JP4318698B2 - Vehicle power switching control method - Google Patents

Description

  The present invention relates to a vehicle power switching control method for selecting power according to a traveling state in a so-called hybrid vehicle including an electric motor (hereinafter referred to as a motor) and an internal combustion engine (hereinafter referred to as an engine) as power sources. It is.

Conventionally, a motor and an engine are provided, and when the vehicle speed, i.e., the vehicle speed is low, the vehicle is driven by the output of the motor. When the amount of change in the accelerator opening exceeds a predetermined value, that is, the vehicle driver needs There is known a vehicle that travels by using both the output of the motor and the output of the engine when the required torque is large. In such a hybrid vehicle, when the amount of change in the accelerator opening is large, by switching to the combined driving in which the motor and the engine are used together with a small accelerator opening than when the accelerator opening is small, acceleration corresponding to the driver's sudden acceleration intention is achieved. What is implemented is disclosed in Patent Document 1.
Japanese Patent No. 3228438

  By the way, when the vehicle speed is adjusted while loosening the pedal force after the accelerator pedal is suddenly operated during acceleration, the driving state requiring high torque is only for a short period. In such a case, since the driving state at a high torque is for a short period, there is a case where the power can be dealt with only by the output of the motor.

  However, in the case of the above-described Patent Document 1, it is detected that the amount of change in the accelerator opening is large for such rough, that is, rough operation of the accelerator pedal, and switching to combined driving is performed. Control is performed. For this reason, the engine is frequently used, and as a result, fuel consumption may be reduced.

  In addition, this is not a preferable driving state in a vehicle that runs using the output of the motor as power as long as the remaining battery capacity of the storage battery for the motor permits. That is, if the engine is started immediately in response to the rough accelerator pedal operation as described above, the fuel consumption will be reduced by operating the engine despite the operating state that can be handled only by the output of the motor. Become.

  Therefore, the present invention aims to eliminate such problems.

  That is, the vehicle power switching control method according to the present invention includes an electric motor capable of generating electricity and an internal combustion engine. When the required torque requested by the driver is low, the vehicle is driven by the output of the electric motor. During traveling, when the demanded torque exceeding the first torque condition satisfies the first duration condition and is continued, the traveling is switched to traveling using the output of the internal combustion engine as power.

  According to such a configuration, when traveling with the output of the electric motor as power, when the required torque continues while satisfying the first duration condition in a state exceeding the first torque condition, Switching from running with the output of the electric motor to running with the output of the internal combustion engine as power. For this reason, when traveling with the output of the motor as power, even if the required torque is suddenly changed to exceed the first torque condition in order to accelerate the vehicle, the required torque remains in the first duration condition. If it does not continue after satisfying the above, it will not be switched to driving using the output of the internal combustion engine as power. Therefore, since the load is applied to the internal combustion engine only when the driver truly asks for an increase in torque, it is possible to reduce fuel consumption and reduce the amount of unnecessary substances in the exhaust gas. Is possible.

  In order not to reduce the acceleration performance, the vehicle speed does not reach the predetermined speed while the required torque exceeding the second torque condition continues while satisfying the second duration condition during traveling by the output of the electric motor. When it does not exceed, what switches to the driving | running | working which uses the output of an internal combustion engine as motive power is preferable. In such a configuration, when traveling on an uphill, such as when traveling with an electric motor output, is not expected to increase in speed, switching to traveling using the output of the internal combustion engine as power, reflecting the driver's intention It is possible to keep the acceleration performance.

  In addition, to ensure that the driver's intention is reflected in the driving, the requested torque exceeding the third torque condition continues while satisfying the third duration condition during driving by the output of the motor. Regardless, it is preferable to switch to running using the output of the internal combustion engine as power when the acceleration of the vehicle does not exceed a predetermined value.

  In addition, in the above configuration, in order to cope with sudden acceleration, at low vehicle speed, it is preferable to determine whether or not to switch to running using the output of the internal combustion engine as power with lower torque than at high vehicle speed. . Alternatively, when the required torque is low, it is preferable to switch to traveling using the output of the internal combustion engine as power when a longer duration condition is satisfied than when high torque is required.

  In order to set the switching from running by the output of the electric motor to running by the output of the internal combustion engine according to the capacity of the electric motor, when the vehicle speed when the required torque exceeds the second torque condition is high When the required torque exceeds a predetermined value at a low vehicle speed, the second duration condition is shortened, and when the vehicle speed when the required torque exceeds the third torque condition is a high vehicle speed. Is preferably configured such that the acceleration condition is lower than when the required torque exceeds a predetermined value at a low vehicle speed.

  In order to improve fuel efficiency in response to the driver's desire for deceleration, the fourth duration condition is required when the required torque is lower than the fourth torque condition during driving using at least the output of the internal combustion engine as power. When the driving is performed while the output of the internal combustion engine is used as the motive power, the required torque is set to the fifth torque condition during the driving using the output of the internal combustion engine as the motive power. It is preferable to switch from running using the output of the internal combustion engine to running using the output of the motor when the vehicle continues below the fifth duration condition and the vehicle speed falls below a predetermined speed.

  The present invention is configured as described above, and when running with the output of the motor as power, even if the required torque is suddenly changed to exceed the first torque condition to accelerate the vehicle, If the required torque does not continue after satisfying the first duration condition, it will not switch to driving that uses the output of the internal combustion engine as power, so the load is applied to the internal combustion engine only when the driver truly asks for an increase in torque. Further, it becomes possible to suppress the consumption of fuel and to reduce the discharge amount of unnecessary substances in the exhaust gas.

  Embodiments of the present invention will be described below with reference to the drawings.

  The vehicle 100 according to the first embodiment includes a motor generator 1 that is an electric motor capable of generating electric power and an engine 2 that is an internal combustion engine, and travels with driving wheels 3 driven by outputs of the motor generator 1 and the engine 2. It is. Specifically, when the required torque requested by the driver is low, the vehicle 100 travels using the output of the motor generator 1 as power, and the driver operates the accelerator pedal 4 in such traveling to obtain the required torque. When the accelerator pedal 4 is depressed during acceleration or climbing, the required torque is high, and when various conditions described below are satisfied, the engine 2 runs with the output of the engine 2 as power. It is. In each embodiment described below, in consideration of fuel consumption, the engine 2 is stopped when traveling with the output of the motor generator 1 as power. In addition, even if it is a case where it is drive | working using the output of the motor generator 1 as motive power, the driving | operation of the engine 2 may be continued.

  The vehicle 100 includes a motor control unit 5 and an engine control unit 6 to control the operation state of the motor generator 1 and the engine 2, and includes a battery 7, a torque converter 8, a clutch 9, a transmission serving as a power source for the motor generator 1. 10, the transmission control part 11 which controls the transmission 10, and the vehicle control part 12 which controls the driving | running | working state of a vehicle are provided.

  The motor generator 1 also operates as a generator when driven by the engine 2 or the drive wheel 3. Thus, the electric power generated by the motor generator 1 that performs a regenerative operation as a generator is applied to the battery 7 through the motor control unit 5 to charge the battery 7. The motor generator 1 is not particularly limited in form as long as it can generate power.

  As the engine 2, various types well known in the art can be applied, and examples thereof include a gasoline engine and a diesel engine. The engine 2 transmits its output to the drive wheels 3 via the torque converter 8, the clutch 9 and the transmission 10. As the torque converter 8, the clutch 9 and the transmission 10, as well as the engine 2, those widely known in the field can be applied, and the description thereof will be omitted.

  The motor control unit 5, the engine control unit 6, the transmission control unit 11, and the vehicle control unit 12 are each configured mainly with a microcomputer, and can communicate control signals and data with each other. The motor control unit 5 is connected to the battery 7 and the motor generator 1 and controls the motor generator 1 based on the state of the battery 7 and the traveling state of the vehicle 100 and based on a signal from the vehicle control unit. The charge state of the battery 7 is controlled. The engine control unit 6 sets the fuel supply amount based on the engine speed, the intake air amount, the cooling water temperature, and the like, and controls the operating state of the engine 2 based on a signal from the vehicle control unit 12. Based on the signal from the vehicle control unit 12, the transmission control unit 11 transmits the output of the motor generator 1 and the output of the engine 2 to the drive wheel 3 individually or simultaneously according to the traveling state of the vehicle 100. The transmission 10 is controlled.

  The vehicle control unit 12 includes an accelerator signal output from an accelerator sensor 13 that detects an operation amount of the accelerator pedal 4, a brake signal output from a brake sensor 15 that detects an operation amount of the brake pedal 14, and a traveling speed of the vehicle 100 ( Hereinafter, it is referred to as a vehicle speed), and further, the intention of the driver who drives the vehicle and the running state of the vehicle are determined based on acceleration and the like. Based on the determination result, the vehicle control unit 12 exchanges control signals and data with the motor control unit 5, the engine control unit 6 and the transmission control unit 11, and the motor generator via each control unit. 1. The engine 2 and the transmission 10 are controlled. The vehicle control unit 12 is basically configured to switch between the case where the output of the motor generator 1 is used as power and the case where the output of the engine 2 is used as main power depending on the battery capacity.

  That is, the vehicle control unit 12 detects the battery capacity, and outputs a signal to drive the motor generator 1 to the motor control unit 5 while the detected battery capacity exceeds half. When it is detected that the battery capacity has become less than half, the output of the motor generator 1 and the output of the engine 2 are used together until reaching the minimum limit capacity that can be used in terms of battery performance. As described above, signals are output to the motor control unit 5, the engine control unit 6, and the transmission control unit 11. In this way, when the motor generator 1 and the engine 2 are used together, if surplus torque is generated, the vehicle control unit 12 performs charge control so that the battery 7 is charged by regenerative power obtained by the regenerative operation by the surplus torque. Execute.

  In the above configuration, the vehicle control unit 12 controls the motor control unit 5 and the engine control unit 6 based on at least the accelerator signal according to the procedure described below. In this case, since the accelerator signal is a signal that changes in proportion to the amount of operation of the accelerator pedal 4 operated by the driver, a required torque indicating a change in torque due to the driver's request is calculated from the change in the accelerator signal. To do. In the power switching control described below, it is assumed that the vehicle is running with the output of the motor generator 1 as power.

  In the control procedure of the power control switching control program shown in FIG. 2, first, in step S <b> 1, the first torque condition for determining the driver's required torque, and the required torque is in a state exceeding the first torque condition. Each first duration condition for determining that it is continuing is calculated. The first torque condition and the first duration condition are calculated based on, for example, respective maps in which representative values are recorded.

  The first torque condition is calculated and set based on the vehicle speed and the required torque within the range of torque that can be generated by the motor generator 1. Specifically, as shown in FIG. 3, the first torque condition is set so as to decrease as the vehicle speed decreases and increase as the vehicle speed increases. This is because the accelerator pedal 4 is operated at a low vehicle speed, so that the driver's intention is to increase the vehicle speed within a short time, so that quick acceleration can be performed. is there.

  On the other hand, as shown in FIG. 4, the first duration condition is calculated and set so that it is longer as the required torque is lower and shorter as it is higher. This is because the low required torque corresponds to the fact that the amount of operation of the accelerator pedal is small, and it can be determined that the driver does not intend to accelerate quickly. In such an operation state, there is a possibility that the output of the motor generator 1 can cope with this, so that the traveling by the output of the motor generator 1 is continued as much as possible.

  In step S2, it is determined whether the required torque exceeds (exceeds) the first torque condition calculated in step S1. In step S3, whether or not the time during which the required torque exceeds the first torque condition exceeds the first duration condition, that is, the state where the required torque exceeds the first torque condition continues. It is determined whether or not the remaining time exceeds the first duration condition.

  In step S <b> 4, the transmission control unit 11 is controlled so that the output of the engine 2 is transmitted to the drive wheels 3, and the power is switched from the output of the motor generator 1 to the output of the engine 2. In this embodiment, the engine 2 is started immediately before the power switching. In step S5, traveling using the output of the engine 2 as power is performed. In step S6, traveling using the output of the motor generator 1 as power is performed.

  In such a configuration, it is assumed that the driver operates the accelerator pedal 4 when the vehicle 100 travels using the output of the motor generator 1 as power. When the accelerator pedal 4 is operated, the accelerator signal changes, and the vehicle control unit 12 calculates the required torque based on the accelerator signal. Then, step S1 and step S2 are executed, and it is determined whether or not the calculated required torque exceeds the first torque condition. If not, the process proceeds to step S6 and travels using the output of the motor generator as power. maintain. That is, when the driver operates the accelerator pedal 4 but the amount of operation is small, it is assumed that the vehicle speed is not intended to be suddenly increased, and traveling by the output of the motor generator 1 is maintained. is there.

  On the other hand, for example, when the accelerator pedal 2 is largely operated, such as when starting, the required torque increases. If the required torque exceeds the first torque condition, it is estimated that the driver intends to increase the vehicle speed (determination of “N” in step S2). In this case, if the state where the required torque exceeds the first torque condition does not exceed the first duration condition (determination of “N” in step S3), that is, the first duration condition is satisfied. By the time, if the operation state is such that the required torque is equal to or lower than the first torque condition in a short time, the travel by the output of the motor generator 1 is continued assuming that the required torque can be handled by the output of the motor generator 1 (step S6). ). Therefore, even if the required torque increases, the engine 2 remains stopped.

  On the other hand, when the required torque exceeds the first torque condition, and the exceeded condition exceeds the first duration condition (shown in FIG. 5), the traveling from the motor output is started. Switching to traveling by the output of the engine (step S1, step S2, step S3, step S4, step S5). That is, it is estimated that the driver intends to increase the vehicle speed according to the magnitude of the required torque and the duration of the state satisfying the above-described conditions. For this reason, in the case of suddenly increasing the operation of the accelerator pedal 4, that is, in the operation of the accelerator pedal (shown in FIG. 6) such that the required torque exceeds the first torque condition but the state does not continue. The running by the output of the motor generator 1 is continued. Therefore, the execution of the traveling by the output of the engine 2 is delayed as much as possible, thereby reducing the opportunity to operate the engine 2, thereby reducing the fuel consumption and reducing the exhaust gas emission amount. It is possible to suppress the influence on the environment.

  In addition, as described above, the first torque condition is set to be lower as the vehicle speed is lower and higher as the vehicle speed is higher, and the first duration condition is longer and higher as the required torque is lower. Therefore, when the amount of operation of the accelerator pedal is large and the vehicle speed is low, for example, at the time of starting, the vehicle is switched to traveling based on engine output at an early stage. For this reason, when the driver wants to accelerate rapidly, the intention can be realized early. On the other hand, when the accelerator pedal is operated roughly, that is, when the required torque temporarily exceeds the first torque condition and does not satisfy the first duration condition, the output of the engine 2 Since it does not switch to driving by, fuel consumption can be improved.

  Next, a second embodiment will be described with reference to FIG. In the second embodiment, for example, in climbing, the vehicle speed is low and the required torque is large, and the switching from traveling by the output of the motor generator 1 to traveling by the output of the engine 2 is delayed, so that the vehicle speed is difficult to increase. It will be solved. For this reason, in the second embodiment, the second torque condition and the second duration condition are added to the first embodiment, and the power switching is preferably performed in the case of the above-described uphill traveling. Is to implement.

  Specifically, first, in step S11, first and second torque conditions and first and second duration conditions are calculated. The first torque condition and the first duration condition are the same as those in the first embodiment. On the other hand, the second torque condition is set lower than the first torque condition, and after calculating the first torque condition, the second torque condition may be calculated based on the first torque condition. Similarly, the second duration condition is set to be the same as the first duration condition or shorter than the first duration condition, and after calculating the first duration condition, the first duration condition is set. It may be calculated based on time conditions.

  In step S12, it is determined whether or not the required torque exceeds the first torque condition. In step S13, it is determined whether or not the state where the requested torque continues beyond the first torque condition continues beyond the first duration condition. The determinations in steps S12 and S13 are the same as those in steps S1 and S2 in the first embodiment described above.

  In step S14, it is determined whether the required torque exceeds (exceeds) the second torque condition calculated in step S11. In step S15, it is determined whether the vehicle speed after the time point when the required torque exceeds the second torque condition (hereinafter referred to as a determination vehicle speed) exceeds the required speed. The required speed may be set according to the magnitude of the required torque when traveling on flat ground, for example.

  In step S16, it is determined whether or not the time during which the requested torque exceeds the second torque condition exceeds the second duration condition. As shown in FIG. 8, the second duration condition is set so as to be longer when the determination vehicle speed is low and shorter as it is higher, for example, by calculation using a map. In step S <b> 17, the transmission control unit 11 is controlled so that the output of the engine 2 is transmitted to the drive wheels 3, and the power is switched from the output of the motor generator 1 to the output of the engine 2. In this embodiment, the engine 2 is started immediately before the power switching. In step S18, travel using the output of the engine 2 as power is performed. In step S19, traveling using the output of the motor generator 1 as power is performed.

  In such a configuration, for example, when the vehicle speed may not increase as usual even if the accelerator pedal 4 is operated as usual due to a difference in the number of passengers, the first torque condition is not satisfied, When the second torque condition is satisfied and the vehicle speed does not reach the required speed and the second duration condition is satisfied, the driving is switched to the driving using the output of the engine 2 as power. For example, as shown in FIG. 9, let us consider a case where the required torque exceeds the second torque condition before exceeding the first torque condition, and the exceeded state continues beyond the second duration condition. .

  In such a driving state, the control proceeds to step S11, step S12, step S14, and step S19 until the driver operates the accelerator pedal 4 and at least the required torque exceeds the second torque condition. The traveling by the output of the motor generator 1 is continued. Therefore, the motor generator 1 is utilized to the maximum and the fuel consumption is suppressed.

  Thereafter, when the required torque increases and exceeds the second torque condition (determination of “N” in step S14), the vehicle speed at that time, that is, the determination vehicle speed exceeds the required speed (“Y in step S15”). "Determining"), the traveling by the output of the motor generator 1 is continued. In contrast, when the required torque increases and exceeds the second torque condition, the determination vehicle speed is lower than the required speed, and the state where the required torque exceeds the second torque condition satisfies the second duration condition. If the control is continued beyond the control, the control sequentially executes step S11, step S12, step S14, step S15, and step S16, and executes step S17 and step S18 to start the engine 2 from the travel by the output of the motor generator 1. Switch to driving with the output of.

  In this way, if the vehicle speed does not reflect the driver's intention even if the required torque is increased, such as when traveling uphill or when the load (passenger number) is different from usual, the first torque condition In addition, the acceleration can be improved by switching to traveling by the output of the engine without waiting for the establishment of the first duration condition. Therefore, since such a state is canceled before the driver notices that the vehicle speed increases slowly, it is possible to avoid travel that hinders the smooth flow of the vehicle.

  Next, a third embodiment will be described with reference to FIG. In the third embodiment, power switching control is performed using acceleration as a determination condition instead of the determination vehicle speed in the second embodiment described above.

  Specifically, first, in step S21, first and third torque conditions and first and third duration conditions are calculated. The first torque condition and the first duration condition are the same as those in the first embodiment. On the other hand, the third torque condition is set lower than the first torque condition, and may be calculated based on the first torque condition after calculating the first torque condition. Similarly, the third duration condition is set to be the same as or shorter than the first duration condition, and after calculating the first duration condition, the first duration condition is set. It may be calculated based on time conditions.

  In step S22, it is determined whether the required torque exceeds the first torque condition. In step S23, it is determined whether or not the state where the requested torque continues beyond the first torque condition continues beyond the first duration condition. The determinations of step S22 and step S23 are the same as steps S1 and S2 of the first embodiment described above.

  In step S24, it is determined whether or not the required torque exceeds (exceeds) the third torque condition calculated in step S21. In step S25, it is determined whether or not the acceleration after the time when the required torque exceeds the third torque condition (hereinafter referred to as determination acceleration) exceeds the required acceleration. The required acceleration may be set according to the magnitude of the required torque when traveling on flat ground, for example.

  In step S26, it is determined whether or not the time during which the required torque exceeds the third torque condition exceeds the third duration condition. The third duration condition has the same tendency as the second duration condition described above. In step S <b> 27, the transmission control unit 11 is controlled so that the output of the engine 2 is transmitted to the drive wheels 3, and the power is switched from the output of the motor generator 1 to the output of the engine 2. In this embodiment, the engine 2 is started immediately before the power switching. In step S28, traveling using the output of the engine 2 as power is performed. In step S29, traveling using the output of the motor generator 1 as power is performed.

  Even in such a configuration, the same operational effects as those of the second embodiment described above can be obtained.

  That is, for example, when climbing up, when the vehicle speed may not increase even if the accelerator pedal 4 is operated, the first torque condition is not satisfied, but the third torque condition is satisfied and the determination acceleration is required. When the third duration condition is satisfied without reaching the acceleration, the driving is switched to the driving using the output of the engine 2 as power.

  In such a driving state, the control proceeds to step S21, step S24, and step S29 until the driver operates the accelerator pedal 4 and at least the required torque exceeds the third torque condition. Continue running with an output of 1. Therefore, the motor generator 1 is utilized to the maximum and the fuel consumption is suppressed.

  Thereafter, when the required torque increases and exceeds the third torque condition (determination of “N” in step S24), the vehicle speed at that time, that is, the determination vehicle speed exceeds the required speed (“Y” in step S25). "Determining"), the traveling by the output of the motor generator 1 is continued. In contrast, when the required torque increases and exceeds the third torque condition, the determination vehicle speed is lower than the required speed, and the state where the required torque exceeds the third torque condition satisfies the third duration condition. If it continues beyond the control, the control executes step S21, step S22, and steps S24 to S26 in order, and executes step S27 and step S28 to travel from the output from the motor generator 1 to the travel from the output of the engine 2. Switch to.

  In this way, if acceleration does not reflect the driver's intention even if the required torque is increased, as in uphill running, without waiting for the first torque condition and the first duration condition to be satisfied. Acceleration can be improved by switching to running with engine output. Therefore, since such a state is canceled before the driver notices that the vehicle speed increases slowly, it is possible to avoid travel that hinders the smooth flow of the vehicle.

  The fourth embodiment shown in FIGS. 12 and 13 has a configuration in which the first to third embodiments described above are integrated. That is, when switching from traveling using the output of the motor generator 1 to traveling using the output of the engine 2 as power, the first to third torque conditions, the first to third duration conditions, the vehicle speed and the acceleration Each condition is judged.

  Specifically, step S31, step S32, and step S33 correspond to step S1, step S2, and step S3 of the first embodiment. In step S34, in response to the determination result in step S33, the first power switching flag is set (= 1). In step S35, the first power switching flag is reset (= 0). Steps S31 to S35 correspond to the control of the first embodiment described above. In the first embodiment, the power is switched based on the establishment of the first duration condition. However, the fourth embodiment is configured to control a flag indicating whether or not to execute power switching.

  Similarly, steps S36 to S41 correspond to the control of the second embodiment. Specifically, step S36, step S37, step S38, and step S39 correspond to step S11, step S12, step S13, and step S14 of the second embodiment. Then, in response to the determination result in step S39, the second power switching flag is set (= 1). In step S35, the second power switching flag is reset (= 0).

  Steps S42 to S47 correspond to the control of the third embodiment. That is, step S42, step S43, step S44, and step S45 correspond to step S21, step S22, step S23, and step S24 of the third embodiment. Then, in response to the determination result of step S46, the third power switching flag is set (= 1). In step S47, the third power switching flag is reset (= 0).

  In step S48, it is determined whether any of the first power switching flag, the second power switching flag, and the third power switching flag is set. If there is a power switching flag that is set, the process proceeds to step S49 where the power for traveling is switched from the output of the motor generator 1 to the output of the engine 2 so far. On the other hand, if none of the power switching flags are set, that is, if all the power switching flags are reset, the process proceeds to step S51, and the travel using the output of the motor generator 1 as power is continued.

  In such a configuration, for example, when the amount of operation of the accelerator pedal 4 is large, the required torque exceeds the first torque condition, and the state continues beyond the first duration condition, that is, the driver quickly In a traveling state where it is desired to increase the vehicle speed, the control executes steps S31 to S34 and sets the first power switching flag. Accordingly, since one of the power switching flags, that is, the first power switching flag is set in step S48, step S49 and step S50 are executed thereafter, and the output of the engine 2 from the travel by the output of the motor generator 1 is executed. Switch to driving by.

  Similarly, when the second power switching flag or the third power switching flag is set according to the operation state of the accelerator pedal 4 of the driver, the vehicle speed, and the acceleration, the timing of the power switching flag is set. Switching from traveling by the output of the motor generator 1 to traveling by the output of the engine 2 is performed. Since the change in the required torque when the second power switching flag and the third power switching flag are set is the same as that in the power switching in the second embodiment and the third embodiment described above, the description is omitted. To do.

  According to such a structure, the effect | action and effect in each embodiment mentioned above are exhibited.

  What will be described below is power switching control when traveling using the output of the engine 2 as power.

  In the fifth embodiment, the driver operates the accelerator pedal 4 after switching from traveling by the output of the motor generator 1 to traveling by the output of the engine 2 described in the first to fourth embodiments. When the operation for decreasing the power is performed, the power is switched when it is estimated that the operation of the accelerator pedal 4 surely reflects the intention of the driver.

  First, in FIG. 14, in step S61, the fourth torque condition and the fourth duration condition are calculated. The fourth torque condition may be the same as the first torque condition described above. Alternatively, the fourth torque condition may be higher than the first torque condition. The fourth torque condition and the fourth duration condition may have the same tendency as the setting of the first torque condition and the first duration condition described above. In step S62, it is determined whether or not the required torque is lower than the fourth torque condition. In step S63, it is determined whether or not the requested torque that has fallen below the fourth torque condition has continued beyond the fourth duration condition in that state.

  In step S64, the transmission control unit 11 is controlled so that the output of the motor generator 1 becomes power. In step S65, traveling using the output of the motor generator 1 as power is performed. In step S66, traveling by the output of the engine 2 is continued. Note that when the power is switched from the output of the engine 2 to the output of the motor generator 1 by controlling the transmission control unit 11, the engine 2 continues to operate in idling operation without stopping, or stops at the time of switching. Any of them may be adopted.

  In such a configuration, for example, when the accelerator pedal 4 is operated by acceleration or the like and traveling by the output of the engine 2 is performed, the required torque falls below the fourth torque condition by returning the accelerator pedal 4. In the case where the current state continues beyond the fourth duration condition, it is estimated that the driver actually intends to reduce the required torque, and the power is switched. That is, in such an operating state, the control sequentially executes Steps S61 to S63, the required torque is lower than the fourth torque condition, and the state continues exceeding the fourth duration condition. ("Y" in step S63), step S64 and step S65 are executed to switch to running based on the output of the motor generator 1.

  On the other hand, when the operation of temporarily returning the accelerator pedal 4 is performed, the traveling by the output of the engine 2 is continued if the time during which the accelerator pedal 4 is returned is shorter than the fourth duration condition. Is. That is, even if it is determined that the required torque has fallen below the fourth torque condition (“N” in step S62), the lower state, that is, the lower time is equal to or less than the fourth duration condition (step S63). If "N"), it is determined that the driver does not actually intend to decrease the required torque, and the power is not switched.

  In this way, when the driver decreases the required torque, the magnitude of the required torque, the torque condition for the required torque (fourth torque condition), and the time condition (fourth duration condition) are satisfied. Only in this case, it is assumed that the driver really intends to reduce the required torque, and the power is switched. Therefore, it is possible to reliably suppress a problem that the power is frequently switched every time the accelerator pedal 4 is operated. . Therefore, fuel consumption can be reduced.

  Next, as in the fifth embodiment described above, in order to accurately estimate the driver's intention to decelerate in the case of performing power switching control when traveling using the output of the engine 2 as power, the vehicle speed An example in which is added to the determination condition for power switching will be described. According to the sixth embodiment, the driver is decelerating when the required torque is reduced by the operation of returning the accelerator pedal 4 or by further operating the brake pedal 14 after the operation. Therefore, the necessity of returning to traveling based on the output of the motor generator 1 can be determined more accurately than in the fifth embodiment described above.

  Specifically, as shown in FIG. 15, in step S71, a fifth torque condition, a required vehicle speed, and a fifth duration condition are calculated. The calculation itself may be the same as the corresponding one in the second embodiment described above. The next step S72 and step S73 correspond to step S62 and step S63 in the fifth embodiment.

  In step S74, it is determined whether or not the vehicle speed when the required torque is lower than the fifth torque condition, that is, the determination vehicle speed is equal to or lower than the required vehicle speed. Step S75, step S76, and step S77 correspond to step S, step S66, step S64, and step S65 in the fifth embodiment.

  In such a configuration, the traveling by the output of the engine 2 is continued until the required torque falls below the fifth torque condition (step S71, step S72, step S75). If the required torque falls below the fifth torque condition, but the lower state does not satisfy the fifth duration condition, i.e. does not continue above the fifth duration condition, the lower state is the fifth duration. In the case where the condition is satisfied but the determination vehicle speed exceeds the necessary vehicle speed, the traveling by the output of the engine 2 is continued (steps S71 to S74 and step S75).

  When the state where the required torque is lower than the fifth torque condition satisfies the fifth duration condition and the determination vehicle speed is equal to or lower than the required vehicle speed, the travel from the output of the engine 2 to the output of the motor generator 1 It switches to driving | running | working (step S71-step S74, step S76, step S77).

  Thus, by determining the determination vehicle speed when the required torque is lower than the fifth torque condition, it is reliably determined that the vehicle is in a deceleration state, and the required torque is the fifth torque condition. It is possible to distinguish the case where the driver is not actively decelerating although it is lower than. For this reason, when the driver really intends to decelerate, the power is quickly switched to the output of the motor generator 1, so that the fuel consumption can be reduced.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The structure explanatory view of the vehicle in the embodiment of the present invention. The flowchart which shows the control procedure of the embodiment. Action explanatory diagram of the same embodiment Action explanatory diagram of the same embodiment Action explanatory diagram of the same embodiment Action explanatory diagram of the same embodiment The flowchart which shows the control procedure of 2nd embodiment of this invention. Action | operation explanatory drawing of the 2nd embodiment. Action | operation explanatory drawing of the 2nd embodiment. The flowchart which shows the control procedure of 3rd embodiment of this invention. The action explanatory view of the third embodiment. The flowchart which shows the control procedure of 4th embodiment of this invention. The flowchart which shows the control procedure of 4th embodiment. The flowchart which shows the control procedure of 5th embodiment of this invention. The flowchart which shows the control procedure of 6th embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Motor generator 2 ... Engine 5 ... Motor control part 6 ... Engine control part 11 ... Transmission control part 12 ... Vehicle control part

Claims (9)

In a vehicle that includes a motor capable of generating electricity and an internal combustion engine, and travels with the output of the motor as power when the required torque required by the driver is low,
A power switching control method for a vehicle that switches to traveling using the output of an internal combustion engine as motive power when a required torque exceeding a first torque condition continues while satisfying a first duration condition during traveling by the output of an electric motor.   The output of the internal combustion engine when the vehicle speed does not exceed the predetermined speed even though the required torque exceeding the second torque condition continues while satisfying the second duration condition during traveling by the output of the electric motor. The vehicle power switching control method according to claim 1, wherein the vehicle is switched to traveling using power.   An internal combustion engine when the acceleration of the vehicle does not exceed a predetermined value while the required torque exceeding the third torque condition continues while satisfying the third duration condition during traveling by the output of the electric motor. The vehicle power switching control method according to claim 1, wherein the vehicle is switched to running using the output of the vehicle as power.   4. The vehicle power switching control method according to claim 1, wherein whether or not to switch to running using the output of the internal combustion engine as power at low vehicle speed is determined by lower torque than at high vehicle speed.   4. The vehicle power switching control method according to claim 1, wherein when the required torque is low, the vehicle is switched to traveling using the output of the internal combustion engine as power when a longer duration condition is satisfied than when high torque is required. .   The second duration condition is made shorter when the vehicle speed when the required torque exceeds the second torque condition is a high vehicle speed than when the required torque exceeds a predetermined value at a low vehicle speed. The vehicle power switching control method according to 4 or 5.   When the vehicle speed when the required torque exceeds the third torque condition is a high vehicle speed, the acceleration condition is set to a lower acceleration than when the required torque exceeds a predetermined value at a low vehicle speed. 5. The vehicle power switching control method according to 5.   During traveling using at least the output of the internal combustion engine as a power source, when the required torque is lower than the fourth torque condition and the fourth duration time condition is satisfied and the motor continues from the traveling using the output of the internal combustion engine as the power source The vehicle power switching control method according to any one of claims 1 to 7, wherein the vehicle is switched to traveling based on the output of the vehicle.   During traveling using at least the output of the internal combustion engine as a motive power, when the required torque falls below the fifth torque condition and continues with the fifth duration condition being satisfied, and the vehicle speed falls below a predetermined speed, the internal combustion engine The power switching control method for a vehicle according to any one of claims 1 to 7, wherein the driving is switched from driving using the output as power to driving using the output of the electric motor.

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