JP2009191686A - Supercharger of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supercharger of an engine capable of raising an exhaust emission control device to an efficient temperature or restraining the lowering of the temperature. <P>SOLUTION: The supercharger of the engine includes an exhaust turbocharger 60 and the exhaust emission control device 56, a control valve 59 arranged in a bypass passage 58 bypassing the exhaust turbocharger in an exhaust passage, a control valve control means 106 for controlling the operation of the control valve, an electric supercharger 34 for supercharging the air of an intake passage 20, an electric supercharger control means 104 for controlling the operation of this electric supercharger, an exhaust emission control device temperature detecting means 116 for detecting the temperature of the exhaust emission control device by a predetermined sensor, and a control means 100 for opening the control valve by the control valve control means and operating the electric supercharger by the electric supercharger control means when the temperature of the exhaust emission control device detected by the exhaust emission control device temperature detecting means is lower than a predetermined temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine supercharger, and more particularly to an engine supercharger having an exhaust turbocharger and an exhaust purification device disposed in an exhaust passage downstream of the exhaust turbocharger.

  Conventionally, before starting the engine, the electric motor provided in the exhaust turbocharger is started to perform supercharging to increase the intake pressure, and with this pressure increase, the air temperature is increased to increase the engine or exhaust purification. An engine that warms up the apparatus is known (Patent Document 1).

JP 2004-332715 A

  However, in the device described in Patent Document 1, the degree of the temperature rise of the air accompanying the rise of the intake pressure is very small, and the engine and the exhaust purification device cannot be sufficiently warmed up. . In particular, the exhaust emission control device is improved in efficiency by appropriately raising the temperature, but the temperature rise of the intake air is not sufficient. Therefore, how to raise the temperature of the exhaust emission control device to a temperature at which efficiency is improved by using the temperature of the exhaust gas due to the operation of the engine after the engine is started becomes a problem. Even if the engine has already been started, the exhaust gas turbocharger turbine may be deprived of heat, for example, and the exhaust gas temperature may decrease and the exhaust purification device temperature may decrease. In addition, after the engine is stopped, the temperature of the exhaust gas purification device may drop, and the exhaust gas may not be sufficiently purified during restart. This is a particularly significant problem with diesel engines with high thermal efficiency.

  The present invention has been made to solve the above-described problems of the prior art, and provides an engine supercharging device capable of raising the exhaust purification device to an efficient temperature or suppressing a decrease in temperature. The purpose is to provide.

  In order to achieve the above object, according to the present invention, an exhaust turbocharger that supercharges air in an intake passage by rotating a compressor disposed in the intake passage by rotation of a turbine disposed in the exhaust passage; An exhaust gas purifying device disposed in an exhaust passage downstream of the exhaust turbocharger, and a bypass passage for bypassing the exhaust turbocharger in the exhaust passage, and the bypass passage A control valve disposed in the control valve, a control valve control means for controlling the operation of the control valve, an electric supercharger that supercharges the air in the intake passage by electrically rotating a compressor disposed in the intake passage, The electric supercharger control means for controlling the operation of the electric supercharger, the exhaust purification apparatus temperature detection means for detecting the temperature of the exhaust purification apparatus by a predetermined sensor, and the exhaust purification apparatus temperature detection means Control means for opening the control valve by means of the control valve control means and operating the electric supercharger by means of the electric supercharger control means when the temperature of the discharged exhaust purification device is lower than the predetermined temperature. It is said.

  In the present invention configured as described above, when the temperature of the exhaust purification device is low, the control valve of the bypass passage that bypasses the exhaust turbocharger is opened, so that the exhaust gas turbocharger takes the heat of the exhaust gas. The exhaust gas can be allowed to flow to the exhaust gas purification device without increasing the temperature of the exhaust gas purification device, or the temperature decrease can be suppressed. On the other hand, torque reduction due to bypassing the exhaust turbocharger can be suppressed by operating the electric supercharger to ensure sufficient torque.

In the present invention, it is preferable that the fuel injection control unit further controls a fuel injector that injects fuel into the cylinder, and the control device includes an exhaust purification device detected by the exhaust purification device temperature detection unit. When the temperature is lower than the predetermined temperature, post injection after main injection is further performed in the cylinder by the fuel injection control means.
In the present invention configured as described above, when the temperature of the exhaust purification device is low, the exhaust gas is generated by the reaction between the air increased by the operation of the electric supercharger and the post-injection after the main injection by the fuel injector. The temperature rises, the temperature of the exhaust purification device can be raised, or the temperature drop can be suppressed.

  In order to achieve the above object, according to the present invention, an exhaust turbocharger that supercharges air in an intake passage by rotating a compressor disposed in the intake passage by rotation of a turbine disposed in the exhaust passage; An exhaust gas purifying device disposed in an exhaust passage downstream of the exhaust turbocharger, and a bypass passage for bypassing the exhaust turbocharger in the exhaust passage, and the bypass passage A control valve disposed in the control valve, a control valve control means for controlling the operation of the control valve, an electric supercharger that supercharges the air in the intake passage by electrically rotating a compressor disposed in the intake passage, An electric supercharger control means for controlling the operation of the electric supercharger, an automatic stop control means for automatically stopping the engine when a predetermined automatic stop condition is satisfied, and an automatic stop by the automatic stop means When the engine is restarted, is characterized by having a control means for actuating the electric supercharger by the electric supercharger control means causes opening the control valve by the control valve control means.

  In the present invention configured as above, the control valve of the bypass passage that bypasses the exhaust turbocharger is opened at the time of restart from the automatic stop when the temperature of the exhaust purification device becomes lower than before the engine stop. Without exhausting the heat of the gas to the exhaust turbocharger, the exhaust gas can flow to the exhaust purification device, thereby increasing the temperature of the exhaust purification device or suppressing a decrease in temperature. On the other hand, torque reduction due to bypassing the exhaust turbocharger can be suppressed by operating the electric supercharger to ensure sufficient torque.

Further, in the present invention, preferably, it further includes a fuel injection control means for controlling a fuel injector that injects fuel into the cylinder, and the control device is configured to restart the engine from the automatic stop by the automatic stop means. Further, post-injection after main injection is performed in the cylinder by the fuel injection control means.
In the present invention configured as described above, at the time of restart from the automatic stop where the temperature of the exhaust gas purification device becomes lower than before the engine stop, the air increased by the operation of the electric supercharger and the main fuel injector are used. The temperature of the exhaust gas rises due to the reaction with the post-injection after the injection, and the temperature of the exhaust purification device can be raised or the temperature drop can be suppressed.

  According to the supercharging device for an engine of the present invention, the exhaust purification device can be raised to an efficient temperature, or the temperature drop can be suppressed.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an overall configuration diagram of an engine controlled by an engine supercharging device according to first and second embodiments of the present invention. Here, although each embodiment demonstrates the case where an engine is applied to a diesel engine, it is applicable similarly to a gasoline engine.

The engine body 1 is provided with a plurality of cylinders 2, and a combustion chamber 2 a is formed in these cylinders 2. In each combustion chamber 2a, an intake port 4 and an exhaust port 6 are opened, and an intake valve 8 and an exhaust valve 10 are provided in these ports. Further, a fuel injection valve 12 is provided for each combustion chamber 2a.
An intake passage 20 that supplies air to each cylinder 2 is connected upstream of the intake port 4 and the intake valve 8, and exhaust gas is led out from each cylinder 2 downstream of the exhaust port 6 and the exhaust valve 10. An exhaust passage 50 is connected.

  The intake passage 20 is formed with a surge tank 22 and an intake manifold 24 that branches from the surge tank 22 to each intake port 4 of each cylinder 2. An air cleaner 26 is provided upstream of the intake passage 20, and an intake pipe 28 extends between the air cleaner 26 and the surge tank 22. An intake throttle valve 30 is provided downstream of the air cleaner 26 of the intake pipe 28. An intercooler 32 is disposed in the intake pipe 28.

  An electric supercharger 34 is provided between the intercooler 32 of the intake pipe 28 and the surge tank 22. The electric supercharger 34 has a compressor 35 that is directly driven by a motor 34a. An electric supercharger bypass passage 36 that bypasses the electric supercharger 34 from the intake pipe 28 and communicates with the upstream side of the surge tank 22 is provided. An electric supercharger bypass valve (intake bypass valve) 38 is provided in the electric supercharge bypass passage 36. An intake shutter valve 40 is provided between the electric supercharger 34 and the electric supercharger bypass valve 38 of the intake pipe 28 and the intercooler 32.

  Next, the exhaust passage 50 includes an exhaust manifold 52 for each cylinder connected to the exhaust port 6 of each cylinder 2, an exhaust pipe 54 downstream thereof, and an exhaust purification device 56 connected downstream of the exhaust pipe 54. I have. The exhaust purification device 56 has a catalytic function and is for collecting diesel smoke exhaust particulates (PM). Specifically, the exhaust purification device 56 is disposed on the downstream side of the oxidation catalyst 56a. It is comprised by the diesel particulate filter (DPF) 56b.

An exhaust turbocharger 60 is provided between the intake passage 20 and the exhaust passage 50. The exhaust turbocharger 60 includes a turbine 62 that rotates by being driven by the energy of exhaust gas, and a compressor 66 that is connected to the turbine 62 via a shaft 64. The turbine 62 of the exhaust turbocharger 60 is provided in the exhaust pipe 54, and the compressor 66 is provided in the intake pipe 28. The exhaust turbocharger 60 supercharges the intake air in the intake pipe 28 by the rotation of the compressor 66 interlocked with the rotation of the turbine 62 by the exhaust energy. The intercooler 32 is configured to cool the air supercharged by the compressor 66.
The above-described electric supercharger 34 may be of a type in which a motor is attached to the exhaust turbocharger 60.

  Further, an exhaust turbo bypass passage 58 that bypasses the turbine 62 of the exhaust turbocharger 60 is formed in the exhaust passage 50 between the exhaust manifold 6 and the exhaust purification device 56. The exhaust turbo bypass passage 58 is provided with an exhaust turbo bypass valve (exhaust bypass valve) 59. When the exhaust turbo bypass valve 59 is open, the exhaust gas mainly passes through the exhaust turbo bypass passage 58. The high-temperature gas flows to the exhaust purification device 56 as it is. On the other hand, when the exhaust turbo bypass valve 59 is closed, the turbine 62 is rotated by the exhaust gas.

  In addition, a high pressure EGR passage 70 and a low pressure EGR passage 80 are provided between the intake passage 20 and the exhaust passage 50. The high-pressure EGR passage 70 communicates between the upstream side of the exhaust pipe 54 with respect to the turbine 62 and the surge tank 22, and is a relatively high temperature and high pressure exhaust gas before driving the exhaust turbocharger 60. The part is returned to the intake passage 20. The high-pressure EGR passage 70 is provided with an EGR valve 72 and an EGR cooler 74 on the upstream side (exhaust side) of the EGR valve 72.

  Further, the low-pressure EGR passage 80 communicates between the exhaust pipe 54 downstream of the exhaust purification device 56 and the intake pipe 28 upstream of the compressor 66 to drive the turbine 62 of the exhaust turbocharger 60. After that, a part of the exhaust gas having a relatively low pressure is returned to the intake passage 20. The low-pressure EGR passage 80 is provided with an EGR valve 82 and an EGR cooler 84 on the upstream side (exhaust side) of the EGR valve 82.

Next, the control system of the engine supercharging device according to the first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram of an engine control system according to the first embodiment of the present invention.
The ECU 100 is a control unit composed of a microprocessor having a CPU, a memory, a counter timer group, an interface, a bus connecting these units, and the like. Specifically, the ECU 100 is connected to the fuel injection valve 12, the electric supercharger 34 (34 a), the electric supercharger bypass valve 38, and the exhaust turbo bypass valve 59.

  The ECU 100 functionally includes a combustion control unit 102 that controls the fuel injection valve 12 to perform main injection, pilot injection, and post-injection of fuel into the cylinder 2 under predetermined conditions as will be described later. The electric supercharger control unit 104 controls the electric supercharger bypass valve 38 so as to open and close the electric supercharger bypass 36 while controlling the electric supercharger 34 (34a) so as to obtain a predetermined rotational speed. And an exhaust bypass valve control unit 106 that operates the exhaust turbo bypass valve 59 under a predetermined condition. Here, the electric supercharger control unit 104 opens the electric supercharger bypass valve 38 of the electric supercharger bypass passage 36 when the electric supercharger 34 is not driven, and opens the electric supercharger bypass valve 38 when driven. close. Thus, when the electric supercharger 34 is not driven, the intake air is guided to the electric supercharger bypass passage 36 to reduce the intake resistance, and when the electric supercharger 34 is driven, the intake air is reliably supplied to the electric supercharger 34. To the compressor 35.

  The ECU 100 is connected to a vehicle speed sensor 110 that detects the vehicle speed of the vehicle, and an air flow sensor 116 that predicts the temperature of the exhaust purification device 56 based on the amount of heat that enters the exhaust purification device 56. In response to the input signals from the sensors, the control units 102, 104 and 106 described above control the devices 12, 34 (34a), 38 and 59, respectively. In order to detect the temperature of the exhaust purification device 56, a catalyst sensor that directly measures the temperature of the exhaust purification device 56 is provided instead of the air flow sensor 116, or the temperature of the exhaust purification device 56 is estimated from the engine water temperature. Alternatively, the timer may be controlled by a map or the like obtained based on a predetermined experimental value.

Next, the contents of control of the engine supercharging device according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart showing a control flow of the engine supercharging device according to the first embodiment of the present invention, and FIG. 4 is a diagram showing the relationship between the crank angle and the injection amount according to the first embodiment of the present invention. .
In FIG. 3, S indicates each step.
First, as shown in FIG. 3, in S1, signals from the vehicle speed sensor 110 and the airflow sensor 116 are read. In S2, the exhaust purification device 56, more specifically, the temperature of the oxidation catalyst 56a (catalyst temperature) is predicted from the signal value of the airflow sensor 116 read in S1, and the predicted value is a predetermined temperature α (for example, 200). It is judged whether it is larger than ° C. When the temperature is higher than the predetermined temperature α, it is assumed that the oxidation catalyst 56a is at the activation temperature, and the routine proceeds to the control during normal traveling from S3 to S8.

  In normal control, first, in S3, it is determined from the signal value of the vehicle speed sensor 110 whether or not the vehicle is accelerating. When it is accelerating, it progresses to S4, and while the electric supercharger control part 104 operates the electric supercharger 34, the intake bypass valve 38 is closed by S5. As a result, the intake air does not pass through the bypass 36 and is supercharged by the electric supercharger 34. On the other hand, when not accelerating, the process proceeds to S6, where the electric supercharger control unit 104 stops the electric supercharger 34, and the intake bypass valve 38 is opened in S7. Thereby, supercharging by the electric supercharger 34 is not performed. After S5 or S7, the process proceeds to S8, and the exhaust turbocharger 60 is operated by closing the exhaust bypass valve 59.

Next, in S2, when the temperature of the exhaust purification device 56 is equal to or lower than the predetermined temperature α, the process proceeds to S9, the electric supercharger control unit 104 operates the electric supercharger 34, and in S10, the intake air bypass is performed. The valve 38 is closed. As a result, the intake air does not pass through the bypass 36 and is supercharged by the electric supercharger 34.
Next, in S <b> 11, the exhaust turbo bypass valve 59 is opened by the exhaust bypass valve control unit 106. As a result, the heat of the exhaust gas reaches the exhaust purification device 56 without being deprived of heat by the turbine 62 of the exhaust turbocharger 60 or the like.
Next, in S12, the combustion control unit 102 performs post injection from the fuel injector 12. As shown in FIG. 4, this post-injection is to inject fuel into the cylinder 2 after main injection (main injection) in the vicinity of TDC, and has the effect of raising the exhaust temperature. For example, unburned fuel is supplied to the exhaust gas purification device 56 by post injection and reacted with the oxidation catalyst 56a, thereby increasing the exhaust gas temperature and further raising the temperature of the DPF 56b to burn soot.

  As described above, in the first embodiment of the present invention, when the temperature of the exhaust purification device 56 is low, the control valve of the bypass passage 58 that bypasses the exhaust turbocharger 60 is opened, so that the heat of the exhaust gas is exhausted. Exhaust gas can flow to the exhaust purification device without being taken away by the turbine 62 of the turbocharger 60, etc., thereby increasing the temperature of the exhaust purification device 56 or suppressing the temperature decrease. On the other hand, the torque reduction due to bypassing the exhaust turbocharger 60 can be suppressed by operating the electric supercharger 34 to ensure sufficient torque. When the temperature of the exhaust gas purification device 56 is low, the temperature of the exhaust gas rises due to the reaction between the air increased by the operation of the electric supercharger 34 and the post-injection after the main injection by the fuel injector 12, The temperature of the purification device 56 can be raised or the temperature drop can be suppressed.

Next, the control system of the engine supercharging device according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram of an engine control system according to the second embodiment of the present invention.
As in the first embodiment, the ECU 100 is connected to the fuel injection valve 12, the electric supercharger 34 (34a), the electric supercharger bypass valve 38, and the exhaust turbo bypass valve 59.

  The ECU 100 functionally includes a combustion control unit 102 that controls the fuel injection valve 12 to perform main injection, pilot injection, and post-injection of fuel into the cylinder 2 under predetermined conditions as will be described later. The electric supercharger control unit 104 controls the electric supercharger bypass valve 38 so as to open and close the electric supercharger bypass 36 while controlling the electric supercharger 34 (34a) so as to obtain a predetermined rotational speed. In addition, an exhaust bypass valve control unit 106 that operates the exhaust turbo bypass valve 59 under a predetermined condition, and an automatic stop control unit 108 that stops the engine under a predetermined condition are included. Here, the electric supercharger control unit 104 opens the electric supercharger bypass valve 38 of the electric supercharger bypass passage 36 when the electric supercharger 34 is not driven, and opens the electric supercharger bypass valve 38 when driven. close. Thus, when the electric supercharger 34 is not driven, the intake air is guided to the electric supercharger bypass passage 36 to reduce the intake resistance, and when the electric supercharger 34 is driven, the intake air is reliably supplied to the electric supercharger 34. To the compressor 35.

  The ECU 100 includes a vehicle speed sensor 110 that detects the vehicle speed of the vehicle, a brake sensor 112 that detects ON / OFF of the brake, an accelerator opening sensor 114 that detects the accelerator opening, and the amount of heat that enters the catalyst. An air flow sensor 116 for predicting the temperature is connected, and the ECU 100 receives input signals from each of these sensors, and each of the devices 12, 34 (34a) is received by each of the control units 102, 104, 106 and 108 described above. ), 38 and 59 are controlled. In order to detect the temperature of the exhaust purification device 56, a catalyst sensor that directly measures the temperature of the exhaust purification device 56 is provided instead of the air flow sensor 116, or the temperature of the exhaust purification device 56 is estimated from the engine water temperature. Alternatively, the temperature of the exhaust gas purification device 56 may be estimated from an automatic stop time (idle stop time) or a timer control using a map or the like obtained based on predetermined experimental values.

  Next, the control contents of the engine supercharging device according to the second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a flowchart showing a control flow of the engine supercharging device according to the second embodiment of the present invention. In FIG. 6, S indicates each step.

  First, as shown in FIG. 6, in S1, signals of the vehicle speed sensor 110, the brake sensor 112, the accelerator opening sensor 114, and the air flow sensor 116 are read. In S2, the automatic stop control unit 108 (see FIG. 5) determines whether or not a stop condition is satisfied from the values of the sensors read in S1. That is, it is determined that the stop condition is satisfied when the signal from the vehicle speed sensor 110 indicates the vehicle speed 0, the brake sensor 112 indicates that the brake is ON, and the signal from the accelerator opening sensor 114 indicates the accelerator opening 0. Note that it may be determined that the stop condition is satisfied even when the brake is OFF (for example, when the side brake is applied).

  If the stop condition is satisfied in S2, the fuel injection is stopped so as to stop the engine, and the electric supercharger control unit 104 stops the electric supercharger 34 in S3, and the electric supercharger in S4. The bypass valve (intake bypass valve) 38 is opened, and the exhaust turbocharger bypass valve 39 is closed by the exhaust bypass valve control unit 106 in S5. Further, in S6, flag 1 is set.

On the other hand, when the stop condition is not satisfied in S2, the flow when the engine is in an operating state according to S7 or later is considered as when the engine is started or when the start is completed. move on.
In S7, it is determined whether or not the flag is 1. When the flag is 1, the engine temperature has been automatically stopped until that time, or the catalyst temperature α is not more than a predetermined value even when the engine is operating as will be described later, and the exhaust purification device 56 is cooled. It is a case. In these cases, control is performed to increase the temperature of the exhaust purification device 56 by the processing of S8 to S11. That is, in S8 and S9, by operating the electric supercharger 34 by the electric supercharger control unit 104 and closing the intake bypass valve 38, the exhaust turbocharger bypass valve 39 is opened as described later. Supercharge to compensate for the reduction in intake efficiency.

Next, in S10, the exhaust gas turbocharger bypass valve 39 is opened by the exhaust gas bypass valve control unit 106. As a result, the exhaust gas that has become hot due to the combustion in the cylinder 2 can be guided to the exhaust turbocharger bypass 28, and the exhaust gas can be guided to the exhaust purification device 56 without being deprived of the exhaust gas by the turbine 62. .
Next, in S <b> 11, the combustion control unit 102 performs post injection from the fuel injector 12. As shown in FIG. 4 described above, this post-injection is to inject fuel into the cylinder 2 after the main injection in the vicinity of TDC, and has the effect of raising the exhaust temperature as in the first embodiment.

  Thereafter, in S12, the exhaust purification device 56, more specifically, the temperature of the oxidation catalyst 56a (catalyst temperature) is predicted from the signal value of the air flow sensor 116 read in S1, and the predicted value is a predetermined temperature α (for example, 200 ° C.). When the temperature is equal to or lower than the predetermined temperature α, the flag 1 is held. On the other hand, when the temperature is higher than the predetermined temperature α, the flag 0 is set in S13 on the assumption that the oxidation catalyst 56a is at the activation temperature. Thus, by setting the flag 0, it is assumed that the engine is operating and the catalyst temperature α is larger than a predetermined value and the exhaust purification device 56 has risen to an efficient temperature in S7 described above. Control proceeds to S19.

  In normal control, first, in S14, it is determined from the signal value of the vehicle speed sensor 110 whether or not the vehicle is accelerating. When it is accelerating, it progresses to S15, and while the electric supercharger control part 104 operates the electric supercharger 34, the intake bypass valve 38 is closed by S16. As a result, the intake air does not pass through the bypass 36 and is supercharged by the electric supercharger 34. On the other hand, if not accelerating, the process proceeds to S17, where the electric supercharger control unit 104 stops the electric supercharger 34, and the intake bypass valve 38 is opened in S18. Thereby, supercharging by the electric supercharger 34 is not performed. After S16 or S18, the process proceeds to S19, where the exhaust turbocharger 60 is operated by closing the exhaust bypass valve 59.

  As described above, in the second embodiment, the control valve 59 of the bypass passage 58 that bypasses the exhaust turbocharger 60 at the time of restart from the automatic stop where the temperature of the exhaust purification device 56 becomes lower than before the engine stop. Therefore, the exhaust gas can be flowed to the exhaust purification device 56 without the heat of the exhaust gas being taken away by the turbine 62 of the exhaust turbocharger 60, thereby increasing the temperature of the exhaust purification device 56. Or the fall of temperature can be suppressed. On the other hand, the torque reduction due to bypassing the exhaust turbocharger 60 can be suppressed by operating the electric supercharger 34 to ensure sufficient torque. Further, at the time of restart from the automatic stop where the temperature of the exhaust purification device 56 becomes lower than before the engine stop, the air increased by the operation of the electric supercharger 34 and the post injection after the main injection by the fuel injector 12 Due to this reaction, the temperature of the exhaust gas rises, and the temperature of the exhaust purification device 56 can be raised or the temperature drop can be suppressed.

Next, specific control examples of the first and second embodiments will be described with reference to FIG. FIG. 7 is a diagram showing the control contents of the engine supercharging device according to the second embodiment of the present invention.
As shown in FIG. 7, the temperature of the exhaust purification device 56 rises in the left part of the diagram. When the temperature of the exhaust purification device 56 is low (first embodiment, second embodiment) or when the engine is restarted (second embodiment), the exhaust bypass valve 59 is fully opened and the motor is electrically operated. The supercharger 34 is activated. When the temperature of the exhaust purification device 56 rises, the opening of the bypass valve 59 is lowered, whereby exhaust gas flows to the turbine 62 side of the exhaust turbocharger 60, and the rotational speed of the exhaust turbocharger 60 increases. I will do it. Further, even if the rotational speed of the electric supercharger 34 is reduced, sufficient intake air can be sent into the cylinder 2 by the operation of the exhaust turbocharger 60.

1 is an overall configuration diagram of an engine controlled by an engine supercharging device according to first and second embodiments of the present invention. FIG. It is a control system block diagram of an engine by a 1st embodiment of the present invention. It is a flowchart which shows the control flow of the supercharging device of the engine by 1st Embodiment of this invention. It is a figure which shows the relationship between the crank angle and injection quantity by 1st Embodiment and 2nd Embodiment of this invention. It is a control system block diagram of the engine by a 2nd embodiment of the present invention. It is a flowchart which shows the control flow of the supercharging device of the engine by 2nd Embodiment of this invention. It is a diagram which shows the control content of the supercharging device of the engine by 2nd Embodiment of this invention.

Explanation of symbols

2 cylinder 20 intake passage 34 electric supercharger 36 electric supercharger bypass passage (intake bypass)
38 Electric supercharger bypass valve (intake bypass valve)
34a Motor 35 Compressor 50 Exhaust passage 56 Exhaust purification device 58 Exhaust turbocharger bypass (exhaust bypass)
59 Exhaust turbocharger bypass valve (exhaust bypass valve)
60 Exhaust turbocharger 62 Turbine 66 Compressor

Claims (4)

An exhaust turbocharger that supercharges air in the intake passage by rotating a compressor disposed in the intake passage by rotation of a turbine disposed in the exhaust passage, and an exhaust passage downstream of the exhaust turbocharger An engine exhaust gas purifying device, comprising:
A bypass passage that bypasses the turbine of the exhaust turbocharger in the exhaust passage;
A control valve disposed in the bypass passage;
Control valve control means for controlling the operation of the control valve;
An electric supercharger that supercharges air in the intake passage by electrically rotating a compressor disposed in the intake passage;
Electric supercharger control means for controlling the operation of the electric supercharger;
Exhaust gas purification device temperature detection means for detecting the temperature of the exhaust gas purification device by a predetermined sensor;
When the temperature of the exhaust purification device detected by the exhaust purification device temperature detection means is lower than a predetermined temperature, the control valve control means opens the control valve and the electric supercharger control means opens the electric supercharger. Control means for operating the machine;
An engine supercharging device comprising: Furthermore, it has fuel injection control means for controlling a fuel injector that injects fuel into the cylinder,
When the temperature of the exhaust purification device detected by the exhaust purification device temperature detection means is lower than a predetermined temperature, the control device further causes post injection after main injection into the cylinder by the fuel injection control means. The engine supercharging device according to claim 1. An exhaust turbocharger that supercharges air in the intake passage by rotating a compressor disposed in the intake passage by rotation of a turbine disposed in the exhaust passage, and an exhaust passage downstream of the exhaust turbocharger An engine exhaust gas purifying device, comprising:
A bypass passage that bypasses the turbine of the exhaust turbocharger in the exhaust passage;
A control valve disposed in the bypass passage;
Control valve control means for controlling the operation of the control valve;
An electric supercharger that supercharges air in the intake passage by electrically rotating a compressor disposed in the intake passage;
Electric supercharger control means for controlling the operation of the electric supercharger;
Automatic stop control means for automatically stopping the engine when a predetermined automatic stop condition is satisfied;
The engine has a control means for opening the control valve by the control valve control means and operating the electric supercharger by the electric supercharger control means when the engine is restarted from the automatic stop by the automatic stop means. The engine supercharger. Furthermore, it has fuel injection control means for controlling a fuel injector that injects fuel into the cylinder,
4. The engine supercharging device according to claim 3, wherein the control device causes post injection after main injection into the cylinder by the fuel injection control means when the engine is restarted from the automatic stop by the automatic stop means. .

Images