JP2009191742A - In-vehicle internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate engine output torque corresponding to demand torque while assisting the operation of a turbocharger by using pressure in a pressure accumulation vessel without requiring the further use of an apparatus expanding an internal combustion engine even if high pressure does not exists in the pressure accumulation vessel in the in-vehicle internal combustion engine provided with a structure controlling and opening a control valve to supply pressure in the pressure accumulation vessel to a turbine of the turbocharger for assisting the operation of the turbocharger when demand torque quantity increases. <P>SOLUTION: This in-vehicle internal combustion engine 10 is provided with a fuel injection quantity correction means increasing and correcting a fuel injection quantity from a fuel injection valve 12 based on pressure in the pressure accumulation vessel 68 when demand torque increases and the pressure in the pressure accumulation vessel 68 is not higher than prescribed pressure. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an in-vehicle internal combustion engine having a configuration capable of assisting an operation of a turbocharger using a pressure in a pressure accumulating vessel.

  It has been proposed that various members are actuated or assisted by using a gas having a high pressure in the pressure accumulating vessel. As an example, Patent Document 1 discloses an acceleration device for a turbocharger that uses compressed air in an accumulator to improve the transient response of a turbocharger mounted in an internal combustion engine. . The device of Patent Document 1 includes an air supply mechanism capable of supplying compressed air between an exhaust port and a turbine according to the engine operating state, and the air supply mechanism supplies compressed air discharged from a pump. A reservoir tank, that is, a pressure accumulating container capable of accumulating and holding, and a valve mechanism for supplying compressed air in the pressure accumulating container between the exhaust port and the turbine are provided. Further, Patent Document 2 discloses an acceleration assist device in an internal combustion engine with a supercharger in which acceleration of the internal combustion engine is detected and a nozzle that blows compressed air to a turbine wheel provided in an exhaust passage is provided. ing. The device of Patent Document 2 includes an exhaust recovery passage branched from an exhaust passage between a turbine and an exhaust brake exhaust shutter provided in the exhaust passage and connected to a high-pressure tank, that is, a pressure accumulating vessel. A one-way valve that is opened when the exhaust brake is applied is interposed in the exhaust recovery passage, while a valve that is opened when the engine is accelerated is interposed in the compressed air passage that connects the pressure accumulating vessel and the nozzle.

  However, in the devices described in Patent Documents 1 and 2, when the pressure in the pressure accumulating vessel is equal to or lower than the pressure necessary to cause the rotational drive to exceed the rotational drive of the turbine wheel due to the pressure generated by the exhaust gas flow The rotational drive of the turbine wheel cannot be appropriately assisted using the pressure. Therefore, a supercharging control device for an internal combustion engine, which has been devised to solve this problem, is disclosed in Patent Document 3. In order to quickly raise the supercharging pressure even when accelerating from a low load state, this device is used to increase the pressure of compressed air generated in the compressor and accumulated in the air tank, that is, the pressure accumulating vessel, when acceleration is requested. , A configuration for jetting toward the turbine rotor of the turbocharger through the nozzle, and further, when the pressure in the pressure accumulating vessel is lower than a predetermined pressure when the acceleration is requested, the pressure from the pressure accumulating vessel An auxiliary positive pressure generator that additionally supplies pressure to the nozzle is provided so as to supplement the pressure.

Japanese Patent Laid-Open No. 62-276221 Japanese Utility Model Publication No. 61-57138 JP 2006-105026 A

  In the apparatus described in Patent Document 3, it is necessary to provide an auxiliary positive pressure generator in addition to the compressor that supplies the compressed air to the pressure accumulating container. On the other hand, in recent years, reduction of vehicles has been desired from the viewpoint of energy saving and the like. In view of this point, the device described in Patent Document 3 in which it is necessary to provide both the auxiliary positive pressure generator and the compressor has a problem to be overcome in terms of reduction.

  Therefore, the present invention was devised in view of such a point, and the purpose thereof is to expand the internal combustion engine even when there is no high pressure in the pressure accumulating container when the required torque amount increases, such as during acceleration. The engine output torque corresponding to the required torque is generated while assisting the operation of the turbocharger using the pressure without requiring further use of the equipment.

  In order to achieve the above object, an in-vehicle internal combustion engine of the present invention includes required torque amount determination means for determining whether or not the required torque amount has increased, an exhaust passage in the accumulator vessel and on the upstream side of the turbine wheel of the turbocharger. A control valve provided in a passage that enables communication with the control valve, and when the affirmative determination is made by the required torque amount determination means, the control valve is controlled to open so that the pressure in the pressure accumulating vessel is supplied to the turbine wheel An on-vehicle internal combustion engine including a control valve control means, wherein the pressure determination means for determining whether or not the pressure in the pressure accumulating vessel is equal to or lower than a predetermined pressure, and a positive determination is made by the required torque amount determination means, and The fuel injection amount correcting means corrects the fuel injection amount to be increased based on the pressure in the pressure accumulating container when the pressure determining means makes an affirmative determination.

  According to this configuration, an affirmative determination is made that the required torque amount has increased by the required torque amount determination means, and an affirmative determination has been made by the pressure determination means that the pressure in the pressure accumulating vessel is equal to or lower than a predetermined pressure. When the control valve control means opens the control valve so that the pressure in the pressure accumulator vessel is supplied to the turbine wheel, the fuel injection amount correction means increases the fuel injection amount based on the pressure in the pressure accumulator vessel. Is done. Therefore, even if the operation assistance for the turbocharger is insufficient due to insufficient pressure in the pressure accumulating vessel, the engine output torque that is insufficient due to this can be compensated by torque increase due to the increase in fuel injection amount. Thus, according to the present invention, even when there is no high pressure in the pressure accumulator vessel when the required torque amount increases, such as during acceleration, without the need for further use of equipment for expanding the internal combustion engine, The engine output torque corresponding to the required torque can be generated while assisting the operation of the turbocharger using the pressure.

  Further, specifically, the fuel injection amount correcting means is responsive to a ratio between a predetermined reference tank pressure and a pressure in the pressure accumulating container at a start time of the valve opening control of the control valve by the control valve control means. It is desirable to correct the fuel injection amount to be increased. By doing so, it becomes possible to appropriately increase the fuel injection amount in consideration of the pressure in the pressure accumulating container at the start of the valve opening control of the control valve by the control valve control means.

  Specifically, the fuel injection amount increase correction amount by the fuel injection amount correction means may be changed based on the supercharging pressure. By doing so, it becomes possible to inject an amount of fuel appropriately following the operating state of the turbocharger. Preferably, the time during which the fuel injection amount is corrected to be increased by the fuel injection amount correcting means is set based on at least one of the engine speed and the transmission gear ratio. By doing so, it becomes possible to appropriately compensate for the shortage of the engine output torque due to the increase in the supercharging pressure due to the lack of the operation assist to the turbocharger by the increase in torque caused by the increase in the fuel injection amount.

  Preferably, the internal combustion engine of the various aspects described above is a compression ignition engine, and the internal combustion engine advances the fuel injection timing by an amount corresponding to the fuel injection amount increase correction amount by the fuel injection amount correction means. Fuel injection timing correction means for correcting the angle is further provided. By doing so, the increased amount of fuel can be appropriately burned in the combustion chamber. Therefore, it is possible to suppress the generation of smoke, that is, exhaust graphite. However, the advance correction amount by the fuel injection timing correction means may be set based on the engine speed. By doing so, it becomes possible to more appropriately supply fuel to the combustion chamber.

  Preferably, the various on-vehicle internal combustion engines perform pressure recovery via an exhaust throttle valve provided in an exhaust passage of the internal combustion engine and a valve from the exhaust passage upstream of the exhaust throttle valve to the pressure accumulating vessel. Accordingly, exhaust throttle valve control means for closing the exhaust throttle valve is further provided. By doing so, it becomes possible to increase the pressure of the exhaust gas and recover the increased pressure to the pressure accumulating vessel.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a schematic configuration of an internal combustion engine system for a vehicle to which the first embodiment is applied. The internal combustion engine (vehicle-mounted internal combustion engine) 10 is a type of compression ignition engine, that is, a diesel engine, that spontaneously ignites by directly injecting light oil as fuel into a combustion chamber 14 in a compressed state from a fuel injection valve 12.

  An intake port 20 facing the combustion chamber 14 of the cylinder 16 and defining a part of the intake passage 18 is formed in the cylinder head 22 and is opened and closed by the intake valve 24. An intake manifold 26 that defines a portion of the intake passage 18 is connected to the cylinder head 22, and a surge tank 28 and an intake pipe 30 that each form a portion of the intake passage 18 are similarly formed on the upstream side thereof. It is connected. An air cleaner 32 is provided on the upstream end side of the intake pipe 30 to remove dust and the like in the air guided to the intake passage 18. A throttle valve 36 whose opening degree is adjusted by the throttle actuator 34 is provided in the intake passage 18.

  On the other hand, an exhaust port 40 facing the combustion chamber 14 of the cylinder 16 and defining a part of the exhaust passage 38 is formed in the cylinder head 22 and is opened and closed by an exhaust valve 42. An exhaust manifold 44 that defines a part of the exhaust passage 38 is connected to the cylinder head 22, and an exhaust pipe 46 and a catalytic converter 48 that each form a part of the exhaust passage 38 are similarly connected downstream of the cylinder head 22. It is connected. The catalytic converter 48 is filled with an exhaust gas purification catalyst including an oxidation catalyst.

  Further, a turbine 50 including a turbine wheel provided in the exhaust passage 38 and driven to rotate by exhaust gas is provided in the middle of the exhaust pipe 46. Correspondingly, a compressor 54 including a compressor wheel that is coaxially connected to the turbine wheel via a rotating shaft 52 and is rotated by the rotational force of the turbine wheel is provided in the middle of the intake pipe 30. That is, the internal combustion engine 10 is provided with a turbocharger 56 provided with a turbocharger 56 having a turbine 50 that extracts exhaust energy and a compressor 54 that supercharges the internal combustion engine 10 with the exhaust energy extracted by the turbine 50. Internal combustion engine. An intercooler 58 is provided on the downstream side of the compressor 54 in order to cool the air compressed by the compressor 54.

  Further, an exhaust throttle valve 60 is provided in the middle of the exhaust passage 38. Here, the exhaust throttle valve 60 is provided on the downstream side of the turbine 50 and on the upstream side of the catalytic converter 48. However, the exhaust throttle valve 60 is provided in another part of the exhaust passage 38 such as an exhaust pipe or an exhaust manifold 44 on the upstream side of the turbine 50. May be. In the first embodiment, the exhaust throttle valve 60 is a butterfly valve and is driven by an actuator 62 that is an electric motor. When the exhaust throttle valve 60 is closed, the exhaust gas flowing through the exhaust passage 38, that is, a fluid such as combustion gas or air, is effectively blocked, and the flow of such fluid downstream from the exhaust throttle valve 60 is substantially blocked. Functions as a shutoff valve. The exhaust throttle valve 60 may be a valve having a configuration that completely closes the exhaust passage 38 when the valve is closed.

  A pipe line 64 is communicated with an exhaust passage (interval passage) J between the exhaust valve 42 and the exhaust throttle valve 60 in the exhaust passage 38. The pipe 64 is partitioned by a pipe member 66. The exhaust passage 38 and the inside of the pressure accumulating vessel 68 can be communicated with each other by a pipe 64. The pressure accumulation container 68 is a container capable of storing pressurized gas. The accumulator 68 can be connected to any location, for example, the exhaust manifold 44, as long as it is an inter-valve passage J. Here, the pressure accumulating vessel 68 is upstream of the exhaust throttle valve 60 and upstream of the turbine 50 in the exhaust passage 38. Connected to the place. The diameter of the pipe line 64 is smaller than the diameter of the exhaust passage 38. A flow rate control valve 70 is provided in the pipe 64 for adjusting the communication state between the pressure accumulating vessel 68 and the exhaust passage 38. The flow control valve 70 is opened and closed by the actuator 72. However, when the flow control valve 70 is opened, the inside of the pressure accumulating vessel 68 and the exhaust passage 38 are communicated with each other, and the flow control valve 70 is closed. Thus, the communication between the pressure accumulating vessel 68 and the exhaust passage 38 is blocked, and the pressure accumulating vessel 68 is substantially sealed. However, here, the flow control valve 70 is a poppet valve. Note that a nozzle may be provided at the downstream end of the pipe line 64, and more preferably, the nozzle is directed to the turbine wheel.

  As will be described later, the pressure (pressure energy) in the exhaust passage 38 is recovered from the exhaust passage 38 into the pressure accumulator 68 through the pipe 64 through the movement of the exhaust gas. On the other hand, the pressure stored in the pressure accumulating vessel 68 is discharged from the pressure accumulating vessel 68 to the exhaust passage 38 through the pipe 64 through the movement of the exhaust gas, and is used. That is, in the first embodiment, the pressure recovery into the pressure accumulating vessel 68 and the use of the pressure therefrom are performed through the same pipe line 64.

  In this case, the exhaust gas collected in the pressure accumulating vessel 68, that is, the pressure of the exhaust gas is supplied to the turbine wheel in the exhaust passage 38 via the pipe line 64 when acceleration is requested, particularly in the early stage of acceleration. It is discharged into the upstream exhaust passage K. The released pressure is used for rotational driving of the turbine wheel of the turbine 50 of the turbocharger 56. Thus, the operation assistance of the turbocharger 56 is executed, and the response of the turbocharger 56 is improved.

  Further, the internal combustion engine 10 includes various sensors that electrically output signals for calculating (detecting or estimating) various values in an electronic control unit (ECU) 80. Here, some of them will be specifically described. An air flow meter 82 for detecting the intake air amount is provided in the intake pipe 30. An intake air temperature sensor 84 for detecting the temperature of intake air is provided near the air flow meter 82, and an intake air temperature sensor 86 for detecting the temperature is also provided downstream of the intercooler 58. A pressure sensor 88 for detecting intake pressure, that is, supercharging pressure, is provided downstream of the intercooler 58 in the intake passage 18. Further, an accelerator opening sensor 92 for detecting a position corresponding to the depression amount of the accelerator pedal 90 operated by the driver, that is, an accelerator opening is provided. A throttle position sensor 94 for detecting the opening of the throttle valve 36 is also provided. Further, a crank position sensor 104 for detecting a crank rotation signal of the crankshaft 102 to which the piston 96 is connected via the connecting rod 100 is attached to the cylinder block 98 in which the piston 96 reciprocates. Here, the crank position sensor 104 is also used as an engine speed sensor for detecting the engine speed (engine speed). Further, a pressure sensor 106 for detecting the pressure of a fluid such as exhaust gas, that is, combustion gas or air, in the inter-valve passage J is provided. A pressure sensor 108 for detecting the pressure in the pressure accumulating vessel 68 is also provided. In addition, although not shown in the drawing, a temperature sensor for detecting the cooling water temperature of the internal combustion engine 10, an oxygen concentration sensor that can detect the oxygen concentration in the exhaust passage, and the like are also provided.

  The ECU 80 is configured by a microcomputer including a CPU, ROM, RAM, A / D converter, input interface, output interface, and the like. The aforementioned various sensors are electrically connected to the input interface. Based on the output signals (detection signals) from these various sensors, the ECU 80 is electrically operated from the output interface (drive signal) so that the internal combustion engine 10 can be smoothly operated or operated according to a preset program. ) Is output. In this way, the operation of the fuel injection valve 12, the opening degree of the throttle valve 36, the exhaust throttle valve 60, the flow control valve 70, and the like are controlled. However, the ECU 80 outputs operation signals to the actuators 34, 62, 72 in order to control the opening degrees of the throttle valve 36, the exhaust throttle valve 60, and the flow rate control valve 70.

  In the internal combustion engine 10, the intake air amount calculated based on the output signal from the air flow meter 82, the engine speed calculated based on the output signal from the crank position sensor 104, that is, the engine load and the engine speed. Usually, the fuel injection amount (fuel amount) and the fuel injection timing are set based on the engine operating state. Preferably, the fuel injection amount is set so that an appropriate air-fuel ratio, for example, a stoichiometric air-fuel ratio mixture is formed in the combustion chamber 14. Based on the fuel injection amount and the fuel injection timing, fuel is injected from the fuel injection valve 12. As described above, the fuel injection amount and the fuel injection timing set by the ECU 80 in the vehicle in the normal state are used in the fuel injection correction control during the operation assist of the turbocharger 56 described later. This may be referred to as a reference fuel injection timing. However, the reference fuel injection amount and the reference fuel injection timing may be an injection amount and injection timing set based only on the intake air amount and the engine speed.

  However, in the internal combustion engine 10, the engine speed calculated based on the output signal from the crank position sensor 104 is equal to or higher than a predetermined speed (fuel cut speed), and the output signal from the accelerator opening sensor 92 is The fuel injection from the fuel injection valve 12 is set to be stopped (fuel cut) when the accelerator opening calculated based on this is 0%, that is, when the accelerator pedal 90 is not depressed. That is, the fuel cut is performed when the engine speed is in a predetermined speed range that is set in advance and the accelerator opening is fully closed while the vehicle is running. However, when such a fuel cut state continues and the engine speed decreases and reaches another predetermined speed (fuel cut return speed), fuel injection is resumed. Further, when the fuel cut is being performed, the fuel injection is resumed also when the accelerator pedal 90 is depressed and the accelerator opening increases to the open side and exceeds 0%. In addition, when the fuel cut is performed, it corresponds in general at the time of deceleration.

  The program is set in advance so that the throttle valve 36 is controlled to close when the fuel is cut. However, the throttle valve 36 is forcibly controlled to be opened during pressure recovery, that is, gas recovery and filling described later. The throttle valve 36 is controlled to be fully opened when the internal combustion engine 10 is started, and is controlled to be fully closed when the internal combustion engine 10 is stopped. During normal travel, the opening degree of the throttle valve 36 is controlled to be an appropriate opening degree according to the engine state, the cooling water temperature, and the like.

  Here, the required torque amount determination means for determining whether or not the required torque amount has increased includes an accelerator opening sensor 92 and a part of the ECU 80. The control means of the flow control valve 70 includes an actuator 72 and a part of the ECU 80. Moreover, the pressure determination means for determining whether or not the pressure in the pressure accumulating container 68 is equal to or lower than a predetermined pressure includes the pressure sensor 108 and a part of the ECU 80. Further, when performing the operation assist of the turbocharger 56 using the pressure in the pressure accumulating vessel 68, the fuel injection is corrected to increase the fuel injection amount so as to compensate for the shortage of the engine output torque due to the insufficient operation assist. Each of the fuel injection timing correction means for correcting the advance of the fuel injection timing by an amount corresponding to the fuel injection amount increase correction amount by the fuel injection amount correction means includes a part of the ECU 80. Composed. Further, the exhaust throttle valve control means for controlling the exhaust throttle valve 60 to close includes an actuator 62 and a part of the ECU 80.

  By the way, during normal travel, the exhaust throttle valve 60 is controlled to be kept fully open, so that the exhaust gas flowing through the exhaust passage 38 passes through the catalytic converter 48 and is released to the outside air. On the other hand, when a predetermined condition for pressure recovery is satisfied, the exhaust throttle valve 60 is controlled to be closed, and the fluid flowing through the exhaust passage 38 is generally blocked. Then, pressure recovery (energy recovery), that is, gas filling into the pressure accumulating vessel 68 is performed by effectively utilizing the fluid thus blocked.

  Hereinafter, the pressure recovery will be described in detail based on the flowchart of FIG. However, the flowchart of FIG. 2 is repeated approximately every 20 ms. As will become clear from the following description, the exhaust gas recovered in the pressure accumulator 68 is generally air.

  However, in the control described below with reference to FIG. 2, during the fuel cut, the exhaust throttle valve 60 in the exhaust passage 38 is closed and the pressure in the valve passage J upstream of the exhaust throttle valve 60 is controlled. When the pressure in the pressure accumulating vessel 68 becomes equal to or higher, the flow control valve 70 is controlled to be opened, and the exhaust gas, that is, the pressure of the exhaust gas, is recovered from the inter-valve passage J to the pressure accumulating vessel 68. It is an example.

  When the internal combustion engine 10 is activated, the ECU 80 first determines in step S201 whether the recovery flag is “1”, that is, whether it is ON. Here, the recovery flag “1” indicates that a predetermined condition for performing pressure recovery is satisfied. On the other hand, when it is “0”, it represents that the predetermined condition for pressure recovery is not satisfied. Since the recovery flag is reset in the initial state, a negative determination is made here. In the first embodiment, the fact that the predetermined condition for pressure recovery is satisfied means that the fuel cut is being executed and the pressure in the pressure accumulating vessel 68 is a predetermined pressure, as will be apparent from the following description. Two things are satisfied:

  If a negative determination is made in step S201, it is determined in next step S203 whether or not a fuel cut (execution) is in progress. Specifically, whether or not the fuel is being cut is determined based on whether or not the fuel injection amount is “0”. Note that during normal travel, in general, a fuel injection amount greater than “0” is introduced and fuel injection is performed in order to produce a predetermined output by the internal combustion engine 10. Therefore, in such a case, a negative determination is made in step S203, and the routine ends.

  If an affirmative determination is made in step S203 that the fuel cut is in progress, then in step S205, the pressure in the pressure accumulator 68 ("inner pressure in FIG. 2") is a pressure allowed for the pressure accumulator 68 and is a predetermined value. It is determined whether the pressure is equal to or lower than a predetermined upper limit pressure stored in the ROM. This is to prevent further pressure recovery from being performed when a sufficient amount of pressure, that is, exhaust gas is stored in the pressure accumulating vessel 68. The pressure in the pressure accumulating vessel 68 is detected based on an output signal from the pressure sensor 108. If a negative determination is made in step S205, the routine ends. However, here, the upper limit pressure is set to a value of 400 kPa as the gauge pressure.

  If an affirmative determination is made in step S205, the recovery flag is set to "1" in step S207, assuming that the predetermined condition for pressure recovery is satisfied. As a result, the pressure recovery control is prioritized over the normal control of the internal combustion engine 10. When step S209 is reached, an actuation signal is output to the actuator 72 so that the flow control valve 70 is closed. Since the flow control valve 70 is basically closed, the flow control valve 70 is kept closed. In the next step S211, an operation signal is output to the actuator 62 so that the exhaust throttle valve 60 is closed (the exhaust throttle valve 60 is controlled to be closed). Thus, the routine ends.

  When the recovery flag is set to “1” (substantially while the recovery flag is “1”), an operation signal is output to the actuator 34 so that the throttle valve 36 is opened. As a result, the throttle valve 36 is fully opened here. This is because the pressure in the inter-valve passage J is more appropriately increased in order to perform pressure recovery more appropriately.

  In step S201 of the next routine, since the collection flag is “1”, an affirmative determination is made. If an affirmative determination is made in step S201, it is next determined in step S213 whether or not a fuel cut is in progress, as in step S203. If an affirmative determination is made here, then in step S215, it is determined whether or not the pressure in the pressure accumulating vessel 68 is equal to or lower than the upper limit pressure, as in step S205. It should be noted that the determination in step S213 and step S215 is performed by controlling to end pressure recovery when the predetermined condition for pressure recovery is not satisfied after the recovery flag is set to “1” in step S207. It is to do.

  If an affirmative determination is made in step S215, then in step S217, it is determined whether or not the pressure in the pressure accumulating vessel 68 is equal to or lower than the pressure in the valve-valve passage J ("back pressure" in FIG. 2). Since the valve closing control of the exhaust throttle valve 60 has already been started at this time, the amount of exhaust gas blocked by the exhaust throttle valve 60 increases and the pressure (pressure energy) increases as time elapses. Then, in order to examine whether or not the pressure has increased to such an extent that it can be recovered, the determination in step S217 is performed. When a negative determination is made in step S217, in the next step S219, an operation signal is output to the actuator 72 so that the flow control valve 70 is closed. This means that if the flow control valve 70 is already closed, the flow control valve 70 remains closed. On the other hand, when an affirmative determination is made in step S217, in the next step S221, an operation signal is output to the actuator 72 so that the flow control valve 70 is opened. As a result, the increased pressure in the inter-valve passage J is recovered in the pressure accumulating container 68 while moving the exhaust gas through the pipe 64.

  The pressure in the pressure accumulating vessel 68 is increased by recovering exhaust gas (mainly air here) having high pressure, that is, high pressure energy. Such pressure recovery is generally continued unless a negative determination is made in step S213 or step S215.

  If a negative determination is made in step S213 or step S215 during pressure recovery, control for ending pressure recovery is performed. If a negative determination is made in any of them, an operation signal is output to the actuator 72 so that the flow control valve 70 is closed in the next step S223. Further, an operation signal is output to the actuator 62 so that the exhaust throttle valve 60 is opened. In step S225, the collection flag is set to “0”. As a result, the internal combustion engine 10 is returned to a normal control state in which pressure recovery is not performed. The throttle valve 36 is controlled based on the engine operating state.

  By the way, in a general turbocharger, when the engine speed belongs to a low speed range, the turbocharger rotation is low because the flow rate of the exhaust gas is small. Therefore, after the accelerator pedal 90 is depressed, There is a time lag or time lag before the supercharging effect appears. Therefore, the pressure in the pressure accumulating vessel 68, that is, high-pressure gas, is used in order to quickly increase the supercharging pressure in a transition period in which the accelerator pedal 90 is depressed and the vehicle accelerates. The use of the pressure recovered in the pressure accumulating vessel 68 will be described in detail based on the flowchart of FIG. However, the flowchart of FIG. 3 is repeated approximately every 20 ms.

  However, in the control for pressure release described below with reference to FIG. 3, when acceleration is requested, the pressure from the pressure accumulating vessel 68 is increased toward the turbine wheel of the turbine 50 in order to increase the rate of increase in the turbine rotation speed. It is the example which materialized supplying. The acceleration request is included when the required torque amount is increased.

  First, in step S301, the ECU 80 determines whether or not the recovery flag is “0”, that is, OFF. Since the flag is reset in the initial state, an affirmative determination is made here. If a negative determination is made in step S301, the routine ends.

  If an affirmative determination is made in step S301, in the next step S303, it is determined whether or not the assist flag is “1”, that is, ON. Here, that the assist flag is “1” indicates that it is necessary to assist the operation of the turbocharger 56, and that it is “0” indicates that Indicates that it is not necessary. Since the assist flag is reset in the initial state, a negative determination is made here.

  If a negative determination is made in step S303, in the next step S305, it is determined whether or not the engine speed is equal to or less than a predetermined speed. When the engine speed is higher than the predetermined speed, there is no need to assist the operation of the supercharger 56. Therefore, when the engine speed exceeds the predetermined speed, a negative determination is made in step S305, and the routine ends. To do. On the other hand, if an affirmative determination is made in step S305 that the engine speed is equal to or lower than the predetermined speed, the process proceeds to step S307. For example, the predetermined rotation speed in the determination in step S305 is 3000 rpm.

  In step S307, it is determined whether or not acceleration, that is, whether or not there is an acceleration request. The determination of whether or not the vehicle is accelerating is equivalent to detecting the acceleration start time and is performed based on the accelerator opening. When the accelerator opening is greater than or equal to a predetermined value and the accelerator opening is increased, the amount of change in the unit predetermined time, that is, the opening speed (accelerator opening opening speed) exceeds the predetermined speed. Sometimes, the ECU 80 determines that acceleration, that is, there is an acceleration request. More specifically, the ECU 80 obtains the accelerator opening based on the output signal from the accelerator opening sensor 92, the accelerator opening is, for example, 20% opening or more, and the accelerator opening opening speed. However, when it exceeds the predetermined speed, which is a reference speed set in advance and stored in the ROM, it is determined that the acceleration is performed. If a positive determination is made in step S307, the process proceeds to step S309. If a negative determination is made in step S307, the routine ends.

  However, as a determination of whether or not there is an acceleration request, a required torque may be obtained from the accelerator opening and the engine speed, and it may be determined whether or not the increase change amount of the required torque exceeds a predetermined amount. It should be noted that an increase in the required torque that exceeds the predetermined amount means that the required torque has increased.

  In step S309, the assist flag is set to “1”, and an operation signal is output to the actuator 72 so that the flow control valve 70 is opened in next step S311 (the flow control valve 70 is controlled to open). In this way, the operation assist of the turbocharger 56 is started.

  In the next and subsequent routines, the recovery flag is “0” and the assist flag is “1”, so that an affirmative determination is made in step S301 and step S303, respectively. In the next step S313, as in step S305, it is determined whether the engine speed is equal to or lower than a predetermined speed.

  If an affirmative determination is made in step S313, it is determined in the next step S315 whether or not the supply time has elapsed. Here, the time to be determined is an elapsed time from when the flow control valve 70 is opened. Here, the ECU 80 measures the time from the time when it reached Step S311 with the built-in timer means, and adopts this time by assuming it as the elapsed time. The supply time serving as a criterion is a predetermined time obtained and set in advance by experiments. Here, the supply time is not a variable but a fixed value, and is 0.5 to 1.5 seconds, particularly preferably 1.0. The second is set and stored in advance in the ROM. However, the supply time used for the determination in step S315 may be variable. The engine operating state when acceleration is requested, the pressure in the exhaust passage K upstream of the turbine wheel, the supercharging pressure, the engine speed, It can be determined based on a transmission gear ratio or the like. If the determination is affirmative here, the routine ends.

  By making a negative determination in step S313 or step S315, control for terminating the operation assist of the turbocharger 56 is performed. If a negative determination is made in step S313 or step S315, an operation signal is output to the actuator 72 so that the flow control valve 70 is closed in step S317. In the next step S319, the assist flag is set to “0”. As a result, the routine ends.

  However, once the assist operation of the turbocharger 58 is started, acceleration (request) is continued in addition to the determinations in the above-described step S313 and step S315 to determine whether to end the assist. A determination of whether or not it may be added. This is because it is no longer necessary to assist the operation of the turbocharger 56 when the acceleration is not continued. Specifically, the accelerator opening changes from the accelerator opening when it is determined that there is an acceleration request to the closing side by a predetermined amount, or the opening degree of the accelerator opening becomes negative and the magnitude exceeds the predetermined amount. When it is determined that the acceleration request is not continued, the above-described control (step S317 and step S319) for ending the operation assist may be performed.

  By the way, as described above, when there is a request for acceleration, that is, when the required torque amount increases, the operation of assisting the turbocharger 56 is performed using the pressure in the pressure accumulating vessel 68, but the pressure accumulating vessel 68 at the time when the operation assist is started. The internal pressure can vary. Depending on the difference in pressure, a difference occurs in the operation assist effect of the turbocharger 56. Specifically, a description will be given based on FIG.

  4 (a), 4 (b), 4 (c), and 4 (d) are graphs showing the pressure in the pressure accumulating vessel 68 when the operation of the turbocharger 56 is assisted as described above (in FIG. 4). Fig. 5 is a graph showing an example of changes in container internal pressure), torque, supercharging pressure, and fuel injection amount. However, in FIG. 4, the pressure in the pressure accumulating container 68 at the start of the operation assist of the turbocharger 56, that is, the curve regarding those when the container internal pressure is the pressure A, is attached with a symbol “A”, and the container at that time A curve relating to those when the internal pressure is the pressure B is given a symbol “B”, and a curve relating to them when the internal pressure of the container is the pressure C is given a symbol “C”. However, in all of the graphs of FIGS. 4A, 4B, 4C, and 4D, a time axis is defined as the horizontal axis, and all these time axes coincide with each other.

  In addition, the ideal torque fluctuation corresponding to the acceleration required level at the time of starting acceleration by using the above pressure, and the container internal pressure (ideal internal pressure) at the time of starting acceleration (request) to realize it are shown in the figure. 4 (b) and (a) are indicated by dotted lines, and those lines are marked with the symbol “I”. Also, FIGS. 4C, 4D, and 4B show the change in the supercharging pressure, the change in the fuel injection amount, and the torque change when the turbocharger 56 is allowed to start naturally without using the pressure. These lines are indicated by thin lines, and the reference numeral N is given to these lines. However, these pressures have a relationship of “pressure A <ideal internal pressure <pressure B <pressure C”.

  As described above, if the pressure in the pressure accumulating vessel 68 is released toward the turbine wheel because of the acceleration request, the pressure in the pressure accumulating vessel 68 decreases. Accordingly, the rotation of the turbine wheel of the turbine 50 is promoted, so that the supercharging pressure is rapidly increased as compared with the case where there is no operation assist of the turbocharger 56 by the pressure supply. The supercharging pressure is the pressure in the intake passage 18 detected based on the output signal from the pressure sensor 88. As a result, the engine output torque rises earlier than when there is no operation assist.

  On the other hand, in the normal fuel injection control of the internal combustion engine 10, the fuel injection amount increases substantially depending on the degree of increase in the supercharging pressure. Therefore, when the pressure in the pressure accumulating vessel 68 at the start of acceleration is the pressure A, the pressure increase rate is higher when the pressure is the pressure B and when the pressure is the pressure C. Therefore, the rate of increase in the fuel injection amount is faster when the pressure is B than when the pressure is A, and when the pressure is C. In view of the fact that the increase in the engine output torque caused by the increase in the fuel injection amount is larger than when the increase rate in the fuel injection amount is higher, basically, the acceleration start time, that is, the operation of the turbocharger 56 is performed. The higher the pressure in the pressure accumulating container 68 at the start of the assist, the faster the boost pressure rises, and therefore the faster the engine output torque increases. As a result, the acceleration feeling of the vehicle equipped with the internal combustion engine 10 is different when the pressure in the pressure accumulating vessel 68 at the start of acceleration, that is, at the start of the operation assist, is low, and the driver or the like feels uncomfortable. There is a possibility to make it.

  Therefore, in the present invention, the shortage of output torque from the internal combustion engine 10 due to the shortage of pressure in the pressure accumulating vessel 68 at the start of acceleration is compensated by the increase in torque due to the increase in fuel injection amount, as will be described below. Further, in order to appropriately burn the increased amount of fuel in the combustion chamber 14, the fuel injection timing is advanced by an amount corresponding to the increased amount. Hereinafter, based on the flowchart of FIG. 5, the fuel injection correction control when the operation assist of the turbocharger 56 is executed will be described. Note that the flowchart of FIG. 5 is repeated approximately every 20 ms.

  In step S501, the ECU 80 determines whether or not the assist flag is “1”. Note that execution of this determination means determining whether or not the required torque amount has increased, as is apparent from the above description.

  If an affirmative determination is made in step S501, it is determined in the next step S503 whether or not the correction flag is “1”. When the correction flag is “1”, it indicates that it is necessary to correct the fuel injection amount and its timing as described later, and when it is “0”, it indicates that it is not necessary to correct them. Since the correction flag is reset in the initial state, it is denied here.

  If a negative determination is made in step S503, it is determined in step S505 whether or not the non-correction flag is “0”. When the non-correction flag is “1”, it indicates that a correction to be described later with respect to the fuel injection amount and its timing is prohibited, and when it is “0”, it indicates that such a prohibition is not performed. Since the non-correction flag is reset in the initial state, it is affirmed here.

  If an affirmative determination is made in step S505, it is determined in step S507 whether or not the pressure in the pressure accumulating container 68 ("container internal pressure" in FIG. 5) is equal to or lower than a predetermined pressure. Here, the predetermined pressure is a fixed pressure and is set to 300 kPa.

  However, the predetermined pressure in step S507 is set so that the pressure in the pressure accumulating vessel 68 at the time when the acceleration request is made appropriately assists the operation of the turbocharger 56 and the engine output torque corresponding to the acceleration request is appropriately set. It is defined to determine whether the pressure is capable of being generated. Therefore, more preferably, this predetermined pressure can be changed according to the acceleration demand level. As the parameter indicating the acceleration request level, one of accelerator opening, accelerator opening opening speed, transmission gear ratio, or any combination thereof may be used.

  If a negative determination is made in step S507, it is assumed that correction of the fuel injection amount and its timing, which will be described later, is not necessary in the current operation assist for the turbocharger 56, and the non-correction flag is set to “1” in step S509. Is set. Then, the routine ends.

  On the other hand, if a positive determination is made in step S507, the correction flag is set to “1” in step S511. Then, the process proceeds to step S513, and the fuel injection amount correction amount α is calculated. The fuel injection amount correction amount α (α11,..., Αmn) includes the pressure ratio k (k1, k2, k3,..., Kn) and the supercharging pressure P (P1, P2, P3,. Pm) is obtained by searching the mapped data as shown in FIG. 6A. The mapped data in FIG. 6 (a) is data that can be determined in advance by experiment in consideration of the required torque that is substantially determined from the accelerator opening and the engine speed. This represents the relationship between the pressure ratio k and the supercharging pressure P based on the pressure in the pressure accumulating vessel, and the fuel injection amount correction amount α. The pressure ratio k is a ratio (C / PS) between the predetermined reference tank pressure C and the pressure PS in the pressure accumulating vessel 68 at the time when the acceleration request is made. Here, the predetermined reference tank pressure is a constant, specifically 300 kPa, but may be a variable. Since the pressure ratio k increases from k1 to kn, the pressure ratio k approaches kn as the pressure PS in the pressure accumulating vessel 68 at the time of the acceleration request decreases, and conversely, the pressure PS increases. The pressure ratio k approaches k1. On the other hand, the supercharging pressure P is the pressure of the intake passage 18 detected based on the output signal from the pressure sensor 88, and is the pressure at that time, that is, at the time of step S513 or the time closest thereto. Preferably it is detected in the routine at that time. The supercharging pressure P increases from P1 to Pm.

  The pressure accumulating vessel 68 at the time when the assist flag is set to “1” in step S309 as the pressure PS in the pressure accumulating vessel 68 at the time when the acceleration request is made, that is, when the valve opening control of the flow rate control valve 70 is started. When the internal pressure is obtained, the pressure ratio k is obtained based on this. Here, it is assumed that “k2” is obtained as the pressure ratio k. As a result, when determining the fuel injection amount correction amount in relation to the current operation assist to the turbocharger 56, the data in the column of the pressure ratio k2 in the map of FIG. 6A (in FIG. 6A). Data in columns surrounded by dotted lines) is used. Then, the fuel injection amount correction amount α is obtained by searching the value of the column with the supercharging pressure P at that time. Since the supercharging pressure increases with time, if the supercharging pressure at the time when acceleration is requested is “P3”, it changes from P3 to P4 and P5 each time the routine is repeated. To do. As a result, values corresponding to the fuel injection amount correction amounts, α32, α42, α52... Are obtained, and the fuel injection amount correction amount α changes in a gradually decreasing direction. This is because the shortage of torque that is compensated by the increase in the fuel injection amount decreases as the supercharging pressure increases. Then, the fuel injection amount correction amount set from time to time is added to the reference fuel injection amount to set the fuel injection amount.

  In the case where the predetermined reference tank pressure C is variable, the predetermined reference tank pressure is particularly preferably set according to the acceleration request level, in the same way as the predetermined pressure in step S507. Amount). In this way, the fuel injection amount correction amount α can be set more appropriately based on the acceleration request level, for example, based on the accelerator opening.

  Subsequent to step S513, in step S515, the fuel injection advance correction amount is calculated. The fuel injection advance correction amount β (β11,..., Βmn) includes the pressure ratio k (k1, k2, k3,..., Kn) and the supercharging pressure P (P1, P2, P3,. , Pm) and the mapped data as shown in FIG. 6B is obtained by searching. The pressure ratio k and the supercharging pressure P are the same as those described in step S513, and here, those obtained in the latest step S513 are used. Note that the mapped data in FIG. 6B is data that can be determined in advance by experiment in consideration of the required torque that is substantially determined from the accelerator opening and the engine speed. This represents the relationship between the pressure P and the fuel injection advance correction amount β.

  For example, when “k2” is obtained as the pressure ratio k in step S513 as described above, “k2” is also used as the pressure ratio in step S515. That is, when the fuel injection advance correction amount β is obtained in the operation assist of the turbocharger 56 this time, the data in the column of the pressure ratio k2 in the map of FIG. 6B (indicated by the dotted line in FIG. 6B). The data in the enclosed column is used. Then, the fuel injection advance correction amount β is obtained by searching the value of that column with the supercharging pressure P at that time. Since the supercharging pressure increases as time elapses, when the supercharging pressure at the time when the acceleration request is made is “P3” as described above, every time the routine is repeated, it is changed from P3 to P4, P5. To change. As a result, values β32, β42, β52,... Corresponding to the fuel injection advance correction amount β are obtained, and the fuel injection advance correction amount β changes in a gradually decreasing direction. This is because as the supercharging pressure increases, the shortage of torque compensated by the increase in the fuel injection amount decreases, so the increase correction amount of the fuel injection amount decreases. Then, the fuel injection advance correction amount β that is set from time to time is applied to the reference fuel injection timing to set the fuel injection timing.

  When the fuel injection timing is set as described above, correction based on the engine speed may be further performed. Specifically, the fuel injection advance correction amount β is set based on the engine speed. This is because the optimum time for injecting fuel changes depending on the engine speed.

  Thus, the current routine is terminated. If a positive determination is made in step S501 of the next routine and a positive determination is made in step S503, the process proceeds to step S513, and the fuel injection amount correction amount is calculated again based on the supercharging pressure P at that time. In step S515, similarly, the fuel injection advance correction amount is calculated again based on the supercharging pressure P at that time. Thus, as long as an affirmative determination is made in both step S501 and step S503, both the fuel injection amount correction amount and the fuel injection advance angle correction amount are obtained, and these are used to determine the reference fuel injection amount and the reference fuel injection timing. It is corrected. In this way, the fuel injection is performed so that the amount of fuel set at that time is injected at the fuel injection timing at that time.

  When the assist flag is set to “0” and the operation assist of the turbocharger 56 is finished, a negative determination is made in step S501 of the routine at that time, and the process proceeds to step S517. In step S517, both the correction flag and the non-correction flag are set to “0”, and the routine ends.

  The effect of performing such fuel injection correction control in parallel with execution of the operation assist of the turbocharger 56 will be described with reference to FIG. In each of FIGS. 7A and 7B, the torque increase corresponding to the required torque, that is, the acceleration required level can be generated only by the operation assist of the turbocharger 56 by the pressure supply from the pressure accumulating vessel 68. And a graph conceptually showing an example of change in torque and supercharging pressure related to both of the cases where this is impossible. FIG. 7 shows examples of changes related to the case where neither the operation assistance of the turbocharger 56 based on the flowchart of FIG. 3 nor the fuel injection correction control based on the flowchart of FIG. 5 is performed. Overlaid on. However, in FIG. 7, a curve related to a case where a torque increase corresponding to the acceleration required level can be generated only by the operation assistance of the turbocharger 56 by the pressure supply from the pressure accumulating vessel 68 is indicated by a symbol “X”. Are indicated by reference numerals “Y1” and “Y2”, respectively, and when the fuel injection correction control as described above is not performed, and the turbocharger 56 A curve related to the case where both the operation assist and the fuel injection correction control are not performed is indicated by a symbol “Z”. In both graphs of FIGS. 7A and 7B, a time axis is defined as the horizontal axis, and these time axes coincide with each other.

  When it is impossible to produce an increase in the engine output torque corresponding to the acceleration request level with only the operation assistance of the turbocharger 56 by the pressure supply from the pressure accumulator vessel 68, the pressure in the pressure accumulator vessel 68 is increased based on the acceleration request. Even if it is discharged toward the turbine wheel, it is impossible to realize an appropriate increase in boost pressure and an increase in torque, as is clear by comparing the curve Y2 indicated by the dotted line with the curve X. However, in addition to this, by performing the fuel injection correction control, it is possible to appropriately increase the torque, as is apparent from the curve Y1 indicated by the bold line. Since the engine output torque can be quickly increased by increasing the fuel injection amount, the increase in the engine speed can be accelerated and the increase in the supercharging pressure can also be accelerated (see FIG. 7B). .

  As described above, when the pressure in the accumulator 68 is only at a pressure that is insufficient for the operation assist to the turbocharger 56, the operation assist of the turbocharger 56 is executed using the pressure. In addition to this, fuel injection is performed so as to inject an amount of fuel that is set to increase at that time at an appropriate fuel injection timing. Therefore, even if the operation assist of the turbocharger 56 is insufficient due to insufficient pressure in the pressure accumulating vessel 68, and this causes a delay in the rise of the engine output torque, the amount corresponding to the insufficient torque is reduced. Fuel is injected into the combustion chamber 14 at an appropriate time to compensate for the shortage of torque. Therefore, when acceleration is requested, the vehicle can be appropriately accelerated without giving the driver a sense of incongruity regardless of the pressure in the pressure accumulating vessel 68 at that time. It becomes possible to provide a feeling of acceleration.

  Further, as described above, even if the pressure in the pressure accumulating vessel 68 is insufficient with respect to the required torque, that is, the acceleration required level, a torque substantially corresponding to the acceleration required level can be generated. It becomes possible to do. Therefore, it is possible to shorten the time for collecting the pressure in the pressure accumulating vessel 68. As a result, the mountability of the pressure accumulating container 68 on the vehicle can be improved, and the vehicle can be easily downsized.

  As described above, the required torque amount has increased, but since the pressure in the pressure accumulating vessel 68 is low, the engine output torque cannot be increased as desired only with the operation assistance of the turbocharger 56 using the same. In addition to the operation assist of the turbocharger 56, fuel injection correction control is executed so as to inject an amount of fuel set to increase at that time at an appropriate fuel injection timing. As a result, the proportion of unburned gas including unburned fuel in the exhaust gas can be high. However, since the gas in the pressure accumulating vessel is generally air as described above and contains a large amount of oxygen, the unburned gas is appropriately removed by mixing the gas and the exhaust gas to reach the catalytic converter 48. Purified (oxidized). Therefore, it is allowed to increase the fuel injection amount as described above.

  In the fuel injection control with correction as described above performed in parallel with the operation assist of the turbocharger 56 by supplying pressure from the pressure accumulating vessel 68, the assist flag is basically “1” here. To be done. However, such fuel injection correction control may be performed during an execution time that is determined in advance or is variably set every time an acceleration request is made. The execution time may be extended after the assist flag is changed from “1” to “0”, or may be shortened to half of the period during which the assist flag is “1”. Preferably, the execution time is determined based on at least one of the engine speed and the transmission gear ratio, and is preferably shortened as the engine speed is higher or the gear ratio is higher (lower gear). This is because the higher the engine speed or the higher the gear ratio, the faster the boost pressure rises and the faster the desired torque can be generated than in other cases.

  In the above description, the fuel injection amount correction amount and the fuel injection advance angle correction amount are obtained separately. However, the fuel injection advance correction amount may be obtained based on the obtained fuel injection amount correction amount.

  Next, a second embodiment will be described. However, since the internal combustion engine system to which the second embodiment is applied is substantially the same as that of the first embodiment, the description thereof is omitted. In addition, each control of pressure recovery, pressure utilization, and fuel injection at the time of pressure utilization in the second embodiment is substantially the same as that in the first embodiment. However, there is a difference between the second embodiment and the first embodiment with respect to the correction of the fuel injection amount at the time of using pressure and the timing thereof. Specifically, the calculation method of the fuel injection amount correction amount in step S513 and the calculation method of the fuel injection advance correction amount in step S515 in the first embodiment are different from those in the second embodiment. . Therefore, only this difference will be described here.

  The fuel injection amount correction amount α in the second embodiment is obtained based on the engine speed in addition to the pressure ratio k and the supercharging pressure P. The ECU 80 has a three-dimensional map in advance in the ROM for calculating the fuel injection amount correction amount α. Then, the ECU 80 determines the three-dimensional map, the engine speed at that time, the pressure ratio k when the acceleration request is made, that is, the start time of the valve opening control of the flow control valve 70, and the supercharging at that time. By performing a search based on the pressure P, the fuel injection amount correction amount α is obtained.

  The fuel injection advance correction amount β in the second embodiment is also obtained based on the engine speed in addition to the pressure ratio k and the supercharging pressure P. The ECU 80 has a three-dimensional map in advance in the ROM for calculating the fuel injection advance correction amount β. Then, the ECU 80 searches the three-dimensional map based on the engine speed at that time, the pressure ratio k at the time when the acceleration request is made, and the supercharging pressure P at that time, so that the fuel An injection advance correction amount β is obtained.

  In the first embodiment, the fuel injection control using the fuel injection amount correction amount and the fuel injection advance angle correction amount thus obtained is performed in parallel with the operation assist of the turbocharger 56. As already explained. Therefore, the effects described in the first embodiment are also exhibited in the second embodiment. In the second embodiment, a modification similar to the modification described with respect to the first embodiment can be applied. For example, in the second embodiment, the predetermined reference tank pressure is set according to the acceleration request level. Particularly preferably, it can be changed based on the accelerator opening (the amount of depression of the accelerator pedal 90).

  As mentioned above, although two embodiment of this invention was described, this invention is not limited to these. In the above two embodiments, when accelerating, the pressure in the pressure accumulator vessel is supplied to the exhaust passage upstream of the turbine wheel, but not only when accelerating, but whenever the required torque amount increases, Such pressure supply may be made. The increase in the required torque amount includes the time when the acceleration request is made, and the case where the required torque for the internal combustion engine is increased, such as when the load increases as the vehicle faces an uphill.

  Further, unlike the two embodiments described above, the fuel injection amount correction amount α may be set mainly based on the accelerator opening or based only on the accelerator opening other than the pressure in the pressure accumulating vessel. However, the fuel injection amount correction amount α is preferably set within a range in which the generation of smoke can be suppressed to a certain extent.

  In both the above embodiments, the pressure in the pressure accumulator vessel is supplied at a position distant from the turbine upstream, but the pressure in the pressure accumulator vessel is supplied to assist the rotational drive of the turbine wheel of the turbine. For example, pressure may be supplied to other locations. For example, a passage that enables the pressure in the pressure accumulating vessel to be supplied directly to the turbine housing of the turbine may be communicated.

  Further, in the above two embodiments, the exhaust gas at the time of fuel cut is recovered in the pressure accumulating vessel 68, but what is stored in the pressure accumulating vessel is not limited to such gas. For example, the exhaust gas, that is, its pressure, may be collected and stored in the pressure accumulating vessel from the exhaust passage when the fuel cut is not being performed. Or you may store the air pressurized by the drive of a compressor, ie, air, in a pressure accumulation container. In this case, an air compressor and a pressure introduction (recovery) valve are provided as a pressure supply device to the pressure accumulating vessel, and this air compressor can be driven using the rotational force of an electric motor or a crankshaft.

  The pressure recovery passage connecting the exhaust passage 38 and the pressure accumulating vessel 68 and the pressure releasing passage connecting various components such as a turbocharger and the pressure accumulating vessel 68 may be separated. When the pressure recovery passage and the pressure release passage are separated, the valve provided in the pressure recovery passage may be a check valve.

  In both the above embodiments, the exhaust throttle valve 60 is a butterfly valve. However, other types of valves may be used. The exhaust throttle valve 60 can be, for example, a poppet valve or a shutter valve. As the exhaust throttle valve 60, a valve provided for an exhaust brake may be used. The flow control valve 70 may be a valve of a type other than the poppet type valve, and may be a butterfly type valve or a shutter type valve.

  In both the above embodiments, one pressure accumulating container 68 is provided, but a plurality of pressure accumulating containers 68 may be provided. When two or more accumulator containers 68 are provided, the accumulator containers 68 can be distributed and arranged in the vehicle.

  In both the above embodiments, the present invention has been described by applying the present invention to a diesel engine. However, the present invention is not limited to this, and the present invention can be applied to various internal combustion engines such as a port injection type gasoline engine and a cylinder injection type gasoline engine. Applicable to institutions. The fuel used is not limited to light oil or gasoline, but may be alcohol fuel, LPG (liquefied natural gas), or the like. Further, the number of cylinders and the cylinder arrangement of the internal combustion engine to which the present invention is applied are arbitrary.

  Further, the present invention can be applied to an internal combustion engine provided with an exhaust gas recirculation (EGR) device for guiding a part of the exhaust gas flowing through the exhaust passage 38 to the intake passage 18. When performing the pressure recovery, the ECGR valve of the EGR device can be appropriately opened and closed so that the pressure in the inter-valve passage J becomes a predetermined pressure or a desired pressure.

  Although the present invention has been described with a certain degree of specificity in the above two embodiments and modifications thereof, various modifications can be made to the present invention without departing from the spirit and scope of the invention described in the claims. It should be understood that modifications and changes are possible. That is, the present invention includes modifications and changes that fall within the scope and spirit of the appended claims and their equivalents.

1 is a conceptual diagram of an internal combustion engine system to which a first embodiment is applied. It is a flowchart for pressure recovery of a 1st embodiment. It is a flowchart for pressure utilization of a 1st embodiment. It is a conceptual graph for demonstrating the influence on the operation assistance of the turbocharger of the pressure in the pressure accumulator when there is an acceleration request. It is a flowchart for fuel injection correction control of a 1st embodiment. (A) is the figure showing the data for calculating | requiring the fuel injection amount correction amount, (b) is the figure showing the data for calculating | requiring the fuel injection advance correction amount. It is a conceptual graph for demonstrating the effect of the fuel-injection correction control based on FIG. 5 and FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 50 Turbine 56 Turbocharger 60 Exhaust throttle valve 68 Accumulation vessel 70 Flow control valve

Claims (7)

A required torque amount determining means for determining whether or not the required torque amount has increased, and a control valve provided in a passage that enables communication between the inside of the pressure accumulating vessel and the exhaust passage on the upstream side of the turbine wheel of the turbocharger; An on-vehicle internal combustion engine comprising: control valve control means for controlling the valve opening so that the pressure in the pressure accumulating vessel is supplied to the turbine wheel when an affirmative determination is made by the required torque amount determination means;
Pressure determining means for determining whether or not the pressure in the pressure accumulating vessel is a predetermined pressure or less;
And a fuel injection amount correcting means for correcting the fuel injection amount to be increased on the basis of the pressure in the pressure accumulating container when the affirmative determination is made by the required torque amount determining means and the affirmative determination is made by the pressure determining means. In-vehicle internal combustion engine characterized by the above.   The fuel injection amount correction means increases the fuel injection amount in accordance with a ratio between a predetermined reference tank pressure and the pressure in the pressure accumulating container at the start of the valve opening control of the control valve by the control valve control means. The on-vehicle internal combustion engine according to claim 1, wherein:   The in-vehicle internal combustion engine according to claim 1 or 2, wherein the fuel injection amount increase correction amount by the fuel injection amount correction means changes based on a supercharging pressure.   4. The time during which the fuel injection amount is corrected to be increased by the fuel injection amount correcting means is set based on at least one of an engine speed and a transmission gear ratio. The in-vehicle internal combustion engine according to any one of the above. The internal combustion engine is a compression ignition engine;
The internal combustion engine further comprises fuel injection timing correction means for correcting the advance of the fuel injection timing by an amount corresponding to the fuel injection amount increase correction amount by the fuel injection amount correction means. 4. The on-vehicle internal combustion engine according to any one of 4 above.   6. The on-vehicle internal combustion engine according to claim 5, wherein the advance angle correction amount by the fuel injection timing correction means is set based on the engine speed. An exhaust throttle valve provided in an exhaust passage of the internal combustion engine;
2. An exhaust throttle valve control means for closing the exhaust throttle valve so as to perform pressure recovery from the exhaust passage upstream of the exhaust throttle valve to the pressure accumulator through the valve. The in-vehicle internal combustion engine according to any one of items 1 to 6.

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