JP3705198B2 - Vehicle power generation control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle power generation control device for controlling a power generation amount of a power generator that is drivingly connected to an output shaft of an internal combustion engine as a drive source.
[0002]
[Prior art]
In recent years, in addition to an internal combustion engine, a technique relating to a so-called hybrid vehicle in which an electric motor supplied with electric power from a battery is mounted as a drive source has been proposed. Such a hybrid vehicle is usually provided with a generator that is drivingly connected to the output shaft of the internal combustion engine, and the electric power obtained by the power generation of the generator is stored in the battery. In addition, since a load corresponding to the power generation amount is added to the engine output shaft during this power generation, it is desirable to set this power generation amount to the minimum necessary to suppress deterioration in fuel consumption of the internal combustion engine. Therefore, in such a vehicle power generation control device, wasteful power generation is performed by constantly monitoring the state of charge of the battery and setting the target power generation amount each time based on this state of charge or stopping power generation. I am trying not to.
[0003]
By the way, when starting this from the state where the power generation by the generator is stopped, for example, as shown by a one-dot chain line in FIG. 11B, the power generation amount E (for example, voltage value) of the generator is charged to the battery. When the target power generation amount ETRG corresponding to is increased at a time (timing t1), the load applied from the generator to the internal combustion engine increases rapidly. As a result, for example, when the internal combustion engine is in an idle operation state, as shown by a one-dot chain line in FIG. 11A, a temporary drop in the engine speed NE may occur due to a sudden increase in load. become. And when such fluctuations occur in the engine rotational speed, such as a drop, the increase in vehicle vibration and noise is unavoidable, and there is a possibility of causing a worst stall.
[0004]
Therefore, conventionally, as a technique for suppressing such fluctuations in engine rotational speed, a power generation control device as described in, for example, Japanese Patent Application Laid-Open No. 8-61193 has been proposed. In the apparatus, as shown by the solid line in FIG. 11 (b), when power generation is started, the power generation amount E is not suddenly raised but gradually increased to the target power generation amount ETRG. ing. Therefore, according to this conventional apparatus, the load generated in the generator does not increase suddenly with the start of power generation, and the fluctuation of the engine rotational speed does not change as shown by the solid line in FIG. As a result, the occurrence of vehicle vibration and noise due to this is suppressed.
[0005]
[Problems to be solved by the invention]
By the way, when the combustion stability of the internal combustion engine is relatively low, such as during idling, the engine speed fluctuation due to the increased load on the generator is more likely to occur. Therefore, in the conventional apparatus, when increasing the load of the generator, that is, the amount of power generation, the increase speed can be set small so that the engine speed does not fluctuate even during such idling operation. I need it.
[0006]
However, if the increase rate of the power generation amount is set in accordance with the idling operation in this way, the power generation capability of the generator is uniformly limited at the start of power generation. For this reason, in the above-described conventional device, for example, when the battery is in an overdischarged state, and when it is desired to secure the power generation capacity of the generator as much as possible, the power generation amount is insufficient and the recovery of the battery charge state is delayed. There was still room for improvement in this regard.
[0007]
The present invention has been made in view of such circumstances, and its purpose is to generate power from a vehicle that can suitably secure a power generation amount while suppressing fluctuations in engine rotation speed when starting power generation by a generator. It is to provide a control device.
[0008]
[Means for Solving the Problems]
Hereinafter, means for solving the above-described problems and the effects thereof will be described.
According to the first aspect of the present invention, a generator that is drivingly connected to the output shaft of the vehicle internal combustion engine, a battery that is charged by the power generation of the generator, and power generation of the generator during the independent operation of the internal combustion engine. In a vehicle power generation control device comprising a control means for controlling the generator so that the power generation amount gradually increases to a predetermined target power generation amount when starting, the control means increases the power generation amount. of Increase per unit time Is variably set based on a factor having a correlation with the combustion stability of the internal combustion engine.
[0009]
In the above configuration, when increasing the power generation amount of the generator Increase per unit time However, unlike the case where it is set uniformly in accordance with, for example, idle operation, this is set to a size suitable for the combustion stability of the internal combustion engine each time. For this reason, in an operation region where the combustion stability of the internal combustion engine is relatively low, such as during idle operation, Increase per unit time Is set small, and a sudden increase in load applied from the generator to the internal combustion engine is suppressed. Therefore, fluctuations in the engine rotation speed accompanying the start of power generation can be suppressed. On the other hand, in an operating region where the combustion stability of the internal combustion engine is relatively high, such as during high-load high-speed rotation, it is difficult for fluctuations in the engine rotation speed due to increased load on the generator to occur. When increasing Increase per unit time Is set larger. Therefore, after power generation is started, the power generation amount quickly increases to the target power generation amount. As a result, according to the above configuration, it is possible to suitably secure the amount of power generation while suppressing fluctuations in the engine rotation speed when starting the power generation by the generator.
[0010]
According to a second aspect of the present invention, in the vehicle power generation control device according to the first aspect, the control means detects the engine load as a factor having a correlation with the combustion stability of the internal combustion engine, and the engine load is large. Sometimes Increase per unit time Is set to be large.
[0011]
When the engine load increases, the amount of fuel used for combustion increases, and the combustion of the internal combustion engine is performed in a stable state. Therefore, according to the above configuration, Increase per unit time Can be suitably variably set according to the relationship between the combustion stability and the engine load.
[0012]
The engine load is described in claim 3. of According to the invention, for example, this can be detected based on at least one of the accelerator operation amount, the throttle opening, the intake air amount, and the intake air pressure in addition to the fuel injection amount.
[0013]
According to a fourth aspect of the present invention, in the vehicle power generation control device according to any one of the first to third aspects, the control means detects an engine rotational speed as a factor having a correlation with the combustion stability of the internal combustion engine. The higher the engine speed, the more Increase per unit time Is set to be large.
[0014]
When the engine rotation speed increases, the drive portion of the internal combustion engine moves with a larger inertia force, so that the internal combustion engine is burned in a stable state. Therefore, according to the above configuration, Increase per unit time Can be suitably variably set according to the relationship between the combustion stability and the engine speed.
[0015]
According to a fifth aspect of the present invention, the control means detects a vehicle travel speed as a factor having a correlation with the combustion stability of the internal combustion engine, and the higher the vehicle travel speed, Increase per unit time Is set to be large.
[0016]
When the vehicle is in a running state, even if the combustion state may deteriorate, the rotational driving force is transmitted from the driving force transmission system of the vehicle to the output shaft of the internal combustion engine. A decrease in engine rotational speed due to the deterioration of the engine is suppressed, and instability of the combustion state is also suppressed. In addition, the tendency that the instability of the combustion state is suppressed by transmitting the rotational driving force of the driving force transmission system to the internal combustion engine in this way becomes more remarkable as the vehicle traveling speed is higher. According to the above configuration of the invention of claim 5, the power generation amount decreases as the vehicle traveling speed increases. Increase per unit time By setting the Increase per unit time Can be suitably variably set in accordance with the relationship between the combustion stability of the internal combustion engine and the vehicle traveling speed.
[0017]
According to a sixth aspect of the present invention, in the vehicle power generation control device according to any one of the first to fifth aspects, the control means is variably set based on the factor as the elapsed time after starting of the internal combustion engine becomes longer. Increase per unit time This is set to be large.
[0018]
Immediately after starting the internal combustion engine, the temperature of the engine combustion chamber is low, and the viscosity of the lubricating oil is high, so that the driving resistance in the driving portion increases due to the influence. For this reason, immediately after start-up, the combustion stability of the internal combustion engine is reduced, and fluctuations in the engine speed are likely to occur. On the other hand, when the elapsed time after start-up becomes longer, the temperature of the engine combustion chamber rises, and the driving resistance in the driving portion gradually decreases. For this reason, the combustion state of the internal combustion engine is also stabilized according to these, and fluctuations in the engine rotational speed are less likely to occur. Therefore, according to the above-described configuration of the invention according to claim 6, the relationship between the elapsed time after the start and the engine combustion stability is Increase per unit time Can be reflected in the settings of Increase per unit time Can be set more suitably.
[0019]
According to a seventh aspect of the present invention, in the vehicle power generation control device according to any one of the first to sixth aspects, the control means is variably set based on the factor as the external load of the internal combustion engine increases. Increase per unit time This is set to be small.
[0020]
If the external load of the internal combustion engine, that is, the load added to the engine output shaft due to the operation of external auxiliary equipment such as an air conditioner, water pump, power steering hydraulic pump, etc., increases the engine rotation due to the increased load on the generator Speed fluctuations tend to occur easily. According to the configuration of the invention according to claim 7, the power generation amount can be reduced while taking into consideration the influence of such an external load on the fluctuation of the engine speed. Increase per unit time Can be suitably set.
[0021]
According to an eighth aspect of the present invention, in the vehicle power generation control device according to any one of the first to seventh aspects, the control means is variably set based on the factor as the coolant temperature of the internal combustion engine is lower. Increase per unit time This is set to be small.
[0022]
When the cooling water temperature of the internal combustion engine is low, the temperature of the lubricating oil becomes low, and thus the driving resistance in the driving portion of the internal combustion engine increases. In such a situation where the drive resistance is increased, the engine speed is likely to fluctuate due to the addition of the load of the generator. According to the above-described configuration of the invention according to claim 8, the relationship between the engine coolant temperature and the ease of occurrence of the engine speed fluctuation is described above. Increase per unit time Can be reflected in the settings of Increase per unit time Can be set as a more preferable one.
[0023]
According to a ninth aspect of the present invention, in the vehicle power generation control device according to any one of the first to eighth aspects, the control means controls a power generation amount of the generator based on a voltage command value, and The larger the amount of charge, the more variable the setting based on the above factors Increase per unit time The voltage command value is set so as to increase.
[0024]
When the amount of charge of the battery is large, in other words, when the charge margin when charging the battery is small, even if the voltage command value output to the generator is the same, the internal resistance of the battery increases. Less current flows through the generator. As a result, the load applied from the generator to the engine output shaft is reduced, and it is difficult for fluctuations in the engine rotation speed to occur. According to the above configuration of the invention according to claim 9, when the amount of charge of the battery is large as described above, and therefore it is difficult for fluctuations in the engine speed to occur, Increase per unit time Can be set large, and the power generation amount of the generator can be secured more.
[0025]
According to a tenth aspect of the present invention, in the vehicle power generation control device according to any one of the first to ninth aspects, the control means controls a power generation amount of the generator based on a voltage command value, and The higher the temperature, the more variably set based on the above factors Increase per unit time The voltage command value is set so as to increase.
[0026]
When the temperature of the battery is high, even if the voltage command value output to the generator is the same, the internal resistance of the battery increases, so the current flowing through the generator decreases. As a result, the load applied from the generator to the engine output shaft is reduced, and it is difficult for fluctuations in the engine rotation speed to occur. According to the above configuration of the invention of claim 10, when the temperature of the battery is high as described above, and therefore it is difficult for fluctuations in the engine rotation speed to occur, the amount of power generation is reduced. Increase per unit time Can be set large, and the power generation amount of the generator can be secured more. The temperature of the battery can be detected by, for example, a temperature sensor provided in the battery. Further, for example, the initial temperature of the battery is estimated based on the outside air temperature detected by the outside air temperature sensor (or the intake air temperature sensor) and the engine coolant temperature detected by the water temperature sensor, and based on the charge / discharge amount of the battery. It is also possible to estimate the temperature rise amount and obtain the battery temperature based on the initial temperature and the temperature rise amount.
[0027]
According to an eleventh aspect of the present invention, in the vehicle power generation control device according to any one of the first to tenth aspects, the control means controls the power generation amount of the generator based on a voltage command value, and the battery The larger the degree of deterioration, the more variably set based on the above factors Increase per unit time The voltage command value is set so as to increase.
[0028]
As the battery progresses, even if the voltage command value output to the generator is the same, the internal resistance of the battery increases, so the current flowing through the generator decreases. As a result, the load applied from the generator to the engine output shaft is also reduced, and fluctuations in the engine speed are less likely to occur. According to the above-described configuration of the invention according to claim 9, when the degree of deterioration of the battery is thus large and therefore it is difficult for fluctuations in the engine speed to occur, the amount of power generation is reduced. Increase per unit time Can be set large, and the power generation amount of the generator can be secured more. The degree of deterioration of the battery can be estimated based on, for example, the usage time of the battery, specifically the total charging time and the total discharging time, or can be estimated from the rate of decrease of the charging amount with respect to the discharging amount.
[0029]
According to a twelfth aspect of the present invention, in the vehicle power generation control device according to any one of the first to eleventh aspects, the operation is stopped by rotating the output shaft by causing the generator to function as an electric motor when starting the vehicle. An automatic starting means for automatically starting the internal combustion engine inside is further provided.
[0030]
In the above configuration, when the operation of the internal combustion engine is stopped when the vehicle is started, automatic start is performed by the automatic start means. Then, when the internal combustion engine starts a self-sustaining operation by this automatic start, power generation by the generator is started. Here, when the vehicle starts, the engine load usually increases due to the operation of the accelerator operation member, so that the engine combustion state becomes stable, and the fluctuation of the engine rotation speed due to the increase in the load of the generator becomes difficult to occur. Yes. According to the above configuration of the invention of claim 12, when starting the vehicle in which the combustion stability of the internal combustion engine is ensured in this way, the internal combustion engine is automatically started and the generator generates power. The amount of power generation can be suitably ensured at the start of power generation.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
The power generation control device for a vehicle according to the present embodiment is provided in a hybrid vehicle equipped with an electric motor as a drive source in addition to the internal combustion engine, and is provided in the vehicle for controlling the power generation function. As shown in FIG. 1, the power generation control device includes a motor generator 12 whose function can be selectively switched as a generator or an electric motor, and a battery electrically connected to the motor generator 12 via an inverter 14. 15 and an electronic control device 16 that performs overall control of the power generation function in accordance with the operating state of the internal combustion engine 10 and the state of charge of the battery 15.
[0032]
Pulleys 24 and 25 are attached to a rotating shaft 13 of the motor generator 12 and a rotating shaft 23 of various auxiliary machines 22 such as a compressor for an air conditioner, a water pump, and a hydraulic pump for power steering. A pulley 26 is attached to one end of the engine output shaft 11 via an electromagnetic clutch 19. A belt 21 for driving auxiliary equipment is hung on each of the pulleys 24 to 26. The belt 21 is drivingly connected to the rotating shaft 13 of the motor generator 12, the rotating shaft 23 of the various auxiliary machines 22, and the engine output shaft 11. The driving force required for the operation of the various auxiliary machines 22 is the internal combustion engine 10 or the motor. It is selectively transmitted from the generator 12. As the driving force transmission system, for example, a gear or a chain can be employed instead of the pulleys 24 to 26 and the belt 21 described above. The connection / disconnection between the engine output shaft 11 and this auxiliary machine driving force transmission system is switched by connecting / disconnecting the electromagnetic clutch 19.
[0033]
A torque converter 27 is connected to the other end of the engine output shaft 11, and the rotational driving force of the engine output shaft 11 is finally transmitted from the torque converter 27 via an automatic transmission 28 or the like to a vehicle not shown. It is transmitted to the drive wheel.
[0034]
The electronic control device 16 includes a rotation speed sensor 30 for detecting the engine rotation speed, a water temperature sensor 31 for detecting the engine cooling water temperature, an intake air amount sensor 32, and an open throttle valve (not shown) for adjusting the intake air amount. A throttle sensor 33 for detecting the degree, an accelerator sensor 34 for detecting the amount of depression of an accelerator pedal (not shown), an accelerator switch 35 for detecting that the accelerator pedal is depressed, and a brake pedal (not shown). Sensors for detecting the engine operating state, such as a brake switch 36 for detecting that the vehicle is depressed, and a shift position sensor 37 for detecting the shift position of the automatic transmission 28, are connected. In addition, a speed sensor 38 that detects the traveling speed of the vehicle and a battery temperature sensor 39 that detects the temperature of the battery 15 are connected to the electronic control unit 16.
[0035]
Based on the detection results of these various sensors 30 to 39, the electronic control device 16 provides a driving force to the internal combustion engine 10 and various auxiliary machines 22 as a motor and a state (power generation state) of the motor generator 12 functioning as a generator. The state to be applied (driving state) is switched through the control of the inverter 14.
[0036]
Further, in addition to the control related to the power generation function of the vehicle, the electronic control unit 16 also executes control related to the automatic start when the automatic stop process of the internal combustion engine 10 is performed, for example. The automatic stop process is, for example,
・ The accelerator pedal is not depressed.
・ The vehicle is stopped
・ Engine speed is below a specified speed
-The amount of charge of the battery 15 is a predetermined amount or more
-The brake pedal is depressed or the shift position of the automatic transmission 28 is in the parking range or neutral position.
And so on when all the conditions are satisfied. It should be noted that various other conditions may be appropriately added or replaced as the engine automatic stop conditions.
[0037]
Hereinafter, a procedure for switching the function of the motor generator 12, a processing procedure for performing automatic start, and a procedure for setting the amount of power generation when the motor generator 12 functions as a generator will be described.
[0038]
The electronic control device 16 engages the electromagnetic clutch 19 when the state of charge of the battery 15 is equal to or less than a predetermined amount during vehicle braking and during normal vehicle travel, and the motor generator 12 functions as a generator. Thus, the inverter 14 is controlled. As a result, the motor generator 12 is drivingly connected to the engine output shaft 11 and the battery 15 is charged.
[0039]
On the other hand, when it is necessary to operate various auxiliary machines 22 such as an air conditioner during the period when the operation of the internal combustion engine 10 is stopped due to the automatic stop process, the electronic control unit 16 opens the electromagnetic clutch 19. At the same time, the inverter 14 is controlled so that the motor generator 12 functions as an electric motor. As a result, the motor generator 12 is disconnected from the drive output from the engine output shaft 11, and the various auxiliary machines 22 are operated by the driving force of the motor generator 12.
[0040]
Further, when the vehicle is started in response to the depression of the accelerator pedal by the driver during the period in which the operation of the internal combustion engine 10 is stopped due to such automatic stop processing, the automatic start processing of the internal combustion engine 10 is performed. Done.
[0041]
FIG. 2 is a flowchart showing a processing procedure for the automatic start control. The series of processes shown in this flowchart is executed on condition that the operation of the internal combustion engine 10 is stopped by the engine automatic stop process.
[0042]
In this series of processing, it is first determined whether or not an engine automatic start condition is satisfied (step 100). Here, for example,
-When the shift position of the automatic transmission 28 is in the drive range, the brake pedal is released and the accelerator pedal is pressed (when the vehicle starts)
When the brake pedal is released and the specified time has elapsed since the release when the shift position is in the drive range
・ When a predetermined time has elapsed after the shift position has been operated from the parking or neutral range to any other shift position.
・ When the vehicle running speed is higher than the specified speed
It is determined that the engine automatic start condition is satisfied when at least one of the various conditions is satisfied. It should be noted that various other conditions may be appropriately added or replaced as the engine automatic start conditions. Here, when the engine automatic start condition is not satisfied (step 100: NO), this series of processing is temporarily terminated. That is, in this case, the engine automatic start process is not performed.
[0043]
On the other hand, when the engine automatic start condition is satisfied (step 100: YES), the engine automatic start process is executed (step 110). In this process, the electronic control unit 16 engages the electromagnetic clutch 19 and rotates the motor generator 12 when the depression of the brake pedal is released, so that the rotational speed of the engine output shaft 11 is the target during idle operation. The rotational speed is increased so as to be close to the rotational speed. Next, the electronic control unit 16 starts the fuel injection signal and the ignition signal by outputting them to the internal combustion engine 10. When the engine speed is increased by the engine automatic starting process and the internal combustion engine 10 starts a self-sustaining operation, the electronic control unit 16 determines this and generates power by the motor generator 12 based on the state of charge of the battery 15 or the like. To start. At the time of this power generation, the electronic control unit 16 controls the power generation amount of the motor generator 12 by outputting a voltage command value to the inverter 14 and matching the power generation voltage of the motor generator 12 with this voltage command value.
[0044]
Hereinafter, the control concerning this electric power generation amount is demonstrated. 3 and 4 are flowcharts showing the processing procedure for this power generation amount control. A series of processing shown in this flowchart is repeatedly executed by the electronic control device 16 at predetermined time intervals.
[0045]
In this series of processing, it is first determined whether or not the internal combustion engine 10 has been started, in other words, whether or not the internal combustion engine 10 has started a self-sustaining operation (step 210). Specifically, for example, it is determined that the engine has been started when the engine speed has increased to a predetermined value or more, or when a predetermined time has elapsed since reaching the predetermined value. Here, when the start of the internal combustion engine 10 is not completed (step 210: NO), the power generation by the motor generator 12 is stopped (step 230), and this series of processes is once ended.
[0046]
On the other hand, when the start is completed (step 210: YES), it is determined whether or not an elapsed time T after the start completion is determined is less than a first predetermined time T1 (step 220). . Here, when the elapsed time T after the start is less than the first predetermined time T1 (step 220: YES), the temperature of the engine combustion chamber is low, and the drive resistance in the drive portion of the internal combustion engine 10 is large. Therefore, it is determined that the combustion state of the internal combustion engine 10 is in an unstable state, and therefore fluctuations in the engine rotational speed are likely to occur due to the influence of the load by the motor generator 12, and the power generation of the motor generator 12 is not started yet. Is temporarily terminated.
[0047]
On the other hand, when the first predetermined time T1 or more has elapsed since the start (step 220: NO), the target value (target voltage command value) applied to the voltage command value E based on the state of charge of the battery 15 is determined. ETRG) is calculated (step 235). Here, basically, the smaller the charge amount of the battery 15 is, the larger the voltage command value E is set, and accordingly, the power generation amount is also set larger. However, for example, when so-called refresh processing is performed to prevent a decrease in the charging capacity of the battery 15, the voltage command value E is set to the maximum regardless of the charge amount of the battery 15.
[0048]
Next, it is determined whether or not the elapsed time T after the start is less than a second predetermined time T2 (> T1) (step 240 in FIG. 4). In this determination, the stability of the combustion state of the internal combustion engine 10 is further determined in the same manner as in the process of step 220 above. That is, when the elapsed time T after start is less than the second predetermined time T2 (step 240: YES), it is determined that the combustion state of the internal combustion engine 10 is not yet sufficiently stable. In this case, it is determined whether or not the accelerator switch is “ON”, that is, whether or not the accelerator pedal is depressed (step 260). Depending on the determination result, the voltage command value E Is gradually set to the target voltage command value ETRG (ie, the amount of increase in power generation command value per unit time), in other words, the degree of increase in power generation amount is variably set (step 270, 275).
[0049]
That is, when the accelerator pedal is depressed (step 260: YES), the gradual change amount S is set to a relatively large predetermined value SA (step 270), while the accelerator pedal is not depressed. (Step 260: NO), the gradual change amount is set to a relatively small predetermined value SB (<SA) (step 275).
[0050]
Here, when the accelerator pedal is depressed, the engine load becomes larger and the fuel injection amount also increases than when the accelerator pedal is not depressed, so that the combustion of the internal combustion engine 10 tends to be relatively stable. Is focused on. When the combustion state is relatively stable as described above, it is difficult for fluctuations in the engine rotation speed due to the load of the motor generator 12 to occur, so that the gradual change amount S of the voltage command value E is set to be relatively large. By increasing the rising speed of the voltage command value E, the power generation amount is ensured as much as possible.
[0051]
On the other hand, when the accelerator pedal is not depressed, the engine load is small and therefore the stability of the combustion state of the internal combustion engine 10 is relatively low. If the stability of the combustion state is low in this way, the engine rotational speed fluctuates easily due to the load of the motor generator 12, so the gradual change amount S of the voltage command value E is set to be relatively small. Therefore, the fluctuation of the engine speed is suppressed as much as possible.
[0052]
On the other hand, if the second predetermined time T2 or more has elapsed since the start in step 240 (step 240: NO), the gradual change amount S of the voltage command value E is uniform regardless of depression of the accelerator pedal. Is set to a predetermined value SNML (SNML> SA, or SNML = SA, or SA>SNML> SB) (step 310). That is, here, when the second predetermined time T2 has elapsed since the start, the combustion state of the internal combustion engine 10 is more stable, so the gradual change amount is also greater than when the predetermined time T2 has not elapsed. By setting S to a large value, the rate of increase of the voltage command value E is further increased to ensure a larger amount of power generation.
[0053]
When the gradual change amount S is variably set according to the elapsed time T after start and the depression state of the accelerator pedal through the processing of the above steps 220 to 310, the voltage command value E is then set according to the gradual change calculation formula (E ← E + S) Calculated (step 280). In this equation, the initial value of the voltage command value E is the terminal open voltage of the battery 15.
[0054]
Then, the voltage command value E and the target voltage command value ETRG are compared (step 290), and after so-called guard processing is performed so that the voltage command value E does not exceed the target voltage command value ETRG (step 300). ), This series of processes is temporarily terminated. The voltage command value E variably set in this way is output from the electronic control unit 16 to the inverter 14, whereby the power generation voltage of the motor generator 12 is controlled.
[0055]
FIG. 5 is a timing chart showing an example of how the engine rotational speed NE changes when starting power generation after the engine is started, and how the voltage command value E changes according to the control of the present apparatus. In this timing chart, time t1 indicates the time when the elapsed time T after starting has reached the first predetermined value T1, and time t2 indicates the time when the elapsed time T has reached the second predetermined value T2. Yes. Further, in this timing chart, an example is given in which a relationship of (SNML>SA> SB) is set for the predetermined values SA, SB, and SNML concerning the gradual change amount S.
[0056]
As indicated by the solid line in this timing chart, the accelerator pedal is not depressed after the engine is started and the engine rotational speed NE is maintained at the target rotational speed during idling (see FIG. ) From time t1 to t2), the gradual change amount S of the voltage command value E ((b) in the figure) (the slope of the solid line in FIG. (B)) is set relatively small (S ← SA). Therefore, the sudden increase in the load of the motor generator 12 is suppressed, and the fluctuation of the engine rotational speed NE and the occurrence of vehicle vibration and noise due to the fluctuation are also suppressed.
[0057]
On the other hand, as indicated by the one-dot chain line in the timing chart, when the accelerator pedal is depressed after the engine is started, such as when the vehicle is started, and the engine rotational speed NE increases, the gradual change amount S ( In FIG. 4B, the inclination of the one-dot chain line is set relatively large (S ← SB). Therefore, the increasing speed of voltage command value E is increased, and the power generation amount of motor generator 12 is ensured as much as possible.
[0058]
After the elapsed time T after starting reaches the second predetermined time T2 (after time t2), the gradual change amount S of the voltage command value E is set to be larger regardless of the depression state of the accelerator pedal (S ←). SNML). Therefore, when the second predetermined time T2 or more has elapsed since the start, the power generation amount of the motor generator 12 is further ensured.
[0059]
As described above, according to the present embodiment, the following operational effects can be achieved.
-The magnitude of the engine load that is highly correlated with the combustion stability of the internal combustion engine 10 is determined based on the depression state of the accelerator pedal. Increase per unit time That is, the gradual change amount S of the voltage command value E is variably set so as to increase. For this reason, the gradual change amount S can be set each time to a size commensurate with the combustion stability of the internal combustion engine 10, and at the start of power generation by the motor generator 12, the amount of power generation is suppressed while suppressing fluctuations in the engine rotational speed NE. Can be suitably secured.
[0060]
In addition, since the gradual change amount S of the voltage command value E increases as the elapsed time T after starting of the internal combustion engine 10 increases, the engine combustion chamber temperature and the magnitude of the drive resistance in the drive portion of the internal combustion engine 10 are increased. For example, the gradual change amount S can be set in accordance with the factors that affect the combustion state of the internal combustion engine 10 and that change according to the elapsed time T after starting. Accordingly, the relationship between the elapsed time T after engine startup and the engine combustion stability can be reflected in the setting of the gradual change amount S, and the gradual change amount S can be set more suitably.
[0061]
Further, usually, when the vehicle starts to increase the engine load due to the accelerator pedal being depressed and the engine combustion stability is ensured accordingly, the motor generator 12 functions as an electric motor, and the engine output shaft 11 is driven to rotate. By doing so, the internal combustion engine 10 that has been stopped is automatically started, so that the amount of power generation can be suitably ensured when starting the power generation.
[0062]
[Other Embodiments]
The above embodiment can be implemented by appropriately changing a part of the control procedure as shown in each of the following modified examples.
[0063]
(1) In the above embodiment, when the elapsed time T after starting has not reached the second predetermined time T2, the gradual change amount S is variably set according to the depression state of the accelerator pedal. On the other hand, for example, only when the engine speed NE exceeds the predetermined value NE1, the gradual change amount S is set to the previous predetermined value SA and is made relatively large. Thus, the gradual change amount S may be variably set according to the magnitude of the engine speed NE. When the engine rotation speed increases, the drive portion of the internal combustion engine 10 moves with a larger inertia force, so that the combustion of the internal combustion engine 10 is performed in a stable state, and the engine rotation speed is increased. Fluctuations are less likely to occur. Therefore, according to the above configuration, the gradual change amount S can be suitably variably set according to the relationship between the combustion stability and the engine speed.
[0064]
(2) Further, a part of the processing shown in the flowchart of FIG. 4 can be changed as shown in FIG. 6, for example. That is, as shown in FIG. 6, when it is determined that the accelerator pedal is depressed (step 260), the engine speed NE is further compared with a predetermined value NE1 (step 261), and the engine speed NE is calculated. Only when the predetermined value NE1 is exceeded, the gradual change amount S is set according to both the accelerator pedal depression state and the engine rotational speed NE, such as setting the gradual change amount S to the previous predetermined value SA and making it relatively large. It may be variably set. According to such a configuration, fluctuations in the engine rotation speed can be more reliably suppressed, and generation of vehicle vibration and noise resulting therefrom can be suitably suppressed.
[0065]
(3) Parameters for variably setting the gradual change amount S include, for example, the accelerator pedal depression state, the engine rotational speed NE, and the elapsed time T after starting, for example, the fuel injection amount, the throttle opening, and the intake air. Those having a correlation with the engine load such as the amount or the intake air pressure can be adopted. Specifically, according to the above embodiment, the gradual change amount S is set to be larger as the fuel injection amount and the intake air amount are larger, and as the throttle opening degree and the intake air pressure are larger. An effect can be obtained.
[0066]
(4) The vehicle traveling speed may be adopted as the parameter, and this may be set so that the gradual change amount S increases as the speed increases. When the vehicle is in a running state, even if the combustion state may deteriorate, the rotational driving force is transmitted from the driving force transmission system of the vehicle to the engine output shaft 11 in the reverse direction. A decrease in engine speed due to deterioration is suppressed, and instability of the combustion state is also suppressed. Further, the tendency that the instability of the combustion state is suppressed by transmitting the rotational driving force of the driving force transmission system to the internal combustion engine 10 in this manner becomes more conspicuous as the vehicle traveling speed is higher. Therefore, according to the above configuration, the gradual change amount S can be suitably variably set according to the relationship between the combustion stability of the internal combustion engine and the vehicle traveling speed.
[0067]
(5) A part of the processing shown in the flowchart of FIG. 4 can be changed as shown in the flowchart of FIG. As shown in the figure, in this example, a correction value KS is set based on the elapsed time T after starting, and the gradual change amount S variably set according to the depression state of the accelerator pedal is further corrected using this. (Steps 276 and 277). Here, as shown in FIG. 8, it is desirable that the correction value KS be set to a larger value as the elapsed time T after start-up becomes longer (KS2> KS1). Even if comprised in this way, there can exist an effect according to the said embodiment.
[0068]
(6) Further, in the modified example of (5), the cooling water temperature of the internal combustion engine 10 is adopted as a parameter for setting the correction value KS instead of the elapsed time T after starting, and the same temperature. Is low The correction value KS may be set so that the correction value KS becomes smaller as the time is shorter, in other words, the gradual change amount S becomes smaller. When the cooling water temperature of the internal combustion engine 10 is low, the temperature of the lubricating oil becomes low, and thus the drive resistance in the drive portion of the internal combustion engine 10 increases. In such a situation where the driving resistance is increased, the engine speed NE is likely to fluctuate due to the load of the motor generator 12. According to the above configuration, the relationship between the cooling water temperature and the ease of occurrence of engine speed fluctuation can be reflected in the setting of the gradual change amount S, and this can be set as a more preferable one. Become.
[0069]
(7) Further, in the case of controlling the power generation amount based on the voltage command value as in the above embodiment, in addition to the elapsed time T after start and the engine coolant temperature, for example, the charge amount of the battery 15 The temperature or the degree of deterioration can be used as a parameter when setting the correction value KS.
[0070]
Specifically, the correction value KS is increased so as to increase as the charge amount of the battery 15 increases, as the temperature of the battery 15 increases, and as the degree of deterioration of the battery 15 increases. The correction value KS is set so that the variable S becomes large. When the charge amount of the battery 15 is large, in other words, when the charge margin amount when charging the battery 15 is small, the internal resistance of the battery 15 increases even when the voltage command value output to the motor generator 12 is the same. Therefore, the current flowing through the motor generator 12 is reduced. Similarly, when the temperature of the battery 15 is high or when the deterioration of the battery 15 progresses (when the deterioration degree is large), the internal resistance of the battery 15 increases, so that the current flowing through the motor generator 12 is small. Become. As a result, even if the same voltage command value is output, the load applied from the motor generator 12 to the engine output shaft 11 is reduced, and fluctuations in the engine speed are less likely to occur.
[0071]
Therefore, according to the above-described configuration, even if the ease of occurrence of engine speed fluctuations differs according to the current flowing through the motor generator 12, the gradual change amount S is set to be larger in accordance with this. As a result, the power generation amount of the motor generator 12 can be secured larger. The deterioration degree of the battery 15 can be estimated from, for example, the usage time of the battery 15, in detail from the total charge time and total discharge time, or can be estimated from the rate of decrease of the charge amount with respect to the discharge amount.
[0072]
(8) In addition, the correction value KS increases as the load acting on the engine output shaft 11 from the air conditioner, water pump, power steering hydraulic pump, or the like, that is, the external load of the internal combustion engine increases. small You may make it set this so that it may become. When the external load of the internal combustion engine 10 increases, fluctuations in the engine speed due to an increase in the load of the motor generator 12 tend to occur. According to the above configuration, the gradual change amount S can be suitably set while taking into consideration the influence of such an external load on the fluctuation of the engine rotation speed.
[0073]
(9) Further, in the embodiment and each modified example, the gradual change amount S and the correction value KS are discretely changed between two or three values. On the other hand, for example, as shown in FIG. 9, the gradual change amount S is set according to parameters such as the accelerator pedal operation amount, and the correction value KS is set to the elapsed time T after starting, the coolant temperature, the charge amount of the battery. Further, it can be changed continuously according to parameters such as temperature and degree of deterioration. FIG. 9 shows an example in which the accelerator pedal depression amount ACCP is adopted as an example of the parameter, and the gradual change amount S is continuously changed in accordance with this.
[0074]
(10) Further, when the gradual change amount S and the correction value KS are continuously changed as in the modified example of (9) above, two or more parameters are referred to, and the gradual change amount S is determined according to each of these parameters. Alternatively, the correction value KS may be continuously variably set. FIG. 10 shows a calculation map when the accelerator pedal depression amount ACCP and the engine speed NE are adopted as parameters when the gradual change amount S is variably set, and the gradual change amount S is variably set based on these. Yes.
[0075]
(11) In the above embodiment, the power generation amount of the motor generator 12 is controlled based on the voltage command value E output to the inverter 14. For example, the current value that flows when the power generation amount of the motor generator 12 is generated. Alternatively, control may be performed based on the amount of electric power obtained.
[0076]
(12) In the above embodiment, the power generation by the motor generator 12 is stopped when the elapsed time T after the start is less than the first predetermined time T1, but the power generation is performed after the gradual change amount S is set to be extremely small, for example. Such stop processing can be omitted, for example. According to this configuration, it becomes possible to secure a larger amount of power generation. Further, for example, when the charge amount of the battery 15 is small, power generation is started as early as possible in this way, while when the charge amount is relatively large, the start of power generation is delayed until the engine combustion state is reliably stabilized. Can also be adopted.
[0077]
(13) In the above embodiment, as an aspect of drivingly connecting the engine output shaft 11 and the generator, that is, the rotating shaft 13 of the motor generator 12, a configuration in which these are connected via a belt 21, a chain, or a gear is shown. However, for example, the engine output shaft 11 and the rotating shaft 13 of the motor generator 12 may be directly connected via a clutch.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating a vehicle power generation control device and peripheral devices according to an embodiment.
FIG. 2 is a flowchart showing a processing procedure for engine automatic start processing;
FIG. 3 is a flowchart showing a processing procedure for power generation amount control.
FIG. 4 is a flowchart showing a processing procedure for power generation amount control.
FIG. 5 is a timing chart showing changes in engine speed and voltage command value.
FIG. 6 is a flowchart showing a modification example of processing related to power generation amount control;
FIG. 7 is a flowchart showing a modification example of processing related to power generation amount control;
FIG. 8 is a function map showing the relationship between the elapsed time after startup and the correction value of the gradual change amount in a modified example.
FIG. 9 is a function map showing a relationship between an accelerator depression amount and a gradual change amount in a modified example.
FIG. 10 is a function map showing a relationship between an accelerator depression amount, an engine speed, and a gradual change amount in a modified example.
FIG. 11 is a timing chart showing changes in engine rotation speed and voltage command value.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Engine output shaft, 12 ... Motor generator, 14 ... Inverter, 15 ... Battery, 16 ... Electronic control unit, 19 ... Electromagnetic clutch, 21 ... Belt, 22 ... Various auxiliary machines, 30-39 ... Various Sensor.

Claims (12)

A generator that is drivingly connected to an output shaft of an internal combustion engine for a vehicle, a battery that is charged by the power generation of the generator, and a power generation amount that is predetermined when starting the power generation of the generator during the independent operation of the internal combustion engine In a vehicle power generation control device comprising control means for controlling the generator to gradually increase to a target power generation amount,
The control means variably sets an increase amount per unit time when increasing the power generation amount based on a factor having a correlation with the combustion stability of the internal combustion engine. 2. The vehicle power generation according to claim 1, wherein the control unit detects an engine load as a factor having a correlation with combustion stability of the internal combustion engine, and sets the increase amount per unit time as the engine load is larger. Control device. The vehicle power generation control device according to claim 2, wherein the control means detects at least one of a fuel injection amount, an accelerator operation amount, a throttle opening, an intake air amount, and an intake air pressure as the engine load. The control means detects an engine speed as a factor having a correlation with the combustion stability of the internal combustion engine, and sets the amount of increase per unit time to be larger as the engine speed is higher. A vehicle power generation control device according to claim 1. 5. The control means detects a vehicle travel speed as a factor having a correlation with the combustion stability of the internal combustion engine, and sets the increase amount per unit time to be larger as the vehicle travel speed is higher. The vehicle power generation control device according to any one of the above. The vehicle according to any one of claims 1 to 5, wherein the control means sets the increase amount per unit time that is variably set based on the factor as the elapsed time after starting of the internal combustion engine becomes longer. Power generation control device. The vehicle according to any one of claims 1 to 6, wherein the control means sets the amount of increase per unit time variably set based on the factor as the external load of the internal combustion engine increases . Power generation control device. The vehicle according to any one of claims 1 to 7, wherein the control means sets the amount of increase per unit time variably set based on the factor as the coolant temperature of the internal combustion engine is lower. Power generation control device. The control means controls the power generation amount of the generator based on a voltage command value, and the voltage is set so that the amount of increase per unit time variably set based on the factor increases as the charge amount of the battery increases. The power generation control device for a vehicle according to any one of claims 1 to 8, wherein a command value is set. The control means controls the power generation amount of the generator based on a voltage command value, and the voltage command is set so that the amount of increase per unit time variably set based on the factor increases as the temperature of the battery increases. The power generation control device for a vehicle according to any one of claims 1 to 9, wherein a value is set. The control means controls the power generation amount of the generator based on a voltage command value, and the voltage is set so that the amount of increase per unit time variably set based on the factor increases as the degree of deterioration of the battery increases. The power generation control device for a vehicle according to any one of claims 1 to 10, wherein a command value is set. The power generation control device for a vehicle according to any one of claims 1 to 11,
A power generation control device for a vehicle, further comprising automatic starting means for automatically starting the internal combustion engine when the operation is stopped by causing the generator to function as an electric motor when the vehicle starts to rotationally drive the output shaft.

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