JP5070004B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle.

  A hybrid vehicle including an engine and one or a plurality of motor generators has been proposed (see, for example, Patent Document 1).

  In hybrid vehicles, fuel efficiency is improved by stopping the engine while it is stopped to reduce wasteful fuel consumption, or by so-called motor driving that stops the engine in a region where engine efficiency is poor and runs only with the motor power. can do.

Japanese Patent No. 3647399

  In a so-called one-motor hybrid system composed of an engine and one motor generator, the motor generator and the motor generator are switched from the motor running that runs with the power of the motor while the engine is stopped to the engine running that runs with the power of the engine. It is necessary to start the engine using a part of the power of the motor generator by fastening the engine. At this time, it is necessary to rotate the number of revolutions of the engine higher than the number of revolutions that can be started. On the other hand, the motor generator is connected to an output shaft for traveling through a gear or the like, and the rotational speed of the motor generator during traveling is determined by the gear ratio between the motor generator and the output shaft, the output shaft and the tire shaft. Is determined by the gear ratio (the reduction ratio of the final reduction gear), the tire moving radius, and the vehicle speed. Therefore, depending on the relationship between the number of revolutions required to start the engine, the gear ratio between the motor generator and the output shaft, and the gear ratio between the engine and the motor generator, the motor generator and the output shaft There are vehicle speeds that cannot start the engine if connected.

  When starting the engine, once the connection between the motor generator and the output shaft is released, the engine is started by the power of the motor generator, and then the engine is started by connecting the motor generator and the output shaft again. However, in this case, since the power of the motor generator is not transmitted to the output shaft while the engine is started, the driving force of the vehicle is lost, which gives the driver a sense of incongruity.

  In addition, it is conceivable that a slip element is provided between the motor generator and the output shaft, and the engine is started by increasing the number of revolutions of the motor generator by sliding between the motor generator and the output shaft. As a result, the number of parts increases and the cost increases, and the fuel consumption deteriorates due to the loss of energy in the slip element.

  In addition to the motor generator for driving in order to start the engine, it is possible to start the engine without depending on the vehicle speed by providing a new motor (starter motor). Invite up.

  The present invention provides a control device for a hybrid vehicle capable of reaching a state where the engine cannot be started while the motor is running.

  In providing the control device, it is preferable that the control device can be implemented with a simple configuration and fuel consumption can be improved.

  Here, the present invention is characterized in that the vehicle speed during motor running is controlled so as not to be lower than the vehicle speed corresponding to the engine speed required for engine start. According to the present invention, it is possible to shift from motor travel to engine travel without causing loss of driving force.

  According to the present invention, since it is possible to shift to engine running where the motor runs without causing loss of driving force, it is possible to reach a state where the engine cannot be started during motor running.

  Further, according to the present invention, since it is possible to switch from motor traveling to engine traveling without increasing the number of components such as slip elements, the cost of the system can be reduced.

  Furthermore, according to the present invention, the energy loss in the slip element due to the addition of the slip element can be eliminated, so that a high fuel efficiency improvement effect can be obtained.

Example 1

  A first embodiment of a control apparatus for a hybrid vehicle of the present invention is shown in FIGS.

  FIG. 1 is a configuration diagram of a hybrid vehicle.

  The engine 1 is connected to a motor generator 3 via a clutch 2a that can be engaged / released.

  The motor generator 3 is connected to the transmission 4 via a clutch 2b that can be engaged / released.

  The clutches 2a and 2b may be friction clutches or meshing dog clutches.

  The motor generator 3 may be directly connected to the transmission 4 without the clutch 2b.

  The transmission 4 is connected to a final reduction gear (not shown) via the output shaft 14 and transmits driving force and rotation to wheels (not shown).

  Motor generator 3 is electrically connected to battery 6 via inverter 5.

  When powering the motor generator 3, the DC power stored in the battery 6 is converted into three-phase DC power by the inverter 5 and supplied to the motor motor generator 3. When the motor generator 3 generates power, AC power is converted into DC power by the inverter 5, supplied to the battery 6, and stored in the battery 6.

  Is the engine 1 a command from the engine control unit 101? The operation of the fuel supply valve, the air throttle valve, and the intake / exhaust valve is controlled based on the control number. The operation of the motor generator 3 is controlled by the inverter 5. The operation of the inverter 5 is controlled by controlling on / off of the semiconductor etching apparatus for power conversion based on a command signal from the motor control unit 103. The battery 6 monitors the state of charge (SOC), and outputs the state of charge (SOC) and charge / discharge allowable power information to the host controller. A battery control unit 104 is provided. The speed change operation of the transmission 4 is controlled by the automatic transmission control unit 102. The operations of the clutches 2 a and 2 b are controlled by the clutch control unit 105.

  Each of the above control units can exchange information with each other via the in-vehicle communication network, and can also exchange information with the general control unit 100, and receives a command signal from the general control unit 100. Yes.

  In this embodiment, the control units described above are provided, and the control described in FIG. 2 and subsequent drawings is performed in cooperation with the control units.

  In the hybrid vehicle control apparatus of the present embodiment, the engine 1 is stopped and the clutch 2a is opened when a predetermined condition is satisfied by the vehicle speed, the storage state of the battery 6 (battery charge rate SOC), the accelerator opening, or the like. Then, the clutch 2b is engaged, the motor generator 3 is powered, and the vehicle is driven only by the power of the motor generator 3 (hereinafter, this state is referred to as “EV mode”).

  When the vehicle speed, the storage state of the battery 6 (battery charge rate SOC), the accelerator opening, etc. are outside the conditions for maintaining the EV mode set in advance, the clutch 2a is engaged and a part of the power of the motor generator 3 is reduced. By adding to the engine 1, the engine 1 is started, and the vehicle is driven by the power of only the engine 1 or the power of the engine 1 and the motor generator 3 (hereinafter, this state is referred to as “HEV mode”).

In general, in order to start the engine 1 from a stopped state, it is necessary to make the rotational speed of the engine 1 higher than a certain rotational speed, that is, the engine starting possible lower limit rotational speed N _emin . This N _emin means the minimum rotation speed (about 100 min ^{−1 to} 200 min ⁻¹ ) at which the engine can rotate independently and the idling rotation speed (about 500 min ^{−1 to} 800 min ⁻¹ ) of the engine.

When switching from the EV mode to the HEV mode, the engine 1 is started by the motor generator 3 via the clutch 2a. For this reason, the rotational speed N _e of the engine 1 cannot be higher than the rotational speed N _m of the motor generator 3.

On the other hand, the motor generator 3 is connected to the wheels via the clutch 2 b and the transmission 4. Therefore, the rotational speed N _m of the motor generator 3 is determined by the following equation by the speed ratio it and the vehicle speed VSP of the transmission.

ここで
Ｎ_m：モータジェネレータ回転数 ［min^-1］
ＶＳＰ：車速 ［km／ｈ］
π：円周率 ［−］
Ｒ_t：タイヤ動半径 ［ｍ］
ｉｆ：最終減速機の減速比 ［−］
ｉｔ：変速機の変速比 ［−］
したがって、モータジェネレータ３の回転数Ｎ_mが、エンジン１の始動可能下限回転数Ｎ_eminより小さい場合、エンジン１を始動することができない。すなわち、エンジン始動下限車速Ｖ_{engon_min}は次式となる。

Where N _m : Motor generator speed [min ^-1 ]
VSP: Vehicle speed [km / h]
π: Pi ratio [−]
R _t : tire moving radius [m]
if: Reduction ratio of the final reduction gear [-]
it: Transmission gear ratio [-]
Thus, the rotational speed N _m of the motor generator 3, when the engine 1 startable lower limit engine speed N _emin smaller, it is impossible to start the engine 1. That is, the engine start lower limit vehicle speed V _{engon_min} is expressed by the following equation.

ここで、
Ｖ_{engon_min}：エンジン始動下限車速 ［km／ｈ］
Ｎ_emin：エンジン始動可能下限回転数 ［min^-1］
そこで本発明の第１の実施形態では、バッテリの蓄電状態（バッテリ充電率ＳＯＣ）に対するＳＯＣしきい値ＳＯＣ_engonと、前記エンジン始動下限車速以上の値に設定した車速しきい値を設け、ＥＶモードで走行中にバッテリの蓄電状態（バッテリ充電率ＳＯＣ）が前記ＳＯＣしきい値より低くなったとき、車速が前記車速しきい値より高い場合には、モータジェネレータ３と変速機４とを接続するクラッチ２ｂを締結し、モータジェネレータのトルクの一部を変速機４に伝達したままエンジン１とモータジェネレータ３とを接続するクラッチ２ａを締結してモータジェネレータのトルクの一部を用いてエンジン１を始動し（このエンジン始動方法を「トルク継続エンジン始動」と呼ぶ）、ＥＶモードで走行中にバッテリの蓄電状態（バッテリ充電率ＳＯＣ）が前記ＳＯＣしきい値より低くなったとき、車速が前記車速しきい値以下である場合には、モータジェネレータ３と変速機４を締結するクラッチ２ｂを開放するか、あるいは変速機４をニュートラル状態にし、モータジェネレータ３のトルクが車輪側に伝達されないようにした状態で、エンジン１とモータジェネレータ３とを接続するクラッチ２ａを締結して、モータジェネレータ３のトルクを用いてエンジン１を始動する（このエンジン始動方法を「トルク中断変速」と呼ぶ）ことを特徴としている。

here,
V _{engon_min} : Engine start lower limit vehicle speed [km / h]
N _emin : Lower engine speed limit [min ^-1 ]
Therefore, in the first embodiment of the present invention, an SOC threshold SOC _engon for the battery storage state (battery charge rate SOC) and a vehicle speed threshold set to a value equal to or higher than the engine start lower limit vehicle speed are provided, and the EV mode is set. When the battery storage state (battery charge rate SOC) is lower than the SOC threshold value during traveling, the motor generator 3 and the transmission 4 are connected if the vehicle speed is higher than the vehicle speed threshold value. The clutch 2b is engaged, and the clutch 1a that connects the engine 1 and the motor generator 3 is engaged while a part of the torque of the motor generator is transmitted to the transmission 4, and the engine 1 is operated using a part of the torque of the motor generator. The engine is started (this engine starting method is referred to as “torque continuation engine starting”). When the charging rate (SOC) is lower than the SOC threshold value, if the vehicle speed is less than or equal to the vehicle speed threshold value, the clutch 2b for fastening the motor generator 3 and the transmission 4 is disengaged, or the transmission 4 is in a neutral state and the torque of the motor generator 3 is not transmitted to the wheel side, the clutch 2a connecting the engine 1 and the motor generator 3 is engaged, and the engine 1 is used using the torque of the motor generator 3. (This engine starting method is called “torque interruption shift”).

Here, the SOC threshold is SOC _engon , which ensures a battery output for starting the engine even after leaving the vehicle stopped for a certain period (for example, one month) or starts the engine at a low temperature. Therefore, it is determined from conditions such as ensuring battery output. _Further , as described above, the vehicle speed threshold value VSP _evmin is determined in consideration of the minimum engine speed at which the engine can stand up and the engine idling engine speed.

FIG. 2 is a flowchart of the first embodiment of the present invention. While the _vehicle is traveling in the EV mode, when the battery storage state (battery charge rate SOC) is lower than the SOC threshold value / SOC _engon in step S21, the process proceeds to step S22.

In step S22, if the vehicle speed is higher than the vehicle speed threshold value V _evmin , the process proceeds to step S23 to start the torque continuation engine and switch to the HEV mode.

On the other hand, if the vehicle speed is _{equal to} or lower than V _evmin in step S22, the process proceeds to step S24 to start the torque interruption engine and switch to the HEV mode.

  FIG. 3 shows the relationship among the SOC threshold value, the vehicle speed threshold value, and the engine starting method.

  According to the embodiment of the present invention, when the battery storage state (battery charge rate SOC) is lower than the SOC threshold value while traveling in the EV mode, the torque is continued when the vehicle speed is higher than the vehicle speed threshold value. The engine is started and switched to the HEV mode. When the vehicle speed is less than the vehicle speed threshold value, the torque interruption engine is started and the HEV mode is switched. As a result, the engine can be started and switched to the HEV mode regardless of the vehicle speed, so that the EV mode is continued and the battery is overdischarged to deteriorate the battery, or the battery is charged (battery charge rate SOC). Thus, it is possible to avoid a situation in which it is impossible to ensure the output necessary for starting the engine due to a decrease in the engine, and the vehicle cannot finally run.

(Example 2)
FIG. 4 shows a second embodiment of the hybrid vehicle control apparatus of the present invention.

FIG. 4 shows the relationship among the SOC threshold value, the vehicle speed threshold value, and the engine starting method in the second embodiment. In the first embodiment shown in FIG. 3, the SOC threshold value is constant, but in this embodiment, the SOC threshold value is set for each vehicle speed as compared to the first embodiment shown in FIG. . According to the present embodiment, when the vehicle speed is in the vicinity of the vehicle speed threshold value V _evmin , the SOC threshold value can be set high, and the frequency at which the torque interruption engine is started can be reduced.

(Example 3)
A third embodiment of the control apparatus for a hybrid vehicle of the present invention is shown in FIGS.

  FIG. 5 is a block diagram showing a third embodiment of the hybrid vehicle of the present invention.

  Engine 1 is connected to motor generator 3 via gears G0 to G2, first clutch 2c and second clutch 2d that can be engaged / released, and gears g0 to g2.

The relationship between the rotational speed N _e of the engine 1 and the rotational speed N _m of the motor generator 3 is as follows when the first clutch 2c is engaged:

の関係がある。また第２クラッチ２ｄを締結した場合には

There is a relationship. When the second clutch 2d is engaged,

の関係がある。ここで、ｎ_g0〜ｎ_g2およびｎ_G0〜ｎ_G2はギアｇ０〜ｇ２およびギアＧ１〜Ｇ２の歯数である。すなわち，モータジェネレータに対するエンジンの変速比は、第１クラッチ２ｃを締結した場合には、

There is a relationship. Here, n _g0 ~n _g2 and n _G0 ~n _G2 is the number of teeth of the gear g0~g2 and gear G1～G2. That is, the speed ratio of the engine with respect to the motor generator is as follows when the first clutch 2c is engaged:

であり、第２クラッチ２ｄを締結した場合には、

When the second clutch 2d is engaged,

となる。ここでは、第１クラッチ２ｃを締結した場合の変速比よりも第２クラッチ２ｄを締結した場合の変速比の方が大きい場合、すなわち

It becomes. Here, when the gear ratio when the second clutch 2d is engaged is larger than the gear ratio when the first clutch 2c is engaged, that is,

である場合について説明する。

A case where

  The motor generator 3 is connected to the transmission 4 via a clutch 2b that can be engaged / released. The motor generator 3 may be directly connected to the transmission 4 without the clutch 2b.

  The transmission 4 is connected to a final reduction gear (not shown) via the output shaft 14 and transmits driving force and rotation to wheels (not shown).

  The motor generator 3 is electrically connected to the battery 6 via the inverter 5.

  When powering the motor generator 3, the power stored in the battery 6 is used, and this power is supplied to the motor generator 3 via the inverter 5. When the motor generator 3 generates power, the generated power is transmitted via the inverter 5. Are supplied to the battery 6 and stored in the battery.

  In the hybrid vehicle control apparatus of the present embodiment, the engine 1 is stopped and the first clutch 2c is satisfied when a predetermined condition is satisfied by the vehicle speed, the storage state of the battery 6 (battery charge rate SOC), the accelerator opening, or the like. Is released, the second clutch 2b is engaged, the motor generator 3 is powered, and the vehicle is driven only by the power of the motor generator 3 (hereinafter, this state is referred to as “EV mode”).

  When the vehicle speed, the battery storage state (battery charge rate SOC), the accelerator opening, etc. deviate from the predetermined conditions for maintaining the EV mode, either the first clutch 2c or the second clutch 2d is engaged, The engine 1 is started by adding a part of the motive power of the motor generator 3 to the engine 1, and the vehicle is driven by the motive power of only the engine 1 or the power of the engine 1 and the motor generator 3 (hereinafter, this state is referred to as “HEV mode ").

FIG. 6 shows the relationship between the vehicle speed and the engine speed of the hybrid vehicle of the third embodiment. The first vehicle speed threshold value V _evmin 1 is set to a vehicle speed higher than the vehicle speed V _{engon_min} 1 corresponding to the engine startable lower limit speed N _emin when the first clutch 2c is engaged, and the second vehicle speed is set. threshold _· V evmin 2 is lower than _V evmin 1, and is set to a higher vehicle speed than the vehicle speed V _{Engon_min} 2 corresponding to the engine start enable lower limit rotation speed Nemin in the case of engaging the second clutch 2d. Here, the engine startable lower limit rotational speed means the minimum rotational speed (about 100 min ^{−1 to} 200 min ⁻¹ ) at which the engine can rotate independently and the engine idling rotational speed (about 500 min ^{−1 to} 800 min ⁻¹ ). .

  Further, an SOC threshold value is set for the storage state of the battery (battery charge rate SOC).

  FIG. 7 is a flowchart of the third embodiment.

While the _vehicle is traveling in the EV mode, if the battery storage state (battery charge rate SOC) becomes lower than the SOC threshold SOC _{engon in} step 71, the process proceeds to step S72.

In S72, if the vehicle speed is higher than the first vehicle speed threshold value V _evmin 1, the process proceeds to S73 to start the first clutch engine and switch to the HEV mode. On the other hand, if the vehicle speed is V _evmin 1 or less in S72, the process proceeds to step S74.

In step S74, if the vehicle speed is higher than the second vehicle speed threshold value V _evmin 2, the process proceeds to step S75 to start the second clutch engine and switch to the HEV mode. On the other hand, if the vehicle speed is less than or equal to V _evmin 2 in S74, the process proceeds to step S76 to start the torque interruption engine and switch to the HEV mode.

  Here, the first clutch engine start is a method in which the first clutch 2c is engaged while the clutch 2b in FIG. 5 is engaged, and the engine is started using a part of the torque of the motor generator 3. The second clutch engine start is a method in which the second clutch 2d is engaged while the clutch 2b in FIG. 5 is engaged, and the engine is started using a part of the torque of the motor generator 3. Further, the torque loss engine start means that the clutch 2b in FIG. 5 is disengaged or the transmission 4 is in the neutral state, and the torque and rotation of the motor generator 3 are not transmitted to the wheel side. This is a method of starting the engine 1 using the torque of the motor generator 3 by engaging the two clutch 2d.

  FIG. 8 shows the relationship among the SOC threshold value, the vehicle speed threshold value, and the engine starting method.

  According to the embodiment of the present invention, when the battery storage state (battery charge rate SOC) is lower than the SOC threshold value while traveling in the EV mode, the torque is continued when the vehicle speed is higher than the vehicle speed threshold value. The engine is started and switched to the HEV mode. When the vehicle speed is less than the vehicle speed threshold value, the torque interruption engine is started and the HEV mode is switched. As a result, the engine can be started and switched to the HEV mode regardless of the vehicle speed, so that the EV mode is continued and the battery is overdischarged to deteriorate the battery, or the battery is charged (battery charge rate SOC). Thus, it is possible to avoid a situation in which it is impossible to ensure the output necessary for starting the engine due to a decrease in the engine, and the vehicle cannot finally run.

Example 4
A fourth embodiment of the present invention is shown in FIG. In the control apparatus for the hybrid vehicle shown in FIGS. 5 to 7 of the third embodiment, the SOC threshold value SOC _engon may be set for each vehicle speed as shown in FIG.

(Example 5)
The hybrid vehicle for realizing the first to fourth embodiments described above may have the configuration shown in FIG.

  In FIG. 10, the motor generator 3 is incorporated in the transmission 4.

  The transmission 4 has a plurality of rotation shafts of a first clutch shaft 15 and a second clutch shaft 16, and the engine 1 is connected to either the engine coupling gears 1 a to 1 c or the first clutch 2 c and the second clutch 2 d. Concatenated with

  The motor generator 3 has a configuration in which the rotor and the stator both rotate. The stator is connected to the first clutch shaft 15 via a gear, and the rotor is connected to the second clutch shaft 16. Yes. As a result, the motor generator 3 rotates by the difference between the rotation speed of the first clutch shaft 15 and the rotation speed of the second clutch shaft 16.

  The first clutch shaft 15 and the second input shaft 16 include transmission gears 31 to 36, and a gear to be fastened by the gear clutches 21 to 24 can be selected.

  When traveling in the EV mode, the engine 1 is stopped, the first clutch 2c and the second clutch 2d are both released, and one of the transmission gears 31 to 33 of the first clutch shaft 15 is The vehicle runs by driving any one of the transmission gears 34 to 36 of the two clutch shaft 16 and driving the motor generator 3.

  When switching from the EV mode to the HEV mode, either the first clutch 2 c or the second clutch 2 d is engaged, and the engine 1 is started by applying a part of the torque of the motor generator 3 to the engine 1.

  In the present embodiment, the inverter, the battery, and the battery control unit are not shown, but are provided in the same manner as in the previous embodiment. The motor control unit and the clutch control unit are accommodated in the transmission control unit 102.

(Example 6)
FIG. 11 shows a sixth embodiment of the hybrid vehicle control device of the present invention.

  The hybrid vehicle of the present embodiment can predict the future traffic situation by referring to the past traffic history to either the configuration shown in FIG. 1, the configuration shown in FIG. 5, or the configuration shown in FIG. A car navigation system having one or both of a function that can be received and a function that can receive the current traffic situation is added.

  FIG. 11 is a flowchart showing the sixth embodiment.

If the battery storage state (battery charge rate SOC) becomes lower than the first SOC threshold value / SOC _engon 1 in step S111 during traveling in the EV mode, the process proceeds to step S112.

  In S112, when the car navigation system predicts that there will be traffic jam in the future within a certain distance range from the current location on the planned route to the preset destination, or when the current traffic jam situation is received, Proceed to step S113, otherwise proceed to step S114.

In S113, if the vehicle speed is higher than the vehicle speed threshold value V _evmin , the process proceeds to S115 to start the torque continuation engine, and if not, the process proceeds to S114.

In S114, if lower than the second SOC threshold · SOC _Engon 2 where the state of charge of the battery (battery charging rate SOC) is set to a first value lower than the SOC threshold · SOC _Engon 1 proceeds to step S116, Otherwise, the process returns to step S112.

In S116, if the vehicle speed is higher than the vehicle speed threshold value V _evmin , the process proceeds to S115 to start the torque continuation engine, and if not, the process proceeds to S117 to start the engine without torque.

Here, the second SOC threshold value is SOC _engon 2, which ensures a battery output for starting the engine even after leaving the vehicle stopped for a certain period (for example, one month) or at low temperatures. It is determined from conditions such as securing battery output for starting the engine. _Further , as described above, the vehicle speed threshold value VSP _evmin is determined in consideration of the minimum engine speed at which the engine can stand _alone , the engine idling engine speed, and the like, and the first SOC threshold value is set as described above. It is set to a value higher than the second SOC threshold value. Accordingly, when it is assumed that there is traffic jam during traveling in the EV mode and the EV traveling at the low vehicle speed continues for a long time, the first SOC set to be higher only when the vehicle speed is higher than the vehicle speed threshold value. When the SOC becomes lower than the threshold value, the engine continues to start the torque and switches to the HEV mode. Therefore, the frequency of starting the engine without torque can be reduced, and the driver's uncomfortable feeling can be reduced.

(Example 7)
FIG. 12 shows a seventh embodiment of the hybrid vehicle control apparatus of the present invention.

  The hybrid vehicle according to the present embodiment has a road gradient calculation unit for obtaining a current road gradient and road gradient information in advance in either the configuration shown in FIG. 1, the configuration shown in FIG. 5, or the configuration shown in FIG. One or both of the stored car navigation system is added.

  FIG. 12 is a flowchart showing the seventh embodiment.

If the battery state of charge (battery charge rate SOC) is lower than the first SOC threshold value / SOC _engon 1 in step S121 while traveling in the EV mode, the process proceeds to step S122.

The road gradient θ of the current location calculated by the road gradient calculation unit in S122 or the maximum road gradient θ within a certain distance from the current location on the planned route to the destination set in advance by the car navigation system is the gradient threshold value. If it is larger than θ _engon , the process proceeds to step S123; otherwise, the process proceeds to step S124.

In S123, if the vehicle speed is higher than the vehicle speed threshold value V _evmin , the process proceeds to S125 to start the torque continuation engine, and if not, the process proceeds to S124.

In S124, if lower than the second SOC threshold · SOC _Engon 2 where the state of charge of the battery (battery charging rate SOC) is set to a first value lower than the SOC threshold · SOC _Engon 1 proceeds to step S126, Otherwise, the process returns to step S122.

In S126, if the vehicle speed is higher than the vehicle speed threshold value V _evmin , the process proceeds to S125 and the torque continuation engine start is performed. Otherwise, the process proceeds to S127 and the torque interruption engine start is performed.

Here, the second SOC threshold value is SOC _engon 2, which ensures a battery output for starting the engine even after leaving the vehicle stopped for a certain period (for example, one month) or at low temperatures. It is determined from conditions such as securing battery output for starting the engine. _Further , as described above, the vehicle speed threshold value V _evmin is determined in consideration of the minimum engine speed at which the engine can stand _alone , the engine idling engine speed, and the like, and the first SOC threshold value is set as described above. It is set to a value higher than the second SOC threshold value. Thus, when it is assumed that EV traveling at a low vehicle speed is continued for a long time while traveling in the EV mode, the first set to be higher only when the vehicle speed is higher than the vehicle speed threshold value. When the SOC becomes lower than the SOC threshold value, the engine continues to start the torque and switches to the HEV mode. Therefore, the frequency of starting the engine without torque can be reduced, and the driver's uncomfortable feeling can be reduced.

The block diagram which shows the 1st Embodiment of this invention. The flowchart which shows the 1st Embodiment of this invention. The relationship between the SOC threshold value, vehicle speed threshold value, and engine starting method which shows the 1st Embodiment of this invention. The relationship between the SOC threshold value, vehicle speed threshold value, and engine starting method which shows the 2nd Embodiment of this invention. The block diagram which shows the 3rd Embodiment of this invention. The relationship between the vehicle speed and engine speed in the 3rd Embodiment of this invention. The flowchart which shows the 3rd Embodiment of this invention. The relationship between the SOC threshold value, vehicle speed threshold value, and engine starting method which shows the 3rd Embodiment of this invention. The relationship between the SOC threshold value, vehicle speed threshold value, and engine starting method which shows the 4th Embodiment of this invention. The block diagram which shows the 5th Embodiment of this invention. The flowchart which shows the 6th Embodiment of this invention. The flowchart which shows the 7th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 1a, 1b, 1c Engine coupling gear 2a, 2b Clutch 2c 1st clutch 2d 2nd clutch 3 Motor generator 4 Transmission 10 Engine output shaft 11, 12 shaft 13 Transmission input shaft 14 Output shaft 15 First clutch shaft 16 Second clutch shafts 21 to 24 Gear clutches 31 to 36 Transmission gears 41 to 43 Driven gears g0 to g2, G0 to G2 Gear if Final reduction gear reduction ratio it Transmission transmission ratio N _e Engine speed N _emin Lower limit of engine start possible rotation the number n _g0 ~n _g2 number of teeth of the gear g0~g2 n _G0 ~n _G2 number of teeth of the gear G0~ gear G2 n _m motor generator rotational speed SOC State of charge, the battery charging rate _SOC engon SOC threshold _SOC engon 1 second 1 of SOC threshold SOC _Engon 2 second SOC threshold V _Evmin vehicle speed threshold V _Evmin 1 first vehicle speed threshold V _Evmin The second vehicle speed threshold value VSP speed V _{Engon_min} engine start lower limit vehicle speed

Claims (8)

engine,
A motor generator, and a battery that stores electric power generated by the motor generator when the motor generator generates power, and supplies electric power to the motor generator when the motor generator generates electric power,
Switch between at least two driving modes and run
In the first traveling mode among the traveling modes, the vehicle travels by at least the power of the engine,
In the second traveling mode among the traveling modes, the engine is stopped and the vehicle travels only by the power of the motor generator.
A control device used in a hybrid vehicle,
An SOC threshold for the state of charge (SOC) of the battery;
Set the vehicle speed threshold for the vehicle speed,
The vehicle speed threshold is a vehicle speed at which the engine cannot be started without connecting the motor generator and the output shaft,
The SOC threshold value is set for each vehicle speed, and at a vehicle speed near the vehicle speed threshold value and higher than the vehicle speed threshold value, the SOC threshold value is set higher than the SOC threshold value at other vehicle speeds. And
When the SOC of the battery becomes lower than the SOC threshold during traveling in the second travel mode, if the vehicle speed is higher than the vehicle speed threshold, a part of the torque of the motor generator is The torque of the motor generator is transmitted to the engine while being transmitted to the engine, and the engine is started.
When the battery SOC is lower than the SOC threshold value during traveling in the second traveling mode, if the vehicle speed is less than the vehicle speed threshold value, the torque of the motor generator is transmitted to the wheels. In addition, the control device for a hybrid vehicle is characterized in that the torque of the motor generator is transmitted to the engine to start the engine. engine,
Motor generator,
A battery that supplies electric power to the motor generator when the motor generator is powered, stores a power that is generated by the motor generator when the motor generator generates power, and a plurality of switches that can be switched between the engine and the motor generator Gear, and
Switch between at least two driving modes and run
In the first traveling mode among the traveling modes, the vehicle travels by at least the power of the engine,
In the second traveling mode among the traveling modes, the engine is stopped and the vehicle travels only by the power of the motor generator.
A control device used in a hybrid vehicle,
An SOC threshold for the state of charge (SOC) of the battery;
A first vehicle speed threshold for vehicle speed;
A second vehicle speed threshold that is lower than the first vehicle speed threshold,
The first vehicle speed threshold is a vehicle speed higher than a vehicle speed corresponding to a lower limit rotational speed at which the engine can be started when the first gear of the plurality of gears is engaged.
The second vehicle speed threshold is a vehicle speed that is higher than a vehicle speed corresponding to a lower limit rotational speed at which the engine can be started when the second gear of the plurality of gears is engaged.
The SOC threshold value is set for each vehicle speed . At a vehicle speed that is close to the first vehicle speed threshold value and higher than the first vehicle speed threshold value, the SOC threshold value is the SOC value at other vehicle speeds. It is set higher than the threshold,
If the vehicle speed is higher than the first vehicle speed threshold when the SOC of the battery becomes lower than the SOC threshold value during traveling in the second travel mode, the torque of the motor generator is reduced. Transmitting the torque of the motor generator to the engine by connecting the first gear while transmitting the part to the wheel, and starting the engine;
When the SOC of the battery becomes lower than the SOC threshold value during traveling in the second traveling mode, the vehicle speed is equal to or lower than the first vehicle speed threshold value, and the second vehicle speed threshold value is reached. If it is higher, the torque of the motor generator is transmitted to the engine by connecting the second gear while transmitting a part of the torque of the motor generator to the wheels, and the engine is started,
When the SOC of the battery becomes lower than the SOC threshold value during traveling in the second traveling mode, if the vehicle speed is less than or equal to the second vehicle speed threshold value, the torque of the motor generator is adjusted to the wheel. Without transmitting to the engine, the torque of the motor generator is transmitted to the engine by connecting any one of the plurality of gears, and the engine is started.
A control apparatus for a hybrid vehicle characterized by the above. In the hybrid vehicle control device according to claim 1,
When the hybrid vehicle has a car navigation system having a function of receiving a current traffic jam situation and / or a function of predicting a future traffic jam situation, ,
A first SOC threshold;
A second SOC threshold value set to a value lower than the first SOC threshold value,
While traveling in the second traveling mode,
The amount of traffic in the current traffic situation received by the car navigation system or the amount of traffic in the future traffic situation predicted by the car navigation system when the battery SOC is lower than the first battery SOC threshold When the vehicle speed is higher than the threshold value and the vehicle speed is higher than the vehicle speed threshold value, or when the battery SOC is lower than the second battery SOC threshold value and the vehicle speed is higher than the vehicle speed threshold value, Transmitting the torque of the motor generator to the engine while transmitting a part of the torque of the motor generator to the wheels, and starting the engine;
When the battery SOC is lower than the second battery SOC threshold and the vehicle speed is lower than the vehicle speed threshold, the torque of the motor generator is transmitted to the engine without transmitting the torque of the motor generator to the wheels. To start the engine,
A control apparatus for a hybrid vehicle characterized by the above. In the hybrid vehicle control device according to claim 1,
The hybrid vehicle includes at least one of a gradient calculation unit that calculates a gradient of a running road surface, a gradient sensor that detects a gradient of the running road surface, and a car navigation system that includes road gradient data. If
A first SOC threshold;
A second SOC threshold set to a value lower than the first SOC threshold;
Set the road slope threshold and
While traveling in the second travel mode, the battery SOC is lower than the first battery SOC threshold and greater than or equal to the second battery SOC threshold, and the vehicle speed is greater than or equal to the vehicle speed threshold. And when the current road surface gradient or the road surface gradient of the planned route is larger than the road surface gradient threshold value, or while traveling in the second traveling mode, the battery SOC is the second battery. When the vehicle speed is lower than the SOC threshold value and the vehicle speed is higher than the vehicle speed threshold value, the torque of the motor generator is transmitted to the engine while a part of the torque of the motor generator is transmitted to the wheels. Start,
When the battery SOC is lower than the second battery SOC threshold and the vehicle speed is less than or equal to the vehicle speed threshold during traveling in the second traveling mode, the torque of the motor generator is applied to the wheels. Without transmitting, the torque of the motor generator is transmitted to the engine to start the engine.
A control apparatus for a hybrid vehicle characterized by the above. engine,
A first clutch shaft to which power is transmitted from the engine via a first clutch;
A second clutch shaft to which power is transmitted from the engine via a second clutch;
A plurality of transmission gears provided between the first clutch shaft and the output shaft and between the second clutch shaft and the output shaft;
A plurality of gear clutches coupled to any of the plurality of transmission gears for transmitting the rotation of the engine to the output shaft;
Transmitting the rotation of the engine to the output shaft via either the first clutch shaft or the second clutch shaft and any of the plurality of gear clutches;
The engine is driven by using the rotational speed that is the difference between the input rotational speed of the transmission gear for traveling that transmits the rotation of the engine to the output shaft and the input rotational speed of the transmission gear other than the traveling gear. Motor generator and
A battery for supplying electric power to the motor generator when the motor generator is powered, and storing electric power generated by the motor generator when the motor generator generates power;
A first travel mode that travels with at least the power of the engine via either the first clutch or the second clutch and any of the plurality of gear clutches;
In the control device for a hybrid vehicle that travels while switching both of the second travel mode in which both the first clutch and the second clutch are released and the motor generator travels only with the power,
An SOC threshold for the state of charge (SOC) of the battery;
Set the vehicle speed threshold for the vehicle speed,
The vehicle speed threshold is a vehicle speed at which the engine cannot be started without connecting the motor generator and the output shaft,
The SOC threshold value is set for each vehicle speed, and at a vehicle speed near the vehicle speed threshold value and higher than the vehicle speed threshold value, the SOC threshold value is set higher than the SOC threshold value at other vehicle speeds. And
When the SOC of the battery becomes lower than the SOC threshold during traveling in the second travel mode, if the vehicle speed is higher than the vehicle speed threshold, a part of the torque of the motor generator is The torque of the motor generator is transmitted to the engine while being transmitted to the engine, and the engine is started.
When the battery SOC is lower than the SOC threshold value during traveling in the second traveling mode, if the vehicle speed is less than the vehicle speed threshold value, the torque of the motor generator is transmitted to the wheels. Without transmitting the torque of the motor generator to the engine to start the engine,
A control apparatus for a hybrid vehicle characterized by the above.

In the hybrid vehicle control device according to claim 5 ,
And a first vehicle speed threshold for vehicle speed;
A second vehicle speed threshold that is lower than the first vehicle speed threshold,
If the vehicle speed is higher than the first vehicle speed threshold when the SOC of the battery becomes lower than the SOC threshold value during traveling in the second travel mode, the torque of the motor generator is reduced. Transmitting the torque of the motor generator to the engine by connecting the first clutch shaft while transmitting the part to the wheel, and starting the engine;
When the SOC of the battery becomes lower than the SOC threshold value during traveling in the second traveling mode, the vehicle speed is equal to or lower than the first vehicle speed threshold value and higher than the second vehicle speed. Is configured to transmit the torque of the motor generator to the engine and start the engine by connecting the second clutch shaft while transmitting a part of the torque of the motor generator to the wheels,
When the SOC of the battery becomes lower than the SOC threshold value during traveling in the second traveling mode, if the vehicle speed is less than or equal to the second vehicle speed threshold value, the torque of the motor generator is adjusted to the wheel. Without transmitting to the motor, by connecting either the first clutch shaft and the second clutch shaft, the torque of the motor generator is transmitted to the engine to start the engine,
A control apparatus for a hybrid vehicle characterized by the above. In the hybrid vehicle control device according to claim 5 ,
When the hybrid vehicle has a car navigation system having a function of receiving current traffic conditions and a function of predicting future traffic conditions, or both,
In addition, the traffic threshold and
A first SOC threshold;
A second SOC threshold value set to a value lower than the first SOC threshold value,
While traveling in the second traveling mode,
The amount of traffic in the current traffic situation received by the car navigation system or the amount of traffic in the future traffic situation predicted by the car navigation system when the battery SOC is lower than the first battery SOC threshold When the vehicle speed is higher than the threshold value and the vehicle speed is higher than the vehicle speed threshold value, or when the battery SOC is lower than the second battery SOC threshold value and the vehicle speed is higher than the vehicle speed threshold value, Transmitting the torque of the motor generator to the engine while transmitting a part of the torque of the motor generator to the wheels, and starting the engine;
When the battery SOC is lower than the second battery SOC threshold and the vehicle speed is lower than the vehicle speed threshold, the torque of the motor generator is transmitted to the engine without transmitting the torque of the motor generator to the wheels. And the hybrid vehicle control device. In the hybrid vehicle control device according to claim 5 ,
The hybrid vehicle includes at least one of a gradient calculation unit that calculates a gradient of a running road surface, a gradient sensor that detects a gradient of the running road surface, and a car navigation system that includes road gradient data. If
A first SOC threshold;
A second SOC threshold set to a value lower than the first SOC threshold;
Set the road slope threshold and
While traveling in the second travel mode, the battery SOC is lower than the first battery SOC threshold and greater than or equal to the second battery SOC threshold, and the vehicle speed is greater than or equal to the vehicle speed threshold. And when the current road surface gradient or the road surface gradient of the planned route is larger than the road surface gradient threshold value, or while traveling in the second traveling mode, the battery SOC is the second battery. When the vehicle speed is lower than the SOC threshold value and the vehicle speed is higher than the vehicle speed threshold value, the torque of the motor generator is transmitted to the engine while a part of the torque of the motor generator is transmitted to the wheels. Start,
When the battery SOC is lower than the second battery SOC threshold and the vehicle speed is less than or equal to the vehicle speed threshold during traveling in the second traveling mode, the torque of the motor generator is applied to the wheels. Without transmitting, the torque of the motor generator is transmitted to the engine and the engine is started.
A control apparatus for a hybrid vehicle characterized by the above.

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