Sampling equipment and sampling method in engine cylinder

Abstract

The invention relates to the technical field of internal combustion engine testing and measuring, and discloses sampling equipment and a sampling method in an engine cylinder. The equipment comprises a sampling probe system which comprises a sampling pipe connected with an engine cylinder pressure measuring channel and a sampler connected with the sampling pipe; the sampling control system is configured to receive a crank angle signal and a camshaft phase signal of the engine and judge the working phase and the top dead center position of an engine cylinder so as to generate a control signal at a preset crank angle; the cooling system comprises a cooling liquid supply device, and the cooling liquid supply device is connected with a cooling flow channel arranged in the sampler to form a circulation loop and is used for cooling the high-temperature gas flowing through the sampler; and the sampling storage system is connected with the gas outlet of the sampler and is used for collecting and storing the cooled gas sample. Based on the equipment, an original cylinder pressure measuring channel is utilized, an engine does not need to be transformed, sampling is accurately controlled through crankshaft and camshaft signals, and a high-quality sample is obtained.

Description

Technical Field

[0001] This application relates to the field of internal combustion engine testing and measurement technology, and in particular to an in-cylinder sampling device and sampling method for an engine. Background Technology

[0002] This section is intended to provide background or context for the embodiments of the invention set forth in the claims. It should not be construed as an admission that the description herein is prior art.

[0003] Key gas parameters such as in-cylinder residual exhaust gas rate and scavenging efficiency are crucial for combustion optimization; however, their accurate measurement has always faced technical bottlenecks. Traditional sampling methods require irreversible modifications to the engine structure, which is costly and interferes with normal in-cylinder operating conditions, failing to reflect the true operating state. Furthermore, the high-temperature and high-pressure environment inside the cylinder can easily damage sampling valves and gas storage units, while conventional technologies struggle to achieve precise timing sampling synchronized with the engine's operating phase at the microsecond level, making it impossible to obtain effective gas samples at specific crankshaft angles.

[0004] In summary, existing technologies have drawbacks such as requiring damage to the engine structure during sampling, interfering with real operating conditions, being unable to withstand high-temperature environments, and being unable to achieve precise phase synchronization with the engine. Summary of the Invention

[0005] The present invention provides an engine in-cylinder sampling device and sampling method, which at least solves the problems in related technologies that require damage to the engine structure during sampling, interfere with real operating conditions, are difficult to withstand high temperature environments, and cannot achieve precise phase synchronization with the engine.

[0006] According to a first aspect of the present invention, an in-cylinder sampling device for an engine is provided, comprising: A sampling probe system includes a sampling tube for connection to an engine cylinder pressure measurement channel and a sampler connected to the sampling tube; A sampling control system includes an electronic control unit (ECU) configured to receive crankshaft angle signals and camshaft phase signals of the engine, and determine the working phase and top dead center position of the engine cylinder based on the crankshaft angle signals and camshaft phase signals, so as to generate a control signal at a preset crankshaft angle. A cooling system, including a coolant supply device, wherein the coolant supply device is connected to a cooling channel disposed in the sampler to form a circulation loop for cooling the high-temperature gas flowing through the sampler; A sampling and storage system, connected to the gas outlet of the sampler, is used to collect and store cooled gas samples; The sampler is an integrated structure, which integrates a high-speed solenoid valve and the cooling channel. The high-speed solenoid valve is electrically connected to the electronic control unit and is used to open or close at a preset crankshaft angle according to the control signal to perform sampling of the gas in the engine cylinder.

[0007] According to an embodiment of the present invention, the sampling tube is connected to the engine cylinder pressure measurement channel via a replaceable adapter.

[0008] According to an embodiment of the present invention, the sampling storage system includes a sampling bag, which is connected to the gas outlet of the sampler via a quick-plug interface.

[0009] According to an embodiment of the present invention, the sampling bag has a single-valve structure or a double-valve structure.

[0010] According to an embodiment of the present invention, the coolant supply device includes a cooling pump for driving coolant to circulate between the cooling channel of the sampler and an external coolant source.

[0011] According to an embodiment of the present invention, the sampling control system further includes a CAN bus analyzer, and the electronic control unit communicates with the engine ECU or the CAN bus analyzer via the CAN bus to obtain the crankshaft angle signal and the camshaft phase signal.

[0012] According to a second aspect of the present invention, an in-cylinder sampling method for an engine is provided, applied to an electronic control unit of a sampling control system, comprising: Acquire the crankshaft angle signal and camshaft phase signal of the engine; Based on the crankshaft angle signal and the camshaft phase signal, cylinder identification processing is performed to identify the compression top dead center position and working phase of each cylinder. Using the identified top dead center of compression as the target reference position, at least one target sampling window is determined, the target sampling window corresponding to the compression stage after valve closure and / or the stage from the end of combustion to the opening of the exhaust valve; When the crankshaft angle corresponding to the target sampling window is reached, a control signal is sent to the sampler, which integrates a high-speed solenoid valve and a cooling channel, to perform in-cylinder gas sampling. The sampled gas sample is cooled by the coolant in the cooling channel as it flows through the sampler. The system controls the delivery of cooled gas samples to a sampling and storage system for storage.

[0013] According to an embodiment of the present invention, the cylinder determination process based on the crankshaft angle signal and the camshaft phase signal includes: The specific tooth identified after the crankshaft tooth loss signal is used as the initial reference position of the top dead center; Read the edge state or level state of the camshaft phase signal near the reference position; According to a preset correspondence, the edge state or level state is matched with the initial reference position to determine whether the initial reference position is the compression top dead center or the exhaust top dead center.

[0014] According to an embodiment of the present invention, the sampling control system further includes a CAN bus analyzer, and the electronic control unit obtains the crankshaft angle signal and camshaft phase signal from the engine ECU or the CAN bus analyzer via the CAN bus.

[0015] According to an embodiment of the present invention, the target sampling window includes a first target sampling window corresponding to the compression phase after the valve is closed, and a second target sampling window corresponding to the phase from the end of combustion to the opening of the exhaust valve; When the crankshaft angle corresponding to the target sampling window is reached, a control signal is sent to the sampler, which integrates a high-speed solenoid valve and a cooling channel, to perform in-cylinder gas sampling, including: Upon reaching the first target sampling window, a first control signal is sent to the sampler to collect a first gas sample; and upon reaching the second target sampling window, a second control signal is sent to the sampler to collect a second gas sample.

[0016] Beneficial effects of the embodiments of the present invention: The engine in-cylinder sampling device provided in this invention, through the coordinated operation of a sampling probe system, a sampling control system, a cooling system, and a sampling storage system, enables precise, multi-cycle, timed, and fixed-point sampling of high-temperature, high-pressure gases within the cylinder under normal engine operating conditions, utilizing the engine's existing cylinder pressure measurement channel. Specifically, an integrated sampler integrates a high-speed solenoid valve with the cooling channel, ensuring reliable execution of sampling actions and long-term stable operation of the device under harsh high-temperature and high-pressure conditions. Simultaneously, the sampling control system, based on the fusion judgment of crankshaft and camshaft signals, achieves precise identification of the working phase and top dead center position of each cylinder, thereby accurately controlling the high-speed solenoid valve to open instantaneously at specific crankshaft rotation angles during compression or after combustion, capturing instantaneous gas samples with clear representativeness of the operating conditions. In summary, this device has a compact structure and a high degree of modularity, enabling the acquisition of high-quality gas samples for accurately calculating key parameters such as in-cylinder exhaust gas residue rate and scavenging efficiency without requiring structural modifications to the engine.

[0017] Details of one or more embodiments of the present invention are set forth in the following drawings and description, so that other features, objects and advantages of the invention will be more readily understood. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of an in-cylinder sampling device provided in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of another engine in-cylinder sampling device provided in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the crankshaft-camshaft signal collaborative cylinder determination and top dead center synchronization logic provided in an embodiment of the present invention.

[0022] In the diagram: 1. Electronic control unit; 2. Engine; 3. CAN bus analyzer; 4. High-speed solenoid valve; 5. Sampler; 6. Sampling tube; 7. Circulating cooling water pump; 8. Sampling bag; 9. Computer. Detailed Implementation

[0023] Embodiments of this embodiment will now be described in more detail with reference to the accompanying drawings. While some embodiments of this embodiment are shown in the drawings, it should be understood that this embodiment can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this embodiment. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this embodiment.

[0024] The accurate measurement of key gas parameters such as residual exhaust gas rate and scavenging efficiency in engine cylinders faces technical bottlenecks. Existing technologies have drawbacks such as requiring damage to the engine structure, interfering with real operating conditions, being unable to withstand high-temperature environments, and being unable to accurately synchronize with the engine phase.

[0025] To address the aforementioned problems, embodiments of the present invention provide an in-cylinder sampling device for engines. Figure 1 This is a schematic diagram of the structure of an in-cylinder sampling device provided in an embodiment of the present invention. Figure 1 As shown, the in-cylinder sampling device for the engine includes a sampling probe system, a sampling control system, a cooling system, and a sampling storage system.

[0026] The sampling probe system includes a sampling tube for connection to an engine cylinder pressure measurement channel and a sampler connected to the sampling tube.

[0027] The sampling control system includes an electronic control unit (ECU) configured to receive crankshaft angle signals and camshaft phase signals from the engine, and determine the working phase and top dead center position of the engine cylinders based on the crankshaft angle signals and camshaft phase signals, so as to generate a control signal at a preset crankshaft angle.

[0028] The cooling system includes a coolant supply device, which is connected to a cooling channel located inside the sampler to form a circulation loop for cooling the high-temperature gas flowing through the sampler.

[0029] The sampling and storage system, connected to the gas outlet of the sampler, is used to collect and store cooled gas samples.

[0030] The sampler is an integrated structure, which integrates a high-speed solenoid valve and a cooling channel. The high-speed solenoid valve is electrically connected to the electronic control unit and is used to open or close at a preset crankshaft angle according to the control signal to perform sampling of the gas in the engine cylinder.

[0031] This embodiment provides an integrated device that can accurately and reliably collect in-cylinder gas at a specific phase through the engine's inherent cylinder pressure measurement channel during normal engine operation.

[0032] Specifically, the engine cylinder sampling device in this embodiment includes a probe system, a sampling control system, a cooling system, and a sampling storage system. The sampling probe system, as the part that directly interacts with the engine cylinder environment, consists of a sampling tube and a sampler. In practical applications, the sampling tube is a hollow tubular structure, and its front end can be mechanically and securely installed at a pre-reserved cylinder pressure measurement hole (i.e., a blow-off pressure hole) on the engine cylinder head via a mechanical interface (such as a thread), thus forming a physical channel from the engine combustion chamber to the external sampling device. The other end of the sampling tube is also securely connected to the sampler using a similar connection method, ensuring the continuity and sealing of the air passage.

[0033] In one alternative embodiment, the sampling device can adopt a modular design to achieve rapid adaptation to multiple engine models. The sampling tube can be connected to the engine cylinder pressure measurement channel via a replaceable dedicated adapter. Specifically, sampling tube adapters of corresponding specifications can be customized to address the differences in thread specifications (e.g., M10, M12, etc.) and structures of the burst pressure holes on different engine cylinder heads. One end of this adapter matches the engine burst pressure hole, and the other end connects to the sampler via a standardized interface (e.g., a unified thread specification). In practical applications, when switching engine models, there is no need to replace or modify the core sampler, cooling, and sampling control system; only a low-cost customized adapter needs to be replaced to quickly and reliably complete the system deployment.

[0034] The sampler is an integrated functional device in this embodiment, and it can adopt a highly integrated structural design. Inside this integrated structure, a high-speed solenoid valve for controlling the sampling airflow is installed, along with a cooling channel surrounding or closely adjacent to the airflow path. This integrated structure not only greatly optimizes the spatial layout and reduces potential leakage points, but also improves the overall structural rigidity and reliability under severe engine vibration. The high-speed solenoid valve, as the actuating element for the sampling action, has an extremely high response speed, enabling it to complete the opening and closing action within microseconds, achieving precise capture of the brief sampling window.

[0035] The sampling control system in this embodiment is responsible for the timing and logic control of the entire sampling process, and its core is the electronic control unit (ECU). In this embodiment, the ECU is configured to communicate with the engine's sensing system or control unit, receiving in real time crankshaft angle signals and camshaft phase signals that characterize the engine's actual operating state. Based on these two signals, the ECU can execute cylinder determination logic: First, it determines the piston's top dead center position and other crankshaft angles using the high-resolution crankshaft angle signal; then, it combines the camshaft phase signal, which undergoes only one jump within a 720-degree crankshaft angle, to distinguish whether the current position is compression top dead center or exhaust top dead center. Through this signal fusion processing, the ECU can accurately identify the operating phase of each cylinder and, based on this, calculate the target crankshaft angle for sampling. Finally, when the preset crankshaft angle is reached, the ECU generates and sends a control signal to directly drive the high-speed solenoid valve in the sampler to perform an opening or closing operation.

[0036] In this embodiment, the cooling system ensures long-term stable operation of the equipment under the high temperature and high pressure environment generated by engine combustion. Specifically, the cooling system consists of a coolant supply device (e.g., a circulating cooling water pump) and a cooling channel integrated into the sampler, forming a closed loop. Driven by the coolant supply device, the coolant continuously flows through the cooling channel inside the sampler. In practical applications, when the high-temperature in-cylinder gas flows through the sampler during sampling, its heat can be quickly carried away by the flowing coolant, achieving effective cooling of the gas. In this process, not only can downstream high-speed solenoid valves, seals, and other precision components be protected from thermal damage, but the chemical state of the gas sample can also be quickly "frozen," preventing subsequent reactions from affecting the accuracy of the analytical results.

[0037] The sampling and storage system is connected downstream of the sampler's gas outlet and can collect and store cooled gas samples. This system may include sampling bags (such as aluminum foil bags) with good chemical stability and sealing properties, and can be connected to the sampler via a quick-connect interface for easy disassembly and replacement after sampling, while ensuring airtightness during the sampling process.

[0038] In summary, the engine cylinder sampling device of this embodiment, through the coordinated operation of the above-mentioned systems, enables timed, fixed-point, and cooled direct sampling of cylinder gas at a specific crankshaft rotation angle without interfering with the normal operation of the engine, providing high-quality raw gas samples for subsequent accurate analysis of the engine cylinder working process.

[0039] For ease of understanding, the engine cylinder sampling device and sampling method provided in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] Figure 2 This is a schematic diagram of another engine in-cylinder sampling device provided in an embodiment of the present invention. Figure 2 As shown, the working steps of each system of the engine in-cylinder sampling device are as follows.

[0041] First, acquire the crankshaft angle signal and camshaft phase signal of engine 2.

[0042] In this embodiment, the electronic control unit 1 of the sampling control system continuously acquires the crankshaft angle signal and camshaft phase signal of the engine 2. The acquired crankshaft angle signal and camshaft phase signal can serve as the time reference for all subsequent judgments and controls. To achieve this, the electronic control unit 1 can connect to the engine 2 source signal in various ways. Optionally, in this embodiment, the electronic control unit 1 can communicate with the vehicle's CAN network via a CAN bus analyzer 3 to acquire high-precision crankshaft and camshaft digital signals from the engine ECU or other nodes on the bus in a non-intrusive manner. Based on this method, direct wire breaking on the engine 2 sensor harness can be avoided, thus preventing potential interference with the original engine signals and ensuring signal integrity and reliability.

[0043] In this embodiment, the crankshaft angle signal can be represented as a high-frequency pulse sequence, and its gear can adopt, for example, a "60-2" missing tooth structure, thereby forming a unique gap representation in the uniform pulses. The camshaft phase signal can be represented as a low-frequency phase signal that undergoes only one level jump within a 720-degree crankshaft angle.

[0044] After obtaining the crankshaft angle signal and camshaft phase signal, cylinder identification processing can be performed based on the crankshaft angle signal and camshaft phase signal to identify the compression top dead center position and working phase of each cylinder.

[0045] In this embodiment, after receiving the crankshaft angle signal and camshaft phase signal, the electronic control unit 1 executes the core cylinder identification logic to accurately identify the working phase of the cylinder.

[0046] Figure 3This is a schematic diagram of the crankshaft-camshaft signal collaborative cylinder determination and top dead center synchronization logic provided in an embodiment of the present invention.

[0047] like Figure 3 The diagram illustrates the logical relationship between the crankshaft position sensor signal and the camshaft position sensor signal in coordinating to achieve cylinder detection and top dead center synchronization. The electronic control unit 1 first monitors the crankshaft angle signal. Upon identifying the "missing tooth" pattern in the crankshaft signal shown in the diagram, it determines the subsequent "second tooth after the missing tooth" as the initial reference position for top dead center, and then... Figure 3 The TDC (Top Dead Center) position is determined by the crankshaft angle signal alone. However, this signal alone cannot distinguish whether the TDC is the compression TDC or the exhaust TDC. Therefore, a camshaft phase signal is introduced: the electronic control unit 1 synchronously reads the TDC reference position of the crankshaft when it is near the reference position. Figure 3 The edge changes (such as the falling edge of the signal) or level state of the camshaft signal. Based on a pre-established correspondence during system calibration (e.g., when the crankshaft is in the TDC position, the camshaft signal appears...), this is determined by... Figure 3 The edge change shown in the figure indicates that the corresponding cylinder is at the top dead center of the compression stroke. This feature of the camshaft phase signal is matched with the crankshaft TDC reference position to uniquely determine which cylinder is at the end of the compression stroke. This fusion strategy of "high-resolution crankshaft positioning (based on the second tooth after the missing tooth and TDC) + camshaft phase recognition (based on the signal edge in the figure)" can ensure absolutely accurate identification and phase tracking of each cylinder throughout the entire engine working cycle.

[0048] Based on accurate cylinder identification, the electronic control unit 1 uses the identified top dead center of the compression as the target reference position to determine at least one target sampling window. The target sampling window corresponds to the compression stage after the valve is closed and / or the stage from the end of combustion to the opening of the exhaust valve.

[0049] Specifically, the electronic control unit 1 uses the identified top dead center of the compression stroke as the target reference position and calculates at least one target sampling window according to a preset program. These windows typically correspond to key stages of engine 2 operation, mainly including the periods from "compression after valve closure to the start of combustion" and "from the end of combustion to the opening of the exhaust valve." The sampling window is defined by a specific crankshaft angle range, for example, from 90°CA to 60°CA before top dead center of the compression stroke.

[0050] Subsequently, when the crankshaft angle corresponding to the target sampling window is reached, a control signal is sent to the sampler 5, which integrates a high-speed solenoid valve 4 and a cooling channel, to perform in-cylinder gas sampling. The sampled gas is cooled by the coolant in the cooling channel as it flows through the sampler 5.

[0051] Specifically, when the electronic control unit 1 determines that the engine 2 has entered the preset target sampling window by tracking the crankshaft angle in real time, it immediately sends an opening control signal to the core component of the sampling probe system—the sampler 5. Upon receiving the pulse width signal from the electronic control unit 1, the high-speed solenoid valve 4 can open instantaneously with a microsecond-level response speed. At this time, because the cylinder of engine 2 is under high pressure, while the sampling storage system pipeline and sampling bag 8 are under normal or negative pressure, the pressure difference drives the gas in the cylinder to rapidly flow into the sampler 5 through the sampling pipe 6.

[0052] In practical applications, the heat of the high-temperature gas can be efficiently transferred by the integrated cooling system the instant it flows through the sampler 5. Specifically, the coolant supply device within the cooling system (taking the circulating cooling water pump 7 as an example in this embodiment) continuously drives the coolant to flow through the precisely designed cooling channels inside the sampler 5, forming a forced circulation. Due to the small inner diameter of the sampling probe and the limited flow rate of the high-temperature gas, effective heat dissipation can be achieved solely through the circulation of the pump body and the water circuit, eliminating the need for an additional large radiator. Based on the above structure, the downstream high-speed solenoid valve 4's operating mechanism and the sampling bag 8 in the sampling and storage system can be protected from high-temperature burns, ensuring the stability and robustness of the equipment during long-term operation. It can also "rapidly freeze" the gas sample, almost stopping the internal chemical reactions, thereby preserving the true composition of the gas at the time of sampling and laying the foundation for subsequent accurate analysis.

[0053] Finally, the cooled gas sample is transported to the sampling and storage system for storage.

[0054] The gas, effectively cooled by the cooling channel inside sampler 5, is delivered to the sampling and storage system through its gas outlet. The sampling bag 8 of the sampling and storage system can be connected to the gas outlet of sampler 5 via a specially designed quick-connect interface. This interface makes the installation and removal of the sampling bag 8 very convenient, greatly improving experimental efficiency. The sampling bag 8 is preferably made of aluminum foil, which has good barrier and sealing properties. Its valve design includes single-valve and double-valve options: the single-valve sampling bag 8 is suitable for offline analysis after sampling, i.e., gas component determination in a laboratory environment; the double-valve sampling bag 8 facilitates connection to online analysis equipment (such as an exhaust gas analyzer) to achieve simultaneous sampling and analysis. During sampling, loosening the gas valve counterclockwise allows for unobstructed airflow; after sampling, tightening the gas valve clockwise achieves a seal, effectively preventing leakage or contamination of the gas sample during storage.

[0055] In an optional embodiment, after successfully collecting and storing the gas sample, the analysis stage can begin. The computer 9 can then perform component analysis on the gas sample, accurately measuring the carbon dioxide (CO2) concentration. Based on the measured concentration value, key performance parameters of the engine 2, such as scavenging efficiency, can be further calculated.

[0056] Optionally, the target sampling window in this embodiment includes a first target sampling window corresponding to the compression phase after the valve is closed, and a second target sampling window corresponding to the phase from the end of combustion to the opening of the exhaust valve. Accordingly, when the first target sampling window is reached, a first control signal is sent to the sampler 5 to collect a first gas sample; and when the second target sampling window is reached, a second control signal is sent to the sampler to collect a second gas sample.

[0057] As a preferred embodiment, this example can be used to perform multi-phase in-cylinder gas sampling, thereby providing a data foundation for the accurate calculation of key parameters such as engine scavenging efficiency and residual exhaust gas rate. The specific steps are as follows: In the program of the electronic control unit 1, two different target sampling windows can be preset. The first target sampling window corresponds to the compression stage after the valve is closed, during which the gas in the cylinder is mainly the exhaust gas remaining from the previous working cycle; the second target sampling window corresponds to the stage after combustion and before the exhaust valve is opened, at which time the gas in the cylinder is a mixture of exhaust gas and newly injected air.

[0058] When engine 2 is operating under the stable condition to be tested, electronic control unit 1 continuously monitors the crankshaft angle. Upon reaching the crankshaft angle corresponding to the first target sampling window, electronic control unit 1 immediately sends a first control signal to sampler 5. This signal drives the high-speed solenoid valve 4 integrated inside sampler 5 to open instantaneously, collecting a first gas sample. The first gas sample is rapidly cooled by the cooling system as it flows through sampler 5, and then transported and stored in the first sampling bag 8 connected to the gas outlet. This first gas sample represents the residual exhaust gas in the cylinder.

[0059] After the first gas sample is collected, the operator can replace the second clean sampling bag 8 with the gas outlet of the sampler 5. The electronic control unit 1 continues to operate, and when it detects the engine entering the second target sampling window, it immediately issues a second control signal to drive the high-speed solenoid valve 4 to open again and collect the second gas sample. This second gas sample is also cooled and stored in the second sampling bag 8. This second gas sample represents the gas-air mixture remaining in the cylinder after scavenging.

[0060] Subsequently, offline gas chromatography analysis or online exhaust gas analysis can be performed on the first and second gas samples stored separately to accurately measure their carbon dioxide concentration. The measured residual exhaust gas carbon dioxide concentration, the carbon dioxide concentration of the mixed gas after scavenging, and the ambient air carbon dioxide concentration are substituted into the following formula (1) to calculate the engine scavenging efficiency under this operating condition.

[0061] (1) in, For scavenging efficiency; The concentration of carbon dioxide in ambient air; The concentration of carbon dioxide in the first gas sample; The concentration of carbon dioxide in the second gas sample.

[0062] Based on the above-mentioned multi-phase sampling method, this embodiment can acquire multiple instantaneous gas samples with clear physical meaning in a single experiment under the same stable operating conditions, thereby improving the accuracy and comprehensiveness of in-cylinder gas parameter measurement.

[0063] It should be noted that the term "comprising" and its variations used in the embodiments of the present invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that, unless explicitly indicated otherwise in the context, they should be understood as "one or more".

[0064] The steps described in the method embodiments provided by this invention can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of protection of this invention is not limited in this respect.

[0065] The term "embodiment" in this specification refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply independence or alternativeity from other embodiments. The various embodiments in this specification are described in a related manner, with reference to each other for similar or identical parts. In particular, for apparatus, device, and system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, and relevant details are referred to in the description of the method embodiments.

[0066] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An engine in-cylinder sampling device characterized by comprising: The application relates to a sampling probe system, a sampling control system, a cooling system, a sampling storage system and an electronic control unit. The sampling probe system comprises a sampling tube for connecting with an engine cylinder pressure measurement channel and a sampler connected with the sampling tube. The sampling control system comprises an electronic control unit configured to receive a crank angle signal and a camshaft phase signal of the engine, and to determine a working phase and a top dead center position of the engine cylinder based on the crank angle signal and the camshaft phase signal, and to generate a control signal at a preset crank angle. The cooling system comprises a cooling liquid supply device connected with a cooling flow channel arranged in the sampler in a circulating loop for cooling high-temperature gas flowing through the sampler. The sampling storage system is connected with a gas outlet of the sampler for collecting and storing the cooled gas sample. The sampler is of an integrated structure and internally integrated with a high-speed electromagnetic valve and the cooling flow channel; the high-speed electromagnetic valve is electrically connected with the electronic control unit and used for being opened or closed at a preset crank angle according to the control signal to perform sampling of the engine in-cylinder gas.

2. The apparatus of claim 1, wherein, The sampling tube is connected with the engine cylinder pressure measurement channel through a replaceable adapter.

3. The apparatus of claim 1, wherein, The sampling storage system comprises a sampling bag connected with the gas outlet of the sampler through a quick plug-in interface.

4. The apparatus of claim 3, wherein, The sampling bag is of a single-valve structure or a double-valve structure.

5. The apparatus of claim 1, wherein, The cooling liquid supply device comprises a cooling pump used for driving the circulation of cooling liquid between the cooling flow channel of the sampler and an external cooling liquid source.

6. The apparatus of claim 1, wherein, The sampling control system further comprises a CAN bus analyzer, and the electronic control unit communicates with the engine ECU or the CAN bus analyzer through a CAN bus to acquire the crank angle signal and the camshaft phase signal.

7. An engine in-cylinder sampling method characterized by comprising: The application relates to an electronic control unit applied to a sampling control system. The electronic control unit comprises: acquiring a crank angle signal and a camshaft phase signal of an engine; determining a compression top dead center position and a working phase of each cylinder based on the crank angle signal and the camshaft phase signal; determining at least one target sampling window corresponding to a compression stage after valve closing and / or a stage from combustion ending to exhaust valve opening, with the compression top dead center as a target reference position; sending a control signal to a sampler integrated with a high-speed electromagnetic valve and a cooling flow channel to perform in-cylinder gas sampling when a crank angle corresponding to the target sampling window is reached, and cooling the sampled gas sample by cooling liquid in the cooling flow channel when the sampled gas sample flows through the sampler; 8. The method of claim 7, wherein, controlling the delivery of the cooled gas sample to a sampling storage system for storage. The determination of the working phase and the top dead center position based on the crank angle signal and the camshaft phase signal comprises: taking a specific tooth after a missing tooth signal of the crank is recognized as an initial reference position of the top dead center; reading an edge state or a level state of the camshaft phase signal near the reference position; matching the edge state or the level state with the initial reference position according to a preset corresponding relationship to determine that the initial reference position is the compression top dead center or the exhaust top dead center.

9. The method of claim 7, wherein, The sampling control system further comprises a CAN bus analyzer, and the electronic control unit acquires the crank angle signal and the camshaft phase signal from the engine ECU or the CAN bus analyzer through a CAN bus.

10. The method of claim 7, wherein, The target sampling window comprises a first target sampling window corresponding to a compression stage after valve closing, and a second target sampling window corresponding to a stage from combustion ending to exhaust valve opening. The control signal for the sampler integrated with a high-speed electromagnetic valve and a cooling flow channel is sent to perform in-cylinder gas sampling when the target sampling window corresponding crank angle is reached, comprising: A first control signal is sent to the sampler to collect a first gas sample when the first target sampling window is reached, and a second control signal is sent to the sampler to collect a second gas sample when the second target sampling window is reached.

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