JP2006249949A - Exhaust gas recirculation device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas recirculation device for an internal combustion engine capable of promoting introduction of exhaust gas at supercharging time for the internal combustion engine while suppressing reduction of output of the internal combustion engine and worsening of response property of the exhaust gas recirculation device. <P>SOLUTION: This exhaust gas recirculation device 15 is applied to the internal combustion engine 1 provided with a mechanical supercharger 5 in an intake passage 3. The intake passage of the internal combustion engine 1 has a first branched passage 31 and a second branched passage 32 branched from a branched position 3a on the downstream side of the mechanical supercharger 5 to lead intake into the same cylinder 2 of the internal combustion engine 1 separately. This device 15 is provided with an exhaust gas recirculation passage 16 for leading exhaust gas from an exhaust passage 4 into the first branched passage 31 of the internal combustion engine 1 and a supercharging pressure adjusting valve 18 arranged in the first branched passage 31 between the branched position 3a in the intake passage 3 and an exhaust gas introducing position 3b for introducing exhaust gas in the exhaust gas recirculating passage 16 and capable of adjusting opening between a fully closed position for closing the first branched passage 31 fully and a fully opened position for opening the first branched passage 31 fully. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust gas recirculation device that recirculates exhaust gas from an internal combustion engine to the internal combustion engine.

  As an exhaust gas recirculation device for an internal combustion engine, a venturi is provided in a downstream intake passage pressurized by a mechanical supercharger, and exhaust of the internal combustion engine is introduced through the venturi, or upstream of a mechanical supercharger There is an engine that introduces exhaust gas from an internal combustion engine into a side intake passage (Patent Document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.

Japanese Patent No. 3085882 JP 2001-82259 A

  The mechanical supercharger is driven by utilizing the rotation of the crankshaft of the internal combustion engine. Therefore, unlike a turbocharger that uses exhaust energy, the pressure in the exhaust passage upstream of the turbine does not increase with the operation of the turbocharger. Therefore, during supercharging, the pressure difference between the intake passage and the exhaust passage downstream of the mechanical supercharger becomes small, and sometimes the pressure in the intake passage exceeds the pressure in the exhaust passage, preventing the introduction of exhaust into the intake passage. The exhaust gas recirculation to the internal combustion engine is limited. Therefore, the exhaust gas recirculation device disclosed in Patent Document 1 promotes the introduction of exhaust gas by using suction by a venturi or a mechanical supercharger at the time of supercharging by a mechanical supercharger.

  However, when a venturi is used, if the amount of intake air increases, the venturi becomes a resistance to intake air, which may cause a decrease in output performance of the internal combustion engine. In addition, when exhaust is introduced upstream of the mechanical supercharger, the volume from the exhaust introduction position to the cylinder of the internal combustion engine inevitably increases, so the responsiveness of the exhaust gas recirculation device may deteriorate. .

  Therefore, an object of the present invention is to provide an exhaust gas recirculation device for an internal combustion engine that can promote introduction of exhaust gas when the internal combustion engine is supercharged while suppressing a decrease in output of the internal combustion engine and a deterioration in response of the exhaust gas recirculation device. .

  The exhaust gas recirculation apparatus for an internal combustion engine according to the present invention is an internal combustion engine that is applied to an internal combustion engine in which a supercharger that is driven by using rotation of a crankshaft of the internal combustion engine or by using rotation of an electric motor is provided in an intake passage. In the exhaust gas recirculation apparatus for an engine, the intake passage of the internal combustion engine is branched from a branch position on the downstream side of the supercharger, and the first branch passage guides intake air separately to the same cylinder of the internal combustion engine An exhaust gas recirculation passage that has a second branch passage and guides exhaust gas from the exhaust passage of the internal combustion engine to the first branch passage; and exhaust gas that is introduced into the branch position of the intake passage and the exhaust gas recirculation passage An adjustment valve disposed in the first branch passage between the introduction position and capable of adjusting an opening between a fully closed position for fully closing the first branch passage and a fully open position for fully opening the first branch passage; To solve the above-mentioned problems. To (claim 1).

  According to this exhaust gas recirculation device, the opening degree of the adjustment valve disposed in the first branch passage can be adjusted from the fully closed position to the fully open position, so that supercharging performed via the first branch passage can be limited. For this reason, when the exhaust gas is recirculated during the supercharging by the supercharger, the supercharging performed through the first branch passage is limited by the regulating valve to suppress the increase in the pressure at the exhaust introduction position. Thus, the introduction of exhaust gas can be promoted, and at the same time, the supercharging performed through the second branch passage can be continued. Therefore, the supercharging by the supercharger driven by using the rotation of the crankshaft of the internal combustion engine or by using the rotation of the electric motor does not hinder the recirculation of the exhaust gas. Thus, the exhaust gas can be recirculated. Further, when it is not necessary to recirculate the exhaust gas, the restriction of supercharging performed via the first branch passage can be canceled by adjusting the adjustment valve. Thereby, supercharging is performed via each of the 1st branch passage and the 2nd branch passage, and it can also control the performance fall of an internal-combustion engine. Furthermore, since the exhaust introduction position of the first branch passage can be as close as possible to the cylinder of the internal combustion engine and an increase in volume from the exhaust introduction position to the cylinder can be suppressed, deterioration of the responsiveness of the exhaust gas recirculation device can be suppressed.

  In the exhaust gas recirculation device for an internal combustion engine of the present invention, the opening degree of the adjustment valve may be adjusted as appropriate, but when the exhaust gas is recirculated to the internal combustion engine via the first branch passage, the first branch passage An adjustment valve control means for controlling the opening of the adjustment valve to the closed side so as to limit supercharging via the valve may be further provided (Claim 2). According to this aspect, the supercharging performed via the first branch passage can be limited by controlling the opening degree of the regulating valve to the closed side.

  In the exhaust gas recirculation apparatus for an internal combustion engine according to the present invention, the first intake port of the first branch passage is configured such that the flow coefficient thereof is larger than the flow coefficient of the second intake port of the second branch passage. (Claim 3). The “flow coefficient of the intake port” referred to here is a dimensionless number indicating the ease of fluid flow to the intake port. When the differential pressure before and after the intake port is the same, the flow rate increases as the flow rate coefficient increases.

  The first intake port and the second intake port when the supercharging performed via the first branch passage is restricted by the regulating valve and the upstream pressure of the second intake port becomes higher than the upstream pressure of the first intake port If the flow rate coefficients of the two intake ports are configured to be the same, a flow rate difference may occur between the first intake port and the second intake port in some cases, and the intake air introduced from the second intake port to the cylinder. May be ejected back to the first intake port side, or introduction of exhaust gas from the first intake port may be restricted. According to this aspect, even if the supercharging performed through the first branch passage is limited by the regulating valve and a difference occurs between the upstream pressure of the first intake port and the upstream pressure of the second intake port, Since the flow coefficient of one intake port is configured to be greater than the flow coefficient of the second intake port and the exhaust flows easily, the difference in flow rate between the first intake port and the second intake port is leveled, resulting in the second intake air. It is possible to prevent the intake air from being blown back from the port side to the first intake port side or the introduction of exhaust gas from the first intake port being restricted.

  The means for giving a difference in flow coefficient between the two intake ports is not particularly limited. For example, one intake port is made larger in diameter than the other, one intake port is formed in a straight line, and the other is curved. It is possible to apply means such as In addition to these, the second intake port may be configured as a helical port. In this case, since the second intake port is configured as a helical port and the flow coefficient is relatively smaller than that of the first intake port, a swirl is generated in the cylinder simultaneously with the above-described effect of reducing the flow difference, Mixing of fuel and air is promoted and good combustion can be realized.

  In the exhaust gas recirculation apparatus for an internal combustion engine according to the present invention, a first intake valve provided in a first intake port included in the first branch passage and a second intake valve provided in a second intake port included in the second branch passage. Each of the first and second intake ports may be provided with a valve drive device that drives at least one of the lift amount and the valve timing so that the flow coefficient of the first intake port is larger than the flow coefficient of the second intake port. (Claim 5). The “flow coefficient of the intake port” referred to here is a dimensionless number indicating the ease of fluid flow to the intake port. When the differential pressure before and after the intake port is the same, the flow rate increases as the flow rate coefficient increases.

  In a mode in which each of the first intake valve and the second intake valve is driven so that the flow rate coefficients of the first intake port and the second intake port are the same, the adjustment valve performs the operation via the first branch passage. When the supercharging is limited and the upstream pressure of the second intake port becomes higher than the upstream pressure of the first intake port, a flow rate difference may occur between the first intake port and the second intake port. Then, it is possible that the intake air introduced from the second intake port to the cylinder is jetted back to the first intake port side or the introduction of exhaust gas from the first intake port is restricted. According to this aspect, even if the supercharging performed through the first branch passage is limited by the regulating valve and a difference occurs between the upstream pressure of the first intake port and the upstream pressure of the second intake port, In each of the first intake valve and the second intake valve, at least one of the lift amount and the valve timing is made different by the valve drive device so that the flow coefficient of the first intake port is larger than the flow coefficient of the second intake port. As a result, the difference in flow rate between the first intake port and the second intake port is leveled, and intake air is jetted back from the second intake port side to the first intake port side, or from the first intake port. It is possible to prevent the introduction of exhaust gas from being restricted.

  In this aspect, either the lift amount or the valve timing may be different between the two intake ports, or both may be different. The means for making at least one of the lift amount and the valve timing different is not limited. For example, a valve mechanism may be configured by providing a cam mechanism including at least a pair of cams having different profiles. In addition, the valve drive device may include a variable valve mechanism capable of changing at least one of the lift amount and the valve timing with respect to each of the first intake valve and the second intake valve. In this case, since the variable valve mechanism can change at least one of the lift amount and the valve timing according to the operating state of the internal combustion engine, the ratio of exhaust to the target intake gas (EGR rate), etc., the EGR rate This is convenient when strict control is required.

  In the exhaust gas recirculation apparatus for an internal combustion engine according to the present invention, the internal combustion engine is disposed in the exhaust passage so as to be rotatable integrally with the compressor disposed in the intake passage in series or in parallel with the supercharger. And another turbocharger that is driven by using the exhaust energy of the internal combustion engine (claim 7). According to this aspect, the two-stage supercharging is realized by the supercharger described above with respect to the internal combustion engine and the other supercharger driven using the exhaust energy. The exhaust gas recirculation device of the invention can be applied.

  As described above, according to the present invention, the intake passage of the internal combustion engine is branched from the branch position on the downstream side of the supercharger, and the first branch passage that guides intake air separately to the same cylinder of the internal combustion engine, The second branch passage is provided, and an adjustment valve whose opening degree can be adjusted is provided between the branch position of the first branch passage and the exhaust position where the exhaust gas is introduced. Since supercharging can be limited by the regulating valve, introduction of exhaust gas into the first branch passage can be promoted, and at the same time, supercharging performed through the second branch passage can be continued. Accordingly, the supercharging by the supercharger does not hinder the exhaust gas recirculation, and the exhaust gas can be recirculated to the internal combustion engine while performing the supercharging.

  FIG. 1 shows an overall configuration of an internal combustion engine to which an exhaust gas recirculation apparatus of the present invention is applied. The internal combustion engine 1 is an in-line four-cylinder four-cycle diesel engine in which four (two in FIG. 1) cylinders 2 are arranged in a line. The internal combustion engine 1 includes a mechanical supercharger (supercharger) 5 that is disposed in an intake passage 3 and is driven using rotation of a crankshaft (not shown), and a turbo that is driven using exhaust energy. A charger (another supercharger) 6 is provided. The turbocharger 6 includes a turbine 6a disposed in the exhaust passage 4 and a compressor 6b disposed in the intake passage 3 so as to be rotatable integrally with the turbine 5a. The mechanical supercharger 5 and the turbocharger 6 realize two-stage supercharging for the internal combustion engine 1. The mechanical supercharger 5 covers a region where the responsiveness of supercharging is deteriorated only by the turbocharger 6 as in the case where the internal combustion engine 1 is requested to accelerate rapidly from a low speed range. It is provided to assist supercharging. The mechanical supercharger 5 may be configured to operate in conjunction with the operation of the internal combustion engine 1 or may be configured to be operated or inactivated using clutch means. The turbocharger 6 is a variable displacement type in which a variable nozzle 6c is provided on the upstream side of the turbine 6a. The opening of the variable nozzle 6c can be adjusted from the maximum throttle position (minimum opening) to the minimum throttle position (maximum opening), and the variable nozzle 6c controls the operating state of the internal combustion engine 1 appropriately. And connected to an engine control unit (ECU) 14 provided for control. The ECU 14 is a known computer including a microprocessor, RAM, ROM and the like.

  In the intake passage 3 of the internal combustion engine 1, the air cleaner 8 for filtering the intake air, the air flow meter 9 for outputting a signal corresponding to the intake air flow, the compressor 6 b, and the intake air compressed by the compressor 6 b are cooled in order from the upstream side. A first intercooler 10A, a supercharger 5, a second intercooler 10B for cooling the intake air compressed by the mechanical supercharger 5, and a throttle valve 11 for adjusting the intake air flow rate are provided. The intake passage 3 is provided with a bypass passage 12 connecting the upstream side of the mechanical supercharger 5 and the downstream side of the second intercooler 10B, and the bypass passage 12 is provided with a bypass valve 13 for adjusting the flow rate. ing. By adjusting the opening degree of the bypass valve 13 appropriately, the supercharging pressure by the mechanical supercharger 5 can be adjusted. The bypass valve 13 is connected to the ECU 14 and controlled.

  The intake passage 3 has a first branch passage 31 and a second branch passage 32 that respectively branch from a branch position 3 a located downstream of the mechanical supercharger 5. The first branch passage 31 and the second branch passage 32 are provided separately for the same cylinder 2, in other words, independently for the same cylinder 2. In order to suppress intake pulsation, the first branch passage 31 has a surge tank 33, and the second branch passage 32 has a surge tank 34. The capacity of the surge tanks 33 and 34 may be the same or different from each other.

  As shown in FIG. 2 in a simplified manner, the first branch passage 31 has a branch portion 31a that branches from the surge tank 33 for each cylinder 2, and a first intake port 35 provided in each branch portion 31a. The second branch passage 32 has a branch portion 32a branching from the surge tank 34 to each cylinder 2 and a second intake port 36 provided in each branch portion 32a. Each intake port 35, 36 communicates with the corresponding cylinder 2. The first intake port 35 is configured such that the flow coefficient is larger than the flow coefficient of the second intake port 36. For this reason, when the differential pressure across the intake port is the same, the flow rate of the first intake port 35 is greater than that of the second intake port 36. In particular, in the present embodiment, although detailed illustration is omitted, the second intake port 36 is configured as a so-called helical port, and a difference in flow coefficient is given to the first intake port 35. Therefore, a swirl is generated in each cylinder 2 and the mixing of fuel and air is promoted, and good combustion can be realized.

  The internal combustion engine 1 also includes a first intake valve 37 that opens and closes the first intake port 35, a second intake valve 38 that opens and closes the second intake port, and a valve drive device that drives the intake valves 37 and 38 to open and close, respectively. 39. Although not shown in detail, the valve drive device 39 transmits the rotation of the crankshaft to the camshaft, and the camshaft is located at a position corresponding to each of the first intake valve 37 and the second intake valve 38. A pair of cams having the same profile is provided. As a result, the intake valves 37 and 38 are opened and closed by the valve drive device 39 with the same lift amount and the same valve timing with respect to the same cylinder 2.

  As shown in FIG. 1, the exhaust passage 4 of the internal combustion engine 1 has an exhaust manifold 41 through which the exhaust discharged from each cylinder 2 is guided. The exhaust passage 4 on the downstream side of the exhaust manifold 41 has a turbocharger 6. Turbine 6a and an exhaust purification device 42 for reducing harmful substances in the exhaust are provided downstream of the turbine 6a. Further, the internal combustion engine 1 is provided with an exhaust gas recirculation device 15 that recirculates the exhaust gas to the internal combustion engine 1 in order to reduce nitrogen oxide in the exhaust gas. The exhaust gas recirculation device 15 is provided in the exhaust gas recirculation passage 16 connecting the exhaust manifold 41 and the surge tank 33 of the first branch passage 31, and the exhaust gas recirculating to the internal combustion engine 1 (hereinafter referred to as EGR gas). And an exhaust gas recirculation valve 17 for adjusting the amount of the exhaust gas recirculation valve 17. The exhaust gas recirculation valve 17 is connected to the ECU 14 and controlled so as to achieve a target EGR rate. As long as the exhaust introduction position 3b into which the EGR gas is introduced is downstream of the branch position 3a of the intake passage 3, it is not necessarily provided in the surge tank 33. Although not shown, a cooling device for cooling the EGR gas may be provided in the exhaust gas recirculation passage 16.

  Generally, when the EGR gas is introduced into the intake system by the exhaust gas recirculation device 15, it is necessary that the pressure of the exhaust system for extracting the EGR gas is higher than the pressure of the intake system that introduces the EGR gas. However, in the case of a supercharging system including a mechanical supercharger driven using the rotation of the crankshaft as in this embodiment, the pressure of the intake system is changed by the operation of the mechanical supercharger. When the pressure balance between the exhaust system and the intake system is lost, sometimes the pressure in the intake system is higher than that in the exhaust system, and the pressure balance is reversed to restrict the introduction of EGR gas. There is also.

  Therefore, in the present embodiment, when the internal combustion engine 1 is being supercharged in two stages, that is, when supercharging is simultaneously performed by the mechanical supercharger 5 and the turbocharger 6, the EGR gas In order to facilitate introduction, a supercharging pressure adjustment valve (regulation valve) 18 is provided between the branch position 3a of the intake passage 3 and the exhaust introduction position 3b into which EGR gas is introduced. The supercharging pressure adjustment valve 18 can be adjusted in opening from a fully closed position where the first branch passage 31 is fully closed to a fully opened position where the first branch passage 31 is fully opened, and is connected to the ECU 14 to appropriately control the opening. . Thereby, the supercharging performed via the 1st branch passage 31 can be restricted. The form of the supercharging pressure adjustment valve 18 is not particularly limited, and may be realized in the form of a butterfly valve, a gate valve or the like as long as the opening degree can be adjusted.

  Next, an outline of the opening control of the variable nozzle 6c, the bypass valve 13, the exhaust gas recirculation valve 17, and the supercharging pressure adjustment valve 18 by the ECU 14 will be described. 3 to 6 schematically show a control map in which the opening degree of each control object is associated with the engine speed (rotational speed) and the load of the internal combustion engine 1. First, when both the engine speed and the load are low, the amount of exhaust passing through the turbine 6a is small, so that the EGR gas can be easily introduced by increasing the pressure at the exhaust extraction position 4b (FIG. 1). Thus, the opening degree of the variable nozzle 6c is controlled to the closed side to make it difficult for the exhaust to pass through the turbine 6a. As shown in FIG. 4, the opening degree of the bypass valve 13 is controlled by the mechanical supercharger 5 so that the supercharging pressure does not increase too much. As shown in FIG. 5, the opening degree of the exhaust gas recirculation valve 17 is controlled to the open side so that the EGR gas can easily pass therethrough. As shown in FIG. 6, the opening degree of the supercharging pressure adjusting valve 18 is controlled to the closed side so that supercharging performed via the first branch passage 31 is limited.

  On the other hand, when both the engine speed and the load are high, the amount of exhaust gas passing through the turbine 6a is large. Therefore, as shown in FIG. 3, the opening of the variable nozzle 6c is set so that the pressure at the exhaust extraction position 4b does not rise too much. Is controlled to the open side so that the exhaust gas easily passes through the turbine 6a. As shown in FIG. 4, the opening degree of the bypass valve 13 is controlled to the closed side in order to effect supercharging by the mechanical supercharger 5. As shown in FIG. 5, the opening degree of the exhaust gas recirculation valve 17 is controlled to the closed side so that the passing amount of the EGR gas does not increase too much. The opening degree of the supercharging pressure adjustment valve 18 is controlled to the opening side so that EGR gas is not introduced excessively as shown in FIG.

  Thus, the ECU 14 can obtain the exhaust gas recirculation amount (EGR amount) according to the operating state by controlling the opening degree of each control object according to the operating state of the internal combustion engine 1.

  According to the above embodiment, when the two-stage supercharging is performed on the internal combustion engine 1, the opening degree of the regulating valve 18 is controlled to the closed side, that is, the first branch passage 31 is throttled. As a result, the supercharging performed via the first branch passage 31 is limited, and an increase in pressure at the exhaust introduction position 3b located on the downstream side of the regulating valve 16 can be suppressed. For this reason, when the EGR gas is introduced by the exhaust gas recirculation device 15, the collapse of the pressure balance between the exhaust introduction position 3b and the exhaust extraction position 4b from which the EGR gas is taken out can be suppressed, so that the introduction of the EGR gas can be promoted. And the supercharging performed via the 2nd branch passage 32 can be continued as it is. Therefore, it is necessary to stop the supercharging by the mechanical supercharger 5 for the introduction of the EGR gas, or the introduction of the EGR gas is limited in a region where the supercharging by the mechanical supercharger 5 is required. Etc. can be avoided. Further, when it is not necessary to recirculate the exhaust gas, the restriction of supercharging performed via the first branch passage 31 can be canceled by adjusting the opening of the supercharging pressure adjusting valve 18 to the open side. Thereby, supercharging is performed via each of the 1st branch passage 31 and the 2nd branch passage 32, and it can also control the performance fall of internal combustion engine 1. Further, the exhaust introduction position 3b of the first branch passage 31 can be brought as close as possible to the cylinder 2 side of the internal combustion engine 1 to suppress an increase in volume from the exhaust introduction position 3b to the cylinder 2. For this reason, the deterioration of the responsiveness of the exhaust gas recirculation device 15 can be suppressed.

  Further, each of the first intake port 35 and the second intake port 36 provided for each cylinder 2 is configured such that the flow coefficient of the first intake port 35 is larger than the flow coefficient of the second intake port 36. Therefore, the supercharging performed through the first branch passage 31 is limited by the supercharging pressure adjusting valve 18, and a difference occurs between the upstream pressure of the first intake port 35 and the upstream pressure of the second intake port 36. However, as a result, the difference in flow rate between the first intake port 35 and the second intake port 36 is leveled, and the intake air is blown back from the second intake port 36 side to the first intake port 35 side, or the first intake port 35 It is possible to prevent the introduction of exhaust from the port 35 from being restricted.

  The present invention is not limited to the above embodiment, and may be implemented in various forms. The supercharging system mounted on the internal combustion engine 1 is not limited to the form shown in FIG. 1, and instead of the mechanical supercharger 5, an electric supercharger such as an electric compressor driven using the rotation of the electric motor is used. It may be provided. Further, the supercharger and the turbocharger are not limited to be arranged in series in the intake passage, and may be arranged in parallel in the intake passage. Further, it is not always necessary to perform the two-stage supercharging between the supercharger and the turbocharger, and a form in which no turbocharger is provided may be used. In short, a turbocharger that does not increase the pressure of the exhaust system of the internal combustion engine during operation like a mechanical supercharger or an electric supercharger, in other words, a supercharger that uses a drive source other than the exhaust energy of the internal combustion engine. The present invention can be applied to an internal combustion engine equipped with a supercharging system including

  In the above embodiment, the second intake port 36 is used as a helical port and a difference in flow coefficient is given to the first intake port 36. For example, the diameter of the first intake port 35 is changed to the diameter of the second intake port 36. The first intake port 35 may be formed in a straight line and the second intake port 36 may be curved.

  The flow coefficient between the two intake ports can be reduced by making at least one of the lift amount and the valve timing of the first intake valve and the second intake valve that open and close each port without making the forms of the two intake ports themselves different from each other. It is also possible to give the difference. For example, the valve drive device 39 shown in FIG. 2 may be changed to one having a cam mechanism including at least a pair of cams having different profiles, and at least one of the lift amount and the valve timing may be made different. Further, the valve driving device 39 may be changed to a known variable valve mechanism that can change at least one of the lift amount and the valve timing, and the variable valve mechanism may be controlled by the ECU 14 in FIG. In this case, at least one of the lift amount and the valve timing can be changed by the variable valve mechanism in accordance with the operating state of the internal combustion engine 1, the target EGR rate, etc., so that strict control of the EGR rate is necessary. Convenient. It should be noted that the shapes of the two intake ports themselves may be different, and at least one of the lift amount and valve timing of the intake valve that opens and closes each intake port may be different.

  In addition, although this invention is applied suitably for a diesel engine, it can also be applied to a gasoline engine.

The figure which showed the whole structure of the internal combustion engine to which the exhaust gas recirculation apparatus of this invention is applied. The figure which simplified and showed the detail of the surge tank downstream vicinity. The figure which showed the outline of the control map which linked | related the opening degree of the variable nozzle with the engine speed and load of the internal combustion engine. The figure which showed the outline of the control map which linked | related the opening degree of the bypass valve with the engine speed and load of the internal combustion engine. The figure which showed the outline of the control map which linked | related the opening degree of the exhaust gas recirculation valve with the engine speed and load of the internal combustion engine. The figure which showed the outline of the control map which linked | related the opening degree of the supercharging pressure adjustment valve with the engine speed and load of the internal combustion engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder 3 Intake passage 3a Branch position 3b Exhaust introduction position 4 Exhaust passage 5 Mechanical supercharger (supercharger)
6 Turbocharger (other turbochargers)
6a Turbine 6b Compressor 14 ECU (regulating valve control means)
15 Exhaust gas recirculation device 16 Exhaust gas recirculation passage 18 Supercharging pressure regulating valve (regulating valve)
31 First branch passage 32 Second branch passage 35 First intake port 36 Second intake port 37 First intake valve 38 Second intake valve 39 Valve drive device

Claims (7)

In an exhaust gas recirculation apparatus for an internal combustion engine that is applied to an internal combustion engine in which a supercharger that is driven using rotation of a crankshaft of the internal combustion engine or using rotation of an electric motor is provided in an intake passage,
The intake passage of the internal combustion engine has a first branch passage and a second branch passage that are branched from a branch position on the downstream side of the supercharger and separately guide intake air to the same cylinder of the internal combustion engine. And
The exhaust gas recirculation passage for introducing exhaust gas from the exhaust passage of the internal combustion engine to the first branch passage, and the first position between the branch position of the intake passage and the exhaust introduction position where the exhaust gas is introduced in the exhaust gas recirculation passage. And an adjustment valve that is disposed in the branch passage and is capable of adjusting an opening between a fully closed position where the first branch passage is fully closed and a fully open position where the first branch passage is fully opened. Engine exhaust gas recirculation device.   Adjustment for controlling the opening degree of the adjusting valve to the closed side so that supercharging performed through the first branch passage is limited when exhaust gas is recirculated to the internal combustion engine through the first branch passage. The exhaust gas recirculation apparatus for an internal combustion engine according to claim 1, further comprising valve control means.   The first intake port of the first branch passage is configured such that the flow coefficient thereof is larger than the flow coefficient of the second intake port of the second branch passage. 2. An exhaust gas recirculation device for an internal combustion engine according to 2.   The exhaust gas recirculation apparatus for an internal combustion engine according to claim 3, wherein the second intake port of the second branch passage is configured as a helical port.   The first intake valve provided in the first intake port of the first branch passage and the second intake valve provided in the second intake port of the second branch passage are respectively connected to the flow rate of the first intake port. 5. The valve drive device according to claim 1, further comprising: a valve drive device that drives the valve by varying at least one of a lift amount and a valve timing so that the coefficient is larger than the flow coefficient of the second intake port. An exhaust gas recirculation device for an internal combustion engine according to the item.   The said valve drive apparatus is provided with the variable valve mechanism in which at least one of the said lift amount with respect to each of the said 1st intake valve and the said 2nd intake valve and the said valve timing can be changed. An exhaust gas recirculation device for an internal combustion engine.   The internal combustion engine includes a compressor disposed in the intake passage in series or in parallel with the supercharger, and a turbine disposed in the exhaust passage so as to rotate integrally with the compressor, and the exhaust energy of the internal combustion engine The exhaust gas recirculation apparatus for an internal combustion engine according to any one of claims 1 to 6, further comprising another supercharger that is driven by using the engine.

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