Low-cost high-precision combustion system

Abstract

The invention discloses a low-cost high-precision combustion system, which relates to the technical field of engine combustion systems, and comprises a cylinder body, a cylinder cover, an air inlet channel, an oil sprayer guide pipe, an air inlet valve guide pipe, a spark plug mounting guide pipe, an exhaust valve guide pipe and an exhaust channel, all the components are arranged in a split mode, independently manufactured and formed and then combined in a welding mode to form the whole combustion system. The air inlet valve guide pipe and the oil sprayer guide pipe are both welded to the air inlet channel, the exhaust valve guide pipe is welded to the exhaust channel, and the air inlet channel, the exhaust channel and the spark plug installation guide pipe are all integrally connected with the cylinder cover in a welded mode. The combustion system is separated from the engine assembly, the thin-wall structure combustion system is made of stainless steel with high strength and good heat transfer performance, and the weight of the engine is reduced; a lubricating oil channel, a cooling water channel and the like are not arranged inside, a large number of partition wall faces of an engine cylinder are saved, the wall face thickness is reduced, design is simplified, and engine manufacturing cost and manufacturing process difficulty are reduced.

Description

Technical Field

[0001] The present invention relates to the technology of engine combustion systems, and specifically to a low-cost and high-precision combustion system. Background Art

[0002] Traditional engine structures include cylinder blocks, cylinder heads, crankcases, etc. They are manufactured through split casting and CNC machining, and then assembled together with high-strength bolts, resulting in large engine volume, heavy weight, complex manufacturing processes, high manufacturing costs, and long production cycles. Summary of the Invention

[0003] An object of the present invention is to provide a low-cost and high-precision combustion system to solve the problems of high cost, complex manufacturing process, and difficulty in high-precision machining of the engine combustion systems produced by the existing technology as mentioned in the above background art.

[0004] To achieve the above object, the present invention provides the following technical solution: A low-cost and high-precision combustion system includes a cylinder block, a cylinder head, an intake passage, an injector duct, an intake valve duct, a spark plug installation duct, an exhaust valve duct, and an exhaust passage; the cylinder block, cylinder head, intake passage, injector duct, intake valve duct, spark plug installation duct, exhaust valve duct, and exhaust passage are all split and independently manufactured and formed, and then combined to form a combustion system by welding; The intake valve duct and the injector duct are both welded to the intake passage, the exhaust valve duct is welded to the exhaust passage, and the intake passage, exhaust passage, and spark plug installation duct are all welded to the cylinder head to form an integral body; the cylinder head is connected to the cylinder block by welding.

[0005] As a further aspect of the present invention: the intake passage is processed and formed by a hydroforming process, specifically, first put a Y-shaped steel pipe into a forming die, then fill the Y-shaped steel pipe with emulsified liquid, and finally use push heads to advance forward at the same speed at the three ends of the Y-shaped steel pipe to pressurize the Y-shaped steel pipe to obtain the intake passage.

[0006] As a further aspect of the present invention: the change in the cross-sectional area of the pipeline on the inner wall surface of the intake passage satisfies that the cross-sectional area of the pipeline on the inner wall surface of the intake passage gradually increases from the intake port to the side close to the valve, and the cross-sectional area of the pipeline on the inner wall surface gradually decreases from the intake passage side close to the valve to the outlet.

[0007] As a further aspect of the present invention: the exhaust passage is a bent pipe, and the intake valve duct, exhaust valve duct, injector duct, and spark plug installation duct are all straight pipes.

[0008] As a further aspect of the present invention: the cylinder head is made by die stamping, the cylinder block is made of straight pipes, and the inner wall of the cylinder block is polished.

[0009] As a further solution of the present invention: an interference fit is adopted at the welded joints between components, and then they are connected by welding.

[0010] As a further solution of the present invention: laser cladding welding is adopted both between the intake passage and the cylinder head and between the exhaust passage and the cylinder head.

[0011] As a further solution of the present invention: the edge of the cylinder head is provided with rounded corners, and the middle part of the cylinder head arches upward to form a cavity, and this cavity is an ellipsoidal cavity.

[0012] As a further solution of the present invention: the combustion system components are made of stainless steel.

[0013] As a further solution of the present invention: the welding method for each component adopts a low-power laser welding method, and the welding sequence is as follows: first, the fuel injector guide pipe is welded on the intake passage, the spark plug installation guide pipe is welded on the cylinder head, then the intake valve guide pipe is welded on the intake passage, the exhaust valve guide pipe is welded on the exhaust passage, then the intake passage is welded on the cylinder head, the exhaust passage is welded on the cylinder head, and finally the cylinder block is welded on the cylinder head; among them, the welding method for each component adopts a low-power laser welding method.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention separates the combustion system from the engine integration so that a thin-walled structure combustion system can be made of stainless steel with high strength and good heat transfer performance to achieve the purpose of weight reduction and cost reduction; and by manufacturing the combustion system separately without internal lubricating oil channels and cooling water channels, etc., a large number of partition surfaces of the engine cylinder block are saved, achieving the effects of reducing the wall thickness, simplifying the design, reducing the manufacturing cost and manufacturing process difficulty of the engine. For the combustion system of the present invention, in order to make up for the defects of uneven workpiece deformation, large stress concentration, low surface roughness of the workpiece, poor dimensional accuracy of the outer shape, etc. existing in mechanical stamping bulging, the intake passage adopts a hydroforming process, which can conveniently customize various shapes, improve the dimensional accuracy and surface quality of the air passage and the guide pipe, so as to reduce friction and improve the intake efficiency. Put the Y-shaped steel pipe into the forming die, then fill the emulsified liquid into the Y-shaped steel pipe, and finally use push heads at the three ends of the Y-shaped steel pipe to push forward at the same speed to pressurize the Y-shaped steel pipe. In order to improve the in-cylinder tumble intensity during intake, the cross-sectional area of the pipeline on the inner wall surface of the intake port in the combustion system of the present invention changes in a state of first increasing and then decreasing. Its cross-sectional area is small at the intake port, which can increase the intake speed and the kinetic energy of the gas. Due to the blockage of the intake valve in the intake port, the gas will be shunted and enter the cylinder from the upper and lower sides respectively. The gas on the upper side generates a clockwise tumble, and the gas on the lower side generates a counterclockwise tumble. The collision of the two gases will weaken the tumble intensity. Therefore, the cross-sectional area of the pipeline on the inner wall surface of the intake port near the valve side is slightly increased to guide the gas, so that the gas converges and enters the cylinder and flows along the exhaust side of the cylinder head. Since the cross-sectional area increases here and the gas speed slows down, the cross-sectional area at the gas outlet needs to be reduced to continue to accelerate the air flow.

[0015] The interfaces between the components of the combustion system of the present invention are circular, and a small amount of interference fit can be used without affecting the inner wall dimensions. Finally, welding is used as the connection to integrate the entire combustion system by welding, which increases the sealing performance and anti-explosion pressure performance and improves the reliability. Moreover, the intake and exhaust airways are welded to the cylinder head, and the laser cladding method without a valve seat ring is adopted to save the valve seat ring. The cylinder head and the cylinder block are welded together, which can save the cylinder gasket and high-strength bolts used for sealing and ensure the integration of the combustion chamber structure.

[0016] Compared with the structure of the combustion system of traditional engines, the combustion system of the present invention will greatly reduce the weight and cost of the engine, while improving the dimensional accuracy, manufacturing consistency, reducing the friction loss, improving the cooling efficiency and suppressing detonation, and further improving the thermal efficiency and power performance of the engine. Brief Description of the Drawings

[0017] Figure 1 is the front view of the low-cost and high-precision combustion system of the present invention; Figure 2 is the perspective view of the intake port of the present invention; Figure 3 is the schematic diagram of the cylinder head structure of the present invention.

[0018] In the figure: 1. Cylinder block; 2. Cylinder head; 3. Intake port; 4. Injector conduit; 5. Intake valve conduit; 6. Spark plug installation conduit; 7. Exhaust valve conduit; 8. Exhaust port. Detailed Description of the Invention

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0020] Please refer to Figure 1 and Figure 3, in the embodiments of the present invention, a low-cost and high-precision combustion system includes a cylinder block 1, a cylinder head 2, an intake passage 3, an injector conduit 4, an intake valve conduit 5, a spark plug installation conduit 6, an exhaust valve conduit 7, and an exhaust passage 8; each of the above components is disassembled and independently manufactured and formed, and then combined by welding to form the overall combustion system; the present invention separates the combustion system from the engine integration so that a thin-walled structure combustion system can be manufactured using high-strength and good heat-transfer stainless steel or other metal materials to achieve the purpose of weight reduction and cost reduction; the engine combustion system designed by the present invention is manufactured separately without built-in lubricating oil channels and cooling water channels, etc., saving a large number of partition surfaces of the cylinder block 1 of the engine, and achieving the purpose of reducing the wall thickness, simplifying the design, and reducing the weight of the engine.

[0021] With the continuous development of technology, especially the significant improvement in the accuracy of stamping and welding processes, the combustion system designed by the present invention abandons the traditional casting and machining processes and is manufactured using the simpler and more efficient stamping and welding processes. Components such as the cylinder block 1, cylinder head 2, intake passage 3, exhaust passage 8, intake valve conduit 5, injector conduit 4, and spark plug installation conduit 6 are all thin-walled, equal-wall-thickness metal material pipe fittings, stamped parts, and hydroformed parts, etc. According to the different cutting angles of the pipe fittings, the interfaces of the pipe fittings are circular or elliptical. During the welding process, interference fit is first achieved by knocking, and then welding is carried out; the interfaces between components are welded structures or elliptical interfaces, with a small amount of interference fit, and the range of interference fit is 0.01 to 0.03 mm to not affect the inner wall dimensions. Interference fit is achieved by knocking on the pipe wall, and then connection is carried out by welding.

[0022] The design features of the present invention: The intake valve conduit 5 and the injector conduit 4 are both welded to the intake passage 3, the exhaust valve conduit 7 is welded to the exhaust passage 8, and the intake passage 3, exhaust passage 8, and spark plug installation conduit 6 are all welded to the cylinder head 2 to form an integral body; the cylinder head 2 and the cylinder block 1 are connected by welding. In order to reduce the deformation of components during welding, the welding method uses low-power laser welding technology, and the specific power range of the low-power laser is 1 kW - 6 kW to reduce the deformation of components during welding; the specific welding sequence is as follows: First, weld the injector conduit 4 to the intake passage 3 and weld the spark plug installation conduit 6 to the cylinder head 2; then weld the intake valve conduit 5 to the intake passage 3 and weld the exhaust valve conduit 7 to the exhaust passage 8; then weld the intake passage 3 to the cylinder head 2 and weld the exhaust passage 8 to the cylinder head 2; finally, weld the cylinder block 1 to the cylinder head 2. When welding the cylinder block 1, a support fixture is needed to support the cylinder block to prevent the cylinder block 1 from deforming.

[0023] The materials of the components of the combustion system of the present invention are made of stainless steel materials, with high strength, good heat transfer, high dimensional control accuracy, good surface quality, and no need for machining.

[0024] For the combustion system of the present invention, in order to make up for the defects of uneven workpiece deformation, large stress concentration, low surface roughness of the workpiece, and poor dimensional accuracy of the external shape existing in mechanical stamping bulging, the intake passage 3 adopts a hydroforming process, which can easily customize various shapes, improve the dimensional accuracy and surface quality of the air passage and the conduit, so as to reduce friction and improve the intake efficiency. The Y-shaped steel pipe is placed in the forming die, then the emulsified liquid is filled into the Y-shaped steel pipe, and finally, push heads are respectively used to advance forward at the same speed at the three ends of the Y-shaped steel pipe to pressurize the Y-shaped steel pipe.

[0025] For the combustion system of the present invention, the exhaust passage 8 adopts a stainless steel elbow pipe, while the intake valve conduit 5, the exhaust valve conduit 7, the fuel injector conduit 4 and the spark plug installation conduit 6 adopt stainless steel straight pipes. The structure is simple and does not require manufacturing. While reducing the weight, it can also improve the dimensional accuracy control of the exhaust passage 8, the intake valve conduit 5, the exhaust valve conduit 7, the fuel injector conduit 4 and the spark plug installation conduit 6.

[0026] The cylinder head 2 of the combustion system of the present invention adopts a stainless steel stamping part. The structure is simple. Using die stamping can accurately form the shape of the cylinder head 2 and precisely control the dimensional accuracy of the combustion chamber, ensuring the consistency of the compression ratio of the engine combustion system.

[0027] For the combustion system of the present invention, the cylinder block 1 is made of stainless steel steel pipe. Various treatments can be carried out on the inner wall surface of the cylinder block 1 according to needs. The inner wall is polished into a mirror surface to make the surface smooth and reduce friction loss. Various patterns can also be customized to improve the adhesion of the lubricating oil, reduce the clearance between the cylinder wall and the piston, and increase the sealing performance of the combustion chamber.

[0028] In the engine combustion system, in-cylinder tumble can increase the turbulence intensity at the end of compression, thereby causing the flame to wrinkle, increasing the front area of the flame and accelerating the heat transfer between the burned gas and the unburned gas, improving the combustion efficiency and the engine performance.

[0029] The faster the intake speed, the greater the gas kinetic energy and the higher the converted tumble intensity. Therefore, for the combustion system of the present invention to improve the in-cylinder tumble intensity during intake, the cross-sectional area of the inner wall pipeline of the intake passage 3 is in the shape of small-large-small. Please refer to Figure 2, the cross-sectional area at the intake port is small, which can increase the intake speed and the kinetic energy of the gas. Due to the obstruction of the valve structure at the connection between the intake passage 3 and the cylinder block 1, the gas will be divided and enter the cylinder from the upper and lower sides respectively. The upper-side gas generates a clockwise tumble, and the lower-side gas generates a counterclockwise tumble. The impact of the two gases will weaken the tumble intensity. The cross-sectional area of the inner wall pipeline of the middle section of the intake passage 3 near the valve is slightly increased to guide the gas so that the gas converges and flows along the exhaust side of the cylinder head 2 after entering the cylinder. Since the cross-sectional area increases here and the gas velocity slows down, the cross-sectional area of the outlet port of the intake passage 3 (i.e., the port near the valve) needs to be reduced to continue accelerating the air flow. In the engine structure, the valve is located at the upper part of the engine and the top of the cylinder combustion chamber. In this application, it refers to the port position where the intake passage 3 is connected to the cylinder block 1.

[0030] The edge of the cylinder head 2 of the combustion system of the present invention needs to be chamfered to guide the gas coming from the intake passage 3, prevent the air flow from directly hitting the cylinder wall, reduce the loss of gas kinetic energy, and the middle part of the cylinder head 2 arches upward and cooperates with the piston top to form an ellipsoidal cavity, so that during the engine compression stroke, the piston moves upward to guide the air flow to form a single tumble and further increase the tumble intensity.

[0031] The interfaces between the components of the combustion system of the present invention are circular. A small amount of interference fit can be used without affecting the inner wall dimensions, and finally welding is used as the connection to integrate the entire combustion system, increasing the sealing performance and anti-detonation pressure performance, improving reliability. Moreover, both the intake passage 3 and the exhaust passage 8 are welded to the cylinder head 2, and the valve seat ringless method of laser cladding is adopted, eliminating the valve seat ring structure. Connecting the cylinder head 2 and the cylinder block 1 by welding does not require the use of a cylinder gasket and high-strength bolts, ensuring the integration of the combustion chamber structure.

[0032] All the materials of the components of the combustion system are made of thin-walled stainless steel. The wall thickness is selected according to the strength requirements of each part and the deformation control requirements after being heated and pressurized during combustion. The heat generated by combustion will be carried out by the cooling water circulation wrapped around the combustion chamber. Compared with the structure of the combustion system of a traditional engine, the combustion system of the present invention will greatly reduce the weight and cost of the engine, while improving the dimensional accuracy, manufacturing consistency, reducing friction loss, improving the cooling efficiency and suppressing detonation, and further improving the thermal efficiency and power performance of the engine.

[0033] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A low-cost, high-precision combustion system, comprising a cylinder block (1), a cylinder head (2), an intake duct (3), an injector conduit (4), an intake valve conduit (5), a spark plug mounting conduit (6), an exhaust valve conduit (7) and an exhaust duct (8); characterized in that: The cylinder block (1), cylinder head (2), intake duct (3), injector conduit (4), intake valve conduit (5), spark plug mounting conduit (6), exhaust valve conduit (7) and exhaust duct (8) are all separately arranged and independently manufactured and formed, and then assembled by welding to form a combustion system; The intake valve guide (5) and the injector guide (4) are both welded to the intake duct (3), the exhaust valve guide (7) is welded to the exhaust duct (8), and the intake duct (3), the exhaust duct (8), and the spark plug mounting guide (6) are all welded to the cylinder head (2) to form an integral whole; the cylinder head (2) and the cylinder body (1) are connected by welding.

2. A low-cost and high-precision combustion system according to claim 1, characterized in that: The air intake duct (3) is formed by a hydraulic bulging process, specifically, first placing a Y-shaped steel pipe into a forming mold, then filling the Y-shaped steel pipe with an emulsion, and finally using pushers at three ends of the Y-shaped steel pipe to push forward at the same speed to pressurize the Y-shaped steel pipe, thereby obtaining the air intake duct (3).

3. A low-cost and high-precision combustion system according to claim 1, characterized in that: The cross-sectional area of ​​the inner wall of the air inlet duct (3) changes in the following manner: the cross-sectional area of ​​the pipe from the air inlet to the inner wall of the air inlet duct (3) close to the valve side gradually increases, and the cross-sectional area of ​​the pipe from the air inlet (3) close to the valve side to the inner wall of the air outlet gradually decreases.

4. A low-cost and high-precision combustion system according to claim 1, characterized in that: The exhaust duct (8) is a curved pipe, and the intake valve conduit (5), the exhaust valve conduit (7), the injector conduit (4) and the spark plug installation conduit (6) are all straight pipes.

5. A low-cost and high-precision combustion system according to claim 1, characterized in that: The cylinder head (2) is made by die stamping, the cylinder body (1) is made by a straight pipe, and the inner wall of the cylinder body (1) is polished.

6. A low-cost and high-precision combustion system according to claim 1, characterized in that: The welding interfaces between the components are connected by interference fit and then welded.

7. A low-cost and high-precision combustion system according to claim 1, characterized in that: Laser cladding welding is used between the intake duct (3) and the cylinder head (2), as well as between the exhaust duct (8) and the cylinder head (2).

8. A low-cost and high-precision combustion system according to claim 1, characterized in that: The edges of the cylinder cover (2) are rounded, and the middle of the cylinder cover (2) is arched upward to form a cavity.

9. A low-cost and high-precision combustion system according to claim 1, characterized in that: The combustion system components are made of stainless steel.

10. A low-cost and high-precision combustion system according to claim 1, characterized in that: The combustion system is welded by laser welding, and the welding sequence is as follows: first, the injector guide tube (4) is welded to the intake duct (3), the spark plug installation guide tube (6) is welded to the cylinder head (2), then the intake valve guide tube (5) is welded to the intake duct (3), the exhaust valve guide tube (7) is welded to the exhaust duct (8), then the intake duct (3) is welded to the cylinder head (2), the exhaust duct (8) is welded to the cylinder head (2), and finally the cylinder block (1) is welded to the cylinder head (2); wherein, the welding method of each component is low-power laser welding.

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