JP2009035122A - Control device for hybrid vehicle - Google Patents

Abstract

An object of the present invention is to prevent deterioration in acceleration performance caused by bypassing exhaust gas while allowing exhaust gas to flow by bypassing a turbine of a turbocharger under predetermined conditions.
In a hybrid vehicle including an engine with a supercharger and a motor generator, a target bypass exhaust flow rate for bypassing a turbine of a turbocharger is calculated based on the operating state of the engine. Based on the target bypass exhaust flow rate, the flow rate adjustment valve 37 for adjusting the bypass exhaust flow rate and the turbine passing exhaust flow rate is controlled. Further, an engine driving force when the target bypass exhaust flow rate bypasses the turbine 13b of the supercharger 13 is calculated, a target assist driving force is calculated from the required driving force of the vehicle and the engine driving force, and the calculated target assist is calculated. The motor generator 3 is controlled so as to have a driving force.
[Selection] Figure 1

Description

  The present invention relates to a control device for a hybrid vehicle including an engine with a supercharger and an assist motor that assists the driving force of the engine as necessary.

In the engine with a supercharger described in Patent Document 1, when the temperature of the exhaust purification catalyst is lower than a predetermined temperature, the exhaust purification catalyst is heated by increasing the amount of bypass exhaust that bypasses the turbine of the supercharger. When the supercharger rotation speed is lower than the predetermined rotation speed, the bypass amount is limited to make the supercharger rotation speed equal to or higher than the predetermined rotation speed, thereby preventing the lubricant from leaking.
JP 2003-166416 A

  However, the above conventional technique has the following problems.

  That is, during the temperature rise of the exhaust purification catalyst, sufficient supercharging cannot be performed, so that the acceleration performance may be deteriorated. On the other hand, when the turbocharger rotational speed is lower than the predetermined rotational speed, a certain amount of exhaust gas passes through the turbine of the supercharger, but the amount of deposit discharge increases at low temperatures such as when starting. As a result, unburned components in the exhaust gas may adhere to the turbocharger, resulting in performance degradation or malfunction of the turbocharger. Further, passing through the turbine increases the heat loss of the exhaust gas, making it difficult to activate the exhaust gas purification device at an early stage.

  The present invention is made paying attention to such a conventional problem, and when necessary, an appropriate amount of exhaust gas flows bypassing the turbocharger turbine, and the exhaust gas bypasses the turbine. The purpose is to prevent the acceleration performance from being deteriorated.

  Therefore, the present invention calculates a target bypass exhaust flow rate for bypassing the turbocharger turbine based on the operating state of the engine, controls the flow rate adjustment valve based on the calculated target bypass exhaust flow rate, and The engine driving force when the bypass exhaust flow bypasses the turbocharger turbine is calculated, the target assist driving force by the assist motor is calculated from the required driving force of the vehicle and the engine driving force, and the calculated target assist driving force and The assist motor is controlled so that

  Here, a state of charge of a battery that supplies power to the assist motor may be detected, and the target bypass exhaust flow rate may be corrected based on the detected state of charge.

  According to the present invention, the bypass exhaust flow rate for bypassing the turbocharger turbine is controlled in accordance with the engine operating condition, and the engine driving force associated with part or all of the exhaust bypassing the turbocharger turbine is controlled. The decrease can be compensated by the driving force of the assist motor. As a result, a predetermined amount of exhaust gas is bypassed, for example, an exhaust purification catalyst provided downstream of the turbine is activated early, or performance degradation of the turbocharger (deposit sticking to the turbine) is prevented. It is possible to prevent the acceleration performance from being lowered.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a hybrid vehicle according to an embodiment of the present invention.

  As shown in FIG. 1, the hybrid vehicle according to the present embodiment includes an engine 1, an automatic transmission 2 connected to an output shaft of the engine 1, a motor generator (M / G) 3, an engine 1, and an automatic transmission. An engine controller (ECM) 4 that controls the operation of the machine 2, a motor controller (MC) 5 that controls the operation of the motor generator 3, and a hybrid controller (HCM) 6 that integrally controls the ECU 4 and MC 5. Is done.

  Motor generator 3 is electrically connected to battery 8 via inverter 7. The motor generator 3 is driven by the engine 1 to generate power and supplies the generated power to the battery 8. Further, it operates with the electric power supplied from the battery 8 to assist the driving force of the engine 1.

  The driving force of the engine 1 is transmitted to a wheel drive shaft (not shown) and / or the motor generator 3 via the automatic transmission 2 and a power transmission mechanism 9 composed of a clutch, a gear and the like, and the driving force of the motor generator 3 is It is transmitted to a wheel drive shaft (not shown) via a power transmission mechanism 9.

  The engine 1 is a diesel engine, and an intake air passage 11 is provided with an air flow meter 12 for detecting an intake air amount, a compressor 13a of a supercharger 13, a collector 14, and an electric throttle 15 from the intake upstream side. Yes. The intake air that has passed through the air flow meter 12 and has been compressed by the compressor 13 a flows into the intake manifold 16 via the collector 14 and the electric throttle 15, and is distributed to each cylinder by the intake manifold 16.

  Each cylinder of the engine 1 is provided with a fuel injection valve 20. Fuel supplied from a fuel tank (not shown) through a fuel supply passage is pressurized by a fuel pump 21 driven by the engine 1 and supplied to the common rail 22. The fuel injection valve 20 guides fuel (high-pressure fuel) stored in the common rail 22 and injects a predetermined amount of fuel into the combustion chamber of each cylinder at a predetermined timing.

  The combustion exhaust from the engine 1 is discharged to the exhaust passage 32 through the exhaust manifold 31. A turbine 13b of the supercharger 13 and an exhaust purification device (catalyst device) 33 are disposed in the exhaust passage 32 from the exhaust upstream side. The turbine 13b rotates as exhaust gas passes through, and thereby the compressor 13a also rotates to compress the intake air. The exhaust purification device 33 is composed of, for example, a NOx trap catalyst and a DPF, and removes harmful substances such as NOx and PM (particulate matter).

  Further, an EGR passage 34 that connects the exhaust manifold 32 immediately downstream of the exhaust manifold 31 and the intake manifold 16 and an EGR valve 35 that opens and closes the EGR passage 34 are provided. By adjusting this, a part of the exhaust (a predetermined amount of exhaust) can be recirculated to the intake system.

  Further, on the downstream side of the connection portion of the EGR passage 34 of the exhaust passage 32, a bypass passage 36 that branches from the upstream side of the turbine 13 b and connects to the upstream side of the exhaust gas purification device 33, and exhaust gas that passes through the bypass passage 36 And a flow rate adjusting valve 37 for adjusting the flow rate (hereinafter referred to as “bypass exhaust flow rate”) and the exhaust flow rate (hereinafter referred to as “turbine passing exhaust flow rate”) that passes through the exhaust passage 32 as it is (that is, through the turbine 13b). ing. In the present embodiment, the flow rate adjusting valve 37 is disposed in the vicinity of a branch portion where the bypass passage 36 branches from the exhaust passage 32, and the ratio of the bypass exhaust flow rate and the turbine passing exhaust flow rate is controlled by controlling the opening degree. (Flow rate) can be adjusted. For example, when the flow rate adjustment valve 37 is fully closed, the exhaust passage 32 is closed and all the exhaust passes through the bypass passage 36 (that is, bypasses the turbine 13b) and flows into the exhaust purification device 33 ( In this case, the bypass flow rate is 1.0). On the other hand, when the flow rate adjustment valve 37 is fully opened, the bypass passage 36 is closed and all exhaust gas passes through the turbine 13b and flows into the exhaust gas purification device 33 (in this case, the bypass flow rate is 0). .

  Detection signals from various sensors are input to the HCM 6. Various sensors include an air flow meter 12 for detecting the intake air amount (Qa), a rotational speed sensor 41 for detecting the engine rotational speed (NE), a vehicle speed sensor 42 for detecting the vehicle speed (VSP), and a driver's accelerator. An accelerator opening sensor 43 that detects an accelerator opening (APS) according to an operation amount, a supercharging pressure sensor 44 that detects a supercharging pressure (Pb), and a state of charge (SOC) that is a representative value of the remaining capacity of the battery 6 A battery sensor 45 for detecting the engine temperature, a water temperature sensor 46 for detecting the engine coolant temperature (Tw), an HC sensor 47 for detecting the unburned HC amount (HC emission amount: Chc) in the exhaust gas upstream of the turbine 13b, and an exhaust purification device. There are a catalyst temperature sensor 48 for detecting the catalyst temperature (Tc) 33, an exhaust temperature sensor 49 for detecting the exhaust temperature (Te) at the inlet of the exhaust gas purification device 33, and the like. However, it is not necessary to provide all the sensors described above, and values (estimated values, calculated values) obtained based on detection signals of other sensors may be used.

  The HCM 8 performs predetermined calculation processing based on detection signals from various sensors, executes various controls for the engine 1 and the automatic transmission 2 via the ECM 4, and executes various controls for the motor generator 3 via the MC 5. .

  In particular, in the present embodiment, the bypass exhaust flow rate is set based on the operating state of the engine 1, the flow control valve 37 is controlled based on the set bypass exhaust flow rate, and according to the set bypass exhaust flow rate. By controlling the assist driving force by the motor generator 3, an amount of exhaust as required bypasses the turbine 13b, while preventing deterioration (decrease) in acceleration performance associated with bypassing the exhaust. Yes.

  Hereinafter, the operation of the HCM 6 during “exhaust bypass” in which exhaust gas flows through the bypass passage 36 will be described.

  FIG. 2 is a flowchart showing the exhaust bypass control (first embodiment) executed by the HCM 8. This flow is started when the key switch is turned on, and is executed at a predetermined cycle.

  In FIG. 2, in S <b> 1, the engine rotation speed (Ne) detected by the rotation speed sensor 41, the vehicle speed (VSP) detected by the vehicle speed sensor 42, the accelerator opening (APS) detected by the accelerator opening sensor 43, The battery charge state (SOC) detected by the battery sensor 45 is read.

  In S2, the unburned HC amount (CHc) detected by the HC sensor 47, the catalyst temperature (Tc) detected by the catalyst temperature sensor 48, and the exhaust temperature (Te) detected by the exhaust temperature sensor 49 are read.

  In S3, it is determined whether or not there is an exhaust temperature increase request. If an exhaust gas temperature increase request has occurred, the process proceeds to S4, and if an exhaust gas temperature increase request has not occurred, the process proceeds to S6. The exhaust gas temperature increase request is generated when the target exhaust gas temperature (tTe) is higher than the current exhaust gas temperature (Te). For example, the amount of PM collected in the DPF becomes equal to or greater than a predetermined value. Occurs when performing DPF regeneration processing for removing removed PM by combustion.

  In S4, the target temperature rise (ΔTe = tTe−Te) is calculated by subtracting the exhaust temperature (Te) read in S2 from the target exhaust temperature (tTe).

In S5, a first bypass flow rate (Rb ₁ ≦ 1.0) is calculated based on the target temperature increase temperature (ΔTe) with reference to a preset table (FIG. 3). As the target temperature rise (ΔTe) is higher, the first bypass flow rate (Rb ₁ ) is set to a larger value, and the ratio of exhaust gas that bypasses the turbine 13b increases. This is to bypass the turbine 13b and keep the exhaust at a high temperature (to prevent heat loss due to passage through the turbine 13b).

In S6, based on the unburned HC amount (CHc) read in S2, the second bypass flow rate (Rb ₂ ≦ 1.0) is obtained with reference to a preset table (FIG. 4). As the unburned HC amount (CHc) increases, the second bypass flow rate (Rb ₂ ) is set to a larger value, and the ratio of exhaust gas that bypasses the turbine 13b increases. This is to prevent performance degradation and malfunction of the supercharger due to adhesion of unburned HC to the turbine 13b. That is, when the exhaust gas passes through the turbine 13b, unburned HC in the exhaust gas becomes a deposit and adheres to the turbine 13b. Thereafter, when the temperature of the supercharger 13 decreases as the engine stops, the deposited deposit solidifies. If the deposit is solidified in the movable part (rotating part) of the turbine 13b, not only the performance of the supercharger 13 is deteriorated but also there is a risk of malfunction. Therefore, when the unburned HC amount (CHc) in the exhaust gas is large, the proportion of exhaust gas to be bypassed is increased. Of course, when the amount of unburned HC in the exhaust gas is equal to or greater than a predetermined value (maximum allowable amount), all the exhaust gas may be bypassed (second bypass flow rate Rb ₂ = 1.0).

In S7, based on the catalyst temperature (Tc) read in S2, a third bypass flow rate (Rb ₃ ≦ 1.0) is obtained with reference to a preset table (FIG. 5). As the catalyst temperature (Tc) is lower, the third bypass flow rate (Rb ₃ ) is set to a larger value, and the ratio of exhaust gas that bypasses the turbine 13b increases. This is because when the catalyst temperature (Tc) is low, the catalyst is not active, so that the exhaust gas that bypasses the turbine 13b and is maintained at a high temperature is supplied to the exhaust gas purification device 33 for early activation. Because.

In S8, the maximum value of the bypass flow rate Rb _1-3 calculated in the above step is selected, and the result is set as the target bypass flow rate tRb1. Since the bypass exhaust flow rate is obtained by multiplying the total exhaust flow rate by the bypass flow rate, obtaining the above bypass flow rates (Rb ₁ , Rb ₂ , Rb ₃ , tRb 1) is substantially “bypass exhaust flow rate”. Is equivalent to calculating.

  In S9, based on the target bypass flow rate tRb1, a target opening (flow adjustment valve opening) tVdeg1 of the flow adjustment valve 37 is set with reference to a preset table or the like.

  In S10, the required driving force (Wt) of the vehicle is calculated based on the vehicle speed (VSP), the accelerator opening (APS), etc. read in S1.

  In S11, an engine driving force We1 at the time of exhaust bypass is calculated. The engine driving force We1 calculated here is obtained through the automatic transmission 2 when a bypass exhaust flow rate obtained by multiplying the total exhaust flow rate by the target bypass flow rate tRb1 flows around the turbine 13b in the current operating state. Driving force transmitted to the wheel drive shaft. For example, the driving force when all the exhaust passes through the turbine 13b is used as the reference engine driving force, and the engine driving force We is calculated in consideration of a decrease caused by bypassing the exhaust. A map having parameters such as the engine speed Ne and the bypass flow rate tRb as parameters is set in advance, and is set based on the engine speed (Ne) read in S1 and the target bypass flow rate tRb1 set in S8. You may make it calculate with reference to a map.

  In S12, based on the battery state of charge (SOC) read in S1, a driving force (maximum assist driving force) Wmp that can be assisted by the motor generator 3 is calculated with reference to a preset table (FIG. 6). .

  In S13, the engine driving force We1 and the maximum assist driving force Wmp are added and compared with the required driving force Wt of the vehicle calculated in S10. If Wt ≦ (We1 + Wmp), the process proceeds to S14, and if Wt> (We1 + Wmp), the process proceeds to S16.

  In S14, a value obtained by subtracting the engine driving force We1 from the required driving force Wt is set as a target assist driving force tWm1 (= Wt−We1).

  In S15, the target opening degree tVdeg1 of the flow rate adjusting valve 37 is output to the ECM4, and the target assist driving force tWm1 calculated in S14 is output to the MC5. Thereby, the ECM 4 controls the flow rate adjustment valve 37 so that the opening degree of the flow rate adjustment valve 37 becomes the target opening degree tVdeg1, and the MC 5 makes the driving force of the motor generator 3 become the target assist driving force tWm1. The motor generator 3, the inverter 7 and the battery 8 are controlled.

  On the other hand, in S16, even if the motor generator 3 assists, the required driving force tW cannot be secured, so the target bypass flow rate tRb1 (that is, the bypass exhaust flow rate) is corrected to decrease (the corrected target bypass flow rate is set to tRb2). ). Such correction is basically performed according to a deficiency (Wt− (We1 + Wmp)) with respect to the required driving force Wt, and the bypass flow rate tRb1 is decreased as the deficiency increases. When the bypass flow rate decreases, the proportion of the exhaust gas that passes through the turbine 13b increases, so that supercharging is performed correspondingly and the engine driving force increases. Thus, the required driving force is realized by the engine driving force at the time of exhaust bypass and the assist driving force of the motor generator 3.

  In S17, based on the corrected target bypass flow rate tRb2, the target opening (flow adjustment valve opening) tVdeg2 of the flow adjustment valve 37 is (re) set.

  In S18, based on the corrected target bypass flow rate tRb2, the engine driving force We2 (> We1) during exhaust bypass is calculated again.

  In S19, a value obtained by subtracting the engine driving force We2 calculated in S18 from the required driving force Wt is set as a target assist driving force tWm2 (= Wt−We2).

  In S20, the target opening tVdeg2 set in S17 is output to ECM4, and the target assist driving force tWm2 set in S18 is output to MC5. Thereby, the ECM 4 controls the flow rate adjustment valve 37 so that the opening degree of the flow rate adjustment valve 37 becomes the target opening degree tVdeg2, and the MC 5 makes the driving force of the motor generator 3 become the target assist driving force tWm2. The motor generator 3, the inverter 7 and the battery 8 are controlled.

  In the present embodiment, the motor generator 3 is the “assist motor” of the present invention, the processing of S3 to S8 of FIG. 2 is the “target bypass exhaust flow rate calculating means” of the present invention, and the processing of S11 of FIG. In the “engine driving force calculation means”, the processing of S9 and S15 in FIG. 2 is the “flow rate adjusting valve control means” of the present invention, and the processing of S14 in FIG. 2 is the “target assist driving force calculation means” of the present invention. The process of S15 in FIG. 2 corresponds to the “motor control means” of the present invention. 2 corresponds to the “upper limit assist driving force calculating means” of the present invention, and the processes of S13 and S16 of FIG. 2 correspond to “bypass exhaust flow rate correcting means” of the present invention.

  According to the present embodiment, a target bypass flow rate (target bypass exhaust flow rate) is calculated based on the operating state of the engine 1, and an exhaust gas (target bypass exhaust flow rate) having a flow rate according to the calculated target bypass flow rate is obtained. While controlling to bypass the turbine, the engine driving force when the bypass exhaust gas flow rate is bypassed is calculated, and the target assist driving force of the motor generator 3 is calculated based on the required driving force of the vehicle and the engine driving force. Then, the motor generator 3 is controlled based on the calculated target driving force. As a result, it is possible to compensate for the decrease in acceleration performance due to this by the driving force of the motor generator 3 while controlling the exhaust amount of exhaust as necessary to bypass the turbine 13 b of the supercharger 13.

  Here, the maximum value selection of the first to third bypass flow rates is performed to set the target bypass flow rate (that is, the bypass exhaust flow rate), so the bypass exhaust flow rate required according to the operation state at that time is set. Can be secured. That is, when it is desired to increase the exhaust temperature, when the amount of unburned HC is large, and when the catalyst temperature is low and the catalyst is not activated, the exhaust flow rate through which the supercharger 13 (turbine) 13b passes is increased. Further, the temperature of the exhaust (and catalyst) can be quickly raised, and deposits can be prevented from adhering to the turbine 13b.

  When the battery charge state (SOC) is low and the required driving force of the vehicle cannot be realized by the engine driving force during exhaust bypass and the assist driving force of the motor generator 3, the target bypass flow rate is decreased and corrected (engine driving force). Therefore, it is possible to suppress the decrease in the acceleration performance while ensuring the bypass exhaust flow rate as much as possible and suppressing the temperature rise of the exhaust and the catalyst and the adhesion of deposits to the turbine 13b.

  Next, another embodiment of the present invention will be described.

  FIG. 7 is a flowchart showing the exhaust bypass control according to the second embodiment of the present invention. In FIG. 7, S31 to S38 are the same as S1 to S8 in FIG.

  In S39, the required driving force (Wt) of the vehicle is calculated based on the vehicle speed (VSP) and the accelerator opening (APS) read in S31, as in S10 of FIG.

  In S40, it is determined whether or not the battery charge state (SOC) is equal to or greater than a first predetermined value (SOC1) set in advance. If SOC ≧ SOC1, the process proceeds to S41, and if SOC <SOC1, the process proceeds to S46. The first predetermined value (SOC1) is, for example, a state where the battery charge amount (remaining amount) is 20%.

  In S41, it is determined whether or not the battery charge state (SOC) is equal to or less than a second predetermined value (SOC2> SOC1) set in advance. If SOC ≦ SOC2, the process proceeds to S42, and if SOC> SOC2, the process proceeds to S51. The second predetermined value (SOC2) is, for example, a state where the battery charge amount (remaining amount) is 80%.

  In S42, similarly to S9 of FIG. 2, the target opening (flow adjustment valve opening) tVdeg1 of the flow adjustment valve 37 is set based on the target bypass flow rate tRb1 with reference to a preset table or the like.

  In S43, as in S11 of FIG. 2, the engine driving force We1 during exhaust bypass is calculated based on the target bypass flow rate tRb1 (target bypass exhaust flow).

  In S44, a value obtained by subtracting the engine driving force We1 from the required driving force Wt is set as a target assist driving force tWm1 (= Wt−We1).

  In S45, the target opening tVdeg1 set in S43 is output to ECM4, and the target assist driving force tWm1 set in S44 is output to MC5.

  On the other hand, in S46, the battery charge state (SOC) is in a low state and the assist driving force by the motor generator 3 may not be sufficiently obtained, so the target bypass flow rate tRb1 is corrected to decrease (target bypass flow rate tRb1). → tRb2 (<tRb1)). In this case, the target bypass flow rate tRb1 may be decreased by a predetermined ratio, or the target bypass flow rate is determined according to the difference between the predetermined reference battery charge state (SOCst) and the current battery charge state SOC. The rate tRb1 may be decreased (decrease as the difference increases). Here, the reference battery charge state (SOCst) may be set in accordance with the vehicle as a battery charge state capable of securing a certain amount of assist driving force, and is basically a value larger than the first predetermined value (SOC1). (For example, the battery charge amount (remaining amount) is 50%). However, it may be the first predetermined value (SOC1). When the battery charge state (SOC) is a predetermined lower limit (SOClow: for example, the battery charge amount (remaining amount) is 5 to 10%) or less, the target bypass flow rate tRb1 is set to 0 (that is, exhaust is bypassed). May not be).

  In S47, the target opening tVdeg2 of the flow control valve 37 is set based on the corrected target bypass flow rate tRb2 (the target bypass exhaust flow after the decrease correction).

  In S48, the engine driving force We2 (> We1) during exhaust bypass is calculated based on the corrected target bypass flow rate tRb2.

  In S49, a value obtained by subtracting the engine driving force We2 calculated in S47 from the required driving force Wt is set as a target assist driving force tWm2 (= Wt−We2).

  In S50, the target opening tVdeg2 set in S47 is output to ECM4, and the target assist driving force tWm2 set in S49 is output to MC5.

  In S51, since the battery charge state (SOC) is sufficiently high and the assist driving force by the motor generator 3 is sufficiently obtained, the target bypass flow rate tRb1 is increased and corrected (target bypass flow rate tRb1 → tRb3). (> TRb1)). In this case, the target bypass flow rate tRb1 may be increased by a predetermined ratio set in advance, or the target bypass flow rate is determined according to the difference between the reference battery charge state (SOCst) and the current battery charge state SOC. You may make it increase tRb1 (it increases, so that a difference is large).

  In S52, the target opening degree tVdeg3 of the flow control valve 37 is set based on the corrected target bypass flow rate tRb3.

  In S53, the engine driving force We3 (<We1) at the time of exhaust bypass is calculated based on the corrected target bypass flow rate tRb3 (target bypass exhaust flow after increase correction).

  In S54, a value obtained by subtracting the engine driving force We3 calculated in S53 from the required driving force Wt is set as a target assist driving force tWm3 (= Wt−We3).

In S55, the target opening tVdeg3 set in S52 is output to ECM4, and the target assist driving force tWm3 set in S54 is output to MC5.

  In the present embodiment, the processes of S40, S41, S46, and S51 in FIG. 7 correspond to the “bypass exhaust flow rate correcting means” of the present invention.

  According to this embodiment, when the battery state of charge (SOC) is lower than the first predetermined value (SOC1), there is a possibility that sufficient assistance from the motor generator 3 may not be obtained, so the target bypass flow rate tRb1 Correct the decrease. Thereby, the fall of the acceleration performance by bypassing exhaust can be suppressed, ensuring a bypass exhaust flow volume as much as possible. Here, when the battery state of charge (SOC) is equal to or lower than a predetermined lower limit (SOClow), it is possible to prevent a significant decrease in acceleration performance by prohibiting exhaust gas from being bypassed.

  When the battery charge state is higher than the second predetermined value (SOC2), the motor generator 3 can exhibit a sufficient driving force, so the target bypass flow rate tRb1 is increased and corrected. As a result, the exhaust gas flow rate can be increased more quickly by increasing the bypass exhaust gas flow rate, and the malfunction of the supercharger 13 caused by deposits or the like on the turbine 13b can be more effectively prevented ( At the same time, the load on the engine 1 is reduced).

  In the above-described embodiments (first and second embodiments), each sensor detection value is used, but an estimated value or a calculated value may be used as described above. For example, in the above embodiment, the exhaust temperature Te and the catalyst temperature Tc are detected, respectively, but only the exhaust temperature Te may be detected, and the catalyst temperature Tc may be estimated based on the detected exhaust temperature Te. .

  Further, although the unburned HC amount CHc is detected, the unburned HC amount is calculated with reference to a preset table (FIG. 8) based on the engine coolant temperature (Tw) or the oil temperature. You may do it. As shown in FIG. 8, the unburned HC amount increases as the cooling water temperature (oil temperature) decreases. Alternatively, the unburned HC amount may be calculated with reference to a preset table (FIG. 10) based on the EGR rate (the unburned HC amount increases as the EGR rate increases). In this case, the EGR rate may be calculated from the opening degree of the EGR valve 35 and the supercharging pressure Pb, or a target EGR rate set based on the engine operating state or the like may be used.

1 is a diagram illustrating a schematic configuration of a hybrid vehicle according to an embodiment of the present invention. It is a flowchart which shows the exhaust gas bypass control which concerns on 1st Embodiment. It is a figure which shows an example of the relationship between target temperature rising temperature and a bypass flow rate. It is a figure which shows an example of the relationship between unburned HC amount and a bypass flow rate. It is a figure which shows an example of the relationship between catalyst temperature and a bypass flow rate. It is a figure which shows an example of the relationship between a battery charge state and the maximum assist drive force. It is a flowchart which shows the exhaust gas bypass control which concerns on 2nd Embodiment. It is a figure which shows an example of the relationship between engine coolant temperature (oil temperature) and unburned HC amount. It is a figure which shows an example of the relationship between an EGR rate and unburned HC amount.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Automatic transmission, 3 ... Motor generator, 4 ... Engine controller (ECM), 5 ... Motor controller (MC), 6 ... Hybrid controller, 13b ... Turbine of supercharger, 32 ... Exhaust passage, 34 ... EGR passage, 35 ... EGR valve, 36 ... bypass passage, 37 ... flow rate adjustment valve, 33 ... exhaust gas purification device (catalyst device), 41 ... rotational speed sensor, 42 ... vehicle speed sensor, 43 ... accelerator opening sensor, 44 ... Supercharging pressure sensor 45 ... Battery sensor 46 ... Water temperature sensor 47 ... HC sensor 48 ... Catalyst temperature sensor 49 ... Exhaust temperature sensor

Claims (10)

A turbocharger turbine is disposed in the exhaust passage, and a bypass passage that branches from the upstream side of the turbine and connects to the downstream side of the turbine, a bypass exhaust flow rate that passes through the bypass passage, and the turbine passes therethrough. A turbocharged engine having a flow regulating valve for regulating a turbine exhaust flow rate;
A control device for a hybrid vehicle, comprising: an assist motor that operates by electric power supplied from a battery and assists the driving force of the engine;
Target bypass exhaust flow rate calculating means for calculating a target bypass exhaust flow rate based on the operating state of the engine;
Flow rate adjusting valve control means for controlling the flow rate adjusting valve based on the calculated target bypass exhaust flow rate;
Engine driving force calculating means for calculating engine driving force when the target bypass exhaust flow rate passes through the bypass passage;
Target assist driving force calculating means for calculating a target assist driving force by the assist motor based on a required driving force of the vehicle and the engine driving force;
Motor control means for controlling the assist motor based on the target assist driving force;
A control apparatus for a hybrid vehicle, comprising: Battery charge state detection means for detecting the charge state of the battery;
Bypass exhaust flow rate correction means for correcting the target bypass exhaust flow rate according to the detected state of charge of the battery;
The hybrid vehicle control device according to claim 1, comprising: An upper limit assist driving force calculating means for calculating an upper limit assist driving force by the assist motor based on the detected state of charge of the battery;
The bypass exhaust flow rate correcting means corrects a decrease in the target bypass exhaust flow rate when a required driving force of the vehicle is larger than a sum of the engine driving force and the upper limit assist driving force. Item 3. A control device for a hybrid vehicle according to Item 2.   The bypass exhaust flow rate correction means corrects to decrease the target bypass exhaust flow rate when the detected state of charge of the battery is lower than a first predetermined value, and the detected state of charge (SOC) of the battery is second. The control apparatus for a hybrid vehicle according to claim 2, wherein the target bypass exhaust flow rate is corrected to be increased when it is higher than a predetermined value (> the first predetermined value). An exhaust purification catalyst is disposed downstream of the turbine in the exhaust passage, and the bypass passage is branched from the upstream side of the turbine and connected to the upstream side of the exhaust purification catalyst,
Comprising catalyst temperature detection means for detecting the temperature of the exhaust purification catalyst;
5. The hybrid vehicle according to claim 1, wherein the target bypass exhaust flow rate calculation unit calculates the target bypass exhaust flow rate based on the detected temperature of the exhaust purification catalyst. Control device. HC amount detection means for detecting the amount of unburned HC discharged from the engine,
The control of the hybrid vehicle according to any one of claims 1 to 4, wherein the target bypass exhaust flow rate calculation means calculates the target bypass exhaust flow rate based on the detected unburned HC amount. apparatus. Exhaust temperature detecting means for detecting the temperature of the exhaust;
An exhaust temperature raising means for raising the temperature of the exhaust gas to a predetermined temperature under a predetermined condition; and
5. The target bypass exhaust flow rate calculation unit calculates the target bypass exhaust flow rate based on a difference between the predetermined temperature and the detected temperature of the exhaust gas. The hybrid vehicle control apparatus described. An exhaust purification catalyst is disposed downstream of the turbine in the exhaust passage, and the bypass passage is branched from the upstream side of the turbine and connected to the upstream side of the exhaust purification catalyst,
Catalyst temperature detecting means for detecting the temperature of the exhaust purification catalyst;
HC amount detection means for detecting the amount of unburned HC discharged from the engine;
Exhaust temperature detecting means for detecting the temperature of the exhaust;
An exhaust temperature raising means for raising the temperature of the exhaust to a predetermined temperature under a predetermined condition,
The target bypass exhaust flow rate calculation means includes a first bypass exhaust flow rate calculated based on the detected temperature of the exhaust purification catalyst, a second bypass exhaust flow rate calculated based on the detected unburned HC amount, and 5. The target bypass exhaust flow rate is calculated by selecting a maximum value of a third bypass exhaust flow rate calculated based on a difference between the predetermined temperature and the detected exhaust gas temperature. The control apparatus of the hybrid vehicle as described in any one of Temperature detecting means for detecting the coolant temperature or oil temperature of the engine,
9. The control apparatus for a hybrid vehicle according to claim 6, wherein the HC amount detection means calculates the unburned HC amount based on the cooling water temperature or oil temperature. The engine has an EGR device that recirculates part of the exhaust gas to the intake system,
The hybrid vehicle control device according to claim 6 or 8, wherein the HC amount detection means calculates the unburned HC amount based on an EGR rate.

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