Engine exhaust valve spring testing method, system, terminal device and storage medium

Abstract

The present invention provides an engine exhaust valve spring test method, system, terminal device and storage medium, the method comprising: performing an exhaust brake working condition test on the engine to be tested, and respectively collecting stress change images and pressure change images under the exhaust brake working condition; performing a fall-off detection on the rocker arm according to the stress change image; if the fall-off detection of the rocker arm is qualified, then performing an intake adjustment detection on the stress change image; if the intake adjustment detection is unqualified, then determining the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image. In the present invention, if the fall-off detection of the rocker arm is qualified and the intake adjustment detection is unqualified, the maximum exhaust back pressure value of the exhaust valve spring can be automatically determined through the zero-crossing condition in the stress change image and the pressure change image, thereby improving the accuracy of the maximum exhaust back pressure value of the exhaust valve spring.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile engines, and in particular to a method, system, terminal equipment and storage medium for testing an engine exhaust valve spring. Background Art

[0002] As a safety configuration, most light trucks are equipped with an exhaust brake system, which serves as an auxiliary brake function for long downhill conditions. By controlling the opening of the butterfly valve on the exhaust tail pipe, the resistance of the engine exhaust channel is increased, so that the piston receives the reverse pressure of the high-pressure gas during the exhaust stroke. At this time, the engine not only does not generate power, but also acts as a load, thereby achieving the function of slowing down and controlling the vehicle speed. However, since the reverse high-pressure gas will cause certain disturbances to the exhaust valve spring on the engine, it may cause the exhaust valve of the engine valve mechanism to rebound or the rocker arm to fly off. If the matching is not good, the valve often rebounds or the rocker arm flies off, which will cause certain damage to the engine valve mechanism, and even cause serious failures such as exhaust valve spring breakage and rocker arm jamming. Therefore, the back pressure test of the exhaust valve spring on the engine is particularly important.

[0003] In the existing engine exhaust valve spring testing process, the maximum exhaust back pressure value of the exhaust valve spring is obtained by simulating the exhaust brake working condition of the engine and directly measuring the pressure of the exhaust brake butterfly valve pipeline under the exhaust brake working condition simulation. However, since the pressure of the exhaust brake butterfly valve pipeline may be different under different working points, the maximum exhaust back pressure value of the exhaust valve spring obtained is inaccurate, thereby reducing the accuracy of the engine exhaust valve spring test. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides an engine exhaust valve spring testing method, system, terminal device and storage medium to solve the problem of low measurement accuracy of the maximum exhaust back pressure value of the exhaust valve spring in the existing engine exhaust valve spring testing process.

[0005] A first aspect of an embodiment of the present invention provides an engine exhaust valve spring testing method, comprising:

[0006] Performing an exhaust brake working condition test on the engine to be tested, and collecting stress changes of the rocker arm of the engine to be tested and pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition, to obtain a stress change image and a pressure change image;

[0007] Performing a fall-off detection on the rocker arm according to the stress change image, wherein the fall-off detection is used to detect whether the rocker arm falls off;

[0008] If the rocker arm drop-off test is qualified, an intake adjustment test is performed on the stress change image, wherein the intake adjustment test is used to detect whether to increase the opening of the intake throttle valve on the engine to be tested;

[0009] If the intake regulation test fails, the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested is determined according to the zero-crossing condition in the stress change image and the pressure change image.

[0010] Furthermore, after performing intake adjustment detection on the stress change image, the method further includes:

[0011] If the intake adjustment test is qualified, the opening of the intake throttle valve is increased, and according to the increased opening of the intake throttle valve, the process returns to execute the steps of respectively collecting the stress changes of the rocker arm of the engine to be tested and the pressure changes of the exhaust brake butterfly valve pipeline under the exhaust braking condition to obtain the stress change image and the pressure change image and the subsequent steps, until the rocker arm fall-off test is qualified and the intake adjustment test is unqualified.

[0012] Further, the performing the fall-off detection on the rocker arm according to the stress change image comprises:

[0013] Respectively obtaining stress differences between adjacent stress points in the stress change image, wherein the stress points are used to represent stress values ​​of the rocker arm at different time points;

[0014] determining a motion interval in the stress change image according to the stress difference;

[0015] If the stress value of any of the stress points in the motion interval is equal to 0, it is determined that the rocker arm has failed the fall-off test;

[0016] If the stress values ​​of the stress points in the movement interval are all greater than 0, it is determined that the rocker arm has passed the fall-off detection.

[0017] Further, the performing air intake adjustment detection on the stress change image includes:

[0018] determining an idle speed interval in the stress variation image according to the stress difference value, and calculating an average stress value of stress points in the idle speed interval;

[0019] If the average stress value is less than the preset stress value, it is determined that the intake adjustment test is qualified;

[0020] If the average stress value is greater than or equal to the preset stress value, it is determined that the intake air regulation test is unqualified.

[0021] Further, the determining of the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image includes:

[0022] Performing zero-crossing detection on the stress change image to obtain the zero-crossing condition, and generating a back pressure detection period according to the working time of the zero-crossing condition and a preset duration;

[0023] The maximum pressure value in the back pressure detection period in the pressure change image is determined as the maximum exhaust back pressure value.

[0024] Furthermore, after increasing the opening of the intake throttle valve, the method further comprises:

[0025] If the rocker arm's fall-off detection fails, and / or the intake throttle valve's opening degree increases by a number greater than a threshold, a test error prompt is sent.

[0026] Furthermore, before performing the exhaust brake working condition test on the engine to be tested, the method further includes:

[0027] The vehicle parameters of the engine to be tested are set according to preset vehicle conditions, and the opening of the intake throttle valve is set according to a preset valve opening.

[0028] A second aspect of an embodiment of the present invention provides an engine exhaust valve spring test system, comprising:

[0029] The working condition test module is used to perform an exhaust brake working condition test on the engine to be tested, and respectively collect the stress change of the rocker arm of the engine to be tested and the pressure change of the exhaust brake butterfly valve pipeline under the exhaust brake working condition to obtain a stress change image and a pressure change image;

[0030] A fall-off detection module, used for performing a fall-off detection on the rocker arm according to the stress change image, wherein the fall-off detection is used for detecting whether the rocker arm falls off;

[0031] an adjustment detection module, for performing an intake adjustment detection on the stress change image if the rocker arm drop detection is qualified, wherein the intake adjustment detection is used to detect whether to increase the opening of the intake throttle valve on the engine to be tested;

[0032] The exhaust back pressure value determination module is used to determine the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image if the intake adjustment test fails.

[0033] A third aspect of an embodiment of the present invention provides a terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the terminal device, wherein when the processor executes the computer program, each step of the engine exhaust valve spring testing method provided by the first scheme is implemented.

[0034] A fourth aspect of an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the various steps of the engine exhaust valve spring testing method provided by the first scheme.

[0035] An engine exhaust valve spring test method, system, terminal device and storage medium provided by the embodiments of the present invention have the following beneficial effects: by respectively collecting the stress changes of the rocker arm of the engine to be tested and the pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition, the stress change data of the rocker arm and the pressure of the exhaust brake butterfly valve pipeline under different working points can be effectively obtained, and the rocker arm can be effectively detected by the stress change image to effectively detect whether the rocker arm has fallen off under the current opening of the intake throttle valve. Based on the rocker arm falling off detection, the accuracy of the engine exhaust valve spring test is effectively improved. By performing intake adjustment detection on the stress change image to detect whether the opening of the intake throttle valve can be increased, the upper limit of the maximum exhaust back pressure value of the exhaust valve spring is increased. If the rocker arm shedding detection is qualified and the intake adjustment detection is unqualified, the maximum exhaust back pressure value of the exhaust valve spring can be automatically determined through the zero-crossing condition and the pressure change image in the stress change image, thereby improving the accuracy of the maximum exhaust back pressure value of the exhaust valve spring and preventing the direct measurement of the pressure of the exhaust brake butterfly valve pipeline, which leads to low measurement accuracy of the maximum exhaust back pressure value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1 It is a flow chart of an implementation of an engine exhaust valve spring testing method provided by an embodiment of the present invention;

[0038] Figure 2 is a schematic diagram of a stress change image provided by an embodiment of the present invention;

[0039] Figure 3is a flow chart of an implementation of an engine exhaust valve spring testing method provided by another embodiment of the present invention;

[0040] Figure 4 It is a structural block diagram of an engine exhaust valve spring test system provided by an embodiment of the present invention;

[0041] Figure 5 It is a structural block diagram of a terminal device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0043] See also Figure 1 , Figure 1 A flowchart of an engine exhaust valve spring testing method provided by an embodiment of the present invention is shown, comprising:

[0044] Step S10, performing an exhaust brake working condition test on the engine to be tested, and collecting stress changes of the rocker arm of the engine to be tested and pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition, to obtain a stress change image and a pressure change image;

[0045] Among them, by performing exhaust brake working condition test on the engine to be tested, the stress change of the rocker arm and the pressure change of the exhaust brake butterfly valve pipeline under the exhaust brake working condition are effectively guaranteed. By collecting the stress change of the rocker arm and the pressure change of the exhaust brake butterfly valve pipeline of the engine to be tested under the exhaust brake working condition, the stress of the rocker arm and the pressure of the exhaust brake butterfly valve pipeline at different working points can be effectively obtained;

[0046] Specifically, in this step, a strain gauge is attached to the rocker arm assembly. Based on the strain gauge, the stress values ​​of the rocker arm at different working points during the exhaust brake working condition test can be effectively collected. According to the relationship between the collected stress value and time, the stress change image is obtained. Optionally, in this step, the stress change image can be displayed by an oscilloscope. The oscilloscope is electrically connected to the strain gauge. The oscilloscope is used to convert the electrical signal collected by the strain gauge into image information. Please refer to Figure 2 , is a schematic diagram of a stress change image provided in this embodiment, Figure 2 The horizontal axis is time, and the vertical axis is the stress value of the rocker arm;

[0047] Furthermore, a high-precision pressure sensor and a pressure reading device are installed on the side of the exhaust brake butterfly valve pipeline close to the engine. The high-precision pressure sensor is used to collect the pressure values ​​of the exhaust designated butterfly valve pipeline at different operating points during the exhaust brake operating test, and the pressure reading device is used to convert the electrical signal collected by the high-precision pressure sensor into a pressure value.

[0048] Optionally, in this step, before performing the exhaust brake working condition test on the engine to be tested, the step further includes:

[0049] Setting vehicle parameters of the engine to be tested according to preset vehicle conditions, and setting the opening of the intake throttle valve according to a preset valve opening;

[0050] Among them, the preset vehicle load condition and the preset valve opening can be set according to user needs. For example, the preset vehicle load condition can be set to half vehicle load condition or full vehicle load condition, etc., and the preset valve opening can be set to 15%, 18%, 19% or 25%, etc.

[0051] Step S20, performing a fall-off detection on the rocker arm according to the stress change image;

[0052] Among them, the fall-off detection is used to detect whether the rocker arm has fallen off. By performing the fall-off detection on the rocker arm, it is detected whether the rocker arm has fallen off when the intake throttle valve is at a preset opening under the exhaust brake condition, thereby improving the accuracy of the engine exhaust valve spring test;

[0053] Step S30, if the rocker arm shedding detection is qualified, then performing an intake adjustment detection on the stress change image;

[0054] Among them, the intake adjustment detection is used to detect whether to increase the opening of the intake throttle valve on the engine to be tested. By detecting whether the opening of the intake throttle valve can be increased, the upper limit of the maximum exhaust back pressure value of the exhaust valve spring is increased, thereby improving the accuracy of the measurement of the maximum exhaust back pressure value of the exhaust valve spring;

[0055] Step S40, if the intake adjustment test fails, determining the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image;

[0056] Among them, if the intake adjustment test fails, it is determined that the opening of the intake throttle valve cannot be increased, that is, the current opening of the intake throttle valve is the maximum opening. Therefore, according to the zero-crossing condition and pressure change image in the stress change image under the current opening of the intake throttle valve, the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested is determined, thereby improving the accuracy of determining the maximum exhaust back pressure value of the exhaust valve spring.

[0057] Optionally, in this step, after performing intake adjustment detection on the stress change image, the step further includes:

[0058] If the intake adjustment test is qualified, the opening of the intake throttle valve is increased, and according to the increased opening of the intake throttle valve, the step of respectively collecting the stress change of the rocker arm of the engine to be tested and the pressure change of the exhaust brake butterfly valve pipeline under the exhaust brake working condition to obtain the stress change image and the pressure change image and subsequent steps are returned to execute, until the rocker arm fall-off test is qualified and the intake adjustment test is unqualified;

[0059] If the intake adjustment test is qualified, it is determined that the opening of the intake throttle valve can be increased. According to the increased opening of the intake throttle valve, the stress change of the rocker arm and the pressure change of the exhaust brake butterfly valve pipeline are collected again under the exhaust brake working condition to obtain an updated stress change image and a pressure change image when the opening of the intake throttle valve is increased. The rocker arm is tested for shedding according to the updated stress change image. If the rocker arm shedding test is qualified, the intake adjustment test is performed on the updated stress change image until the intake adjustment test fails.

[0060] Further, in this step, determining the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image includes:

[0061] Performing zero-crossing detection on the stress change image to obtain the zero-crossing condition, and generating a back pressure detection period according to the working time of the zero-crossing condition and a preset duration;

[0062] Among them, by performing zero-crossing detection on the stress change image to detect whether there is a zero-crossing condition in the stress change image, the working time of the zero-crossing condition is obtained, and the back pressure detection period is generated according to the working time of the zero-crossing condition and the preset time length. Preferably, the preset time length can be set according to demand. For example, the preset time length can be set to 10ms, 1s or 3s, etc. For example, when the working time of the zero-crossing condition is A and the preset time length is set to 1s, the generated back pressure detection period is [A-1, A+1].

[0063] Determining the maximum pressure value in the back pressure detection period in the pressure change image as the maximum exhaust back pressure value;

[0064] in, Figure 2 The time period of the elliptical framed area is the back pressure detection period. In this step, all pressure values ​​within the back pressure detection period in the pressure change image are obtained, and the maximum pressure value obtained is determined as the maximum exhaust back pressure value.

[0065] In this embodiment, by respectively collecting the stress changes of the rocker arm of the engine to be tested and the pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition, the data changes of the stress of the rocker arm and the pressure of the exhaust brake butterfly valve pipeline under different working points can be effectively obtained. By performing a fall-off detection on the rocker arm through the stress change image, it can be effectively detected whether the rocker arm has fallen off under the current opening of the intake throttle valve. Based on the fall-off detection of the rocker arm, the accuracy of the engine exhaust valve spring test is effectively improved. By performing an intake adjustment detection on the stress change image to detect whether the opening of the intake throttle valve can be increased, the upper limit of the maximum exhaust back pressure value of the exhaust valve spring is increased by detecting whether the opening of the intake throttle valve can be increased. If the fall-off detection of the rocker arm is qualified and the intake adjustment detection is unqualified, the maximum exhaust back pressure value of the exhaust valve spring can be automatically determined through the zero-crossing working condition and the pressure change image in the stress change image, thereby improving the accuracy of the maximum exhaust back pressure value of the exhaust valve spring and preventing the phenomenon of low measurement accuracy of the maximum exhaust back pressure value caused by directly measuring the pressure of the exhaust brake butterfly valve pipeline.

[0066] See also Figure 3 , Figure 3 FIG. 1 is a flowchart of an engine exhaust valve spring testing method provided by another embodiment of the present invention. Figure 1 Embodiment, the engine exhaust valve spring test method provided in this embodiment is used to Figure 1 Step S20 in the embodiment is further refined to include:

[0067] Step S21, respectively obtaining stress differences between adjacent stress points in the stress change image;

[0068] Among them, the stress point is used to characterize the stress value of the rocker arm at different time points. By respectively obtaining the stress difference between adjacent stress points in the stress change image, the stress change intensity of the rocker arm between adjacent time points can be effectively obtained. When the stress difference is larger, the stress change intensity between adjacent time points corresponding to the stress difference is larger;

[0069] Step S22, determining the motion interval in the stress change image according to the stress difference;

[0070] Among them, the first maximum stress difference is determined as the first mutation operating point, the second maximum stress difference is determined as the second mutation operating point, and in the stress change image, the area formed between the first mutation operating point and the second mutation operating point is determined as the movement interval.

[0071] Step S23, if the stress of any of the stress points in the motion interval is equal to 0, it is determined that the rocker arm is unqualified in the drop-off detection;

[0072] If the stress value of any stress point in the motion range is equal to 0, it is determined that the rocker arm has fallen off, that is, the rocker arm falling off detection fails;

[0073] Step S24, if the stress values ​​of the stress points in the motion interval are all greater than 0, it is determined that the rocker arm has passed the shedding test;

[0074] Among them, if the stress values ​​of the stress points in the movement range are all greater than 0, it is determined that the rocker arm has not fallen off, that is, the rocker arm falling off detection is qualified.

[0075] Optionally, in this embodiment, with respect to step S30, the performing intake adjustment detection on the stress change image includes:

[0076] determining an idle speed interval in the stress variation image according to the stress difference value, and calculating an average stress value of stress points in the idle speed interval;

[0077] The duration values ​​of the first mutation operating point and the second mutation operating point are obtained respectively. If the duration value of the first mutation operating point is greater than the duration value of the second mutation operating point, the idle end point is determined as the time point corresponding to the duration value of the second mutation operating point, and the area formed between the starting time point and the idle end point in the stress change image is determined as the idle interval;

[0078] If the duration value of the first sudden change operating point is less than the duration value of the second sudden change operating point, the idle end point is determined as the time point corresponding to the duration value of the first sudden change operating point, and the area formed between the starting time point and the idle end point in the stress change image is determined as the idle interval;

[0079] In this step, the accuracy of the intake air regulation detection is effectively improved by calculating the average stress value of the stress points in the idle speed range.

[0080] If the average stress value is less than the preset stress value, it is determined that the intake adjustment test is qualified;

[0081] Among them, the preset stress value can be set according to user needs. If the average stress value is less than the preset stress value, the current opening of the intake throttle valve has a large margin, and the opening of the intake throttle valve can be increased, that is, the intake adjustment test is qualified;

[0082] If the average stress value is greater than or equal to the preset stress value, it is determined that the intake air regulation test is unqualified;

[0083] If the average stress value is greater than or equal to the preset stress value, the current opening of the intake throttle valve does not have a large margin, and the opening of the intake throttle valve cannot be increased, that is, the intake adjustment test fails;

[0084] Furthermore, in the present embodiment, after increasing the opening of the intake throttle valve, it also includes: if the rocker arm fall-off detection fails, and / or the number of times the opening of the intake throttle valve increases is greater than a threshold value, a test error prompt is sent, wherein the test error prompt is sent to remind the user that an error has occurred in the current engine exhaust valve spring test and manual review is required.

[0085] In this embodiment, by respectively acquiring the stress difference between adjacent stress points in the stress change image, the stress change intensity of the rocker arm between adjacent time points can be effectively obtained. Based on the stress change intensity of the rocker arm between adjacent time points, the movement interval in the stress change image can be effectively determined. Based on the stress value of the stress point in the determined movement interval, it can be effectively judged whether the rocker arm fall-off detection is qualified, thereby improving the accuracy of the rocker arm fall-off detection.

[0086] See also Figure 4 , Figure 4 1 is a structural block diagram of an engine exhaust valve spring test system 100 provided in an embodiment of the present invention. In this embodiment, the engine exhaust valve spring test system 100 includes various units for executing Figure 1 , Figure 3 For details, please refer to the steps in the corresponding embodiment. Figure 1 , Figure 3 as well as Figure 1 , Figure 3 For the convenience of explanation, only the parts related to this embodiment are shown. Figure 4 The engine exhaust valve spring test system 100 includes: a working condition test module 10, a fall-off detection module 11, an adjustment detection module 12 and an exhaust back pressure value determination module 13, wherein:

[0087] The working condition test module 10 is used to perform an exhaust brake working condition test on the engine to be tested, and respectively collect the stress changes of the rocker arm of the engine to be tested and the pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition to obtain a stress change image and a pressure change image.

[0088] Among them, by performing exhaust brake working condition test on the engine to be tested, the stress change of the rocker arm and the pressure change of the exhaust brake butterfly valve pipeline under the exhaust brake working condition are effectively guaranteed. By collecting the stress change of the rocker arm and the pressure change of the exhaust brake butterfly valve pipeline of the engine to be tested under the exhaust brake working condition, the stress of the rocker arm and the pressure of the exhaust brake butterfly valve pipeline at different working points can be effectively obtained;

[0089] Specifically, in this step, a strain gauge is attached to the rocker arm assembly. Based on the strain gauge, the stress values ​​of the rocker arm at different operating points during the exhaust brake operating test can be effectively collected, and the stress change image is obtained according to the relationship between the collected stress value and time. Optionally, in this step, the stress change image can be displayed by an oscilloscope, which is electrically connected to the strain gauge. The oscilloscope is used to convert the electrical signal collected by the strain gauge into image information.

[0090] Furthermore, a high-precision pressure sensor and a pressure reading device are installed on the side of the exhaust brake butterfly valve pipeline close to the engine. The high-precision pressure sensor is used to collect the pressure values ​​of the exhaust designated butterfly valve pipeline at different operating points during the exhaust brake operating test, and the pressure reading device is used to convert the electrical signal collected by the high-precision pressure sensor into a pressure value.

[0091] Optionally, the operating condition test module 10 is further used to: set vehicle parameters of the engine to be tested according to preset vehicle conditions, and set the opening of the intake throttle valve according to a preset valve opening.

[0092] The fall-off detection module 11 is used to perform a fall-off detection on the rocker arm according to the stress change image, wherein the fall-off detection is used to detect whether the rocker arm falls off.

[0093] Optionally, the fall-off detection module 11 is further used to: respectively obtain stress differences between adjacent stress points in the stress change image, wherein the stress points are used to represent stress values ​​of the rocker arm at different time points;

[0094] determining a motion interval in the stress change image according to the stress difference;

[0095] If the stress value of any of the stress points in the motion interval is equal to 0, it is determined that the rocker arm has failed the fall-off test;

[0096] If the stress values ​​of the stress points in the movement interval are all greater than 0, it is determined that the rocker arm has passed the fall-off detection.

[0097] The adjustment detection module 12 is used to perform an intake adjustment detection on the stress change image if the rocker arm drop detection is qualified. The intake adjustment detection is used to detect whether to increase the opening of the intake throttle valve on the engine to be tested.

[0098] Optionally, the adjustment detection module 12 is also used for: if the intake adjustment test is qualified, increasing the opening of the intake throttle valve, and according to the increased opening of the intake throttle valve, returning to execute the steps of respectively collecting the stress changes of the rocker arm of the engine to be tested and the pressure changes of the exhaust brake butterfly valve pipeline under the exhaust braking condition to obtain the stress change image and the pressure change image and subsequent steps, until the rocker arm fall-off test is qualified and the intake adjustment test is unqualified.

[0099] Further, the adjustment detection module 12 is also used to: determine the idle speed interval in the stress change image according to the stress difference value, and calculate the average stress value of the stress points in the idle speed interval;

[0100] If the average stress value is less than the preset stress value, it is determined that the intake adjustment test is qualified;

[0101] If the average stress value is greater than or equal to the preset stress value, it is determined that the intake air regulation test is unqualified.

[0102] Furthermore, the adjustment detection module 12 is also used to send a test error prompt if the rocker arm's fall-off detection fails, and / or the number of times the opening of the intake throttle valve increases is greater than a threshold number.

[0103] The exhaust back pressure value determination module 13 is used to determine the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image if the intake adjustment test fails.

[0104] Optionally, the exhaust back pressure value determination module 13 is further used to: perform zero-crossing detection on the stress change image to obtain the zero-crossing condition, and generate a back pressure detection period according to the working time of the zero-crossing condition and a preset duration;

[0105] The maximum pressure value in the back pressure detection period in the pressure change image is determined as the maximum exhaust back pressure value.

[0106] In this embodiment, by respectively collecting the stress changes of the rocker arm of the engine to be tested and the pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition, the data changes of the stress of the rocker arm and the pressure of the exhaust brake butterfly valve pipeline under different working points can be effectively obtained. By performing a fall-off detection on the rocker arm through the stress change image, it can be effectively detected whether the rocker arm has fallen off under the current opening of the intake throttle valve. Based on the fall-off detection of the rocker arm, the accuracy of the engine exhaust valve spring test is effectively improved. By performing an intake adjustment detection on the stress change image to detect whether the opening of the intake throttle valve can be increased, the upper limit of the maximum exhaust back pressure value of the exhaust valve spring is increased by detecting whether the opening of the intake throttle valve can be increased. If the fall-off detection of the rocker arm is qualified and the intake adjustment detection is unqualified, the maximum exhaust back pressure value of the exhaust valve spring can be automatically determined through the zero-crossing working condition and the pressure change image in the stress change image, thereby improving the accuracy of the maximum exhaust back pressure value of the exhaust valve spring and preventing the phenomenon of low measurement accuracy of the maximum exhaust back pressure value caused by directly measuring the pressure of the exhaust brake butterfly valve pipeline.

[0107] Figure 5 FIG. 2 is a block diagram of a terminal device 2 provided in another embodiment of the present invention. Figure 5 As shown, the terminal device 2 of this embodiment includes: a processor 20, a memory 21, and a computer program 22 stored in the memory 21 and executable on the processor 20, such as a program for the engine exhaust valve spring test method. When the processor 20 executes the computer program 22, the steps in each embodiment of the above-mentioned engine exhaust valve spring test method are implemented, such as Figure 1 S10 to S40 as shown, or Figure 3 Alternatively, the processor 20 implements the above when executing the computer program 22 Figure 3 The functions of each module in the corresponding embodiment are, for example, Figure 4 For details on the functions of modules 10 to 13, please refer to Figure 3 The relevant descriptions in the corresponding embodiments are not repeated here.

[0108] Exemplarily, the computer program 22 may be divided into one or more units, which are stored in the memory 21 and executed by the processor 20 to complete the present invention. The one or more units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program 22 in the terminal device 2. For example, the computer program 22 may be divided into a working condition test module 10, a fall-off detection module 11, an adjustment detection module 12, and an exhaust back pressure value determination module 13, and the specific functions of each module are as described above.

[0109] The terminal device may include, but is not limited to, a processor 20 and a memory 21. Those skilled in the art will appreciate that Figure 5 It is only an example of the terminal device 2 and does not constitute a limitation on the terminal device 2. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device may also include input and output devices, network access devices, buses, etc.

[0110] The processor 20 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0111] The memory 21 may be an internal storage unit of the terminal device 2, such as a hard disk or memory of the terminal device 2. The memory 21 may also be an external storage device of the terminal device 2, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal device 2. Further, the memory 21 may also include both an internal storage unit and an external storage device of the terminal device 2. The memory 21 is used to store the computer program and other programs and data required by the terminal device. The memory 21 may also be used to temporarily store data that has been output or is to be output.

[0112] The embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following can be achieved:

[0113] Performing an exhaust brake working condition test on the engine to be tested, and collecting stress changes of the rocker arm of the engine to be tested and pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition, to obtain a stress change image and a pressure change image;

[0114] Performing a fall-off detection on the rocker arm according to the stress change image, wherein the fall-off detection is used to detect whether the rocker arm falls off;

[0115] If the rocker arm drop-off test is qualified, an intake adjustment test is performed on the stress change image, wherein the intake adjustment test is used to detect whether to increase the opening of the intake throttle valve on the engine to be tested;

[0116] If the intake regulation test fails, the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested is determined according to the zero-crossing condition in the stress change image and the pressure change image.

[0117] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for testing an engine exhaust valve spring, characterized in that: include: Performing an exhaust brake working condition test on the engine to be tested, and collecting stress changes of the rocker arm of the engine to be tested and pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake working condition, to obtain a stress change image and a pressure change image; Performing a fall-off detection on the rocker arm according to the stress change image, wherein the fall-off detection is used to detect whether the rocker arm falls off; If the rocker arm drop-off test is qualified, an intake adjustment test is performed on the stress change image, wherein the intake adjustment test is used to detect whether to increase the opening of the intake throttle valve on the engine to be tested; If the intake regulation test fails, the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested is determined according to the zero-crossing condition in the stress change image and the pressure change image.

2. The engine exhaust valve spring testing method according to claim 1, characterized in that: After performing intake adjustment detection on the stress change image, the method further includes: If the intake adjustment test is qualified, the opening of the intake throttle valve is increased, and according to the increased opening of the intake throttle valve, the process returns to execute the steps of respectively collecting the stress changes of the rocker arm of the engine to be tested and the pressure changes of the exhaust brake butterfly valve pipeline under the exhaust brake condition to obtain the stress change image and the pressure change image and the subsequent steps, until the rocker arm fall-off test is qualified and the intake adjustment test is unqualified.

3. The engine exhaust valve spring testing method according to claim 1, characterized in that: The performing the falling-off detection on the rocker arm according to the stress change image comprises: Respectively obtaining stress differences between adjacent stress points in the stress change image, wherein the stress points are used to represent stress values ​​of the rocker arm at different time points; determining a motion interval in the stress change image according to the stress difference; If the stress value of any of the stress points in the motion interval is equal to 0, it is determined that the rocker arm has failed the drop-off test; If the stress values ​​of the stress points in the movement interval are all greater than 0, it is determined that the rocker arm has passed the fall-off detection.

4. The engine exhaust valve spring testing method according to claim 3, characterized in that: The performing air intake adjustment detection on the stress change image includes: determining an idle speed interval in the stress variation image according to the stress difference value, and calculating an average stress value of stress points in the idle speed interval; If the average stress value is less than the preset stress value, it is determined that the intake adjustment test is qualified; If the average stress value is greater than or equal to the preset stress value, it is determined that the intake air regulation test is unqualified.

5. The engine exhaust valve spring testing method according to claim 1, characterized in that: The step of determining the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image comprises: Performing zero-crossing detection on the stress change image to obtain the zero-crossing working condition, and generating a back pressure detection period according to the working time of the zero-crossing working condition and a preset duration; The maximum pressure value in the back pressure detection period in the pressure change image is determined as the maximum exhaust back pressure value.

6. The engine exhaust valve spring testing method according to claim 2, characterized in that: After increasing the opening of the intake throttle valve, the method further includes: If the rocker arm fall-off detection fails, and / or the number of times the opening of the intake throttle valve increases is greater than a threshold number, a test error prompt is sent.

7. The engine exhaust valve spring testing method according to any one of claims 1 to 6, characterized in that: Before the exhaust brake working condition test is performed on the engine to be tested, the method further includes: The vehicle parameters of the engine to be tested are set according to preset vehicle conditions, and the opening of the intake throttle valve is set according to a preset valve opening.

8. An engine exhaust valve spring test system, characterized in that: include: The working condition test module is used to perform an exhaust brake working condition test on the engine to be tested, and respectively collect the stress change of the rocker arm of the engine to be tested and the pressure change of the exhaust brake butterfly valve pipeline under the exhaust brake working condition to obtain a stress change image and a pressure change image; A fall-off detection module, used for performing a fall-off detection on the rocker arm according to the stress change image, wherein the fall-off detection is used for detecting whether the rocker arm falls off; an adjustment detection module, for performing an intake adjustment detection on the stress change image if the rocker arm drop detection is qualified, wherein the intake adjustment detection is used to detect whether to increase the opening of the intake throttle valve on the engine to be tested; The exhaust back pressure value determination module is used to determine the maximum exhaust back pressure value of the exhaust valve spring on the engine to be tested according to the zero-crossing condition in the stress change image and the pressure change image if the intake adjustment test fails.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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