WO2020062738A1

WO2020062738A1 - Engine and method for stratified compression ignition of fuel in cylinder

Info

Publication number: WO2020062738A1
Application number: PCT/CN2019/072723
Authority: WO
Inventors: 杜家坤; 陈泓; 李钰怀; 冶麟
Original assignee: 广州汽车集团股份有限公司
Priority date: 2018-09-26
Filing date: 2019-01-22
Publication date: 2020-04-02
Also published as: CN110953066A; CN110953066B

Abstract

An engine comprises a cylinder (11), a cylinder head (12), a piston (13), and a fuel injector (14). The cylinder head (12) is provided on the cylinder (11). The piston (13) is movably provided in the cylinder (11). A combustion chamber (101) is formed between the cylinder head (12) and the piston (13). The fuel injector (14) is provided on the cylinder head (12). The fuel injector (14) is used to inject fuel into the combustion chamber (101). A helical air inlet channel (121) and an exhaust channel (123) are provided on the cylinder head (12). An exhaust guide channel (125) is connected between the helical gas inlet channel (121) and the exhaust channel (123). An exhaust control valve (126) for controlling an exhaust flow rate is provided on the exhaust guide channel (125). When the engine is in an intake stroke, exhaust and air pass through the helical gas inlet channel to form a vortex gas mixture, and then enter the combustion chamber of the cylinder. The engine avoids knocks caused by spontaneous combustion of a gas mixture at a gasoline end when a compression ratio is high, and improves heat efficiency. Also disclosed is a method for stratified compression ignition of fuel in a cylinder.

Description

TECHNICAL FIELD

[0001] The present invention relates to the technical field of engine compression ignition, and in particular, to an engine and a combustion method in a fuel cylinder.

Background technique

[0002] Because of the limitation of knocking, some ignition gasoline engines have a compression ratio much lower than that of diesel engines based on compression ignition. Since the thermal efficiency of the engine is directly related to the compression ratio, the thermal efficiency of existing gasoline engines is relatively low.

[0003] Currently, gasoline engines mainly use tumble stratification. Because tumble flow is easily broken during compression and has poor retention, the stratified mixture formed by the intake stroke often cannot be maintained before ignition, making it difficult to form a stable near the spark plug. A suitable oil-gas mixture is not conducive to the advantages of stratification.

Summary of invention

Problem solution

Technical solutions

[0004] In view of this, the present invention provides an engine that can avoid knocking caused by the spontaneous combustion of a gas mixture at the end of gasoline fuel under high compression ratio conditions, and improve thermal efficiency.

[0005] An engine includes a cylinder, a cylinder head, a piston, and an injector, the cylinder head is disposed on the cylinder, the piston is movably disposed in the cylinder, and the cylinder head and the cylinder A combustion chamber is formed between the pistons, the fuel injector is arranged on the cylinder head, the fuel injector is used to inject fuel into the combustion chamber, and the cylinder head is provided with a spiral intake duct and an exhaust duct An exhaust gas guide channel is connected between the spiral intake channel and the exhaust gas channel, and an exhaust gas control valve for controlling the flow of exhaust gas is provided on the exhaust gas guide channel, and when the engine is in an intake stroke, the exhaust gas is After the air and air pass through the spiral inlet, a vortex mixed gas is formed and enters the combustion chamber of the cylinder.

[0006] In an embodiment of the present invention, an end surface of the piston is located in the combustion chamber, and the end surface is recessed in a direction away from the cylinder head.

[0007] In an embodiment of the present invention, an end of the piston is recessed in a direction away from the cylinder head to form a first A combustion tank and a second combustion tank, the first combustion tank is located in a middle portion of the piston, and the second combustion tank is disposed along a circumferential direction of the first combustion tank.

[0008] In an embodiment of the present invention, the second combustion tank is an annular groove and surrounds the periphery of the first combustion tank, and the depth of the second combustion tank is greater than the depth of the first combustion tank. shallow.

[0009] In an embodiment of the present invention, the fuel injector is provided at a middle portion of the cylinder head along an axis of the cylinder.

[0010] In an embodiment of the present invention, a first intake valve is provided in the spiral intake passage, a tangential intake passage is further provided on the cylinder head, and a tangential intake passage is provided in the helical intake passage. The second intake valve is provided with an exhaust valve in the exhaust passage.

[0011] In an embodiment of the present invention, a preheating plug is further provided on the cylinder head, and the preheating plug is disposed near the fuel injector.

[0012] In an embodiment of the present invention, an ejection tube is provided at an end of the exhaust gas guide channel, the ejection tube is disposed in the spiral intake channel, and the ejection tube is along the spiral The intake direction of the air inlet is set.

[0013] The present invention also provides a method for stratified combustion in a fuel cylinder, which is applied to the engine described above. The method for stratified combustion in a fuel cylinder includes:

[0014] During the intake stroke of the engine, the exhaust gas and air pass through the spiral intake passage to form a vortex mixed gas into the cylinder, and the mixed gas throws the exhaust gas and part of the air close to the gas under the action of vortex inertia. Peripheral area of the side wall of the cylinder;

[0015] using the fuel injector to inject fuel into the cylinder during the intake stroke, and the fuel is gasified and mixed with exhaust gas and air in the peripheral area under the action of vortex inertia;

[0016] using the fuel injector to inject fuel into the cylinder during a compression stroke, and the fuel is gasified and mixed with air in a central area of the cylinder; and

[0017] At the end of the compression stroke, the mixed gas in the central region is first compressed to form a plurality of fire nuclei, and the plurality of fire nuclei ignite the mixed gas in the peripheral region.

[0018] In an embodiment of the present invention, when the engine is in a compression stroke, a first combustion groove on an end surface of the piston is used to restrict fuel to a central region of the cylinder.

[0019] In an embodiment of the present invention, when the engine is in a cold start and low temperature operating condition, a glow plug is used to preheat the working fluid in the cylinder.

[0020] In an embodiment of the present invention, when the engine is in a low-speed, low-load operating condition, the exhaust gas is controlled The opening degree of the control valve is less than

The degree of opening of the exhaust gas control valve when fully opened, and controls the fuel injector to inject a single fuel during the intake stroke.

[0021] In an embodiment of the present invention, when the engine is in a low-speed, high-load operating condition, the opening degree of the exhaust gas control valve is controlled to be less than

1 / ^

The degree of opening of the exhaust control valve when fully opened, and controls the injector to inject fuel multiple times during the intake stroke.

[0022] In an embodiment of the present invention, when the engine is in a medium-speed, low-load operating condition, controlling the opening degree of the exhaust gas control valve to be greater than

1 /: ^

[0023] In an embodiment of the present invention, when the engine is in a medium-speed, high-load condition, controlling the opening degree of the exhaust gas control valve to be less than

1/2

The beneficial effects of the invention

Beneficial effect

[0024] The cylinder head of the engine of the present invention is provided on the cylinder, and the piston is movably disposed in the cylinder. A combustion chamber is formed between the cylinder head and the piston. An injector is provided on the cylinder head. Fuel injection, the cylinder head is provided with a spiral intake duct and an exhaust duct, an exhaust gas guide duct is connected between the spiral intake duct and the exhaust duct, and an exhaust gas control valve for controlling the exhaust gas flow is provided on the exhaust gas duct. During the intake stroke of the engine, the exhaust gas and air pass through the spiral intake passage to form a vortex mixture into the combustion chamber of the cylinder.发 of the invention The motive can avoid the strong knock caused by the spontaneous combustion of the gas mixture at the end of the gasoline fuel under the condition of high compression ratio without changing the existing gasoline fuel. Moreover, higher compression ratios have significant advantages in improving thermal efficiency. In addition, the control method of gasoline split combustion provides a technical approach for the control of non-equivalent ratio combustion processes such as lean lean gasoline.

Brief description of the drawings

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic diagram of a partial structure of an engine of the present invention.

[0026] FIG. 2 is a schematic structural diagram of an engine of the present invention during an intake stroke.

[0027] FIG. 3 is a schematic structural diagram of the engine of the present invention during a compression stroke.

[0028] FIG. 4 is a schematic flow chart of a method for stratified combustion in a fuel cylinder according to the present invention.

Invention Examples

Embodiments of the invention

[0029] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

1 is a schematic diagram of a partial structure of an engine of the present invention. As shown in FIG. 1, the engine 10 includes a plurality of sets of cylinders 11, a cylinder head 12, a piston 13, and an injector 14. The engine 10 of the present invention is a gasoline engine, and the compression ratio of the engine 10 is 13-17, which is higher than the compression ratio of the existing gasoline engine.

[0031] The end of the cylinder 11 is closed, and the cylinder head 12 is provided on the open end of the cylinder 11.

[0032] The cylinder head 12 is provided with a spiral intake passage 121, a tangential intake passage (not shown), and an exhaust passage 123. The spiral intake passage 121, the tangential intake passage, and the exhaust passage 123 communicate with the combustion chamber 101. The spiral intake passage 121 is provided with a first intake valve 122 that controls the spiral intake passage 121 to open and close the combustion chamber 101. The tangential intake passage is provided with a second intake valve that controls the tangential intake passage to open and close the combustion chamber 101, and the exhaust passage 123 is provided with an exhaust valve that controls the exhaust passage 123 to open and close the combustion chamber 101. For the valve 124, for functions and functions of the first intake valve 122, the second intake valve, and the exhaust valve 124, refer to the prior art, and details are not described herein again.

[0033] An exhaust gas guide channel 125 is connected between the spiral intake channel 121 and the exhaust channel 123, that is, one end of the exhaust gas guide channel 125 is in communication with the spiral intake channel 121, and the other end of the exhaust gas guide channel 125 is connected to the exhaust gas. The passage 123 communicates, and the exhaust gas guide passage 125 is used to introduce part of the exhaust gas in the exhaust passage 123 into the spiral intake passage 121. The exhaust gas guideway 125 is provided with an exhaust gas control valve 126 for controlling the flow rate of the exhaust gas. By adjusting the opening degree of the exhaust gas control valve 126, the intake is controlled. The exhaust gas flow rate of the spiral inlet 121. In this embodiment, when the engine 10 is in the intake stroke, the opening degree of the exhaust gas control valve 126 is adjusted so that the exhaust gas enters the spiral intake passage 121, and the exhaust gas and air pass through the spiral intake passage 121 to form a vortex mixed gas and enter the cylinder. 11.

[0034] In another preferred embodiment, an end of the exhaust gas guide 125 is provided with an ejection tube (not shown), the ejection tube is disposed in the spiral inlet 121, and the ejection tube is along the spiral The intake direction of the intake passage 121 is set. The ejection pipe introduces the exhaust gas to one side of the spiral inlet 121, which is beneficial to increasing the stratification of the exhaust gas and the air, and ensuring that the subsequent combustion can proceed smoothly.

[0035] The piston 13 is movably disposed in the cylinder 11, the piston 13 is connected to the connecting rod through a pin, and the connecting rod is connected to the crankshaft. The piston 13 moves up and down in the cylinder 11, and the cylinder head 12 and the piston 13 are formed. Variable volume combustion chamber 101. The end surface 131 of the piston 13 is located in the combustion chamber 101, and the end surface 131 of the piston 13 is recessed in the direction of the cylinder head 12. The recessed end surface 131 of the piston 13 can be used as a small combustion chamber. Preferably, the end surface of the piston 13 is 131 is recessed in a direction away from the cylinder head 12 to form a first combustion groove 102 and a second combustion groove 103, the first combustion groove 102 is located in the middle of the piston 13, the axis of the first combustion groove 102 coincides with the axis of the piston 13, and the second combustion The groove 103 is provided along the circumferential direction of the first combustion groove 102, that is, the second combustion groove 103 is an annular groove and is provided around the periphery of the first combustion groove 102. The depth of the second combustion tank 103 is shallower than the depth of the first combustion tank 102. It is worth mentioning that the combustion chamber 101 of the cylinder 11 includes a central region 101 a near the axis of the cylinder 11 and a peripheral region 101 b near the side wall of the cylinder 11, that is, the peripheral region 101 b surrounds the central region 101 a. The first combustion tank 102 is located in the combustion chamber. In the central region 101a of 101, the second combustion tank 103 is located in the peripheral region 101b of the combustion chamber 101.

[0036] When the engine 10 is in the intake stroke, the vortex mixed gas formed by the spiral intake passage 121 enters the cylinder 11, the density of the exhaust gas is large, and the exhaust gas and part of the air are thrown into the side wall near the cylinder 11 under the action of the vortex inertia. In the peripheral area 101b of the air, the air input from the tangential intake port enters the central area 101a of the cylinder 11, and further, a layered phenomenon of exhaust gas and air mixture is formed in the cylinder 11. In this embodiment, when the engine 10 is in the compression stroke, the first combustion tank 102 and the second combustion tank 103 are small combustion chambers, the central region 101a has a high oxygen content, and the peripheral region 101b has a high exhaust gas content. The exhaust gas will inhibit chemical reactions. As the pressure and temperature of the combustion chamber 101 increase instantaneously, the mixed gas in the central region 101a is first compression-ignited in the region above the first combustion tank 102, thereby forming multiple fire nuclei, and each of the fire nuclei ignites the peripheral region at the same time. 101b mixed gas.

[0037] An injector 14 is provided on the cylinder head 12, and the injector 14 is used to inject fuel into the combustion chamber 101. The fuel is described as an example. For gasoline, it is not limited to this. The injector 14 is disposed along the axis of the cylinder 11 in the middle of the cylinder head 12, and the nozzle of the injector 14 faces the first combustion groove 102 of the piston 13. When the engine is in the compression stroke, the gasoline ejected by the fuel injector 14 is within the area defined by the first combustion tank 102. In this embodiment, a preheating plug is further provided on the cylinder head 12. The preheating plug is provided near the injector 14. The preheating plug is used to heat the working fluid in the combustion chamber 101 to ensure that the fuel can be successfully compression-ignited.

[0038] FIG. 2 is a schematic structural diagram of an engine of the present invention during an intake stroke. Fig. 3 is a structural diagram of the engine of the present invention during a compression stroke. Fig. 4 is a schematic flow chart of a method for stratified combustion in a fuel cylinder according to the present invention. As shown in FIG. 2, FIG. 3 and FIG. 4, the present invention also relates to a method for stratified combustion in a fuel cylinder, which overcomes the problem that a conventional gasoline engine needs to be matched with a complex ignition system, by adopting a higher compression ratio It has great potential in improving thermal efficiency. The method for stratified combustion in a fuel cylinder of the present invention uses the above-mentioned engine 10, and the steps include:

[0039] Step 1: During the intake stroke of the engine 10, the exhaust gas and air pass through the spiral intake passage 121 to form a vortex mixed gas into the cylinder 11, and the mixed gas throws the exhaust gas and part of the air into the cylinder 11 under the action of the vortex inertia. The peripheral region 101b of the sidewall.

[0040] Specifically, during the intake stroke of the engine 10, controlling the opening of the first intake valve 122 and the second intake valve, and simultaneously adjusting the opening degree of the exhaust gas control valve 126 to control the amount of exhaust gas entering the spiral intake passage 121, The exhaust gas and air pass through the spiral inlet 121 to form a vortex mixture into the cylinder 11. Due to the high density of the exhaust gas, the exhaust gas and part of the air are thrown into the peripheral area 101b near the side wall of the cylinder 11 due to the eddy current inertia. The input air enters the central area 101 a of the cylinder 11.

[0041] In step two, the fuel is injected into the cylinder 11 during the intake stroke by means of the injector 14. After the fuel is vaporized, it is mixed with the exhaust gas and air in the peripheral area 101b under the action of the swirl inertia.

[0042] Specifically, during the intake stroke of the engine 10, the injector 14 injects gasoline fuel into the cylinder 11, the density of the gasoline is relatively high, and it is thrown into the peripheral region 101b near the side wall of the cylinder 11 under the action of eddy current inertia. And mixed with exhaust gas and air to achieve stratification of gasoline, exhaust gas and air mixture.

[0043] In step three, the fuel is injected into the cylinder 11 during the compression stroke by using the fuel injector 14, and the fuel is gasified and mixed with the air in the central area 101a of the cylinder 11.

[0044] Specifically, during the compression stroke of the engine 10, the injector 14 injects a small amount of gasoline fuel into the cylinder 11, and the injected gasoline fuel enters the first combustion tank 102 of the piston 13, and the first combustion tank 102 discharges gasoline Fuel limit In the central region 101a of the cylinder 11, to avoid the diffusion of gasoline fuel into the cylinder 11 of the peripheral region 101b, ₁₀ la at this time the air mixing gasoline fuel and the central region to form a more stable mixture. It is worth mentioning that because the vortex mixture in the peripheral area 101b flows around the axis of the cylinder 11, when the piston 13 moves in the direction close to the cylinder head 12, the vortex mixture will not be destroyed, which is beneficial to the layering of the mixture Advantage.

[0045] Step 4. At the end of the compression stroke, the mixture in the central area 101a is first compressed to form a plurality of fire cores, and the fire cores ignite the mixture in the peripheral area 101b.

[0046] Specifically, at the end of the compression stroke, the temperature and pressure in the cylinder 11 increase, and the mixed gas in the central region 10a of the cylinder 11 can be compression-ignited to form a plurality of fire cores due to the sufficient oxygen content. The peripheral region 101b has a large amount of exhaust gas, a small amount of oxygen in the exhaust gas, and a large amount of carbon dioxide. Carbon dioxide does not participate in chemical reactions and can be used as an inhibitor of chemical reactions. It can reduce the chemical reaction rate of gasoline fuel in the peripheral region 101b. The region 101a is in a state of being fired at a plurality of points at the same time, and can be used as a high-energy ignition source to ignite the mixed gas in the peripheral region 101b of the cylinder 11.

[0047] Further, when the engine 10 is in a cold start and low temperature operating condition, the working fluid (mixed air of air and fuel) in the cylinder 11 is preheated by using a glow plug to ensure that the fuel can catch fire naturally.

[0048] Further, when the engine 10 is in a low-speed, low-load operating condition, the opening degree of the control exhaust gas control valve 126 is less than

The exhaust control valve 126 is opened when it is fully opened, and controls the fuel injector 14 to inject a single fuel during the intake stroke. In this embodiment, the smaller opening degree of the exhaust gas control valve 126 can prevent the exhaust gas from spreading rapidly in the cylinder 11 to form a homogeneous exhaust gas distribution, which is beneficial to the smooth progress of combustion.

[0049] Further, when the engine 10 is in a low-speed, high-load operating condition, the opening degree of the control exhaust gas control valve 126 is less than

The exhaust gas control valve 126 is fully opened, and controls the injector 14 to inject fuel multiple times during the intake stroke. Preferably, the injector 14 injects fuel 2 to 3 times, but not limited to this.

[0050] Further, when the engine 10 is in a medium-speed, low-load operating condition, the opening degree of the control exhaust gas control valve 126 is greater than 1/2

Exhaust control valve 126 opens when fully opened, and controls injector 14 to inject a single fuel during the intake stroke

[0051] Further, when the engine 10 is in a medium-speed, high-load operating condition, the opening degree of the control exhaust gas control valve 126 is less than

1 / ^

[0052] The cylinder head 12 of the engine 10 of the present invention is disposed on the cylinder 11, the piston 13 is movably disposed in the cylinder 11, a combustion chamber 101 is formed between the cylinder head 12 and the piston 13, and the injector 14 is disposed on the cylinder head. The fuel injector 14 is used to inject fuel into the combustion chamber 101. The cylinder head 12 is provided with a spiral intake passage 121 and an exhaust passage 123. An exhaust gas guide is connected between the spiral intake passage 121 and the exhaust passage 123. The exhaust path 125 and the exhaust guide path 125 are provided with an exhaust gas control valve 126 for controlling the exhaust gas flow rate. When the engine 10 is in the intake stroke, the exhaust gas and air pass through the spiral intake passage 121 to form a vortex mixed gas into the combustion of the cylinder 11 Room 101. The engine 10 of the present invention can avoid the strong knock caused by the spontaneous combustion of the gas mixture at the end of the gasoline fuel under the condition of high compression ratio without changing the existing gasoline fuel. Moreover, higher compression ratios have significant advantages in improving thermal efficiency. In addition, the control method of gasoline split combustion provides a technical approach for the control of non-equivalent ratio combustion processes such as lean lean gasoline.

[0053] The engine 10 of the present invention uses vortexes to form a stratified layer of gasoline, exhaust gas, and air in the cylinder 11, that is, a spiral intake port 121 is used to cooperate with a relatively large molecular weight exhaust gas to form a peripheral region 101b oxygen in the cylinder 11. A layered state with a low content and a high oxygen content in the central region 101a. At the same time, the inhibitory effect of the exhaust gas on the chemical reaction is used to control the chemical reaction rate of the gasoline to avoid 10 lb of the mixed gas in the peripheral area of the combustion chamber 101 from spontaneously igniting during the compression stroke. In addition, the high oxygen concentration of the central area 101a of the cylinder 11 is used to form a gasoline and air mixture with the fuel to ensure local spontaneous ignition at a high compression ratio. Since the self-ignition ignition location occurs in the central area 101a of the cylinder 11, the existing The knock caused by the spontaneous combustion of the mixed gas at the end of the gasoline engine is different, and the spontaneous ignition region can ignite the mixed gas (gasoline, air, exhaust gas) in the peripheral region 101b as a large number of independent high-energy fire nuclei. [0054] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall be included in the present invention. Within the scope of the invention.

Industrial applicability

[0055] The cylinder head of the engine of the present invention is disposed on the cylinder, and the piston is movably disposed in the cylinder. A combustion chamber is formed between the cylinder head and the piston. An injector is disposed on the cylinder head. Fuel injection, the cylinder head is provided with a spiral intake duct and an exhaust duct, an exhaust gas guide duct is connected between the spiral intake duct and the exhaust duct, and an exhaust gas control valve for controlling the exhaust gas flow is provided on the exhaust gas duct. During the intake stroke of the engine, the exhaust gas and air pass through the spiral intake passage to form a vortex mixture into the combustion chamber of the cylinder. The engine of the present invention can avoid the strong knock caused by the spontaneous combustion of the gas mixture at the end of the gasoline fuel under the condition of high compression ratio without changing the existing gasoline fuel. Moreover, higher compression ratios have significant advantages in terms of improved thermal efficiency. In addition, the control method of gasoline stratified combustion provides a technical approach for the control of non-equivalent ratio combustion processes such as lean lean gasoline.

Claims

Claim

[Claim 1] An engine comprising a cylinder, a cylinder head, a piston, and an injector. The cylinder head is disposed on the cylinder, the piston is movably disposed in the cylinder, and the cylinder head and A combustion chamber is formed between the pistons, the fuel injector is disposed on the cylinder head, the fuel injector is used to inject fuel into the combustion chamber, and the cylinder head is provided with a spiral feed An air passage and an exhaust passage, an exhaust gas guide passage is connected between the spiral intake passage and the exhaust passage, and an exhaust gas control valve for controlling an exhaust gas flow is provided on the exhaust gas guide passage, and when the engine is in During the air stroke, exhaust gas and air are passed through the spiral inlet to form a vortex mixed gas and enter the combustion chamber of the cylinder.

[Claim 2] The engine according to claim 1, wherein an end surface of the piston is located in the combustion chamber, and the end surface is recessed in a direction away from the cylinder head.

[Claim 3] The engine according to claim 2, wherein an end of the piston is recessed to form a first combustion groove and a second combustion groove facing away from the cylinder head, and the first combustion groove is located at In the middle of the piston, the second combustion groove is provided along a circumferential direction of the first combustion groove.

[Claim 4] The engine according to claim 3, wherein the second combustion groove is an annular groove and surrounds the periphery of the first combustion groove, and the depth of the second combustion groove is smaller than The first combustion tank has a shallow depth.

[Claim 5] The engine according to claim 1, wherein the fuel injector is provided at a middle portion of the cylinder head along an axis of the cylinder.

[Claim 6] The engine according to claim 1, wherein a first intake valve is provided in the spiral intake passage, and a tangential intake passage is further provided on the cylinder head, and the cut A second intake valve is provided in the intake passage, and an exhaust valve is provided in the exhaust passage.

[Claim 7] The engine according to claim 1, wherein a preheating plug is further provided on the cylinder head, and the preheating plug is disposed near the fuel injector.

[Claim 8] The engine according to claim 1, wherein an end of the exhaust gas guide is provided with an ejection pipe, and the ejection pipe is provided in the spiral intake passage, and the exhaust pipe The injection pipe is arranged along the intake direction of the spiral intake passage.

[Claim 9] A method for stratified combustion in a fuel cylinder is applied to the engine according to any one of claims 1 to 8, characterized in that the method for stratified combustion in a fuel cylinder includes:

During the intake stroke of the engine, the exhaust gas and air pass through the spiral inlet to form a vortex mixed gas into the cylinder, and the mixed gas throws the exhaust gas and part of the air near the side wall of the cylinder under the action of vortex inertia Peripheral area

Using the fuel injector to inject fuel into the cylinder during the intake stroke, and after the fuel is vaporized, it is mixed with exhaust gas and air in the peripheral area under the action of vortex inertia;

Using the fuel injector to inject fuel into the cylinder during a compression stroke, and the fuel is vaporized and mixed with air in a central region of the cylinder; and

At the end of the compression stroke, the mixture in the central region is first compressed to form a plurality of fire nuclei, and the plurality of fire nuclei ignite the mixture in the peripheral region.

[Claim 10] The method for stratified combustion in a fuel cylinder according to claim 9, wherein when the engine is in a compression stroke, the fuel is restricted to the first combustion groove on the end surface of the piston A central area of the cylinder.

[Claim 11] The method of stratified combustion in a fuel cylinder according to claim 9, wherein when the engine is in a cold start and low temperature operating condition, a glow plug is used to perform a working fluid in the cylinder. Warm up.

[Claim 12] The method for stratified combustion in a fuel cylinder according to claim 9, characterized in that, when the engine is in a low-speed, low-load operating condition, controlling the opening degree of the exhaust gas control valve to be less than

1/3

The degree of opening of the exhaust control valve when it is fully opened, and controls the fuel injector to inject a single fuel during the intake stroke.

[Claim 13] The method of stratified combustion in a fuel cylinder according to claim 9, characterized in that, when the engine is in a low-speed, high-load operating condition, controlling the opening degree of the exhaust gas control valve to be less than

[Claim 14] The method of stratified combustion in a fuel cylinder according to claim 9, characterized in that, when the engine is in a medium-speed, low-load operating condition, controlling the opening degree of the exhaust gas control valve to be greater than

[Claim 15] The method of stratified combustion in a fuel cylinder according to claim 9, characterized in that, when the engine is at a medium speed and a large load condition, controlling the opening degree of the exhaust gas control valve to be less than

1 / ^