JP3620541B2 - Drive control apparatus for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the fuel consumption efficiency in a hybrid vehicle which is equipped with an engine and an electric motor as a power source at travelling, and travels using the engine and the electric motor each in its proper way according to operating conditions. <P>SOLUTION: In case that it is judged to be at decelerating travel by steps SA1-SA3, this drive controller stops the fuel supply to the engine at step SA4. It judges whether the break is ON or not at step SA6. If the break is ON, it releases the first clutch CE<SB>1</SB>at step SA10 so as to cut off the engine and also it increases the regenerative torque of a motor generator 14 by the amount equivalent to engine brake force at step SA9. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a drive control device for a hybrid vehicle, and more particularly to control during deceleration traveling.

  In a normal engine vehicle that travels using an engine that operates by fuel combustion as a power source, the fuel supply to the engine is stopped at a predetermined vehicle speed or higher when the throttle valve is decelerated with the valve fully closed and there is no risk of engine stall. A fuel cut technique is described in Patent Document 1, for example. According to such a technique, fuel is not supplied to the engine during deceleration traveling that does not require engine torque, so that fuel efficiency is improved.

JP 58-187565 A JP-A-7-67208

  On the other hand, a hybrid vehicle that includes an engine and an electric motor as a power source when the vehicle travels, and that uses the engine and the electric motor depending on driving conditions is described in Patent Document 2, for example. In such a hybrid vehicle, a fuel supply control technology for the engine during deceleration traveling has not been established yet.

  The present invention has been made in the background as described above. The object of the present invention is to provide an engine and an electric motor as a power source when the vehicle travels, and the engine and the electric motor according to operating conditions. It is to further improve fuel efficiency in a hybrid vehicle that travels in a plurality of operation modes having different operating states.

In order to achieve the above object, the first invention includes an engine that operates by combustion of fuel and an electric motor that operates by electric energy as a power source when the vehicle travels. In a hybrid vehicle that travels in a plurality of operation modes with different operating states of the electric motor, (a) clutch means for disconnecting the engine from the electric motor, and (b) engagement of the clutch means if the brake is not ON even when the accelerator is off. An engine disconnecting means for releasing the clutch means and disconnecting the engine from the electric motor when the accelerator is off and the brake is on. ) When the engine is disconnected by the engine disconnecting means, A braking force supplementing means for supplementing the braking force by the regenerative braking, and having a.

  According to a second aspect of the present invention, in the hybrid vehicle drive control device according to the first aspect, the engine disconnecting means releases the clutch means on condition that fuel supply to the engine is stopped during deceleration traveling. It is characterized by disconnecting the engine.

  According to a third aspect of the present invention, in the hybrid vehicle drive control device according to the first aspect, the engine disconnecting means releases the clutch means and disconnects the engine on condition that the catalyst temperature is equal to or higher than a predetermined value. To do.

  According to a fourth aspect of the present invention, in the hybrid vehicle drive control device according to the first aspect of the invention, the engine disconnecting means releases the clutch means on the condition that the engine disconnecting means is an operating region that runs using the electric motor as a power source. It is characterized by separating.

The fifth invention includes an engine that operates by fuel combustion and an electric motor that operates by electric energy as a power source during vehicle travel, and the operating states of the engine and the electric motor differ depending on operating conditions. (A) clutch means for disconnecting the engine from the electric motor, and (b) maintaining the clutch means in an engaged state if the brake is not ON even during deceleration traveling . The engine is forcibly rotated as the vehicle travels, and when the vehicle is decelerating and the brake is ON, the clutch means is released to disconnect the engine from the electric motor, and (c) the engine disconnecting means. When the engine is disconnected, the braking force equivalent to the engine braking force is supplemented by regenerative braking. A braking force supplementing device, and having a.

  According to a sixth aspect of the present invention, in the hybrid vehicle drive control device of the fifth aspect, the engine disconnecting means releases the clutch means and disconnects the engine on condition that fuel supply to the engine is stopped. It is characterized by.

  According to a seventh aspect of the invention, in the hybrid vehicle drive control device of the fifth aspect, the engine disconnecting means releases the clutch means and disconnects the engine on the condition that the catalyst temperature is equal to or higher than a predetermined value. To do.

  According to an eighth aspect of the present invention, in the hybrid vehicle drive control device according to the fifth aspect of the present invention, the engine disconnecting means releases the clutch means on the condition that the engine disconnecting means is an operating region that runs using the electric motor as a power source. It is characterized by separating.

According to a ninth aspect of the present invention, in the drive control apparatus for a hybrid vehicle according to any one of the first to eighth aspects, an automatic transmission is disposed between the engine, the electric motor, and drive wheels. And

According to the first invention, when the accelerator is off and the brake is on, the engine is disconnected from the electric motor, and the braking force corresponding to the engine braking force is supplemented by the regenerative braking by the braking force supplementing means. Regardless of this, the braking force does not change and the driver does not feel uncomfortable, and the power storage device can be charged by regenerative braking to improve fuel efficiency. If the brake is not ON even when the accelerator is off, the clutch means is maintained in the engaged state, and the engine is forcibly rotated as the vehicle travels. Therefore, at the time of reacceleration, the engine output is quickly increased with the fuel supply. The driving force intended by the driver can be obtained quickly.

In the fifth aspect of the invention, when the vehicle is decelerated without requiring engine torque and the brake is on, the engine is disconnected from the electric motor, and the braking force corresponding to the engine braking force is supplemented by the regenerative braking by the braking force supplementing means. Therefore, the braking force does not change regardless of the engine being disconnected and the driver does not feel uncomfortable, and the power storage device can be charged by regenerative braking to improve fuel efficiency. Even when the vehicle is decelerating, if the brake is not ON, the clutch means is maintained in the engaged state, and the engine is forcibly rotated as the vehicle travels. Thus, the driving force intended by the driver can be obtained quickly.

  In the present invention, for example, the output type of the engine and the electric motor is synthesized or distributed by a switching type in which the power source is switched by connecting / disconnecting power transmission by a clutch, for example, by combining or distributing a planetary gear device or the like. The present invention can be applied to various types of hybrid vehicles equipped with an engine and an electric motor as a power source when the vehicle travels, such as a mixed type that assists an electric motor.

  When the vehicle is decelerating when the fuel supply stop means stops the fuel supply to the engine, for example, whether or not the accelerator operation means such as an accelerator pedal is not operated for a predetermined time or more, or the accelerator operation amount Is approximately zero and is determined by a deceleration traveling determination means for determining whether or not the rate of change of the vehicle speed has become a predetermined value or less.

  In addition, the driving region where the electric motor is used as the power source is not only the motor driving region where the electric motor is used as the power source but also the engine + motor driving region where the electric motor and the engine are used as the power sources. Also good. In the case of the engine + motor running region, it is desirable to control the motor torque in anticipation of the engine start delay at the time of reacceleration.

  In the hybrid vehicle, an operation region such as a motor travel region that travels using only the electric motor as a power source and an engine travel region that travels using only the engine as a power source is set. In order to reduce the fuel consumption and the like as much as possible, the driving state such as the accelerator operation amount and the vehicle speed is set as a parameter by a map or an arithmetic expression. Further, it is desirable that the engine resonance region where NVH (noise, vibration, rough riding comfort) deteriorates due to the resonance of the drive system due to the vibration of the engine is a motor travel region that travels using only the electric motor as a power source.

Further, the engine disconnecting means when the catalyst temperature is low when stopped rotating disconnect the engine, then because the generation of exhaust gas of the NO _X and CO, etc. when starting the engine is a concern, the catalyst temperature is lower than a predetermined value Sometimes it is desirable to provide an engine separation limiting means for prohibiting engine separation by the engine separation means.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a skeleton diagram of a hybrid drive device 10 of a hybrid vehicle including a drive control device according to an embodiment of the present invention.

  In FIG. 1, this hybrid drive device 10 is for an FR (front engine / rear drive) vehicle, and is an engine 12 such as an internal combustion engine that operates by combustion of fuel, and a motor generator that functions as an electric motor and a generator. 14, a single pinion type planetary gear device 16, and an automatic transmission 18 are provided along the longitudinal direction of the vehicle, and left and right drive wheels are connected from the output shaft 19 via a propeller shaft and a differential device (not shown). The driving force is transmitted to the (rear wheel).

Planetary gear set 16 is a synthetic distributing mechanism for mechanically synthesizing force distributor, constitutes an electric torque converter 24 together with the motor-generator 14, the ring gear 16r is connected to the engine 12 via the first clutch CE _1, The sun gear 16 s is connected to the rotor shaft 14 r of the motor generator 14, and the carrier 16 c is connected to the input shaft 26 of the automatic transmission 18. Further, the sun gear 16s and the carrier 16c is adapted to be connected by the second clutch CE _2. The first clutch CE ₁ corresponds to clutch means for disconnecting the engine 12 from the drive system.

The output of the engine 12 is transmitted to the first clutch CE ₁ via a flywheel 28 for suppressing rotational fluctuation and torque fluctuation, and a damper device 30 made of an elastic member such as a spring or rubber. The first clutch CE ₁ and the second clutch CE ₂ are both friction type multi-plate clutches that are engaged and released by a hydraulic actuator.

  The automatic transmission 18 is a combination of a sub-transmission 20 composed of a front-type overdrive planetary gear unit and a main transmission 22 of four forward speeds and one reverse speed composed of a simple connected three planetary gear train.

Specifically, the auxiliary transmission 20 includes a single pinion type planetary gear device 32, a hydraulic clutch C ₀ and a brake B ₀ that are frictionally engaged by a hydraulic actuator, and a one-way clutch F _0. Has been. The main transmission 22 includes three sets of single-pinion type planetary gear units 34, 36, and 38, hydraulic clutches C ₁ and C ₂ that are frictionally engaged by hydraulic actuators, brakes B ₁ and B ₂ , B ₃ and B ₄ and one-way clutches F ₁ and F ₂ are provided.

Then, the hydraulic circuit 40 is switched by excitation and non-excitation of the solenoid valves SL1 to SL4 shown in FIG. 2, or the hydraulic circuit 40 is mechanically switched by a manual shift valve connected to a shift lever (not shown). As a result, the clutches C ₀ , C ₁ , C ₂ and the brakes B ₀ , B ₁ , B ₂ , B ₃ , B ₄ are controlled to be engaged and disengaged, respectively, and as shown in FIG. ), Five forward speeds (1st to 5th), and one reverse speed (Rev) are established.

  The automatic transmission 18 and the electric torque converter 24 are substantially symmetrical with respect to the center line, and the lower half of the center line is omitted in FIG.

  “○” in the clutch, brake, and one-way clutch column in FIG. 3 indicates engagement, and “●” indicates that the shift lever is in the engine brake range, for example, the low speed range such as “3”, “2”, and “L” range. Engaged when operated and blank indicates disengaged.

  In this case, the neutral N, the reverse shift speed Rev, and the engine brake range are established by mechanically switching the hydraulic circuit 40 by a manual shift valve mechanically connected to the shift lever. The shift between 1st and 5th is electrically controlled by solenoid valves SL1 to SL4.

Further, the speed ratio of the forward gear stage decreases stepwise from 1st to 5th, and the 4th speed ratio i ₄ = 1. FIG. 3 shows an example of the gear ratio of each gear stage.

As shown in the operation table of FIG. 3, the shift between the second gear (2nd) and the third gear (3rd) is performed by engaging the second brake B ₂ and the third brake B _3.・ Clutch-to-clutch shift that changes the released state together. In order to perform this speed change smoothly, the circuit shown in FIG. 4 is incorporated in the hydraulic circuit 40 described above.

  4, reference numeral 70 indicates a 1-2 shift valve, reference numeral 71 indicates a 2-3 shift valve, and reference numeral 72 indicates a 3-4 shift valve. The communication state of each port of these shift valves 70, 71, 72 at each gear position is as shown below the respective shift valves 70, 71, 72. In addition, the number shows each gear stage.

A third brake B ₃ is connected via an oil passage 75 to a brake port 74 that communicates with the input port 73 at the first and second shift stages among the ports of the 2-3 shift valve 71. An orifice 76 is interposed in the oil passage, and a damper valve 77 is connected between the orifice 76 and the third brake B ₃ . The damper valve 77 performs a buffering action by sucking a small amount of hydraulic pressure when the line pressure is suddenly supplied to the third brake B ₃ .

Reference numeral 78 denotes a B-3 control valve, and the engagement pressure P _B3 of the third brake B ₃ is directly controlled by the B-3 control valve 78. That is, the B-3 control valve 78 includes a spool 79, a plunger 80, and a spring 81 interposed therebetween, and an oil passage 75 is connected to an input port 82 opened and closed by the spool 79, and An output port 83 that is selectively communicated with the input port 82 is connected to the third brake B ₃ . Further, the output port 83 is connected to a feedback port 84 formed on the front end side of the spool 79.

  On the other hand, in the port 85 opened at the place where the spring 81 is disposed, a port 86 for outputting the D range pressure at the third speed or higher among the ports of the 2-3 shift valve 71 is provided via the oil passage 87. Communicated. A linear solenoid valve SLU is connected to the control port 88 formed on the end side of the plunger 80.

  Therefore, the B-3 control valve 78 has a pressure regulation level set by the elastic force of the spring 81 and the hydraulic pressure supplied to the port 85, and the higher the signal pressure supplied to the control port 88, the higher the elastic force by the spring 81. Is configured to be large.

  Further, reference numeral 89 in FIG. 4 denotes a 2-3 timing valve. The 2-3 timing valve 89 includes a spool 90 and a first plunger 91 each having a small-diameter land and two large-diameter lands. A spring 92 disposed between them and a second plunger 93 disposed on the opposite side of the first plunger 91 across the spool 90 are provided.

  An oil passage 95 is connected to the intermediate port 94 of the 2-3 timing valve 89, and the oil passage 95 is the third or higher gear position of the 2-3 shift valve 71 and the brake port 74. Is connected to a port 96 which can be communicated with.

  Further, the oil passage 95 branches in the middle and is connected to a port 97 opened between the small diameter land and the large diameter land via an orifice. A port 98 selectively communicated with the intermediate port 94 is connected to the solenoid relay valve 100 through an oil passage 99.

Then, the linear solenoid valve SLU is connected to the port that is open to an end portion of the first plunger 91, and the second brake B ₂ via an orifice to the port which is opened to the end of the second plunger 93 connected Has been.

The oil passage 87 is for supplying and discharging hydraulic pressure to and from the second brake B ₂ , and a small-diameter orifice 101 and an orifice 102 with a check ball are interposed in the middle. The oil passage 103 branched from the oil passage 87 is provided with a large-diameter orifice 104 provided with a check ball that opens when the second brake B _{2 is} discharged. The oil passage 103 is an orifice described below. It is connected to the control valve 105.

Orifice control valve 105 is a valve for controlling the exhaust圧速degree from the second brake B _2, the second brake B ₂ is connected to a port 107 formed in an intermediate portion to be opened and closed by the spool 106 The oil passage 103 is connected to a port 108 formed below the port 107 in the figure.

A port 109 formed above the port 107 to which the second brake B ₂ is connected is selectively connected to the drain port, and is connected to the port 109 via an oil passage 110. The port 111 of the B-3 control valve 78 is connected. The port 111 is a port that is selectively communicated with the output port 83 to which the third brake B ₃ is connected.

  A control port 112 formed at the end of the port of the orifice control valve 105 opposite to the spring that presses the spool 106 is connected to the port 114 of the 3-4 shift valve 72 via an oil passage 113. The port 114 is a port that outputs a signal pressure of the third solenoid valve SL3 at a speed lower than the third speed, and outputs a signal pressure of the fourth solenoid valve SL4 at a speed higher than the fourth speed. is there.

  Further, an oil passage 115 branched from the oil passage 95 is connected to the orifice control valve 105, and the oil passage 115 is selectively communicated with the drain port.

  In the 2-3 shift valve 71, the port 116 that outputs the D-range pressure at a speed lower than the second speed is a port 117 that opens at a position where the spring 92 is disposed in the 2-3 timing valve 89. It is connected via an oil passage 118. In addition, a port 119 communicated with the oil passage 87 at a gear position below the third gear position of the 3-4 shift valve 72 is connected to the solenoid relay valve 100 via the oil passage 120.

In FIG. 4, reference numeral 121 denotes an accumulator for the second brake B ₂ , and an accumulator control pressure adjusted according to the hydraulic pressure output from the linear solenoid valve SLN is supplied to the back pressure chamber. This accumulator control pressure is configured to increase as the output pressure of the linear solenoid valve SLN decreases. Therefore, the transitional hydraulic pressure P _B2 for engaging / releasing the second brake B ₂ changes at a higher pressure as the signal pressure of the linear solenoid valve SLN becomes lower. The other clutches C ₁ and C ₂ for shifting, and the brake B ₀ are also provided with accumulators, and the above-mentioned accumulator control pressure is applied so that the transient hydraulic pressure during shifting depends on the torque T _{I of the} input shaft 26 and the like. Are controlled.

Further, reference numeral 122 denotes a C-0 exhaust valve, and further reference numeral 123 denotes an accumulator for the clutch C _0. The C-0 exhaust valve 122 operates so as to engage the clutch C ₀ in order to apply the engine brake only in the second gear position in the second speed range.

Therefore, according to the hydraulic circuit 40 described above, if the port 111 of the B-3 control valve 78 communicates with the drain, the engagement pressure P _B3 of the third brake B ₃ is directly applied by the B-3 control valve 78. The pressure can be regulated, and the pressure regulation level can be changed by the linear solenoid valve SLU.

Further, the spool 106 of the orifice control valve 105, if the position shown in the left half of the figure, the second brake B ₂ allows ejection pressure through the orifice control valve 105, thus the second brake B ₂ The drain speed can be controlled.

Further, the shift from the second shift stage to the third shift stage is performed by so-called clutch-to-clutch shift that gently releases the third brake B ₃ and gently engages the second brake B _2. By controlling the release transient hydraulic pressure P _B3 of the third brake B ₃ driven by the linear solenoid valve SLU based on the input shaft torque T _I to the input shaft 26, the shift shock can be suitably reduced. The control of the hydraulic pressure P _B3 based on the input shaft torque T _I can be performed in real time by feedback control or the like, but may be performed based only on the input shaft torque T _I at the start of the shift.

As shown in FIG. 2, the hybrid drive apparatus 10 includes a hybrid control controller 50 and an automatic transmission control controller 52. These controllers 50 and 52 include a microcomputer having a CPU, a RAM, a ROM, and the like. From the accelerator operation amount sensor 62, an accelerator operation amount (an operation amount of an accelerator operation means such as an accelerator pedal) θ _AC , a brake switch 64 from the brake ON, OFF, except that the signal representative of the catalyst temperature T _S of the exhaust pipe from the catalyst temperature sensor 66 are supplied, the input shaft rotational speed N _I of the automatic transmission 18, the output shaft rotation of the automatic transmission 18 Number N _O (corresponding to vehicle speed V), engine torque T _E , motor torque T _M , engine speed N _E , motor speed N _M , power storage amount SOC of power storage device 58 (see FIG. 5), shift lever operation range Etc., and signal processing is performed according to a preset program.

The engine torque T _E is obtained from the throttle valve opening, the fuel injection amount, etc., the motor torque T _M is obtained from the motor current, etc., and the charged amount SOC is the motor current during charging when the motor generator 14 functions as a generator, Required from charging efficiency.

  The output of the engine 12 is controlled according to the operating state by controlling the throttle valve opening, fuel injection amount, ignition timing, and the like by the hybrid control controller 50.

  As shown in FIG. 5, the motor generator 14 is connected to a power storage device 58 such as a battery via an M / G controller (inverter) 56, and the hybrid control controller 50 supplies electric energy from the power storage device 58. , And a rotational driving state in which the motor is rotated at a predetermined torque; The rotor shaft 14r is switched to a no-load state that allows the rotor shaft 14r to freely rotate.

The first clutch CE ₁ and the second clutch CE ₂ are switched between engaged and disengaged states when the hydraulic circuit 40 is switched by the hybrid control controller 50 via an electromagnetic valve or the like.

In the automatic transmission 18, the excitation state of the solenoid valves SL1 to SL4 and the linear solenoid valves SLU, SLT, and SLN is controlled by the automatic transmission control controller 52, and the hydraulic circuit 40 is switched or hydraulic control is performed. The gear position is switched in accordance with a predetermined shift condition. The speed change condition is set by a speed change map using parameters such as the accelerator operation amount θ _AC and the vehicle speed V, for example.

  For example, as described in Japanese Patent Application No. 7-294148 filed earlier by the applicant of the present application, the hybrid control controller 50 has one of nine operation modes shown in FIG. 7 according to the flowchart shown in FIG. The engine 12 and the electric torque converter 24 are operated in the selected mode.

  In FIG. 6, in step S <b> 1, whether or not an engine start request has been made is determined by, for example, running the engine 12 as a power source or driving the motor generator 14 by the engine 12 to charge the power storage device 58. It is determined whether or not there is a command to start 12.

If there is a start request, mode 9 is selected in step S2. In the mode 9, as apparent from FIG. 7, the first clutch CE ₁ is engaged (ON), the second clutch CE ₂ is engaged (ON), and the engine 12 is connected to the engine 12 via the planetary gear unit 16 by the motor generator 14. The engine 12 is started by performing engine start control such as fuel injection.

This mode 9 is performed with the automatic transmission 18 being neutral when the vehicle is stopped, and when traveling with only the motor generator 14 with the first clutch CE ₁ released as in mode 1, the first clutch CE _{1 is used.} And the motor generator 14 is operated with an output exceeding the required output required for traveling, and the engine 12 is driven to rotate with a surplus output exceeding the required output.

  Further, even when the vehicle is traveling, it is possible to temporarily execute the mode 9 with the automatic transmission 18 being neutral. As the engine 12 is started by the motor generator 14 in this way, a starter (such as an electric motor) dedicated to starting becomes unnecessary, the number of parts is reduced, and the apparatus is inexpensive.

On the other hand, if the determination in step S1 is negative, that is, if there is no engine start request, step S3 is executed to determine whether there is a request for braking force, for example, whether the brake is on or not. Whether the lever operating range is an engine brake range such as L or 2 (the range in which the shift control is performed only at the low speed gear stage and the engine brake or the regenerative braking is applied) and the accelerator operation amount θ _AC is 0, or simply Whether the accelerator operation amount θ _AC is 0 or not is determined.

  If this determination is affirmative, step S4 is executed. In step S4, it is determined whether or not the storage amount SOC of power storage device 58 is greater than or equal to a predetermined maximum storage amount B. If SOC ≧ B, mode 8 is selected in step S5, and if SOC <B, step S4 is performed. Mode 6 is selected in S6. The maximum power storage amount B is the maximum power storage amount allowed to charge the power storage device 58 with electrical energy, and is set to a value of about 80%, for example, based on the charge / discharge efficiency of the power storage device 58.

In mode 8 selected in step S5, the first clutch CE ₁ is engaged (ON), the second clutch CE ₂ is engaged (ON), and the motor generator 14 is unloaded as shown in FIG. The engine 12 is stopped, i.e., the throttle valve is closed and the fuel injection amount is set to 0, so that the braking force by the rubbing rotation and pumping action of the engine 12, that is, the engine brake is applied to the vehicle, The brake operation by the driver is reduced, and the driving operation becomes easier. Further, since motor generator 14 is in a no-load state and is freely rotated, it is avoided that the amount of charge SOC of power storage device 58 becomes excessive and impairs performance such as charge / discharge efficiency.

In mode 6 selected in step S6, as apparent from FIG. 7, the first clutch CE ₁ is released (OFF), the second clutch CE ₂ is engaged (ON), the engine 12 is stopped, the motor generator 14 is charged, and the motor generator 14 is rotationally driven by the kinetic energy of the vehicle to charge the power storage device 58 and to apply a regenerative braking force such as an engine brake to the vehicle. The brake operation by is reduced and the driving operation becomes easy.

In addition, since the first clutch CE ₁ is released and the engine 12 is shut off, there is no energy loss due to the rubbing of the engine 12, and it is executed when the storage amount SOC is less than the maximum storage amount B. The power storage amount SOC of the power storage device 58 does not become excessive and performance such as charge / discharge efficiency is not impaired.

  On the other hand, if the determination in step S3 is negative, that is, if there is no request for braking force, step S7 is executed to determine whether engine start is requested, for example, using engine 12 as a power source such as mode 3. Judgment is made based on whether or not the traveling vehicle is stopped, that is, whether or not the vehicle speed V = 0.

If this determination is affirmative, step S8 is executed. In step S8, it is determined whether or not the accelerator is ON, that is, whether or not the accelerator operation amount θ _AC is larger than a predetermined value of substantially zero. If the accelerator is ON, mode 5 is selected in step S9, and the accelerator is ON. If not, mode 7 is selected in step S10.

In the mode 5 selected in the above step S9, as apparent from FIG. 7, the first clutch CE ₁ is engaged (ON), the second clutch CE ₂ is released (OFF), the engine 12 is put into an operating state, The vehicle is started by controlling the regenerative braking torque of the motor generator 14.

More specifically, if the gear ratio of the planetary gear device 16 is ρ _E , engine torque T _E : output torque of the planetary gear device 16: motor torque T _M = 1: (1 + ρ _E ): ρ _E for example, if the order of 0.5 which is a common value of the gear ratio [rho _E, by half the torque of the engine torque T _E motor generator 14 is shared, approximately 1.5 times the torque of the engine torque T _E Output from the carrier 16c.

That is, it is possible to perform a high torque start that is (1 + ρ _E ) / ρ _E times the torque of the motor generator 14. Further, if the motor current is cut off and the motor generator 14 is brought into a no-load state, the output from the carrier 16c becomes 0 only by the reverse rotation of the rotor shaft 14r, and the vehicle is stopped.

In other words, the planetary gear device 16 in this case functions as a starting clutch and a torque amplifying device. By gradually increasing the motor torque (regenerative braking torque) _TM from 0 and increasing the reaction force, the engine torque T _The vehicle can be smoothly started with an output torque (1 + ρ _E ) times _E.

Here, in this embodiment, a motor generator having a torque capacity of approximately ρ _E times the maximum torque of the engine 12, that is, a motor generator 14 having a small capacity as small as possible while ensuring the necessary torque is used. It is small and inexpensive.

Further, in this embodiment, the output of the engine 12 is increased by increasing the throttle valve opening and the fuel injection amount in response to the increase of the motor torque T _M , and the engine rotation accompanying the increase of the reaction force. thereby preventing engine stall or the like due to the reduction in the number N _E.

In mode 7 selected in step S10, as apparent from FIG. 7, the first clutch CE ₁ is engaged (ON), the second clutch CE ₂ is released (OFF), the engine 12 is put in the operating state, and the motor The generator 14 is made electrically neutral with no load, and the rotor shaft 14r of the motor generator 14 is freely rotated in the reverse direction so that the output to the input shaft 26 of the automatic transmission 18 becomes zero. Accordingly, it is not necessary to stop the engine 12 at a time when the vehicle is stopped while traveling with the engine 12 as a power source, such as in the mode 3, and the engine start in the mode 5 is substantially possible.

On the other hand, if the determination in step S7 is negative, that is, if there is no engine start request, step S11 is executed to determine whether or not the request output Pd is equal to or less than a first determination value P1 set in advance. The required output Pd is an output necessary for traveling of the vehicle including the running resistance, and is based on the accelerator operation amount θ _AC and its change speed, the vehicle speed V (output shaft rotational speed N _O ), the shift stage of the automatic transmission 18 and the like. It is calculated by a predetermined data map, an arithmetic expression, or the like. The first determination value P1 is a boundary value between a middle load region that travels using only the engine 12 as a power source and a low load region that travels using only the motor generator 14 as a power source, and energy efficiency including when the engine 12 is charged. In consideration of the above, in the engine resonance region where the exhaust gas amount and the fuel consumption amount are reduced as much as possible and the drive system resonates due to the vibration of the engine 12 and the NVH deteriorates, the motor generator 14 alone is used as the power source. It is determined in advance by experiments or the like.

  If the determination in step S11 is affirmative, that is, if the required output Pd is equal to or less than the first determination value P1, it is determined in step S12 whether or not the storage amount SOC is greater than or equal to a preset minimum storage amount A. If ≧ A, mode 1 is selected in step S13. On the other hand, if SOC <A, mode 3 is selected in step S14. The minimum storage amount A is the minimum storage amount allowed to take out electrical energy from the power storage device 58 when traveling using the motor generator 14 as a power source. For example, 70% based on the charge / discharge efficiency of the power storage device 58 A value of about is set.

In the mode 1, as apparent from FIG. 7, the first clutch CE ₁ is released (OFF), the second clutch CE ₂ is engaged (ON), the engine 12 is stopped, and the motor generator 14 is requested to output. The vehicle is driven by Pd, and the vehicle is driven using only the motor generator 14 as a power source.

Also in this case, since the first clutch CE ₁ is released and the engine 12 is shut off, there is little rubbing loss as in the mode 6, and efficient motor drive is achieved by appropriately controlling the shift of the automatic transmission 18. Control is possible.

  Further, this mode 1 is executed when the required output Pd is in a low load region where the first determination value P1 or less and the power storage amount SOC of the power storage device 58 is greater than or equal to the minimum power storage amount A. Therefore, the engine 12 is used as a power source. The energy efficiency is superior to that of traveling and fuel consumption and exhaust gas can be reduced, and the storage amount SOC of the power storage device 58 does not decrease from the minimum storage amount A and the performance such as charge / discharge efficiency is not impaired.

In mode 3 selected in step S14, as apparent from FIG. 7, the first clutch CE ₁ and the second clutch CE ₂ are both engaged (ON), the engine 12 is put into an operating state, and the motor generator 14 is regeneratively braked. Thus, the electric energy generated by the motor generator 14 is charged to the power storage device 58 while the vehicle is running with the output of the engine 12. The engine 12 is operated with an output equal to or higher than the required output Pd, and current control of the motor generator 14 is performed such that the motor generator 14 consumes a surplus power larger than the required output Pd.

  On the other hand, if the determination in step S11 is negative, that is, if the request output Pd is greater than the first determination value P1, in step S15, the request output Pd is greater than the first determination value P1 and greater than the second determination value P2. It is determined whether or not it is small, that is, whether or not P1 <Pd <P2.

  The second determination value P2 is a boundary value between a medium load region that travels using only the engine 12 as a power source and a high load region that travels using both the engine 12 and the motor generator 14 as power sources, and includes when the engine 12 is charged. In consideration of the energy efficiency, the amount of exhaust gas and the amount of fuel consumption is determined in advance by experiments or the like so as to reduce as much as possible.

  If P1 <Pd <P2, it is determined in step S16 whether or not SOC ≧ A. If SOC ≧ A, mode 2 is selected in step S17, and if SOC <A, step S14. Select mode 3. If Pd ≧ P2, it is determined whether or not SOC ≧ A in step S18. If SOC ≧ A, mode 4 is selected in step S19, and if SOC <A, mode 2 is selected in step S17. select.

In the mode 2, as apparent from FIG. 7, the first clutch CE ₁ and the second clutch CE ₂ are both engaged (ON), the engine 12 is operated at the required output Pd, and the motor generator 14 is in a no-load state. Therefore, the vehicle is driven using only the engine 12 as a power source.

In mode 4, both the first clutch CE ₁ and the second clutch CE ₂ are engaged (ON), the engine 12 is put into an operating state, and the motor generator 14 is driven to rotate. The vehicle is driven at a high output by using both power sources.

  This mode 4 is executed in a high load region where the required output Pd is equal to or higher than the second determination value P2, but since the engine 12 and the motor generator 14 are used in combination, only one of the engine 12 and the motor generator 14 is used. Compared to traveling as a power source, energy efficiency is not significantly impaired, and fuel consumption and exhaust gas can be reduced. Further, since the storage amount SOC is executed when the storage amount SOC is equal to or greater than the minimum storage amount A, the storage amount SOC of the power storage device 58 does not drop below the minimum storage amount A and performance such as charge / discharge efficiency is not impaired.

  Summarizing the operating conditions of the above modes 1 to 4, if the storage amount SOC ≧ A, in the low load region where Pd ≦ P1, the mode 1 is selected in step S13, and only the motor generator 14 is driven as the power source. In the medium load region of <Pd <P2, mode 2 is selected in step S17 and the engine 12 is driven using only the engine 12 as a power source. In the high load region of P2 ≦ Pd, mode 4 is selected in step S19 and the engine 12 and the motor generator are driven. It travels using both of 14 as a power source.

FIG. 9 is a mode switching map that is substantially equivalent to the switching conditions of the operation modes 1, 2, and 4 in which the accelerator operation amount θ _AC and the vehicle speed V are set as parameters, and the required output Pd is obtained. Instead, mode switching may be performed according to the mode switching map. The mode 1 region corresponds to the motor travel region, the mode 2 region corresponds to the engine travel region, and the mode 4 region corresponds to the engine + motor travel region.

  Further, when SOC <A, the power storage device 58 is charged by executing the mode 3 of step S14 in the medium and low load region where the required output Pd is smaller than the second determination value P2, but the required output Pd is the second In a high load region that is equal to or greater than the determination value P2, mode 2 is selected in step S17, and the engine 12 performs high output travel without charging.

  Mode 2 of step S17 is executed when P1 <Pd <P2 in the medium load region and SOC ≧ A, or when Pd ≧ P2 is high load region and SOC <A, but generally in the medium load region. Since the engine 12 is more energy efficient than the motor generator 14, fuel consumption and exhaust gas can be reduced as compared with the case where the motor generator 14 is used as a power source.

  In the high load region, mode 4 in which the motor generator 14 and the engine 12 are used together is desirable. However, when the storage amount SOC of the power storage device 58 is smaller than the minimum storage amount A, only the engine 12 in the above mode 2 is used. By performing the operation using as the power source, it is avoided that the storage amount SOC of the power storage device 58 is less than the minimum storage amount A and the performance such as charge / discharge efficiency is impaired.

On the other hand, the hybrid control controller 50 performs signal processing in accordance with the flowchart of FIG. 8 in preference to the mode switching control of FIG. 6 during predetermined deceleration travel, and performs fuel cut control of the engine 12 and regenerative control of the motor generator 14, Engagement / release control of the first clutch CE ₁ is performed. Steps SA1 to SA3 in FIG. 8 correspond to the deceleration travel determination means, step SA4 corresponds to the fuel supply stop means, step SA9 corresponds to the braking force supplement means, and step SA10 corresponds to the engine disconnection means.

In FIG. 8, in step SA1, based on the signal supplied from the accelerator operation amount sensor 62, it is determined whether or not an accelerator off time T _AC representing a time during which the accelerator pedal is not depressed is equal to or greater than a predetermined time α. The If this determination is negative, it is determined in step SA2 based on the signal supplied from the accelerator operation amount sensor 62 whether or not the accelerator operation amount θ _AC is substantially zero at the present time. If this determination is affirmative, it is determined in step SA3 whether or not the rate of change ΔV of the vehicle speed V is smaller than a predetermined value −β, in other words, whether or not the vehicle is in a predetermined deceleration state.

When the determination at step SA1 is affirmed or when the determination at step SA3 is affirmative, fuel supply to the engine 12 is stopped at step SA4 (fuel cut control). In step SA5, the regenerative braking torque of motor generator 14 is controlled, a predetermined regenerative braking force is applied to the vehicle, and power storage device 58 is charged corresponding to the braking force. This regenerative braking is performed while the first clutch CE ₁ is maintained in the engaged (ON) state at this stage, unlike the mode 6 in FIG. The second clutch CE ₂ is in an engaged (ON) state.

Next, in step SA6, it is determined whether or not a brake ON signal is supplied from the brake switch 64. If this determination is affirmative, in step SA7, the catalyst temperature sensor 66 determines whether or not the catalyst temperature T _S in the exhaust pipe is equal to or higher than a predetermined value γ. The predetermined value γ is set to a temperature at which generation of exhaust gas such as NO _x and CO becomes a problem when the engine 12 is started again after being stopped.

If the determination in step SA7 is affirmative, it is determined in step SA8 whether or not the operation region is traveled using the motor generator 14 as a power source, and whether or not mode 1 or 4 is selected in accordance with the operation mode determination subroutine of FIG. Alternatively, the determination is made based on whether or not the operation region is mode 1 or 4 in FIG. If this determination is negative, that is, in the driving region where only the engine 12 is used as the power source, the first clutch CE ₁ is maintained in the engaged (ON) state, and the engine 12 is forced to rotate according to the vehicle speed. Be made.

On the other hand, if the determination in step SA8 is affirmative, in step SA9, the regenerative torque of the motor generator 14 is controlled to compensate for the disappearance of the engine braking force due to the disconnection of the engine 12 in step SA10. The braking force by regeneration is increased by an amount corresponding to the force. Subsequently, in step SA10, the first clutch CE ₁ is released (OFF), and the engine 12 is disconnected from the planetary gear device 16 and stopped. Regenerative torque control in step SA9, it is desirable to perform in correspondence with the reduction in the engine braking force by the first release control of the clutch CE ₁ step SA10.

  As described above, according to this embodiment, the fuel supply to the engine 12 is stopped at the time of deceleration traveling that does not require the engine torque by the step SA4 corresponding to the fuel supply stop means, so that the fuel efficiency is improved.

Further, when the fuel supply to the engine 12 is stopped, the determination in step SA8 is NO in the operating region where the engine 12 is driven only by the power source, and the engagement (ON) state of the first clutch CE ₁ is maintained. Since the engine 12 is forcibly rotated as the vehicle travels, the engine output is quickly increased along with the fuel supply when the accelerator pedal is depressed and reaccelerated. Even if the driving force to be obtained is obtained quickly, there is no possibility of causing a feeling of rattling.

On the other hand, in the operating region where the motor generator 14 is used as the power source, the determination in step SA8 is YES, the first clutch CE ₁ is released in step SA10, the engine 12 is disconnected, and the rotation is stopped. Sometimes, the driving force intended by the driver can be obtained quickly by increasing the output of the motor generator 14, so there is no fear of feeling sticky. In the mode 4 engine + motor running region, the start-up delay of the engine 12 is anticipated at the time of reacceleration, and the motor torque is controlled to be larger by that amount.

  In addition, if the engine 12 is disconnected when the brake is ON at step SA6, the engine braking force due to rubbing rotation or pumping action cannot be obtained. In this embodiment, in step SA9, this corresponds to the engine braking force. Since the regenerative torque of the motor generator 14 is increased by that amount, the braking force does not change and the driver does not feel uncomfortable, and the power storage device 58 is charged by the regenerative braking, so that the fuel efficiency is further improved. .

If the engine 12 is disconnected and stopped when the catalyst temperature T _S is low, the generation of exhaust gases such as NO _x and CO becomes a problem when the engine 12 is started next time. _{When S} is lower than the predetermined value γ, the determination in step SA7 is NO, and disconnection of the engine 12 is prohibited. Therefore, such a problem of exhaust gas when the engine 12 is restarted is avoided.

  As mentioned above, although one Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the automatic transmission 18 having the first reverse speed and the fifth forward speed is used. However, as shown in FIG. It is also possible to employ an automatic transmission 60 composed only of the main transmission 22 and perform shift control at four forward speeds and one reverse speed as shown in FIG. Note that the present invention can also be applied to a hybrid vehicle that does not include a transmission.

  The present invention can be implemented in various other modes without departing from the gist of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating a configuration of a hybrid drive device of a hybrid vehicle including a drive control device that is an embodiment of the present invention. It is a figure explaining the control system with which the hybrid drive device of FIG. 1 is equipped. It is a figure explaining the action | operation of the engagement element which materializes each gear stage of the automatic transmission of FIG. It is a figure which shows a part of hydraulic circuit of the automatic transmission of FIG. It is a figure explaining the connection relation of the controller for hybrid control of FIG. 2, and an electric torque converter. It is a flowchart explaining the basic action | operation of the hybrid drive device of FIG. It is a figure explaining the operating state of each mode 1-9 in the flowchart of FIG. It is a flowchart explaining the principal part of the control action used as the characteristic of this invention. It is a figure which illustrates the map preset as a parameter with the amount of accelerator operation and vehicle speed used in order to switch a motive power source according to driving | running conditions. FIG. 2 is a skeleton diagram illustrating a configuration of a hybrid drive device including an automatic transmission different from the embodiment of FIG. 1. It is a figure explaining the action | operation of the engagement element which materializes each gear stage of the automatic transmission of FIG.

Explanation of symbols

12: Engine 14: Motor generator (electric motor) 18, 60: Automatic transmission 50: Controller for hybrid control 58: Power storage device CE ₁ : First clutch (clutch means)
Step SA4: Fuel supply stopping means Step SA9: Braking force complementing means Step SA10: Engine disconnecting means

Claims (9)

An engine that operates by fuel combustion and an electric motor that operates by electric energy are provided as a power source when the vehicle travels, and the operation state of the engine and the electric motor varies depending on operating conditions in a plurality of operation modes. In a traveling hybrid vehicle,
Clutch means for disconnecting the engine from the electric motor;
If the brake is not ON even when the accelerator is off, the clutch means is maintained in the engaged state, and the engine is forcibly rotated as the vehicle travels. However, when the accelerator is off and the brake is ON, the clutch means is released and the clutch means is released. Engine disconnecting means for disconnecting the engine from the electric motor;
Braking force complementing means for complementing braking force corresponding to engine braking force by regenerative braking when the engine is disconnected by the engine disconnecting means;
A drive control apparatus for a hybrid vehicle, comprising: 2. The hybrid vehicle according to claim 1, wherein the engine disconnecting unit disengages the engine by releasing the clutch unit on condition that fuel supply to the engine is stopped during deceleration traveling. 3. Drive control device. 2. The drive control apparatus for a hybrid vehicle according to claim 1, wherein the engine disconnecting unit releases the clutch unit and disconnects the engine on condition that a catalyst temperature is equal to or higher than a predetermined value. 2. The drive control of the hybrid vehicle according to claim 1, wherein the engine disconnecting unit releases the clutch unit and disconnects the engine on condition that the engine is in an operation region where the electric motor is used as a power source. apparatus. An engine that operates by combustion of fuel and an electric motor that operates by electric energy are provided as a power source when the vehicle travels, and the operation state of the engine and the electric motor varies depending on the operating conditions. In a traveling hybrid vehicle,
Clutch means for disconnecting the engine from the electric motor;
If the brake is not ON even during deceleration, the clutch means is maintained in the engaged state, and the engine is forcibly rotated as the vehicle travels. However, when the brake is ON and the brake is ON, the clutch means is released. Engine separating means for separating the engine from the electric motor;
Braking force complementing means for complementing braking force corresponding to engine braking force by regenerative braking when the engine is disconnected by the engine disconnecting means;
A drive control apparatus for a hybrid vehicle, comprising: 6. The drive control apparatus for a hybrid vehicle according to claim 5, wherein the engine disconnecting unit releases the clutch unit and disconnects the engine on condition that fuel supply to the engine is stopped. The drive control apparatus for a hybrid vehicle according to claim 5, wherein the engine disconnecting means releases the clutch means and disconnects the engine on condition that the catalyst temperature is equal to or higher than a predetermined value. 6. The drive control of a hybrid vehicle according to claim 5, wherein the engine disconnecting means releases the clutch means and disconnects the engine on condition that the engine is in an operating region where the electric motor is used as a power source. apparatus. The drive control apparatus for a hybrid vehicle according to any one of claims 1 to 8 , wherein an automatic transmission is disposed between the engine and the electric motor and drive wheels.

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