A lubrication system for an engine and a control method
By introducing a design that connects the pressure relief valve and the feedback oil chamber into the engine lubrication system, the problems of excessive oil pump power consumption and lubrication circuit leakage caused by poor oil flow during cold starts are solved, achieving rapid response and stable lubrication effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DONGFENG MOTOR GRP
- Filing Date
- 2023-11-14
- Publication Date
- 2026-07-21
Smart Images
Figure CN117418916B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of engine lubrication technology, and more particularly to an engine lubrication system and control method. Background Technology
[0002] The function of the oil pump is to increase the oil to a certain pressure and force it to the moving surfaces of various engine parts, thereby lubricating and cooling the engine components.
[0003] In current technical solutions, to ensure the main oil circuit pressure of the engine meets the target pressure requirement, a feedback oil circuit is drawn from the oil passage to the oil pump feedback chamber. When the main oil circuit pressure exceeds the target pressure, the feedback oil circuit pressure pushes the slider to rotate against the spring force, thereby reducing the eccentricity between the oil pump rotor and the slider, and thus reducing the oil pump displacement. However, during a cold start of a car engine, the high viscosity of the oil leads to high oil flow resistance and excessive oil pressure in the main oil circuit. Furthermore, due to the high viscosity and slow oil flow, the oil cannot quickly enter the oil pump feedback chamber, resulting in a slow response. The oil pump operates at maximum displacement, further increasing the oil pressure in the main oil circuit, leading to excessive oil pump power consumption and even leakage in the engine lubrication circuit. Summary of the Invention
[0004] In view of this, the main objective of the present invention is to provide a lubrication system and control method for an engine, so as to solve the technical problems of how to improve the response speed of the feedback oil chamber during cold start of an automobile engine, and avoid excessive power consumption of the oil pump and leakage of the engine lubrication circuit.
[0005] To achieve the above objectives, embodiments of the present invention provide a lubrication system for an engine, the lubrication system comprising: an oil storage structure having an oil storage chamber for storing engine oil; a lubrication oil passage communicating with the oil storage chamber and used for lubricating engine components; and an oil pump disposed in the lubrication oil passage for driving engine oil from the oil storage chamber into the lubrication oil passage and driving the engine oil to circulate within the lubrication oil passage; wherein the oil pump has a feedback oil chamber and a pressure relief valve, the oil pressure in the feedback oil chamber is negatively correlated with the displacement of the oil pump, and the feedback oil chamber is connected to the pressure relief valve.
[0006] Furthermore, the lubrication circuit includes: a main oil circuit having the oil pump and used for lubricating the components of the engine; a pressure relief branch connecting the pressure relief valve and the feedback oil chamber; and a feedback branch connecting the main oil circuit and the feedback oil chamber.
[0007] Furthermore, the pressure relief branch is connected in parallel with the feedback branch, the pressure relief branch has a first switching valve, and the feedback branch has a second switching valve.
[0008] Furthermore, the pressure relief branch is connected to the feedback oil chamber through the feedback branch; wherein, the feedback branch has a solenoid valve, the solenoid valve has a first opening, a second opening and a third opening that can be controlled to open and close, the first opening is connected to the pressure relief branch, the second opening is connected to the feedback oil chamber, and the third opening is connected to the oil storage chamber.
[0009] Furthermore, the first opening is equipped with a one-way valve.
[0010] This invention also provides a control method for a lubrication system, which is applied to the lubrication system of the engine described above. The control method includes: acquiring state data of the engine and determining the working state of the engine based on the state data; starting the oil pump and connecting the pressure relief valve to the feedback oil chamber when the working state is a cold start state, and maintaining the oil pressure in the feedback oil chamber; and isolating the pressure relief valve from the feedback oil chamber when the duration of maintaining the oil pressure in the feedback oil chamber reaches a duration threshold.
[0011] Further, the lubrication circuit includes a main oil circuit, a pressure relief branch connecting the pressure relief valve and the feedback oil chamber, and a feedback branch connecting the main oil circuit and the feedback oil chamber; the step of starting the oil pump and connecting the pressure relief valve to the feedback oil chamber and maintaining the oil pressure in the feedback oil chamber in the cold start state includes: starting the oil pump in the cold start state; controlling the connection between the pressure relief branch and the feedback oil chamber, and controlling the isolation between the feedback branch and the feedback oil chamber; the step of controlling the isolation between the pressure relief valve and the feedback oil chamber when the duration of maintaining the oil pressure in the feedback oil chamber reaches a duration threshold includes: controlling the isolation between the pressure relief branch and the feedback oil chamber when the duration of the connection between the pressure relief branch and the feedback oil chamber reaches the duration threshold, and controlling the connection between the feedback branch and the feedback oil chamber.
[0012] Further, the feedback branch is connected in parallel with the pressure relief branch, the pressure relief branch has a first switching valve, and the feedback branch has a second switching valve; controlling the pressure relief branch to communicate with the feedback oil chamber and controlling the feedback branch to isolate from the feedback oil chamber includes: controlling the first switching valve to open and the second switching valve to close; controlling the pressure relief branch to isolate from the feedback oil chamber and controlling the feedback branch to communicate with the feedback oil chamber when the duration of communication between the pressure relief branch and the feedback oil chamber reaches the duration threshold includes: controlling the first switching valve to close and controlling the second switching valve to open when the duration of the first switching valve being open and the second switching valve being closed is greater than the duration threshold.
[0013] Furthermore, the pressure relief branch has a solenoid valve, which has a first opening, a second opening, and a third opening that can be controlled to open and close. The first opening is connected to the pressure relief branch, the second opening is connected to the feedback oil chamber, and the third opening is connected to the oil storage chamber. Controlling the connection between the pressure relief branch and the feedback oil chamber, and controlling the isolation between the feedback branch and the feedback oil chamber, includes: controlling the first opening and the second opening to open, and controlling the third opening to close.
[0014] Furthermore, a temperature sensor is installed in the lubrication oil circuit, and the status data includes: the engine speed; acquiring the engine status data and determining the engine's operating status based on the status data includes: acquiring the engine speed and acquiring the oil temperature by the temperature sensor; when the engine speed is less than a speed threshold and the oil temperature is less than a temperature threshold, the engine is determined to be in a cold start state.
[0015] This invention provides a lubrication system for an engine, comprising an oil reservoir, a lubrication oil passage, and an oil pump. The oil reservoir has an oil storage chamber for storing engine oil. The lubrication oil passage is connected to the oil storage chamber and is used to lubricate engine components. The oil pump is disposed in the lubrication oil passage and is used to drive engine oil from the oil storage chamber into the lubrication oil passage and drive the engine oil to circulate within the lubrication oil passage. The oil pump has a feedback oil chamber and a pressure relief valve. The oil pressure in the feedback oil chamber is negatively correlated with the displacement of the oil pump, and the feedback oil chamber is connected to the pressure relief valve. During a cold start, the engine oil viscosity is very high, and the oil pump operates at maximum displacement. Due to the poor fluidity of the oil at low temperatures, the oil in the main oil circuit cannot flow to the feedback oil chamber in time. This causes the oil pump to operate at a high displacement, further increasing the pressure in the engine's main oil circuit. By installing a pressure relief valve on the oil pump, the high-pressure oil is discharged when the valve opens, preventing excessive pressure on the engine's main oil circuit. Furthermore, the design of connecting the pressure relief valve to the feedback oil chamber allows some oil to be directly introduced into the feedback oil chamber, effectively shortening the time it takes for the oil to reach the chamber. Within a short time, the oil pressure in the feedback oil chamber pushes the slider to rotate against the spring force, reducing the eccentricity between the oil pump rotor and the slider, thus reducing the oil pump's displacement. This avoids excessive oil pump power consumption and leaks in the engine's lubrication system. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of a lubrication system for an engine provided in an embodiment of the present invention;
[0017] Figure 2This is a schematic diagram of the structure of an engine oil pump provided in an embodiment of the present invention;
[0018] Figure 3 A schematic diagram of the structure of another engine lubrication system provided in an embodiment of the present invention;
[0019] Figure 4 A schematic flowchart illustrating a control method for a lubrication system provided in an embodiment of the present invention;
[0020] Figure 5 A schematic flowchart of another control method for a lubrication system provided in an embodiment of the present invention;
[0021] Figure 6 A schematic flowchart of another control method for a lubrication system provided in an embodiment of the present invention;
[0022] Figure 7 This is a flowchart illustrating another control method for a lubrication system provided in an embodiment of the present invention.
[0023] Explanation of reference numerals in the attached figures
[0024] 100. Lubrication system; 110. Oil reservoir structure; 111. Oil reservoir chamber; 120. Lubricating oil circuit; 121. Main oil circuit; 122. Pressure relief branch; 1221. First switching valve; 123. Feedback branch; 1231. Second switching valve; 1232. Solenoid valve; 12321. First opening; 12322. Second opening; 12323. Third opening; 130. Oil pump; 131. Feedback oil chamber; 1311. Feedback oil chamber inlet; 132. Pressure relief valve; 133. Slider; 134. Rotating pin; 135. Blade; 136. Rotor; 137. Spring; 138. Sealing rubber; 139. Pump body; 141. Oil pump outlet; 150. Oil cooler and oil filter. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0026] The specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction. For example, different combinations of specific technical features can form different embodiments and technical solutions. To avoid unnecessary repetition, the various possible combinations of the specific technical features in this invention will not be described separately.
[0027] In the following description, the terms "first," "second," etc., are used merely to distinguish different objects and do not indicate that the objects have the sameness or relationship. It should be understood that the directional descriptions "above," "below," "outside," and "inside" refer to the orientation under normal use conditions, while "left" and "right" refer to the left and right directions shown in the corresponding diagrams, which may or may not be the left and right directions under normal use conditions.
[0028] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. The term "connection," unless otherwise specified, includes both direct and indirect connections.
[0029] In specific embodiments, the engine's lubrication system is suitable for lubricating any type of engine. For example, the engine's lubrication system is suitable for diesel engines; for example, the engine's lubrication system is suitable for gasoline engines; the engine's lubrication system is suitable for lubricating any type of automobile engine. For example, the engine's lubrication system is suitable for new energy hybrid passenger cars, providing depressurized lubrication during cold starts of the hybrid passenger car engine; for example, the engine's lubrication system is suitable for new energy commercial hybrid buses, providing depressurized lubrication during cold starts of the commercial hybrid bus engine. The control method is the same as the control method described above for the lubrication system. For ease of explanation, the following description uses the application of this lubrication system to new energy hybrid passenger cars as an example.
[0030] In some embodiments, such as Figure 1 and Figure 2 As shown, the lubrication system 100 includes an oil reservoir 110, a lubrication oil passage 120, and an oil pump 130. The oil reservoir 110 has an oil reservoir 111 for storing engine oil. The lubrication oil passage 120 is connected to the oil reservoir 111 and is used to lubricate the engine components. The oil pump 130 is disposed in the lubrication oil passage 120 and is used to drive engine oil from the oil reservoir 111 into the lubrication oil passage 120 and drive the engine oil to circulate within the lubrication oil passage 120.
[0031] Specifically, to facilitate a full understanding and explanation of this application, the principle of the engine lubrication system and the problems existing in current lubrication systems will first be explained. Currently, a variable displacement oil pump is commonly used. When the engine is running forward, the operation of the oil pump 130 drives the rotor 136 to rotate counterclockwise. The space between the two vanes 135 in the left chamber gradually increases, forming a vacuum, and the oil in the oil pan is drawn into the left chamber. The space between the two vanes 135 in the right chamber gradually decreases, forming pressure, and then the pressurized oil is sprayed out to lubricate the engine components. The rotor 136 of the oil pump 130 rotates continuously under the drive of the engine crankshaft, and the oil is continuously pumped out. The oil pump 130 achieves its pumping function by relying on the eccentricity between the rotor 136 and the slider 133. The smaller the eccentricity between the rotor 136 and the slider 133, the smaller the change in space between the vanes 135 when the rotor 136 rotates. As the number of revolutions increases, the amount of oil pumped by the oil pump decreases. When the eccentricity between the rotor 136 and the slider 133 is zero, the oil pump 130 cannot produce pressurized oil. To meet the lubrication requirements of the engine components from the main oil circuit 121, a feedback oil circuit is typically connected to either the main oil circuit 121 or the oil outlet of the oil pump 130. This feedback oil circuit connects the main oil circuit 121 or the oil outlet of the oil pump 130 to the feedback oil chamber 131, allowing oil from the oil pump 130 outlet or the main oil circuit 121 to flow into the feedback oil chamber 131. The oil in the feedback oil chamber 131 pushes the slider 133 to rotate clockwise around the rotating pin 134, overcoming the spring force of the spring 137. This ultimately reduces the eccentricity between the slider 133 and the rotor 136, thereby reducing the displacement of the oil pump 130.
[0032] The feedback oil circuit connects to the oil outlet of the oil pump 130. Fluctuations in the oil pressure at the oil outlet of the oil pump 130 cause fluctuations in the oil pump's displacement, which in turn leads to pressure fluctuations in the main oil circuit 121. Furthermore, there is a significant difference between the oil pressure at the oil outlet of the oil pump 130 and the oil pressure in the main oil circuit 121; the oil pressure at the oil pump 130 is higher than that in the main oil circuit 121. Therefore, the oil pressure introduced into the feedback oil circuit from the oil pump 130's outlet differs from the required oil pressure in the main oil circuit 121, resulting in a certain degree of error in its control accuracy. When the feedback oil circuit is connected to the main oil circuit 121, during a cold start of the engine, the engine oil first needs to fill the oil passage cavity from the oil outlet of the oil pump 130 to the main oil circuit 121, as well as the oil passage cavity from the main oil circuit 121 to the feedback oil circuit inlet, and the volume of the oil cooler and oil filter 150. Due to the very high viscosity of the engine oil, its fluidity is poor at low temperatures, and the feedback time is long. The engine oil in the main oil circuit 121 cannot flow to the feedback oil cavity 131 in time. Furthermore, the oil pump 130 operates at its maximum displacement, which causes the oil pump 130 to operate at a high displacement. The oil discharged by the oil pump 130 will further increase the pressure of the engine's main oil circuit 121, resulting in prolonged high oil pressure in the engine. This will increase the power consumption of the oil pump 130 and cause leakage in the engine's lubrication circuit.
[0033] The lubrication system 100 of this application includes an oil storage structure 110, a lubrication oil passage 120, and an oil pump 130. The oil storage structure 110 has an oil storage chamber 111 for storing engine oil. The engine oil required for lubrication of engine parts is obtained from the oil storage chamber 111. Under the action of the oil pump 130, the engine oil in the oil storage chamber 111 is sucked into the lubrication oil passage 120. The lubrication oil passage 120 is used to deliver the engine oil to various parts of the engine for lubrication. At the same time, the engine oil used to lubricate the parts flows back to the oil storage chamber 111, thereby realizing reuse. The engine oil pan is part of the oil storage structure 110, and the receiving cavity in the oil pan for storing engine oil is part of the oil storage chamber 111.
[0034] The oil pump 130 has a feedback oil chamber 131 and a pressure relief valve 132. The oil pressure in the feedback oil chamber 131 is negatively correlated with the displacement of the oil pump 130, and the feedback oil chamber 131 is connected to the pressure relief valve 132.
[0035] Specifically, the space enclosed by the slider 133, rotating pin 134, pump body 139, and sealing rubber 138 is the feedback oil chamber 131. After the engine oil enters the feedback oil chamber 131, the engine oil in the feedback oil chamber 131 pushes the slider 133 to overcome the elastic force of the spring 137 and rotate clockwise around the rotating pin 134, ultimately reducing the eccentricity between the slider 133 and the rotor 136, thereby reducing the displacement of the oil pump 130. It can be simply understood that the greater the oil pressure in the feedback oil chamber 131, the greater the force that the engine oil in the feedback oil chamber 131 exerts on the slider 133 to overcome the elastic force of the spring 137, the greater the distance the slider 133 moves, the smaller the eccentricity between the slider 133 and the rotor 136, and the smaller the displacement of the oil pump 130. Therefore, the oil pressure in the feedback oil chamber 131 is negatively correlated with the displacement of the oil pump 130. Considering that the engine oil viscosity is very high during cold starts and its fluidity is poor at low temperatures, the oil cannot quickly flow into the feedback oil chamber 131 to adjust the displacement of the oil pump 130. Furthermore, if the oil pump 130 operates at its maximum displacement, it will be in a high-displacement state, further increasing the pressure in the engine's main oil circuit 121. Therefore, a pressure relief valve 132 is installed in the oil pump 130. When the outlet pressure of the oil pump 130 becomes excessive, the pressure relief valve 132 opens, utilizing the pressure relief valve 132... Opening 2 discharges the high-pressure oil into the oil reservoir 111, avoiding excessive pressure on the engine's main oil circuit 121. Part of the oil in the pressure relief valve 132 is directly introduced into the feedback oil chamber 131, bypassing the main oil circuit 121, effectively shortening the response time of the feedback oil chamber 131. Within a short time, the oil pressure in the feedback oil chamber pushes the slider 133 to rotate against the spring force. Any design that can introduce the oil from the pressure relief valve 132 into the feedback oil chamber 131 meets the requirements; specific embodiments will be given later.
[0036] This invention provides a lubrication system for an engine, comprising an oil reservoir, a lubrication oil passage, and an oil pump. The oil reservoir has an oil storage chamber for storing engine oil. The lubrication oil passage is connected to the oil storage chamber and is used to lubricate engine components. The oil pump is disposed in the lubrication oil passage and is used to drive engine oil from the oil storage chamber into the lubrication oil passage and drive the engine oil to circulate within the lubrication oil passage. The oil pump has a feedback oil chamber and a pressure relief valve. The oil pressure in the feedback oil chamber is negatively correlated with the displacement of the oil pump, and the feedback oil chamber is connected to the pressure relief valve. During a cold start, the engine oil viscosity is very high, and the oil pump operates at maximum displacement. Due to the poor fluidity of the oil at low temperatures, the oil in the main oil circuit cannot flow to the feedback oil chamber in time. This causes the oil pump to operate at a high displacement, further increasing the pressure in the engine's main oil circuit. By installing a pressure relief valve on the oil pump, the high-pressure oil is discharged when the valve opens, preventing excessive pressure on the engine's main oil circuit. Furthermore, the design of connecting the pressure relief valve to the feedback oil chamber allows some oil to be directly introduced into the feedback oil chamber, effectively shortening the time it takes for the oil to reach the chamber. Within a short time, the feedback oil chamber uses the oil pressure to push the slider to rotate against the spring force, thereby reducing the eccentricity between the oil pump rotor and the slider, reducing the oil pump displacement, and thus avoiding excessive oil pump power consumption and leakage in the engine lubrication circuit.
[0037] In some embodiments, such as Figure 1As shown, the lubrication circuit 120 includes a main oil circuit 121, a pressure relief branch 122, and a feedback branch 123. The main oil circuit 121 has an oil pump 130 and is used to lubricate engine components. The pressure relief branch 122 connects to the pressure relief valve 132 and the feedback oil chamber 131. The feedback branch 123 connects to the main oil circuit 121 and the feedback oil chamber 131. Specifically, to achieve lubrication of engine components by engine oil, the lubrication circuit 120 includes a main oil circuit 121, which is connected to the oil reservoir 111. An oil pump 130 is installed on the main oil circuit 121. The oil pump 130 draws oil from the oil reservoir 111 and uses it to lubricate engine components through the main oil circuit 121. The specific dimensions of the main oil circuit 121 are not required or limited here, as long as they meet the actual needs. When the engine is cold-started, the main oil circuit 121 already has a large pressure. To prevent the pressure in the main oil circuit 121 from increasing further, the lubrication circuit 120 also includes a pressure relief branch 122. The pressure relief branch 122 connects the pressure relief valve 132 and the feedback oil chamber 131. It can be understood that when the pressure relief valve 132 is open, the engine oil can flow directly into the feedback oil chamber 131 through the pressure relief branch 122. This method can avoid the engine oil flowing into the feedback oil chamber 131 through the main oil circuit 121, shortening the path and time. It should be emphasized here that the pressure relief branch 122 can also connect the pressure relief valve 132 and the oil reservoir 111. When the pressure relief valve 132 is open, some engine oil can flow directly into the oil reservoir 111 through the pressure relief valve 132, and some engine oil can flow into the feedback oil chamber 131 through the feedback oil chamber inlet 1311. To facilitate real-time adjustment of the oil pump 130's displacement, the lubrication circuit 120 also includes a feedback branch 123. The feedback branch 123 connects the main oil circuit 121 and the feedback oil chamber 131. The oil pump 130's displacement is adjusted in real-time based on the oil pressure difference between the target oil pressure and the actual oil pressure in the main oil circuit 121. Similarly, the specific dimensions of the pressure relief branch 122 and the feedback branch 123 are not required here, as long as they meet actual needs. The specific connection method between the pressure relief branch 122 and the feedback branch 123 will be described below.
[0038] In some embodiments, such as Figure 3As shown, the pressure relief branch 122 and the feedback branch 123 can be controlled independently. The pressure relief branch 122 and the feedback branch 123 are connected in parallel. The pressure relief branch 122 has a first switching valve 1221, and the feedback branch 123 has a second switching valve 1231. When rapid pressure reduction is required, only the first switching valve 1221 can be opened and the second switching valve 1231 can be closed. The oil from the oil pump outlet 141 flows into the feedback oil chamber 131. At this moment, the oil pressure in the feedback oil chamber 131 increases rapidly, and the slider 133 moves rapidly, quickly reducing the displacement of the oil pump 130. After the oil temperature rises and its fluidity increases, it can be adjusted in real time according to the actual needs of the main oil circuit 121. At this time, only the second switching valve 1231 can be opened and the first switching valve 1221 can be closed. The displacement of the oil pump 130 can be adjusted in real time according to the oil pressure difference between the target oil pressure and the actual oil pressure in the main oil circuit 121.
[0039] In some embodiments, such as Figure 1 As shown, the pressure relief branch 122 and the feedback branch 123 can be interconnected. The feedback branch 123 has a solenoid valve 1232, which has a first opening 12321, a second opening 12322 and a third opening 12323 that can be controlled to open and close. One end of the pressure relief branch 122 is connected to the pressure relief valve 132, and the other end is connected to the first opening 12321 of the solenoid valve 1232. The second opening 12322 is connected to the feedback oil chamber 131, so that the pressure relief branch 122 is connected to the feedback oil chamber 131 through the feedback branch 123. The third opening 12323 is connected to the oil storage chamber 111. Each opening can be controlled independently. For example, to increase the oil pressure in the feedback oil chamber 131, the first opening 12321 and the second opening 12322 are opened, and the third opening 12323 is closed. The oil from the oil pump outlet 141 can enter the feedback oil chamber 131 through the pressure relief branch 122 via the first opening 12321 and the second opening 12322, thereby increasing the oil pressure in the feedback oil chamber 131. For example, to maintain the stability of the oil pressure in the feedback oil chamber 131, the second opening 12322 is closed. The oil in the feedback oil chamber 131 cannot be increased or discharged, maintaining a stable pressure, thereby ensuring a stable discharge of the oil pump 130. For example, in order to increase the displacement of the oil pump 130, the second opening 12322 and the third opening 12323 are opened, and the first opening 12321 is closed. The oil in the feedback oil chamber 131 can enter the oil storage chamber 111 through the feedback branch 123 via the second opening 12322 and the third opening 12323, thereby reducing the oil pressure in the feedback oil chamber 131.
[0040] In some embodiments, to simplify operation, the first opening 12321 is provided with a one-way valve, so that the oil can only flow from the pressure relief valve 132 into the feedback oil chamber 131 and cannot flow from the feedback oil chamber 131 to the pressure relief valve 132, thereby ensuring that the first opening 12321 and the second opening 12322 are always in the open state.
[0041] This embodiment provides a control method for a lubrication system, which is applicable to systems such as... Figures 1 to 3 The lubrication system shown in any of the images. Please refer to [the image]. Figure 4 , Figure 4 This is a flowchart illustrating a control method for a lubrication system provided in an embodiment of the present invention. The control method includes the following steps:
[0042] Step S100: Obtain engine status data and determine engine operating status based on the status data.
[0043] Specifically, the first step is to obtain the engine's status information, including engine temperature and engine speed. Any method that can acquire these parameters is acceptable. For example, a speed sensor can be installed on the engine crankshaft to obtain the crankshaft speed. A crankshaft speed greater than zero indicates the engine is running, while a crankshaft speed of zero indicates the engine is stopped. Alternatively, a temperature sensor can be installed in the oil pan to obtain the engine oil temperature. When the oil temperature is below a preset threshold, the engine oil is considered to be in a low-temperature state; when the oil temperature is not lower than the preset threshold, the engine oil is considered to be in a non-low-temperature state. The specific preset temperature threshold is not limited; for example, a preset threshold of 5 degrees Celsius would indicate that the engine oil is in a low-temperature state when the oil temperature is below 5 degrees Celsius. When the engine is running and the engine oil is in a low-temperature state, the control system determines that the engine is in a cold start state.
[0044] Step S200: In the cold start state, start the oil pump and connect the pressure relief valve to the feedback oil chamber, and maintain the oil pressure in the feedback oil chamber.
[0045] Specifically, when the control system determines that the engine is in a cold start state, it sends a control command. The oil pump responds to this command and begins operation. Simultaneously, due to the high viscosity and pressure of the oil at low temperatures, the high-pressure oil pushes the pressure relief valve open, allowing oil to flow into the feedback oil chamber. The oil pressure in the feedback oil chamber determines the oil pump's displacement. During a cold start, the oil pump's displacement should be minimized to operate at its minimum displacement. The oil pressure in the feedback oil chamber is determined based on this minimum displacement. For example, by setting the minimum oil pump displacement, the oil pressure can be set, such as 2 bar (1 bar = 100 kPa). When the oil pressure in the feedback oil chamber reaches the required level, the control system prevents oil from entering or leaving the chamber, thus maintaining stable oil pressure.
[0046] In step S300, while maintaining the oil pressure in the feedback oil chamber for a duration threshold, the pressure relief valve is isolated from the feedback oil chamber.
[0047] Specifically, while maintaining stable oil pressure in the feedback oil chamber, the control system isolates the pressure relief valve from the feedback oil chamber, preventing oil from entering or leaving it. The specific duration threshold is not limited; the purpose of maintaining this duration is to ensure that the oil pumped by the oil pump has filled the entire engine oil passage. The oil pump solenoid valve then enters its normal control mode, and oil in the main oil circuit enters the feedback oil chamber through the solenoid valve. The oil pump displacement is controlled in real-time to ensure the engine's main oil circuit pressure reaches the target pressure. For example, if the duration threshold is 4 seconds, the oil pressure in the feedback oil chamber is maintained constant for 4 seconds. Within 4 seconds, the oil pumped by the oil pump has filled the entire engine oil passage. After 4 seconds, the control system allows oil to flow in or out of the feedback oil chamber.
[0048] In some embodiments, such as Figure 5 As shown, Figure 5 This is a flowchart illustrating another control method for a lubrication system provided in an embodiment of the present invention, based on... Figure 4 , Figure 5 In step S200, when the operating state is cold start, the oil pump is started, and the pressure relief valve is connected to the feedback oil chamber, and the oil pressure in the feedback oil chamber is maintained, including:
[0049] Step S210: Start the oil pump while the working state is cold start.
[0050] Specifically, the lubrication circuit includes the main oil circuit, the pressure relief branch connecting the pressure relief valve and the feedback oil chamber, and the feedback branch connecting the main oil circuit and the feedback oil chamber. When the control system determines that the engine is in a cold start state, the control system sends a control command. The oil pump responds to the control command and runs, while the pressure relief valve is also opened by the high-pressure oil.
[0051] Step S220: Control the pressure relief branch to connect with the feedback oil chamber, and control the feedback branch to isolate from the feedback oil chamber.
[0052] Specifically, if a control valve switch exists in the pressure relief branch, the control system also needs to open the valve in the pressure relief branch to connect the pressure relief branch with the feedback oil chamber, allowing the oil in the pressure relief valve to flow into the feedback oil chamber. Simultaneously, to maintain stable oil pressure in the feedback oil chamber, the control system needs to isolate the feedback branch from the feedback oil chamber. For example, if a valve is installed on the feedback branch, the control system can close the valve in the feedback branch to ensure isolation between the feedback branch and the feedback oil chamber, preventing the oil in the feedback oil chamber from flowing into the feedback branch.
[0053] Figure 5 Step S300, where the duration of maintaining the oil pressure in the feedback oil chamber reaches a duration threshold, involves controlling the pressure relief valve to isolate from the feedback oil chamber, including:
[0054] Step S310: When the duration of the pressure relief branch and the feedback oil chamber being connected reaches a time threshold, the pressure relief branch is isolated from the feedback oil chamber, and the feedback branch is connected to the feedback oil chamber.
[0055] Specifically, when maintaining stable oil pressure in the feedback oil chamber, the control system isolates the pressure relief valve from the feedback oil chamber, preventing oil from entering or leaving it. The specific duration threshold is not limited; for example, a threshold of 4 seconds maintains constant oil pressure in the feedback oil chamber for 4 seconds. Once the pressure relief branch is connected to the feedback oil chamber for the required duration (after 4 seconds), the control system connects the feedback branch to the feedback oil chamber, allowing oil to flow in or out. The oil pump solenoid valve enters normal control mode, and oil from the main oil passage enters the feedback oil chamber via the solenoid valve, controlling the oil pump displacement in real time to ensure the engine's main oil passage pressure reaches the target pressure.
[0056] In some embodiments, such as Figure 6 As shown, Figure 6 This is a flowchart illustrating another control method for a lubrication system provided in an embodiment of the present invention, based on... Figure 5 , Figure 6 Step S220, which controls the connection between the pressure relief branch and the feedback oil chamber and controls the isolation between the feedback branch and the feedback oil chamber, includes:
[0057] Step S221: Control the first switching valve to open and the second switching valve to close.
[0058] Specifically, the pressure relief branch and the feedback branch are connected in parallel. The pressure relief branch has a first switching valve, and the feedback branch has a second switching valve. When the control system controls the first switching valve to open, the pressure relief branch is connected to the feedback oil chamber. When the control system controls the second switching valve to close, the feedback branch is isolated from the feedback oil chamber.
[0059] Figure 6 Step S310 further includes step S311, where, under the condition that the duration of the first switching valve being open and the second switching valve being closed is greater than a duration threshold, the first switching valve is controlled to close and the second switching valve is controlled to open.
[0060] Specifically, within a preset time threshold, to maintain stable oil pressure in the feedback oil chamber, the control system closes both the first and second switching valves to isolate the pressure relief valve from the feedback oil chamber, preventing oil from entering or leaving the chamber. After the time threshold is exceeded, the control system closes the first switching valve and opens the second switching valve, connecting the feedback branch to the feedback oil chamber, allowing oil to flow in or out of the chamber.
[0061] In some embodiments, such as Figure 7 As shown, Figure 7 This is a flowchart illustrating another control method for a lubrication system provided in an embodiment of the present invention, based on... Figure 5 , Figure 7 Step S220, which controls the connection between the pressure relief branch and the feedback oil chamber and controls the isolation between the feedback branch and the feedback oil chamber, includes:
[0062] Step S222: Control the first opening and the second opening to open, and control the third opening to close.
[0063] Specifically, the pressure relief branch has a solenoid valve with a first opening, a second opening, and a third opening that can be controlled to open and close. The first opening is connected to the pressure relief branch, the second opening is connected to the feedback oil chamber, and the third opening is connected to the oil reservoir. The feedback branch is also connected to the first opening and contains a control valve. At this time, the control system controls the opening of the first and second openings to connect the pressure relief branch to the feedback oil chamber, allowing the oil in the pressure relief valve to flow into the feedback oil chamber. Simultaneously, to maintain stable oil pressure in the feedback oil chamber, the control system needs to isolate the feedback branch from the feedback oil chamber by closing the control valve in the feedback branch and closing the third opening, preventing oil in the feedback oil chamber from flowing into the feedback branch and the oil reservoir.
[0064] It should be noted that after the oil flows into the feedback chamber in the pressure relief branch, the control system can also close the second opening to seal off the oil in the oil pump feedback chamber, preventing it from draining and fixing the oil pump at a preset displacement. If the pressure relief branch has a check valve, there is no need to close the second opening, and the oil will still be unable to flow from the feedback chamber into the pressure relief channel. If it is necessary to increase the oil displacement appropriately, the second and third openings can be opened to allow some of the oil in the oil pump feedback chamber to drain into the engine oil reservoir.
[0065] If the first opening is in some embodiments, such as Figure 4 As shown, Figure 4 Step S100 of the process involves acquiring engine status data and determining the engine's operating status based on the status data, including:
[0066] Step S110: Obtain the engine speed and the oil temperature using a temperature sensor.
[0067] Specifically, a temperature sensor is installed in the lubrication circuit, and the status data includes the engine speed. A speed sensor is installed on the engine crankshaft to obtain information about the engine crankshaft speed, and a temperature sensor is installed in the oil pan to obtain information about the engine oil temperature.
[0068] Step S120: When the engine speed is less than the speed threshold and the oil temperature is less than the temperature threshold, the engine is determined to be in a cold start state.
[0069] Specifically, the crankshaft speed is less than a speed threshold, which is not limited to any particular speed threshold, such as 1000 revolutions per minute; and the engine oil temperature is lower than a temperature threshold, such as 5 degrees Celsius. When the engine speed is less than 1000 revolutions per minute and the engine oil temperature is less than 5 degrees Celsius, the engine is determined to be in a cold start state.
[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.
Claims
1. A control method for a lubrication system, characterized in that, The control method is applied to the lubrication system of an engine, the lubrication system including an oil reservoir, a lubrication oil passage, and an oil pump; the oil reservoir has an oil reservoir for storing engine oil; the lubrication oil passage is connected to the oil reservoir and is used to lubricate the engine components; the oil pump is disposed in the lubrication oil passage and is used to drive engine oil from the oil reservoir into the lubrication oil passage and drive the engine oil to circulate within the lubrication oil passage; wherein, the oil pump has a feedback oil chamber and a pressure relief valve, the oil pressure in the feedback oil chamber is negatively correlated with the displacement of the oil pump, and the feedback oil chamber is connected to the pressure relief valve, the control method includes: Acquire the status data of the engine, and determine the operating status of the engine based on the status data; When the working state is cold start, start the oil pump, connect the pressure relief valve to the feedback oil chamber, and maintain the oil pressure in the feedback oil chamber; When the duration for which the oil pressure in the feedback oil chamber is maintained reaches a time threshold, the pressure relief valve is isolated from the feedback oil chamber, specifically including: When the duration of communication between the pressure relief branch and the feedback oil chamber reaches the specified duration threshold, the pressure relief branch is isolated from the feedback oil chamber, and the feedback branch is connected to the feedback oil chamber.
2. The control method according to claim 1, characterized in that, The lubrication circuit includes a main oil circuit, a pressure relief branch connecting the pressure relief valve and the feedback oil chamber, and a feedback branch connecting the main oil circuit and the feedback oil chamber. The step of starting the oil pump and connecting the pressure relief valve to the feedback oil chamber in the cold start state, and maintaining the oil pressure in the feedback oil chamber, includes: When the operating state is cold start, start the oil pump; The pressure relief branch is connected to the feedback oil chamber, and the feedback branch is isolated from the feedback oil chamber.
3. The control method according to claim 2, characterized in that, The feedback branch is connected in parallel with the pressure relief branch, the pressure relief branch has a first switching valve, and the feedback branch has a second switching valve; The control of connecting the pressure relief branch to the feedback oil chamber and the control of isolating the feedback branch from the feedback oil chamber include: Control the first switching valve to open and the second switching valve to close; When the duration of communication between the pressure relief branch and the feedback oil chamber reaches the specified duration threshold, controlling the isolation of the pressure relief branch from the feedback oil chamber and controlling the communication between the feedback branch and the feedback oil chamber includes: When the duration of the first switching valve being open and the second switching valve being closed exceeds a duration threshold, the first switching valve is controlled to close and the second switching valve is controlled to open.
4. The control method according to claim 2, characterized in that, The feedback branch has a solenoid valve, which has a first opening, a second opening and a third opening that can be controlled to open and close. The first opening is connected to the pressure relief branch, the second opening is connected to the feedback oil chamber, and the third opening is connected to the oil storage chamber. The control of connecting the pressure relief branch to the feedback oil chamber and the control of isolating the feedback branch from the feedback oil chamber include: The first opening and the second opening are controlled to open, and the third opening is controlled to close.
5. The control method according to claim 4, characterized in that, The first opening is equipped with a one-way valve.
6. The control method according to claim 1, characterized in that, A temperature sensor is installed in the lubrication circuit, and the status data includes: engine speed; The step of acquiring the engine's status data and determining the engine's operating status based on the status data includes: The engine speed is obtained and the oil temperature is obtained by the temperature sensor; When the engine speed is less than a speed threshold and the oil temperature is less than a temperature threshold, the engine is determined to be in a cold start state.