JP2017180427A - Turbocharging-type engine and method for inputting load for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turbocharging-type engine that has a supercharger with high responsiveness to partial load input while maintaining a relatively simple configuration and can prevent an engine body from stalling, and to provide a method for inputting load for the same.SOLUTION: The turbocharging-type engine includes: a waste gate passage 62 for connecting an exit side and an entrance side of a first turbine 1b in an exhaust passage 27; and a waste gate valve 63 disposed in the waste gate passage 62. The turbocharging-type engine executes a waste gate opening process for maintaining the waste gate valve 63 in an opening state when inputting partial load to an engine body 26.SELECTED DRAWING: Figure 1

Description

The present invention comprises an engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber,
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
The present invention relates to a turbocharged engine including a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed, and a method for loading the same.

An engine-driven generator that is rotationally driven by the rotational power generated by the engine body is required to follow the load suddenly. In particular, in the case of an emergency generator, it is required that a load as large as possible can be quickly applied from a no-load state immediately after starting the engine body (partial load application). If the partial load input rate, which is the ratio of the initial input load to the rated output of the engine body, is high, even if a power failure occurs, it is possible to supply power quickly and stably to an important load that needs to be supplied with priority.
On the other hand, in a turbocharged engine equipped with a turbocharger composed of a turbine that is rotated by exhaust energy of exhaust gas and a compressor that is connected to the turbine and driven to rotate, the speed of the engine body is controlled when the load increases rapidly. In addition to device delay, the turbocharger response delay prevents the necessary fresh air from being supplied to the engine body quickly, resulting in a decrease in output shaft rotation speed and stall (engine stop). .
In response to such problems, compressed nitrogen is introduced before the turbine when a partial load is applied in order to promote an increase in the amount of fuel input due to a rise in the rotation of the turbocharger when the partial load is applied, that is, an increase in intake pressure (Patent Document 1), a system that temporarily supplies compressed air from an air replenishment source to the engine body when a partial load is applied (see Patent Document 2), and a small load is applied before a large load is applied when a partial load is applied. A switch (see Patent Document 3) that switches the load application state is proposed.

  In addition, as a turbocharged engine for automobiles that changes according to the speed of the automobile, rather than maintaining the rotational speed of the engine body at the target rotational speed, a waist connecting the outlet side and the inlet side of the turbine in the exhaust path The thing provided with the gate path and the waste gate valve arrange | positioned at the said waste gate path is known (refer patent document 4).

Japanese Patent No. 4580092 Japanese Patent No. 3608775 Japanese Patent No. 3592555 JP 2000-205055 A

However, each of the techniques disclosed in Patent Documents 1 to 3 has the following problems. In the technique disclosed in Patent Document 1, it is necessary to always provide compressed nitrogen, which increases the cost and makes the configuration complicated.
In the technique disclosed in Patent Document 2, when the emergency generator combined with the emergency generator is rotationally driven by the rotational power generated by the engine body, a part of the intake pressure can be accumulated during operation. When the engine main body rotationally drives the emergency generator, as in the technique disclosed in Patent Document 1, it is necessary to always provide compressed air, resulting in high costs and a complicated configuration.
In the technique disclosed in Patent Document 3, it is necessary to switch the load application state, and it is necessary to prepare a load suitable for the load switching.
Further, in the automobile engine disclosed in Patent Document 4, the wastegate valve is opened at the initial stage of acceleration regardless of the load, but the engine output response is improved when maintaining the rotational speed at the target rotational speed. Therefore, the point of operating the wastegate valve when the load is applied has not been studied.

  The present invention has been made in view of the above-described problems, and the object thereof is to maintain a relatively simple configuration while maintaining high engine output responsiveness to partial load input and causing the engine body to stall. It is an object to provide a turbocharged engine and a method for loading the same.

[Configuration 1]
To achieve the above object, the turbocharged engine according to the present invention has the following characteristic configuration:
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
A wastegate path connecting the outlet side and the inlet side of the first turbine, the outlet side and the inlet side of the second turbine, or the outlet side of the first turbine and the inlet side of the second turbine in the exhaust path; And a wastegate valve disposed in the wastegate path,
A supercharging control means for executing a wastegate opening process for maintaining the wastegate valve in an open state when a partial load is applied to the engine body is provided.

According to said characteristic structure, in an engine main body, a wastegate path is provided in an exhaust path, and a wastegate valve is arrange | positioned in the wastegate path. Then, in a state where the rotational speed of the engine main body is maintained at the target rotational speed by the rotational speed maintaining means, the waste gate opening process is executed and the waste gate valve is maintained open when a partial load is applied to the engine main body. As a result, the exhaust gas flow in the waste gate passage is allowed, so the pressure on the inlet side of the waste gate passage in the exhaust passage is reduced to the same level as the outlet side pressure, and the pumping loss in the exhaust stroke is reduced. Is done.
In addition, by turning the wastegate valve in the open state, the rotational power of the turbine is reduced, and as a result, the rotational speed of the supercharger is reduced, but in the first place in the low load range when partial load is applied, Since the flow of fresh air is reduced in the intake passage (the pressure of fresh air is reduced) and sucked into the combustion chamber, the original function of the supercharger is not utilized, and supercharging above atmospheric pressure is not necessary. In other words, when the partial load is turned on, even if the rotational speed of the supercharger is reduced by opening the wastegate valve, the throttle of the fresh air flow is alleviated and the engine output is reduced. Can be suppressed.
Therefore, when a partial load is applied to the engine body in such a state, the pumping loss is reduced, and the response of the engine output, which is the work of the rotational power generated by the engine body to the load, is reduced. It will be improved.
Therefore, according to the present invention, it is possible to provide a turbocharged engine having high engine output responsiveness to partial load application and a load application method thereof while maintaining a relatively simple configuration.

[Configuration 2]
Another characteristic configuration of the turbocharged engine according to the present invention is that the supercharging control means executes a wastegate closing process for closing the wastegate valve after a partial load is applied to the engine body. .

According to the above characteristic configuration, after the partial load is applied, the wastegate valve opened by the wastegate opening process is closed by executing the wastegate closing process. Then, since the flow of fresh air in the wastegate path is prohibited, the inlet side pressure becomes larger than the turbine outlet side pressure, the turbine rotational speed increases, and the compressor compresses the fresh air. As a result, the engine efficiency can be improved and a more stable operation state can be maintained.
Therefore, it is possible to provide a turbocharged engine that can prevent the engine body from falling into a stall and a method for loading the same.

[Configuration 3]
Another characteristic configuration of the turbocharged engine according to the present invention is that a throttle valve is disposed downstream of the supercharger in the intake passage, and the rotational speed is increased in accordance with an initial load applied to the engine body. The maintenance means executes the maintenance control of the rotational speed of the engine body, whereby the opening of the throttle valve is enlarged.

According to the above characteristic configuration, the rotational speed maintaining means increases the engine output and maintains the rotational speed of the engine body as the partial load is applied to the engine body. The opening of the throttle valve provided on the side is suddenly expanded to rapidly increase the flow rate of the fuel and air-fuel mixture guided to the engine body, or the fuel supply amount is rapidly increased. Further, as in the latter case, when the fuel supply amount is suddenly increased, a throttle valve is used to increase the air supply amount in order to maintain the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber at a desired air-fuel ratio. The opening of the is rapidly expanded.
That is, if a throttle valve is disposed on the downstream side of the compressor in the intake passage, the engine output can be increased by responding to the partial load input to the engine body by rapidly increasing the opening.
In addition, when the wastegate opening process is executed and the turbocharger speed decreases, the supercharging pressure, which is the pressure on the outlet side of the compressor, decreases, but the throttle valve opening slightly increases accordingly. As a result, it is possible to quickly avoid a decrease in the intake pressure to the combustion chamber and maintain a stable operation state.

[Configuration 4]
Another characteristic configuration of the turbocharged engine according to the present invention is such that a residual load is applied to the engine body subsequent to the partial load, and the supercharging control means is configured to apply the residual load to the engine body. The waste gate closing process is executed before the introduction of the above.

According to the above characteristic configuration, after the partial load is applied, after the wastegate closing process is executed and the fresh air is sufficiently compressed by the compressor, the residual load following the partial load is input. Therefore, the engine output can be gradually increased stably with high responsiveness even in the middle load region and the high load region.
In addition, regarding the partial load to be input in such a state where the wastegate opening process is executed, the engine output response is taken into consideration within a range of 0% to 40% with respect to the rated output of the engine body. Preferably there is. The remaining load that is input up to the rated output after execution of the wastegate closing process may be input once, but it is desirable to ensure engine stability by supplying it in multiple times. .

[Configuration 5]
Another characteristic configuration of the turbocharged engine according to the present invention is that the wastegate valve has a low output when the engine main body has insufficient output after the partial load is applied and before the wastegate closing process is performed. A correction means for executing a correction process for correcting the opening degree to the reduction side is provided.

According to the above characteristic configuration, even if the engine body output shortage occurs after the partial load is applied and before the wastegate closing process is performed, for example, in a situation where the opening of the throttle valve cannot be further expanded in the fully opened state. By executing the above correction process, it is possible to solve the shortage of the output of the engine body without depending on the increase in the opening of the throttle valve, and to maintain the rotation speed of the engine body at the target rotation speed.
That is, in the above correction process, if the opening degree of the wastegate valve is corrected to the reduction side, the rotation speed of the supercharger can be increased, and the supercharging pressure for fresh air can be increased. It can be increased moderately.

[Configuration 6]
Another characteristic configuration of the turbocharged engine according to the present invention is that an intake air is introduced into the combustion chamber when the output of the engine body is insufficient after the partial load is applied and before the wastegate closing process is performed. The correction means is provided for executing a correction process for correcting the air-fuel ratio of the air-fuel mixture to the fuel rich side.

According to the above characteristic configuration, even if the engine body output shortage occurs after the partial load is applied and before the wastegate closing process is performed, for example, in a situation where the opening of the throttle valve cannot be further expanded in the fully opened state. By executing the above correction process, it is possible to solve the shortage of the output of the engine body without depending on the increase in the opening of the throttle valve, and to maintain the rotation speed of the engine body at the target rotation speed.
That is, in the above correction process, if the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber is corrected to the fuel rich side, the amount of fuel input to the combustion chamber per cycle can be increased, and as a result, the engine output is reduced. It can be increased moderately.

[Configuration 7]
Another characteristic configuration of the turbocharged engine according to the present invention is that the waste gate path connects an outlet side and an inlet side of the first turbine.

  According to the above characteristic configuration, since the wastegate valve is disposed in the wastegate path that connects the outlet side and the inlet side of the first turbine, the exhaust gas flowing through the wastegate valve has a certain temperature by the second turbine. descend. Therefore, since the heat resistance and durability required for the wastegate valve can be lowered, a turbocharged engine can be configured at low cost, which is preferable.

[Configuration 8]
Another characteristic configuration of the turbocharged engine according to the present invention includes an intake bypass path connecting an outlet side and an inlet side of the first compressor in the intake path, and an intake bypass valve disposed in the intake bypass path And with
The supercharging control means executes a bypass opening process for maintaining the intake bypass valve in an open state together with the waste gate opening process when a partial load is applied to the engine body.

According to the above characteristic configuration, when the partial load is applied, while the wastegate opening process is performed as described above and the rotation speed of the supercharger is decreasing, the bypass opening process is performed in conjunction therewith. When executed, the intake bypass valve disposed in the intake bypass passage is opened. Then, since the flow of fresh air in the intake bypass passage connecting the outlet side and the inlet side of the compressor in the intake passage is permitted, the fresh air is sucked in through the compressor whose rotational speed has decreased. In comparison, the pressure loss in the intake passage is reduced, and as a result, the pumping loss in the intake stroke is reduced.
Therefore, the response of the engine output to the initial charging can be further improved.

[Configuration 9]
Another characteristic configuration of the turbocharged engine according to the present invention is that the waste gate path connects an outlet side of the first turbine and an inlet side of the second turbine.

  According to said characteristic structure, the responsiveness of the engine output with respect to partial load injection can be improved more, and is suitable.

[Configuration 10]
Another characteristic configuration of the turbocharged engine according to the present invention is disposed in the intake bypass path connecting the outlet side of the second compressor and the inlet side of the first compressor in the intake path, and the intake bypass path. And an intake bypass valve
The supercharging control means executes a bypass opening process for maintaining the intake bypass valve in an open state together with the waste gate opening process when a partial load is applied to the engine body.

According to the above characteristic configuration, the pressure loss in the intake passage is further reduced, and as a result, the pumping loss in the intake stroke is further reduced.
Therefore, the response of the engine output to the initial charging can be further improved.

[Configuration 11]
Another characteristic configuration of the turbocharged engine according to the present invention is that the supercharging control unit performs the waste block closing process after executing the waste gate closing process after the initial load is applied to the engine body. The point is to execute.

  According to the above characteristic configuration, after the partial load is applied, when the wastegate closing process and the bypass closing process are executed to close the wastegate valve and the intake bypass valve, the intake bypass valve is opened and the compressor is subjected to a compression load. In such a state, the wastegate valve is closed prior to the intake bypass valve, and the rotational power of the turbine is increased. Then, the rotational speed of the supercharger can be temporarily increased. Thereafter, the intake bypass valve is closed while the rotation speed of the supercharger is high, and compression of fresh air by the compressor is started, so that the supercharging pressure can be quickly increased, for example, to a partial load. It is possible to prepare for the input of the remaining load.

[Configuration 12]
In order to achieve the above object, a method for loading a turbocharged engine according to the present invention includes:
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
A wastegate path connecting the outlet side and the inlet side of the first turbine, the outlet side and the inlet side of the second turbine, or the outlet side of the first turbine and the inlet side of the second turbine in the exhaust path; Providing a wastegate valve disposed in the wastegate path,
A wastegate closing process for performing a wastegate opening process for maintaining the wastegate valve in an open state when a partial load is applied to the engine body, and closing the wastegate valve after the initial load is applied to the engine body. The point is to execute.

  That is, the method for loading the turbocharged engine according to the present invention is preferably executed by the turbocharged engine according to the present invention described so far, and therefore the same operational effects can be achieved. .

[Configuration 13]
To achieve the above object, the turbocharged engine according to the present invention has the following characteristic configuration:
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
An intake bypass passage connecting the outlet side and the inlet side of the first compressor, the outlet side and the inlet side of the second compressor, or the outlet side of the second compressor and the inlet side of the first compressor in the intake passage; And an intake bypass valve disposed in the intake bypass path,
There is a supercharging control means for performing a bypass opening process for maintaining the intake bypass valve in an open state when an initial load is applied to the engine body.

According to the above characteristic configuration, an intake bypass path is provided in the engine body of the turbocharged engine, and the intake bypass valve is disposed in the intake bypass path. Then, in a state where the rotational speed of the engine body is maintained at the target rotational speed by the rotational speed maintaining means, the bypass opening process is executed, and the intake bypass valve is maintained open when a partial load is applied to the engine body. Then, since the flow of fresh air in the intake bypass passage is permitted, the pressure difference between the outlet side pressure and the outlet side pressure of the compressor is reduced, and the rotational load of the compressor is reduced. The machine's rotational speed is increased. And since the responsiveness of the supercharger is higher when the rotational speed of the supercharger is higher, a partial load is applied to the engine body in this state, and the engine body with respect to the load is generated. The response of the engine output, which is the work of the rotational power, can be improved.
Therefore, according to the present invention, it is possible to provide a turbocharged engine in which the responsiveness of the supercharger with respect to partial load input is high while maintaining a relatively simple configuration, and a load input method thereof.

[Configuration 14]
Another characteristic configuration of the turbocharged engine according to the present invention is that the supercharging control means executes a bypass closing process for closing the intake bypass valve after a partial load is applied to the engine body.

According to the above characteristic configuration, after the partial load is applied, the intake bypass valve opened by the bypass opening process is closed by executing the bypass closing process. Then, since the flow of fresh air in the intake bypass passage is prohibited, the pressure difference of the outlet side pressure with respect to the inlet side pressure of the compressor becomes large so that the compressor can sufficiently compress the fresh air. As a result, the engine efficiency can be improved and a more stable operation state can be maintained.
Therefore, it is possible to provide a turbocharged engine that can prevent the engine body from falling into a stall and a method for loading the same.

[Configuration 15]
Another characteristic configuration of the turbocharged engine according to the present invention is that a throttle valve is disposed on the downstream side of the compressor in the intake passage,
As the partial load is applied to the engine body, the rotation speed maintaining means executes the engine rotation speed maintenance control, whereby the opening degree of the throttle valve is increased.

According to the above characteristic configuration, the rotational speed maintaining means increases the engine output and maintains the rotational speed of the engine as the partial load is applied to the engine body. The amount of fuel and air-fuel mixture introduced to the engine is suddenly increased or the amount of fuel supply is suddenly increased by rapidly increasing the opening of the throttle valve provided in the engine. Further, as in the latter case, when the fuel supply amount is suddenly increased, a throttle valve is used to increase the air supply amount in order to maintain the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber at a desired air-fuel ratio. The opening of the is rapidly expanded.
On the other hand, when the bypass opening process is executed and the rotation speed of the compressor is increased, fresh air is discharged from the outlet side of the compressor toward the downstream side thereof at a relatively high speed.
Therefore, in this state, when a partial load is applied to the engine body and the opening of the throttle valve arranged downstream of the compressor is increased, the newly discharged high-speed immediately after the expansion of the throttle valve. Since the gas is filled into the combustion chamber with its strong inertia, the engine output response can be further improved.

[Configuration 16]
Another characteristic configuration of the turbocharged engine according to the present invention is that the supercharging control means gradually reduces the opening degree of the intake bypass valve as the engine output increases in the bypass closing process. .

  According to the above characteristic configuration, in the bypass closing process after the partial load is applied, the opening of the intake bypass valve is gradually reduced as the engine output increases, so that the compressor rotation load due to the intake bypass valve being blocked. As the engine output increases, the exhaust energy of the exhaust gas supplied to the turbine increases as the engine output increases. Therefore, the rotational speed of the supercharger can be maintained at a high level even after the partial load is applied, and a decrease in engine efficiency and a stall due to a sudden blockage of the intake bypass valve can be avoided.

[Configuration 17]
Another characteristic configuration of the turbocharged engine according to the present invention is that when the supercharging control means causes an insufficient output of the engine main body after the partial load is applied and before the bypass closing process is performed. The correction means for executing the correction process for correcting the opening degree of the intake bypass valve to the reduction side is provided.

According to the above characteristic configuration, even after the partial load is input and before the bypass closing process is performed, for example, in the situation where the throttle valve opening cannot be further expanded in the fully opened state, By executing the correction process, it is possible to solve the shortage of output of the engine body without depending on the increase in the opening of the throttle valve, and to maintain the rotation speed of the engine body at the target rotation speed.
In other words, in the above correction process, if the opening degree of the intake bypass valve is corrected to the reduction side, the rotational load of the compressor can be increased, and the supercharging pressure for fresh air can be increased. Can be increased.

[Configuration 18]
Another characteristic configuration of the turbocharged engine according to the present invention is that when the supercharging control means causes an insufficient output of the engine main body after the partial load is applied and before the bypass closing process is performed. And a correction means for executing a correction process for correcting the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber to the fuel rich side.

According to the above characteristic configuration, even after the partial load is input and before the bypass closing process is performed, for example, in the situation where the throttle valve opening cannot be further expanded in the fully opened state, By executing the correction process, it is possible to solve the shortage of output of the engine body without depending on the increase in the opening of the throttle valve, and to maintain the rotation speed of the engine body at the target rotation speed.
That is, in the above correction process, if the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber is corrected to the fuel rich side, the amount of fuel input to the combustion chamber per cycle can be increased, and as a result, the engine output is reduced. It can be increased moderately.

[Configuration 19]
Another characteristic configuration of the turbocharged engine according to the present invention is that the intake bypass path connects an outlet side and an inlet side of the first compressor.

  According to the above characteristic configuration, since the intake bypass valve is disposed in the intake bypass path that connects the outlet side and the inlet side of the first compressor, the fresh air flowing through the intake bypass valve is compressed before being compressed by the compressor. Of relatively low temperature. Therefore, since the heat resistance and durability required for the intake bypass valve can be lowered, a turbocharged engine can be configured at low cost, which is preferable.

[Configuration 20]
Another characteristic configuration of the turbocharged engine according to the present invention is that the intake bypass path connects an outlet side of the second compressor and an inlet side of the first compressor.

  According to said characteristic structure, the responsiveness of the engine output with respect to partial load injection can be improved more, and is suitable.

[Configuration 21]
Further, the characteristic configuration of the turbocharging engine load application method according to the present invention for achieving the above object is as follows:
An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
An intake bypass passage connecting the outlet side and the inlet side of the first compressor, the outlet side and the inlet side of the second compressor, or the outlet side of the second compressor and the inlet side of the first compressor in the intake passage; An intake bypass valve disposed in the intake bypass path,
A bypass opening process is performed to maintain the intake bypass valve in an open state when a partial load is applied to the engine body, and a bypass closing process is performed to close the intake bypass valve after the partial load is applied to the engine body. In the point.

  That is, the method for loading the turbocharged engine according to the present invention is preferably executed by the turbocharged engine according to the present invention described so far, and therefore the same operational effects can be achieved. .

Schematic configuration diagram of turbocharged engine Explanatory drawing which shows the processing flow in 1st Embodiment of the load injection method of a turbocharged engine. Explanatory drawing which shows the state transition in 1st Embodiment of the load injection method of a turbocharged engine Explanatory drawing which shows the processing flow in 2nd Embodiment of the load injection method of a turbocharged engine. Explanatory drawing which shows the state transition in 2nd Embodiment of the load injection method of a turbocharged engine Explanatory drawing which shows the processing flow in 3rd Embodiment of the load injection method of a turbocharged engine. Explanatory drawing which shows the processing flow of the correction process in 3rd Embodiment. Explanatory drawing which shows the state transition in 3rd Embodiment of the load injection method of a turbocharged engine Explanatory drawing which shows the processing flow in 4th Embodiment of the load injection method of a turbocharged engine. Explanatory drawing which shows the state transition in 4th Embodiment of the load injection method of a turbocharged engine Explanatory drawing which shows the processing flow in 5th Embodiment of the load injection method of a turbocharged engine. Explanatory drawing which shows the processing flow of the correction process performed with the load injection method of 2nd Embodiment. Explanatory drawing which shows the state transition in 5th Embodiment of the load injection method of a turbocharged engine Graph showing relationship between turbocharger load ratio and turbocharger efficiency Schematic configuration diagram of turbocharged engine Schematic configuration diagram of turbocharged engine

[First Embodiment]
Hereinafter, a turbocharged engine according to a first embodiment will be described with reference to the drawings.
A turbocharged engine 100 shown in FIG. 1 rotates an output shaft 50 by compressing and burning an air-fuel mixture M of a fuel gas F (an example of fuel) such as natural gas and air A in a combustion chamber 26a. The exhaust gas E exhausted from the combustion chamber 26a is supplied to an engine body 26 that generates rotational power in the form and a turbine provided in an exhaust passage 27 of the engine body 26, and the intake air is connected to the turbines (1b, 2b). And a supercharger (1, 2) that compresses the air-fuel mixture M as fresh air sucked into the combustion chamber 26a by a compressor (1a, 2a) provided in the passage 20, and further, the detection result of a sensor or the like An engine control unit (hereinafter referred to as an ECU) comprising a computer that controls the operation of the engine 100 by controlling various auxiliary machines such as control valves based on the input signals. Called.) 40 are provided.

  In the present embodiment, the supercharger has the first supercharger 1 having the first turbine 1b and the first compressor 1a, and the second supercharger 2 having the second turbine 2b and the second compressor 2a. Configured. The first turbine 1b is arranged on the downstream side of the second turbine 2b in the exhaust passage 27, and the first compressor 1a is arranged on the upstream side of the second compressor 1a in the intake passage 20. That is, in the intake passage 20 and the exhaust passage 27, the second supercharger 2 is disposed closer to the engine body 26.

  Although this type of engine 100 is not shown in detail, the mixture M taken as fresh air from the intake passage 20 into the combustion chamber 26a is spark-ignited by a spark plug in a state compressed by the rise of the piston. By combustion and expansion, the piston is pushed down to output rotational power from the output shaft 50, and the exhaust gas E generated by the combustion is pushed out from the combustion chamber 26a to the exhaust passage 27 and discharged to the outside.

The intake passage 20 includes an air cleaner 21 that purifies the air A, a venturi mixer 14 that mixes the fuel gas F with the air A at an appropriate ratio, and a compressor (1a) that compresses the air-fuel mixture M mixed in the mixer 14. 2a), a throttle valve 24 capable of adjusting the intake amount of the air-fuel mixture M into the combustion chamber 26a by adjusting the opening degree, and an intercooler 25 for cooling the air-fuel mixture M are provided in the order of description from the upstream side.
That is, the air-fuel mixture M generated by mixing the fuel gas F and the air A by the mixer 14 in the intake passage 20 is compressed by the compressor (1a, 2a), and then passed through the throttle valve 24 at a predetermined flow rate. And is cooled by the intercooler 25 and introduced into the combustion chamber 26 a of the engine body 26.

  In the fuel supply path 11 for introducing the fuel gas F to the mixer 14, a differential pressure regulator that keeps the difference between the pressure of the combustion air in the intake path 20 upstream of the mixer 14 and the pressure of the fuel gas F in the fuel supply path 11 constant. 12, a fuel supply amount adjustment valve 13 for adjusting the supply amount of the fuel gas F supplied to the combustion chamber 26a via the mixer 14 is provided.

The output shaft 50 is provided with a rotation speed sensor 51 that measures the rotation speed of the output shaft 50 as the rotation speed of the engine body 26.
The ECU 40 adjusts the supply amount of the fuel gas F to the combustion chamber 26a by controlling the opening of the fuel supply amount adjustment valve 13 based on the rotation speed of the engine body 26 measured by the rotation speed sensor 51. By doing so, it functions as a rotational speed maintaining means 42 for maintaining the rotational speed of the engine body 26 at a desired target rotational speed.

The exhaust passage 27 is provided with an oxygen sensor 53 that detects the oxygen concentration of the exhaust gas E.
The ECU 40 adjusts the mixing ratio of the air A to the fuel gas F supplied to the mixer 14 by controlling the opening of the throttle valve 24 based on the oxygen concentration of the exhaust gas E detected by the oxygen sensor 53. Thus, it functions as air-fuel ratio control means 43 that maintains the air-fuel ratio of the air-fuel mixture M generated by the mixer 14 at a desired air-fuel ratio such as the theoretical air-fuel ratio.

The superchargers (1, 2) supply the exhaust gas E discharged from the combustion chamber 26a to the turbines (1b, 2b) provided in the exhaust passage 27 of the engine body 26, and are connected to the turbines (1b, 2b). The turbocharger is configured to compress the air-fuel mixture M sucked into the combustion chamber 26a by compressors (1a, 2a) provided in the intake passage 20 in a state. That is, the supercharger (1, 2) rotates the turbine (1b, 2b) by the enthalpy and kinetic energy of the exhaust gas E flowing through the exhaust passage 27, and takes in the intake air by the rotational force of the turbine (1b, 2b). The compressor (1a, 2a) disposed in the passage 20 is rotationally driven, and so-called supercharging is performed in which the air-fuel mixture M as fresh air flowing through the intake passage 20 is supplied to the combustion chamber 26a in a compressed state.
In addition, when this type of turbocharger (1, 2) is operated at a relatively high output, the amount of exhaust gas E supplied to the turbine (1b, 2b) increases. The rotational speed of the turbine (1b, 2b) and the compressor (1a, 2a) connected to the turbine (1b, 2b) increases (hereinafter referred to as “the rotational speed of the supercharger (1, 2)”). As a result, the compressor (1a, 2a), that is, the pressure between the compressors (1a, 2a) and the throttle valve 24 in the intake passage 20 (hereinafter referred to as “supercharging pressure”) increases. On the other hand, when operation is performed at a relatively low output, the amount of exhaust gas E supplied to the turbines (1b, 2b) decreases, so that the rotational speed of the superchargers (1, 2) decreases, resulting in The supercharging pressure is reduced.

The emergency generator 28 is connected to the output shaft 50, and the rotational power output from the output shaft 50 is used as a drive source for the emergency generator 28.
A power load 29 is connected to the emergency generator 28 via a power line and a switch 52. For example, the engine body 26 is activated by the ECU 40 that receives an activation command signal from the outside during a power failure, and the output shaft When the switch 52 is switched from an open state (a state in which power flow is interrupted) to a closed state (a state in which power flow is allowed) with the rotation of the motor 50 being performed, a power load is applied to the emergency generator 28. A power generation load corresponding to the power required at 29 is input, and accordingly, a rotational load necessary for rotationally driving the emergency generator 28 with respect to the output shaft 50 is input. Hereinafter, the switching of the switch 52 from the open state to the closed state in the initial stage after starting the engine body 26 in this manner and applying a rotational load to the output shaft 50 of the engine body 26 will be referred to as partial load application. There is a case.

  In the present embodiment, the turbocharged engine 100 includes an intake bypass passage 60 that connects the outlet side and the inlet side of the first compressor 1a in the intake passage 20, and an intake bypass valve 61 that is disposed in the intake bypass passage 60. It is configured with. The intake bypass path 60 includes an outlet side of the first compressor 1a (downstream side of the first compressor 1a and the upstream side of the second compressor 2a in the intake path 20) and an inlet side (upstream side of the first compressor 1a in the intake path 20). And the downstream side of the mixer 14). In other words, the intake bypass path 60 bypasses the first compressor 1a. The intake bypass valve 61 is configured to be adjustable in opening.

  The turbocharged engine 100 further includes a wastegate path 62 that connects the inlet side and the outlet side of the first turbine 1b in the exhaust path 27, and a wastegate valve 63 that is disposed in the wastegate path 62. It is configured. The wastegate path 62 includes an inlet side of the first turbine 1b (downstream of the second turbine 2b and the upstream side of the first turbine 1b in the exhaust path 27) and an outlet side (downstream of the first turbine 1b in the exhaust path 27). And the upstream side of the oxygen sensor 53). In other words, the wastegate path 62 bypasses the first turbine 1b. The wastegate valve 63 is configured to be adjustable in opening.

  The ECU 40 executes a wastegate opening process for maintaining the wastegate valve 63 in an open state when a partial load is applied to the engine body 26, and closes the wastegate valve 63 after the partial load is applied to the engine body 26. It functions as supercharging control means 41 that executes wastegate closing processing.

Hereinafter, the detailed configuration of the turbocharged engine 100 of the first embodiment will be described with reference to FIGS. 2 and 3 together with the processing flow and state transition state of the load application method.
When there is a start command to the engine body 26, the ECU 40 starts the engine body 26 while adjusting the opening of the fuel supply amount adjusting valve 13 based on the start command (# 01 in FIG. 2).
Thereafter, the rotational speed maintaining means 42 that the ECU 40 functions is based on the rotational speed of the engine body 26 measured by the rotational speed sensor 51 so that the rotational speed of the engine body 26 becomes a constant target rotational speed Rt. Rotational speed maintenance control for controlling the opening degree of the fuel supply amount adjusting valve 13 is executed (# 02 in FIG. 2). The ECU 40 continues to execute the rotation speed maintenance control while the engine body 26 is activated.
Further, in this way, when the engine body 26 is in the no-load state before the partial load Q1 is input, the opening degree of the throttle valve 24 is maintained at the smallest opening degree S1.

Next, when there is a partial load input command, the supercharging control means 41 in which the ECU 40 functions executes a wastegate opening process when the partial load Q1 is input to the engine body 26 based on the input command ( # 03, # 04 in FIG.
In other words, just before the partial load Q1 is turned on, that is, in the no-load state in which the engine output is substantially zero, the supercharging control means 41 performs the first turbine at the timing of # 04 in FIG. The opening degree of the waste gate valve 63 provided in the waste gate path 62 that bypasses 1b is changed from the closing side opening degree W1 (about 0%) to the opening side opening degree W2 (about 50%) larger than the opening degree. The waste gate valve 63 is opened in such a manner that it is changed to.
Then, since the flow of the exhaust gas E in the waste gate path 62 is permitted, the inlet side pressure of the first turbine 1b in the exhaust path 27 is the same as the outlet side pressure (substantially atmospheric pressure) of the first turbine 1b. As a result, the pumping loss in the exhaust stroke is reduced.

  By opening the wastegate valve 63, the rotational power of the first turbine 1b is reduced, and as a result, the rotational speed of the first supercharger 1 is reduced. Therefore, the opening degree of the throttle valve 24 is increased from the opening degree S1 to the opening degree S2 that is slightly larger than the opening degree S1 in accordance with the decrease in the rotational speed of the first supercharger 1 due to the wastegate opening process. The outlet pressure of the engine, in other words, the intake pressure to the combustion chamber 26a is kept constant, and fluctuations in engine output are suppressed.

  Also, in this wastegate opening process, if the opening degree of the wastegate valve 63 is fully opened (100%), the rotation of the first compressor 1a substantially stops, and the intake air necessary for applying the partial load Q1 The amount may not be secured. Therefore, in the present embodiment, in the wastegate opening process (# 04 in FIG. 2), the opening after the wastegate valve 63 is opened is set to an opening W2 of about 50%. Thereby, the first compressor 1a can be appropriately rotated while the rotational power of the first turbine 1b is appropriately reduced, and the necessary intake air amount can be ensured.

Then, the ECU 40 executes a partial load Q1 (for example, a load of about 40% with respect to the rated load (100% load)) in a state where the wastegate opening process is executed and the pumping loss is reduced. That is, the emergency generator 28 starts to be rotationally driven by the rotational power of the engine body 26 (# 05 in FIG. 2).
At this time, since the pumping loss is reduced, the responsiveness to the load is increased, so that the engine output can be made to follow the input partial load Q1 satisfactorily. As a result, in the engine body 26, the air-fuel mixture M is appropriately supplied following the application of the partial load Q1, and after the partial load Q1 is supplied, it is possible to prevent the rotation speed from dropping significantly and causing a stall. Is done.
Note that the opening W2 of the wastegate valve 63 expanded by this wastegate opening process is a change in the flow rate of the exhaust gas E in the wastegate passage 62 before and after the partial load Q1 is charged, and the exhaust gas E emission amount from the combustion chamber 26a. It is set as appropriate according to the change of.

  As the partial load Q1 is applied to the engine main body 26, the rotation speed maintaining means 42 increases the engine output and maintains the rotation speed of the engine main body 26. The supply amount of the fuel gas F is increased by increasing the valve opening. Further, as the opening of the fuel supply amount adjusting valve 13 increases, the air / fuel ratio control means 43 supplies air to maintain the air / fuel ratio of the mixture M sucked into the combustion chamber 26a at a desired air / fuel ratio. In order to increase the amount, the opening degree of the throttle valve 24 is increased to, for example, the opening degree S5 which is the largest 100% opening degree.

The supercharging control means 41 in which the ECU 40 functions performs a wastegate closing process when the engine rotational speed is maintained at the target rotational speed Rt after the partial load Q1 is applied to the engine body 26 (FIG. 2). # 06).
In other words, when the partial load charging time has elapsed after the partial load Q1 is started, it is determined that the partial load Q1 has been fully charged, and the supercharging control is performed at timing # 06 in FIG. The means 41 changes the opening degree of the wastegate valve 63 provided in the wastegate path 62 from the opening side opening W2 to the closing side opening W1 (substantially 0%) smaller than the opening degree. The waste gate valve 63 is closed.
Then, the flow of the exhaust gas E in the waste gate path 62 is prohibited, so that the inlet side pressure (exhaust pressure) becomes larger than the outlet side pressure (substantially atmospheric pressure) of the first turbine 1b. The rotational speed of the turbine 1b is increased, and the air-fuel mixture M is sufficiently compressed by the first compressor 1a. As a result, the engine efficiency is improved and a more stable operation state is maintained.

  In the present embodiment, the determination of the completion of the partial load application is made when the partial load application time (a fixed time) has elapsed after the partial load is applied to the engine body. However, when the fluctuations in the rotational speed of the engine main body 26 and the frequency of the generated power output from the emergency generator 28 driven to rotate by the engine main body 26 are settled, it is determined that the partial load application is completed. It doesn't matter.

  In addition, by setting the wastegate valve 63 in the closed state, the rotational power of the first turbine 1b is increased, and as a result, the rotational speed of the first supercharger 1 is increased. Therefore, the opening degree of the throttle valve 24 is reduced from the opening degree S5 to a smaller opening degree S3 in accordance with the increase in the rotational speed of the first supercharger 1 due to the wastegate closing process. The outlet side pressure, in other words, the intake pressure to the combustion chamber 26a is maintained constant, and fluctuations in engine output are suppressed.

After executing the partial load Q1 (# 05 in FIG. 2) and the wastegate closing process (# 06 in FIG. 2) in this way, the residual load that is input subsequent to the partial load is input (FIG. 2). 2 # 07). Note that FIG. 3 shows an example in which the remaining load following the partial load Q1 is divided into a second load Q2 and a third load Q3 and input stepwise.
Further, at the remaining loads Q2 and Q3, since the wastegate valve 63 is kept closed, the opening degree of the throttle valve 24 gradually increases as the load is applied. Specifically, as the second load Q2 is turned on, the opening of the throttle valve 24 increases from the opening S3 to a larger opening S4, and as the third load Q3 is turned on, the throttle valve 24 opens. The degree is increased from the opening degree S4 to the opening degree S5 which is larger than the opening degree S4.

Further, in the load application method of the present embodiment described so far, the intake bypass valve 61 disposed in the intake bypass passage 60 that bypasses the first compressor 1a in the intake passage 20 may be maintained in a normally closed state. However, it may be opened / closed in synchronism with the opening / closing operation of the waste gate valve 63.
That is, the supercharging control means 41 executes a bypass opening process for maintaining the intake bypass valve 61 in the open state together with the wastegate opening process (# 04 in FIG. 2) when the partial load Q1 is applied to the engine body 26. After the partial load Q1 is applied to the engine body 26, a bypass closing process for closing the intake bypass valve 61 is executed together with a wastegate closing process (# 06 in FIG. 2).
Then, when the waste gate opening process (# 04 in FIG. 2) is executed and the rotational speed of the first supercharger 1 is reduced, the bypass opening process is executed, and the mixture M in the intake bypass passage 60 is reduced. Since the flow is allowed, the pressure loss in the intake passage 20 is reduced, and as a result, the pumping loss in the intake stroke is reduced.

[Second Embodiment]
Next, the detailed configuration of the turbocharged engine 100 of the second embodiment will be described with reference to FIGS. 4 and 5 together with the processing flow and state transition of the load application method.
In addition, about the description which overlaps with the said 1st Embodiment, it may omit.

Similar to the first embodiment, the ECU 40 starts the engine body 26 (# 01 in FIG. 4), and then executes rotation speed maintenance control (# 02 in FIG. 4).
Next, when there is a partial load input command, the supercharging control means 41 in which the ECU 40 functions executes a wastegate opening process when the partial load Q1 is input to the engine body 26 based on the input command ( # 03, # 04-1 in FIG.
In other words, just before the partial load Q1 is turned on, that is, in the no-load state where the engine output is substantially zero, the supercharging control means 41 performs the first turbine at the timing of # 04 in FIG. By changing the opening degree of the wastegate valve 63 provided in the wastegate path 62 that bypasses 1b from the closing side opening degree W1 (about 0%) to the fully open (100%) opening degree W3, The valve 63 is opened, and the pumping loss in the exhaust stroke is reduced.

Moreover, the opening degree of the throttle valve 24 is expanded from the opening degree S1 to a slightly larger opening degree S2 ′ in accordance with the decrease in the rotational speed of the first supercharger 1 due to the wastegate opening process. Variation is suppressed.
In the present embodiment, in the wastegate opening process (# 04-1 in FIG. 4), the opening degree of the wastegate valve 63 is opened larger than the opening degree W2 (about 50%) in the first embodiment. Since the angle is expanded to the degree W3 (about 100%), the opening degree of the throttle valve 24 is also enlarged to the opening degree S2 ′ larger than the opening degree S2 in the first embodiment.

  Further, the supercharging control means 41 in which the ECU 40 functions simultaneously with the waste gate opening process (# 04-1 in FIG. 4), the bypass opening process (# 04- in FIG. 4) for maintaining the intake bypass valve 61 in the open state. 2) is executed to reduce the pumping loss in the intake stroke.

  Then, the ECU 40 executes the wastegate opening process and the bypass opening process, and inputs the partial load Q1 (for example, a load of 40% with respect to the rated load (100% load)) while the pumping loss is reduced. Execute (# 05 in FIG. 4).

The supercharging control means 41 in which the ECU 40 functions does not wait for the engine rotational speed to be maintained at the target rotational speed Rt after the partial load Q1 is applied to the engine body 26. The blocking process is executed (# 06-1 in FIG. 4).
In other words, when the opening of the throttle valve 24 reaches the fully open opening S5 as the partial load Q1 is turned on, it is determined that the partial load Q1 has been turned on. At the timing, the supercharging control means 41 changes the opening degree of the waste gate valve 63 provided in the waste gate path 62 from the opening degree W3 on the closing side to the closing side opening degree W1 (substantially 0%). ), The waste gate valve 63 is closed.
Further, the supercharging control means 41 in which the ECU 40 functions simultaneously with the waste gate closing process (# 06-1 in FIG. 4), the bypass closing process (# 06 in FIG. 4) for maintaining the intake bypass valve 61 in the closed state. 2) is executed, and the mixture M is supercharged by the first supercharger 1.

Then, the flow of the exhaust gas E in the waste gate path 62 is prohibited, so that the inlet side pressure (exhaust pressure) becomes larger than the outlet side pressure (substantially atmospheric pressure) of the first turbine 1b. The rotational speed of the turbine 1b increases, and the air-fuel mixture M is sufficiently compressed by the first compressor 1a. As a result, the engine rotational speed quickly returns to the target rotational speed Rt, and the engine efficiency is improved. Thus, a more stable operating state is maintained.
Further, the opening degree of the throttle valve 24 is reduced from the opening degree S5 to an opening degree S3 smaller than the opening degree S5 in accordance with the increase in the rotational speed of the first supercharger 1 due to the wastegate closing process, and the fluctuation of the engine output is changed. It is suppressed.

[Third Embodiment]
Next, the detailed configuration of the turbocharged engine 100 of the third embodiment will be described with reference to FIGS. 6 to 10 together with the processing flow and state transition of the load application method.
In addition, about the description which overlaps with the said 1st and 2nd embodiment, it may omit.

The ECU 40 activates the engine main body 26 (# 01 in FIG. 6), and then executes the rotation speed maintenance control (# 02 in FIG. 6), as in the first and second embodiments.
Next, as in the first and second embodiments, the supercharging control means 41 in which the ECU 40 functions has a partial load Q1 applied to the engine body 26 based on the charging instruction when there is a partial load charging command. The waste gate opening process is executed immediately before the injection of the engine (# 03, # 04-1, FIG. 8, # 04 in FIG. 6), and at the same time, the bypass opening process for maintaining the intake bypass valve 61 in the open state. (# 04-2 in FIG. 6 and # 04 in FIG. 8) are executed.
Then, the ECU 40 executes the wastegate opening process and the bypass opening process, and inputs the partial load Q1 (for example, a load of 40% with respect to the rated load (100% load)) while the pumping loss is reduced. Execute (# 05 in FIGS. 6 and 8).
Then, as the partial load Q1 is supplied to the engine body 26, the rotation speed maintaining means 42 increases the engine output and maintains the rotation speed of the engine body 26. The amount of fuel gas F supplied is increased by increasing the valve opening 13. Further, as the opening of the fuel supply amount adjusting valve 13 increases, the air / fuel ratio control means 43 supplies air to maintain the air / fuel ratio of the mixture M sucked into the combustion chamber 26a at a desired air / fuel ratio. In order to increase the amount, the opening degree of the throttle valve 24 is increased to, for example, the opening degree S5 which is the largest 100% opening degree.

However, even if the opening degree of the throttle valve 24 is fully opened, the engine output is insufficient and the rotational speed of the engine body 26 is insufficient in the state where the rotational speed of the first supercharger 1 is reduced due to the wastegate opening process. May significantly decrease (for example, about 100 rpm) with respect to the target rotation speed Rt.
Therefore, the ECU 40 performs the engine main body 26 after applying the partial load (# 05 in FIGS. 6 and 8) and before executing the wastegate closing process (# 06-1 in FIG. 6 and # 06 in FIG. 8). Functions as a correcting means for executing a predetermined correction process (# 05-1 in FIG. 6) described later. By executing this correction processing, the output shortage of the engine body 26 is resolved without relying on the increase in the opening of the throttle valve 24, and the rotation speed of the engine body 26 is maintained at the target rotation speed Rt.
Hereinafter, details of the correction processing will be described with reference to FIG.

In this correction processing, first, it is determined whether or not the deviation of the rotational speed of the engine body 26 from the target rotational speed Rt (hereinafter referred to as “rotational speed deviation”) exceeds a predetermined reference value ΔRt (for example, about 100 rpm). (# 11 in FIG. 7).
When the rotational speed deviation exceeds the reference value ΔRt, the opening degree of the waste gate valve 63 is changed from the opening degree W3 (about 100%) to a smaller opening degree W2 (about 50%). (# 12-1 in FIGS. 7 and 8).
Further, at the same time as the opening degree of the wastegate valve 63 is reduced (# 12-1 in FIGS. 7 and 8), the opening degree of the intake bypass valve 61 is also increased from the opening degree I3 (about 100%) to that. It is reduced in such a manner that it is changed to a small opening I2 (about 50%) (# 12-2 in FIGS. 7 and 8).
Then, the flow of the exhaust gas E in the waste gate path 62 is restricted (squeezed), and the inlet side pressure (exhaust pressure) becomes larger than the outlet side pressure (substantially atmospheric pressure) of the first turbine 1b, and the first turbine. The rotational speed of 1b increases to some extent. Then, the air-fuel mixture M is compressed to some extent by the first compressor 1a, and as a result, the engine output increases moderately.

  In FIG. 6, when the bypass opening process (# 04-2) and the bypass closing process (# 06-2) are not performed, the opening degree reduction process of the intake bypass valve 61 is performed in the correction process in FIG. (# 12-2) will be omitted.

Further, simultaneously with the reduction of the opening degree of the waste gate valve 63 (# 12-1 in FIGS. 7 and 8) and the reduction of the opening degree of the intake bypass valve 61 (# 12-2 in FIGS. 7 and 8), the fuel By increasing the opening of the supply amount adjusting valve 13 by a predetermined amount, the air ratio of the air-fuel mixture M sucked into the combustion chamber 26a changes from λ0 (for example, about 1.8) to λ1 (for example, about 1.2). In this manner, the air-fuel ratio of the air-fuel mixture M is corrected to the fuel rich side (# 12-3 in FIGS. 7 and 8).
Then, the amount of fuel input to the combustion chamber 26a per cycle increases, and as a result, the engine output increases moderately.
Then, by executing such correction processing and increasing the engine output, the shortage of output of the engine body 26 is resolved, and the engine rotation speed is maintained at the target rotation speed Rt.

After execution of such correction processing (# 05-1 in FIG. 6), wastegate closing processing (# 06-1 in FIG. 6) was executed at the stage where the engine rotation speed was maintained at the target rotation speed Rt. Later, bypass block processing (# 06-2 in FIG. 6) is executed.
That is, after the partial load Q1 is turned on (# 05 in FIG. 6), the intake bypass valve 61 is maintained in an open state to allow the air-fuel mixture M to flow through the intake bypass passage 60 and be compressed by the first compressor 1a. In a state where no load is applied, the waste gate valve 63 is closed, and the exhaust gas E is prevented from flowing through the waste gate path 62, and the rotational power of the first turbine 1b is increased. Then, the rotation speed of the first supercharger 1 temporarily increases. Thereafter, the intake bypass valve 61 is closed while the rotation speed of the first supercharger 1 is high, and the compression of the air-fuel mixture M by the first compressor 1a is started, so that the supercharging pressure rises quickly. To prepare for the input of the second load Q2 following the partial load Q1.

In the third embodiment, in the correction process (# 05-1 in FIG. 6), the opening degree reduction process (# 12-1 in FIGS. 7 and 8) of the wastegate valve 63 and the combustion chamber 26a are performed. Although it is configured to perform both the correction process (# 12-3 in FIGS. 7 and 8) of the air-fuel ratio of the intake air-fuel mixture M to the fuel rich side, only one of these processes is performed separately. You may comprise so that it may perform.
Further, in FIG. 8, the correction process (# 12-3) of the air-fuel ratio of the air-fuel mixture M sucked into the combustion chamber 26a to the fuel rich side (# 12-3) is reduced to the opening degree of the wastegate valve 63 (FIGS. Although the process is started at an earlier stage than # 12-1) in FIG. 8, these processes may be performed simultaneously or in the reverse order.

[Fourth Embodiment]
Hereinafter, the detailed configuration of the turbocharged engine 100 of the fourth embodiment will be described based on FIGS. 9 and 10 together with the processing flow and state transition of the load application method.
When there is a start command to the engine main body 26, the ECU 40 starts the engine main body 26 while adjusting the opening of the fuel supply amount adjusting valve 13 based on the start command (# 01 in FIG. 9).
Thereafter, the rotational speed maintaining means 42 that the ECU 40 functions is based on the rotational speed of the engine body 26 measured by the rotational speed sensor 51 so that the rotational speed of the engine body 26 becomes a constant target rotational speed. Rotational speed maintenance control for controlling the opening of the supply amount adjusting valve 13 is executed (# 02 in FIG. 9). The ECU 40 continues to execute the rotation speed maintenance control while the engine body 26 is activated.

Next, when there is a partial load input command, the supercharging control means 41 in which the ECU 40 functions executes a bypass opening process when a partial load is applied to the engine body 26 based on the partial load input command ( # 03, 04 in FIG.
In other words, the supercharging control means 41 bypasses the first compressor 1a at the timing of # 04 in FIG. 10 immediately before the partial load is input, that is, in the no-load state where the engine output is substantially zero. In the form of changing the opening degree of the intake bypass valve 61 provided in the intake bypass path 60 from the closing side opening degree B1 (substantially 0%) to the opening side opening degree B2 larger than the opening degree. 61 is opened.
Then, since the flow of the air-fuel mixture M in the intake bypass passage 60 is allowed, the supercharging pressure is reduced from the pressure P2 before the bypass opening process to the pressure P1 lower than that, thereby the first compressor 1a. The pressure difference of the outlet side pressure (in other words, the supercharging pressure) with respect to the inlet side pressure (substantially atmospheric pressure) of the engine becomes small, the rotational load of the first compressor 1a is reduced, and as a result, the rotational speed of the supercharger is reduced by the bypass process. It will be in the state which rose from the previous rotational speed T1 to the larger rotational speed T2.
In addition, in order to suppress the fluctuation (decrease) in the engine output accompanying the decrease in the supercharging pressure due to the bypass opening process as described above, the opening of the throttle valve 24 is slightly expanded in accordance with the opening of the intake bypass valve 61. Thus, the outlet side pressure of the throttle valve 24, in other words, the intake pressure to the combustion chamber 26a is maintained constant.

Then, the ECU 40 executes the partial load in a state where the bypass opening process is executed and the rotation speed of the first supercharger 1 is increasing. That is, the emergency generator 28 starts to rotate with the rotational power of the engine body 26 (# 05 in FIG. 9).
At this time, as shown in FIG. 10, the first supercharger 1 is driven at a high rotational speed at the timing of partial load application (# 05 in FIG. 9), and the responsiveness to the load is high. Since it becomes high, the rotational speed is made to follow well with respect to the input partial load. As a result, in the engine main body 26, the air-fuel mixture M is appropriately supplied following the partial load application, and after the partial load is applied, it is possible to prevent the rotation speed from being greatly reduced and falling into a stall.
Note that the opening degree B2 of the intake bypass valve 61 expanded by the bypass opening process is a change in the flow rate of the mixture M in the intake bypass passage 60 before and after the partial load is applied and a change in the intake amount of the mixture M with respect to the combustion chamber 26a. It is set appropriately according to

  When the rotational speed maintaining means 42 increases the engine output and maintains the rotational speed of the engine body 26 as the partial load is applied to the engine body 26, the valve of the fuel supply amount adjustment valve 13 The amount of fuel gas F supplied is increased by increasing the opening. Further, as the opening of the fuel supply amount adjusting valve 13 increases, the air / fuel ratio control means 43 supplies air to maintain the air / fuel ratio of the mixture M sucked into the combustion chamber 26a at a desired air / fuel ratio. In order to increase the amount, the opening degree of the throttle valve 24 is increased.

On the other hand, when the bypass opening process (# 04) is executed and the rotational speed of the first compressor 1a is increased, the air-fuel mixture M becomes relatively high from the outlet side of the first compressor 1a toward the downstream side. It will be in the state where it is discharged.
Therefore, in this state, when a partial load is applied to the engine body 26 and the opening of the throttle valve 24 disposed on the downstream side of the first compressor 1a is expanded, immediately after the throttle valve 24 is expanded, The air-fuel mixture M discharged at a high speed fills the combustion chamber 26a with its strong inertia force.

The supercharging control means 41 in which the ECU 40 functions performs a bypass closing process after the partial load is applied to the engine body 26 (# 06 in FIG. 9).
In other words, when the partial load application time has elapsed since the start of the partial load application, it is determined that the partial load application has been completed, and the supercharging control means 41 determines at timing # 06 in FIG. The intake air bypass valve 61 provided in the intake air bypass passage 60 is changed from the opening degree B2 on the opening side to the opening degree B1 (substantially 0%) on the closing side smaller than the opening degree. The valve 61 is closed.
Then, since the flow of the air-fuel mixture M in the intake bypass passage 60 is prohibited, the pressure difference between the outlet side pressure (supercharging pressure) and the inlet side pressure of the first compressor 1a becomes large, and the supercharging pressure is increased. Increases to a pressure P3 higher than the pressure P2 before the bypass opening process, and the air-fuel mixture M is sufficiently compressed by the first compressor 1a. As a result, the engine efficiency is improved and the operation state is further stabilized. Will be maintained.

Further, in this bypass closing process, the supercharging control means 41 gradually reduces the opening degree of the intake bypass valve 61 at a predetermined increase rate as the engine output increases.
Then, the exhaust energy of the exhaust gas E supplied to the first turbine 1b increases due to the increase in the engine output in accordance with the increase in the rotational load of the first compressor 1a due to the blockage of the intake bypass valve 61. Therefore, even after the partial load is applied, the rotational speed of the first supercharger 1 can be maintained at a high level, and a decrease in engine efficiency and a stall due to a sudden blockage of the intake bypass valve 61 are avoided.
Then, the ECU 40 increases the engine output to the rated output Q2 simultaneously with the execution of the bypass opening process and the bypass closing process (# 07).
Further, in order to suppress the fluctuation (rise) of the engine output accompanying the increase of the supercharging pressure due to the bypass closing process as described above, the opening degree of the throttle valve 24 is slightly reduced in accordance with the closing of the intake bypass valve 61. Thus, the outlet side pressure of the throttle valve 24, in other words, the intake pressure to the combustion chamber 26a is maintained constant.

[Fifth Embodiment]
Hereinafter, the detailed configuration of the turbocharged engine 100 of the fifth embodiment will be described with reference to FIGS. 11 to 13 together with the processing flow and state transition state of the load application method.
In addition, about the description which overlaps with the said 4th Embodiment, it may omit.

As in the fourth embodiment, the ECU 40 starts the engine body 26 (# 01 in FIG. 11), and then executes rotational speed maintenance control (# 02 in FIG. 11).
Next, when there is a partial load input command, the supercharging control means 41 in which the ECU 40 functions performs a bypass opening process immediately before the partial load Q1 is input to the engine body 26 performed based on the input command. This is executed (# 03 in FIG. 11, # 04 in FIGS. 11 and 13).
In other words, just before the partial load Q1 is turned on, that is, in the no-load state where the engine output is substantially zero, the supercharging control means 41 performs the first compressor at the timing of # 04 in FIG. In the form of changing the opening degree of the intake bypass valve 61 provided in the intake bypass path 60 bypassing 1a from the closing side opening degree I1 (about 0%) to the fully opening degree (100%) opening degree I3. The valve 61 is opened to reduce the pumping loss in the intake stroke.
Further, the opening of the throttle valve 24 is expanded from the opening S1 to a slightly larger opening S2 in accordance with the decrease in the supercharging pressure due to the bypass opening process, and the fluctuation of the engine output is suppressed.

Then, the ECU 40 performs a bypass opening process and the partial load Q1 (for example, a load of 40% with respect to the rated load (100% load)) while the rotation speed of the first supercharger 1 is increasing. The charging is executed (# 05 in FIGS. 11 and 13).
Then, as the partial load Q1 is supplied to the engine body 26, the rotation speed maintaining means 42 increases the engine output and maintains the rotation speed of the engine body 26. The amount of fuel gas F supplied is increased by increasing the valve opening 13. Further, as the opening of the fuel supply amount adjusting valve 13 increases, the air / fuel ratio control means 43 supplies air to maintain the air / fuel ratio of the mixture M sucked into the combustion chamber 26a at a desired air / fuel ratio. In order to increase the amount, the opening degree of the throttle valve 24 is increased to, for example, the opening degree S5 which is the largest 100% opening degree.

However, even if the opening degree of the throttle valve 24 is fully opened, the engine output is insufficient and the rotational speed of the engine body 26 is less than the target rotational speed Rt when the boost pressure is reduced by the bypass opening process. In some cases (for example, about 100 rpm).
Therefore, when the output of the engine body 26 is insufficient after the partial load is input (# 05 in FIGS. 11 and 13) and before the bypass closing process is executed (# 06 in FIG. 11), the ECU 40 It functions as a correction means for executing a predetermined correction process (# 05-1 in FIG. 11) described later. By executing this correction processing, the output shortage of the engine body 26 is resolved without relying on the increase in the opening of the throttle valve 24, and the rotation speed of the engine body 26 is maintained at the target rotation speed Rt.
Hereinafter, the details of the correction processing will be described with reference to FIG.

In this correction processing, first, it is determined whether or not the deviation of the rotational speed of the engine body 26 from the target rotational speed Rt (hereinafter referred to as “rotational speed deviation”) exceeds a predetermined reference value ΔRt (for example, about 100 rpm). (# 11 in FIG. 12).
When the rotational speed deviation exceeds the reference value ΔRt, the opening degree of the intake bypass valve 61 is changed from the opening degree I3 (about 100%) to a smaller opening degree I2 (about 50%). (# 12-1 in FIGS. 12 and 13).
Then, the air-fuel mixture M is compressed to some extent by the first compressor 1a, and as a result, the engine output increases moderately.

Further, simultaneously with the reduction of the opening degree of the intake bypass valve 61 (# 12-1 in FIGS. 12 and 13), the opening degree of the fuel supply amount adjusting valve 13 is increased by a predetermined amount, whereby the intake air is introduced into the combustion chamber 26a. The air-fuel ratio of the air-fuel mixture M is corrected to the fuel rich side in such a form that the air ratio of the air-fuel mixture M changes from λ0 (for example, about 1.8) to λ1 (for example, about 1.2) (FIG. 12). And # 12-2 in FIG.
Then, the amount of fuel input to the combustion chamber 26a per cycle increases, and as a result, the engine output increases moderately.
Then, by executing such correction processing and increasing the engine output, the shortage of output of the engine body 26 is resolved, and the engine rotation speed is maintained at the target rotation speed Rt.

After such correction processing (# 05-1 in FIG. 11) is executed, bypass closing processing (# 06 in FIG. 13) is executed when the engine speed is maintained at the target rotation speed Rt.
That is, after the partial load Q1 is input (# 05 in FIG. 11), the intake bypass valve 61 is closed while the rotational speed of the first supercharger 1 is high, and the mixture M by the first compressor 1a is blocked. Since the compression is started, the supercharging pressure rises quickly, and it is prepared for the input of the second load Q2 following the partial load Q1.

Then, after executing the partial load Q1 (# 05 in FIG. 13) and the bypass closing process (# 06 in FIG. 13) in this way, the residual loads Q2 and Q3 that are input following the partial load are input. . Note that FIG. 13 shows an example in which the remaining load following the partial load Q1 is divided into a second load Q2 and a third load Q3 and is input stepwise.
In addition, during the remaining loads Q2 and Q3, since the intake bypass valve 61 is kept closed, the opening degree of the throttle valve 24 gradually increases as the load is applied. Specifically, as the second load Q2 is turned on, the opening of the throttle valve 24 increases from the opening S3 to a larger opening S4, and as the third load Q3 is turned on, the throttle valve 24 opens. The degree is increased from the opening degree S4 to the opening degree S5 which is larger than the opening degree S4.

  In the fifth embodiment, the correction process (# 12-2) of the air-fuel ratio of the air-fuel mixture M sucked into the combustion chamber 26a to the fuel rich side in FIG. Although the process is started at an earlier stage than the reduction process (# 12-1 in FIGS. 11 and 13), these processes may be performed simultaneously or in the reverse order.

[Relationship between turbocharger load ratio and efficiency]
The graph of FIG. 14 shows the relationship between the load ratio (horizontal axis) of the compressor and the efficiency (vertical axis) of the supercharger. According to this graph, it is understood that the efficiency of the supercharger increases as the load ratio increases up to around the load ratio 0.5. Here, at a specific partial load, (1) when the intake pressure is generated using two superchargers, and (2) the same intake pressure (bypassing one supercharger), one supercharger Compare with the case where it is generated. In the state of (2), when the load ratio of one supercharger is 0.4, the supercharger efficiency is increased by 8 points% from the graph of FIG. Considering the case of (1) at this time, since the load ratio of each supercharger is 0.2, the efficiency of the two superchargers is only increased by 5 points%. From the above examination, at a specific partial load, one supercharger (for example, the first supercharger) is used rather than covering the intake pressure with the two supercharger stages (the first supercharger 1 and the second supercharger 2). Bypassing the supercharger 1) and supplying the intake pressure with only one supercharger (second supercharger 2), it can be said that the operation with high supercharger efficiency is achieved.

[Sixth Embodiment]
In the first to fifth embodiments, the turbocharged engine 100 is configured such that the intake bypass passage 60 bypasses the first compressor 1a and the wastegate passage 62 bypasses the first turbine 1b. In the sixth embodiment shown in FIG. 15, the turbocharged engine 100 is configured such that the intake bypass passage 60 bypasses the second compressor 2a and the wastegate passage 62 bypasses the second turbine 2b.

  That is, in the present embodiment, the turbocharged engine 100 includes an intake bypass path 60 that connects the outlet side and the inlet side of the second compressor 2 a in the intake path 20, and an intake bypass valve 61 that is disposed in the intake bypass path 60. And is configured. The intake bypass path 60 includes an outlet side of the second compressor 2a (downstream of the second compressor 2a and the upstream side of the throttle valve 24 in the intake path 20) and an inlet side (upstream of the second compressor 2a in the intake path 20 and To the downstream side of the first compressor 1a).

  Further, the turbocharged engine 100 includes a wastegate passage 62 that connects the inlet side and the outlet side of the second turbine 2b in the exhaust passage 27, and a wastegate valve 63 disposed in the wastegate passage 62. It is configured. The wastegate path 62 has an inlet side (downstream of the combustion chamber 26a and upstream of the second turbine 2b in the exhaust path 27) and an outlet side (downstream of the second turbine 2b in the exhaust path 27) and the second turbine 2b. The upstream side of the first turbine 1b).

  In the turbocharged engine 100 according to the sixth embodiment configured as described above, various controls performed in the turbocharged engine 100 according to the first to fifth embodiments described above are similarly performed. Is called.

[Seventh Embodiment]
In the first to fifth embodiments, the turbocharged engine 100 is configured such that the intake bypass passage 60 bypasses the first compressor 1a and the wastegate passage 62 bypasses the first turbine 1b. In the seventh embodiment shown in FIG. 16, turbocharging is performed so that the intake bypass passage 60 bypasses the first compressor 1a and the second compressor 2a, and the wastegate passage 62 bypasses the first turbine 1b and the second turbine 2b. An expression engine 100 is configured.

  In other words, in the present embodiment, the turbocharged engine 100 is disposed in the intake bypass path 60 that connects the outlet side of the second compressor 2 a and the inlet side of the first compressor 1 a in the intake path 20, and the intake bypass path 60. And an intake bypass valve 61. The intake bypass path 60 includes an outlet side of the second compressor 2a (a downstream side of the second compressor 2a and an upstream side of the throttle valve 24 in the intake path 20) and an inlet side of the first compressor 1a (a first compressor in the intake path 20). 1a and the downstream side of the mixer 14).

  Further, the turbocharged engine 100 includes a wastegate passage 62 connecting the inlet side of the second turbine 2b and the outlet side of the first turbine 1b in the exhaust passage 27, and a wastegate valve disposed in the wastegate passage 62. 63. The wastegate path 62 includes an inlet side of the second turbine 2b (a downstream side of the combustion chamber 26a and an upstream side of the second turbine 2b in the exhaust path 27) and an outlet side of the first turbine 1b (the first turbine in the exhaust path 27). 1b and upstream of the oxygen sensor 53).

  In the turbocharged engine 100 according to the seventh embodiment configured as described above, various controls performed in the turbocharged engine 100 according to the first to fifth embodiments described above are similarly performed. Is called.

[Other Embodiments]
Other embodiments of the present invention will be described. Note that the configuration of each embodiment described below is not limited to being applied independently, and can be applied in combination with the configuration of other embodiments as long as no contradiction arises.

(1) In the above embodiment, the rotation speed maintaining means 42 controls the opening of the fuel supply amount adjusting valve 13 in order to maintain the rotation speed of the engine body 26 at a desired target rotation speed, and the air-fuel ratio control means 43. However, in order to maintain the air-fuel ratio of the air-fuel mixture M generated by the mixer 14 at a desired air-fuel ratio such as the stoichiometric air-fuel ratio, the opening degree of the throttle valve 24 is controlled. The means 42 adjusts the opening degree of the throttle valve 24 to maintain the rotational speed of the engine body 26 at a desired target rotational speed, and the air-fuel ratio control means 43 controls the opening degree of the fuel supply amount adjusting valve 13. The air-fuel ratio of the air-fuel mixture M generated by the mixer 14 may be maintained at a desired air-fuel ratio such as the stoichiometric air-fuel ratio.

(2) In the above embodiment, the case where the partial load is input after executing the waste gate opening process when the partial load input command is issued has been described. However, the partial load is input without the input of the initial input command. In such a case, the wastegate opening process may be executed unconditionally immediately after starting the engine to prepare for partial load application.

(3) In the above-described embodiment, regarding the determination of completion of partial load application, it is determined that partial load application has been completed when a partial load application time (constant time) has elapsed after the partial load is applied to the engine body. did.
However, regarding the determination of the completion of the partial load application, the partial load application is completed when fluctuations in the rotational speed of the engine body 26 and the frequency of the power generated by the emergency generator 28 driven to rotate by the engine body 26 are settled. You may comprise so that it may determine.

(4) In the above embodiment, the configuration in which the opening of the intake bypass valve 61 is gradually reduced as the engine output increases in the bypass closing process has been described. You may comprise so that a degree may be closed in steps or at a stretch.

(5) In the above embodiment, the case where the partial load is input after executing the bypass opening process when the partial load input command is issued (# 03, 04, # 05 in FIG. 9) has been described. If there is no input of the initial input command and a partial load is input, the bypass opening process is executed unconditionally immediately after the engine is started, so that it is prepared for partial load input. It doesn't matter.

1: First supercharger (supercharger)
1a: 1st compressor 1b: 1st turbine 2: 2nd supercharger (supercharger)
2: Claim 2a: Second compressor 2b: Second turbine 20: Intake passage 24: Throttle valve 26: Engine body 26a: Combustion chamber 27: Exhaust passage 41: Supercharging control means 42: Rotational speed maintaining means 60: Intake bypass passage 61: Intake bypass valve 62: Wastegate path 63: Wastegate valve 100: Turbocharged engine A: Air E: Exhaust gas M: Air-fuel mixture

Claims (21)

An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
A wastegate path connecting the outlet side and the inlet side of the first turbine, the outlet side and the inlet side of the second turbine, or the outlet side of the first turbine and the inlet side of the second turbine in the exhaust path; And a wastegate valve disposed in the wastegate path,
A turbocharged engine comprising a supercharging control means for performing a wastegate opening process for maintaining the wastegate valve in an open state when a partial load is applied to the engine body.   The turbocharged engine according to claim 1, wherein the supercharging control means executes a wastegate closing process for closing the wastegate valve after a partial load is applied to the engine body. A throttle valve is disposed downstream of the supercharger in the intake passage;
3. The turbo according to claim 2, wherein the opening degree of the throttle valve is increased by the rotation speed maintaining means executing the rotation speed maintaining control of the engine body with the introduction of a partial load to the engine body. Supercharged engine. The engine body is charged with a residual load following the partial load,
The turbocharged engine according to claim 2 or 3, wherein the supercharging control means executes the wastegate closing process before the remaining load is applied to the engine body.   Correction means for executing a correction process for correcting the opening degree of the waste gate valve to the reduction side when an output shortage of the engine body occurs after the partial load is applied and before the waste gate closing process is executed. The turbocharged engine according to any one of claims 2 to 4, further comprising:   A correction process for correcting the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber to the fuel rich side when an output shortage of the engine body occurs after the partial load is applied and before the waste gate closing process is performed. The turbocharged engine according to any one of claims 2 to 5, further comprising a correcting unit that executes the following.   The turbocharged engine according to any one of claims 1 to 6, wherein the waste gate path connects an outlet side and an inlet side of the first turbine. An intake bypass path connecting the outlet side and the inlet side of the first compressor in the intake path, and an intake bypass valve disposed in the intake bypass path,
The turbocharger type according to claim 7, wherein the supercharging control means executes a bypass opening process for maintaining the intake bypass valve in an open state together with the wastegate opening process when a partial load is applied to the engine body. engine.   The turbocharged engine according to any one of claims 1 to 6, wherein the wastegate path connects an outlet side of the first turbine and an inlet side of the second turbine. An intake bypass path connecting the outlet side of the second compressor and the inlet side of the first compressor in the intake path, and an intake bypass valve disposed in the intake bypass path,
The turbocharger according to claim 9, wherein the supercharging control means executes a bypass opening process for maintaining the intake bypass valve in an open state together with the wastegate opening process when a partial load is applied to the engine body. engine.   The turbocharged engine according to claim 6, wherein the supercharging control means executes the bypass closing process after executing the wastegate closing process after the partial load is applied to the engine body. An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
A wastegate path connecting the outlet side and the inlet side of the first turbine, the outlet side and the inlet side of the second turbine, or the outlet side of the first turbine and the inlet side of the second turbine in the exhaust path; Providing a wastegate valve disposed in the wastegate path,
A wastegate closing process for performing a wastegate opening process for maintaining the wastegate valve in an open state when a partial load is applied to the engine body, and closing the wastegate valve after the partial load is applied to the engine body. The turbocharged engine load input method to be executed. An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharged engine comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed;
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
An intake bypass passage connecting the outlet side and the inlet side of the first compressor, the outlet side and the inlet side of the second compressor, or the outlet side of the second compressor and the inlet side of the first compressor in the intake passage; And an intake bypass valve disposed in the intake bypass path,
A turbocharged engine comprising a supercharging control means for performing bypass opening processing for maintaining the intake bypass valve in an open state when a partial load is applied to the engine body.   The turbocharged engine according to claim 13, wherein the supercharging control means executes a bypass closing process for closing the intake bypass valve after a partial load is applied to the engine body. A throttle valve is disposed downstream of the compressor in the intake passage,
15. The turbo engine according to claim 14, wherein the opening degree of the throttle valve is increased by the rotation speed maintaining means performing the rotation speed maintaining control of the engine with the introduction of a partial load to the engine body. Feeding engine.   The turbocharged engine according to claim 14 or 15, wherein the supercharging control means gradually reduces the opening degree of the intake bypass valve as the engine output increases in the bypass closing process.   A correction process in which the supercharging control means corrects the opening degree of the intake bypass valve to the reduction side when an output shortage of the engine body occurs after the partial load is applied and before the bypass closing process is performed. The turbocharged engine according to any one of claims 14 to 16, further comprising a correcting unit that executes the following.   The supercharging control means is configured to reduce the air-fuel ratio of the air-fuel mixture sucked into the combustion chamber when the output of the engine body is insufficient after the partial load is applied and before the bypass closing process is performed. The turbocharged engine according to any one of claims 14 to 17, further comprising correction means for executing a correction process for correcting to the side.   The turbocharged engine according to any one of claims 13 to 18, wherein the intake bypass path connects an outlet side and an inlet side of the first compressor.   The turbocharged engine according to any one of claims 13 to 18, wherein the intake bypass path connects an outlet side of the second compressor and an inlet side of the first compressor. An engine body that generates rotational power by compressing and burning a mixture of fuel and air in a combustion chamber;
Exhaust gas discharged from the combustion chamber is supplied to a turbine provided in an exhaust passage of the engine body, and fresh air taken into the combustion chamber is compressed by a compressor provided in the intake passage while being connected to the turbine. A turbocharger,
A turbocharging engine load application method comprising a rotation speed maintaining means for maintaining a rotation speed of the engine body at a target rotation speed,
The supercharger has a first supercharger having a first turbine and a first compressor, and a second supercharger having a second turbine and a second compressor,
The first turbine is disposed downstream of the second turbine in the exhaust passage;
The first compressor is disposed upstream of the second compressor in the intake passage;
An intake bypass passage connecting the outlet side and the inlet side of the first compressor, the outlet side and the inlet side of the second compressor, or the outlet side of the second compressor and the inlet side of the first compressor in the intake passage; An intake bypass valve disposed in the intake bypass path,
A bypass opening process is performed to maintain the intake bypass valve in an open state when a partial load is applied to the engine body, and a bypass closing process is performed to close the intake bypass valve after the partial load is applied to the engine body. How to load a turbocharged engine.

Images