Large cylinder bore natural gas engine

Abstract

The invention discloses a large-bore natural gas engine, comprising a cylinder block and a cylinder head, wherein the cylinder head is mounted on the cylinder block, an intake structure is arranged on the cylinder head, and a combustion structure is arranged on the cylinder block; the invention relates to the technical field of engines, adopts a 96mm large-bore and 118mm large-stroke design, the stroke-to-bore ratio reaches 1.23, the single-cylinder displacement reaches 0.854L, the power of the engine is increased, and a 41° asymmetric valve angle design is adopted, the large valve angle can improve the turbulence intensity, thereby accelerating the flame propagation speed, and reducing the knock tendency, the linear motion direction of the intake valve forms an angle of 18° with the vertical direction, the linear motion direction of the outlet valve forms an angle of 23° with the vertical direction, and the inlet and outlet valves are asymmetrically distributed, under the condition of the valve angle, the intake resistance is small, the charging efficiency is high, the power and economy are taken into consideration, the exhaust angle is suitable, the interference of the intake and exhaust airflow is small, and the exhaust is stable and smooth.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and more particularly to a large-bore natural gas engine. Background Art

[0002] Among various alternative fuels for automobiles, natural gas has attracted much attention due to its cleanliness, large reserves, high calorific value, low pollution and good economic efficiency. The development of natural gas vehicles has important practical significance for improving urban air quality and alleviating my country's energy pressure.

[0003] In recent years, the proportion of natural gas products has gradually increased. At the same time, with the implementation of diesel National VI emissions, natural gas products are relatively easy to upgrade emissions and have low usage costs, so there are new opportunities in the natural gas market. There is a lack of a large-displacement power product with good environmental adaptability, low cost, compact layout, strong power, and good economy. At present, the domestic and foreign automotive industries lack a large-power, low-cost gas engine product, and plan to develop an inline four-cylinder gas engine with a displacement of more than 3L. Summary of the invention

[0004] The object of the present invention is to provide a high-power engine with stable combustion.

[0005] Provided is a large-cylinder natural gas engine, comprising a cylinder block and a cylinder head, wherein the cylinder head is mounted on the cylinder block, an air intake structure is provided on the cylinder head, and a combustion structure is provided on the cylinder block;

[0006] The air intake structure comprises: an air intake passage, an air outlet passage, an air intake valve, an air outlet valve and two valve seat rings;

[0007] The inlet passage is arranged on the cylinder head, the outlet passage is arranged on the cylinder head, the inlet valve is arranged on the cylinder head, and the inlet valve is located at one end of the inlet passage, the outlet valve is arranged on the cylinder head, and the outlet valve is located at one end of the outlet passage, two valve seat rings are installed on the cylinder head, and the two valve seat rings are matched with the inlet valve and the outlet valve respectively;

[0008] The linear motion direction of the inlet valve forms an angle of 18° with the vertical direction, and the linear motion direction of the outlet valve forms an angle of 23° with the vertical direction;

[0009] The two valve seat rings each include: a seat ring body, a first chamfer, a press-fitting boss, a press-fitting inclined surface, a step and a second chamfer;

[0010] The seat ring body is installed on the cylinder head, the first chamfer is arranged on the seat ring body, the press-fitting boss is arranged on the seat ring body, and the press-fitting boss is located at the lower end of the first chamfer, the press-fitting inclined surface is arranged on the seat ring body, and the press-fitting inclined surface is located at the lower end of the press-fitting boss, the step is arranged on the seat ring body, and the step is located at the lower end of the press-fitting inclined surface, and the second chamfer is arranged on the seat ring body, and the second chamfer is located at the lower end of the step.

[0011] Optionally, the air intake valve comprises: a rod body, a rolled fillet, an umbrella-shaped end and a groove;

[0012] The rolled fillet is provided at one end of the rod body, the umbrella-shaped end head is installed at the one end of the rolled fillet, and the groove is provided on the lower wall surface of the umbrella-shaped end head.

[0013] Optionally, the combustion structure comprises: a piston and a spherical groove;

[0014] The piston is installed on the cylinder body, and the spherical groove is arranged on the upper wall surface of the piston.

[0015] Optionally, a peripheral structure is also included;

[0016] The peripheral structure includes: a cover shield, a flywheel housing, an air pump, an oil pan and an intake manifold;

[0017] The cover shield is installed on the cylinder head, the flywheel housing is installed on the cylinder body, the air pump is installed on the flywheel housing, the oil pan is installed on the cylinder body, and the intake manifold is installed on the intake passage.

[0018] Optionally, the intake manifold comprises: a pressure stabilizing chamber and a branch pipe;

[0019] The pressure stabilizing chamber is a cylindrical structure, the branch pipe is installed on the pressure stabilizing chamber, and the branch pipe is a spiral structure.

[0020] Optionally, one end of the cylinder cover is a hemispherical structure.

[0021] Optionally, the diameter of the cylinder liner in the cylinder block is 96 mm, the length of the cylinder liner in the cylinder block is 167 mm, and the stroke length is 118 mm.

[0022] Optionally, the difference between the radius of the outer wall surface of the seat ring body and the radius of the inner wall surface of the second chamfer is 6.1 mm.

[0023] According to the technical content disclosed in the present invention, the following beneficial effects are achieved: a 96mm large cylinder diameter and 118mm large stroke design is adopted, the stroke-to-cylinder diameter ratio reaches 1.23, the single-cylinder displacement reaches 0.854L, the power of the engine is increased, and a 41° asymmetric valve angle design is adopted. The large valve angle can increase the turbulence intensity, thereby accelerating the flame propagation speed and reducing the knock tendency. The linear motion direction of the intake valve forms an angle of 18° with the vertical direction, and the linear motion direction of the outlet valve forms an angle of 23° with the vertical direction. The inlet and outlet valves are asymmetrically distributed. Under the condition of the valve angle, the intake resistance is small, the charging efficiency is high, and both Power and economy, the exhaust angle is appropriate, the interference of intake and exhaust airflow is small, the exhaust is smooth and stable, the special-shaped seat ring structure can increase the interference fit length with the cylinder head, and at the same time prevent the seat ring and the box cover from being squeezed, deformed and fractured during the press-fitting process. The groove of the umbrella-shaped end and the spherical groove on the piston together form a spherical combustion chamber structure, which is easy to burn and makes the combustion stable. One end of the cylinder head is a hemispherical structure to reduce the invalid volume. The spherical groove on the piston and the cylinder head are machined to improve the finish, easy to form tumble flow, low friction coefficient, and the spiral structure with a large flow coefficient intake manifold design realizes a high tumble ratio and a high flow coefficient airway design while reducing noise.

[0024] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0026] Figure 1 It is a schematic diagram of the main structure of a large-cylinder natural gas engine provided according to an embodiment;

[0027] Figure 2 A schematic diagram of the rear view structure of a large-cylinder natural gas engine provided according to an embodiment;

[0028] Figure 3 A schematic diagram of the three-dimensional structure of a cylinder block of a large-bore natural gas engine provided according to an embodiment;

[0029] Figure 4 It is a schematic cross-sectional structural diagram of a cylinder block of a large-bore natural gas engine provided according to an embodiment;

[0030] Figure 5 A schematic diagram of a valve arrangement structure of a large-cylinder natural gas engine provided according to an embodiment;

[0031] Figure 6 A schematic diagram of a valve seat assembly structure of a large-bore natural gas engine provided in accordance with an embodiment;

[0032] Figure 7 A schematic diagram of the structure of a valve seat ring of a large-cylinder natural gas engine provided according to an embodiment;

[0033] Figure 8 A schematic diagram of the structure of an intake valve of a large-cylinder natural gas engine provided according to an embodiment;

[0034] Fig. 9 A schematic diagram of the structure of an intake manifold of a large-cylinder natural gas engine provided according to an embodiment;

[0035] Fig.10 A schematic diagram of a cylinder head structure of a large-bore natural gas engine provided according to an embodiment;

[0036] Fig.11 The diagram is a schematic diagram of a piston structure of a large-bore natural gas engine provided according to an embodiment.

[0037] Explanation of the reference numerals: 1-cylinder block, 2-cylinder head, 3-intake passage, 4-exhaust passage, 5-intake valve, 6-exhaust valve, 7-valve seat ring, 701-seat ring body, 702-first chamfer, 703-press-fit boss, 704-press-fit slope, 705-step, 706-second chamfer, 501-rod body, 502-rolled fillet, 503-umbrella-shaped end, 504-groove, 18-piston, 19-spherical groove, 20-cover shield, 21-flywheel housing, 22-air pump, 23-oil pan, 24-intake manifold, 2401-pressure stabilizing chamber, 2402-branch pipe. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0039] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0040] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0041] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0042] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0043] Provided is a large-bore natural gas engine, comprising a cylinder block 1 and a cylinder head 2, wherein the cylinder head 2 is mounted on the cylinder block 1, an air intake structure is provided on the cylinder head 2, and a combustion structure is provided on the cylinder block 1;

[0044] It should be noted that: as a preferred embodiment, further, the diameter of the cylinder liner in the cylinder block 1 is 96 mm, the length of the cylinder liner in the cylinder block 1 is 167 mm, the stroke length is 118 mm, the stroke-to-bore ratio reaches 1.23, and the single-cylinder displacement reaches 0.854 L, which has the advantage of high power;

[0045] In the specific implementation process, the intake structure can preferably adopt the following structure, which includes: an intake duct 3, an outlet duct 4, an intake valve 5, an outlet valve 6 and two valve seat rings 7; the intake duct 3 is arranged on the cylinder head 2, the outlet duct 4 is arranged on the cylinder head 2, the intake valve 5 is arranged on the cylinder head 2, and the intake valve 5 is located at one end of the intake duct 3, the outlet valve 6 is arranged on the cylinder head 2, and the outlet valve 6 is located at one end of the outlet duct 4, and the two valve seat rings 7 are installed on the cylinder head 2, and the two valve seat rings 7 are matched with the intake valve 5 and the outlet valve 6 respectively;

[0046] The linear motion direction of the inlet valve 5 forms an angle of 18° with the vertical direction, and the linear motion direction of the outlet valve forms an angle of 23° with the vertical direction;

[0047] It should be noted that: the angle between the intake valve 5 and the outlet valve is 41 degrees, and the intake valve 5 and the outlet valve adopt an asymmetric valve angle design, the linear motion direction of the intake valve 5 forms an angle of 18 degrees with the vertical direction, and the linear motion direction of the outlet valve forms an angle of 23 degrees with the vertical direction. Under the condition of this valve angle, the intake resistance is small, the charging efficiency is high, the power and economy are taken into consideration, the exhaust angle is appropriate, the interference of the intake and exhaust airflow is small, and the exhaust is stable and smooth;

[0048] In the specific implementation process, both valve seat rings 7 can preferably adopt the following structure, which includes: a seat ring body 701, a first chamfer 702, a press-fitting boss 703, a press-fitting inclined surface 704, a step 705 and a second chamfer 706; the seat ring body 701 is installed on the cylinder head 2, the first chamfer 702 is arranged on the seat ring body 701, the press-fitting boss 703 is arranged on the seat ring body 701, and the press-fitting boss 703 is located at the lower end of the first chamfer 702, the press-fitting inclined surface 704 is arranged on the seat ring body 701, and the press-fitting inclined surface 704 is located at the lower end of the press-fitting boss 703, the step 705 is arranged on the seat ring body 701, and the step 705 is located at the lower end of the press-fitting inclined surface 704, and the second chamfer 706 is arranged on the seat ring body 701, and the second chamfer 706 is located at the lower end of the step 705;

[0049] It should be noted that: the press-fitting boss 703, the press-fitting inclined surface 704 and the step 705 are provided to increase the matching surface between the seat ring body 701 and the cylinder head 2, and to increase the contact surface between the seat ring body 701 and the cylinder head 2. Preferably, further, the difference between the radius dimension of the outer wall surface of the seat ring body 701 and the radius dimension of the inner wall surface of the second chamfer 706 is 6.1 mm. At the same time, the first chamfer 702 and the second chamfer 706 prevent the seat ring body 701 and the tank cover from being squeezed, deformed and fractured during the press-fitting process.

[0050] In the specific implementation process, the intake valve 5 can preferably adopt the following structure, which includes: a rod body 501, a rolled fillet, an umbrella-shaped end head 503 and a groove 504; the rolled fillet is opened at one end of the rod body 501, the umbrella-shaped end head 503 is installed at one end of the rolled fillet, and the groove 504 is opened on the lower wall surface of the umbrella-shaped end head 503;

[0051] It should be noted that: the bottom of the rod body 501 is connected to the umbrella-shaped end 503 by rolling fillet to ensure sufficient strength of the valve, and the bottom surface of the umbrella-shaped end 503 is designed with a groove 504 to reduce the overall weight;

[0052] In the specific implementation process, the combustion structure can preferably adopt the following structure, which includes: a piston 18 and a spherical groove 19; the piston 18 is installed on the cylinder body 1, and the spherical groove 19 is opened on the upper wall surface of the piston 18;

[0053] It should be noted that the groove 504 of the umbrella-shaped end 503 and the spherical groove 19 on the piston 18 together form a spherical combustion chamber structure, which is easy to burn and makes the combustion stable. As a preferred embodiment, further, one end of the cylinder head 2 is a hemispherical structure to reduce the dead volume. The spherical groove 19 on the piston 18 and the cylinder head 2 are machined to improve the finish, easily form tumble flow, and have a low friction coefficient.

[0054] In the specific implementation process, it also includes a peripheral structure, which can preferably adopt the following structure, including: a cover shield 20, a flywheel housing 21, an air pump 22, an oil pan 23 and an intake manifold 24; the cover shield 20 is installed on the cylinder head 2, the flywheel housing 21 is installed on the cylinder body 1, the air pump 22 is installed on the flywheel housing 21, the oil pan 23 is installed on the cylinder body 1, and the intake manifold 24 is installed on the intake duct 3;

[0055] It should be noted that: the cover shield 20 adopts a cast aluminum structure and an integrated breathing system, and has the advantages of reliable product and compact layout; the flywheel housing 21 can be adjusted to adapt to gearboxes of different sizes and forms, and the cylinder body 1 does not need to be modified; the air pump 22 is arranged on the flywheel housing 21 and driven by the crankshaft, which can provide an efficient and reliable braking power source; the oil pan 23 adopts a thin-walled stamping structure, which has the advantages of lightweight and compact layout;

[0056] In the specific implementation process, the intake manifold 24 may preferably adopt the following structure, which includes: a pressure stabilizing chamber 2401 and a branch pipe 2402; the pressure stabilizing chamber 2401 is a cylindrical structure, the branch pipe 2402 is installed on the pressure stabilizing chamber 2401, and the branch pipe 2402 is a spiral structure;

[0057] It should be noted that the center line of the branch pipe 2402 is designed as a spiral structure, the average flow coefficient of each cylinder is increased to 0.7473 (increased by 10.55%), the intake resistance of the branch pipe 2402 is only 234Pa (reduced by 12.68%), and the pressure stabilizing chamber 2401 is a cylindrical structure. Combined with the spiral structure of the branch pipe 2402, a high intake tumble ratio and a high flow coefficient are achieved, while reducing noise.

[0058] In summary, the design of 96mm large cylinder diameter and 118mm large stroke is adopted, the stroke-to-bore ratio reaches 1.23, and the single-cylinder displacement reaches 0.854L, which increases the power of the engine. The design of 41° asymmetric valve angle is adopted. The large valve angle can increase the turbulence intensity, thereby accelerating the flame propagation speed and reducing the tendency of knock. The linear motion direction of the intake valve 5 forms an angle of 18° with the vertical direction, and the linear motion direction of the outlet valve forms an angle of 23° with the vertical direction. The inlet and outlet valves are asymmetrically distributed. Under the condition of this valve angle, the intake resistance is small, the charging efficiency is high, and both power and economy are taken into consideration. The exhaust angle is appropriate, and the intake and exhaust are The airflow interference is small, and the exhaust is smooth and stable. The special-shaped seat ring structure can increase the interference fit length with the cylinder head 2, and at the same time prevent the seat ring and the box cover from being squeezed, deformed and fractured during the press-fitting process. The groove 504 of the umbrella-shaped end 503 and the spherical groove 19 on the piston 18 form a spherical combustion chamber structure, which is easy to burn and makes the combustion stable. One end of the cylinder head 2 is a hemispherical structure to reduce the invalid volume. The spherical groove 19 on the piston 18 and the cylinder head 2 are machined to improve the finish, easily form tumble flow, have a low friction coefficient, and the spiral structure has a large flow coefficient. The intake manifold 24 design realizes an airway design with a high tumble ratio and a high flow coefficient, while reducing noise.

[0059] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A large-bore natural gas engine, characterized in that: It comprises a cylinder body (1) and a cylinder head (2), wherein the cylinder head (2) is mounted on the cylinder body (1), an air intake structure is provided on the cylinder head (2), and a combustion structure is provided on the cylinder body (1); The air intake structure comprises: an air intake passage (3), an air outlet passage (4), an air intake valve (5), an air outlet valve (6) and two valve seat rings (7); The intake duct (3) is arranged on the cylinder head (2), the outlet duct (4) is arranged on the cylinder head (2), the intake valve (5) is arranged on the cylinder head (2), and the intake valve (5) is located at one end of the intake duct (3), the outlet valve (6) is arranged on the cylinder head (2), and the outlet valve (6) is located at one end of the outlet duct (4), and two valve seat rings (7) are installed on the cylinder head (2), and the two valve seat rings (7) are matched with the intake valve (5) and the outlet valve (6) respectively; The linear motion direction of the air inlet valve (5) forms an angle of 18° with the vertical direction, and the linear motion direction of the air outlet valve forms an angle of 23° with the vertical direction; The two valve seat rings (7) each comprise: a seat ring body (701), a first chamfer (702), a press-fitting boss (703), a press-fitting inclined surface (704), a step (705) and a second chamfer (706); The seat ring body (701) is mounted on the cylinder head (2); the first chamfer (702) is arranged on the seat ring body (701); the press-fitting boss (703) is arranged on the seat ring body (701), and the press-fitting boss (703) is located at the lower end of the first chamfer (702); the press-fitting inclined surface (704) is arranged on the seat ring body (701), and the press-fitting inclined surface (704) is located at the lower end of the press-fitting boss (703); the step (705) is arranged on the seat ring body (701), and the step (705) is located at the lower end of the press-fitting inclined surface (704); the second chamfer (706) is arranged on the seat ring body (701), and the second chamfer (706) is located at the lower end of the step (705); The air intake valve (5) comprises: a rod body (501), a rolled fillet, an umbrella-shaped end (503) and a groove (504); The rolled fillet is formed at one end of the rod body (501), the umbrella-shaped end head (503) is mounted at one end of the rolled fillet, and the groove (504) is formed on the lower wall of the umbrella-shaped end head (503). The combustion structure comprises: a piston (18) and a spherical groove (19); The piston (18) is mounted on the cylinder body (1), and the spherical groove (19) is opened on the upper wall surface of the piston (18) and also includes a peripheral structure; The peripheral structure comprises: a cover shield (20), a flywheel housing (21), an air pump (22), an oil pan (23) and an intake manifold (24); The cover shield (20) is mounted on the cylinder head (2), the flywheel housing (21) is mounted on the cylinder body (1), the air pump (22) is mounted on the flywheel housing (21), the oil pan (23) is mounted on the cylinder body (1), and the intake manifold (24) is mounted on the intake duct (3). The intake manifold (24) includes: a pressure stabilizing chamber (2401) and a branch pipe (2402); The pressure stabilizing chamber (2401) is a cylindrical structure, the branch pipe (2402) is installed on the pressure stabilizing chamber (2401), and the branch pipe (2402) is a spiral structure.

2. A large-bore natural gas engine according to claim 1, characterized in that: One end of the cylinder cover (2) is a hemispherical structure.

3. A large-bore natural gas engine according to claim 1, characterized in that: The diameter of the cylinder liner in the cylinder body (1) is 96 mm, the length of the cylinder liner in the cylinder body (1) is 167 mm, and the stroke length is 118 mm.

4. A large-bore natural gas engine according to claim 1, characterized in that: The difference between the radius of the outer wall surface of the seat ring body (701) and the radius of the inner wall surface of the second chamfer (706) is 6.1 mm.

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