JP2015155276A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve both early warm-up of a catalyst for exhaust gas purification and improvement in fuel consumption in a hybrid vehicle using an engine and a MG (motor generator) as a power source.

SOLUTION: At the time of request for catalyst warm up, a required exhaust heat quantity (an exhaust heat quantity of an engine 11 required for the warm up of a catalyst 22) is satisfied while a required engine output is satisfied, and the operation point of the engine 11 is set so that the divergence of engine efficiency is within a first threshold, and the divergence of an engine speed is within a second threshold with respect to an operation point satisfying the required engine output on an optimum fuel consumption line connecting the operation points where the consumption of the engine 11 becomes optimum. Thus, by increasing the exhaust heat quantity of the engine 11 more than the case of operating the engine 11 at the operation point of the optimum fuel consumption line, the catalyst can be warmed up early. Also, by decreasing the reduction of the engine efficiency with respect to the operation point of the optimum fuel consumption line, the deterioration of the fuel consumption is suppressed, and the fluctuation of the engine speed is reduced.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a vehicle control device including a catalyst for purifying exhaust gas from an engine mounted as a power source of the vehicle.

  In recent years, vehicles equipped with an engine (internal combustion engine) are provided with a catalyst such as a three-way catalyst in order to purify exhaust gas from the engine. However, since the exhaust gas purification rate of the catalyst is low until the catalyst is warmed up to the activation temperature after the engine is started, it is necessary to warm up the catalyst early in order to improve the exhaust gas purification rate.

  As a technology for warming up the catalyst at an early stage in a hybrid vehicle in which an engine and an MG (motor generator) are mounted as a power source of the vehicle and a battery that exchanges electric power with the MG is mounted, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-123). No. 158303). This system sets a first warm-up time, which is the execution time of the first warm-up control, based on the battery storage ratio when a catalyst warm-up request is made, and the warm-up engine is based on the first warm-up time. After setting the power and the second warm-up time, which is the execution time of the second warm-up control, and executing the first warm-up control over the first warm-up time, the second warm-up control is performed for the second warm-up time. To run. At this time, in the first warm-up control, the engine is operated at an operating point that outputs a power value of approximately 0, and in the second warm-up control, the engine power during warm-up is set to the fuel efficiency operation line (the engine is operated efficiently). The engine is operated at the operating point output on the operating line).

JP 2012-158303 A

  In the technique of the above-mentioned Patent Document 1, when the catalyst is required to warm up, a self-sustained operation (idle operation) in which the engine is operated at an operating point that outputs approximately zero power and the engine power during warming up on the fuel consumption operation line. The fuel-consumption operation line operation is performed so that the engine is operated at the output operating point. However, the self-sustained operation may deteriorate the fuel efficiency because the engine efficiency decreases. In addition, in the fuel efficiency operation line operation, the exhaust heat amount of the engine is reduced, and therefore the warm-up time of the catalyst may be prolonged.

  Therefore, the problem to be solved by the present invention is to provide a vehicle control device that can achieve both early warm-up of the catalyst and improvement of fuel consumption.

  In order to solve the above problems, an invention according to claim 1 is a vehicle including an engine (11) mounted as a power source of the vehicle and a catalyst (22) for purifying exhaust gas of the engine (11). When the catalyst (22) is requested to warm up, the controller (22) warms up while satisfying the output of the engine (11) (hereinafter referred to as “required engine output”) set based on the required travel power of the vehicle. The operating point that satisfies the required engine output on the optimal fuel consumption line that connects the operating point at which the fuel consumption of the engine (11) is optimal while satisfying the exhaust heat amount of the engine (11) required for the aircraft (hereinafter referred to as “required exhaust heat amount”) On the other hand, an operating point setting means (25) is provided for setting the operating point of the engine (11) such that the deviation in efficiency of the engine (11) is within the first threshold.

  With this configuration, the engine can be operated at an operating point that satisfies the required engine output while satisfying the required exhaust heat amount (that is, an operating point that satisfies the required exhaust gas amount on the output line that connects the operating points that satisfy the required engine output). . Therefore, the amount of exhaust heat of the engine can be increased and the catalyst can be warmed up earlier than when the engine is operated at an operating point that satisfies the required engine output on the optimum fuel efficiency line. In addition, a decrease in engine efficiency with respect to an operating point that satisfies the required engine output on the optimum fuel efficiency line can be reduced (within the first threshold), and deterioration in fuel efficiency can be suppressed.

FIG. 1 is a diagram showing a schematic configuration of a drive control system for a hybrid vehicle in one embodiment of the present invention. FIG. 2 is a flowchart (part 1) showing the flow of processing of the engine operating point setting routine. FIG. 3 is a flowchart (part 2) showing the flow of processing of the engine operating point setting routine. FIG. 4 is a diagram illustrating a method for setting the operating point of the engine. FIG. 5 is a graph showing the relationship between the engine rotation speed and the amount of exhaust heat. FIG. 6 is a graph showing the relationship between engine speed and engine efficiency.

Hereinafter, an embodiment embodying a mode for carrying out the present invention will be described.
First, a schematic configuration of a drive control system for a hybrid vehicle will be described with reference to FIG.
An engine 11 that is an internal combustion engine and a motor generator (hereinafter referred to as “MG”) 12 are mounted as power sources for the vehicle. The power of the output shaft (crankshaft) of the engine 11 is transmitted to the transmission 13 via the MG 12, and the power of the output shaft of the transmission 13 is transmitted to the wheels 16 via the differential gear mechanism 14, the axle 15 and the like. . The transmission 13 may be a stepped transmission that switches the shift speed step by step from a plurality of shift speeds, or may be a CVT (continuously variable transmission) that shifts continuously.

  A rotating shaft of the MG 12 is connected between the engine 11 and the transmission 13 in a power transmission system for transmitting the power of the engine 11 to the wheels 16 so that the power can be transmitted. Further, a first clutch 17 for interrupting power transmission is provided between the engine 11 and the MG 12, and a second clutch 18 for interrupting power transmission is provided between the MG 12 and the transmission 13. Is provided. These clutches 17 and 18 may be hydraulically driven hydraulic clutches or electromagnetically driven electromagnetic clutches. An inverter 19 that drives the MG 12 is connected to the battery 20, and the MG 12 exchanges power with the battery 20 via the inverter 19.

  On the other hand, the exhaust pipe 21 of the engine 11 is provided with a catalyst 22 such as a three-way catalyst for purifying the exhaust gas. The air-fuel ratio or rich / lean of the exhaust gas is set on the upstream side and the downstream side of the catalyst 22 respectively. Exhaust gas sensors 23 and 24 (air-fuel ratio sensor, oxygen sensor, etc.) to be detected are provided.

  The hybrid ECU 25 is a computer that comprehensively controls the entire vehicle and reads output signals from various sensors and switches such as an accelerator sensor, a shift switch, a brake switch, a vehicle speed sensor (not shown), and the like. Detect the operating state. The hybrid ECU 25 includes control signals and data between an engine ECU 26 that controls the engine 11, an MG-ECU 27 that controls the inverter 19 to control the MG 12, and a transmission ECU 28 that controls the transmission 13 and the clutches 17 and 18. Signals etc. are transmitted / received, and engine 11, MG12, transmission 13, clutches 17 and 18 etc. are controlled by each ECU26-28 according to the driving | running state of a vehicle.

  In this embodiment, the hybrid ECU 25 executes an engine operating point setting routine shown in FIGS. 2 and 3 to be described later, whereby the output of the engine 11 (hereinafter referred to as “required engine output”) set based on the required traveling power of the vehicle. The operating point of the engine 11 (for example, engine speed and engine torque) is set as follows.

  As shown in FIG. 4, when the catalyst 22 is not warmed-up (when no warm-up request is generated), the requested engine output on the optimum fuel consumption line connecting the operating points at which the fuel consumption of the engine 11 is optimum is achieved. The operating point of the engine 11 is set so as to satisfy In this case, the engine 11 is operated at an operating point that satisfies the required engine output on the optimum fuel consumption line.

  On the other hand, when the warm-up of the catalyst 22 is requested (when the warm-up request is generated), the exhaust heat amount of the engine 11 required for warming up the catalyst 22 while satisfying the required engine output (hereinafter referred to as “required exhaust heat amount”). ) And the engine 11 so that the deviation of the engine efficiency is within the first threshold and the deviation of the engine speed is within the second threshold with respect to the operating point that satisfies the required engine output on the optimum fuel consumption line. Set the operating point. In this case, the operating point that satisfies the required engine output while satisfying the required engine output (that is, the operating point that satisfies the required exhaust heat amount on the output line that connects the operating points that satisfy the required engine output, in other words, the required exhaust heat amount is satisfied. The engine 11 is operated at an operating point satisfying the required engine output on the warm-up priority line connecting the operating points.

  In this embodiment, when the catalyst 22 is requested to warm up, the output of the engine 11 required for warming up the catalyst 22 (hereinafter referred to as “catalyst warm-up engine output”) is calculated based on the required exhaust heat quantity, and the travel request is calculated. The requested engine output is set based on the power, the maximum battery power (the maximum power of the battery 20), and the catalyst warm-up engine output.

  Specifically, when the required travel power is equal to or less than the sum of the battery maximum power and the catalyst warm-up engine output, the travel required power can be realized even if the required engine output is set to the catalyst warm-up engine output. Therefore, the required engine output is set to the catalyst warm-up engine output.

  On the other hand, when the required travel power is larger than the sum of the battery maximum power and the catalyst warm-up engine output, if the required engine output is set to the catalyst warm-up engine output, Since the required travel power cannot be realized, the required engine output is set to the difference between the required travel power and the maximum battery power (that is, a value larger than the catalyst warm-up engine output).

Hereinafter, processing contents of the engine operating point setting routine of FIGS. 2 and 3 executed by the hybrid ECU 25 in the present embodiment will be described.
The engine operating point setting routine shown in FIGS. 2 and 3 is repeatedly executed at a predetermined cycle during the power-on period of the hybrid ECU 25, and serves as operating point setting means in the claims.

  When this routine is started, first, in step 101, sensor values (detected values) necessary for control such as the accelerator opening, the vehicle speed, the MG rotational speed (the rotational speed of MG12), etc. are read and the catalyst temperature (catalyst 22) is read. ) And an estimated value (calculated value) such as a battery temperature (temperature of the battery 20) is read. In the case of a system including a sensor for detecting the catalyst temperature or a sensor for detecting the battery temperature, a sensor value (detection value) of the catalyst temperature or the battery temperature may be read.

Thereafter, the process proceeds to step 102 where adjustment of the battery output upper limit value Wout (the output upper limit value of the battery 20), the target catalyst warm-up time (the target warm-up time of the catalyst 22), the gear ratio of the transmission 13, and the ignition retard amount. The setting values necessary for control such as the amount θdiff and the adjustment amount Qdiff of the required exhaust heat amount (required warm-up heat amount) are read.
Thereafter, the process proceeds to step 103, where the required travel power Pd of the vehicle is calculated based on the accelerator opening and the vehicle speed using a map or a mathematical expression.

Thereafter, the routine proceeds to step 104, where a catalyst warm-up request flag is set based on the current catalyst temperature and the target catalyst temperature (for example, the activation temperature of the catalyst 22). In this case, for example, when the current catalyst temperature is lower than the target catalyst temperature, the catalyst warm-up request flag is set to ON, which means that a warm-up request for the catalyst 22 has been generated. On the other hand, if the current catalyst temperature is equal to or higher than the target catalyst temperature, the catalyst warm-up request flag is reset to OFF (off), which means that no warm-up request for the catalyst 22 has been generated.
After this, the routine proceeds to step 105, where it is determined whether or not the catalyst warm-up request flag is ON (the catalyst 22 warm-up request has been generated).

If it is determined in step 105 that the catalyst warm-up request flag is OFF (no catalyst 22 warm-up request has been generated), the process proceeds to step 123, where the required engine output Pe is determined from the travel required power Pd. A value obtained by subtracting the battery charge / discharge power Pbatt (Pd−Pbatt) is set.
Pe = Pd -Pbatt

Thereafter, the routine proceeds to step 124, where the operating point of the engine 11 (the target engine speed Ntg and the target engine torque Ttg is set so as to satisfy the required engine output Pe on the optimal fuel consumption line connecting the operating points at which the fuel consumption of the engine 11 is optimal. ) Is set. Specifically, the engine rotational speed Nopt and the engine torque Topt at the operating point that satisfies the required engine output Pe on the optimal fuel consumption line are set as the target engine rotational speed Ntg and the target engine torque Ttg, respectively.
Ntg = Nopt
Ttg = Topt

On the other hand, if it is determined in step 105 that the catalyst warm-up request flag is ON (the warm-up request for the catalyst 22 has been generated), the process proceeds to step 106, where the current catalyst temperature and the target catalyst temperature are determined. The required exhaust heat quantity Qr (the exhaust heat quantity of the engine 11 necessary for warming up the catalyst 22) is calculated based on
Thereafter, the routine proceeds to step 107, where the catalyst warm-up engine output Pth (the output of the engine 11 necessary for warming up the catalyst 22) is calculated based on the required exhaust heat quantity Qr by a map or a mathematical expression.

  Thereafter, the routine proceeds to step 108, where it is determined whether or not the required travel power Pd is equal to or less than the sum (k × Wout + Pth) of the battery maximum power (k × Wout) and the catalyst warm-up engine output Pth. Here, the battery maximum power (k × Wout) is the maximum value of the traveling power by the battery 20 (the traveling power by the MG 12 driven by the power of the battery 20).

If it is determined in step 108 that the required travel power Pd is equal to or less than the sum (k × Wout + Pth) of the battery maximum power (k × Wout) and the catalyst warm-up engine output Pth, the required engine output Pe is Even if the catalyst warm-up engine output Pth is set, the required travel power Pd can be realized. Therefore, the routine proceeds to step 109, where the required engine output Pe is set to the catalyst warm-up engine output Pth.
Pe = Pth

On the other hand, if it is determined in step 108 that the required travel power Pd is larger than the sum (k × Wout + Pth) of the battery maximum power (k × Wout) and the catalyst warm-up engine output Pth, the required engine output If Pe is set to the catalyst warm-up engine output Pth, the travel required power Pd cannot be realized even if the travel power by the battery 20 is set to the battery maximum power (k × Wout). Pe is set to the difference between the required travel power Pd and the battery maximum power (k × Wout).
Pe = Pd−k × Wout

  Thereafter, the process proceeds to step 111, the ignition retard amount θretard is set to an initial value (for example, 0), and then the process proceeds to step 112, where the engine speed threshold Nth (second threshold) is set to a predetermined value. This predetermined value is a value that can suppress adverse effects (for example, deterioration of noise and vibration) due to fluctuations in engine rotation speed.

  Thereafter, the process proceeds to step 113, and the engine efficiency threshold value ηth (first threshold value) is set by a map or a mathematical expression in accordance with the target catalyst warm-up time. Here, the engine efficiency threshold value ηth is set such that the engine efficiency threshold value ηth increases as the target catalyst warm-up time is shorter.

  Thereafter, the processing in steps 114 to 122 in FIG. 3 satisfies the required engine output Pe while satisfying the required exhaust heat quantity Qr, and the engine efficiency is different from the operating point that satisfies the required engine output Pe on the optimum fuel efficiency line. The operating point (target engine speed Ntg and target engine torque Ttg) of the engine 11 is set so that the deviation of the engine speed is within the threshold value ηth and the threshold value Nth.

  First, at step 114, based on the ignition retard amount θretard, the required engine output Pe, and the required exhaust heat quantity Qr, the engine speed Nr that satisfies the required exhaust heat quantity Qr while satisfying the required engine output Pe is calculated. Specifically, if the ignition retard amount and the engine output are fixed, the relationship between the engine speed and the exhaust heat quantity (see FIG. 5) is determined. Therefore, the engine speed Nr corresponding to the required exhaust heat quantity Qr Calculated by The map or mathematical expression of the engine speed Nr is set for each ignition retard amount θretard and for each requested engine output Pe. The engine speed Nr calculated in step 114 is referred to as “the engine speed Nr that satisfies the required exhaust heat quantity Qr”.

  Thereafter, the routine proceeds to step 115, where the engine speed Nopt that satisfies the required engine output Pe on the optimum fuel efficiency line is calculated based on the ignition retard amount θretard and the required engine output Pe. The engine speed Nopt calculated in step 115 is referred to as “the engine speed Nopt of the optimum fuel consumption line”.

  Thereafter, the routine proceeds to step 116, where the engine efficiency ηr when the engine 11 is operated at the engine speed Nr satisfying the required exhaust heat quantity Qr is calculated. Specifically, when the engine output is fixed, the relationship between the engine rotational speed and the engine efficiency (see FIG. 6) is determined, so the engine efficiency ηr corresponding to the engine rotational speed Nr satisfying the required exhaust heat quantity Qr is represented by a map or a mathematical formula, etc. Calculated by The map or mathematical expression of the engine efficiency ηr is set for each required engine output Pe. The engine efficiency ηr calculated in step 116 is referred to as “engine efficiency ηr satisfying the required exhaust heat quantity Qr”.

  Thereafter, the routine proceeds to step 117, where the engine efficiency ηopt when the engine 11 is operated at the engine speed Nopt of the optimum fuel efficiency line is calculated. Specifically, the engine efficiency ηopt corresponding to the engine speed Nopt of the optimum fuel consumption line is calculated by a map or a mathematical expression. The engine efficiency ηopt calculated in step 117 is referred to as “the engine efficiency ηopt of the optimum fuel efficiency line”.

  Thereafter, the routine proceeds to step 118, where Nr−Nopt ≦ Nth (the difference between the engine rotational speed Nr satisfying the required exhaust heat quantity Qr and the engine rotational speed Nopt of the optimum fuel consumption line is equal to or smaller than a threshold Nth) and ηopt−ηr ≦ ηth It is determined whether or not the difference between the engine efficiency ηopt of the optimum fuel efficiency line and the engine efficiency ηr satisfying the required exhaust heat quantity Qr is equal to or less than the threshold value ηth.

If it is determined in step 118 that Nr−Nopt ≦ Nth and ηopt−ηr ≦ ηth, the routine proceeds to step 122 where the engine speed Nr satisfying the required exhaust heat quantity Qr is set to the target engine speed Ntg. And the target engine torque Ttg (= Pe / Ntg) is set based on the target engine speed Ntg and the required engine output Pe.
Ntg = Nr
Ttg = Pe / Ntg

On the other hand, if it is determined in step 118 that Nr−Nopt> Nth, or if it is determined that ηopt−ηr> ηth, the routine proceeds to step 119, where the ignition retard amount θretard is reached. Is increased by an adjustment amount θdiff (that is, corrected so that the exhaust heat quantity of the engine 11 increases).
θretard = θretard + θdiff

  Thereafter, the routine proceeds to step 120, where it is determined whether or not the ignition retardation amount θretard exceeds the retardation limit, and the ignition retardation amount θretard does not exceed the retardation limit (ignition retardation amount θretard is the retardation limit). If it is determined that the following is true, the process returns to step 114.

On the other hand, if it is determined in step 120 that the ignition retard amount θretard exceeds the retard limit, the routine proceeds to step 121, where the required exhaust heat quantity Qr is corrected to be reduced by the adjustment amount Qdiff (that is, the engine speed is reduced). The difference (Nr−Nopt) and the difference in engine efficiency (ηopt−ηr) are corrected so as to decrease), and the process returns to step 107.
Qr = Qr -Qdiff

Thereafter, if it is determined in step 118 that Nr−Nopt ≦ Nth and ηopt−ηr ≦ ηth, the routine proceeds to step 122 where the engine speed Nr satisfying the required exhaust heat quantity Qr is set to the target engine speed. The target engine torque Ttg (= Pe / Ntg) is set based on the target engine speed Ntg and the required engine output Pe.
Ntg = Nr
Ttg = Pe / Ntg

  In the present embodiment described above, when the warming-up request of the catalyst 22 is required, the engine efficiency is improved with respect to the operating point that satisfies the required engine output Pe while satisfying the required engine output Pe and satisfies the required engine output Pe on the optimum fuel efficiency line. The operating point (target engine speed Ntg and target engine torque Ttg) of the engine 11 is set so that the deviation is within the threshold value ηth and the engine speed deviation is within the threshold value Nth.

  In this way, the operating point that satisfies the required engine output Pe while satisfying the required exhaust heat quantity Qr (that is, the operating point that satisfies the required exhaust heat quantity Qr on the output line connecting the operating points that satisfy the required engine output Pe), in other words. The engine 11 can be operated at an operating point that satisfies the required engine output Pe on the warm-up priority line that connects operating points that satisfy the required exhaust heat quantity Qr. Therefore, the amount of exhaust heat of the engine 11 can be increased and the catalyst 22 can be warmed up earlier than when the engine is operated at an operating point that satisfies the required engine output Pe on the optimum fuel efficiency line.

  In addition, since the operating point of the engine 11 is set so that the deviation of the engine efficiency is within the threshold value ηth with respect to the operating point that satisfies the required engine output Pe on the optimal fuel efficiency line, the required engine output Pe is set on the optimal fuel efficiency line. A decrease in engine efficiency with respect to the operating point to be satisfied can be reduced (within the threshold value ηth), and deterioration in fuel consumption can be suppressed.

  Further, since the operating point of the engine 11 is set so that the deviation of the engine speed is within the threshold value Nth with respect to the operating point that satisfies the required engine output Pe on the optimal fuel efficiency line, the required engine output Pe on the optimal fuel efficiency line. The fluctuation of the engine speed with respect to the operating point that satisfies the condition can be reduced (within the threshold value Nth), and adverse effects (for example, deterioration of noise and vibration) due to the fluctuation of the engine speed can be suppressed.

  Furthermore, in this embodiment, since the threshold ηth of engine efficiency is set according to the target catalyst warm-up time, the threshold ηth is set to an appropriate value by changing the threshold ηth according to the target catalyst warm-up time. can do. For example, by increasing the threshold ηth as the target catalyst warm-up time is shorter, the warm-up of the catalyst 22 can be prioritized over the engine efficiency (fuel consumption) as the target catalyst warm-up time is shorter.

  In this embodiment, when the catalyst 22 is required to warm up, the catalyst warm-up engine output Pth is calculated based on the required exhaust heat quantity Qr, and the travel required power Pd, the battery maximum power (k × Wout), and the catalyst warm-up engine are calculated. The requested engine output Pe is set based on the output Pth. In this way, the required engine output Pe can be set so that the travel required power Pd can be realized in consideration of the battery maximum power (k × Wout) and the catalyst warm-up engine output Pth.

  Specifically, when the required travel power Pd is equal to or less than the sum (k × Wout + Pth) of the battery maximum power (k × Wout) and the catalyst warm-up engine output Pth, the required engine output Pe is set as the catalyst warm-up engine output. Even if it is set to Pth, the required travel power Pd can be realized, so the required engine output Pe is set to the catalyst warm-up engine output Pth. Thus, the required engine output Pe can be set so that the required travel power Pd can be realized while ensuring the catalyst warm-up engine output Pth (engine output necessary for warming up the catalyst 22). On the other hand, when the required travel power Pd is larger than the sum (k × Wout + Pth) of the battery maximum power (k × Wout) and the catalyst warm-up engine output Pth, the required engine output Pe is set to the catalyst warm-up engine output Pth. If set, the travel request power Pd cannot be realized even if the travel power from the battery 20 is set to the battery maximum power (k × Wout). Therefore, the request engine output Pe is set to the travel request power Pd and the battery maximum power (k × Wout). ) (That is, a value larger than the catalyst warm-up engine output Pth). Thus, even when the travel required power Pd is larger than the sum (k × Wout + Pth) of the battery maximum power (k × Wout) and the catalyst warm-up engine output Pth, the catalyst warm-up engine output Pth (warm-up of the catalyst 22). The required engine output Pe can be set so that the required travel power Pd can be realized while ensuring the necessary engine output).

  In the above-described embodiment, the engine operating point setting routine is executed by the hybrid ECU 25. However, the present invention is not limited to this, and the engine operating point setting routine is executed by an ECU other than the hybrid ECU 25 (for example, the engine ECU 26). Alternatively, the engine operating point setting routine may be executed by both the hybrid ECU 25 and another ECU.

  Further, in the above embodiment, the operation of the engine 11 is performed so that the deviation of the engine efficiency is within the threshold value ηth and the deviation of the engine speed is within the threshold value Nth with respect to the operating point that satisfies the required engine output Pe on the optimum fuel consumption line. However, the present invention is not limited to this, and the engine rotational speed condition is omitted, and the engine efficiency deviation is within the threshold ηth with respect to the operating point that satisfies the required engine output Pe on the optimum fuel efficiency line. The operating point of the engine 11 may be set so as to be.

  Furthermore, in the above-described embodiment, the engine efficiency threshold value ηth is set according to the target catalyst warm-up time. However, the present invention is not limited to this, and the engine efficiency threshold value ηth may be a fixed value set in advance.

  Further, the present invention is not limited to the hybrid vehicle having the configuration shown in FIG. 1, but can be implemented by being applied to hybrid vehicles having various configurations in which an engine and MG are mounted as a power source of the vehicle. For example, a hybrid vehicle in which a plurality of MGs are arranged in a power transmission system that transmits engine power to wheels, a hybrid vehicle in which an engine and a plurality of MGs are connected via a power split mechanism (for example, a planetary gear mechanism), and driving by the engine The present invention may be applied to a hybrid vehicle that drives an axle different from the axle to be driven by MG.

  Furthermore, the present invention is not limited to a hybrid vehicle using an engine and MG as a power source, and the present invention may be applied to a vehicle using only an engine as a power source.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... MG (motor generator), 20 ... Battery, 22 ... Catalyst, 25 ... Hybrid ECU (operating point setting means)

Claims (6)

In a vehicle control device comprising an engine (11) mounted as a vehicle power source and a catalyst (22) for purifying exhaust gas of the engine (11),
When the catalyst (22) is requested to warm up, the catalyst (22) is warmed up while satisfying the output of the engine (11) set based on the required travel power of the vehicle (hereinafter referred to as “required engine output”). The engine (11) exhaust heat quantity (hereinafter referred to as “required exhaust heat quantity”) necessary for the engine is satisfied, and the required engine output is satisfied on an optimum fuel consumption line connecting operating points at which the fuel consumption of the engine (11) is optimized. An operating point setting means (25) is provided for setting the operating point of the engine (11) so that the deviation of the efficiency of the engine (11) with respect to the operating point is within a first threshold value. A vehicle control device.   The operating point setting means (25) is configured such that a deviation in efficiency of the engine (11) is within the first threshold with respect to an operating point that satisfies the required engine output on the optimum fuel efficiency line, and the engine (11). 2. The vehicle control device according to claim 1, wherein the operating point of the engine is set so that a difference in rotational speed of the engine is within a second threshold value.   The vehicle control device according to claim 1 or 2, wherein the operating point setting means (25) sets the first threshold according to a target warm-up time of the catalyst (22). The engine (11) and the motor generator (12) are mounted as a power source of the vehicle, and a battery (20) for transferring power to and from the motor generator (12) is mounted.
The operating point setting means (25) calculates the output of the engine (11) necessary for warming up the catalyst (22) (hereinafter referred to as “catalyst warming engine output”) based on the required exhaust heat quantity, The vehicle control according to any one of claims 1 to 3, wherein the required engine output is set based on the required travel power, the maximum power of the battery (20), and the catalyst warm-up engine output. apparatus.   The operating point setting means (25), when the required travel power is equal to or less than the sum of the maximum power of the battery (20) and the catalyst warm-up engine output, outputs the requested engine output to the catalyst warm-up engine output. The vehicle control device according to claim 4, wherein the vehicle control device is set as follows.   The operating point setting means (25) determines the required engine output as the required travel power when the required travel power is greater than the sum of the maximum power of the battery (20) and the catalyst warm-up engine output. The vehicle control device according to claim 4 or 5, wherein the difference is set to a difference from the maximum power of the battery (20).

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