Efficient air inlet diesel engine cylinder cover and air inlet vortex adjusting method

Abstract

The invention relates to an efficient air inlet diesel engine cylinder cover and an air inlet vortex adjusting method, and belongs to the technical field of engines, two air inlet channels are transversely parallel, mutually independent and tangential, the air inlet resistance is small, and the air inlet efficiency is high; the combined design of the long air inlet channel and the short air inlet channel is adopted, air flow distribution on the periphery of the cylinder wall and at the cylinder center is optimized in the air inlet stroke through differentiated geometrical shapes, high-speed and orderly flowing of air in the cylinder is achieved, disordered air flow in the cylinder is reduced, oil and gas can be evenly mixed, air inlet of the diesel engine is efficient, air inlet vortex in the cylinder is controllable, and the service life of the diesel engine is prolonged. And oil and gas in the cylinder are uniformly mixed, efficient and clean combustion is achieved, and energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a high-efficiency air-intake diesel engine cylinder head and an air-intake vortex adjustment method. Background Art

[0002] A prerequisite for efficient diesel engine combustion is a uniform fuel-air mixture. Traditional diesel engine fuel systems have low injection pressures and large fuel injection particle size, requiring strong intake vortexes to further disperse the fuel. The cylinder head intake duct is generally designed with a spiral structure to achieve strong vortexes within the cylinder. However, strong vortexes can cause high intake resistance and reduce intake efficiency. With the increasing requirements of emission regulations, fuel injection systems have been upgraded from traditional mechanical fuel systems to electronically controlled high-pressure common rail fuel injection systems. This significantly increases injection pressure and reduces fuel injection particle size. Excessive vortexes can affect fuel-air mixing and reduce intake efficiency. Therefore, it is necessary to appropriately adjust the intake vortex within the cylinder to improve intake efficiency and optimize in-cylinder combustion. Summary of the Invention

[0003] In response to the shortcomings of the existing technology, the present invention provides a high-efficiency intake diesel engine cylinder head and intake swirl adjustment method, aiming to improve the diesel engine intake efficiency, optimize the intake swirl in the cylinder, match the current mainstream high-pressure common rail fuel system, and achieve good oil-gas mixing, efficient combustion, energy saving and emission reduction.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: A high-efficiency air-intake diesel engine cylinder head comprises an injector hole, cylinder head bolt holes, two intake ducts and two exhaust ducts. The injector hole is located in the center of the cylinder hole, and the air ducts are arranged to avoid the cylinder head bolt holes and other hole systems. The two intake ducts are arranged in parallel horizontally, namely a long intake duct and a short intake duct. The two intake ducts are independent of each other and are both tangential air ducts. When viewed from the top surface of the cylinder head, the long intake duct is approximately a straight line, and the short intake duct is approximately a circular arc. After entering the cylinder, the airflow in the long intake duct and the short intake duct rotates around the cylinder in the same direction.

[0005] Furthermore, the direction passing through the center of the cylinder hole and perpendicular to the intake side is defined as the vertical direction of the cylinder center. The angle α between the center line of the two intake valves and the vertical direction of the cylinder center is 20°~45°, and the angle β≈α between the center line of the two exhaust valves and the vertical direction of the cylinder center is 20°~45°.

[0006] Furthermore, the throat diameters of the long intake duct and the short intake duct are the same, that is, the intake duct throat diameter Di, Di / D=0.29~0.3, where D is the cylinder diameter of the cylinder head.

[0007] Furthermore, the intake dive angle γ of the long air inlet and the short air inlet is 10°~40°, and the intake dive angles of the long air inlet and the short air inlet are the same or different.

[0008] Furthermore, the two exhaust ducts are respectively a long exhaust duct and a short exhaust duct, and the two are converged at the terminal outlet to merge into one exhaust outlet.

[0009] Furthermore, the throat diameters of the long exhaust duct and the short exhaust duct are the same, that is, the exhaust duct throat diameter De, De / D=0.25~0.27, where D is the cylinder diameter of the cylinder head.

[0010] Furthermore, the air inlet area of ​​the long air inlet duct is ≥ the air inlet throat area, and the long air inlet duct presents a uniform and gradually shrinking transition in cross section from the air inlet to the air inlet throat; the air inlet area of ​​the short air inlet duct is ≥ the air inlet throat area, and the short air inlet duct presents a uniform and gradually shrinking transition in cross section from the air inlet to the air inlet throat.

[0011] The present invention also provides an intake vortex adjustment method for a high-efficiency intake diesel engine cylinder head, which can adjust the intake vortex intensity in the cylinder by adjusting the intake port area of ​​the long intake duct and the intake port area of ​​the short intake duct, or adjusting the intake dive angle.

[0012] Furthermore, reducing the air intake area of ​​the long air intake duct by 5%~10% and increasing the air intake area of ​​the short air intake duct by 5%~10% can reduce the swirl ratio by 10%~20%. Conversely, increasing the air intake area of ​​the long air intake duct by 5%~10% and reducing the air intake area of ​​the short air intake duct by 5%~10% can increase the swirl ratio by 10%~20%.

[0013] Furthermore, reducing the intake dive angle γ can reduce the tangential inlet duct vortex intensity. Every 5° reduction in the intake dive angle can reduce the swirl ratio by 5%~10%. Increasing the intake dive angle γ can increase the tangential inlet duct vortex intensity. Every 5° increase in the intake dive angle can increase the swirl ratio by 5%~10%.

[0014] Beneficial effects: The diesel engine cylinder head of the present invention adopts a unique air duct arrangement, which significantly optimizes the air flow movement and combustion efficiency in the cylinder; the two intake ducts are independent of each other, and both are tangential intake ducts, with small intake resistance and high intake efficiency; a combination of long and short intake ducts is adopted, and through differentiated geometric shapes, the air flow distribution around the cylinder wall and the cylinder center is optimized during the intake stroke, achieving high-speed and orderly flow of gas in the cylinder, reducing the chaotic airflow in the cylinder, and being conducive to uniform mixing of oil and gas, so that the diesel engine intake is efficient and the intake vortex in the cylinder is controllable, promoting uniform mixing of oil and gas in the cylinder, and achieving efficient and clean combustion, energy saving and emission reduction.

[0015] In addition, the present invention can adjust the ratio of the air intake volume of the two air ducts by adjusting the size ratio of the two air inlet ducts, and thus can simply and efficiently adjust the intake vortex to achieve the optimal design goal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1Schematic diagram of the airway arrangement structure of the high-efficiency air-intake diesel engine cylinder head of the present invention (viewed from the top surface of the cylinder head); Figure 2 For the present invention Figure 1 AA cross-sectional view; Figure 3 It is a three-dimensional axonometric cross-sectional view of the cylinder head of the high-efficiency air-intake diesel engine of the present invention.

[0017] Figure numerals: 1 intake side, 2 exhaust side, 3 long intake duct, 4 short intake duct, 5 long exhaust duct, 6 short exhaust duct, 7 cylinder head bolt hole, 8 injector hole. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1-3 As shown, an embodiment of a high-efficiency air-intake diesel engine cylinder head is provided, wherein the cylinder head includes an air-intake side 1, an exhaust side 2, two air-intake passages, two exhaust passages, a cylinder head bolt hole 7, and an injector hole 8.

[0020] Two intake ducts are arranged on the intake side, namely long intake duct 3 and short intake duct 4. The long intake duct 3 and short intake duct 4 are independent of each other and the intake does not affect each other. Two exhaust ducts are arranged on the exhaust side, namely long exhaust duct 5 and short exhaust duct 6. The two exhaust ducts converge at the end outlet and merge into one exhaust outlet.

[0021] There are an intake side 1 and an exhaust side 2 on the cylinder head. The intake side 1 is provided with an intake port of a long intake duct 3 and a short intake duct 4. The exhaust side 2 is provided with a combined exhaust outlet of a long exhaust duct 5 and a short exhaust duct 6. The cylinder head bolt holes 7 are arranged approximately evenly around the cylinder hole. The intake duct and exhaust duct avoid all cylinder head bolt holes 7 and other hole systems. The injector hole 8 is located at the center of the cylinder, that is, the center of the cylinder hole.

[0022] Both air inlets are tangential, smooth and independent of each other. Figure 1 As shown, looking down from the top of the cylinder head, the direction of the long intake duct 3 is approximately straight, and the direction of the short intake duct 4 is approximately arc-shaped, which bends in the direction away from the long intake duct 3. After the airflow in the long intake duct 3 and the short intake duct 4 enters the cylinder, the direction of the rotation around the cylinder tends to be consistent, avoiding the formation of airflow collision. The two exhaust ducts on the exhaust side converge at the end outlet and merge into one exhaust outlet.

[0023] Each cylinder has four valves, two intake valves and two exhaust valves. Figure 1As shown, the direction passing through the center of the cylinder hole and perpendicular to the intake side surface 1 is defined as the vertical direction of the cylinder center. Then, the angle α between the center line of the two intake valves and the vertical direction of the cylinder center is 20°~45°, and the angle β between the center line of the two exhaust valves and the vertical direction of the cylinder center is roughly equal to the angle α between the center line of the two intake valves and the vertical direction of the cylinder center, that is, β≈α.

[0024] The throat diameters of the long intake duct 3 and the short intake duct 4 are the same, which is denoted as the intake duct throat diameter Di, where Di / D=0.29~0.3, and D is the cylinder diameter.

[0025] The throat diameters of the long exhaust duct 5 and the short exhaust duct 6 are the same, which is denoted as the exhaust duct throat diameter De, then De / D=0.25~0.27, where D is the cylinder diameter.

[0026] like Figure 2 As shown, the intake dive angle γ of the long air inlet duct 3 and the short air inlet duct 4 is 10°~40°. The intake dive angles of the long air inlet duct 3 and the short air inlet duct 4 can be the same or different, but are all set within this range.

[0027] The air inlet area of ​​the long air inlet duct 3 is greater than or equal to the air inlet throat area, and the long air inlet duct 3 presents a uniform and gradually shrinking cross-section transition from the air inlet to the air inlet throat; similarly, the air inlet area of ​​the short air inlet duct 4 is greater than or equal to the air inlet throat area, and the short air inlet duct 4 presents a uniform and gradually shrinking cross-section transition from the air inlet to the air inlet throat.

[0028] During the intake process of the diesel engine, the long intake duct 3 and the short intake duct 4 take in air at the same time. The airflow in the long intake duct 3 is tangential to the cylinder wall, forming a spiral airflow around the cylinder wall, which is used to accelerate the airflow movement around the cylinder wall; the airflow in the short intake duct 4 forms a centrifugal force due to the nearly circular arc trend of the airflow. When the airflow enters the cylinder, it is deflected inward due to the centrifugal force and enters the cylinder near the center of the cylinder hole. The short intake duct 4 has a shorter path and a larger curvature, forming a weaker spiral airflow, which is used to accelerate the airflow movement at the cylinder center; the airflow trend of the short intake duct 4 entering the cylinder is the same as that of the long intake duct 3, avoiding interference between the airflows; the airflow of the long intake duct 3 and the short intake duct 4 divides the cylinder volume into two parts, an outer part and an inner part, with one strong intake vortex and the other weak intake vortex, realizing high-speed and orderly flow of gas in the cylinder, reducing the chaotic airflow in the cylinder, and facilitating uniform mixing of oil and gas; at the same time, since both the long intake duct 3 and the short intake duct 4 are tangential intake ducts, the intake resistance is small and the intake efficiency is high.

[0029] Furthermore, the high-efficiency intake cylinder head designed by the present invention can adjust the intake volume of the long intake duct 3 and the short intake duct 4 by adjusting the intake port area and the intake dive angle of the long intake duct 3 and the short intake duct 4, thereby adjusting the intake vortex intensity in the cylinder. The specific implementation method is as follows.

[0030] When it is necessary to reduce the swirl, reducing the air inlet area of ​​the long air inlet duct 3 by 5%~10% and increasing the air inlet area of ​​the short air inlet duct by 5%~10% can reduce the swirl ratio by 10%~20%.

[0031] Reducing the intake dive angle γ can reduce the horizontal component of the airflow and increase the vertical downward component of the airflow. The horizontal component of the airflow helps to increase the vortex. Therefore, reducing the intake dive angle γ can reduce the tangential inlet vortex intensity. Every time the intake dive angle is reduced by about 5°, the swirl ratio can be reduced by 5%~10%.

[0032] Conversely, when the swirl needs to be increased, increasing the inlet area of ​​the long inlet duct 3 by 5%~10% and reducing the inlet area of ​​the short inlet duct by 5%~10% can increase the swirl ratio by 10%~20%.

[0033] Increasing the intake dive angle γ can increase the tangential inlet vortex intensity. Every increase of the intake dive angle by about 5° can increase the swirl ratio by 5%~10%.

[0034] It can be seen from this that by adjusting the size ratio of the two intake ducts, the intake volume ratio of the two ducts can be adjusted, and then the intake vortex can be adjusted simply and efficiently to achieve the optimal design goal.

[0035] It should be noted that the attached Figure 1-3 The embodiment shown is a cylinder head of a multi-cylinder diesel engine, but the diesel engine cylinder head described in the present invention is not limited to the number of cylinders and is applicable not only to a multi-cylinder structure but also to a single-cylinder structure.

[0036] The technical solution of the present invention optimizes the design of the intake duct on the diesel engine cylinder head. Both the long intake duct 3 and the short intake duct 4 are tangential intake ducts with low intake resistance and high intake efficiency. The two intake ducts are one long and one short, one straight and one curved. The geometric difference between the two intake ducts is used to optimize the airflow trend, achieve high-speed and orderly flow of gas in the cylinder, reduce the chaotic airflow in the cylinder, and is conducive to uniform mixing of oil and gas. It can better meet the needs of the high-pressure common rail fuel injection system, enable the diesel engine to have efficient intake and controllable intake vortex in the cylinder, promote uniform mixing of oil and gas in the cylinder, achieve efficient and clean combustion, energy saving and emission reduction, and the present invention also provides a method for adjusting the intake vortex. By adjusting the size ratio of the two intake ducts, the intake volume ratio of the two ducts can be adjusted, so that the intake vortex can be adjusted simply and efficiently to achieve the optimal design goal.

[0037] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high-efficiency intake diesel engine cylinder head, comprising an injector hole, a cylinder head bolt hole, two intake passages, and two exhaust passages. The injector hole is located in the center of the cylinder hole, and the air passages are arranged away from the cylinder head bolt hole and other hole systems. The invention is characterized in that: The two intake ducts are arranged horizontally in parallel, namely the long intake duct and the short intake duct. The two intake ducts are independent of each other and are both tangential ducts. Looking down from the top of the cylinder head, the long intake duct is approximately a straight line, and the short intake duct is approximately a circular arc. After the airflow in the long intake duct and the short intake duct enters the cylinder, the direction of rotation around the cylinder tends to be the same.

2. A high-efficiency air-intake diesel engine cylinder head according to claim 1, characterized in that: The direction passing through the center of the cylinder hole and perpendicular to the intake side is defined as the vertical direction of the cylinder center. The angle α between the center line of the two intake valves and the vertical direction of the cylinder center is 20°~45°, and the angle β≈α between the center line of the two exhaust valves and the vertical direction of the cylinder center.

3. The high-efficiency air-intake diesel engine cylinder head according to claim 1, characterized in that: The throat diameters of the long intake duct and the short intake duct are the same, that is, the intake duct throat diameter Di, Di / D=0.29~0.3, where D is the cylinder diameter of the cylinder head.

4. The high-efficiency air-intake diesel engine cylinder head according to claim 1, characterized in that: The intake dive angle γ of the long air inlet and the short air inlet is 10°~40°, and the intake dive angles of the long air inlet and the short air inlet are the same or different.

5. The high-efficiency air-intake diesel engine cylinder head according to claim 1, characterized in that: The two exhaust ducts are a long exhaust duct and a short exhaust duct, which converge at the end outlet and merge into one exhaust outlet.

6. A high-efficiency air-intake diesel engine cylinder head according to claim 5, characterized in that: The throat diameters of the long exhaust duct and the short exhaust duct are the same, that is, the exhaust duct throat diameter De, De / D=0.25~0.27, where D is the cylinder diameter of the cylinder head.

7. The high-efficiency air-intake diesel engine cylinder head according to claim 1, characterized in that: The air inlet area of ​​the long air inlet duct is greater than or equal to the air inlet throat area, and the long air inlet duct presents a uniform and gradually shrinking transition in cross section from the air inlet to the air inlet throat. The air inlet area of ​​the short air inlet duct is greater than or equal to the air inlet throat area, and the short air inlet duct presents a uniform and gradually shrinking transition in cross section from the air inlet to the air inlet throat.

8. The method for adjusting the intake swirl of a high-efficiency intake diesel engine cylinder head according to any one of claims 1 to 7, characterized in that: By adjusting the intake port area of ​​the long intake duct and the short intake duct, or adjusting the intake dive angle, the intake vortex intensity in the cylinder can be adjusted.

9. The intake swirl adjustment method according to claim 8, characterized in that: Reducing the air intake area of ​​the long air intake duct by 5%~10% and increasing the air intake area of ​​the short air intake duct by 5%~10% can reduce the swirl ratio by 10%~20%. Conversely, increasing the air intake area of ​​the long air intake duct by 5%~10% and reducing the air intake area of ​​the short air intake duct by 5%~10% can increase the swirl ratio by 10%~20%.

10. The intake swirl adjustment method according to claim 8, characterized in that: Reducing the intake dive angle γ can reduce the tangential inlet vortex intensity. Every 5° reduction in the intake dive angle can reduce the swirl ratio by 5%~10%. Increasing the intake dive angle γ can increase the tangential inlet vortex intensity. Every 5° increase in the intake dive angle can increase the swirl ratio by 5%~10%.

Images