JP2007278207A - Control device of internal combustion engine and hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase fuel economy performance while avoiding knocking of an internal combustion engine, in a control device of the internal combustion engine and a hybrid vehicle. <P>SOLUTION: In the hybrid vehicle capable of assisting a drive force by a motor, a maximum cylinder pressure crank angle PmaxCA which is the crank angle at which the cylinder pressure of the internal combustion engine is maximum is detected (step 100). A deviation ΔPmaxCA between the maximum cylinder pressure crank angle PmaxCA and a predetermined best heat efficiency, maximum cylinder pressure crank angle PmaxMBTCA at which the heat efficiency is best is obtained (step 102). The larger the deviation ΔPmaxCA is, the larger a drive force assist amount by the motor is increased by increasing the supply amount of electric energy from a battery to the motor (step 112). The ratio of the hydrogen added is so corrected that the maximum cylinder pressure crank angle PmaxCA near the judgement heat efficiency, maximum cylinder pressure crank angle PmaxMBTCA (steps 104 to 110). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine and a hybrid vehicle.

  In a spark ignition internal combustion engine such as a gasoline engine, when other operating conditions are constant, there is an ignition timing at which the generated torque is maximum, that is, the thermal efficiency is the best. Such ignition timing is called MBT (Minimum advance for the Best Torque). MBT varies depending on the engine speed and load, and also varies depending on the air-fuel ratio, intake air temperature, and the like.

  On the other hand, when the ignition timing is MBT, it is known that the crank angle at which the in-cylinder pressure (combustion pressure) is maximum is substantially constant regardless of other operating conditions. Japanese Utility Model Publication No. 6-3192 discloses an ignition timing control device for an internal combustion engine that uses this to control the ignition timing to MBT. That is, in this device, the cylinder pressure maximum crank angle (in-cylinder pressure maximum timing) is detected based on a signal from the cylinder pressure sensor, and a deviation between the detected value and a target value corresponding to MBT is fed back to determine the ignition timing. Is corrected so that the maximum in-cylinder pressure crank angle coincides with the target value, so that the ignition timing coincides with MBT.

No. 6-3192 JP 2004-239138 A

  Generally, in a spark ignition internal combustion engine, knocking is more likely to occur as the ignition timing is advanced. According to the above-described conventional apparatus, the ignition timing can be controlled to MBT in an operating range where knocking does not occur. However, in practice, in the high load range, the ignition timing cannot be advanced to MBT in many cases due to the occurrence of knocking. For this reason, in a high load region, it is often necessary to operate at an ignition timing later than MBT. As a result, thermal efficiency is lowered, and improvement in fuel consumption is prevented.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for an internal combustion engine and a hybrid vehicle that can improve fuel efficiency while avoiding knocking of the internal combustion engine. And

In order to achieve the above object, a first invention is a control device for an internal combustion engine,
Main fuel supply means for supplying main fuel to the spark ignition internal combustion engine;
Auxiliary fuel supply means for supplying auxiliary fuel having a combustion promoting action to the internal combustion engine;
In-cylinder pressure maximum crank angle detection means for detecting an in-cylinder pressure maximum crank angle that is a crank angle at which the in-cylinder pressure of the internal combustion engine is maximized;
When the detected value of the maximum in-cylinder pressure crank angle is delayed as compared with the target value of the maximum in-cylinder pressure crank angle determined so that the thermal efficiency is the best, the addition ratio of the auxiliary fuel is increased. An auxiliary fuel addition amount calculating means for calculating the additional amount of the auxiliary fuel;
It is characterized by providing.

The second invention is the first invention, wherein
The auxiliary fuel is hydrogen or alcohol.

The third invention is the first or second invention, wherein
When the detected value of the in-cylinder pressure maximum crank angle is advanced as compared with the target value, the auxiliary fuel addition amount calculating means is configured to increase the auxiliary fuel addition amount so that the auxiliary fuel addition ratio becomes smaller. Is calculated.

The fourth invention is a hybrid vehicle comprising a spark ignition type internal combustion engine and another power source, and capable of assisting the driving force by the other power source,
Main fuel supply means for supplying main fuel to the internal combustion engine;
Auxiliary fuel supply means for supplying auxiliary fuel having a combustion promoting action to the internal combustion engine;
Energy storage means for storing energy for supply to the other power source;
In-cylinder pressure maximum crank angle detection means for detecting an in-cylinder pressure maximum crank angle that is a crank angle at which the in-cylinder pressure of the internal combustion engine is maximized;
The larger the deviation between the detected value of the in-cylinder pressure maximum crank angle and the target value of the in-cylinder pressure maximum crank angle determined so that the thermal efficiency is optimal, the larger the energy supply from the energy storage means to the other power source An assist amount increasing means for increasing a driving force assist amount by the other power source by increasing the amount;
Auxiliary fuel addition ratio correction for correcting the addition ratio of the auxiliary fuel so that the actual maximum in-cylinder pressure crank angle approaches the target value based on the deviation between the detected value of the maximum in-cylinder pressure crank angle and the target value Means,
It is characterized by providing.

  According to the first aspect of the present invention, when the detected value of the maximum cylinder pressure crank angle is delayed as compared with the target value determined so that the thermal efficiency is optimal, the addition of auxiliary fuel having a combustion promoting action is added. The ratio can be increased. When the auxiliary fuel addition ratio increases, the combustion acceleration effect is amplified, so that the position of the maximum in-cylinder pressure crank angle is advanced, and the target value can be brought close to the optimum thermal efficiency. In other words, according to the first aspect, it is possible to shift to the best thermal efficiency state (MBT state) without advancing the ignition timing. Therefore, even in a high load range, knocking does not become an obstacle, and driving in the best thermal efficiency state is possible, so that fuel efficiency can be improved.

  According to the second invention, by using hydrogen or alcohol as the auxiliary fuel, the above effects can be obtained easily and reliably.

  According to the third invention, when the detected value of the maximum cylinder pressure crank angle is advanced as compared with the target value determined so that the thermal efficiency becomes the best, the auxiliary fuel addition ratio is reduced. Thus, the position of the in-cylinder pressure maximum crank angle can be delayed. Therefore, even when the in-cylinder pressure maximum crank angle is advanced from the target value, the optimum thermal efficiency can be shifted by bringing the in-cylinder pressure maximum crank angle closer to the target value.

  According to the fourth aspect of the invention, the larger the deviation between the detected value of the in-cylinder pressure maximum crank angle and the target value determined so that the thermal efficiency is optimum, the more the driving force assist amount by the other power source is increased. Can do. For this reason, even when the engine output is insufficient due to a decrease in the thermal efficiency of the internal combustion engine, the shortage can be compensated for by another power source, so that a decrease in running performance can be avoided. According to the fourth aspect of the invention, the auxiliary fuel addition ratio can be corrected so that the in-cylinder pressure maximum crank angle approaches the target value determined so that the thermal efficiency is the best. That is, it is possible to shift to the best thermal efficiency state without changing the ignition timing. For this reason, even in the high load region of the internal combustion engine, the best thermal efficiency can be obtained without knocking being an obstacle. In a hybrid vehicle, since the internal combustion engine is usually operated only in a high load region, the fuel efficiency of the hybrid vehicle can be further improved by improving the thermal efficiency in the high load region.

Embodiment 1 FIG.
[Description of system configuration]
FIG. 1 is a diagram for explaining the system of the present embodiment. As shown in FIG. 1, the system of the present embodiment includes a four-cycle spark ignition type internal combustion engine 2. FIG. 1 shows only one of a plurality of cylinders included in the internal combustion engine 2. Each cylinder of the internal combustion engine 2 is provided with a piston 31, an intake valve 32, an exhaust valve 33, and a spark plug 34.

The internal combustion engine 2 of the present embodiment can be operated using gasoline as a main fuel and hydrogen (H ₂ ) as an auxiliary fuel. A gasoline injector 10 and a hydrogen injector 11 are respectively arranged in the intake port 35 of each cylinder of the internal combustion engine 2, and gasoline and hydrogen gas can be injected into the intake port 35. The gasoline injector 10 may be installed so that gasoline can be directly injected into the cylinder, unlike the configuration shown in the figure. The hydrogen injector 11 may also be installed so that hydrogen gas can be directly injected into the cylinder.

  The system of the present embodiment includes a gasoline tank 12 that stores gasoline and a hydrogen tank 13 that stores compressed hydrogen gas. The gasoline in the gasoline tank 12 is pressurized by the fuel pump 36, regulated by the regulator valve 37, and then supplied to the gasoline injector 10. The compressed hydrogen gas in the hydrogen tank 13 is regulated by a regulator valve 38 and then supplied to the hydrogen injector 11.

  In the present embodiment, the case where gasoline is used as the main fuel of the internal combustion engine 2 will be described. However, the main fuel of the internal combustion engine 2 in the present invention is not limited to gasoline, for example, LP gas, natural gas Organic hydride or the like may be used.

  In the present embodiment, the hydrogen gas to be supplied to the injector 11 is stored in the hydrogen tank 13 as a gas, but the hydrogen storage method is not limited to this. For example, it may be stored in a tank as liquid hydrogen or stored in a state of being stored in a hydrogen storage alloy. Alternatively, hydrogen may be generated in the system by dehydrogenating an organic hydride fuel such as cyclohexane or decalin using a catalyst or by electrolyzing water.

  Further, the internal combustion engine 2 includes an intake variable valve mechanism 39 that varies the valve opening characteristics (opening / closing timing, operating angle, etc.) of the intake valve 32, and an exhaust variable valve valve that varies the valve opening characteristics of the exhaust valve 33. A mechanism 40 is provided.

  Further, the internal combustion engine 2 is provided with a turbocharger 41. An exhaust passage 14 of the internal combustion engine 2 is connected to the exhaust turbine of the turbocharger 41, and the turbocharger 14 is operated by the energy of the exhaust gas.

  An intake passage 42 of the internal combustion engine 2 is connected to the intake compressor of the turbocharger 41. The intake air that has been compressed by the intake compressor of the turbocharger 41 and has risen in temperature is cooled by the intercooler 43 and then distributed to the intake port 35 of each cylinder by an intake manifold (not shown).

  A throttle valve 44 for adjusting the intake air amount is installed in the intake passage 42 downstream of the intercooler 43. The throttle valve 44 is an electronically controlled throttle that is driven by a throttle motor (not shown). An air flow meter 45 that detects the intake air amount is installed in the intake passage 42 upstream of the turbocharger 41. In the present invention, the internal combustion engine 2 may be a naturally aspirated engine that does not include a supercharger.

  The internal combustion engine 2 is provided with an in-cylinder pressure sensor 46. The in-cylinder pressure sensor 46 can detect the pressure (combustion pressure) generated in the cylinder.

  The system of this embodiment further includes an ECU (Electronic Control Unit) 30. In addition to the various actuators and sensors described above, the ECU 30 is connected to an accelerator opening sensor 23 that detects the amount of depression of the accelerator pedal and a crank angle sensor 47 that detects the crank angle. According to the crank angle sensor 47, the rotational position and rotational speed (engine speed NE) of the crankshaft of the internal combustion engine 2 can be detected. The ECU 30 controls the operation state of the internal combustion engine 2 by controlling the operation of each actuator based on the detection signal from each sensor.

[Features of Embodiment 1]
The internal combustion engine 2 of the present embodiment is operated by using gasoline supplied from the gasoline injector 10 as a main fuel and supplying hydrogen as auxiliary fuel from the hydrogen injector 11 as necessary.

  The internal combustion engine 2 can be switched to a mode operating at λ> 1 (lean air-fuel ratio) in addition to a mode operating at an excess air ratio λ = 1 (theoretical air-fuel ratio) or λ <1 (rich air-fuel ratio). It may be. When the internal combustion engine 2 is operated at a lean air-fuel ratio, combustion can be promoted / improved by adding hydrogen having a high combustion speed. For this reason, since it can be stably burned even at a lean air-fuel ratio, it can be operated even at a leaner air-fuel ratio than when it is burned only with gasoline.

  Here, MBT (Minimum advance for the Best Torque) will be described. FIG. 2 is a diagram showing an example of a cylinder pressure waveform generated during one cycle of the internal combustion engine 2. The solid line in FIG. 2 is the in-cylinder pressure during combustion, and the broken line is the in-cylinder pressure during motoring. As shown in FIG. 2, at the time of combustion, the crank angle at which the in-cylinder pressure P is maximum is usually after the top dead center (TDC). Hereinafter, the crank angle at which the in-cylinder pressure P is maximum is referred to as “in-cylinder pressure maximum crank angle” and is represented by the symbol PmaxCA.

  FIG. 3 is a diagram showing the relationship between the in-cylinder pressure maximum crank angle PmaxCA and the ignition timing SA. As shown in the figure, as the ignition timing SA is advanced, the in-cylinder pressure maximum crank angle PmaxCA is also advanced and approaches the top dead center. Conversely, as the ignition timing SA is delayed, the in-cylinder pressure maximum crank angle PmaxCA is also delayed, and is away from the top dead center.

  In the theoretical constant volume cycle, it is most efficient to instantaneously reach the maximum pressure from the compression pressure at the top dead center (that is, at a combustion period of zero), but an actual internal combustion engine 2 having a combustion period of a certain length. If the ignition timing SA is set too early, the in-cylinder pressure maximum crank angle PmaxCA becomes too close to the top dead center, and the period during which the combustion pressure acts before the top dead center becomes longer, resulting in an increase in compression work and output. (Torque) decreases. On the other hand, if the ignition timing SA is too late, the in-cylinder pressure maximum crank angle PmaxCA is too far from the top dead center, the substantial expansion ratio becomes small, and the output decreases. For this reason, the internal combustion engine 2 generally has an ignition timing SA with the highest output, that is, an ignition timing SA with the best thermal efficiency. This is MBT.

  The MBT varies depending on the engine speed NE and the load (intake air amount), and also varies depending on the excess air ratio λ (air / fuel ratio) and the intake air temperature. On the other hand, as described above, whether or not the thermal efficiency is optimal is determined by the position of the cylinder pressure maximum crank angle PmaxCA. Therefore, the cylinder pressure maximum crank angle PmaxCA at the time of MBT, that is, the best thermal efficiency, depends on other operating conditions. It takes almost a constant value. This constant value, that is, the maximum in-cylinder pressure crank angle PmaxCA when the thermal efficiency is the best, is hereinafter referred to as “the best thermal efficiency in-cylinder pressure maximum crank angle” and is represented by the symbol PmaxMBTCA.

  In the internal combustion engine 2 of the present embodiment, the best thermal efficiency cylinder pressure maximum crank angle PmaxMBTCA is assumed to be 15 ° ATDC regardless of other operating conditions. That is, in the internal combustion engine 2, it is assumed that the thermal efficiency is the best when the in-cylinder pressure maximum crank angle PmaxCA is 15 ° ATDC.

  In the conventional internal combustion engine, in order to move the position of the in-cylinder pressure maximum crank angle PmaxCA, the ignition timing SA has to be changed. For this reason, in order to achieve the best thermal efficiency, it is necessary to change the ignition timing SA to move the position of the maximum in-cylinder pressure crank angle PmaxCA to match the maximum in-cylinder pressure maximum crank angle PmaxMBTCA. However, since knocking is likely to occur in a high load region, there are many cases where the ignition timing SA cannot be advanced to a point where the maximum in-cylinder pressure crank angle PmaxCA matches the maximum in-cylinder pressure maximum crank angle PmaxMBTCA. For this reason, in a high load region, it was often necessary to operate with a thermal efficiency lower than the best thermal efficiency.

  On the other hand, in the internal combustion engine 2 of this embodiment using hydrogen as an auxiliary fuel, the position of the in-cylinder pressure maximum crank angle PmaxCA can be moved by changing the hydrogen addition ratio (addition amount). FIG. 4 is a diagram showing the relationship among the in-cylinder pressure maximum crank angle PmaxCA, the ignition timing SA, and the hydrogen addition ratio. In addition, the value of the hydrogen addition ratio in FIG. 4 is a value when converted into heat quantity.

  Since hydrogen has a higher combustion speed than gasoline, it has an action of promoting combustion. Therefore, in the internal combustion engine 2, the cylinder pressure maximum crank angle PmaxCA can be advanced (advanced) by increasing the hydrogen addition ratio without changing the ignition timing SA. For this reason, as shown in FIG. 4, the graph of the in-cylinder pressure maximum crank angle PmaxCA as shown in FIG. 3 can be shifted to the advance side as the hydrogen addition ratio is increased.

  In the internal combustion engine 2, by utilizing the above, it is possible to obtain a state with the best thermal efficiency without changing the ignition timing SA. For example, it is assumed that the current ignition timing SA is set at a position indicated by an arrow in FIG. 4 and the in-cylinder pressure maximum crank angle PmaxCA is a value indicated by a point A. At point A, the maximum in-cylinder pressure crank angle PmaxCA is delayed from 15 ° ATDC which is the maximum in-cylinder pressure maximum crank angle PmaxMBTCA, and therefore the thermal efficiency is not the best. In this case, when the hydrogen addition ratio is increased by 5 points (15% → 20%), the position of the maximum cylinder pressure crank angle PmaxCA is advanced (advanced) to match the maximum crank angle PmaxMBTCA with the best thermal efficiency. be able to. In this manner, the internal combustion engine 2 can be shifted to the best thermal efficiency state by increasing the hydrogen addition ratio without advancing the ignition timing SA.

  Therefore, in the present embodiment, the current maximum in-cylinder pressure crank angle PmaxCA is detected based on the signal from the in-cylinder pressure sensor 46, and according to the deviation ΔPmaxCA between the detected value and the predetermined maximum thermal efficiency best in-cylinder pressure maximum crank angle PmaxMBTCA. By correcting the hydrogen addition ratio, control was performed so that the maximum cylinder pressure PmaxCA in the cylinder pressure coincides with the maximum crank angle PmaxMBTCA in the best cylinder efficiency.

  Specifically, the correction value KPmax of the hydrogen addition ratio necessary to make the in-cylinder pressure maximum crank angle PmaxCA coincide with the thermal efficiency best in-cylinder pressure maximum crank angle PmaxMBTCA is calculated. The correction value KPmax is a value added to the reference hydrogen addition rate HR1, as will be described later. FIG. 5 is a map for calculating the correction value KPmax in accordance with the deviation ΔPmaxCA between the maximum in-cylinder pressure crank angle PmaxCA and the thermal efficiency best in-cylinder pressure maximum crank angle PmaxMBTCA. In the present embodiment, the map shown in FIG. 5 is stored in the ECU 30 in advance, and the correction value KPmax is calculated with reference to this map.

  The map shown in FIG. 5 can be created as follows. First, the relationship among the in-cylinder pressure maximum crank angle PmaxCA, the ignition timing SA, and the hydrogen addition ratio in the internal combustion engine 2, that is, the relationship as shown in FIG. According to this investigation result, it is possible to grasp how much the in-cylinder pressure maximum crank angle PmaxCA moves when the hydrogen addition ratio is changed. Based on this understanding, if the relationship between the deviation ΔPmaxCA and the correction value KPmax of the hydrogen addition ratio necessary to move the in-cylinder pressure maximum crank angle PmaxCA by the deviation ΔPmaxCA is mapped, the map shown in FIG. 5 is obtained. Can do.

[Specific Processing in Embodiment 1]
FIG. 6 is a flowchart of a routine executed by the ECU 30 in the present embodiment in order to realize the above function. Note that this routine is repeatedly executed every operating cycle of the internal combustion engine 2 or every predetermined time. According to the routine shown in FIG. 6, first, the current maximum cylinder pressure crank angle PmaxCA is detected (step 100). Specifically, by sampling the signal of the in-cylinder pressure sensor 46 at every predetermined crank angle (for example, every 1 ° CA), the in-cylinder pressure P for each crank angle is detected, and the in-cylinder pressure P is maximized in one cycle. The crank angle when the value Pmax is taken is acquired as the in-cylinder pressure maximum crank angle PmaxCA.

Next, a deviation ΔPmaxCA between the maximum in-cylinder pressure crank angle PmaxCA detected in step 100 and the predetermined maximum thermal efficiency maximum in-cylinder pressure crank angle PmaxMBTCA is calculated (step 102). In the present embodiment, since the maximum cylinder pressure PmaxMBTCA with the best thermal efficiency is 15 ° ATDC as described above, ΔPmaxCA is calculated based on the following equation.
ΔPmaxCA ＝ PmaxCA−PmaxMBTCA
= PmaxCA-15

  Subsequently, a process for obtaining a correction value KPmax of the hydrogen addition ratio corresponding to the deviation ΔPmaxCA obtained in step 102 is performed (step 104). Specifically, the correction value KPmax of the hydrogen addition ratio is calculated based on the map shown in FIG.

  Next, a process for obtaining a reference hydrogen addition rate HR1 [%] based on the operating conditions of the internal combustion engine 2 is performed (step 106). The ECU 30 stores in advance a map that defines the relationship between the operating conditions such as the engine speed NE, the load (intake air amount), the excess air ratio λ (air-fuel ratio), and the hydrogen addition ratio HR1 suitable for the operating conditions. Has been. Here, by referring to the map, the value of the standard hydrogenation rate HR1 corresponding to the current operating condition is acquired.

Next, a process for obtaining a corrected hydrogen addition ratio HR2 by correcting the reference hydrogen addition ratio HR1 obtained in step 106 with the correction value KPmax obtained in step 104 is performed (step 108). . Specifically, HR2 is calculated based on the following equation.
HR2 = HR1 + KPmax

  Then, based on the corrected hydrogen addition ratio HR2 calculated in step 108, a process for adding hydrogen is executed (step 110). In the present embodiment, it is assumed that the required supply heat amount to the internal combustion engine 2 is calculated based on the current operation state by the processing of another routine. In this step 110, the amount of hydrogen to be injected from the hydrogen injector 11 is calculated based on the required supply heat amount and the hydrogen addition ratio HR2, and the valve opening time of the hydrogen injector 11 is controlled based on the calculated value. By doing so, hydrogenation is performed.

  According to the routine shown in FIG. 6, the correction value KPmax of the hydrogen addition ratio is calculated according to the map shown in FIG. 5 based on the deviation ΔPmaxCA, so that the maximum in-cylinder pressure crank angle PmaxCA is the maximum in-cylinder pressure maximum crank angle PmaxMBTCA. The later the time is, the more the hydrogen addition rate is corrected to be larger than the present time. As a result, combustion is further promoted by the action of hydrogen, so that the position of the in-cylinder pressure maximum crank angle PmaxCA can be advanced (advanced). Therefore, the in-cylinder pressure maximum crank angle PmaxCA can be matched with the thermal efficiency best in-cylinder pressure maximum crank angle PmaxMBTCA.

  Thus, in this embodiment, the cylinder pressure maximum crank angle PmaxCA can be matched with the thermal efficiency best cylinder pressure maximum crank angle PmaxMBTCA by increasing the hydrogen addition ratio without advancing the ignition timing SA. . For this reason, even in the high load range, the internal combustion engine 2 can be shifted to the state where the thermal efficiency is the best, that is, the MBT state, without being inhibited by knocking. Therefore, the fuel efficiency performance of the internal combustion engine 2, particularly the fuel efficiency performance in a high load range (high torque range) can be improved.

  Further, since hydrogen has an action of promoting / improving combustion, knocking can be made more difficult to occur when the hydrogen addition ratio is increased. In the present embodiment, when the maximum in-cylinder pressure crank angle PmaxCA is delayed as compared with the maximum in-cylinder pressure maximum crank angle PmaxMBTCA, the hydrogen addition ratio is corrected to increase. For this reason, knocking is less likely to occur, so that the internal combustion engine 2 can be operated in the best thermal efficiency state (MBT state) while reliably preventing knocking even in a high load range.

  Further, according to the map shown in FIG. 5, when the value of the deviation ΔPmaxCA is negative, the hydrogen addition rate correction value KPmax is calculated as a negative value. That is, in the present embodiment, when the maximum in-cylinder pressure crank angle PmaxCA is advanced as compared with the maximum in-cylinder pressure maximum crank angle PmaxMBTCA, the hydrogen addition ratio is corrected to be smaller than the present. As a result, since the combustion promoting action by hydrogen is weakened, the position of the in-cylinder pressure maximum crank angle PmaxCA can be delayed. Therefore, the in-cylinder pressure maximum crank angle PmaxCA can be matched with the thermal efficiency best in-cylinder pressure maximum crank angle PmaxMBTCA.

  That is, in this embodiment, the maximum in-cylinder pressure crank angle PmaxCA is more advanced than the maximum in-cylinder pressure maximum crank angle PmaxMBTCA. The best in-cylinder pressure maximum crank angle PmaxMBTCA can be corrected so as to shift to the best thermal efficiency state.

  The present invention can obtain a particularly excellent fuel efficiency improvement effect when applied to a hybrid vehicle in which the high load range (high torque range) of the internal combustion engine 2 is frequently used. Needless to say.

  Further, in this embodiment, the value of the maximum thermal efficiency best in-cylinder pressure maximum crank angle PmaxMBTCA is assumed to be constant (15 ° ATDC) regardless of the operating conditions, but the value of the best thermal efficiency in-cylinder pressure maximum crank angle PmaxMBTCA depends on the operating conditions. If some change is recognized, the value of the maximum crank angle PmaxMBTCA with the best thermal efficiency in-cylinder pressure may be set according to the operating conditions.

  In the map shown in FIG. 5 used in the present embodiment, the hydrogen addition rate correction value KPmax is calculated as a proportional term to the deviation ΔPmaxCA. However, the method of calculating the correction value KPmax is not limited to this. For example, the correction value KPmax may be calculated using a differential term and an integral term together.

  In the first embodiment described above, the gasoline injector 10 and the gasoline tank 12 are the “main fuel supply means” in the first invention, and the hydrogen injector 11 and the hydrogen tank 13 are the “auxiliary fuel” in the first invention. In the “supply means”, the maximum cylinder pressure PmaxMBTCA with the best thermal efficiency corresponds to the “target value of the maximum cylinder pressure in the first aspect of the invention”. Further, when the ECU 30 executes the process of step 100, the “in-cylinder pressure maximum crank angle detecting means” in the first aspect of the invention executes the processes of steps 102 to 110, thereby executing the first and third steps. The “auxiliary fuel addition amount calculating means” in the present invention is realized.

Embodiment 2. FIG.
Next, the second embodiment of the present invention will be described with reference to FIG. 7 to FIG. 10. The description will focus on the differences from the first embodiment described above, and the same matters will be described. Omitted or simplified.

[Description of system configuration]
FIG. 7 is a diagram for explaining the hybrid vehicle according to the second embodiment of the present invention. A hybrid vehicle (hereinafter simply referred to as “vehicle”) 1 of the present embodiment shown in FIG. 7 includes an internal combustion engine system, a three-shaft power distribution and integration mechanism 3, a motor (electric motor) 4 shown in FIG. And a generator 5.

  The power distribution and integration mechanism 3 includes a planetary gear mechanism. The planetary carrier of the power distribution and integration mechanism 3 is connected to the crankshaft of the internal combustion engine 2. The ring gear of the power distribution and integration mechanism 3 is connected to the motor 4 and is also connected to the input side of the drive system 6. The sun gear of the power distribution and integration mechanism 3 is connected to the generator 5.

  The output side of the drive system 6 is connected to the front drive shaft 7 of the vehicle 1. The power transmitted by the drive system 6 drives the drive wheels 8 via the front drive shaft 7. The vehicle 1 of the present embodiment is a front-wheel drive vehicle having front wheels as drive wheels 8, but the vehicle of the present invention may be a rear-wheel drive vehicle having rear wheels 9 as drive wheels, or an all-wheel drive vehicle. Good.

  The power distribution and integration mechanism 3 can bisect the power of the internal combustion engine 2 and transmit it to the generator 5 and the drive system 6 (drive wheels 8). Further, the power distribution and integration mechanism 3 can integrate the power of the internal combustion engine 2 and the power of the motor 4 and transmit them to the drive system 6 (drive wheels 8).

  An exhaust purification catalyst 15 for purifying exhaust gas is disposed in the middle of the exhaust passage 14 of the internal combustion engine 2. The exhaust purification catalyst 15 is composed of, for example, a three-way catalyst, an occlusion reduction type NOx catalyst, a selective reduction type NOx catalyst, or the like. Moreover, what combined those functions may be used.

  Each of the motor 4 and the generator 5 is configured as a known synchronous generator motor that can be driven as a generator and can be driven as a motor. In the vehicle 1, the electric power generated by the generator 5 can be charged to the battery 20 via the inverter 18 and the boost converter 19. In addition, the motor 4 can be driven by the electric energy stored in the battery 20 via the boost converter 19 and the inverter 18. Further, in the vehicle 1, the motor 4 can be driven by applying the electric power generated by the generator 5 to the motor 4 through the inverter 18. In the vehicle 1, other power storage means such as a capacitor may be used instead of the battery 20.

  In the vicinity of the internal combustion engine 2, an auxiliary machine 21 such as an electric air conditioner compressor is arranged. The auxiliary machine 21 is driven by electric power supplied from the battery 20 via the inverter 18. The vehicle 1 is also provided with a vehicle speed sensor 22 that detects the vehicle speed and an accelerator opening sensor 23 that detects the amount of depression of the accelerator pedal.

  The hybrid system including the internal combustion engine 2 in such a vehicle 1 is controlled by the ECU 30. The ECU 30 is connected to the various actuators, sensors, power conversion devices, batteries, and the like described above.

[Features of Embodiment 2]
In the vehicle 1, the required driving force can be covered by the internal combustion engine 2 and the motor 4. Then, the drive ratio between the internal combustion engine 2 and the motor 4 is controlled so that the overall efficiency is optimized in accordance with the traveling state. Specifically, the internal combustion engine 2 is controlled so as to operate on an optimum fuel consumption line, that is, in a high load range (high torque range) that has good thermal efficiency (low fuel consumption rate) and is set in advance. During acceleration, in addition to the driving force of the internal combustion engine 2, the electric energy stored in the battery 20 is supplied to the motor 4 via the boost converter 19 and the inverter 18 to increase the driving ratio of the motor 4. Thus, the vehicle 1 can be driven with a large driving force. On the other hand, the internal combustion engine 2 is not operated in the low load region where the thermal efficiency is low, and the vehicle can run only with the motor 4.

  In the present embodiment, the internal combustion engine 2 is controlled in the same manner as in the first embodiment. In other words, if the thermal efficiency of the internal combustion engine 2 is reduced because the maximum in-cylinder pressure crank angle PmaxCA is deviated from the maximum in-cylinder pressure maximum crank angle PmaxMBTCA, the hydrogen addition ratio is corrected based on the deviation ΔPmaxCA between the two. By doing so, the cylinder pressure maximum crank angle PmaxCA is controlled to coincide with the thermal efficiency best cylinder pressure maximum crank angle PmaxMBTCA. With such control, the internal combustion engine 2 can be shifted to the best thermal efficiency state without causing knocking even in a high load range, so that fuel efficiency can be improved.

  Furthermore, in this embodiment, when there is a deviation ΔPmaxCA between the maximum in-cylinder pressure crank angle PmaxCA and the maximum in-cylinder pressure maximum crank angle PmaxMBTCA, the larger the deviation ΔPmaxCA, the more electric energy stored in the battery 20 is. By supplying to the motor 4, control is performed such that the drive ratio of the motor 4 is increased. The advantage of performing this control will be described with reference to FIG.

  FIG. 8 is a diagram showing a thermal efficiency map of the internal combustion engine 2. In FIG. 8, the curve indicated by the thick solid line is the torque Te at full load (WOT), the curve indicated by the thin solid line is the isothermal efficiency line (isofuel consumption rate line), and the curve indicated by the broken line is equal Output line.

  As described above, the internal combustion engine 2 is controlled to operate on the predetermined optimum fuel consumption line in the high load region. Now, it is assumed that the target operating point of the internal combustion engine 2 is a point A on the optimum fuel consumption line in FIG. At this time, if the ignition timing SA cannot be advanced to MBT due to the occurrence of knocking and is operated at the ignition timing SA delayed from the MBT, the torque Te decreases, so the actual operating point is point B It becomes. Point B has lower thermal efficiency and lower engine output than point A. For this reason, when such a situation occurs, not only the fuel efficiency is deteriorated, but also the required traveling output (vehicle driving force) cannot be obtained, so that traveling performance and drivability are deteriorated.

  On the other hand, in the above case, if the engine speed NE is increased from the point B and the engine speed NE is controlled to increase until reaching the point C on the same output line as the point A, the point A Therefore, it is possible to avoid a decrease in driving performance and drivability. However, as the engine speed NE increases, the friction loss of the internal combustion engine 2 increases, and the thermal efficiency tends to decrease. For this reason, as shown in FIG. 8, when the point B is shifted to the point C, the operation is performed in a region where the thermal efficiency exceeds the isothermal efficiency line and the thermal efficiency is lower. For this reason, from the viewpoint of fuel efficiency, even if driving at point A, which is the target operating point, cannot be realized, driving at point B is preferable to shifting to point C.

  Therefore, in this embodiment, when the operation state of the internal combustion engine 2 is not in the MBT state (the best thermal efficiency state) and the target engine output is not obtained, the drive ratio of the motor 4 is increased. The amount of assist by the motor 4 is increased. As a result, a shortage of engine output can be compensated for by the driving force of the motor 4, so that a reduction in driving output (vehicle driving force) can be avoided, and a reduction in driving performance and drivability can be reliably prevented. it can.

  Further, according to the above control, even if the internal combustion engine 2 cannot be operated at the target operating point, an increase in the assist amount by the motor 4 can be expected. It is not necessary to ensure the same engine output. That is, in the above example, even if the operation cannot be performed at the point A of the target operating point, it is not necessary to shift to the point C, and the operation may be performed at the point B. For this reason, the fall of thermal efficiency can be suppressed and the deterioration of a fuel consumption can be prevented.

  Further, as described above, while the amount of assist by the motor 4 is increased and the running performance is ensured, the hydrogen addition ratio is corrected in the same manner as in the first embodiment, so that the internal combustion engine 2 has the best thermal efficiency. The operation can be shifted to the state (target operating point). That is, according to the present embodiment, fuel efficiency can be improved while ensuring excellent running performance.

[Specific Processing in Second Embodiment]
FIG. 9 is a flowchart of a routine executed by the ECU 30 in the present embodiment in order to realize the above function. Note that this routine is repeatedly executed every operating cycle of the internal combustion engine 2 or every predetermined time. In FIG. 9, the same steps as those shown in FIG. 6 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  The routine shown in FIG. 9 is the same as the routine shown in FIG. 6 described above except that step 112 is inserted between steps 102 and 104. According to the routine shown in FIG. 9, as in the first embodiment, the current maximum in-cylinder pressure crank angle PmaxCA is first detected (step 100), and then the maximum in-cylinder pressure crank angle PmaxCA and the maximum thermal efficiency maximum in-cylinder pressure are determined. A deviation ΔPmaxCA from the crank angle PmaxMBTCA is calculated (step 102).

  In the following step 112, first, the correction value EPmax of the drive ratio of the motor 4 corresponding to the deviation ΔPmaxCA obtained in step 102 is obtained. FIG. 10 is a map for obtaining the correction value EPmax. According to the map shown in FIG. 10, the correction value EPmax of the drive ratio of the motor 4 is calculated to be larger as the deviation ΔPmaxCA is larger. When the deviation ΔPmaxCA is large, the deviation from the best thermal efficiency state is large, so the engine output is reduced accordingly. According to the map shown in FIG. 10, in order to cope with this, the assist amount by the motor 4 can be increased in accordance with the decrease range of the engine output.

  Further, according to the map shown in FIG. 10, when the deviation ΔPmaxCA is positive, that is, when the maximum in-cylinder pressure crank angle PmaxCA is behind the maximum in-cylinder pressure maximum crank angle PmaxMBTCA, the deviation ΔPmaxCA is negative. That is, the correction value EPmax is calculated to be larger than when the in-cylinder pressure maximum crank angle PmaxCA is ahead of the thermal efficiency best in-cylinder pressure maximum crank angle PmaxMBTCA. This is because even if the absolute value of the deviation ΔPmaxCA is the same, the engine output is greater when the maximum in-cylinder pressure crank angle PmaxCA is behind the maximum in-cylinder pressure maximum crank angle PmaxMBTCA than when it is advanced This corresponds to the large drop in

  In the vehicle 1, the required travel output is calculated based on the accelerator opening and the vehicle speed by the processing of other routines, and based on the required travel output, the reference drive ratio (driving force burden ratio) of the motor 4 is calculated. It has been calculated. In step 112, the corrected motor driving ratio is calculated by adding the correction value EPmax of the motor driving ratio obtained as described above to the reference motor driving ratio. Then, in order to realize the corrected motor driving ratio, the electric energy supply amount from the battery 20 to the motor 4 is increased, and the driving force assist amount by the motor 4 is increased.

  According to the processing of step 112 described above, when the engine output (torque) is reduced because the operating state of the internal combustion engine 2 is not in the best thermal efficiency state, the motor is compensated for the shortage. The assist amount by 4 can be increased appropriately. For this reason, the running performance and drivability of the vehicle 1 can be surely prevented. Further, since it is not necessary to control to compensate for the decrease in torque by increasing the engine speed NE, it is possible to suppress the deterioration of the thermal efficiency of the internal combustion engine 2 and to ensure good fuel efficiency.

  According to the routine shown in FIG. 9, following the process of step 112, the processes of steps 104 to 110 are performed as in the routine shown in FIG. That is, the hydrogen addition ratio is corrected in accordance with the deviation ΔPmaxCA, and the maximum in-cylinder pressure crank angle PmaxCA is controlled to coincide with the best in-cylinder pressure maximum crank angle PmaxMBTCA. Thereby, the internal combustion engine 2 can be shifted to the best thermal efficiency state without causing knocking.

  As described above, in this embodiment, when a situation occurs in which the operation state of the internal combustion engine 2 cannot be brought into the best thermal efficiency due to the occurrence of a knock or the like, the driving performance is reduced by increasing the assist amount by the motor 4. In addition, the internal combustion engine 2 can be shifted to the best thermal efficiency state by correcting the hydrogen addition ratio to the internal combustion engine 2. For this reason, fuel consumption performance can be improved without impairing running performance.

  In the second embodiment described above, a hybrid vehicle including an electric motor (motor 4) as a power source other than the internal combustion engine 2 has been described as an example. However, the hybrid vehicle in the present invention is limited to an electric hybrid. Instead, for example, a mechanical hybrid such as a pressure accumulating hybrid may be used.

  In the second embodiment described above, the motor 4 is the “other power source” in the fourth aspect of the invention, and the gasoline injector 10 and the gasoline tank 12 are the “main fuel supply means” in the fourth aspect of the invention. The hydrogen injector 11 and the hydrogen tank 13 are the “auxiliary fuel supply means” in the fourth aspect of the invention, and the thermal efficiency best cylinder pressure maximum crank angle PmaxMBTCA is the “target value of the cylinder pressure maximum crank angle” in the fourth aspect of the invention. 20 corresponds to the “energy storage means” in the fourth invention. Further, when the ECU 30 executes the process of step 100, the “in-cylinder pressure maximum crank angle detecting means” in the fourth invention executes the processes of steps 102 and 112. The “assist amount increasing means” implements the processes of steps 104 to 110 described above, thereby realizing the “auxiliary fuel addition ratio correcting means” in the fourth invention.

Embodiment 3 FIG.
Next, the third embodiment of the present invention will be described with reference to FIG. 11 to FIG. 14. The difference from the above-described first embodiment will be mainly described, and the same matters will be described. Omitted or simplified.

[Description of system configuration]
FIG. 11 is a diagram for explaining the system configuration of the third embodiment. The system shown in FIG. 11 includes an internal combustion engine 2 that uses alcohol as an auxiliary fuel. As the alcohol, ethanol, methanol or the like can be used.

  The system shown in FIG. 11 replaces the hydrogen injector 11 and the hydrogen tank 13 in FIG. 1 with an alcohol injector 48 that injects alcohol into the intake port 35 and an alcohol that stores alcohol to be supplied to the alcohol injector 48. And a tank 49. The alcohol in the alcohol tank 49 is pressurized by the fuel pump 50, regulated by the regulator valve 51, and then supplied to the alcohol injector 48.

  A knock sensor 52 for detecting knock is attached to the internal combustion engine 2 of the system shown in FIG. The configuration of the system shown in FIG. 11 is the same as that of the system shown in FIG.

[Features of Embodiment 3]
Alcohol, which is an oxygen-containing fuel, has an action of suppressing knocking and an action of promoting combustion. For this reason, as shown in FIG. 12, the cylinder pressure maximum crank angle PmaxCA can be advanced (advanced) as the alcohol addition ratio increases. In the third embodiment, the same effect as in the first embodiment can be obtained by using alcohol as an auxiliary fuel instead of hydrogen.

[Specific Processing in Embodiment 3]
FIG. 13 is a flowchart of a routine executed by the ECU 30 in the present embodiment in order to realize the above function. Note that this routine is repeatedly executed every operating cycle of the internal combustion engine 2 or every predetermined time. In FIG. 13, the same steps as those shown in FIG. 6 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  According to the routine shown in FIG. 13, it is first determined whether or not knock has occurred in the internal combustion engine 2 based on the signal from the knock sensor 52 (step 114). In the present embodiment, the control is performed for a case where the ignition timing SA cannot be advanced to MBT due to the occurrence of knock. For this reason, when it is determined that no knock has occurred, the current processing cycle is terminated.

  On the other hand, if the occurrence of knocking is recognized in step 114, the current in-cylinder pressure maximum crank angle PmaxCA is detected based on the signal from the in-cylinder pressure sensor 46, as in the first embodiment. (Step 100). Subsequently, as in the first embodiment, a deviation ΔPmaxCA between the detected maximum in-cylinder pressure crank angle PmaxCA and a predetermined maximum thermal efficiency best in-cylinder pressure crank angle PmaxMBTCA is calculated (step 102).

  Next, processing for obtaining a correction value CPmax of the alcohol addition ratio is performed in accordance with the deviation ΔPmaxCA obtained in step 102 (step 116). Specifically, a correction value CPmax for the alcohol addition ratio is calculated based on the map shown in FIG. According to the map shown in FIG. 14, the larger the deviation ΔPmaxCA is in the positive direction, the larger the correction value CPmax is calculated.

  Further, according to the map shown in FIG. 14, when the deviation ΔPmaxCA is negative, the correction value CPmax is set to zero. Under circumstances where knocking occurs, it is normal that the deviation ΔPmaxCA becomes a negative value, that is, that the maximum cylinder pressure PmaxCA in the cylinder pressure is more advanced than the maximum crank angle PmaxMBTCA with the best thermal efficiency. I can say no. For this reason, in the present embodiment, when the deviation ΔPmaxCA is negative, the correction value CPmax is set to zero and the alcohol addition ratio is not corrected.

  Subsequent to the process in step 116, a process for obtaining a reference alcohol addition ratio CR1 [%] based on the operating conditions of the internal combustion engine 2 is performed (step 118). The ECU 30 stores in advance a map that defines the relationship between operating conditions such as the engine speed NE, load (intake air amount), excess air ratio λ (air-fuel ratio), and the alcohol addition ratio CR1 suitable for the operating conditions. Has been. Here, the reference value of the alcohol addition ratio CR1 corresponding to the current operating condition is acquired by referring to the map.

Next, a process for obtaining the corrected alcohol addition ratio CR2 is performed by correcting the reference alcohol addition ratio CR1 obtained in step 118 by the correction value CPmax obtained in step 116 (step 120). . Specifically, CR2 is calculated based on the following equation.
CR2 = CR1 + CPmax

  Then, based on the corrected alcohol addition ratio CR2 calculated in step 120, a process for adding alcohol is executed (step 122). In the present embodiment, it is assumed that the required supply heat amount to the internal combustion engine 2 is calculated based on the current operation state by the processing of another routine. In this step 122, the amount of alcohol to be injected from the alcohol injector 48 is calculated based on the required supply heat amount and the alcohol addition ratio CR2, and the valve opening time of the alcohol injector 48 is controlled based on the calculated value. By doing so, alcohol addition is performed.

  According to the routine shown in FIG. 13 described above, the correction value CPmax of the alcohol addition ratio is calculated according to the map shown in FIG. 14 based on the deviation ΔPmaxCA, so that the cylinder pressure maximum crank angle PmaxCA is the thermal efficiency best cylinder pressure maximum crank angle PmaxMBTCA. As the time is delayed, the alcohol addition ratio is corrected to be larger than the current rate. As a result, the knock suppression effect by alcohol is amplified, and knocking can be avoided. Further, since the combustion promotion effect by alcohol is amplified, the position of the maximum cylinder pressure crank angle PmaxCA can be advanced (advanced), and the maximum cylinder pressure crank angle PmaxCA is matched with the maximum cylinder pressure PmaxMBTCA with the best thermal efficiency. be able to. In this way, even in the high load range, the internal combustion engine 2 can be operated in the best thermal efficiency state, that is, in the MBT state, without being hindered by knocking. Therefore, the fuel efficiency performance of the internal combustion engine 2, particularly the fuel efficiency performance in a high load range (high torque range) can be improved.

  In the third embodiment described above, the gasoline injector 10 and the gasoline tank 12 are the “main fuel supply means” in the first invention, and the alcohol injector 48 and the alcohol tank 49 are the “auxiliary fuel” in the first invention. In the “supply means”, the maximum cylinder pressure PmaxMBTCA with the best thermal efficiency corresponds to the “target value of the maximum cylinder pressure in the first aspect of the invention”. Further, when the ECU 30 executes the process of step 100, the “cylinder pressure maximum crank angle detecting means” in the first aspect of the invention executes the processes of steps 102 and 116-122. The “auxiliary fuel addition amount calculation means” in the present invention is realized.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is a figure which shows an example of the waveform of the in-cylinder pressure which arises in 1 cycle of an internal combustion engine. It is a figure which shows the relationship between the cylinder pressure maximum crank angle PmaxCA and ignition timing SA. It is a figure which shows the relationship between the cylinder pressure maximum crank angle PmaxCA, ignition timing SA, and a hydrogen addition ratio. It is a figure which shows the relationship between deviation (DELTA) PmaxCA and the correction value KPmax of a hydrogen addition ratio. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a figure for demonstrating the hybrid vehicle of Embodiment 2 of this invention. It is a figure which shows the thermal efficiency map of an internal combustion engine. It is a flowchart of the routine performed in Embodiment 2 of this invention. It is a figure which shows the relationship between deviation (DELTA) PmaxCA and the correction value EPmax of a motor drive ratio. It is a figure for demonstrating the system configuration | structure of Embodiment 3 of this invention. It is a figure which shows the relationship between the cylinder pressure maximum crank angle PmaxCA, the ignition timing SA, and the alcohol addition ratio. It is a flowchart of the routine performed in Embodiment 3 of the present invention. It is a figure which shows the relationship between deviation (DELTA) PmaxCA and the correction value CPmax of the alcohol addition ratio.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 2 Internal combustion engine 3 Power distribution integration mechanism 4 Motor 5 Generator 6 Drive system 7 Front drive shaft 8 Drive wheel 10 Gasoline injector 11 Hydrogen injector 14 Exhaust passage 15 Exhaust purification catalyst 18 Inverter 19 Boost converter 20 Battery 22 Vehicle speed sensor 23 Accelerator Opening sensor 30 ECU (Electronic Control Unit)
31 Piston 32 Intake valve 33 Exhaust valve 41 Turbocharger 42 Intake passage 44 Throttle valve 45 Air flow meter 46 In-cylinder pressure sensor 47 Crank angle sensor 48 Alcohol injector 49 Alcohol tank 52 Knock sensor

Claims (4)

Main fuel supply means for supplying main fuel to the spark ignition internal combustion engine;
Auxiliary fuel supply means for supplying auxiliary fuel having a combustion promoting action to the internal combustion engine;
In-cylinder pressure maximum crank angle detection means for detecting an in-cylinder pressure maximum crank angle that is a crank angle at which the in-cylinder pressure of the internal combustion engine is maximized;
When the detected value of the maximum in-cylinder pressure crank angle is delayed as compared with the target value of the maximum in-cylinder pressure crank angle determined so that the thermal efficiency is the best, the addition ratio of the auxiliary fuel is increased. An auxiliary fuel addition amount calculating means for calculating the additional amount of the auxiliary fuel;
A control device for an internal combustion engine, comprising:   2. The control apparatus for an internal combustion engine according to claim 1, wherein the auxiliary fuel is hydrogen or alcohol.   When the detected value of the in-cylinder pressure maximum crank angle is advanced as compared with the target value, the auxiliary fuel addition amount calculation means is configured to reduce the supplementary fuel addition amount so that the supplementary fuel addition ratio decreases. The control device for an internal combustion engine according to claim 1 or 2, wherein A hybrid vehicle comprising a spark ignition internal combustion engine and another power source, the driving power being assisted by the other power source,
Main fuel supply means for supplying main fuel to the internal combustion engine;
Auxiliary fuel supply means for supplying auxiliary fuel having a combustion promoting action to the internal combustion engine;
Energy storage means for storing energy for supply to the other power source;
In-cylinder pressure maximum crank angle detection means for detecting an in-cylinder pressure maximum crank angle that is a crank angle at which the in-cylinder pressure of the internal combustion engine is maximized;
The larger the deviation between the detected value of the in-cylinder pressure maximum crank angle and the target value of the in-cylinder pressure maximum crank angle determined so that the thermal efficiency is optimal, the larger the energy supply from the energy storage means to the other power source An assist amount increasing means for increasing a driving force assist amount by the other power source by increasing the amount;
Auxiliary fuel addition ratio correction for correcting the auxiliary fuel addition ratio so that the actual maximum in-cylinder pressure crank angle approaches the target value based on the deviation between the detected value of the maximum in-cylinder pressure crank angle and the target value Means,
A hybrid vehicle comprising:

Images