JP2010247604A - Vehicle drive control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a system recirculation loss while maintaining energy utilization efficiency of an engine as much as possible, in a vehicle drive control system. <P>SOLUTION: A vehicle drive control device 40 for controlling overall operation of elements configuring a driving system 12 of a vehicle, includes: a system recirculation determination processing part 44 for determining whether or not a system recirculation loss has occurred when the driving force of an engine 14 is partially used for power generation, and when a driving force is generated by the other of a first rotation electrical machinery 18 or a second rotation electrical machinery 20 with the generated power; a calculation part 46 for, when the system recirculation state is determined, calculating the number of engine cylinders that eliminate the system recirculation loss; and a part 48 for changing the number of operating cylinders of the engine 14 to the calculated number of engine cylinders. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle drive control system, and in particular, a vehicle drive control system in which an engine, a first rotating electrical machine, and a second rotating electrical machine are coupled by a power distribution mechanism and the output is supplied to a drive shaft of the vehicle. About.

  In a vehicle equipped with a rotating electrical machine and an engine, a power distribution mechanism is used to appropriately distribute the power of the engine and the power of the rotating electrical machine. At this time, it is necessary to control the drive of the engine and the rotating electrical machine in consideration of the energy efficiency of the entire drive system.

  For example, in Patent Document 1, in a power output device for a hybrid vehicle in which an engine, a generator, and an electric motor are coupled via a planetary gear, power obtained by driving the generator is output to the drive shaft via the planetary gear. It is described that a recirculation path is formed in which a part of the motive energy is circulated in the order of the electric motor, the generator, the planetary gear, and the electric motor. And it is stated that such energy circulation reduces the energy efficiency of the entire device by reducing the energy with small loss that is directly output from the engine to the drive shaft through the planetary gear as the circulating energy increases. Yes.

  As a technology related to the present invention, Patent Document 2 discloses a drive control device for a hybrid vehicle, in order to prevent overcharge of the battery, when the battery charge state is less than 60%, the six cylinders of the engine are used. Operate everything and allow the battery to be charged with its power generation output. If the battery is charged 80% or more, operate the engine in two cylinders. If the battery reaches 100%, stop the engine. Is stated.

  Further, in Patent Document 3, as a hybrid electric vehicle, when power generation is performed by changing the engine speed together with the generator field current for the required power generation amount, the engine speed cannot be so low so as not to increase the throttle loss. Therefore, it is stated that the number of engine cylinders is reduced.

  Further, in Patent Document 4, as a power output device, when the engine stop is prohibited because the starting power is insufficient due to the low temperature of the battery, only a part of the plurality of cylinders is selected when the target power of the engine is small. It is stated that the fuel required for the continuous operation of the engine can be saved by supplying fuel.

JP 2002-17005 A JP-A-5-199609 JP 7-317581 A JP 2004-44669 A

  As described in Patent Document 1, in a vehicle including an engine, a generator driven by the engine, and a motor driven by generated power obtained by the generator, the motive energy generated by the engine is directly driven by the vehicle. In addition to the route transmitted to the shaft, a part of the route is distributed to the generator by the power distribution mechanism, and the distributed power energy is converted into generated power, and the electric motor generates the power energy with the power to drive the vehicle. There is a route to transmit to the shaft. In other words, the energy transmitted to the drive shaft of the vehicle includes a direct component in which the energy generated by the engine is directly transmitted and a circulating component that passes through the engine-generator-electric power-motor. Here, energy, power energy, and electric power all have dimensions of power.

  In this way, the mechanical energy of the engine circulates through the electric system via the power distribution mechanism, returns to the mechanical energy, and is transmitted to the drive shaft of the vehicle, which is called energy recirculation or system recirculation. . This system recirculation converts the engine mechanical energy into electrical energy and then converts the electrical energy back into mechanical energy, so the engine mechanical energy is used directly. In comparison, energy utilization efficiency is reduced by the amount of energy conversion that passes twice. That is, as the system recirculation component increases, the energy utilization efficiency of the entire drive system decreases.

  Generally, the power distribution mechanism determines the operating point of the engine so as to maximize the energy utilization efficiency of the engine. In order to suppress the occurrence of system recirculation, it is sufficient to change the operating point of this engine. However, if it is left as it is, the energy utilization efficiency of the engine alone is lowered, and the energy utilization efficiency of the entire drive system is also lowered. Become.

  An object of the present invention is to provide a vehicle drive control system that can suppress a system recirculation loss while maintaining the energy utilization efficiency of an engine as much as possible.

  A vehicle drive control system according to the present invention is a vehicle drive control system in which an engine, a first rotating electrical machine, and a second rotating electrical machine are coupled by a power distribution mechanism and the output is supplied to a drive shaft of the vehicle. A part of the driving force of the engine is used for power generation because one of the first rotating electric machine and the second rotating electric machine is generating electric power in the operating state, and the generated electric power is used to generate the first rotating electric machine or the second rotating electric machine. A system recirculation determination means for determining whether or not the other of the two rotating electric machines is in a state where a system recirculation loss is caused by generating a driving force; Based on the relationship in which the engine speed is changed by changing the number of operating cylinders under constant power conditions and the relationship in which the system recirculation loss is changed by changing the engine speed , Characterized in that it comprises means for calculating the number of engine cylinders, which can be the energy loss is zero, and the cylinder number changing means for changing the number of operating cylinders of the engine to the number of engine cylinders is calculated, the.

  Further, in the vehicle drive control system according to the present invention, the system recirculation determining means is one in which the engine is in a steady operation state and is one of the first rotating electric machine and the second rotating electric machine and coupled to the engine. It is preferable to determine that a system recirculation loss is occurring when the rotating electrical machine is rotating.

  With the above configuration, when it is determined that the vehicle drive control system is in the system recirculation state, the engine speed is changed by changing the number of operating cylinders of the engine under a constant power condition, and the engine speed Calculate the number of engine cylinders that can make the system recirculation loss zero based on the relationship that the system recirculation loss is changed by changing the number, and change the number of operating cylinders of the engine to the calculated number of engine cylinders To do.

  Changing the number of operating cylinders of the engine can change the output of the engine according to the number of operating cylinders, but the energy utilization efficiency of the engine can be maintained almost as it is. Therefore, the system recirculation loss can be made zero while maintaining the energy utilization efficiency of the engine as much as possible.

  Further, in the vehicle drive control system, the system recirculation determination means is configured such that the engine is in a steady operation state and one of the first rotating electric machine and the second rotating electric machine connected to the engine rotates. It is determined that there is a system recirculation loss. System recirculation means that the mechanical energy of the engine is once converted into electrical energy and returned to mechanical energy, so when two rotating electric machines are provided, one of them is a generator and the other is Occurs when the motor is an electric motor, for example, also when passing through a power storage device. The most typical example is when the rotating electrical machine connected to the engine is generating power, that is, when the rotating electrical machine is rotating. According to the above configuration, it is possible to easily determine the presence or absence of system recirculation in this typical case.

It is a figure which shows the structure of the vehicle drive control system in embodiment which concerns on this invention. It is a figure explaining system recirculation. In embodiment which concerns on this invention, it is a flowchart which shows the procedure which suppresses a system recirculation loss, maintaining the energy utilization efficiency of an engine. In embodiment which concerns on this invention, it is a figure explaining the mode of a change of the operating point of an engine.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a description will be given of a vehicle drive system in which an engine and two rotating electrical machines are connected by a power distribution mechanism using a planetary mechanism, but other configurations may be used. For example, the transmission may be omitted, and a power distribution mechanism other than the planetary mechanism may be used.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram showing a configuration of the vehicle drive control system 10. The vehicle drive control system 10 includes a vehicle drive system 12 and a vehicle drive control device 40 that controls the operation of each element constituting the drive system 12 as a whole. The vehicle drive control device 40 is connected to operators of the shift lever 34, the accelerator pedal 36, and the brake pedal 38, and is connected to the storage device 50.

  The vehicle drive control system 10 has a function of controlling the drive of the vehicle in accordance with the content required by the operation of the user's operator, but here, in particular, the energy recirculation while maintaining the efficiency for the energy furnace of the engine as much as possible. It has a function of performing control to suppress loss.

  The vehicle drive system 12 includes an engine 14, a first rotating electrical machine 18, and a second rotating electrical machine 20 as drive sources. Here, the power of the engine 14, the first rotating electrical machine 18, and the second rotating electrical machine 20 is appropriately distributed according to the user's request via the power distribution mechanism 26, and the propeller shaft 24 and the fixed stage speed reducer 28. Is transmitted to the drive shaft 25 of the vehicle via the wheel to drive the wheels 30.

  The engine 14 is a so-called internal combustion engine, and here is one of the drive sources of the vehicle. The engine 14 has a plurality of cylinders that operate sequentially according to a predetermined operation cycle. Each cylinder has a piston that reciprocates within the cylinder, and each piston is connected to the crankshaft while shifting the operation phase from each other, and the crankshaft is smoothly moved by the cooperative operation of each piston. Rotate. This crankshaft is connected to the output shaft of the engine 14.

  Here, an engine 14 having eight cylinders is used. The number of operating cylinders of the engine 14 can be changed under the control of the vehicle drive control device 40. If not all of the eight cylinders are operated and some of the cylinders are operated, the torque output from the engine 14 is substantially proportional to the number of operating cylinders.

  The state of the reduction is substantially equivalent to the torque-rotational speed characteristic of the engine 14 that is obtained by directly reducing the magnitude of the torque. In other words, by changing the number of operating cylinders, it is possible to reduce the magnitude of the torque in proportion to the torque-rotational speed characteristic while maintaining the energy utilization efficiency of the engine 14 almost as it is. Details of the change in the number of operating cylinders will be described later.

  The first rotating electrical machine (MG1) 18 and the second rotating electrical machine (MG2) 20 are motor generators (MG) mounted on the vehicle, and are power storage devices 33 (described later) included in the power source / drive circuit unit 32. This is a three-phase synchronous rotating electric machine that functions as a motor when electric power is supplied from the engine 14 and functions as a generator when driven by the engine 14 or when braking the vehicle. In the example of FIG. 1, one of the two rotating electrical machines 18 and 20 is used as a generator for charging the power storage device 33, and the other is used mainly as a drive motor for driving the vehicle.

  That is, as described above, the first rotating electrical machine (MG1) 18 is driven by the engine 14 mounted on the vehicle and used as a generator, and the generated electric power is used to supply the power storage device 33. The second rotating electrical machine (MG2) 20 is used for traveling the vehicle, receives power from the power storage device 33 during power running, functions as a motor to drive the drive shaft 25 of the vehicle, and generates power during braking. The regenerative energy can be recovered and supplied to the power storage device 33.

  The power distribution mechanism 26 is a planetary mechanism. The sun gear, which is an external gear, is connected to the rotation shaft of the first rotating electrical machine 18, and the second rotation via the transmission 22 is connected to the ring gear, which is an internal gear. The output shaft of the engine 14 via the damper 16 is used as a carrier that revolves a plurality of pinions that are external gears arranged between the ring gear and the sun gear. Is connected.

  The shift lever 34 connected to the vehicle drive control device 40 is an operator used when the user changes the shift position. The shift position state selected by the user is detected by a shift position sensor and transmitted to the vehicle drive control device 40 via an appropriate signal line.

  The accelerator pedal 36 is an operator used when the user desires acceleration / deceleration. The amount of depression of the accelerator pedal 36 corresponds to the torque required by the user. The amount of depression of the accelerator pedal 36, which is also referred to as an accelerator opening, is detected by an accelerator opening sensor and transmitted to the vehicle drive control device 40 via an appropriate signal line.

  The brake pedal 38 is an operator used when the user desires to brake the vehicle. The amount of depression of the brake pedal 38 corresponds to the user's required braking force. The amount of depression of the brake pedal 38 is detected by a brake depression amount sensor and transmitted to the vehicle drive control device 40 via an appropriate signal line.

  The storage device 50 is a device that stores a vehicle drive control program executed in the vehicle drive control device 40. Here, in particular, an operation characteristic diagram 52 of the engine 14 used when changing the number of operating cylinders of the engine 14 is stored. Details of the operation characteristic diagram of the engine 14 will be described later.

  The vehicle drive control device 40 has a function of controlling the elements constituting the drive system 12 of the vehicle as a whole. Further, here, in particular, it has a function of performing control for suppressing system recirculation loss while maintaining the energy utilization efficiency of the engine 14 as much as possible. The vehicle drive control device 40 can be configured by a computer or the like suitable for mounting on a vehicle. Moreover, the function of the vehicle drive control apparatus 40 can also be made into a part of function of another vehicle-mounted computer. For example, the function of the vehicle drive control device 40 can be given to a hybrid ECU that controls the entire vehicle.

  The vehicle drive control device 40 receives a user request via an operator such as an accelerator pedal 36 and the like, and a drive control processing unit 42 that controls the operation of each element of the drive system 12 and a driving force of the engine 14. Is used for power generation, and it is determined whether or not the other one of the first rotating electrical machine 18 and the second rotating electrical machine 20 generates a driving force with the generated power, thereby causing a system recirculation loss. The system recirculation determination processing unit 44 and the relationship in which the engine speed is changed by changing the number of operating cylinders of the engine 14 under a constant power condition when it is determined that the system is in the system recirculation state, and the engine speed An engine cylinder number calculation processing unit 46 for calculating the number of engine cylinders capable of reducing the system recirculation loss to zero based on the relationship in which the system recirculation loss is changed by changing the number; Configured to include a number of cylinders change processing unit 48 to change the number of operating cylinders of the engine 14 to the number of engine cylinders that.

  Such a function can be realized by executing software. Specifically, this can be realized by executing a system recirculation suppression control routine of the vehicle drive control program. Some of these functions may be executed by hardware.

  The operation of the above configuration, in particular, each function of the vehicle drive control device 40 will be described with reference to FIGS. First, the state of system recirculation will be described with reference to FIG. 2, and then the state of vehicle drive control will be described with reference to the flowchart of FIG.

  FIG. 2 is a diagram for explaining the state of system recirculation. This figure shows how energy 60 output from the engine 14 is generated when the engine 14, the first rotating electrical machine 18, the second rotating electrical machine 20, and the power distribution mechanism 26 are provided therebetween. FIG. 4 is a schematic diagram showing whether or not a drive shaft 25 is transmitted.

  In FIG. 2, energy 60 output from the engine 14 is mechanical energy, but is transmitted to the carrier of the power distribution mechanism 26 as described above. The power distribution mechanism 26 converts the rotational speed and torque according to the gear ratio between the carrier and the ring gear, and transmits the energy 62 to the propeller shaft 24. Further, a part of the energy 64 is transmitted to the first rotating electrical machine 18 by converting the rotational speed and the torque according to the gear ratio of the carrier and the sun gear.

  Here, since the power distribution mechanism 26 is mechanical power distribution, assuming that the distribution efficiency is 1, energy 60 = energy 62 + energy 64.

The first rotating electrical machine (MG1) 18 converts mechanical energy 64 into electrical energy 65 by generating electric power based on the transmitted energy 64. Here, energy conversion is performed by mechanical-electromagnetic conversion. Therefore, when the conversion efficiency is a ₁ %, energy 65 = a ₁ × (energy 64).

  The generated electrical energy 65 charges the power storage device 33 in accordance with an instruction from the vehicle drive control device 40, and electric power is discharged from the power storage device 33 as necessary. Here, the description is simplified. Therefore, it is assumed that the energy 65 is not used to charge the power storage device 33 but is entirely supplied to the second rotating electrical machine 20.

When electric power is supplied to the second rotating electrical machine 20 through charging and discharging of the power storage device 33, the charge / discharge efficiency a ₂ of the power storage device 33 is multiplied by the energy 65 and corresponds to the energy 60. As a part, less energy is supplied to the second rotating electrical machine 20. Here, since charging / discharging of the electrical storage device 33 is not performed, a ₂ = 1 may be set.

The second rotating electrical machine 20 acts as a motor using the supplied electrical energy 65 and outputs mechanical energy 66 to its output shaft. Here, energy conversion is performed by electromagnetic-mechanical conversion. Therefore, if the conversion efficiency is a ₃ %, energy 66 = a ₃ × (energy 65) = a ₁ × a ₃ × (energy 64). That is, energy 66 = a ₁ × a ₃ × (energy 64) is output from the second rotating electrical machine 20 to the propeller shaft 24 via the transmission 22.

  As described above, since the energy 62 is output from the engine 14 to the propeller shaft 24 via the power distribution mechanism 26, the energy 68 = (energy 62) + (energy 66) is output to the propeller shaft 24. This energy is transmitted to the drive shaft 25 of the vehicle.

  Here, when the energy 60 output from the engine 14 and the energy 68 actually transmitted to the drive shaft 25 of the vehicle are compared, the energy 68 is compared with the energy 60, Δ energy = (energy 60) − (Energy 68) = (Energy 60) − (Energy 62) − (Energy 66) is reduced. When the distribution ratio of the energy 60 to the energy 62 is β, (energy 62) = β × (energy 60) and (energy 64) = (1−β) × (energy 60). This Δ energy is a loss generated by once converting mechanical energy into electrical energy and then circulating it again as mechanical energy. This corresponds to system recirculation loss.

Here, when β and a ₁ , a ₃ are used, the system recirculation loss Δ energy is Δ energy = (energy 60) − (energy 62) − (energy 66) = (energy 60) −β × (energy 60 ) -a ₁ × a ₃ × (energy 64) = {(1-β ) - (1-β) × a 1 × a 3} × ( energy 60) = (1-β) × (1-a 1 × a ₃ ) × (energy 60).

  In order to suppress the system recirculation loss Δ energy, the system recirculation of engine 14 -generator-motor-propeller shaft 24 may be suppressed. Since this system recirculation is determined by power distribution in the power distribution mechanism 26, it can be suppressed by control by the vehicle drive control device 40.

  One specific method is to perform power distribution so that the generator 14 is not driven by the engine 14. Another method is not to supply electric power from the power storage device 33 to the electric motor. By combining these methods, control for suppressing system recirculation can be performed. However, if the power distribution is changed, the operating point of the engine 14 is changed as it is, so that the energy utilization efficiency of the engine 14 alone is lowered. That is, if the system recirculation loss is suppressed, the energy utilization efficiency of the engine 14 is reduced.

  FIG. 3 is a flowchart showing a control procedure for suppressing the system recirculation loss while maintaining the energy utilization efficiency of the engine 14 as much as possible. Here, it is first determined whether or not the engine 14 is in steady operation (S10). The reason for this determination is that when the engine 14 is in steady operation, the operating point of the engine 14 is set so as to maximize the energy utilization efficiency of the engine 14, so that system recirculation may have occurred. Is high. In other words, when the operating point of the engine 14 is set so as to be the maximum energy utilization efficiency, the user's acceleration / deceleration request or the like instructed by the shift lever 34, the accelerator pedal 36, and the brake pedal 38 is realized under the conditions. Therefore, the first rotating electrical machine 18, the second rotating electrical machine 20, and the power storage device 33 are effectively used. That is, there is a high possibility that the vehicle is operating while performing system recirculation.

  Next, it is determined whether or not system recirculation has occurred (S12). Since system recirculation occurs when energy enters and exits at least one of the first rotating electrical machine 18, the second rotating electrical machine 20, and the power storage device 33, it is determined by monitoring the entry and exit of these energies. It can be performed. The energy storage device 33 can input and output energy by monitoring a charge / discharge control signal. Regarding the first rotating electrical machine 18 and the second rotating electrical machine 20, it can be determined that system recirculation has occurred when it is detected that either of them is operating as a generator.

  Most typically, since the first rotating electrical machine 18 often generates power by receiving the driving force of the engine 14, whether or not the system recirculation occurs depending on whether or not the first rotating electrical machine 18 rotates. It can be judged.

  If the determination in step S12 is affirmative and system recirculation has occurred, then the required engine speed at which the system recirculation loss is zero is calculated (S14). This step is executed by the function of the system recirculation determination processing unit 44 of the vehicle drive control device 40. As described above, when the engine 14 is in steady operation, the operating point at which the single energy use efficiency of the engine 14 is maximized is used, and this is moved to an operating point where system recirculation does not occur. You can do it.

  This calculation can be performed by changing the operating point of the engine 14 under a constant power condition so that the system recirculation loss is reduced and the system recirculation loss is just zero. One typical example is to calculate the power distribution so that the rotation speed of the first rotating electrical machine 18 can be zero under the constant power of the engine 14.

  FIG. 4 shows how the required engine speed for obtaining zero system recirculation loss is obtained. This figure is an operation characteristic diagram 52 of the engine 14 and can be obtained in advance according to the specification of the vehicle. And it memorize | stores in the memory | storage device 50 connected to the vehicle drive control apparatus 40, and can read and utilize as needed.

  Although shown in the map format in FIG. 4, the storage device 50 can store data in other formats. For example, the engine speed, torque, power, number of cylinders, energy utilization efficiency, etc. can be stored in the form of a look-up table, a calculation formula or the like that can output a desired one as an input variable. it can.

Operation characteristic diagram 52, the horizontal axis represents the required engine rotational speed N _E, the engine required torque T _E on the vertical axis is taken. Since the product of the rotation speed and the torque is power, equal power lines are indicated by P ₁ , P ₂ , and P ₃ . Here, P ₁ <P ₂ <P ₃ . Further, the equal energy utilization efficiency lines of the engine 14 obtained experimentally are indicated by α ₁ , α ₂ , α ₃ , and α ₄ . Here, α ₁ > α ₂ > α ₃ > α ₄ .

The operating point setting line of the engine 14 is indicated by C _8. The operating point setting line C ₈ is set so that the required operating point of the engine 14 (N _E , T _E ) passes through a point where the energy utilization efficiency is as high as possible. That is, the operating point setting line C ₈ is drawn along the direction orthogonal to the equal energy utilization efficiency line through the maximum point of the equal energy utilization efficiency line. Here, C ₈ indicates an operating point setting line when the engine 14 operates all eight cylinders.

4, if the engine 14 is stationary operation, the intersection of a required torque indicated by the accelerator pedal 36, and equal power line indicating a required power determined by the running speed of the vehicle, the operating point setting line C ₈ Is the actual operating point. In the example of FIG. 4, the required power is P ₂ and the intersection (N _E1 , T _E1 ) between the equal power line P ₂ and the operating point setting line C ₈ is the actual operating point. As shown in FIG. 4, this operating point is set at a position where the energy utilization efficiency of the engine 14 is higher than α ₁ and is almost the maximum efficiency.

When an affirmative determination is made in S12 in FIG. 3, 4, calculated under the constant power condition, i.e. on an equal power line P _2, to move the operating point, the system recirculation losses at the respective points Is done. The calculation of the system recirculation loss can be obtained by Δenergy = (1−β) × (1−a ₁ × a ₃ ) × (energy 60) as described in FIG. Since (1-β) is the ratio of energy output from the engine 14 that is distributed to power generation, the system recirculation loss can be suppressed by reducing the ratio of distribution to power generation as much as possible.

Assuming that the operating point when the system recirculation loss is zero is calculated as (N _E2 , T _E2 ), the calculation in S14 is the required engine speed = N _E1 . At this time, if the engine 14 has 8 cylinders, the energy utilization efficiency of the engine 14 at this operating point (N _E2 , T _E2 ) is initially between α ₃ and α _{4 as} shown in FIG. The energy utilization efficiency is lower than the energy utilization efficiency α ₁ or more at the operating point (N _E1 , T _E1 ).

Therefore, in S16 of FIG. 3, the engine can be operated at the operating point (N _E2 , T _E2 ) using the relationship that the engine speed N _E is changed by changing the number of operating cylinders of the engine 14 under a constant power condition. The number of operating cylinders of the engine 14 is calculated. This step is executed by the function of the engine cylinder number calculation processing unit 46 of the vehicle drive control device 40.

When the number of operating cylinders of the engine 14 is changed, the torque-rotational speed characteristic of the operating point setting line changes so as to substantially correspond to that obtained by directly reducing the magnitude of the torque. In FIG. 4, the operating point setting line when the number of operating cylinders is 7 is indicated by C ₇ , the operating point setting line when the number of operating cylinders is ₆ is indicated by C ₆ , and the operating point when the number of operating cylinders is 5 the setting line are indicated by C _5. As shown in FIG. 4, when the number of operating cylinders is changed, the operating point setting line at that time becomes a contraction of the vertical axis substantially in proportion to the decreasing rate of the number of operating cylinders.

In the above example, the number of operating cylinders of the engine 14 that can operate at the operating point (N _E2 , T _E2 ) under the condition that the power is P ₂ is 6 cylinders. The operating point setting line C _{6 at} this time is substantially the same as the original operating point setting line C _{8 in} which the vertical axis is reduced by the ratio of the number of operating cylinders 6/8 = 0.75. Therefore, as long as the operating point is changed on the equal power line _{P 2 (N E2, T E2} ) does not significantly move from the original operating point (N _E1, T _E1), the operating point (N _E2, T _E2) is The operating point setting line C ₆ is also in the vicinity of the maximum energy utilization efficiency point. That is, the energy utilization efficiency of the engine 14 can be maintained as it is, with the energy utilization efficiency being substantially the same as the energy utilization efficiency at the initial operating point (N _E1 , T _E1 ) that is α ₁ or more.

  When the number of operating cylinders of the engine 14 is calculated in this way, the operating state of the engine 14 is changed to the calculated number of operating cylinders (S18). This step is executed by the function of the cylinder number change processing unit 48 of the vehicle drive control device 40.

  In this way, by changing the number of operating cylinders of the engine 14, the system recirculation loss can be made zero while maintaining the energy utilization efficiency as much as possible. Of course, to maximize overall energy efficiency, the energy utilization efficiency of the engine 14 can be maintained while causing a slight system recirculation loss.

  The vehicle drive control system according to the present invention can be used in a system in which an engine, a first rotating electrical machine, and a second rotating electrical machine are coupled by a power distribution mechanism and the output is supplied to a drive shaft of the vehicle.

  DESCRIPTION OF SYMBOLS 10 Vehicle drive control system, 12 Drive system, 14 Engine, 16 Damper, 18, 20 Rotating electric machine, 22 Transmission, 24 Propeller shaft, 25 Drive shaft, 26 Power distribution mechanism, 28 Fixed stage reducer, 30 Wheel, 32 Power supply Drive circuit unit, 33 power storage device, 34 shift lever, 36 accelerator pedal, 38 brake pedal, 40 vehicle drive control device, 42 drive control processing unit, 44 system recirculation determination processing unit, 46 engine cylinder number calculation processing unit, 48 Cylinder number change processing unit, 50 storage device, 52 operation characteristic diagram, 60, 62, 64, 65, 66, 68 energy.

Claims (2)

In a vehicle drive control system in which an engine, a first rotating electrical machine, and a second rotating electrical machine are coupled by a power distribution mechanism and an output thereof is supplied to a drive shaft of the vehicle,
Since the engine is in a steady operation state and one of the first rotating electric machine or the second rotating electric machine is generating electric power, a part of the driving force of the engine is used for electric power generation, and the first rotation is generated by the generated electric power. System recirculation determination means for determining whether the other of the electric machine or the second rotating electric machine is in a state where a system recirculation loss is caused by generating a driving force;
When it is determined that the system is in a recirculation state, the engine speed is changed by changing the number of operating cylinders under a constant power condition, and the system recirculation loss is changed by changing the engine speed. Means for calculating the number of engine cylinders that can reduce the system recirculation loss to zero based on
Cylinder number changing means for changing the number of operating cylinders of the engine to the calculated number of engine cylinders;
A vehicle drive control system comprising: The vehicle drive control system according to claim 1,
System recirculation judgment means
A state in which a system recirculation loss occurs when the engine is in a steady operation state and one of the first rotating electric machine or the second rotating electric machine and the rotating electric machine coupled to the engine is rotating. A vehicle drive control system characterized in that it is determined that

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