JP5407659B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle that performs driving force assist for applying driving force to a vehicle by electric power of a battery when it is determined that acceleration operation is performed during traveling by driving force of an engine.

  Conventionally, even in series type hybrid vehicles that use the engine exclusively as a motor power supply source, even in parallel type hybrid vehicles in which the engine output shaft and motor output shaft are both mechanically connected to the drive wheels, engine output is insufficient. In such a case, it is known to perform driving force assist for applying driving force to the vehicle by the electric power of the battery.

  For example, Patent Document 1 discloses a hybrid that includes an engine as a travel drive source, a motor generator that assists in generating power by engine output or engine output by battery power, and charge amount detection means that detects battery charge amount SOC. In the vehicle control device, when the detected SOC is smaller than a predetermined lower limit value, the shift assist operation region is limited to the high rotation / high load side operation region of the engine, while the predetermined lower limit value is exceeded. In the case where there are too many, the shift assist operation region is not limited, and the entire operation region is set according to the SOC.

JP 2005-341644 A

  By the way, in the thing of the said patent document 1, in order to utilize the remaining battery electric power effectively, as the battery charge amount SOC is small, the high speed rotation in which the feeling of deceleration due to the torque interruption at the time of shifting is increased in the shift assist region. Although limited to a high load region, Patent Document 1 does not show a case where a large driving force assist cannot be applied.

  The present invention has been made in view of such points, and an object of the present invention is to apply driving power to a vehicle by electric power of a battery when it is determined that acceleration operation is performed during traveling by driving power of the engine. An object of the present invention is to provide a technique for improving acceleration performance even when a large driving force assist using battery power cannot be applied in a hybrid vehicle control device that performs driving force assist.

  In order to achieve the above object, according to the present invention, a compression stroke injection ratio is obtained so that a high engine output can be obtained separately from the first acceleration control means for performing driving force assist for applying driving force to the vehicle by the electric power of the battery. The second acceleration control means for changing is provided.

According to a first aspect of the invention, an engine, a travel motor driven by at least battery power, acceleration determination means for determining acceleration operation of the engine, and acceleration by the acceleration determination means during traveling by the driving force of the engine A hybrid vehicle control device comprising: first acceleration control means for performing driving force assist that applies driving force to the vehicle by electric power of the battery when it is determined to be driving, wherein the engine is It is a dual fuel engine that can selectively use liquid fuel and gaseous fuel as the fuel to be used, and can obtain higher output when using liquid fuel than when using gaseous fuel . At the time of injection in which gaseous fuel is injected from the intake stroke to the compression stroke of the cylinder by the SOC detection means for detecting the SOC and the fuel injection valve Depending on the electric power of the battery when the acceleration is determined by the acceleration determining means during traveling by the control means and the driving force of the engine and the SOC detected by the SOC detecting means is less than a predetermined reference value A second acceleration control means for limiting the driving force assist and increasing the compression stroke injection rate; and the acceleration operation is determined during operation of the engine using gaseous fuel, and the SOC is less than a predetermined reference value, And a fuel switching control means for controlling to switch the used fuel to the liquid fuel when it is determined that an output corresponding to the required acceleration of the vehicle cannot be obtained. is there.

  According to the first aspect of the present invention, the first acceleration control is performed when the acceleration determination means determines that the vehicle is accelerating during traveling by the driving force of the engine and the SOC detected by the SOC detection means is greater than or equal to the predetermined reference value. The means causes the driving force assist to apply the driving force to the vehicle by the electric power of the battery. As a result, the required engine output is supplemented by the battery power, so that it is possible to perform engine control with priority on fuel efficiency without being limited to securing the output.

  On the other hand, when it is determined that the vehicle is accelerating during traveling by the driving force of the engine and the SOC is less than a predetermined reference value, the second acceleration control means limits the driving force assist by the battery power and the compression stroke injection ratio Increase. As a result, the intake amount in the intake stroke is increased, and gaseous fuel is injected by the increased intake amount, so that high engine output can be obtained, and output priority engine control is possible.

  As described above, the acceleration performance can be improved when the SOC is less than the predetermined reference value while the fuel efficiency is improved when the SOC is the predetermined reference value or more.

Further, according to the first invention, when the control limit of the second acceleration control means in the case of using a gaseous fuel, i.e., acceleration operation during operation of the engine is determined, SOC is less than a predetermined reference value In addition, when it is determined that the output corresponding to the required acceleration of the vehicle cannot be obtained with the gaseous fuel, the fuel switching control means switches the used fuel to a liquid fuel that can obtain a higher output than when the gaseous fuel is used. Therefore, the deterioration of the acceleration performance can be suppressed.

According to a second aspect of the present invention, an engine, a travel motor driven by at least battery power, acceleration determination means for determining acceleration operation of the engine, and acceleration by the acceleration determination means during traveling by the driving force of the engine A hybrid vehicle control device comprising: first acceleration control means for performing driving force assist that applies driving force to the vehicle by electric power of the battery when it is determined to be driving, wherein the engine is can be used with liquid and gaseous fuels selectively as fuel used, and a dual-fuel engine that substantially the same output can be obtained in the case of using a case and a liquid fuel using a gaseous fuel, the battery SOC An injection timing system for injecting gaseous fuel from the intake stroke to the compression stroke of the cylinder by means of an SOC detection means for detecting the fuel and a fuel injection valve. And driving by the power of the battery when the acceleration determining means determines that the vehicle is accelerating during traveling by the driving force of the engine and the SOC detected by the SOC detecting means is less than a predetermined reference value. A second acceleration control means for limiting the force assist and increasing the compression stroke injection rate; and when the acceleration operation is determined during operation of the engine using liquid fuel and the SOC is less than a predetermined reference value, the fuel used is characterized in that it further comprises a fuel switching control means for controlling to switch to gas fuel, the.

According to the second aspect of the present invention, the first acceleration control is performed when the acceleration determination means determines that the vehicle is accelerating during traveling by the driving force of the engine and the SOC detected by the SOC detection means is greater than or equal to the predetermined reference value. The means causes the driving force assist to apply the driving force to the vehicle by the electric power of the battery. As a result, the required engine output is supplemented by the battery power, so that it is possible to perform engine control with priority on fuel efficiency without being limited to securing the output.

On the other hand, when it is determined that the vehicle is accelerating during traveling by the driving force of the engine and the SOC is less than a predetermined reference value, the second acceleration control means limits the driving force assist by the battery power and the compression stroke injection ratio. Increase. As a result, the intake amount in the intake stroke is increased, and gaseous fuel is injected by the increased intake amount, so that high engine output can be obtained, and output priority engine control is possible.

As described above, the acceleration performance can be improved when the SOC is less than the predetermined reference value while the fuel efficiency is improved when the SOC is the predetermined reference value or more.

Further, according to the second invention, when the substantially same output in the case of using a case and a liquid fuel using a gaseous fuel is obtained, since the second acceleration control means to increase the compression stroke injection ratio, in the intake stroke The intake air amount increases and high engine output is obtained. Thereby, deterioration of acceleration performance can be suppressed.

  According to the hybrid vehicle control device of the present invention, when it is determined that the engine is accelerating during operation and the SOC is equal to or greater than a predetermined reference value, the first acceleration control means uses the battery power to assist the driving force. On the other hand, when it is determined that the engine is accelerating during operation and the SOC is less than a predetermined reference value, the second acceleration control means limits the driving force assist and increases the compression stroke injection ratio. Therefore, it is possible to improve fuel efficiency when the SOC is equal to or higher than a predetermined reference value, and improve acceleration performance when the SOC is lower than the predetermined reference value.

It is a schematic block diagram of the hybrid vehicle carrying the control apparatus of the hydrogen engine which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the engine control map which set the operating area | region of the engine. It is a schematic block diagram of the engine control apparatus. It is a time chart of 1st acceleration control, The figure (a) is a time change of the battery SOC, The figure (b) is a time change of the battery electric power assist amount, The figure (c) is a time change of an engine speed. (D) is a figure which shows the time change of a required driving force, respectively. FIG. 4A is a time chart of first and second acceleration control, where FIG. 1A shows the time change of the battery SOC, FIG. 2B shows the time change of the fuel injection ratio, and FIG. 1C shows the engine speed. FIG. 4D is a diagram showing the time change of the required driving force. 3 is a control flowchart of the PCM according to the first embodiment. 10 is a control flowchart of PCM according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a hybrid vehicle equipped with a hydrogen engine control device according to an embodiment of the present invention. The vehicle 1 includes an engine 5 and first and second motors 7 and 9 as power sources. The engine 5 is used only for power generation, and all the power for moving the vehicle 1 depends on the motors 7 and 9. It is a series hybrid vehicle. The vehicle 1 is provided with a power train control module (PCM) 3 and a current and voltage sensor 61 in addition to the engine 5 and the first and second motors 7 and 9, and the first motor (generator) 7 and the second motor 1. A battery 11 capable of charging / discharging the electric power generated by the motor 9 (traveling motor), a first inverter 17 connected to the battery 11 and the first motor 7, the first inverter 17, the battery 11 and the second And a second inverter 19 connected to the motor 9.

  The engine 5 is a rotary engine, and is a dual fuel engine that can be driven by selectively switching between gasoline and hydrogen with less exhaust emissions when the catalyst is inactive than gasoline. . When hydrogen is selected by operating the fuel selector switch 63 (see FIG. 3), hydrogen in the hydrogen tank 13 is supplied to the injector 33 for hydrogen injection (see FIG. 3), while gasoline is selected. Then, the gasoline in the gasoline tank 15 is supplied to the injector 35 for gasoline injection. Exhaust emission refers to harmful components (HC, CO, NOx, etc.) contained in the exhaust gas after passing through the catalyst. Further, the engine 5 can obtain a higher output when gasoline is used than when hydrogen is used as fuel.

  The output shaft of the engine 5 is connected to the output shaft of the first motor 7, and the first motor 7 is rotationally driven by the engine 5 to generate electric power. The AC generated power generated by the first motor 7 is converted into DC power by the first inverter 17 and charged in the battery 11 or supplied to the second inverter 19.

  On the other hand, the second inverter 19 converts the DC power supplied by the discharge of the battery 11 or the DC power supplied from the first inverter 17 into AC power, and supplies the AC power to the second motor 9. The battery 11 is charged with the regenerative power from.

  The second motor 9 is connected to the left and right front wheels (drive wheels) 21a, 21a through the differential gear 23 among the four wheels 21a, 21a, 21b, 21b on the front, rear, left, and right, and according to the control map shown in FIG. Controlled by PCM3. That is, the second motor 9 is driven by the electric power supplied from the battery 11 at the time of low torque operation where the output torque required for the second motor 9 is low, such as during constant speed operation of the vehicle 1 or when the vehicle is started. (Region A in FIG. 2), high torque operation that is driven by electric power supplied from the first motor 7 driven by the engine 5 during medium torque operation (region B in FIG. 2) and has high output torque at the time of sudden acceleration, etc. Sometimes it is driven by electric power supplied from both the first motor 7 and the battery 11 (region C in FIG. 2).

  As shown in FIG. 3, the engine 5 has rotors 27, 27 that are substantially triangular in rotor housing chambers (cylinders) 25, 25 surrounded by a bowl-shaped rotor housing having a trochoid inner peripheral surface and side housings. It is configured to be accommodated, and three working chambers are defined on the outer peripheral side thereof. Although not shown, the engine 5 is integrated by sandwiching two rotor housings between three side housings, and the rotors 27 and 27 are accommodated in two cylinders 25 and 25 formed therebetween, respectively. FIG. 3 shows the two cylinders 25, 25 in an expanded state.

  The rotor 27 rotates around the eccentric shaft 29 in a state where the seal portions respectively disposed on the three tops of the outer periphery are in contact with the inner peripheral surface of the trochoid of the rotor housing, and the axial center of the eccentric shaft 29 is rotated. Revolve around. Then, while the rotor 27 makes one rotation, the working chambers formed between the tops of the rotor 27 move in the circumferential direction, and intake, compression, expansion (combustion), and exhaust strokes are performed. Is generated from the eccentric shaft 29 via the rotor 27.

  The cylinders 25 and 25 of the engine 5 are provided with two spark plugs 31 and 31, respectively. The two spark plugs 31 and 31 are disposed near the short axis of the rotor housing, The cylinders 25 and 25 are provided with two hydrogen injection injectors (direct injection injectors) 33 for directly injecting the hydrogen supplied from the hydrogen tank 13 into the cylinder (one in each cylinder in FIG. 3). Only two hydrogen injectors 33 are arranged in the axial direction of the eccentric shaft 29 in the vicinity of the long axis of the rotor housing.

  In addition, each cylinder 25, 25 communicates with an intake passage 37 so as to communicate with the working chamber in the intake stroke, and communicates with an exhaust passage 39 so as to communicate with the working chamber in the exhaust stroke. . The intake passage 37 and the exhaust passage 39 are connected by an EGR passage 41, and the exhaust of the exhaust passage 39 is operated by operating an EGR valve actuator 45 that controls the opening degree of the EGR valve 43 provided in the EGR passage 41. A part of the gas is returned to the intake passage 37.

  On the upstream side of the intake passage 37, an air flow sensor 65 that detects the intake amount and a throttle valve 47 that is driven by an actuator 49 such as a stepping motor to adjust the cross-sectional area of the intake passage 37 are disposed. A gasoline injection injector 35 for injecting gasoline supplied from the gasoline tank 15 into the intake passage 37 is disposed downstream of the passage 37. The exhaust passage 39 is provided with a three-way catalyst 51 as an exhaust purification catalyst for purifying exhaust.

  A linear air-fuel ratio sensor 53 that detects the oxygen concentration in the exhaust gas is disposed upstream of the three-way catalyst 51. The linear air-fuel ratio sensor 53 is provided with a heater 53b. The heater 53b heats the element 53a and maintains the element 53a at a predetermined temperature.

  The spark plugs 31 and 31, the EGR valve actuator 45, the actuator 49 of the throttle valve 47, the injectors 33 and 35 for hydrogen and gasoline injection, the first and second motors 7 and 9, the first and second inverters 17 and 19 The linear air-fuel ratio sensor 53 and the like are controlled by the PCM 3 as control means.

  The PCM 3 includes at least a vehicle speed sensor 55 that detects the speed of the vehicle 1, an accelerator opening sensor 57 that detects the accelerator opening, and an engine rotation that detects the engine speed as signals necessary for the control according to the present embodiment. The output signals of the number sensor 59, the current sensor 61a and the voltage sensor 61b, the fuel selector switch 63, the air flow sensor 65, and the linear air-fuel ratio sensor 53 are input.

  In the control device for the hydrogen engine in the present embodiment, hydrogen is supplied from the hydrogen injection injector 33 to the engine 5 when hydrogen is used, and gasoline is supplied from the gasoline injection injector 35 to the engine 5 when gasoline is used. The engine 5 is driven. Then, the PCM 3 controls the hydrogen injection injector 33 so that hydrogen is injected from the intake stroke to the compression stroke of the cylinder 25. Thus, the PCM 3 constitutes an injection timing control means for injecting hydrogen (gaseous fuel) from the intake stroke to the compression stroke of the cylinder by the hydrogen injection injector 33.

  Further, air-fuel ratio control is executed by the PCM 3 when using hydrogen and when using gasoline. That is, based on the output signal from the linear air-fuel ratio sensor 53, feedback control is performed to control the throttle opening and the engine speed so that the air-fuel ratio upstream of the three-way catalyst 51 becomes the target air-fuel ratio. .

  The PCM 3 determines that the operation state of the engine 5 has shifted from the steady operation state to the acceleration operation state based on the output signal from the accelerator opening sensor 57, and also includes a vehicle speed sensor 55, an accelerator opening sensor 57, and Based on the output signal from the engine speed sensor 59, the required acceleration degree of the vehicle 1 is detected. Thus, the PCM 3 constitutes an acceleration determination means for determining the acceleration operation of the engine 5 together with the accelerator opening sensor 57, and the vehicle 1 together with the vehicle speed sensor 55, the accelerator opening sensor 57 and the engine speed sensor 59. The acceleration / deceleration state detecting means for detecting the required acceleration degree is also configured.

  Further, when the PCM 3 determines that the acceleration operation is being performed during traveling by the driving force of the engine 5 (power generated by the first motor 7 that is rotationally driven by the engine 5), the driving force is applied to the vehicle 1 by the power of the battery 11. The first acceleration control for performing the driving force assist to be applied, and the acceleration operation during the traveling by the driving force of the engine 5, and when the SOC of the battery 11 is less than a predetermined reference value, the power of the battery 11 Second acceleration control is performed to limit the driving force assist and increase the compression stroke injection ratio. Thus, the PCM 3 constitutes the first acceleration control means and the second acceleration control means of the present invention.

  Note that the SOC is an amount representing the state of charge of the battery 11, and the fully charged state is represented by SOC of 100%, while the state where the amount of charge is zero represents SOC of 0%. Further, since the open circuit voltage (voltage at no load) of the battery 11 and the SOC of the battery 11 have a one-to-one correspondence, the SOC can be obtained by measuring the voltage and current of the battery 11. Then, the PCM 3 calculates the SOC of the battery 11 based on the detected current and voltage value of the battery 11. Thus, the PCM 3 constitutes an SOC detection means for detecting the SOC of the battery together with the current sensor 61a and the voltage sensor 61b.

  Hereinafter, the first and second acceleration control by the PCM 3 will be described with reference to time charts shown in FIGS. 4 and 5. 4 and 5, the solid line indicates the case where the SOC is a predetermined reference value (for example, 45%) or more, and the broken line or the two-dot chain line indicates the case where the SOC is less than the predetermined reference value.

  When the PCM 3 determines that the acceleration operation is being performed while the vehicle is driven by the driving force of the engine 5, the PCM 3 performs the first acceleration control to set the engine speed to the target engine speed corresponding to the required acceleration. As shown in FIG. 4), only the first acceleration control has the following problems both when the SOC is 45% or more and when the SOC is less than 45%. That is, when the SOC is less than 45%, as shown in FIG. 4B, the driving force assist that applies the driving force to the vehicle 1 by the electric power of the battery 11 as compared with the case where the SOC is 45% or more. The amount (battery power assist amount) decreases.

  In order to compensate for such a decrease in the battery power assist amount, as shown by the phantom line (two-dot chain line) in FIG. 4C, the SOC increases the engine speed when the SOC is less than 45%. Faster than the speed of increase of the engine speed when 45% or more, in other words, the time to reach the target engine speed when the SOC is less than 45%, the target engine speed when the SOC is 45% or more Make it shorter than the time to reach the number. Then, since the power generated by the first motor 7 increases by the increased engine speed, the second motor 9 is driven by the increased generated power to compensate for the decrease in the battery power assist amount. .

  However, if an attempt is made to compensate for the decrease in the battery power assist amount due to such an increase in engine speed, when the accelerator is depressed and accelerated from a certain running state, the engine speed is increased depending on whether the SOC is large or small. Since the way of ascent changes, the passenger may feel uncomfortable.

  In order to prevent the passenger from feeling uncomfortable, when only the first acceleration control is performed without increasing the engine speed, as shown in FIG. 4D, the SOC is less than 45%. The required driving force must be reduced compared to the required driving force when the SOC is 45% or more (see the white arrow in FIG. 4D).

  Therefore, in the control device for the hydrogen engine in the present embodiment, the second acceleration control is performed when it is determined that the acceleration operation is being performed while the engine 5 is driven by the driving force and the SOC of the battery 11 is less than a predetermined 45%. Like to do. Thus, when performing the second acceleration control, the PCM 3 rotates the engine when the operating state of the engine 5 before acceleration and the required acceleration of the vehicle 1 are the same as those during the control by the first acceleration control. The compression stroke injection ratio is controlled so that the way of increasing the number coincides with the way of increasing the engine speed by the first acceleration control.

  Specifically, as shown in FIG. 5A, the PCM 3 performs the first acceleration control when the SOC is 45% or more, and performs the second acceleration control when the SOC is less than 45%. Then, as shown in FIG. 5B, when the SOC is 45% or more, priority is given to fuel efficiency, and the injection ratio between the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 50: 50. Set to. On the other hand, when the SOC is less than 45%, the injection ratio between the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 90: 10. As a result, the intake amount in the intake stroke is increased, and hydrogen fuel is added and injected by the increased intake amount to obtain a high engine output. As shown in FIG. 5D, the SOC is 45%. Even in the case of the lower limit, the required driving force when the SOC is 45% or more can be satisfied.

  Furthermore, the PCM 3 does not change the injection ratio from compression stroke injection: intake stroke injection = 50: 50 to compression stroke injection: intake stroke injection = 90: 10, but as shown in FIG. Change it gently. As a result, the increase speed of the engine speed that needs to be increased rapidly in order to compensate for the decrease in the battery power assist amount shown by the phantom line (two-dot chain line) in FIG. It is possible to match the way of increasing the engine speed when the SOC is 45% or more and the way of increasing the engine speed when the SOC is less than 45%.

  Further, the PCM 3 determines that the acceleration operation is determined during the operation of the engine 5 using hydrogen, and determines that the SOC is less than a predetermined 45% and an output corresponding to the required acceleration of the vehicle 1 cannot be obtained. Sometimes control is performed to switch the fuel used to gasoline. In other words, the PCM 3 is configured to suppress deterioration in acceleration performance by switching the fuel used to gasoline that can obtain a higher output than when hydrogen is used. Thus, the PCM 3 is determined to perform acceleration operation during operation of the engine 5 using hydrogen (gaseous fuel), and an output corresponding to the required acceleration of the vehicle 1 is obtained with an SOC of less than 45%. When it is determined that there is no fuel, the fuel switching control means for controlling the fuel to be switched to gasoline (liquid fuel) is also configured.

-Processing operation of control device-
Here, the processing operation of the control device will be described based on the flowchart shown in FIG.

  First, in the first step SA1, the fuel selected by operating the fuel changeover switch 63, the vehicle speed detected by the vehicle speed sensor 55, the accelerator opening detected by the accelerator opening sensor 57, and the engine speed sensor 59 The PCM 3 reads the engine speed N detected by the above and the current of the battery 11 detected by the current sensor 61a and the voltage value of the battery 11 detected by the voltage sensor 61b. Thereafter, the process proceeds to step SA2.

  In the next step SA2, the PCM 3 calculates the required power required for the first motor 7 based on the required output to the internal combustion engine (vehicle speed, accelerator opening, and engine speed N), and then proceeds to step SA3. . In the next step SA3, the PCM 3 calculates the SOC of the battery 11 based on the current and voltage value of the battery 11 read in step SA1, and then proceeds to step SA4.

  In the next step SA4, it is determined whether or not the operating state is the engine operating region. More specifically, the operating state is a region (region B in FIG. 2) driven by electric power supplied from the first motor 7 driven by the engine 5 such as during medium torque operation, or the engine 5 such as during high torque operation. It is determined whether it belongs to the area | region (area | region C of FIG. 2) driven with the electric power supplied from both the 1st motor 7 and battery 11 which are driven by. When the determination in step SA4 is NO, that is, when the operating state is determined to be a region (region A in FIG. 2) driven by the power supplied from the battery 11 such as during low torque operation or vehicle start. Advances to step SA5.

  In the next step SA5, motor traveling control is performed in which the second motor 9 is driven by the electric power supplied from the battery 11, and then the process returns. On the other hand, if the determination in step SA4 is yes, the process proceeds to step SA6.

  In the next step SA6, it is determined whether or not hydrogen has been selected by operating the fuel selector switch 63. If the determination in step SA6 is no, the process proceeds to step SA7, gasoline is selected as the fuel, and the process returns. On the other hand, if the determination in step SA6 is yes, the process proceeds to step SA8.

  In the next step SA8, hydrogen is selected as the fuel, the process proceeds to step SA9, the throttle opening and the engine speed N are determined based on the vehicle speed and the accelerator opening read in step SA1, and then the process proceeds to step SA10.

  In the next step SA10, it is determined whether or not an acceleration operation is performed. More specifically, it is determined whether or not the operating state belongs to a region (region C in FIG. 2) driven by electric power supplied from both the first motor 7 driven by the engine 5 and the battery 11. When the determination in step SA3 is NO, that is, it is determined that the operating state belongs to a region (region B in FIG. 2) driven by electric power supplied from the first motor 7 driven by the engine 5. If so, go to Step SA11.

  In the next step SA11, the driving force assist amount (battery power assist amount) by the power of the battery 11 is set to 0, and then the process proceeds to step SA12. In the next step SA12, the injection ratio of the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 50: 50, and then the process returns.

  On the other hand, when the determination in step SA10 is YES, that is, when it is determined that the operating state belongs to region C in FIG. 2, the process proceeds to step SA13. Then, in the next step SA13, it is determined whether or not the SOC of the battery 11 calculated in step SA3 is 45% or more. If the determination in step SA10 is yes, the process proceeds to step SA14.

  In the next step SA14, the battery power assist amount is set large, and then the process proceeds to step SA12. In the next step SA12, the injection ratio of the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 50: 50, and then the process returns.

  On the other hand, when the determination in step SA13 is NO, that is, when the SOC of the battery 11 calculated in step SA3 is less than 45%, the process proceeds to step SA15, and even if the battery power assist amount is small, the hydrogen fuel It is determined whether the required power calculated in step SA2 can be satisfied by increasing the compression stroke injection ratio. When the determination in step SA13 is YES, the process proceeds to step SA16, the battery power assist amount is limited (set to a small value), and then the process proceeds to step SA17. In the next step SA17, the injection ratio of the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 90: 10, and then the process returns.

  On the other hand, when the determination in step SA15 is NO, that is, when it is determined that the required power cannot be satisfied by increasing the compression stroke injection ratio of hydrogen fuel when the battery power assist amount is small. In step SA18, the gasoline operation control using gasoline as fuel is set, and then the process returns.

-Effect-
According to the present embodiment, when it is determined that the vehicle is accelerating during traveling by the driving force of the engine 5 and the detected SOC is 45% or more, the PCM 3 applies driving force to the vehicle 1 by the power of the battery 11. The first control to be given is performed. As a result, the required engine output is supplemented by the battery power, so that it is possible to perform engine control with priority on fuel efficiency without being limited to securing the output.

  On the other hand, when it is determined that the vehicle is accelerating during traveling by the driving force of the engine 5 and the SOC is less than 45%, the PCM 3 performs the second acceleration control for limiting the battery power assist and increasing the compression stroke injection ratio. Do. As a result, the intake amount in the intake stroke is increased, and gaseous fuel is injected by the increased intake amount, so that high engine output can be obtained, and output priority engine control is possible.

  As described above, when the SOC is 45% or more, the fuel efficiency can be improved, and when the SOC is less than 45%, the acceleration performance can be improved.

  Further, the PCM 3 determines how to increase the engine speed when the operating state of the engine 5 before acceleration and the required acceleration are the same as those during the first control, and how to increase the engine speed during the first control. The second acceleration control is performed so as to match. Specifically, the PCM 3 performs the second acceleration control so as to obtain only a high engine output by increasing the compression stroke injection ratio while maintaining the same way of increasing the engine speed as in the first control. Thereby, it can suppress that the way of the engine speed increase at the time of acceleration changes with values of SOC, and can suppress that a passenger | crew feels uncomfortable.

  Further, the PCM 3 determines that the acceleration operation is determined at the control limit of the second acceleration control when the gaseous fuel is used, that is, during the operation of the engine 5, the SOC is less than 45%, and the hydrogen fuel is a vehicle. When it is determined that the output corresponding to the required acceleration of 1 cannot be obtained, control is performed so that the fuel used is switched to gasoline that can output higher than hydrogen, so that deterioration of acceleration performance can be suppressed. Thus, the PCM 3 is determined to perform acceleration operation during operation of the engine 5 using hydrogen (gaseous fuel), and an output corresponding to the required acceleration of the vehicle 1 is obtained with an SOC of less than 45%. When it is determined that there is no fuel, the fuel switching control means for controlling the fuel to be switched to gasoline (liquid fuel) is also configured.

(Embodiment 2)
The present embodiment is different from the first embodiment in the control procedure in the case where the acceleration operation is determined during the operation of the engine 5 using the fuel to be used and the liquid fuel, and the SOC is less than a predetermined reference value. Hereinafter, differences from the first embodiment will be described.

  The engine 5 is a dual fuel engine that can selectively use liquid fuel and gaseous fuel as the fuel to be used, and can obtain substantially the same output when using gaseous fuel and when using liquid fuel. Here, examples of the liquid fuel include ethanol fuel, and examples of the gaseous fuel include hydrogen fuel.

  When the acceleration operation is determined during the operation of the engine 5 using the liquid fuel and the SOC is less than 45%, the PCM 3 switches the used fuel to the gaseous fuel. Thus, the PCM 3 has a fuel switching control means for controlling to switch the used fuel to the gaseous fuel when the acceleration operation is determined during the operation of the engine 5 using the liquid fuel and the SOC is less than 45%. Will also constitute.

-Processing operation of control device-
Here, the processing operation of the control device will be described based on the flowchart shown in FIG.

  In each step of steps SB1 to SB5, the same control as that of steps SA1 to SA5 of the first embodiment is executed. If the determination in step SB4 is YES, the process proceeds to step SB6, where the throttle opening and the engine speed N are determined based on the vehicle speed and the accelerator opening read in step SB1, and then the process proceeds to step SB7.

  In the next step SB7, it is determined whether or not gaseous fuel has been selected by operating the fuel selector switch 63. When the determination in step SB7 is YES, the process proceeds to step SB8. In the next step SB8, the gas fuel operation using the gaseous fuel as the fuel is set, and then the process proceeds to step SB9.

  In the next step SB9, it is determined whether or not an acceleration operation is performed. More specifically, it is determined whether or not the operating state belongs to a region (region C in FIG. 2) driven by electric power supplied from both the first motor 7 driven by the engine 5 and the battery 11. When the determination in step SB9 is NO, that is, it is determined that the operating state belongs to the region driven by the electric power supplied from the first motor 7 driven by the engine 5 (region B in FIG. 2). If so, go to Step SB10.

  In the next step SB10, the battery power assist amount is set to 0, and then the process proceeds to step SB11. In the next step SB11, the injection ratio of the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 50: 50, and then the process returns.

  On the other hand, when the determination in step SB9 is YES, that is, when it is determined that the operating state belongs to the region C in FIG. 2, the process proceeds to step SB12. Then, in the next step SB12, it is determined whether or not the SOC of the battery 11 calculated in step SB3 is 45% or more. When the determination in step SB12 is YES, the process proceeds to step SB13.

  In the next step SB13, the battery power assist amount is set large, and thereafter, the process proceeds to step SB11. In the next step SB11, the injection ratio of the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 50: 50, and then the process returns.

  On the other hand, when the determination in step SB12 is NO, that is, when the SOC of the battery 11 calculated in step SB3 is less than 45%, the process proceeds to step SB14, where the battery power assist amount is set small, and then step SB15 is performed. Proceed to In the next step SB15, the injection ratio of the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 90: 10, and then the process returns.

  On the other hand, when the determination in step SB7 is NO, the process proceeds to step SB16 to perform a liquid fuel operation using liquid fuel as the fuel, and then proceeds to step SB17. In the next step SB17, it is determined whether or not an acceleration operation is performed. When the determination in step SB17 is NO, that is, when it is determined that the operating state belongs to the region B in FIG. 2, the process proceeds to step SB18, the battery power assist amount is set to 0, and then the process returns.

  On the other hand, when the determination in step SB17 is YES, that is, when it is determined that the operating state belongs to the region C in FIG. 2, the process proceeds to step SB19, and the SOC of the battery 11 calculated in step SB3 is 45% or more. It is determined whether or not. When the determination in step SB19 is NO, the process proceeds to step SB20. In the next step SB20, the fuel is switched from the liquid fuel to the gaseous fuel to set the gaseous fuel operation, and then the process proceeds to step SB14.

  In the next step SB14, the battery power assist amount is set small, and then the process proceeds to step SB15. In the next step SB15, the injection ratio of the compression stroke and the intake stroke is set to compression stroke injection: intake stroke injection = 90: 10, and then the process returns.

  On the other hand, when the determination in step SB19 is YES, the process proceeds to step SB21, the battery power assist amount is set large, and then the process returns.

-Effect-
According to the present embodiment, when substantially the same output is obtained when using gaseous fuel and when using liquid fuel, the PCM 3 increases the compression stroke injection ratio, so the intake amount in the intake stroke increases and is high. Engine output can be obtained. Thereby, deterioration of acceleration performance can be suppressed.

(Other embodiments)
The present invention is not limited to the embodiments, and can be implemented in various other forms without departing from the spirit or main features thereof.

  In each of the above embodiments, the vehicle 1 is a series hybrid vehicle. However, the present invention is not limited to this, and the operating state of the engine 5 before acceleration during the control by the first acceleration control and the control by the second acceleration control, and If the requested acceleration degree of the vehicle 1 is the same, the vehicle 1 may be a parallel hybrid vehicle if the control for matching the way of increasing the engine speed is not performed.

  In each of the above embodiments, the SOC reference value for limiting battery power assist is set to 45%. However, the SOC is not limited to this, and may be determined as appropriate according to the capacity of the battery 11 or the like.

  Further, in each of the above embodiments, when the SOC is 45% or more, the injection ratio is set to compression stroke injection: intake stroke injection = 50: 50, and when the SOC is less than 45%, the injection ratio is compressed. Although stroke injection: intake stroke injection = 90: 10 is set, the present invention is not limited to this, and other injection ratios may be adopted as long as the required output can be obtained.

  As described above, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the present invention provides a control device for a hybrid vehicle that performs driving force assist for applying driving force to a vehicle by electric power of a battery when it is determined that acceleration operation is being performed during traveling by the driving force of the engine. Etc. are useful.

1 Vehicle 3 PCM (first acceleration control means) (second acceleration control means) (acceleration determination means) (injection timing control means) (acceleration / deceleration state detection means) (fuel switching control means) (SOC detection means)
5 Engine 7 First motor (generator)
9 Second motor (traveling motor)
11 Battery 33 Injector for hydrogen injection (fuel injection valve)
55 Vehicle speed sensor (acceleration / deceleration state detection means)
57 Accelerator opening sensor (acceleration determination means) (acceleration / deceleration state detection means)
59 Engine speed sensor (acceleration / deceleration state detection means)
61a Current sensor (SOC detection means)
61b Voltage sensor (SOC detection means)

Claims (2)

An engine, a travel motor driven by at least battery power, acceleration determination means for determining acceleration operation of the engine, and when the acceleration determination means determines acceleration operation during traveling by the driving force of the engine And a first acceleration control means for performing driving force assist for applying driving force to the vehicle with the electric power of the battery, and a hybrid vehicle control device comprising:
The above engine is a dual fuel engine that can selectively use liquid fuel and gaseous fuel as the fuel to be used, and can obtain higher output when using liquid fuel than when using gaseous fuel. ,
SOC detecting means for detecting the SOC of the battery;
Injection timing control means for injecting gaseous fuel from the intake stroke to the compression stroke of the cylinder by a fuel injection valve;
When the acceleration determination means determines that the vehicle is accelerating during traveling by the driving force of the engine and the SOC detected by the SOC detection means is less than a predetermined reference value, the driving force assist by the battery power is performed. Second acceleration control means for limiting and increasing the compression stroke injection rate;
When the acceleration operation is determined during operation of the engine using the gaseous fuel, the SOC is less than a predetermined reference value, and it is determined that an output corresponding to the required acceleration of the vehicle cannot be obtained. A control device for a hybrid vehicle, further comprising fuel switching control means for controlling the fuel to be used to switch to liquid fuel . An engine, a travel motor driven by at least battery power, acceleration determination means for determining acceleration operation of the engine, and when the acceleration determination means determines acceleration operation during traveling by the driving force of the engine And a first acceleration control means for performing driving force assist for applying driving force to the vehicle with the electric power of the battery, and a hybrid vehicle control device comprising:
The engine is a dual fuel engine that can selectively use liquid fuel and gaseous fuel as the fuel to be used, and can obtain substantially the same output when using gaseous fuel and when using liquid fuel.
SOC detecting means for detecting the SOC of the battery;
Injection timing control means for injecting gaseous fuel from the intake stroke to the compression stroke of the cylinder by a fuel injection valve;
When the acceleration determination means determines that the vehicle is accelerating during traveling by the driving force of the engine and the SOC detected by the SOC detection means is less than a predetermined reference value, the driving force assist by the battery power is performed. Second acceleration control means for limiting and increasing the compression stroke injection rate;
The acceleration operation is determined during operation of the engine using liquid fuel, and, if the SOC is less than the predetermined reference value, further comprising a fuel switching control means for controlling so as to switch the fuel used in the gaseous fuel, the and control apparatus for a hybrid vehicle, wherein it is.

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