JP2013001249A - Pressing controller for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately apply pressing torque regardless of a limited output of a battery.SOLUTION: Even if the upper limit value of an output of a battery 54 for supplying electric power to a second motor generator MG2 is limited by a battery output limit means 78, pressing guarantee torque stmg is selected by a pressing guarantee torque setting means 76 and a MAX selecting means 80, so that power is supplied to the second motor generator MG2 from the battery 54 exceeding the limited upper limit value and the second motor generator MG2 is operated at pressing torque otmg. Thus the pressing torque otmg is appropriately applied regardless of the limited output of the battery 54, and the generation of tooth a striking sound caused by a drop of pressing torque or the vibration of vehicle caused by the hunting of pressing torque can be prevented.

Description

  The present invention relates to a hybrid vehicle, and more particularly to an improvement in pressing control that applies a pressing torque to a drive system by an electric motor when an engine is operating in a vehicle stopped state.

  In a hybrid vehicle including an engine and an electric motor, a rattling noise is generated due to pulsation (torque fluctuation) of the engine by applying a pressing torque to the drive system by the electric motor when the engine is operating in a vehicle stop state. It has been proposed to prevent it from occurring. The hybrid vehicle described in Patent Document 1 is an example, and is a split type in which an engine, a first motor generator, and an output member are connected via a power split mechanism (such as a planetary gear device). The first motor generator is driven to rotate in response to the rotation, but the power split mechanism, the reduction gear, etc. may generate rattling noise due to the pulsation of the engine. A pressing torque is applied by a two-motor generator.

JP 2010-83387 A

  However, in such a pushing control device for a hybrid vehicle, for example, when the battery output (power supply amount) is limited at low temperatures or when the remaining battery charge SOC of the battery is reduced, the pushing is performed accordingly. The torque is limited, and the effect of preventing rattling noise cannot be obtained properly, or the pressing torque is hunted to cause vehicle vibration.

  The present invention has been made against the background of the above circumstances, and an object thereof is to make it possible to appropriately apply the pressing torque regardless of the output limit of the battery.

  In order to achieve such an object, the present invention provides a hybrid vehicle pressing control device that applies a pressing torque to a drive system by an electric motor when an engine is operating in a vehicle stopped state. Even when the upper limit value of the output is limited, power can be supplied from the battery to the electric motor exceeding the limited upper limit value so that the pressing torque can be generated by the electric motor. It is characterized by being allowed.

  In the pressing control device for a hybrid vehicle of the present invention, even when the upper limit value of the output of the battery that supplies power to the electric motor is limited, the pressing limit is set so that the pressing torque can be generated by the electric motor. The power is allowed to be supplied from the battery to the electric motor beyond the upper limit value, so that the pressing torque can be properly applied regardless of the battery output limit. It is possible to prevent the generation of noise or the generation of vehicle vibration due to the pressing torque hunting. In other words, the pressing torque is applied when the engine is operating in a vehicle stop state, and the torque is relatively small. On the other hand, the upper limit value of the battery output is limited when the remaining power SOC is low or when the temperature is low In consideration of the case where a large battery output is suddenly required due to the driver's output request, etc. Even if the electric motor is supplied with power exceeding the upper limit at the time of the limit, there is almost no possibility that the battery is immediately disabled due to a further decrease in the remaining power storage SOC.

1 is a skeleton diagram illustrating an example of a hybrid vehicle to which the present invention is preferably applied. FIG. 2 is a functional block diagram illustrating functions that the electronic control device of the hybrid vehicle of FIG. 1 has for torque control of a second motor generator MG2.

  The present invention is preferably applied to a split-type hybrid vehicle in which an engine, a first motor generator, and an output member are connected via a power split mechanism (such as a planetary gear device). A pressing torque is applied by a second motor generator coupled to the power transmission path.

  The pressing torque is applied when the engine is operating in the vehicle stop state. The vehicle stop state is a parking state in which the drive system is mechanically held in the rotation stop state by the parking lock mechanism, a D (drive) range, or the like. This is a case where the rattling noise caused by the pulsation of the engine becomes a problem when the vehicle is stopped in the vehicle driving state. When a large pressing torque is applied when starting or stopping the engine when the engine is operating, for example, during independent operation for heating or warming up or during load operation for battery charging, etc. However, it is desirable that the pressing torque is applied by supplying power exceeding the upper limit value when the battery output is limited during steady operation where the pressing torque is relatively small except when the engine is started or stopped. That is, when the pressing torque changes according to the operating state of the engine, it is not always necessary to allow the power supply from the battery so that all the pressing torque can be generated, and a relatively small part It may be allowed to supply power exceeding the upper limit value when the battery output is limited only when the pressing torque is.

  The upper limit value of the battery output is limited, for example, when the remaining battery charge SOC is low or at a low temperature. When the remaining battery charge SOC (battery voltage, etc.) further decreases and reaches a predetermined lower limit value, In order to protect the battery, the use of the battery may be further restricted. At that time, it is desirable to prohibit the application of the pressing torque.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a skeleton diagram for explaining a hybrid vehicle 10 to which the present invention is preferably applied. This hybrid vehicle 10 includes an engine 16 that is an internal combustion engine that generates power by combustion of fuel, a first motor generator MG1 and a second motor generator MG2 that can be used as an electric motor and a generator, respectively, and a single pinion type The planetary gear unit 18 is provided on the same axis. The engine 16 is mechanically connected to the input shaft 24 via the damper 22 without any fluid transmission such as a torque converter. In the present embodiment, the second motor generator MG2 corresponds to the electric motor described in claim 1.

  The hybrid vehicle 10 is of a split type, and the planetary gear unit 18 functions as a power split mechanism that splits the power of the engine 16 into an output sprocket 26 that is an output member and a first motor generator MG1. That is, the input shaft 24 is connected to the carrier C1 of the planetary gear unit 18 so as not to be relatively rotatable, while the output sprocket 26 is connected to the ring gear R1 so as not to be relatively rotatable, and the sun gear S1 is connected to the first motor. When the rotor of the generator MG1 is connected so as not to be relatively rotatable and the carrier C1 is rotationally driven by the engine 16, the torque according to the reaction torque (braking torque) of the first motor generator MG1 connected to the sun gear S1 is obtained. The ring gear R1 and the output sprocket 26 are driven to rotate. Further, the rotor of the second motor generator MG2 is connected to the output sprocket 26 so as not to be relatively rotatable, and is also driven to rotate by the second motor generator MG2.

  The output sprocket 26 is mechanically connected to the countershaft 30 via a chain 28, and the torque transmitted to the countershaft 30 is further reduced by a large gear 32 and a small gear 34 provided integrally. It is transmitted to the left and right front wheels 42L, 42R via the device 36, the differential gear device 38, and a pair of axles 40L, 40R. A parking gear 44 is provided integrally with the large gear 32 of the speed reducer 36. When the seat flavor 60 is operated to the “P” position for parking, the parking gear is engaged with a parking lock pole by a parking lock device (not shown). And a parking lock state in which the rotation is mechanically prevented. In FIG. 1, a steering device that changes the steering angle of the front wheels 42L and 42R is omitted.

  The first motor generator MG1 and the second motor generator MG2 are connected to a battery 54 via an inverter 52, and the torque at the time of power running that functions as an electric motor and at the time of regeneration that functions as a generator is controlled. Further, the operating state of the engine 16 is controlled by an engine control device 56 having an electronic throttle valve, a fuel injection device, and the like. The inverter 52 and the engine control device 56 are controlled by an electronic control device 50 having a microcomputer or the like, and the electronic control device 50 has a signal indicating the remaining power storage SOC from the battery 54, specifically Is supplied with a signal representing the battery voltage. Further, a signal representing the battery temperature Tbatt is supplied from the battery temperature sensor 55 and a signal representing the operation position Psh of the shift lever 60 is supplied from the lever position sensor 58. The shift lever 60 corresponds to drive state selection means for selecting the drive state of the vehicle, and includes a “P” position for parking, an “R” position for reverse travel, a “D” position for forward travel, and power transmission. The “N” position or the like for shutting off can be selected. The electronic control unit 50 also corresponds to a signal representing the accelerator operation amount (opening) Acc, which is the operation amount of the accelerator pedal, a signal representing the engine rotational speed Ne, and the vehicle speed V (the output rotational speed Nout of the output sprocket 26 and the like). ), A signal representing the rotational speed (MG1 rotational speed) NMG1 of the first motor generator MG1, a signal representing the rotational speed (MG2 rotational speed) NMG2 of the second motor generator MG2, and the like. A signal representing information is supplied.

  The electronic control device 50 has various functions shown in FIG. 2 for torque control of the second motor generator MG2. The requested motor torque calculating means 70 calculates the requested motor torque rtmg based on the requested output amount such as the accelerator operation amount Acc. When the vehicle stops with Acc = 0, rtmg = 0 or a predetermined creep torque is set. The pressing torque setting means 72 is used when the vehicle is parked when the shift lever 60 is operated to the “P” position or when the vehicle is stopped in the driving state where the shift lever 60 is operated to the “D” or “R” position. When the engine 16 is in the operating state, the pressing torque otmg is set according to the operating state. The pressing torque otmg is for preventing the rattling noise from being generated due to the pulsation of the engine 16, etc., for the operating state of the engine 16, that is, during the independent operation for heating or warming up or for charging the battery or the like. Depending on whether the engine is in a load operation, when the engine 16 is started, when the engine 16 is stopped, or the like. When the engine 16 is started or stopped, a larger pressing torque otmg is set as compared with a steady operation such as a self-sustained operation or a load operation. The pressing limiting unit 74 forcibly sets the pressing torque otmg set by the pressing torque setting unit 72 to 0 when the remaining power SOC of the battery 54, that is, the battery voltage reaches a predetermined lower limit value. To.

  By adding the required motor torque rtmg calculated by the required motor torque calculating means 70 and the pressing torque otmg set by the pressing torque setting means 72 by the adding means 75, the total motor torque tmg (= rtmg + otmg) is obtained. Calculated. The total motor torque tmg is limited by the upper / lower limit limiting means 86 to the upper limit value tmgmax or less and to the lower limit value tmgmin or more, and the second motor with the total motor torque tmg limited by these upper limit value tmgmax and lower limit value tmgmin. The inverter 52 is controlled by the motor torque command means 88 so that the generator MG2 is operated. For example, when the operation position of the shift lever 60 is at the “P”, “D”, or “R” position and the engine 16 is in an operating state, the required motor torque rtmg = 0 and the total motor torque tmg = When the total motor torque tmg is within the range between the upper limit value tmgmax and the lower limit value tmgmin, the second motor generator MG2 is operated substantially with the pressing torque otmg. The pressing torque otmg is applied to the ring gear R1 and the output sprocket 26 of the planetary gear unit 18 so that the gears of the respective parts such as the planetary gear unit 18 and the counter shaft 30 are pressed, and the gear 16 is rattled by the pulsation of the engine 16 or the like. Generation of sound is prevented.

  On the other hand, the signal representing the pressing torque otmg is also supplied to the pressing guarantee torque setting means 76. The pressing guarantee torque setting means 76 ensures that the second electric motor generator MG2 is operated with the pressing torque otmg when the engine 16 is in a self-sustained operation or a load operation even when the upper limit value of the output of the battery 54 is limited. The pressing torque otmg is set to the pressing guarantee torque stmg. In cases other than self-sustained operation or load operation, such as when the engine 16 is started or stopped, the pressing guarantee torque stmg is set to zero.

  The battery output limiting means 78 limits the upper limit value of the output (supplied power amount) of the battery 54 when the remaining power SOC of the battery 54 is lower than a predetermined value or when the battery temperature Tbatt is lower than the predetermined temperature. The torque generated by the second motor generator MG2 by the limited amount of power is output to the MAX selection means 80 as the limit torque α. This limit torque α is a value smaller than the pressing torque otmg when the engine 16 is in a self-sustained operation or a load operation, and the upper limit of the total motor torque tmg is limited by the upper and lower limit limiting means 86 by the limit torque α. There is a possibility that a sufficient pressing torque cannot be obtained and a rattling noise is generated, or vehicle vibration occurs due to the hunting of the pressing torque. Limiting the battery output by the battery output limiting means 78 is performed at a stage where there is a margin in the remaining amount of stored SOC in anticipation of safety, considering the case where a sudden large battery output is required due to the driver's output request, etc. Is done. The use lower limit value at which the pressing limit means 74 forcibly sets the pressing torque otmg to 0 is lower than the remaining power SOC where the battery output is limited by the battery output limiting means 78. It is.

  The MAX selection means 80 compares the pressing guarantee torque stmg set by the pressing guarantee torque setting means 76 with the limiting torque α supplied from the battery output limiting means 78, and selects the larger one. In other words, when the pressing torque otmg is set by the pressing torque setting means 72 when the engine 16 is in a self-sustained operation or a load operation when the vehicle is stopped, even if the upper limit value of the battery output is limited by the battery output limiting means 78 A pressing guarantee torque stmg representing the pressing torque otmg is selected by the MAX selection means 80. Further, when the pressing torque otmg = 0, such as when the vehicle is traveling, the limit torque α is selected. When the upper limit value of the battery output is not limited by the battery output limiting means 78, the predetermined allowable maximum output is compared with the pressing guaranteed torque stmg, and the allowable maximum output is selected. This allowable maximum output is also compared in terms of the torque generated by the second motor generator MG2 based on the allowable maximum output.

  The upper limit value setting means 82 compares the maximum torque determined by various restrictions due to ratings, heat, and the like regarding the battery 54 and the second motor generator MG2 with the torque selected by the MAX selection means 80, and the smaller torque is set. Is selected and set to the upper limit value tmgmax. When the pressing torque otmg is set by the pressing torque setting means 72 when the engine 16 is in a self-sustained operation or a load operation when the vehicle is stopped, and the upper limit value of the battery output is limited by the battery output limiting means 78, Since the pressing guarantee torque stmg representing the pressing torque otmg is selected by the MAX selection means 80, the pressing guarantee torque stmg is normally set to the upper limit value tmgmax unless the maximum torque is largely limited by heat or the like. . Then, the upper limit of the total motor torque tmg is restricted by the upper / lower limit restricting means 86 using the upper limit value tmgmax, so that even when the upper limit of the battery output is restricted by the battery output restricting means 78, the pressing torque otmg The 2-motor generator MG2 is activated, and the generation of rattling noise due to the pulsation of the engine 16 and the like is appropriately prevented.

  The lower limit value setting means 84 selects the maximum value of the minimum torque determined by various restrictions such as the rating, output (power), heat, etc. regarding the battery 54 and the second motor generator MG2, and sets it to the lower limit value tmgmin. Then, the lower limit of total motor torque tmg is limited by upper / lower limit limiting means 86 using this lower limit value tmgmin, whereby second motor generator MG2 is operated with a torque equal to or higher than the lower limit value tmgmin.

  Thus, in the hybrid vehicle 10 of the present embodiment, even when the upper limit value of the output of the battery 54 that supplies power to the second motor generator MG2 is restricted by the battery output restriction means 78, the pressing guarantee torque setting means 76. When the pressing guarantee torque stmg is selected by the MAX selection means 80, it is allowed that electric power is supplied from the battery 54 to the second electric motor generator MG2 beyond the limited upper limit value, and the pressing torque otmg. Thus, the second motor generator MG2 is operated. As a result, the pressing torque otmg is appropriately applied regardless of the output limit of the battery 54, and a rattling sound is generated when the pressing torque is reduced, or vehicle vibration is generated when the pressing torque is hunted. Is prevented.

  Here, the pressing torque otmg is applied when the engine 16 is operating in the vehicle stop state, and the torque otmg is relatively small, whereas the upper limit value of the battery output is limited when the remaining power SOC is reduced. Considering the case where a large battery output is suddenly required due to the driver's output request etc. at low temperature, etc., the pressing torque otmg is implemented at a stage where the remaining power storage SOC is relatively high in anticipation of safety For this reason, even if power is supplied to the second motor generator MG2 beyond the upper limit at the time of battery output limitation, there is almost no possibility that the battery 54 will be immediately disabled due to a further decrease in the remaining power SOC, etc. Control can be implemented appropriately.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

  DESCRIPTION OF SYMBOLS 10: Hybrid vehicle 16: Engine 50: Electronic controller 54: Battery 72: Pushing torque setting means 76: Pushing guarantee torque setting means 78: Battery output restriction means 80: MAX selection means MG2: 2nd motor generator (electric motor) ) Otmg: Pushing torque α: Limit torque

Claims (1)

In a pushing control device for a hybrid vehicle that applies pushing torque to a drive system by an electric motor when the engine is operating in a vehicle stop state,
Even when the upper limit value of the output of the battery that supplies power to the electric motor is limited, the pressing torque is generated by the electric motor so that the pressing torque can be generated from the battery beyond the limited upper limit value. A hybrid vehicle pressing control device characterized in that it is allowed to supply electric power to an electric motor.

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