JP2002195070A - Hybrid vehicle and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the failure of an engine generated, accompanying quick braking of a hybrid vehicle. SOLUTION: This hybrid vehicle is equipped with an engine 11; a dynamo motor 16; an output shaft 14 connected to a driving wheel; a differential gear device in which each gear element is connected to the engine 11, the dynamo motor 16, and the output shaft 14 respectively; an engine speed monitoring processing means 91 for monitoring the engine speed in a state with the driving of the engine 11 being stopped; an engine rotation direction detecting processing means 92 for detecting the reverse direction rotation of the engine 11, based on the engine speed; and an engine rotation preventing processing means 93 for preventing the reverse direction rotation of the engine 11 by driving the dynamo motor 16, when the reverse direction rotation of the engine 11 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, a hybrid vehicle in which part of the engine torque is distributed to a generator motor and the remainder is distributed to driving wheels, has a planetary gear unit having a sun gear, a ring gear and a carrier. A carrier and an engine are connected, a ring gear is connected to a driving wheel, a sun gear is connected to a generator motor, and rotation output from the ring gear and the driving motor is transmitted to the driving wheel to generate a driving force. I have to.

[0003] When a hybrid vehicle is driven with the drive motor driven and the engine stopped, it is not necessary to generate torque, that is, generator motor torque by the generator motor. Is swung around. Therefore, the transmission of the switching signal for driving the generator motor to the inverter is stopped, and the generator motor is shut down or the torque of the generator motor is controlled.
m].

[0004]

However, in the above-mentioned conventional hybrid vehicle, when the drive motor is driven and the driving of the engine is stopped, the hybrid vehicle is driven. When sudden braking is performed, the rotation speed of the drive motor, that is, the rotation speed of the drive motor, rapidly decreases. The engine may be rotated in the opposite direction due to the inertia of the generator motor swung while the hybrid vehicle is running. There is a risk of failure.

The present invention solves the above-mentioned problems of the conventional hybrid vehicle, and provides a hybrid vehicle and a control method therefor that can prevent the engine from being damaged due to sudden braking. The purpose is to:

[0006]

For this purpose, a hybrid vehicle according to the present invention includes an engine, a generator motor, an output shaft connected to driving wheels, at least three gear elements, and each gear. A differential gear device whose elements are respectively connected to the engine, the generator motor and the output shaft,
Engine rotation speed monitoring processing means for monitoring the engine rotation speed in a state where the driving of the engine is stopped;
Engine rotation direction detection processing means for detecting that the engine is going to rotate in the reverse direction based on the engine rotation speed, and driving the generator motor when it is detected that the engine is going to rotate in the reverse direction Engine rotation prevention processing means for preventing the engine from rotating in the reverse direction.

In another hybrid vehicle of the present invention, the engine rotation prevention processing means drives the generator motor so that the engine rotation speed becomes zero.

[0008] In still another hybrid vehicle according to the present invention, the engine rotation prevention processing means drives the generator motor so that the engine rotation speed takes a positive value.

In still another hybrid vehicle according to the present invention, the positive value is a predetermined value equal to or higher than an idle speed.

[0010] Still another hybrid vehicle according to the present invention includes an engine, a generator motor, an output shaft connected to driving wheels, and at least three gear elements, wherein each gear element includes the engine, the power generator, and the like. A differential gear device respectively connected to a generator motor and an output shaft, generator motor rotation speed monitoring processing means for monitoring a generator motor rotation speed in a state where the engine is stopped, and the generator motor rotation speed However, there is provided an engine rotation prevention processing means for driving the generator motor so that the engine speed does not fall below a lower limit set to prevent the engine from rotating in the reverse direction.

In a control method for a hybrid vehicle according to the present invention, an engine, a generator motor, an output shaft connected to driving wheels, and at least three gear elements are provided, each gear element comprising the engine, the generator motor, and the like. And a hybrid vehicle having a differential gear connected to the output shaft.

The engine speed is monitored in a state where the driving of the engine is stopped, and it is detected that the engine is going to rotate in the reverse direction based on the engine speed, and the engine is going to rotate in the reverse direction. Is detected, the generator motor is driven to prevent the engine from rotating in the reverse direction.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a functional block diagram of a hybrid vehicle according to an embodiment of the present invention.

In the drawing, 11 is an engine, 16 is a generator motor, 14 is an output shaft connected to driving wheels (not shown), and 13 is provided with at least three sun gears S, ring gears R and carriers CR as gear elements. , Each carrier CR, sun gear S and ring gear R
1, a planetary gear unit as a differential gear unit connected to the generator motor 16 and the output shaft 14, respectively;
1 is an engine speed monitoring processing means for monitoring the engine speed in a state where the driving of the engine 11 is stopped, and 92 detects that the engine 11 is going to rotate in the reverse direction based on the engine speed. The engine rotation direction detection processing means 93 drives the generator motor 16 to prevent the engine 11 from rotating in the reverse direction when the engine 11 is detected to rotate in the reverse direction. Prevention processing means. Note that 25
Is a drive motor.

FIG. 2 is a conceptual diagram of a hybrid vehicle according to an embodiment of the present invention.

In FIG. 1, reference numeral 11 denotes an engine (E / G) disposed on a first axis, and reference numeral 12 denotes an engine (E / G) disposed on the first axis, which is generated by driving the engine 11. An output shaft for outputting rotation, 13 is disposed on the first axis, and a planetary gear unit as a differential gear device for performing a speed change with respect to the rotation input via the output shaft 12, and 14 is An output shaft, which is disposed on one axis line and outputs the rotation after shifting in the planetary gear unit 13, 15 is a first counter drive gear as an output gear fixed to the output shaft 14, and 16 is the A first electric motor, which is arranged on one axis and is connected to the planetary gear unit 13 via a transmission shaft 17 similarly arranged on the first axis, and further mechanically connected to the engine 11. A generator motor (G) as a.

The output shaft 14 has a sleeve shape and is disposed so as to surround the output shaft 12. Further, the first counter drive gear 15 is a planetary gear unit 1.
3 is provided on the engine 11 side.

The planetary gear unit 13
Is at least a sun gear S as a first gear element,
A pinion P meshing (engaging) with the sun gear S, a ring gear R serving as a second gear element meshing with the pinion P, and a carrier CR serving as a third gear element rotatably supporting the pinion P; The sun gear S is connected to the generator motor 16 via the transmission shaft 17, the ring gear R is connected to the drive wheel 37 via the output shaft 14 and a predetermined gear train, and the carrier CR is connected to the engine 11 via the output shaft 12. Is done. In addition, the carrier CR and the case 10
And a one-way clutch F is provided when the rotation in the forward direction is transmitted from the engine 11 to the carrier CR, and the one-way clutch F is released from the generator motor 16 or the drive motor 25 in the reverse direction. The rotation is locked when the rotation is transmitted to the carrier CR so that the rotation in the opposite direction is not transmitted to the engine 11.

Further, the generator motor 16 is fixed to the transmission shaft 17 and is rotatably disposed.
1, a stator 22 disposed around the rotor 21 and a coil 23 wound around the stator 22. The generator motor 16 generates electric power by rotation transmitted through a transmission shaft 17. The coil 23 is connected to a battery (not shown) and supplies a direct current to the battery. A brake B is provided between the rotor 21 and the case 10, and by engaging the brake B, the rotor 21 can be fixed and the rotation of the generator motor 16 can be stopped.

A reference numeral 25 denotes a second parallel to the first axis.
And a drive motor (M) 26 as a second electric motor, which is mechanically connected to the generator motor 16 with each other, is disposed on the second axis, and the drive motor 25 Reference numeral 27 denotes a second counter drive gear as an output gear fixed to the output shaft 26. The drive motor 25 is connected to the output shaft 2.
6, the rotor 40 is rotatably disposed, a stator 41 disposed around the rotor 40, and a coil 42 wound around the stator 41.

The drive motor 25 generates a drive motor torque by a current supplied to the coil 42. To that end, the coil 42 is connected to the battery,
DC current from the battery is converted into AC current and supplied. The generator motor 16
The drive motor 25 and the drive wheel 37 are mechanically connected.

In order to rotate the driving wheels 37 in the same direction as the rotation of the engine 11, a counter shaft 30 is disposed on a third axis parallel to the first and second axes. A first counter driven gear 31 and a first counter driven gear 3
The second counter driven gear 32 having more teeth than one is fixed. Further, the first counter driven gear 31
And the first counter drive gear 15 are meshed with each other, and the second counter driven gear 32 and the second counter drive gear 27 are meshed with each other, and the rotation of the first counter drive gear 15 is reversed. The rotation of the second counter drive gear 27 is inverted by the first counter driven gear 31 and transmitted to the second counter driven gear 32.

Further, a differential pinion gear 33 having fewer teeth than the first counter driven gear 31 is fixed to the counter shaft 30.

A differential device 36 is arranged on a fourth axis parallel to the first to third axes,
The differential ring gear 35 of the differential device 36 meshes with the differential pinion gear 33. Therefore, the rotation transmitted to the differential ring gear 35 is distributed by the differential device 36 and the driving wheels 37
Is transmitted to Reference numeral 38 denotes a generator motor rotation speed sensor that detects the rotation speed of the generator motor 16, that is, the generator motor rotation speed NG, and 39 denotes a rotation speed of the drive motor 25, that is, a drive that detects the drive motor rotation speed NM. It is a motor rotation speed sensor.

As described above, not only can the rotation generated by the engine 11 be transmitted to the first counter driven gear 31, but also the rotation generated by the drive motor 25 can be transmitted to the second counter driven gear 32.
, The hybrid vehicle can be driven by driving the engine 11 and the drive motor 25.

Next, the operation of the planetary gear unit 13 will be described.

FIG. 3 is a diagram illustrating the operation of the planetary gear unit according to the embodiment of the present invention, and FIG. 4 is a vehicle speed diagram according to the embodiment of the present invention.

As shown in FIG. 2, in the planetary gear unit 13, the carrier CR is the engine 11, the sun gear S is the generator motor 16, and the ring gear R is the drive wheel 37 via the output shaft 14. Since the rotation speed of the ring gear R and the output shaft 14 are
, The output rotation speed NO is equal, the rotation speed of the carrier CR and the rotation speed of the engine 11, that is, the engine rotation speed NE are equal,
The rotation speed of the sun gear S becomes equal to the generator motor rotation speed NG. And the number of teeth of the ring gear R is equal to the sun gear S
When the number of teeth is made ρ times (in this embodiment, twice), the relationship of (ρ + 1) × NE = 1 × NG + ρ × NO is established. Therefore, the engine rotation speed NE NE = (1 × NG + ρ × NO) / (ρ + 1) (1) can be calculated based on the output rotation speed NO and the generator motor rotation speed NG.

Further, the torque generated by the engine 11, that is, the engine torque TE, the output shaft 14
, Ie, the output torque TO and the torque generated by the generator motor 16, ie, the generator motor torque TG, are: TE: TO: TG = (ρ + 1): ρ: 1 (2) Become a relationship and receive reaction from each other.

Next, a control device for a hybrid vehicle having the above-described configuration will be described.

FIG. 5 is a block diagram showing a control device for a hybrid vehicle according to an embodiment of the present invention.

In the figure, 11 is an engine, 16 is a generator motor, 25 is a drive motor, and 43 is a battery.
Reference numeral 46 denotes an engine control device as engine control means for controlling the engine 11, and the engine control device 46 sends an instruction signal such as a throttle opening θ to the engine 11. 47 is a generator motor control device as generator motor control means for controlling the generator motor 16,
The generator motor control device 47 sends a current command value IG to the generator motor 16. Reference numeral 49 denotes a drive motor control device as drive motor control means for controlling the drive motor 25, and the drive motor control device 49 sends a current command value IM to the drive motor 25.

Reference numeral 51 denotes a vehicle control device, which comprises a CPU, a storage device, and the like (not shown), and controls the overall operation of the hybrid vehicle. Reference numeral 44 denotes a battery remaining amount for detecting the remaining battery charge SOC as the state of the battery 43. A detecting device, 52 is an accelerator pedal, 53 is a vehicle speed sensor for detecting the vehicle speed V, 55 is an accelerator switch as accelerator operation detecting means for detecting the amount of depression of the accelerator pedal 52, that is, the accelerator opening α, 61 is a brake pedal ,
62 is a brake switch as a brake operation detecting means for detecting the depression amount β of the brake pedal 61, 38 is a generator motor rotation speed sensor for detecting the generator motor rotation speed NG, and 39 is detecting the drive motor rotation speed NM. The drive motor rotation speed sensor 72 is a battery voltage sensor that detects the battery voltage VB as the state of the battery 43. Note that the battery remaining amount detecting device 44 and the battery voltage sensor 72 constitute a battery state detecting means.

The vehicle control unit 51 sends an engine control signal to the engine control unit 46 to set the start / stop of the engine 11 or to set the generator motor rotation speed N
G and the drive motor rotation speed NM are read, and the engine rotation speed NE is calculated based on the equation (1).
A target value of the engine speed NE, that is, a target engine speed NE ^* is set in the engine control device 46, and a target value of the generator motor speed NG, that is, the target generator motor is set in the generator motor control device 47. The target value of the rotation speed NG ^* and the generator motor torque TG, that is, the target generator motor torque TG ^* is set, and the target value of the drive motor torque TM, that is, the target drive motor torque TM ^* and the drive motor torque correction value δTM.

In this embodiment, the vehicle control device 51 calculates the engine speed NE. However, an engine speed sensor (not shown) is provided, and the engine speed sensor is provided by the engine speed sensor. The rotation speed NE can also be detected. In the present embodiment, the vehicle speed V is detected based on the output rotation speed NO.
It can also be detected by the rotation speed of the drive wheel 37 or the like.

Next, the operation of the hybrid vehicle having the above configuration will be described.

FIG. 6 is a flowchart showing the operation of the hybrid vehicle according to the embodiment of the present invention.

First, a target output torque calculation processing means (not shown) of the vehicle control device 51 (FIG. 5) performs a target output torque calculation process and sends the vehicle speed V detected by the vehicle speed sensor 53 and the vehicle speed V sent from the engine control device 46. When the throttle opening θ is read and the accelerator pedal 52 is depressed, a first vehicle driving force map (not shown) is referred to,
When the brake pedal 61 is depressed, referring to a second vehicle driving force map (not shown), it is necessary to drive the hybrid vehicle, which is set in advance in accordance with the vehicle speed V and the throttle opening θ. The vehicle driving force Q is calculated, and a target value of the output torque TO, that is, the target output torque TO ^* is calculated based on the calculated vehicle driving force Q. The target output torque TO ^* is calculated based on the vehicle driving force Q and the gear ratio GO in a predetermined gear train from the output shaft 14 (FIG. 2) to the driving wheels 37.

Subsequently, an engine target operating state setting processing means (not shown) of the vehicle control device 51 performs an engine target operating state setting process, refers to an engine target operating state map (not shown), and calculates the efficiency of the engine operating points. set a good engine operating point as a state target engine operation, the engine rotational speed NE at the target engine operating state is calculated as the target engine rotational speed NE ^*, sends the target engine speed NE ^* to the engine control device 46, Set.

Subsequently, the generator motor control processing means (not shown) of the vehicle controller 51 performs a generator motor control process to calculate a target generator motor rotation speed NG ^* . For this purpose, the generator motor control processing means reads the vehicle speed V and calculates the output rotation speed NO by the following equation based on the vehicle speed V and the gear ratio GO.

NO = V · GO (3) Then, the target generator motor rotation speed setting processing means of the generator motor control processing means performs target generator motor rotation speed setting processing, and executes the target engine rotation speed processing. Based on NE ^* and output rotational speed NO, target generator motor rotational speed NG ^* is calculated by the following equation, sent to generator motor control device 47, and set.

NG ^* = NO− (NO−NE ^* ) · (1 + ρ) / ρ (4) By the way, when the hybrid motor vehicle is driven by driving the drive motor 25, the engine 11 and When at least one of the generator motors 16 is driven, at least one of the engine torque TE and the generator motor torque TG becomes equal to the ring gear torque TR.
When the ring gear torque TR is transmitted to the drive wheels 37 as it is, the running feeling of the hybrid vehicle decreases. Therefore, when driving the drive motor 26, the drive motor torque TM is corrected by the amount of the ring gear torque TR.

While it is difficult to determine the engine torque TE, the generator motor torque TG can be calculated easily based on the generator motor rotation speed NG. Therefore, the generator motor torque calculation means (not shown) of the generator motor control device 47 refers to a generator motor torque map (not shown) to calculate a generator motor torque TG corresponding to the generator motor rotation speed NG. The generator motor torque TG is sent to the vehicle control device 51. Then, a drive motor control processing unit (not shown) of the vehicle control device 51 performs a drive motor control process. The drive motor torque correction value calculation processing means of the drive motor control processing means performs drive motor torque correction value calculation processing, and the generator motor torque TG sent from the generator motor control device 47 and the number of teeth of the sun gear S The drive motor torque correction value δTM is calculated based on the ratio of the number of teeth of the second counter drive gear 27 to the gear ratio, ie, the gear ratio γ1 between the generator motor 16 and the drive motor 25.

In this case, the drive motor torque correction value δ
TM is calculated as follows.

That is, when the inertia of the generator motor 16 is InG and the angular acceleration (rate of change in rotation) of the generator motor 16 is αG, the sun gear torque TS applied to the sun gear S is as follows: TS = TG + InG · αG 5) Since the angular acceleration αG is extremely small,
By approximating the sun gear torque TS and the generator motor torque TG, the following equation can be obtained: TS = TG (6) If the number of teeth of the ring gear R is ρ times the number of teeth of the sun gear S, the ring gear torque TR is ρ times the sun gear torque TS.

When the counter gear ratio, that is, the ratio of the number of teeth of the second counter drive gear 27 to the number of teeth of the counter driven gear 32 is i, the drive motor torque correction value δTM is δTM = ρ · TS · i = ρ · TG · i (7) Since the gear ratio γ1 is γ1 = ρ · i (8), the drive motor torque correction value δTM is δTM = γ1 · TG (9).

Subsequently, the target drive motor torque calculation processing means of the drive motor control processing means performs target drive motor torque calculation processing, refers to a target drive motor torque map (not shown), and considers torque fluctuations. The target drive motor torque TM ^* corresponding to the accelerator opening α and the vehicle speed V is calculated. Then, the drive motor control processing means sends the drive motor torque correction value δTM and the target drive motor torque TM ^* to the drive motor control device 49 and sets them.

Subsequently, the engine controller 46 drives the engine 11, the generator motor controller 47 drives the generator motor 16, and the drive motor controller 49 drives the drive motor 25. That is, the engine control device 46
From the vehicle control device 51, the target engine speed NE ^*
Is sent, an instruction signal such as the throttle opening θ is generated so that the deviation ΔNE between the engine rotational speed NE and the target engine rotational speed NE ^* becomes zero, and the engine 11 is driven by the instruction signal. .

The current command value generation processing means of the generator motor control device 47 performs a current command value generation process,
From the vehicle control device 51, the target generator motor rotation speed NG ^*
Is sent, a current command value IG is generated such that a deviation ΔNG between the generator rotation speed NG and the target generator motor rotation speed NG ^* becomes 0, and the current command value IG is converted to the generator motor 16. To drive the generator motor 16 to control the rotation speed.

When the drive motor command value calculation processing means (not shown) of the drive motor control device 49 receives the drive motor torque correction value δTM and the target drive motor torque TM ^* from the vehicle control device 51, by subtracting the drive motor torque correction value δTM from the drive motor torque TM ^* drive motor torque command value STM ^* STM ^* = calculated TM ^* -δTM ...... (10).

Subsequently, the current command value generation processing means (not shown) of the drive motor control device 49 sets the current command value so that the deviation ΔTM between the drive motor torque TM and the drive motor torque command value STM ^* becomes zero. A value IM is generated, the current command value IM is sent to the drive motor 25, and the drive motor 25 is driven.

In the hybrid vehicle having the above configuration, the drive motor torque T
Since M is larger than the engine torque TE, when the hybrid vehicle starts, only the drive motor 25 is driven,
The driving of the engine 11 is stopped.

After the vehicle starts, when the vehicle speed V reaches an engine start vehicle speed sufficient to start the engine 11, the engine 11 is started by driving the generator motor 16, and thereafter, the generator motor 16, The drive motor 25 and the engine 11 are driven. Note that the drive of the engine 11 can be stopped by driving only the drive motor 25 in a state other than when the hybrid vehicle starts moving. In this case, the vehicle control device 51 cuts the fuel by sending a drive / stop instruction signal to the engine control device 46 or by sending a fuel cut signal to the engine control device 46.

When the generator motor rotation speed NG is low, the efficiency of the generator motor 16 is reduced. Therefore, when the target generator motor rotation speed NG ^* becomes 1500 [rpm] or less, the brake B is engaged. The generator motor 16 is stopped.

By the way, it is not necessary to generate the generator motor torque TG by the generator motor 16 when the hybrid motor vehicle is running with the drive motor 25 being driven and the engine 11 being stopped. The generator motor 16 is swung. Therefore, the generator motor control device 47 stops sending a switching signal for driving the generator motor 16 to an inverter (not shown) and shuts down the generator motor 16 or performs torque control of the generator motor 16. , The generator motor torque TG is set to 0 [Nm]. In this case, in the vehicle speed diagram, as shown in FIG. 4, the output rotation speed NO takes a positive value, the engine rotation speed NE takes a substantially zero value, and the generator motor rotation speed NG takes a negative value. take.

When the torque control of the generator motor 16 is performed, the control mode setting processing means (not shown) of the vehicle control device 51 sets the control mode to torque control. Then, the target generator motor torque setting processing means (not shown) of the vehicle control device 51 performs a target generator motor torque setting process, and calculates a target generator motor torque TG ^* based on the target output torque TO ^*. The target generator motor torque TG ^* is sent to the generator motor controller 47 and set.

Then, the generator motor control device 47
Is the target generator motor torque TG from the vehicle control device 51.
^* Is sent, the target generator motor torque TG ^*
Calculates a generator motor torque instruction value STG ^* based on. Subsequently, the current command value generation processing means of the generator motor control device 47 generates a deviation ΔTG between the generator motor torque TG and the generator motor torque command value STG ^*.
A current command value IG is generated so that the current command value IG becomes 0, and the current command value IG is sent to the generator motor 16 so that the
Drive. Thus, the torque control of the generator motor 16 is performed.

Next, the flowchart will be described. Step S1 A target output torque calculation process is performed. Step S2 Engine target operating state setting processing is performed. Step S3 A generator motor control process is performed. Step S4 Drive motor control processing is performed. Step S5: The engine 11 and the drive motor 25 are driven.

By the way, when the hybrid motor vehicle is driven with the drive motor 25 being driven and the driving of the engine 11 being stopped, the driver operates the brake pedal 6.
When the hybrid vehicle is suddenly depressed by depressing 1 (step 1), the drive motor rotational speed NM suddenly decreases as the output rotational speed NO suddenly decreases. The engine 11 may be rotated in the reverse direction due to the inertia of the generator motor 16 which is swung during the running of the hybrid vehicle. , Engine 11
May break down.

Therefore, in the present embodiment, when the engine 11 tries to rotate in the reverse direction, the generator motor 1
The control mode 6 is switched from the torque control mode to the rotation speed control mode.

FIG. 7 is a flowchart showing the operation of the rotation speed control process of the generator motor according to the embodiment of the present invention, and FIG. 8 is a time chart showing the operation of the hybrid vehicle according to the embodiment of the present invention.

In this case, when the hybrid vehicle is driven with the drive motor 25 driven and the engine 11 stopped, as shown in FIG. 8, the vehicle speed V and the drive motor rotation speed NM become positive. Value, the generator motor rotation speed NG takes a negative value, and the engine rotation speed NE and the generator motor torque TG become zero. During this time, the engine rotation speed monitoring processing means 91 of the vehicle control device 51 (FIG. 1)
Performs the engine rotation speed monitoring process, and monitors by reading the engine rotation speed NE calculated based on the equation (1).

When the hybrid vehicle is suddenly braked at the timing t1, the engine speed NE tends to take a negative value as shown by the broken line. At this time,
The engine rotation direction detection processing means 92 of the vehicle control device 51 detects whether the engine 11 is going to rotate in the reverse direction based on the engine rotation speed NE. When the engine rotation direction detection processing means 92 detects that the engine 11 is going to rotate in the reverse direction, the control mode setting processing means performs control mode setting processing to control the generator motor 16. The mode is changed from the torque control mode to the rotation speed control mode.

Subsequently, the engine rotation prevention processing means 93 of the vehicle control device 51 performs an engine rotation prevention process and drives the generator motor 16. For this purpose, the engine rotation prevention processing means 93 reads the vehicle speed V, and
Then, based on the gear ratio GO, the output rotation speed NO is calculated by Expression (3). Next, the target generator motor rotation speed setting processing unit (not shown) of the engine rotation prevention processing unit 93 performs a target generator motor rotation speed setting process to set the target engine rotation speed NE ^* to 0 [rpm]. Based on the output rotation speed NO, the target generator motor rotation speed NG ^* NG ^* = NO− (NO−0) · (1 + ρ) / ρ = −NO / ρ is calculated by Expression (4), and the generator motor control is performed. It is sent to the device 47 and set.

As a result, as shown in FIG.
And the drive motor rotation speed NM gradually decreases, the generator motor rotation speed NG gradually increases, the engine rotation speed NE maintains 0 [rpm], and the generator motor torque T
G takes a predetermined value. Then, at timing t2, the vehicle speed V becomes 0 [km / h], and the drive motor rotation speed NM, the engine rotation speed NE, and the generator motor rotation speed NG become 0.
At [rpm], the generator motor torque TG becomes 0 [Nm].

As described above, when the engine 11 attempts to rotate in the reverse direction, the generator motor 16 is driven, the rotation speed is controlled, and the engine rotation speed NE becomes 0 [rpm].
Therefore, the rotation of the engine 11 in the reverse direction is prevented, and the failure of the engine 11 can be prevented.

When the one-way clutch F is broken, the engine 11 can be prevented from rotating in the reverse direction.

In the present embodiment, the target engine speed NE ^* is set to 0 [rpm], but the target engine speed NE ^{* is set} to a positive value, for example, a predetermined value equal to or higher than the idle speed. You can also In that case, the engine speed NE becomes a positive value, for example, a predetermined value equal to or higher than the idle speed. By doing so, it is possible to prevent the occurrence of cranking vibration in the engine 11.

When the engine 11 and the generator motor 16 are connected via a damper (not shown), the target engine speed NE ^* can be prevented from generating resonance vibration in the damper. It can be set to a value higher than the rotation speed.

In this embodiment, the expression (1)
The engine 11 attempts to rotate in the reverse direction based on the engine speed NE calculated on the basis of the engine speed NE. However, not only the rotation speed of the engine 11 but also the rotation direction may be detected. In the case of using an engine rotational speed sensor that can be used, the engine rotational speed monitoring processing means 91 reads the engine rotational speed NE and the rotational direction from the engine rotational speed sensor, and the engine rotational direction detection processing means 92 performs processing based on the rotational direction. It can also detect whether the engine 11 is going to rotate in the reverse direction.

Next, the flowchart will be described. Step S11 It is detected that the engine 11 is going to rotate in the reverse direction. Step S12 The control mode of the generator motor 16 is set to the rotation speed control mode. Step S13: Calculate the target generator motor rotation speed NG ^* and end the process.

In the above-described embodiment, the engine speed NE is monitored when the driving of the engine 11 is stopped. However, by monitoring the generator motor speed NM, The engine 11 can be prevented from rotating in the reverse direction. For this purpose, a generator motor rotation speed monitoring processing means and an engine rotation prevention processing means (not shown) are provided in the vehicle control device 51. In addition, the vehicle control device 51
The engine 1 corresponds to the vehicle speed V or the output rotation speed NO.
A generator motor rotation speed map is set in which a lower limit is set so as to prevent 1 from trying to rotate in the reverse direction.

The generator motor rotation speed monitoring processing means performs a generator motor rotation speed monitoring process to monitor the generator motor rotation speed NM. Further, the engine rotation prevention processing means performs an engine rotation prevention process, and refers to the generator motor rotation speed map, so that the generator motor rotation speed NM can be prevented from falling below the lower limit value. The motor rotation speed NG is calculated, and the generator motor 16 is driven.

The present invention is not limited to the above embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0076]

As described above in detail, according to the present invention, in a hybrid vehicle, an engine, a generator motor, an output shaft connected to driving wheels, and at least three gear elements are provided. Wherein each gear element is the engine,
A differential gear unit connected to the generator motor and the output shaft, an engine rotation speed monitoring processing unit that monitors the engine rotation speed when the driving of the engine is stopped, and an engine based on the engine rotation speed. Engine rotation direction detection processing means for detecting an attempt to rotate in the reverse direction, and driving the generator motor to rotate the engine in the reverse direction when the engine is detected to rotate in the reverse direction Engine rotation prevention processing means for preventing the occurrence of the rotation.

In this case, when it is detected that the engine is going to rotate in the reverse direction, the generator motor is driven to prevent the engine from rotating in the reverse direction.
It is possible to prevent the engine from breaking down.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a hybrid vehicle according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a hybrid vehicle according to an embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of the planetary gear unit according to the embodiment of the present invention.

FIG. 4 is a vehicle speed diagram in the embodiment of the present invention.

FIG. 5 is a block diagram showing a control device for a hybrid vehicle according to an embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of the hybrid vehicle according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation of a generator motor rotation speed control process according to the embodiment of the present invention.

FIG. 8 is a time chart illustrating an operation of the hybrid vehicle according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 engine 13 planetary gear unit 14 output shaft 16 generator motor 25 drive motor 37 drive wheel 91 engine rotation speed monitoring processing means 92 engine rotation direction detection processing means 93 engine rotation prevention processing means CR carrier R ring gear S sun gear

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G093 AA07 DA06 DB05 EA03 EB08 EB09 FA04 FA10 FB05 5H115 PG04 PI16 PI22 PI29 PU08 PU24 PU25 PV09 RB08 RE01 SE04 SE05 SE06 SJ12 SJ13 TB01 TE02 TI02 TI05 TO01 TO21 TO23 TR20 TU14

Claims (6)

[Claims] 1. An engine, a generator motor, an output shaft connected to drive wheels, and at least three gear elements, each gear element being connected to the engine, generator motor and output shaft, respectively. A differential gear device, engine rotation speed monitoring processing means for monitoring the engine rotation speed when the driving of the engine is stopped, and detecting that the engine is about to rotate in the reverse direction based on the engine rotation speed. When the engine rotation direction detection processing means detects that the engine is going to rotate in the opposite direction,
A hybrid vehicle comprising: engine rotation prevention processing means for driving a generator motor to prevent the engine from rotating in the reverse direction. 2. The hybrid vehicle according to claim 1, wherein said engine rotation prevention processing means drives a generator motor so that an engine rotation speed becomes zero. 3. The hybrid vehicle according to claim 1, wherein the engine rotation prevention processing means drives the generator motor so that the engine rotation speed takes a positive value. 4. The hybrid vehicle according to claim 3, wherein said positive value is a predetermined value equal to or higher than an idle rotation speed. 5. An engine, a generator motor, an output shaft connected to driving wheels, and at least three gear elements, each gear element being connected to the engine, generator motor and output shaft, respectively. A differential gear device, a generator motor rotation speed monitoring processing means for monitoring the generator motor rotation speed in a state where the engine is stopped, and the generator motor rotation speed is set so that the engine rotates in the opposite direction. A hybrid-type vehicle having engine rotation prevention processing means for driving a generator motor so as not to fall below a lower limit value set to prevent the occurrence of the rotation. 6. An engine, a generator motor, an output shaft connected to drive wheels, and at least three gear elements, each gear element being connected to the engine, generator motor and output shaft, respectively. In the control method of the hybrid vehicle having a gear device, the engine rotation speed is monitored in a state where the driving of the engine is stopped, and based on the engine rotation speed, it is detected that the engine is going to rotate in the reverse direction, A control method for a hybrid vehicle, comprising: driving a generator motor to prevent the engine from rotating in the reverse direction when the engine is detected to rotate in the reverse direction.