JP2008045405A - Supercharging control device - Google Patents

Abstract

The present invention provides a supercharging control device capable of effectively utilizing energy of air that has become a high pressure after passing through a compressor.
A supercharging control device according to the present invention guides a turbo unit 11 having a compressor and at least a part of supercharged air on the downstream side of the compressor to the inside of the compressor in the same direction as the rotation direction of a compressor-side impeller 11d. When the operating state of the recirculation passage 25, the electromagnetic valve 27 for switching the opening and closing of the recirculation passage 25 and the turbo unit 11 is determined and it is determined that the electromagnetic valve 27 should be opened from the determination result, the electromagnetic valve 27 is opened. And an engine ECU 16 that controls the valve. As a result, when it is determined that the solenoid valve 27 should be opened, the supercharged air that has once reached a high pressure is guided to the inside of the compressor, so that the compressor-side impeller 11d rotates at a higher rotational speed. Thus, the energy of the air that has become high pressure can be used effectively.
[Selection] Figure 1

Description

  The present invention relates to a supercharging control device including a supercharger having a compressor.

2. Description of the Related Art Conventionally, it has been proposed to arrange a compressor on an internal combustion engine, that is, an intake passage of the engine, and perform supercharging by the compressor to obtain high output or low fuel consumption. A typical turbocharger is such a turbocharger. In the supercharger with an electric motor described in Patent Document 1, when it is determined that surge avoidance should be performed from a supercharged surge state, an open / close valve of a cold air introduction path branched from an intake passage downstream of the compressor and connected to the compressor is provided. By opening the valve, at least part of the air cooled by the intercooler is guided to the periphery of the motor through the cold air introduction path. On the other hand, when it is determined that the surge avoidance operation is unnecessary, the on-off valve is closed, so that the air that has passed through the intercooler is guided to the internal combustion engine.
JP 2005-69178 A

  According to the above-described supercharger with a motor, when surge avoidance operation is necessary, the air to the internal combustion engine is guided by guiding a part of the high-pressure cold air that has passed through the intercooler after passing through the compressor to the periphery of the motor. Even when the supply amount is small, the amount of air passing through the supercharger can be secured, and the occurrence of surge can be suppressed. Furthermore, the motor can be cooled by guiding the cooled air around the motor.

  However, the cold air that has cooled the electric motor is sent to the upstream side of the compressor side impeller in the intake passage, that is, upstream by the cold air introduction path. For this reason, the cold air that has once become a high pressure after passing through the compressor returns to become almost equal to the atmospheric pressure, resulting in energy loss, and the energy of the air that has become high pressure after passing through the compressor cannot be used effectively.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a supercharging control device that can effectively use the energy of air that has become a high pressure after passing through a compressor.

  A supercharging control device according to the present invention includes a supercharger having a compressor, and supercharging introduction that guides at least a part of the supercharging air downstream of the compressor to the inside of the compressor in the same direction as the rotation direction of the compressor impeller. Control means for opening the opening / closing valve when it is determined that the opening / closing valve should be opened based on the operating state of the turbocharger. And.

  According to the supercharging control device according to the present invention, when it is determined by the control means that the introduction on-off valve that switches between opening and closing of the supercharging air introduction path should be opened based on the operating state of the supercharger, The introduction opening / closing valve is opened by the control means. As a result, when it is determined that the introduction opening / closing valve should be opened, the supercharged air that has once become a high pressure after passing through the compressor of the supercharger does not return almost equal to the atmospheric pressure. Because it is guided to the inside of the compressor in the same direction as the rotation direction of the compressor impeller, the compressor impeller rotates at a higher rotational speed without loss of energy, and the high pressure air after passing through the compressor Energy can be used effectively.

  Further, in the supercharging control device according to the present invention, the control means determines the surge state of the supercharger, and when it is determined that surge avoidance is to be performed based on the determination result, opens the introduction on-off valve. preferable.

  In this way, the surge state of the turbocharger is determined by the control means, and when the control means determines from the determination result that surge avoidance should be performed, the introduction opening / closing valve is opened by the control means. . Thereby, even when it is determined that surge avoidance should be performed, the energy of air that has become high pressure after passing through the compressor can be used effectively.

  In the supercharging control device according to the present invention, the introduction opening / closing valve variably controls the opening degree of the supercharging air introduction path, and the control means is based on the flow rate of the supercharging air passing through the supercharging air introduction path. It is preferable to determine the opening degree of the supercharging air introduction path and open the introduction opening / closing valve at the determined opening degree.

  In this way, the opening degree of the supercharging air introduction path is determined by the control means based on the flow rate of the supercharging air passing through the supercharging air introduction path, and the introduction opening / closing valve is controlled by the determined opening degree. It is opened by means. Thereby, the flow rate of the supercharged air led to the inside of the compressor can be variably controlled based on the flow rate of the supercharged air passing through the supercharged air introduction path.

  Further, in the supercharging control device according to the present invention, the supercharging air introduction path has a storage tank that stores at least a part of the supercharging air on the downstream side of the compressor, and the storage tank stores the stored supercharging air. A supply on / off valve that switches between opening and closing of the supercharged air supply path for supplying the air to the intake passage of the internal combustion engine, and the control means determines the operating state of the internal combustion engine and opens the supply on / off valve from the determination result If determined, it is preferable to open the supply on / off valve.

  In this way, when the operation state of the internal combustion engine is determined by the control means, and the control means determines that the supply opening / closing valve should be opened from the determination result, the supply opening / closing valve of the air storage tank is controlled. It is opened by means. As a result, when it is determined that the supply on / off valve should be opened, the supercharged air stored in the air storage tank is supplied to the internal combustion engine. It can be used effectively.

  Further, in the supercharging control device according to the present invention, the control means determines the ambient environment of the vehicle, and when it is determined that the vehicle is in an environment in which acceleration is performed from the determination result, the introduction opening / closing valve is opened. Is preferred.

  In this way, the surrounding environment of the vehicle is determined by the control means, and when the control means determines that the vehicle is in an environment where acceleration is performed based on the determination result, the introduction opening / closing valve is opened by the control means. Is done. Thereby, even when it is determined that the vehicle is in an environment where acceleration is performed, the energy of air that has become high pressure after passing through the compressor can be used effectively.

  According to the present invention, it is possible to effectively use the energy of air that has become a high pressure after passing through the compressor.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a configuration of an internal combustion engine when a turbocharger device with an electric motor is used as a supercharging control device according to the present invention. Here, a cylinder injection type gasoline engine will be described as an example, but the present invention can be similarly applied to a gasoline engine that injects fuel into an intake pipe and a diesel engine.

  The engine 1 is a multi-cylinder engine, but here, a cross section of only one cylinder is shown. The engine 1 is a type of engine in which fuel is injected onto the upper surface of a piston 4 in a cylinder 3 by an injector 2. The engine 1 is a so-called lean burn engine that enables stratified combustion. That is, the engine 1 compresses the air that has passed through the intake passage 5 and is sucked into the cylinder 3 with the piston 4, and injects the fuel from the injector 2 into the inside of the recess formed in the upper surface of the piston 4. The rich air-fuel mixture is collected in the vicinity of the spark plug 7 and ignited by the spark plug 7 to be burned. This enables combustion with a small amount of fuel relative to the air in the entire combustion chamber. Further, by performing lean combustion while supercharging more intake air by a turbo unit 11 to be described later, fuel consumption is suppressed, and not only high output but also fuel efficiency is realized.

  An intake passage 5 and an exhaust passage 6 are connected to the cylinder 3, and opening and closing thereof are controlled by an intake valve 8 and an exhaust valve 9 provided therebetween. An air cleaner 10, a turbo unit 11 as a supercharger having a compressor, an intercooler 12, a throttle valve 13, and an intake pressure sensor 19 are arranged on the intake passage 5 from the upstream side. On the other hand, a turbo unit 11 and an exhaust purification catalyst 23 are disposed on the exhaust passage 6 from the upstream side. The turbo unit 11 is disposed so as to straddle the intake passage 5 and the exhaust passage 6.

  The air cleaner 10 is a filter that removes dust and dirt in the intake air. In the turbo unit 11, a compressor-side impeller 11d that is a rotor blade disposed on the intake passage 5 side and a turbine-side impeller 11e that is a rotor blade disposed on the exhaust passage 6 side are connected by a common rotating shaft. . Here, the compressor-side impeller 11d functions as a compressor that compresses intake air. The turbine-side impeller 11e, which is a rotor blade disposed on the exhaust passage 6 side, functions as a turbine that is rotationally driven by exhaust energy. Hereinafter, this connected portion is simply referred to as a turbine / compressor 11a. Further, a rotor, that is, a permanent magnet is fixed to the rotating shaft, and a stator, that is, a coil wound around an iron core, is disposed around the rotor, thereby constituting an electric motor 11b having the rotating shaft as an output shaft. The electric motor 11b is an AC motor that is electrically connected to the inverter 21, and also functions as a generator having a rotating shaft as an input shaft. The inverter 21 is electrically connected to the battery 22. These turbine / compressor 11a and electric motor 11b are accommodated in the housing 11c.

  An air-cooled intercooler 12 is disposed downstream of the turbo unit 11 on the intake passage 5. This intercooler 12 reduces the volume and improves the charging efficiency into the cylinder 3 by cooling the intake air whose temperature has increased in accordance with the air compression at the time of supercharging by the turbo unit 11, that is, the pressure increase. It is.

  A throttle valve 13 that adjusts the intake air amount is disposed downstream of the intercooler 12. The throttle valve 13 is a so-called electronically controlled throttle valve and is driven by a throttle motor 17. A throttle positioning sensor 18 for detecting the opening degree is arranged.

  The intake passage 5 is provided with a return passage 25 branched from the intake passage 5 between the turbo unit 11 and the intercooler 12 and connected to the housing 11 c of the turbo unit 11. A compressor-side impeller 11d is disposed in the housing 11c. For this reason, the recirculation passage 25 guides and recirculates the intake air, that is, at least part of the supercharged air on the downstream side of the turbo unit 11 to the compressor-side impeller 11 d inside the turbo unit 11. Here, the recirculation passage 25 guides the intake air into the turbo unit 11 in the same direction as the rotation direction D of the compressor-side impeller 11d. The reflux passage 25 corresponds to the supercharged air introduction passage according to the present invention.

  On the recirculation passage 25, an air storage tank 29 and an electromagnetic valve 27 as an introduction opening / closing valve are arranged from the upstream side. The solenoid valve 27 is composed of a plurality of vanes. Further, the air storage passage 26 extends from the air storage tank 29 and joins the intake passage 5 between the turbo unit 11 and the intercooler 12. An electromagnetic valve 28 is disposed on the air storage passage 26. The air storage tank 29 is a container for storing at least a part of intake air, that is, supercharged air on the downstream side of the turbo unit 11. When the pressure in the intake passage 5 becomes equal to or higher than a predetermined pressure, a part of the intake air is temporarily stored in the air storage tank 29. A part of the stored intake air is supplied toward the electromagnetic valve 27 on the downstream side of the recirculation passage 25 and the electromagnetic valve 28 on the downstream side of the air storage passage 26 based on a signal from the engine ECU 16. Here, when the electromagnetic valve 28 is opened, a part of the intake air that has been stored and has become high pressure is opened to the reflux passage 25. On the other hand, if the solenoid valve 28 is opened, a part of the stored intake air is opened to the intake passage 5. Note that a reverse support valve is provided inside the air storage tank 29 at a portion where the recirculation passage 25 and the air storage passage 26 are connected.

  The electromagnetic valve 27 is a valve that switches opening and closing of the reflux passage 25. Thereby, the opening degree of the reflux passage 25 is variably controlled arbitrarily. The electromagnetic valve 28 is a valve for switching opening and closing of the air storage passage 26 that supplies the intake air stored in the air storage tank 29 to the intake passage 5. The reflux passage 25 corresponds to the supercharged air introduction passage according to the present invention. The air storage passage 26 corresponds to the supercharged air supply passage according to the present invention.

  The crankshaft is provided with a crank angle sensor 20, and the accelerator pedal 14 is provided with an accelerator opening sensor 15, and the signal is input to an engine ECU 16 for engine control. In addition, the engine ECU 16 receives signals from the throttle positioning sensor 18, the intake pressure sensor 19, and the battery 22, and controls the operation of the injector 2, spark plug 7, throttle motor 17, and inverter 21. When the engine ECU 16 determines the operating state of the turbo unit 11, for example, the surge state, and determines that the surge avoidance should be performed and the solenoid valve 27 should be opened based on the determination result, the engine ECU 16 The valve 27 is opened. Further, the engine ECU 16 determines whether or not the engine 1 is in an operating state, for example, a state where acceleration control is necessary, and determines that the acceleration control should be performed and the solenoid valve 28 should be opened from the determination result. Opens the solenoid valve 28. When the electromagnetic valve 28 is opened, the throttle valve 13 is opened by the throttle motor 17 substantially simultaneously.

  Here, the determined surge state includes information regarding whether or not surging has occurred and, if so, the degree of occurrence of surging. Further, the engine ECU 16 determines the opening degree of the recirculation passage 25 based on the flow rate of the supercharged air that passes through the recirculation passage 25 and flows into the air storage tank 29, and opens the recirculation passage 25 with the determined opening degree. Open the valve. The engine ECU 16 also serves as control means according to the present invention. Note that the control means may be provided separately from the engine ECU 16 or may be incorporated in a control computer in another vehicle.

  Further, the engine ECU 16 determines whether or not the surrounding environment of the vehicle on which the supercharging control device according to the present invention is mounted, for example, whether the vehicle is in an environment in which acceleration control is performed, from each of the sensors described above, and the determination result Therefore, when it is determined that the vehicle is in an environment in which acceleration control is to be performed, the electromagnetic valve 27 is opened to suppress the output of air to the engine 1 side. Here, the environment in which the acceleration control is performed is, for example, an environment where the vehicle is at the end of a curve, an environment where the vehicle starts a slope, or an environment where the vehicle starts a slope on a curve. Note that, when the electromagnetic valve 27 is opened, the motor 11b forcibly drives the turbine / compressor 11a almost simultaneously, so that pre-assist is started. Then, the rotational speed of the turbo unit 11 is controlled by driving the electric motor 11b so as to be a predetermined rotational speed, and the pre-assist is continued.

  The turbo unit 11 according to the present invention can be operated as a normal turbocharger device that performs supercharging only by exhaust energy, but the turbo / compressor 11a is forcibly driven by the electric motor 11b to increase the supercharging efficiency. It is also possible to raise. In particular, when the driver depresses the accelerator pedal 14, by performing this forced driving, the time lag of the operation of the turbocharger device can be reduced, the engine speed can be increased early, and the response is improved. To do. Further, the turbine / compressor 11a is driven by exhaust gas, and the input shaft of the electric motor 11b is rotated to generate regenerative power. The generated electric power is stored in the battery 22, and a part of the exhaust energy can be recovered. .

  The turbo unit 11 according to the present invention recirculates and guides at least a part of the intake air to the compressor side impeller 11d inside the compressor in the same direction as the tangential direction of the rotation direction D of the compressor side impeller 11d by the return passage 25. The rotation speed of the compressor side impeller 11d is increased. Hereinafter, a structure in which intake air is recirculated into the housing 11c in the same direction as the tangential direction of the rotation direction D of the compressor-side impeller 11d will be described with reference to a cross-sectional view taken along the arrow in FIG. FIG. 2 is a cross-sectional view taken along line II-II around the compressor-side impeller 11d of the turbo unit 11 shown in FIG.

  Eight compressor side impellers 11d are arranged at substantially equal intervals along the circumferential direction around the rotation axis Ax. Each compressor-side impeller 11d has a substantially rhombus shape, and one of the four sides is along the circumferential direction. For this reason, the intake air from the recirculation passage 25 easily enters the gap portion 11f between the compressor-side impellers 11d adjacent to each other. When the compressor-side impeller 11d rotates, in the portion where the recirculation passage 25 and the gap portion 11f approach each other, the intake air introduction direction 25a from the recirculation passage 25 and the entry direction 11g into which the intake air enters the gap portion 11f are substantially the same. Because of the direction, the compressor impeller rotates at a higher rotational speed.

  The above-described reflux is performed by controlling the opening, opening, and closing of the electromagnetic valve 27. Further, the intake air is supplied from the air storage tank 29 to the downstream side of the air storage passage 26 by controlling the opening, opening, and closing of the electromagnetic valve 28. Below, this recirculation | reflux control and supply control are demonstrated with reference to the flowchart of FIG. This control is repeatedly executed at a predetermined timing by the engine ECU 16 from when the power switch of the vehicle is turned on until it is turned off.

  First, in step S <b> 10, at least a part of the intake air, that is, the supercharged air on the downstream side of the turbo unit 11 is stored in the storage tank 29. A part of the stored intake air is supplied to the downstream side of the recirculation passage 25 and the air storage passage 26 based on a signal from the engine ECU 16.

  In the next step S20, it is determined by the engine ECU 16 whether or not a surge has occurred. In step S <b> 20, an operation state such as a surge state of the turbo unit 11 is determined. The determination of the surge state is based on, for example, the negative pressure in the intake pipe measured by the intake pressure sensor 19 and an actual measurement value of an atmospheric pressure sensor (not shown) or a measurement value of the intake pressure sensor 19 before the operation of the engine 1. This is performed by determining that a surge has occurred when it is determined that the small flow rate and high compression ratio are based on the atmospheric pressure and the air flow rate by an air flow meter (not shown). If it is determined that a surge has occurred, that is, if the engine ECU 16 determines that the surge should be avoided from the determination result, the process proceeds to step S24. On the other hand, when it is determined that no surge has occurred, that is, when it is determined by the engine ECU 16 that the surge need not be avoided based on the determination result, the routine proceeds to step S22, where the introduction on-off valve, that is, the electromagnetic The valve 27 is controlled to be closed. If the valve is already closed, the state is maintained. In this case, all the supercharged air that has passed through the turbo unit 11 passes through the intercooler 12, the throttle valve 13, and the intake passage 5 and is sent to the cylinder 3. And a series of control is complete | finished.

  In step S <b> 24, the opening degree of the recirculation passage 25 is determined by the engine ECU 16 based on the flow rate of the supercharged air that passes through the recirculation passage 25 and flows into the air storage tank 29. The opening degree of the reflux passage 25 becomes wider as the flow rate of the supercharged air increases. For example, the opening degree of the reflux passage 25 may be determined in proportion to the flow rate of the supercharged air. Then, the process proceeds to step S26.

  In step S26, the solenoid valve 27 is controlled to open at the opening determined in step S24. If the valve is already open, that state is maintained. As a result, the supercharged air that has once increased in pressure and passed through the air storage tank 29 is introduced into the compressor-side impeller 11d without returning to almost the same as the atmospheric pressure. For this reason, the compressor-side impeller 11d rotates at a higher rotational speed without causing energy loss. As a result, the energy of the supercharged air that has become a high pressure can be used effectively. Then, the process proceeds to step S30.

  In step S30, it is determined by the engine ECU 16 whether or not the high rotation of the engine 1 is necessary. In step S30, a required operating state such as the rotational state of the engine 1 is determined. The determination of the required rotational state requires, for example, high rotation of the engine 1 when it is determined that the accelerator opening measured by the accelerator opening sensor 15 is equal to or greater than a predetermined accelerator opening. Is determined. If it is determined that high rotation of the engine 1 is necessary, that is, if the engine ECU 16 determines that the solenoid valve 28 should be opened from the determination result, the process proceeds to step S34. On the other hand, if it is determined that the engine 1 is not required to rotate at high speed, that is, if it is determined by the engine ECU 16 that the solenoid valve 28 should be closed from the determination result, the routine proceeds to step S32, where the supply on / off valve, The solenoid valve 28 is controlled to be closed. If the valve is already closed, the state is maintained. In this case, all the supercharged air stored in the air storage tank 29 is stored as it is, or is sent to the electromagnetic valve 27. And a series of control is complete | finished.

  In step S <b> 34, the opening degree of the air storage passage 26 is determined by the engine ECU 16 based on the accelerator opening degree measured by the accelerator opening degree sensor 15. For example, the opening degree of the air storage passage 26 may be determined in proportion to the accelerator opening degree. Then, the process proceeds to step S36.

  In step S36, the solenoid valve 28 is controlled to open at the opening determined in step S34. If the valve is already open, that state is maintained. As a result, the supercharged air stored in the air storage tank 29 is supplied to the engine 1 and the rotational speed of the engine 1 increases. As a result, the energy of the supercharged air that has become a high pressure can be used effectively during acceleration or the like. And a series of control is complete | finished.

  The supercharged air thus introduced into the compressor side impeller 11d is sent to the intercooler 12 by the compressor side impeller 11d after rotating the compressor side impeller 11d. Thereby, a part of the intake air circulates. Here, the case where the air after rotation of the compressor-side impeller 11d is returned to the intercooler 12 has been described as an example. However, the air after rotation may be discharged as it is, or at any position in the exhaust passage 6, for example, The exhaust gas may be combined with the exhaust gas upstream or downstream of the turbine-side impeller 11e or downstream of the exhaust purification catalyst 23.

  According to the supercharging control device of the present embodiment, the operating state of the turbo unit 11 is determined by the engine ECU 16, and based on the determination result, the engine ECU 16 determines that the electromagnetic valve 27 for switching the opening and closing of the reflux passage 25 should be opened. If this happens, the electromagnetic valve 27 is opened by the engine ECU 16. Thus, when it is determined that the solenoid valve 27 should be opened, the supercharged air that has once become a high pressure after passing through the compressor of the turbo unit 11 does not return almost equal to the atmospheric pressure. It is led into the compressor in the same direction as the rotation direction of the compressor side impeller 11d. For this reason, the compressor-side impeller 11d is rotated at a higher rotational speed by the energy as the speed form without increasing the rotational speed of the turbo unit 11 without losing energy as a form of pressure. . As a result, the rotational energy of the air that has become high pressure after passing through the compressor can be recovered and used effectively.

  Further, when the engine ECU 16 determines the surge state of the turbo unit 11 and, from the determination result, the engine ECU 16 determines that surge avoidance is to be performed, the electromagnetic valve 27 is opened by the engine ECU 16. Thereby, even when it is determined that surge avoidance should be performed, the energy of air that has become high pressure after passing through the compressor can be used effectively.

  Further, the opening degree of the recirculation passage 25 is determined by the engine ECU 16 based on the flow rate of the supercharged air passing through the recirculation passage 25, and the electromagnetic valve 27 is opened by the engine ECU 16 at the determined opening degree. The opening degree of the recirculation passage 25 is configured to be widened as the flow rate of the supercharged air increases. Thereby, based on the flow rate of the supercharged air that passes through the reflux passage 25, the flow rate of the supercharged air that is guided to the inside of the compressor can be variably controlled, and the rotation corresponding to the supercharged air from the small flow rate to the large flow rate. It is possible to optimize the air flow rate in the direction.

  Further, when the engine ECU 16 determines the operating state of the engine 1 and the engine ECU 16 determines from the determination result that the solenoid valve 28 should be opened, the engine ECU 16 opens the solenoid valve 28 of the air storage tank 29. To be spoken. As a result, when it is determined that the solenoid valve 28 should be opened, the supercharged air stored in the air storage tank 29 is supplied to the engine 1, so that the energy of the air that has become high pressure after passing through the compressor Can be used effectively when needed, such as during acceleration.

  Further, when the environment surrounding the vehicle is determined by the engine ECU 16 and the engine ECU 16 determines from the determination result that the vehicle is in an environment where acceleration is performed, the electromagnetic valve 27 is opened by the engine ECU 16. At substantially the same time as the opening of the valve, the electric motor 11b forcibly drives the turbine / compressor 11a and pre-assist is started. Thereby, when the driver depresses the accelerator pedal 14, the time lag of the operation of the turbocharger device can be reduced, the engine speed can be increased early, and the response is improved. Furthermore, even when it is determined that the vehicle is in an environment where acceleration is performed, the energy of air that has become high pressure after passing through the compressor can be used effectively.

  In addition, this invention is not limited to embodiment mentioned above. For example, in the above-described embodiment, the output shaft of the electric motor 11b coincides with the rotating shaft of the turbine / compressor 11a. However, the present invention can also be applied to a turbocharger device with an electric motor in a case where the output shaft of the electric motor does not coincide with the rotating shaft of the turbine / compressor, for example, via a speed reduction mechanism using a gear or the like.

  Furthermore, instead of the electromagnetic valve 27 for adjusting the flow rate of the recirculated intake air, that is, the recirculated air, the cross-sectional area of the recirculation passage 25 through which the recirculated air passes may be a variable control valve. The flow rate of the recirculation air can be adjusted by integrally forming the recirculation passage 25 and the valve whose cross-sectional area is variable and changing the cross-sectional area of the recirculation passage 25. In other words, the flow rate can be adjusted by variably controlling the air passage area. By this adjustment, the reflux air having a relatively high flow velocity can be supplied to the compressor-side impeller 11d. FIG. 4 is an end view when an arbitrary portion of the return passage 25 is viewed from the inflow direction of the return air. A reflux passage 25 having an end surface of a substantially rectangular gap formed by inserting a part of the convex portion that is substantially fitted into the concave portion is formed in the concave portion. The sectional area, that is, the passage area of air can be variably controlled by inserting and removing the convex portion with respect to the concave portion along the direction indicated by the arrow in FIG. Since the portion where the flow rate is adjusted is the portion where the passage cross-sectional area in the recirculation passage 25 is changed, the flow velocity of the recirculation air can be increased by reducing this cross-sectional area. For this reason, by adjusting the flow rate adjusting portion, that is, the valve whose cross-sectional area is variably controlled, immediately before the compressor side impeller 11d, the flow rate of the recirculation air supplied to the compressor side impeller 11d is increased. Can do.

  Furthermore, the supercharger according to the present invention is not limited to a turbocharger with an electric motor, and may be an electric compressor that drives a compressor with an electric motor. This compressor may be a centrifugal compressor using rotor blades having the same configuration as the compressor section of the turbocharger device, or may be another axial compressor or a so-called supercharger.

It is the schematic which shows the structure of the internal combustion engine using the supercharging control apparatus which concerns on this invention. FIG. 2 is a cross-sectional view taken along line II-II around the compressor side impeller shown in FIG. 1. It is a flowchart which shows the control in the supercharging control apparatus of FIG. It is a schematic block diagram which shows the structure of the modification of an introductory on-off valve or a supply on-off valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Injector, 3 ... Cylinder, 4 ... Piston, 5 ... Intake passage, 6 ... Exhaust passage, 7 ... Spark plug, 8 ... Intake valve, 9 ... Exhaust valve, 10 ... Air cleaner, 11 ... Turbo unit, 11a ... turbine / compressor, 11b ... electric motor, 11c ... housing, 11d ... compressor side impeller, 11e ... turbine side impeller, 11f ... gap, 11g ... entry direction, 12 ... intercooler, 13 ... throttle valve, 14 ... accelerator pedal , 15 ... accelerator opening sensor, 16 ... engine ECU, 17 ... throttle motor, 18 ... throttle positioning sensor, 19 ... intake pressure sensor, 20 ... crank angle sensor, 21 ... inverter, 22 ... battery, 23 ... exhaust purification catalyst, 25 ... recirculation passage, 25a ... introduction direction, 26 ... air storage passage, 7, 28 ... electromagnetic valve, 29 ... gas storage tank, Ax ... rotary shaft, D ... rotational direction.

Claims (5)

A turbocharger having a compressor;
A supercharging air introduction path for guiding at least a part of the supercharging air on the downstream side of the compressor into the compressor in the same direction as the rotation direction of the impeller of the compressor;
An on / off valve that switches between opening and closing the supercharged air introduction path;
And a control means for opening the introduction on-off valve when it is determined that the introduction on-off valve should be opened based on an operating state of the supercharger. apparatus. 2. The control unit according to claim 1, wherein the control unit determines a surge state of the supercharger and opens the introduction opening / closing valve when determining from the determination result that surge avoidance should be performed. Supercharge control device. The introduction on-off valve variably controls the opening degree of the supercharged air introduction path,
The control means determines an opening degree of the supercharged air introduction path based on a flow rate of supercharged air passing through the supercharged air introduction path, and opens the introduction opening / closing valve at the determined opening degree. The supercharging control device according to claim 1 or 2, characterized in that The supercharged air introduction path has an air storage tank that stores at least a part of the supercharged air on the downstream side of the compressor,
The air storage tank has a supply on / off valve that switches between opening and closing of a supercharged air supply path that supplies the stored supercharged air to the intake passage of the internal combustion engine,
The control means determines the operating state of the internal combustion engine, and opens the supply opening / closing valve when it is determined that the supply opening / closing valve should be opened from the determination result. The supercharging control apparatus in any one of -3. The said control means judges the surrounding environment of a vehicle, and when it judges that the said vehicle exists in the environment where acceleration is performed from the determination result, the said on-off valve is opened. The supercharging control device according to any one of 4.

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