1857results about "Cylinder heads" patented technology

The present invention provides a water circulation structure for a motorcycle engine, belonging to the technical field of motorcycles. It solves the technical problems of insufficient compactness of the existing engine water circulation structure and affecting the circulation effect. The water circulation structure of this motorcycle engine includes a reversing housing located on one side of the cylinder block. The reversing housing has a liquid inlet chamber and a liquid outlet chamber separated by a thin wall. The thin wall has a liquid passing port communicating the liquid inlet chamber and the liquid outlet chamber. Both ends of the water circuit are respectively communicated with the liquid inlet chamber and the liquid outlet chamber. The inner wall of the liquid inlet chamber has a liquid inlet for communicating with the cooling water tank, and the inner wall of the liquid outlet chamber has a liquid outlet for communicating with the cooling water tank. The thermostat is located in the liquid outlet chamber, and one end of the thermostat closes the liquid outlet. The other end of the thermostat is arranged towards the liquid passing port. After being heated, the thermostat can close the liquid passing port and open the liquid outlet. The present invention can ensure a sufficient circulating cooling effect while improving the structural compactness.

The invention discloses an air cooling system of an engine and the engine, the air cooling system comprises an engine body and a cooling system, the cooling system comprises a fan assembly, and the fan assembly comprises a fan and a fan cover provided with an air outlet I; the wind scooper is used for forming a cooling air duct for cooling the engine body, and the cooling air duct communicates with the air outlet I; the flow guide piece is arranged in the cooling air duct and used for forming a cooling air branch air duct to distribute and guide the cooling air to the area, close to the air inlet side, of the cylinder head spark plug I; according to the air cooling system of the engine and the engine, the air guide cover is connected with the fan cover, so that the cooling air channel for cooling the cylinder body and the cylinder head is formed, sufficient cooling of the cylinder body and the cylinder head can be achieved, meanwhile, the cooling effect on a spark plug can be improved by arranging the flow guide piece to guide cooling air to the spark plug area of the cylinder head, and the service life of the engine is prolonged. The utilization rate of cooling air is increased, heat dissipation of all parts of the engine is uniform, and therefore the requirements for dynamic property, economical efficiency and reliability of the engine are met.

An internal combustion engine has a uniblock that defines a blind cylinder bore that terminates within the uniblock. A piston is inserted into the cylinder bore from a bottom end of the cylinder bore. Parallel first and second vertical planes extend along first and second lateral sides of the cylinder bore. A cylinder zone being defined between the first and second vertical planes. A crosshead is coupled to the piston. A first crankshaft has a first crankshaft axis that extends parallel to the first vertical plane and that is positioned outside of the cylinder zone. A second crankshaft has a second crankshaft axis that extends parallel to the second vertical plane and that is positioned outside of the cylinder zone. The first crankshaft is coupled to the crosshead with a first connecting rod and the second crankshaft is coupled to the crosshead with a second connecting rod.

An internal combustion engine to reduce abrasion with a piston while retaining oil film on an upper portion of a cylinder includes: a cylinder block that includes a cylinder, and a piston that is stored in the cylinder in a manner capable of reciprocating along an axis line of the cylinder, in which the cylinder includes a multi-bulging inner circumference portion in which a diameter in a thrust-anti thrust direction is a minimal diameter.

An engine and a vehicle comprising same. The engine comprises a main cylinder body (10), end covers (30), a timing cover (50), and an oil pan (60), wherein a left cylinder body (101) and a right cylinder body (102) of the main cylinder body are arranged in the left-right direction; the left cylinder body and the right cylinder body define a crankshaft cavity (20); the left cylinder body and the right cylinder body are each provided with a combustion chamber (11) extending in the horizontal direction; the end covers comprise a left cylinder cover (301) provided on the left side of the left cylinder body and a right cylinder cover (302) provided on the right side of the right cylinder body; the timing cover is located on one side of the main cylinder body and is fixed to at least one of the left cylinder body, the right cylinder body, the left cylinder cover and the right cylinder cover; the oil pan is arranged on the lower portion of the main cylinder body and is communicated with the crankshaft cavity.

The invention discloses a cam shaft box, an engine and a vehicle, the cam shaft box comprises an ignition coil mounting hole, the ignition coil mounting hole is used for mounting an ignition coil, the ignition coil mounting hole comprises a sealing section, and the ignition coil is matched with the inner wall of the sealing section; and the exhaust hole is formed in the side wall of the ignition coil mounting hole and located in the lower side of the sealing section, and the ignition coil mounting hole is communicated with the outside through the exhaust hole. The exhaust hole is formed in the lower side of the sealing section, exhaust does not need to pass through the sealing section, and exhaust is smoother.

The embodiment of the invention provides a cylinder cover assembly, a horizontally-opposed engine, a hybrid power assembly and a vehicle, the cylinder cover assembly comprises a body, an air flow channel and a cooling liquid channel are arranged in the body, and the body comprises a lower side and an upper side which are arranged in a deviating mode in the vertical direction; the airflow channel comprises an air inlet and an air outlet, the air inlet is formed in the lower side, and the air outlet is formed in the upper side; the cooling liquid channel surrounds at least part of the airflow channel and comprises a water inlet and a water outlet, the water inlet is formed in the lower side, and the water outlet is formed in the upper side. The air inlet of the airflow channel and the water inlet of the cooling liquid channel are formed in the lower side, and the exhaust port of the airflow channel and the water outlet of the cooling liquid channel are formed in the upper side, so that the influence of bubbles on cooling liquid flowing can be reduced, accumulation of the bubbles can be avoided, and the cooling effect of the cylinder cover assembly can be improved.

The invention discloses an efficient and high-precision numerical simulation method for an air cooling field of a diesel engine. The method comprises the following steps: (1) based on a porous medium model theory, using a defined porous medium model to replace an internal structure of an original radiator to establish a three-dimensional radiator simplified model containing a porous medium area; (2) according to the dimensionless similarity of speed distribution of a fan rotational flow main body section, the dissipation rate generation and diffusion term coefficient of a turbulent energy dissipation equation in a standard k-epsilon turbulence model are adjusted, (3) the standard k-epsilon turbulence model is adopted for a forced convection dominant area, the k-epsilon turbulence model corrected by the turbulent flow viscosity coefficient is adopted for a natural convection dominant area, and the turbulent flow viscosity coefficient of the natural convection dominant area is corrected. In order to guarantee smooth and stable transition of turbulence viscosity, a k-epsilon turbulence model corrected by turbulence viscosity coefficient linear interpolation is adopted for a transition area of forced convection and natural convection; and (4) a diesel engine air cooling field numerical simulation technology based on partition processing is adopted. According to the method, high-precision numerical simulation on the basis of a small number of grids is realized.

A cylinder head for an internal combustion engine with a combustion chamber, including a base body with a combustion chamber wall for closing off the combustion chamber of the internal combustion engine, the base body having a hole which penetrates the combustion chamber wall with a first opening and includes a contact section with a tapered inner contact surface; and a sealing sleeve which has a sealing section with a tapered outer sealing surface, wherein the sealing sleeve and the base body are clamped together in such a way that the contact surface and the sealing surface are in sealing contact, and wherein at least one of the contact section and the sealing section is at least partially plastically deformed.

In order to enable improvement with respect to recycling performance, achieve further reduction in weight, and improve environmental performance, a cylinder liner (30) according to the present disclosure has a structure in which, out of an inner face (21i) of a cylinder (21) in a reciprocating engine, the cylinder liner is provided in only a partial region over which a piston ring (50) fit onto a piston (40) that performs reciprocal motion in the cylinder (21) slides, and a liner entire length L along an axial direction of the cylinder (21) is smaller than an inner diameter B of the cylinder, and recessed and protruding forms are formed on one lower end portion (30d) that is an end portion toward a bottom dead center side of the piston ring (50) in the axial direction.

The invention provides a liquid ammonia in-cylinder direct injection engine combustion system and method with an active pre-combustion chamber, and relates to the technical field of internal combustion engines, the liquid ammonia in-cylinder direct injection engine combustion system comprises a cylinder cover and a cylinder sleeve arranged below the cylinder cover, the pre-combustion chamber is vertically arranged in the center of the cylinder cover, a liquid ammonia injector is arranged on one side of the pre-combustion chamber, and the active pre-combustion chamber is arranged in the cylinder sleeve. A hydrogen ejector and a spark plug are arranged on the pre-combustion chamber; and spraying holes are formed in the pre-combustion chamber and located in the bottom of the pre-combustion chamber, and the spraying holes of the pre-combustion chamber face one side of the liquid ammonia ejector. According to the liquid ammonia in-cylinder direct injection engine combustion system and method with the active pre-combustion chamber, the effect that diffusion combustion is promoted through premixed combustion of ammonia fuel is achieved, accurate control over the combustion initial point and the heat release rate is achieved, and the requirements for the low hydrogen energy ratio, high ignition efficiency and high heat efficiency of an ammonia fuel engine in the full working condition range are met.

The utility model discloses a combined type engine cylinder block convenient to cool, which comprises an engine cylinder block body, a piston groove arranged in the middle of the engine cylinder block body, an engine cylinder cover arranged at the upper end of the engine cylinder block body in an attached mode and a cooling pipe, and the cooling pipe is installed in a connecting groove in a clamping mode. And cooling liquid is arranged in the cooling pipe, the mounting mechanisms are symmetrically arranged on the left side and the right side of the engine cylinder cover, and the mounting mechanisms are used for limiting the position between the engine cylinder cover and the engine cylinder block body. According to the combined type engine cylinder block convenient to cool, cooling liquid is introduced into the engine cylinder block body, so that heat in the engine cylinder block body can be taken out, the heat dissipation and cooling effects are achieved, the cooling pipes are bent, the actual heat dissipation area is increased, the heat dissipation efficiency is improved, and through the arrangement of the mounting mechanism, the positioning rod and the mounting cap, the cooling effect is improved. And the engine cylinder block body can be conveniently disassembled, maintained and overhauled.

The air cylinder cover comprises a body, a plurality of cylinder openings are formed in the body, the cylinder openings and a cylinder body are used for forming a combustion chamber in a surrounding mode, and the multiple cylinder openings are sequentially arranged in the first direction at intervals; a first connecting hole is formed in the body, and a fixing piece for connecting the body and the cylinder body passes through the first connecting hole; a second connecting hole is formed in the body, and a connecting piece for connecting the body and the cam bearing seat passes through the second connecting hole; the first connecting holes and the second connecting holes are arranged at intervals in the second direction perpendicular to the first direction. By means of the arrangement, the torque of the cylinder cover in the front-back direction (namely the extending direction of the cam shaft) can be balanced, deformation or displacement possibly caused by staggered arrangement of the cam bearing seat and the cylinder cover bolt on the cylinder cover in the front-back direction is avoided, and therefore it is guaranteed that stress on the cylinder cover in the up-down direction and the front-back direction is relatively uniform; and the structural strength and the bearing capacity of the cylinder cover are improved.

The utility model discloses a cylinder block of a two-cylinder engine, comprising a cylinder body of a gantry-type structure, wherein the cylinder body is provided with two cylinder holes, wherein the axis of the cylinder holes and the axis of the crankshaft hole are not in the same plane, wherein a closed water jacket assembly is provided on the top of the cylinder body, wherein a plurality of water jackets in the closed water jacket assembly are arranged along the outer peripheral wall of the cylinder hole, wherein an inter-cylinder water hole connected with the water jacket is provided between the two cylinder holes, wherein the inter-cylinder water hole forms a V-shaped distribution with adjacent water jackets; wherein the cylinder body is provided with a balancing shaft mounting hole for mounting the balancing shaft; wherein the cylinder body is provided with a main oil circuit, a main oil supply oil circuit, and an auxiliary oil supply oil circuit, wherein the gantry-type cylinder body is adopted, and wherein the closed water jacket assembly and the balancing shaft mounting hole are provided on the top of the cylinder body, thereby greatly improving the structural strength of the top surface of the cylinder body, reducing the deformation of the cylinder hole, and significantly improving the NVH performance of the engine after assembling the balancing shaft.

The V-shaped engine cooling water jacket comprises a first water distribution cavity and a second water distribution cavity which are communicated through a water inlet cavity, the first water distribution cavity and the second water distribution cavity are each provided with a plurality of water outlets, and the water outlets correspond to engine cylinders one to one; a water inlet is formed in the position, close to the second water distribution cavity, of the water inlet cavity, a first flow guide structure and a second flow guide structure are arranged at the water inlet, the first flow guide structure conducts flow guide on cooling liquid entering the second water distribution cavity, and the second flow guide structure conducts flow guide on a water outlet, close to the water inlet, of the second water distribution cavity; the communicated water inlet cavity, the first water distribution cavity and the second water distribution cavity form a U-shaped structure; according to the cooling water jacket suitable for the V-shaped engine, the cooling water jacket forms a three-dimensional structure of a smooth channel in the water inlet cavity, so that the fluidity of cooling liquid is improved, the flowing resistance of the cooling liquid is reduced, and the distribution uniformity of the cooling liquid is ensured.

The present invention discloses an all-terrain vehicle and its engine. The engine includes: a cylinder provided with an exhaust port and a first cooling channel; a crankcase disposed below the cylinder, the top of the crankcase being spaced a predetermined distance from the exhaust port, the crankcase including a second cooling channel communicating with the first cooling channel; a water pump disposed on one side of the crankcase; a cylinder inlet pipe, one end of the cylinder inlet pipe being connected to the water pump, the cylinder inlet pipe being fixedly attached to the top of the crankcase and spaced apart from the cylinder, and the other end of the cylinder inlet pipe communicating with the second cooling channel. Thus, the cylinder inlet pipe and the exhaust pipe can be effectively spaced apart further, so that the high-temperature exhaust pipe can be prevented from affecting the low-temperature cylinder inlet pipe, the cooling water temperature of the cylinder inlet pipe can be effectively reduced, the working reliability of the engine can be ensured, and the fuel efficiency of the engine can be improved.

An engine system in which blow-by gas with a specific gravity less than 1 with reference to air is generatable includes a cylinder block. The cylinder block includes a cylinder and a crank chamber which are arranged in an up / down direction, the crank chamber being positioned below the cylinder. An internal peripheral face of the cylinder block has a ventilation port that connects to a ventilation passage that connects an internal space of the crank chamber with an external space out of the cylinder block, and that is open. The ventilation port is placed above a center in the up / down direction in the crank chamber.

The application discloses a cylinder liner, an engine and a ship, and belongs to the technical field of engines.The cylinder liner comprises a first pipe, a second pipe and a first heat-conducting layer.The first pipe has a first through hole penetrating through the first pipe along a first direction, and the first through hole is used for guiding a piston.The second pipe has a second through hole penetrating through the second pipe along the first direction, the first pipe is arranged in the second through hole along the first direction, and the first through hole and the second through hole are communicated.The first heat-conducting layer surrounds the first pipe, and the first heat-conducting layer is arranged between the first pipe and the second pipe along a direction perpendicular to the first direction, and is connected with the first pipe and the second pipe respectively.The cylinder liner is divided into the first pipe and the second pipe, different materials can be used, the cylinder liner can ensure smooth friction with the piston, and better compactness can be obtained, so that the possibility of cavity erosion of the cylinder liner is reduced.

The utility model discloses an air cylinder assembly with a crankshaft cavity exhaust channel and an engine, and relates to the technical field of engines. Comprising a cylinder block body, and a plurality of crankshaft cavities communicating side by side are formed in the cylinder block body; a main blow-by channel is formed in the front end of the cylinder block body, and an auxiliary blow-by channel is formed in the rear end of the cylinder block body. A front-end air communicating hole is formed in the position, close to the front end of the air cylinder body, of the first crankshaft cavity and can communicate with the main air communicating channel. A rear-end blow-by hole is formed in the tail crankshaft cavity close to the rear end of the cylinder block body and can be communicated with the auxiliary blow-by channel; one path of oil gas in the crankshaft cavity is discharged to the oil-gas separator gas taking hole through the main blow-by channel via the front-end blow-by hole, and the other path of oil gas is discharged to the oil-gas separator gas taking hole through the auxiliary blow-by channel via the rear-end blow-by hole; and an oil-gas conveying path is prolonged, so that oil-gas separation is more thorough, and the oil-gas separation effect is further improved.

The invention provides an opposed piston two-stroke diesel engine vector air inlet-space injection combustion system which comprises an air cylinder sleeve, an air inlet piston, an exhaust piston and a plurality of oil injectors, and the air inlet piston, the exhaust piston and the inner wall of the air cylinder sleeve are matched to form a combustion chamber. A plurality of vector air inlets and exhaust ports are formed in the positions, close to the air inlet piston and the exhaust piston, of the air cylinder sleeve respectively, each vector air inlet is composed of a direct-flow air port and a vortex air port, and the direct-flow air ports and the vortex air ports are arranged at intervals in the circumferential direction; the number of the oil sprayers is two, and the two oil sprayers are arranged on the center face of the air cylinder sleeve in a staggered mode so that the oil sprayers can be arranged in a reverse vortex mode. The problems that an opposed piston two-stroke diesel engine is insufficient in combustion, low in scavenging efficiency and the like are solved, oil and gas in a cylinder can be rapidly and sufficiently mixed through the system, the combustion process is effectively accelerated, combustion in the cylinder is more sufficient, and the combustion efficiency is improved.

The invention relates to the technical field of generators, and discloses an efficient heat dissipation piston generator which comprises a power generation body mechanism, wind collection and flow guide mechanisms are arranged on the two sides of the power generation body mechanism, and an air inlet and flow guide mechanism is arranged on one side of each wind collection and flow guide mechanism. According to the piston generator with the efficient heat dissipation function, through the arrangement of the power generation body mechanism, the air collection flow guide mechanism, the air inlet flow guide mechanism, the water mist spraying cooling mechanism and the seepage water collection mechanism, an active spraying cooling technology can be adopted in the using process, and micron-sized water mist is evenly sprayed to the surface of a power generation unit through the water mist spraying mechanism; and meanwhile, directional airflow is formed in combination with an air inlet flow guide structure to accelerate evaporation of liquid drops, so that heat is efficiently taken away, and compared with a traditional passive heat dissipation mode, the scheme remarkably improves the heat dissipation efficiency and reduces dependence on the environment wind speed.

The invention provides a glow plug hot surface ignition methanol machine adopting high-pressure rotational flow umbrella spraying, which relates to the technical field of methanol engines, and comprises a combustion chamber defined by a cylinder body, a piston and a cylinder cover, a methanol rotational flow umbrella spraying ejector and a glow plug, the piston is arranged in the cylinder body, and the cylinder cover is arranged at the top of the cylinder body; the piston is connected to the connecting rod; the methanol rotational flow umbrella spraying ejector is arranged in the cylinder cover and is communicated with the combustion chamber; the methanol rotational flow umbrella spraying ejector is used for spraying methanol into the methanol cylinder to form methanol umbrella-shaped spray; the glow plug is arranged in the cylinder cover and is communicated with the combustion chamber; and the glow plug is used for igniting the methanol umbrella-shaped spray sprayed into the cylinder body. According to the invention, the cylinder cover is punched and additionally provided with the glow plug, the methanol rotational flow umbrella spray ejector is arranged in the center of the cylinder cover, the methanol rotational flow umbrella spray ejector ejects methanol umbrella-shaped spray, and the methanol umbrella-shaped spray does not have a fuel rarefied area between methanol oil beams, so that efficient and clean diffusion combustion of the methanol machine can be realized.

The invention discloses an ammonia hydrogen fuel engine combustion system and method, and belongs to the technical field of clean energy, the system comprises a shell, the shell is provided with a combustion chamber, a pre-combustion chamber, an air inlet channel and an exhaust channel, and the pre-combustion chamber, the air inlet channel and the exhaust channel communicate with the combustion chamber; the injection valve set comprises an air inlet channel hydrogen injection valve, a pre-combustion chamber hydrogen injection valve, a direct injection hydrogen injection valve and an air inlet channel ammonia injection valve. The supply assembly comprises a hydrogen supply unit and an ammonia gas supply unit, the ammonia gas supply unit supplies ammonia gas to the combustion chamber through a gas inlet channel ammonia gas injection valve, and the hydrogen supply unit supplies hydrogen gas to the combustion chamber through a gas inlet channel hydrogen injection valve, a pre-combustion chamber hydrogen injection valve and a direct injection hydrogen injection valve; switching of the pure hydrogen premixed combustion mode, the pure hydrogen stratified combustion mode and the ammonia-hydrogen mixed combustion mode is achieved by adjusting the injection valve set and the supply assembly, the problems of abnormal combustion, power reduction and NOX and N2O emission existing on the engine are solved, and the operation stability of the engine is improved.

The utility model discloses an air-cooled engine body which comprises a base and a box body, the bottom face of the base extends downwards to form an air guide plate installation hole, the air guide plate installation hole is used for installing an air guide plate, the lower end of the air guide plate installation hole extends to the position below the base, and the base and the air guide plate form a cooling air channel. According to the engine base, the problems that an existing engine base is low in heat dissipation efficiency and affects engine oil cooling are solved, the air guide plate installation hole is formed in the base in a downward extending mode, the air guide plate is fixed to the lower end of the air guide plate installation hole, the air guide plate is fixed to the lower end of the air guide plate installation hole, and the air guide plate is fixed to the lower end of the air guide plate installation hole. A cooling air channel is formed between the base and the air deflector, airflow is introduced into the cooling air channel through the lower ventilation holes, the heat dissipation capacity of the base is improved, and the cooling speed of engine oil in the engine body is increased.

The invention relates to the technical field of engine cooling, in particular to a cylinder cover cooling water jacket and a cooling control method. The cooling water jacket comprises a lower water jacket, an upper water jacket and a main water jacket; the lower water jacket and the upper water jacket are communicated through an exhaust upper water opening and a middle upper water opening; the upper water jacket is provided with a partition plate, the partition plate partitions one side of the upper water jacket and divides the upper water jacket into an air inlet partition and an air outlet partition, the air outlet upper water opening is located in the range of the air outlet partition, and the middle upper water opening is located between the air outlet partition and the air inlet partition. The main water jacket is located on the side face of the upper water jacket, cooling liquid of the exhaust subarea enters the main water jacket through a water inlet, and the cooling liquid of the air inlet subarea can be converged into the water inlet through a bypass hole formed in the partition plate. Partitioned cooling of the air inlet channel area and the exhaust channel area of the cylinder cover is achieved through the cooling water jacket, the cooling strategy is flexibly adjusted according to different application requirements, and therefore heat management and performance of an engine are optimized.

This invention discloses an exhaust system for a six-cylinder, four-valve engine, including a cylinder head and an exhaust pipe. The cylinder head contains coolant and has several cooling water passages. A guide edge is provided within the cylinder head, and guide holes are formed between the guide edge and the top and bottom surfaces of the cylinder head. A set of mounting holes is located above the guide holes on the front end face of the cylinder head. The exhaust pipe is fixed to the front end of the cylinder head through the mounting holes. The exhaust pipe has a segmented structure, and a sealing structure is provided at the joints of the segments. This invention eliminates dead zones in the coolant flow, improving coolant fluidity and preventing excessively high surface temperatures in the cylinder head's water passages. The installation of long bolts on the exhaust pipe, through control of positioning errors and fitting clearances, ensures that the bolts and holes do not interfere, preventing stress caused by interference and exhaust pipe breakage at high temperatures. The composition of the exhaust pipe has been improved, enhancing its high-temperature resistance.

The invention discloses a combined air inlet two-stage combustion six-stroke engine, and relates to the field of power energy. In order to overcome the defects that in the prior art, a six-stroke engine is insufficient in gas inlet in the secondary combustion stage, poor in oil-gas mixing quality and low in combustion efficiency, according to the technical scheme, the six-stroke engine comprises a combustion chamber assembly, a fuel injector, a transmission mechanism and a gas distribution mechanism; the gas distribution mechanism comprises a gas inlet pipeline, an exhaust pipeline, a gas storage cavity, a gas inlet pipeline valve, a scavenging duct and a scavenging duct one-way valve, the working cycle of the engine comprises two times of gas inlet and two times of oil injection combustion acting, and the gas storage cavity releases gas to supplement fresh air in the combustion chamber in the second time of gas inlet. The combustion chamber assembly comprises a cylinder, a piston and a cylinder cover, the piston reciprocates in the cylinder, and the cylinder and the cylinder cover are closed to form a combustion chamber. The invention is suitable for improving the heat efficiency and output performance of the engine, especially for an internal combustion engine power system requiring multiple combustion work.

The invention relates to the technical field of cylinder sleeves and detection thereof, in particular to a burr-shaped cast-in type cylinder sleeve and a detection method thereof. The cylinder sleeve is made of cast iron and is cast into the cylinder body through a die-casting or gravity casting process, and a plurality of burrs are formed on the peripheral face of the cylinder sleeve. At least one burr meets the following conditions: in the burr-shaped cast-in cylinder sleeve, the diameter of the burr at the position 0.25 mm away from the top end is L1, and the diameter of the burr at the position 0.4 mm away from the top end is L2; and the ratio of the diameter L1 to the diameter L2 is more than or equal to 0.65 and less than or equal to 1.15. The specific shapes of the burrs are limited by limiting the diameter sizes of the two special positions, away from the top end, of the burrs, so that the binding rate between the single burrs and the cylinder body and the binding rate between the cylinder sleeve and the cylinder body are guaranteed, good heat dissipation performance between the cylinder sleeve and the cylinder body is guaranteed, and it is guaranteed that the cylinder sleeve does not deform in the working process.

The invention discloses an engine, a hybrid power assembly and a vehicle, the engine comprises a component to be subjected to oil return and an oil return pump assembly, the component to be subjected to oil return is provided with a plurality of oil return areas, and at least part of the oil return areas are located at the two opposite ends of the component to be subjected to oil return; the oil return pump assembly is provided with an oil return opening, and the oil return opening is connected with the oil return areas at the two opposite ends. Therefore, at least part of the oil return areas are arranged at the two opposite ends of the component to be subjected to oil return respectively, so that the oil return pump assembly can return oil to the component to be subjected to oil return from different positions, the oil return efficiency can be improved, oil return dead angles are eliminated, the oil return pump assembly is not prone to air suction, and then the operation stability of an engine is guaranteed.

The invention provides an opposed-piston two-stroke diesel engine air inlet rotational flow-combined injection combustion system which comprises an air cylinder sleeve, an air inlet piston, an exhaust piston and oil injectors, the air inlet piston and the exhaust piston are correspondingly arranged in the air cylinder sleeve and form a combustion space, and the multiple oil injectors are evenly distributed in the position, corresponding to the combustion space, of the air cylinder sleeve in the circumferential direction. Air inlets and air outlets are formed in the two ends of the air cylinder sleeve in the circumferential direction respectively, the multiple air inlets are matched to form a spiral shape, the air outlets are composed of straight air ports and inclined air ports, external air enters the air cylinder through the air inlets to form air inlet rotational flow, and a formed rotational flow layer pushes waste gas to be exhausted from the air outlets along the axis of the air cylinder sleeve. Fuel oil injected by the multiple oil injectors forms a space oil beam, and the injection direction of the space oil beam is opposite to the rotation direction of air inlet rotational flow formed in the cylinder, so that oil and gas are fully mixed and combusted. According to the invention, oil and gas can be rapidly and fully mixed, the combustion process is improved, and the combustion efficiency is improved.