JP2009270435A - Exhaust-gas recovering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To store gas in larger quantity in an accumulator, in an exhaust-gas-recovering device wherein an exhaust throttle-valve provided in an exhaust passage of an internal combustion engine is closed, and the exhaust gas is recovered from an exhaust-passage upstream of the exhaust throttle-valve into an accumulator. <P>SOLUTION: The exhaust-gas recovering device includes an exhaust throttle-valve 62 provided in the exhaust passage 28 of the internal combustion engine 10, and the accumulator 70 communicating through a valve 72 to an exhaust passage J upstream of the exhaust throttle-valve 62. Cooling equipment is provided to an exhaust-gas-recovering passage RP which connects an exhaust passage J upstream of the exhaust throttle-valve 62 and the inside of the accumulator 70. The cooling equipment is preferably an EGR cooler 44. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhaust gas recovery device that closes an exhaust throttle valve provided in an exhaust passage of an internal combustion engine and recovers exhaust gas from an exhaust passage upstream of the exhaust throttle valve to a pressure accumulator.

  It has been proposed to store a gas having a high pressure in a pressure accumulating vessel and operate various members or assist the operation using the gas. For example, Patent Document 1 discloses an acceleration device for a turbocharger that uses compressed air in a pressure accumulating vessel to improve the transient response of a turbocharger mounted in an internal combustion engine. This device is equipped with an air supply mechanism capable of supplying compressed air between the exhaust port and the turbine according to the engine operating state, and this air supply mechanism accumulates and holds the compressed air discharged from the pump. And a valve mechanism for supplying compressed air in the pressure accumulator between the exhaust port and the turbine.

Japanese Patent Laid-Open No. 62-276221

  When the apparatus described in Patent Document 1 is mounted on a vehicle, it is desired to reduce the pressure accumulator vessel and to store more gas in the accumulator vessel from the viewpoint of reducing the size of the vehicle and expanding the gas discharge timing. desired.

  Therefore, the present invention has been made in view of such a point, and an object thereof is to store more gas in the pressure accumulating vessel with respect to the internal volume of the pressure accumulating vessel.

  In order to achieve the above object, an exhaust gas recovery apparatus according to the present invention includes an exhaust throttle valve provided in an exhaust passage of an internal combustion engine, and a pressure accumulating container capable of communicating with the exhaust passage upstream of the exhaust throttle valve via the valve. The exhaust gas recovery apparatus is provided with a cooling device in an exhaust gas recovery passage connecting the exhaust passage upstream of the exhaust throttle valve and the pressure accumulating vessel.

  According to this configuration, since the cooling device is provided in the exhaust gas recovery passage that connects the exhaust passage upstream of the exhaust throttle valve and the inside of the pressure accumulator vessel, the cooling device is recovered from the exhaust passage upstream of the exhaust throttle valve to the pressure accumulator vessel. The exhaust gas is appropriately cooled by the cooling device. Therefore, since the density of the exhaust gas collected in the pressure accumulating vessel is increased, it becomes possible to store more exhaust gas in the pressure accumulating vessel with respect to the internal volume of the pressure accumulating vessel.

  More preferably, the cooling device may be an EGR cooler provided in an EGR device of the internal combustion engine. In this case, the exhaust gas in the exhaust passage on the upstream side of the exhaust throttle valve can be recovered by the EGR cooler and then recovered into the pressure accumulating vessel.

  The exhaust gas recovery device includes a fuel cut determination unit that determines whether or not a fuel cut is in progress, and a fuel cut that determines whether or not a predetermined time has elapsed when the fuel cut determination unit makes an affirmative determination. When the affirmative determination is made by the time determination means and the fuel cut determination means, and the affirmative determination is made by the fuel cut time determination means, the exhaust throttle valve in the open state is closed to collect the exhaust gas. Exhaust throttle valve control means for controlling may be provided. In this case, when an affirmative determination is made by the fuel cut determination means and an affirmative determination is made by the fuel cut time determination means, the exhaust throttle valve control means determines whether the exhaust throttle valve in the open state is to be collected. Since the valve closing control is performed, the exhaust throttle valve is kept open until the fuel cut time elapses for a predetermined time. Therefore, until the fuel cut time elapses for a predetermined time, the exhaust gas mainly consisting of air that has passed through the cylinder reaches the exhaust passage upstream of the exhaust throttle valve and can flow downstream of the exhaust throttle valve. Therefore, when the exhaust throttle valve control means controls the exhaust throttle valve to close, the exhaust gas in the exhaust passage on the upstream side of the exhaust throttle valve can be a gas whose temperature is low to some extent and mainly air. Therefore, exhaust gas having a sufficiently low temperature and clean to some extent can be collected in the pressure accumulating vessel.

  In addition, the exhaust gas recovery device determines whether or not a fuel cut time has elapsed when a fuel cut determination unit that determines whether or not a fuel cut is in progress and when the fuel cut determination unit makes an affirmative determination. When the fuel cut time determining means and the fuel cut time determining means are affirmatively determined and when the fuel cut time determining means is affirmatively determined, the exhaust throttle valve that is in an open state is used to collect exhaust gas. An exhaust throttle valve control means for performing valve closing control, and an EGR valve control means for controlling an EGR valve provided on the downstream side of the EGR cooler of the EGR device, wherein when the fuel cut determination means makes a positive determination, the EGR When the valve is controlled to open, the EGR valve is positively determined by the fuel cut determining means and when the fuel cut time determining means is positively determined. It may comprise an EGR valve control means for closing the control. In this case, when an affirmative determination is made by the fuel cut determination means and an affirmative determination is made by the fuel cut time determination means, the exhaust throttle valve control means determines whether the exhaust throttle valve in the open state is to be collected. Since the valve closing control is performed, the exhaust throttle valve is kept open until the fuel cut time elapses for a predetermined time. The EGR valve is controlled to open by the EGR valve control means when the fuel cut determination means makes an affirmative determination, and when the fuel cut determination means makes an affirmative determination and the fuel cut time determination means makes an affirmative determination, the EGR valve Therefore, the EGR valve is opened until the fuel cut time elapses for a predetermined time, and the EGR valve is closed when the fuel cut time elapses for the predetermined time. Therefore, until the fuel cut time elapses for a predetermined time, the exhaust gas mainly consisting of air that has passed through the cylinder reaches the exhaust passage upstream of the exhaust throttle valve and can flow downstream of the exhaust throttle valve. At the same time, the exhaust gas mainly existing in the burned gas that has already existed in the EGR passage can be promoted to be discharged from the EGR passage. Therefore, when the exhaust throttle valve control means controls the exhaust throttle valve to close or when the EGR valve control means controls the EGR valve to close, the exhaust gas in the exhaust passage upstream of the exhaust throttle valve or the EGR passage May be a gas mainly having a low temperature and mainly air. Therefore, exhaust gas having a sufficiently low temperature and clean to some extent can be collected in 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 a vehicle internal combustion engine system to which the embodiment is applied. The internal combustion engine 10 is a type of internal combustion engine, that is, a diesel engine, that spontaneously ignites by directly injecting light oil as fuel from a fuel injection valve 12 into a combustion chamber in a compressed state.

  An intake port that faces the combustion chamber of the cylinder 14 and defines a part of the intake passage 16 is formed in the cylinder head and is opened and closed by an intake valve. An intake manifold 18 that defines a portion of the intake passage 16 is connected to the cylinder head, and an intake pipe 20 that also defines a portion of the intake passage 16 is connected to the upstream side thereof. An air cleaner 22 is provided on the upstream end side of the intake pipe 20 in order to remove dust and the like in the air guided to the intake passage 16. A throttle valve 26 whose opening is adjusted by the throttle actuator 24 is provided in the intake passage 16.

  On the other hand, an exhaust port that faces the combustion chamber of the cylinder 14 and defines a part of the exhaust passage 28 is formed in the cylinder head and is opened and closed by an exhaust valve. An exhaust manifold 30 that defines a part of the exhaust passage 28 is connected to the cylinder head, and an exhaust pipe 32 that also defines a part of the exhaust passage 28 is connected to the downstream side thereof. A catalytic converter 34 filled with an exhaust gas purification catalyst is provided in the middle of the exhaust passage 28.

  Further, an exhaust gas recirculation (EGR) device 36 is provided to guide part of the exhaust gas flowing through the exhaust passage 28 to the intake passage 16. The EGR device 36 includes an EGR pipe 40 that defines an EGR passage 38 that connects the exhaust passage 28 and the intake passage 16, an EGR valve 42 for adjusting the communication state of the EGR passage 38, and exhaust gas that is recirculated (EGR gas). And an EGR cooler 44 for cooling. Here, one end on the upstream side of the EGR pipe 40 is connected to the exhaust manifold 30, and the other end on the downstream side thereof is connected to the intake manifold 18. The EGR valve 42 is provided on the downstream side of the EGR cooler 44, and its opening degree is adjusted by an actuator 46. Here, the EGR valve 42 is a poppet type valve.

  Further, a turbine 50 including a turbine wheel 48 provided in the exhaust passage 28 and driven to rotate by exhaust gas is provided in the middle of the exhaust pipe 32. Correspondingly, a compressor 56 including a compressor wheel 54 that is coaxially connected to the turbine wheel 48 via the rotary shaft 52 and is rotated by the rotational force of the turbine wheel 48 is provided in the middle of the intake pipe 20. Yes. That is, the internal combustion engine 10 is provided with a turbocharger provided with a turbocharger 58 having a turbine 50 for extracting exhaust energy and a compressor 56 for supercharging the internal combustion engine 10 with the exhaust energy extracted by the turbine 50. Internal combustion engine. An intercooler 60 is provided in the intake passage on the downstream side of the compressor 56 in order to cool the air compressed by the compressor 56.

  Further, an exhaust throttle valve 62 is provided in the middle of the exhaust passage 28. Here, the exhaust throttle valve 62 is provided on the downstream side of the turbine 50 and on the upstream side of the catalytic converter 34, but may be provided in another part of the exhaust passage 28. In this embodiment, the exhaust throttle valve 62 is a butterfly valve, and is driven by an actuator 64 that is an electric motor or a negative pressure diaphragm actuator. When the exhaust throttle valve 62 is closed, the exhaust gas flowing through the exhaust passage 28, that is, burned gas (including combustion gas) or air, is effectively damped, and the exhaust throttle valve 62 is more effective than the exhaust throttle valve 62 of such fluid. It functions as a shut-off valve that generally shuts off the downstream flow. The exhaust throttle valve 62 may be configured to reduce the flow passage cross-sectional area of the exhaust passage by about 50% when the valve is closed, or the exhaust passage 28 is completely closed when the valve is closed. A valve having such a configuration may be used.

  Further, a communication passage 68 defined by a pipe member 66 is provided so that the exhaust gas in the exhaust passage J upstream of the exhaust throttle valve 62 can be taken out. One end of the communication path 68 is connected to the EGR path 38, and specifically, is connected to an EGR path downstream of the EGR cooler 44. More specifically, the one end of the communication passage 68 is connected to an EGR passage between the EGR cooler 44 and the EGR valve 42. The other end of the communication path 68 is connected to the pressure accumulating container 70. The pressure accumulating container 70 is a container that can store pressurized gas. Here, the pressure accumulating container 70 is a container having a relatively small internal volume.

  Thus, the communication passage 68 and a part of the EGR passage 38 constitute an exhaust gas recovery passage RP, and the exhaust passage J upstream of the exhaust throttle valve 62 and the pressure accumulating vessel 70 are connected to each other. The EGR cooler 44 is provided in the exhaust gas recovery passage RP connecting the two. The EGR passage constituting a part of the exhaust gas recovery passage RP is a passage from the upstream end of the EGR passage 38 to the EGR valve 42 in the EGR passage 38. Therefore, when exhaust gas recovery, which will be described later, is performed, the exhaust gas in the exhaust passage J upstream of the exhaust throttle valve 62 passes through a part of the EGR passage 38, passes through the EGR cooler 44, reaches the communication passage 68, and accumulates the pressure accumulating vessel. It will be collected in 70. The EGR cooler 44 is used as a cooling device that cools the exhaust gas that is recovered during exhaust gas recovery.

  A flow control valve 72 is provided in the communication path 68 for adjusting the communication state between the pressure accumulating vessel 70 and the exhaust path 28. The flow control valve 72 is operated by the actuator 74. It should be noted that the installation location of the flow control valve 72 is preferably located on the EGR passage in the communication passage 68 so as to prevent the exhaust gas from entering the communication passage 68 as much as possible.

  The exhaust gas recovery passage RP is also used as an exhaust gas discharge passage EP, as will be described later. Through this exhaust gas discharge passage EP, the pressure accumulating vessel 70 and the exhaust passage K upstream of the turbine wheel 48 are connected, and the exhaust gas in the pressure accumulating vessel 70 is supplied to the exhaust passage K upstream of the turbine wheel 48. It becomes possible.

  Here, the pressure accumulation container 70 will be described in detail with reference to FIG. FIG. 2 shows an enlarged view of the pressure accumulating vessel 70 whose left side is a cross-sectional view, and the pressure accumulating vessel 70 is depicted as being symmetrical in FIG. The pressure accumulating vessel 70 is provided with a gas or pressure inlet / outlet port 70 m at a lower portion thereof. In other words, the inlet / outlet port 70m is provided in the pressure accumulation container 70 so as to be positioned below the pressure accumulation container 70 when the pressure accumulation container 70 is installed. In addition, illustration and description of the member which supports the pressure accumulation container 70 so that the entrance / exit 70m is located in such a place are abbreviate | omitted here. More specifically, as is apparent from FIG. 2, the inlet / outlet port 70 m is provided so as to be positioned at the lowermost part of the pressure accumulating vessel 70. However, “downward” indicates a downward direction in the vertical direction, and “lower part” indicates a lower portion. Specifically, the inlet / outlet port 70m is provided at or near a portion where the liquid accumulates due to its own weight when there is a liquid in the pressure accumulating container 70. In addition, the entrance / exit 70m serves as the filling port of the pressure accumulating container 70 and the discharge port thereof. However, the filling port is mainly for filling gas, and the discharge port is for discharging gas.

  In the pressure accumulating vessel 70, an adsorbent 80 capable of adsorbing gas is provided. The adsorbent 80 is mainly composed of activated carbon. Specifically, the adsorbent 80 is configured such that powdery activated carbon is packed in a mesh-like bag formed with a plurality of holes through which gas can flow. Yes. In addition, the adsorbent 80 may be configured with a material other than activated carbon as a main component, and may include at least one of activated carbon, zeolite, alumina, and carbon molecular sieve. Further, the adsorbent 80 can be a block-like object such as a molded body in addition to the powder-like body.

  Further, a filter member 82 is provided in the pressure accumulating container 70. The filter member 82 may be configured to include a zeolitic material, and here is configured from zeolite. Zeolite has fine pores, has aluminosilicate as a main component, and has a skeleton made of silicon dioxide as a basic skeleton. Zeolite can adsorb and release water molecules in its micropores, and can adsorb harmful exhaust gas components such as sulfur components such as SOx (sulfur oxide). In this specification, the component in the gas removed by the filter member 82 may be referred to as an impurity, and the impurity includes exhaust gas components such as moisture, PM, and sulfur. However, the filter member 82 may be configured with a component other than zeolite as a main component, and may include at least one of zeolite, silica gel, and alumina. Further, the filter member 82 may be a powdery body or a block-like object such as a molded body. When the filter member 82 is mainly composed of a powdery body, like the adsorbent 80, these powdery bodies can be put into a bag body and integrated.

  Here, the adsorbent 80 and the filter member 82 are made of different substances. This is because each use and purpose are different. However, the present invention does not exclude that the adsorbent 80 and the filter member 82 are made of the same material.

  As is clear from FIG. 2, the filter member 82 is provided in the pressure accumulating container 70 so as to be located between the adsorbent 80 and the inlet / outlet port 70 m as a filling port of the pressure accumulating container 70. In order to secure these positional relationships, the support member 84 is disposed in the pressure accumulating vessel 70 here. The support member 84 also functions as a separator that separates the adsorbent 80, the filter member 82, and the inlet / outlet port 70m so as to clarify the mutual positional relationship. The support member 84 is composed of an upper plate member 84u and a lower plate member 84d. The upper plate member 84u and the lower plate member 84d are formed with a plurality of holes over the entire surface so that the gas can flow properly.

  The lower plate member 84d is arranged at a predetermined distance from the entrance / exit 70m so that a space S is secured below the lower plate member 84d of the support member 84 in the pressure accumulator 70. This is because when there is a liquid such as water in the pressure accumulating container 70, the liquid can be separated from the adsorbent 80 and the filter member 82 and stored in the space S. Therefore, a part of the pressure accumulating container 70 forming the space S can be referred to as a water reservoir. Further, the lower plate-shaped member 84d forming the upper end of the space S is separated from the entrance / exit 70m by a predetermined distance in order to secure a wide area where the gas can move between the entrance / exit 70m and the adsorbent 80. Arranged. Preferably, when considering the shape of the pressure accumulating vessel 70 as a rotating body itself formed by rotating the planar outer shape of FIG. 2 around its central axis C, the outer diameter A of the lower plate member 84d is the maximum of the pressure accumulating vessel 70. It is 50% or more of the inner diameter B. More preferably, the cross-sectional area of the cross section in the container (perpendicular to the axis C) of the location where the lower plate member 84d is disposed in the pressure accumulator container 70 is the cross section in the container (the axis C It is good that it is 50% or more of the cross-sectional area of (orthogonal).

  As is clear from the above description, the space S, the filter member 82, and the adsorbent 80 in the vicinity of the entrance / exit 70m are positioned in the pressure accumulating container 70 in order from the lower side to the upper side. Therefore, the gas that has entered the pressure accumulating vessel 70 from the inlet / outlet 70 m passes through the space S and reaches the filter member 82, and impurities are removed by the filter member 82 before reaching the adsorbent 80. On the contrary, the gas on the adsorbent 80 side in the pressure accumulating vessel 70, for example, the gas adsorbed by the adsorbent 80 is released from the adsorbent 80 by being separated from the adsorbent 80, reaches the filter member 82, and reaches the filter member 82. It passes through 82 and the space S in order, and is discharged from the entrance / exit 70m.

  Here, the amount of the adsorbent 80 put in the pressure accumulating container 70 will be described. Based on FIG. 3, the relationship between the amount of gas with which the pressure accumulating vessel 70 is collected and filled and the amount of adsorbent will be described. In the test system, each curve in the graph of FIG. 3 is obtained when the inside of the pressure accumulating vessel 70 in the atmospheric pressure state is communicated with the exhaust passage J corresponding to the upstream side of the exhaust throttle valve 62 having a gauge pressure of 450 kPa. The change in the weight (increase) in the pressure accumulating container 70 is shown. In this experiment, the adsorbent 80 was not put into the pressure accumulating container 70 (curve α), the adsorbent 80 was only half of the adsorbent 80 (curve β), and the adsorbent 80 was put into the accumulator 70. The weight change in the pressure accumulating vessel 70 when compared with the entire inside (curve γ) was compared. In this experiment, the pressure in the portion corresponding to the exhaust passage J on the upstream side of the exhaust throttle valve 62 and the internal volume of the pressure accumulating container itself were made the same except that the amount of adsorbent was varied. As is apparent from FIG. 3, the weight of the pressure accumulating vessel 70 has increased at a substantially constant rate from the start of communication between the inside of the pressure accumulating vessel 70 and the portion corresponding to the exhaust passage J. However, the weight increases as the amount of adsorbent increases. The period has become longer. As the amount of adsorbent increases, the weight increase width increases. Since this increase in weight has a correlation with continued gas introduction into the pressure accumulating vessel 70, it can be seen that the amount of gas introduced into the pressure accumulating vessel 70 increases as the amount of adsorbent increases. As a result, it is clear that filling the pressure accumulating container 70 with as much adsorbent 80 as possible allows filling the accumulating container 70 with more gas, that is, storing gas at a higher density. became. Therefore, the amount of the adsorbent is increased as much as possible, and an amount of the filter member 82 sufficient to properly perform the impurity removing function is inserted, and the filter member 82 functions properly as a water reservoir and allows appropriate circulation and movement of gas. It has been found that the shape or the like of the pressure accumulating vessel 70 should be designed so as to ensure the space S having such a size and shape.

  As shown in FIG. 3, the results are shown in FIG. 3 using the pressure accumulating vessel 70 having the appropriate amount of the adsorbent 80 and the filter member 82 as described above and having the space S formed in the lower part near the entrance / exit 70m. In the experiment, impurities are removed by the filter member 82 at the time of gas filling, and on the other hand, the moisture in the space S and these impurities are multiplied by the gas discharge and discharged from the pressure accumulating vessel 70 at the time of gas discharge. The graph of weight change was obtained. That is, when the gas of a predetermined pressure was repeatedly filled for a predetermined time, the weight change (weight increase) curves of the pressure accumulating vessel 70 at that time almost overlapped. Conversely, when the gas was repeatedly released until the inside became atmospheric pressure, the weight change (weight decrease) curves of the pressure accumulating vessel 70 at that time almost overlapped. Therefore, it was found that by using the pressure accumulating vessel 70 having the above-described configuration, high-density gas filling and gas discharge can be repeated in the same manner in the pressure accumulating vessel. In addition, when the gas filling and the gas discharge (that is, the pressure recovery and the pressure release) can be repeated in the same manner in the pressure accumulator, the weight of the pressure accumulator 70 in the atmospheric pressure state before the gas filling and the gas discharge The weight of the subsequent pressure accumulation container 70 in the atmospheric pressure state was substantially the same.

  Further, the internal combustion engine 10 includes various sensors that electrically output signals for obtaining (detecting or estimating) various values in an electronic control unit (ECU) 90. Here, some of them will be specifically described. An air flow meter 92 for detecting the amount of intake air is provided in the intake pipe 20. An intake air temperature sensor 94 for detecting the temperature of the intake air is provided near the air flow meter 92, and an intake air temperature sensor 96 for detecting the temperature is also provided on the downstream side of the intercooler 60. Further, a pressure sensor 98 for detecting intake pressure, that is, supercharging pressure, is provided in the middle of the intake pipe 20. Further, an accelerator opening sensor 102 for detecting a position corresponding to the depression amount of the accelerator pedal 100 operated by the driver, that is, an accelerator opening is provided. A throttle position sensor 104 for detecting the opening of the throttle valve 26 is also provided. Furthermore, in order to detect the opening degree (EGR opening degree) of the EGR valve 42, a valve lift sensor 106 for detecting the lift amount is also provided here. A crank position sensor 108 for detecting a crank rotation signal of a crankshaft connected to the piston via a connecting rod is attached to the cylinder block (or the vicinity thereof) where the piston reciprocates. Here, the crank position sensor 108 is also used as an engine speed sensor for obtaining the engine speed (engine speed). Further, a pressure sensor 110 is provided for detecting the pressure of the exhaust gas in the exhaust passage J upstream of the exhaust throttle valve 62, that is, the pressure of a fluid such as combustion gas or air. Further, a pressure sensor 112 for detecting the pressure in the pressure accumulating container 70 is also provided. Furthermore, a temperature sensor 114 for detecting the coolant temperature of the internal combustion engine 10 is provided.

  The ECU 90 includes a microcomputer including a CPU, ROM, RAM, A / D converter, input interface, output interface, and the like. The various sensors are electrically connected to the input interface. Based on the output signals (detection signals) from these various sensors, the ECU 90 is electrically connected from the output interface so that the internal combustion engine 10 can be smoothly operated or operated in accordance with a preset program (including data). An operation signal (drive signal) is output to In this way, the operation of the fuel injection valve 12, the opening degree of the throttle valve 26, the EGR valve 42, the exhaust throttle valve 62, the flow control valve 72, and the like are controlled. However, the ECU 90 outputs an operation signal to each actuator 24, 46, 64, 74 in order to control the opening degrees of the throttle valve 26, the EGR valve 42, the exhaust throttle valve 62, and the flow rate control valve 72.

  Here, the fuel cut determination means for determining whether or not the fuel cut is in progress includes a part of the ECU 90, and also determines whether or not the fuel cut time has elapsed for a predetermined time. The means includes a part of the ECU 90. Further, the exhaust gas recovery condition determination means for determining whether or not the exhaust gas recovery condition is satisfied includes a part of the ECU 90. The exhaust throttle valve control means includes an actuator 64 for driving the exhaust throttle valve 62 and a part of the ECU 90. The EGR valve control means includes an actuator 46 for driving the EGR valve 42 and a part of the ECU 90. Further, the flow control valve control means includes an actuator 74 for driving the flow control valve 72 and a part of the ECU 90.

  In the internal combustion engine 10, the intake air amount obtained based on the output signal from the air flow meter 92, the engine speed obtained based on the output signal from the crank position sensor 108, that is, the engine load and the engine speed are represented. Usually, the fuel injection amount (fuel amount) and the fuel injection timing are set based on the engine operating state. Based on the fuel injection amount and the fuel injection timing, fuel is injected from the fuel injection valve 12.

  However, in the internal combustion engine 10, the engine speed obtained based on the output signal from the crank position sensor 108 is equal to or higher than a predetermined speed (fuel cut speed), and based on the output signal from the accelerator opening sensor 102. Thus, the fuel injection from the fuel injection valve 12 is set to be stopped (fuel cut) when the accelerator opening required is 0%, that is, when the accelerator pedal 100 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 100 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 26 is controlled to close when the internal combustion engine 10 is in the fuel cut state. However, during exhaust gas recovery, which will be described later, the throttle valve 26 is forcibly controlled to open. The throttle valve 26 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 traveling, the opening degree of the throttle valve 26 is controlled to an appropriate opening degree according to the engine state, the coolant temperature, and the like.

  Further, the opening degree of the EGR valve 42 is controlled based on the engine operating state of the internal combustion engine 10 determined based on output signals from the various sensors. Here, data determined in advance by experiments and stored so as to decrease the EGR amount as the region to which the engine operating state belongs is on the higher load side is stored in the ROM. Further, the EGR opening degree derived based on the engine operating state is corrected so that the EGR valve 42 is temporarily closed in a transition period in which the accelerator pedal 100 is depressed and the internal combustion engine 10, that is, the vehicle is accelerated. .

  By the way, during normal travel, the exhaust throttle valve 62 is controlled to be kept fully open, so that the exhaust gas flowing through the exhaust passage 28 passes through the catalytic converter 34 and is released to the outside air. On the other hand, when a predetermined condition for exhaust gas recovery is satisfied, the exhaust throttle valve 62 is controlled to be closed, and the fluid flowing through the exhaust passage 28 is generally blocked. Then, exhaust gas recovery (pressure energy recovery), that is, gas filling into the pressure accumulating vessel 70 is performed by effectively using the fluid thus blocked.

  Hereinafter, exhaust gas recovery will be described in detail with reference to the flowchart of FIG. However, the flowchart of FIG. 4 is repeated every predetermined time, for example, approximately every 8 ms. As will be apparent from the following description, the exhaust gas recovered in the pressure accumulator 70 is generally made of air, and the temperature of the recovered gas is relatively low. Deterioration and performance degradation of the adsorbent 80 and the filter member 82 due to heat hardly occur.

  However, in the control described below with reference to FIG. 4, during the fuel cut, the exhaust throttle valve 62 of the exhaust passage 28 is closed and the pressure in the exhaust passage J upstream of the exhaust throttle valve 62 is accumulated. An example in which the flow rate control valve 72 is controlled to open when the pressure in the container 70 becomes equal to or higher, and the exhaust gas, that is, the pressure energy of the exhaust gas, is recovered from the exhaust passage J to the pressure accumulation container 70. It is.

  When the internal combustion engine 10 is activated, the ECU 90 first determines in step S401 whether or not the recovery flag is “1”, that is, whether it is ON. Here, the recovery flag being “1” indicates that a predetermined condition for exhaust gas recovery is satisfied. On the other hand, when it is “0”, it indicates that a predetermined condition for exhaust gas recovery is not satisfied. Since the recovery flag is reset in the initial state, a negative determination is made here. In the present embodiment, the fact that the predetermined condition for exhaust gas recovery is satisfied means that the fuel is being cut and the pressure in the pressure accumulating vessel 70 is equal to or lower than the predetermined pressure, as will be apparent from the following description. And that exhaust gas mainly composed of burned gas from the exhaust passage J and the EGR passage 38 upstream of the exhaust throttle valve 62 is discharged.

  If a negative determination is made in step S401, then in step S403, it is determined whether or not the internal combustion engine 10 is in a fuel cut state, that is, 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”. However, it may be determined whether or not the fuel cut execution condition described above is satisfied. 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 S403.

  If an affirmative determination is made in step S403 that the fuel cut is in progress, then in step S405, the pressure in the pressure accumulating container 70 ("container internal pressure" in FIG. 4) is a pressure allowed for the pressure accumulating container 70, and is predetermined. 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 exhaust gas recovery from being performed when a sufficient amount of pressure, that is, exhaust gas is stored in the pressure accumulating vessel 70. The pressure in the pressure accumulating vessel 70 is obtained based on an output signal from the pressure sensor 112. 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 S405, an operation signal is output to the actuator 46 so that the EGR valve 42 opens in the next step S407 (the EGR valve 42 is controlled to open). Thereby, the opening degree of the EGR valve 42 is controlled here to the full opening degree. Note that the opening of the EGR valve 42 is performed in preference to the normal control described above, and therefore the opening degree of the EGR valve 42 that is the target for control at this time does not depend on the engine operating state.

  In step S409 following step S407, it is determined whether or not a predetermined time has elapsed. Here, the time to be determined is a continuous time during which the fuel is cut (fuel cut time), and specifically, is a time during which the routine that is positively determined in step S403 is continuously repeated. Here, the ECU 90 is a built-in timer means, and measures the time from the time when the first affirmative determination is made in step S405 in a plurality of continuous routines to reach step S407. Adopted by assuming the fuel cut time. Further, the predetermined time serving as a determination criterion is a time that is obtained in advance through experiments and is stored in the ROM in advance. Preferably, the predetermined time is a time required for exhaust gas mainly burnt gas to be discharged from the exhaust passage J upstream of the exhaust throttle valve 62. Here, as described above, since the EGR valve 42 is opened during the fuel cut, the exhaust gas that has been in the EGR passage 38 at the start of the opening of the EGR valve 42 is used for this predetermined time. It is also the time required for exhausting from the EGR passage 38 so that the air that has reached the exhaust passage 28 via the cylinder 14 during the cut is replaced with the main exhaust gas, in other words, the EGR passage 38 is sufficiently It is also the time needed to ventilate. However, the predetermined time may be as short as possible so that the exhaust gas can be recovered quickly. The degree of exhaust gas discharge from the exhaust passage J upstream of the exhaust throttle valve and the degree of ventilation in the EGR passage 38 that are desired to be achieved at this time are collected into the pressure accumulating vessel 70 thereafter. The exhaust gas has a low temperature that is lower than the desired temperature and is a desired level of clean gas, and the predetermined time in step S409 is determined based on this.

  While a negative determination is made in step S409, unless the negative determination is made in step S403 or step S405, the exhaust gas mainly composed of burned gas from the exhaust passage J and the EGR passage 38 upstream of the exhaust throttle valve 62 is used. Emission continues. On the other hand, if a negative determination is made in step S409 and a negative determination is made in step S403 or step S405 of the next routine, the process proceeds to step S411, and the forced opening of the EGR valve 42 in step S407 is released. Therefore, the EGR valve 42 is controlled based on the engine operating state as described above. Note that the timer means is reset when an affirmative determination is made in step S409 or the process reaches step S411.

  If an affirmative determination is made in step S409, the recovery flag is set to “1” in step S413, assuming that the predetermined condition for exhaust gas recovery is satisfied. As a result, the exhaust gas recovery control is prioritized over the normal control of the internal combustion engine 10. In step S415, an actuation signal is output to the actuator 46 so that the EGR valve 42 is closed. As a result, the communication between the EGR passage 38 and the intake passage 16 is blocked, and the exhaust gas recovery passage RP can connect only the exhaust passage J upstream of the exhaust throttle valve 62 and the pressure accumulating vessel 70. become. At this time, the EGR valve 42 may be driven to the closed side at a speed corresponding to the pressure of the exhaust passage J upstream of the exhaust throttle valve 62. In step S415, an operation signal is output to the actuator 74 so that the flow control valve 72 is closed. Since the flow control valve 72 is basically closed, the flow control valve 72 is kept in its closed state. In the next step S417, an operation signal is output to the actuator 64 so that the exhaust throttle valve 62 in the valve open state is closed (the exhaust throttle valve 62 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 24 so that the throttle valve 26 is opened. Thereby, here, the throttle valve 26 is fully opened. This is because the pressure in the exhaust passage J on the upstream side of the exhaust throttle valve 62 is more appropriately increased in order to recover the exhaust gas more appropriately. Further, the throttle valve 26 is maintained and controlled in an open state with a predetermined opening such as a fully opened opening after the EGR valve 42 is forcibly opened in step S407 until it reaches step S411 or S415. May be. Thus, before the exhaust throttle valve 62 is controlled to be closed in step S417, exhaust gas exhaust from the exhaust passage J upstream of the exhaust throttle valve 62 and / or ventilation of the EGR passage 38 can be further promoted. Become.

  In step S401 of the next routine, an affirmative determination is made because the collection flag is “1”. If an affirmative determination is made in step S401, it is then determined in step S419 whether or not a fuel cut is in progress, as in step S403. If an affirmative determination is made here, then in step S421, it is determined whether or not the pressure in the pressure accumulating vessel 70 is equal to or lower than the upper limit pressure in the same manner as in step S405. Note that the determination in step S419 and step S421 is that the exhaust gas recovery is terminated when the predetermined condition for exhaust gas recovery is not satisfied after the recovery flag is set to "1" in step S413. This is for control.

  If an affirmative determination is made in step S421, it is next determined in step S423 whether or not the pressure in the pressure accumulating container 70 is equal to or lower than the pressure in the exhaust passage J ("back pressure" in FIG. 4). At this time, since the exhaust throttle valve 62 has already been controlled to close, the pressure (pressure energy) of the exhaust gas blocked by the exhaust throttle valve 62 increases with time. 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 S423 is performed. When a negative determination is made in step S423, an operation signal is output to the actuator 74 so that the flow control valve 72 is closed in the next step S425. This means that when the flow control valve 72 is already closed, the flow control valve 72 is left as it is. On the other hand, if the determination in step S423 is affirmative, in the next step S427, an actuation signal is output to the actuator 74 so that the flow control valve 72 is opened (the valve opening is controlled). As a result, the exhaust gas having an increased pressure in the exhaust passage J upstream of the exhaust throttle valve is recovered in the pressure accumulator 70 through the exhaust gas recovery passage RP. At this time, the exhaust gas passes through the EGR cooler 44 while flowing through the exhaust gas recovery passage RP, so that the exhaust gas recovered in the pressure accumulator 70 is sufficiently cooled. Therefore, since a relatively high-density exhaust gas reaches the pressure accumulating vessel 70, more exhaust gas can be recovered in the pressure accumulating vessel 70.

  By collecting exhaust gas (mainly air here) having a high pressure, that is, high pressure energy, the weight of the pressure accumulating vessel 70 increases as shown in FIG. 3 and the pressure in the pressure accumulating vessel 70 increases. Such collection is generally continued unless a negative determination is made in step S419 or step S421.

  If a negative determination is made in step S419 or step S421 during exhaust gas recovery, control for terminating exhaust gas recovery is performed. If a negative determination is made in any of them, the forced closing of the EGR valve 42 is released in the next step S429, so that the EGR valve 42 is returned to the normal control state. In addition, an operation signal is output to the actuator 74 so that the flow control valve 72 is closed. Further, an operation signal is output to the actuator 64 so that the exhaust throttle valve 62 opens. In step S431, the collection flag is set to “0”. As a result, the internal combustion engine 10 is returned to a normal control state in which exhaust gas recovery is not performed. The throttle valve 26 is controlled based on the engine operating state.

  As described above, since the exhaust throttle valve 62 is closed after the fuel cut time has elapsed after the start of the fuel cut, the exhaust throttle valve 62 is closed when the exhaust throttle valve 62 is closed. Some exhaust gas is primarily composed of air that simply passes through the cylinder 14 and reaches it. Further, since the EGR valve 42 is further opened while the fuel cut time elapses for a predetermined time, the exhaust gas mainly composed of the burned gas in the EGR passage 38 before the fuel cut is started is the exhaust throttle valve 62. Before the valve is closed. Further, as described above, since the EGR cooler 44 is disposed in the EGR passage 38, the exhaust gas circulated to the exhaust passage 28 through the EGR passage 38 is sufficient until the fuel cut time elapses for a predetermined time. To be cooled. Therefore, the exhaust gas in the exhaust gas recovery passage RP at the start of closing the exhaust throttle valve 62, particularly the exhaust gas in the EGR passage 38 and the exhaust gas in the exhaust passage J are sufficiently low in temperature (high density). ) And clean gas. Therefore, it becomes possible to collect and store more exhaust gas in the pressure accumulating vessel 70 with respect to its internal volume. In addition, since the temperature of the exhaust gas collected in the pressure accumulating vessel 70 is low in this manner, the deterioration of the adsorbent 80 and the like in the pressure accumulating vessel 70 due to the heat is appropriately suppressed. Further, the exhaust gas recovered in the pressure accumulating vessel 70 is a clean gas, and since the amount of harmful exhaust gas components contained in the exhaust gas is small, the pressure accumulating vessel 70 itself and the adsorbent 80 and the like due to the harmful exhaust gas components are reduced. Deterioration can be suppressed.

  As is apparent from the above description, such exhaust gas recovery is performed when the fuel cut determination means for determining whether or not the fuel cut is in progress and when the fuel cut determination means makes an affirmative determination. A fuel cut time determination means for determining whether or not the fuel cut time is positively determined by the fuel cut determination means and when the fuel cut time determination means is The exhaust throttle valve control means for closing the exhaust throttle valve 62, and the EGR valve control means for controlling the EGR valve 42 provided downstream of the EGR cooler 44 of the EGR device 36, wherein the fuel cut determination When the affirmative determination is made by the means, the EGR valve 42 is controlled to open, the affirmative determination is made by the fuel cut determination means, and the fuel cut time determination means The EGR valve 42 when an affirmative determination is made and a EGR valve control means for closing control is performed by an exhaust gas recovery system. However, when an affirmative determination is made by the fuel cut determination means and an affirmative determination is made by the fuel cut time determination means, the exhaust throttle valve 62 in which the exhaust throttle valve control means is open is closed to collect the exhaust gas. When an affirmative determination is made by the fuel cut determination means that the valve control is to be performed, the exhaust throttle valve control means delays the closing control of the exhaust throttle valve until a predetermined time elapses after the determination. In other words. That is, as described above, the fuel cut determination means, the fuel cut time determination means, and the exhaust throttle valve control means for controlling the exhaust throttle valve 62 to close when the determination is positive by both the determination means, When a positive determination is made by the fuel cut determination means, the exhaust throttle valve control means for closing the exhaust throttle valve 62 during the fuel cut so as to collect the exhaust gas to the pressure accumulator 70, It is equivalent to providing a delay means for delaying the closing control of the exhaust throttle valve 62 by the exhaust throttle valve control means until the fuel cut time elapses after the determination. Note that such delay means may be configured to include a part of the ECU 90.

  In addition, as described above, the exhaust gas mainly composed of air is collected and filled in the pressure accumulator 70, so that sulfur components, PM, oil, etc. are contained in the exhaust gas led from the inlet / outlet 70m into the pressure accumulator 70. Even if included, their amounts are negligible. Further, although there may be slight impurities in the exhaust gas, they are also appropriately removed by the filter member 82. The water generated by being removed by the filter member 82 or condensed due to high pressure moves downward due to its own weight, and preferably accumulates in the space S. Further, a sulfur component as an impurity, a part of moisture, and the like can be adsorbed by the filter member 82. Only the exhaust gas that has passed through the filter member 82 is adsorbed to the adsorbent 80 so as to be released. Thus, when the exhaust gas is recovered and filled, impurities in the exhaust gas introduced into the pressure accumulating vessel 70 can be appropriately removed by the filter member 82 on the upstream side of the adsorbent 80, so that these sulfur components and moisture are adsorbed. It can prevent more reliably reaching to the material 80. Accordingly, it is possible to prevent the gas adsorption performance of the adsorbent 80 from being lowered.

  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, so that the intake air flow is reduced after the accelerator pedal 100 is depressed. There is a time lag or time lag before the supercharging effect appears. Therefore, in the transition period in which the accelerator pedal 100 is depressed and the vehicle is accelerated, the pressure in the pressure accumulating vessel 70, that is, high-pressure gas, is used to quickly increase the supercharging pressure. The pressure recovered in the pressure accumulating vessel 70, that is, the use of exhaust gas will be described in detail with reference to the flowchart of FIG. However, the flowchart of FIG. 5 is repeated every predetermined time, for example, approximately every 8 ms.

  However, in the control for exhaust gas discharge described below with reference to FIG. 5, when there is an acceleration request, in order to increase the increase rate of the turbine rotation speed and improve the response of the turbocharger, the turbine 50 This is an example in which the pressure supply from the pressure accumulating vessel 70 toward the turbine wheel 48 is realized.

  First, in step S501, the ECU 90 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 S501, the routine ends.

  If an affirmative determination is made in step S501, in the next step S503, it is determined whether or not the assist flag is “1”, that is, ON. Here, when the assist flag is “1”, it means that the operation of the turbocharger 58 needs to be assisted, whereas when it is “0”, 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 S503, it is determined in next step S505 whether or not the engine speed is equal to or lower 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 58. Therefore, when the engine speed exceeds the predetermined speed, a negative determination is made in step S505, and the routine ends. To do. On the other hand, if an affirmative determination is made in step S505 that the engine speed is equal to or lower than the predetermined speed, the process proceeds to step S507. For example, the predetermined rotation speed in the determination in step S505 is 3000 rpm.

  In step S507, it is determined whether or not acceleration, that is, whether or not there is an acceleration request. The determination as to whether or not the vehicle is accelerating is equivalent to obtaining 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 90 determines that acceleration, that is, there is an acceleration request. More specifically, the ECU 90 obtains the accelerator opening based on the output signal from the accelerator opening sensor 102, the accelerator opening is, for example, 20% 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 an affirmative determination is made in step S507, then a determination in step S509 is performed. If a negative determination is made in step S507, the routine ends.

  In step S509, it is determined whether or not the pressure in the pressure accumulating container 70 is equal to or higher than a predetermined pressure. The predetermined pressure is a pressure required at least for assisting the operation of the turbocharger 58, and is obtained in advance by experiments and stored in the ROM. Specifically, the predetermined pressure may be 200 kPa as a gauge pressure. The predetermined pressure may be a value obtained by adding an extra pressure of, for example, 100 kPa to the pressure in the exhaust passage K upstream of the turbine wheel 48. If a negative determination is made in step S509, the routine ends. On the other hand, if an affirmative determination is made in step S509, the assist flag is set to “1” in the next step S511, and an operation signal is output to the actuator 74 so that the flow control valve 72 is opened in the next step S513 (flow rate). The control valve 72 is controlled to open). In this way, the operation assist of the turbocharger 58 is started.

  The EGR valve 42 may be maintained in the closed state while the flow rate control valve 72 is opened and the operation of the turbocharger 58 is being assisted. In the present embodiment, the pressure in the pressure accumulating vessel 70, that is, the exhaust gas is supplied to the exhaust passage K through a part of the EGR passage 38 when the flow control valve 72 is opened. Therefore, since the EGR valve 42 is closed at that time, the exhaust gas from the pressure accumulating vessel 70 can appropriately reach the exhaust passage K without reaching the intake passage 16.

  In the next and subsequent routines, since the collection flag is “0” and the assist flag is “1”, affirmative determination is made in steps S501 and S503, respectively. In the next step S515, as in step S505, it is determined whether the engine speed is equal to or lower than a predetermined speed.

  If an affirmative determination is made in step S515, it is determined in a next step S517 whether or not the supply time has elapsed. Here, the time to be determined is an elapsed time from when the flow control valve 72 is opened and the exhaust gas discharge passage EP is opened. Here, the ECU 90 measures the time from the time when it reached Step S511 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 stored in the ROM. However, the supply time used for the determination in step S517 may be variable, and may be determined based on the engine operating state when acceleration is requested, the pressure in the exhaust passage K upstream of the turbine wheel 48, and the like. .

  If an affirmative determination is made in step S517 that the supply time has not elapsed, in the next step S519, it is determined whether or not the pressure in the pressure accumulating container 70 is equal to or higher than the predetermined pressure, as in step S509. If the determination is affirmative here, the routine ends.

  By making a negative determination in any of steps S515 to S519, control for terminating the operation assist of the turbocharger 58 is performed. If a negative determination is made in any of steps S515 to S519, an operation signal is output to the actuator 74 so that the flow control valve 72 is closed in step S521. In the next step S523, the assist flag is set to “0”. As a result, the routine ends. This resets the timer means.

  However, once the assist operation of the turbocharger 58 is started, whether or not to end it is determined by continuing acceleration (request) in addition to the determination from step S515 to step S519. A determination of whether or not it may be added. This is because it is no longer necessary to perform the operation assist of the turbocharger 58 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 is not continued, the above-described control (step S521 and step S523) for ending the operation assist may be performed on the assumption that the acceleration is not continued.

  As described above, in this embodiment, when the impurities are removed by the filter member 82 and the gas filled in the accumulator 70 with high density using the gas adsorbing ability of the adsorbent 80 is released, the filter member 82 is passed through the space S and discharged from the entrance / exit 70 m, and is used for assisting the operation of the turbocharger 58. Accordingly, it is possible to discharge from the pressure accumulating vessel 70 the water adsorbed by the filter member 82 and water that may contain sulfur components and nitrogen components accumulated in the space S by multiplying the gas release at this time. Regardless of whether or not there is water in the space S, these impurities themselves can also be collected in the space S by their own weight, and can be discharged from the pressure accumulating vessel 70 by taking out gas discharge.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, in the above embodiment, an EGR cooler is used as the cooling device, but other cooling devices can be used. For example, an intercooler may be used. When using an EGR cooler or an intercooler, existing equipment can be used as a cooling device, which is advantageous in terms of cost.

  Moreover, although the adsorbent etc. have been arrange | positioned in the pressure accumulation container 70 in the said embodiment, these do not need to be provided. As described above, a cooling device is provided in the exhaust gas recovery passage that connects the exhaust passage upstream of the exhaust throttle valve and the inside of the pressure accumulator, so that a sufficient amount of exhaust gas can be recovered in the pressure accumulator. It is.

  Moreover, in the said embodiment, although the entrance / exit 70m played the role of the filling port and the discharge port, the filling port and the discharge port may be provided separately. When the filling port and the discharge port are provided separately, it is preferable that the exhaust gas recovery passage and the exhaust gas discharge passage are completely independent. Further, when the filling port and the discharge port are provided separately, the arrangement of the exhaust gas filled in the pressure accumulating container from the filling port so that the exhaust gas can reach the adsorbent only after passing through the filter member. It is good to be determined. This is because by allowing the gas to pass through the filter member, it is possible to suppress the impurities in the gas from reaching the adsorbent, and thus it is possible to prevent deterioration of the adsorbent. When the filling port and the discharge port are provided separately, the gas adsorbed by the adsorbent may reach the space S and be discharged from the discharge port without passing through the filter member. This is because the water and impurities in the space S can be appropriately discharged by discharging the gas in the pressure accumulating container from the discharge port through at least the space S. Further, the filter member is not limited to being disposed inside the pressure accumulating container, and may be disposed outside the pressure accumulating vessel, for example, in the communication path 68. As long as the gas filled in the pressure accumulating vessel passes through before reaching the adsorbent, that is, if it is a location upstream of the adsorbent in the gas flow to the pressure accumulating vessel, the filter member can be arranged at various locations. .

  The exhaust gas recovery passage and the exhaust gas discharge passage may be separated. When the exhaust gas recovery passage and the exhaust gas discharge passage are separated, a valve provided in the exhaust gas recovery passage is A check valve may be used. Further, when the exhaust gas recovery passage and the exhaust gas discharge passage are separated, the exhaust gas discharge passage may be communicated with any portion of the exhaust passage upstream of the turbine wheel, for example, in the turbine housing. Communication is enabled. Further, for example, a nozzle may be provided at the downstream end of the exhaust gas discharge passage.

  Further, in the above embodiment, when accelerating, the pressure in the pressure accumulating vessel is supplied to the exhaust passage upstream of the turbine wheel. However, not only when accelerating, but when the required supercharging amount increases. A pressure supply may be made. When the required supercharging amount increases, it includes a case where the required load on the internal combustion engine increases, such as when accelerating and when the load increases as the vehicle faces an uphill.

  In the above embodiment, the exhaust gas in the pressure accumulating vessel, that is, the pressure that it has is used for the operation assistance of the turbocharger. However, this does not limit the pressure or gas application within the accumulator vessel, which can be used for a variety of other applications.

  Moreover, in the said embodiment, although the exhaust throttle valve 62 was a butterfly type valve, it may be a valve of other types. The exhaust throttle valve 62 can be, for example, a poppet valve or a shutter valve. As the exhaust throttle valve 62, a valve provided for an exhaust brake may be used. The EGR valve 42 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. Further, the flow control valve 72 may be divided into two valves for recovery and discharge. The various actuators for driving these valves are not limited to electric motors or negative pressure diaphragm actuators, and may be various actuators available to those skilled in the art.

  Moreover, in the said embodiment, although it decided to provide one pressure accumulation container 70, it may be provided with two or more. When two or more accumulator containers 70 are provided, the accumulator containers 70 can be distributed and arranged in the vehicle.

  In the above embodiment, the present invention is applied 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. It is applicable to. 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 of the internal combustion engine to which the present invention is applied may be any number.

  Although the present invention has been described with a certain degree of specificity in the above-described embodiments and modifications thereof, various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention described in the claims. It must be understood that 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 for a vehicle to which an embodiment is applied. It is a partial cross-section enlarged view of a pressure accumulation container. It is the graph which represented the container weight change at the time of gas filling with respect to the filling time in three pressure accumulators provided with different amounts of adsorbents. It is a control flowchart for exhaust gas recovery of an embodiment. It is a control flowchart for exhaust gas discharge of an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 38 EGR passage 44 EGR cooler 48 Turbine wheel 50 Turbine 58 Turbo supercharger 62 Exhaust throttle valve 68 Communication passage 70 Accumulation vessel 72 Flow control valve RP Exhaust gas recovery passage EP Exhaust gas discharge passage

Claims (4)

An exhaust gas recovery apparatus comprising: an exhaust throttle valve provided in an exhaust passage of an internal combustion engine; and an accumulator vessel that can communicate with the exhaust passage upstream of the exhaust throttle valve via the valve,
An exhaust gas recovery apparatus, wherein a cooling device is provided in an exhaust gas recovery passage connecting the exhaust passage upstream of the exhaust throttle valve and the pressure accumulating vessel.   The exhaust gas recovery device according to claim 1, wherein the cooling device is an EGR cooler provided in an EGR device of the internal combustion engine. Fuel cut determination means for determining whether or not a fuel cut is in progress;
A fuel cut time determination means for determining whether or not a predetermined time has elapsed when the fuel cut determination means makes a positive determination;
An exhaust throttle valve that controls closing of the exhaust throttle valve that is open to collect exhaust gas when the fuel cut determination means makes a positive determination and the fuel cut time determination means makes a positive determination. The exhaust gas recovery apparatus according to claim 1, further comprising a control unit. Fuel cut determination means for determining whether or not a fuel cut is in progress;
A fuel cut time determination means for determining whether or not a predetermined time has elapsed when the fuel cut determination means makes a positive determination;
An exhaust throttle valve that controls closing of the exhaust throttle valve that is open to collect exhaust gas when the fuel cut determination means makes a positive determination and the fuel cut time determination means makes a positive determination. Control means;
EGR valve control means for controlling an EGR valve provided on the downstream side of the EGR cooler of the EGR device, wherein when the fuel cut determination means makes an affirmative determination, the EGR valve is controlled to open, and the fuel cut determination The exhaust gas recovery apparatus according to claim 2, further comprising: an EGR valve control means for closing the EGR valve when a positive determination is made by the means and a positive determination is made by the fuel cut time determination means. .

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