JP6173004B2 - Vehicle control device - Google Patents

Description

  The present invention includes an idling stop control means for automatically stopping the engine when a predetermined automatic stop condition is satisfied, a power storage means for storing and supplying electric power necessary for the vehicle, and generating electric power by the driving force of the engine. The present invention relates to a vehicle control device including a power generation unit that charges the power storage unit, and a prohibiting unit that prohibits automatic stop of the engine by the control unit when the storage amount of the power storage unit falls below a predetermined amount.

  Conventionally, a so-called idling stop vehicle starts an engine by an IG (ignition) on operation, and thereafter executes idling stop control until the engine stops by an IG off operation, and a predetermined automatic stop condition is satisfied. The engine is automatically stopped and the engine is automatically restarted when a predetermined restart condition is satisfied.

  In vehicles equipped with this kind of idling stop control function, the starter is driven by the discharge power of the in-vehicle battery, the engine is restarted, the alternator is driven by the driving force of the engine to generate electricity, and the in-vehicle battery is charged. Therefore, the in-vehicle battery is frequently charged and discharged, and is used in a very severe environment. In particular, when the temperature of the battery is low (for example, 10 ° C. or lower), the charging performance of the battery is lowered. Therefore, in order to ensure the durability performance of the battery, it is necessary to take a long charging time.

  On the other hand, a predetermined amount (for example, 90%) determined in advance from a state in which SOC (State Of Charge) indicating the ratio of the remaining amount with respect to the capacity at the time of full charge, which is an index of the storage state of the battery, is 100% due to battery discharge Since it may become difficult to restart the engine when it falls below the limit, it is also considered that the idling stop is prohibited and the engine does not automatically stop to maintain the battery durability performance (Patent Document) 1).

JP 2000-192830 A (paragraphs 0004, 0007, 0010, etc.)

  However, in the apparatus described in Patent Document 1 described above, when control is performed to increase the charging time when the battery temperature is low, the SOC is less than a predetermined amount, and automatic engine stop by idling stop is prohibited. Although the battery is charged by the alternator, since the temperature of the battery is low, the charging time of the battery becomes longer than when the battery is not low. At this time, since the charging of the battery is continued until the SOC is restored to a specified amount (for example, 100%), the prohibition state of the automatic engine stop by the idling stop is continued while the charging of the battery is continued. As a result, the prohibition time of the engine automatic stop due to idling stop becomes longer, and the opportunity of the engine automatic stop due to idling stop decreases, and there is a possibility that the fuel consumption cannot be improved.

  An object of the present invention is to make it possible to prevent as much as possible a decrease in the chance of automatically stopping an engine for improving fuel efficiency while ensuring the durability performance of a power storage means.

In order to achieve the above-described object, the vehicle control device of the present invention includes an idling stop control unit that automatically stops the engine when a predetermined automatic stop condition is satisfied, and a power storage unit that stores and supplies necessary power to the vehicle. Power generation means for generating electric power by the driving force of the engine and charging the power storage means to the power storage means, and the idling stop control means by the idling stop control means when the power storage amount of the power storage means falls below a predetermined amount. In a vehicle control device including a prohibiting unit that prohibits automatic engine stop, an acquiring unit that acquires an ambient temperature of the power storage unit, the ambient temperature by the acquiring unit is equal to or lower than a predetermined temperature, and When the variable control condition that the automatic stop of the engine by the prohibiting means is prohibited is satisfied, the variable control condition is not satisfied. And a power generation control means for variably controlling the power generating means to increase the generated voltage of the power generator than in the power generation control unit has been preset on the basis of the generated voltage of the ambient temperature and the power generating means The power generation means is variably controlled according to the generated voltage for a set time (claim 1).

Further, the power generation control unit, the variable control of the power generating means may be set an upper limit in accordance with the state of the vehicle (claim 2).

  According to the first aspect of the present invention, the engine is controlled by the prohibiting means when the ambient temperature of the power storage means acquired by the acquisition means is lower than a predetermined temperature and the power storage amount of the power storage means falls below a predetermined amount. When the variable control condition that the automatic stop of the engine is prohibited is satisfied, the power generation control means variably controls the power generation means so that the power generation voltage of the power generation means becomes higher than when the variable control condition is not satisfied. While the automatic stop of the engine due to the stop is prohibited, the power storage means is charged in a state where the power generation voltage of the power generation means is controlled to be high, and the time until the power storage amount of the power storage means recovers from a predetermined amount or less Can be shortened compared with the case where the power generation voltage is not raised high, and the opportunity to automatically stop the engine to improve fuel consumption can be prevented as much as possible.

  Accordingly, it is possible to shorten the duration of the state in which the engine is automatically stopped due to idling stop while ensuring the durability performance of the power storage means, and it is possible to prevent deterioration of fuel consumption without increasing the power generation voltage.

Further, when the ambient temperature of the charge reservoir means is below a predetermined temperature, the amount specified in the state where the storage amount of the storage means is lowered to a predetermined amount (e.g., 100%) charging time required to recover, ambient temperature The lower the voltage is, the longer the voltage is, and even when the ambient temperature is the same, the lower the charging voltage of the power storage means, the longer the power is. Therefore, based on the ambient temperature of the power storage means and the power generation voltage (charge voltage) of the power generation means, The set time for variably controlling is set by mapping it and storing it in the storage unit, etc., and the generated voltage (charge voltage) corresponding to the current ambient temperature of the power storage means acquired by the acquisition means and the set time are mapped The power generation control means is variably controlled by the power generation control means so that the power generation voltage is set to the read set time and the power generation voltage. The time the stop is prohibited can be as short as possible, yet the raise wasteful power generation voltage can be further prevented.

  In addition, if the generated voltage is increased too much, the life of the vehicle headlamp will be shortened, and the wiper will operate at a higher speed. Therefore, the generated voltage such as the life of the headlamp and the operating speed of the wiper will be increased. It is desirable to set an upper limit on the generated voltage so that the operation of the electrical components of the vehicle will not be affected by the excess. Furthermore, when the vehicle is traveling in a high load state, for example, when the accelerator is fully open, it is better to suppress the power consumption of the entire vehicle as much as possible in order to reduce the workload of the power generation means and suppress the engine load. Therefore, it is desirable to set an upper limit so as not to increase the power generation voltage (charging voltage) of the power generation means for charging even when the power storage means is being charged.

Therefore, as in the invention according to claim 2 , the power generation control means sets the upper limit according to the state of the vehicle to the generated voltage in the variable control of the power generation means, so that the operation of the electrical components of the vehicle, the running state, etc. This can prevent the performance of the vehicle from being affected.

It is a block diagram of one embodiment of a control device for vehicles of the present invention. 2 is a timing chart for explaining the operation of FIG. 1.

  Next, an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the idling stop vehicle 1 has one battery 2 having a relatively small capacity of 12 V, which is a power storage means in the present invention, in order to reduce weight, size, and the like. The negative terminal is connected to the body of the idling stop vehicle 1.

  The engine 3 as a drive source of the idling stop vehicle 1 has a transmission-side CVT 4, and a torque converter (including a lock-up clutch mechanism) 5 is interposed between the CVT 4 and the engine 3.

  The engine 3 is started by a starter 6. The starter 6 is supplied with power from the battery 2 via a relay 7 and generates a driving force for starting the engine 3. Further, a battery sensor 8 provided close to the battery 2 between the positive electrode terminal of the battery 2 and the relay 7 causes the temperature (atmosphere temperature), voltage, and current detection signals of the battery 2 to be sent to an engine control unit described later. The rotational force of the engine 3 is transmitted to the alternator 9, which is a generator corresponding to the power generation means in the present invention, via the belt 10, and the battery 2 is charged by the power generation output of the alternator 9 while the vehicle is running. Is called. The above-described battery sensor 8 corresponds to an acquisition unit in the present invention. The temperature of the battery 2 may be an outside air temperature or may be estimated from the outside air temperature. That is, the acquisition means described above is not limited to that provided close to the battery 2.

  Further, as shown in FIG. 1, the idling stop vehicle 1 is provided with an idling stop control unit (corresponding to idling stop control means in the present invention) 11 formed by an ECU for idling stop control, and an ECU for engine control is provided. An engine control unit 12 to be formed, a brake control unit 13 formed by a vehicle stability control (VSC) ECU for skid control, and a CVT control unit 14 formed by an ECU for CVT (Continuously Variable Transmission) control are provided. -14 are each formed by a microcomputer or the like, and exchange information via a communication bus 16 such as CAN.

  Then, the idling stop control unit 11 has a predetermined engine automatic stop condition in which the deceleration is less than a predetermined value (for example, the stop lamp is lit and is not more than a predetermined vehicle speed and less than a predetermined deceleration, etc. Is confirmed, the engine stop command is output to the engine control unit 12 when the vehicle speed is reduced to a predetermined vehicle speed or less (for example, 7 km / h or less) even if the travel is not completely stopped. Is automatically stopped. Subsequently, when the driver removes his foot from the brake pedal in the automatic stop state, it is confirmed by the idling stop control unit 11 that a predetermined engine restart condition is satisfied, and the stopped engine 3 is automatically restarted. The

  Further, as shown in FIG. 1, a vehicle speed sensor 17 that detects the vehicle speed and gives the vehicle speed information to the brake control unit 13 is provided, and the brake control unit 13 detects detection information of the master cylinder pressure (brake hydraulic pressure) of the brake mechanism. Is provided, and the dashboard is provided with a display unit 19 formed by a combination meter. Various display data received via the communication bus 16 are displayed on the display unit 19. Yes.

  Furthermore, a signal corresponding to the lighting state of the headlamp is sent from the headlamp switch 20 for setting on / off of the headlamp of the idling stop vehicle 1 and switching between high beam and low beam to the idling stop control unit 11 via the communication bus 16. In addition to the output, the wiper switch 21 for switching the wiper on / off and switching between low speed, high speed, and intermittent outputs a signal corresponding to the operation state of the wiper to the idling stop control unit 11 via the communication bus 16. .

  By the way, the engine control unit 12 decreases the SOC, which is an index indicating the storage state (storage amount) of the battery 2, from a predetermined amount (for example, 100%) to a predetermined amount (for example, 90%) or less. When the SOC has decreased below a predetermined amount, control is performed to prohibit this even if the automatic stop condition of the engine 3 is satisfied. Such an engine automatic stop prohibition control function of the engine control unit 12 corresponds to the prohibition means in the present invention.

  Further, the ambient temperature of the battery 2 detected by the battery sensor 8 is taken in by the engine control unit 12, and the ambient temperature at that time is equal to or lower than a predetermined temperature (for example, 10 ° C.), and the battery 2 is under a predetermined amount (90%) or less, and automatic stop of the engine 3 is prohibited, it is determined that the variable control condition is satisfied, and the engine control unit 12 causes the alternator 9 that is a generator to The alternator 9 is variably controlled, for example, by controlling the excitation current of the rotor coil so that the generated voltage is increased as compared with the case where the variable control condition is not satisfied. Specifically, the generated voltage of the alternator 9 satisfies the variable control condition. It is variably controlled to a high voltage in the range of 13.0 V to 15.5 V, which is higher than 12.5 V in the normal case. Such a variable control function of the alternator 9 by the engine control unit 11 corresponds to the power generation control means in the present invention.

  At this time, when the ambient temperature of the battery 2 by the battery sensor 8 is equal to or lower than a predetermined temperature (10 ° C.), the SOC (storage amount) of the battery 2 is reduced from a predetermined amount, for example, 100% to a predetermined amount, for example, 90%. The charging time required until the SOC is restored to the specified amount (100%) is longer as the ambient temperature of the battery 2 is lower, and is longer as the charging voltage of the battery 2 is lower even at the same ambient temperature. Become.

  Therefore, for example, when the generated voltage is changed by 0.5 V from 13.0 V to 15.5 V, the SOC of the battery 2 is changed from 90% to 100 when the ambient temperature is different by 2 ° C. from 0 ° C. to 10 ° C. The time required for recovery to% is experimentally obtained in advance as the set time in the present invention, and this is mapped and stored in the ROM or RAM incorporated in the engine control unit 12 or the external ROM or RAM. Store it in the department.

  For example, since the life of the headlamp is shortened if it continues to be lit when the power generation voltage of the alternator 9 is 15 V or higher, the power generation voltage of the alternator 9 is preferably less than 15 V. Since the operation speed increases when the voltage is 14 V or higher, it is generally desirable that the power generation voltage of the alternator 9 is less than 14 V.

  Therefore, based on signals from the headlamp switch 20 and the wiper switch 21, the engine control unit 11 determines whether the headlamp is lit and whether the wiper is operating, and only the headlamp is lit. If so, 15V is set as the upper limit value when the power generation voltage of the alternator 9 is variably controlled. If the wiper is in operation, 14V is set as the upper limit value when the power generation voltage of the alternator 9 is variably controlled. Control that does not affect the operation of electrical components such as headlamps and wipers is performed.

  Then, the engine controller 12 reads and reads the set time corresponding to the current ambient temperature of the battery 2 at the generated voltage less than the upper limit set as described above from the map of the storage unit described above. The alternator 9 is variably controlled by the engine control unit 12 so that the generated voltage is within the range of 13.0 V to 15.5 V, which is higher than the normal 12.5 V, so that the generated voltage becomes the set voltage for the set time. Such a variable control function of the power generation voltage of the alternator 9 by the engine control unit 12 corresponds to the power generation control means in the present invention.

  Thus, for example, as shown by the solid line in FIG. 2A, when the SOC (charged amount) of the battery 2 falls below a predetermined amount (90%), idling is performed as shown by the solid line in FIG. If the engine controller 12 prohibits the engine 3 from being automatically stopped by the stop controller 11, and the ambient temperature of the battery 2 at this time is higher than a predetermined temperature of 10 ° C., the solid line in FIG. In addition, the engine control unit 12 controls the power generation voltage of the alternator 9 to the normal 12.5 V to charge the battery 2, and as shown in FIG. ), The prohibition of the automatic stop of the engine 3 is released.

  However, as described above, when the automatic stop of the engine 3 by the idling stop control unit 11 is prohibited by the engine control unit 12, if the ambient temperature of the battery 2 by the battery sensor 8 is equal to or lower than a predetermined temperature (10 ° C.). Since the variable control condition is satisfied, as shown by the broken line in FIG. 2 (c), the engine control unit 12 causes the generator 9 to generate a higher voltage than 12.5V in the normal case where the variable control condition is not satisfied. For example, when the alternator 9 is variably controlled to 15.5 V, the time required for the SOC of the battery 2 to recover to the specified amount (100%) is short as shown by the broken line in FIG. Thus, it returns to the specified amount (100%) earlier than in the case of the normal power generation voltage indicated by the solid line in FIG. Will be shortened T time than the time the automatic stop of the engine 3 by the ring stop control unit 11 is inhibited by the engine control unit 12 of the solid line in FIG. (B).

  Next, the idling stop operation of the idling stop vehicle 1 having the above-described configuration will be briefly described. When the driver commands an engine start by turning on an IG key (not shown), an IG on signal is, for example, Input to the idling stop control unit 11 from the communication bus 16, and based on this input, the idling stop control unit 11 instantaneously energizes the relay 7 to turn it on, and powers the battery 2 to the starter 6 to start the starter 6. Then, the stopped engine 3 is started (initial start). When the engine 3 is started and the battery 2 is once fully charged with the power generated by the alternator 9, the idling stop control unit 11 thereafter performs idling stop control until the engine 3 is stopped by turning off the IG key. Execute.

  The idling stop control unit 11 includes information on the engine control unit 12 (engine information such as engine speed and cooling water temperature), information on the current and temperature of the battery 2, and the brake control unit 13 via the communication bus 16. , Information on the vehicle speed detected by the vehicle speed sensor 17 and the master cylinder pressure by the hydraulic pressure sensor 18, information on switches in various parts of the vehicle such as a stop lamp switch and a courtesy switch (not shown), and the like are input.

  Based on this information, the idling stop control unit 11 during idling stop control confirms that the driver depresses the brake pedal according to the red signal of the traffic signal, and the master cylinder pressure is equal to or higher than the predetermined depressing pressure. When detected, the vehicle travels by confirming that a predetermined engine automatic stop condition for idling stop control (for example, a condition that the stop lamp is lit (the brake fluid pressure is equal to or higher than the predetermined pressure) and the vehicle speed is equal to or lower than the predetermined vehicle speed) is satisfied If the vehicle speed drops below a predetermined vehicle speed (for example, 7 km / h or less) during traveling even if the vehicle does not stop completely, an engine stop command is output to the engine control unit 12, and the engine control unit 12 throttles the fuel throttle. The engine 3 is automatically stopped.

  At this time, if the ambient temperature of the battery 2 by the battery sensor 8 is equal to or lower than a predetermined temperature (10 ° C.) and the SOC of the battery 2 is equal to or lower than a predetermined amount (90%), the engine control unit 12 controls the variable control condition. Therefore, the automatic stop of the engine 3 due to the idling stop described above is prohibited, the drive of the engine 3 is continued, the power generation state of the alternator 9 is maintained, and the battery 2 is continuously charged.

  Further, during the prohibition of the automatic stop of the engine 3, the alternator 9 is variably controlled by the engine control unit 12 in order to increase the power generation voltage of the alternator 9 as a generator as compared with the case where the variable control condition is not satisfied. At this time, based on signals from the headlamp switch 20 and the wiper switch 21, an upper limit is set for the power generation voltage of the alternator 9 so as not to affect the operation of electrical components such as a headlamp and a wiper. The set time corresponding to the current ambient temperature of the battery 2 at the value of the generated voltage is read from the map, and the alternator 9 is variably controlled by the engine control unit 12 so that the read set time is equal to the generated voltage. .

  Then, when it is detected that the master cylinder pressure has dropped to a predetermined opening pressure when the driver releases his foot from the brake pedal, for example, when the traffic signal changes to a green light while the engine 3 is automatically stopped due to idling stop, the idling stop is performed. The control unit 11 confirms that a predetermined engine restart condition for the idling stop control is satisfied, and the idling stop control unit 11 instantaneously energizes the relay 7 to turn it on, and supplies the power of the battery 2 to the starter 6 to start the starter. 6 is started, and the stopped engine 3 is automatically restarted. Thereafter, automatic stop of the engine 3 based on establishment of a predetermined engine stop condition during deceleration and automatic restart of the engine 3 based on establishment of a predetermined engine restart condition are alternately performed.

  At this time, when the engine 3 is restarted, the engine speed information reaches the speed indicating complete explosion, the brake force returns to the original state changing according to the master cylinder pressure, and the accelerator pedal is not depressed. This is a so-called idling state, and even in this idling state, the creep force that can start the idling stop vehicle 1 is generated by the engine 3 and the torque converter 5.

  Therefore, according to the above-described embodiment, the ambient temperature of the battery 2 by the battery sensor 8 is equal to or lower than a predetermined temperature (10 ° C.), and the predetermined amount (90%) of the SOC (storage amount) of the battery 2 When the variable control condition that the automatic stop of the engine 3 is prohibited due to the decrease to the following is satisfied, the engine controller 12 causes the generated voltage of the alternator 9 to be higher than in the normal case where the variable control condition is not satisfied. Since the alternator 9 is variably controlled, the battery 2 is charged while the power generation voltage of the alternator 9 is controlled to be high while the automatic stop of the engine 3 due to idling stop is prohibited. Normally, the power generation voltage is not increased high until the (accumulated amount) recovers from the predetermined amount (90%) or less to the specified amount (100%). If can also be shorter than the opportunity to automatically stop the engine 3 for improving the fuel efficiency can be prevented from being reduced as much as possible.

  Therefore, while maintaining the durability performance of the battery 2, it is possible to shorten the duration of the prohibition state of the automatic stop of the engine 3 due to idling stop, and prevent deterioration of fuel consumption without increasing the power generation voltage of the alternator 9 unnecessarily. It becomes possible to do.

  In addition, when the ambient temperature of the battery 2 is equal to or lower than a predetermined temperature (10 ° C.), the state in which the SOC (storage amount) of the battery 2 is reduced from the reduced state to the predetermined amount (90%) to the specified amount (100%). The required charging time becomes longer as the ambient temperature of the battery 2 is lower, and becomes longer as the charging voltage of the battery 2 is lower even at the same ambient temperature. Therefore, the ambient temperature of the battery 2 and the power generation voltage (charging) of the alternator 9 are charged in advance. The setting time for variably controlling the power generation voltage of the alternator 9 is mapped and stored in the storage unit based on the voltage, and the power generation voltage (charging) corresponding to the current ambient temperature of the battery 2 by the battery sensor 8 is set. Voltage) and set time are read from the map, and the alternator 9 is variably controlled by the engine control unit 12 so that the read set time and the generated voltage become the same. It is thus possible to extremely short time the automatic stop of the engine 3 is prohibited by the idling stop, yet wasted is possible to prevent the increase the power generation voltage of the alternator 9 more.

  Further, the engine control unit 12 sets an upper limit according to the operation state of the vehicle electrical component to the generated voltage in the variable control of the alternator 9, so that the life of the headlamp which is the electrical component of the vehicle is shortened or the wiper operation It is possible to prevent the vehicle performance from being affected without increasing the speed and causing the driver to feel uncomfortable.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. It may be a capacitive capacitor.

  For example, in the above-described embodiment, a description is given of a case where an upper limit is set for the power generation voltage so that the operation of the vehicle electrical components such as headlamps and wipers is not affected by excessively increasing the power generation voltage of the alternator 9. However, for example, when the vehicle is running with the accelerator fully open, it is better to suppress the power consumption of the vehicle as much as possible. Therefore, even if the battery 2 is being charged, the alternator for charging is used. The upper limit may be set so as not to increase the power generation voltage (charge voltage) 9.

  In addition, when the variable control condition is satisfied without performing the upper limit of the generated voltage as in the above-described embodiment, variable control is performed to uniformly increase the generated voltage from a normal voltage value to a predetermined constant voltage value. It may be.

  Further, in the above-described embodiment, the example in which the ambient temperature of the battery 2 is 10 ° C. or lower is given as the variable control condition. However, the variable control condition is not limited to 10 ° C., and the charging performance of the battery can be ensured. What is necessary is just to set to temperature.

  In the above-described embodiment, an example in which the present invention is applied to a vehicle in which only the engine is mounted as a drive source has been described. However, the present invention is also applied to a so-called hybrid vehicle in which both the engine and the battery are mounted as drive sources. can do.

1 ... idling stop vehicle 2 ... battery (power storage means)
3 ... Engine 9 ... Alternator (power generation means)
11 ... Idling stop control unit (idling stop control means)
12 ... Engine control section (prohibiting means, power generation control means)

Claims (2)

Idling stop control means for automatically stopping the engine when a predetermined automatic stop condition is satisfied, power storage means for storing and supplying electric power necessary for the vehicle, power generation by the driving force of the engine, and the generated power to the power storage means In a vehicle control device comprising: a power generation means for charging; and a prohibiting means for prohibiting the automatic stop of the engine by the idling stop control means when a storage amount of the power storage means falls below a predetermined amount. ,
Obtaining means for obtaining an ambient temperature of the power storage means;
The variable control condition is not satisfied when the ambient temperature by the acquiring unit is equal to or lower than a predetermined temperature and the automatic control of the engine by the prohibiting unit is prohibited. and a power generation control means for variably controlling the power generating means to increase the generated voltage of the power generator than for,
The vehicle control device, wherein the power generation control means variably controls the power generation means to a set time preset based on the ambient temperature and the power generation voltage of the power generation means . The power generation control unit, the variable control of the power generating means, vehicle control apparatus according to claim 1, characterized in that an upper limit in accordance with the state of the vehicle.

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