Engine cooling methods

Abstract

This application relates to an engine cylinder head, an engine cooling method, and an engine. One aspect of the provided engine cylinder head includes: an upper water jacket; a lower water jacket; a first pressure valve disposed at the connection between the upper and lower water jackets; and a second pressure valve disposed at the connection between the lower water jacket and the engine cylinder block water jacket. Using the engine cylinder head provided in this application simplifies the cooling structure, reduces energy consumption, and improves cooling efficiency.

Description

Technical Field

[0001] This application relates to the technical field of engine cooling, and in particular to an engine cylinder head, an engine cooling method, and an engine. Background Technology

[0002] With the development of engine technology, engines generate a lot of heat during operation. In order to prevent overheating from causing damage to engine parts and performance degradation, and to optimize emission performance, effective cooling of the engine is required.

[0003] Traditionally, a cooling system arranged in series is installed in the engine cylinder head, allowing the coolant to flow sequentially through the cylinder block, cylinder head, engine cooler, and other accessories. Alternatively, multiple manifolds, thermostats, and flow divider mechanisms are installed in the engine cylinder head to achieve effective engine cooling.

[0004] However, traditional engine cooling methods have low cooling efficiency. Summary of the Invention

[0005] Therefore, it is necessary to address the problem of low engine cooling efficiency in the existing technology by providing an engine cylinder head, engine cooling method, and engine that can improve cooling efficiency.

[0006] In a first aspect, this application provides an engine cylinder head, which adopts the following technical solution:

[0007] An engine cylinder head, comprising:

[0008] Upper water jacket; lower water jacket;

[0009] The first pressure valve is located at the connection between the upper and lower water jackets;

[0010] The second pressure valve is located at the connection between the lower water jacket and the engine cylinder block water jacket.

[0011] In one embodiment, the provided engine cylinder head further includes:

[0012] A middle partition is set between the upper water jacket and the lower water jacket, and a central through hole is opened on the middle partition.

[0013] In one embodiment, the first pressure valve in the provided engine cylinder head includes: a first elastic element that abuts against a central through hole in the middle partition via a first baffle plate.

[0014] In one embodiment, the first pressure valve in the provided engine cylinder head further includes: a first connecting portion, one end of which is connected to a first elastic member, and the other end of which is connected to the top plate of the engine cylinder head.

[0015] In one embodiment, the first connecting portion in the provided engine cylinder head is interference-fitted with the top plate.

[0016] In one embodiment, the second pressure valve provided in the engine cylinder head includes:

[0017] The second elastic member has one end connected to the bottom plate of the engine cylinder head via the second connecting part, and the other end abutting against the bottom limiting platform of the bottom plate via the second baffle.

[0018] In one embodiment, the provided engine cylinder head further includes a water pump, the outlet of which is connected to the inlet of the lower water jacket.

[0019] In one embodiment, the opening pressure of the first pressure valve in the provided engine cylinder head is less than the opening pressure of the second pressure valve.

[0020] Secondly, this application provides an engine cooling method applied to the engine cylinder head as described in the first aspect. The engine cooling method comprises the following steps:

[0021] Obtain the engine's corresponding thermal load information;

[0022] When the heat load information is low, control the coolant pressure to be less than or equal to the opening pressure of the first pressure valve;

[0023] When the heat load information is high, the coolant pressure is controlled to be greater than the opening pressure corresponding to the first pressure valve and less than or equal to the opening pressure corresponding to the second pressure valve.

[0024] When the heat load information is high, the coolant pressure is controlled to be greater than the opening pressure corresponding to the second pressure valve.

[0025] Thirdly, this application provides an engine, including the engine cylinder head as described in the first aspect.

[0026] The aforementioned engine cylinder head, engine cooling method, and engine, wherein the engine cylinder head provided includes: an upper water jacket; a lower water jacket; a first pressure valve disposed at the connection between the upper and lower water jackets; and a second pressure valve disposed at the connection between the lower water jacket and the engine cylinder block water jacket. In this application, the engine cylinder head is divided into multiple cooling zones by the first and second pressure valves, simplifying the cooling structure. Under any engine operating condition, all coolant always flows through the nose area, which has the greatest heat dissipation demand. For areas with low cooling demand, the flow of coolant in the upper water jacket and cylinder block water jacket is controlled by controlling the opening and closing states of the first and second pressure valves, achieving on-demand coolant distribution. This ensures effective cooling of the combustion chamber, cylinder walls, and nose area while reducing energy consumption and improving cooling efficiency. Attached Figure Description

[0027] Figure 1 This is an exploded view of the engine cylinder head structure in one embodiment;

[0028] Figure 2 This is a schematic cross-sectional view of the engine cylinder head in one embodiment;

[0029] Figure 3 This is a schematic cross-sectional view of the upper water jacket in one embodiment;

[0030] Figure 4 This is a schematic cross-sectional view of the lower water jacket in one embodiment;

[0031] Figure 5 This is a schematic diagram of the structure of the first pressure valve in one embodiment;

[0032] Figure 6 This is a schematic diagram of the structure of the second pressure valve in one embodiment;

[0033] Figure 7 This is a schematic diagram of the coolant flow in one embodiment;

[0034] Figure 8 This is a flowchart illustrating the steps of an engine cooling method in one embodiment;

[0035] Attached image annotations:

[0036] 1. Upper water jacket; 2. Lower water jacket; 21. Coolant inlet; 22. Air intake side through hole; 23. Exhaust side through hole; 3. First pressure valve; 31. First elastic element; 32. First baffle plate; 33. First connecting part; 4. Second pressure valve; 41. Second elastic element; 42. Second baffle plate; 43. Second connecting part; 5. Middle partition plate; 51. Middle through hole; 52. Middle limiting platform; 6. Top plate; 7. Bottom plate; 71. Bottom limiting platform; 72. Bottom through hole. Detailed Implementation

[0037] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0038] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0039] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0043] The following is combined with Figure 1-8 The embodiments of this application will be described in further detail.

[0044] The engine cylinder head provided in this embodiment is applied to an engine cylinder with a layered water jacket, see reference. Figures 1 to 4 An embodiment of this application provides an engine cylinder head including: an upper water jacket 1; a lower water jacket 2; a first pressure valve 3 disposed at the connection between the upper water jacket 1 and the lower water jacket 2; and a second pressure valve 4 disposed at the connection between the lower water jacket 2 and the engine cylinder block water jacket.

[0045] The upper water jacket 1 is located at the top of the entire cylinder head, typically surrounding the cylinder, ensuring effective cooling of components such as the cylinder head, combustion chamber, and valves. The lower water jacket 2 is located at the bottom of the entire cylinder head, surrounding the lower part of the combustion chamber and the cylinder wall, used to cool the nose bridge area and the lower part around the combustion chamber. The nose bridge area is a narrow region between the cylinder block and the cylinder head, located near the combustion chamber, spark plugs, or fuel injectors. Due to its compact structure and proximity to the high-temperature combustion chamber, it is prone to high-temperature accumulation and is the part with the highest coolant demand in the entire engine, requiring effective cooling.

[0046] The cylinder block water jacket includes an intake-side water jacket and an exhaust-side water jacket. The intake-side water jacket is located on the intake side of the cylinder block, surrounding the intake passage, to prevent excessive temperature from affecting air density and combustion efficiency. The exhaust-side water jacket is located on the exhaust side of the cylinder block, surrounding the exhaust passage, to help absorb heat during the exhaust process and prevent excessive temperature.

[0047] The lower water jacket 2 has a coolant inlet 21 near the bottom of the cylinder head, and an intake-side through-hole 22 communicating with the intake-side water jacket. The portion near the exhaust-side water jacket has an exhaust-side through-hole 23 communicating with the exhaust-side water jacket. The upper water jacket 1, lower water jacket 2, intake-side water jacket, and exhaust-side water jacket are connected by coolant pipes, forming a closed loop. The coolant flows through each water jacket and coolant pipe, absorbs heat, and then flows back to the radiator for cooling, collectively constituting the engine cylinder cooling system to ensure the engine operates at its optimal temperature.

[0048] In one possible implementation, the lower water jacket 2 is connected to the upper water jacket 1 via a first pressure valve 3, and to the intake-side water jacket via a second pressure valve 4. The outlet of the lower water jacket 2 is connected to the exhaust-side water jacket. During engine cooling, the first pressure valve 3 and the second pressure valve 4 are initially closed, isolating the upper water jacket 1 and the lower water jacket 2. Coolant can only enter the lower water jacket 2 to cool the engine's nose area, and then flows through the exhaust-side water jacket into the radiator. Adjusting the coolant pressure opens the first pressure valve 3 while keeping the second pressure valve 4 closed, allowing coolant to enter the upper water jacket 1 from the lower water jacket 2, simultaneously cooling the lower nose area and upper region of the engine, and then flowing into the radiator. Further adjusting the coolant pressure opens both the first pressure valve 3 and the second pressure valve 4, allowing coolant to enter the intake-side water jacket, and then flowing into the radiator to cool the lower nose area, upper region, intake passage, and exhaust passage of the engine.

[0049] In one possible implementation, the engine cylinder head further includes a top plate 6 and a bottom plate 7. The top plate 6 is the upper structure of the cylinder head, primarily connected to the valve train. It may be designed with interfaces or flanges for connecting the intake and exhaust manifolds, connecting to the engine's intake and exhaust systems to ensure air or air-fuel mixture enters the combustion chamber and exhausts combustion gases. The top plate 6 may also have threaded holes, located directly above the cylinder, for mounting spark plugs to ensure even ignition of the air-fuel mixture in the combustion chamber, or for mounting fuel injectors to inject fuel into the combustion chamber for combustion.

[0050] The base plate 7 is the lower structure of the cylinder head, forming a closed combustion chamber with the piston top. Valve seats can be provided on the base plate 7 for mounting and securing intake and exhaust valves. The lower surface of the base plate 7 can be connected to the cylinder block via a cylinder head gasket, which seals the combustion chamber, coolant passages, and oil passages, preventing leakage of combustion gases, coolant, or oil between the cylinder head and cylinder block. Optionally, the top plate 6 and the base plate 7 can be integrally formed.

[0051] The aforementioned engine cylinder head includes: an upper water jacket 1; a lower water jacket 2; a first pressure valve 3, disposed at the connection between the upper water jacket 1 and the lower water jacket 2; and a second pressure valve 4, disposed at the connection between the lower water jacket 2 and the engine cylinder block water jacket. In this embodiment, the engine cylinder head is divided into multiple cooling zones by the first pressure valve 3 and the second pressure valve 4, simplifying the cooling structure. Under any engine operating condition, all coolant always flows through the nose area with the greatest heat dissipation demand. For areas with low cooling demand, the flow of coolant in the upper water jacket 1 and the cylinder block water jacket is controlled by controlling the opening and closing states of the first pressure valve 3 and the second pressure valve 4, achieving on-demand distribution of coolant. This ensures effective cooling of the combustion chamber, cylinder wall, and nose area while reducing energy consumption and improving cooling efficiency.

[0052] See Figures 1 to 4 In one embodiment of this application, the engine cylinder head further includes a central partition 5, disposed between the upper water jacket 1 and the lower water jacket 2. The central partition 5 has a central through hole 51. By controlling the opening and closing state of the central through hole 51, the upper water jacket 1 and the lower water jacket 2 can be connected or disconnected. Optionally, the central through hole 51 is located on the central limiting platform 52 of the central partition 5.

[0053] See Figure 5 In one embodiment of this application, the first pressure valve 3 in the engine cylinder head includes a first elastic member 31, one end of which abuts against the central through hole 51 on the partition plate 5 via a first baffle plate 32. During engine cooling, when the coolant pressure Px is less than or equal to the opening pressure P1 of the first pressure valve 3, the first elastic member 31 abuts against the central through hole 51 on the partition plate 5 via the first baffle plate 32, and the first pressure valve 3 is in a disconnected state. The coolant flows through the lower water jacket 2 and cannot enter the upper water jacket 1 through the partition plate 5 and the first pressure valve 3. When the coolant pressure Px is greater than the opening pressure P1 of the first pressure valve 3, the first elastic member 31 and the first baffle plate 32 separate from the central through hole 51 on the partition plate 5, and the first pressure valve 3 is in an open state. The upper water jacket 1 and the lower water jacket 2 are connected, and the coolant can enter the upper water jacket 1 through the partition plate 5 and the first pressure valve 3.

[0054] In one possible implementation, the first elastic element 31 is a spring.

[0055] In one possible implementation, the first pressure valve 3 further includes a first connecting portion 33, one end of which is connected to the first elastic member 31, and the other end is connected to the top plate 6 of the engine cylinder head. Optionally, the first connecting portion 33 is interference-fitted with the top plate 6, or the first connecting portion 33 is bolted to a threaded hole on the top plate 6.

[0056] Optionally, the first pressure valve 3 may further include a guide member, sleeved on the outside of the first elastic member 31 or inserted inside the first elastic member 31, for limiting the movement direction of the first elastic member 31. Optionally, the first pressure valve 3 may further include a sealing ring, sleeved on the first baffle plate 32, for preventing coolant leakage.

[0057] Figure 6 A schematic diagram of the structure of the second pressure valve 4 in one embodiment of this application is shown. (See also...) Figure 6 In one embodiment of this application, the second pressure valve 4 in the engine cylinder head includes: a second elastic member 41, one end of the second elastic member 41 is connected to the bottom plate 7 of the engine cylinder head through a second connecting part 43, and the other end of the second elastic member 41 abuts against the bottom limiting platform 71 of the bottom plate 7 and the bottom through hole 72 opened on the bottom limiting platform 71 through a second baffle plate 42. During engine cooling, when the coolant pressure Px is less than or equal to the opening pressure P2 of the second pressure valve 4, the second elastic element 41 abuts against the bottom limiting platform 71 via the second baffle 42, and the second pressure valve 4 is in a blocking state, preventing coolant from entering the intake-side water jacket through the second pressure valve 4. When the coolant pressure Px is greater than the opening pressure P2 of the second pressure valve 4, the second elastic element 41 and the second baffle 42 separate from the bottom limiting platform 71, and the second pressure valve 4 is in an open state, connecting the lower water jacket 2 and the intake-side water jacket, allowing coolant in the lower water jacket 2 to enter the intake-side water jacket through the second pressure valve 4. In one possible embodiment, the second elastic element 41 is a spring.

[0058] In one possible implementation, the engine cylinder head further includes a water pump, the outlet of which is connected to the inlet of the lower water jacket 2. The water pump converts electrical energy or other energy into mechanical energy, generating a pressure difference to pump water from the inlet to the outlet, thereby driving the coolant flow. The pressure Px of the coolant output by the water pump is controlled by adjusting parameters such as the pump's speed and flow rate. In one possible implementation, by using the water pump to control the coolant to operate at the lowest possible flow rate while meeting a specific pressure under different heat load conditions, water pump power consumption can be saved by 10% to 30%, achieving high efficiency and energy saving.

[0059] In one possible implementation, the opening pressure P1 of the first pressure valve 3 is less than the opening pressure P2 of the second pressure valve 4. During engine cooling, coolant flows from the water pump outlet through the inlet of the lower water jacket 2. When the engine starts and the heat load is low, the bottom nose area needs cooling. The coolant pressure Px is controlled so that Px < P1 and Px < P2. Both the first pressure valve 3 and the second pressure valve 4 are closed, and the coolant flows through the lower water jacket 2 to cool the nose area. After absorbing heat, the coolant flows out of the lower water jacket 2 through the outlet and enters the exhaust side water jacket to cool the high-temperature exhaust side cylinder liner. As the heat load increases, when the engine heat load is high and the upper part of the cylinder head needs cooling, the water pressure Px of the lower water jacket 2 is controlled so that P1 < Px < P2. The first pressure valve 3 opens, and the second pressure valve 4 closes. Some coolant enters the upper water jacket 1 through the first pressure valve 3 to cool the valve guide area. As the heat load continues to increase, when it is necessary to cool the intake side cylinder liner, Px > P2, and both the first pressure valve 3 and the second pressure valve 4 are opened. Part of the coolant enters the intake side water jacket through the second pressure valve 4 to cool the intake side cylinder liner. Specifically, after all the coolant flows through the bridge area, about 30% of the coolant cools the upper half of the cylinder head, and the remaining 70% of the coolant cools the cylinder liner.

[0060] In one possible implementation, the outlets of the upper water jacket 1, the intake-side water jacket, and the exhaust-side water jacket are connected to the cylinder block water collection channel to collect the coolant after absorbing heat. The cylinder block water collection channel is connected to the engine cooler, and the collected coolant is used to cool the engine cooler, forming an overall series and partially parallel coolant circuit to achieve precise cooling of each component and further improve coolant utilization efficiency.

[0061] In one possible implementation, the coolant flowing through the mechanical cooler flows into the radiator, and after the radiator cools down, it flows into the inlet of the water pump to achieve circulating cooling.

[0062] In this embodiment, during engine cooling, by controlling the coolant pressure, all low-temperature coolant can flow through the cylinder head bridge area, ensuring sufficient cooling of the bridge area. Under low heat load, by shutting off the first pressure valve 3 and the second pressure valve 4, the upper water jacket 1 and the intake side water jacket are blocked, reducing the effective volume of the coolant by about 20%, achieving rapid warm-up while effectively cooling the bridge area. Under high load, the lower water jacket 2, the upper water jacket 1, and the intake side water jacket are opened to achieve a variable volume water jacket, improving cooling efficiency.

[0063] Figure 7 A schematic diagram of coolant flow is shown in one embodiment of this application. (See attached diagram.) Figures 1 to 7In one embodiment of this application, the engine cylinder head includes: an upper water jacket 1, a lower water jacket 2, and:

[0064] A middle partition 5 is disposed between the upper water jacket 1 and the lower water jacket 2, and a central through hole 51 is provided on the middle partition 5.

[0065] The first pressure valve 3 is located at the connection between the upper water jacket 1 and the lower water jacket 2. The first pressure valve 3 includes: a first elastic member 31, which abuts against the central through hole 51 on the middle partition plate 5 through the first baffle plate 32; and a first connecting part 33, one end of which is connected to the first elastic member 31 and the other end of which is connected to the top plate 6 of the engine cylinder head. The first connecting part 33 is interference-fitted with the top plate 6.

[0066] The second pressure valve 4 is located at the connection between the lower water jacket 2 and the engine cylinder block water jacket. The second pressure valve 4 includes a second elastic element 41, one end of which is connected to the bottom plate 7 of the engine cylinder head via a second connecting part 43, and the other end of which abuts against the bottom limiting platform 71 of the bottom plate 7 via a second baffle plate 42. The opening pressure of the first pressure valve 3 is less than the opening pressure of the second pressure valve 4.

[0067] The water pump's outlet is connected to the inlet of the lower water jacket 2.

[0068] The cylinder block water collection channel connects to the outlets of the upper water jacket 1, the intake-side water jacket, and the exhaust-side water jacket to collect the coolant after it has absorbed heat. The cylinder block water collection channel is connected to the engine cooler, using the collected coolant to cool the engine cooler. The coolant flowing through the engine cooler flows into the radiator, where it is cooled further before flowing into the water pump inlet, thus achieving circulating cooling.

[0069] Figure 8 A flowchart illustrating the steps of an engine cooling method provided in one embodiment of this application is shown. Figure 8 As shown, an engine cooling method provided in one embodiment of this application includes steps 802 to 808. Wherein:

[0070] Step 802: Obtain the thermal load information corresponding to the engine.

[0071] Step 804: When the heat load information is low, control the coolant pressure to be less than or equal to the opening pressure corresponding to the first pressure valve 3.

[0072] Step 806: When the heat load information is high, control the coolant pressure to be greater than the opening pressure corresponding to the first pressure valve 3 and less than or equal to the opening pressure corresponding to the second pressure valve 4.

[0073] Step 808: When the heat load information is high load, control the coolant pressure to be greater than the opening pressure corresponding to the second pressure valve 4.

[0074] The opening pressure of the first pressure valve 3 is less than the opening pressure of the second pressure valve 4.

[0075] Optionally, the load type corresponding to the heat load information can be determined as low load, high load, or high load by using a preset mapping relationship between heat load information and load type.

[0076] One embodiment of this application provides an engine including the engine cylinder head as described in the above embodiments.

[0077] In one embodiment, the engine cylinder head includes: an upper water jacket 1, a lower water jacket 2, and:

[0078] A middle partition 5 is disposed between the upper water jacket 1 and the lower water jacket 2, and a central through hole 51 is provided on the middle partition 5.

[0079] The first pressure valve 3 is located at the connection between the upper water jacket 1 and the lower water jacket 2. The first pressure valve 3 includes: a first elastic member 31, which abuts against the central through hole 51 on the middle partition plate 5 through the first baffle plate 32; and a first connecting part 33, one end of which is connected to the first elastic member 31 and the other end of which is connected to the top plate 6 of the engine cylinder head. The first connecting part 33 is interference-fitted with the top plate 6.

[0080] The second pressure valve 4 is located at the connection between the lower water jacket 2 and the cylinder block water jacket of the engine. The second pressure valve 4 includes a second elastic member 41. One end of the second elastic member 41 is connected to the bottom plate 7 of the engine cylinder head through the second connecting part 43, and the other end of the second elastic member 41 abuts against the bottom limiting platform 71 of the bottom plate 7 through the second baffle plate 42.

[0081] The water pump's outlet is connected to the inlet of the lower water jacket 2.

[0082] The opening pressure of the first pressure valve 3 is less than the opening pressure of the second pressure valve 4.

[0083] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An engine cooling method, characterized in that, The method is applied to an engine cylinder head, which includes: an upper water jacket; a lower water jacket; a first pressure valve disposed at the connection between the upper water jacket and the lower water jacket; and a second pressure valve disposed at the connection between the lower water jacket and the cylinder block water jacket of the engine. The cylinder block water jacket includes an intake-side water jacket and an exhaust-side water jacket. The upper water jacket, the lower water jacket, the intake-side water jacket, and the exhaust-side water jacket are connected by coolant pipes. The opening pressure of the first pressure valve is less than the opening pressure of the second pressure valve. The method includes: Obtain the engine's corresponding thermal load information; when the thermal load information is low load, control the coolant pressure to be less than or equal to the opening pressure of the first pressure valve, so that both the first and second pressure valves are closed, the coolant flows through the lower water jacket to cool the nose area, and the coolant that has absorbed heat flows out of the lower water jacket from the outlet and enters the exhaust side water jacket to cool the exhaust side cylinder liner. When the heat load information is high, the coolant pressure is controlled to be greater than the opening pressure corresponding to the first pressure valve and less than or equal to the opening pressure corresponding to the second pressure valve. The first pressure valve opens and the second pressure valve closes, and part of the coolant enters the upper water jacket through the first pressure valve to cool the valve guide area. When the heat load information is high, the coolant pressure is controlled to be greater than the opening pressure of the second pressure valve. Both the first and second pressure valves are opened, and part of the coolant enters the intake side water jacket through the second pressure valve to cool the intake side cylinder liner.

2. The engine cooling method according to claim 1, characterized in that, The engine cylinder head also includes: A partition plate is disposed between the upper water jacket and the lower water jacket, and a central through hole is provided on the partition plate.

3. The engine cooling method according to claim 2, characterized in that, The first pressure valve includes: a first elastic element that abuts against the central through hole on the middle partition plate via a first baffle plate.

4. The engine cooling method according to claim 3, characterized in that, The first pressure valve further includes a first connecting part, one end of which is connected to the first elastic element, and the other end of which is connected to the top plate of the engine cylinder head.

5. The engine cooling method according to claim 4, characterized in that, The first connecting part is interference-fitted with the top plate.

6. The engine cooling method according to claim 1, characterized in that, The second pressure valve includes: The second elastic member has one end connected to the bottom plate of the engine cylinder head via a second connecting part, and the other end of the second elastic member abuts against the bottom limiting platform of the bottom plate via a second baffle plate.

7. The engine cooling method according to claim 1, characterized in that, The engine cylinder head also includes a water pump, the outlet of which is connected to the inlet of the lower water jacket.

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