CN111622840A

CN111622840A - Reciprocating piston type internal combustion engine with adjustable compression ratio

Info

Publication number: CN111622840A
Application number: CN202010642991.9A
Authority: CN
Inventors: 刘金宏
Original assignee: Dongguan Hongda Power Technology Co ltd
Current assignee: Dongguan Hongda Power Technology Co ltd
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2020-09-04

Abstract

The invention relates to a reciprocating piston type internal combustion engine with adjustable compression ratio, which discloses a scheme that a cylinder body is connected with a crankcase by a sliding nested box body, and the compression ratio can be continuously and variably adjusted as required by adjusting the distance and the position between the cylinder body and the crankcase, so that the engine can use a proper compression ratio under various working conditions, and the engine can achieve higher performance and thermal efficiency when running under various working conditions; the emission of pollutant and harmful substances can be effectively reduced; a variety of different grade fuels can be used; the scheme of the invention has simple structure, does not need to change the main parts of the engine greatly, and is easy to produce and implement.

Description

Reciprocating piston type internal combustion engine with adjustable compression ratio

Technical Field

The present invention relates to a reciprocating piston internal combustion engine.

Background

The reciprocating piston type internal combustion engine refers to a piston type internal combustion engine with a piston performing reciprocating linear motion in a cylinder. The four-stroke reciprocating piston engine forms a working cycle by four sequential steps of air intake, air compression, combustion and expansion work and exhaust formed by piston motion, and the working process is formed by continuous repeated cycle. The reciprocating piston type internal combustion engine can be divided into ignition type and compression ignition type according to the ignition mode, and mainly comprises a gasoline engine and a diesel engine respectively.

The thermal efficiency of the existing gasoline engine is about 35 percent generally and reaches 40 percent at most, and the thermal efficiency of the diesel engine is about 40 percent generally and reaches 46 percent at most. Reciprocating piston type internal combustion engines have been developed for more than one hundred years, various technologies are relatively mature, but the thermal efficiency is not high, and further improvement of the thermal efficiency is difficult.

Even though the highest thermal efficiency of the current reciprocating piston type internal combustion engine is not high, in practical use, the reciprocating piston type internal combustion engine still cannot achieve high thermal efficiency under most working conditions, and can only achieve low thermal efficiency under most working conditions, namely, the reciprocating piston type internal combustion engine runs under low thermal efficiency under most working conditions, for example, the highest thermal efficiency of a common gasoline engine which is currently used as an automobile engine is about 37%, but in practical use, the thermal efficiency of the reciprocating piston type internal combustion engine is often not 30% under most working conditions. The reason why the reciprocating piston type internal combustion engine is difficult to reach the ideal maximum thermal efficiency state in the using process is that most of the prior reciprocating piston type internal combustion engines are fixed compression ratio engines, and the maximum thermal efficiency state can be reached only under specific working conditions, namely the working conditions suitable for the compression ratio of the reciprocating piston type internal combustion engine, the ideal running state of the engine under the corresponding power and rotating speed, and the maximum thermal efficiency can be reached. Under other working conditions, such as when the power is small, the required air quantity and the fuel quantity are correspondingly small, the engine reduces the air intake quantity through adjusting the intake valve, and the corresponding compression ratio of the actual air intake quantity cannot reach the marked compression ratio of the engine, so the actual compression ratio of the engine at the moment is low, the thermal efficiency of the engine is also low, and due to the fact that the actual working conditions are diversified when the automobile runs, the automobile cannot run under ideal conditions under most conditions, namely the ideal thermal efficiency is difficult to achieve under most conditions. For example, when the automobile runs on an expressway and an urban road, the fuel efficiency is completely different, and the oil consumption is greatly different. At low power, the fixed compression ratio engine has a relatively low thermal efficiency and also has a relatively low torque and power.

The compression ratio of the engine is adjusted according to different working condition states, so that the engine can work at the compression ratio suitable for the engine under different working conditions, a lower compression ratio is used under high load, a higher compression ratio is used under low load, and higher thermal efficiency can be achieved under different working conditions. Until now, various adjustable variable compression ratio schemes have been developed in the internal combustion engine, but the variable compression ratio schemes are all complex, so that the design and manufacturing cost of the engine is greatly increased, and the complex variable compression ratio schemes cause greater mechanical loss, so that the generated effect is not obvious, and the practical application is difficult to achieve. For example, the core technology of the variable compression ratio SVC engine developed by swedish engineers is to connect the top of the engine body (including the cylinder and the cylinder cover) through a hinge, and rotate the top of the engine body, incline the top of the cylinder body to change the relative position of the combustion chamber and the top surface of the piston, change the volume of the combustion chamber, and thus change the compression ratio, and the compression ratio can range from 8:1 to 14: 1; the hinge type connection makes the machine body difficult to seal, and because the pressure and the vibration between the piston and the cylinder cover are large, the hinge type stop block structure is difficult to ensure the stability of the machine body, and finally, the cost is too high to put into production. The VC-Turbo variable compression ratio engine only produced daily, which can be actually produced in mass and applied at present, is different from the crank connecting rod structure of the traditional engine in the scheme of the VC-Turbo variable compression ratio engine produced daily, and the VC-Turbo variable compression ratio engine produced daily is an original multi-connecting rod system, wherein a crank pin lever is arranged on a shaft neck, one end of the crank pin lever is connected with a piston connecting rod, the other end of the crank pin lever is connected with a control connecting rod, the control rod is connected with an eccentric shaft, and the compression ratio can be; stepless switching between 8:1 (high performance) and 14:1 (high efficiency) of the compression ratio of the engine can be realized. The variable compression ratio technology of an MCE-5 engine of French company is similar to that of a VC-Turbo engine of Nissan products, a lever with gears is used for connecting a plurality of connecting rods, the maximum characteristic is that a piston guided by a ball bearing system is used, the piston and the connecting rod of the piston are in rigid connection, and the piston does not generate radial pressure and slapping on a cylinder. The VC-Turbo engine and the MCE-5 engine both use a multi-connecting-rod and lever structure, so that the engine structure is very complex, particularly, the stress on the shaft neck used as a lever fulcrum is multiplied, the mass and the mechanical loss of a motion mechanism of the engine are increased on the whole, although the power and the thermal efficiency of the engine are improved compared with those of a common engine, the power and the thermal efficiency of the engine do not have better advantages compared with those of the current engine with the highest performance, but the design and manufacturing cost of the engine is greatly increased, and the mechanical complexity also inevitably causes the increase of the failure rate; for example, inflixidi QX50, which carries a variable compression ratio engine, compares with audi Q5 and bme X3, both in urban road and highway tests, which do not offer any advantage in terms of power and fuel efficiency, even doubts about the efficiency of the variable compression ratio engine solution.

The problem that is difficult to solve at present is how to enable an engine to meet the requirement of achieving ideal power and thermal efficiency under various working conditions, and to design and produce a simple and low-cost variable compression ratio engine scheme capable of achieving high thermal efficiency and high power performance under different working conditions.

Disclosure of Invention

In order to enable the engine to achieve corresponding ideal strong power performance and high thermal efficiency under different working conditions, a variable compression ratio engine is required to be used, and the engine is required to adapt to compression ratio under different working conditions; how to realize the engine scheme which can achieve stronger power and high thermal efficiency under different working conditions is a problem which is difficult to solve; the invention provides a reciprocating piston type internal combustion engine scheme with adjustable compression ratio, which can completely solve the problems.

The scheme of the reciprocating piston type internal combustion engine is closely related to the structure of the engine body, and the engine body of the reciprocating piston type internal combustion engine generally comprises four parts, namely a cylinder cover, a cylinder body, a crankcase, an oil storage tank and the like from top to bottom in sequence; the cylinder head is a separate component that makes up the combustion chamber, usually in combination with the air distribution structure; the cylinder block and the crankcase of the prior internal combustion engine are usually combined into a whole to form a machine body, because the pressure or the pulling force generated between the cylinder block and the crankshaft is very large, the side pressure of the cylinder block is also relatively large, the vibration between the cylinder block and the crankshaft is also very strong, the combination of the cylinder block and the crankshaft is favorable for the compactness and the stability of the machine body of the engine, and the machine body is easy to overcome various stresses such as the pressure, the pulling force and the like and.

The scheme of the invention is that the body of the reciprocating piston type internal combustion engine is divided into two parts, the part above the cylinder cover and the cylinder body is an upper body, the part below the crankcase and the oil storage tank is a lower body, the cylinder body and the crankcase are connected by a sliding nested box body, and the box body nest between the cylinder body and the crankcase is sealed by an oil seal to prevent the leakage of the engine oil; a plurality of sliding columns fixedly connected are arranged outside the crankcase, a sliding sleeve ring fixedly connected correspondingly is arranged outside the cylinder body (the sliding sleeve ring and the cylinder body can be also exchanged, the crankcase is fixedly connected with the sliding sleeve ring, and the cylinder body is fixedly connected with the sliding columns), so that the sliding sleeve ring is sleeved on the sliding columns and can slide along the sliding columns, the sliding direction is consistent with the sliding direction of the nested and connected box body, and the cylinder body and the crankcase also correspondingly slide to change the distance and the position between the cylinder body and the crankcase; the other end of the crankcase is fixed with the sliding column, the sliding columns are connected with each other through a beam frame to form a rigid fixing frame, a positioner is arranged between the fixing frame and the cylinder block along the sliding direction, the positioner is a component capable of adjusting and fixing the sliding position, for example, a hydraulic positioner or a spiral positioner is used, the cylinder block and the crankcase can slide through the sliding sleeve ring and the sliding column by adjusting the positioner, and the positioner can be fixed at any sliding point to fix the positions of the cylinder block and the crankcase; in order to achieve tighter and more accurate positioning and better rigidity, a plurality of positioners can be uniformly arranged between the connections; the compression ratio of the reciprocating piston type internal combustion engine is adjusted by adjusting the distance and the position of the cylinder block and the crankcase.

The case between the cylinder block and the crankcase is connected in a nested manner, the distance can be changed by sliding, but the case is difficult to bear large stress and vibration, so a sliding guide member capable of bearing large stress and vibration is needed, and the sliding column and the sliding sleeve ring are members which have the functions of sliding guide and bearing tensile force, pressure and lateral stress and also weaken and prevent vibration, so the sliding column and the sliding sleeve ring are required to have enough stability and rigidity when being fixedly connected with the crankcase and the cylinder block respectively.

The fixing frame connected with the sliding column can play a role of stabilizing the sliding column, and the positioner between the fixing frame and the cylinder block can adjust and fix the distance and the position between the cylinder block and the crankcase. The mount needs to withstand the compression forces and the tension forces when the piston is compressing and expanding to perform work, and vice versa when the engine is sucking intake air, so the mount must also be sufficiently stable and rigid.

In order to stabilize the positioning and reduce vibration, a strong compression spring can be added between the cylinder block and the crankcase at the position of the positioner, and the cylinder block and the crankcase are compacted.

The specific structure of the nested chassis of the reciprocating piston type internal combustion engine is shown in figure 1, wherein figure 1 is a top view structural diagram of a nested connection transverse section of a body box body, and the figure is marked as follows: 1. the engine comprises a slip collar, 2 sliding columns, 3 engine block nested cases, 4 crankcase nested cases, 5 positioners, 6 engine block external wing plates and 7 engine block external reinforcing ribs. In fig. 1, a cylinder block nested case (3) is nested outside a crankcase nested case (4) inside, and the two cases are sealed by oil seals and are connected in a sliding manner. The two sides of the cylinder body case are respectively provided with a plurality of slip ring rings (1), a plurality of sliding columns (2) and a plurality of locators (5), and in order to strengthen the connection and fixation of all the parts, two sides of the cylinder body case are respectively provided with a cylinder body outer wing plate (6), so that the slip ring rings (1) and the locators (5) can be connected and fixed on the cylinder body outer wing plates (6), all the parts are firmly and fixedly connected on the cylinder body, and the rigidity of the cylinder body outer wing plates (6) and the cylinder body case can be enhanced by cylinder body outer reinforcing ribs (7).

The specific structure of the wide side of the reciprocating piston type internal combustion engine is shown in fig. 2, and fig. 2 is a plane view structure diagram of the wide side of the engine body, wherein the drawing is marked as follows: 1. the engine comprises a slip collar, 2 sliding columns, 3 cylinder block nested cases, 4 crankcase nested cases, 8 cylinder block case inclined planes, 9 cylinder blocks, 10 fixing frames, 11 crankcase outer wing plates, 12 crankcase outer reinforcing ribs, 13 crankcase case inclined planes, 14 crankcase and 15 oil storage tanks. As can be seen from fig. 2, the upper body part comprises: slip ring (1), the nested quick-witted case of cylinder block (3), cylinder block quick-witted case inclined plane (8), four positions of cylinder block (9), lower fuselage portion includes: seven positions such as slip post (2), nested quick-witted case of crankcase (4), crankcase pterygoid lamina (11), crankcase external reinforcement rib (12), crankcase machine case inclined plane (13), crankcase (14), batch oil tank (15), also with mount (10) of slip post (2) fixed connection, upper fuselage and lower fuselage form fixed part respectively, can slide along slip post (2) and sliding sleeve ring (1), make nested quick-witted case also along with sliding, thereby change distance and position between upper and lower fuselage two parts, reach the purpose that changes the compression ratio.

The long side of the reciprocating piston internal combustion engine is specifically constructed as shown in fig. 3, fig. 3 is a long side head-up structural view of the body, wherein the drawing is marked as follows: 1. the engine comprises a slip collar, 2 sliding columns, 3 cylinder block nested cases, 4 crankcase nested cases, 5 positioners, 6 cylinder block outer wing plates, 7 cylinder block outer reinforcing ribs, 8 cylinder block case inclined planes, 9 cylinder blocks, 10 fixing frames, 11 crankcase outer wing plates, 12 crankcase outer reinforcing ribs, 13 crankcase case inclined planes, 14 crankcases and 15 oil storage tanks. In the head-up diagram of fig. 3, the upper chassis comprises: slip ring (1), the nested quick-witted case of cylinder block (3), the outer pterygoid lamina of cylinder block (6), cylinder block external reinforcement rib (7), cylinder block quick-witted case inclined plane (8), six positions of cylinder block (9), lower fuselage includes: the compression engine comprises seven parts, namely a sliding column (2), a crankcase nested case (4), a crankcase outer wing plate (11), a crankcase outer reinforcing rib (12), a crankcase case inclined plane (13), a crankcase (14), an oil storage tank (15) and the like, and further comprises a fixing frame (10) fixedly connected with the sliding column (2), a positioner (5) is connected with the fixing frame (10) and the cylinder outer wing plate (6), the fixing frame (10) and the positioner (5) mainly play a role in adjusting and fixing an upper machine body and a lower machine body, the distance between the upper machine body and the lower machine body can be continuously adjusted according to needs and fixed at any point position through adjustment and positioning of the positioner (5), and any compression ratio in an adjusting range is realized. The cylinder body outer wing plate (6) is mainly connected and fixed with a part related to the connection of the upper machine body, and the crankcase outer wing plate (11) is mainly connected and fixed with a part related to the connection of the lower machine body.

The scheme of the invention can freely adjust the distance between the upper machine body and the lower machine body as required through the simplest slidable nested connection of the cylinder body and the crankcase, thereby realizing the adjustment of the compression ratio as required. The scheme of the invention is mainly implemented and adjusted outside the machine body, all parts in the machine body are basically not influenced, the structure composition is relatively simple, but in order to ensure the stress and the stability of the machine body, all parts and used materials which need to be added are more, so the weight of the whole machine body can be increased more. Compared with the prior fixed compression ratio engine, the scheme mode of the invention is most similar, most of mechanical parts do not need to be changed, and when the engine is fixed in position, the engine is actually equivalent to the engine with the fixed compression ratio, but the scheme of the invention can ensure that the engine can use the proper compression ratio under various working conditions to achieve higher thermal efficiency; in other types of variable compression ratio engines, mechanical parts such as connecting rods are changed, and therefore various performances of the engines are possibly affected.

The scheme of the invention is suitable for the reciprocating piston type internal combustion engine with an in-line multi-cylinder structure, but for engines with a V-shaped cylinder body structure or other cylinder body structures, the cylinder bodies are not in the same plane, and the nested sliding connection of the cylinder box bodies is difficult to perform, so the scheme is difficult to be applied.

It should be noted that, particularly, increasing the compression ratio is a main factor for increasing the thermal efficiency of the engine; the variable compression ratio engine can carry out adaptive compression ratio adjustment according to different working conditions, so that the engine can realize relatively high thermal efficiency under different working conditions; however, for a fuel engine, detonation is an important factor restricting the improvement of the compression ratio, the performance and the thermal efficiency of the engine, particularly for a gasoline engine, detonation is one of the biggest bottlenecks in improving the compression ratio and the thermal efficiency, when the compression ratio is high, the mixed gas mixed with fuel in a combustion chamber can be subjected to compression ignition before a piston reaches a top dead center, the detonation and detonation phenomena are easy to generate, and therefore the improvement of the compression ratio and the fuel efficiency is restricted. To fundamentally improve the thermal efficiency of the engine, it is not sufficient, if the compression ratio is raised only at a small power so as to raise the efficiency by raising the expansion ratio, but it is also meaningless. The vehicles currently using variable compression ratio engines do not have particularly higher fuel efficiency than the conventional excellent vehicles, and the restriction of knocking is the most important reason, in addition to the mechanical structural reason. Only by improving the compression ratio through the variable compression ratio and realizing the change of the fuel combustion mode of the engine, the improvement of the compression ratio and the thermal efficiency can be fundamentally realized. For example, a gasoline engine can realize compression ignition and ignition through a lean-burn combustion mode, thereby realizing higher compression ratio and thermal efficiency; it is also possible to achieve a higher compression ratio by increasing the explosion limit of knocking or the like, such as decreasing the fuel mixture concentration to increase the explosion limit of fuel combustion. According to different requirements, different combustion modes are adopted under different working conditions, or different fuel concentrations are used, or proper air inflow is used, so that the highest compression ratio used under the current working condition and the same fuel quantity can be adjusted as far as possible, and higher thermal efficiency is obtained.

For a gasoline engine, the scheme of the reciprocating piston type internal combustion engine with the adjustable compression ratio can effectively reduce the emission of pollutants and harmful substances. The air-fuel ratio of the mixed gas of the gasoline engine is 12-14, the power is the maximum, under the condition, the gasoline engine carries out anoxic combustion and can generate a large amount of carbon monoxide, one oxygen molecule in the combusted working medium gas is split into two oxygen atoms, each oxygen atom is recombined to generate a gas molecule (carbon monoxide or water), the increasing ratio of the mole number (the amount of substances) is the highest, the air quantity is small, the temperature of the working medium gas is higher, the working medium gas has the maximum pressure increasing ratio under the state, and the thermal efficiency of the working medium gas is the maximum; however, because the air ratio is small, high temperature is easily generated during combustion, and nitrogen oxides are easily generated; moreover, the oxygen-deficient combustion also leads to incomplete combustion, and Hydrocarbons (HC) remain; therefore, under the condition of oxygen-poor combustion of the gasoline engine, a large amount of pollutant and harmful substances are discharged, and a three-way catalytic converter is required to be used for waste gas treatment so as to reduce the pollutant and discharge. The performance and efficiency of an engine can be generally considered when a gasoline engine of an automobile is adjusted, anoxic combustion with a lower air-fuel ratio can be used when idling, low-power and low-load and high-load are carried out, and a large amount of harmful pollutant emission can still be generated inevitably even if an exhaust gas treatment measure is taken. For the fixed compression ratio engine, under the working condition of low power and low load, oxygen-poor combustion is carried out, and some engines also use exhaust gas recirculation technology of exhaust gas reuse because the used air quantity is less, the actual compression ratio is quite low, and even if the pressure rise ratio of working medium gas reaches higher, the total thermal efficiency is still quite low. The scheme of the internal combustion engine with the adjustable compression ratio can completely use the air-fuel ratio of excess air, even use a lean-burn compression ignition combustion mode, so that the compression ratio can reach a high level, the heat efficiency of the internal combustion engine can be greatly improved, and harmful pollutants generated during oxygen-deficient combustion can not be generated. Of course, the present invention can also use oxygen-deficient combustion, and the performance and thermal efficiency will be much improved due to much higher compression compared to previous engines, but this is not necessary at all in low power and low load situations, because the present invention can achieve higher thermal efficiency using lean-burn combustion and does not produce harmful pollutants.

For fuel oil fuels with different labels, the engine can adjust the proper compression ratio according to the requirement, can use gasoline fuels with various labels, and can effectively inhibit and prevent the occurrence of deflagration by using the proper compression ratio according to the fuel oil with different labels; even if the engine is made of materials that provide adequate performance, the engine can be designed to be an internal combustion engine that can use a variety of different types and grades of fuel, such as gasoline fuel, and diesel fuel.

The invention has the advantages that the structure and the composition are simple, the main parts of the prior fixed compression ratio engine do not need to be greatly changed, and the production and the implementation are easy; the structure is simple and direct, and the side effect is small; generally, combustion is carried out by using a larger air-fuel ratio, so that the emission of pollutant and harmful substances can be effectively reduced; a variety of different grade fuels can be used; the compression ratio is easy to adjust according to requirements, and the high performance and the high thermal efficiency can be achieved for the operation of the engine under various working conditions.

Drawings

The figures and their designations are explained below.

FIG. 1 is a top view in transverse section of a nested fuselage-box connection.

Fig. 2 is a plan view of the wide side of the fuselage.

Fig. 3 is a long side view of the body in elevation.

The labels in the figure are: 1. a slip collar, 2 sliding columns, 3 engine case nested with cylinder block, 4 engine case nested with crankcase,

5. a locator, 6, an outer wing plate of the cylinder body, 7, an outer reinforcing rib of the cylinder body, 8, an inclined plane of a case of the cylinder body,

9. a cylinder body, 10 a fixed frame, 11 a crankcase external wing plate, 12 a crankcase external reinforcing rib,

13. crankcase chassis inclined plane, 14 crankcase, 15 oil storage tank.

Detailed Description

A reciprocating piston internal combustion engine with adjustable compression ratio.

The embodiment of the invention takes a 1.6-liter four-cylinder turbocharged direct injection gasoline engine as a prototype to carry out improved design, such as the construction scheme of figures 1, 2 and 3. This example differs from the prototype in that the cylinder block and crankcase are separate components, and are slidably nested in a nested chassis. As shown in figure 1, a cylinder block nested case (3) is arranged outside, a crankcase nested case (4) is arranged inside, the cylinder block nested case and the crankcase nested case are nested and connected together, and the joints are sealed by oil seals to prevent oil leakage and can slide with each other. As shown in fig. 1 and fig. 3, two fixed cylinder block outer wing plates (6) are respectively arranged at two sides outside the cylinder body, and three slip rings (1), four locators (5) and two cylinder body outer reinforcing ribs (7) are fixed on each cylinder block outer wing plate (6); the positioner is a controllable hydraulic piston, and the distance between the cylinder body and the crankcase can be adjusted by adjusting the length of the hydraulic piston. As shown in fig. 3, two fixed crankcase external wing plates (11) are respectively arranged at two outer sides of the crankcase, and three sliding columns (2), four locators (5) and five crankcase external reinforcing ribs (12) are fixed on each crankcase external wing plate (11); the sliding column (2) is rigidly connected with a fixed frame (10), and two ends of the positioner (5) are respectively connected with the fixed frame (10) and an external wing plate (6) of the cylinder body.

In order to make the connection between the cylinder block and the crankcase more compact and stable, the engine of the embodiment adds a strong spring between the outer wing plate (6) of the cylinder block and the outer wing plate (11) of the crankcase at the position of each locator (5), so that the case of the cylinder block can be tightly pressed on the locator, and the deviation shake and vibration of the cylinder block and the upper body can be prevented.

The adjustable compression ratio of the engine of this example is set to be between 8 and 30.

The electric turbocharger is added to the engine, so that the air inlet pressure can be adjusted at any time according to needs, the air inlet quantity of the engine can be adapted to the compression ratio to meet the required working condition, and the power performance of the engine can be adjusted at any time.

The engine of the embodiment has the advantages that in addition to the great change of the cylinder body and the crankcase body, the parts related to the change of the position of the cylinder body and the crankcase body are added, the parts comprise the slip collar (1), the slip column (2), the cylinder body nested case (3), the crankcase nested case (4), the positioner (5) and the like, other main parts of the engine basically do not need to be changed, but the air distribution system is usually combined with the cylinder cover, the power of the air distribution system is generally derived from a crankshaft and is transmitted by a chain or a belt, when the compression ratio is changed, the relative position of the upper body and the lower body is also changed, the transmission of the chain or the belt is affected, so that the compression wheel which can be adjusted along with the change of the compression ratio is added to the chain or the belt transmission, when the compression ratio is increased, the compression wheel is also loosened along with, the power and angle of the chain or belt to the transmission of the air distribution system are not changed.

The working condition and the running mode of the engine. When the engine runs under the working condition of idling or micro power and low load, the engine is adjusted to use larger or even maximum compression ratio, and can use larger air-fuel ratio and compression ignition and lean combustion modes. When the engine works under the working conditions of medium power and medium load, the engine is operated in an ignition and ignition mode, an air-fuel ratio with an excess air coefficient of about 1.2 is used, fuel in each cycle process can be injected at intervals, the premixed excess air coefficient of the first injection is required to be more than 1.6 (in order to prevent the engine from catching fire, the injection during ignition can be increased), the explosion limit is increased by reducing the concentration of mixed gas so as to improve the compression ratio, and the compression ratio is required to be adjusted to be close to a slight detonation level; the rest of the oil in each cycle can be injected into the combustion chamber once or more after the ignition combustion for combustion. When the engine is operating at high power and high load conditions, operating in a light-on-ignition mode, an air-fuel ratio with an excess air ratio of around 0.9 is used, and the premixed excess air ratio for the first injection should be around 1.5, and likewise, the compression ratio should be adjusted to approach a slight knock. When the engine works at the maximum power and the maximum load, the compression ratio is adjusted to be 8 (the actual compression ratio is higher due to turbocharging), the fuel quantity per cycle reaches the maximum, and the mixed gas obtained by premixing the first fuel injection is close to slight detonation, so that as much fuel as possible is subjected to homogeneous mixing.

Estimation of engine performance. The common fixed compression ratio of the prototype engine is about 9.5, the minimum compression ratio of the engine of the embodiment is 8, under the same conditions, the maximum air intake amount per cycle of the engine of the embodiment is more than that of the prototype engine, the maximum fuel consumption amount per cycle is more, and therefore the maximum power and the maximum torque of the engine of the embodiment are both much higher than those of the prototype engine. The engine of the embodiment is provided with the electric turbocharger, can quickly reach a high-load state, and has quick and strong power response. The engine of the embodiment can improve the explosion limit by reducing the premixed fuel amount and use the compression ratio as large as possible under the condition of the same fuel amount at the medium and high load, can effectively inhibit and prevent the occurrence of the detonation, and greatly improves the thermal efficiency, and compared with a prototype engine, the compression ratio and the thermal efficiency are both much higher. When the engine of the embodiment is in an idling state or a micro power low load state, a large air-fuel ratio can be used, compression ignition and lean combustion modes are used, the compression ratio and the heat efficiency are greatly improved, and the emission of pollutant and harmful substances can be effectively reduced due to the use of an excessive air-fuel ratio and the compression ignition mode. The adjustable compression ratio range of the engine of the embodiment is 8-30, but because a compression ignition combustion mode and a lean combustion mode are used and a two-stage turbocharger is used, the actual compression ratio is only limited by the performance of the engine and actual adjustment results, if the performance of the engine can provide enough support, the compression ratio can even exceed 30, even if the constant-volume heating model with the compression ratio of 30 is calculated, the theoretical maximum thermal efficiency can reach 67 percent, and the actual maximum thermal efficiency can reach more than 50 percent, but because the operation of the engine is simultaneously limited by environmental protection standards, the maximum combustion temperature is limited, the actual power and the power can not be very high in the state of the maximum thermal efficiency. The prototype engine is a fixed compression ratio engine, when the prototype engine is operated under a low-power low-load working condition, the fuel quantity is reduced, the fuel quantity per cycle is also reduced, the air consumption is also reduced, but the space of a combustion chamber is not changed, so that the actual compression ratio is much smaller, and the thermal efficiency is relatively lower. The engine of the embodiment of the invention can adjust the compression ratio at any time to be suitable for corresponding working conditions, can use larger air-fuel ratio when operating under the working conditions of low power and low load, improves the explosion limit of detonation, can use larger compression ratio to obtain higher thermal efficiency, so the engine can keep higher thermal efficiency under various working conditions and has higher fuel efficiency under various working conditions. The engine of this example may also use various different grades of gasoline fuel.

Claims

1. A reciprocating piston internal combustion engine, characterized by: the reciprocating piston type internal combustion engine is divided into two parts, wherein the part above a cylinder cover and a cylinder block is an upper body, the part below a crankcase and an oil storage tank is a lower body, the cylinder block and the crankcase are connected by a slidable nested box body, and the box body between the cylinder block and the crankcase is nested and sealed by an oil seal to prevent the leakage of engine oil; a plurality of sliding columns fixedly connected are arranged outside the crankcase, a sliding sleeve ring fixedly connected correspondingly is arranged outside the cylinder body (the sliding sleeve ring and the cylinder body can be also exchanged, the crankcase is fixedly connected with the sliding sleeve ring, and the cylinder body is fixedly connected with the sliding columns), so that the sliding sleeve ring is sleeved on the sliding columns and can slide along the sliding columns, the sliding direction is consistent with the sliding direction of the nested and connected box body, and the cylinder body and the crankcase also correspondingly slide to change the distance and the position between the cylinder body and the crankcase; the other end of the crankcase is fixed with the sliding columns, the sliding columns are connected with each other through a beam frame to form a rigid fixing frame, a positioner is arranged between the fixing frame and the cylinder block along the sliding direction, the positioner is a component capable of adjusting and fixing the sliding position, the cylinder block and the crankcase can slide through the sliding sleeve ring and the sliding columns by adjusting the positioner, and the positioner can be fixed at any sliding point to fix the positions of the cylinder block and the crankcase; in order to achieve tighter and more accurate positioning and better rigidity, a plurality of positioners can be uniformly arranged between the connections; the compression ratio of the reciprocating piston type internal combustion engine is adjusted by adjusting the distance and the position of the cylinder block and the crankcase.