JP4211243B2 - Charge control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a charge control device, and more particularly, to a charge control device that charges a secondary battery by executing at least two charge modes with different charge pressure levels.
[0002]
[Prior art]
2. Description of the Related Art A vehicle drive device (for example, Japanese Patent Application Laid-Open No. 11-147424) having a configuration in which a motor generator is connected to a crankshaft of an internal combustion engine is known. In this technique, when the vehicle is driven by the driving force of the internal combustion engine, the motor generator is used as a generator to charge the secondary battery (referred to as “power generation mode”). Further, at the time of deceleration of the vehicle, fuel cut is executed, and the running energy of the vehicle is regenerated as electric power by a motor generator as a generator to charge the secondary battery (referred to as “regenerative mode”). Furthermore, during the automatic stop of the internal combustion engine, the motor generator is used as an electric motor to drive the auxiliary machine, and during the automatic start, the motor generator is used as an electric motor to start the internal combustion engine or start the vehicle. Yes.
[0003]
In such an internal combustion engine, in the power generation mode, if the secondary battery is fully charged (charging rate 100%), the secondary battery cannot store any more in the regenerative mode. This makes it possible to improve fuel efficiency.
[0004]
For this reason, in the power generation mode, the charge rate of the secondary battery must always be less than 100%, for example, 60 to 70%, except for a special charging mode such as refresh charging.
[0005]
[Problems to be solved by the invention]
However, in the power generation mode, the charging pressure (for example, 37.5 V) applied to the secondary battery in order to set the charging rate of the secondary battery to 70%, for example, exceeds 70% in the regeneration mode. (For example, 100%) is set lower than a charging pressure (for example, 42V) that enables it. For this reason, when it switches from the state which is performing regeneration mode to the state which performs electric power generation mode, a charge pressure will fall rapidly.
[0006]
Thus, even when the charging pressure rapidly decreases, the terminal voltage of the secondary battery does not decrease rapidly but gradually decreases due to the nature of the secondary battery. For this reason, a voltage difference arises between the terminal voltage of a secondary battery, and charging device side, such as an inverter. At this time, since the charging device side is in the power generation mode, the terminal of the secondary battery is electrically connected. Therefore, while the terminal voltage of the secondary battery is higher than the charging pressure, current flows from the secondary battery to the charging device side.
[0007]
Therefore, until just before, the electric energy stored in the secondary battery by regenerating the vehicle running energy in the regeneration mode is wasted as heat energy in the charging device or returned to the motor generator to A phenomenon such as an unnecessary increase in output torque occurs. For this reason, a part or all of the regenerated energy disappears, and the fuel efficiency improvement effect cannot be obtained sufficiently.
[0008]
An object of the present invention is to prevent wasteful consumption of electric energy charged by regeneration or the like as described above when executing at least two charging modes having different charging pressure levels for a secondary battery. It is.
[0009]
[Means for Solving the Problems]
  In the following, means for achieving the above object and its effects are described.
  The charge control device according to claim 1 is provided for a secondary battery.A power generation mode for charging at a low charge pressure using the power generated by the output of the internal combustion engine for driving the vehicle, and a regenerative mode for charging at a high charge pressure using the regenerative power by the running energy of the vehicle,A charge control device for charging the secondary battery by executingThe regenerationFrom modeSaid departureWhen switching the charging mode to the power mode, gradually change the charging pressure.In addition, the degree of gradual change is switched according to the traveling state of the vehicle or the operating state of the internal combustion engine for driving the vehicle.The charging pressure gradual change means is provided.
[0010]
  The charging pressure gradual change means is a high charging pressure charging mode.Regenerative modeTo low charging pressure charging modeIs the power generation modeWhen switching the charging mode, the charging pressure is gradually changed. For this reason, high charging pressureRegenerationLow charge pressure from modeDepartureAlso in the process of switching to the electric mode and thereafter, the potential difference between the terminal voltage of the secondary battery and the charging device side is substantially the same. Thus, the amount of current flowing from the secondary battery to the charging device side can be almost eliminated.In addition, depending on the vehicle speed, the internal combustion engine speed, and the like, the state of charge and the degree of charge of the secondary battery until just before the mode change differ. For this reason, the charging pressure gradual change means switches the degree of gradual change according to the running state of the vehicle or the driving state of the vehicle driving internal combustion engine, so that the charging pressure can be gradually changed at an appropriate speed according to the situation. As a result, the charging pressure can be shifted to an appropriate state as quickly as possible, wasteful consumption of regenerative energy can be prevented, and the fuel efficiency improvement effect of the internal combustion engine can be sufficiently obtained.
[0014]
Further, as a secondary effect, a change in power generation load is gradually made when the mode is switched from the regeneration mode to the power generation mode, so that a sudden change in running torque is not caused and a shock to the vehicle can be suppressed.
[0015]
  Claim2In the charging control device described in claim1In the configuration described above, charging in the power generation mode has an upper limit of an intermediate charging rate set to a charging rate of less than 100%, and charging in the regenerative mode has an upper limit of a charging rate exceeding the intermediate charging rate. Means are provided.
[0016]
By setting in this way, it is possible to prevent 100% of the secondary battery from being charged in the power generation mode, and to effectively execute the travel energy regeneration of the vehicle in the regeneration mode. Then, when the mode is shifted to the power generation mode after the regeneration mode, it is possible to prevent wasteful consumption of regenerative energy, to sufficiently obtain the fuel efficiency improvement effect of the internal combustion engine, and to suppress the shock to the vehicle. it can.
[0017]
  Claim3In the charging control device described in claim1Or2In the configuration described above, the charging pressure gradual change means gradually increases the charging pressure both when switching the charging mode from the regeneration mode to the power generation mode and when switching the charging mode from the power generation mode to the regeneration mode. It is characterized by changing.
[0018]
Even when the charging mode is switched from the power generation mode to the regeneration mode, the charging pressure may be gradually changed. As a result, even when the mode is switched from the power generation mode to the regeneration mode, the power generation load is gradually changed, so that a shock to the vehicle can also be suppressed.
[0021]
  Claim4In the charging control device described in claim1~3In the configuration described in any one of the above, power generation in the power generation mode and the regeneration mode is performed by a motor generator that is interlocked with the rotation of the output shaft of the internal combustion engine for driving the vehicle.
[0022]
Thus, by using the motor generator as an electric motor, it is possible to drive an auxiliary machine, start an internal combustion engine, and travel the vehicle, and use the motor generator as a generator to produce the above-described effects.
[0023]
In particular, since the motor generator is switched to a state in which the electric energy of the secondary battery is consumed as an electric motor, the charging rate is appropriately controlled by the above-described operational effects, and the operational effect that can prevent wasteful consumption of regenerative energy is important. Become.
[0024]
  Claim5In the charging control device described in claim1~4In any one of the configurations described above, the vehicle-driving internal combustion engine includes an automatic stop / start function that automatically stops when the engine stop condition is satisfied and automatically starts when the engine start condition is satisfied. And
[0025]
Even in an internal combustion engine for driving a vehicle having such an automatic stop / start function, it is possible to prevent wasteful consumption of regenerative energy, to sufficiently obtain the fuel consumption improvement effect of the internal combustion engine, and to suppress a shock to the vehicle. be able to.
[0026]
In particular, the internal combustion engine is frequently started by automatic start, and a state in which the electric energy of the secondary battery is consumed frequently by an electric motor such as a motor generator is frequently generated. The effect of preventing wasteful consumption of energy is important.
[0027]
  Claim6In the charging control device described in claim4In the configuration described above, both the vehicle drive internal combustion engine and the motor generator are used for vehicle travel, and either or both of the vehicle drive internal combustion engine and the motor generator are driven according to the travel state of the vehicle. The vehicle is driven to travel by force.
[0028]
In this way, even when the internal combustion engine and the motor generator as an electric motor are both used for vehicle travel, such as in a hybrid car system, the charging rate can be controlled appropriately and wasteful consumption of regenerative energy can be prevented. In addition, the fuel efficiency improvement effect of the internal combustion engine can be sufficiently obtained, and the shock to the vehicle can be suppressed.
[0029]
In particular, in such a system, a state in which the electric energy of the secondary battery is consumed frequently occurs, so that the charging rate is appropriately controlled by the above-described operational effects, and the operational effects that can prevent wasteful consumption of regenerative energy. Is important.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
[Embodiment 1]
FIG. 1 is a system configuration diagram of a vehicle internal combustion engine to which the above-described invention is applied and a control device therefor. Here, a gasoline engine (hereinafter referred to as “engine”) 2 is used as the internal combustion engine. The engine 2 is an in-cylinder injection type gasoline engine in which fuel is directly injected from a fuel injection valve into a combustion chamber and ignited by a spark plug.
[0031]
Here, the output of the engine 2 is output from the crankshaft 2a of the engine 2 to the output shaft 6a side via a torque converter 4 and an automatic transmission (automatic transmission: hereinafter referred to as “A / T”) 6, and finally Is transmitted to the wheel. Apart from this, the output of the engine 2 is transmitted to the belt 14 via a pulley 10 connected to the crankshaft 2a. The other pulleys 16 and 18 are rotated by the output transmitted by the belt 14. The pulley 10 is provided with an electromagnetic clutch 10a, which is turned on (connected) and turned off (cut off) as necessary so that transmission / non-transmission of output can be switched between the pulley 10 and the crankshaft 2a. Yes.
[0032]
Of the pulleys 16 and 18, the pulley 16 is connected to the rotation shaft of the auxiliary machine 22 and can be driven by the rotational force transmitted from the belt 14. Examples of the auxiliary machine 22 include an air conditioner compressor, a power steering pump, an engine cooling water pump, and the like. Although shown as one auxiliary machine 22 in FIG. 1, one or more of an air conditioner compressor, a power steering pump, an engine cooling water pump, and the like actually exist. And it comprises so that it may rotate in conjunction with the belt 14 by providing a pulley, respectively. In the first embodiment, it is assumed that an air conditioner compressor, a power steering pump, and an engine cooling water pump are provided as the auxiliary machine 22.
[0033]
Further, a motor generator (hereinafter referred to as “M / G”) 26 is interlocked with the belt 14 by the pulley 18. The M / G 26 functions as a generator as needed (hereinafter referred to as “power generation mode” or “regeneration mode”), and thereby the rotational force transmitted from the engine 2 or wheels via the pulley 18 is converted into electric energy. Convert to Further, the M / G 26 functions as a motor (electric motor) as required (hereinafter referred to as “drive mode”) to rotate one or both of the engine 2 and the auxiliary machine 22 via the pulley 18 and the belt 14. .
[0034]
Here, the M / G 26 is electrically connected to the inverter 28. When the M / G 26 is set to the power generation mode or the regeneration mode, the inverter 28 controlled by the eco-run ECU 40 described later adjusts the charging pressure and the power generation amount (power generation load) by switching, so that the M / G 26 For charging the electric energy to the battery 30 (here, 36V) for the battery 30 (corresponding to the secondary battery) and to the battery 34 for the low-voltage power source (here 12V) via the DC / DC converter 32, Further, switching is made so as to be a power source for the ignition system, meters, ECUs and others.
[0035]
Furthermore, the inverter 28 charges the high-voltage power supply battery 30 by the eco-run ECU 40 so that the charging rate is 70% (corresponding to the intermediate charging rate) at the charging pressure Vl in the power generation mode. In the regenerative mode, the high-voltage power supply battery 30 can be charged up to a charging rate of 100% at the charging pressure Vh (Vh> Vl). As a result, a function as a charging rate control means is realized.
[0036]
When power generation by the M / G 26 is not performed, the high-voltage power supply battery 30 and the low-voltage power supply battery 34 are connected via the DC / DC converter 32, and thus supplied from the high-voltage power supply battery 30 side. The low-voltage power supply battery 34 is configured to constantly increase the charging rate to 100% by the electric power generated.
[0037]
When the M / G 26 is set to the drive mode, the inverter 28 drives the M / G 26 by supplying power to the M / G 26 from the high-voltage power supply battery 30 that is a power source. Thus, via the pulley 18 and the belt 14, the auxiliary machine 22 is rotated when the engine is stopped, and the crankshaft 2a is rotated as necessary at the time of automatic start, automatic stop, or vehicle start. At this time, the inverter 28 can adjust the rotational speed of the M / G 26 by adjusting the supply of electric energy from the high-voltage power supply battery 30.
[0038]
A starter 36 is provided to start the engine 2 during cold start. The starter 36 is supplied with electric power from the low-voltage power supply battery 34 and can start the engine 2 by rotating the ring gear.
[0039]
The A / T 6 is provided with an electric hydraulic pump 38 to which electric power is supplied from the low-voltage power supply battery 34, and supplies hydraulic oil to the hydraulic control unit inside the A / T 6. Using this hydraulic oil, a control valve in the hydraulic control unit adjusts the operating states of the clutch, brake and one-way clutch inside the A / T 6 and switches the shift state as necessary.
[0040]
The eco-run ECU 40 executes the above-described on / off switching of the electromagnetic clutch 10a, mode control of the M / G 26 and the inverter 28, control of the starter 36, charge rate control for the batteries 30 and 34, and the like. Further, driving on / off of the auxiliary machine 22 excluding the water pump, driving control of the electric hydraulic pump 38, shift control of the A / T 6, fuel injection control by the fuel injection valve 42, opening control of the throttle valve 46 by the electric motor 44 The opening degree control of the exhaust gas recirculation (EGR) valve and other engine control are executed by the engine ECU 48. In addition, by providing a VSC (Vehicle Stability Control) -ECU 50, automatic control of brakes in each wheel is also executed.
[0041]
The eco-run ECU 40 detects the rotation speed of the rotation shaft of the M / G 26 from the rotation speed sensor built in the M / G 26, whether the driver has started the economy running system, and other data from the eco-run switch. Here, the economy running system (hereinafter abbreviated as “eco-run system”) automatically stops the internal combustion engine when the vehicle is stopped after starting with a starter switch or at an intersection to improve fuel efficiency. This is an automatic stop / start system that automatically starts the internal combustion engine during start operation and enables the vehicle to start.
[0042]
Further, the engine ECU 48 detects the engine coolant temperature THW from the water temperature sensor, the accelerator opening ACCP from the accelerator opening sensor, the steering angle θ of the steering from the steering angle sensor, the vehicle speed SPD from the vehicle speed sensor, the throttle opening TA from the throttle opening sensor, Shift position sensor to shift position SHFT, engine speed sensor to engine speed NE, intake pressure sensor to intake pressure PM, auto air conditioner operating state, air / fuel ratio sensor to air / fuel ratio A / F appearing in exhaust components, and other data It is detected for engine control. The VSC-ECU 50 also detects whether or not the brake pedal is depressed and other data from the brake switch for braking control and the like.
[0043]
Each of these ECUs 40, 48, and 50 is configured with a microcomputer as the center, and the CPU executes necessary arithmetic processing in accordance with a program written in the internal ROM, and various kinds of processing are performed based on the calculation results. Control is being executed. These arithmetic processing results and data detected as described above can be exchanged by communicating with each other between the ECUs 40, 48 and 50, and control can be executed in conjunction with each other. It has become.
[0044]
The eco-run ECU 40 executes the eco-run system as described above. During the automatic stop of the engine 2 by this eco-run system, the electromagnetic clutch 10a is disengaged, and the M / G 26 is used using the electric energy stored in the high-voltage power supply battery 30 in response to an air conditioner drive request or a power steering drive request. To drive air conditioner compressors and power steering pumps. Further, when the automatic start condition is established during such automatic stop, the automatic start process is executed to connect the electromagnetic clutch 10a, and the M / G 26 using the electric energy of the high-voltage power supply battery 30 is connected. The vehicle is started by driving and the engine 2 is automatically started.
[0045]
Further, the engine ECU 48 controls the combustion mode so as to execute stratified combustion at low load and low rotation, and perform homogeneous combustion at the time of other operation or at the start time or immediately after the start according to the engine operating state. When the combustion mode is set to stratified combustion, the throttle valve 46 is almost fully opened regardless of the degree of the accelerator opening ACCP, and an amount of fuel considerably smaller than the stoichiometric air-fuel ratio with respect to the intake air amount is compressed. It is controlled so that it is injected in the latter period. As a result, at the ignition timing, ignition is performed to the ignitable rich air-fuel mixture that exists in the vicinity of the ignition plug in a layered manner, and stratified combustion is performed. On the other hand, when the combustion mode is set to homogeneous combustion, the opening degree of the throttle valve 46 is adjusted in accordance with the degree of the accelerator opening degree ACCP, and the amount that becomes the stoichiometric air-fuel ratio (in some cases, becomes deeper than the stoichiometric air-fuel ratio). Amount) of fuel is controlled to be injected during the intake stroke. As a result, at the ignition timing, a homogeneous air-fuel mixture is ignited with a stoichiometric air-fuel ratio (possibly richer than the stoichiometric air-fuel ratio) occupying the entire combustion chamber, and homogeneous combustion is performed.
[0046]
Next, a charging pressure setting process for charging the high-voltage power supply battery 30 by the power generation of the M / G 26 will be described. This process is shown in the flowchart of FIG. This process is repeatedly executed by the eco-run ECU 40 in a time cycle. The steps in the flowchart corresponding to the individual processing contents are represented by “S˜”.
[0047]
When the charge pressure setting process is started, it is first determined whether or not there has been a mode change for the M / G 26 (S110). If there is no mode change (“NO” in S110), it is next determined whether or not the current mode is the power generation mode (S120). If the current mode is not the power generation mode (“NO” in S120), it is next determined whether or not the current mode is the regeneration mode (S130). Here, if the current mode is not the regenerative mode (“NO” in S130), this process is temporarily terminated as it is.
[0048]
On the other hand, if there is a mode change (“YES” in S110), it is next determined whether or not it is a change from the regeneration mode to the power generation mode (S140). If it is not a change from the regeneration mode to the power generation mode (“NO” in S140), it is next determined whether or not the change is from the power generation mode to the regeneration mode (S150). If it is not a change from the power generation mode to the regeneration mode (“NO” in S150), this process is temporarily terminated as it is.
[0049]
Here, when the mode change from the regeneration mode to the power generation mode occurs (“YES” in S110, “YES” in S140), the step for gradual change from the map according to the running state of the vehicle, here the vehicle speed SPD. The voltage width dV is calculated (S160), and this process is temporarily terminated. That is, in the regenerative mode, the M / G 26 is rotated by the running energy of the vehicle to generate electric power, and the high-voltage power supply battery 30 is charged. An appropriate step voltage width dV for gradual change is set at the time of reduction. The map in this case is set in advance by experiments and stored in the ROM of the eco-run ECU 40.
[0050]
In the next control cycle, since there is no mode change (“NO” in S110), it is determined whether or not the current mode is the power generation mode (S120). Here, since the power generation mode is set after the mode change (“YES” in S120), it is next determined whether or not the charge pressure control amount Vx is set to a voltage higher than the charge pressure Vl in the power generation mode. (S170). Immediately after switching from the regeneration mode to the power generation mode, the charge pressure control amount Vx remains the charge pressure Vh in the immediately preceding regeneration mode, and Vh (42 V in the present embodiment)> Vl (in the present embodiment). 3xV), Vx = Vh> Vl (“YES” in S170). Therefore, as shown in the following equation 1, the current charge pressure control amount Vx is subtracted by the step voltage width dV for gradual change calculated in step S160, and a new charge pressure control amount Vx is set (S180). .
[0051]
[Expression 1]
Vx ← Vx−dV [Formula 1]
In this way, this process is once completed. As a result, the eco-run ECU 40 uses the electric power generated by the M / G 26 to adjust the charge pressure to the charge pressure control amount Vx that is reduced by the step voltage width dV for gradual change from the previous control cycle, thereby increasing the high-voltage power supply. The inverter 28 is adjusted so that the battery 30 is charged.
[0052]
Thereafter, when the power generation mode continues (“NO” in S110, “YES” in S120), as long as Vx> Vl (“YES” in S170), the charge pressure control amount Vx is reduced according to the above equation 1 (S180). ), The charging pressure for the high-voltage power supply battery 30 is gradually reduced.
[0053]
If the condition of Vx> Vl is not satisfied as a result of repeating the gradual change of the charge pressure control amount Vx (“NO” in S170), the charge pressure control amount Vx is then charged to the power generation mode. The voltage Vl is set (S190), and the process is temporarily terminated. Thereafter, as long as the power generation mode continues (“NO” in S110, “YES” in S120), “NO” is determined in Step S170 and Step S190 is executed. The voltage Vl is maintained.
[0054]
Next, when the mode change from the power generation mode to the regenerative mode occurs (“YES” in S110, “NO” in S140, “YES” in S150), the operating state of the engine 2, here the engine rotational speed NE). Accordingly, the step voltage width dV for gradual change is calculated from the map (S200), and this process is temporarily terminated. That is, when shifting from the power generation mode to the regeneration mode, the upper limit of the charging rate of the high-voltage power supply battery 30 changes from 70% to 100%, and the electric load increases. Therefore, when the power generation load increases, the running torque may change suddenly, causing a shock to the vehicle. In the present embodiment, in order to prevent this shock, an increase in the power generation load is gradually changed by setting an appropriate gradual change step voltage width dV according to the engine speed NE. The map in this case is set in advance by experiments and stored in the ROM of the eco-run ECU 40.
[0055]
In the next control cycle, since there is no mode change (“NO” in S110), it is determined whether or not the current mode is the power generation mode (S120). Here, since the regeneration mode is set after the mode change (“NO” in S120), it is next determined whether or not the current mode is the regeneration mode (S130). Since it is currently in the regeneration mode (“YES” in S130), it is next determined whether or not the charge pressure control amount Vx is set to a voltage lower than the charge pressure Vh in the regeneration mode (S210). If it is immediately after switching from the power generation mode to the regeneration mode, the charge pressure control amount Vx is the charge pressure Vl in the immediately previous power generation mode, and Vl <Vh, so Vx = Vl <Vh (in S210, “ YES "). Therefore, as shown in the following equation 2, the current charge pressure control amount Vx is added to the step voltage width dV for gradual change calculated in step S200, and a new charge pressure control amount Vx is set (S220). .
[0056]
[Expression 2]
Vx ← Vx + dV [Formula 2]
In this way, this process is once completed. As a result, the eco-run ECU 40 uses the power generated by the M / G 26 to adjust the charging pressure to the charging pressure control amount Vx that is increased by the step voltage width dV for gradual change from the previous control cycle, and the high-voltage power supply. The inverter 28 is adjusted so that the battery 30 is charged.
[0057]
Thereafter, when the power generation mode continues (“NO” in S110, “NO” in S120, “YES” in S130), as long as Vx <Vh (“YES” in S210)), the charge pressure control amount Vx according to Equation 2 above is satisfied. Is increased (S220), and the charging pressure for the high-voltage power supply battery 30 is gradually increased.
[0058]
If the condition of Vx <Vh is not satisfied as a result of repeating such gradual change of the charge pressure control amount Vx (“NO” in S210), the charge pressure control amount Vx is then charged to the regeneration mode. The voltage Vh is set (S230), and this process is temporarily terminated. Thereafter, as long as the regeneration mode continues (“NO” in S110, “NO” in S120, “YES” in S130), it is determined as “NO” in Step S210 and Step S230 is executed. Vx is maintained at the charging voltage Vh in the regeneration mode.
[0059]
An example of the processing by the charging pressure setting processing (FIG. 2) is shown in the timing chart of FIG. If the power generation mode is changed to the regeneration mode at time t0, the charging pressure control amount Vx gradually increases from the power generation mode charging pressure Vl to the regeneration mode charging pressure Vh. When the regeneration mode is shifted to the power generation mode, the charge pressure control amount Vx gradually decreases from the regeneration mode charge pressure Vh to the power generation mode charge pressure Vl.
[0060]
As shown in FIG. 3B as a comparative example, when the power generation mode is shifted to the regeneration mode (time t10), the charge pressure control amount Vx is immediately switched from the power generation mode charge pressure Vl to the regeneration mode charge pressure Vh. If this happens, the battery terminal voltage will rise immediately. However, when switching from the regeneration mode to the power generation mode (time t11), when the charge pressure control amount Vx is immediately switched from the regeneration mode charge pressure Vh to the power generation mode charge pressure Vl, the battery terminal voltage immediately decreases. It does not occur, and gradually decreases between times t11 and t12. For this reason, as indicated by hatching, the charging voltage (Vx = Vl) in the inverter 28 becomes lower than the terminal voltage of the high-voltage power supply battery 30. Therefore, a reverse current flows from the high-voltage power supply battery 30 to the inverter 28 side.
[0061]
In the configuration described above, the charge pressure setting process (FIG. 2) corresponds to a process as the charge pressure gradual change means.
According to the first embodiment described above, the following effects can be obtained.
[0062]
(I). In the charge pressure setting process (FIG. 2), the charge pressure is gradually changed when the charge mode is switched from the regeneration mode to the power generation mode. For this reason, the potential difference between the terminal voltage of the high-voltage power supply battery 30 and the charging voltage of the inverter 28 changes almost the same. Therefore, a voltage difference as shown by hatching in FIG. 3B does not occur, and current backflow from the high-voltage power supply battery 30 to the inverter 28 side can be prevented, so that wasteful consumption of regenerative energy can be prevented, and the engine The fuel efficiency improvement effect 2 can be sufficiently obtained.
[0063]
(B). The charging pressure is gradually changed when the charging mode is switched from the regeneration mode to the power generation mode, and the charging pressure is also gradually changed when the charging mode is switched from the power generation mode to the regeneration mode. For this reason, in both the mode switching from the regeneration mode to the power generation mode and the mode switching from the power generation mode to the regeneration mode, a sudden change in the running torque is not caused and a shock to the vehicle can be suppressed.
[0064]
(C). Based on the vehicle speed SPD, the step voltage width dV for gradual change is set reflecting the state of charge and the degree of charge of the high-voltage power supply battery 30 immediately before the mode switching from the regeneration mode to the power generation mode. For this reason, the charge pressure can be gradually changed at an appropriate speed according to the state of charge and the degree of charge. As a result, the charge pressure control amount Vx can be shifted to an appropriate state as quickly as possible, the backflow of current can be prevented, and wasteful consumption of regenerative energy can be prevented, and the fuel efficiency of the engine 2 can be improved. You can get enough.
[0065]
(D). Here, the M / G 26 that generates electricity as a generator and drives an auxiliary machine, starts an engine, and travels a vehicle is used as an electric motor. Then, automatic stop and automatic start are executed by the eco-run system. As described above, the engine 2 is frequently started by the eco-run system, and the state where the electric energy of the battery 30 for the high-voltage power source by the M / G 26 is consumed frequently occurs. For this reason, the operation and effect that can appropriately control the charging rate of the high-voltage power source battery 30 by the above-described operation and prevent wasteful consumption of regenerative energy become particularly important.
[0066]
[Other embodiments]
-In the charging pressure setting process (Fig. 2), the charging pressure is gradually changed both when shifting from the regeneration mode to the power generation mode and when shifting from the power generation mode to the regeneration mode. The charging pressure may be gradually changed only in the case of shifting to (1). Also in this case, wasteful consumption of regenerative energy can be prevented, and the fuel efficiency improvement effect of the engine 2 can be sufficiently obtained. Moreover, a shock when shifting from the regeneration mode to the power generation mode can also be prevented.
[0067]
In steps S160 and S200 of the charging pressure setting process (FIG. 2), the step voltage width dV for gradual change is set according to the vehicle running state such as the vehicle speed SPD or the engine operating state such as the engine speed NE. Each may be a fixed value. In this case, steps S160 and S200 may be common values.
[0068]
In the above embodiment, the driving force is transferred between the engine 2 and the M / G 26. In addition to this, the engine and the M / G 26 are switched according to the running state, It can also be used together and applied to a vehicle of a hybrid system that runs the vehicle.
[0069]
In the above embodiment, the M / G 26 that also serves as an electric motor is used as the generator, but the present invention can also be applied to the case where a dedicated generator is used.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a vehicle internal combustion engine and a control device thereof according to a first embodiment.
FIG. 2 is a flowchart of a charging pressure setting process executed by the eco-run ECU according to the first embodiment.
FIG. 3 is a timing chart showing an example of processing according to Embodiment 1 and a comparative example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Engine, 2a ... Crankshaft, 4 ... Torque converter, 6 ... A / T, 6a ... Output shaft, 10 ... Pulley, 10a ... Electromagnetic clutch, 14 ... Belt, 16, 18 ... Pulley, 22 ... Auxiliary machine, 26 ... M / G, 28 ... Inverter, 30 ... Battery for high-voltage power supply, 32 ... DC / DC converter, 34 ... Battery for low-voltage power supply, 36 ... Starter, 38 ... Electric hydraulic pump, 40 ... Eco-run ECU, 42 ... Fuel injection valve 44 ... Electric motor, 46 ... Throttle valve, 48 ... Engine ECU, 50 ... VSC-ECU.

Claims (6)

A power generation mode in which the secondary battery is charged at a low charging pressure using the power generated by the output of the internal combustion engine for driving the vehicle, and a regeneration mode in which the secondary battery is charged at a high charging pressure using the regenerative power generated by the vehicle running energy A charge control device for charging the secondary battery by executing,
When switching the charging mode to the power generation mode from said regenerative mode, causes gradually changing the charge voltage, according to the operating state of the traveling state or the vehicle-driving internal combustion engine of the vehicle, switches the extent of gradual change A charging control device comprising charging pressure gradual change means. 2. The configuration according to claim 1, wherein charging in the power generation mode has an upper limit of an intermediate charging rate set to a charging rate of less than 100%, and charging in the regeneration mode has an upper limit of a charging rate exceeding the intermediate charging rate. A charge control device comprising a charge rate control means . 3. The configuration according to claim 1 , wherein the charging pressure gradual change unit is configured to switch the charging mode from the regeneration mode to the power generation mode and to switch the charging mode from the power generation mode to the regeneration mode. A charging control device characterized by gradually changing the charging pressure . In the configuration of any one of claims 1 to 3, by the motor generator in conjunction with the rotation of the output shaft of the vehicle-driving internal combustion engine, the power generation in the power generation mode and the regeneration mode is characterized Rukoto performed Charge control device. 5. The vehicle drive internal combustion engine according to claim 1 , further comprising an automatic stop / start function that automatically stops when an engine stop condition is satisfied and automatically starts when the engine start condition is satisfied. Tei Rukoto charge control device according to claim. 5. The configuration according to claim 4 , wherein the internal combustion engine for driving the vehicle and the motor generator are both used for traveling of the vehicle, and either the internal combustion engine for driving the vehicle or the motor generator according to a traveling state of the vehicle or charge control device, characterized that you travel drive the vehicle by both the driving force.

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