Engine lubricating system and control method therefor

Abstract

The present invention relates to the field of lubricating of engines, and provides an engine lubricating system. The lubricating system comprises: a cylinder body oil path provided with a first oil pump, the cylinder body oil path being used for lubricating a cylinder body component of an engine; a cylinder cover oil path provided with a second oil pump, the second oil pump being an electronic pump, and the cylinder cover oil path being used for lubricating a cylinder cover component of the engine; and a connecting oil path connecting the cylinder body oil path and the cylinder cover oil path, and an electric control valve being provided in the connecting oil path, wherein the cylinder body oil path is provided with an oil pressure sensor. According to the lubricating system, the driving energy of the oil pumps can be adjusted more freely, and the energy waste of engine oil can be reduced. The present invention also provides a control method applied to the lubricating system.

Description

Engine lubrication system and control method thereof Technical Field

[0001] The present invention relates to the field of engine lubrication, and in particular to an engine lubrication system and a control method thereof. Background Art

[0002] During the lubrication process of the engine, the oil needs to be guided to the various moving parts of the engine through the lubrication system to lubricate the various moving parts of the engine. The relevant engine drives the oil to circulate in the pipeline through the oil pump. When the engine is in the cold start state, the oil pressure of the lubrication oil circuit needs to be quickly established. It takes a long time to establish the oil pressure, which may cause poor lubrication of the moving parts and lead to damage.

[0003] Summary of the Invention

[0004] The present invention provides an engine lubrication system and a control method thereof, which are used to solve the problem of how to shorten the time for establishing oil pressure.

[0005] An embodiment of the present invention provides a lubrication system for an engine, which includes: a cylinder oil circuit having a first oil pump, and the cylinder oil circuit is configured to lubricate the cylinder components of the engine; a cylinder head oil circuit having a second oil pump and the second oil pump is an electronic pump, and the cylinder head oil circuit is configured to lubricate the cylinder head components of the engine; a connecting oil circuit connecting the cylinder oil circuit and the cylinder head oil circuit, and having an electric control valve in the connecting oil circuit; wherein the cylinder oil circuit is provided with an oil pressure sensor.

[0006] Furthermore, the first oil pump is a mechanical pump.

[0007] Furthermore, the first oil pump is an electronic pump.

[0008] Furthermore, the maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump.

[0009] Furthermore, the lubrication system further includes: an oil temperature sensor configured to obtain the oil temperature in the cylinder oil circuit; and a heating element disposed in the oil pan of the engine.

[0010] An embodiment of the present invention also provides a control method for a lubrication system, which is applied to the lubrication system of the engine as described above. The control method includes: when the engine is stopped and the vehicle is powered on, controlling the second oil pump to turn on; when the engine is running, obtaining the oil pressure of the cylinder oil circuit by the oil pressure sensor; when the oil pressure is higher than the first oil pressure threshold, controlling the first oil pump and / or the second oil pump to turn on.

[0011] Furthermore, the first oil pump is a mechanical pump, and when the engine is stopped and the vehicle is powered on, controlling the second oil pump to turn on includes: when the engine is stopped and the vehicle is powered on, controlling the electronically controlled valve to open and controlling the second oil pump to turn on.

[0012] Furthermore, the first oil pump is an electronic pump, and controlling the second oil pump to turn on when the engine is stopped and the vehicle is powered on includes: controlling the first oil pump and the second oil pump to turn on when the engine is stopped and the vehicle is powered on.

[0013] Furthermore, the maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump, and the lubrication system also includes an oil temperature sensor provided in the cylinder oil circuit. When the oil pressure is higher than the first oil pressure threshold, controlling the first oil pump and / or the second oil pump to turn on includes: when the oil pressure is higher than the first oil pressure threshold, obtaining the oil temperature of the engine oil in the cylinder oil circuit by the oil temperature sensor; when the oil temperature is lower than the first oil temperature threshold, controlling the electric control valve to open, controlling the first oil pump to turn on and controlling the second oil pump to turn off; when the oil temperature is higher than the first oil pressure threshold, controlling the electric control valve to close, controlling the first oil pump and the second oil pump to turn on.

[0014] Furthermore, the lubrication system also includes an oil temperature sensor arranged in the cylinder oil circuit and a heating element arranged in the oil pan of the engine; when the engine is in the running state, before the oil pressure sensor obtains the oil pressure of the cylinder oil circuit, the control method also includes: when the engine is stopped and the vehicle is powered on, the oil temperature sensor obtains the oil temperature of the engine oil, and when the oil temperature of the engine oil is lower than a second oil temperature threshold, the heating element is controlled to turn on.

[0015] An embodiment of the present invention provides a lubrication system, comprising a cylinder oil circuit having a first oil pump and configured to lubricate cylinder components of an engine, and a cylinder head oil circuit having a second oil pump and configured to lubricate cylinder head components of the engine. The cylinder block components and cylinder head components are lubricated respectively by the independently operable cylinder oil circuit and cylinder head oil circuit, thereby enabling the lubrication system to meet the oil requirements of the cylinder block components and cylinder head components while reducing the displacement requirement of the oil pump, thereby reducing the volume of the lubrication system. Furthermore, the second oil pump is an electronic pump. When the engine is stopped and powered on, the second oil pump can be controlled to start and the electronically controlled valve can be controlled to open. Thus, a certain oil pressure can be pre-established in the cylinder block oil circuit and the cylinder head oil circuit by the second oil pump before the engine is started. After the engine is started, the oil pressure in the lubrication oil circuit is detected by an oil pressure sensor. When the oil pressure in the lubrication oil circuit reaches a first oil pressure threshold, the first oil pump and / or the second oil pump is controlled to start so that the oil pressure in the lubrication oil circuit reaches a target oil pressure. It can be understood that by starting the second oil pump in advance to establish a certain pressure in the lubricating oil circuit in advance, and the engine oil fills the entire engine lubricating oil circuit, during the starting process, since the engine oil has filled the entire engine oil channel, after the engine starts, the oil pressure at various positions in the lubricating oil circuit can be quickly established, shortening the oil pressure establishment time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a schematic structural diagram of a lubrication system for an engine provided by an embodiment of the present invention;

[0017] FIG2 is a diagram showing the relationship between the oil pressure demand of oil-using components in an engine and the engine speed when the lubrication system provided by an embodiment of the present invention is applied thereto;

[0018] FIG3 is a schematic structural diagram of another engine lubrication system provided by an embodiment of the present invention;

[0019] FIG4 is a schematic flow chart of a method for controlling a lubrication system according to an embodiment of the present invention;

[0020] FIG5 is a flow chart of another method for controlling a lubrication system according to an embodiment of the present invention;

[0021] FIG6 is a flow chart of another method for controlling a lubrication system provided by an embodiment of the present invention.

[0022] Description of Reference Numerals

[0023] 100, cylinder oil circuit; 110, first oil pump; 120, first filter element; 200, cylinder head oil circuit; 210, second oil pump; 220, second filter element; 300, connecting oil circuit; 310, electronically controlled valve; 410, main bearing; 420, camshaft; 430, high-pressure fuel pump; 440, chain tensioner; 450, variable valve timing system; 460, supercharger; 500, oil pressure sensor; 600, oil temperature sensor; 700, heating element. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present 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 only used to explain the present invention and are not intended to limit the present invention.

[0025] The various specific technical features described in the specific embodiments may be combined in any suitable manner, unless they are inconsistent. For example, different embodiments and technical solutions may be formed by combining different specific technical features. To avoid unnecessary repetition, the various possible combinations of the specific technical features in the present invention will not be described separately.

[0026] In the following description, the terms "first, second, ..." are used solely to distinguish different objects and do not imply any similarities or connections between the objects. It should be understood that the directions "upper," "lower," "outer," and "inner" refer to directions during normal use, while "left" and "right" refer to the left-right directions shown in the corresponding schematic diagrams, which may or may not be the left-right directions during normal use.

[0027] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a..." does not preclude the presence of other identical elements in the process, method, article, or apparatus comprising that element. The term "connected," unless otherwise specified, includes both direct and indirect connections.

[0028] In the following specific embodiments, the engine lubrication system can be applied to any type of engine. For example, the lubrication system can be applied to both gasoline and diesel engines. The lubrication system can be applied to any vehicle driven by an engine. For example, the lubrication system can be applied to a passenger car or a truck directly driven by an engine. For ease of explanation, the following description of the structure of the lubrication system is based on the example of a gasoline engine.

[0029] In some embodiments, as shown in FIG1 , a lubrication system includes a cylinder oil circuit 100, a cylinder head oil circuit 200, and a connecting oil circuit 300. The cylinder oil circuit 100 includes a first oil pump 110 and is configured to lubricate the cylinder components of the engine. The connecting oil circuit 300 includes an electrically controlled valve 310. Exemplarily, components within the cylinder include a main bearing 410, which is located between the cylinder block and the crankshaft. The first oil pump 110 is configured to circulate engine oil within the cylinder oil circuit 100. This oil, during its circulation within the cylinder oil circuit 100, is directed to the main bearing 410 for lubrication, thereby reducing wear on the main bearing 410. Optionally, the cylinder block oil circuit 100 further includes a first filter 120. After passing through the first filter 120, the engine oil flows to the main bearing 410. This filtering by the first filter 120 before the oil flows to the main bearing 410 reduces the impact of impurities in the oil on the main bearing 410. The cylinder head oil circuit 200 includes a second oil pump 210, configured to lubricate the engine's cylinder head components. Exemplarily, components within the cylinder head include a camshaft 420, which is configured to drive the engine's valves via rotating cams, and a high-pressure fuel pump 430, which is configured to pressurize the fuel in the fuel rail. The second oil pump 210 is configured to circulate the engine oil within the cylinder head oil circuit 200, thereby directing the oil to the camshaft 420 and the high-pressure fuel pump 430 for lubrication. Optionally, cylinder head oil passage 200 further includes a second filter element 220. After being filtered by second filter element 220, the engine oil flows to camshaft 420 and high-pressure fuel pump 430, reducing the impact of impurities in the engine oil on camshaft 420 and high-pressure fuel pump 430. Optionally, if the engine's valve train is driven by a transmission chain, the cylinder head assembly further includes a chain tensioner 440. Chain tensioner 440 is configured to compress the transmission chain to reduce the possibility of the transmission chain separating from the sprocket. Cylinder head oil passage 200 is further configured to guide the engine oil to chain tensioner 440 for lubrication. Optionally, if the engine has a variable valve timing system, the cylinder head assembly further includes a variable valve timing system 450. Variable valve timing system 450 is connected to camshaft 420 and can rotate camshaft 420 to change the engine's valve timing. The cylinder head oil circuit 200 is also configured to guide the engine oil to the variable valve timing system, trigger the variable valve timing system or drive the variable valve timing system to drive the camshaft 420 to rotate, thereby changing the valve timing of the engine. At the same time, the moving pairs in the variable valve timing system are lubricated by the engine oil.When the engine has a supercharging system, the cylinder head assembly also includes a supercharger 460. The supercharger 460 drives the impeller in the intake pipe to rotate through the impact force of the exhaust gas in the exhaust pipe or the torque of the crankshaft, thereby improving the engine's intake capacity. The cylinder head oil circuit 200 is configured to guide the engine oil to the moving pairs in the supercharger 460 to lubricate the moving pairs of the supercharger 460.

[0030] It should be noted that the cylinder block and cylinder head components have different oil requirements. The following, using Figure 2 as an example, illustrates how the oil requirements of the cylinder block and cylinder head components change as the engine speed increases, taking the cylinder block components comprising the main bearing 410 in Figure 1 and the cylinder head components comprising the high-pressure fuel pump 430, chain tensioner 440, variable valve timing system 450, and supercharger 460 in Figure 1 as examples. As shown in Figure 2, the oil requirement of the main bearing 410 continues to increase as the engine speed increases, and this demand is directly proportional to the engine speed. The oil requirements of the high-pressure fuel pump 430, chain tensioner 440, and variable valve timing system 450 remain unchanged. In the low speed range, since supercharger 460 has not yet intervened in engine operation, supercharger 460's demand for oil is zero. After the engine speed reaches the supercharger 460 intervention speed, supercharger 460's demand for oil increases. As the engine speed increases, the rate of increase in supercharger 460's demand for oil decreases until supercharger 460's demand for oil does not increase with increasing engine speed. In summary, in the low speed range, the cylinder head component's demand for oil is greater than that of the cylinder block component. In the high speed range, the cylinder block component's demand for oil is greater than that of the cylinder head component. Moreover, the trend of the cylinder block component's demand for oil with engine speed is different from that of the cylinder head component's demand for oil with engine speed. If a single lubrication system is used to lubricate both the cylinder block and cylinder head components, the oil demand of either the cylinder block or cylinder head will either be unable to be fully met, or a large-displacement oil pump will be required, resulting in a larger lubrication system. The lubrication system provided by the embodiment of the present invention is provided with a split cylinder oil circuit 100 and a cylinder head oil circuit 200, and the cylinder oil circuit 100 and the cylinder head oil circuit 200 respectively have an independent first oil pump 110 and a second oil pump 210, so that the cylinder oil circuit 100 and the cylinder head oil circuit 200 can respectively operate independently according to the demand for engine oil of the cylinder components and the demand for engine oil of the cylinder head components. That is, by decoupling the control of the cylinder oil circuit 100 and the cylinder head oil circuit 200, it is possible to reduce the displacement required by the oil pump while meeting the demand for engine oil of the cylinder components and the cylinder head components respectively, thereby reducing the volume of the lubrication system.

[0031] At the same time, the second oil pump 210 is an electronic pump. The second oil pump 210 can operate when the engine is stopped, so that the second oil pump 210 can be controlled to start when the engine is stopped and powered on, so as to pre-establish a certain oil pressure in the cylinder oil circuit 100 and the cylinder head oil circuit 200 and form an oil film on the surface of the cylinder components and the cylinder head components. After the engine is started, the oil pressure in the cylinder oil circuit 100 is obtained by the oil pressure sensor 500 arranged in the cylinder oil circuit 100. When the oil pressure in the cylinder oil circuit 100 reaches the first oil pressure threshold, the first oil pump 110 and / or the second oil pump 210 is controlled to start. It can be understood that by starting the second oil pump in advance to establish a certain pressure in the lubricating oil circuit in advance, and the engine oil fills the entire engine lubricating oil circuit. During the starting process, since the engine oil has filled the entire engine oil channel, the oil pressure at various positions in the lubricating oil circuit can be quickly established after the engine is started, thereby shortening the oil pressure establishment time.

[0032] An embodiment of the present invention provides a lubrication system, which includes a cylinder oil circuit having a first oil pump and configured to lubricate the cylinder body components of the engine, and a cylinder head oil circuit having a second oil pump and configured to lubricate the cylinder head components of the engine, so that the cylinder body components and the cylinder head components are lubricated respectively through the cylinder oil circuit and the cylinder head oil circuit that can operate independently, so that the lubrication system can reduce the displacement demand of the oil pump while meeting the oil demand of the cylinder body components and the cylinder head components, thereby reducing the volume of the lubrication system. At the same time, the second oil pump is an electronic pump. When the engine is stopped and powered on, it can control the second oil pump to start and control the electronic control valve to open, so that the second oil pump can pre-establish a certain oil pressure in the cylinder oil circuit and the cylinder head oil circuit before the engine is started, and detect the oil pressure in the lubricating oil circuit through the oil pressure sensor after the engine is started. When the oil pressure in the lubricating oil circuit reaches the first oil pressure threshold, the first oil pump and / or the second oil pump is controlled to start so that the oil pressure in the lubricating oil circuit reaches the target oil pressure. It can be understood that by starting the second oil pump in advance to establish a certain pressure in the lubricating oil circuit in advance, and the engine oil fills the entire engine lubricating oil circuit. During the starting process, since the engine oil has filled the entire engine oil channel, after the engine is started, the oil pressure at various positions in the lubricating oil circuit can be quickly established, shortening the oil pressure establishment time.

[0033] In some embodiments, as shown in FIG1 , the first oil pump 110 is a mechanical pump. It can be understood that the cylinder oil circuit 100 is configured to lubricate cylinder components, including the main bearing 410 . The oil demand of the main bearing 410 is proportional to the engine speed. Furthermore, the mechanical pump is connected to the engine crankshaft so that the crankshaft drives the mechanical pump, and the oil flow rate of the mechanical pump is proportional to the engine speed. Specifically, by making the first oil pump 110 a mechanical pump, the oil flow rate of the first oil pump 110 can be adapted to the oil demand of the main bearing 410 , eliminating the need to control the first oil pump 110, thereby simplifying the control of the lubrication system. Meanwhile, the second oil pump 210 is an electronic pump that can control the oil flow rate of the oil pump by actively controlling the oil pump speed, thereby ensuring that the oil flow rate of the second oil pump 210 meets the oil demand of the cylinder head components.

[0034] In some embodiments, as shown in Figure 1, the first oil pump 110 is an electronic pump, which can drive the oil flow of the first oil pump 110 and the second oil pump 210 according to the demand for oil volume of the cylinder block components and the cylinder head components when the engine is in a cold start state, so that the first oil pump and the second oil pump can be started before the cold start, so that the first oil pump and the second oil pump can respectively initially establish a certain oil pressure in the oil circuit.

[0035] In some embodiments, as shown in FIG1 , the maximum displacement of the first oil pump 110 is greater than the maximum displacement of the second oil pump 210. It can be understood that when the engine is operating at high speed, the cylinder block's demand for oil is greater than the cylinder head's demand for oil. Therefore, making the maximum displacement of the first oil pump 110 greater than the maximum displacement of the second oil pump 210 can match the oil demands of the cylinder block and cylinder head, respectively. This reduces the size of the oil pump while meeting the oil demands of both the cylinder block and cylinder head, further reducing the volume of the lubrication system.

[0036] In some embodiments, as shown in Figure 3, the lubrication system also includes an oil temperature sensor 600 and a heating element 700. The oil temperature sensor 600 is configured to obtain the temperature of the engine oil, and the heating element 700 is configured to heat the engine oil. If the temperature of the engine oil is detected to be low before the engine is cold started, the heating element 700 can be controlled to start to preheat the engine oil, thereby reducing the viscosity of the engine oil in advance before the cold start, and then enabling the second oil pump 210 to drive the engine oil to circulate in the cylinder oil circuit 100 and the cylinder head oil circuit 200 during the subsequent cold start process. The heating element 700 is arranged in the oil pan of the engine, thereby heating the engine oil of the lubrication system as a whole.

[0037] An embodiment of the present invention further provides a method for controlling a lubrication system, which is applied to a lubrication system of an engine as shown in any one of FIG. 1 to FIG. 3 .

[0038] In some embodiments, as shown in FIG4 , FIG4 is a flow chart of a control method for a lubrication system provided by an embodiment of the present invention. The flow of the control method includes:

[0039] Step S101: When the engine is stopped and the vehicle is powered on, control the second oil pump to start.

[0040] It can be understood that when the engine is stopped and the vehicle is powered on, the engine is considered to be in a state ready to start. In this state, the second oil pump is pre-activated to establish a certain oil pressure in the cylinder oil circuit and the cylinder head oil circuit before the engine starts. It should be noted that the specific strategy for controlling whether to activate the first oil pump and whether to control the electronically controlled valve to open in step S101 may vary depending on the type of the first oil pump. For example, if the first oil pump is a mechanical pump, step S101 specifically involves, when the engine is stopped and the vehicle is powered on, controlling the second oil pump to activate and controlling the electronically controlled valve to open, i.e., pre-activating a certain oil pressure in the cylinder oil circuit and the cylinder head oil circuit via the second oil pump. For example, if the first oil pump is an electronic pump, step S101 specifically involves, when the engine is stopped and the vehicle is powered on, controlling the first oil pump and the second oil pump to activate, i.e., pre-activating the oil pressure in the cylinder oil circuit and the cylinder head oil circuit via the first oil pump and the second oil pump. It should be noted that when both the first oil pump and the second oil pump are turned on, the electronically controlled valve can be opened so that the first oil pump and the second oil pump jointly drive the engine oil to pre-establish oil pressure in the cylinder oil circuit and the cylinder head oil circuit. The electronically controlled valve can also be closed so that the first oil pump pre-establishes oil pressure in the cylinder oil circuit and the second oil pump pre-establishes oil pressure in the cylinder head oil circuit.

[0041] Step S102: When the engine is running, the oil pressure of the cylinder oil circuit is obtained by the oil pressure sensor.

[0042] It can be understood that during the engine starting process, the oil pressure in the cylinder is obtained through the oil pressure sensor to monitor the oil pressure in the cylinder oil circuit.

[0043] Step S103: When the oil pressure is higher than the first oil pressure threshold, control the first oil pump and / or the second oil pump to start.

[0044] It can be understood that when the engine is running, when the oil pressure in the cylinder oil circuit reaches the first oil pressure threshold, it is considered that the oil pressure in the cylinder oil circuit and the cylinder head oil circuit has been initially established. In this state, the first oil pump and / or the second oil pump is controlled to turn on so that the oil pressure in the cylinder oil circuit and the cylinder head oil circuit continues to increase to the target oil pressure, wherein the target oil pressure is the oil pressure corresponding to the minimum amount of engine oil required for the normal operation of the cylinder components and the cylinder head components.

[0045] In some embodiments, the maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump, and the lubrication system further includes an oil temperature sensor 600 disposed in the cylinder oil circuit. As shown in FIG5 , FIG5 is a flow chart of another control method for a lubrication system provided by an embodiment of the present invention. Unlike the control method shown in FIG4 , step S103 in FIG4 includes:

[0046] Step S201: When the oil pressure is higher than a first oil pressure threshold, the oil temperature of the engine oil in the cylinder oil circuit is obtained by an oil temperature sensor.

[0047] It can be understood that when the engine is in operation, the oil temperature in the cylinder oil circuit is monitored by the oil temperature sensor 600 .

[0048] Step S202: When the oil temperature is lower than the first oil temperature threshold, the electronically controlled valve is controlled to open, the first oil pump is controlled to open, and the second oil pump is controlled to close. When the oil temperature is higher than the first oil temperature threshold, the electronically controlled valve is controlled to close, and the first oil pump and the second oil pump are controlled to open.

[0049] It can be understood that when the oil temperature of the engine oil is lower than the first oil temperature threshold, the viscosity of the engine oil is relatively high, and the oil pressure in the cylinder oil circuit and the cylinder head oil circuit can be maintained above the target oil pressure by a smaller amount of engine oil. Turning on the first oil pump with a larger maximum displacement alone can meet the oil pressure requirements of the cylinder oil circuit and the cylinder head oil circuit at the same time. In this state, only the first oil pump is turned on and the electronically controlled valve is opened to allow the first oil pump to drive the engine oil to circulate in the cylinder oil circuit and the cylinder head oil circuit, thereby saving the energy required to drive the engine oil while ensuring that the oil pressure in the cylinder oil circuit and the cylinder head oil circuit meets the requirements. When the oil temperature of the engine oil is higher than the first oil temperature threshold, the viscosity of the engine oil decreases, and a larger flow of engine oil is required to keep the oil pressure in the cylinder oil circuit and the oil pressure in the cylinder head oil circuit above the target oil pressure. The maximum displacement of the first oil pump can no longer meet the required flow requirement. In this state, the first oil pump and the second oil pump are controlled to open and close the electronic control valve, so that the lubrication system enters the split lubrication mode, and the oil pressure in the cylinder oil circuit meets the requirement through the first oil pump, and the oil pressure in the cylinder head oil circuit meets the requirement through the second oil pump.

[0050] In some embodiments, the lubrication system further includes an oil temperature sensor 600 disposed in the cylinder oil circuit and a heating element 700 disposed in the oil pan of the engine. As shown in FIG6 , FIG6 is a flow chart of another control method for a lubrication system provided by an embodiment of the present invention. The difference from the control method shown in FIG4 is that, before step S102 in FIG4 , the control method further includes:

[0051] Step S301: When the engine is stopped and the vehicle is powered on, the oil temperature sensor 600 obtains the oil temperature of the engine oil. When the oil temperature of the engine oil is lower than the oil temperature threshold, the heating element 700 is controlled to turn on.

[0052] It can be understood that when the vehicle is powered on and the engine has not yet started, the engine is in a state of waiting to start. In this state, the temperature of the engine oil is obtained by the oil temperature sensor, and when the temperature of the engine oil is lower than the oil temperature threshold, the engine oil is preheated by starting the heating element, thereby reducing the viscosity of the engine oil in advance, thereby reducing the difficulty of establishing oil pressure in the lubricating oil circuit during the subsequent cold start process. At the same time, the heating element is arranged in the oil pan of the engine, and can heat the entire engine oil without starting the oil pump to make the oil flow. Optionally, step S301 can be performed simultaneously with step S101 in Figure 4, so that by starting the oil pump to circulate the oil, the heat exchange between the heating element and the engine oil is accelerated, thereby further improving the heating effect of the heating element on the engine oil.

[0053] 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 lubrication system for an engine, characterized in that: The lubrication system comprises: a cylinder oil circuit having a first oil pump, wherein the cylinder oil circuit is configured to lubricate cylinder components of the engine; a cylinder head oil circuit, having a second oil pump and the second oil pump is an electronic pump, the cylinder head oil circuit being configured to lubricate the cylinder head components of the engine; A connecting oil circuit, connecting the cylinder oil circuit and the cylinder head oil circuit, and an electric control valve is provided in the connecting oil circuit; Wherein, the cylinder oil circuit is provided with an oil pressure sensor.

2. The lubrication system according to claim 1, characterized in that: The first oil pump is a mechanical pump.

3. The lubrication system according to claim 1, characterized in that: The first oil pump is an electronic pump.

4. The lubrication system according to claim 2, characterized in that: The maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump.

5. The lubrication system according to claim 3, characterized in that: The maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump.

6. The lubrication system according to claim 1, characterized in that: The lubrication system further comprises: an oil temperature sensor configured to obtain a temperature of the engine oil in the cylinder oil circuit; The heating element is arranged in the oil pan of the engine.

7. A control method for a lubrication system, characterized in that: The control method is applied to the lubrication system according to any one of claims 1 to 6, and the control method comprises: When the engine is stopped and the vehicle is powered on, controlling the second oil pump to start; When the engine is in operation, the oil pressure sensor obtains the oil pressure of the cylinder oil circuit; When the oil pressure is higher than the first oil pressure threshold, the first oil pump and / or the second oil pump is controlled to start.

8. The control method according to claim 7, characterized in that: The first oil pump is a mechanical pump, and when the engine is stopped and the vehicle is powered on, controlling the second oil pump to start includes: When the engine is stopped and the vehicle is powered on, the electronically controlled valve is controlled to open and the second oil pump is controlled to open.

9. The control method according to claim 7, characterized in that: The first oil pump is an electronic pump, and when the engine is stopped and the vehicle is powered on, controlling the second oil pump to start includes: When the engine is stopped and the vehicle is powered on, the first oil pump and the second oil pump are controlled to start.

10. The control method according to claim 7, characterized in that: The maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump, the lubrication system further comprises an oil temperature sensor provided in the cylinder oil circuit, and when the oil pressure is higher than the first oil pressure threshold, controlling the first oil pump and / or the second oil pump to start comprises: When the oil pressure is higher than a first oil pressure threshold, the oil temperature sensor acquires the oil temperature of the engine oil in the cylinder oil circuit; When the oil temperature is lower than the first oil temperature threshold, the electronically controlled valve is controlled to open, the first oil pump is controlled to start and the second oil pump is controlled to close; when the oil temperature is higher than the first oil pressure threshold, the electronically controlled valve is controlled to close, and the first oil pump and the second oil pump are controlled to open.

11. The control method according to claim 8, characterized in that: The maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump, the lubrication system further comprises an oil temperature sensor provided in the cylinder oil circuit, and when the oil pressure is higher than the first oil pressure threshold, controlling the first oil pump and / or the second oil pump to start comprises: When the oil pressure is higher than a first oil pressure threshold, the oil temperature sensor acquires the oil temperature of the engine oil in the cylinder oil circuit; When the oil temperature is lower than the first oil temperature threshold, the electronically controlled valve is controlled to open, the first oil pump is controlled to start and the second oil pump is controlled to close; when the oil temperature is higher than the first oil pressure threshold, the electronically controlled valve is controlled to close, and the first oil pump and the second oil pump are controlled to open.

12. The control method according to claim 9, characterized in that: The maximum displacement of the first oil pump is greater than the maximum displacement of the second oil pump, the lubrication system further comprises an oil temperature sensor provided in the cylinder oil circuit, and when the oil pressure is higher than the first oil pressure threshold, controlling the first oil pump and / or the second oil pump to start comprises: When the oil pressure is higher than a first oil pressure threshold, the oil temperature sensor acquires the oil temperature of the engine oil in the cylinder oil circuit; When the oil temperature is lower than the first oil temperature threshold, the electronically controlled valve is controlled to open, the first oil pump is controlled to start, and the second oil pump is controlled to close; when the oil temperature is higher than the first oil pressure threshold, In this state, the electronically controlled valve is controlled to be closed, and the first oil pump and the second oil pump are controlled to be opened.

13. The control method according to claim 7, characterized in that: The lubrication system further includes an oil temperature sensor disposed in the cylinder oil circuit and a heating element disposed in the oil pan of the engine; When the engine is in operation, before the oil pressure sensor acquires the oil pressure of the cylinder oil circuit, the control method further includes: When the engine is stopped and the vehicle is powered on, the oil temperature sensor obtains the oil temperature of the engine oil, and when the oil temperature of the engine oil is lower than a second oil temperature threshold, the heating element is controlled to turn on.

14. The control method according to claim 8, characterized in that: The lubrication system further includes an oil temperature sensor disposed in the cylinder oil circuit and a heating element disposed in the oil pan of the engine; When the engine is in operation, before the oil pressure sensor acquires the oil pressure of the cylinder oil circuit, the control method further includes: When the engine is stopped and the vehicle is powered on, the oil temperature sensor obtains the oil temperature of the engine oil, and when the oil temperature of the engine oil is lower than a second oil temperature threshold, the heating element is controlled to turn on.

15. The control method according to claim 9, characterized in that: The lubrication system further includes an oil temperature sensor disposed in the cylinder oil circuit and a heating element disposed in the oil pan of the engine; When the engine is in operation, before the oil pressure sensor acquires the oil pressure of the cylinder oil circuit, the control method further includes: When the engine is stopped and the vehicle is powered on, the oil temperature sensor obtains The oil temperature of the engine oil is controlled to turn on the heating element when the oil temperature of the engine oil is lower than a second oil temperature threshold.

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