Engine cooling system, engine cooling method and vehicle

Abstract

The present application relates to an engine cooling system, an engine cooling method, and a vehicle, and relates to the field of vehicle technology. The engine cooling system includes a cylinder head water jacket, which includes an upper cylinder head water jacket and a lower cylinder head water jacket. The lower cylinder head water jacket is connected to the upper cylinder head water jacket, and the upper cylinder head water jacket and the lower cylinder head water jacket are interconnected. The upper cylinder head water jacket and the lower cylinder head water jacket are provided with an engine coolant inlet. By providing an engine coolant inlet in the upper cylinder head water jacket, the main flow of coolant enters the engine from the upper cylinder head water jacket, then flows through the lower cylinder head water jacket and enters the cylinder body. Gravity is used to increase the flow rate of the coolant, and the resistance of the cooling system is reduced through a top-to-bottom cooling path, thereby improving the heat transfer coefficient and cooling efficiency. At the same time, the coolant can first flow through the cylinder head area with greater cooling demand, avoiding excess cylinder liner cooling resources and reducing engine power consumption.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to an engine cooling system, an engine cooling method, and a vehicle. Background Art

[0002] In traditional commercial vehicle engine cooling systems, the coolant typically flows from a water pump into the engine block's water jacket, then through the cylinder liner's water jacket, and then upward into the cylinder head's water jacket. If the engine is equipped with an exhaust gas recirculation (EGR) system, the coolant, after flowing through the cylinder head's water jacket, also needs to enter the EGR cooler water jacket to control the exhaust gas temperature.

[0003] However, in this cooling system, the coolant must first pass through the cylinder block and the cylinder liner water jacket. The flow resistance between these two parts is significant, especially due to the narrow structure of the cylinder liner. This high resistance forces the cooling system's water pump to output higher power to maintain sufficient coolant flow, increasing system power consumption and reducing cooling efficiency. Summary of the Invention

[0004] Based on this, it is necessary to provide an engine cooling system, an engine cooling method and a vehicle to address the problem of how to reduce engine power consumption and improve cooling efficiency.

[0005] The present application provides an engine cooling system, including a cylinder head water jacket, wherein the cylinder head water jacket includes:

[0006] Cylinder head upper water jacket;

[0007] A lower water jacket of the cylinder head, connected to the upper water jacket of the cylinder head;

[0008] Wherein, an engine coolant inlet is provided on the upper water jacket of the cylinder head.

[0009] In one embodiment, the engine coolant inlet is arranged on the upper water jacket of the cylinder head corresponding to the middle cylinder, and the middle cylinder is used to indicate the cylinder in the middle position among N cylinders; wherein the N cylinders are arranged in sequence, N≥3.

[0010] In one embodiment, the engine cooling system further comprises a water collecting chamber and a cooler water jacket, the cooler water jacket is in communication with the water collecting chamber, and the water collecting chamber is provided with a liquid inlet;

[0011] The lower water jacket of the cylinder head is provided with a first liquid outlet, and the first liquid outlet is used to be connected to the liquid inlet of the water collecting chamber.

[0012] In one embodiment, the engine includes a plurality of cylinders, and the first liquid outlet of the cylinder head lower water jacket corresponding to at least one of the cylinders is used to be connected to the liquid inlet of the water collecting chamber through a thermostat channel.

[0013] In one embodiment, the first liquid outlet of the lower water jacket of the cylinder head includes at least one main liquid outlet and at least one auxiliary liquid outlet, each of the main liquid outlets is used to be directly connected to the liquid inlet of the water collecting chamber, and each of the auxiliary liquid outlets is used to be connected to the liquid inlet of the water collecting chamber through a thermostat, and the cylinders corresponding to the main liquid outlets and the cylinders corresponding to the auxiliary liquid outlets are alternately arranged.

[0014] In one embodiment, the engine coolant inlet on the upper water jacket of the cylinder head is located on the air intake side of the cylinder head, and the first liquid outlet of the lower water jacket of the cylinder head is located on the exhaust side of the cylinder head.

[0015] In one embodiment, the engine cooling system further comprises a cylinder water jacket, wherein the cylinder water jacket comprises a cylinder jacket water jacket and a body water jacket that are interconnected, and the cylinder jacket water jacket is provided with a liquid inlet;

[0016] The cylinder head lower water jacket is provided with a second liquid outlet, and the second liquid outlet is used to be connected to the liquid inlet of the cylinder liner water jacket.

[0017] In one embodiment, the upper water jacket of the cylinder head and the lower water jacket of the cylinder head are connected from top to bottom in the nose bridge area, wherein the upper and lower water jacket connecting area between the upper water jacket of the cylinder head and the lower water jacket of the cylinder head is crescent-shaped.

[0018] A second aspect of the present application further provides an engine cooling method, which is applied to the engine cooling system provided in the first aspect of the present application. The engine cooling method comprises:

[0019] Controls the coolant to enter the engine from the engine coolant inlet on the upper water jacket of the cylinder head;

[0020] Controlling the coolant to flow from the upper water jacket of the cylinder head into the lower water jacket of the cylinder head through the upper and lower communicating areas;

[0021] A portion of the coolant is controlled to flow from the air intake side of the cylinder head lower water jacket into the cylinder body water jacket, and the remaining portion of the coolant is controlled to flow from the air exhaust side of the cylinder head lower water jacket into the water collecting chamber.

[0022] The third aspect of the present application further provides a vehicle, which includes the engine cooling system provided in the first aspect of the present application.

[0023] In the above-mentioned engine cooling system, the cylinder head water jacket includes an upper cylinder head water jacket and a lower cylinder head water jacket, the lower cylinder head water jacket being connected to the upper cylinder head water jacket, and the upper cylinder head water jacket and the lower cylinder head water jacket being interconnected. The upper cylinder head water jacket is provided with an engine coolant inlet. This application provides for an engine coolant inlet by providing the engine coolant inlet in the upper cylinder head water jacket of the cylinder head, for example by directly connecting the water pump outlet to the engine cooling inlet of the upper cylinder head water jacket. This allows the main flow of coolant to enter the engine through the engine cooling inlet of the upper cylinder head water jacket. By providing the engine coolant inlet in the upper cylinder head water jacket, coolant enters the engine from the upper cylinder head water jacket, then flows through the upper cylinder head water jacket, through the lower cylinder head water jacket, and into the cylinder block. This utilizes gravity to increase the flow velocity of the coolant, and reduces the resistance of the cooling system through a top-to-bottom cooling path, thereby improving the heat transfer coefficient and cooling efficiency. At the same time, the coolant can first flow through the cylinder head area with greater cooling requirements, especially the area above the valve seat and the combustion chamber, flow through the lower water jacket of the cylinder head and then enter the cylinder liner water jacket, thereby avoiding excessive cylinder liner cooling resources and reducing engine power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a schematic structural diagram of an engine cooling system in some embodiments of the present application.

[0026] Figure 2 This is a schematic diagram of the engine coolant inlet in some embodiments of the present application.

[0027] Figure 3 This is a schematic diagram of the structure of the cylinder head water jacket in some embodiments of the present application.

[0028] Figure 4 This is a schematic diagram of water flow distribution in the lower water jacket of the cylinder head when the thermostat is closed in some embodiments of the present application.

[0029] Figure 5 This is a schematic diagram of water flow distribution in the lower water jacket of the cylinder head when the thermostat is open in some embodiments of the present application.

[0030] Figure 6 This is a flow chart of an engine cooling method in some embodiments of the present application.

[0031] Description of Figure Numbers:

[0032] 1. Cylinder head water jacket; 2. Cylinder block water jacket; 3. Water collecting chamber; 4. Cooler water jacket; 11. Cylinder head upper water jacket; 12. Cylinder head lower water jacket; 13. Upper and lower water jacket connecting area; 111. Engine coolant inlet; 121. First liquid outlet; 122. Second liquid outlet; 123. Thermostat channel; 21. Cylinder liner water jacket; 22. Body water jacket. DETAILED DESCRIPTION

[0033] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0034] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0036] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0037] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0038] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0039] In current engine cooling systems, a water pump pumps coolant to the cylinder block's water jacket. The coolant then flows through the cylinder liner water jacket and upward to the cylinder head water jacket. In gas engines, the coolant, after flowing through the cylinder head, must enter the EGR cooler water jacket. Gas engines have much higher combustion and exhaust temperatures than diesel engines, placing a greater demand on engine cooling capacity.

[0040] According to traditional engine cooling methods, all coolant must flow through the cylinder liner before being distributed to the cylinder head. However, there is significant resistance between the cylinder block's main water jacket and the cylinder liner's water jacket. The narrow structure of the cylinder liner further exacerbates this flow resistance. This high resistance forces the cooling system's water pump to output higher power to maintain sufficient coolant flow, increasing system power consumption.

[0041] Furthermore, since the cylinder liner primarily contacts the piston sidewall, its temperature is not as high as that of the combustion chamber and cylinder head areas, so the cooling requirements for the cylinder liner are relatively low. However, due to the resistance distribution and flow path arrangement in traditional designs, a large amount of coolant still needs to flow through the cylinder liner water jacket. This not only wastes cooling resources, but also results in the coolant flow rate and cooling capacity being reduced by the time it reaches the cylinder head. The cylinder head area has a greater cooling demand, especially the area above the valve seats and combustion chamber, where combustion temperatures are the highest. However, due to excessive coolant consumption by the cylinder liner, cylinder head cooling is often suboptimal.

[0042] In order to solve the problem of high engine power consumption and low cooling efficiency in the cooling system of related technologies, please refer to Figure 1An embodiment of the present application provides an engine cooling system, which includes a cylinder head water jacket 1, wherein the cylinder head water jacket 1 includes an upper cylinder head water jacket 11 and a lower cylinder head water jacket 12, and the lower cylinder head water jacket 12 is connected to the upper cylinder head water jacket 11.

[0043] An engine coolant inlet 111 is provided on the upper water jacket 11 of the cylinder head.

[0044] In the embodiment of the present application, the cylinder head upper water jacket 11 and the cylinder head lower water jacket 12 are interconnected, wherein an engine coolant inlet 111 is provided on the cylinder head upper water jacket 11. For example, the engine coolant inlet 111 of the cylinder head upper water jacket 11 is used to connect to a water pump. By directly connecting the water pump outlet to the engine coolant inlet 111 of the cylinder head upper water jacket 11, the main flow of coolant enters the engine through the engine coolant inlet 111 of the cylinder head upper water jacket 11.

[0045] In the aforementioned engine cooling system, the cylinder head water jacket 1 includes an upper cylinder head water jacket 11 and a lower cylinder head water jacket 12. The lower cylinder head water jacket 12 is connected to the upper cylinder head water jacket 11 and interconnected. An engine coolant inlet 111 is provided in the upper cylinder head water jacket 11. By providing the engine coolant inlet 111 in the upper cylinder head water jacket 11, coolant enters the engine from the upper cylinder head water jacket 11, then flows through the upper cylinder head water jacket 11, through the lower cylinder head water jacket 12, and finally into the cylinder block. This utilizes gravity to increase the coolant flow rate, and the top-down cooling path reduces the resistance of the cooling system, thereby improving the heat transfer coefficient and cooling efficiency. Furthermore, the coolant can first flow through cylinder head areas with greater cooling requirements, particularly those above the valve seats and combustion chambers, before flowing through the lower cylinder head water jacket 12 and entering the cylinder liner water jacket 21. This prevents excess cylinder liner cooling resources and reduces engine power consumption.

[0046] Optionally, the engine coolant inlet 111 of the cylinder head upper water jacket 11 is located on the cylinder head intake side. Since coolant inlets are typically sealed with O-rings, high temperatures can easily affect the sealing performance if the engine coolant inlet 111 is located on the cylinder head exhaust side. Therefore, placing the engine coolant inlet 111 on the cylinder head intake side further improves the reliability of the engine cooling system. Furthermore, the cylinder head exhaust side typically houses components such as the water collection chamber 3 and the EGR cooler, limiting their placement space.

[0047] In some embodiments, the engine includes multiple cylinders, and there can be one or more engine coolant inlets 111. The upper water jacket 11 of the cylinder head corresponding to each cylinder can have an engine coolant inlet 111 on the exhaust side of the cylinder head, or the upper water jacket 11 of the cylinder head corresponding to some of the multiple cylinders can have an engine coolant inlet 111 on the exhaust side of the cylinder head.

[0048] In some preferred embodiments, the engine coolant inlet 111 is provided on the upper water jacket 11 of the cylinder head corresponding to the middle cylinder, and the middle cylinder is used to indicate the cylinder in the middle position among N cylinders; wherein the N cylinders are arranged in sequence, and N≥3.

[0049] For example, if the engine has an odd number of cylinders, and the odd-numbered cylinders are arranged in series, the middle cylinder may refer to the cylinder in the middle of the odd-numbered cylinders. For example, in a three-cylinder engine, where the first, second, and third cylinders are arranged in series, the middle cylinder may refer to the second cylinder. The engine coolant inlet 111 is located in the upper water jacket 11 of the cylinder head corresponding to the second cylinder.

[0050] For example, the engine has an even number of cylinders, which are arranged in series. The middle cylinders may refer to the two cylinders in the middle of the even number of cylinders. For example, the middle cylinders of a 6-cylinder engine may refer to the 3rd and 4th cylinders.

[0051] Please refer to Figure 2 The engine has six cylinders, namely the 1st, 2nd, 3rd, 4th, 5th, and 6th cylinders. The 1st, 2nd, 3rd, 4th, 5th, and 6th cylinders are arranged in series. The engine coolant inlet 111 is provided on the upper water jacket 11 of the cylinder head of the 3rd and 4th cylinders. Specifically, the upper water jacket 11 of the cylinder head of the 3rd cylinder has an engine coolant inlet 111 on the air intake side of the cylinder head, and the upper water jacket 11 of the cylinder head of the 4th cylinder has an engine coolant inlet 111 on the air intake side of the cylinder head.

[0052] In this embodiment, the engine coolant inlet 111 is located in the cylinder head upper water jacket 11 corresponding to the middle cylinder. If the engine coolant inlet 111 were located at the front, the coolant would need to flow through six cylinders to reach the rear end of the engine. In this embodiment, the engine coolant inlet 111 is located on the intake side of the cylinder head, specifically in the cylinder head upper water jacket 11 corresponding to cylinders 3 and 4. This allows the coolant to cool the entire engine by flowing through only three cylinders, effectively reducing flow resistance and, consequently, engine energy consumption. Furthermore, the coolant flows from the cylinder head upper water jacket 11 to the cylinder head lower water jacket 12, utilizing the coolant's own gravity. This results in a faster flow rate to the lower water jacket, thereby achieving a higher heat transfer coefficient. This engine cooling process, which flows from the center to the sides and from top to bottom, further reduces engine energy consumption.

[0053] In some embodiments, the engine cooling system further includes a water collection chamber 3 and a cooler water jacket 4. The cooler water jacket 4 is in communication with the water collection chamber 3. The water collection chamber 3 is provided with a liquid inlet. The cylinder head lower water jacket 12 is provided with a first liquid outlet 121, which is connected to the liquid inlet of the water collection chamber 3. In this way, the coolant flows out of the first liquid outlet 121 of the cylinder head lower water jacket 12 and enters the water collection chamber 3. The coolant then flows upward within the water collection chamber 3 and enters the cooler water jacket 4.

[0054] In some preferred embodiments, the engine coolant inlet 111 on the upper water jacket 11 of the cylinder head is located on the air intake side of the cylinder head, and the first liquid outlet 121 of the lower water jacket 12 of the cylinder head is located on the exhaust side of the cylinder head.

[0055] In this embodiment, the first liquid outlet 121 of the cylinder head lower water jacket 12 is located on the cylinder head exhaust side. That is, the liquid inlet of the water collection chamber 3, connected to the first liquid outlet 121, is located in the cylinder head lower water jacket 12, on the cylinder head exhaust side. By locating the engine coolant inlet 111 on the cylinder head intake side and the first liquid outlet 121 connected to the water collection chamber 3 on the cylinder head exhaust side, the coolant must flow through the nose bridge area before entering the water collection chamber 3, achieving targeted cooling at key locations.

[0056] In some embodiments, the engine includes multiple cylinders, and the first liquid outlet 121 of the cylinder head lower water jacket 12 corresponding to at least one cylinder is used to connect to the liquid inlet of the water collecting chamber 3 through the thermostat channel 123 .

[0057] A thermostat is provided in the thermostat channel 123 . The thermostat is a valve that controls the flow path of the coolant. The thermostat opens and closes the flow of the liquid through thermal expansion or contraction.

[0058] In the embodiment of the present application, each of the cylinder head lower water jackets 12 corresponding to each of the multiple cylinders is provided with a first liquid outlet 121. The first liquid outlet 121 of the cylinder head lower water jacket 12 corresponding to at least one cylinder is connected to the liquid inlet of the water collection chamber 3 via a thermostat passage 123. The thermostat passage 123 selectively enables the connection between the first liquid outlet 121 and the water collection chamber 3. When the thermostat is open, coolant flows from the first liquid outlet 121 through the thermostat passage 123 and into the water collection chamber 3 and the cooler water jacket 4.

[0059] The exhaust temperature will reach a peak under the rated operating conditions of the engine. Under this condition, the EGR cooler needs more coolant to remove the heat. However, under most operating conditions, the exhaust temperature will not be very high. At this time, the coolant flow rate can be appropriately reduced. The flow resistance inside the EGR cooler is very high. Appropriately reducing the coolant flow rate can reduce power consumption.

[0060] In this embodiment, the EGR cooler's water inlet is connected to the cylinder head lower water jacket 12 via the water collection chamber 3. By installing a thermostat at the first liquid outlet 121 of the cylinder head lower water jacket 12 corresponding to at least one cylinder, when the engine enters high-speed, high-load conditions, the water temperature rises, and the thermostat automatically opens, allowing more coolant to flow through the EGR cooler. This effectively improves the EGR cooler's cooling efficiency, reduces exhaust gas temperature, prevents high-temperature exhaust gas from entering the cylinder and causing engine knock, and ensures reliable engine operation. The thermostat dynamically distributes coolant flow, ensuring cooling capacity under high thermal load conditions while reducing engine power consumption under low load conditions.

[0061] In some preferred embodiments, the first liquid outlet 121 of the lower water jacket 12 of the cylinder head includes at least one main liquid outlet and at least one auxiliary liquid outlet, each main liquid outlet is used to be directly connected to the liquid inlet of the water collecting chamber 3, and each auxiliary liquid outlet is used to be connected to the liquid inlet of the water collecting chamber 3 through a thermostat, and the cylinders corresponding to the main liquid outlets and the cylinders corresponding to the auxiliary liquid outlets are alternately arranged.

[0062] For example, please refer to Figure 2 The engine has six cylinders, namely the 1st, 2nd, 3rd, 4th, 5th, and 6th cylinders. These cylinders are arranged in series, and each cylinder is provided with a first liquid outlet 121 on the exhaust side of the cylinder head. The first liquid outlet 121 corresponding to the 1st, 3rd, and 5th cylinders is a primary liquid outlet, i.e., the first liquid outlet 121 corresponding to the 1st, 3rd, and 5th cylinders is directly connected to the liquid inlet of the water collecting chamber 3. The first liquid outlet 121 corresponding to the 2nd, 4th, and 6th cylinders is a secondary liquid outlet. Thermostat devices are provided at the first liquid outlets 121 corresponding to the 2nd, 4th, and 6th cylinders, respectively. The first liquid outlets 121 corresponding to the 2nd, 4th, and 6th cylinders are connected to the liquid inlet of the water collecting chamber 3 via thermostat channels 123.

[0063] In this way, coolant flows through the cylinder head lower water jacket 12 to the first liquid outlet 121 on the exhaust side of cylinders 1, 3, and 5, before entering the water collection chamber 3. From there, the coolant flows upward into the EGR cooler water jacket 4. When the thermostat is open, coolant also enters the water collection chamber 3 through the thermostat passages 123 of cylinders 2, 4, and 6. By installing three thermostats at the outlet of the cylinder head lower water jacket 12, dynamic distribution of EGR cooler water flow is achieved, reducing cooling system resistance under low-load conditions and ensuring efficient and reliable cooling of the EGR cooler under high-load conditions.

[0064] The following will be combined Figures 3 to 5 The water flow distribution of the cylinder head lower water jacket 12 is explained as an example.

[0065] When the engine is running at low speed and low load, the system has low cooling requirements. At this time, the thermostat channel 123 located at the 2nd, 4th and 6th cylinders is closed. Figure 4 At this time, part of the coolant from the 6th cylinder will flow to the 5th cylinder and enter the water collecting chamber 3 through the first liquid outlet 121 of the 5th cylinder. When the engine enters the high-speed and high-load working condition, more heat enters the cooling system, causing the water temperature to rise. When the water temperature is higher than the corresponding preset value of the thermostat, the thermostat channel 123 will open. Please refer to Figure 5 At this time, the coolant of the 2nd, 4th and 6th cylinders does not need to detour to enter the adjacent cylinders, but flows directly from the cylinder to the water collecting chamber 3. The resistance between the lower water jacket 12 of the cylinder head and the water collecting chamber 3 is reduced, and more coolant will flow to the water collecting chamber 3, which effectively improves the cooling effect of the EGR cooler, reduces the temperature of the exhaust gas, avoids high-temperature exhaust gas from entering the cylinder and causing engine knock, and ensures reliable operation of the engine.

[0066] In some embodiments, the engine cooling system further includes a cylinder water jacket 2, which includes a cylinder liner water jacket 21 and a body water jacket 22 that are interconnected. The cylinder liner water jacket 21 is provided with a liquid inlet, and the cylinder head lower water jacket 12 is provided with a second liquid outlet 122, which is used to connect to the liquid inlet of the cylinder liner water jacket 21.

[0067] In some preferred embodiments, the cylinder liner is positioned below the cylinder head lower water jacket 12, and the liquid inlet of the cylinder liner water jacket 21 is located in the cylinder head lower water jacket 12 and on the bottom plane of the cylinder head. This allows the coolant to flow from the cylinder head lower water jacket 12 into the cylinder liner water jacket 21 with the advantage of gravity, resulting in a higher flow rate.

[0068] Please continue to refer to Figure 1 A cylinder block water jacket 2 is arranged below the cylinder head water jacket 1. A cylinder liner water jacket 21 within the cylinder block water jacket 2 is located on the cylinder head's intake side, while a body water jacket 22 within the cylinder block water jacket 2 is located on the cylinder head's exhaust side. A liquid inlet is defined within the cylinder liner water jacket 21. A second liquid outlet 122 is defined within the cylinder head's lower water jacket 12 on the intake side. This second liquid outlet 122 is configured to connect to the liquid inlet of the cylinder liner water jacket 21.

[0069] In conjunction with the aforementioned lower water jacket 12 of the cylinder head, a first liquid outlet 121 is provided on the exhaust side. The first liquid outlet 121 is used to connect to the liquid inlet of the water collecting chamber 3. In this way, the coolant in the upper water jacket 11 of the cylinder head passes through the connection between the upper water jacket 11 and the lower water jacket 12 of the cylinder head, and is divided into two streams inside the lower water jacket 12 of the cylinder head, cooling the intake side bottom plate and the exhaust side bottom plate of the cylinder head respectively. The coolant on the intake side of the lower water jacket 12 of the cylinder head flows to the second liquid outlet 122 and then enters the cylinder liner water jacket 21. After cooling the cylinder liner, the coolant enters the main body water jacket 22. The coolant on the exhaust side of the lower water jacket 12 of the cylinder head flows to the first liquid outlet 121 and then enters the water collecting chamber 3. The water flows upward inside the water collecting chamber 3 and enters the EGR cooler water jacket 4.

[0070] In this embodiment, the cylinder liner water jacket 21 and the cooler water jacket 4 are connected in parallel at the cylinder head lower water jacket 12, which ensures that all the engine coolant is used to cool the cylinder head base plate, thereby ensuring the reliability of the cylinder head base plate.

[0071] Furthermore, the water pump outlet is connected to the cylinder head upper water jacket 11. After the coolant flows from the upper cylinder head water jacket 11 through the lower cylinder head water jacket 12, a portion of the coolant is diverted to the cylinder liner water jacket 21. Compared to the traditional series cooling method, the parallel connection method appropriately reduces the water flow rate of the cylinder liner. In traditional cooling methods, the cooling capacity of the cylinder liner is excessive, and the coolant resistance between the cylinder liner and the body water jacket 22 is extremely large, accounting for 50% of the cooling system. This embodiment reduces the coolant flow rate through the cylinder liner water jacket 21, avoiding excessive cooling of the cylinder liner while also reducing the cooling system resistance and engine power consumption, achieving a 20% reduction in cooling system resistance.

[0072] In some embodiments, the upper water jacket 11 of the cylinder head and the lower water jacket 12 of the cylinder head are connected from top to bottom in the nose bridge area, wherein the upper and lower water jacket connecting area 13 between the upper water jacket 11 of the cylinder head and the lower water jacket 12 of the cylinder head is crescent-shaped.

[0073] Please refer to Figure 4 and Figure 5 The connecting area 13 of the upper and lower water jackets is designed as a meniscus structure, and the coolant in the upper water jacket 11 of the cylinder head enters the lower water jacket 12 of the cylinder head through the meniscus structure. Figure 4 and Figure 5"IN" represents the air intake duct and "EX" represents the exhaust duct. The two air intake ducts and the two exhaust ducts are arranged around the crescent structure, and one end of the upper and lower water jacket communication area 13 of the crescent structure is close to one air intake duct, and the other end of the upper and lower water jacket communication area 13 of the crescent structure is close to the other air intake duct. The inlet and inlet nose bridge areas are opposite to the openings at both ends of the upper and lower water jacket communication areas 13, and the connection between the inlet and inlet nose bridge areas is cleverly disconnected, so that more coolant water flow can directly rush into the inlet and exhaust nose bridge areas and the exhaust and exhaust nose bridge areas, reducing the coolant flow in the low-temperature area, effectively improving the cooling capacity of the high-temperature area, and ensuring high reliability of the cylinder head.

[0074] Based on the same inventive concept, embodiments of the present application also provide an engine cooling method for use with the aforementioned engine cooling system. The solution provided by this method is similar to the solution described in the aforementioned engine cooling system. Therefore, the specific limitations of one or more engine cooling method embodiments provided below can be found in the aforementioned limitations of the engine cooling system and will not be further elaborated here.

[0075] like Figure 6 As shown, an embodiment of the present application provides an engine cooling method, which includes the following steps:

[0076] Step 602 : Control the coolant to enter the engine from the engine coolant inlet 111 on the upper water jacket 11 of the cylinder head.

[0077] Step 604 : Control the coolant to flow from the upper water jacket 11 of the cylinder head into the lower water jacket 12 of the cylinder head through the upper and lower communication areas.

[0078] Among them, the upper water jacket 11 of the cylinder head includes the upper intake side water jacket of the cylinder head and the upper exhaust side water jacket of the cylinder head. After the coolant enters the upper water jacket 11 of the cylinder head, it is divided into two water flows inside the upper water jacket 11 of the cylinder head. One part enters the upper intake side water jacket of the cylinder head, and the remaining part enters the upper exhaust side water jacket of the cylinder head, cooling the cylinder head intake and exhaust passages respectively. Then, after being combined into one water flow in the connecting area of ​​the upper and lower water jackets of the cylinder head, it flows into the lower water jacket 12 of the cylinder head.

[0079] Step 606 , controlling a portion of the coolant to flow from the intake side of the cylinder head lower water jacket 12 into the cylinder body water jacket 2 , and controlling the remaining portion of the coolant to flow from the exhaust side of the cylinder head lower water jacket 12 into the water collecting chamber 3 .

[0080] After flowing into the lower water jacket 12 of the cylinder head, the coolant is divided into two streams within the lower water jacket 12, cooling the intake and exhaust side bottom plates of the cylinder head, respectively. The water on the intake side of the lower water jacket 12 flows to the second liquid outlet 122 on the intake side before entering the cylinder liner water jacket 21. After cooling the cylinder liner, the coolant enters the main body water jacket 22. The water on the exhaust side of the lower water jacket 12 flows to the first liquid outlet 121 and enters the water collection chamber 3. The coolant then flows upward from the water collection chamber 3 into the EGR cooler water jacket 4.

[0081] In a specific embodiment, the engine has six cylinders, namely cylinder 1, cylinder 2, cylinder 3, cylinder 4, cylinder 5, and cylinder 6. Cylinder 1, cylinder 2, cylinder 3, cylinder 4, cylinder 5, and cylinder 6 are arranged in a straight line. After the main water flow enters the cylinder head water jacket 1, it is divided into two streams inside the upper water jacket 11 of the cylinder head, cooling the cylinder head intake and exhaust ducts respectively. Then, it is combined into one water flow at the connection point between the upper and lower water jackets of the cylinder head. Next, it is divided into two streams again inside the lower water jacket 12 of the cylinder head, cooling the cylinder head intake side bottom plate and exhaust side bottom plate respectively. The above water flow organization is called the "split, combine, and split" method. Among them, the water flow on the intake side flows to the intake side outlet and then enters the cylinder liner water jacket 21. After cooling the cylinder liner, the water flow enters the main body water jacket 22. The exhaust-side water flows toward the first liquid outlet 121 on the exhaust side of cylinders 1, 3, and 5, then enters the water collection chamber 3. The water then flows upward within the water collection chamber 3 and enters the EGR cooler water jacket 4. When the thermostat is open, the exhaust-side water also flows into the water collection chamber 3 through the thermostat passage 123 of cylinders 2, 4, and 6.

[0082] refer to Figures 3 to 5 As shown, the water flow from the upper water jacket 11 of the cylinder head converges in the connecting area between the upper and lower water jackets, and is then diverted for cooling in the cylinder head baseplate area. When the engine is operating at low speed and low load, the system's cooling requirements are low. The thermostat passages 123 located in cylinders 2, 4, and 6 are closed. At this time, some coolant from cylinder 6 flows to cylinder 5, entering the water collection chamber 3 through the first outlet 121 on the exhaust side. When the engine enters high speed and high load conditions, more heat enters the cooling system, causing the water temperature to rise. When the water temperature reaches 95°C or higher, the thermostat passages 123 open. Coolant from the exhaust side of cylinders 2, 4, and 6 flows directly from their own cylinders to the water collection chamber 3, eliminating the need to detour to adjacent cylinders. The resistance between the lower water jacket 12 of the cylinder head and the water collection chamber 3 is reduced, allowing more coolant to flow into the water collection chamber 3. This effectively improves the cooling effect of the EGR cooler, lowers the exhaust gas temperature, and prevents high-temperature exhaust gas from entering the cylinders and causing engine knock, ensuring reliable engine operation.

[0083] The embodiments of the present application have the following beneficial effects:

[0084] (1) The engine is cooled by water flowing from the center to both sides and from top to bottom, which reduces engine energy consumption and improves engine cooling efficiency.

[0085] (2) Parallel connection is achieved at the lower water jacket of the cylinder head to ensure that all coolant flows through the cylinder head base plate, thereby improving the reliability of the cylinder head base plate.

[0086] (3) A thermostat device can be installed at the first liquid outlet of the lower water jacket of the cylinder head to reduce the water flow through the cylinder jacket and realize the distribution of the coolant flow of the EGR cooler on demand, thereby ensuring the reliability of the engine while reducing the engine power consumption.

[0087] (4) The "crescent" structure at the connection point between the upper and lower water jackets improves the utilization rate of the coolant.

[0088] In the description of this specification, reference to the terms "some embodiments" or "other embodiments" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0089] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0090] The above-described embodiments merely represent several implementation methods of the present application. 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 a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An engine cooling system comprising a cylinder head water jacket, characterized in that: The cylinder head water jacket comprises: Cylinder head upper water jacket; a lower water jacket of the cylinder head, connected to the upper water jacket of the cylinder head, and the lower water jacket of the cylinder head is arranged below the upper water jacket of the cylinder head; Wherein, an engine coolant inlet is provided on the upper water jacket of the cylinder head; The engine cooling system further comprises a water collecting chamber and a cooler water jacket, wherein the cooler water jacket is in communication with the water collecting chamber, and the water collecting chamber is provided with a liquid inlet; The lower water jacket of the cylinder head is provided with a first liquid outlet, and the first liquid outlet is used to be connected to the liquid inlet of the water collecting chamber; The engine comprises a plurality of cylinders, and a first liquid outlet of a lower water jacket of a cylinder head corresponding to at least one of the cylinders is connected to a liquid inlet of the water collecting chamber through a thermostat channel; The first liquid outlet of the lower water jacket of the cylinder head includes at least one main liquid outlet and at least one auxiliary liquid outlet. Each main liquid outlet is used to be directly connected to the liquid inlet of the water collecting chamber, and each auxiliary liquid outlet is used to be connected to the liquid inlet of the water collecting chamber through a thermostat. The cylinders corresponding to the main liquid outlets and the cylinders corresponding to the auxiliary liquid outlets are arranged alternately.

2. The engine cooling system according to claim 1, characterized in that The engine coolant inlet is arranged on the upper water jacket of the cylinder head corresponding to the middle cylinder, and the middle cylinder is used to indicate the cylinder in the middle position among N cylinders; wherein the N cylinders are arranged in sequence, and N≥3.

3. The engine cooling system according to claim 1, characterized in that The engine coolant inlet on the upper water jacket of the cylinder head is located on the air intake side of the cylinder head, and the first liquid outlet of the lower water jacket of the cylinder head is located on the exhaust side of the cylinder head.

4. The engine cooling system according to any one of claims 1 to 3, characterized in that: The engine cooling system further comprises a cylinder water jacket, wherein the cylinder water jacket comprises a cylinder jacket water jacket and a body water jacket which are interconnected, and the cylinder jacket water jacket is provided with a liquid inlet; The cylinder head lower water jacket is provided with a second liquid outlet, and the second liquid outlet is used to be connected to the liquid inlet of the cylinder liner water jacket.

5. The engine cooling system according to claim 1, characterized in that The upper water jacket of the cylinder head and the lower water jacket of the cylinder head are connected from top to bottom in the nose bridge area, wherein the upper and lower water jacket connecting areas between the upper water jacket of the cylinder head and the lower water jacket of the cylinder head are crescent-shaped.

6. An engine cooling method, characterized in that: Applied to the engine cooling system according to any one of claims 1 to 5, the method comprises: Controls the coolant to enter the engine from the engine coolant inlet on the upper water jacket of the cylinder head; Controlling the coolant to flow from the upper water jacket of the cylinder head into the lower water jacket of the cylinder head through the upper and lower communicating areas; A portion of the coolant is controlled to flow from the air intake side of the cylinder head lower water jacket into the cylinder body water jacket, and the remaining portion of the coolant is controlled to flow from the air exhaust side of the cylinder head lower water jacket into the water collecting chamber.

7. A vehicle, characterized in that: Comprising the engine cooling system according to any one of claims 1 to 5.

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