Hybrid vehicle

Abstract

The invention provides a hybrid vehicle. The present disclosure provides a hybrid vehicle that suppresses a draggable weight of the vehicle from being greatly reduced during traveling in a traction mode and that affects drivability. A hybrid vehicle is provided with: an engine and a motor for travel; a power storage device that exchanges power with the motor; and a control device that, during the traction mode, controls the engine and the motor so as to travel along with the operation of the engine. When the traction mode is instructed, the control device permits the traction mode when the power storage ratio of the power storage device is higher than a threshold value, and prohibits the traction mode when the power storage ratio is equal to or lower than the threshold value.

Description

Technical Field The present disclosure relates to a hybrid vehicle. Background Art Conventionally, in a hybrid vehicle equipped with an engine for driving, a motor, and a power storage device that exchanges power with the motor, in a towing mode in which the vehicle is towed by a towed vehicle, a technique has been proposed to prohibit the intermittent operation of the engine and keep the engine running continuously (see, for example, Patent Document 1). In this hybrid vehicle, by such control, it is easy to ensure sufficient driving force in the towing mode. Prior Art Documents Patent Documents Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-112447 Summary of the Invention In the above hybrid vehicle, during driving in the towing mode, as the accelerator operation amount increases, the required power for driving tends to increase. To supply the required power, the output from the power storage device tends to increase, and the state of charge ratio of the power storage device tends to decrease. When the state of charge ratio of the power storage device is sufficiently reduced during driving in the towing mode, in order to protect the power storage device, the output of the motor is restricted relatively greatly, and the towable weight of the vehicle is reduced relatively significantly, which may affect the drivability. The main object of the hybrid vehicle of the present disclosure is to suppress a relatively significant reduction in the towable weight of the vehicle during driving in the towing mode, which may affect the drivability. The hybrid vehicle of the present disclosure adopts the following means to achieve the above main object.

[0001] The gist of the hybrid vehicle of the present disclosure is to include: An engine for driving and a motor; a power storage device that exchanges power with the motor; and a control device that controls the engine and the motor in a manner that the vehicle travels with the operation of the engine during the towing mode, wherein when the control device is instructed of the towing mode, if the state of charge ratio of the power storage device is higher than a threshold value, the towing mode is permitted; if the state of charge ratio is equal to or lower than the threshold value, the towing mode is prohibited. In the hybrid vehicle of the present disclosure, when instructed of the towing mode, if the state of charge ratio of the power storage device is higher than the threshold value, the towing mode is permitted; if the state of charge ratio is equal to or lower than the threshold value, the towing mode is prohibited. Thereby, it is possible to suppress a significant reduction in the state of charge ratio of the power storage device during driving in the towing mode, and a relatively significant reduction in the towable weight of the vehicle, which may affect the drivability.

[0002] In the above-described hybrid vehicle (the hybrid vehicle described in [1]), a reporting device for reporting information may also be provided, and when the traction mode is prohibited, the control device controls the reporting device to report prohibition-related information associated with the meaning of prohibiting the traction mode. Here, the prohibition-related information may be information indicating the meaning of prohibiting the traction mode, information indicating the meaning of prohibiting the traction mode due to the state of charge ratio being below the threshold, or information indicating the meaning of maintaining a mode other than the traction mode (for example, a normal mode in which the vehicle travels with intermittent engine operation).

[0003] In the above-described hybrid vehicle (the hybrid vehicle described in [1] or [2]), a traction mode switch for indicating the traction mode may also be provided, and when the traction mode switch is operated by the user, the control device determines that the traction mode is indicated. Here, the traction mode switch may be configured as a hard switch or a soft switch displayed on a display unit or the like.

[0004] In the above-described hybrid vehicle (the hybrid vehicle described in [1] or [2]), when the vehicle and the towed object are connected, the control device may determine that the traction mode is indicated.

[0005] In the above-described hybrid vehicle (the hybrid vehicle described in [1] or [2]), when the vehicle load exceeds a predetermined load, the control device may determine that the traction mode is indicated.

[0006] In the above-described hybrid vehicle (the hybrid vehicle described in any one of [1] to [5]), the control device may set the threshold value in such a manner that it increases as the altitude of the current location of the vehicle and / or the predetermined driving route increases. The altitude of the predetermined driving route may be the average altitude of each location on the predetermined driving route or the maximum value of the altitudes of each location.

[0007] In the above-described hybrid vehicle (the hybrid vehicle described in any one of [1] to [6]), the control device may set the threshold value in such a manner that it increases as the road surface gradient of the current location of the vehicle and / or the predetermined driving route increases on the uphill side. The road surface gradient of the predetermined driving route may be the average road surface gradient of each location on the predetermined driving route or the maximum value of the road surface gradients of each location.

[0008] In the above-described hybrid vehicle (the hybrid vehicle described in any one of [1] to [7]), when the vehicle travels with the engine stopped, the control device may set the threshold value to be higher than when the vehicle travels with the engine running.

[0009] In the above-described hybrid vehicle (the hybrid vehicle according to any one of [1] to [8]), it is also possible that when the state of charge ratio during traveling in the traction mode reaches a second threshold value less than the threshold value, the control device ends the traction mode.

[0010] In the above-described hybrid vehicle (the hybrid vehicle according to [9]), it is also possible to further include a reporting device for reporting information. When the control device ends the traction mode because the state of charge ratio reaches the second threshold value or less during traveling in the traction mode, the control device controls the reporting device to report end-related information associated with the meaning of ending the traction mode. Here, the end-related information may be information indicating the meaning of ending the traction mode, information indicating the meaning of ending the traction mode due to the state of charge ratio reaching the second threshold value or less, or information indicating the meaning of shifting to a mode other than the traction mode (for example, the above-described normal mode). BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present disclosure. Figure 2 is a flowchart showing an example of a processing routine in the normal mode. Figure 3 is a flowchart showing an example of a processing routine in the traction mode. Figure 4 is a flowchart showing an example of a processing routine in the normal mode. Figure 5 is a flowchart showing an example of a processing routine in the normal mode. Figure 6 is a flowchart showing an example of a processing routine in the normal mode. Figure 7 is a flowchart showing an example of a processing routine in the normal mode. Figure 8 is a flowchart showing an example of a processing routine in the normal mode. Figure 9 is a schematic configuration diagram of a hybrid vehicle according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION With reference to the accompanying drawings, a mode for implementing the present disclosure will be described. Figure 1 is a schematic configuration diagram of a hybrid vehicle 20 according to an embodiment of the present disclosure. As Figure 1 shown, the hybrid vehicle 20 according to the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, a connector 56, a charger 58, a navigation device 60, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70. The engine 22 is configured as an internal combustion engine that outputs power using fuels such as gasoline and light oil. The crankshaft 23 of the engine 22 is connected to the carrier of the planetary gear 30. The engine 22 is operationally controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24. The engine ECU 24 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. The engine ECU 24 inputs signals from various sensors via the input port. For example, the engine ECU 24 inputs the crank angle θcr from a crank position sensor 23a that detects the rotational position of the crankshaft 23. The engine ECU 24 outputs various control signals via the output port. For example, the engine ECU 24 outputs control signals to an intake valve, a fuel injection valve, and a spark plug (all not shown). The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr of the crankshaft 23. The engine ECU 24 communicates with the HV ECU 70. The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of the planetary gear 30 is connected to the rotor of the motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 37 that is connected to drive wheels 39a and 39b via a differential gear 38. The carrier of the planetary gear 30 is connected to the crankshaft 23 of the engine 22 as described above. The motors MG1 and MG2 are configured as synchronous motor generators, for example. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30 as described above. The rotor of the motor MG2 is connected to the drive shaft 37. The inverters 41 and 42 are configured as inverter circuits having a plurality of switching elements. The inverters 41 and 42 are connected to the battery 50 via drive power lines 54. The motors MG1 and MG2 are rotationally driven by performing switching control of the plurality of switching elements of the inverters 41 and 42 using a motor electronic control unit (hereinafter referred to as "motor ECU") 40. The motor ECU 40 includes a microcomputer in the same manner as the engine ECU 24. The motor ECU 40 inputs signals from various sensors via the input port. For example, the motor ECU 40 inputs the rotational positions θm1 and θm2 from rotational position sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2. The motor ECU 40 outputs various control signals via the output port. For example, the motor ECU 40 outputs control signals to the inverters 41 and 42. The motor ECU 40 calculates the electrical angles θe1 and θe2 and the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2. The motor ECU 40 communicates with the HV ECU 70. The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel metal hydride secondary battery. The battery 50 is connected to the inverters 41 and 42 via the power line 54 for driving as described above. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as "battery ECU") 52. The battery ECU 52 includes a microcomputer in the same manner as the engine ECU 24. The battery ECU 52 inputs signals from various sensors via an input port. For example, the battery ECU 52 inputs the voltage Vb from the voltage sensor 51v installed between the terminals of the battery 50, the current Ib from the current sensor 51i installed at the output terminal of the battery 50, and the temperature Tb from the temperature sensor 51t installed in the battery 50. The battery ECU 52 calculates the state of charge (SOC) of the battery 50 based on the cumulative value of the current Ib of the battery 50. The battery ECU 52 communicates with the HV ECU 70. The connector 56 is configured to be connectable to an external AC power source such as a household power supply or a commercial power supply. The external power source is provided at a charging point such as a home or a charging station. The connector 56 is connected to the power line 54 for driving via the power line 57 for charging. The charger 58 is provided on the power line 57 for charging and is configured to convert the AC power from the external power source into DC power and then into a voltage and supply it to the battery 50 when the connector 56 and the external power source are connected. Hereinafter, supplying the power from the external power source to the battery 50 via the power line 57 for charging and the power line 54 for driving to charge the battery 50 is referred to as "external charging". The navigation device 60 includes a main body 61 having a control unit built therein, a GPS antenna 62, and a display 63. The control unit of the main body 61 includes a microcomputer and a storage medium (such as a hard disk or an SSD). Map information and the like are stored in the storage medium. The map information includes service information (such as sightseeing information and parking lots), road information for each driving section (such as between traffic lights and between intersections), and the like. The road information includes distance information, width information, number of lanes information, regional information (urban area, suburbs), category information (ordinary road, highway), slope information, legal speed, and the like. The GPS antenna 62 receives information related to the current location of the vehicle. The display 63 is configured as a touch panel type display and can display various information such as map information, the current location of the vehicle, and a predetermined driving route from the current location of the vehicle to the destination, and can also enable the user to input various instructions. When the user operates the display 63 to set a destination, the main body 61 sets a predetermined driving route from the current location of the vehicle to the destination based on the map information, the current location of the vehicle, and the destination, and displays the set predetermined driving route on the display 63 for route guidance. The navigation device 60 communicates with the HV ECU 70. The HVECU 70, like the engine ECU 24, also has a microcomputer. The HVECU 70 inputs signals from various sensors via the input ports. For example, the HVECU 70 inputs a signal from the power switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, a brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85. The HVECU 70 also inputs a vehicle speed V from the vehicle speed sensor 87, a vehicle acceleration a from the acceleration sensor 88, a road surface gradient θrd (a positive value for the uphill side and a negative value for the downhill side) from the gradient sensor 89, and an altitude EL from the altitude sensor 90. The HVECU 70 also inputs a signal from the traction mode switch 91 that indicates the traction mode for towing a towed object while driving. As the towed object, for example, a vehicle, a ship, etc. can be cited. The HVECU 70 outputs various control signals via the output ports. For example, the HVECU 70 outputs a control signal to the charger 58, a control signal to the display unit 92 installed on the instrument panel, and a control signal to the speaker 93. As described above, the HVECU 70 communicates with the main bodies 61 of the engine ECU 24, the motor ECU 40, the battery ECU 52, and the navigation device 60. The hybrid vehicle 20 of the embodiment selects one from a plurality of driving modes including a normal mode and a traction mode and drives. The normal mode includes a CD (Charge Depleting) mode and a CS (Charge Sustaining) mode. The CD mode is a mode in which electric driving (EV driving) is prioritized over hybrid driving (HV driving) in such a way that the state of charge SOC of the battery 50 is reduced. EV driving is driving without the operation of the engine 22. HV driving is driving with the operation of the engine 22. The CS mode is a mode in which EV driving and HV driving are used in combination in such a way that the state of charge SOC of the battery 50 is maintained within a management range including a target ratio SOC* (for example, a threshold Shv described later). The traction mode is a mode in which EV driving is prohibited and only HV driving is performed. Thereby, compared with the case of performing EV driving, the towable weight of the vehicle is increased. Here, the external charging and the normal mode will be described. When the hybrid vehicle 20 is parked at a charging point and the connection of the connector 56 to an external power source is made and the charging start condition is satisfied, the external charging control of the charger 58 is started in a manner to perform external charging, and when the charging end condition is satisfied, the external charging control is ended. Regarding the charging start condition, for example, a condition where the user instructs to start external charging is used. Regarding the charging end condition, for example, a condition where the state of charge SOC of the battery 50 reaches a threshold Sfl or more near full charge is used. Moreover, when the system is started after the external charging of the hybrid vehicle 20 ends, in the case of the normal mode, the CD mode is initially selected, and then when the state of charge SOC of the battery 50 reaches a threshold Shv or less that is lower than the threshold Sfl to a certain extent, the system shifts to the CS mode. Next, the HV running and the EV running will be described in sequence. During HV running, the HVECU 70 initially sets the required torque Td* for running according to the accelerator opening Acc and the vehicle speed V, and sets the required power Pd* for running according to the set required torque Td* and the rotational speed Nd of the drive shaft 37 (the rotational speed Nm2 of the motor MG2). Next, the HVECU 70 sets the required power Pe* of the engine 22 according to the required power Pd* and the charge / discharge required power Pb* of the battery 50, and sets the target rotational speed Ne* and the target torque Te* of the engine 22 and the torque commands Tm1*, Tm2* of the motors MG1, MG2 in a manner to output the required power Pe* from the engine 22 and output the required torque Td* to the drive shaft 37. Moreover, the HVECU 70 sends the target rotational speed Ne* and the target torque Te* of the engine 22 to the engine ECU 24, and sends the torque commands Tm1*, Tm2* of the motors MG1, MG2 to the motor ECU 40. The engine ECU 24 performs the operation control of the engine 22 in a manner to make the engine 22 operate according to the target rotational speed Ne* and the target torque Te*. The motor ECU 40 controls the inverters 41, 42 in a manner to drive the motors MG1, MG2 according to the torque commands Tm1*, Tm2*. During EV running, the HVECU 70 initially sets the required torque Td* in the same manner as during HV running. Next, the HVECU 70 sets the set value of the torque command Tm1* of the motor MG1 to 0, and sets the required torque Td* as the torque command Tm2* of the motor MG2, and sends the set torque commands Tm1*, Tm2* of the motors MG1, MG2 to the motor ECU 40. The motor ECU 40 controls the inverters 41, 42 in a manner to drive the motors MG1, MG2 with the torque commands Tm1*, Tm2*. In addition, in the embodiment, in both the normal mode and the towing mode, when the state of charge (SOC) of the battery 50 reaches a threshold Smin which is lower than a certain level compared to the threshold Shv, in order to protect the battery 50, the output of the motor MG2 is restricted relatively significantly. Therefore, when the SOC of the battery 50 in the towing mode reaches below the threshold Smin, the towable weight of the vehicle can be reduced relatively significantly. Next, the operation of the hybrid vehicle 20 according to the embodiment will be described, particularly the operation in the normal mode and when the towing mode is indicated. Figure 2 FIG. is a flowchart showing an example of a processing routine in the normal mode executed by the HV ECU 70. This routine is repeatedly executed when in the normal mode. In Figure 2 the processing routine in the normal mode, the HV ECU 70 first determines whether the towing mode switch 91 is set to ON (step S100). This process is to determine whether the towing mode is indicated. When the HV ECU 70 determines that the towing mode switch 91 is not set to ON, it determines that the towing mode is not indicated and ends this routine. In this case, the hybrid vehicle 20 continues the normal mode. When the HV ECU 70 determines in step S100 that the towing mode switch 91 is set to ON, it determines that the towing mode is indicated and determines whether the state of charge (SOC) of the battery 50 is higher than the threshold Sref1 (step S110). Here, the threshold Sref1 is a threshold for determining whether the permission condition for the towing mode is satisfied. The threshold Sref1 is determined to be a value that is larger than the threshold Smin by a certain degree. When the HV ECU 70 determines in step S110 that the SOC of the battery 50 is higher than the threshold Sref1, it determines that the permission condition for the towing mode is satisfied and permits the towing mode (step S120). In this case, the hybrid vehicle 20 transfers from the normal mode to the towing mode. When the hybrid vehicle 20 transfers from the EV driving in the normal mode to the towing mode, it starts HV driving by starting the engine 22 and starts the towing mode. On the other hand, when the hybrid vehicle 20 transfers from the HV driving in the normal mode to the towing mode, it maintains the HV driving and starts the towing mode. Next, the HV ECU 70 controls the display 63 so as to display transfer information indicating the transfer from the normal mode to the towing mode on the display 63 of the navigation device 60 (step S130), and ends this routine. The report of the transfer information may be performed by displaying it on the display unit 92, outputting sound from the speaker 93, etc. instead of displaying it on the display 63. When the HVECU 70 determines in step S110 that the state of charge SOC of the battery 50 is equal to or lower than the threshold Sref1, it determines that the permission condition for the traction mode is not satisfied, prohibits the traction mode (step S140), and controls the display 63 to display prohibition-related information associated with the meaning of prohibiting the traction mode on the display 63 (step S150), and this example routine ends. In this case, the hybrid vehicle 20 continues the normal mode. The report of the prohibition-related information may be performed by displaying it on the display unit 92, outputting sound from the speaker 93, etc. instead of displaying it on the display 63. The prohibition-related information may be information indicating the meaning of prohibiting the traction mode, information indicating the meaning of prohibiting the traction mode due to the state of charge SOC of the battery 50 being equal to or lower than the threshold Sref1, or information indicating the meaning of maintaining a mode other than the traction mode (specifically, the normal mode). The prohibition-related information may also include, in addition to any one of these, information indicating the meaning of prompting charging of the battery 50. Regarding the prohibition-related information, for example, there may be cited "It is difficult to maintain the vehicle speed in the traction mode, so the traction mode is prohibited. Please charge the battery and then turn on the traction mode switch again.", "The traction mode is prohibited. Please stop the vehicle in a safe place, charge the battery, and then turn on the traction mode switch again.", etc. In the hybrid vehicle 20, during traveling in the traction mode, compared with traveling in the normal mode, when the accelerator 83 is depressed significantly, the required power Pd* for traveling tends to increase. To supply the required power Pd*, the output from the battery 50 tends to increase, and the state of charge SOC of the battery 50 tends to decrease. When the state of charge SOC of the battery 50 during traveling in the traction mode reaches equal to or lower than the above-mentioned threshold Smin, the output of the motor MG2 is restricted relatively greatly, and the towable weight of the vehicle decreases relatively significantly, which may affect the drivability. Based on this, in the embodiment, it is set that when the HVECU 70 determines that the state of charge SOC of the battery 50 is equal to or lower than the threshold Sref1, the traction mode is prohibited and the meaning of prohibiting the traction mode is reported. Thereby, it is possible to suppress the state of charge SOC reaching the threshold Smin or lower during traveling in the traction mode and the towable weight of the vehicle decreasing relatively significantly, which affects the drivability. In addition, the user can know the meaning that the traction mode is prohibited. Further, in the embodiment, it is set that when the HVECU 70 prohibits the traction mode, the traction mode switch 91 is returned to the off state and its meaning is displayed on the display 63, etc. for reporting. Next, the processing when it is the traction mode will be described. Figure 3 It is a flowchart showing an example of a processing routine in the traction mode executed by the HVECU 70. This example routine starts to be executed when the traction mode is started. In Figure 3In the processing routine during the towing mode, the HVECU 70 first determines whether the towing mode switch 91 is set to off (step S200). This process is to determine whether an instruction to cancel the towing mode is given. When the HVECU 70 determines that the towing mode switch 91 is not set to off, it determines that no instruction to cancel the towing mode is given, and determines whether the state of charge SOC of the battery 50 has become equal to or less than the threshold Sref2 (step S210). Here, the threshold Sref2 is a threshold for determining whether the end condition of the towing mode regarding the state of charge SOC is satisfied. The threshold Sref2 is determined to be a value less than the threshold Sref1 and greater than the threshold Smin. When the HVECU 70 determines that the state of charge SOC of the battery 50 has not reached equal to or less than the threshold Sref2, it determines that the end condition of the towing mode regarding the state of charge SOC is not satisfied, and returns to step S200. In this case, the hybrid vehicle 20 continues the towing mode. When the HVECU 70 determines in step S200 that the towing mode switch 91 is set to off, it determines that an instruction to cancel the towing mode is given, and ends the towing mode (step S220). In this case, the hybrid vehicle 20 shifts from the towing mode to the normal mode. Next, the HVECU 70 controls the display 63 so as to display the first end-related information associated with the meaning of the end of the towing mode on the display 63 (step S230), and ends this routine. The report of the first end-related information may be performed by displaying it on the display unit 92, outputting a sound from the speaker 93, etc. instead of displaying it on the display 63. The first end-related information may be information indicating the end of the towing mode or information indicating a shift to a mode other than the towing mode (specifically, the normal mode). When the HVECU 70 determines in step S210 that the state of charge SOC of the battery 50 has reached below the threshold Sref2, it is determined that the end condition for the traction mode regarding the state of charge SOC is satisfied, and the traction mode is ended (step S240). The display 63 is controlled in such a way that the second end-related information associated with the meaning of the ended traction mode is displayed on the display 63 (step S250), and this routine ends. The reporting of the second end-related information may be performed by displaying it on the display unit 92, outputting sound from the speaker 93, etc. instead of displaying it on the display 63. The second end-related information may be the same as the first end-related information or may be information indicating the meaning that the traction mode has ended due to the state of charge SOC of the battery 50 reaching below the threshold Sref2. By ending the traction mode when the state of charge SOC of the battery 50 reaches below the threshold Sref2 which is greater than the threshold Smin, that is, by ending the traction mode before the state of charge SOC reaches below the threshold Smin, it is possible to suppress the significant reduction in the towable weight of the vehicle during driving in the traction mode and thus affect the drivability. In addition, the user can be informed of the meaning that the traction mode has ended. In the hybrid vehicle 20 of the present embodiment described above, when the traction mode switch 91 is turned on, if the state of charge SOC of the battery 50 is higher than the threshold Sref1, the traction mode is permitted and the meaning is reported. If the state of charge SOC of the battery 50 is below the threshold Sref1, the traction mode is prohibited and the meaning is reported. Thereby, it is possible to suppress the significant reduction in the towable weight of the vehicle during driving in the traction mode and thus affect the drivability. In addition, the user can be informed of the meaning that the traction mode has been prohibited. In the above embodiment, it is assumed that when the traction mode switch 91 is turned on, the HVECU 70 determines that the traction mode is instructed and permits or prohibits the traction mode according to whether the state of charge SOC of the battery 50 is higher than the threshold Sref1, but it is not limited thereto. For example, the HVECU 70 may replace Figure 2 the processing routine in the normal mode of Figure 4 or Figure 5 the processing routine in the normal mode. Hereinafter, the explanations will be given in sequence. Explanation Figure 4 the processing routine in the normal mode of Figure 2The processing routine is different when in normal mode. In this routine, HVECU70 initially determines whether the vehicle and the towed object are connected (step S101). This process is the same as the process of step S100, and is a process for determining whether the towing mode is indicated. This process is performed, for example, based on a signal from a connection detection sensor that detects whether the vehicle and the towed object are connected. When HVECU70 determines that the vehicle and the towed object are not connected, it determines that the towing mode is not indicated and ends this routine. On the other hand, when HVECU70 determines that the vehicle and the towed object are connected, it determines that the towing mode is indicated and enters step S110. Therefore, when the vehicle and the towed object are connected, it is determined that the towing mode is indicated, and the towing mode can be permitted or prohibited according to whether the storage ratio SOC of the battery 50 is higher than the threshold value Sref1. In addition, the HVECU 70 executes Figure 4 In the case of the normal mode processing routine, HVECU70 can also replace Figure 3 The process of step S200 of the towing mode processing routine determines whether the connection between the vehicle and the towed object is released, thereby determining whether the towing mode is released. illustrate Figure 5 This routine is similar to the one in that the processing in step S100 is replaced by the processing in step S102. Figure 2 The processing routine is different when in normal mode. In this routine, HVECU70 initially determines whether the vehicle load exceeds the predetermined load (step S102). This process is the same as the process of step S100, which is a process for determining whether the traction mode is instructed. HVECU70 can also estimate the vehicle load based on the vehicle speed V and the required torque Td* or the required power Pd*, and determine whether the vehicle load exceeds the predetermined load based on whether the estimated vehicle load exceeds the assumed load of the vehicle and the occupants. HVECU70 can also estimate the weight based on the required torque Td* or the required power Pe* and the road slope θrd, and determine whether the vehicle load exceeds the predetermined load based on whether the estimated weight exceeds the assumed weight of the vehicle and the occupants. When HVECU70 determines in step S102 that the vehicle load is not above the predetermined load, it determines that the traction mode is not instructed and ends this routine. On the other hand, when HVECU70 determines that the vehicle load exceeds the predetermined load, it determines that the traction mode is instructed and enters step S110. Thus, when the vehicle load exceeds a predetermined load, it is determined that the towing mode is instructed, and the towing mode can be permitted or prohibited depending on whether the charge ratio SOC of the battery 50 is higher than the threshold value Sref1. In addition, the HVECU 70 executes Figure 5 In the case of the normal mode processing routine, HVECU70 can also replace Figure 3In the traction mode, it is determined whether the vehicle load is less than a predetermined load in the process of step S200 of the processing routine, so as to determine whether it is instructed to cancel the traction mode. In the above embodiment, it is assumed that the threshold Sref1 is a constant value, but it is not limited thereto. For example, the HVECU 70 may also replace Figure 2 the normal mode processing routine of Figure 6 and Figure 7 and Figure 8 any normal mode processing routine of Description Figure 6 the normal mode processing routine of Figure 2 This routine is different from the normal mode processing routine of In Figure 6In the normal mode processing routine, it is assumed that the HVECU 70 sets the threshold Sref1 based on the altitude EL of the current location of the vehicle, but it is not limited thereto. For example, the HVECU 70 may use the altitude ELsr of the predetermined driving route from the current location of the vehicle to the destination instead of the altitude EL of the current location of the vehicle. The altitude ELsr may be the average value of the altitudes of the respective locations of the predetermined driving route, or may be the maximum value of the altitudes of the respective locations. Description Figure 7 The normal mode processing routine. This routine is different from the normal mode processing routine of Figure 2 in that the processing of step S105 is added. In this routine, when the HVECU 70 determines in step S100 that the traction mode switch 91 is set to ON, it sets the threshold Sref1 based on the road surface slope θrd from the slope sensor 89, i.e., the road surface slope θrd of the current location of the vehicle (step S105), and proceeds to step S110. In this case, the HVECU 70 sets the threshold Sref1 based on, for example, the road surface slope θrd and the second map. The second map is a map showing the relationship between the road surface slope θrd and the threshold Sref1, and is determined in advance through experiments, analysis, machine learning, etc. The HVECU 70 applies the road surface slope θrd to the second map, and derives and sets the corresponding threshold Sref1 from the second map. In the second map, the threshold Sref1 is determined to become higher as the road surface slope θrd becomes larger. The threshold Sref1 may also be determined to become continuously (linearly or curvilinearly) higher as the road surface slope θrd becomes larger. The threshold Sref may also be determined to become discontinuously (stepwise) higher as the road surface slope θrd becomes larger. The threshold Sref1 may also be determined to be higher when the road surface slope θrd is equal to or greater than the threshold θrdref than when it is less than the threshold θrdref. The larger the road surface slope θrd, the easier it is for the vehicle to decelerate, so the accelerator opening Acc tends to become larger. Therefore, the larger the road surface slope θrd, the easier it is for the required power Pd* for driving to become larger, and in order to supply the required power Pd*, the output from the battery 50 tends to become larger, and the state of charge SOC of the battery 50 tends to decrease. Therefore, during driving in the traction mode, the larger the road surface slope θrd, the easier it is for the state of charge SOC to reach below the threshold Smin. Accordingly, in this modification example, it is assumed that the HVECU 70 sets the threshold Sref1 in such a manner that it becomes higher as the road surface slope θrd becomes larger. As a result, the larger the road surface slope θrd, the more difficult it is to permit the traction mode. As a result, it is possible to suppress the state of charge SOC reaching below the threshold Smin during driving in the traction mode and a relatively large reduction in the towable weight of the vehicle, which affects the drivability. In Figure 7In the normal mode processing routine, it is assumed that the HVECU 70 sets the threshold Sref1 based on the road surface gradient θrd of the current location of the vehicle, but it is not limited to this. For example, the HVECU 70 may use the road surface gradient θrdsr of the predetermined driving route from the current location of the vehicle to the destination instead of the road surface gradient θrd of the current location of the vehicle. The road surface gradient θrdsr may be the average value of the road surface gradients at each location of the predetermined driving route or the maximum value. Description Figure 8 Normal mode processing routine. This routine is different from the normal mode processing routine of Figure 2 in that the processing of step S106 is added. In this routine, when the HVECU 70 determines in step S100 that the traction mode switch 91 is set to ON, it sets the threshold Sref1 according to whether the vehicle is performing EV driving or HV driving (step S106) and proceeds to step S110. In this case, when the vehicle is performing EV driving, the HVECU 70 sets a larger value as the threshold Sref1 than when the vehicle is performing HV driving. When transferring from EV driving in the normal mode to the traction mode, HV driving is started by starting the engine 22 and the traction mode is started. On the other hand, when transferring from HV driving in the normal mode to the traction mode, the HV driving is maintained and the traction mode is started. Therefore, when transferring from EV driving in the normal mode to the traction mode, the state of charge SOC of the battery 50 at the start of the traction mode is more likely to be lower than when transferring from HV driving in the normal mode to the traction mode. Accordingly, in this modification, it is assumed that the HVECU 70 sets a larger value as the threshold Sref1 when the vehicle is performing EV driving than when the vehicle is performing HV driving. As a result, when the vehicle is performing EV driving, it is more difficult to permit the traction mode than when the vehicle is performing HV driving. As a result, it is possible to prevent the state of charge SOC from reaching below the threshold Smin during driving in the traction mode and the towable weight of the vehicle from being significantly reduced, which affects the drivability. In Figure 8 the normal mode processing routine, it is assumed that the HVECU 70 sets the threshold Sref1 according to whether the vehicle is performing EV driving or HV driving, but it is not limited to this. For example, the HVECU 70 may also set the threshold Sref1 according to whether it is the CD mode or the CS mode in the normal mode. In Figures 6 - 8In the normal mode of a processing routine or the like, it is assumed that the HVECU 70 sets a threshold value Sref1 according to the altitude EL, the reference altitude ELsr, the road surface gradient θrd, the reference road surface gradient θrdsr, whether the vehicle is performing EV driving or HV driving, and any one of the CD mode and the CS mode in the normal mode, but it is not limited thereto. For example, the HVECU 70 may also set multiple threshold values Sref1 according to the altitude EL, the reference altitude ELsr, the road surface gradient θrd, the reference road surface gradient θrdsr, whether the vehicle is performing EV driving or HV driving, and any one of the CD mode and the CS mode in the normal mode. Figures 6 - 8 The process of step S100 of the processing routine in the normal mode can be replaced by Figure 4 The process of step S101 of the processing routine in the normal mode can also be replaced by Figure 5 The process of step S102 of the processing routine in the normal mode. In these cases, Figure 3 The process of step S200 of the processing routine in the towing mode can also be replaced by a process of determining whether the connection between the vehicle and the towed object is released or a process of determining whether the vehicle load is less than a predetermined load. In the embodiment, it is assumed that the battery 50 is used as the power storage device, but it is not limited thereto. For example, a capacitor can also be used as the power storage device. In the embodiment, it is assumed that the hybrid vehicle 20 includes an engine ECU 24, a motor ECU 40, a battery ECU 52, and an HVECU 70, but it is not limited thereto. For example, at least two of the engine ECU 24, the motor ECU 40, the battery ECU 52, and the HVECU 70 may be integrally formed. In the embodiment, it is assumed that the hybrid vehicle 20 includes a connector 56, a charging power line 57, and a charger 58 for AC charging that uses AC power from an external power source to charge the battery 50, but it is not limited thereto. For example, the hybrid vehicle 20 may not include the connector 56, the charging power line 57, and the charger 58. That is, the hybrid vehicle 20 may also be a vehicle that does not perform external charging. In addition, the hybrid vehicle 20 may instead of the connector 56, the charging power line 57, the charger 58 or in addition to these, also include a DC charging connector and a DC charging power line for DC charging that uses DC power from an external power source to charge the battery 50. In the above embodiment, it is assumed that the hybrid vehicle 20 includes an engine 22, a planetary gear 30, motors MG1, MG2, and a battery 50, but it is not limited thereto. For example, it can also be as Figure 9As shown in the hybrid vehicle 120, it includes an engine 22, a clutch CL, a motor MG, an inverter IV, a battery 50, and a transmission TM. In the hybrid vehicle 120, the engine 22 is connected to the drive wheels 39a and 39b via the clutch CL, the motor MG, the transmission TM, and a drive shaft 37, and the inverter IV for driving the motor MG and the battery 50 are connected to a drive power line 54. Explain the correspondence between the main elements of the embodiment and the main elements of the invention described in the Summary of the Invention. In the embodiment, the engine 22 corresponds to the "engine", the motor MG2 corresponds to the "motor", the battery 50 corresponds to the "power storage device", and the HVECU 70, the engine ECU 24, and the motor ECU 40 correspond to the "control device". In addition, at least one of the display 63, the display unit 92, and the speaker 93 corresponds to the "reporting device". Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the Summary of the Invention is an example for specifically explaining the manner in which the embodiment implements the invention described in the Summary of the Invention, so it does not limit the elements of the invention described in the Summary of the Invention. That is, the interpretation of the invention described in the Summary of the Invention should be based on the description of that part, and the embodiment is only a specific example of the invention described in the Summary of the Invention. As described above, the manner for implementing the present disclosure has been described using the embodiment, but the present disclosure is not limited to such an embodiment at all, and of course, it can be implemented in various ways without departing from the gist of the present disclosure.

Industrial Applicability

Claims

1. A hybrid vehicle, comprising: An engine and a motor for driving; a power storage device that exchanges power with the motor; and a control device that controls the engine and the motor in a manner that enables driving while the engine is operating in a towing mode, wherein When the control device is instructed to enter the towing mode, if the state of charge of the power storage device is higher than a threshold value, the towing mode is permitted; if the state of charge is below the threshold value, the towing mode is prohibited.

2. The hybrid vehicle according to claim 1, wherein It further comprises a reporting device for reporting information, When the control device prohibits the towing mode, it controls the reporting device to report prohibition-related information associated with the meaning of prohibiting the towing mode.

3. The hybrid vehicle according to claim 1 or 2, wherein It further comprises a towing mode switch for instructing the towing mode, When the control device detects that the towing mode switch has been operated by the user, it determines that the towing mode has been instructed.

4. The hybrid vehicle according to claim 1 or 2, wherein When the vehicle and the towed object are connected, the control device determines that the towing mode has been instructed.

5. The hybrid vehicle according to claim 1 or 2, wherein When the vehicle load exceeds a predetermined load, the control device determines that the towing mode has been instructed.

6. The hybrid vehicle according to claim 1 or 2, wherein The control device sets the threshold value in such a way that it increases as the current location of the vehicle and / or the altitude of the predetermined driving route increases.

7. The hybrid vehicle according to claim 1 or 2, wherein The control device sets the threshold value in such a way that it increases as the road surface gradient of the current location of the vehicle and / or the predetermined driving route increases on the uphill side.

8. The hybrid vehicle according to claim 1 or 2, wherein When driving while the engine operation stops, the control device sets the threshold value higher than when driving with the engine operating.

9. The hybrid vehicle according to claim 1 or 2, wherein During driving in the towing mode, when the state of charge reaches below a second threshold value that is less than the threshold value, the control device ends the towing mode.

10. The hybrid vehicle according to claim 9, wherein It further comprises a reporting device for reporting information, When the control device ends the towing mode because the state of charge reaches below the second threshold value during driving in the towing mode, it controls the reporting device to report end-related information associated with the meaning of ending the towing mode.

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