JP2017115774A - Power supply system for engine with electrically-driven type supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure a stable power supply for driving an electrically-driven type supercharger.SOLUTION: This invention relates to a power supply system for an engine with an electrically-driven supercharger comprising: an electrically-driven type supercharger 30 for supercharging intake by an electric motor to a combustion chamber of the engine; a mechanical supercharger T for supercharging to the combustion chamber of the engine under utilization of exhaust energy of the engine; a first power supply device 41 for supplying power for driving the electrically-driven supercharger 30; a second power supply device 42 for supplying electrical power for driving an adjustment valve for adjusting a recovery amount of the exhaust energy of the engine; and regenerative electric power storage means E with a distributing device for distributing the electrical power generated through regenerative power generation at the engine or a vehicle installed with the engine to a first power supply device 41 and a second power supply device 42. The regenerative electric power storage means E comprises a rotating electric machine 20 for performing regenerative power generation through rotation of the engine; and electrical power control means 51 for controlling an amount of regenerative power by the rotating electric machine 20, and the first power source device 41 comprises a battery 41 storing the regenerative electrical power by the rotating electric machine 20 through chemical energy.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an engine power supply system for driving an electric supercharger in an engine including an electric supercharger that supercharges intake air with an electric motor.

  Engines equipped with a mechanical supercharger that supercharges intake air introduced into a combustion chamber using the energy of exhaust gas are widely adopted.

  This type of mechanical supercharger, also called a turbocharger, is configured by arranging a compressor in the middle of the intake passage of the engine, placing a turbine in the middle of the exhaust passage, and rotating the turbine with exhaust gas flowing through the exhaust passage. The compressor is operated to increase the amount of intake air into the combustion chamber to improve the engine torque.

  Further, the mechanical supercharger is provided with a waste gate valve that adjusts the amount of flow into the turbine by diverting a part of the exhaust gas. The supercharging pressure of intake air can be controlled by adjusting the amount of exhaust gas passing through the turbine with a waste gate valve.

  Conventional waste gate valves have been controlled by pneumatic actuators using supercharging pressure as a power source, but in recent years, electric waste gate valves that are controlled to open and close by an electric motor have also been adopted. By making the wastegate valve electric, it can be driven even when the supercharging pressure is low, and more precise control is possible.

  Furthermore, in recent years, various types of electric superchargers have been proposed in which the compressor is driven by an electric motor in addition to the supercharger using the energy of the exhaust gas. The electric supercharger has an advantage that it can be supercharged arbitrarily by supplying electric power regardless of the operating state of the engine (see, for example, Patent Document 1).

JP-A-2005-163694

  By the way, when driving an electric supercharger, much electric power is required. However, it is expected that more electric power will be required as the operating range using the electric supercharger increases or as the capacity of the electric supercharger increases. In addition, the electric power required for the mechanical supercharger wastegate valve tends to further increase. For this reason, it is desired to secure a stable power source for driving these superchargers.

  Therefore, an object of the present invention is to secure a stable power source for driving a supercharger in an engine power supply system using an electric supercharger and a mechanical supercharger having an electric wastegate valve. It is.

  In order to solve the above-mentioned problems, the present invention supercharges an electric supercharger that supercharges intake air with an electric motor into a combustion chamber of the engine, and supercharges the combustion chamber of the engine using exhaust energy of the engine. Supplying power for driving a mechanical supercharger, a first power supply for supplying electric power for driving the electric supercharger, and a regulating valve for adjusting the recovery amount of exhaust energy of the engine And a regenerative power storage means comprising a distribution device that distributes power generated by regenerative power generation in the engine or a vehicle equipped with the engine to the first power supply device and the second power supply device. The power system of the engine with an electric supercharger equipped with is adopted.

  Here, the regenerative power storage means includes a rotating electrical machine that regenerates power by rotating an engine, and a power control means that controls the amount of regenerative power generated by the rotating electrical machine, and the first power supply device includes the rotating electrical machine The structure provided with the storage battery which stores the regenerative electric power generated by chemical energy with chemical energy is employable.

  As the storage battery, for example, a general lead storage battery mounted on a vehicle may be employed, but in particular, a lithium ion battery may be employed.

  The regenerative power storage means includes a rotating electrical machine that regenerates power by rotating an engine, and a power control means that controls the amount of regenerative power generated by the rotating electrical machine, and the first power supply device is powered by the rotating electrical machine. A configuration including a capacitor that electrostatically stores the generated regenerative power can be employed.

  In each of these configurations, the second power supply device can employ a configuration for supplying power to a device for starting and igniting an engine and an electrical component of a vehicle on which the engine is mounted.

  Here, the distribution device preferentially stores the power generated by regenerative power generation in the first power supply device, and preferentially stores the power generated by other than regenerative power generation in the second power supply device. A configuration for switching can be employed.

  The power control means includes a required power generation amount calculation means for calculating a required power generation amount as power to be generated by the rotating electrical machine, and a rotating electrical machine that controls a regenerative power generation amount by the rotating electrical machine based on the required power generation amount. It is possible to employ a configuration including control means.

  According to the present invention, the kinetic energy possessed by the vehicle at the time of deceleration can be utilized as a drive power source for the electric supercharger by regenerative power generation, and as a result, a stable power source for driving the supercharger can be secured. Furthermore, the fuel consumption of the engine can be improved.

1 is a schematic diagram of a power supply system for an engine with an electric supercharger showing an embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram conceptually showing a power supply system 10 (hereinafter simply referred to as “power supply system 10”) of an engine with an electric supercharger according to this embodiment.

  The engine with an electric supercharger of this embodiment is mounted on a vehicle as a driving source for traveling, and has a combustion chamber inside the engine body 1, and the engine body 1 has an intake passage 4 for sending intake air into the combustion chamber, A fuel injection device that injects fuel into the exhaust passage 3, the intake passage 4, and the combustion chamber drawn out from the combustion chamber is provided.

  The intake passage 4 leading to the combustion chamber cools the intake valve flowing through the intake passage 4 and the throttle valve 5 that adjusts the flow passage area of the intake passage 4 toward the upstream side from the intake port that is a connection portion to the combustion chamber. An intake air cooling device 6, a mechanical compressor 11 of a mechanical supercharger T that supercharges intake air by exhaust energy, an electric supercharger 30 that supercharges intake air by a driving force of the electric motor, an air cleaner 7, and the like are provided.

  In the exhaust passage 3, the exhaust turbine 12 of the mechanical supercharger T that rotates by exhaust energy from an exhaust port that is a connection portion to the combustion chamber to the downstream side, unburned hydrocarbon (HC) in the exhaust, etc. There are provided an exhaust purification unit 8, a silencer 9 and the like provided with a catalyst for removing harmful substances.

  The electric supercharger 30 includes an electric compressor as an electric motor that supercharges intake air into the combustion chamber. When the electric compressor is driven by supplying electric power, the intake air flowing in the intake passage 4 is supercharged.

  The mechanical supercharger T includes a mechanical compressor 11 that is disposed in the intake passage 4 and supercharges intake air that is introduced into the combustion chamber, and an exhaust turbine 12 that is disposed in the exhaust passage 3. When the exhaust turbine 12 is rotated by the flowing exhaust gas, the rotation is transmitted to the mechanical compressor 11 in the intake passage 4. The intake air flowing through the intake passage 4 is supercharged by the rotation of the mechanical compressor 11.

  Also, an exhaust bypass device 60 that includes an exhaust bypass passage 61 that connects the upstream side and the downstream side of the exhaust turbine 12 in the exhaust passage 3, and an exhaust bypass valve 62 as an adjustment valve that opens and closes the exhaust bypass passage 61, so-called A waste gate valve device is provided. If the exhaust bypass valve 62 is opened, a part of the exhaust gas flowing to the exhaust turbine 12 side is diverted to the exhaust bypass passage 61 side, and the exhaust energy applied to the exhaust turbine 12 is reduced.

  The exhaust bypass valve 62 is an electric waste gate valve that is controlled to open and close by an electric motor.

  A vehicle equipped with this engine is provided with an electronic control unit (Electronic Control Unit) 50 for controlling the engine. The electronic control unit 50 gives commands necessary for fuel injection by the fuel injection device, control of supercharging pressure, control of the opening of the throttle valve 5, and other control of the engine. Electric power necessary for the operation of the engine is supplied from a power supply device 40 provided in a vehicle on which the engine is mounted.

  Further, the electronic control unit 50 includes an electric supercharger control unit 56 that controls the electric supercharger 30. Furthermore, the electronic control unit 50 includes waste gate valve control means 57 that controls opening and closing of the electric exhaust bypass valve 62. The drive power for the electric supercharger 30 and the exhaust bypass valve 62 is also supplied from the power supply device 40.

  The power supply system 10 includes a first power supply device 41 as a power supply device 40 that supplies power for driving the electric supercharger 30, and power generated by regenerative power generation during deceleration of a vehicle equipped with an engine. Regenerative power storage means E stored in a power supply device 40 including the first power supply device 41.

  By the regenerative power generation of the regenerative power storage means E, the kinetic energy possessed by the vehicle at the time of deceleration can be utilized as a power source for driving the electric supercharger 30, and as a result, the fuel consumption of the engine can be improved. That is, it is possible to improve fuel efficiency by converting energy that has been discarded as frictional heat of the brake into electric power as regenerative power generation (regenerative brake).

  Here, the power supply device 40 supplies power to the first power supply device 41 that supplies power for driving the electric supercharger 30, the device that starts and ignites the engine, and various electrical components mounted on the vehicle. Is provided separately from the second power supply 42 for supplying the power.

  That is, the first power supply device 41 functions as a power supply device 40 that supplies power for driving the electric supercharger 30, and the second power supply device 42 is an electric exhaust in the mechanical supercharger T. The bypass valve 62 is driven, and other electric power is supplied for operating the engine and vehicle components.

  In addition, when the electric supercharger 30 has an intake bypass passage that supplies intake air to a route that passes through the electric compressor when the electric compressor is not driven, an electric motor provided in the intake bypass passage. May be controlled by the electric power from the first power supply device 41.

  The regenerative power is stored with priority over the first power supply device 41 for the electric supercharger 30. For this reason, the power supply capability to the electric supercharger 30 that consumes a large amount of power is increased, and the power supply to the electric supercharger 30 is stabilized.

  Here, the regenerative electric power storage means E that stores the electric power generated by the regenerative power generation in the power supply device 40 includes the rotating electrical machine 20 including the alternator 22 that generates the regenerative power by the rotation of the crankshaft 2 in the engine body 1, and the rotating electrical machine 20. Power control means 51 for controlling the amount of regenerative power generation. In addition, a charge controller 45 is provided as a distribution device that controls the amount of power generated by regenerative power generation, the amount of charge to the power supply device 40, and the charging destination according to a command from the power control means 51. The power control means 51 is provided in the electronic control unit 50.

  In this embodiment, as the power supply device 40, a storage battery is employed for each of the first power supply device 41 and the second power supply device 42. The storage battery is a so-called chemical battery having a function of storing regenerative power generated by the rotating electrical machine 20 using chemical energy. A chemical battery converts chemical energy contained in a substance contained therein into direct-current power through a chemical reaction.

  As this storage battery, a lead storage battery mounted on a general vehicle may be adopted, but in particular, a lithium ion battery can be adopted as one corresponding to regenerative power generation. Lithium ion batteries with small performance degradation in a discharged state have better regenerative power acceptability than lead storage batteries and the like, and therefore can recover more energy discarded during deceleration and improve fuel efficiency. It is particularly preferable to employ this lithium ion battery as the first power supply device 41 that takes precedence over regenerative power generation.

  Moreover, you may employ | adopt the capacitor | condenser which stores electric power electrostatically as the power supply device 40 replaced with this storage battery. The structure of the capacitor includes two electric conductor flat plates through a dielectric made of an insulator. When a DC voltage is applied to the two electric conductor flat plates, electric charge as electrical energy is stored.

  Even when a capacitor is used as the power supply device 40, regenerative power generation is more acceptable than when a lead storage battery or the like is used. Similarly, more energy that is discarded during deceleration can be recovered and fuel consumption can be improved. it can. It is particularly preferable to employ this capacitor as the first power supply device 41 that takes precedence over regenerative power generation.

  Here, the power control means 51 switches the power generated by regenerative power generation to the first power supply device 41 and the power generated by other than regenerative power generation to the second power supply device 42 so as to store it with priority. A storage location control means 52 is provided for instructing an instruction to the charge controller 45 which is a distribution device.

  The power control unit 51 includes a required power generation amount calculation unit 53 that calculates a required power generation amount as power to be generated by the rotating electrical machine 20, a request output unit 54 that instructs the charge controller 45 to request the required power generation amount, and a required power generation amount. Is provided with rotating electric machine control means 55 for controlling the amount of regenerative power generated by the rotating electric machine 20 based on the above.

  The engine body 1 is provided with a rotation speed sensor that detects the rotation speed of the crankshaft 2 of the engine, an accelerator opening sensor that detects the amount of depression of the accelerator, a vehicle speed sensor that detects the speed of the vehicle, and the like.

  Information on these various sensors can be acquired by the electronic control unit 50 through a cable. The vehicle speed sensor can detect the vehicle speed of the vehicle, and based on the information, the electronic control unit 50 can determine whether the vehicle is accelerating, decelerating, stopping, or the like. .

  The alternator 22 is connected to a crank pulley 21 attached to the crankshaft 2 of the engine body 1 via an endless member such as a belt 23 so that the rotation of the crankshaft 2 is transmitted. The alternator 22 is electrically connected to the plus terminals of the power supply devices 40 of the charging controller 45, the first power supply device 41, and the second power supply device 42 through a power supply cable. The negative terminals of the first power supply device 41 and the second power supply device 42 are connected to a ground 43 such as a vehicle body.

  The required power generation amount calculation means 53 detects the respective charge amounts of the first power supply device 41 and the second power supply device 42, and calculates the required power generation amount as the power generation amount to be generated by the alternator 22 based on the charge amounts. To do. The required power generation amount increases as the remaining charge amount of the first power supply device 41 and the second power supply device 42, that is, the amount of electricity charged in each power supply device 41, 42 at that time decreases. Is calculated as follows. The required power generation amount calculation means 53 can calculate the required power generation amounts for the first power supply device 41 and the second power supply device 42 separately.

  Then, when the required power generation amount calculated by the required power generation amount calculation unit 53 is greater than zero (0), the request output unit 54 uses the required power generation amount as a required power generation signal as the rotating electric machine control unit 55 or the charge controller 45 Etc., and other control means. In addition, when the required power generation amount is zero, there is no power generation request, so that the required power generation signal is not transmitted.

  The rotating electrical machine control means 55 and the charge controller 45 control the operation of the alternator 22 based on the transmitted required power generation amount so that the power generation amount of the alternator 22 becomes the required power generation amount. The control at this time will be described by dividing into an operation state in which regenerative power generation is possible and an operation state in which power generation other than regenerative power generation is possible.

  When the driving state of the vehicle is in a state where regenerative power generation is possible, the electric power generated by the regenerative power generation of the alternator 22 is preferentially charged to the first power supply device 41. However, the charging destination can be switched to the second power supply device 42 when the first power supply device 41 is in a fully charged state or a predetermined remaining charge amount or more. When both the first power supply device 41 and the second power supply device 42 are fully charged, regenerative power generation is not performed and power generation by the alternator 22 is stopped. Thereby, since the action of the regenerative brake cannot be expected, control such as switching to the operation of the mechanical brake is performed as necessary.

  When the driving state of the vehicle is a state where regenerative power generation cannot be performed, the power generated by the alternator 22 is preferentially charged to the second power supply device 42. However, the charging destination can be switched to the first power supply device 41 when the second power supply device 42 is in a fully charged state or a predetermined remaining charge amount or more. The control when both the first power supply device 41 and the second power supply device 42 are in a fully charged state is the same as that described above.

  Here, the electronic control unit 50 determines whether the driving state is a state where regenerative power generation is possible or a state where regenerative power generation is not possible based on information such as a rotational speed sensor, an accelerator opening sensor, a vehicle speed sensor, and the like. can do.

  When the remaining charge amount of the first power supply device 41 is equal to or greater than the minimum remaining charge amount required for driving the electric supercharger 30 in the operation state where supercharging is required, the electric supercharger control is performed. The means 56 sends a drive command to the electric supercharger controller 46. The electric supercharger controller 46 drives the electric supercharger 30 with a predetermined output, and supercharges intake air necessary for operation.

  When the remaining charge amount of the first power supply device 41 is lower than the minimum remaining charge amount necessary for driving the electric supercharger 30, the electric supercharger control means 56 is operated by the electric supercharger controller 46. A command to stop driving or lower the driving force is sent to. The electric supercharger controller 46 performs control to stop the driving of the electric supercharger 30 or to reduce the output of the electric supercharger 30. At this time, when the second power supply device 42 can be selected as the power supply device 40 for the electric supercharger 30, the remaining charge amount of the second power supply device 42 is sufficiently large. Only, the power source for driving the electric supercharger 30 may be switched to the second power supply device 42.

  Moreover, you may perform control which raises the supercharging pressure of the mechanical supercharger T according to the fall of the output of the electric supercharger 30 at this time. The control for increasing the supercharging pressure by the mechanical supercharger T is performed by increasing the amount of exhaust gas supplied to the exhaust turbine 12 by the waste gate valve control means 57 controlling the exhaust bypass valve 62 in the closing direction. It can be carried out.

  As described above, in general, a vehicle using an engine as a power source has been conventionally equipped with a lead storage battery in order to store electric power generated by a generator. Since the lead storage battery has a characteristic that the performance deteriorates in a discharged state, it is preferable to keep the charged state. However, in order to store the power generated by regenerative power generation, it is necessary to prepare the lead storage battery in a discharged state and prepare for receiving power. As described above, putting a lead storage battery into a discharge state leads to deterioration in performance, so there is a limit to the amount of power received in regenerative power generation, that is, the amount of discharge during standby of the lead storage battery for regenerative power generation.

  Therefore, as in the present invention, the first power supply device 41 that supplies power for driving the electric supercharger 30 includes the exhaust bypass valve 62 of the mechanical supercharger T. By providing separately from the second power supply device 42 that supplies power to devices other than the electric supercharger 30, it is possible to secure a large capacity for storing power when regenerative power generation is performed. It was. Further, as a first power supply device 41 that supplies electric power for driving the electric supercharger 30, a lithium ion battery or the like is employed instead of the lead storage battery, so that standby in a discharge state such as a lead storage battery is performed. The fear of performance degradation due to can be resolved.

  Further, the first power supply device 41 is provided separately from other devices other than the electric supercharger 30, in particular, the second power supply device 42 which is a device for supplying electric power to the electric exhaust bypass valve 62. Thus, even if the supply of electric power from the first power supply device 41 to the electric supercharger 30 cannot be performed due to a failure or the like, the waste gate valve control means 57 causes the electric power from the second power supply device 42 to be supplied. By controlling the electric exhaust bypass valve 62, the supercharging can be continuously controlled. Conversely, when the electric power supply from the second power supply device 42 to the electric exhaust bypass valve 62 cannot be performed due to a failure or the like, the electric supercharger control means 56 is connected to the first power supply device 41. By controlling the electric supercharger 30 with the electric power from the supercharger, the supercharging can be continuously controlled.

  Although the engine with an electric supercharger of this embodiment is a four-cycle gasoline engine for automobiles, the present invention is not limited to this embodiment, and other types of engines equipped with an electric supercharger, such as a diesel engine, for example. But this invention can be applied.

DESCRIPTION OF SYMBOLS 1 Engine body 2 Crankshaft 3 Exhaust passage 4 Intake passage 5 Throttle valve 6 Intake cooling device 7 Air cleaner 8 Exhaust purification part 9 Silencer 10 Power supply system 11 Mechanical compressor 12 Exhaust turbine 20 Rotating electric machine 22 Alternator 30 Electric supercharger 40 Power supply device 41 First power supply device 42 Second power supply device 50 Electronic control unit 51 Power control means 52 Power storage destination control means 53 Required power generation amount calculation means 54 Request output means 55 Rotating electrical machine control means 56 Electric supercharger control means 57 Wastegate valve control means 60 Wastegate valve device 61 Exhaust bypass passage 62 Exhaust bypass valve T Mechanical supercharger

Claims (7)

An electric supercharger that supercharges intake air with an electric motor into the combustion chamber of the engine;
A mechanical supercharger for supercharging the combustion chamber of the engine using exhaust energy of the engine;
A first power supply for supplying power for driving the electric supercharger;
A second power supply device for supplying electric power for driving an adjustment valve for adjusting an exhaust energy recovery amount of the engine;
Regenerative power storage means comprising a distribution device for distributing power generated by regenerative power generation in the engine or a vehicle equipped with the engine to the first power supply device and the second power supply device;
An engine power supply system with an electric supercharger. The regenerative power storage means is
A rotating electrical machine that generates regenerative power by rotating the engine;
Power control means for controlling the amount of regenerative power generated by the rotating electrical machine;
With
The first power supply device
A storage battery that stores regenerative power generated by the rotating electrical machine using chemical energy,
A power supply system for an engine with an electric supercharger according to claim 1. The power supply system for an engine with an electric supercharger according to claim 2, wherein the storage battery is a lithium ion battery. The regenerative power storage means is
A rotating electrical machine that generates regenerative power by rotating the engine;
Power control means for controlling the amount of regenerative power generated by the rotating electrical machine;
With
The first power supply device
A capacitor for electrostatically storing the regenerative power generated by the rotating electrical machine,
A power supply system for an engine with an electric supercharger according to claim 1. The second power supply is
The power supply system for an engine with an electric supercharger according to any one of claims 1 to 4, wherein electric power is supplied to an apparatus for starting and igniting the engine and an electrical component of a vehicle on which the engine is mounted. The distributor is
Any one of Claims 1-5 which switches so that electric power generated by regenerative power generation may be preferentially stored in the first power supply device, and electric power generated by other than regenerative power generation may be preferentially stored in the second power supply device. A power supply system for an engine with an electric supercharger according to claim 1. The power control means includes
Required power generation amount calculating means for calculating a required power generation amount as power to be generated by the rotating electrical machine;
A rotating electrical machine control means for controlling a regenerative power generation amount by the rotating electrical machine based on the required power generation amount;
A power supply system for an engine with an electric supercharger according to claim 6.

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