JP2016175501A - Hybrid vehicle and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle and a control method therefor such that while regeneration efficiency in a higher speed travel than usual is improved, a fuel consumption is reduced without stopping a steering assist in an auto-cruising mode and loss of energy consumed by an engine brake and a foot brake before entering traffic congestion is suppressed so as to improve fuel economy.SOLUTION: A hybrid vehicle comprises a speed reduction mechanism 30 which connects a propeller shaft 25 to a rotary shaft 32 of a motor generator 33 and a driving shaft 46 of a second power steering pump 45 respectively, and a switching device which switches a supply source for a power steering fluid to a steering unit 53 to the second power steering pump 45, and a controller 80 is configured to perform control to predict a traffic congestion section L6 and a speed reduction section L5, to select one of an assist travel and a motor travel until the speed reduction section L5 is reached, and to change a charged state Ce of a battery 35 at a starting point B thereof to a low charged state Cl.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hybrid vehicle and a control method thereof, and more specifically, while reducing the fuel consumption without stopping the steering assist in the auto-cruise mode while improving the regeneration efficiency at the time of high-speed traveling than before, and The present invention relates to a hybrid vehicle and a control method for the same that suppress a loss of energy that is wasted by engine brakes and foot brakes before entering a traffic jam to improve fuel efficiency.

  In recent years, a hybrid vehicle (hereinafter referred to as “HEV”) including a hybrid system having an engine and a motor generator that are controlled in combination according to the driving state of the vehicle has attracted attention from the viewpoint of improving fuel efficiency and environmental measures. Yes. In the HEV, when the vehicle is accelerated or started, the driving force is assisted by the motor generator, while regenerative power generation is performed by the motor generator during inertia traveling or braking (see, for example, Patent Document 1).

  In such a so-called parallel HEV, the motor generator is normally connected to the drive system of the vehicle from the engine side of the transmission for shifting the rotational power of the engine. For this reason, when the HEV is traveling at high speed (for example, 50 to 90 km / h), the transmission is shifted to a high speed, so that the regenerative braking torque in the motor generator is reduced and the power generation is increased. There is a problem that it is difficult to improve the efficiency of regenerative power generation because it is out of the efficiency point.

  Further, since it is necessary to change the layout of the powertrain components of the existing vehicle in order to arrange the motor generator, there is a problem that it is not easy to convert the existing vehicle to HEV.

  In order to solve such a problem, the inventor uses a propeller shaft of a vehicle and a rotation shaft of a motor generator via a reduction mechanism having the rotation shaft of the motor generator as an input shaft and the propeller shaft as an output shaft. Invented to connect.

  Furthermore, the inventor focused on the fuel consumption in the auto cruise mode in order to improve the fuel efficiency of the newly devised HEV, and more specifically to improve the fuel efficiency of large vehicles such as HEV buses and trucks. .

  In the auto-cruise mode, based on the map information including the gradient and distance of the travel path to be traveled and the HEV vehicle weight, the engine travels with the driving force of the engine, and the assist with the driving force of both the engine and the motor generator. The vehicle speed is maintained at the target speed by appropriately selecting traveling, motor traveling that travels with the driving force of the motor generator, and inertia traveling that does not apply the driving force of the engine and the motor generator.

  However, in large vehicles such as buses and trucks, hydraulic steering units are used as steering units (power steering) to assist the driver's steering from the viewpoint of output, steering performance, and reliability. During this time, it is necessary to always supply power steering fluid to the hydraulic steering unit from a power steering pump that is driven by transmission of the driving force of the engine. Therefore, there is a problem in that the fuel consumption cannot be reduced because the engine cannot be stopped during the motor running or the inertia running.

  In addition, when a traffic jam section is obtained from map information, it is necessary to reduce the HEV vehicle speed to the traffic jam speed in the traffic jam section with the braking force of the engine brake, foot brake, etc. before entering the traffic jam section. There is a problem in that energy loss due to these occurs and fuel consumption deteriorates.

JP 2002-238105 A

  The object of the present invention is to improve the regenerative efficiency during high-speed driving than before, reduce the fuel consumption without stopping the steering assist in the auto-cruise mode, and before entering the traffic jam, It is an object of the present invention to provide a hybrid vehicle and a method for controlling the same that can improve fuel efficiency by suppressing loss of energy wasted due to braking.

  The hybrid vehicle of the present invention that achieves the above object is a propeller shaft that connects a transmission that is connected to a diesel engine via a clutch and a differential that drives a drive wheel, and is electrically connected to the diesel engine and a battery. A hybrid system having a motor generator, a first power steering pump connected to the diesel engine, a steering unit for assisting steering using a power steering fluid supplied from the first power steering pump, and at least a traffic congestion section In a hybrid vehicle comprising a map information acquisition device that acquires map information including a vehicle weight estimation device that estimates vehicle weight, a vehicle speed acquisition device that acquires vehicle speed, and a control device, the propeller shaft and the motor generator A speed reduction mechanism that connects the rotation axis of the motor to the rotation axis of the motor generator as an input axis and the propeller shaft as an output axis, and a second power steering pump coupled to the propeller shaft via the reduction mechanism; A switching device that switches the power supply source of the power steering fluid supplied to the steering unit from the first power steering pump to the second power steering pump when the first power steering pump stops with the stop of the diesel engine; The inertial running that does not transmit the driving force of the diesel engine and the motor generator to the propeller shaft when the auto cruise mode for maintaining the vehicle speed within a preset target speed range is set. Is selected based on the map information and the vehicle weight, In addition to controlling the diesel engine to be stopped by stopping the fuel injection and stopping the diesel engine during recreational driving, at least the regenerative braking by the regenerative power generation of the traffic jam section and the motor generator is operated Then, before entering the traffic jam section, control is performed to predict the deceleration section that decelerates the vehicle speed to the traffic jam speed in the traffic jam section based on the map information and the vehicle weight, and the predicted deceleration Before reaching the start point of the section, select at least one of the assist traveling or the motor traveling that travels with the driving force transmitted from the motor generator to the propeller shaft via the speed reduction mechanism, and start the section. The charging state of the battery at the point is set to a full discharge state or more and a half charge state or less. Further, it is characterized in that it is configured to perform control to make it in a low charge state.

Further, the hybrid vehicle control method of the present invention that achieves the above object is an engine that travels with a driving force transmitted from a diesel engine to a propeller shaft via a clutch and a transmission when the auto-cruise mode is set. Assist traveling that travels with both driving force of the diesel engine and driving force transmitted to the propeller shaft via a speed reduction mechanism from a motor generator electrically connected to the battery; and
Based on the map information and the vehicle weight, a motor speed that travels with the driving force of the motor generator and an inertial driving that does not transmit the driving force of the diesel engine and the motor generator to the propeller shaft are selected at appropriate times. While maintaining the preset target speed range and automatically driving, when the coasting is selected, the clutch is disengaged to stop the diesel engine and stop when the diesel engine stops. Instead of the first power steering pump, a control method for a hybrid vehicle that supplies power steering fluid to the steering unit by driving the second power steering pump with the rotational power transmitted from the propeller shaft via the speed reduction mechanism, Depending on the traffic jam section and regenerative power generation of the motor generator Based on the map information and the vehicle weight, the vehicle speed is decelerated to decelerate the vehicle speed to the traffic speed in the traffic jam section before entering the traffic jam section by operating at least a regenerative brake. By selecting either the assist driving or the motor driving until the starting point of the vehicle is reached, the charging state of the battery at the starting point is set to a full charge state or more and a half charge state or less. It is a method characterized by making a state.

  According to the hybrid vehicle and its control method of the present invention, the regenerative efficiency during high-speed traveling can be improved by connecting the rotating shaft of the motor generator and the propeller shaft via the speed reduction mechanism.

  In addition, the second power steering pump is connected to the propeller shaft via a speed reduction mechanism, and the power steering fluid supply source when the driving of the first power steering pump is stopped is switched to the second power steering pump, thereby driving the first power steering pump. Even if the engine stops, the supply of power steering fluid to the steering unit is always maintained, so that it is possible to avoid stopping the steering assist.

  In addition, while coasting in the auto cruise mode, the clutch is disengaged and the fuel injection is stopped to stop the diesel engine and the idling stop state. Can be reduced.

  In addition, predict the traffic jam zone and the deceleration zone that decelerates the vehicle speed to the traffic jam speed in the traffic jam zone before entering the traffic jam zone by operating at least the regenerative brake and reach the start point of the deceleration zone Until it is selected, assist driving or motor driving, and the motor generator is driven to rotate by the electric power charged in the battery, and the engine speed of the diesel engine is reduced to the low speed side or the output is suppressed. Can reduce fuel consumption.

  In addition, the battery charge state is set to a low charge state before reaching the start point of the deceleration zone.Therefore, during deceleration in the deceleration zone, an opportunity to operate the regenerative brake that regenerates the motor generator is given. Can be increased.

  In other words, predict the opportunity to decelerate the vehicle speed to the congestion speed, in other words, predict the chance that the battery can be charged by operating the regenerative brake, and before that, perform assist driving or motor driving to determine the battery charge state in advance By keeping the battery in a low charge state, while maintaining the battery charge state within the appropriate range, it increases the chances of regenerative braking when decelerating the vehicle speed to the congestion speed, so it is wasted when operating the engine brake and foot brake. Energy consumption can be suppressed, and fuel consumption by driving the diesel engine for power generation by the motor generator can be suppressed, thereby improving fuel efficiency.

It is a block diagram of the hybrid vehicle which consists of embodiment of this invention. It is a block diagram which shows the vehicle-mounted network and control signal line of FIG. It is a flowchart explaining the control method of the hybrid vehicle which consists of embodiment of this invention. Explanatory diagram illustrating the relationship between vehicle speed, engine torque, motor generator torque, battery charge state, and altitude when driving in the auto cruise mode up to the deceleration zone and decelerating after releasing the auto cruise mode from the deceleration zone It is.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a hybrid vehicle according to an embodiment of the present invention. In addition, the dashed-dotted line of FIG. 2 has shown the vehicle-mounted network and the control signal line.

  This hybrid vehicle (hereinafter referred to as “HEV”) is a large vehicle such as a bus or a truck, and includes a hybrid system having a diesel engine 10 and a motor generator 33 that are controlled in combination according to the driving state of the vehicle. Yes. The HEV also includes a power steering system having a steering unit 53 that assists the steering of the steering 54 using the power steering fluid 51. Further, the HEV is configured to execute the auto cruise mode when the auto cruise operation switch 81 is turned on by the driver in the control device 80.

  First, the HEV hybrid system will be described. In the diesel engine 10, the crankshaft 13 is rotationally driven by thermal energy generated by the combustion of fuel in a plurality (six in this example) of cylinders 12 formed in the engine body 11. The rotational power of the crankshaft 13 is transmitted to the transmission 20 through the fluid coupling 14 and the wet multi-plate clutch 15 (hereinafter referred to as the clutch 15). A dry clutch may be used instead of the fluid coupling 14 and the wet multi-plate clutch 15.

  The transmission 20 uses an AMT that automatically shifts gears to a target gear determined based on the HEV operating state and preset map data. The transmission 20 includes a main transmission mechanism 21 capable of shifting input rotational power in a plurality of stages, and a sub-transmission mechanism capable of shifting rotational power transmitted from the main transmission mechanism 21 into two stages, a low speed stage and a high speed stage. 22.

  The rotational power changed by the transmission 20 is transmitted to the differential 26 through the propeller shaft 25 connected to the output shaft 23, and is distributed as a driving force to a pair of driving wheels 27 made of double tires.

  The motor generator 33 is electrically connected to the battery 35 through the inverter 34.

  The diesel engine 10 and the motor generator 33 are controlled by a control device 80. Specifically, the diesel engine 10 uses the engine speed Ne detected by the speed sensor 86 and the accelerator pedal depression amount detected by the accelerator opening sensor 92 to inject fuel into the cylinder 12 and the injection timing. Is adjusted. Further, the motor generator 33 adjusts the frequency of the inverter 34 and the current value between the battery 35 and the motor generator 33 according to the state of charge (SOC) of the battery 35, and the motor generator 33 when the HEV starts or accelerates. While assisting at least a part of the driving force, regenerative power generation is performed by the motor generator 33 during inertial running or braking, and surplus kinetic energy is converted into electric power to charge the battery 35.

  The propeller shaft 25 and the rotating shaft 32 of the motor generator 33 are connected via a speed reduction mechanism 30. The speed reduction mechanism 30 uses the rotating shaft 32 of the motor generator 33 as an input shaft and the propeller shaft 25 as an output shaft. That is, in the speed reduction mechanism 30, the speed reduction ratio (Nm / Np), which is the ratio of the rotation speed Np of the propeller shaft 25 to the rotation speed Nm of the motor generator 33, is greater than 1.0. Note that this reduction ratio may be set to either fixed or variable.

  By providing the speed reduction mechanism 30, the regenerative braking torque of the motor generator 33 can be increased by the speed reduction mechanism 30 regardless of the gear stage of the transmission 20 during inertia traveling during high speed travel, thereby improving the regenerative efficiency. can do.

  In addition, since the speed reduction mechanism 30 is only newly attached to the propeller shaft 25 of the vehicle, and the layout of the powertrain component can be changed very little, the conversion from the existing vehicle can be performed more easily than before. .

  Next, the HEV power soaring system will be described. In this power steering system, the drive shaft 41 of the first power steering pump 40 is connected to the crankshaft 13 of the diesel engine 10 via a V-belt 42 or a gear, and the first power steering pump 40 driven by the diesel engine 10. However, the power steering fluid 44 is pumped to the first hydraulic circuit 43. The steering unit 53 assists the steering of the steering 54 using the supplied power steering fluid 51. Note that since the HEV of this embodiment is a large vehicle, a hydraulic steering unit including a hydraulic power cylinder having a large output and excellent steering performance and reliability is used as the steering unit 53.

  The second power steering pump 45 is connected to the propeller shaft 25 via the speed reduction mechanism 30. A double check valve 49 for switching the power supply source of the power steering fluid 51 from the first power steering pump 40 to the second power steering pump 45, various hydraulic circuits (first hydraulic circuit 43, second hydraulic circuit 47 and main hydraulic circuit 50), and When the first power steering pump 40 is stopped by the switching device including the accumulator 52 as the diesel engine 10 is stopped, the power source fluid 51 supplied to the steering unit 53 is supplied from the first power steering pump 40 to the first power steering pump 40. It is switched to the 2 power steering pump 45.

  The first hydraulic circuit 43 communicates the first power steering pump 40 and the double check valve 49. The second hydraulic circuit 47 communicates the second power steering pump 45 and the double check valve 49. It should be noted that the upstream end portion of the first hydraulic circuit 43 upstream of the first power steering pump 40 and the upstream end portion of the second hydraulic circuit 47 upstream of the second power steering pump 45 store the power steering fluids 44 and 48. Not connected to reservoir tank. The main hydraulic circuit 50 communicates the double check valve 49 and the steering unit 53. Further, the middle of the passage of the main hydraulic circuit 50 is branched and connected to the accumulator 52.

  The drive shaft 46 of the second power steering pump 45 is connected to the propeller shaft 25 via the speed reduction mechanism 30. Specifically, the propeller shaft 25 of the speed reduction mechanism 30 of the second power steering pump 45 and the motor generator 33 are connected. The first power transmission path 104 is connected to the propeller shaft 25 via a second power transmission path 105 arranged separately. In addition, the 1st power transmission path 104 and the 2nd power transmission path 105 can illustrate a gear mechanism, a belt mechanism, and a chain mechanism. If the second power transmission path 105 is configured to be connectable to the propeller shaft 25, the connection with the propeller shaft 25 can be released when the second power steering pump 45 is not driven, and the drive loss can be reduced accordingly.

  The double check valve 49 preferentially guides the higher one of the power steering fluids 44 and 48 supplied from the first power steering pump 40 and the second power steering pump 45 to the steering unit 53 via the main hydraulic circuit 50. It is a valve. Therefore, it is preferable that the set discharge pressure of the power steering fluid 48 of the second power steering pump 45 is set to be smaller than the setting discharge pressure of the power steering fluid 44 of the first power steering pump 40. Specifically, the second power steering pump 45 is provided with a relief valve. By adjusting the relief valve, the set discharge pressure of the second power steering pump 45 is smaller than the set discharge pressure of the first power steering pump 40. The value has been adjusted.

  The accumulator 52 accumulates the power steering fluid 51 (= 44, 48) supplied from the first power steering pump 40 and the second power steering pump 45 via the double check valve 49, and the supply source of the power steering fluid 51 is the double check valve 49. The accumulated power steering fluid 51 is supplied to the steering unit 53. Since this accumulator 52 can suppress a large fluctuation in the pressure of the power steering fluid 51 supplied to the steering unit 53, it is possible to avoid a deterioration in drivability.

  In this way, the second power steering pump 45 is connected to the propeller shaft 25 via the speed reduction mechanism 30, and the supply source of the power steering fluid 51 is switched from the first power steering pump 40 to the second power steering pump 45 by the switching device. Even when the power steering fluid 44 is not supplied from the first power steering pump 40 during traveling, the power steering fluid 48 pumped from the second power steering pump 45 driven by the rotational power of the propeller shaft 25 via the speed reduction mechanism 30 is converted into the steering unit. 53 can be supplied. Thereby, even if the diesel engine 10 is stopped during traveling, it is possible to avoid stopping the steering assist of the steering 54 during traveling.

  When the power steering fluid 44 is not supplied from the first power steering pump 40 during traveling, for example, when the diesel engine 10 stops, the first power steering pump 40 fails or the first hydraulic circuit 43 is damaged. A case where the vehicle falls into a situation and a case where the HEV travels only by the driving force of the motor generator 33 can be exemplified.

  Next, the auto cruise mode will be described. This auto-cruise mode is used especially when driving on a highway, and the program stored in the control device 80 automatically runs HEV when the auto-cruise operation switch 81 is turned on by the driver. It is a mode that runs on the street.

  Specifically, when the auto-cruise operation switch 81 is turned on, the control device 80 performs map information and vehicle weight acquired by the map information acquisition device 82 for engine travel, assist travel, motor travel, and inertia travel. This mode is a mode in which HEV is automatically driven while being selected in a timely manner based on the vehicle weight M estimated by the estimation device 83 and maintaining the vehicle speed V acquired by the wheel speed sensor 84 within a preset target speed range.

  During the auto-cruise mode, if the accelerator pedal depression is detected by the accelerator opening sensor 92, the acceleration can be accelerated by the driving force from the diesel engine 10. When the brake pedal opening sensor 93 detects the depression of the brake pedal, the depression of a clutch pedal (not shown), or the release of the auto cruise operation switch 81 is released, the auto cruise mode is released. The

  The target speed range is a range between the upper limit speed vb and the lower limit speed vc with reference to the target speed va. The target speed va, the upper limit speed vb, and the lower limit speed vc can be set to arbitrary values by the driver. For example, the target speed va is set to 70 km / h or more and 90 km / h or less, and the upper limit speed vb is the target speed vb. The speed va is set to 0 km / h or higher and +10 km / h or lower, and the lower limit speed vc is set to -10 km / h or higher and 0 km / h or lower to the target speed va.

  The map information acquisition device 82 communicates with a satellite positioning system (GPS) connected to the control device 80 to acquire the current position of the HEV, and with a server storing 3D road data. It comprises means for acquiring three-dimensional road data including the slope θ and the travel distance s of the travel road, and means for extracting the slope θ and the travel distance s of the travel path from which the HEV will travel. As described above, a device that obtains a gradient θ for each traveling distance s by dividing a traveling distance s of 500 km or less into a traveling distance s every 500 m, and a device that obtains a traveling distance s for each gradient θ. It can be illustrated.

  The map information acquisition device 82 is not particularly limited as long as it has a function capable of acquiring at least the gradient θ and the travel distance s of the travel path. For example, the map information acquisition device 82 is stored in a drive recorder. An example of obtaining the gradient θ and the travel distance s of the travel path from the obtained three-dimensional road data is also possible. Further, the gradient θ may be calculated based on values acquired by the wheel speed sensor 84 and the acceleration sensor (G sensor) 85.

  The vehicle weight estimation device 83 is stored in the control device 80 and is transmitted to the drive wheel 27, specifically, a program for estimating the vehicle weight M when the control device 80 performs motor travel at the time of starting acceleration. Assuming that the driving force Fm is equal to the running resistance R, the motor rotation sensor 36 that obtains the output torque Tm of the motor generator 33 acquired by the inverter 34 and the rotation speed of the motor generator 33 in the motor running at the time of start acceleration. A program for estimating the vehicle weight M can be exemplified based on the acquired vehicle acceleration (hereinafter referred to as acceleration) a.

  The specific configuration of the vehicle weight estimation device 83 is not particularly limited as long as it has a function capable of estimating the vehicle weight M of HEV. However, the output torque Tm and acceleration at the time of starting acceleration by motor traveling are not limited. If the vehicle weight M is estimated based on a, the vehicle weight M can be estimated even when the vehicle speed V is low (speed of 30 km / h or less), and the rolling resistance Rr and air resistance of the running resistance R are estimated. Since each of Rd and the climbing resistance Rs can be disabled and the variables can be reduced, the vehicle weight M can be estimated more accurately and simply. In addition, the time of starting acceleration by motor running includes the time of HEV reverse.

  The control method in the auto cruise mode will be described below as a function of the control device 80. First, when the auto cruise operation switch 81 is turned on by the driver while the HEV is running, the control device 80 maintains the vehicle speed V within the target speed range based on the map information and the estimated vehicle weight M. Any one of engine running, assist running, motor running, and inertia running is selected as appropriate.

  The engine travels the HEV by the driving force Fe transmitted from the diesel engine 10 to the propeller shaft 25 via the clutch 15 and the transmission 20. In the assist travel, the HEV travels with both the driving force Fe from the diesel engine 10 and the driving force Fm transmitted from the motor generator 33 to the propeller shaft 25 via the speed reduction mechanism 30. In the motor travel, the HEV is traveled by the driving force Fm from the motor generator 33 with the clutch 15 disengaged. In inertial running, the HEV is run without transmitting the driving force of the diesel engine 10 and the motor generator 33 to the propeller shaft 25.

  Further, the control device 80 controls the clutch 15 to be disengaged and stop the fuel injection to stop the diesel engine 10 during coasting, and maintains the idling stop state during coasting. doing.

  As described above, even if the first power steering pump 40 is stopped when the diesel engine 10 is stopped, the power steering fluid 51 is constantly supplied from the second power steering pump 45 connected to the propeller shaft 25 to the steering unit 53. During the HEV traveling, the diesel engine 10 can be stopped without stopping the steering assist. Therefore, the fuel consumption during inertia traveling can be reduced by setting the clutch 15 to the disconnected state and stopping the diesel engine 10 by stopping the fuel injection during inertia traveling.

  Further, since the diesel engine 10 is stopped during coasting, the exhaust gas 71 from the exhaust valve 70 can be reduced, so that the exhaust gas is disposed in the exhaust passage 73 and passes through the exhaust manifold 72 from the exhaust valve 70. Thus, it is possible to suppress a reduction in the purification capacity of the exhaust gas purification device 75 that purifies the exhaust gas 71 that has driven the turbine 74. As a result, when the purification capacity of the exhaust gas purification device 75 is lowered, the fuel that does not contribute to the driving force of the HEV is injected to increase the temperature of the exhaust gas 71 to recover the purification capacity of the exhaust gas purification device 75. Since the opportunity for regeneration is reduced, the fuel consumption required for the regeneration can also be reduced. As the exhaust gas purification device 75, for example, a collection device that collects particulate matter in the exhaust gas 71 can be exemplified, and accumulation of particulate matter on the collection device is suppressed during motor running and inertia running. Therefore, fuel consumption necessary for regeneration of the collection device can be suppressed.

  In addition, the clutch 15 is disengaged during inertia traveling and the diesel engine 10 is stopped by stopping fuel injection, so that the rotational power of the propeller shaft 25 is reduced by the rotational drag of the diesel engine 10. Since this can also be avoided, energy loss during motor running and inertia running can be reduced to further improve fuel efficiency.

  In addition, the control device 80 may perform control to stop the diesel engine 10 by stopping the fuel injection while disengaging the clutch 15 while the motor is running.

  As described above, since the motor travel is stopped as well as the inertia travel, the fuel consumption during the motor travel can be reduced and the reduction in the purification capacity of the exhaust gas purification device 75 can be suppressed. Fuel consumption can be improved.

  In such HEV, the control device 80 is configured to perform control to predict the traffic congestion section L6 and the deceleration section L5 before entering the traffic congestion section L6 based on the map information and the vehicle weight M. The Then, the control device 80 selects either assist traveling or motor traveling until it reaches the starting point B of the deceleration zone L5, and sets the state of charge (SOC) Ce of the battery 35 at the starting point B. It is configured to perform control so that the low charge state Cl is set to the full discharge state (0%) or more and less than the half charge state (50%).

  For example, on a highway, the traffic congestion section L6 is a section of a traveling road in which a train that repeats a low speed travel or stop transmission at a traffic speed vd of 40 km / h or less continues for 1 km or more and 15 minutes or more. It can be illustrated.

The deceleration section L5 is predicted to reduce the vehicle speed V to the congestion speed vd in the traffic congestion section L6 by applying at least a braking force by operating the regenerative braking by the regenerative power generation of the motor generator 33 before entering the traffic congestion section L6. This is a section of the travel route to be performed. In this deceleration section L5, the slope θ5 is a steep downhill, and it is predicted that the vehicle speed V will be maintained at the lower limit speed vc or more when it is assumed that the inertial traveling with the diesel engine 10 stopped is performed. Assuming that the regenerative brake is operated in at least a part of the vehicle, it is possible to exemplify a downhill road where the vehicle speed V is predicted to be maintained below the upper limit speed vb. For example, when the HEV vehicle weight M is 25 t Can illustrate a downhill road where the gradient θ5 is 3% or more and the travel distance s5 is 500 m or more.

  The high charge state Ch is a state of 50% or more, preferably 60% or more when the state of charge of the battery 35 is 0% full discharge and 100% full charge, and the low charge state Cl is 50% or more. %, Preferably 40% or less. The appropriate operating range of the charging state Ce of the battery 35 is determined depending on the type of the battery 35. For example, the high charging state Ch and the low charging state Cl are set to the upper limit value and the lower limit value of the operating range. May be.

  A control method in the HEV auto-cruise mode will be described below as a function of the control device 80 based on the flowchart of FIG. In this control method, while the HEV is traveling, the driver is turning on the auto-cruise operation switch 81, and the vehicle is traveling in the auto-cruise mode on the steep ascending slope L3 (gradient θ3, distance s3) before the steeply descending slope L1. Shall be performed.

  First, in step S10, the control device 80 predicts whether or not the traffic congestion section L6 acquired by the map information acquisition device 82 is on the road ahead of HEV. If it is predicted in step S10 that there is no traffic jam section L6, this control method is completed. If it is predicted that there is a traffic jam section L6, the process proceeds to step S20.

  Next, in step S20, the control device 80 predicts whether or not there is a deceleration section L5 before the traffic jam section L6 based on the map information and the vehicle weight M. If it is predicted in step S20 that there is no deceleration zone L5, this control method is completed, and the process proceeds to step S30 in which it is predicted that there is a deceleration zone L5. When there is no deceleration section L5, for example, it is an uphill with a steep slope, and the engine resistance, that is, only the driving force of the diesel engine 10 is transmitted only by the driving resistance including the force in the reverse direction due to the gravitational acceleration applied to the vehicle body. If there is a steep uphill road that cannot maintain the vehicle speed V within the target speed range unless the 20 gears are downshifted, or if the slope is a gentle downhill and the vehicle is moving forward due to gravitational acceleration applied to the vehicle body If the directional force does not overcome the running resistance and there is a gentle downhill road before the traffic congestion section L6, the vehicle speed V cannot be maintained within the target speed range unless the driving force of either the diesel engine 10 or the motor generator 33 is applied. In other words, if the driving force is not applied, the travel path where the vehicle speed V decreases due to travel resistance is in front of the traffic congestion section L6. It is the case.

  Next, in step S30, the control device 80 acquires the charge state Ce of the battery 35, and determines whether or not the charge state Ce is equal to or lower than the low charge state Cl. If the charge state Ce is equal to or lower than the low charge state Cl in step S30, the control method is completed, and if the charge state Ce exceeds the low charge state Cl, the process proceeds to step S40.

  Next, in step S40, the control device 80 rotationally drives the motor generator 33 and proceeds to step S50. In step S40, in the case of engine running, switching to assist running or motor running is performed. At this time, the control device 80 may select either assist traveling or motor traveling based on the map information and the vehicle weight M. For example, during traveling on the steep uphill road L3 as in this embodiment, the assist traveling is selected, the driving force from the motor generator 33 in the assist traveling is increased, and the output of the diesel engine 10 is decreased. Further, in the case of an uphill but gentle slope slope or a flat road, the diesel engine 10 is stopped by switching from assist travel to motor travel.

  Next, in step S50, the control device 80 determines whether or not the vehicle has reached the start point B of the deceleration zone L5 based on the map information. If the start point B has not been reached in step S50, the process returns to step S40 to maintain the rotational drive of the motor generator 33. If the start point B has been reached, the process proceeds to step S60.

  Next, in step S60, the control device 80 cancels the auto-cruise mode and the control method is completed.

  FIG. 4 shows the relationship among the vehicle speed V, the output torque Te of the diesel engine 10, the output torque Tm of the motor generator 33, the charging state Ce of the battery 35, and the altitude H in the steep climb slope L3, the deceleration section L5, and the traffic jam section L6. An example is shown.

  Steps S10 to S30 are performed at the point A when the vehicle is traveling on the steeply uphill road L3 by assist traveling. Here, the point B is predicted to be the start point of the deceleration section L5 and the point C is predicted to be the start point of the traffic jam section L6, and the charge state Ce of the battery 35 is determined to be above the low charge state Cl. Then, step S40 is performed from the point A, and the assist traveling is performed in which the output of the diesel generator 10 is reduced while the output of the motor generator 33 is increased.

  Step S40 is continued from point A to point B, and at point B, the battery 35 is charged by the battery 35 due to the rotation of the motor generator 33 due to the rotation of the motor generator 33, and the charge state Ce of the battery 35 becomes the low charge state Cl. S50 and step S60 are performed, and the auto-cruise mode is canceled. Then, until the point C, the driver maintains the HEV in the inertial driving similar to the auto-cruise mode, regenerates the motor generator 33 and activates the regenerative brake, and charges the battery 35 while the vehicle speed V is congested. Decelerate to speed vd and enter traffic jam section L6 from point C.

  Since such control is performed, the assist traveling or the motor traveling is selected up to the starting point B of the inertia traveling, the motor generator 33 is rotationally driven by the electric power charged in the battery 35, and the output of the diesel engine 10 is selected. Since the engine speed Ne is reduced and the engine speed Ne is set to the low speed side, fuel consumption during traveling can be reduced.

  In addition, since the charging state Ce of the battery 35 is set to the low charging state Cl by the start point B of the deceleration zone L5, the operation opportunity of the regenerative brake for regenerating the motor generator 33 is increased in the deceleration zone L5. be able to.

  That is, an opportunity to decelerate the vehicle speed V to the traffic speed vd is predicted, in other words, an opportunity to charge the battery 35 by operating the regenerative brake, and an assist traveling or a motor traveling is performed before that. By setting the charging state Ce to the low charging state Cl in advance, while maintaining the charging state Ce of the battery 35 in an appropriate range, the chance of regenerative braking when decelerating the vehicle speed V to the congestion speed vd is increased. Loss of energy consumed unnecessarily when the engine brake or foot brake is operated can be suppressed, and fuel consumption by driving the diesel engine 10 for power generation by the motor generator 33 can be suppressed, so that fuel efficiency can be improved.

  In the HEV described above, the control device 80 performs control for canceling the auto-cruise mode at the start point B of the deceleration zone L5, and first controls the regenerative brake that regenerates power with the motor generator 33 among the plurality of brakes. It is desirable to be configured to do

  As shown in FIG. 4, at point B, the control device 80 regenerates the motor generator 33 to operate the regenerative brake. As a result, the battery 35 is charged with electric power generated by the power generation, and the braking force due to the running resistance and the regenerative brake is greater than the force in the forward direction due to the gravitational acceleration, and the vehicle speed V is decelerated to the congestion speed vd.

  By performing such control, the control device 80 can reliably increase the regeneration opportunity of the motor generator 33 during inertial traveling in the deceleration zone L5, so that fuel efficiency can be further improved.

  If the vehicle speed V does not decelerate to the congestion speed vd even when the regenerative brake is activated, it is preferable to sequentially activate the engine brake, the auxiliary brake, and the foot brake. As described above, when the braking force by the brake is gradually increased, the vehicle speed V is smoothly decelerated to the congestion speed vd without applying a sudden braking force, so that drivability can be improved.

  Further, in the HEV described above, the control device 80 sets the start point B of the deceleration zone L5 based on the map information, the vehicle weight M, and the regenerative braking force due to the operation of the regenerative brake, that is, the congestion speed vd, It is desirable to perform control to set the travel distance s5 of the deceleration zone L5 according to the gradient θ of the deceleration zone L5 and the vehicle weight M.

  For example, in FIG. 4, the vehicle speed V may be decelerated slightly before the start point B, and in this case, the front point may be the start point B of the deceleration section L5. In this way, by setting the start point B of the deceleration zone L5 in consideration of the regenerative power due to the operation of the regenerative brake, it is possible to suppress the loss of energy that is wasted when the engine brake and the foot brake are operated. It becomes advantageous for improvement.

  In the HEV described above, it is desirable that the control device 80 is configured to perform control for setting the low charge state Cl according to the travel distance s5 of the deceleration zone L5. For example, when the reference of the travel distance s5 acquired by the map information acquisition device 82 is set to 500 m, the low charge state Cl is set to a higher value when the travel distance s5 is shorter than 500 m, and the travel distance s5 is When it is longer than 500 m, the low charge state Cl is set to a lower value.

  By performing such control, it is possible to suppress that the charging state of the battery 35 exceeds the high charging state Ch or stop the regenerative braking due to the regenerative power generation of the motor generator 33 during the deceleration of the deceleration section L5. Regenerative power generation by the generator 33 can increase the chance of charging the battery 35 by converting the energy during braking into electric power, and reducing the loss of energy wasted when the engine brake and foot brake are operated. Can do.

DESCRIPTION OF SYMBOLS 10 Diesel engine 15 Clutch 20 Transmission 25 Propeller shaft 26 Differential 27 Drive wheel 30 Deceleration mechanism 32 Rotation shaft 33 Motor generator 35 Battery 40 First power steering pump 45 Second power steering pump 49 Double check valve 53 Steering unit 80 Control device 81 Auto cruise operation Switch 82 Map information acquisition device 83 Vehicle weight estimation device 84 Wheel speed sensor L5 Deceleration section L6 Traffic jam section

Claims (5)

A hybrid system having a propeller shaft that couples a transmission connected to a diesel engine via a clutch and a differential that drives a drive wheel, a hybrid system that has a motor generator electrically connected to the diesel engine and a battery, and the diesel engine A first power steering pump, a steering unit that assists steering using the power steering fluid supplied from the first power steering pump, a map information acquisition device that acquires map information including at least a traffic jam section, In a hybrid vehicle including a vehicle weight estimation device that estimates vehicle weight, a vehicle speed acquisition device that acquires vehicle speed, and a control device,
A reduction mechanism that connects the propeller shaft and the rotation axis of the motor generator with the rotation axis of the motor generator as an input shaft and the propeller shaft as an output shaft, and is coupled to the propeller shaft via the reduction mechanism. When the first power steering pump stops with the stop of the diesel engine, the power steering fluid supplied to the steering unit is supplied from the first power steering pump to the second power steering pump. A switching device for switching to a pump,
When the auto cruise mode for maintaining the vehicle speed within a preset target speed range is set for the control device, inertial traveling that does not transmit the driving force of the diesel engine and the motor generator to the propeller shaft is performed on the map. When selecting based on the information and the vehicle weight, in addition to performing the control to stop the diesel engine by stopping the fuel injection and stopping the clutch during the inertia traveling,
The map information and the traffic congestion section and a deceleration section that decelerates the vehicle speed to a traffic congestion speed in the traffic congestion section before operating the regenerative brake by regenerative power generation of the motor generator and entering the traffic congestion section. Control to predict based on the vehicle weight,
Further, at least one of the assist traveling or the motor traveling that travels with the driving force transmitted from the motor generator to the propeller shaft via the deceleration mechanism until the predicted starting point of the deceleration section is reached. A hybrid vehicle characterized in that it is configured to perform control to select and set a state of charge of the battery at the start point to a low charge state set to a full discharge state or more and a half charge state or less. The control device performs control to cancel the auto cruise mode at the start point,
2. The hybrid vehicle according to claim 1, wherein in the deceleration section, control is performed to first operate a regenerative brake that regenerates power by the motor generator among a plurality of brakes.   The hybrid vehicle according to claim 1, wherein the control device is configured to perform control for setting the start point based on the map information, the vehicle weight, and a regenerative braking force generated by regenerative braking.   The hybrid vehicle according to any one of claims 1 to 3, wherein the control device is configured to perform control for setting the low charge state in accordance with a distance of the deceleration section. When the auto cruise mode is set, the engine travels with the driving force transmitted from the diesel engine to the propeller shaft via the clutch and transmission, and is electrically connected to the driving force and the battery of the diesel engine. Assist traveling that travels with both driving force transmitted from the motor generator to the propeller shaft via the speed reduction mechanism, motor traveling that travels with the driving force of the motor generator, and driving force of the diesel engine and the motor generator Inertia traveling that is not transmitted to the propeller shaft is selected on a timely basis based on the map information and the vehicle weight, and the vehicle speed is maintained within a preset target speed range to automatically travel,
When the inertial running is selected, the clutch is disengaged to stop the diesel engine, and instead of the first power steering pump that is stopped when the diesel engine is stopped, the speed reduction mechanism is changed from the propeller shaft. A method for controlling a hybrid vehicle that drives a second power steering pump with rotational power transmitted via a power supply to supply power steering fluid to a steering unit,
Map information and vehicle information on a traffic jam section and a deceleration section that decelerates the vehicle speed to the jam speed in the traffic jam section before entering the traffic jam section by operating at least a regenerative brake by regenerative power generation of the motor generator. Based on weight,
By selecting either the assist traveling or the motor traveling until the predicted start point of the deceleration zone is reached, the state of charge of the battery at the start point is set to a full discharge state or more and a half charge state or less. A control method for a hybrid vehicle, wherein a set low charge state is set.