JP5056482B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control apparatus for a hybrid vehicle having an engine and a motor as a power source.

The technique of patent document 1 is disclosed as a hybrid vehicle. This publication includes a first fastening element that connects and disconnects the engine and the motor, and a second fastening element that connects and disconnects the motor and the drive wheel, and has an engine use travel mode in which the engine travels while being included in the power source. Even when the minimum gear ratio (for example, 1st speed) is selected, including when starting, the second fastening element is slipped at an extremely low speed that is lower than the minimum speed at which the engine can stand by itself. One that travels while ensuring rotation is known.
JP 2001-263383 A

  However, when the traveling mode is continued, there is a possibility that the heat generated by the second fastening element becomes excessive.

  The present invention has been made paying attention to the above problem, and an object thereof is to provide a control device for a hybrid vehicle that can suppress excessive heat generation of the second fastening element.

  In order to achieve the above object, according to the present invention, the motor travel control means is selected when the charged amount of the battery is equal to or greater than the first charged amount, and the engine use slip is selected when it is less than the second charged amount that is smaller than the first charged amount. When the travel control means is selected, and the motor travel control means is selected, if the battery charge amount is greater than or equal to the second charge amount and less than the first charge amount, the motor travel control means is used, and the engine use slip travel control is performed. When the battery storage amount is equal to or more than the second storage amount and less than the first storage amount when the means is selected, the engine use slip travel control means When the duration time is longer than the predetermined time, the difference between the first charged amount and the second charged amount is changed.

  Therefore, in the hybrid vehicle control apparatus of the present invention, the travel control means can be frequently switched, and the amount of heat generated by the second fastening element can be suppressed.

  Hereinafter, the best mode for realizing a control device for a hybrid vehicle of the present invention will be described based on an embodiment shown in the drawings.

  First, the drive system configuration of the hybrid vehicle will be described. FIG. 1 is an overall system diagram showing a hybrid vehicle by rear wheel drive to which the engine start control device of the first embodiment is applied. As shown in FIG. 1, the drive system of the hybrid vehicle in the first embodiment includes an engine E, a first clutch CL1, a motor generator MG, a second clutch CL2, an automatic transmission AT, a propeller shaft PS, It has a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel RL (drive wheel), and a right rear wheel RR (drive wheel). FL is the front left wheel and FR is the front right wheel.

  The engine E is, for example, a gasoline engine, and the valve opening degree of the throttle valve and the like are controlled based on a control command from the engine controller 1 described later. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine E and the motor generator MG, and the control created by the first clutch hydraulic unit 6 based on a control command from the first clutch controller 5 described later. Fastening / release including slip fastening is controlled by hydraulic pressure.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and the three-phase AC generated by the inverter 3 is generated based on a control command from a motor controller 2 described later. It is controlled by applying. The motor generator MG can operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (hereinafter, this state is referred to as “power running”), or when the rotor is rotated by an external force. Can function as a generator that generates electromotive force at both ends of the stator coil to charge the battery 4 (hereinafter, this operation state is referred to as “regeneration”). Note that the rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL and RR, and is generated by the second clutch hydraulic unit 8 based on a control command from the AT controller 7 described later. The fastening / release including slip fastening is controlled by the control hydraulic pressure.

  The automatic transmission AT is a transmission that automatically switches the stepped gear ratio such as 5 forward speeds, 1 reverse speed, etc. according to the vehicle speed, accelerator opening, etc., and the second clutch CL2 is newly added as a dedicated clutch However, some frictional engagement elements are used among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT. Details will be described later.

  The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR as vehicle drive shafts. The first clutch CL1 and the second clutch CL2 are, for example, wet multi-plate clutches that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid.

  This hybrid drive system has three travel modes according to the engaged / released state of the first clutch CL1. The first travel mode is an electric vehicle travel mode (hereinafter abbreviated as “EV travel mode”) as a motor use travel mode that travels using only the power of the motor generator MG as a power source with the first clutch CL1 opened. It is. The second travel mode is an engine use travel mode (hereinafter abbreviated as “HEV travel mode”) in which the first clutch CL1 is engaged and the engine E is included in the power source. The third travel mode is an abbreviated engine use slip travel mode (hereinafter referred to as “WSC travel mode”) in which the second clutch CL2 is slip-controlled while the first clutch CL1 is engaged and the engine E is included in the power source. ). This mode is a mode in which creep running can be achieved particularly when the battery SOC is low or the engine water temperature is low. When transitioning from the EV travel mode to the HEV travel mode, the first clutch CL1 is engaged and the engine is started using the torque of the motor generator MG.

  The “HEV travel mode” has three travel modes of “engine travel mode”, “motor assist travel mode”, and “travel power generation mode”.

  In the “engine running mode”, the drive wheels are moved using only the engine E as a power source. In the “motor assist travel mode”, the drive wheels are moved by using the engine E and the motor generator MG as power sources. The “running power generation mode” causes the motor generator MG to function as a generator at the same time as the drive wheels RR and RL are moved using the engine E as a power source.

  During constant speed operation or acceleration operation, motor generator MG is operated as a generator using the power of engine E. Further, during deceleration operation, the braking energy is regenerated and generated by the motor generator MG and used for charging the battery 4.

  Further, as a further mode, there is a power generation mode in which the motor generator MG is operated as a generator using the power of the engine E when the vehicle is stopped.

  Next, the control system of the hybrid vehicle will be described. As shown in FIG. 1, the hybrid vehicle control system according to the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. The AT controller 7, the second clutch hydraulic unit 8, the brake controller 9, and the integrated controller 10 are configured. The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, and the integrated controller 10 are connected via a CAN communication line 11 that can exchange information with each other. Has been.

  The engine controller 1 inputs the engine speed information from the engine speed sensor 12, and controls the engine operating point (Ne: engine speed, Te: engine torque) according to the target engine torque command from the integrated controller 10, etc. For example, to a throttle valve actuator (not shown). Information such as the engine speed Ne is supplied to the integrated controller 10 via the CAN communication line 11.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor generator MG, and according to a target motor generator torque command from the integrated controller 10 or the like, the motor operating point (Nm: motor generator) of the motor generator MG. A command for controlling the rotation speed (Tm: motor generator torque) is output to the inverter 3. The motor controller 2 monitors the battery SOC indicating the state of charge of the battery 4. The battery SOC information is used as control information for the motor generator MG and is supplied to the integrated controller 10 via the CAN communication line 11. Is done.

  The first clutch controller 5 inputs sensor information from the first clutch hydraulic pressure sensor 14 and the first clutch stroke sensor 15, and according to the first clutch control command from the integrated controller 10, the first clutch CL1 is engaged / released. A command to control is output to the first clutch hydraulic unit 6. Information on the first clutch stroke C1S is supplied to the integrated controller 10 via the CAN communication line 11.

  The AT controller 7 inputs sensor information from the accelerator opening sensor 16, the vehicle speed sensor 17, the second clutch hydraulic pressure sensor 18, and an inhibitor switch that outputs a signal corresponding to the position of the shift lever operated by the driver. 10 is output to the second clutch hydraulic unit 8 in the AT hydraulic control valve in response to the second clutch control command from 10. Information on the accelerator pedal opening APO, the vehicle speed VSP, and the inhibitor switch is supplied to the integrated controller 10 via the CAN communication line 11.

  The brake controller 9 inputs sensor information from a wheel speed sensor 19 and a brake stroke sensor 20 that detect the wheel speeds of the four wheels. For example, when the brake is depressed, braking is performed with respect to the required braking force obtained from the brake stroke BS. When the braking force alone is insufficient, the regenerative cooperative brake control is performed based on the regenerative cooperative control command from the integrated controller 10 so that the shortage is supplemented by the mechanical braking force (braking force by the friction brake).

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 10 detects the motor rotational speed Nm, and the second clutch output rotational speed N2out. A second clutch output speed sensor 22 for detecting the second clutch, a second clutch torque sensor 23 for detecting the second clutch transmission torque capacity TCL2, a brake hydraulic pressure sensor 24, and a temperature sensor 10a for detecting the temperature of the second clutch CL2. The information from the G sensor 10b for detecting the longitudinal acceleration and the information obtained through the CAN communication line 11 are input.

  The integrated controller 10 also controls the operation of the engine E according to the control command to the engine controller 1, the operation control of the motor generator MG based on the control command to the motor controller 2, and the first control command to the first clutch controller 5. Engagement / release control of the clutch CL1 and engagement / release control of the second clutch CL2 by a control command to the AT controller 7 are performed.

  Below, the control calculated by the integrated controller 10 of Example 1 is demonstrated using the block diagram shown in FIG. For example, this calculation is performed by the integrated controller 10 every control cycle of 10 msec. The integrated controller 10 includes a target driving force calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, an operating point command unit 400, and a shift control unit 500.

  The target driving force calculation unit 100 calculates a target driving force tFoO from the accelerator pedal opening APO and the vehicle speed VSP using the target driving force map shown in FIG.

  The mode selection unit 200 includes a road surface gradient estimation calculation unit 201 that estimates a road surface gradient based on the detection value of the G sensor 10b. The road surface gradient estimation calculation unit 201 calculates the actual acceleration from the wheel speed acceleration average value of the wheel speed sensor 19 and the like, and estimates the road surface gradient from the deviation between the calculation result and the G sensor detection value.

  Furthermore, the mode selection unit 200 includes a duration estimation unit 202 that estimates the duration of the WSC travel mode. The duration estimation unit 202 estimates based on the following information.

  (i) When the time when both the accelerator pedal and the brake pedal are not depressed is longer than the predetermined time, it is estimated that the duration time is long. Whether or not the accelerator pedal is depressed is detected by an accelerator opening sensor 16 or the like. Further, whether or not the brake pedal is depressed is detected by the brake stroke sensor 20 or the like.

  The fact that both the accelerator pedal and the brake pedal are not depressed is when creep running control is being performed. In the first embodiment that does not include a torque converter, when the SOC is low, the WSC traveling mode is selected, so there is a high possibility that the WSC traveling mode is continuously selected. On the other hand, if the SOC is high, the EV travel mode is selected, but the EV region will eventually disappear, and then the WSC travel mode is entered. In any case, it can be estimated that the WSC driving mode is continuously selected.

  (ii) If the number of times the accelerator pedal is changed to the brake pedal or the brake pedal is changed to the accelerator pedal within the predetermined time is more than the predetermined number of times, it is estimated that the duration is long. When the accelerator operation and the brake operation are frequently performed, for example, when a garage or a traffic jam is performed in a low vehicle speed range. Also at this time, it can be estimated that the WSC travel mode is continuously selected as described above. In addition, as a specific count, for example, the accelerator pedal is released within a predetermined time after the accelerator pedal is operated, and the brake pedal is released within a predetermined time from when it is switched to the brake pedal. In this case, it is counted that one step change has been made.

  (iii) If the brake pedal is depressed more than a predetermined number of times when the WSC travel mode is selected, it is estimated that the duration time is long. In this case as well, it is estimated that the WSC driving mode is continuously selected when the vehicle is traveling in a traffic jam.

  (iv) It is estimated that the duration is long when the vehicle is traveling in the EV traveling mode at a vehicle speed lower than the lower limit vehicle speed VSP1, which is a vehicle speed for switching between the WSC traveling mode and the HEV traveling mode described later. That is, if the EV travel time in the HEV region is long, there is a high possibility that the WSC travel mode will be selected when the vehicle speed decreases as the SOC decreases, and it can be estimated that the WSC travel mode is selected continuously.

  In addition, the mode selection unit 200 sets the EVON line to a low SOC in a target charge / discharge amount map described later based on the detected temperature of the second clutch CL2, the estimated road surface gradient, and the estimated duration. A threshold value changing unit 203 for changing to the side. FIG. 4 is a schematic diagram showing a target charge / discharge amount map changed by the threshold changing unit 203. The threshold value changing unit 203 determines that the duration is long from the state where the EVON line is set to SOC 50%, or when the estimated gradient is equal to or higher than a predetermined value, or when the second clutch temperature becomes equal to or higher than a predetermined value. Switch the EVON line to SOC 40%. The operation when the SOC threshold is changed by the threshold changing unit 203 will be described later.

  Next, the mode map will be described. FIG. 5 shows a normal mode map. The normal mode map has an EV travel mode, a WSC travel mode, and an HEV travel mode, and calculates the target mode from the accelerator pedal opening APO and the vehicle speed VSP. However, even if the EV travel mode is selected, if the battery SOC is equal to or lower than the predetermined value, the “HEV travel mode” or the “WSC travel mode” is forcibly set as the target mode.

  In the normal mode map of FIG. 5, the HEV → WSC switching line has a rotational speed smaller than the idle rotational speed of the engine E when the automatic transmission AT is in the first speed in the region below the predetermined accelerator opening APO1. It is set in a region lower than the lower limit vehicle speed VSP1. Further, since a large driving force is required in a region where the accelerator opening APO1 is equal to or greater than the predetermined accelerator opening APO1, the WSC travel mode is set up to a vehicle speed VSP1 ′ region that is higher than the lower limit vehicle speed VSP1. When the battery SOC is low and the EV travel mode cannot be achieved, the WSC travel mode is selected even when starting.

  When the accelerator pedal opening APO is large, it may be difficult to achieve the request with the engine torque corresponding to the engine speed near the idle speed and the torque of the motor generator MG. Here, more engine torque can be output if the engine speed increases. From this, if the engine speed is increased and a larger torque is output, even if the WSC drive mode is executed up to a vehicle speed higher than the lower limit vehicle speed VSP1, the WSC drive mode is changed to the HEV drive mode in a short time. be able to. This case corresponds to the WSC region extended to the lower limit vehicle speed VSP1 ′ shown in FIG.

  The target charge / discharge calculation unit 300 calculates the target charge / discharge power tP from the battery SOC using the target charge / discharge amount map shown in FIG. In the target charge / discharge amount map, the EVON line for permitting or prohibiting the EV travel mode or the MWSC travel mode is set to SOC = 50%, and the EVOFF line is set to SOC = 35%. Further, as described above, the EVON line is changed to SOC = 40% based on the command of the threshold value changing unit 203.

  When SOC ≧ 50%, the EV driving mode area appears in the normal mode map of FIG. Once the EV driving mode area appears in the mode map, this area continues to appear until the SOC drops below 35%.

  When SOC <35%, the EV drive mode area disappears in the normal mode map of FIG. When the EV drive mode area disappears from within the mode map, this area continues to disappear until the SOC reaches 50%.

  The operating point command unit 400 uses the accelerator pedal opening APO, the target driving force tFoO, the target mode, the vehicle speed VSP, and the target charging / discharging power tP as a target for reaching the operating point, as a transient target engine torque. The target motor generator torque, the target second clutch engagement capacity, the target gear position of the automatic transmission AT, and the first clutch solenoid current command are calculated. Further, the operating point command unit 400 is provided with an engine start control unit that starts the engine E when the EV travel mode is changed to the HEV travel mode.

  The shift control unit 500 drives and controls the solenoid valve in the automatic transmission AT so as to achieve the target second clutch engagement capacity and the target shift speed according to the shift schedule shown in the shift map. In the shift map, a target gear position is set in advance based on the vehicle speed VSP and the accelerator pedal opening APO.

[About WSC drive mode]
Next, details of the WSC travel mode will be described. The WSC traveling mode is characterized in that the engine E is maintained in an operating state, and has high responsiveness to a required driving force change. Specifically, the first clutch CL1 is completely engaged, the second clutch CL2 is slip-controlled as a transmission torque capacity TCL2 corresponding to the required driving force, and travels using the driving force of the engine E and / or motor generator MG. .

  In the hybrid vehicle of the first embodiment, there is no element that absorbs the difference in rotational speed unlike the torque converter. Therefore, when the first clutch CL1 and the second clutch CL2 are completely engaged, the vehicle speed is determined according to the rotational speed of the engine E. End up. The engine E has a lower limit value based on the idling engine speed for maintaining the self-sustaining rotation, and the idling engine speed further increases when the engine is idling up due to warm-up operation of the engine. In addition, when the required driving force is high, there may be a case where the HEV traveling mode cannot be quickly changed.

  On the other hand, in the EV travel mode, since the first clutch CL1 is released, there is no limit associated with the lower limit value due to the engine speed. However, in the case where it is difficult to travel in the EV travel mode due to restrictions based on the battery SOC, or in a region where the required driving force cannot be achieved only by the motor generator MG, there is no means other than generating stable torque by the engine E.

  Therefore, when the vehicle speed range is lower than the vehicle speed corresponding to the lower limit value and it is difficult to travel in the EV travel mode, or when the required driving force cannot be achieved only by the motor generator MG, the engine speed is set to the predetermined rotational speed. The WSC traveling mode is selected in which the second clutch CL2 is slip controlled and the engine torque is used for traveling.

  FIG. 6 is a schematic diagram showing the engine operating point setting process in the WSC running mode, and FIG. 7 is a map showing the engine target speed in the WSC running mode.

  When the driver operates the accelerator pedal in the WSC travel mode, the target engine speed characteristic corresponding to the accelerator pedal opening is selected based on FIG. 7, and the target engine speed corresponding to the vehicle speed is set based on this characteristic. Is done. Then, the target engine torque corresponding to the target engine speed is calculated by the engine operating point setting process shown in FIG.

  Here, the operating point of the engine E is defined as a point defined by the engine speed and the engine torque. As shown in FIG. 6, it is desirable that the engine operating point is operated on a line (hereinafter referred to as “α line”) connecting operating points with high output efficiency of the engine E.

  However, when the engine speed is set as described above, an operating point away from the α line is selected depending on the driver's accelerator pedal operation amount (required driving force). Therefore, in order to bring the engine operating point closer to the α line, the target engine torque is feedforward controlled to a value that takes the α line into consideration.

  On the other hand, the motor generator MG executes the rotational speed feedback control using the set engine rotational speed as the target rotational speed. Since the engine E and the motor generator MG are now in a directly connected state, the motor generator MG is controlled so as to maintain the target rotational speed, so that the rotational speed of the engine E is also automatically feedback-controlled. It becomes.

  At this time, the torque output from motor generator MG is automatically controlled so as to fill the deviation between the target engine torque determined in consideration of the α-ray and the required driving force. In the motor generator MG, a basic torque control amount (regeneration / power running) is given so as to fill the deviation, and further feedback control is performed so as to match the target engine speed.

  When the required driving force is smaller than the driving force on the α line at a certain engine speed, the engine output efficiency increases as the engine output torque is increased. At this time, the motor generator MG recovers the energy corresponding to the increased output, and the torque input to the second clutch CL2 becomes the torque required by the driver, and efficient power generation is possible.

  However, since the upper limit of torque that can be generated is determined according to the state of the battery SOC, the required power generation output (SOC required power generation power) from the battery SOC and the deviation between the torque at the current operating point and the torque on the α line (α It is necessary to consider the magnitude relationship with the (line generated power).

  FIG. 6A is a schematic diagram when the α-ray generated power is larger than the SOC required generated power. Since the engine output torque cannot be increased above the SOC required power generation, the operating point cannot be moved on the α line. However, fuel efficiency is improved by moving to a more efficient point.

  FIG. 6B is a schematic diagram when the α-ray generated power is smaller than the SOC required generated power. Since the engine operating point can be moved on the α line within the SOC required power generation range, in this case, it is possible to generate power while maintaining the operating point with the highest fuel efficiency.

  FIG. 6C is a schematic diagram when the engine operating point is higher than the α line. When the operating point corresponding to the required driving force is higher than the α line, the engine torque is reduced on the condition that the battery SOC has a margin, and the shortage is compensated by the power running of the motor generator MG. As a result, the required driving force can be achieved while improving the fuel efficiency.

  As shown in FIG. 6B, the generated power defined by the α-ray is prioritized over the SOC required maximum generated power, but when the SOC threshold is changed by the threshold changing unit 203, the WSC In the traveling mode, the generated power defined by the α ray is further increased as the power generation amount. In other words, the engine operating point is moved to a region above the α line, and the generated power is increased accordingly.

[Operation when the SOC threshold is changed by the threshold changing unit]
Next, the reason why the threshold value changing unit 203 changes the SOC threshold value and the operation thereof will be described. In the WSC travel mode, since the second clutch CL2 is slip-controlled, the second clutch CL2 generates heat, but at the same time, because the SOC is low, for example, as shown in FIG. Then, the SOC gradually increases. When SOC reaches 50%, the EVON line is exceeded, so the WSC drive mode is changed to the EV drive mode.

  In the EV travel mode, the first clutch CL1 is released and the second clutch CL2 is completely engaged, so the temperature of the second clutch CL2 starts to decrease. At the same time, the SOC begins to decline again. When the SOC falls below 35%, the WSC drive mode is entered again. As described above, when the WSC traveling mode is selected, the vehicle travels between SOC = 35% and SOC = 50%. At this time, if the interval between the EVOFF line and the EVON line is wide, the time for selecting the WSC travel mode is so long that the temperature of the second clutch CL2 may exceed the clutch burn start temperature. On the other hand, if the interval between the EVOFF line and the EVON line is wide, it is considered that the time for selecting the EV driving mode can be secured. However, when the temperature of the second clutch CL2 is lowered in the EV running mode, there are the following characteristics with respect to the clutch temperature characteristics.

  Here, the temperature characteristics of the second clutch CL2 will be described. FIG. 8 is a diagram illustrating a temperature change when the second clutch CL2 is slip-controlled and the temperature is increased and then completely engaged. As shown in FIG. 8, when the second clutch CL2 is completely engaged, it decreases by ΔT1 within the first predetermined time t, and further decreases by ΔT2 (<ΔT1) within the subsequent predetermined time t. That is, when considering the temperature reduction efficiency, it can be said that the temperature can be efficiently reduced if the first predetermined time t is used from the complete fastening. In other words, even if the complete fastening time is ensured for a long time, the temperature cannot always be lowered efficiently.

  That is, if the interval between the EVOFF line and the EVON line is wide, the time for selecting the EV driving mode can be secured, but the temperature reduction efficiency is not necessarily good, and there is a concern that the temperature rises due to the long time for selecting the WSC driving mode. Turned out to be stronger.

  Therefore, a scene that is concerned that the WSC driving mode is continuously executed, a scene in which the vehicle load is high and the temperature of the second clutch CL2 may be increased due to the WSC driving mode, or the temperature of the second clutch CL2 is actually In a scene that has risen rapidly, the interval between the EVOFF line and the EVON line is reduced.

  FIG. 9 is a flowchart showing threshold change processing.

In step S1, it is determined whether or not the duration is long. If it is determined that the duration is long, the process proceeds to step S4. Otherwise, the process proceeds to step S2.
In step S2, it is determined whether or not the estimated gradient is larger than a predetermined value. If it is determined that the estimated gradient is larger than the predetermined value, the process proceeds to step S4. Otherwise, the process proceeds to step S3.
In step S3, it is determined whether or not the temperature of the second clutch CL2 is higher than a predetermined value. If the temperature is higher, the process proceeds to step S4. Otherwise, the process proceeds to step S5.
In step S4, the EVON line is set to SOC = 40%.
In step S5, the EVON line is set to SOC = 50%.

  Here, the operation based on the flowchart will be described using a comparative example. FIG. 10 is a time chart showing how the EV driving mode and the WSC driving mode are alternately selected according to the SOC in normal control, and FIG. 11 is a target charge / discharge amount map showing the SOC movement of the time chart shown in FIG. It is the written schematic.

  As shown in FIG. 10, when the SOC is larger than 50% and the state where the EV driving mode is selected is continued, the SOC gradually decreases. As shown in FIG. 11, the point P1 gradually moves leftward in FIG. When the SOC becomes less than 35%, that is, below the EVOFF line, the EV travel mode area disappears from the normal mode map, so the mode is forcibly switched to the WSC travel mode.

  In the WSC running mode, since the power generation request is made simultaneously to recover the SOC (see FIG. 6B), the SOC starts to recover. As shown in FIG. 11, the point P1 gradually moves rightward in FIG. However, in the WSC travel mode, since the slip amount of the second clutch CL2 is large, the temperature of the second clutch CL2 increases rapidly.

  At this time, until the SOC exceeds 50%, that is, exceeds the EVON line, the WSC traveling mode is forcibly selected, so the temperature of the second clutch CL2 may exceed the burning start temperature. Here, the burning start temperature is a temperature at which the second clutch CL2 becomes excessively hot and may be welded when the slip state ends, and is a value that is appropriately set based on specification specifications, experiments, or the like. It is.

  That is, as shown in FIG. 11, when the SOC is controlled to reciprocate between the EVON line and the EVOFF line, attention is paid to the temperature change of the second clutch CL2. At this time, there is a scene where the temperature Tempcl2 of the second clutch CL2 exceeds the burning start temperature many times, and the required durability of the second clutch CL2 cannot be ensured.

  FIG. 12 is a time chart when the EVON line is changed in the first embodiment, and FIG. 13 is a schematic diagram in which the SOC movement of the time chart shown in FIG. 12 is written in the target charge / discharge amount map.

  As shown in FIG. 13, when the EVON line is changed to SOC = 40%, the timing from the transition from the EV travel mode to the WSC travel mode to the transition to the EV travel mode again becomes earlier. At this time, since the operation is performed so that the generated power in the WSC traveling mode is larger than that of the normal α-ray power generation, the SOC increase speed can be increased.

  Thereby, the continuous driving time in the WSC driving mode can be shortened. Moreover, the temperature of the second clutch CL2 can be efficiently lowered by increasing the number of times of transition from the WSC travel mode to the EV travel mode.

  That is, as described with reference to FIG. 8, in view of the temperature decrease characteristic at the time of fastening, it is advantageous to positively use a region where the temperature that can be decreased per unit time is large. In other words, it is the drive of the motor generator MG, that is, the battery power that suppresses the temperature drop, and since this battery power can be used to efficiently lower the temperature, it is possible to efficiently cool only in the region where the temperature drop gradient is large. it can.

As described above, the effects listed below can be obtained in the first embodiment.
(1) A duration estimation unit 202 (duration estimation unit) that estimates whether or not the duration of the WSC travel mode (engine-use slip travel control unit) is long, and when the estimated duration is longer than a predetermined time And a threshold value changing unit 203 (threshold value changing means) for changing the difference between the EVON line (first charged amount) and the EVOFF line (second charged amount).

  Therefore, it is possible to frequently change between the WSC travel mode and the EV travel mode, and the heat generation amount of the second clutch CL2 can be suppressed.

  (2) The difference between the temperature sensor 10a that detects the temperature of the second clutch CL2 and the EVON line (first charged amount) and the EVOFF line (second charged amount) when the detected temperature is equal to or higher than a predetermined value. A threshold value changing unit 203 (threshold value changing means) for changing the value to be smaller is provided.

  Therefore, it is possible to frequently change between the WSC travel mode and the EV travel mode, and the heat generation amount of the second clutch CL2 can be suppressed.

  (3) Road surface gradient estimation calculation unit 201 that estimates a road surface gradient that is a vehicle load, and when the estimated road surface gradient is equal to or greater than a predetermined value, EVON line (first charged amount) and EVOFF line (second charged amount) And a threshold value changing unit 203 (threshold value changing means) for changing the difference so as to be small.

  Therefore, it is possible to frequently change between the WSC travel mode and the EV travel mode, and the heat generation amount of the second clutch CL2 can be suppressed.

  (4) The threshold value changing unit 203 reduces the EVON line (first power storage amount). Therefore, it is possible to lengthen the time in the EV travel mode and shorten the travel time in the WSC travel mode.

  (5) When the time when both the accelerator pedal and the brake pedal are not depressed is longer than the predetermined time, it is assumed that the duration time is long.

  The fact that both the accelerator pedal and the brake pedal are not depressed is when creep running control is being performed. In the first embodiment that does not include a torque converter, when the SOC is low, the WSC traveling mode is selected, so there is a high possibility that the WSC traveling mode is continuously selected. On the other hand, if the SOC is high, the EV travel mode is selected, but the EV region will eventually disappear, and then the WSC travel mode is entered. In any case, it can be estimated that the WSC driving mode is continuously selected.

  (6) If the number of times the accelerator pedal is switched to the brake pedal or the brake pedal is changed to the accelerator pedal within the predetermined time is more than the predetermined number of times, it is assumed that the duration is long.

  When the accelerator operation and the brake operation are frequently performed, for example, when a garage or a traffic jam is performed in a low vehicle speed range. Also at this time, it can be estimated that the WSC travel mode is continuously selected as described above.

  (7) When the WSC drive mode is selected and the brake pedal is depressed more than a predetermined number of times, it is assumed that the duration is long.

  When the brake operation is frequently performed, for example, when a garage or a traffic jam is performed in a low vehicle speed range. Also at this time, it can be estimated that the WSC driving mode is continuously selected.

  (8) When the vehicle travels in the EV travel mode at a vehicle speed lower than the lower limit vehicle speed VSP1 that is the vehicle speed for switching between the WSC travel mode and the HEV travel mode, it is assumed that the duration is long.

  That is, if the EV travel time in the HEV region is long, there is a high possibility that the WSC travel mode will be selected when the vehicle speed decreases as the SOC decreases, and it can be estimated that the WSC travel mode is selected continuously.

  (9) In the normal WSC traveling mode, in the configuration in which the motor generator MG is used to generate α-ray power using the engine driving force, when the SOC threshold is changed by the threshold changing unit 203, the motor generator MG generates power more than before the change. The amount was increased. Specifically, the engine was driven in a region above the α-ray to obtain a larger power generation.

  Therefore, it is possible to increase the SOC increase speed in the WSC travel mode, and it is possible to transition to the EV travel mode more quickly. Thereby, heat_generation | fever of 2nd clutch CL2 can be suppressed.

  As described above, the description is based on the first embodiment. However, the present invention is not limited to the above-described configuration, and other configurations can be taken without departing from the scope of the present invention.

  For example, in the first embodiment, the threshold changing unit 203 changes the EVON line to a value that lowers the SOC. On the other hand, the EVOFF line may be changed to a value that increases the SOC. FIG. 14 is a schematic diagram showing a target charge / discharge amount map changed by the threshold changing unit 203. The threshold value changing unit 203 determines that the duration is long from the state where the EVOFF line is set to SOC = 35%, or when the estimated gradient is equal to or higher than a predetermined value, or the second clutch temperature is equal to or higher than a predetermined value. Then, switch the EVOFF line to SOC = 40%. Thereby, it is possible to frequently switch between the EV driving mode and the WSC driving mode while maintaining a high SOC state.

  In the first embodiment, the EVON line is changed to a value that lowers the SOC. However, the EVON line and the EVOFF line may be a single line. FIG. 15 is a schematic diagram showing a target charge / discharge amount map changed by the threshold changing unit 203. The threshold value changing unit 203 changes the state where the EVON line is set to SOC = 50% to the position where the EVOFF line is set to SOC = 35% so that the EVON line matches the EVOFF line. Also good. Thereby, the EV driving mode and the WSC driving mode can be switched more finely. When the EVON line and the EVOFF line are matched, for example, the matched value is not limited to SOC = 35%, but may be changed to another SOC value.

  In the first embodiment, the road surface gradient is detected or estimated as the vehicle load. However, the presence / absence of vehicle traction or the like may be detected, or the in-vehicle load may be detected. This is because when the vehicle load is large in this manner, the vehicle speed increases slowly and the second clutch CL2 is likely to generate heat.

  Further, although the temperature sensor 10a is provided as means for detecting the temperature of the second clutch CL2, the heat generation amount may be estimated based on the differential rotation of the second clutch CL2 and the transmission torque capacity TCL2.

  In the first embodiment, the FR type hybrid vehicle has been described. However, an FF type hybrid vehicle may be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram illustrating a rear-wheel drive hybrid vehicle according to a first embodiment. FIG. 3 is a control block diagram illustrating an arithmetic processing program in the integrated controller according to the first embodiment. It is a figure which shows an example of the target driving force map used for target driving force calculation in the target driving force calculating part of FIG. It is a figure which shows an example of the target charging / discharging amount map used for the calculation of target charging / discharging electric power in the target charging / discharging calculating part of FIG. It is a figure which shows the normal mode map used for selection of the target mode in the mode selection part of FIG. It is the schematic showing the engine operating point setting process in WSC driving mode. It is a map showing the engine target speed in WSC driving mode. It is a figure showing the temperature change characteristic of a 2nd clutch. It is a flowchart showing a SOC threshold value change process. 6 is a time chart showing a state in which EV driving mode and WSC driving mode are alternately selected in accordance with SOC in normal control. It is the schematic which wrote the motion of SOC of the time chart shown in FIG. 12 in the target charging / discharging amount map. It is a time chart showing a mode that EV drive mode and WSC drive mode are alternately selected according to SOC when a SOC threshold is changed. It is the schematic which wrote the motion of SOC of the time chart shown in FIG. 12 in the target charging / discharging amount map. It is a figure which shows an example of the target charging / discharging amount map used for the calculation of target charging / discharging electric power in the target charging / discharging calculating part of FIG. 2 in another Example. It is a figure which shows an example of the target charging / discharging amount map used for the calculation of target charging / discharging electric power in the target charging / discharging calculating part of FIG. 2 in another Example.

Explanation of symbols

E engine
CL1 1st clutch
MG motor generator
CL2 2nd clutch
AT automatic transmission 1 engine controller 2 motor controller 3 inverter 4 battery 5 first clutch controller 6 first clutch hydraulic unit 7 AT controller 8 second clutch hydraulic unit 9 brake controller 10 integrated controller 24 brake hydraulic sensor
100 Target driving force calculator
200 Mode selection section
300 Target charge / discharge calculator
400 Operating point command section

Claims (10)

Engine,
A motor,
A first fastening element interposed between the engine and the motor to connect and disconnect the engine and the motor;
A second fastening element interposed between the motor and the drive wheel to connect and disconnect the motor and the drive wheel;
A battery for supplying power to the motor;
Engine use slip running control means for running by the torque of the engine by fastening the first fastening element and slip fastening the second fastening element;
Motor travel control means that travels by torque of the motor by releasing the first fastening element and fastening or slip fastening the second fastening element;
When the stored amount of the battery is equal to or greater than the first stored amount, the motor travel control means is selected, and when the stored amount is less than the second stored amount less than the first stored amount, the engine use slip travel control unit is selected, When the motor travel control means is selected, when the amount of charge of the battery is equal to or greater than the second charge amount and less than the first charge amount, the motor travel control means is used, and the engine use slip travel control means Normal control means for selecting the engine use slip travel control means when the stored amount of the battery is equal to or more than the second stored amount and less than the first stored amount when
Duration estimation means for estimating whether or not the duration of the engine use slip travel control means is longer than a predetermined time;
When the estimated duration is longer than a predetermined time, threshold changing means for changing so that a difference between the first charged amount and the second charged amount is reduced;
A control apparatus for a hybrid vehicle, comprising: Engine,
A motor,
A first fastening element interposed between the engine and the motor to connect and disconnect the engine and the motor;
A second fastening element interposed between the motor and the drive wheel to connect and disconnect the motor and the drive wheel;
A battery for supplying power to the motor;
Engine use slip running control means for running by the torque of the engine by fastening the first fastening element and slip fastening the second fastening element;
Motor travel control means that travels by torque of the motor by releasing the first fastening element and fastening or slip fastening the second fastening element;
When the stored amount of the battery is equal to or greater than the first stored amount, the motor travel control means is selected, and when the stored amount is less than the second stored amount less than the first stored amount, the engine use slip travel control unit is selected, When the motor travel control means is selected, when the amount of charge of the battery is equal to or greater than the second charge amount and less than the first charge amount, the motor travel control means is used, and the engine use slip travel control means Normal control means for selecting the engine use slip travel control means when the stored amount of the battery is equal to or more than the second stored amount and less than the first stored amount when
Temperature detecting means for detecting or estimating the temperature of the second fastening element;
When the detected temperature is equal to or higher than a predetermined value, threshold change means for changing the difference between the first charged amount and the second charged amount to be small;
A control apparatus for a hybrid vehicle, comprising: Engine,
A motor,
A first fastening element interposed between the engine and the motor to connect and disconnect the engine and the motor;
A second fastening element interposed between the motor and the drive wheel to connect and disconnect the motor and the drive wheel;
A battery for supplying power to the motor;
Engine use slip running control means for running by the torque of the engine by fastening the first fastening element and slip fastening the second fastening element;
Motor travel control means that travels by torque of the motor by releasing the first fastening element and fastening or slip fastening the second fastening element;
When the stored amount of the battery is equal to or greater than the first stored amount, the motor travel control means is selected, and when the stored amount is less than the second stored amount less than the first stored amount, the engine use slip travel control unit is selected, When the motor travel control means is selected, when the amount of charge of the battery is equal to or greater than the second charge amount and less than the first charge amount, the motor travel control means is used, and the engine use slip travel control means Normal control means for selecting the engine use slip travel control means when the stored amount of the battery is equal to or more than the second stored amount and less than the first stored amount when
Vehicle load detecting means for detecting or predicting the vehicle load;
When the detected vehicle load is equal to or greater than a predetermined value, threshold changing means for changing the difference between the first charged amount and the second charged amount to be small;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to any one of claims 1 to 3,
The control device for a hybrid vehicle, wherein the threshold value changing means reduces the first power storage amount. In the hybrid vehicle control device according to any one of claims 1 to 4,
The control device for a hybrid vehicle, wherein the threshold value changing means increases the second power storage amount. In the hybrid vehicle control device according to claim 1,
The control device for a hybrid vehicle, wherein the duration estimation means estimates that the duration is long when the time when both the accelerator pedal and the brake pedal are not depressed is longer than a predetermined time. In the hybrid vehicle control device according to claim 1 or 6,
The hybrid vehicle characterized in that the duration estimation means estimates that the duration is long when the number of times the accelerator pedal is switched from the accelerator pedal to the brake pedal or from the brake pedal to the accelerator pedal within a predetermined time is greater than or equal to the predetermined number of times. Control device. In the control apparatus of the hybrid vehicle as described in any one of Claim 1 or 6 or 7,
The control apparatus for a hybrid vehicle, characterized in that the duration estimation means estimates that the duration is long when the brake pedal is not less than a predetermined number of times when the engine use slip traveling control means is selected. In the control apparatus of the hybrid vehicle as described in any one of Claim 1 or 6 thru | or 8,
An engine running control means for fastening the first and second fastening elements and running by the torque of the engine;
The normal control means is means for selecting the engine travel control means when the vehicle speed is equal to or higher than a predetermined vehicle speed when the engine use slip travel control means is selected;
The control apparatus for a hybrid vehicle, wherein the duration estimation means estimates that the duration is long when the motor travel control means is traveling for a long time at the predetermined vehicle speed or higher. In the control apparatus of the hybrid vehicle as described in any one of Claims 1 thru | or 9,
The motor is a motor generator capable of generating electricity,
When the engine use slip running control means generates power by the motor using engine driving force and the threshold value changing means is changed so that the difference between the first charged amount and the second charged amount is reduced, A control apparatus for a hybrid vehicle, wherein the power generation amount of the motor is made larger than before the change.

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