JP2008240721A - Accessory drive method for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that increase of intake air and fuel is necessary for obtaining torque required for driving accessories and a great amount of fuel is consumed, and that fuel economy is deteriorated when an internal combustion engine operates under idling condition or the internal combustion engine operates at low speed. <P>SOLUTION: This invention relates to an accessory drive method for a vehicle driving the accessory including at least air conditioning device mounted in the vehicle by one of the internal combustion engine and an electric motor in the vehicle provided with the internal combustion engine, the electric motor functioning as a generator, and a chargeable electric power source supplying power to the electric motor and capable of traveling with the internal combustion engine used as a power source. Drive force necessary for travel of the vehicle is output by the internal combustion engine, the accessory is driven by the electric motor, and the accessory is driven by the internal combustion engine if at least remaining capacity of the electric power source is less than capacity required for driving the accessory. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle accessory driving method for effectively driving an accessory in a vehicle equipped with an electric motor for driving the accessory.

Conventionally, in a vehicle in which only an internal combustion engine such as a gasoline engine or a diesel engine is mounted, for example, an automobile, an auxiliary device such as a compressor of a mounted air conditioner (hereinafter referred to as an air conditioner) or a hydraulic pump for power steering. Is generally driven by an internal combustion engine. On the other hand, in a hybrid vehicle equipped with an internal combustion engine and an electric motor, the auxiliary machine is driven by the electric motor while the internal combustion engine is stopped and when an acceleration command is issued to the internal combustion engine, and other operations are performed. In the situation, there is known one that drives an auxiliary machine by an internal combustion engine (for example, Patent Document 1).
JP2004-291707

  By the way, generally, when the internal combustion engine is idling, the torque is suppressed without being operated at the optimum ignition timing (MBT). Therefore, when trying to drive the accessory during idling, it is necessary to increase intake air and fuel in order to obtain the torque required to drive the accessory. The same thing occurs when the internal combustion engine is operated at a low speed. This is to prevent the internal combustion engine from being stopped even if the torque is rapidly increased by advancing the ignition timing so that the necessary torque can be obtained during the idling operation or low-speed operation described above. .

  As described above, when an auxiliary machine is driven by an internal combustion engine as in Patent Document 1 during idling operation or low speed operation, a large amount of fuel is consumed, resulting in a reduction in fuel consumption. Such a state tends to become more prominent for an internal combustion engine having a smaller displacement.

  Therefore, the present invention aims to improve such a state.

  That is, the vehicle accessory driving method of the present invention includes an internal combustion engine, an electric motor that also functions as a generator, and a rechargeable power source that supplies electric power to the electric motor, and can travel using the internal combustion engine as a power source. A vehicle accessory driving method for selectively driving an auxiliary machine including at least an air conditioning device mounted on a vehicle by one of an internal combustion engine and an electric motor, which is necessary for traveling when the vehicle travels. The driving force is output by the internal combustion engine, the auxiliary machine is driven by the electric motor, and the auxiliary machine is driven by the internal combustion engine at least when the remaining capacity of the power source is less than the capacity required for driving the auxiliary machine.

  According to such a configuration, when the remaining capacity of the power source that supplies electric power for operating the electric motor is equal to or greater than the capacity required for driving the auxiliary machine, the auxiliary machine is driven by the electric motor, so that the burden on the internal combustion engine is reduced. It is reduced. Therefore, the amount of intake air and fuel to be increased to drive the auxiliary machine is greatly reduced, so that it is possible to prevent a decrease in fuel consumption accompanying the driving of the auxiliary machine.

  In addition, since the electric motor is specialized in driving the auxiliary machine, a small-sized one can be applied. For this reason, since the power supply for the electric motor may have a small capacity and a low inter-terminal voltage, the mounting space occupied by these can be reduced.

  In order to increase the use efficiency of the electric motor, the regenerative operation of the electric motor, the driving of auxiliary equipment by the electric motor, and the internal combustion engine so that the charge / discharge balance of the electric power source is within a certain range when the remaining capacity of the electric power source is reduced. It is preferable to selectively drive the auxiliary machine. If it is such, it will become possible to convert the surplus energy obtained by driving | running | working of a vehicle into electricity, and to accumulate | store it, and can raise the use efficiency of energy.

  The present invention is configured as described above, and when the remaining capacity of the power source that supplies power for operating the electric motor is greater than the capacity required for driving the auxiliary machine, the auxiliary machine is driven by the electric motor. The burden on the organization can be reduced. As a result, an increase in the intake air amount and the fuel amount to drive the auxiliary machine is significantly reduced, so that it is possible to prevent a reduction in fuel consumption accompanying the driving of the auxiliary machine.

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

  In this embodiment, the vehicle includes an internal combustion engine 1, an electric motor 2 that also functions as a generator, a battery 3 and a power control device 4 that constitute a rechargeable power source that supplies electric power to the electric motor 2, the internal combustion engine 1 and And an electronic control device 6 for controlling the compressor 5 of the air conditioner as an auxiliary machine.

  As the internal combustion engine 1, various types known in the art such as a gasoline engine and a diesel engine can be applied. The internal combustion engine 1 can transmit the driving force to the drive wheels via a clutch, a transmission, a propeller shaft, an operating gear, and the like, and an air conditioner compressor 5 and an electric motor 2 that are air conditioners are provided. For example, it is selectively driven via a transmission unit 7 that combines a belt, a pulley, an electromagnetic clutch, and the like.

  Since the electric motor 2 does not output a driving force necessary for traveling of the vehicle, an electric motor having a smaller output than that of the electric motor 2 for traveling of the vehicle may be employed. Specifically, in the case of a small vehicle, in other words, when the displacement of the internal combustion engine 1 is not large, the electric motor 2 is a small one having an output of about 1.5 kw to 2 kw, for example. In the electric motor 2, the output shaft 2a can selectively drive the compressor 5 of the air conditioner by the configuration as described above. Further, the electric motor 2 is configured to function as a generator by being selectively driven by the internal combustion engine 1 and driving wheels.

  Thus, since it is the small electric motor 2, what has a low voltage and a small capacity | capacitance is applicable also about the battery 3 used as the power supply. As a result, the space they occupy in the engine room of the vehicle need not be increased. For this reason, it can employ | adopt optimally with respect to a vehicle with a relatively small engine room. Since the battery 3 is for an electric motor, the voltage between terminals is, for example, 24V to 36V.

  The power control device 4 is electrically connected between the electric motor 2 and the battery 3 to supply electric power to the electric motor 2 and to charge the battery 3 with electric power generated by the electric motor 2. The power control device 4 includes an inverter or a DC-DC converter depending on the type of the electric motor 2. Furthermore, the power control device 4 includes a charging circuit that supplies the battery 3 with alternating current supplied from a power line (such as a light line or a distribution line) in a home instead of being converted into direct current. In this embodiment, the power control device 4 includes both an inverter and a DC-DC converter, and is usually a 12V battery such as an electric device other than the motor 2 such as a headlight or an electronic control device 6 from the battery 3. Is configured so that power can be supplied to the power source. In the case where the electric motor 2 is for AC and the electric power control device 4 includes only an inverter, a low voltage, that is, a 12 V battery is provided for the electronic control device 6 in addition to the battery 3 for the electric motor 2. In this case, the internal combustion engine 1 includes an alternator for charging the low-voltage battery.

  The electronic control unit 6 controls the operation of the internal combustion engine 1 based on the operation state of an accelerator pedal (not shown) and the traveling state of the vehicle, and based on a signal output from a charge capacity sensor that detects the remaining capacity of the battery 3. Thus, the mechanical connection between the power control device 4 and the internal combustion engine 1 and the electric motor 2 is controlled so that the electric power generated by the regenerative operation of the electric motor 2 is charged in the battery 3 when the vehicle is running at a reduced speed. The electronic control unit 6 detects that the vehicle is decelerating from the operation amount of the throttle valve and / or the vehicle speed, and temporarily stops the fuel supply to the internal combustion engine 1 during the decelerating vehicle.

  The electronic control device 6 stores a program for controlling the internal combustion engine 1, the power control device 4, and the auxiliary machine according to the traveling state of the vehicle. Among them, the configuration of an auxiliary machine drive program for controlling the power control device 4 and thus the electric motor 2 will be described below with reference to FIG.

  First, in step S1, it is determined whether or not the remaining capacity of the battery 3 is greater than or equal to a set value. The set value is set to a value necessary for the electric motor 2 to output a driving force that can drive the compressor 5 of the air conditioner. In step S2, it is determined whether or not the air conditioner is on. If it is determined that the air conditioner is off, the control is terminated. On the other hand, when it is determined that the air conditioner is on, the compressor 5 of the air conditioner is driven by the electric motor 2 in step S3.

  If it is determined in step S1 that the remaining capacity of the battery 3 is less than the set value, it is determined in step S4 whether or not the vehicle is traveling at a reduced speed. If it is determined that the vehicle is traveling at a reduced speed, the electric motor 2 is regenerated in step S5 and the battery 3 is charged. In this case, the electric motor 2 is driven by the internal combustion engine 1 or drive wheels. If it is determined that the vehicle is not decelerating, it is determined in step S6 whether the air conditioner is on. If it is determined that the air conditioner is on, the compressor 5 of the air conditioner is driven by the internal combustion engine 1 in step S7. That is, the mechanical connection between the electric motor 2 and the compressor 5 of the air conditioner is disconnected, and the internal combustion engine 1 and the compressor 5 are mechanically connected so that the driving force of the internal combustion engine 1 is transmitted to the compressor 5 of the air conditioner instead. Connecting. If the air conditioner is not on, the control is terminated.

  In such a configuration, it is assumed that the battery 3 is fully charged before the vehicle travels. That is, since the power control device 4 includes a charging circuit, the battery 3 is charged by electrically connecting the power control device 4 to a household outlet while the vehicle is parked in a garage, for example. Therefore, the remaining capacity of the battery 3 is in a full state and is equal to or greater than the set value. When the vehicle travels in this state and the air conditioner is used (turned on), the control executes steps S1 to S3, and the electric motor 2 drives the compressor 5 of the air conditioner. The vehicle travels by the driving force of the internal combustion engine 1.

  Since the compressor 5 is driven by the electric motor 2 in this manner, even if the internal combustion engine 1 is in an idling operation state due to a signal or a parking lot, for example, the compressor 5 of the air conditioner is not a load on the internal combustion engine 1. In addition, there is no need to increase intake air or fuel. Therefore, it is possible to prevent the fuel consumption of the internal combustion engine 1 from being lowered. Further, since the battery 3 can be charged when the vehicle is not used for a long time such as at night, it is possible to increase the state in which the compressor 5 of the air conditioner can be driven only by the electric motor 2 when the vehicle is used.

  On the other hand, if the remaining capacity of the battery 3 is reduced by continuing running and the vehicle is running at a reduced speed, step S4 and step S5 are executed to regenerate the electric motor 2, That is, the electric motor 2 is driven by the internal combustion engine 1 or by driving wheels so that the electric motor 2 functions as a generator. The electric power generated by the electric motor 2 charges the battery 3 via the electric power control device 4.

  In this case, charging is controlled so that the charge / discharge balance of the battery 3 is within a substantially constant range. In other words, the battery 3 is always charged such that the remaining capacity changes in a state centered on the above set value. Therefore, surplus mechanical energy at the time of traveling can be used effectively, and the battery 3 can be always used as the power source of the electric motor 2.

  If the air conditioner is on during the regenerative operation of the electric motor 2 as described above, the compressor 5 of the air conditioner is driven by the internal combustion engine 1 by executing steps S6 and S7. In this case, since the vehicle is decelerating, the supply of fuel is temporarily stopped, that is, the fuel is cut. For this reason, fuel consumption is not reduced. Moreover, even when the remaining capacity of the battery 3 is reduced in this way, or even in the extreme case, there is almost no remaining capacity, the air conditioner can be cooled and heated while traveling.

  Further, when the battery 3 has sufficient capacity to drive the electric motor 2 after the travel is completed, the room can be cooled and heated while the vehicle is stopped before the next travel. In other words, basically, there is one that drives the compressor 5 of the air conditioner by the electric motor 2, so that the air conditioning can be performed even when the internal combustion engine 1 is not operating. In this case, the electronic control device 6 may be configured to include a wireless remote control circuit and to combine a remote control transmitter that transmits a signal to the remote control circuit.

  In the above-described embodiment, the power control device 4 includes the charging circuit. However, the power control device 4 may be configured to use a stationary charger in a home or a gas station.

  In addition, instead of the charge capacity sensor, the charge / discharge current and the terminal voltage of the battery 3 may be measured, and the remaining capacity may be estimated (detected) based on the integrated value of the charge / discharge current and the terminal voltage. . Such a method for detecting the remaining capacity of the battery 3 is not limited to the above-described method, and a method widely known in the field may be adopted as appropriate.

  Further, in the above-described embodiment, when the remaining capacity becomes less than the set value, the electric motor 2 is regeneratively operated so that the charge / discharge balance of the battery 3 is in a substantially constant range, and the electric motor 2 performs the air conditioning. However, if the remaining capacity is not sufficient to drive the compressor 5 of the air conditioner, the driving of the compressor 5 of the air conditioner by the electric motor 2 is prohibited until the remaining capacity is restored to the predetermined capacity. You may comprise.

  In addition, as long as the battery 3 is not fully charged, that is, when there is room for charging in the battery 3, the regenerative operation of the electric motor 2 is performed at the time of decelerating driving, and the remaining capacity is always set to the set value. The configuration may be maintained in the above state. The control in this case will be described with reference to FIG.

  First, it is determined whether or not the remaining capacity (battery remaining amount) of the battery 3 is greater than or equal to a set value (step S101). The set value is set corresponding to a capacity sufficient to drive the compressor 5 of the air conditioner by the electric motor 2 as in the above-described embodiment. If the remaining capacity is greater than or equal to the set value, it is determined whether or not the air conditioner is operating (ON) (step S102).

  If the air conditioner is operating, it is determined whether or not the vehicle is traveling at a reduced speed (step S103). If it is determined that the vehicle is traveling at a reduced speed, the internal combustion engine 1 drives the compressor 5. (Step S104) On the other hand, when the vehicle is not traveling at a reduced speed, the electric motor 2 cannot be regeneratively operated, so the compressor 5 is driven by the electric motor 2 (Step S105). In this case, power is supplied from the battery 3 to other auxiliary machines, and the alternator is not operated (step S106). In this way, when the air conditioner is operating, the compressor 5 is driven by either the internal combustion engine 1 or the electric motor 5 depending on whether the vehicle is traveling, that is, decelerating.

  On the other hand, if the air conditioner is not operating, it is determined whether or not the vehicle is decelerating (step S107). If the vehicle is decelerating, the motor 5 can be regeneratively operated. to decide. That is, it is determined whether or not the remaining capacity of the battery 3 is less than full charge (step S108). If the remaining capacity is not fully charged, that is, if the remaining capacity is less than full charge, the electric motor 5 is regenerated (step S109). On the other hand, when the electric motor 2 is in a regenerative operation, the compressor 5 is driven by the internal combustion engine 1, so that the internal combustion engine 1 also drives the alternator, and thus the alternator supplies power to other auxiliary machines. (Step S110).

  As described above, when the remaining capacity of the battery 3 is equal to or greater than the set value, the air conditioner is operating, traveling at a reduced speed, and the remaining capacity is less than full charge, and the air conditioner is not operating. When the vehicle is decelerating and the remaining capacity is less than full charge, the electric motor 5 is regeneratively operated.

  On the other hand, when it is determined that the remaining capacity of the battery 3 is less than the set value, it is determined whether or not the air conditioner is operating (step S111), and when it is determined that the air conditioner is operating. The compressor 5 of the air conditioner is driven by the internal combustion engine 1 (step S112). After this, and when it is determined that the air conditioner is not operating, it is determined whether or not the vehicle is decelerating (step S113). If it is determined that the vehicle is decelerating, the remaining capacity is less than full charge. If there is, the electric motor 2 is regeneratively operated (step S114, step S115).

  And since the compressor 5 of the air conditioner is driven by the internal combustion engine 1 and the electric motor 2 is regeneratively operated, when the regenerative operation is not being performed and when the regenerative operation is not being performed, the alternator is used to (Step S116).

  Thus, since the electric motor 2 is regeneratively operated according to the running state of the vehicle and the charged state of the battery 3, the battery 3 can be charged efficiently. In other words, even when the battery 3 has a sufficient remaining capacity that can drive the compressor 5 of the air conditioner in which the electric motor 2 is an auxiliary machine, the traveling at that time is decelerated and the remaining capacity of the battery 3 is fully charged. In the case where the battery voltage is lowered, the electric motor 2 is regenerated and the battery 3 is charged. Therefore, the battery 3 can be charged frequently while the vehicle is in use, and the charging state in which the auxiliary machine can be driven by the electric motor 2 can be maintained, so that the opportunity for driving the auxiliary machine by the internal combustion engine 1 is reduced. Can improve fuel efficiency. Moreover, according to such a structure, the charging circuit mentioned above can also be abbreviate | omitted and the operation | work which charges the battery 3 before driving | running | working can also be abbreviate | omitted.

  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.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic structure explanatory drawing of embodiment of this invention. The flowchart which shows the control procedure of the embodiment. The flowchart which shows the control procedure in the modification of the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Electric motor 3 ... Battery 5 ... Compressor 6 ... Electronic control unit

Claims (2)

In a vehicle capable of running using an internal combustion engine as a power source, the internal combustion engine, an electric motor that also functions as a generator, and a rechargeable power source that supplies electric power to the electric motor. Is a vehicle auxiliary drive method for selectively driving an auxiliary machine including one of an internal combustion engine and an electric motor,
The driving force required for traveling when the vehicle travels is output by the internal combustion engine, and the auxiliary machine is driven by the electric motor,
A vehicle accessory driving method for driving an accessory by an internal combustion engine when at least a remaining capacity of a power source is less than a capacity required for driving the accessory.   When the remaining capacity of the power supply decreases, the regenerative operation of the electric motor, the driving of the auxiliary equipment by the electric motor, and the driving of the auxiliary equipment by the internal combustion engine are selectively performed so that the charge / discharge balance of the power supply is within a certain range. The method of driving an auxiliary machine for a vehicle according to claim 1.

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