the camshaft is less than the wear distance threshold, proceed to the next step;

[0045] Step S33: Obtain the coordinates (Xbi, Ybi) of each point on the cam base circle after the cyclic wear test. Repeat step S13 to calculate the actual center coordinates and actual radius of the cam base circle after the cyclic wear test using the least squares method.

[0046] Step S34: Repeat steps S14-S16 to calculate the actual roundness error of the cam base circle after the cyclic wear test;

[0047] Step S35: Subtract the initial roundness error from the actual roundness error and take the absolute value to obtain the roundness change of the cam base circle;

[0048] Step S36: Collect the outer diameter of the camshaft body at the cam mounting point after the cyclic wear test and record it as the actual outer diameter of the camshaft body;

[0049] Step S37: Subtract the initial outer diameter of the shaft body from the actual outer diameter of the shaft body and take the absolute value to obtain the wear amount of the outer diameter of the shaft body at the cam mounting location.

[0050] Furthermore, the pressure test process in step S4 includes the following sub-steps:

[0051] Step S41: Obtain the historical operating temperature of the same type of camshaft, iterate through and compare the historical operating temperatures of all the same type of camshaft to obtain the maximum value of the historical operating temperature, and record the maximum value of the historical operating temperature of the same type of camshaft as the test temperature.

[0052] Step S42: Fix the shaft at the mounting cam of the camshaft in the circular test device, preheat the shaft at the mounting cam of the camshaft to the test temperature, gradually increase the pressure of the circular test device until the shaft of the camshaft breaks, and record the pressure corresponding to the breakage as the shaft yield pressure.

[0053] Step S43: Measure the distance from the tip of the cam to the lowest point of the bottom of the cam base circle and record it as the cam length. Fix the cam base circle part in the fixture, preheat the tip of the cam to the test temperature, and periodically apply pressure to the tip of the cam until the cam length changes. Record the pressure at the corresponding moment as the cam deformation pressure of the cam tip.

[0054] Furthermore, the analysis process in step S5 includes the following sub-steps:

[0055] Step S51: Compare the shaft yield pressure at the cam mounting point with the shaft yield pressure threshold, and compare the cam deformation pressure at the cam tip with the cam deformation pressure threshold.

[0056] Step S52: If the shaft yield pressure at the cam mounting cam is less than the shaft yield pressure threshold or the cam deformation pressure at the cam tip is less than the cam deformation pressure threshold, then the corresponding camshaft is recorded as a product with unqualified durability.

[0057] Step S53: If the shaft yield pressure at the cam mounting point is greater than or equal to the shaft yield pressure threshold and the cam deformation pressure at the cam tip is greater than or equal to the cam deformation pressure threshold, then proceed to the next step.

[0058] Step S54: Compare the roundness change of the cam base circle with the standard roundness change, and compare the outer diameter wear of the camshaft at the cam mounting location with the standard outer diameter wear.

[0059] Step S55: If the roundness change of the cam base circle is less than the standard roundness change and the wear of the outer diameter of the shaft at the cam mounting point is less than the standard wear of the outer diameter, then the corresponding camshaft is recorded as a durable qualified product.

[0060] If the roundness change of the cam base circle is greater than or equal to the standard roundness change, or the wear of the outer diameter of the shaft at the cam mounting point is greater than or equal to the standard wear of the outer diameter, then the corresponding camshaft will be recorded as a product with unqualified durability.

[0061] Secondly, an electronic device, characterized in that the electronic device comprises:

[0062] A memory that stores a computer program;

[0063] The processor is communicatively connected to the memory. When the computer program is executed by the processor, it implements the aforementioned method for testing the durability of a camshaft.

[0064] Thirdly, a computer-readable storage medium having a computer program stored thereon, characterized in that the program, when executed by a processor, implements the aforementioned method for testing the durability of a camshaft.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] 1. This invention first collects the initial parameters of the camshaft used in plug-in hybrid electric vehicles, then places the camshaft in a camshaft test bench and conducts a cyclic wear test on the camshaft, and then collects the characteristic data of the camshaft after the cyclic wear test. This invention realizes the effective analysis of the wear state of the camshaft at different speeds.

[0067] 2. The present invention also conducts pressure tests on the shaft body and cam tip at the cam mounting cam under specific temperature conditions. At the same time, based on the results of the cyclic wear test and the pressure test, the durability of the camshaft is comprehensively analyzed. The present invention realizes the durability test of the camshaft under different actual application conditions. Attached Figure Description

[0068] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0069] Figure 1 This is a flowchart of the method of the present invention;

[0070] Figure 2 This is a schematic diagram of the camshaft in this invention;

[0071] Figure 3 This is a schematic diagram of the cam in this invention;

[0072] Figure 4 This is a schematic diagram of the cyclic wear test device in this invention;

[0073] Figure 5 This is a schematic diagram of the annular pressure device in this invention;

[0074] Figure 6 This is a schematic diagram of the electronic device in this invention. Detailed Implementation

[0075] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0076] Example 1: Please refer to Figures 1-5 As shown, the technical solution provided by this invention is: a durability testing method for a camshaft, the specific method being as follows:

[0077] In this embodiment, multiple camshafts are selected from the same batch of camshafts used in plug-in hybrid electric vehicles for durability testing. The selected multiple camshafts are divided into two groups, one group for cyclic wear testing and the other group for pressure testing.

[0078] Step S1: Collect the initial parameters of the camshaft used in the plug-in hybrid electric vehicle;

[0079] In this embodiment, the data acquisition process in step S1 is as follows:

[0080] Step S11, please refer to Figure 2 As shown, the camshaft is divided into the cam, the camshaft shaft, and the shaft at which the cam is mounted.

[0081] Step S12, please refer to Figure 3 As shown, the arc end of the cam is denoted as the cam base circle. The cam is placed in a plane rectangular coordinate system, and the coordinates (Xai, Yai) of each point on the cam base circle are obtained, i=1,2,...,n, where n is a positive integer and i is the number of each point on the base circle.

[0082] Step S13: Calculate the initial center coordinates (Xc, Yc) and initial radius Rjy of the cam base circle using the least squares method.

[0083] The calculation process for the initial center coordinates of the cam base circle and the initial radius of the cam base circle in step S13 is as follows:

[0084] Step S131: Sum the abscissas of all points on the cam base circle, take the average value, and multiply by 2 to obtain the initial abscissa Xc of the cam base circle center.

[0085] Similarly, the initial center ordinate Yc of the cam base circle is obtained by summing the ordinates of all points on the cam base circle, taking the average value, and then multiplying by 2.

[0086] Step S132, using the formula The initial radius Rjy of the cam base circle is calculated;

[0087] Step S14, using the formula The actual distances rsj from each point on the cam base circle to the center of the cam base circle are calculated.

[0088] Step S15: Subtract the radius of the cam base circle from the actual distance from each point on the cam base circle to the center of the cam base circle to obtain the radial deviation of each point on the cam base circle;

[0089] Step S16: Iterate through and compare the radial deviations of all points on the cam base circle to obtain the maximum and minimum values ​​of the radial deviations. Subtract the minimum value of the radial deviation from the maximum value of the radial deviations at each point on the cam base circle to obtain the initial roundness error of the cam base circle.

[0090] Step S17: Obtain the coordinates of each point on the corresponding profile of the cam. Iterate through and compare the ordinates of each point on the cam profile in the first and second quadrants to obtain the maximum value of the ordinate. Record the point corresponding to the maximum value of the ordinate as the cam tip. Obtain the horizontal and vertical coordinates of the cam tip and record them as the initial cam tip coordinates (Xt1, Yt1).

[0091] Step S18: Measure the outer diameter of the camshaft body at the cam mounting point and record it as the initial outer diameter of the camshaft body.

[0092] Step S2: Place the camshaft in the camshaft test bench and perform a cyclic wear test on the camshaft;

[0093] Furthermore, the experimental process in step S2 includes the following sub-steps:

[0094] Step S21, please refer to Figure 4 As shown, one end of the camshaft is connected to the rotating module, the other end of the camshaft is installed in the fixing device, and the test base is installed below the camshaft, ensuring that each cam on the camshaft is aligned with the metal block;

[0095] In this embodiment, the camshaft test bench is used to simulate the actual working state of the camshaft opening or closing the valve in the engine. The camshaft test bench includes a rotating module and a test base. The rotating module can actually be a rotary motor. The fixing device is a clamp that can fix the camshaft. There are fixing springs on the test base, and a metal block is fixed on each spring. In this embodiment, the spring elastic coefficient is set to be the same as the spring elastic coefficient in the actual application of the camshaft.

[0096] Step S22: Set a first rotational speed, a second rotational speed, and a third rotational speed for the rotating module; wherein the speed of the first rotational speed is lower than the speed of the second rotational speed, and the speed of the second rotational speed is lower than the speed of the third rotational speed;

[0097] Step S23: Perform a cyclic wear test on the camshaft;

[0098] The specific test procedure for the cyclic wear test in step S23 is as follows:

[0099] Step S231: Adjust the rotation speed of the rotating module to the first rotation speed, so that the camshaft operates at the first rotation speed for a first fixed time;

[0100] Step S232: After the camshaft has been operating at the first speed for a first fixed time, oil is sprayed onto the surface of the camshaft. At the same time, the speed of the rotating module is adjusted to the second speed, so that the camshaft continues to operate at the second speed for a second fixed time.

[0101] Step S233: After the camshaft has been operating at the second speed for a second fixed time, oil is sprayed onto the surface of the camshaft, and at the same time the speed of the rotating module is adjusted to the third speed, so that the camshaft continues to operate at the third speed for a third fixed time.

[0102] Step S234: After the camshaft has been operating at the third speed for the third fixed time, clean the oil off the camshaft surface and stop the test.

[0103] Among them, the duration of the first fixed duration is less than the duration of the second fixed duration and the duration of the third fixed duration, and the duration of the second fixed duration is greater than the duration of the third fixed duration;

[0104] In this embodiment, the camshaft is operated at a first speed to simulate the wear scenario of the camshaft during engine cold start, and the camshaft is operated at a second speed to simulate the wear scenario of the camshaft during normal engine operation. Since this stage is normal operation, the second fixed time is the longest. The camshaft is operated at a third speed to simulate the wear scenario of the camshaft during engine overload operation.

[0105] For example, in this embodiment, the first rotational speed can be 1000 rpm and the first fixed duration is 1 hour; the second rotational speed is 2000 rpm and the second fixed duration is 5 hours; the third rotational speed is 3500 rpm and the third fixed duration is 2 hours.

[0106] Step S235: Steps S231-S234 are recorded as cyclic wear test;

[0107] Step S24: Repeat the cyclic wear test on the camshaft a fixed number of times;

[0108] For example, the camshaft is subjected to a fixed number of cyclic wear tests, which is 30 times.

[0109] Step S3: Collect feature data of the camshaft after the cyclic wear test;

[0110] In this embodiment, the feature data acquisition process in step S3 is as follows:

[0111] Step S31: Obtain the actual coordinates (Xt2, Yt2) of the cam tip after the cyclic wear test, and use the formula... The wear distance JL of the cam tip in the camshaft is calculated;

[0112] Step S32: Compare the wear distance of the cam tip in the camshaft with the wear distance threshold.

[0113] If the wear distance of the cam tip in the camshaft is greater than or equal to the wear distance threshold, the corresponding camshaft will be marked as a product with unqualified durability.

[0114] If the wear distance of the cam tip in the camshaft is less than the wear distance threshold, proceed to the next step;

[0115] Step S33: Obtain the coordinates (Xbi, Ybi) of each point on the cam base circle after the cyclic wear test. Repeat step S13 to calculate the actual center coordinates and actual radius of the cam base circle after the cyclic wear test using the least squares method.

[0116] Step S34: Repeat steps S14-S16 to calculate the actual roundness error of the cam base circle after the cyclic wear test;

[0117] Step S35: Subtract the initial roundness error from the actual roundness error and take the absolute value to obtain the roundness change of the cam base circle;

[0118] Step S36: Collect the outer diameter of the camshaft body at the cam mounting location after the cyclic wear test and record it as the actual outer diameter of the camshaft body;

[0119] Step S37: Subtract the initial outer diameter of the shaft body from the actual outer diameter of the shaft body and take the absolute value to obtain the wear amount of the outer diameter of the shaft body at the cam mounting location.

[0120] Step S4: Perform a pressure test on the shaft and cam tip at the cam mounting point of the camshaft under specific temperature conditions;

[0121] In this embodiment, the pressure test process in step S4 includes the following sub-steps:

[0122] Step S41: Obtain the historical operating temperature of the same type of camshaft, iterate through and compare the historical operating temperatures of all the same type of camshaft to obtain the maximum value of the historical operating temperature, and record the maximum value of the historical operating temperature of the same type of camshaft as the test temperature.

[0123] Step S42, please refer to Figure 5 As shown, the shaft at the mounting cam of the camshaft is fixed in the circular test device. The shaft at the mounting cam of the camshaft is preheated to the test temperature. The pressure of the circular test device is gradually increased until the shaft of the camshaft breaks. The pressure corresponding to the breakage is recorded as the shaft yield pressure.

[0124] In this embodiment, the ring testing device is a ring-shaped pressure device, and the inner ring of the ring testing device is fitted onto the shaft body at the cam mounting point of the camshaft.

[0125] Step S43: Measure the distance from the tip of the cam to the lowest point of the bottom of the cam base circle and record it as the cam length. Fix the cam base circle part in the fixture. Preheat the tip of the cam to the test temperature. Use a pressure device to periodically apply pressure to the tip of the cam until the cam length changes. Record the pressure at the corresponding moment as the cam deformation pressure of the cam tip.

[0126] It should be explained that applying pressure to the tip of the cam using a pressure device periodically means: applying pressure to the tip of the cam for 1 minute and then stopping the application of pressure for 10 seconds.

[0127] In this embodiment, preheating the shaft body and cam tip at the cam mounting point of the camshaft to the test temperature is to simulate the pressure resistance of the shaft body and cam tip under extreme operating temperatures.

[0128] Step S5: Based on the results of the cyclic wear test and pressure test, a comprehensive analysis of the camshaft's durability is conducted.

[0129] In this embodiment, the analysis process in step S5 includes the following sub-steps:

[0130] Step S51: Compare the shaft yield pressure at the cam mounting point with the shaft yield pressure threshold, and compare the cam deformation pressure at the cam tip with the cam deformation pressure threshold.

[0131] Step S52: If the shaft yield pressure at the cam mounting cam is less than the shaft yield pressure threshold or the cam deformation pressure at the cam tip is less than the cam deformation pressure threshold, then the corresponding camshaft is recorded as a product with unqualified durability.

[0132] Step S53: If the shaft yield pressure at the cam mounting point is greater than or equal to the shaft yield pressure threshold and the cam deformation pressure at the cam tip is greater than or equal to the cam deformation pressure threshold, then proceed to the next step.

[0133] Step S54: Compare the roundness change of the cam base circle with the standard roundness change, and compare the outer diameter wear of the camshaft at the cam mounting location with the standard outer diameter wear.

[0134] Step S55: If the roundness change of the cam base circle is less than the standard roundness change and the wear of the outer diameter of the shaft at the cam mounting point is less than the standard wear of the outer diameter, then the corresponding camshaft is recorded as a durable qualified product.

[0135] If the roundness change of the cam base circle is greater than or equal to the standard roundness change, or the wear of the outer diameter of the shaft at the cam mounting point is greater than or equal to the standard wear of the outer diameter, then the corresponding camshaft will be recorded as a product with unqualified durability.

[0136] In this application, if a corresponding calculation formula appears, the above calculation formula is a dimensionless calculation. The weighting coefficient, proportional coefficient and other coefficients in the formula are set to quantify each parameter to obtain a result value. The size of the weighting coefficient and proportional coefficient is only required to not affect the proportional relationship between the parameter and the result value.

[0137] Example 2: Figure 6 This is a schematic diagram of the structure of an electronic device, which may include a processor, a communication interface, a memory, and a communication bus. The processor, communication interface, and memory communicate with each other via the communication bus. The processor can call logical instructions from the memory to execute a camshaft durability testing method. This method includes: acquiring initial parameters of the camshaft used in a plug-in hybrid electric vehicle; placing the camshaft in a camshaft test bench and performing a cyclic wear test on the camshaft; acquiring characteristic data of the camshaft after the cyclic wear test; performing a pressure test on the shaft body and cam tip at the cam mounting point of the camshaft under specific temperature conditions; and conducting a comprehensive analysis of the camshaft durability based on the results of the cyclic wear test and the pressure test.

[0138] Furthermore, when the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0139] On the other hand, this application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by a computer, the computer is able to execute a camshaft durability test method provided by the above methods. The method includes: collecting initial parameters of the camshaft used in a plug-in hybrid electric vehicle; placing the camshaft in a camshaft test bench and performing a cyclic wear test on the camshaft; collecting characteristic data of the camshaft after the cyclic wear test; performing a pressure test on the shaft body and cam tip at the cam mounting point of the camshaft under specific temperature conditions; and performing a comprehensive analysis of the durability of the camshaft based on the results of the cyclic wear test and the pressure test.

[0140] In another aspect, this application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, performs a durability test method for a camshaft provided above. The method includes: acquiring initial parameters of a camshaft used in a plug-in hybrid electric vehicle; placing the camshaft in a camshaft test bench and performing a cyclic wear test on the camshaft; acquiring characteristic data of the camshaft after the cyclic wear test; performing a pressure test on the shaft body and cam tip at the cam mounting point of the camshaft under specific temperature conditions; and performing a comprehensive analysis of the durability of the camshaft based on the results of the cyclic wear test and the pressure test.

[0141] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0142] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A durability test method for a camshaft, characterized by, The application relates to a camshaft parameter acquisition method for a plug-in hybrid drive vehicle. The method comprises the following steps: S1, collecting initial parameters of a camshaft for a plug-in hybrid drive vehicle; The collecting process in the step S1 comprises the following steps: S11, dividing the camshaft into cams and shaft bodies at camshaft cam mounting positions; S12, recording the arc end of the cam as a cam base circle, placing the cam in a plane rectangular coordinate system, and obtaining the coordinates (Xai, Yai) of each point on the cam base circle, wherein i=1, 2,..., n, n is a positive integer, and i is the number of each point on the base circle; S13, obtaining initial center coordinates (Xc, Yc) of the cam base circle center and an initial radius Rjy of the cam base circle by a least square method; S131, adding the horizontal coordinates of each point on the cam base circle, taking the average value, multiplying the average value by 2, and obtaining the initial center horizontal coordinate Xc of the cam base circle center; Step S132, the initial radius Rjy of the cam base circle is calculated by the formula ​ Similarly, adding the vertical coordinates of each point on the cam base circle, taking the average value, multiplying the average value by 2, and obtaining the initial center vertical coordinate Yc of the cam base circle center; S2, placing the camshaft in a camshaft test bed and performing a cycle wear test on the camshaft; S3, collecting characteristic data of the camshaft after the cycle wear test; S4, performing a pressure test on the shaft body at the camshaft cam mounting position and the cam peach tip under a specific temperature condition; 2. A durability test method of a camshaft according to claim 1, characterized in that, S5, comprehensively analyzing the durability of the camshaft according to the cycle wear test and the pressure test results. Step S14, the actual distance rsj of each point of the cam base circle to the center of the cam base circle is calculated by the formula ​ The collecting process in the step S1 further comprises the following steps: S15, subtracting the radius of the cam base circle from the actual distance from each point on the cam base circle to the cam base circle center to obtain the radial deviation of each point on the cam base circle; S16, traversing and comparing the radial deviations of all points on the cam base circle to obtain the maximum value and the minimum value of the radial deviation, subtracting the minimum value of the radial deviation from the maximum value of the radial deviation of each point on the cam base circle to obtain the initial roundness error of the cam base circle; S17, obtaining the coordinates of each point on the cam profile, traversing and comparing the vertical coordinates of the cam profile points in the first quadrant and the second quadrant to obtain the maximum value of the vertical coordinates, recording the point corresponding to the maximum value of the vertical coordinates as the cam peach tip, and obtaining the horizontal and vertical coordinates of the cam peach tip and recording the initial peach tip coordinates (Xt1, Yt1) of the cam peach tip; 3. A method of endurance testing of a camshaft according to claim 2, characterized in that S18, measuring the outer diameter of the shaft body at the camshaft cam mounting position and recording the initial shaft body outer diameter. The test process in the step S2 comprises the following sub-steps: S21, connecting one end of the camshaft with a rotating module, mounting the other end of the camshaft in a fixing device, mounting a test base under the camshaft, and aligning each cam on the camshaft with a metal block; S22, setting a first rotating speed, a second rotating speed and a third rotating speed for the rotating module, wherein the first rotating speed is lower than the second rotating speed, and the second rotating speed is lower than the third rotating speed; S23, performing a cycle wear test on the camshaft; 4. A method of endurance testing of a camshaft according to claim 3, characterized in that S24, repeatedly performing a cycle wear test on the camshaft for a fixed number of times. The cycle wear test in the step S23 comprises the following steps: S231, adjusting the rotating speed of the rotating module to the first rotating speed, and making the camshaft work at the first rotating speed for a first fixed time length; Step S232, after the camshaft works at the first fixed time length at the first rotating speed, oil is sprayed on the surface of the camshaft, and the rotating speed of the rotating module is adjusted to the second rotating speed, so that the camshaft continues to work at the second rotating speed for a second fixed time length; Step S233, after the camshaft works at the second fixed time length at the second rotating speed, oil is sprayed on the surface of the camshaft, and the rotating speed of the rotating module is adjusted to the third rotating speed, so that the camshaft continues to work at the third rotating speed for a third fixed time length; Step S234, after the camshaft works at the third fixed time length at the third rotating speed, the surface of the camshaft is cleaned of oil and the test is stopped; Wherein, the length of the first fixed time length is less than the length of the second fixed time length and the length of the third fixed time length, and the length of the second fixed time length is greater than the length of the third fixed time length; Step S235, steps S231-S234 are recorded as a cycle wear test.

5. A method of endurance testing of a camshaft according to claim 4, characterized in that The feature data collection process in step S3 is as follows: Step S31, obtaining the actual cam nose coordinates (Xt2, Yt2) of the cam nose after the cyclic wear test, through the formula The wear distance JL of the cam nose in the camshaft is calculated. Step S32, compare the wear distance of the cam peach tip in the camshaft with the wear distance threshold value; If the wear distance of the cam peach tip in the camshaft is greater than or equal to the wear distance threshold value, the corresponding camshaft is recorded as a durability unqualified product; If the wear distance of the cam peach tip in the camshaft is less than the wear distance threshold value, proceed to the next step; Step S33, obtain the coordinates (Xbi, Ybi) of each point of the cam base circle after the cycle wear test, and repeat step S13 to calculate the actual center coordinates of the center of the cam base circle and the actual radius of the cam base circle after the cycle wear test by the least square method; Step S34, repeat steps S14-S16 to calculate the actual roundness error of the cam base circle after the cycle wear test; Step S35, subtract the actual roundness error from the initial roundness error to obtain the roundness change of the cam base circle; Step S36, collect the actual shaft body outer diameter of the camshaft installation cam after the cycle wear test and record it as the actual shaft body outer diameter; Step S37, subtract the actual shaft body outer diameter from the initial shaft body outer diameter to obtain the outer diameter wear of the shaft body at the cam installation cam.

6. A method of endurance testing of a camshaft according to claim 5, characterized in that The pressure test process in step S4 includes the following sub-steps: Step S41, obtain the historical working temperature of the same type of camshaft, and traverse and compare the historical working temperature of all the same type of camshafts to obtain the maximum value of the historical working temperature, and record the maximum value of the historical working temperature of the same type of camshaft as the test temperature; Step S42, fix the shaft body at the cam installation cam of the camshaft in the circular ring test device, preheat the shaft body at the cam installation cam of the camshaft to the test temperature, gradually increase the pressure of the circular ring test device until the shaft body of the camshaft breaks, and record the corresponding pressure as the yield pressure of the shaft body; Step S43, measure the distance from the cam peach tip to the lowest point of the bottom of the cam base circle as the cam length, fix the cam base circle part in the clamp, preheat the cam peach tip to the test temperature, and periodically apply pressure to the cam peach tip until the cam length changes, and record the corresponding pressure as the cam deformation pressure of the cam peach tip.

7. A method of endurance testing of a camshaft according to claim 6, characterized in that The analysis process in step S5 includes the following sub-steps: Step S51, comparing the shaft yield pressure at the cam shaft mounting cam with the shaft yield pressure threshold value, and comparing the cam deformation pressure of the cam nose with the cam deformation pressure threshold value; Step S52, if the shaft yield pressure at the cam shaft mounting cam is less than the shaft yield pressure threshold value or the cam deformation pressure of the cam nose is less than the cam deformation pressure threshold value, the corresponding cam shaft is recorded as a durability unqualified product; Step S53, if the shaft yield pressure at the cam shaft mounting cam is greater than or equal to the shaft yield pressure threshold value and the cam deformation pressure of the cam nose is greater than or equal to the cam deformation pressure threshold value, the next step is entered; Step S54, comparing the roundness change amount of the cam base circle with the standard roundness change amount, and comparing the outer diameter wear amount of the shaft body at the cam shaft mounting cam with the outer diameter wear standard amount; Step S55, if the roundness change amount of the cam base circle is less than the standard roundness change amount and the outer diameter wear amount of the shaft body at the cam shaft mounting cam is less than the outer diameter wear standard amount, the corresponding cam shaft is recorded as a durability qualified product; If the roundness change amount of the cam base circle is greater than or equal to the standard roundness change amount or the outer diameter wear amount of the shaft body at the cam shaft mounting cam is greater than or equal to the outer diameter wear standard amount, the corresponding cam shaft is recorded as a durability unqualified product.

8. An electronic device, comprising: The electronic device comprises: a memory storing a computer program; a processor in communication with the memory, when the computer program is executed by the processor, the method of any one of claims 1-7 is implemented.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the method of any one of claims 1 to 7. The program is executed by the processor to implement the method of any one of claims 1 to 7.

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