JP2014124994A - Control unit of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control unit of a hybrid vehicle capable of reducing a frequency, by which a transition is made to a power circulation mode, when partial cylinder running is switched into all-cylinders running.SOLUTION: A control unit according to the present invention is adapted to a hybrid vehicle including an engine 3 that can perform partial cylinder running and all-cylinders running; a first motor generator 4; and a second motor generator 5. When calculating a request discharge quantity of a battery on the basis of a storage ratio of the battery 16, the control unit makes the request discharge quantity for the partial cylinder running larger than the request discharge quantity for the all-cylinders running.

Description

  The present invention relates to a control device applied to a hybrid vehicle including an engine and a motor / generator as a driving power source.

  This is applied to a hybrid vehicle equipped with a cylinder deactivation engine capable of partial cylinder operation in which a part of a plurality of cylinders is deactivated and a single motor. There is known a control device that secures engine output for power generation by changing the gear ratio to the low speed side to increase the engine speed (Patent Document 1).

JP 2006-292114 A

  In the hybrid vehicle, in addition to the configuration including one motor as in Patent Document 1, the engine power is divided into a first motor / generator and an output unit, and the second motor / generator outputs via a gear. There is also a form connected to the part. When the idle cylinder engine is mounted as the engine of the hybrid vehicle in this form, the engine speed changes on the equal power line before and after switching between the partial cylinder operation and the full cylinder operation. Since the engine and the first motor / generator are connected to a differential mechanism that allows differential rotation, the motor speed of the first motor / generator also changes as the engine speed changes. In particular, when the partial cylinder operation is switched to the full cylinder operation, there is a problem that the motor rotation speed of the first motor / generator is lowered and the power circulation mode is easily entered.

  Accordingly, an object of the present invention is to provide a control device for a hybrid vehicle that can reduce the frequency of entering the power circulation mode when switching from partial cylinder operation to full cylinder operation.

  The control device according to the present invention includes a plurality of cylinders, a partial cylinder operation in which some of the plurality of cylinders are deactivated and the remaining cylinders are operated, and all of the plurality of cylinders are operated. An engine capable of performing cylinder operation, a first motor / generator, an output unit for transmitting torque to drive wheels, and a difference in distributing torque of the engine to the first motor / generator and the output unit; A control device applied to a hybrid vehicle comprising a moving mechanism, a second motor / generator coupled to the output unit via a gear, and a battery capable of supplying electric power to the second motor / generator. Engine control means for causing the engine to execute the full-cylinder operation and the partial cylinder operation, and a discharge amount for calculating the required discharge amount for the battery based on the storage rate of the battery. And when the engine performs each of the partial cylinder operation and the full cylinder operation, the output unit from the second motor generator increases as the required discharge amount calculated by the discharge amount calculation unit increases. Motor control means for controlling the second motor / generator so as to increase the torque transmitted to the engine, wherein the discharge amount calculation means is configured such that the required discharge amount during the partial cylinder operation is equal to that during the all cylinder operation. The required discharge amount is calculated so as to be larger than the required discharge amount.

  According to this control device, since the required discharge amount for the battery is larger during partial cylinder operation than during full cylinder operation, the battery is likely to be discharged during partial cylinder operation, and the battery charge rate is lower than during full cylinder operation. It is driven in the state. Therefore, when switching from partial cylinder operation to full cylinder operation, the first motor generator or the second motor generator generates electric power in addition to the required output output to the drive wheels to compensate for the decrease in the battery storage rate. Therefore, engine output for charging the battery is required. Therefore, it is necessary to keep the engine speed high in order to obtain the engine output required for charging after switching from partial cylinder operation to full cylinder operation. The decrease can be suppressed. Thereby, since the fall of the motor rotation speed of a 1st motor generator can also be suppressed, the frequency which enters into a power circulation mode can be reduced. As a result, fuel consumption is improved.

  As one aspect of the control device of the present invention, the discharge amount calculating means is configured such that the required output exceeds the engine output when the engine output exceeds the engine output when the engine is operated at the maximum efficiency point in the partial cylinder operation. The required discharge amount may be calculated so that the required discharge amount is larger than that in the case of an output or less (Claim 2). According to this aspect, when the required output exceeds the engine output when the engine is operated at the maximum efficiency point in the partial cylinder operation, the required discharge amount becomes larger than the case where the required output is less than this. That is, in such a case, the assist amount by the first motor / generator or the second motor / generator increases. This increases the frequency at which the engine can be operated at the maximum efficiency point after switching from partial cylinder operation to full cylinder operation.

  As one aspect of the control device of the present invention, the vehicle has a state of the differential mechanism, a differential state in which the torque of the engine is distributed to the first motor / generator and the output unit, and distribution thereof. A lock means capable of switching between a non-differential state to be stopped is provided, and the differential mechanism is in the non-differential state and the engine is operated in the partial cylinder operation or the differential mode. From the second operation mode in which the mechanism is in the differential state and the engine is operated in the partial cylinder operation, the differential mechanism is in the differential state and the engine is in the differential state when the required output becomes a predetermined value or more. An operation mode control means for switching to a normal operation mode that operates in the all-cylinder operation is further provided so that the predetermined value is smaller in the first operation mode than in the second operation mode. It may be a constant (claim 3). According to this aspect, the condition for switching to the normal operation mode is more relaxed in the first operation mode in the non-differential state and the partial cylinder operation than in the second operation mode in the differential state and the partial cylinder operation. Therefore, it becomes easier to switch from the first operation mode to the normal operation mode than when switching from the second operation mode to the normal operation mode. Thereby, since the engine control is restricted by the vehicle speed and the degree of freedom is low and the fuel consumption tends to be deteriorated, the chance of being forced to continue the first operation mode is reduced, so that the fuel consumption is improved.

  As one aspect of the control device of the present invention, the engine control means, when the storage rate of the battery becomes equal to or less than a threshold for forcibly charging the battery while the engine is performing the partial cylinder operation, You may forcibly switch from partial cylinder operation to the all cylinder operation. According to this aspect, when the battery is to be forcibly charged, the battery is charged by forcibly switching from the partial cylinder operation to the all cylinder operation. Therefore, even if the discharge amount is increased during partial cylinder operation, it is possible to avoid an excessive decrease in the battery storage rate, so that an excessive burden is not imposed on the battery. Therefore, there is no possibility of narrowing the choices of usable batteries because no special capacity is required for the batteries.

  As described above, according to the control device of the present invention, since the required discharge amount for the battery is larger during partial cylinder operation than during full cylinder operation, the battery is easily discharged during partial cylinder operation. In comparison, the battery is operated in a state where the storage rate of the battery is lowered. For this reason, it is possible to suppress the respective reductions in the engine speed and the motor speed associated with the switching from the partial cylinder operation to the full cylinder operation, so that the frequency of reaching the power circulation mode can be reduced. This improves fuel efficiency.

The figure which showed the whole structure of the vehicle to which the control apparatus of one form of this invention was applied. The figure explaining the operating point of the engine at the time of hybrid mode. The figure which showed an example of the charge / discharge amount calculation map used at the time of all cylinder operation. The figure which showed an example of the charge / discharge amount calculation map used at the time of partial cylinder driving | operation. The figure which showed the other example of the charging / discharging amount calculation map used at the time of partial cylinder driving | operation. The figure explaining transition of the operating point of an engine in the case of switching from partial cylinder operation to all cylinder operation. The alignment chart in the case of switching from partial cylinder operation to full cylinder operation. The flowchart which showed an example of the control routine which concerns on a 1st form. The figure explaining the effect at the time of calculating discharge amount using the map of FIG. 4A. The collinear diagram which showed each case of the case where assist is performed by the first motor / generator and the case where assist is performed by the second motor / generator. The flowchart which showed an example of the control routine which concerns on a 2nd form.

(First form)
As shown in FIG. 1, the vehicle 1 is configured as a hybrid vehicle in which a plurality of power sources are combined. The vehicle 1 includes an engine 3 and two motor generators 4 and 5 as driving power sources. The engine 3 is configured as an in-line four-cylinder internal combustion engine including four cylinders 10. The engine 3 can execute partial cylinder operation in which two of the four cylinders 10 are deactivated and the remaining two are operated in addition to the full cylinder operation in which all the four cylinders 10 are operated.

  The engine 3 and the first motor / generator 4 are connected to a power split mechanism 6 as a differential mechanism. The first motor / generator 4 has a stator 4a and a rotor 4b. The first motor / generator 4 functions as a generator that generates power by receiving the power of the engine 3 distributed by the power split mechanism 6 and also functions as an electric motor driven by AC power. Similarly, the second motor / generator 5 includes a stator 5a and a rotor 5b, and functions as an electric motor and a generator, respectively. Each motor / generator 4, 5 is connected to a battery 16 via a motor control device 15. The motor control device 15 converts the electric power generated by each motor / generator 4, 5 into direct current and stores it in the battery 16, and converts the electric power of the battery 16 into alternating current and supplies it to each motor / generator 4, 5.

  The power split mechanism 6 is configured as a single pinion type planetary gear mechanism. The power split mechanism 6 is a planetary that holds a sun gear S as an external gear, a ring gear R as an internal gear arranged coaxially with the sun gear S, and a pinion P meshing with these gears S and R so as to be able to rotate and revolve. Carrier C. The engine torque output from the engine 3 is transmitted to the planetary carrier C of the power split mechanism 6. The rotor 4 b of the first motor / generator 4 is connected to the sun gear S of the power split mechanism 6. Torque output from the power split mechanism 6 via the ring gear R is transmitted to the output gear train 20. The output gear train 20 functions as an output unit for transmitting torque to the drive wheels 18. The output gear train 20 includes an output drive gear 21 that rotates integrally with the ring gear R of the power split mechanism 6, and an output driven gear 22 that meshes with the output drive gear 21. A second motor / generator 5 is connected to the output driven gear 22 via a gear 23. The gear 23 rotates integrally with the rotor 5 b of the second motor / generator 5. Torque output from the output driven gear 22 is distributed to the left and right drive wheels 18 via the differential device 24.

  The power split mechanism 6 is provided with a motor lock mechanism 25 as a lock means. The motor lock mechanism 25 divides the state of the power split mechanism 6 into a differential state in which the torque of the engine 3 is distributed to the first motor / generator 4 and the output gear train 20 and a non-differential state in which the distribution is stopped. You can switch between them. The motor lock mechanism 25 is configured as a wet multi-plate type brake mechanism. The motor lock mechanism 25 is switched between an engaged state in which the rotation of the rotor 4b of the first motor / generator 4 is prevented and a released state in which the rotation of the rotor 4b is allowed. Switching between the engaged state and the released state of the motor lock mechanism 25 is performed by a hydraulic actuator (not shown). When the motor lock mechanism 25 is operated to the engaged state, the rotation of the rotor 4b of the first motor / generator 4 is prevented. Thereby, the rotation of the sun gear S of the power split mechanism 6 is also prevented. For this reason, the distribution of the torque of the engine 2 to the first motor / generator 4 is stopped, and the power split mechanism 6 enters a non-differential state.

  Control of each part of the vehicle 1 is controlled by an electronic control unit (ECU) 30. The ECU 30 performs various controls on the engine 3, the motor / generators 4 and 5, the motor lock mechanism 25, and the like. Hereinafter, main control performed by the ECU 30 in relation to the present invention will be described. Various information on the vehicle 1 is input to the ECU 30. For example, the rotational speed and torque of each motor / generator 4, 5 are input to the ECU 30 via the motor control device 15. The ECU 30 also includes an output signal of an accelerator opening sensor 32 that outputs a signal corresponding to the amount of depression of the accelerator pedal 31, an output signal of a vehicle speed sensor 33 that outputs a signal corresponding to the vehicle speed of the vehicle 1, and a battery 16. And an output signal of the SOC sensor 34 that outputs a signal corresponding to the storage rate. The ECU 30 refers to the output signal of the accelerator opening sensor 32 and the output signal of the vehicle speed sensor 33 to calculate the required drive torque requested by the driver, and performs various operations so that the system efficiency for the required drive torque is optimized. The vehicle 1 is controlled while switching modes. For example, in the low load region where the thermal efficiency of the engine 3 is reduced, the EV mode in which the combustion of the engine 3 is stopped and the second motor / generator 5 is driven is selected. Further, when the torque is insufficient with the internal combustion engine 3 alone, a hybrid mode is selected in which the second motor / generator 5 is used together with the engine 3 as a driving source for traveling.

  When the hybrid mode is selected, the ECU 30 sets the state of the power split mechanism 6 to the differential state and uses the power of the split engine 3 to generate power with the first motor / generator 4 and the power The state of the dividing mechanism 6 is switched to the non-differential state by operating the motor lock mechanism 25 to stop the distribution of the power of the engine 3 to the first motor / generator 4 and to output the power of the engine 3 to the output gear train 20. Switch to non-differential operation mode according to the situation. As shown in FIG. 2, in the differential operation mode, the engine 3 is controlled by the ECU 30 so that the operating point E defined by the engine speed and the engine torque moves on a preset operating line L. The A curve Lp intersecting the operation line L is an equal power line. The operation line L is determined in advance by a simulation or a test using an actual machine so that the fuel consumption of the engine 3 is optimized and noise can be reduced. The switching from the differential operation mode to the non-differential operation mode is performed, for example, when the first motor / generator 4 exceeds the allowable limit and becomes high temperature or when the differential operation mode is performed, the first motor / generator 4 is switched. This is performed when the power circulation mode in which the rotation is negative is to be avoided. In the non-differential operation mode, the engine speed and the vehicle speed have a one-to-one relationship. Therefore, the operating point of the engine 3 cannot be controlled on the operating line L without being restricted by the vehicle speed as in the differential operation mode.

  As described above, since the engine 3 can perform all-cylinder operation and partial cylinder operation, the operation line L is prepared for each operation mode. Since the engine 3 that performs the partial cylinder operation corresponds to downsizing to the low displacement engine, when the operation line L in FIG. 2 is for all cylinder operation, the operation line L for the partial cylinder is used. ′ Is located on the lower torque side than the operation line L as indicated by a broken line. Therefore, when the partial cylinder operation is executed in the differential operation mode, the operating point E of the engine 3 is controlled on the operating line L ′.

  Further, the ECU 30 monitors the storage rate of the battery 16 and calculates a required discharge amount or a required charge amount with respect to the storage rate of the battery 16 so that the storage rate of the battery 16 is maintained within a predetermined range. When there is a discharge request, the ECU 30 drives at least one of the first motor / generator 4 and the second motor / generator 5 so that power corresponding to the required discharge amount is consumed. On the other hand, when there is a charge request, the ECU 30 controls the first motor / generator 4 and the second motor / generator 5 so that electric power corresponding to the required charge amount is generated.

  The present embodiment is characterized in that the required discharge amount with respect to the storage rate of the battery 16 is different between the full cylinder operation and the partial cylinder operation. That is, the ECU 30 calculates a larger required discharge amount during partial cylinder operation than during full cylinder operation. Accordingly, when the engine 3 performs the partial cylinder operation, the battery 16 is easily discharged. In other words, the amount of assist by the first motor / generator 4 or the second motor / generator 5 is greater during partial cylinder operation than during full cylinder operation. On the other hand, when the engine performs all cylinder operation, the battery 16 is easily charged. That is, the amount of power generated by the first motor / generator 4 or the second motor / generator 5 is greater during full cylinder operation than during partial cylinder operation.

  The calculation of the required discharge amount and the required charge amount is performed based on the charge / discharge amount calculation maps M0 to M2 shown in FIGS. 3, 4A, and 4B. In these maps M <b> 0 to M <b> 2, the required discharge amount or the required charge amount is associated with the storage rate of the battery 16. Therefore, the ECU 30 refers to the output signal of the SOC sensor 34, acquires the current power storage rate, and searches these maps M0 to M2 to calculate the required discharge amount or the required charge amount corresponding to the current power storage rate. To do. The map M0 is a map used during all cylinder operation, and the maps M1 and M2 are used during partial cylinder operation. As is apparent from a comparison between the map M0, the map M1, and the map M2, the map M1 and the map M2 used during partial cylinder operation give a required discharge amount larger than that of the map M0 when compared at the same power storage rate. Further, the map M2 gives a larger required discharge amount with the same storage rate than the map M1. Therefore, if the characteristics of these maps M0 to M2 are ranked in terms of ease of discharge, M0 <M1 <M2.

  The ECU 30 calculates the required discharge amount or the required charge amount using the map M1 or the map M2 during the partial cylinder operation, and controls the first motor generator 4 and the second motor generator based on the calculation result, The storage rate of the battery 16 usually changes around 50%. When the partial cylinder operation is switched to the full cylinder operation, the required discharge amount or the required charge amount is calculated based on the map M0. Therefore, the required discharge amount is smaller than that during the partial cylinder operation and the charge request is likely to occur. Become. When there is a charge request, the first motor / generator 4 or the second motor / generator 5 needs to generate electric power corresponding to the required charge amount. In order to maintain the required output to be output from the vehicle 1, it is necessary to increase the engine output corresponding to the required charge amount.

  Therefore, as shown in FIG. 5, when switching from partial cylinder operation to full cylinder operation, the operating point of the engine 3 is added by the amount corresponding to the required charge amount from the point A on the operating line L ′ during partial cylinder operation. It moves to the intersection B of the equal power line Lp1 and the operation line L during all-cylinder operation (solid arrow). On the other hand, when there is no charge request, the operating point of the engine 3 moves along the equal power line Lp0 from the point A and moves to the intersection C between the operating line L and the equal power line Lp0 during all cylinder operation. (Dotted line arrow). As apparent from a comparison between the B point and the C point, when there is a charge request, a decrease in the engine speed is suppressed more than when there is no charge request. Since the engine 3 and the first motor / generator 4 are differentially rotated with each other by the power split mechanism 6, the motor rotational speed also changes as the engine rotational speed changes. Therefore, as shown in the collinear diagram of FIG. 6, the power at which the motor rotation speed of the first motor / generator 4 becomes negative rotation by suppressing the decrease in the engine rotation speed after the shift from the partial cylinder operation to the all cylinder operation. The frequency of entering the circulation mode can be reduced.

  Next, an example of a control routine performed by the ECU 30 will be described with reference to FIG. The control routine program of FIG. 7 is held in the ECU 30. The control routine of FIG. 7 is repeatedly executed at predetermined intervals in the differential operation mode and the partial cylinder operation. In step S1, the ECU 30 determines whether or not the forced charging mode is set. The forced charging mode is set when the storage rate of the battery 16 is equal to or less than a threshold set as a case where the battery 16 should be charged forcibly. In the forced charging mode, the process proceeds to step S3, where the ECU 30 forcibly switches the operation of the engine 3 from the partial cylinder operation to the full cylinder operation to control the first motor generator and the second motor generator 5 to control the battery 16. Charge. On the other hand, if it is not the forced charging mode, the process proceeds to step S2.

  In step S2, the ECU 30 determines whether or not the required output Pd exceeds the limit output Pmax during partial cylinder operation. The required output Pd is calculated based on the vehicle speed of the vehicle 1 and the accelerator opening. The vehicle speed is acquired based on the output signal of the vehicle speed sensor 33, and the accelerator opening is acquired based on the output signal of the accelerator opening sensor 32. If the required output Pd exceeds the limit output Pmax, the partial cylinder operation cannot be maintained, so the process proceeds to step S3 to switch from the partial cylinder operation to the full cylinder operation. On the other hand, if the requested output Pd does not exceed the limit output Pmax, that is, if the requested output Pd is less than or equal to the limit output Pmax, the process proceeds to step S4.

  In step S4, the ECU 30 determines whether or not the required output Pd exceeds the maximum thermal efficiency output. As shown in FIG. 8, the highest thermal efficiency output means the engine output when the engine 3 is operated at the highest efficiency point, and the highest efficiency point means the center C of the thermal efficiency contour line H ′ during partial cylinder operation. 'Means. The operation line L ′ is preset to pass through the center C ′. As shown in FIG. 8, when the equal power line Lp corresponding to the required output Pd is located on the higher rotation high torque side than the equal power line Lp0 passing through the center C ′, the required output Pd exceeds the output of the highest thermal efficiency. Corresponds to the case.

  If the required output Pd does not exceed the maximum thermal efficiency output, that is, if the required output Pd is less than or equal to the maximum fuel efficiency output, the process proceeds to step S5. In step S5, the ECU 30 reads the map M1 shown in FIG. 4A and obtains the current storage rate of the battery 16 with reference to the output signal of the SOC sensor 34. Then, the required discharge amount or the required charge amount corresponding to the acquired power storage rate is calculated by searching the map M1. Then, the process proceeds to step S9. On the other hand, when the required output Pd exceeds the maximum thermal efficiency output, the process proceeds to step S6. In step S <b> 6, the ECU 30 reads the map M <b> 2 shown in FIG. 4B, and obtains the current storage rate of the battery 16 with reference to the output signal of the SOC sensor 34. Then, the required discharge amount or the required charge amount corresponding to the acquired power storage rate is calculated by searching the map M2.

  In step S7, the ECU 30 determines whether or not the required discharge amount calculated in step S6 is a predetermined value or more. If the required discharge amount is equal to or greater than the predetermined value, the process proceeds to step S8, and the first motor / generator 4 is driven with an output corresponding to the required discharge amount to assist the output. Then, the process proceeds to step S9. As described above, the map M2 has a characteristic that discharge is easier than the map M1. When the required discharge amount increases and the requested assist amount becomes higher than a predetermined value, it is possible to improve the efficiency by executing the assist by the first motor / generator 4 instead of the assist by the second motor / generator 5. is there. This is because, as shown in FIG. 9, the first motor / generator 4 can be assisted at a lower speed than when the second motor / generator 5 assists, and the electrical efficiency is increased. In this way, by performing the assist by the first motor / generator 4, the engine speed can be maintained on the low speed side. Therefore, as shown in FIG. 8, the engine 3 can be operated at or near the output of the highest thermal efficiency. Further, by performing such processing, when switching from partial cylinder operation to full cylinder operation, the engine 3 is controlled to the operating point where the charge request is added together with the assist request, so that the maximum is possible even during the full cylinder operation. The engine 3 can be operated at or near the output of thermal efficiency. In other words, the frequency at which the engine 3 is operated at the maximum efficiency point after switching during all cylinder operation increases. As a result, by switching the operation mode, an operation of reciprocating between the outputs with the highest thermal efficiency is urged as indicated by the arrow in FIG. 8, so that the fuel consumption is improved as compared with the case where only the map M1 is provided during partial cylinder operation.

  In step S9, the ECU 30 assigns the required discharge amount or the required charge amount calculated in step S5 or step S6 to the charge / discharge variable Ep. The charge / discharge variable Ep can have a positive or negative value. When the required discharge amount is calculated in step S5 or S6, it is assigned to the charge / discharge variable Ep as a positive value, and when the required charge amount is calculated, it is assigned as a negative value. In step S10, the ECU 30 calculates the engine output Pe, that is, the operating point of the engine 3, using the formula: Pe = Pd-Ep. As is apparent from this calculation formula, when the required discharge amount is calculated, the assist amount increases, so that the engine output is reduced. On the other hand, when the required charge amount is calculated, power generation is required, so the engine output is calculated to increase by the amount required for power generation.

  The ECU 30 controls the engine 3 and the first motor / generator 4 so that the engine 3 is operated with the engine output Pe calculated by the above processing. The ECU 30 controls the second motor / generator 5 such that the torque transmitted from the second motor / generator 5 to the output gear train 20 increases as the required discharge amount increases.

  When the ECU 30 executes the control routine shown in FIG. 7, the battery 16 is easily discharged during partial cylinder operation, and the battery 16 is operated in a state where the storage rate of the battery 16 is lower than during full cylinder operation. Therefore, since it is necessary to keep the engine speed high in order to obtain the engine output required for charging after switching from partial cylinder operation to full cylinder operation, the engine speed associated with the switch from partial cylinder operation to full cylinder operation must be maintained. The decrease can be suppressed. Thereby, since the fall of the motor rotation speed of the 1st motor generator 4 can also be suppressed, the frequency which enters into a power circulation mode can be reduced. In particular, when the battery 16 is to be forcibly charged in step S1 of FIG. 7, the battery 16 is charged by forcibly switching from the partial cylinder operation to the all cylinder operation. Therefore, even if the discharge amount is increased during partial cylinder operation, it is possible to avoid an excessive decrease in the battery storage rate, so that an excessive burden is not applied to the battery 16. Therefore, since the battery 16 is not required to have a special ability, there is no possibility of narrowing the choices of usable batteries. By executing the control described above, the ECU 30 functions as an engine control unit, a discharge amount calculation unit, and a motor control unit according to the present invention.

(Second form)
Next, a second embodiment of the present invention will be described with reference to FIG. In the second mode, the condition in which the engine 3 is operated in the full cylinder operation and is returned to the normal operation mode in the differential operation mode is the first operation mode in which the engine 3 is operated in the partial cylinder operation and in the non-differential operation mode. And the engine 3 is operated in the partial cylinder operation and is different from the second operation mode in the differential operation mode. The control routine program shown in FIG. 10 is held in the ECU 30, and is read out in a timely manner and repeatedly executed at predetermined intervals. This control routine may be executed in parallel with the control routine of the first embodiment.

  In step S11, the ECU 30 determines whether or not the engine 3 is operated in the partial cylinder operation. When the engine 3 is operated by partial cylinder operation, the process proceeds to step S2. If the engine 3 is not operated in partial cylinder operation, that is, if it is operated in full cylinder operation, the subsequent processing is skipped and the current routine is finished.

  In step S12, the ECU 30 determines whether or not the operation mode is the non-differential operation mode, that is, whether or not the power split mechanism 6 is in the non-differential state. In the case of the non-differential operation mode, the process proceeds to step S13. In this case, the current operation mode is the first operation mode described above. If it is not the non-differential operation mode, that is, if it is the differential operation mode, the process proceeds to step S14. In this case, the current operation mode is the second operation mode described above. In step S13, the ECU 30 sets a predetermined value α that is a threshold value of a required output for returning from the first operation mode to the normal operation mode. On the other hand, in step S14, the ECU 30 sets a predetermined value β, which is a threshold value of a request output for returning from the second operation mode to the normal operation mode. The predetermined value α is smaller than the predetermined value β.

  In step S15, the ECU 30 determines whether the required output Pd is equal to or greater than a predetermined value α. When the required output Pd is greater than or equal to the predetermined value α, the operation mode is switched from the first operation mode to the normal operation mode, so that the motor lock mechanism 25 is operated in step S17 to switch from the non-differential operation mode to the differential operation mode. In S18, the engine 3 is switched from partial cylinder operation to full cylinder operation. Thereby, the operation mode returns from the first operation mode to the normal operation mode. On the other hand, if the requested output Pd is less than the predetermined value α, the subsequent processing is skipped and the current routine is finished. Thereby, the operation mode is maintained in the first operation mode.

  In step S16, the ECU 30 determines whether or not the required output Pd is equal to or greater than a predetermined value β. When the required output Pd is equal to or greater than the predetermined value β, the engine 3 is switched from the partial cylinder operation to the full cylinder operation in step S18 in order to switch from the second operation mode to the normal operation mode. Thereby, the operation mode returns from the first operation mode to the normal operation mode. On the other hand, if the requested output Pd is less than the predetermined value β, the subsequent processing is skipped and the current routine is finished. Thereby, the operation mode is maintained in the second operation mode.

  According to the above control routine, since the predetermined value α is smaller than the predetermined value β, the condition for returning to the normal operation mode is relaxed in the first operation mode than in the second operation mode. Therefore, it becomes easy to switch from the first operation mode to the normal operation mode. Thereby, since the engine control is restricted by the vehicle speed and the degree of freedom is low and the fuel consumption tends to be deteriorated, the chance of being forced to continue the first operation mode is reduced, so that the fuel consumption is improved. The ECU 30 functions as an operation mode control unit according to the present invention by executing the control routine of FIG.

  The present invention is not limited to the above embodiments, and can be implemented in various forms within the scope of the gist of the present invention. In the above embodiment, the maps M0 to M2 in which the required discharge amount and the required charge amount are associated with the battery storage rate are used to calculate the required discharge amount. For example, instead of using the above-mentioned form, it is also possible to calculate the required discharge amount each time using a predetermined empirical formula including the storage rate as a variable.

  In the above embodiment, as the map for calculating the required discharge amount at the time of partial cylinder operation, two maps having characteristics that are easier to discharge than the map used at the time of all cylinder operation are properly used according to the required output. Preparing is only an example. One map having characteristics that are easier to discharge than the map used when operating all cylinders may be used for partial cylinders.

  In each said form, the 1st motor generator 4 is locked by the motor lock mechanism 25, and the power split mechanism 6 as a differential mechanism is switched from a differential state to a non-differential state. However, the locking means for switching the differential mechanism from the differential state to the non-differential state is not limited to the case of preventing the rotation of the first motor / generator itself. For example, the power transmission path from the differential mechanism to the first motor / generator is separated by a clutch, and the locking mechanism is implemented in such a manner that the elements on the differential mechanism side are fixed, and the differential mechanism is in a differential state by the locking mechanism. It is also possible to switch from a non-differential state.

DESCRIPTION OF SYMBOLS 1 Vehicle 3 Engine 4 1st motor generator 5 Second motor generator 20 Output gear train (output part)
25 Motor lock mechanism (locking means)
30 ECU (engine control means, motor control means, discharge amount calculation means)

Claims (4)

It has a plurality of cylinders and can execute a partial cylinder operation in which some of the plurality of cylinders are deactivated and the remaining cylinders are operated, and a full cylinder operation in which all the cylinders are operated. An engine,
A first motor generator;
An output for transmitting torque to the drive wheels;
A differential mechanism that distributes the torque of the engine to the first motor / generator and the output unit;
A second motor / generator coupled to the output unit via a gear;
A battery capable of supplying power to the second motor generator;
A control device applied to a hybrid vehicle comprising:
Engine control means for causing the engine to execute the full cylinder operation and the partial cylinder operation;
A discharge amount calculating means for calculating a required discharge amount for the battery based on a storage rate of the battery;
When the engine performs each of the partial cylinder operation and the full cylinder operation, the torque transmitted from the second motor / generator to the output unit increases as the required discharge amount calculated by the discharge amount calculation means increases. Motor control means for controlling the second motor / generator so as to increase
With
The discharge amount calculating means calculates the required discharge amount so that the required discharge amount during the partial cylinder operation is larger than the required discharge amount during the full cylinder operation. Control device.   When the required output exceeds the engine output when the engine is operated at the maximum efficiency point in the partial cylinder operation, the discharge amount calculating means is configured to reduce the required discharge compared to a case where the required output is less than the engine output. The control device according to claim 1, wherein the required discharge amount is calculated so as to increase the amount. In the vehicle, the state of the differential mechanism can be switched between a differential state in which the torque of the engine is distributed to the first motor / generator and the output unit, and a non-differential state in which the distribution is stopped. Locking means are provided,
A first operation mode in which the differential mechanism is in the non-differential state and the engine is operated in the partial cylinder operation, or a first operation mode in which the differential mechanism is in the differential state and the engine is operated in the partial cylinder operation. Further provided is an operation mode control means for switching from the two operation modes to a normal operation mode in which the differential mechanism is in the differential state and the engine is operated in the all-cylinder operation when a required output becomes a predetermined value or more. ,
2. The control device according to claim 1, wherein the predetermined value is set to be smaller in the first operation mode than in the second operation mode.   The engine control means forcibly shifts from the partial cylinder operation to the full cylinder operation when the storage rate of the battery is equal to or less than a threshold value for forcibly charging the battery while the engine is executing the partial cylinder operation. The control apparatus as described in any one of Claims 1-3 switched automatically.

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