Test method and system for effect of oil aeration on valve train dynamics

Abstract

The application provides a test method and system for the influence of oil gas content on valve mechanism dynamics, which comprises the following steps: flowing oil into an oil-gas mixing device at a specific temperature and a specific pressure; controlling gas to mix with the oil at a specific flow rate, and measuring the gas content in the mixed gas, which is the initial gas content; measuring the gas distribution parameters of the gas distribution mechanism, recording the initial gas distribution parameters, and judging the initial state of the gas distribution mechanism; adjusting the flow rate of the gas mixed with the oil according to the initial state; measuring the gas content of the stabilized oil, recording the nth gas content; measuring the gas distribution parameters, recording the nth gas distribution parameters, and judging the current state of the gas distribution mechanism; comparing the current state and the initial state of the gas distribution mechanism, and judging whether they are consistent; and if not, determining the nth gas content as the maximum gas content value of the gas distribution mechanism. The application can quickly, effectively and quantitatively analyze the influence of different oil gas contents on the valve mechanism, and realize the test of the influence of the gas content on the valve performance.

Description

Technical Field

[0001] This invention belongs to the field of engine lubrication performance testing technology, and specifically relates to a test method and a test system for implementing the method for testing the influence of oil gas content on valve mechanism dynamics. Background Technology

[0002] An engine requires a lubrication system to operate, and the engine oil in this system inevitably contains some gas. Increased gas content affects the oil's lifespan and also significantly impacts friction pairs and hydraulic components within the engine. With modern engines operating at high speeds and under harsh conditions, the amount of gas in the engine oil has a significant impact on the engine's valve train. High gas content can lead to valve breakage, and it also puts considerable strain on the lubrication system.

[0003] Existing CAE simulation technology commonly used in the automotive testing field cannot calculate the impact of oil gas content on the valve mechanism. Furthermore, current bench tests for studying oil gas content primarily focus on its effect on the oil pump system. For example, patent CN212563693U discloses a test bench for testing the impact of oil gas content on oil pump performance, but lacks a testing system and method for studying the impact of different gas contents on the valve train. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that the existing technology lacks a testing system and method for studying the effect of different gas contents on gas distribution mechanisms.

[0005] To address the aforementioned technical problems, this invention provides a test method for the influence of engine oil gas content on valve mechanism dynamics. The test method is executed by a test system for the influence of engine oil gas content on valve mechanism dynamics. The test system includes an engine oil temperature control device, an oil-gas mixing device, a gas content measuring device, and a valve train mechanism connected in sequence and in communication, as well as a drive motor connected to the valve train mechanism and a valve train parameter measuring device for measuring the valve train parameters. The test method includes:

[0006] S1: The oil temperature control device ensures that the oil flows into the oil-air mixing device at a specific temperature and pressure; the drive motor is activated to drive the valve train.

[0007] S2: The gas is controlled to mix with the engine oil at a specific flow rate by the oil-gas mixing device. The gas content in the engine oil after the gas mixture is measured by the gas content measuring device and recorded as the initial gas content. The valve timing parameters of the engine oil after the gas mixture passes through the valve timing mechanism are measured by the valve timing parameter measuring device and recorded as the initial valve timing parameters. The initial state of the valve timing mechanism is determined based on the initial valve timing parameters.

[0008] S3: Adjust the flow rate of the gas mixed with engine oil in the oil-gas mixing device according to the initial state of the gas distribution mechanism;

[0009] S4: Measure the gas content of the stabilized engine oil using a gas content measuring device and record the gas content as the nth gas content; measure the gas distribution parameters of the engine oil after mixing with gas as it passes through the gas distribution mechanism using a gas distribution parameter measuring device and record the gas distribution parameters as the nth gas distribution parameter; determine the current state of the gas distribution mechanism based on the nth gas distribution parameter.

[0010] S5: Compare the current state and the initial state of the gas distribution mechanism to determine whether the current state of the gas distribution mechanism is consistent with the initial state of the gas distribution mechanism.

[0011] If so, adjust the flow rate of the gas mixed with the engine oil in the oil-gas mixing device again according to the initial state of the gas distribution mechanism, and continue to step S4;

[0012] If not, then the gas content of the nth gas is determined to be the maximum gas content value of the gas distribution mechanism;

[0013] Where n represents the number of times the gas flow rate mixed with the engine oil is adjusted.

[0014] By adopting the above scheme, the performance of the valve train under different gas content conditions is collected by changing the gas content in the engine oil. This allows for rapid, effective, and quantitative analysis of the impact of different engine oil gas contents on the valve mechanism, enabling the testing of the effect of gas content on valve performance. The testing method is convenient, and the results are intuitive and reliable. This solves the problem of being unable to calculate the impact of engine oil gas content on the valve mechanism in CAE simulation calculations, and is of great significance for the design of valve mechanisms.

[0015] According to another specific embodiment of the present invention, the test method disclosed in this embodiment includes valve lift as a valve timing parameter, and initial valve lift as an initial valve timing parameter. In step S2, the step of determining the initial state of the valve timing mechanism based on the initial valve timing parameters includes: calculating the difference between the theoretical maximum valve lift of the valve timing mechanism and the initial valve lift, and determining the initial state of the valve timing mechanism based on the comparison result of the absolute value of the difference with a preset threshold. Wherein, if the absolute value of the difference is less than the preset threshold, the initial state of the valve timing mechanism is determined to be normal; if the absolute value of the difference is greater than or equal to the preset threshold, the initial state of the valve timing mechanism is determined to be abnormal.

[0016] In step S3, if the initial state of the gas distribution mechanism is normal, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is increased; if the initial state of the gas distribution mechanism is abnormal, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is decreased.

[0017] According to another specific embodiment of the present invention, in the test method disclosed in the embodiment of the present invention, in steps S3 and S5, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is increased or decreased by such that the change in the gas content of the engine oil is 1-3%.

[0018] According to another specific embodiment of the present invention, the test method disclosed in the embodiment of the present invention includes an nth valve lift as the nth valve timing parameter; in step S4, determining the current state of the valve timing mechanism based on the nth valve timing parameter includes: calculating the difference between the theoretical maximum valve lift of the valve timing mechanism and the nth valve lift, and determining the current state of the valve timing mechanism based on the comparison result of the absolute value of the difference with a preset threshold; wherein, if the absolute value of the difference is less than the preset threshold, the current state of the valve timing mechanism is determined to be normal; if the absolute value of the difference is greater than or equal to the preset threshold, the current state of the valve timing mechanism is determined to be abnormal.

[0019] According to another specific embodiment of the present invention, the test method disclosed in the embodiment of the present invention has a preset threshold of 0.1~0.2mm.

[0020] According to another specific embodiment of the present invention, in the test method disclosed in the embodiment of the present invention, the specific temperature in step S1 is 90~110℃ and the specific pressure is 300~400kPa.

[0021] The present invention also provides a test system for the effect of oil gas content on valve mechanism dynamics, used to perform the test method of the present invention for the effect of oil gas content on valve mechanism dynamics; the test system includes an oil temperature control device, an oil-gas mixing device, a gas content measuring device and a valve train mechanism connected in sequence and in communication, as well as a drive motor connected to the valve train mechanism and a valve train parameter measuring device for measuring the valve train mechanism valve train parameters.

[0022] Among them, the oil temperature control device is used to ensure that the oil flows into the oil-gas mixing device at a specific temperature and pressure; the oil-gas mixing device is used to control the gas to mix with the oil at a specific flow rate; the gas content measuring device is used to measure the gas content of the oil after the gas mixture; the drive motor is used to drive the valve train mechanism to operate; and the valve train parameter measuring device is used to measure the valve train parameters when the oil passes through the operating valve train mechanism.

[0023] By adopting the above scheme, the oil-gas mixing device and the valve train mechanism are innovatively combined, and the gas content measuring device and the valve train parameter measuring device are integrated to form a complete test system for the dynamic influence of the valve train mechanism. This system can quickly, effectively and quantitatively analyze the influence of oil gas content on the valve train mechanism, and solve the problem of not being able to calculate the influence of oil gas content on the valve train mechanism in CAE simulation calculation.

[0024] According to another specific embodiment of the present invention, the test system disclosed in the embodiment of the present invention includes an oil-gas mixing device comprising an oil inlet pipe, a compressed air pipe, a one-way valve, an air flow control valve, a mixing chamber, and an oil outlet pipe.

[0025] One end of the oil inlet pipe is connected to the oil temperature control device, and the other end of the oil inlet pipe is connected to one end of the mixing chamber, so that the oil from the oil temperature control device enters the mixing chamber through the oil inlet pipe; one end of the compressed air pipe is inserted into the mixing chamber from the side wall of the mixing chamber, and one end of the compressed air pipe is provided with multiple vent holes spaced apart along the length of the compressed air pipe. The multiple vent holes are used to introduce gas from the compressed air pipe into the mixing chamber to mix with the oil in the mixing chamber.

[0026] An air flow control valve is located at the other end of the compressed air pipe, and the flow rate of gas entering the mixing chamber through the compressed air pipe is controlled by controlling the angle of the air flow control valve; a one-way valve is located on the compressed air pipe, between the air flow control valve and multiple vent holes in the gas flow direction, and is used to restrict the oil in the mixing chamber from flowing out through the compressed air pipe; the other end of the mixing chamber is connected to one end of the oil outlet pipe, so that the oil mixed with the gas in the mixing chamber flows out from the oil outlet pipe.

[0027] The above scheme provides an oil-gas mixing device with a simple structure and easy operation.

[0028] According to another specific embodiment of the present invention, the test system disclosed in the embodiment of the present invention includes a valve train mechanism comprising a valve train test bench and a valve train cylinder head; a drive motor is connected to the valve train cylinder head for driving the valve train cylinder head to move; and a valve train parameter measuring device includes a laser displacement sensor.

[0029] The above scheme uses a laser displacement sensor to measure valve lift, which has high measurement accuracy.

[0030] According to another specific embodiment of the present invention, the test system disclosed in the embodiment of the present invention further includes an oil sensor, an oil filter, an encoder, a torque sensor, and a diaphragm pump; the oil sensor and the oil filter are disposed between the oil-gas mixing device and the gas content measuring device; the encoder and the torque sensor are disposed between the drive motor and the cylinder head; the oil temperature control device and the valve train are connected, and the diaphragm pump is disposed between the oil temperature control device and the valve train.

[0031] The above scheme enables the circulating flow of engine oil in the testing system; the oil temperature and pressure sensor is used to collect the oil temperature and pressure, and the oil filter is used to remove impurities from the oil. The encoder is used to collect the displacement data of the cylinder head; the torque sensor is used to collect the torque data of the drive motor.

[0032] The beneficial effects of this invention are:

[0033] This invention provides a testing method and system for assessing the impact of engine oil gas content on valve mechanism dynamics. It innovatively combines an oil-gas mixing device and a valve train mechanism, integrating a gas content measuring device and a valve train parameter measuring device to form a complete testing system for assessing the dynamic impact on the valve train mechanism. By changing the gas content in the engine oil and collecting data on the valve train mechanism performance under different gas content conditions, the system can quickly, effectively, and quantitatively analyze the influence of engine oil gas content on the valve train mechanism. This allows for testing the effect of gas content on valve performance. The testing method is convenient, and the results are intuitive and reliable, solving the problem of being unable to calculate the impact of engine oil gas content on the valve train mechanism in CAE simulation calculations. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the test system for the effect of oil gas content on valve mechanism dynamics provided in Embodiment 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of the cylinder head connecting base plate of the valve train in the test system for the effect of oil gas content on valve dynamics according to Example 1 of the present invention.

[0036] Figure 3 This is a schematic diagram of one embodiment of the oil-gas mixing device in the test system for the effect of engine oil gas content on valve mechanism dynamics provided in Embodiment 1 of the present invention;

[0037] Figure 4 This is a partial three-dimensional structural schematic diagram of an embodiment of the oil-gas mixing device in the test system for the effect of engine oil gas content on valve mechanism dynamics provided in Embodiment 1 of the present invention.

[0038] Figure 5 This is a flowchart of a test method for the effect of oil gas content on valve mechanism dynamics provided in Embodiment 2 of the present invention;

[0039] Figure 6 This is a schematic diagram showing the relationship between gas content and valve lift obtained from a single test of the test method for the effect of oil gas content on valve mechanism dynamics provided in Example 2 of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1: Engine oil temperature control device;

[0042] 2: Oil-gas mixing device;

[0043] 201: Oil inlet pipe; 202: Compressed air pipe; 203: Check valve; 204: Air flow control valve; 205: Mixing chamber; 206: Oil outlet pipe; 207: Vent hole;

[0044] 3: Gas content measuring device;

[0045] 4: Gas distribution mechanism;

[0046] 401: Valve train; 402: Cylinder head assembly; 403: Oil inlet; 404: Oil outlet; 405: Mounting hole; 406: Bolt hole;

[0047] 5: Gas distribution parameter measuring device;

[0048] 6: Drive motor;

[0049] 7: Oil pressure sensor;

[0050] 8: Oil filter;

[0051] 9: Encoder;

[0052] 10: Torque sensor;

[0053] 11: Diaphragm pump. Detailed Implementation

[0054] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0055] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0056] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0057] Example 1

[0058] This invention provides a testing system for the effect of oil gas content on valve mechanism dynamics, such as... Figure 1As shown, the testing system includes an oil temperature control device 1, an oil-air mixing device 2, an air content measuring device 3, and a valve train 4, which are connected in sequence and interconnected. It also includes a valve train parameter measuring device 5 for measuring the valve train parameters of the valve train 4, and a drive motor 6 connected to the valve train 4. It should be noted that the testing system is also connected to a control unit, such as a computer, and the operator controls the testing system through the control unit.

[0059] The oil temperature control device 1 controls the temperature and pressure of the oil during the test, ensuring it flows into the oil-gas mixing device 2 at a specific temperature and pressure. The oil then sequentially enters the gas content measuring device 3 and the gas distribution mechanism 4, flowing along the test system. The oil-gas mixing device 2 is connected to the oil temperature control device 1, the gas content measuring device 3, and a gas compression device. This device controls the continuous flow of gas, such as compressed air, into the oil-gas mixing device 2 at a specific flow rate, mixing the gas with the flowing oil. Therefore, the gas content of the mixed oil can be adjusted by controlling the gas flow rate. The gas content measuring device 3 measures the gas content of the oil after mixing with the gas. This device can be a commonly used gas content measuring device, such as an oil gas content meter.

[0060] The valve train 4 is a test device used to simulate the valve train in a real vehicle. In a real vehicle, the valve train functions by periodically opening and closing valves during engine scavenging to ensure the engine draws in fresh air and expels exhaust gases as needed. This invention utilizes an existing valve train test device capable of simulating this process. According to one specific embodiment of the invention, the valve train 4 simulates an overhead valve train structure, including a valve train platform 401 and a cylinder head 402. A drive motor 6 is connected to the cylinder head 402 to drive its movement. Specifically, the valve train platform 401 includes a cylinder head connecting base plate and a base plate support; the cylinder head 402 includes a cover, camshaft, valves, springs, rocker arms, and a cylinder head. The cylinder head connecting base plate connects to the cylinder head 402 and allows the gas-containing oil in the valve train platform 401 to enter the oil passages in the cylinder head 402. The specific structure of the cylinder head connecting base plate is as follows... Figure 2 As shown, the cylinder head 402 is connected to the cylinder head connecting base plate via fixing holes 405 and bolt holes 406 on the cylinder head connecting base plate, and is assembled according to the engine's standard installation torque to ensure the cylinder head 402 is tightly fitted against the cylinder head connecting base plate. The drive motor 6 rotates in the normal rotation direction of the engine, specifically as shown in the diagram. Figure 2The camshaft moves along the Y-axis, and the connecting shaft of the drive motor 6 is connected to the camshaft in the cylinder head 402. This allows the camshaft in the cylinder head 402 to be driven by the rotation of the drive motor 6, providing driving force for the rotation of the camshaft and the opening of the valves. The oil inlet hole 403 and oil outlet hole 404 on the cylinder head connecting base plate allow the oil containing gas to enter the oil passage in the cylinder head 402 through the cylinder head connecting base plate. When the camshaft rotates, the oil passes through the oil passage in the cylinder head 402 into the hydraulic tappets and various lubrication holes. The valves reciprocate up and down under the drive of the camshaft, simulating the valve mechanism of an actual vehicle engine.

[0061] The valve timing parameter measuring device 5 is disposed on or near the valve timing mechanism 4, and is used to measure the valve timing parameters when engine oil passes through the operating valve timing mechanism 4. Specific valve timing parameters may include valve lift, vibration, noise, etc. The valve timing parameter measuring device 5 may include a laser displacement sensor, a vibration sensor, a noise sensor, etc. According to one specific embodiment of the present invention, the valve timing parameters include valve lift, and the valve timing parameter measuring device 5 includes a laser displacement sensor, resulting in high measurement accuracy.

[0062] The testing system can be configured for unidirectional flow, with the engine oil collected after flowing out from the valve train 4. Alternatively, the testing system can be configured as a recirculation path. According to one specific embodiment of the present invention, such as... Figure 1 As shown, the test system also includes a diaphragm pump 11. The oil temperature control device 1 and the valve train 4 are connected, and the diaphragm pump 11 is located between the oil temperature control device 1 and the valve train 4. During the test, the oil flowing out of the valve train 4 is ultimately drawn back into the oil temperature control device 1 through the diaphragm pump 11, thereby realizing the circulation and use of oil in the test system.

[0063] The test system for the influence of oil gas content on valve mechanism dynamics provided by this invention innovatively combines an oil-gas mixing device and a valve train mechanism, and integrates a gas content measuring device and a valve train parameter measuring device to form a complete test system for the influence of valve train dynamics. It can quickly, effectively, and quantitatively analyze the influence of oil gas content on valve mechanism, and solve the problem of not being able to calculate the influence of oil gas content on valve mechanism in CAE simulation calculation.

[0064] According to one specific embodiment of the present invention, such as Figure 1As shown, the test system also includes an oil sensor 7, an oil filter 8, an encoder 9, and a torque sensor 10. The oil sensor 7 and oil filter 8 are located between the oil-air mixing device 2 and the gas content measuring device 3. The oil sensor 7 may include a temperature sensor and a pressure sensor to collect the oil temperature and pressure, transmitting this data to the test control unit. The control unit uses the collected data to control the oil temperature control device 1 to adjust the oil temperature and pressure during the test. The oil filter 8 is specifically located downstream of the oil sensor 7 to remove impurities such as dust, metal particles, carbon deposits, and soot particles from the oil. The encoder 9 and torque sensor 10 are located between the drive motor 6 and the cylinder head 402. Specifically, the encoder 9 is located near the cylinder head 402 to collect the displacement data of the cylinder head 402 and transmit it to the test control unit. The torque sensor 10 is located near the drive motor 6 to collect the torque data of the drive motor 6 and transmit it to the test control unit. The test control unit controls the operation of drive motor 6 based on the received data to more accurately simulate the operation of the engine.

[0065] According to one specific embodiment of the present invention, a simple and easy-to-operate oil-gas mixing device 2 is also provided, specifically, as shown in... Figures 3-4 As shown, the oil-gas mixing device 2 includes an oil inlet pipe 201, a compressed air pipe 202, a one-way valve 203, an air flow control valve 204, a mixing chamber 205, and an oil outlet pipe 206. One end of the oil inlet pipe 201 is connected to the oil outlet of the oil temperature control device 1, and the other end is connected to one end of the mixing chamber 205, so that the oil from the oil temperature control device 1 enters the mixing chamber 205 through the oil inlet pipe 201. One end of the compressed air pipe 202 is inserted into the mixing chamber 205 from the side wall of the mixing chamber 205, and the other end is connected to the gas compression device, so that compressed air can enter the oil-air mixing device 2 from the compressed air pipe 202. Furthermore, the end of the compressed air pipe 202 located in the mixing chamber 205 has multiple vent holes 207 spaced along its length, which are used to introduce gas from the compressed air pipe 202 into the mixing chamber 205 to mix with the oil in the mixing chamber 205. Further, the opening of the vent holes 207 can be configured to be in the same direction as the oil flow, making it difficult for oil to enter the compressed air pipe 202.

[0066] like Figure 3As shown, an air flow control valve 204 is located at the other end of the compressed air pipe 202. The angle of the air flow control valve 204 controls whether the mixing chamber 205 and the gas compression device are connected, and when connected, the flow rate of gas entering the mixing chamber 205 through the compressed air pipe 202. A one-way valve 203 is located on the compressed air pipe 202, between the air flow control valve 204 and multiple vent holes 207 in the gas flow direction, to prevent and restrict the flow of oil from the mixing chamber 205 through the compressed air pipe 202. The other end of the mixing chamber 205 is connected to one end of the oil outlet pipe 206, allowing the oil mixed with gas in the mixing chamber 205 to flow out of the mixing chamber 205 from the oil outlet pipe 206.

[0067] Example 2

[0068] This invention also provides a test method for the effect of oil gas content on valve mechanism dynamics. The test method is performed using the test system for the effect of oil gas content on valve mechanism dynamics described in Example 1. After the test system is installed, it is powered on, the oil temperature control system is turned on, and oil is introduced before the test method begins. Figure 5 As shown, the test method includes the following steps:

[0069] S1: The oil temperature control device causes the oil to flow into the oil-gas mixing device at a specific temperature and pressure, and then sequentially enters the gas content measuring device 3 and the valve train 4, thus achieving flow along the test system. The specific temperature and pressure refer to the oil temperature and pressure required for the test, in order to test the effect of different gas contents on the valves at a fixed oil pressure and temperature. The specific temperature and pressure are set according to experience and needs. According to one specific embodiment of the present invention, the specific temperature is 90~110℃ and the specific pressure is 300~400kPa; further, the specific temperature is 100℃ and the specific pressure is 350kPa.

[0070] At the same time, the drive motor is activated to drive the air distribution mechanism.

[0071] S2: The gas is controlled to mix with the engine oil at a specific flow rate by the oil-gas mixing device. The gas content in the engine oil after the gas mixture is measured by the gas content measuring device and recorded as the initial gas content. The valve timing parameters of the engine oil after the gas mixture passes through the valve timing mechanism are measured by the valve timing parameter measuring device and recorded as the initial valve timing parameters. The initial state of the valve timing mechanism is determined based on the initial valve timing parameters.

[0072] Specifically, when the gas content measuring device is Figure 3When the oil-gas mixing device 2 shown is used, the air flow control valve 204 is opened to a certain angle α0, so that the gas enters the mixing chamber 205 through the one-way valve 203 and the vent 207 on the compressed air pipe 202 and mixes with the engine oil. After the engine oil and gas are mixed, the engine oil gas content under the initially adjusted compressed air flow control valve 204 is measured by the gas content measuring device 3. Specifically, three measurements can be performed, and then the average value is taken to obtain the engine oil gas content under the stable state, and the result is recorded as the initial gas content X0.

[0073] Valve timing parameters can specifically include valve lift, vibration, noise, etc. Based on the obtained initial valve timing parameters, and referring to the values ​​of valve timing parameters under different operating states of the valve timing mechanism, such as normal or abnormal, obtained through experience or calibration, the initial state of the valve timing mechanism is determined.

[0074] According to one specific embodiment of the present invention, the valve timing parameters include valve lift, and the initial valve timing parameters include initial valve lift.

[0075] The steps for determining the initial state of the valve train based on initial valve timing parameters include: measuring the maximum valve lift H0 at the initial air-fuel ratio using a laser displacement sensor, and recording this as the initial valve lift. Based on the pre-stored theoretical maximum valve lift H of the valve train, the difference between the theoretical maximum valve lift and the initial valve lift is calculated. The initial state of the valve train is determined by comparing the absolute value of the difference (|H-H0|) with a preset threshold. If the absolute value of the difference is less than the preset threshold, the initial state of the valve train is considered normal; if the absolute value of the difference is greater than or equal to the preset threshold, the initial state of the valve train is considered abnormal. Specifically, the preset threshold is obtained through calibration and reflects the error range of the maximum valve lift of the valve train. According to one specific embodiment of the present invention, the preset threshold is 0.1~0.2 mm.

[0076] More specifically, the preset threshold can be 0.15mm, and the method for judging the initial state of the valve train includes: if |H-H0| < 0.15mm, the initial state of the valve train is judged to be normal; if |H-H0| ≥ 0.15mm, the initial state of the valve train is judged to be abnormal.

[0077] It should be noted that gas content refers to the percentage of gas in the engine oil by volume.

[0078] S3: Adjust the flow rate of the gas mixed with engine oil in the oil-gas mixing device according to the initial state of the gas distribution mechanism.

[0079] Specifically, according to one embodiment of the present invention, if the initial state of the valve train is normal, the flow rate of the gas mixed with engine oil in the oil-gas mixing device is increased; if the initial state of the valve train is abnormal, the flow rate of the gas mixed with engine oil in the oil-gas mixing device is decreased. More specifically, using... Figure 3 When the oil-gas mixing device 2 shown is used, the gas flow rate is increased or decreased by adjusting the angle of the compressed air flow control valve 204.

[0080] Furthermore, the magnitude of the increase or decrease in the flow rate of the gas mixed with the engine oil in the oil-gas mixing device can be set based on experience or needs. According to one specific embodiment of the present invention, the magnitude of the increase or decrease in the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is such that the change in the gas content of the engine oil is 1-3%, more specifically, the change in the gas content of the engine oil is 2%.

[0081] S4: Measure the gas content of the stabilized engine oil using a gas content measuring device and record the gas content as the nth gas content; measure the gas distribution parameters of the engine oil after mixing with gas as it passes through the gas distribution mechanism using a gas distribution parameter measuring device and record the gas distribution parameters as the nth gas distribution parameter; determine the current state of the gas distribution mechanism based on the nth gas distribution parameter.

[0082] Specifically, the gas content of the engine oil under the current compressed air flow control valve is measured using a gas content measuring device. Three measurements can be performed, and the average value is taken and recorded as the nth gas content X. n Where n represents the number of times the gas flow rate mixed with the engine oil is adjusted.

[0083] According to one specific embodiment of the present invention, determining the current state of the valve train based on the nth valve train parameter includes: calculating the difference between the theoretical maximum valve lift of the valve train and the nth valve lift, and determining the current state of the valve train based on the comparison result of the absolute value of the difference with a preset threshold; specifically, the maximum valve lift H at the current air content is measured by a laser displacement sensor. n Let this be the lift of the nth valve. Based on the pre-stored theoretical maximum valve lift H of the valve train, calculate the difference between the theoretical maximum valve lift and the lift of the nth valve, and then use the absolute value of the difference (|HH|) to... n The current state of the gas distribution mechanism is determined by comparing the result with the preset threshold.

[0084] If the absolute value of the difference is less than a preset threshold, the current state of the gas distribution mechanism is determined to be normal; if the absolute value of the difference is greater than or equal to the preset threshold, the current state of the gas distribution mechanism is determined to be abnormal.

[0085] S5: Compare the current state and the initial state of the gas distribution mechanism to determine whether the current state of the gas distribution mechanism is consistent with the initial state of the gas distribution mechanism.

[0086] If not, i.e., the current state is normal / abnormal and the initial state is abnormal / normal, then determine the gas content X of the nth gas. n This refers to the maximum permissible limit of gas content, i.e., the maximum gas content value, of the gas distribution mechanism of this model.

[0087] If so, i.e., both the current state and the initial state are normal or abnormal, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is adjusted again according to the initial state of the valve train. Specifically, if the initial state of the valve train is normal, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is increased; if the initial state of the valve train is abnormal, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is decreased. Further, in one specific embodiment, the increase or decrease in the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is such that the change in the gas content of the engine oil is 2%. After adjustment, return to step S4 and repeat steps S4-S5. Continue operating in the above manner until the current state is inconsistent with the initial state of the valve train, i.e., the valve train state changes abruptly from normal to abnormal or from abnormal to normal, at which point the maximum gas content value is obtained.

[0088] It should be noted that in this step, the current state of the gas distribution mechanism can be compared with the initial state to determine whether the current state of the gas distribution mechanism is consistent with the initial state of the gas distribution mechanism; alternatively, the current state of the gas distribution mechanism (recorded as the nth state) can be compared with the state after the last adjustment (recorded as the n-1th state) to determine whether the current state of the gas distribution mechanism is consistent with the state after the last adjustment; the processing method after the judgment is the same.

[0089] The relationship between gas content and valve lift can be obtained from the collected gas content values ​​and valve lift data; for example Figure 6 As shown, this is the method of using Figure 4 The diagram shows the relationship between air content and valve lift in an experiment conducted using the air content measuring device shown. The graph illustrates the relationship between air content and valve lift under different oil air content conditions. The solid black line represents the relationship between valve lift and crankshaft angle at an air content of X0, where the oil air content is relatively low. When the air flow control valve is adjusted to increase the oil air content to Xn, the gray line indicates the relationship between valve lift and crankshaft angle. At this point, a significant valve lift difference appears at the maximum valve lift, and this difference exceeds a preset threshold. Therefore, Xn is determined to be the maximum allowable air content of the valve train in this experiment, i.e., the maximum air content value.

[0090] The test method for the influence of oil gas content on valve mechanism dynamics provided by this invention can quickly, effectively, and quantitatively analyze the influence of different oil gas contents on the valve mechanism by changing the gas content in the oil and collecting the performance of the valve mechanism under different gas content conditions. It realizes the test of the influence of gas content on valve performance. The test method is convenient and the results are intuitive and reliable. It solves the problem of not being able to calculate the influence of oil gas content on valve mechanism in CAE simulation calculation, which is of great significance for the design of valve mechanism.

[0091] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A test method for the effect of engine oil gas content on valve mechanism dynamics, characterized in that, The test method is performed using a test system for the effect of oil gas content on valve mechanism dynamics. The test system includes an oil temperature control device, an oil-air mixing device, an oil content measuring device, and a valve train mechanism connected in sequence and in communication, as well as a drive motor connected to the valve train mechanism and a valve train parameter measuring device for measuring the valve train parameters. The test method includes the following steps: S1: The oil temperature control device causes the oil to flow into the oil-air mixing device at a specific temperature and pressure; the drive motor is activated to drive the valve train. S2: The gas is controlled to mix with the engine oil at a specific flow rate by the oil-gas mixing device, and the gas content in the engine oil after mixing is measured by the gas content measuring device and recorded as the initial gas content; the gas distribution parameter is measured by the gas distribution parameter measuring device when the engine oil after mixing passes through the gas distribution mechanism and recorded as the initial gas distribution parameter; the initial state of the gas distribution mechanism is determined based on the initial gas distribution parameter. S3: Adjust the flow rate of the gas mixed with the engine oil in the oil-gas mixing device according to the initial state of the gas distribution mechanism; S4: Measure the gas content of the stabilized engine oil using the gas content measuring device, and record the gas content as the nth gas content; measure the gas distribution parameters of the engine oil mixed with the gas as it passes through the gas distribution mechanism using the gas distribution parameter measuring device, and record the gas distribution parameters as the nth gas distribution parameter; determine the current state of the gas distribution mechanism based on the nth gas distribution parameter. S5: Compare the current state and the initial state of the gas distribution mechanism to determine whether the current state of the gas distribution mechanism is consistent with the initial state of the gas distribution mechanism. If so, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is adjusted again according to the initial state of the gas distribution mechanism, and step S4 continues; If not, then the nth gas content is determined to be the maximum gas content value of the gas distribution mechanism; Where n represents the number of times the flow rate of the gas mixed with the engine oil is adjusted.

2. The test method as described in claim 1, characterized in that, The valve timing parameters include valve lift, and the initial valve timing parameters include initial valve lift; In step S2, the step of determining the initial state of the gas distribution mechanism based on the initial gas distribution parameters includes: Calculate the difference between the theoretical maximum valve lift of the valve train and the initial valve lift, and determine the initial state of the valve train based on the comparison of the absolute value of the difference with a preset threshold; wherein, If the absolute value of the difference is less than the preset threshold, then the initial state of the gas distribution mechanism is determined to be normal. If the absolute value of the difference is greater than or equal to the preset threshold, then the initial state of the gas distribution mechanism is determined to be abnormal. In step S3, if the initial state of the gas distribution mechanism is normal, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is increased; if the initial state of the gas distribution mechanism is abnormal, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is decreased.

3. The test method as described in claim 2, characterized in that, In steps S3 and S5, the flow rate of the gas mixed with the engine oil in the oil-gas mixing device is increased or decreased by such that the change in the gas content of the engine oil is 1-3%.

4. The test method as described in claim 2, characterized in that, The nth valve timing parameter includes the nth valve lift; In step S4, determining the current state of the gas distribution mechanism based on the nth gas distribution parameter includes: Calculate the difference between the theoretical maximum valve lift of the valve train and the nth valve lift, and determine the current state of the valve train based on the comparison between the absolute value of the difference and a preset threshold; wherein, If the absolute value of the difference is less than the preset threshold, then the current state of the gas distribution mechanism is determined to be normal. If the absolute value of the difference is greater than or equal to the preset threshold, then the current state of the gas distribution mechanism is determined to be abnormal.

5. The test method as described in claim 2, characterized in that, The preset threshold is 0.1~0.2mm.

6. The test method according to any one of claims 1-5, characterized in that, In step S1, the specific temperature is 90~110℃ and the specific pressure is 300~400kPa.

7. A test system for the effect of engine oil gas content on valve mechanism dynamics, characterized in that, The test method for performing the effect of oil gas content on valve mechanism dynamics as described in any one of claims 1-6; The testing system includes an oil temperature control device, an oil-air mixing device, an air content measuring device, and an air distribution mechanism connected in sequence and in communication, as well as a drive motor connected to the air distribution mechanism and an air distribution parameter measuring device for measuring the air distribution parameters of the air distribution mechanism; wherein, The oil temperature control device is used to ensure that the oil flows into the oil-air mixing device at a specific temperature and pressure. The oil-gas mixing device is used to control the gas to mix with the engine oil at a specific flow rate; The gas content measuring device is used to measure the gas content of the engine oil after the gas is mixed. The drive motor is used to drive the gas distribution mechanism to operate; The valve timing parameter measuring device is used to measure the valve timing parameters when the engine oil passes through the operating valve timing mechanism.

8. The testing system as described in claim 7, characterized in that, The oil-gas mixing device includes an oil inlet pipe, a compressed air pipe, a one-way valve, an air flow control valve, a mixing chamber, and an oil outlet pipe; wherein... One end of the oil inlet pipe is connected to the oil temperature control device, and the other end of the oil inlet pipe is connected to one end of the mixing chamber, so that the oil from the oil temperature control device enters the mixing chamber through the oil inlet pipe; One end of the compressed air pipe is inserted into the mixing chamber from the side wall of the mixing chamber, and one end of the compressed air pipe is provided with a plurality of vent holes spaced apart along the length of the compressed air pipe. The plurality of vent holes are used to introduce gas from the compressed air pipe into the mixing chamber to mix with the engine oil in the mixing chamber. The air flow control valve is located at the other end of the compressed air pipe, and the flow rate of the gas entering the mixing chamber through the compressed air pipe is controlled by controlling the angle of the air flow control valve. The one-way valve is disposed on the compressed air pipe and is located between the air flow control valve and the plurality of vent holes in the gas flow direction, for the purpose of restricting the oil in the mixing chamber from flowing out through the compressed air pipe; The other end of the mixing chamber is connected to one end of the oil outlet pipe so that the oil mixed with the gas in the mixing chamber flows out from the oil outlet pipe.

9. The testing system as described in claim 7 or 8, characterized in that, The valve train includes a valve train platform and a valve train cylinder head; the drive motor is connected to the valve train cylinder head and is used to drive the valve train cylinder head to move. Furthermore, the gas distribution parameter measuring device includes a laser displacement sensor.

10. The testing system as described in claim 9, characterized in that, The testing system also includes an oil sensor, an oil filter, an encoder, a torque sensor, and a diaphragm pump; The oil sensor and the oil filter are disposed between the oil-gas mixing device and the gas content measuring device; The encoder and the torque sensor are disposed between the drive motor and the cylinder head. The oil temperature control device is connected to the valve train mechanism, and the diaphragm pump is located between the oil temperature control device and the valve train mechanism.

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