A method and system for testing the strength of an engine piston
By conducting a super knock test on the cylinder with the highest combustion pressure during engine piston strength testing, the problem of difficulty in confirming piston strength was solved, ensuring the piston's qualification during the development stage and avoiding damage and recalls.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DONGFENG MOTOR GRP
- Filing Date
- 2023-03-21
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies cannot effectively determine whether the strength of engine pistons is up to standard, which makes them prone to damage during customer use. Existing engine bench testing methods cannot confirm whether the piston safety factor is appropriate.
By determining the combustion pressure corresponding to different ignition advance angle offsets, the cylinder with the highest combustion pressure in the engine is identified, and a super knock test is conducted to determine whether the engine piston strength is up to standard.
This allows for the early detection of piston strength defects during the development phase, avoiding the risks of damage and recalls, and ensuring the compliance of engine piston strength.
Smart Images
Figure CN116296415B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of engine piston testing technology, and in particular to a method and system for testing engine piston strength. Background Technology
[0002] With the development of engine technology, engines are becoming increasingly stronger, and engine pistons are evolving towards higher strength and lighter weight. This has led to the development of some testing methods for the mechanical strength and thermal fatigue of piston units. However, piston damage during customer use is still unavoidable.
[0003] After an engine has been used for a period of time, carbon deposits in the combustion chamber are more likely to cause knocking (or super knocking). If the piston's safety margin is too low, the engine piston is more prone to damage. Pistons are designed with a certain safety margin, generally between 1.05 and 1.50. A lower safety margin can reduce piston weight and size, which helps to reduce engine weight. However, the appropriate safety margin cannot be determined by current engine bench testing methods, which can easily lead to pistons with low safety margins being damaged during customer use.
[0004] Therefore, determining whether the piston's strength is up to standard is a pressing technical problem that needs to be solved. Summary of the Invention
[0005] The main objective of this invention is to provide a method and system for testing the strength of engine pistons, which can detect the strength of engine pistons, ensure the qualification of engine piston strength, and also detect piston strength defects early in the development stage, effectively avoiding the risk of recall due to damage.
[0006] In a first aspect, this application provides a method for testing the strength of an engine piston, the method comprising the following steps:
[0007] Determine the combustion pressure corresponding to different ignition advance angle offsets;
[0008] By using the combustion pressure corresponding to the different ignition advance angle offsets, the cylinder with the highest combustion pressure in each cylinder of the engine under the same ignition advance angle is determined.
[0009] A super knock test is conducted on the cylinder with the highest combustion pressure in the engine to determine whether the engine piston strength is up to standard.
[0010] In conjunction with the first aspect mentioned above, as an optional implementation method, after the engine is run to the set operating condition, the ignition advance angle offset is gradually increased on the base ignition angle.
[0011] Based on the gradual increase of the ignition advance angle offset, the combustion pressure of the engine corresponding to each level of ignition advance angle offset is determined.
[0012] In conjunction with the first aspect mentioned above, as an optional implementation method, the range of combustion pressure in the engine cylinder is controlled by adjusting the ignition advance angle offset.
[0013] In conjunction with the first aspect mentioned above, as an optional implementation method, the engine operating conditions when super knock occurs are set, wherein the operating conditions include: engine speed, load, ignition advance angle offset, time, and temperature;
[0014] A super knock test was conducted on the cylinder with the highest combustion pressure under engine operating conditions, and the test data were recorded.
[0015] The test data are statistically analyzed. If the engine is found to be undamaged after exceeding the set number of tests, the engine piston strength is determined to be qualified.
[0016] In conjunction with the first aspect mentioned above, as an optional implementation method, a cyclic super knock test is performed on the cylinder with the highest combustion pressure according to a preset interval.
[0017] In conjunction with the first aspect mentioned above, as an optional implementation method, when continuous super knocking occurs during the test, the number of super knocking events generated by the engine can be controlled by adjusting the enriched air-fuel ratio, torque reduction, and VVT angle.
[0018] Secondly, this application provides an engine piston strength testing system, the system comprising:
[0019] Combustion analyzer, which is used to determine the combustion pressure corresponding to different ignition advance angle offsets;
[0020] An automatic calibration unit is used to determine the cylinder with the highest combustion pressure in each cylinder of the engine under the same ignition advance angle, based on the combustion pressure corresponding to the different ignition advance angle offsets.
[0021] The data processing unit is used to perform a super knock test on the cylinder with the highest combustion pressure in the engine to determine whether the engine piston strength is up to standard.
[0022] In conjunction with the second aspect mentioned above, as an optional implementation method, it also includes: an ECU, which is used to control the number of super knocks generated by the engine by adjusting the enriched air-fuel ratio, torque reduction and VVT angle when continuous super knock occurs during the test.
[0023] In conjunction with the second aspect above, as an optional implementation, the automatic calibration unit is also used to gradually increase the ignition advance angle offset on the base ignition angle after the engine is run to the set operating condition.
[0024] Based on the gradual increase of the ignition advance angle offset, the combustion pressure of the engine corresponding to each level of ignition advance angle offset is determined.
[0025] In conjunction with the second aspect above, as an optional implementation, the data processing unit is also used to set the engine operating conditions when super knock occurs, wherein the operating conditions include: engine speed, load, ignition advance angle offset, time, and temperature;
[0026] A super knock test was conducted on the cylinder with the highest combustion pressure under engine operating conditions, and the test data were recorded.
[0027] The test data are statistically analyzed. If the engine is found to be undamaged after exceeding the set number of tests, the engine piston strength is determined to be qualified.
[0028] This application provides a method and system for testing engine piston strength. The method includes the following steps: determining the combustion pressure corresponding to different ignition advance angle offsets; determining the cylinder with the highest combustion pressure among all cylinders of the engine at the same ignition advance angle based on the combustion pressure corresponding to the different ignition advance angle offsets; and conducting a super knock test on the cylinder with the highest combustion pressure to determine whether the engine piston strength is qualified. This application can detect engine piston strength, ensuring the qualification of engine piston strength, and can also detect piston strength defects early in the development stage, effectively avoiding the risk of recall due to damage.
[0029] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the invention. Attached Figure Description
[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.
[0031] Figure 1 This is a flowchart of an engine piston strength test method provided in the embodiments of this application;
[0032] Figure 2 This is a schematic diagram of an engine piston strength testing system provided in an embodiment of this application;
[0033] Figure 3 This is a schematic diagram of an ECU controller provided in an embodiment of this application;
[0034] Figure 4 This is a schematic diagram of a computer-readable program medium provided in an embodiment of this application. Detailed Implementation
[0035] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.
[0036] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. Some of the block diagrams shown in the drawings represent functional entities and do not necessarily correspond to physically or logically independent entities.
[0037] This application provides an engine piston strength testing method and system, which can detect the engine piston strength, ensure the engine piston strength is qualified, and also detect piston strength defects early in the development stage, effectively avoiding the risk of damage and recall.
[0038] To achieve the aforementioned technical effects, the general concept of this application is as follows:
[0039] A method for testing the strength of an engine piston, the method comprising the following steps:
[0040] S101: Determine the combustion pressure corresponding to different ignition advance angle offsets.
[0041] S102: Based on the combustion pressure corresponding to the different ignition advance angle offsets, determine the cylinder with the highest combustion pressure among all cylinders of the engine under the same ignition advance angle.
[0042] S103: A super knock test is conducted on the cylinder with the highest combustion pressure in the engine to determine whether the engine piston strength is up to standard.
[0043] The embodiments of this application will be further described in detail below with reference to the accompanying drawings.
[0044] Reference Figure 1 , Figure 1 The diagram shown is a flowchart of an engine piston strength testing method provided by the present invention. Figure 1 As shown, the method includes the following steps:
[0045] Step S101: Determine the combustion pressure corresponding to different ignition advance angle offsets.
[0046] Specifically, the engine operating conditions for generating knock are set by the automatic calibration unit. It should be noted that the engine operating conditions are: speed 2000±50r / min, load 5% of full load, and intake air temperature (or temperature after intercooling) ±3℃.
[0047] Understandably, the higher the engine speed, the shorter the time of each working cycle, and the more times super knock occurs when the ignition timing is advanced by the same amount of time. Continuous super knock in one cylinder can easily damage the engine. At 2000 rpm, the torque has already reached its maximum, and the engine's operating pressure is close to its maximum value, making it easy to generate super knock.
[0048] It should be noted that advance ignition means that the spark plug ignites the combustible mixture in the combustion chamber before the piston reaches top dead center of the compression stroke. The angle through which the crankshaft rotates from the moment of ignition to the moment the piston reaches top dead center of the compression stroke is called the ignition advance angle.
[0049] "Super knock," also known as low-speed pre-ignition, is an abnormal combustion phenomenon unique to turbocharged and direct-injection engines.
[0050] Understandably, following standard combustion pressure measurement methods, cylinder pressure sensors are installed in each cylinder and connected to a combustion analyzer. The engine is run at its operating load: 2000 rpm, 100% load. An ignition advance angle offset (An) is added to the base ignition angle using an automatic calibration unit, maintained for 0.3 seconds. It should be noted that the ignition angle offset is experimentally determined; the ignition angle is increased incrementally, and the knock pressure data at different offset angles is recorded. The maintenance time only needs to reliably generate one super knock. The combustion pressure is then observed to see if it reaches the knock pressure requirement. Normal combustion pressure is around 80 bar; a knock pressure exceeding 110 bar is considered super knock.
[0051] Understandably, assuming there are 12345 cylinders, by gradually increasing the ignition offset, it is determined which of these cylinders has the combustion pressure to reach the explosion pressure requirement.
[0052] In one embodiment, the engine is operated to its operating speed and load: 2000 r / min at 100% load. The ignition advance angle offset is then gradually increased from the base ignition angle. Based on this gradual increase in ignition advance angle offset, the combustion pressure corresponding to each level of ignition advance angle offset is determined. For ease of understanding, an example is provided: assuming an offset of 3 degrees corresponds to a combustion pressure of 110 bar, and 4 degrees corresponds to a combustion pressure of 120 bar.
[0053] In one embodiment, the range of in-cylinder combustion pressure is controlled by adjusting the ignition advance angle offset. It can be understood that the combustion pressure of super-knock is controlled by the amount of ignition advance angle offset; for example, a knock pressure of 130-150 bar corresponds to a 7-degree advance angle, while an 8-degree advance angle results in a knock pressure between 140-170 bar. The combustion pressure is controlled at 130-150 bar. It should be noted that the purpose of controlling the combustion pressure within a certain range is: too low a pressure will not achieve the desired testing effect, while too high a pressure can easily damage the engine. (The knock pressure in subsequent tests was controlled within this range.) Knock pressure: The pressure during super-knock combustion.
[0054] Step S102: Based on the combustion pressure corresponding to the different ignition advance angle offsets, determine the cylinder with the highest combustion pressure in each cylinder of the engine under the same ignition advance angle.
[0055] Specifically, the combustion pressure corresponding to the offset has been determined above. This means that each cylinder has data on the correspondence between the ignition advance angle offset An and the cylinder pressure. It was determined that, under the same ignition advance angle offset An, the cylinder with the highest cylinder pressure would be tested (each cylinder is equipped with a pressure sensor; the pressures of each cylinder are different, so the test is conducted on the cylinder with the highest pressure). The cylinder with the highest cylinder pressure is more prone to knocking. It should be noted that super-knock combustion has a certain degree of randomness; the same ignition advance angle offset An value will result in different combustion pressures, likely falling within a certain range. This difference in combustion pressure is understandable because combustion is highly complex, and the microscopic conditions of each combustion cycle are different. The likelihood of falling within a certain range is understandable; it reflects the required testing intensity (knock pressure) range. If a higher testing intensity is desired (due to a lack of confidence in the design safety factor), the ignition advance angle offset An can be controlled to be slightly larger.
[0056] Different burst pressures require different ignition advance offsets. The magnitude of the burst pressure indicates different levels of test reinforcement and can be applied to different piston safety factors. It's understandable that for a given engine, a burst pressure of 130° is highly probable when the ignition advance angle offset An is 5°, and a burst pressure of 135° is highly probable when the ignition advance angle offset An is 6°.
[0057] During the test, the larger the ignition advance angle offset An is, the greater the explosion pressure. If the piston is not damaged, the design needs to be strengthened, and the safety factor will be higher.
[0058] Optionally, by establishing the corresponding combustion pressure based on different ignition advance angle offsets, a relationship between the ignition advance angle offset and the engine combustion pressure can be established. By establishing this relationship, the cylinder with the highest combustion pressure in each cylinder of the engine under the same ignition advance angle can be determined.
[0059] Step S103: Conduct a super knock test on the cylinder with the highest engine combustion pressure to determine whether the piston strength of the engine is qualified.
[0060] Specifically, during the test, it is determined that cylinders with lower cylinder pressures do not install knock sensors and ordinary spark plugs are used. Only the first cylinder needs to be tested. The cylinder with the highest cylinder pressure installs a cylinder pressure sensor to measure and record the combustion pressure until 5000 super knock combustions are accumulated for a single cylinder or the engine is damaged.
[0061] Set the engine operating conditions when super knock occurs. The operating conditions include: engine speed, load, ignition advance angle offset, time, and temperature. Conduct a super knock test on the cylinder with the highest combustion pressure according to the engine operating conditions and record the test data. Statistically analyze the test data. When the set test次数 is exceeded and the engine is detected to be undamaged, it is determined that the piston strength of the engine is qualified. For easy understanding, an example is given. The engine speed is 2000 ± 50 r / min, the load is full load ± 5%, the intake air temperature (or temperature after the intercooler) is the specified temperature in the design task book ± 3°C. The engine runs 10 revolutions in 0.3 s, and each cylinder fires and does work 5 times. After the ignition angle is advanced and causes a super knock in one of the 5 work cycles, the ECU takes protective measures (enrich the air-fuel ratio, reduce torque, adjust the VVT angle). The engine can produce at most one super knock combustion within 0.3 s. Continuous super knocks result in greater combustion pressure in the cylinder and are likely to damage the engine. Super knocks are extremely unlikely to occur in actual driving. In this test condition, super knocks are artificially created continuously.
[0062] In one embodiment, a cyclic super knock test is conducted on the cylinder with the highest combustion pressure at a preset interval. It can be understood that a knock test is conducted every two minutes (a knock can occur within two minutes). When continuous knocks occur during the test, the number of super knocks generated by the engine is controlled by adjusting the enriching air-fuel ratio, reducing torque, and VVT angle of the engine. Table 1 shows the cyclic operating conditions of the super knock combustion pressure test.
[0063] Table 1
[0064]
[0065] In one embodiment, each high-pressure explosion test cycle generates a corresponding combustion pressure value. The data monitoring and storage platform monitors, records, and stores this value in real time. After the test, the data file is opened and checked one by one, and statistics are performed. The statistical results are shown in Table 2 (Combustion Pressure Statistics Table). The range of explosion pressure is statistically analyzed. A larger range indicates a higher degree of test intensity and a safer piston. Generally, 5000 tests are conducted (empirical data). If the engine is still intact after 5000 tests, the test is passed. It should be noted that 120-140 explosion pressure is already very high, and the selection of the offset angle is mainly for this range. If the statistical data is likely to occur above 170, the piston design safety margin must be very large, which would be wasteful and increase costs. It should also be noted that to determine the cylinder pressure of the statistical result, the corresponding ignition advance angle offset An should be used. When the test intensity is light, the statistical result will likely be distributed around 110, so the ignition advance angle offset An corresponding to 110 should be used. When the test intensity is heavy, the statistical result will likely be distributed around 140, so the ignition advance angle offset An corresponding to 140 should be used.
[0066] Table 2
[0067]
[0068]
[0069] In one embodiment, super knock is generated by actively advancing the ignition angle of a certain cylinder of the engine to increase the combustion pressure of that cylinder. The combustion pressure inside the engine cylinder can be controlled within a certain range, and its magnitude can be adjusted by controlling the ignition advance angle. The super knock pressure is recorded by a combustion analyzer and stored together with the engine operating parameters for combustion pressure distribution statistics. After a certain number of super knock combustions, whether the engine is intact can determine whether the piston safety factor is qualified.
[0070] Understandably, once the test engine, control system, and measurement and recording system are in communication and preparations are complete, the relationship between the offset angle An and the burst pressure of the test engine is determined; the cylinder with the largest cylinder is identified, the test begins, the used offset angle An is determined, the test data is recorded, and the data recorded after the test ends (or is terminated) is statistically analyzed to determine the cylinder pressure distribution and whether the test passes or fails. If the engine remains intact after 5000 cycles, the test passes, indicating that the piston safety margin is appropriate; if the engine piston is damaged during the test, the test fails, indicating that the piston safety margin is insufficient, and the piston safety margin needs to be increased.
[0071] Reference Figure 2 , Figure 2 The diagram shown is a schematic of an engine piston strength testing system provided by the present invention. Figure 2 As shown, the system includes:
[0072] The system comprises a combustion analyzer 201, an automatic calibration unit 202, a data processing unit 203, an ECU 204, and an engine 205. The combustion analyzer 201 monitors and records the combustion pressure during knocking. The automatic calibration unit 202 determines the engine's operating conditions and advances the ignition angle of a specific cylinder as needed to induce knocking combustion. The data processing unit 203 records and stores engine operating parameters and in-cylinder combustion pressure. Essentially, the automatic calibration unit 202 controls the ECU 204 to change the ignition angle to induce knocking, while the combustion analyzer 201 and data processing unit 203 record the data. It should also be noted that the data processing unit is connected to both the combustion analyzer and the ECU, the ECU is connected to the automatic calibration unit, and the engine is connected to both the combustion analyzer and the ECU.
[0073] Combustion analyzer 201: It is used to determine the combustion pressure corresponding to different ignition advance angle offsets.
[0074] Automatic calibration unit 202: It is used to determine the cylinder with the highest combustion pressure in each cylinder of the engine under the same ignition advance angle by using the combustion pressure corresponding to the different ignition advance angle offsets.
[0075] Data processing unit 203: It is used to perform a super knock test on the cylinder with the highest combustion pressure in the engine to determine whether the engine piston strength is up to standard.
[0076] Furthermore, in one possible implementation, the automatic calibration unit is also used to gradually increase the ignition advance angle offset on the base ignition angle after the engine is run to the set operating condition.
[0077] Based on the gradual increase of the ignition advance angle offset, the combustion pressure of the engine corresponding to each level of ignition advance angle offset is determined.
[0078] Furthermore, in one possible implementation, it also includes: an ECU, used to control the range of in-cylinder combustion pressure of the engine based on adjusting the ignition advance angle offset.
[0079] Furthermore, in one possible implementation, the data processing unit is also used to set the engine operating conditions when super knock occurs, wherein the operating conditions include: engine speed, load, ignition advance angle offset, time, and temperature.
[0080] A super knock test was conducted on the cylinder with the highest combustion pressure under engine operating conditions, and the test data were recorded.
[0081] The test data are statistically analyzed. If the engine is found to be undamaged after exceeding the set number of tests, the engine piston strength is determined to be qualified.
[0082] Furthermore, in one possible implementation, the data processing unit is also used to perform a cyclic super knock test on the cylinder with the highest combustion pressure according to a preset interval.
[0083] Furthermore, in one possible implementation, the ECU is used to control the number of super-knocks generated by the engine by adjusting the enriched air-fuel ratio, torque reduction, and VVT angle when continuous super-knock occurs during the test.
[0084] For EUC controllers, refer to the following: Figure 3 To describe an electronic device 300 according to this embodiment of the present invention. Figure 3 The electronic device 300 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.
[0085] like Figure 3 As shown, the electronic device 300 is manifested in the form of a general-purpose computing device. The components of the electronic device 300 may include, but are not limited to: at least one processing unit 310, at least one storage unit 320, and a bus 330 connecting different system components (including storage unit 320 and processing unit 310).
[0086] The storage unit stores program code that can be executed by the processing unit 310, causing the processing unit 310 to perform the steps described in the "Embodiment Methods" section of this specification according to various exemplary embodiments of the present invention.
[0087] Storage unit 320 may include readable media in the form of volatile storage units, such as random access memory (RAM) 321 and / or cache memory 322, and may further include read-only memory (ROM) 323.
[0088] Storage unit 320 may also include a program / utility 324 having a set (at least one) of program modules 325, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.
[0089] Bus 330 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.
[0090] Electronic device 300 can also communicate with one or more external devices (e.g., keyboard, pointing device, Bluetooth device, etc.), one or more devices that enable a user to interact with electronic device 300, and / or any device that enables electronic device 300 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 350. Furthermore, electronic device 300 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 360. As shown, network adapter 360 communicates with other modules of electronic device 300 via bus 330. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 300, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.
[0091] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.
[0092] The present invention also provides a computer-readable storage medium having stored thereon a program product capable of implementing the methods described above in this specification. In some possible embodiments, various aspects of the present invention may also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the present invention described in the "Exemplary Methods" section above.
[0093] refer to Figure 4 As shown, a program product 400 for implementing the above-described method according to an embodiment of the present invention is described. This product may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.
[0094] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.
[0095] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.
[0096] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.
[0097] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java and C++, and conventional procedural programming languages such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).
[0098] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.
[0099] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.
[0100] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
Claims
1. A method for testing the strength of an engine piston, characterized in that, include: Determine the combustion pressure corresponding to different ignition advance angle offsets; By using the combustion pressure corresponding to the different ignition advance angle offsets, the cylinder with the highest combustion pressure in each cylinder of the engine under the same ignition advance angle is determined. A super knock test is conducted on the cylinder with the highest combustion pressure in the engine to determine whether the engine piston strength is up to standard. The engine operating conditions for generating super knock are set, including: engine speed, load, ignition advance angle offset, time and temperature. A super knock test was conducted on the cylinder with the highest combustion pressure under engine operating conditions, and the test data were recorded. The test data are statistically analyzed. If the engine is found to be undamaged after exceeding the set number of tests, the engine piston strength is determined to be qualified.
2. The method according to claim 1, characterized in that, The determination of the combustion pressure corresponding to different ignition advance angle offsets includes: After the engine is run to the set operating condition, the ignition advance angle offset is gradually increased on the base ignition angle. Based on the gradual increase of the ignition advance angle offset, the combustion pressure of the engine corresponding to each level of ignition advance angle offset is determined.
3. The method according to claim 2, characterized in that, Also includes: The range of combustion pressure in the engine cylinder is controlled by adjusting the ignition advance angle offset.
4. The method according to claim 1, characterized in that, Also includes: A cyclic super knock test is conducted on the cylinder with the highest combustion pressure at preset intervals.
5. The method according to claim 1, characterized in that, Also includes: When continuous super knocking occurs during the test, the number of super knocking events is controlled by adjusting the engine's enriched air-fuel ratio, torque reduction, and VVT angle.
6. An engine piston strength testing system, characterized in that, include: Combustion analyzer, which is used to determine the combustion pressure corresponding to different ignition advance angle offsets; An automatic calibration unit is used to determine the cylinder with the highest combustion pressure in each cylinder of the engine under the same ignition advance angle, based on the combustion pressure corresponding to the different ignition advance angle offsets. The data processing unit is used to perform a super knock test on the cylinder with the highest combustion pressure in the engine to determine whether the engine piston strength is up to standard. The data processing unit is also used to set the engine operating conditions when super knock occurs, wherein the operating conditions include: engine speed, load, ignition advance angle offset, time and temperature; A super knock test was conducted on the cylinder with the highest combustion pressure under engine operating conditions, and the test data were recorded. The test data are statistically analyzed. If the engine is found to be undamaged after exceeding the set number of tests, the engine piston strength is determined to be qualified.
7. The system according to claim 6, characterized in that, Also includes: The ECU is used to control the number of super knocks generated by the engine by adjusting the enriched air-fuel ratio, torque reduction, and VVT angle when continuous super knocks occur during the test.
8. The system according to claim 7, characterized in that: The automatic calibration unit is also used to gradually increase the ignition advance angle offset on the base ignition angle after the engine is run to the set operating condition. Based on the gradual increase of the ignition advance angle offset, the combustion pressure of the engine corresponding to each level of ignition advance angle offset is determined.