JP3799646B2 - Hybrid vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hybrid vehicle that travels using an engine and a motor as drive sources.
[0002]
[Prior art]
Conventionally, a vehicle is mounted with an internal combustion engine such as a gasoline engine or a diesel engine as a drive source, and travels by obtaining energy by burning gasoline or light oil. These drive sources have the advantage that high output can be obtained and long-distance traveling is possible.₂ , NO_x There is a problem that gases such as these adversely affect the environment.
[0003]
Therefore, with the recent depletion of fossil energy and the increase of environmental problems, development of low noise and low pollution vehicles is desired, and among them, electric vehicles are cited as the most attention.
This electric vehicle uses an electric motor as a drive source, drives the electric motor with electric power charged in a battery, and has an advantage that there is no exhaust gas and low noise.
[0004]
However, since this electric vehicle is equipped with a heavy battery, the weight of the vehicle becomes heavy and the running efficiency is lowered. In addition, sufficient output cannot be obtained only with the electric power charged in the battery, and sudden acceleration or There is a drawback that it is not possible to run long distances. Further, in order to use a once used battery again, a long charging time is required, and the range of use must be limited.
[0005]
Therefore, a hybrid vehicle equipped with an internal combustion engine and an electric motor has been proposed. Various types of hybrid vehicles are provided. For example, rotation generated by driving an engine is transmitted to a generator to drive the generator, and electric power obtained by the generator is sent to a battery for charging. Further, a series (series) hybrid vehicle in which the electric motor is driven by the electric power of the battery, or a parallel (parallel) type in which the driving force of the engine and the electric motor is transmitted to the output shaft to drive the vehicle. There are hybrid vehicles.
[0006]
[Problems to be solved by the invention]
FIG. 23 is a diagram showing an engine maximum efficiency region and a best fuel consumption curve. Even in the case of a parallel type hybrid vehicle, an average of 10 kW of energy is required when traveling in an urban area where there are many low-speed travels, and an average of 30 kW of energy is required when traveling at the same speed on the same vehicle. As shown in FIG. 23, in the parallel hybrid vehicle, even when the engine is operated in the optimum fuel consumption line, the engine can be driven in a high efficiency region during high speed traveling (point B in the figure) When running at low speed in an urban area (point A in the figure), there is a problem that the engine efficiency cannot be increased.
[0007]
In addition, a large output is required when the vehicle is accelerated or when the vehicle is traveling at a high speed. However, if the output is covered by a motor, the battery is overdischarged and the battery life is shortened.
[0008]
An object of the present invention is to provide a hybrid vehicle capable of constantly driving an engine with high efficiency and low fuel consumption by appropriately switching between a motor running state, an engine / motor running state, and the like according to a running condition. .
[0009]
[Means for Solving the Problems]
Such an object is achieved by the present invention described below.
[0010]
(1) the engine,
A generator capable of controlling the rotational speed;
A drive output shaft that outputs the driving force of the drive wheels;
A differential gear device in which a first gear element is connected to an output shaft of the engine, a second gear element is connected to a rotor of the generator, and a third gear element is connected to the drive output shaft;
An electric motor coupled to the drive output shaft;
Generator stopping means for stopping rotation of the generator;
Engine control means for controlling the output of the engine;
Generator control means for controlling the rotation of the generator;
Traveling load detection means for detecting the traveling load;
Travel load detected by the travel load detection meansAnd capacity of power storage meansDepending on the drive output shaftWithout the output of the engine being transmittedThe electric motorPowerCommunicatedBeIn the first traveling mode, part of the engine output is transmitted to the generator and the rest is transmitted to the drive output shaft.BeThe second driving mode andA third traveling mode in which the generator is stopped by stopping the generator and the outputs of the engine and the electric motor are output to the drive output shaft;A hybrid vehicle, characterized by comprising travel mode selection means for selecting the vehicle.
[0011]
(2)Engine,
A generator capable of controlling the rotational speed;
A drive output shaft that outputs the driving force of the drive wheels;
A differential gear device in which a first gear element is connected to an output shaft of the engine, a second gear element is connected to a rotor of the generator, and a third gear element is connected to the drive output shaft;
An electric motor coupled to the drive output shaft;
Generator stopping means for stopping rotation of the generator;
Engine control means for controlling the output of the engine;
Generator control means for controlling the rotation of the generator;
A first travel mode in which the output of the electric motor is transmitted to the drive output shaft without being transmitted to the drive output shaft in accordance with the output of the electric motor and the allowable output of the power storage means; A second travel mode in which a part is transmitted to the generator and the rest is transmitted to the drive output shaft, and the generator is stopped by stopping the generator, and the outputs of the engine and the electric motor are transmitted to the drive output shaft It has a driving mode selection means for selecting the output third driving mode.Hybrid vehicle.
[0012]
(3)The engine control means controls the throttle of the engine so that the engine is driven on an optimum fuel consumption line.The hybrid vehicle according to (1) or (2) above.
[0014]
  (4) In any one of the above (1) to (3), the engine control means controls the engine to be driven at a load or more determined according to the capacity of the power storage means. The described hybrid vehicle.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
<First Embodiment>
Hereinafter, a first embodiment of a hybrid vehicle of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a conceptual diagram showing a hybrid vehicle drive apparatus according to a first embodiment of the present invention. In the figure, on the first axis, an engine 11, an engine output shaft 12 that outputs a rotation generated by driving the engine 11, and a speed change with respect to the rotation input through the engine output shaft 12. A planetary gear unit 13 which is a differential gear device to be performed, a unit output shaft 14 to which rotation after shifting in the planetary gear unit 13 is output, a first counter drive gear 15 fixed to the unit output shaft 14, and normal travel In the state, a generator 16 that mainly functions as a generator and a transmission shaft 17 that connects the generator 16 and the planetary gear unit 13 are arranged. The unit output shaft 14 has a sleeve shape and is disposed so as to surround the engine output shaft 12. The first counter drive gear 15 is disposed closer to the engine 11 than the planetary gear unit 13.
[0018]
The planetary gear unit 13 rotatably supports the sun gear S that is the second gear element, the pinion P that meshes with the sun gear S, the ring gear R that is the third gear element meshed with the pinion P, and the pinion P. And a carrier CR which is a first gear element.
[0019]
The sun gear S is connected to the generator 16 via the transmission shaft 17, the ring gear R is connected to the first counter drive gear 15 via the unit output shaft 14, and the carrier CR is connected to the engine via the engine output shaft 12. 11 is connected.
[0020]
Further, the generator 16 is fixed to the transmission shaft 17 and includes a rotor 21 that is rotatably disposed, a stator 22 that is disposed around the rotor 21, and a coil 23 that is wound around the stator 22. I have. The generator 16 generates electric power by the rotation transmitted through the transmission shaft 17. The coil 23 is connected to a battery 19 (FIG. 4) that is a power storage means, and supplies power to the battery 19 to charge it.
[0021]
An electric motor 25, a motor output shaft 26 that outputs the rotation of the electric motor 25, and a second counter drive gear 27 fixed to the motor output shaft 26 are arranged on a second axis parallel to the first axis. Has been.
[0022]
The electric motor 25 includes a rotor 37 fixed to the motor output shaft 26 and rotatably arranged, a stator 38 disposed around the rotor 37, and a coil 39 wound around the stator 38. I have. The electric motor 25 generates torque by the current supplied to the coil 39. For this purpose, the coil 39 is connected to the battery 19 so that a current is supplied from the battery 19.
[0023]
When the hybrid vehicle of the present invention is in a decelerating state, the electric motor 25 receives rotation from drive wheels (not shown) to generate regenerative power, and supplies the regenerative power to the battery 19 for charging.
[0024]
In order to rotate a driving wheel (not shown) in the same direction as the rotation of the engine 11, a counter shaft 31 is disposed as a drive output shaft on a third axis parallel to the first axis and the second axis. Yes. A counter driven gear 32 is fixed to the counter shaft 31.
[0025]
Further, the counter driven gear 32 and the first counter drive gear 15 and the counter driven gear 32 and the second counter drive gear 27 are engaged with each other, so that the rotation of the first counter drive gear 15 and the rotation of the second counter drive gear 27 are performed. Is inverted and transmitted to the counter driven gear 32.
Further, a differential pinion gear 33 having a smaller number of teeth than the counter driven gear 32 is fixed to the counter shaft 31.
[0026]
A diff ring gear 35 is disposed on a fourth axis parallel to the first axis, the second axis, and the third axis, and the diff ring gear 35 and the diff pinion gear 33 are engaged with each other. Further, a differential device 36 is fixed to the differential ring gear 35, and the rotation transmitted to the differential ring gear 35 is differentially transmitted by the differential device 36 and transmitted to the drive wheels.
[0027]
Thus, not only the rotation generated by the engine 11 can be transmitted to the counter driven gear 32, but also the rotation generated by the electric motor 25 can be transmitted to the counter driven gear 32, so that only the electric motor 25 is transmitted. The hybrid vehicle can be driven in a motor drive mode in which the engine 11 and the electric motor 25 are driven, and in a motor drive mode in which the engine 11 and the electric motor 25 are driven. Further, by controlling the electric power generated in the generator 16, the rotation speed of the transmission shaft 17 can be controlled. If the rotation of the generator 16 is stopped, all the output of the engine 11 is transmitted to the drive output shaft. Is done.
[0028]
The operation of the planetary gear unit 13 of the hybrid vehicle having the above configuration will be described. 2A is a conceptual diagram of the planetary gear unit 13 (FIG. 1) according to the first embodiment of the present invention, and FIG. 2B is a speed during normal running of the planetary gear unit 13 according to the first embodiment of the present invention. FIG. 3 is a torque diagram during normal running of the planetary gear unit 13 according to the first embodiment of the present invention.
[0029]
In the present embodiment, the number of teeth of the ring gear R of the planetary gear unit 13 is twice the number of teeth of the sun gear S, as shown in FIG. Therefore, the rotational speed of the unit output shaft 14 connected to the ring gear R (hereinafter referred to as “ring gear rotational speed”) is NR, and the rotational speed of the engine output shaft 12 connected to the carrier CR (hereinafter referred to as “engine rotational speed”). .) Is NE, and the rotational speed of the transmission shaft 17 connected to the sun gear S (hereinafter referred to as “generator rotational speed”) is NG, the relationship between NR, NE, and NG is shown in FIG. As shown,
[0030]
NG = 3 ・ NE-2 ・ NR
[0031]
It becomes. Further, the torque output from the ring gear R to the unit output shaft 14 (hereinafter referred to as “ring gear torque”) is TR, the torque of the engine 11 (hereinafter referred to as “engine torque”) is TE, and the generator torque is TG. Then, the relationship between TR, TE, and TG is as shown in FIG.
[0032]
TE: TR: TG = 3: 2: 1
[0033]
It becomes.
During normal driving of the hybrid vehicle, the ring gear R, the carrier CR, and the sun gear S are all rotated in the forward direction, and as shown in FIG. 2B, the ring gear rotational speed NR (= output rotational speed). NOUT), engine speed NE, and generator speed NG all take positive values.
[0034]
The engine torque TE is input to the carrier CR, and the engine torque TE is received by the reaction force of the first counter drive gear 15 and the generator 16 shown in FIG. As a result, as shown in FIG. 3, the ring gear torque TR is output from the ring gear R to the unit output shaft 14, and the generator torque TG is output from the sun gear S to the transmission shaft 17.
[0035]
The ring gear torque TR and the generator torque TG are obtained by apportioning the engine torque TE by a torque ratio determined by the number of teeth of the planetary gear unit 13, and on the torque diagram, the ring gear torque TR and the generator torque TG Is the engine torque TE.
[0036]
Next, the control system of the hybrid vehicle of the present invention will be described in detail based on the block diagram of FIG. The control means constituting the control system of the present embodiment includes a vehicle control device 41, an engine control device 42, a motor control device 43, and a generator control device 44. These control devices 41, 42, 43, and 44 are, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) storing various programs and data, and a RAM (Random Access Memory) used as a working area. And a microcomputer equipped with a memory).
[0037]
The vehicle control device 41 and the engine control device 42 constitute an engine control means, the vehicle control device 41 and the generator control device 44 constitute a generator control means and a generator stop means, and the vehicle control device 41 selects a travel mode. Means are configured.
[0038]
Further, this control system serves as a travel load detecting means, an accelerator sensor 45 for detecting an accelerator opening α indicating the degree of demand for the vehicle driving force of the driver, a vehicle speed sensor 46 for detecting the vehicle speed V, and a battery 19. A battery sensor 48 for detecting the remaining battery charge SOC is provided. Detection values detected by the respective sensors 45, 46 and 48 are supplied to the vehicle control device 41.
[0039]
The vehicle control device 41 controls the entire hybrid vehicle. The vehicle control device 41 travels only by the output of the electric motor 25. The vehicle control device 41 travels while rotating the electric motor 25, the engine 11, and the generator 16. The travel mode is selected, and the mode is changed based on the supplied accelerator opening α, vehicle speed V, and remaining battery charge SOC. This change determination is made based on the maps shown in FIGS.
[0040]
For example, referring to FIG. 5, when the remaining battery SOC is less than 30%, the engine 11 is always driven with the second traveling mode including when the vehicle is stopped. The electric power generated in the generator 16 by driving the engine 11 is stored in the battery 19 and controlled so that the remaining battery charge SOC increases.
[0041]
When the remaining battery SOC is 30% or more and less than 50%, the mode switching vehicle speed V * 1 is set to 0 km / h, the engine 11 is stopped only when the vehicle is stopped, and the auxiliary machine needs to be driven. Is idling, and immediately after the start of traveling, the engine 11 is started and the vehicle travels in the second traveling mode.
[0042]
When the remaining battery SOC is 50% or more and less than 80%, the mode switching vehicle speed V * 1 is set to 20 km / h, and when the vehicle speed is less than 20 km / h, the vehicle travels in the first mode and 20 km / h. In the above case, the vehicle travels in the second travel mode.
[0043]
When the remaining battery SOC is 80% or more, the mode switching vehicle speed V * 1 is set to 80 km / h in principle, and the mode switching is performed based on FIG. That is, when the accelerator opening degree α is 70% or more, the mode switching vehicle speed V * 1 is set to 20 km / h, and when the vehicle speed is less than 20 km / h, the vehicle travels in the first travel mode and 20 km / h. In the above case, the vehicle travels in the second travel mode. By running in the second running mode, power from the generator 16 driven by the engine 11 is supplied, and excessive discharge from the battery 19 is suppressed. Further, when the vehicle speed is 20 km / h or less, since the speed is low and high electric power is not required, the vehicle travels with an electric motor.
[0044]
In order to prevent hunting, the mode switching vehicle speed V * 1 is smaller than the value when switching from the first traveling mode to the second traveling mode than the value when switching from the second traveling mode to the first traveling mode. Thus, hysteresis may be provided. This hysteresis is similarly provided for the switching value (30%, 50%, 80%) of the remaining battery charge SOC for changing the mode switching vehicle speed V * 1 and the switching value (70%) of the accelerator opening α. it can.
[0045]
In addition to the control described above, when the output of the electric motor 25 exceeds the battery allowable output, the second traveling mode may be set and control may be performed so as to suppress excessive discharge from the battery 19. The battery allowable output is determined by the remaining battery charge SOC and the temperature of the battery 19, and is determined by, for example, a map shown in FIG. The determination based on the battery allowable output may be performed by detecting the battery output or the amount of battery voltage drop that changes in accordance with the change in the output of the electric motor 25 in addition to the case where the output of the electric motor 25 is detected. Good.
[0046]
Further, when the vehicle control device 41 supplies the throttle opening signal θ and the engine ON / OFF signal to the engine control device 42 and switches to the second travel mode, the vehicle control device 41 sends the engine ON signal to the first travel. An engine OFF signal is supplied when switching to the mode.
[0047]
Further, the vehicle control device 41 determines the target motor torque TM * corresponding to the accelerator opening α from the accelerator sensor 45 and the vehicle speed V from the vehicle speed sensor 46 based on the map shown in FIG. This is supplied to the motor control device 43 as a motor torque command value TM *.
[0048]
Furthermore, when the motor torque command value TM * is switched from the first travel mode to the second travel mode, it is corrected in advance so that the torque variation accompanying the start of the engine 11 is absorbed and the torque transmitted to the drive wheels does not vary. Value. That is, as described above, the gear ratio of the ring gear R and the sun gear S in the planetary gear unit 13 is TE: TG: TR (TOUT; output torque from the engine) = 3: 1: 2, and is driven by starting and stopping the engine. The torque fluctuation ΔTM transmitted to the wheel can be obtained as ΔTM = TOUT × i = TG × 2 × i, where i is the counter gear ratio.
[0049]
When the vehicle control device 41 switches the travel mode, the motor control command value TM * is corrected by a torque fluctuation ΔTM caused by starting or stopping the engine and supplied to the motor control device 43. Furthermore, torque fluctuations caused by fluctuations in the generator speed NG are also absorbed by correcting the motor torque command value TM *.
[0050]
As another function of the vehicle control device 41, the control target rotational speed NG * of the generator 16 is supplied to the generator control device 44. The target rotational speed NG * is determined based on the map shown in FIG. That is, the larger the load, the higher the number of revolutions of the generator 16 is controlled to increase the power to be generated. In the present embodiment, the map is set such that the higher the accelerator opening α is, the higher the rotational speed is, and the lower the remaining battery charge SOC is, the higher the rotational speed is.
[0051]
In addition, when switching from the first travel mode to the second travel mode, the vehicle control device 41 performs control to reduce the generator rotational speed NG by adding the generator torque TG in order to start the engine 11. That is, as shown in FIG. 10, when the generator torque is applied to the generator 16 in the direction of decreasing the generator rotational speed NG in the first traveling mode (dashed line in the figure) in which only the electric motor travels, Torque is applied in the direction in which the engine 11 is rotated, and the engine 11 is rotated (solid line in the figure). Thereby, the engine 11 can be started.
[0052]
Based on the selection command signal input from the vehicle control device 41, the engine control device 42 drives the engine 11 in a driving state in which engine torque is output (ON state) and a non-driving state in which engine torque is not generated. Switch to (OFF state). Further, the throttle opening degree θ is controlled in accordance with the actual engine speed NE input from the engine speed sensor provided in the engine 11 so that the engine 11 is driven with high efficiency.
[0053]
The motor control device 43 controls the current (torque) IM of the electric motor 25 so that TM = TM *.
[0054]
The generator control device 44 controls the rotational speed NG of the generator 16 and controls the current (torque) IG so that the control target rotational speed NG * input from the vehicle control device 41 is obtained. The generator control device 44 monitors the output torque TG of the generator 16 and the actual rotational speed NG of the generator 16 and inputs the values to the vehicle control device 41, respectively.
[0055]
Hereinafter, the control operation of the vehicle control device 41 will be described based on the flowcharts shown in FIGS. 11 to 13. The accelerator opening α is read (step S101), and the remaining battery charge SOC and the vehicle speed V are read (step S102). Then, it is determined whether or not the accelerator opening α is larger than 70% (step S103).
[0056]
When the accelerator opening α is 70% or less, the mode switching vehicle speed V * 1 is determined from the read battery remaining amount SOC based on the map shown in FIG. 5 (step S104). The mode switching vehicle speed V * 1 is compared with the read vehicle speed V (step S106).
[0057]
On the other hand, when the accelerator opening α is larger than 70%, it is determined whether or not the vehicle speed V is larger than 20 km / h (step S105). If the vehicle speed V is 20 km / h or less, step S104 is executed.
[0058]
In step S106, when the vehicle speed V is equal to or less than the mode switching vehicle speed V * 1, the current travel mode is determined (step S107). When it is the first travel mode in which the motor travels only, the process proceeds to the first travel mode routine. If it is not in the first travel mode, a signal for setting the throttle opening θ to 0% is supplied to the engine control device 42 (step S108), and further a fuel cut signal (OFF signal) is supplied to the engine control device 42 (step S108). S109). Next, after the control of the generator 16 is turned off and idling (step S120), the process proceeds to the first travel mode routine.
[0059]
On the other hand, if the vehicle speed V is greater than the mode switching vehicle speed V * 1 in step S106 and if the vehicle speed V is greater than 20 km / h in step S105, the current travel mode is first determined (step S121). In the case of the two travel mode, the second travel mode routine is executed. In the first traveling mode, the generator 16 is turned on to generate the generator torque TG, the engine 11 is started by the generator 16 by the method shown in FIG. 10 (step S122), and further the fuel After supplying the supply signal (ON signal) to the engine control device 42 to start the engine 11 (step S123), the second travel mode routine is executed.
[0060]
FIG. 12 is a flowchart showing a first travel mode routine. In the first travel mode, first, the accelerator opening α and the vehicle speed V are read (step S124), and the target motor torque TM * is calculated from the map shown in FIG. 8 (step S125). The calculated TM * is supplied to the motor control device 43 (step S126).
[0061]
FIG. 13 is a flowchart showing the second travel mode routine. In the second traveling mode, the engine 11 and the generator 16 are driven. First, the accelerator opening α and the vehicle speed V are read (step S131), and the target motor torque TM * corresponding to the accelerator opening α and the vehicle speed V is calculated from the map shown in FIG. 8 (step S132). Further, the generator torque TG is read from the generator controller 44 (step S133), and a torque correction value ΔTM is calculated from the generator torque TG (step S134). From the target motor torque TM * calculated in step S132, the correction value ΔTM is corrected to finally determine the target motor torque TM * (step S135).
[0062]
The target motor torque TM * determined in step S135 is supplied to the motor control device 43 (step S136). Next, the remaining battery charge SOC is read (step S137), and the target rotational speed NG * of the generator is calculated based on the read remaining battery charge SOC and the map shown in FIG. 9 (step S138). Then, the calculated target rotational speed NG * is supplied to the generator control device 44 (step S139). By calculating from the generator torque, the engine torque is estimated without using a torque sensor.
[0063]
FIG. 14 shows another example of the control operation of the vehicle control device 41 in the present embodiment. The control for comparing the output of the electric motor 25 with the battery allowable output and determining the switching to the second travel mode is shown. It is a flowchart in the case of performing.
[0064]
The accelerator opening α and the vehicle speed V are read (step S151), and the target motor torque is calculated from the read values of the accelerator opening α and the vehicle speed V based on the map shown in FIG. 8 (step S152).
[0065]
Next, a motor output WKW is obtained (step S153). The motor output WKW is obtained by the product of the target motor torque TM * obtained in step S152 and the rotation speed NM of the electric motor 25 (WKW = TM ** × NM). Here, the motor speed NM is obtained from the vehicle speed V.
[0066]
The remaining battery charge SOC and the battery temperature are read (step S154), and the battery allowable output BKW is calculated from these values based on the map shown in FIG. 7 (step S155).
[0067]
The motor output WKW obtained in step S153 is compared with the battery allowable output BKW calculated in step S155. If the battery allowable output BKW is larger than the motor output WKW, the remaining battery level S0C read in step S154 5 and the map shown in FIG. 5, the mode switching vehicle speed V * 1 is determined, and the traveling state is determined by the mode switching vehicle speed V * 1, the accelerator opening α and the vehicle speed V read in step S151. It is determined whether the first travel mode or the second travel mode is set (step S157).
[0068]
In step S156, if the battery allowable output BKW is equal to or less than the motor output WKW, the output WG of the generator 16 is obtained (step S158). The generator output WG is obtained by subtracting the battery allowable output BKW from the motor output WKW (WG = WKW−BKW). Then, the rotation of the generator 16 is controlled so that this generator output WG is obtained, and the second traveling mode routine shown in FIG. 13 is executed. Further, the torque that varies with the generator control in step S158 is corrected in steps S134 and S135 in the second travel mode routine.By adopting a configuration in which the motor torque is corrected according to the drive of the generator, a good running feeling can be maintained.
[0069]
In addition, when the second travel mode is set in step S157, the second travel mode routine is similarly executed. If the first travel mode is set in step S157, the first travel mode routine shown in FIG. 12 is executed.
By the control operation described above, overdischarge of the battery 19 can be prevented, the battery life can be extended, the travel distance can be extended, and highly efficient travel is possible.
[0070]
Second Embodiment
Next, a second embodiment of the present invention will be described. FIG. 15 is a conceptual diagram showing the configuration of the driving apparatus of the second embodiment. In the hybrid vehicle of this embodiment, a brake B, which is a friction engagement means as a generator stop means, is interposed between the rotor 21 of the generator 16 and the case. By engaging the brake B, the rotor 21 is fixed, and the rotation of the generator 16 and the sun gear S is stopped.
[0071]
FIG. 16 is a block diagram showing a control system of the second embodiment. Engagement and release of the brake B are controlled by an actuator 58 to which an ON / OFF signal is supplied from the vehicle control device 41. The actuator 58 engages the brake B when the ON signal is supplied from the vehicle control device 41, and releases the brake B when the OFF signal is supplied. The brake B in this embodiment is a wet brake and is operated by hydraulic pressure supplied from a pressure oil source. As the pressure oil source, for example, an electric hydraulic pump, a hydraulic pump driven by rotation of the engine output shaft 12, or the like can be used. Since other configurations are the same as those in the first embodiment, the same components as those in FIG.
[0072]
The operation of the vehicle control device 41 in this embodiment will be described. The present embodiment is configured to switch between motor travel using only the electric motor 25 as a drive source and hybrid travel using the electric motor 25 and the engine 11 as drive sources according to the travel load. Then, the configuration is switched between a case where the generator 16 travels while generating power by rotating the generator 16 and a case where the generator 16 travels without generating power.
[0073]
That is, the traveling mode includes a first traveling mode that travels by the output of only the electric motor 25, a second traveling mode that travels by the output of the electric motor 25 and the engine 11 while generating power in the generator 16, and the generator 16 In the state where the rotor 21 is fixed, the mode is switched to three modes of the third travel mode in which the vehicle travels by the outputs of the electric motor 25 and the engine 11.
[0074]
Specifically, the vehicle travels at a higher load, such as the first travel mode when traveling at a low load such as low speed travel, the third travel mode when traveling at a high load such as high speed travel, and the like when accelerating at a high speed. Occasionally, the vehicle travels by switching to the second travel mode.
[0075]
As in the operation in the first embodiment, the vehicle control device 41 in the present embodiment determines the mode switching vehicle speed V * 1 for switching from the first travel mode from the map shown in FIG. Control is performed so that the vehicle travels in one travel mode. When the load is high, the mode switching accelerator opening α1 * is determined based on the map shown in FIG. 17, and the mode is changed between the second traveling mode and the third traveling mode according to the accelerator opening α. Can be switched. The map shown in FIG. 17 is set so that the region of the second traveling mode is expanded as the remaining battery level S0C decreases, and the region of the second traveling mode is expanded as the accelerator opening α is increased. ing.
[0076]
FIG. 18 is a map showing the mode switching vehicle speed V * 1 and the mode switching accelerator opening α1 * when the battery remaining amount S0C is 60%, and shows the areas where the vehicle travels in each mode. When the remaining battery capacity S0C is 60%, the mode switching vehicle speed V * 1 is set to 20 km / h from the map shown in FIG. 5, and the mode switching accelerator opening α1 * from the map shown in FIG. Is set to 40%. Further, if the generator 16 is not rotated at 30 km / h or less, the rotational speed of the engine 11 becomes too small, and the efficiency and vibration are deteriorated. Therefore, regardless of the remaining battery power S0C and the accelerator opening α, 30 km / h Below h, the vehicle is controlled to travel in the second travel mode.
[0077]
When switching from the second traveling mode to the third traveling mode, an ON signal is supplied to the actuator 58 to stop the rotation of the generator 16, and when switching to the reverse, an OFF signal is supplied to rotate the generator 16. To do. Here, the actuator 58 includes an electromagnetic valve that opens and closes when an ON / OFF signal is supplied, and a hydraulic cylinder that is supplied with pressure oil from a pressure oil source when the electromagnetic valve is opened and closed. The friction plate of the brake B is engaged and released.
[0078]
Furthermore, the vehicle control device 41 determines the target rotational speed NG * of the generator 16 based on the remaining battery amount S0C and the accelerator opening α based on the map shown in FIG. This map is set so that the target rotational speed NG * increases as the battery remaining amount S0C decreases and as the accelerator opening α increases. In other words, if the remaining battery charge S0C decreases, the power generation amount is increased to recover the charge amount, and if the accelerator opening α is increased, the battery consumption is increased, so the power generation amount is increased to suppress the decrease in the charge amount. is doing.
[0079]
Further, since the efficiency of the generator 16 is reduced when the generator 16 is at a low speed, the brake B is engaged and the vehicle travels in the third travel mode when the target rotational speed NG * is 1500 rpm or less. .
[0080]
In addition to the above control operation, the vehicle control device 41 according to the present embodiment, when the output of the electric motor 25 exceeds the battery allowable output, is changed from the first or third travel mode to the second, similarly to the first embodiment. It is good also as what controls to switch to driving | running | working mode and suppress the excessive discharge from the battery 19. FIG. Since the calculation of the battery allowable output is the same as the content described in the first embodiment, the description thereof is omitted. When the output of the electric motor 25 does not exceed the battery allowable output, the above control operation is performed, and each mode is selected based on the maps shown in FIGS.
[0081]
In the second embodiment described above, switching between motor traveling and hybrid traveling is determined by the mode switching vehicle speed, but can also be determined by the mode switching accelerator opening. For example, when the accelerator opening degree α is small, the first traveling mode is set, and when the accelerator opening degree α is large, the second traveling mode is set. In addition, the area in which each mode is selected is changed according to the remaining battery level S0C. When the remaining battery level S0C is large, the area in which the first traveling mode is selected is increased, and when the remaining mode is small, the first mode is selected. It can set so that the area | region where 2 driving modes are selected may become large.
[0082]
FIG. 20 is a map for calculating the mode switching accelerator opening α2 * from the battery remaining amount S0C. In this map, when the remaining battery SOC is 30% or more and less than 55%, the mode switching accelerator opening α2 * 1 is set to 0, and the engine 11 is stopped or idled only when the accelerator is released, and even the accelerator is slightly engaged. When the engine is depressed, the engine 11 is immediately started and the vehicle travels in the second travel mode. In addition, when the remaining battery charge SOC is 55% or more and less than 80%, the mode switching accelerator opening α2 * increases according to the remaining battery charge S0C, and is always first when the remaining battery charge S0C is 80% or more. The travel mode is set.
[0083]
FIG. 21 is a map showing the mode switching accelerator opening α1 * and the mode switching accelerator opening α2 * when the battery remaining amount S0C is 60%, and shows the areas where the vehicle travels in each mode. is there. The mode switching accelerator opening α2 * is 20% from FIG. 20, and the mode switching accelerator opening α1 * is set to 40% from FIG. When the value of the battery remaining amount S0C is small, as is apparent from the maps of FIGS. 17 and 20, the values of the mode switching accelerator openings α1 * and α2 * are small, and the second travel mode region in the map of FIG. Spread. As shown in the speed diagram of the planetary gear unit in FIG. 22, when the engine 11 is stopped (NE = 0) and the vehicle runs at a high speed (large NOUT), the generator 16 rotates at a high speed (NG). Large), since an excessive load is generated on the generator 16, the engine 11 is not stopped at a vehicle speed of 80 km / h or higher, and hybrid travel is performed.
[0084]
When the travel mode is switched from the first travel mode to the third travel mode, the engine 11 is started by driving the generator 16, and then the brake B is engaged to enter the third travel mode. The engine 11 may be started by engaging the brake B to enter the third traveling mode.
[0085]
In each of the embodiments described above, the vehicle speed V and the accelerator opening degree α are used as the travel loads. However, for example, the rotation speed of the electric motor 25 and the rotation speed of the engine 11 can be used instead of the vehicle speed. Further, the motor torque command value TM * may be used instead of the accelerator opening.
[0086]
In addition, it has been described that the engine control device 42 controls the throttle opening θ to drive the engine, but it is desirable to drive the engine in the optimum combustion line shown in FIG. Further, the line C in FIG. 23 may be changed according to the battery remaining amount S0C. For example, when the remaining battery charge SOC decreases, the line C can be increased to increase the engine output. For this reason, the energy generated by the generator can be increased.
[0087]
Examples of the remaining battery capacity S0C in the above description include battery voltage, integrated value of battery power, integrated value of battery current, and the like. Further, since the battery remaining amount S0C decreases as the consumption due to traveling increases, an integrated value of traveling energy consumption can be used instead of the battery remaining amount S0C. Such travel consumption energy can be obtained by, for example, the product of the output rotation speed and the output torque. Specifically, since the output rotation speed is proportional to the vehicle speed, it can be calculated from a vehicle speed sensor, and the output torque can be calculated from the drive motor torque and the generator torque.
[0088]
For example, under severe traveling conditions such as mountain traveling, the integrated value of the travel energy consumption is increased, so that the region of the second travel mode is expanded and the amount of power generation during traveling is increased.
[0089]
Examples of the power storage means include a capacitor, a flywheel battery, a hydraulic (pneumatic) accumulator, and the like in addition to the battery used in each of the above embodiments. The capacitor is a large-capacity capacitor, and the remaining power capacity can be known by detecting the voltage of the capacitor. A flywheel battery is a battery that puts power in and out by driving and regenerating the flywheel with a motor coaxially arranged on the flywheel, and knows the remaining power capacity by detecting the number of rotations of the flywheel. be able to. A hydraulic (pneumatic) accumulator is a battery that draws power into and out of the accumulator by a hydraulic (pneumatic) pump connected to the accumulator, and the remaining power capacity is hydraulic (pneumatic) ) Can be detected.
[0090]
Examples of the battery include lead batteries, nickel / cadmium batteries, nickel / iron batteries, nickel / zinc batteries, and lithium batteries.
In the present invention, the electric power generated by the generator 16 in the second traveling mode is not stored in the battery 19 but directly supplied to the electric motor 25, and the shortage of the electric power supplied from the generator is supplied from the battery 19. It is also possible to make up for it and to store the excess supply in the battery 19. In this case, energy loss during battery storage and discharge can be suppressed.
[0091]
  In the hybrid vehicle of the present invention described above, the driving efficiency of the engine is improved by selecting the driving mode according to the driving load and the capacity of the power storage means, or the output of the electric motor and the allowable output of the power storage means. Fuel consumption, low pollution, and long distance driving can be realized.
[0092]
  For example, when driving in an urban area with a low load, the first driving mode is often selected, and it is not necessary to drive the engine in a low efficiency region. Moreover, since the charge amount can be maintained at an appropriate value by selecting the second travel mode, the life of the power storage means can be extended. Further, by selecting the third traveling mode, the generator rotation can be stopped by the generator stopping means at the low speed of the generator rotation at which the generator efficiency is reduced.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram illustrating a drive device for a hybrid vehicle according to a first embodiment of the present invention.
FIG. 2 is a conceptual diagram and a velocity diagram of a planetary gear unit in the first embodiment of the present invention.
FIG. 3 is a torque diagram of the planetary gear unit according to the first embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a control system in the first embodiment of the present invention.
FIG. 5 is a map for determining a mode switching vehicle speed in the first embodiment of the present invention.
FIG. 6 is a map showing a drive region in each mode in the first embodiment of the present invention.
FIG. 7 is a map for obtaining a battery allowable output in the first embodiment of the present invention.
FIG. 8 is a map for obtaining a target motor torque in the first embodiment of the present invention.
FIG. 9 is a map for obtaining a target rotational speed of the generator in the first embodiment of the present invention.
FIG. 10 is a velocity diagram showing the rotation state of each element of the planetary gear unit when the engine is started in the first embodiment of the present invention.
FIG. 11 is a flowchart showing a control operation of the vehicle control device in the first embodiment of the present invention.
FIG. 12 is a flowchart showing a control operation of the vehicle control device in the first embodiment of the present invention.
FIG. 13 is a flowchart showing a control operation of the vehicle control device in the first embodiment of the present invention.
FIG. 14 is a flowchart showing a control operation of the vehicle control device in the first embodiment of the present invention.
FIG. 15 is a conceptual diagram showing a drive device for a hybrid vehicle in a second embodiment of the present invention.
FIG. 16 is a block diagram showing a configuration of a control system in a second embodiment of the present invention.
FIG. 17 is a map for determining a mode switching accelerator opening in the second embodiment of the present invention.
FIG. 18 is a map showing a drive region in each mode in the second embodiment of the present invention.
FIG. 19 is a map for obtaining a target rotational speed of the generator in the second embodiment of the present invention.
FIG. 20 is a map for determining a mode switching accelerator opening in the second embodiment of the present invention.
FIG. 21 is a map showing a drive region in each mode in the second embodiment of the present invention.
FIG. 22 is a velocity diagram showing a rotation state of each element of the planetary gear unit when the engine is stopped in the second embodiment of the present invention.
FIG. 23 is a characteristic curve diagram of the engine.
[Explanation of symbols]
11 Engine
13 Planetary gear unit (differential gear unit)
16 Generator
21 Rotor
25 Electric motor
31 Countershaft (drive output shaft)
41 Vehicle control device
42 Engine control device
43 Motor controller
44 Generator control device
45 Accelerator sensor
46 Vehicle speed sensor
58 Actuator
B brake (friction engagement means)
CR carrier (first gear element)
S Sun gear (second gear element)
R ring gear (third gear element)

Claims (4)

Engine,
A generator capable of controlling the rotational speed;
A drive output shaft that outputs the driving force of the drive wheels;
A differential gear device in which a first gear element is connected to an output shaft of the engine, a second gear element is connected to a rotor of the generator, and a third gear element is connected to the drive output shaft;
An electric motor coupled to the drive output shaft;
Generator stopping means for stopping rotation of the generator;
Engine control means for controlling the output of the engine;
Generator control means for controlling the rotation of the generator;
Traveling load detection means for detecting the traveling load;
According to the capacity of the detected running load and the power storage unit in the running load detecting means, a first traveling mode in which the output of the electric motor without output of the engine to the drive output shaft is transmitted is transmitted When a second driving mode in which part of the output of the engine remains is transmitted to the generator is transmitted to the drive output shaft, the generator output of the electric motor and the engine generator is stopped by the stop Characterized in that it has a travel mode selection means for selecting a third travel mode that is output to the drive output shaft . Engine,
A generator capable of controlling the rotational speed;
A drive output shaft that outputs the driving force of the drive wheels;
A differential gear device in which a first gear element is connected to an output shaft of the engine, a second gear element is connected to a rotor of the generator, and a third gear element is connected to the drive output shaft;
An electric motor coupled to the drive output shaft;
Generator stopping means for stopping rotation of the generator;
Engine control means for controlling the output of the engine;
Generator control means for controlling the rotation of the generator;
A first travel mode in which the output of the electric motor is transmitted to the drive output shaft without being transmitted to the drive output shaft in accordance with the output of the electric motor and the allowable output of the power storage means; A second traveling mode in which a part is transmitted to the generator and the rest is transmitted to the drive output shaft, and the generator is stopped by stopping the generator, and the outputs of the engine and the electric motor are transmitted to the drive output shaft. A hybrid vehicle , characterized by comprising travel mode selection means for selecting an output third travel mode . The hybrid vehicle according to claim 1 , wherein the engine control unit controls an engine throttle so that the engine is driven on an optimum fuel consumption line . The hybrid vehicle according to any one of claims 1 to 3, wherein the engine control unit controls the engine to be driven at a load or more determined according to a capacity of the power storage unit .

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