Engine cooling system, engine cooling method and vehicle

Abstract

The invention relates to an engine cooling system, an engine cooling method and a vehicle, and relates to the technical field of vehicles. The engine cooling system comprises a cylinder cover water jacket, the cylinder cover water jacket comprises a cylinder cover upper-layer water jacket and a cylinder cover lower-layer water jacket, the cylinder cover lower-layer water jacket is connected with the cylinder cover upper-layer water jacket, the cylinder cover upper-layer water jacket and the cylinder cover lower-layer water jacket are communicated with each other, and an engine cooling liquid inlet is formed in the cylinder cover upper-layer water jacket. The engine cooling liquid inlet is formed in the cylinder cover upper-layer water jacket, so that main water flow of cooling liquid enters an engine from the cylinder cover upper-layer water jacket, then flows through the cylinder cover lower-layer water jacket and then enters a cylinder body, the flowing speed of the cooling liquid is increased through the gravity factor, and the resistance of a cooling system is reduced through a cooling path from top to bottom; therefore, the heat exchange coefficient is increased, and the cooling efficiency is improved. Meanwhile, cooling liquid can firstly flow through a cylinder cover area with a larger cooling requirement, cylinder sleeve cooling resource surplus is avoided, and engine power consumption is reduced.

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 the traditional commercial vehicle engine cooling system, the coolant flow path is usually pumped from the water pump into the engine block water jacket, then through the cylinder liner water jacket, and then upward into the cylinder head water jacket. If the engine is equipped with an exhaust gas recirculation (EGR) system, the coolant must flow into the EGR cooler water jacket after flowing through the cylinder head water jacket to control the temperature of the exhaust gas.

[0003] However, in the above cooling system, the coolant must first pass through the cylinder block and the cylinder jacket. The water flow resistance between these two parts is very large, especially the narrow structure of the cylinder jacket further aggravates the fluid resistance. This high resistance forces the water pump in the cooling system to output more power to maintain sufficient coolant flow, which increases the power consumption of the system and reduces the 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, and 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 with the liquid inlet of the water collecting chamber.

[0012] In one of the embodiments, the engine includes 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 used to be connected to a liquid inlet of the water collecting chamber through a thermostat channel.

[0013] In one of the embodiments, 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 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, 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;

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

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

[0018] The 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, and the engine cooling method comprises:

[0019] Control 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 also provides a vehicle, which includes the engine cooling system provided in the first aspect of the present application.

[0023] In the above 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 is connected to the upper cylinder head water jacket, the upper cylinder head water jacket and the lower cylinder head water jacket are interconnected, wherein an engine coolant inlet is provided on the upper cylinder head water jacket. The present application provides an engine coolant inlet by opening the engine coolant inlet on the upper cylinder head water jacket of the cylinder head, for example, directly connecting the water outlet of the water pump to the engine cooling inlet of the upper cylinder head water jacket, so that the main water flow of the coolant enters the engine from the engine cooling inlet of the upper cylinder head water jacket. By opening the engine coolant inlet on the upper cylinder head water jacket, the coolant enters the engine from the upper cylinder head water jacket, and then flows through the upper cylinder head water jacket and the lower cylinder head water jacket before entering the cylinder body, the flow velocity of the coolant is increased by utilizing the gravity factor, and the resistance of the cooling system is reduced through the top-down cooling path, thereby improving the heat exchange coefficient and the cooling efficiency. At the same time, the coolant can first flow through the cylinder head area with greater cooling needs, 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 cooling resources of the cylinder liner and reducing engine power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. 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] FIG. 1 is a schematic diagram of the structure of an engine cooling system in some embodiments of the present application.

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

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

[0028] FIG. 4 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] FIG. 5 is a schematic diagram of water flow distribution in the lower water jacket of the cylinder head when the thermostat is opened in some embodiments of the present application.

[0030] FIG. 6 is a schematic 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 body 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] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature 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. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in 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 a central 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 a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0039] In the current engine cooling system, the water pump pumps the coolant to the cylinder body water jacket, and then the coolant flows through the cylinder jacket water jacket and then goes up to the cylinder head water jacket. If it is a gas engine, the coolant needs to enter the EGR cooler water jacket after flowing through the cylinder head. For gas engines, the combustion temperature and exhaust temperature are much higher than those of diesel engines, so the demand for engine cooling capacity will be greater.

[0040] According to the traditional engine cooling method, all coolant must flow through the cylinder liner before being distributed to the cylinder head. However, the resistance between the cylinder body water jacket and the cylinder liner water jacket is very large, especially the narrow structure of the cylinder water jacket further aggravates the fluid resistance. This high resistance forces the water pump in the cooling system to output more power to maintain sufficient coolant flow, which increases the power consumption of the system.

[0041] In addition, since the cylinder liner mainly contacts the piston side wall, its temperature is not as high as that of the combustion chamber and cylinder head area, so the cooling demand of the cylinder liner is relatively small. However, due to the resistance distribution and flow path arrangement in the traditional design, the coolant still needs to flow through the cylinder liner water jacket in large quantities, which not only wastes cooling resources, but also causes the flow rate and cooling capacity of the coolant to be weakened when it reaches the cylinder head. The cooling demand of the cylinder head area is greater, especially the area above the valve seat and the combustion chamber, which is where the combustion temperature is the highest. However, due to excessive consumption of coolant by the cylinder liner, the cooling effect of the cylinder head often does not reach the optimal level.

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

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

[0044] The cylinder head upper water jacket 11 and the cylinder head lower water jacket 12 of the embodiment of the present application are connected to each other, wherein the cylinder head upper water jacket 11 is provided with an engine coolant inlet 111. Exemplarily, the engine coolant inlet 111 of the cylinder head upper water jacket 11 is used to connect with a water pump, and by directly connecting the water pump outlet to the engine coolant inlet 111 of the cylinder head upper water jacket 11, the main water flow of the coolant enters the engine from the engine coolant inlet 111 of the cylinder head upper water jacket 11.

[0045] In the above 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 the upper cylinder head water jacket 11 and the lower cylinder head water jacket 12 are interconnected, wherein the upper cylinder head water jacket 11 is provided with an engine coolant inlet 111. By opening the engine coolant inlet 111 on the upper cylinder head water jacket 11, the coolant enters the engine from the upper cylinder head water jacket 11, and then flows through the lower cylinder head water jacket 12 through the upper cylinder head water jacket 11 and then enters the cylinder body, the flow velocity of the coolant is increased by the gravity factor, the resistance of the cooling system is reduced through the top-down cooling path, and then the heat exchange coefficient and the cooling efficiency are improved. At the same time, the coolant can first flow through the cylinder head area with greater cooling demand, especially the area above the valve seat and the combustion chamber, and then flow through the lower cylinder head water jacket 12 and then enter the cylinder liner water jacket 21, thereby avoiding excessive cylinder liner cooling resources and reducing engine power consumption.

[0046] Optionally, the engine coolant inlet 111 of the upper water jacket 11 of the cylinder head is located on the intake side of the cylinder head. Since the coolant inlet is generally sealed with an O-ring, if the engine coolant inlet 111 is located on the exhaust side of the cylinder head, high temperature will easily affect its sealing performance. Thus, by arranging the engine coolant inlet 111 on the intake side of the cylinder head, the reliability of the engine cooling system is further improved. At the same time, the exhaust side of the cylinder head is usually provided with parts such as a water collecting chamber 3 and an EGR cooler, and the layout space is limited.

[0047] In some embodiments, the engine includes multiple cylinders, and there may be one or more engine coolant inlets 111. The cylinder head upper water jacket 11 corresponding to each cylinder may have an engine coolant inlet 111 on the exhaust side of the cylinder head, or the cylinder head upper water jacket 11 corresponding to some of the multiple cylinders may 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 arranged 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, N≥3.

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

[0050] Exemplarily, 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 FIG2 , the number of the engine cylinders is 6, namely the 1st cylinder, the 2nd cylinder, the 3rd cylinder, the 4th cylinder, the 5th cylinder and the 6th cylinder, the 1st cylinder, the 2nd cylinder, the 3rd cylinder, the 4th cylinder, the 5th cylinder and the 6th cylinder are arranged in series, and the engine coolant inlet 111 is provided on the cylinder head upper water jacket 11 of the 3rd cylinder and the 4th cylinder. Specifically, the cylinder head upper water jacket 11 of the 3rd cylinder has an engine coolant inlet 111 on the cylinder head air intake side, and the cylinder head upper water jacket 11 of the 4th cylinder has an engine coolant inlet 111 on the cylinder head air intake side.

[0052] In this embodiment, the engine coolant inlet 111 is opened on the upper water jacket 11 of the cylinder head corresponding to the cylinder in the middle position. If the engine coolant inlet 111 is set at the front end, the coolant needs to flow through 6 cylinders to reach the rear end of the engine. In this embodiment, the engine coolant inlet 111 is set on the air intake side of the cylinder head, specifically on the upper water jacket 11 of the cylinder head corresponding to the 3rd and 4th cylinders. The coolant only needs to flow through 3 cylinders to achieve the cooling of the entire engine, which effectively reduces the flow resistance and thus reduces the engine energy consumption. At the same time, the coolant flows from the upper water jacket 11 of the cylinder head to the lower water jacket 12 of the cylinder head, utilizing the coolant's own gravity. The coolant flows faster when flowing to the lower water jacket, thereby achieving a higher heat transfer coefficient. The engine is cooled by the water flow path from the middle to both sides and from top to bottom, which further reduces the engine energy consumption.

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

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

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

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

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

[0058] The cylinder head lower layer water jackets 12 corresponding to the multiple cylinders of the embodiment of the present application are all provided with first liquid outlets 121, wherein the first liquid outlet 121 of the cylinder head lower layer water jacket 12 corresponding to at least one cylinder is connected to the liquid inlet of the water collecting chamber 3 through the thermostat channel 123. Whether the first liquid outlet 121 is connected to the water collecting chamber 3 can be selectively set through the thermostat channel 123. When the thermostat is turned on, the coolant enters the water collecting chamber 3 and the cooler water jacket 4 from the first liquid outlet 121 through the thermostat channel 123.

[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 take away 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 water inlet of the EGR cooler is connected to the lower water jacket 12 of the cylinder head through the water collecting chamber 3. By setting a thermostat device at the first liquid outlet 121 of the lower water jacket 12 of the cylinder head corresponding to at least one cylinder, when the engine enters a high-speed and high-load condition, the water temperature rises, the thermostat device automatically opens, and more coolant will flow through the EGR cooler, effectively improving the cooling effect of the EGR cooler, reducing the temperature of the exhaust gas, avoiding high-temperature exhaust gas from entering the cylinder to cause engine knock, and ensuring reliable operation of the engine. The dynamic distribution of the coolant flow is achieved through the thermostat device, which not only ensures the cooling capacity under high thermal load conditions, but also reduces the engine power consumption under low load.

[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 continue to refer to Figure 2. The number of engine cylinders is 6, namely the 1st cylinder, the 2nd cylinder, the 3rd cylinder, the 4th cylinder, the 5th cylinder and the 6th cylinder. The 1st cylinder, the 2nd cylinder, the 3rd cylinder, the 4th cylinder, the 5th cylinder and the 6th cylinder are arranged in sequence in a straight line, and the 1st cylinder to the 6th cylinder are respectively provided with a first liquid outlet 121 on the exhaust side of the cylinder head. Among them, the first liquid outlets 121 corresponding to the 1st cylinder, the 3rd cylinder, and the 5th cylinder are main liquid outlets, that is, the first liquid outlets 121 corresponding to the 1st cylinder, the 3rd cylinder, and the 5th cylinder are used to directly connect with the liquid inlet of the water collecting chamber 3; the first liquid outlets 121 corresponding to the 2nd cylinder, the 4th cylinder, and the 6th cylinder are auxiliary liquid outlets, and the thermostat device is arranged at the first liquid outlets 121 corresponding to the 2nd cylinder, the 4th cylinder, and the 6th cylinder, respectively, and the first liquid outlets 121 corresponding to the 2nd cylinder, the 4th cylinder, and the 6th cylinder are connected with the liquid inlet of the water collecting chamber 3 through the thermostat channel 123.

[0063] In this way, the coolant flows through the lower water jacket 12 of the cylinder head to the first liquid outlet 121 on the exhaust side of the 1st, 3rd and 5th cylinders and then enters the water collecting chamber 3. The coolant flows upward inside the water collecting chamber 3 and enters the EGR cooler water jacket 4. When the thermostat is turned on, the coolant will also enter the water collecting chamber 3 through the thermostat channel 123 of the 2nd, 4th and 6th cylinders. By setting three thermostats at the outlet of the lower water jacket 12 of the cylinder head, the dynamic distribution of the water flow of the EGR cooler is realized, the resistance of the cooling system can be reduced under low load conditions, and the efficient and reliable cooling of the EGR cooler can be ensured under high load conditions.

[0064] The water flow distribution of the lower water jacket 12 of the cylinder head will be exemplarily described below in conjunction with FIG. 3 to FIG. 5 .

[0065] When the engine is running at low speed and low load, the system does not have high demand for cooling. At this time, the thermostat channels 123 located in the 2nd, 4th and 6th cylinders are in a closed state. Taking the 5th and 6th cylinders as an example, please refer to Figure 4. At this time, part of the coolant in the 6th cylinder will flow to the 5th cylinder and enter the water collection chamber 3 through the first liquid outlet 121 of the 5th cylinder. When the engine enters a high-speed and high-load condition, more heat enters the cooling system, causing the water temperature to rise. When the water temperature is greater than the preset value corresponding to the thermostat, the thermostat channel 123 will open. Please refer to Figure 5. At this time, the coolant in the 2nd, 4th and 6th cylinders does not need to bypass the adjacent cylinders, but flows directly from the cylinder to the water collection chamber 3. The resistance between the lower water jacket 12 of the cylinder head and the water collection chamber 3 is reduced, and more coolant will flow to the water collection chamber 3, which effectively improves the cooling effect of the EGR cooler, reduces the temperature of the exhaust gas, and avoids high-temperature exhaust gas from entering the cylinder to cause engine knock, ensuring reliable operation of the engine.

[0066] In some embodiments, the engine cooling system further includes a cylinder block 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, and the second liquid outlet 122 is used to connect with the liquid inlet of the cylinder liner water jacket 21.

[0067] In some preferred embodiments, the cylinder liner is disposed below the cylinder head lower water jacket 12, and the liquid inlet of the cylinder liner water jacket 21 is disposed in the cylinder head lower water jacket 12 and is located at the bottom plane of the cylinder head. In this way, the coolant has a gravity advantage when entering the cylinder liner water jacket 21 from the cylinder head lower water jacket 12, and a higher flow rate can be obtained.

[0068] Please continue to refer to Figure 1. A cylinder water jacket 2 is arranged below the cylinder head water jacket 1. The cylinder jacket water jacket 21 in the cylinder water jacket 2 is located on the cylinder head air intake side, and the body water jacket 22 in the cylinder jacket 2 is located on the cylinder head exhaust side. The cylinder jacket water jacket 21 is provided with a liquid inlet, and the lower water jacket 12 of the cylinder head is provided with a second liquid outlet 122 on the air intake side. The second liquid outlet 122 is used to connect with the liquid inlet of the cylinder jacket water jacket 21.

[0069] In combination with the aforementioned cylinder head lower water jacket 12, a first liquid outlet 121 is provided on the exhaust side. The first liquid outlet 121 is used to connect with the liquid inlet of the water collecting chamber 3. In this way, the coolant of the cylinder head upper water jacket 11 passes through the connection between the cylinder head upper water jacket 11 and the cylinder head lower water jacket 12, and is divided into two streams of water inside the cylinder head lower water jacket 12, respectively cooling the cylinder head intake side bottom plate and the exhaust side bottom plate. The coolant on the intake side of the cylinder head lower water jacket 12 flows to the second liquid outlet 122 and then enters the cylinder jacket water jacket 21. The coolant cools the cylinder jacket and then enters the body water jacket 22. The coolant on the exhaust side of the cylinder head lower water jacket 12 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 required to cool the cylinder head bottom plate, thereby ensuring the reliability of the cylinder head bottom plate.

[0071] Furthermore, the water pump outlet is connected to the upper water jacket 11 of the cylinder head, and after the coolant flows from the upper water jacket 11 of the cylinder head through the lower water jacket 12 of the cylinder head, a part of the coolant is diverted to enter the cylinder liner water jacket 21. Compared with the traditional series connection method, the parallel connection method appropriately reduces the water flow of the cylinder liner. In the traditional cooling method, 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, which can account for 50% of the cooling system. This embodiment reduces the coolant flow through the cylinder liner water jacket 21, avoids excessive cooling of the cylinder liner, and can reduce the resistance of the cooling system, reduce the power consumption of the engine, and can reduce the resistance of the cooling system by 20%.

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

[0073] Please refer to Figures 4 and 5. The upper and lower water jacket connecting area 13 is designed as a crescent structure, and the coolant of the upper water jacket 11 of the cylinder head enters the lower water jacket 12 of the cylinder head through the crescent structure. In Figures 4 and 5, "IN" represents the intake duct, and "EX" represents the exhaust duct. Two intake ducts and two exhaust ducts are arranged around the crescent structure, and one end of the upper and lower water jacket connecting area 13 with a crescent structure is close to one intake duct, and the other end of the upper and lower water jacket connecting area 13 with a crescent structure is close to another intake duct. The inlet and inlet nose bridge areas are opposite to the openings at both ends of the upper and lower water jacket connecting area 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 in the high-temperature area, and ensuring the high reliability of the cylinder head.

[0074] Based on the same inventive concept, the embodiment of the present application also provides an engine cooling method applied to the above engine cooling system. The implementation solution provided by the method is similar to the implementation solution recorded in the above engine cooling system, so the specific limitations in one or more engine cooling method embodiments provided below can refer to the above limitations on the engine cooling system, and will not be repeated here.

[0075] As shown in FIG6 , an embodiment of the present application provides an engine cooling method, the method comprising the following steps:

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

[0077] Step 604 , controlling the coolant to flow from the cylinder head upper water jacket 11 into the cylinder head lower water jacket 12 through the upper and lower communicating areas.

[0078] Among them, the upper water jacket 11 of the cylinder head includes an upper intake side water jacket of the cylinder head and an 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 to cool the cylinder head intake and exhaust passages respectively. Subsequently, the coolant is combined into one water flow in the connecting area of ​​the upper and lower water jackets of the cylinder head and then flows into the lower water jacket 12 of the cylinder head.

[0079] Step 606 , controls 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 controls 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 the coolant flows into the lower water jacket 12 of the cylinder head, it 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 water flow on the intake side of the lower water jacket 12 of the cylinder head flows to the second liquid outlet 122 on the intake side and then enters the cylinder jacket water jacket 21. After the coolant cools the cylinder jacket, it enters the body water jacket 22. The water flow 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 coolant flows upward inside the water collecting chamber 3 and enters the EGR cooler water jacket 4.

[0081] In a specific embodiment, the number of engine cylinders is 6, namely, the 1st cylinder, the 2nd cylinder, the 3rd cylinder, the 4th cylinder, the 5th cylinder and the 6th cylinder, and the 1st cylinder, the 2nd cylinder, the 3rd cylinder, the 4th cylinder, the 5th cylinder and the 6th cylinder are arranged in a straight line. After the main water flow enters the cylinder head water jacket 1, it is divided into two water flows inside the upper water jacket 11 of the cylinder head, respectively cooling the cylinder head intake and exhaust passages, and then merged into one water flow at the connection point between the upper and lower water jackets of the cylinder head, and then divided into two water flows again inside the lower water jacket 12 of the cylinder head, respectively cooling the cylinder head intake side bottom plate and the exhaust side bottom plate, and the above water flow organization is called the "split, merge 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, and the water flow enters the body water jacket 22 after cooling the cylinder liner. The water flow on the exhaust side flows to the first liquid outlet 121 on the exhaust side of the 1st, 3rd and 5th cylinders 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. When the thermostat is opened, the water flow on the exhaust side also enters the water collecting chamber 3 through the thermostat channel 123 of the 2nd, 4th and 6th cylinders.

[0082] As shown in FIG. 3 to FIG. 5, the water flow of the upper water jacket 11 of the cylinder head is gathered together in the connecting area of ​​the upper and lower water jackets, and then divided and cooled in the bottom plate area of ​​the cylinder head. When the engine is running at low speed and low load, the system does not have a high demand for cooling. At this time, the thermostat channel 123 located in the 2nd, 4th and 6th cylinders is in a closed state. At this time, part of the coolant in the 6th cylinder will flow to the 5th cylinder and enter the water collecting chamber 3 through the first liquid outlet 121 on the exhaust side. When the engine enters a high-speed and high-load condition, more heat enters the cooling system, causing the water temperature to rise. When the water temperature is ≥95°C, the thermostat channel 123 will open. At this time, the coolant on the exhaust side of the 2nd, 4th and 6th cylinders does not need to bypass 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, and avoids high-temperature exhaust gas from entering the cylinder to cause engine knock, ensuring reliable operation of the engine.

[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 on-demand distribution of the coolant flow of the EGR cooler, thereby ensuring the reliability of the engine and reducing the power consumption of the engine.

[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, the description with reference to the terms "some embodiments", "other embodiments", etc. 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 description of the above terms does not necessarily refer to the same embodiment or example.

[0089] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached 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 cylinder head lower water jacket connected to the cylinder head upper water jacket, wherein the cylinder head lower water jacket is arranged below the cylinder head upper water jacket; Wherein, an engine coolant inlet is provided on the upper water jacket of the cylinder head.

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 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 with the liquid inlet of the water collecting chamber.

4. The engine cooling system according to claim 3, characterized in that: 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 used to be connected to a liquid inlet of the water collecting chamber through a thermostat channel.

5. The engine cooling system according to claim 4, characterized in that: 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.

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

7. The engine cooling system according to any one of claims 1 to 6, 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 with the liquid inlet of the cylinder liner water jacket.

8. The engine cooling system according to claim 1, characterized in that: The cylinder head upper water jacket and the cylinder head lower water jacket are connected from top to bottom in the nose bridge area, wherein the upper and lower water jacket connecting area between the cylinder head upper water jacket and the cylinder head lower water jacket is in a crescent shape.

9. An engine cooling method, characterized in that: Applied to the engine cooling system according to any one of claims 1 to 8, the method comprising: Control 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.

10. A vehicle, characterized in that: Comprising an engine cooling system as claimed in any one of claims 1 to 8.

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