CN108730014B

CN108730014B - Engine and automobile

Info

Publication number: CN108730014B
Application number: CN201710264758.XA
Authority: CN
Inventors: 苏方旭; 王福志; 马世博; 王沛; 向清华; 张艳青; 贺燕铭; 田安民; 陈桂祥
Original assignee: BAIC Motor Powertrain Co Ltd
Current assignee: BAIC Motor Powertrain Co Ltd
Priority date: 2017-04-21
Filing date: 2017-04-21
Publication date: 2020-03-06
Anticipated expiration: 2037-04-21
Also published as: CN108730014A

Abstract

The invention provides an engine and an automobile, wherein the engine comprises: a compressor; the device comprises a cylinder, a piston rod; the air inlet manifold is connected with the compressor and the air inlet valve respectively; the air return valve is arranged on the combustion chamber and is connected with an air inlet of the air compressor through an air return pipe to form an air passage; when the air return valve is opened, a part of air in the combustion chamber flows to an air inlet position of the compressor through the air passage. The engine and the automobile provided by the embodiment of the invention can realize different working modes, improve the working boundary of the compressor in the Atkinson mode, improve the running efficiency of the supercharger, keep away from surge and improve the charging efficiency of the engine.

Description

Engine and automobile

Technical Field

The invention relates to the technical field of automobile manufacturing, in particular to an engine and an automobile.

Background

With the technology progress of the change day by day, people are pursuing higher and higher quality of life. Automobiles are increasingly indispensable as important means of transportation for improving people's daily lives. People have increasingly stringent requirements on the comfort, safety and reliability of automobiles, so that the requirements on various automobile manufacturers are also increasingly high. In addition, the improvement of advanced processes, structural designs and other modes is also beneficial to automobile manufacturers to save the production cost and increase the market competitiveness of the automobile manufacturers.

The engine is the heart of the automobile, and the performance of the engine is directly related to the quality of the automobile and the riding feeling of passengers.

The atkinson cycle plus boost is a current hot technology combination that reduces engine fuel consumption while maintaining engine torque. The Atkinson cycle is very effective for reducing the oil consumption rate of medium and small loads, but the Atkinson cycle has several natural problems under large load and full load, and the first is that the compression ratio is large and the knocking is high; secondly, the compression stroke intake valve is not closed (the closing time is later than the Otto cycle), the intake air is pressed back to the intake manifold, the pressure of the manifold is high, and the charging efficiency is reduced; thirdly, in the case of a supercharged engine, the manifold pressure is high but the charging efficiency is low, which means that the compressor pressure ratio is high but the gas flow is low, so that low-speed large-load surge is easily generated, and the matching of the supercharger is difficult.

For ease of understanding, FIG. 1 illustrates a valve profile comparison schematic for an Atkinson cycle versus an Otto cycle. Wherein, the abscissa is 0-180 degrees as the power stroke, 180-360 degrees as the exhaust stroke, 360-540 degrees as the intake stroke, and 540-720 degrees as the compression stroke. The valve profiles of the Atkinson cycle and the Otto cycle in an exhaust stroke are not greatly different, the valve profiles in an intake stroke are obviously different, and the closing time of the valve of the Atkinson cycle is delayed compared with that of the Otto cycle. Fig. 2 illustrates a schematic diagram of the difference between the charging efficiency calculated by the atkinson cycle and the otto cycle according to the state of the gas in the intake manifold, wherein the charging efficiency in the full rotation speed range is lower than 0.8 for the atkinson-cycle supercharged engine, and the charging efficiency in the almost full rotation speed range is higher than 0.8 for the otto-cycle supercharged engine. FIG. 3 illustrates a map of the operation of the compressor in an Otto-cycle supercharged engine, for which the combined operating conditions of low engine speed and full load can be operated to the position indicated by the open dots in the figure, due to the low manifold pressure and therefore low pressure ratio, and Atkinson-cycle engine. However, for an atkinson cycle engine, under the condition that the air inflow is not changed, the manifold pressure is increased, the pressure ratio of the supercharger is improved, and the combined operation condition moves to a position which is marked by a solid mark in a figure, so that the efficiency of the supercharger is reduced, and the risk of surging of the supercharger is increased more seriously.

Disclosure of Invention

The invention provides an engine and an automobile, aiming at solving the technical problems that in the prior art, the pressure of a manifold is increased under the condition that the air inflow is not changed, and the surge risk of a supercharger is increased.

In order to solve the technical problems, the invention adopts the following technical scheme:

in a first aspect, an embodiment of the present invention provides an engine, including:

a compressor;

the device comprises a cylinder, a piston rod;

the air inlet manifold is connected with the compressor and the air inlet valve respectively; and the number of the first and second groups,

the air return valve is arranged on the combustion chamber and is connected with an air inlet of the air compressor through an air return pipe to form an air passage;

when the air return valve is opened, a part of air in the combustion chamber flows back to the air inlet position of the compressor through the air passage.

In the engine, the air return pipe comprises a first output port, and the air return pipe is connected with the air inlet of the air compressor through the first output port.

The engine further comprises an EGR cooler, the EGR cooler is arranged in the air return pipe, and an outlet of the EGR cooler is connected with the first output port.

In the engine, the air return pipe further comprises a second output port, and the second output port is respectively connected with the outlet of the EGR cooler and the air outlet of the compressor.

The engine further comprises a first control valve which is respectively connected with the outlet of the EGR cooler, the first output port and the second output port and controls the connection or disconnection of the first output port and the second output port.

The engine further comprises a control mechanism, and the control mechanism controls the opening or closing of the air return valve.

The control mechanism is a second control valve, and the second control valve comprises an electromagnetic valve or a hydraulic valve.

In the engine, the gas passage is provided with a check valve.

Wherein, above-mentioned engine still includes: an air filter, an exhaust manifold, a turbine, and a catalyst;

the air filter is connected with the air compressor, the exhaust manifold is connected with the exhaust valve, and the turbine is respectively connected with the exhaust manifold and the catalyst.

In a second aspect, embodiments of the present invention provide an automobile including an engine as described above.

The embodiment of the invention has the beneficial effects that: in the engine provided by the embodiment of the invention, the return valve is arranged in the combustion chamber, and the gas passage is formed between the combustion chamber and the gas inlet of the gas compressor, so that in the preset working process of the engine, gas in the combustion chamber can flow to the position of the gas inlet of the gas compressor through the gas passage, different working modes can be realized, the working boundary of the gas compressor can be improved in the Atkinson mode, the running efficiency of the supercharger is improved, the surge is kept away, and the gas charging efficiency of the engine is improved.

Drawings

FIG. 1 shows a schematic diagram of valve profile comparison for an Atkinson cycle and an Otto cycle;

FIG. 2 is a graph illustrating the difference between the calculated charging efficiency of the Atkinson cycle and the Otto cycle based on the state of the gas in the intake manifold;

FIG. 3 is a schematic representation of a map of the operation of the compressor in an Otto cycle supercharged engine and an Atkinson cycle engine;

FIG. 4 is a schematic illustration of a first configuration of an engine provided in accordance with an embodiment of the present invention;

FIG. 5 is a schematic diagram of a second construction of an engine according to an embodiment of the present invention;

FIG. 6 shows a schematic cylinder diagram of a three cylinder engine in one example of the present invention;

FIG. 7 is a schematic representation of the operation of an engine in one particular example of use of the invention.

Wherein in the figure:

1, an air compressor; 2-a cylinder; 21-inlet valve, 22-exhaust valve; 23-a spark plug; 3-an intake manifold; 4-return valve; 5-air return pipe; 51-a first output port; 52-a second output port; 6-an EGR cooler; 7-a first control valve; 8-air filter; 9-an exhaust manifold; 10-a turbine; 11-catalyst.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 4, an embodiment of the present invention provides an engine including: a compressor 1; a cylinder 2, an air inlet valve 21, an exhaust valve 22 and an ignition plug 23 are arranged on a cylinder cover of the cylinder 2, and a combustion chamber is formed inside the cylinder 2; an intake manifold 3, wherein the intake manifold 3 is respectively connected with the compressor 1 and the intake valve 21; the air return valve 4 is arranged on the combustion chamber and is connected with an air inlet of the compressor 1 through an air return pipe 5 to form an air passage; when the air return valve 4 is opened, a part of air in the combustion chamber flows to the air inlet position of the compressor 1 through the air passage.

In the above embodiment, the number of the cylinders 2 included in the engine is not limited, and may be 1 or more (2), and the cylinder head of each cylinder 2 is provided with a plurality of intake valves 21 and a plurality of exhaust valves 22.

In one example, the engine has three cylinders 2, the engine is a three-cylinder engine 20, as shown in fig. 6, which is one cylinder, two cylinders, and three cylinders in sequence from left to right; wherein the upper side in fig. 6 is the intake side of the cylinder head of each cylinder 2, including two intake valves 21; the lower side in fig. 6 is the exhaust side of the cylinder head of each cylinder 2, including the exhaust valve 22; in the middle is a spark plug 23, with a return valve 4 provided on the cylinder head side of each cylinder 2.

In the above embodiment, when the engine is in the atkinson cycle mode, the gas in the combustion chamber flows into the intake port of the compressor 1 through the return valve 4 in the intake stroke or the compression stroke (where parameters such as the specific time, duration, and return valve opening degree of the return valve are determined as required). Thus, the effective compression ratio in the cylinder can be reduced under the same air inflow when the engine is under a large load or a full load so as to inhibit knocking, the pressure of the air inlet manifold 3 is effectively reduced (the air is not pushed back to the air inlet manifold 3), and the air inlet efficiency calculated according to the manifold state is improved; meanwhile, the pressure of the air inlet manifold 3 is reduced, and the pressure of the air inlet of the air compressor 1 is increased (the effect brought by pushing back air through the air return valve 4), so that the pressure ratio of the supercharger is reduced, the operation efficiency of the supercharger is improved, the operation working condition of the air compressor 1 is improved, the working boundary of the air compressor 1 is improved, and the working boundary is close to a higher-efficiency area of the air compressor 1 and is far away from a surge area; compared with the existing mode of adopting a larger air inlet wrap angle, the air charging efficiency of the engine is improved. In addition, the fuel in the gas returns to the air intake system again, so that the economic efficiency is not worried about to be lost, and the influence on the operation of the catalyst is not worried about.

Obviously, in the embodiment of the invention, the engine is equivalent to the improvement of the oil consumption of the medium and low load brought by the traditional Atkinson cycle under the Atkinson cycle mode; the effective compression ratio is reduced to weaken the knocking tendency at the time of heavy load, and the dynamic property of the engine is improved; the combined operation condition of the compressor and the engine is improved, the compressor and the engine move to a more reasonable area and are further away from a surge area, and therefore matching of a supercharger and exertion of the effect of the supercharger are facilitated.

In addition, the problem of poor cold start caused by cold start of the traditional Atkinson cycle engine can be solved. The engine provided by the embodiment of the invention controls the return valve not to be opened when in cold start, thereby canceling the Atkinson effect, and the starting effect when the engine is used as a traditional engine is even better than that of the traditional engine, because the compression ratio of the engine provided by the embodiment of the invention is larger than that of the traditional engine under the general condition.

When the engine is in an external EGR (Exhaust Gas Recirculation) working mode, at the end of a power stroke or an Exhaust stroke (parameters such as specific opening time and duration of the return valve 4 and the opening degree of the return valve are determined according to requirements), combustion Exhaust Gas in a combustion chamber returns to an air inlet of the compressor 1 through the return valve 4, so that the external EGR mode is realized, and the beneficial effects of reducing the oil consumption rate and improving the knocking brought by the EGR are achieved. In the embodiment of the invention, the Atkinson cycle mode and the EGR mode can be combined to run, and the beneficial effects of two cycles are realized simultaneously, namely the effects of saving oil and improving detonation brought by the external EGR mode and the effects of saving oil, improving detonation, keeping away from surge, improving torque and the like brought by the Atkinson cycle mode can be realized simultaneously.

In some embodiments, the opening of the return valve 4 does not need to be large and the opening time does not need to be long (depending on the specific matching determination), since the gas is not pushed back into the high-pressure intake manifold 3, but is pushed back into the intake port of the compressor 1 at a pressure close to normal atmospheric pressure.

Referring to fig. 5, in an embodiment, the air return pipe 5 includes a first output port 51, and the air return pipe 5 is connected to the air inlet of the compressor 1 through the first output port 51. When the return valve 4 is opened, the gas in the combustion chamber can flow to the air inlet of the compressor 1 through the return pipe 5 and the first output port 51.

In some embodiments, to better realize the EGR mode, the engine may further include an EGR cooler 6, where the EGR cooler 6 is disposed in the air return pipe 5, and an outlet of the EGR cooler 6 is connected to the first output port 51.

Wherein, referring to fig. 4 and 5, in one example the engine is a three-cylinder engine, the EGR cooler 6 may be connected to the EGR cooler 6 by a four-way connection 12.

Wherein a passage from the combustion chamber to the intake manifold 3 can be established for a better use and a more flexible control of the engine of the invention. Referring to fig. 5, in some embodiments of the present invention, the air return pipe 5 further includes a second output port 52, and the second output port 52 is connected to an outlet of the EGR cooler 6 and an outlet of the compressor 1, respectively. Through this second output port 52, gas in the combustion chamber can flow to the intake manifold 3 through the return valve 4.

Through the arrangement of the first output port 51 and the second output port 52, an Atkinson cycle effect is realized under a small load, namely, gas is pushed back to the intake manifold 3 from the combustion chamber through the return valve 4, so that the effect of reducing pumping loss is more obvious; the external EGR effect is realized at large load or full load, which is equivalent to high-pressure EGR, and the EGR lag is effectively improved.

Referring to fig. 5, in an embodiment, in order to facilitate controlling the connection and disconnection of the first output port 51 and the second output port 52 of the muffler 5, the engine may further include a first control valve 7, where the first control valve 7 is connected to the outlet of the EGR cooler 6, the first output port 51, and the second output port 52, respectively, and controls the connection and disconnection of the first output port 51 and the second output port 52. Through this first control valve 7, the gas that is exported in the combustion chamber can be controlled and exported through first delivery outlet 51 or export through second delivery outlet 52 to satisfy actual demand. The first control valve 7 may be a three-way valve.

In some embodiments, the engine may further include a control mechanism that controls the opening or closing of the return valve 4 so as to achieve a flexible opening and closing characteristic of the return valve 4, thereby better achieving different operating modes of the engine, such as an EGR mode, an atkinson mode, or a combined mode.

In one embodiment, the control mechanism is a second control valve, and the second control valve includes a solenoid valve or a hydraulic valve. Of course, the control mechanism may be other mechanisms capable of flexibly controlling the opening and closing of the return valve.

For example, the control mechanism may be a first lobe provided on an intake camshaft, and the intake Valve and the return Valve of the present invention can be adjusted by the engine using an intake VVT (Variable Valve Timing) of a general atkinson cycle engine by the first lobe, or the intake VVT having a large adjustment range as in the general atkinson cycle engine may be used for the purpose of adjusting the intake Valve and the return Valve of the present invention. For another example, the control mechanism may also be a second lobe disposed on the exhaust camshaft. Also for example, the control mechanism may be a separate camshaft. Of course, in the above example, the camshaft-based control mechanism such as the first lobe, the second lobe, or the independent camshaft is used, and there is a limit to the engine that can realize the motion modes such as the EGR mode, the atkinson mode, and the combination mode by the return valve.

In some embodiments, a one-way valve is disposed on the gas passageway. In this way, it is possible to prevent a situation in which a small load airflow flows from the inlet of the compressor 1 to the combustion chamber through the return valve 4 in some use scenarios where flexibility is not high.

In addition, referring to fig. 4 and 5, to better realize the performance of the engine provided by the embodiment of the present invention, the engine may further include: an air filter 8, an exhaust manifold 9, a turbine 10, and a catalyst 11; the air filter 8 is connected with the compressor 1, the exhaust manifold 9 is connected with the exhaust valve 22, and the turbine 10 is respectively connected with the exhaust manifold 9 and the catalyst 11. Here, the fresh air enters the compressor 1 after being filtered by the air filter 8, flows to the intake manifold 3 through the compressor 1, and then enters the cylinder 2 from the intake manifold 3 through the intake valve 21; exhaust gases from the combustion chamber enter the exhaust manifold 9 through an exhaust valve 22, flow through the exhaust manifold 9 to the turbine 10, through the turbine 10 to the catalyst 11, and finally through the exhaust system to the atmosphere.

Referring to FIG. 7, in one specific example of use, the engine operation includes an intake stroke, a compression stroke, a power stroke, and an exhaust stroke.

When the engine is in the EGR mode, the specific working process is as follows:

intake stroke (360-540 °): the air inlet valve 21 is in an open state, the exhaust valve 22 is in a closed state, at the moment, the piston moves from an air inlet top dead center to a bottom dead center, fresh air flows to the air compressor 1 from the air filter 8, flows to the air inlet manifold 3 through the air compressor 1, and then enters the air cylinder 2 from the air inlet manifold 3 through the air inlet valve 21;

compression stroke (540-720 °): the intake valve 21 is in a closed state, and the exhaust valve 22 is in a closed state, at which time the piston moves from a bottom dead center to a compression top dead center;

acting stroke (0-180 degree): the air inlet valve 21 is in a closed state, the air outlet valve 22 is in a closed state, combustible mixed gas in the cylinder 2 is combusted, and at the moment, the piston moves from the top dead center to the bottom dead center to push the crankshaft to do work in a rotating manner;

exhaust stroke (180-360 °): the intake valve 21 is in a closed state, the exhaust valve 22 is in an open state, the return valve 4 is opened at a set timing angle (the opening angle can also start from the power stroke) according to a first preset control strategy (the first preset control strategy can be set according to actual requirements) and is closed after a preset period of time, at the moment, the piston moves from a bottom dead center to a top dead center, part of exhaust gas combusted in the cylinder 2 is discharged from the combustion chamber through the exhaust valve 22 to enter an exhaust manifold 9, flows to the turbine 10 through the exhaust manifold 9, flows to the catalyst 11 through the turbine 10, and finally enters the atmosphere through an exhaust system; the other part of the air is discharged from a combustion chamber through an air return valve 4, enters an EGR cooler 6 through an air return pipe 5, flows to the air inlet position of the compressor 1 after being cooled, and then enters the compressor 1 after being mixed with fresh air.

In the EGR mode, the air return valve 4 is opened according to a first preset control strategy between the final stage of the power stroke and the early stage of the air intake stroke, so that the external EGR with high-pressure air taking and low-pressure air return is realized, and the beneficial effects of reducing the oil consumption rate and improving the knocking brought by the external EGR are realized. Wherein the intake stroke, compression stroke, and power stroke may be the same as a conventional engine when the engine is in the EGR mode, during which strokes the return valve is in a closed state.

When the engine is in the Atkinson mode, the specific working process is as follows:

intake stroke (360-540 °): the intake valve 21 is in an open state, the exhaust valve 22 is in a closed state, the return valve 4 is opened at a set timing angle according to a second predetermined control strategy (the second predetermined control strategy can be set according to actual requirements) and is closed after a predetermined period (wherein, the closing angle can be closed in a compression stroke), at this time, the piston moves from an intake top dead center to a bottom dead center, fresh air flows to the compressor 1 from the air filter 8, flows to the intake manifold 3 through the compressor 1, and then enters the cylinder 2 from the intake manifold 3 through the intake valve; wherein a part of gas in the cylinder 2 is left in the cylinder 2; another part of the gas flows to the position of the gas inlet of the compressor 1 or the position of the gas outlet of the compressor 1 through the return valve 4, that is, the part of the gas can flow to the position of the gas inlet of the compressor 1 through the first output port 51 or flow to the position of the gas outlet of the compressor 1 through the second output port 52, and the part of the gas can be controlled according to actual requirements;

compression stroke (540-720 °): the intake valve 21 is in a closed state, the exhaust valve 22 is in a closed state, and the return valve 4 is in an open state (the specific open state is set according to actual requirements), at which time, the piston moves from a bottom dead center to a compression top dead center; a part of gas in the cylinder 2 remains in the cylinder 2; the other part of the gas flows to the position of the gas inlet of the gas compressor 1 or the position of the gas outlet of the gas compressor 1 through the return valve 4, wherein the part of the gas can be controlled to flow to the position of the gas inlet of the gas compressor 1 or the position of the gas outlet of the gas compressor 1 according to actual needs;

acting stroke (0-180 degree): the intake valve 21 is in a closed state, the exhaust valve 22 is in a closed state, combustible mixed gas in the cylinder of the cylinder 2 is combusted, and at the moment, the piston moves from the top dead center to the bottom dead center to push the crankshaft to do work in a rotating manner;

exhaust stroke (180-360 °): the inlet valve 21 is in a closed state and the exhaust valve 22 is in an open state, at which time the piston moves from the bottom dead center to the top dead center, and the exhaust gas burned in the cylinder 2 is discharged from the exhaust valve 22 out of the combustion chamber into the exhaust manifold 9, flows through the exhaust manifold 9 to the turbine 10, flows through the turbine 10 to the catalyst 11, and finally passes through the exhaust system to the atmosphere.

In the Atkinson mode, the return valve 4 is controlled to be opened according to a second preset control strategy between the earlier stage of an intake stroke and a compression stroke, so that the Atkinson cycle effect is realized, the opening of a throttle valve can be increased under a small load, the pumping loss is reduced, and the oil consumption is improved; the efficiency of the compressor 1 and the charging efficiency of the intake manifold 3 can be improved under a large load, the combined running state of a supercharger and an engine can be improved while knocking is inhibited, and the torque of the engine, particularly the low-speed torque, can be improved. Wherein the power stroke and the exhaust stroke may be the same as in a conventional engine when the engine is in atkinson mode, during which strokes the return valve is in a closed state.

The engine provided by the embodiment of the invention is suitable for various supercharged and engine structures matched with the engine, such as a turbocharged engine, a mechanical supercharged engine, an electronic supercharged engine and the like.

The invention also provides an automobile comprising the engine.

Since the structure of the automobile body is the prior art, and the structure of the engine has been described in detail in the above embodiments, the specific structure of the automobile in this embodiment is not described in detail.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

In the description of the present invention, it is to be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that the terms "mounted," "disposed," and "connected" are to be construed broadly unless otherwise explicitly stated or limited. For example, the connection can be fixed, detachable or integrated; may be directly connected or indirectly connected through an intermediate. The fixed connection can be common technical schemes such as welding, threaded connection and clamping. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Moreover, it is noted that, in the embodiments of the present invention, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. An engine, comprising:

a compressor (1);

the device comprises a cylinder (2), wherein an air inlet valve (21), an air outlet valve (22) and an ignition plug (23) are arranged on a cylinder cover of the cylinder (2), and a combustion chamber is formed inside the cylinder (2);

the air inlet manifold (3), the air inlet manifold (3) is respectively connected with the compressor (1) and the air inlet valve (21); and the number of the first and second groups,

the air return valve (4) is arranged on the combustion chamber and is connected with an air inlet of the air compressor (1) through an air return pipe (5) to form an air passage;

when the air return valve (4) is opened, a part of air in the combustion chamber flows to the air inlet position of the compressor (1) through the air passage;

the air return pipe (5) comprises a first output port (51), and the air return pipe (5) is connected with an air inlet of the compressor (1) through the first output port (51);

the engine also comprises an EGR cooler (6), the EGR cooler (6) is arranged on the air return pipe (5), and an outlet of the EGR cooler (6) is connected with the first output port (51);

the air return pipe (5) further comprises a second output port (52), and the second output port (52) is respectively connected with an outlet of the EGR cooler (6) and an air outlet of the compressor (1);

the engine further comprises a first control valve (7), wherein the first control valve (7) is respectively connected with an outlet of the EGR cooler (6), a first output port (51) and a second output port (52) and controls the connection or disconnection of the first output port (51) and the second output port (52).

2. The engine of claim 1, further comprising a control mechanism that controls the opening or closing of the return valve.

3. The engine of claim 2, wherein the control mechanism is a second control valve comprising a solenoid valve or a hydraulic valve.

4. The engine of claim 1, wherein a one-way valve is disposed on the gas passage.

5. The engine of claim 1, further comprising: an air filter (8), an exhaust manifold (9), a turbine (10), and a catalyst (11);

the air filter (8) is connected with the compressor (1), the exhaust manifold (9) is connected with the exhaust valve (22), and the turbine (10) is respectively connected with the exhaust manifold (9) and the catalyst (11).

6. An automobile, characterized by comprising an engine according to any one of claims 1 to 5.