Control device for hybrid vehicle with cylinder deactivation

The present invention relates to a control device for a hybrid vehicle, and more particularly to a control device for a hybrid vehicle capable of cylinder deactivation.

[0002] In general, in a parallel hybrid vehicle, various controls such as assisting driving the output of an engine by a motor during acceleration and charging the battery by deceleration regeneration during deceleration are performed, and the battery is used. It is possible to satisfy the driver's request while ensuring the remaining capacity (electrical energy) of the engine. Further, structurally, since the engine and the motor are arranged in series, the structure can be simplified, the weight of the entire system can be reduced, and the degree of freedom of mounting on the vehicle is high. Here, the parallel hybrid vehicle is provided with a clutch between the engine and the motor in order to eliminate the influence of engine friction (engine braking) during deceleration regeneration (for example, Japanese Patent Application Laid-Open No. 2000-97068). See).

[0003] However, in the case of a structure in which a clutch is provided between the engine and the motor, the structure becomes complicated by the amount of the clutch provided, and the mountability deteriorates. At the same time, since the clutch is used, deceleration regeneration or running It has the disadvantage that the transmission efficiency of the power transmission system is reduced. On the other hand, it has been proposed to perform cylinder deactivation operation in which at least one cylinder is deactivated by stopping the valve at the time of deceleration to reduce the pumping loss of the engine and improve the regeneration efficiency by the motor. According to this, by reducing the pumping loss and adding the amount equivalent to the conventional engine brake as the amount of regeneration, the amount of regeneration is increased without impairing the deceleration commercial value, and that amount is distributed to the motor assist to improve fuel efficiency. Can be improved.

[0004] However, in a hybrid vehicle control device in which engine friction is reduced by deactivating the cylinder during deceleration and the amount of regeneration is increased by that amount, the cylinder is used. When the deactivation does not function due to a failure, there is a problem that the energy management is adversely affected because it is not possible to secure an increase in the amount of regeneration due to the cylinder deactivation as compared with the normal case. Therefore, the present invention provides a control device for a hybrid vehicle that can prevent the battery and the like from becoming discharged in the event of a failure in which the deceleration suspension system cannot operate and prevent deterioration of fuel efficiency.

[Means for Solving the Problems] In order to solve the above problems, the invention according to claim 1 describes an engine (for example, engine E in the embodiment) and a motor (for example, for example) as a drive source of a vehicle. The motor M) in the embodiment is provided, fuel supply to the engine is stopped when the vehicle is decelerated, regenerative braking is performed by the motor according to the deceleration state, and the engine operates all cylinders and at least all cylinders. It is a cylinder deactivation engine that can be switched to cylinder deactivation operation in which one or more cylinders are deactivated. At least, the cylinder deactivation operation is performed according to the deceleration state of the vehicle to reduce the pumping loss of the engine and improve the regeneration efficiency by the motor. In the control device of the hybrid vehicle to be operated, the cylinder engine<u style="single">Rest cylinder operation becomes infeasible</u>Motor output limiting means for detecting an abnormality (for example, step S702 and step S704 in the embodiment), and limiting the output of the motor when an abnormality of the resting cylinder engine is detected by the abnormality detecting means. (For example, step S411A, step S411C in the embodiment) is provided. With this configuration, when the abnormality detecting means detects an abnormality in the cylinder rest engine, the regenerative energy that can be secured if the cylinder rest operation is normally performed is reduced as compared with the normal state, so that the motor This can be dealt with by limiting the assist by the motor by the output limiting means.

[0006] The invention according to claim 2 is characterized in that the operating state of the engine is detected and the output of the motor is limited in a low load state of the engine. With such a configuration, it is possible to limit the output of the motor without giving a sense of discomfort to the driver in a low load state of the engine in which the driver's intention to accelerate is not so large.

[0007] The invention according to claim 3 is that the output limitation of the motor by the motor output limiting means reduces the assist amount of the engine by the motor (for example, the ECO assist amount ECOAST in the embodiment) as compared with the normal state. It is characterized in that it is performed based on a map (for example, the assist amount at the time of a rest cylinder failure #ASTPWRFS map in the embodiment). With this configuration, it is possible to assist the engine by the motor using a map with a reduced amount of assist in the event of a failure of the idle cylinder engine.

[0008] In the invention described in claim 4, the output limitation of the motor by the motor output limiting means is a correction coefficient smaller than 1 for correcting the assist amount of the engine by the motor (for example, the correction coefficient during rest of the cylinder # in the embodiment). It is characterized by being performed based on KFSAST). With this configuration, in the event of a failure of the idle cylinder engine, it is possible to assist the engine by the motor by correcting the assist amount to be reduced by the correction coefficient.

[0009] The invention according to claim 5 detects the remaining capacity of the battery for driving the motor, and the remaining battery capacity falls below a predetermined first threshold value (for example, the boundary between zone A and zone B in the embodiment). In this case, the motor output is limited according to the remaining battery capacity. With this configuration, when the remaining battery capacity falls below a predetermined first threshold value, it is possible to assist by the motor while preventing a further decrease in the remaining battery capacity.

[0010] The invention according to claim 6 is the case where the remaining capacity of the battery for driving the motor is equal to or less than the second threshold value (for example, the boundary between zone B and zone C in the embodiment) equal to or less than the first threshold value. Is characterized in that the output to the motor is prohibited. With this configuration, when the remaining capacity of the battery becomes equal to or less than the second threshold value, it is possible to prohibit the assist by the motor and prevent the remaining capacity of the battery from further decreasing.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a parallel hybrid vehicle according to an embodiment of the present invention, which has a structure in which an engine E as a drive source, a motor M, and a transmission T are directly connected in series. The driving force of both the engine E and the motor M is transmitted to the front wheels Wf, which are the driving wheels, via a transmission T (may be a manual transmission) such as a CVT. When the hybrid vehicle decelerates, the fuel supply is stopped and the driving force is transmitted from the front wheel Wf side to the motor M side, and the motor M functions as a generator to generate so-called regenerative braking force according to the deceleration state. , Recovers the kinetic energy of the car body as electrical energy. In addition, in FIG. 1, for convenience of explanation, related parts are also described for both the manual mission vehicle and the CVT vehicle.

[0012] The drive and regenerative operation of the motor M are performed by the power drive unit (PDU) 2 in response to a control command from the motor CPU 1M of the motor ECU 1. A high-voltage nickel-metal hydride (Ni-MH) battery 3 that transfers electrical energy to and from the motor M is connected to the power drive unit 2, and the battery 3 is, for example, a module in which a plurality of cells are connected in series as one unit. Further, a plurality of modules are connected in series. The hybrid vehicle is equipped with a 12-volt auxiliary battery 4 for driving various accessories, and the auxiliary battery 4 is connected to the battery 3 via a downverter 5 which is a DC-DC converter. The down burter 5 controlled by FIECU 11 steps down the voltage of the battery 3 to charge the auxiliary battery 4. The motor ECU 1 includes a battery CPU 1B that protects the battery 3 and calculates the remaining battery capacity SOC. Further, a CVTEC U21 that controls the transmission T, which is the CVT, is connected to the transmission T.

[0013] In addition to the motor ECU 1 and the down burter 5, the FIECU 11 operates a fuel injection valve 75 for adjusting a fuel supply amount to the engine E, a starter motor, and controls ignition timing and the like. Therefore, the FIECU 11 has a signal from the vehicle speed sensor S1 that detects the vehicle speed VP, a signal from the engine speed sensor S2 that detects the engine speed NE, and a signal from the shift position sensor S3 that detects the shift position of the transmission T. , A signal from the brake switch S4 that detects the operation of the brake pedal 8, a signal from the clutch switch S5 that detects the operation of the clutch pedal 9, and a throttle opening sensor S6 that detects the throttle opening TH of the throttle valve 32. , A signal from the intake pipe negative pressure sensor S7 that detects the intake pipe negative pressure, a signal from the knock sensor S8, and the like are input.

[0014] BS indicates a booster linked to a brake pedal, and the booster BS has a master power internal negative pressure sensor S9 for detecting a brake master power internal negative pressure (hereinafter referred to as a master power internal negative pressure). It is provided. The negative pressure sensor S9 in the master power is connected to FIECU11. The intake pipe negative pressure sensor S7 and the throttle opening sensor S6 are provided in the intake passage 30, and the master power internal negative pressure sensor S9 is provided in the communication passage 31 connected to the intake passage 30.

[0015] Here, the intake passage 30 is provided with a secondary air passage 33 connecting the upstream side and the downstream side of the throttle valve 32, and the secondary air passage 33 is provided with a control valve 34 for opening and closing the secondary air passage 33. Has been done. The secondary air passage 33 is for supplying a small amount of air into the cylinder even when the throttle valve 32 is fully closed. The control valve 34 is opened and closed by a signal from FIECU 11 in response to the intake pipe negative pressure detected by the intake pipe negative pressure sensor S7. The POIL sensor S10, the solenoid of the spool valve 71, and the TOIL sensor S11, which will be described later, are also connected to FIECU11.

[0016] The engine E has three cylinders having a variable valve timing mechanism VT for cylinder deactivation operation on the intake side and the exhaust side, and one cylinder having a normal valve operation mechanism NT that does not perform cylinder deactivation operation. have. The engine E is a cylinder deactivation engine that can be switched between all cylinder operation that operates all cylinders (4 cylinders) and cylinder deactivation operation that deactivates three cylinders, and cylinder deactivation operation at least according to the deceleration state of the vehicle. To reduce pumping loss and increase the amount of regeneration that can be recovered by the motor M to improve regeneration efficiency, the intake valve and exhaust valve of the deactivated cylinder are deactivated by the variable valve timing mechanism VT. That is, the structure is such that the intake / exhaust passage can be closed.

Reference numeral 70 denotes an oil pump, and 71 indicates a spool valve. The oil pump 70 and the spool valve 71 supply oil to the variable valve timing mechanism VT. A spool valve 71 is connected to the discharge side of the oil pump 70. Each variable valve timing mechanism VT operates by the oil pump 70 acting on the cylinder deactivation side passage 72 and the cylinder deactivation side passage 73 of the spool valve 71, and cylinder deactivation operation and all cylinder operation are performed. It can be switched. The POIL sensor S10 is connected to the cylinder deactivation side passage 73. The POIL sensor S10 monitors the oil pressure in the cylinder deactivation side passage 73, which is low pressure during cylinder deactivation and high pressure during normal operation.

The fuel injection valve 75 is provided in each cylinder, and the knock sensor S8 connected to FIECU 11 is provided in the cylinder provided with the variable valve timing mechanism VT so that the misfire state of each cylinder can be detected. ing. Further, the TOIL sensor S11 for detecting the oil temperature is provided and supplied to the supply passage 74, which is the discharge side passage of the oil pump 70 and branches from the passage to the spool valve 71 to supply hydraulic oil to the engine E. The temperature of the hydraulic fluid is monitored.

Zoning of Battery Remaining Capacity SOC Next, zoning of the battery remaining capacity SOC (so-called remaining capacity zoning) will be described. The remaining capacity of the battery is calculated by the battery CPU1B, and is calculated based on, for example, voltage, discharge current, temperature, and the like. To explain this example, the normal use area is zone A (SOC 40% to SOC 75%), the provisional use area is zone B (SOC 25% to SOC 40%), and the over-discharge area is below it. A zone C (SOC 0% to SOC 25%) is partitioned. Zone D (SOC 75% or more), which is an overcharge area, is provided above Zone A. Here, the boundary portion between the normal use region A and the provisional use region B constitutes the first threshold value, and the boundary portion between the zone B and the overdischarge region zone C is the first threshold value. It constitutes two thresholds.

"MA (motor) basic mode" Next, the MA (motor) basic mode for determining the mode in which the motor M is operated will be described with reference to the flowcharts shown in FIGS. 2 and 3. .. This process is repeated at a predetermined cycle.

[0021] The MA (motor) basic mode includes "idle mode", "idle stop mode", "deceleration mode", "cruise mode", and "acceleration mode". In the idle mode, the fuel supply following the fuel cut is restarted and the engine E is maintained in the idle state. In the idle stop mode, the engine is stopped under certain conditions, for example, when the vehicle is stopped. Further, in the deceleration mode, regenerative braking by the motor M is executed, in the acceleration mode, the engine E is assisted by the motor M, and in the cruise mode, the motor M is not driven and the vehicle runs by the driving force of the engine E. The hybrid vehicle in this embodiment is a CVT vehicle, but for reasons of specification, each flowchart shown below is also described for a manual transmission (MT) vehicle.

[0022] In step S051 of FIG. 2, it is determined whether or not the MT / CVT determination flag F_AT is "1". If the determination result is "YES" (CVT vehicle), the process proceeds to step S060, and if the determination result is "NO" (MT vehicle), the process proceeds to step S052. In step S060, it is determined whether or not the CVT in-gear determination flag F_ATNP is "1". If the determination result is "YES" (N, P range), the process proceeds to step S083, and if the determination result is "NO" (in gear), the process proceeds to step S060A.

[0023] In step S060A, it is determined whether or not the switchback is in progress (the shift position cannot be specified during the shift lever operation) based on whether or not the switchback flag F_VSWB is "1". If the determination result is "YES" (during switchback), the process proceeds to step S085, the mode shifts to the "idle mode", and the control ends. In idle mode, engine E remains idle. If the determination result in step S060A is "NO" (not in switchback), the process proceeds to step S054.

[0024] In step S083, it is determined whether or not the engine stop control execution flag F_FCMG is "1". If the determination result in step S083 is "NO", the process shifts to the "idle mode" in step S085 and the control ends. If the determination result in step S083 is "YES", the process proceeds to step S084, the mode shifts to the "idle stop mode", and the control ends. In the idle stop mode, the engine is stopped under certain conditions, for example, when the vehicle is stopped.

[0025] In step S052, it is determined whether or not the neutral position determination flag F_NSW is "1". If the determination result is "YES" (neutral position), the process proceeds to step S083, and if the determination result is "NO" (in gear), the process proceeds to step S053. In step S053, it is determined whether or not the clutch connection determination flag F_CLSW is 1. If the determination result is "YES" (clutch disengaged), the process proceeds to step S083, and if the determination result is "NO" (clutch engagement), the process proceeds to step S054.

[0026] In step S054, it is determined whether or not the IDLE determination flag F_THIDLMG is "1". If the determination result is "NO" (fully closed), the process proceeds to step S061, and if the determination result is "YES" (not fully closed), the process proceeds to step S054A. In step S054A, the engine speed increase flag F_NERGNUP at the time of half-clutch judgment is set to "0", and the process proceeds to step S055.

[0027] In step S055, it is determined whether or not the motor assist determination flag F_MAST is "1". This flag is a flag for determining whether or not to assist the engine E by the motor M. If it is "1", it means that there is an assist request, and if it is "0", it means that there is no assist request. The motor assist determination flag is set by the assist trigger determination process. If the determination result in step S055 is "NO", the process proceeds to step S061. If the determination result in step S055 is "YES", the process proceeds to step S056.

[0028] In step S056, it is determined whether or not the MT / CVT determination flag F_AT is 1. If the determination result is "YES" (CVT vehicle), the process proceeds to step S057, and if the determination result is "NO" (MT vehicle), the process proceeds to step S058. In step S057, it is determined whether or not the brake ON determination flag F_BKSW is 1. If the determination result is "YES" (brake ON), the process proceeds to step S063, and if the determination result is "NO" (brake OFF), the process proceeds to step S058.

[0029] In step S058, it is determined whether or not the final charge command value REGENF is "0" or less. If the determination result is "YES", the process proceeds to the "acceleration mode" in step S059. In the acceleration mode, the engine E is assisted by the motor M, and the process proceeds to step S059A. If the determination result in step S058 is "NO", the control ends. In step S059A, it is determined whether or not the assist execution permission flag F_ANYAST that permits the execution of any of the assists is "1". If the determination result is "YES", that is, if the execution of any of the assists is permitted, the control is terminated, and if the determination result is "NO", the process proceeds to step S063.

[0030] In step S061, it is determined whether or not the MT / CVT determination flag F_AT is "1". If the determination result is "NO" (MT vehicle), the process proceeds to step S063, and if the determination result is "YES" (CVT vehicle), the process proceeds to step S062. In step S062, it is determined whether or not the reverse position determination flag F_ATPR is "1". If the determination result is "YES" (reverse position), the process proceeds to step S085, and if the determination result is "NO" (other than the reverse position), the process proceeds to step S063.

[0031] In step S063, it is determined whether or not the vehicle speed VP is "0". If the determination result is "YES", the process proceeds to step S083, and if the determination result is "NO", the process proceeds to step S064. In step S064, it is determined whether or not the engine stop control execution flag F_FCMG is "1". If the determination result is "NO", the process proceeds to step S065, and if the determination result is "YES", the process proceeds to step S084.

[0032] In step S065, it is determined whether or not the shift change forced REGEN release determination process delay timer TNERGN is 0. If the determination result is "YES", the process proceeds to step S066, and if the determination result is "NO", the process proceeds to step S068. In step S066, it is determined whether or not the rate of change DNE of the engine speed is smaller than the negative value of the REGEN-excluded judgment engine speed #DNRGNCUT by the DNE. Here, the determination engine speed #DNRGNCUT without REGEN by DNE is the change rate DNE of the engine speed NE, which is the standard for determining whether or not to subtract the power generation amount according to the change rate DNE of the engine speed.

[0033] As a result of the determination in step S066, if it is determined that the down (decrease rate) of the engine speed NE is large (YES), the process proceeds to step S082. In step S082, the engine speed increase flag F_NERGNUP at the time of half-clutch determination is set to "1", and the process proceeds to step S085.

[0034] As a result of the determination in step S066, if the engine speed NE is increased (increased) or the engine speed NE is decreased (decreased rate) is small (NO), the process proceeds to step S067. In step S067, it is determined whether or not the MT / CVT determination flag F_AT is 1. If the determination result is "NO" (MT vehicle), the process proceeds to step S079, and if the determination result is "YES" (CVT vehicle), the process proceeds to step S068. In step S079, it is determined whether or not the half-clutch determination flag F_NGRHCL is "1". If a half-clutch judgment is made as a result of the judgment (YES), the process proceeds to step S082. If the half-clutch determination is not made (NO), the process proceeds to step S080.

[0035] In step S080, the previous gear position NGR and the current gear position NGR1 are compared, and the gear positions of this time and the previous time are compared to determine whether or not there has been an upshift. If the gear position shifts up as a result of the determination in step S080, the process proceeds to (NO) step S082. As a result of the determination in step S080, if the gear position has not been shifted up this time and the previous time (YES), the process proceeds to step S068.

[0036] In step S068, it is determined whether or not the engine speed increase flag F_NERGNUP at the time of determining the half-clutch is "1". As a result of the judgment, if it is necessary to raise the engine speed at the time of half-clutch judgment and the flag is set (= 1) (YES), the process proceeds to step S081 and the lower limit value of the engine speed for charging set for each gear. Add the increased rotation speed #DNERGNUP to prevent hunting to #NERGNLx, set this added value to the lower limit of the charging engine speed NERGNL, and proceed to step S070. As a result of the determination in step S068, if it is not necessary to increase the engine speed at the time of half-clutch determination and the flag is reset (= 0) (NO), the process proceeds to step S069, and the charging engine set for each gear Set the lower limit of the engine speed #NERGNLx to the lower limit of the engine speed for charging NERGNL and proceed to step S070.

Then, in step S070, it is determined whether or not the engine speed NE is equal to or less than the lower limit value of the charging engine speed NERGNL. As a result of the determination, if the rotation speed is low (NE NERGNL, YES), the process proceeds to step S082. As a result of the determination, if the rotation speed is high (NE&gt; NERGNL, NO), the process proceeds to step S071.

[0038] In step S071, it is determined whether or not the vehicle speed VP is equal to or less than the deceleration mode brake determination lower limit vehicle speed #VRGNBK. This deceleration mode brake judgment lower limit vehicle speed #VRGNBK is a value having hysteresis. As a result of the determination, if the vehicle speed VP deceleration mode brake determination lower limit vehicle speed #VRGNBK, (YES), the process proceeds to step S074. As a result of the determination in step S071, if vehicle speed VP&gt; deceleration mode brake determination lower limit vehicle speed #VRGNBK, (NO), the process proceeds to step S072. In step S072, it is determined whether or not the brake ON determination flag F_BKSW is "1". If the determination result is "YES", the process proceeds to step S073, and if the determination result is "NO", the process proceeds to step S074.

[0039] In step S073, it is determined whether or not the IDLE determination flag F_THIDLMG is "1". If the result of the determination is "NO" (throttle is fully closed), the process proceeds to the "deceleration mode" in step S078 and the control is terminated. In the "deceleration mode", regenerative braking by the motor M is executed. If the result of the determination in step S073 is "YES", the process proceeds to step S074.

[0040] In step S074, it is determined whether or not the fuel cut flag F_FC is "1". This flag is a fuel cut judgment flag that becomes "1" and cuts fuel when regeneration by the motor M is being performed in the "deceleration mode" of step S078. As a result of the determination in step S074, if the deceleration fuel is being cut (YES), the process proceeds to step S078. As a result of the determination in step S074, if the fuel is not being cut (NO), the process proceeds to step S075. In step S075, the final assist command value ASTPWRF is subtracted, and the process proceeds to step S076.

[0041] In step S076, it is determined whether or not the final assist command value ASTPWRF is 0 or less. If the determination result is "YES", the process shifts to the "cruise mode" in step S077 and the control ends. In cruise mode, the motor M is not driven and the vehicle runs with the driving force of the engine E. Further, depending on the operating state of the vehicle, the motor M may be regeneratively operated or used as a generator to charge the battery 3. If the determination result in step S076 is "NO", the control ends.

Acceleration Mode Hereinafter, the processing of the acceleration mode in step S059 described above, that is, the processing of comparing various assist amounts and selecting / outputting the optimum mode will be described with reference to the accompanying drawings. Here, in the acceleration mode, assist (ECO assist, step S320) when the engine output is in a low load state and assist (WOT assist, step S322) when the engine output is in a high load state are mainly performed. 4 and 5 are flowcharts showing the processing of the acceleration mode.

[0043] First, in step S301 shown in FIG. 4, it is determined whether or not the acceleration mode is for assisting the engine E. If the determination result is "YES", that is, in the acceleration mode for assisting, the process proceeds to step S302. On the other hand, if the determination result is "NO", that is, if the mode is other than the acceleration mode in which assist is not performed, the process proceeds to step S304 described later.

[0044] In step S302, the flag value of the air-fuel ratio assist establishment recognition flag F_DACCPCHG for preventing the driver's feeling of output from suddenly changing when the assist is established when switching from stoichiometric to lean burn is set to " Judge whether it is "1" or not. If the determination result is "YES", the process proceeds to step S308 described later. On the other hand, if this determination result is "NO", the process proceeds to step S303, the flag value of the air-fuel ratio assist establishment recognition flag F_DACCPCHG is set to "0", and the process proceeds to step S308.

[0045] In step S304, "0" is set in the final assist command value ASTPWRF, the final ECO assist command value ECOASTF, and the final WOT assist command value WOTASTF. Then, in step S305, it is determined whether or not the flag value of the lean burn determination flag F_KCMLB in the previous process was "1". If the determination result is "NO", the process proceeds to step S303 described above. On the other hand, if the determination result is "YES", that is, during lean burn, the process proceeds to step S306.

[0046] In step S306, it is determined whether or not the flag value of the lean burn determination flag F_KCMLB is "1". If the determination result is "YES", that is, if lean burn is being continued, the process proceeds to step S303 described above. On the other hand, if this determination result is "NO", that is, when the lean burn is switched to stoichiometric, the process proceeds to step S307, and the flag value of the air-fuel ratio switching assist establishment recognition flag F_DACCPCHG is set to "1". Proceed to step S308.

[0047] In step S308, it is determined whether or not the MT / CVT determination flag F_AT is "1". If this determination result is "YES" (CVT vehicle), the process proceeds to step S309, and it is determined whether or not the flag value of the flag F_ISASTWT that requests the assist standby state at the time of starting from idle stop is "1". To do. If the determination result in step S309 is "YES", proceed to step S310, set the final assist command value ASTPWRF to "0", proceed to step S311, and set the final charge command value REGENF to "0". Then, a series of processing is completed. On the other hand, if the determination result in step S308 is "NO" (MT vehicle), or if the determination result in step S309 is "NO", the process proceeds to step S313.

Next, in step S313, the WOT assist calculation process is executed to calculate the final WOT assist command value WOTASTF. Next, in step S314, the ECO assist calculation process is executed to calculate the ECO assist command value ECOAST and the final ECO assist command value ECOASTF.

Then, in step S315, either the WOT assist flag F_WOTAST instructing the execution of assist during WOT (fully open increase) control or the ECO assist flag F_ECOAST instructing the execution of assist in a low load state. Determine if the flag value is "1". If this determination result is "NO", the process proceeds to step S316 described later, the flag value of the assist execution permission flag F_ANYAST that permits the execution of any assist is set to "0", and the above-mentioned step S310 is performed. move on. On the other hand, if the determination result is "YES", the process proceeds to step S317, the flag value of the assist execution permission flag F_ANYAST that permits the execution of any assist is set to "1", and the process proceeds to step S318.

[0050] In step S318, it is determined whether or not the ECO assist command value ECOAST is equal to or greater than the final WOT assist command value WOTASTF. If this determination result is "YES", the process proceeds to step S319, the ECO assist command value ECOAST is set in the normal assist command value ACCAST in the acceleration mode, the process proceeds to step S320, and the engine E is assisted in a low load state. Assuming that the ECO assist state is set, the process proceeds to step S323 described later. On the other hand, if this determination result is "NO", the process proceeds to step S321, the final WOT assist command value WOTASTF is set in the normal assist command value ACCAST, the process proceeds to step S322, and the engine is operated during WOT (fully open increase) control. Assuming that the WOT assist state assists E, the process proceeds to step S323 described later.

[0051] In step S323, the state of the system is set to the acceleration mode. Then, in step S324, the normal assist command value ACCAST is set in the final assist command value ASTPWRF. Next, in step S325, a table search is performed for the assist amount upper limit value ASTVHG that changes according to the vehicle speed VP. Then, in step S326, it is determined whether or not the final assist command value ASTPWRF is equal to or greater than the assist amount upper limit value ASTVHG. If the determination result is "NO", the process proceeds to step S311 described above. On the other hand, if this determination result is "YES", the process proceeds to step S327, the assist amount upper limit value ASTVHG is set in the final assist command value ASTPWRF, and the process proceeds to step S311.

[0052] "ECO assist calculation process" By the way, if there is an abnormality in the cylinder deactivation engine, that is, if the variable valve timing mechanism VT fails and the cylinder deactivation is not performed, engine friction such as air flowing in the intake / exhaust passage as in the normal state is reduced. Therefore, the amount of regeneration that was expected will decrease. Therefore, if the control in the acceleration mode is performed with the assist amount set in anticipation of the reduction in engine friction, the battery 3 tends to discharge. However, even so, when the variable valve timing mechanism VT fails, if all the assists in the acceleration mode are stopped, the commercial value deteriorates. Therefore, unlike the WOT assist in the high load state where the driver's intention to accelerate is large, in the ECO assist in the low load state where the driver's intention to accelerate is relatively small, the assist amount is limited when the variable valve timing mechanism VT fails. Therefore, he tried to satisfy the driver's willingness to accelerate without any discomfort without adversely affecting energy management.

[0053] Hereinafter, the ECO assist calculation process in step S314 described above, that is, the process of calculating the assist amount in the low load state of the engine will be described with reference to the accompanying drawings. 6 and 7 are flowcharts showing the ECO assist calculation process. First, in step S401 shown in FIG. 6, it is determined whether or not the MT / CVT determination flag F_AT is 1. If the determination result is "YES" (CVT vehicle), the process proceeds to step S405 described later. On the other hand, when this determination result is "NO" (MT vehicle), the process proceeds to step S402, and it is determined whether or not the flag value of the intake pipe negative pressure motor assist determination flag F_MASTPB is "1". Here, the intake pipe negative pressure motor assist determination flag F_MASTPB is a flag that becomes "1" when the intake pipe negative pressure exceeds a predetermined threshold value and permits ECO assist (step S422).

[0054] If the determination result in step S402 is "YES", the process proceeds to step S408 described later. On the other hand, if the determination result in step S402 is "NO", the process proceeds to step S403, the final ECO assist command value ECOASTF is set to "0", and the process proceeds to step S404. Then, in step S404, the flag value of the ECO assist flag F_ECOAST is set to "0", and a series of processing is completed.

[0055] Further, in step S405, it is determined whether or not the flag value of the throttle motor assist determination flag F_MASTTH is "1". Here, the throttle motor assist determination flag F_MASTTH is a flag that becomes "1" when the throttle opening degree exceeds a predetermined threshold value and permits ECO assist (step S422). If the determination result is "NO", the process proceeds to step S403 described above. On the other hand, if this determination result is "YES", the process proceeds to step S406, and it is determined whether or not the reverse position determination flag F_ATPR is "1". If the determination result in step S406 is "YES" (reverse position), the process proceeds to step S414, which will be described later. On the other hand, if the determination result in step S406 is "NO" (other than the reverse position), the process proceeds to step S407.

[0056] In step S407, a predetermined R range assist permission delay # TMECATRD is set in the R range assist permission delay timer TECATDLY, and the process proceeds to step S408. Next, in step S408, a predetermined gradual addition update timer #TMECASTN is set in the subtraction timer TMECOAST, the process proceeds to step S409, and a predetermined gradual addition term #DECASTPN is set in the final ECO assist command value gradual addition term DECOASTP. To step S411.

[0057] In step S411, it is determined whether or not the designated suspension failure is in progress. If the determination result is "YES", the process proceeds to step S411A, and if the determination result is "NO", the process proceeds to step S411B. In step S114A, the assist amount #ASTPWRFS at the time of suspension failure determined according to the engine speed and the negative pressure of the intake pipe is obtained by searching the map, set to the ECO assist command value ECOAST, and the process proceeds to step S412. Here, the assist amount #ASTPWRFS at the time of a cylinder break failure is a limited (for example, 70%, 80%) assist amount as compared with the normal state. In addition, the assist amount #ASTPWRFS when the cylinder is closed is switched between MT and CVT vehicles. In step S411B, the assist amount #ASTPWR when cylinder deactivation is normally performed is obtained by map search, set to the ECO assist command value ECOAST, and the process proceeds to step S412. In addition, this assist amount #ASTPWR is also switched between MT cars and CVT cars.

[0058] Here, during the designated suspension failure in step S411, for example, the variable valve timing mechanism VT or the spool valve 71 of the cylinder that can be suspended should fail for some reason, and the corresponding intake / exhaust valve Means an abnormality in the suspension engine that prevents the intake and exhaust passages from being closed. As will be described later, the abnormality can be determined by monitoring the signal of the knock sensor S8 when the cylinder is closed, but when the valve timing mechanism VT fails in this way, the fuel supply to the failed cylinder is supplied. It will be stopped.

Next, in step S412, it is determined whether or not the flag value of the energy storage zone B flag F_ESZONEB is 1. If the determination result is "YES", that is, if it is determined that the remaining battery capacity SOC is in zone B, the process proceeds to step S413. On the other hand, if the determination result is "NO", the process proceeds to step S418 described later. In step S413, the ECO assist amount coefficient is obtained as the table value #KQBECAST by map search according to the remaining battery capacity SOC. Then, the value obtained by multiplying the ECO assist command value ECOAST by the ECO assist amount coefficient table value #KQBECAST is newly set as the ECO assist command value ECOAST, and the process proceeds to step S418. The table value #KQBECAST, which is the ECO assist amount coefficient, is a coefficient that changes in an increasing tendency as the remaining battery capacity increases. That is, the larger the remaining battery capacity, the larger the assist amount is set.

[0060] Further, in step S414, a predetermined gradual addition update timer #TMECASTR is set in the subtraction timer TMECOAST, the process proceeds to step S415, and a predetermined gradual addition term #DECASTPR is set in the final ECO assist command value gradual addition term DECOASTP. Set and proceed to step S416. In step S416, it is determined whether or not the assist permission delay timer TECATDLY in the R range is 0. If the determination result is "NO", the process proceeds to step S403 described above. On the other hand, if the determination result is "YES", the process proceeds to step S417, the ECO assist command value ECOAST is set to the predetermined R range assist amount #ECOASTR, and the process proceeds to step S418.

[0061] In step S418, it is determined whether or not the flag value of the energy storage zone C flag F_ESZONEC is "1". If the determination result is "YES", that is, if it is determined that the remaining battery capacity SOC is in zone C, the process proceeds to step S419. On the other hand, if the determination result is "NO", the process proceeds to step S426 described later.

[0062] In step S419, it is determined whether or not the flag value of the ECO assist flag F_ECOAST is "1". If the determination result is "NO", the process proceeds to step S403 described above. On the other hand, if the determination result is "YES", the process proceeds to step S420, and it is determined whether or not the acceleration mode is in which the engine E is assisted in the previous process. If the determination result in step S420 is "NO", the process proceeds to step S403 described above. On the other hand, if the determination result in step S420 is "YES", that is, in the previous process, the assist mode is the acceleration mode, the process proceeds to step S421.

[0063] In step S421, it is determined whether or not the subtraction timer TECASTC is "0". If the determination result is "NO", the process proceeds to step S422, the flag value of the ECO assist flag F_ECOAST is set to "1", and a series of processing is completed. On the other hand, if the determination result is "YES", the process proceeds to step S423, the subtraction timer TECASTC is set with the predetermined gradually subtraction update timer #TMECASTC, and the process proceeds to step S424.

[0064] In step S424, a value obtained by subtracting a predetermined gradually subtraction term #DECASTC from the final ECO assist command value ECOASTF is newly set as the final ECO assist command value ECOASTF. Then, in step S425, it is determined whether or not the final ECO assist command value ECOASTF is "0" or less. If the determination result is "YES", the process proceeds to step S403 described above. On the other hand, if the determination result is "NO", the process proceeds to step S422 described above.

Further, in step S426, it is determined whether or not the ECO assist command subtraction timer TECOAST is 0. If the determination result is "NO", the process proceeds to step S422 described above. On the other hand, if this determination result is "YES", the process proceeds to step S427, and it is determined whether or not the flag value of the assist establishment recognition flag F_DACCPCHG at the time of switching the air-fuel ratio is "1". If the determination result in step S427 is "YES", the process proceeds to step S428, the subtraction timer TMECOAST is set to the predetermined gradual addition update timer #TMECASTG, and the final ECO assist command value gradual addition term DECOASTP is set. Gradually set the addition term #DECASTPG and proceed to step S429. On the other hand, if the determination result in step S427 is "NO", the process proceeds to step S429.

[0066] In step S429, the subtraction timer TMECOAST is set in the ECO assist command subtraction timer TECOAST, the process proceeds to step S430, and it is determined whether or not the ECO assist command value ECOAST is equal to or higher than the final ECO assist command value ECOASTF. If the determination result is "YES", the process proceeds to step S435 described later. On the other hand, when this determination result is "NO", the process proceeds to step S431, and the value obtained by subtracting the predetermined gradually subtraction term #DECOASTM from the final ECO assist command value ECOASTF is newly added to the final ECO assist command value ECOASTF. Set as.

Next, in step S432, it is determined whether or not the final ECO assist command value ECOASTF is equal to or greater than the ECO assist command value ECOAST. If this determination result is "YES", the process proceeds to step S433, the flag value of the air-fuel ratio switching assist establishment recognition flag F_DACCPCHG is set to "0", and the process proceeds to step S422 described above. On the other hand, when this determination result is "NO", the process proceeds to step S434, the ECO assist command value ECOAST is set in the final ECO assist command value ECOASTF, and the process proceeds to step S433 described above.

[0068] Further, in step S435, a value obtained by adding the final ECO assist command value gradually adding term DECOASTP to the final ECO assist command value ECOASTF is newly set as the final ECO assist command value ECOASTF. Then, in step S436, it is determined whether or not the final ECO assist command value ECOASTF is equal to or higher than the ECO assist command value ECOAST. If the determination result is "YES", the process proceeds to step S433 described above. On the other hand, if the determination result is "NO", the process proceeds to step S422 described above.

[0069] FIG. 8 shows a partial replacement of the flowchart shown in FIG. 6, and shows the replaced portion and the processing before and after the replaced portion. Specifically, the processes of steps S411, S411A, and S411B in the flowchart of FIG. 6 are replaced with steps S410, S411, and S411C shown in FIG. Therefore, other processes are the same as the flowchart of FIG. 6, and the description thereof will be omitted. In step S409, as described above, the final ECO assist command value gradually adding term DECOASTP is set to the predetermined gradually adding term #DECASTPN, and the process proceeds to step S410. In this step S410, the assist amount #ASTPWR is obtained by map search and ECO assist. Set the command value to ECOAST and proceed to step S411. In addition, this assist amount #ASTPWR is also switched between MT cars and CVT cars.

[0070] Then, in step S411, it is determined whether or not the designated suspension failure is in progress. If the determination result is "YES", the process proceeds to step S411C, and if the determination result is "NO", the process proceeds to step S412. In step S411C, the assist correction coefficient map at the time of suspension failure, which is determined according to the engine speed and the negative pressure of the intake pipe, is searched to obtain the correction coefficient #KFSAST at the time of suspension, and the ECO assist command value ECOAST is closed. The value obtained by multiplying the cylinder speed correction coefficient #KFSAST is newly set as the ECO assist command value ECOAST, and the process proceeds to step S412. Here, the correction coefficient #KFSAST at the time of rest is a value smaller than 1 (for example, 0.7, 0.8, etc.), and the assist amount is limited as compared with the normal time, that is, the ECO assist command value ECOAST. There is. In addition, this correction coefficient #KFSAST at the time of suspension is also switched between MT cars and CVT cars.

Next, the fuel supply control in the case of abnormality detection will be described based on the flowchart of FIG. This flowchart determines whether or not an abnormality has occurred in the variable valve timing mechanism VT of a cylinder capable of cylinder deactivation by detecting a misfire with the knock sensor S8, and if an abnormality occurs, the cylinder is deactivated. The driving force of the engine is secured by the cylinders that are not operated, and at the same time, the supply of fuel to the cylinders that can be deactivated is stopped. For example, if the variable valve timing mechanism VT does not function due to a failure and the intake / exhaust valves do not completely close the intake port and the exhaust port, or if the spool valve 71 fails, it is preferable to stop the fuel supply. Because. The following process is repeated at a predetermined cycle.

[0072] In step S701, the knock sensor signal is monitored and the process proceeds to step S702. Thereby, the failure of the variable valve timing mechanism VT can be detected. Next, in step S702, it is determined from the monitor result in step S701 whether or not there is an abnormality in the variable valve timing mechanism VT. If the determination result is "YES", the process proceeds to step S706, and if the determination result is "NO", the process proceeds to step S703. In step S706, it is determined whether or not all the cylinders (three cylinders) have an abnormality. If the determination result is "YES", fuel is cut for all cylinders in step S707, and the above process is repeated. If the determination result in step S706 is "NO", the fuel is cut only for the cylinder having an abnormality in step S708, and the above process is repeated.

[0073] In step S703, the POIL sensor S10 signal is monitored and the process proceeds to step S704. As a result, the POIL sensor S10 can monitor whether or not the pressure states of the cylinder deactivation side passage 72 and the cylinder deactivation side passage 73 are normal. Next, in step S704, it is determined whether or not the spool valve 71 is abnormal from the monitor result in step S703. If the determination result is "YES", the process proceeds to step S707. If the determination result in step S704 is "NO", the process proceeds to step S705 and the above process is repeated.

Therefore, according to the above embodiment, when the variable valve timing mechanism VT is abnormal in step S702 of FIG. 9, or when the spool valve 71 is abnormal in step S704, the cylinder rest operation is normally performed. If the variable valve timing mechanism VT is functioning normally, the regenerative energy that could be secured by the reduction in pumping loss will decrease. Therefore, in step S411A in FIG. 6 and step S411C in FIG. It is possible to limit the amount of assist by the motor M to cope with this, and therefore, appropriate energy management can be performed even when the deceleration valve timing system fails.

[0075] In particular, the output of the motor M is limited without giving a sense of discomfort to the driver during ECO assist in a low load state of the engine E in which the driver's intention to accelerate is not so large even in the acceleration mode (step S411A, step). Since S411C) is possible, proper energy management can be performed without deteriorating the commercial value even when the cylinder is deactivated. In addition, when the cylinder deactivation engine fails, that is, when the cylinder deactivation is not performed due to the failure of the variable valve timing mechanism VT, a map with a reduced assist amount is used, or the assist amount is reduced with a correction coefficient smaller than 1. Since it is possible to assist the engine E by the motor M with the reduced assist amount, it is possible to surely prevent the energy management from being adversely affected by the excessive carry-out of electric energy.

[0076] On the other hand, when the remaining battery capacity falls below the boundary between Zone A and Zone B, for example, 40%, the assist amount is reduced in step S413 to prevent a further decrease in the remaining battery capacity. Since the assist by the motor M is possible, it is possible to satisfy the driver's intention to accelerate to some extent according to the remaining battery capacity while suppressing the decrease in the remaining battery capacity as much as possible. Further, when the remaining battery capacity is the boundary between Zone B and Zone C, for example, 25% or less, the assist by the motor M is prohibited (step S403, step S404), and the remaining battery capacity is further reduced. Since it can be stopped, the minimum required remaining battery capacity can be secured.

Although the present invention has described the case where a battery is used to drive the motor, a capacitor can be used instead of the battery. Also, only one or more cylinders can be paused. In addition, when setting the limited ECO assist amount at the time of cylinder deactivation failure, if the assist amount is reduced only by the pumping loss of the engine increased due to the failure, the energy balance will be balanced and the appropriate energy will be obtained. Can manage.

[Effect of the Invention] As described above, according to the invention described in claim 1, when the abnormality detecting means detects an abnormality of the cylinder rest engine, the cylinder rest operation is normally performed. Since the regenerative energy that can be secured extra is reduced by the amount of the reduced pumping loss, it is possible to cope with this by limiting the assist by the motor by the motor output limiting means, and therefore, the deceleration suspension system. There is an effect that proper energy management can be performed even if the engine breaks down.

[0079] According to the invention of claim 2, in addition to the effect of the invention of claim 1, the motor does not give a sense of discomfort to the driver in a low load state of the engine in which the driver's intention to accelerate is not so large. Since it is possible to limit the output of the engine, there is an effect that appropriate energy management can be performed without deteriorating the commercial value even when the cylinder is out of order.

[0080] According to the invention of claim 3, in addition to the effect of the invention of claim 1, when the cylinder rest engine fails, the engine is assisted by the motor using a map in which the assist amount is reduced. This has the effect of reliably preventing adverse effects on energy management due to excessive removal of electrical energy.

[0081] According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, when the cylinder rest engine fails, the assist amount is corrected by a correction coefficient so as to be reduced by the motor. Since it is possible to assist the engine, there is an effect that it is possible to surely prevent an adverse effect on energy management due to an excessive amount of electric energy taken out. [0082] According to the invention described in claim 5, claim 1 In addition to the effects of the invention described in the above, when the remaining battery capacity falls below a predetermined first threshold value, the remaining capacity of the battery can be reduced because the motor can assist while preventing the remaining capacity of the battery from further decreasing. While suppressing as much as possible, there is an effect that the driver's intention to accelerate can be satisfied to some extent according to the remaining battery capacity.

[0083] According to the invention described in claim 6, in addition to the effect of the invention described in claim 5, when the remaining capacity of the battery becomes equal to or less than the second threshold value, the assist by the motor is prohibited and the remaining capacity of the battery is prohibited. Since it is possible to prevent the battery from further decreasing, there is an effect that the minimum required remaining battery capacity can be secured.

BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] Fig. 1 is an overall configuration diagram of a hybrid vehicle according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an MA basic mode according to an embodiment of the present invention.

FIG. 3 is a flowchart showing an MA basic mode according to an embodiment of the present invention.

FIG. 4 is a flowchart showing an acceleration mode according to an embodiment of the present invention.

FIG. 5 is a flowchart showing an acceleration mode according to the embodiment of the present invention.

FIG. 6 is a flowchart showing an ECO assist calculation process according to the embodiment of the present invention.

FIG. 7 is a flowchart showing an ECO assist calculation process according to the embodiment of the present invention.

FIG. 8 is a flowchart showing a main part of another aspect of the ECO assist calculation process according to the embodiment of the present invention.

FIG. 9 is a flowchart showing a fuel supply control according to an embodiment of the present invention.

[Description of Code] E Engine M Motor S702, S704 (Abnormality Detection Means) S411A, S411C (Motor Output Limiting Means)