JP6511787B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle capable of driving by independently driving an engine and an electric motor.

  In recent years, hybrid vehicles having an engine and an electric motor as drive sources are becoming widespread. Since hybrid vehicles can be controlled to rotate their wheels with an electric motor without starting the engine according to the driving situation, it is said that the consumption of petroleum fuel can be reduced and the amount of carbon dioxide emissions can be reduced. .

  Furthermore, in recent years, a plug-in hybrid car that can easily charge a battery provided in a vehicle by connecting the vehicle and a power outlet with a charging cable is also spreading. Plug-in hybrid cars can be recharged from household power supplies as well as electric appliances, and the capacity of the battery is also large. Therefore, compared to conventional hybrid cars, the distance that can be traveled only by the electric motor with one charge A long travel distance (hereinafter referred to as a continuous travel distance using only the electric motor) can be secured.

  By the way, as the continuous travel distance only by the electric motor of the hybrid vehicle becomes long, a situation may occur where fuel in the fuel tank is not consumed for a long time. The fact that the fuel in the fuel tank is not consumed for a long time leads to the deterioration of the fuel in the fuel tank.

  Deterioration of the fuel in the fuel tank may lower the startability of the engine, or may deteriorate the combustion state of the fuel or cause deterioration of members such as the fuel tank and the fuel pump. In addition, with the spread of plug-in hybrid cars, it is considered that the situation in which the engine is not started for a long time will further increase in the future.

  Therefore, in Patent Document 1, with regard to fuel supply to the fuel tank, the history of timing and amount of replenishment is stored, the degree of deterioration of the fuel in the fuel tank is calculated based on the history, and the degree of deterioration is greater than or equal to a predetermined level. There is disclosed a technology for transitioning to an operation mode (fuel consumption mode) in which the engine is forcibly started to consume fuel when it is reached.

JP, 2009-255680, A

  According to the technique of Patent Document 1, the ratio of the fuel whose elapsed time after replenishment to the total fuel in the fuel tank is a fixed value or more, that is, the ratio of the fuel to be degraded is calculated each time. For this reason, there is a problem that the degree of deterioration can not be accurately calculated if the error in the amount of fuel replenishment measured at the time of refueling is large.

  For example, in the case of a fuel tank for measuring the amount of fuel stored by detecting the level of the liquid level, if the vehicle is inclined or the liquid level is not stable due to the fluctuation of the fuel level, the replenishment amount of fuel is accurately determined. It can not be measured. In addition, in the case where the refueling is performed repeatedly and little by little, since the amount of replenishment at each replenishment opportunity is small, the total amount of replenishment may not be accurately integrated. This is because a small amount of refueling tends to make it difficult to accurately grasp the amount of refueling since the change in liquid level is very small.

  Furthermore, the device for detecting the storage amount of fuel in the fuel tank has an upper limit in the detectable range. For this reason, if the storage amount of fuel exceeds the upper limit, it is not possible to grasp an accurate storage amount and a change in the storage amount. That is, in the case of so-called full tank refueling, a refueling amount smaller than the actual refueling amount of fuel is calculated, and in many cases the correct refueling amount can not be grasped.

  In these cases, although the degree of deterioration of the fuel in the fuel tank is not so large, the proportion of the fuel to be deteriorated becomes large because the amount of replenishment is counted small, and the mode is shifted to the fuel consumption mode. It is assumed that Therefore, in the method of controlling the operation mode by the ratio of the fuel to be degraded in the fuel tank, it is considered that there is a situation where the fuel is consumed wastefully.

  Therefore, an object of the present invention is to provide a control device of a hybrid vehicle capable of accurately controlling the operation mode by accurately grasping the deterioration state of the fuel in the fuel tank.

  In order to solve the above-described problems, the present invention provides an engine start mode in which the engine is started by supplying fuel from the fuel tank to the engine, and only driving force of the electric motor by cutting off the fuel supply to the engine. In a control device of a hybrid vehicle capable of selecting an electric travel mode for traveling in a standby mode and a standby mode in which the supply of fuel to the engine is shut off and the electric motor is not driven, storage is performed to detect the storage amount of fuel in the fuel tank. Amount detection means, Refueling amount calculation means for calculating the replenishment amount of fuel to the fuel tank by change of the storage amount, and when the replenishment amount of fuel is a predetermined amount or more, the replenishment is counted once Refueling number storage means, refueling storage means for storing the counted timing of refueling and refueling amount at that time, Electric travel mode or standby mode The counted supplemented count has adopted a control apparatus for a hybrid vehicle and a driving mode control means for performing control to shift to the engine start mode is less than the predetermined number of times within a predetermined period of time in de.

  At this time, when fuel is replenished over the detection upper limit storage amount detected by the storage amount detecting means, the replenishment frequency integrating means is configured to calculate the replenishment amount even if the replenishment amount of the fuel is smaller than the predetermined amount. If the amount of fuel replenishment is equal to or greater than the second predetermined amount smaller than the predetermined amount, it is possible to adopt a configuration in which the replenishment is counted once.

  Further, a pressure sensor is provided in the fuel tank, and the storage amount detected by the storage amount detecting means is in the detection upper limit storage amount if there is replenishment of fuel over the detection upper limit storage amount detected by the storage amount detecting means. And the structure judged by the pressure or pressure change by the pressure sensor being more than predetermined pressure is employable.

  In each of these configurations, the operation mode control means may be configured to perform at least one refueling even if the counted number of refuelings in the electric drive mode or the standby mode is less than a predetermined number within a predetermined period. When the fuel supply amount is equal to or more than the third predetermined amount which is larger than the predetermined amount, it is possible to adopt a configuration in which control for maintaining the electric travel mode or the standby mode is performed.

According to the present invention, when the amount of fuel refilled into the fuel tank is equal to or greater than the predetermined amount, the refilling is counted once, and the counted number of times of refilling is determined in advance under the electric drive mode or the standby mode. When the number is less than the predetermined number, the engine start mode is entered, and when the number is equal to or more than the predetermined number, control for maintaining the electric travel mode or the standby mode is performed.
That is, as in the prior art, the fuel is not controlled by the ratio of the fuel to be degraded in the fuel tank, but the fuel is supplied a predetermined number of times within a predetermined time period. It was made to grasp the deterioration state of the fuel in the tank more accurately. For this reason, wasteful fuel consumption can be eliminated and the operation mode can be accurately controlled.

FIG. 1 is an overall view of an apparatus showing an embodiment of the present invention. It is a graph which shows control of this invention. It is a flowchart which shows control of this invention.

  Embodiments of the present invention will be described based on the drawings. This embodiment is a control device of a hybrid vehicle provided with an engine 1 and an electric motor 15 as drive sources.

  An example of a main device mounted on a hybrid vehicle is briefly shown in FIG. The hybrid vehicle includes an engine 1 and an electric motor 15 as drive sources for traveling on a vehicle body provided with wheels capable of traveling on a road surface.

  In the vehicle body, a generator for generating electricity by rotation of the engine 1, rechargeable batteries, a fuel tank 30 for supplying fuel to the engine 1, an inverter for controlling rotation of the electric motor 15, vehicle An electronic control unit 20 that controls the entire control device and other necessary devices are mounted. In the drawings, only main devices constituting the present invention are displayed, and the others are not shown.

  In this embodiment, although a gasoline engine provided with a fuel injection valve 9 is adopted as the engine 1, other engines such as a gasoline engine or a diesel engine that generate driving force by burning a fuel May be adopted.

  As shown in FIG. 1, in the engine 1, a piston 3 is accommodated in a cylinder, and an intake passage 4 and an exhaust passage 6 are connected to a combustion chamber 2. In the intake passage 4 and the exhaust passage 6, the opening to the combustion chamber 2 is opened and closed by the operation of the intake valve 5 and the exhaust valve 7, respectively.

  The intake passage 4 is provided with a throttle valve 11 that changes the degree of opening of the passage to adjust the amount of intake air supplied to the combustion chamber 2. A surge tank 10 is provided downstream of the throttle valve 11. An air cleaner 12 is provided on the upstream end side of the intake passage 4, and a fuel injection valve 9 for injecting fuel into the intake passage 4 is provided on the downstream end side of the intake passage 4. Further, the air cleaner 12 is provided with an air flow sensor 14 for detecting the amount of intake air to the intake passage 4, and the surge tank 10 is provided with an intake pressure sensor 13, and information obtained therefrom is controlled by the electronic control unit 20. It is used.

  The fuel tank 30 is usually provided at the rear of the vehicle body or the like. A fuel pump 32 is provided in the fuel tank 30. The fuel pump 32 is connected to a fuel supply pipe 34 that constitutes a fuel supply passage to the engine 1. The fuel supply pipe 34 is connected to the fuel injection valve 9 via the delivery pipe 36.

  In addition, the fuel tank 30 includes a fuel supply port 35 used when the fuel is internally refilled, a storage amount detection unit 31 for detecting the storage amount of fuel in the fuel tank 30, and the pressure in the fuel tank 30 and pressure. A pressure sensor 33 is provided to detect the change of.

  In this embodiment, a device provided with a float floating on the fuel in the fuel tank 30 is adopted as the storage amount detection means 31. The float moves up and down in the fuel tank 30 according to the fuel level position, and the position in the raising and lowering direction is converted into an electric signal, so that the electronic control unit 20 stores the amount of fuel in the fuel tank 30 Can be detected.

  The pressure sensor 33 is provided at an upper portion in the fuel tank 30, and can detect the pressure of the space above the liquid surface of the fuel in the fuel tank 30. When refueling port 35 is opened for refueling, the air pressure in the space becomes atmospheric pressure, and then the air pressure in the space increases as refueling is performed.

  By the way, the storage amount detection means 31 has a detection upper limit storage amount which is an upper limit value capable of detecting the storage amount, and when the fuel level becomes more than that, it always becomes full display and can not detect an increase in the storage amount. It has become. The code | symbol F of FIG. 1 shows the liquid level corresponding to detection upper limit storage amount. However, the pressure sensor 33 detects that the detected upper limit storage amount is higher than the detected upper limit storage amount, that is, when fuel is supplied across the detected upper limit storage amount. Since the pressure exceeding the corresponding upper limit pressure is detected, it is possible to recognize that the fuel supply over the detected upper limit storage amount has been made by the pressure or the pressure change.

  The engine 1 has an engine start mode in which the engine 1 is activated by the supply of fuel from the fuel tank 30 to the combustion chamber 2 under the control of the operation mode control means 24 included in the electronic control unit 20; It is possible to selectively control each operation mode of the electric traveling mode in which the supply is interrupted and the vehicle travels only by the driving force of the electric motor 15, and the standby mode in which the supply of fuel to the engine 1 is shut off and the electric motor 15 is not driven either. It has become. In the case of a vehicle having a structure in which the driving force of both the engine 1 and the electric motor 15 can be transmitted to the driving wheels, the traveling mode by both driving forces is one of the engine start modes since the engine 1 is started. Specify.

  For example, in the electric traveling mode, the electricity stored in the battery is converted by the inverter and the electric motor 15 is rotated to rotate the drive wheels for traveling. At this time, by disengaging the clutch provided in the middle of the power transmission path, the engine 1 is separated from the drive wheels, and the drive force is not transmitted from the engine 1 to the drive wheels.

  In the engine start mode, fuel is supplied to the combustion chamber 2 and the engine is started. In the idling state, the clutch provided in the middle of the power transmission path is disengaged. When traveling by the driving force of the engine 1, the drive wheel is rotated by the driving force of the engine 1 to travel by connecting the clutch. At this time, the vehicle travels while charging the battery with the generator.

  In the engine start mode, the amount of fuel to be supplied to the combustion chamber 2 and the timing of injection are determined in accordance with the state of the engine 1, the traveling condition of the vehicle, etc., and the injection of the fuel injection valve 9 is performed according to the determination. Time and injection timing are controlled. Control of the fuel pump 32 for supplying necessary fuel is performed by the fuel pump control means 25 provided in the electronic control unit 20.

  The fuel injection valve 9 is configured such that fuel does not flow into the combustion chamber 2 when the engine 1 is not started. At that time, when the pressure in the fuel supply pipe 34 and the delivery pipe 36 increases, a part of the fuel can be returned to the fuel tank 30 through a route different from the fuel supply pipe 34.

  Further, the electronic control unit 20 calculates the amount of fuel replenishment to the fuel tank 30 by the change in the amount of fuel stored in the fuel tank 30 at the time of refueling, and the amount of fuel replenishment The system is provided with a refueling number accumulating means 22 which counts the refueling as one time in the case of the fixed amount or more, and a refueling storage means 23 which stores the counted timing of refueling of fuel and the refueling amount of the fuel at that time.

  Hereinafter, the control method will be described based on the graph of FIG. 2 and the flowchart of FIG. 3. First, the vehicle is started in step S1 shown in FIG. Each operation mode of the engine start mode, the electric travel mode, and the standby mode is selected, and the vehicle travels appropriately based on the driver's operation. During operation, in step S2, it is determined whether refueling (refueling) has been performed. The presence or absence of fuel replenishment can be detected, for example, by a pressure change of the pressure sensor 33 or the like.

  When the fuel supply is completed, it is determined in step S3 whether or not the refueling is the fuel supply over the upper limit storage amount detected by the storage amount detection means 31.

  The amount of storage detected by the storage amount detection means 31 detects whether the supply of fuel is the supply of fuel over the detection upper limit storage amount detected by the storage amount detection means 31 (hereinafter referred to as full tank refueling) It is judged by the fact that the storage amount has been reached and that the pressure by the pressure sensor 33 has exceeded the upper limit pressure corresponding to the detected upper limit storage amount. Here, without using the numerical value of pressure, it may be determined whether or not full tank refueling is performed only by the fact that the storage amount is the detection upper limit storage amount.

  The fuel supply amount calculating means 21 detects the storage amount of the fuel in the fuel tank 30 before and after the fuel supply, and calculates the amount of the supplied fuel based on the difference between the storage amounts.

  If it is not full tank refueling, the process proceeds to step S4. In step S4, when the amount of fuel supplied is equal to or more than a predetermined amount G1 (for example, see FIG. 2), the replenishment number accumulating means 22 counts the replenishment as one time (step S5). At this time, the number N of times of refueling is +1. If the amount of fuel supplied is less than the predetermined amount G1, the supply is not counted. At this time, the above-mentioned predetermined amount, which is a threshold value for determining whether or not fuel supply is counted once, is referred to as a first threshold value. The first threshold can be, for example, 5 liters.

  For example, in FIG. 2, the vertical axis indicates the amount of fuel stored in the fuel tank 30. With the passage of time shown on the horizontal axis, a total of three refuelings are performed, and among them, the first and third refueling amounts excluding the second one are the refueling determination predetermined amount G1, that is, the first It is refueling above the threshold.

  Moreover, when it is full tank refueling, it transfers to step S9. In step S9, when the amount of supplied fuel is equal to or greater than a second predetermined amount set to a value smaller than the predetermined amount G1, the number-of-repairs integration unit 22 counts the replenishment as one time (see FIG. Step S5). At this time, the number N of times of refueling is +1. Also, if the amount of fuel supplied is less than the second predetermined amount, the supply is not counted. At this time, the above-mentioned second predetermined amount, which is a threshold for determining whether or not the fuel supply in full tank refueling is counted once, is hereinafter referred to as a second threshold. The second threshold may be, for example, 3 liters smaller than the first threshold. All the information on the refueling is stored by the refueling storage means 23.

  Next, in step S6, the number of times of refueling N is calculated. The number of times of refueling N is the number of times of refueling counted within a period traced back from the present to the past for a predetermined period (predetermined period T1 (for example, see FIG. 2)). The predetermined predetermined period T1 can be a period in which the deterioration of the fuel is feared by leaving the fuel, and is appropriately determined according to the type and specification of the fuel. For example, the predetermined period T1 can be three months or the like.

  In step S7, if the number of times of replenishment N counted by the number of times of replenishment accumulation means 22 is less than the predetermined number of times N1 within the predetermined period T1, the process proceeds to step S10. In step S10, the operation mode is controlled to the fuel consumption mode.

  In the control to the fuel consumption mode, when the current operation mode is the engine start mode, the engine start mode is continued until consumption of a predetermined amount of fuel is performed. In the electric drive mode or the standby mode, the engine 1 is forcibly started, and the start state of the engine 1 is continued until consumption of a predetermined amount of fuel is performed. Therefore, the operating condition changes during traveling, and in the case of normal control, transitioning from the engine start mode to the electric drive mode or the standby mode is not performed, and the engine start mode is maintained as it is. .

  That is, in this fuel consumption mode, the engine 1 is started for the purpose of forcibly consuming the fuel. Therefore, after the transition to the fuel consumption mode, the engine 1 being started is started according to the driving condition of the vehicle. It is also assumed that the driving force is transmitted to the drive wheels, and also assumed that the driving force of the engine 1 being activated is not transmitted to the drive wheels. Here, the case where the driving force of the engine 1 being activated is not transmitted to the drive wheels is the state where the vehicle is running with a stop or inertia while the engine 1 is activated, or only the driving force of the electric motor 15 Are transmitted to the drive wheels.

  In addition, the amount of fuel forcibly consumed, that is, the above-described predetermined amount of fuel is the amount of fuel remaining in the fuel tank 30 in order to suppress the deterioration of the fuel in the fuel tank 30. And, in order to reduce the proportion of the deteriorated fuel, it is appropriately determined according to the amount of fuel to be supplied next. For example, when the remaining amount of fuel in the fuel tank 30 is 40 liters, the fuel consumption mode is maintained until 10 liters of fuel is consumed, and the remaining amount of fuel in the fuel tank 30 is 20 liters. In some cases, the fuel consumption mode is maintained until the fuel is consumed by 5 liters of fuel.

  In step S7, when the number N of times of replenishment counted by the replenishment number integrating means 22 is equal to or more than the predetermined number N1 within the predetermined period T1, the process proceeds to step S8. In step S8, the operation mode is controlled to the normal mode.

  In the control to the normal mode, when the current operation mode is the engine start mode, the engine start mode is continued under normal control. Even when the current operation mode is the electric drive mode or the standby mode, the electric drive mode or the standby mode is continued under normal control. That is, the operation control mode that is normally performed is continued according to the required driving conditions such as the traveling torque and the load.

  In addition to the flow chart shown in FIG. 3, the operation mode control means 24 counts the number of replenishments counted by the number-of-replications integration means 22 even if the number of replenishments is less than the predetermined number N1 within the predetermined period T1. If the amount of fuel replenishment in at least one of the refueling operations is equal to or greater than a third predetermined amount determined to be larger than the predetermined amount G1 (first threshold value), the normal mode is controlled. That is, when the current operation mode is the electric drive mode or the standby mode, the electric drive mode or the standby mode is maintained.

  Here, the third predetermined amount can be set to, for example, 15 liters. Even if the counted number of times of refueling N is less than the determined number, it can be determined that there is no need to worry about the deterioration of the fuel if the fuel is replenished with a certain amount of fuel. The control of the operation mode based on the third predetermined amount can be performed, for example, between step S7 and step S10 shown in the flowchart of FIG.

  In this embodiment, a device provided with a float floating on the fuel of the fuel tank 30 is adopted as the storage amount detecting means 31, but the storage amount detecting means 31 may be adopted by various means other than the float. For example, a device that can recognize the fuel level position by a contact or non-contact sensor may be used.

  As described above, according to the present invention, when the amount of fuel replenishment into the fuel tank 30 is equal to or greater than the predetermined amount G1, the replenishment is counted once and the counted replenishment is performed under the electric drive mode or the standby mode. When the number of times N is less than the predetermined number of times N1 within a predetermined predetermined period T1, control is made to maintain the electric drive mode or the standby mode when the number of times N1 or more. Therefore, the deterioration state of the fuel in the fuel tank 30 can be more accurately reflected in the control. For this reason, wasteful fuel consumption can be eliminated and the operation mode can be accurately controlled.

  Also, in the case of so-called full tank refueling, the amount of fuel replenishment tends to be calculated to be smaller than the actual amount of fuel replenishment, so the refueling amount that is the basis of the refueling count at full tank refueling is By setting the predetermined amount G1, which is the basis of the normal counting, to a second predetermined amount smaller than the predetermined amount G1, it is possible to make the grasp of the deterioration state of the fuel more accurate.

  Furthermore, even if the counted number of times of replenishment is less than the predetermined number of times N1 within the predetermined period T1, the amount of fuel replenishment in at least one replenishment is larger than the predetermined amount G1 which is the basis of normal counting. In the case of the predetermined amount or more, the forced fuel consumption is not performed, so wasteful fuel consumption can be suppressed more effectively.

DESCRIPTION OF SYMBOLS 1 engine 2 combustion chamber 3 piston 4 intake passage 5 intake valve 6 exhaust passage 7 exhaust valve 8 spark plug 9 fuel injection valve 10 surge tank 11 throttle valve 12 air cleaner 13 intake pressure sensor 14 air flow sensor 15 electric motor 20 electronic control unit 21 fuel Refueling amount calculating means 22 Refilling number accumulating means 23 Refueling storing means 24 Operation mode control means 25 Fuel pump control means 30 Fuel tank 31 Storage amount detecting means 32 Fuel pump 33 Pressure sensor 34 Fuel supply pipe 35 Refueling port 36 Delivery pipe

Claims (3)

An engine start mode in which the engine is started by supplying fuel from the fuel tank to the engine, an electric travel mode in which the fuel supply to the engine is shut off and the vehicle travels with only the driving force of the electric motor In a control device of a hybrid vehicle capable of selecting a standby mode in which the supply is interrupted and the electric motor is not driven.
Storage amount detecting means for detecting the storage amount of fuel in the fuel tank;
Refueling amount calculation means for calculating the refueling amount of the fuel tank by changing the storage amount;
A replenishment number counting means for counting the replenishment once if the replenishment amount of the fuel is equal to or more than a predetermined amount;
Refueling storage means for storing the counted timing of refueling and the amount of refueling at that time;
Even operating condition the electric traveling mode or the standby mode is selected, when the counted supplemented count is less than the predetermined number of times within a predetermined time period which is determined in advance, it shifts to the engine start mode Operation mode control means for performing control;
Bei to give a,
When the fuel is replenished over the detection upper limit storage amount detected by the storage amount detecting means, the replenishment frequency integrating means replenishes the fuel even if the replenishment amount of the fuel is smaller than the predetermined amount. The control device of a hybrid vehicle that counts the replenishment as one time when the amount is equal to or more than a second predetermined amount smaller than the predetermined amount . A pressure sensor in the fuel tank;
The presence or absence of the replenishment of fuel straddling the detection upper limit storage amount by the storage amount detection means that the storage amount detected by the storage amount detection means is in the detection upper limit storage amount, and the pressure or pressure change by the pressure sensor is The control device of a hybrid vehicle according to claim 1 , which is determined by having a predetermined pressure or more. Wherein the operation mode control means is a driving condition of the electric travel mode or the standby mode is selected, it is less than the predetermined number of times within a predetermined period in which the counted supplemented number predetermined, at least 1 times when more than a predetermined amount of fuel in the replenishment supply amount of the predetermined amount greater than the third control of the hybrid vehicle according to claim 1 or 2 performs control to keep the electric travel mode or the standby mode apparatus.

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