A large displacement aluminum alloy cylinder block

Abstract

This application proposes a large-displacement aluminum alloy cylinder block, including a cylinder block and a cylinder head. The cylinder block has multiple cylinder bores, and a U-shaped water jacket is provided around each bore. A first water inlet and a first water outlet are respectively located on both sides of the cylinder block, and the inlet and outlet are connected to the two ends of the U-shaped water jacket. The cylinder head is connected to the upper side of the cylinder block and seals the multiple cylinder bores. A cylinder head water jacket is provided inside the cylinder head, and the cylinder head water jacket has a second water inlet and a second water outlet. A thermostat is provided at the first water outlet of the cylinder block, and a micro-circulation channel is also provided above the first water outlet, communicating with the second water inlet to regulate the cooling circulation between the U-shaped water jacket and the cylinder head water jacket via the thermostat. In this application embodiment, the U-shaped water jacket surrounds the cylinder bores, providing uniform cooling, avoiding localized overheating and deformation of the cylinder barrel, and ensuring the sealing of the piston rings and the durability of the engine.

Description

Technical Field

[0001] This application relates to the field of automotive engine technology, and more particularly to a large-displacement aluminum alloy cylinder block. Background Technology

[0002] Due to the mutual constraints and balance between fuel consumption, power, and emission regulations, small-displacement engines cannot meet the power requirements of commercial vehicles and need to be replaced by large-displacement engines. The increase in displacement also requires a larger cylinder block size. Using cast iron cylinder blocks would result in excessive engine weight, leading to excessive fuel consumption and poor fuel economy. Cast aluminum cylinder blocks are needed to reduce the weight of the cylinder block and thus control the total weight of the engine. However, the material properties of cast aluminum cylinder blocks determine that their strength is much lower than that of cast iron, resulting in poor wear resistance of cylinder bores and low strength in the main stress areas. Because aluminum alloys have high thermal conductivity and heat up quickly, but their high-temperature resistance is insufficient, if the cooling effect of the cylinder block cannot meet the requirements, it will lead to thermal deformation or performance degradation, affecting the stability and durability of the engine under high-temperature conditions. Utility Model Content

[0003] This application proposes a large-displacement aluminum alloy cylinder block, relating to the field of automotive engine technology. The application of a partitioned U-shaped water jacket and the water jacket design for layered cooling of the cylinder block and cylinder head maximize the cooling effect of the engine. The micro-circulation water channel design in the thermostat cavity ensures the timely opening and closing of the thermostat and improves the accuracy of the engine cooling system operation.

[0004] In a first aspect, embodiments of this application provide a large-displacement aluminum alloy cylinder block, including a cylinder block and a cylinder head; The cylinder body is provided with multiple cylinder holes, and a U-shaped water jacket is provided around the cylinder holes; a first water inlet and a first water outlet are respectively provided on both sides of the cylinder body, and the water inlet and the water outlet are respectively connected to the two ends of the U-shaped water jacket; The cylinder head is connected to the upper side of the cylinder block and seals the multiple cylinder bores; the cylinder head is provided with a cylinder head water jacket, which is provided with a second water inlet and a second water outlet; a thermostat is provided at the first water outlet of the cylinder block, and a micro-circulation water channel is provided above the first water outlet. The micro-circulation water channel is connected to the second water inlet to regulate the cooling circulation between the U-shaped water jacket and the cylinder head water jacket through the thermostat.

[0005] In this embodiment, a U-shaped water jacket surrounds the cylinder bore, providing uniform cooling, preventing localized overheating and deformation of the cylinder barrel, and ensuring the sealing of the piston rings and the durability of the engine. By designing the orifice diameter of the micro-circulation water channel, the coolant flow ratio distributed to the cylinder block and cylinder head can be precisely controlled. This achieves the ideal state of "keeping the cylinder block slightly warm to reduce friction, while keeping the cylinder head sufficiently cooled to suppress knocking."

[0006] Optionally, a V-shaped water channel is provided on the partition between two adjacent cylinder bores, and the two ends of the V-shaped water channel are connected to the two sides of the U-shaped water jacket located in the cylinder bore.

[0007] In the embodiments of this application, the temperature of the nose bridge area is significantly reduced, preventing cylinder deformation, cylinder scoring, and oil coking caused by local overheating, thereby greatly improving the durability of the engine.

[0008] Optionally, the cylinder block is an inline engine cylinder block, and the axes of the cylinder bores are located in the same plane.

[0009] In the embodiments of this application, the U-shaped water jacket and V-shaped water channel are easier to design and manufacture on regular, symmetrical inline cylinder blocks, which can ensure that each cylinder receives uniform and powerful cooling.

[0010] Optionally, a cast iron cylinder liner is also embedded in the cylinder bore.

[0011] In the embodiments of this application, cast iron (especially phosphorus and boron alloy cast iron) has extremely excellent wear resistance, and its metal microstructure can well maintain the oil film and reduce the wear of the friction pair.

[0012] Optionally, the cylinder block is also provided with an oil cooler on the exhaust side to reduce the temperature of the engine oil entering the main oil passage.

[0013] In this embodiment, the engine oil temperature is maintained within an optimal operating range to ensure that the engine oil always maintains ideal viscosity and lubrication performance, providing the most fundamental protection for the engine.

[0014] Optionally, the cylinder block is provided with multiple mounting holes on the intake and exhaust sides to fix the cylinder block in the vehicle body.

[0015] In this embodiment, the thickness of the threaded hole and the engagement length of the bolt are increased for the main load-bearing suspension mounting hole to improve the strength of the cylinder body. Optionally, the cylinder block has multiple reinforcing ribs arranged on the intake side, exhaust side, front end face, and rear end face.

[0016] In this embodiment, by arranging reinforcing ribs on the intake side, exhaust side, front face and rear face, a thin-walled box structure is transformed into a high-rigidity space truss structure.

[0017] Optionally, the diameter ratio of the first water outlet to the second water outlet is 1:2.8.

[0018] In this embodiment, the flow rate of coolant flowing to the cylinder head water jacket is much greater than the flow rate flowing to the cylinder block water jacket.

[0019] Optionally, the lower side of the cylinder block is further provided with a crankshaft hole, and a bearing cap is connected to the crankshaft hole via a locating pin. The locating pin has an interference fit with the cylinder block and a clearance fit with the bearing cap.

[0020] In this embodiment, the application of the bearing cover locating pin avoids the risk of misalignment during secondary assembly due to interference fit, ensuring the accuracy of secondary assembly of the bearing cover and reducing the difficulty of disassembly and assembly. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This application provides a schematic diagram of the structure of the intake side of a large-displacement aluminum alloy cylinder block. Figure 2 This application provides a schematic diagram of the structure of the exhaust side of a large-displacement aluminum alloy cylinder block in an embodiment of the present application. Figure 3 This application provides a schematic diagram of the structure of a U-shaped water jacket in a large-displacement aluminum alloy cylinder block. Figure 4 This application provides a schematic diagram of the structure of the cylinder bore in a large-displacement aluminum alloy cylinder block. Figure 5 A schematic diagram illustrating the connection between the cylinder block and the bearing cap in a large-displacement aluminum alloy cylinder block, provided as an embodiment of this application; Figure 6 This is a schematic diagram of the cylinder head structure in a large-displacement aluminum alloy cylinder block, provided as an embodiment of this application.

[0023] Explanation of reference numerals in the attached figures: 1. Cylinder block; 2. First water inlet; 3. Suspension mounting hole; 4. First water outlet; 5. Oil cooler mounting interface; 6. U-shaped water jacket; 7. Cylinder head water inlet; 8. Cylinder bore; 9. Cast iron cylinder liner; 10. Micro-circulation water channel; 11. V-shaped water channel; 12. Locating pin; 13. Bearing cap; 14. Cylinder head; 15. Second water inlet; 16. Second water outlet. Detailed Implementation

[0024] To better understand the technical solutions in this specification, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0025] It should be understood that the described embodiments are merely some, not all, of the embodiments in this specification. All other embodiments obtained by those skilled in the art based on the embodiments in this specification without inventive effort are within the scope of protection of this specification.

[0026] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this specification. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0027] The existing dual-motor distributed electric drive (there is also an axial flux distributed electric drive, which also has the following problems) uses oil-cooled motors and water-cooled motor controllers, resulting in two cooling systems. The cooling system design is complex and includes components such as oil coolers, oil pumps, and oil filters. This not only increases the cost but also makes the entire system large, which cannot meet the requirements of small car applications.

[0028] In view of this, according to Figures 1 to 6 As shown, this application embodiment provides a large displacement aluminum alloy cylinder block, including a cylinder block 1 and a cylinder head 14; The cylinder body 1 has multiple cylinder holes 8 inside, and a U-shaped water jacket 6 is provided around the cylinder holes 8; a first water inlet 2 and a first water outlet 4 are respectively provided on both sides of the cylinder body 1, and the water inlet and the water outlet are respectively connected to the two ends of the U-shaped water jacket 6. The cylinder head 14 is connected to the upper side of the cylinder body 1 and seals the multiple cylinder holes 8. The cylinder head 14 is provided with a cylinder head 14 water jacket, and the cylinder head 14 water jacket is provided with a second water inlet 15 and a second water outlet 16. A thermostat is provided at the first water outlet 4 of the cylinder body 1, and a micro-circulation water channel 10 is also provided above the first water outlet 4. The micro-circulation water channel 10 is connected to the second water inlet 15 so as to regulate the cooling circulation between the U-shaped water jacket 6 and the cylinder head 14 water jacket through the thermostat.

[0029] In this embodiment, the cylinder body 1 has a U-shaped water jacket 6 surrounding the cylinder bore 8, with a first water inlet 2 and a first water outlet 4 on both sides. Mounted on the cylinder body 1, it has its own cylinder head 14 water jacket, with independent second water inlet 15 and second water outlet 16. A micro-circulation water channel 10 is located above the first water outlet 4 of the cylinder body 1, directly connecting the water outlet path of the cylinder body 1 and the second water inlet 15 of the cylinder head 14. It is controlled by a thermostat. The thermostat is the "master switch" and "dispatch center" for the entire cooling flow. Furthermore, a cylinder head water inlet 7 is also provided at the connection between the first water inlet and the U-shaped water jacket 6 on the cylinder body 1. The cylinder head water inlet 7 is connected to the second water inlet 15 in the cylinder head 14 water jacket. This embodiment adopts a layered cooling design, with independent water outlets for the cylinder body 1 and cylinder head 14.

[0030] Specifically, the cold start rapid warm-up phase: Operating status: Engine coolant temperature is low, thermostat is closed. Main coolant outlet (large circulation to radiator) is blocked.

[0031] Circulation path: Driven by the pump, the coolant enters the U-shaped water jacket 6 of the cylinder block 1 to absorb heat from the cylinder block 1. Since the main circuit is closed, most of the heated coolant passes through the micro-circulation channel 10, a "shortcut," and directly enters the cylinder head 14 water jacket. After further absorbing heat from the high-temperature combustion chamber, valves, and other components in the cylinder head 14 water jacket, it flows out from the second outlet 16, typically returning to the water pump or heating system.

[0032] The coolant circulates within a small confined area (cylinder block 1 → micro-circulation water channel 10 → cylinder head 14), resulting in a short flow path and low resistance. This allows for rapid collection and uniform distribution of heat from various engine components, causing a rapid rise in both coolant and engine body temperature. The engine reaches its optimal operating temperature more quickly, oil viscosity decreases rapidly, and mechanical friction is reduced, thereby decreasing wear and fuel consumption during cold starts. The coolant, already at a relatively high temperature, can be used for cabin heating during the initial warm-up phase, enhancing comfort.

[0033] Normal high-temperature operating phase (high load): Operating status: The engine coolant temperature reaches the thermostat opening temperature, and the thermostat opens. The main circulation path (leading to the radiator) is open.

[0034] Circulation path: The coolant absorbs heat in the U-shaped water jacket 6 of the cylinder block 1. After the thermostat opens, the coolant enters the main circulation through the main outlet and flows to the radiator for powerful cooling. The cylinder head 14 achieves its own cooling through an independent cylinder head 14 water jacket, which is independent of the cooling of the cylinder block 1.

[0035] By designing the orifice diameter of the micro-circulation water channel 10, the coolant flow ratio distributed to the cylinder block 1 and cylinder head 14 can be precisely controlled. This achieves the ideal state of "keeping the cylinder block 1 slightly warm to reduce friction, while keeping the cylinder head 14 sufficiently cooled to suppress knocking." The U-shaped water jacket 6 surrounds the cylinder bore 8, providing uniform cooling, avoiding localized overheating and deformation of the cylinder barrel, and ensuring the sealing of the piston rings and the durability of the engine.

[0036] In some embodiments, a V-shaped water channel 11 is provided on the partition between two adjacent cylinder bores 8, and the two ends of the V-shaped water channel 11 are connected to the U-shaped water jacket 6 located on both sides of the cylinder bore 8.

[0037] In this embodiment of the application, the "nose area" between two adjacent combustion chambers in a multi-cylinder engine is one of the hottest regions. Heat accumulates here from both sides, but the conventional cooling water jacket has limited space in this area, resulting in slow or even stagnant coolant flow, which easily leads to hot spots.

[0038] The V-shaped water channel 11 creates a highly efficient coolant flow path, allowing coolant to flow from one side of the U-shaped water jacket 6 through the V-shaped water channel 11 to the other side. This breaks up the stagnant water zone in the nose area, bringing a continuous supply of fresh, low-temperature coolant. Furthermore, the tip of the V-shaped water channel 11 is positioned directly against the hottest area, achieving precise directional cooling. This significantly reduces the temperature in the nose area, preventing cylinder deformation, cylinder scoring, and oil coking caused by localized overheating, greatly improving engine durability.

[0039] Furthermore, in traditional cooling systems, the cylinder bore 8 at the end of the water flow path (usually the last cylinder) may have a higher temperature because the coolant has absorbed heat from the preceding cylinder bores 8, leading to uneven operating temperatures across cylinders and affecting the engine's smooth operation and lifespan. The V-shaped water channel 11 connects the various U-shaped water jackets 6 in both longitudinal and transverse directions, forming a three-dimensional, interconnected water channel network. This results in a more uniform distribution of coolant throughout the cylinder block 1 and better pressure balance. This ensures that all cylinders receive nearly consistent cooling, thereby guaranteeing the uniformity of cylinder operation and the overall stability of the engine.

[0040] In some embodiments, the cylinder block 1 is an inline engine cylinder block 1, and the axes of the cylinder bores 8 are located in the same plane. The U-shaped water jacket 6 and the V-shaped water channel 11 are easier to design and manufacture on a regular and symmetrical inline cylinder block 1, which can ensure that each cylinder receives uniform and powerful cooling.

[0041] In some embodiments, a cast iron cylinder liner 9 is also embedded in the cylinder bore 8.

[0042] In this embodiment, the piston rings and cylinder walls reciprocate under high speed, high pressure, and imperfect lubrication conditions, making wear inevitable. Cast iron (especially phosphorus and boron alloy cast iron) possesses excellent wear resistance, and its metallic microstructure effectively maintains the oil film, reducing wear on the friction pair. Aluminum alloys are relatively soft, and their hardness, rigidity, and wear resistance cannot directly meet the requirements for cylinder walls. The cast iron cylinder liner 9 provides a hard and stable "skeleton" for each cylinder, withstanding the lateral thrust of the piston and high-speed friction.

[0043] In some embodiments, an oil cooler (not shown) is also provided on the exhaust side of the cylinder block 1, according to Figure 2 As shown, an oil cooler mounting interface 5 is designed only on the cylinder block 1 for mounting and fixing the oil cooler to reduce the temperature of the engine oil entering the main oil passage.

[0044] In this embodiment, large-displacement engines, especially during high-load operation (such as aggressive driving, traction, and high-speed cruising), generate enormous amounts of heat. Engine oil absorbs this heat during lubrication, causing its temperature to rise rapidly. Excessively high engine oil temperature leads to a decrease in viscosity, making it too thin (like water) and unable to form a sufficiently strong oil film. This results in poor lubrication of critical moving parts such as pistons, crankshafts, and camshafts, increased wear, and may even lead to serious failures such as cylinder scoring and bearing seizure. The oil cooler acts as a "radiator" for the engine oil. High-temperature engine oil flows through its interior, transferring heat to the coolant flowing outside through heat exchange. Maintaining the engine oil temperature within an optimal operating range (typically around 90°C-110°C) ensures that the oil always maintains ideal viscosity and lubrication performance, providing fundamental protection for the engine.

[0045] In some embodiments, the cylinder block 1 is provided with a plurality of suspension mounting holes 3 on the intake side and exhaust side, so that the cylinder block 1 is fixedly connected to the vehicle body.

[0046] In this embodiment of the application, in order to improve the strength of the cylinder body 1, the thickness of the threaded hole and the engagement length of the bolt are increased for the main load-bearing suspension mounting hole 3.

[0047] In some embodiments, the cylinder block 1 has multiple reinforcing ribs arranged on the intake side, exhaust side, front end face, and rear end face.

[0048] In this embodiment, the elastic modulus of aluminum alloy is lower than that of cast iron, meaning it is more prone to deformation under the same stress. By arranging reinforcing ribs throughout the intake side, exhaust side, front face, and rear face, a thin-walled box-shaped structure is transformed into a high-rigidity space truss structure.

[0049] In some embodiments, the diameter ratio of the first water outlet 4 to the second water outlet 16 is 1:2.8.

[0050] In this embodiment, according to fluid mechanics, in a parallel pipeline, the flow rate of the fluid is proportional to the square of the pipe diameter (when the pressure difference is the same). The flow cross-sectional area of ​​the second outlet 16 (cylinder head 14 side) is approximately 2.82 ≈ 7.84 times that of the first outlet 4 (cylinder block 1 side). This results in a much larger flow rate of coolant to the water jacket of the cylinder head 14 than to the water jacket of the cylinder block 1. The cylinder head 14 is the "ceiling" of the combustion chamber, directly bearing the highest flame temperature. The area around the exhaust valves and spark plug mounts is an extreme hotspot. The 1:2.8 diameter ratio design ensures that there is nearly 8 times the coolant flow rate of the cylinder block 1 to flush these critical areas and quickly remove heat. This greatly reduces the overall temperature and hotspot risk of the cylinder head 14, which is the basis for allowing the engine to use a higher compression ratio and a higher turbo boost value, thereby increasing power and torque. When the thermostat is closed, due to the pressure difference between the first outlet and the cylinder head 14 water jacket, the coolant will flow to the cylinder head 14 water jacket through the micro-circulation channel 10. The micro-circulation channel 10 can ensure that the water temperature in this cavity is consistent with the temperature of the cylinder head 14 water jacket, avoiding delay in the opening or closing of the thermostat, making the engine cooling system more precise and responsive.

[0051] In some embodiments, the lower side of the cylinder body 1 is further provided with a crankshaft hole, and a bearing cap 13 is connected to the crankshaft hole via a locating pin 12. The locating pin 12 is interference-fitted with the cylinder body 1 and clearance-fitted with the bearing cap 13.

[0052] In this embodiment, when the crankshaft rotates at high speed, the axes of all main journals must be strictly aligned. If the centers of the bearing holes are not aligned, it will lead to crankshaft jamming, abnormal wear, and power loss. The core function of the locating pin 12 is not to bear the main load, but to precisely determine the circumferential and lateral positions between the bearing cap 13 and the cylinder block 1 before the bolts are tightened. This prevents slight misalignment of the bearing cap 13 during bolt tightening and ensures that each bearing hole is perfectly aligned with the semi-circular hole on the cylinder block 1. The high-precision coaxiality of all bearing holes is the foundation for smooth, low-friction operation of the crankshaft.

[0053] The positioning pin 12 is interference-fitted with the cylinder body 1, ensuring that once the positioning pin 12 is pressed into the cylinder body 1, it becomes an immovable part of the cylinder body 1 and will not be pulled out or loosened when the bearing cover 13 is disassembled. This provides an absolutely reliable reference for the entire positioning system. All bearing covers 13 are positioned with reference to this pin fixed to the cylinder body 1.

[0054] The locating pin 12 and the bearing cap 13 are clearance-fitted, facilitating assembly and disassembly. During installation, the bearing cap 13 can be easily fitted onto the locating pin 12 without forceful hammering. During maintenance, the bearing cap 13 can be easily removed after loosening the bolts, while the locating pin 12 remains securely attached to the cylinder body 1. The minute clearance compensates for extremely slight dimensional deviations in the cylinder body 1, bearing cap 13, and locating pin 12 during manufacturing, preventing assembly difficulties due to accumulated tolerances. Although it is a clearance fit, the clearance is very small (typically a few micrometers to tens of micrometers), sufficient to precisely guide the bearing cap 13 into the correct position, achieving final accurate positioning.

[0055] The above description is merely a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of protection of this specification.

Claims

1. A large-displacement aluminum alloy cylinder block, characterized in that, Including the cylinder block and cylinder head; The cylinder body is provided with multiple cylinder holes, and a U-shaped water jacket is provided around the cylinder holes; a first water inlet and a first water outlet are respectively provided on both sides of the cylinder body, and the water inlet and the water outlet are respectively connected to the two ends of the U-shaped water jacket; The cylinder head is connected to the upper side of the cylinder block and seals the multiple cylinder bores; the cylinder head is provided with a cylinder head water jacket, which is provided with a second water inlet and a second water outlet; a thermostat is provided at the first water outlet of the cylinder block, and a micro-circulation water channel is provided above the first water outlet. The micro-circulation water channel is connected to the second water inlet to regulate the cooling circulation between the U-shaped water jacket and the cylinder head water jacket through the thermostat.

2. The large-displacement aluminum alloy cylinder block according to claim 1, characterized in that, A V-shaped water channel is also provided on the partition between two adjacent cylinder bores, and the two ends of the V-shaped water channel are connected to the U-shaped water jacket located on both sides of the cylinder bore.

3. The large-displacement aluminum alloy cylinder block according to claim 2, characterized in that, The cylinder block is an inline engine cylinder block, and the axes of the cylinder bores are located in the same plane.

4. The large-displacement aluminum alloy cylinder block according to claim 3, characterized in that, A cast iron cylinder liner is also embedded in the cylinder bore.

5. The large-displacement aluminum alloy cylinder block according to claim 1, characterized in that, The cylinder block is also equipped with an oil cooler on the exhaust side to reduce the temperature of the engine oil entering the main oil passage.

6. The large-displacement aluminum alloy cylinder block according to claim 1, characterized in that, The cylinder block is also provided with multiple mounting holes on the intake and exhaust sides to ensure that the cylinder block is fixedly connected to the vehicle body.

7. The large-displacement aluminum alloy cylinder block according to claim 1, characterized in that, The cylinder block has multiple reinforcing ribs arranged on the intake side, exhaust side, front face, and rear face.

8. The large-displacement aluminum alloy cylinder block according to claim 1, characterized in that, The diameter ratio of the first water outlet to the second water outlet is 1:2.

8.

9. The large displacement aluminum alloy cylinder block according to any one of claims 1 to 8, characterized in that, The lower side of the cylinder block is also provided with a crankshaft hole, and a bearing cap is connected to the crankshaft hole by a locating pin.

10. The large-displacement aluminum alloy cylinder block according to claim 9, characterized in that, The locating pin has an interference fit with the cylinder body and a clearance fit with the bearing cap.

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