car

Abstract

The system main relay can be turned on without causing any problems while the vehicle is running with the system main relay turned off. [Solution] A control device for an automobile, which includes an electric motor that inputs and outputs power for driving, a power storage device that exchanges power with the electric motor, and a system main relay attached to the power line to which the power storage device is connected, will, when turning on the system main relay while driving with the system main relay turned off, stop the operation of electrical equipment that receives power from the power line and limit the rotation speed of the electric motor before turning on the system main relay.

Description

Technical Field

[0001] The present disclosure relates to an automobile, and more particularly to an automobile including an electric motor that inputs and outputs driving power, a power storage device, and a system main relay that connects and disconnects the power storage device.

Background Art

[0002] Conventionally, as this type of automobile, there has been proposed one that starts the engine by cranking the engine with a motor by turning on the system main relay, and then starts the retreat running by turning off the system main relay (see, for example, Patent Document 1). In this automobile, when the driving of the motor by the drive circuit is stopped after starting the engine and before turning off the system main relay, the boost converter is controlled so that the voltage on the high-voltage power line side becomes higher than the back electromotive voltage of the motor. Thereby, the reverse current of the motor flowing into the power storage device is suppressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the factor for turning off the system main relay is released while the vehicle is running with the system main relay turned off, it is preferable to turn on the system main relay for normal running. However, if the system main relay is inadvertently turned on, inconveniences such as an excessive voltage acting or an excessive current flowing occur.

[0005] The main object of the automobile of the present disclosure is to turn on the system main relay without causing inconvenience while the vehicle is running with the system main relay turned off. [Means for solving the problem]

[0006] The automobile of this disclosure employs the following means to achieve the primary objective described above.

[0007] The automobile of this disclosure comprises an electric motor for inputting and outputting power for driving, a power storage device for exchanging power with the electric motor, a system main relay attached to a power line to which the power storage device is connected for connecting and disconnecting the power storage device, and a control device for controlling the electric motor, The control device is characterized in that, when turning on the system main relay while the vehicle is running with the system main relay turned off, it stops the operation of electrical equipment that receives power from the power line and limits the rotational speed of the electric motor before turning on the system main relay.

[0008] The vehicle control device of this disclosure, when turning on the system main relay while the vehicle is running with the system main relay turned off, stops the operation of electrical equipment receiving power from the power line and limits the rotational speed of the electric motor before turning on the system main relay. In other words, it creates an arc-free state for the system main relay before turning on the system main relay. As a result, it is possible to turn on the system main relay and return to a normal driving state, avoiding the inconvenience of excessive voltage or excessive current flow that may occur when the system main relay is turned on unintentionally. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of a hybrid vehicle 20 as one embodiment of the present invention. [Figure 2] This flowchart shows an example of the SMR switching process performed by HVECU70. [Modes for carrying out the invention]

[0010] Next, embodiments for carrying out the present invention will be described. Figure 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 as one embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a motor 30, an inverter 32, a clutch K0, an automatic transmission 40, a high-voltage battery 60, a system main relay 60a, a low-voltage battery 62, a DC / DC converter 64, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0011] The engine 22 is configured as an internal combustion engine that outputs power using fuel such as gasoline or diesel from a fuel tank. The crankshaft 23 of this engine 22 is connected to the rotating shaft 31 (rotor) of the motor 30 via a clutch K0. The engine 22 is operated and controlled by an electronic control unit for the engine (hereinafter referred to as "engine ECU") 24. The engine ECU 24 is configured as a microcomputer centered on a CPU. The engine ECU 24 receives input such as the crank angle θcr from a crank position sensor 23a that detects the rotational position of the crankshaft 23 of the engine 22, and the coolant temperature Tw from a water temperature sensor (not shown) that detects the temperature of the coolant in the engine 22. The engine ECU 24 also outputs various control signals for operating and controlling the engine 22. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr of the crankshaft 23 from the crank position sensor 23a.

[0012] The crankshaft 23 of the engine 22 is connected to a starter motor 25 for cranking the engine 22 and an alternator 26 that generates electricity using power from the engine 22. The starter motor 25 and alternator 26 are connected to a low-voltage power line 63 along with a low-voltage battery 62 and are controlled by the HVECU 70.

[0013] The motor 30 is configured as a synchronous generator-motor and has a rotor with permanent magnets embedded in the rotor core and a stator with three-phase coils wound around the stator core. The rotating shaft 31 to which the rotor of this motor 30 is fixed is connected to the crankshaft 23 of the engine 22 via a clutch K0 and is also connected to the input shaft 41 of the automatic transmission 45. The inverter 32 is used to drive the motor 30 and is connected to the high-voltage side power line 61. The motor 30 is rotationally driven by the switching control of multiple switching elements of the inverter 32 by the motor electronic control unit (hereinafter referred to as "motor ECU") 34. The motor ECU 34 is configured as a microcomputer centered on a CPU. The motor ECU 34 receives input such as the rotational position θm from a rotational position sensor 30a that detects the rotational position of the rotor (rotating shaft 31) of the motor 30, and the phase currents Iu, Iv from current sensors that detect the phase currents of each phase of the motor 30. The motor ECU 34 outputs control signals to the inverter 32. The motor ECU 34 calculates the rotational speed Nm of the motor 30 based on the rotational position θm of the rotor (rotating shaft 31) of the motor 30 as measured by the rotational position sensor 30a.

[0014] Clutch K0 is configured, for example, as a hydraulically driven friction clutch, controlled by HVECU 70, and connects and disconnects the crankshaft 23 of engine 22 from the rotating shaft 31 of motor 30.

[0015] The automatic transmission 40 includes a torque converter 43 and a 6-speed automatic transmission 45. The torque converter 43 is configured as a general fluid transmission device and transmits power from the input shaft 41 connected to the rotating shaft 31 of the motor 30 to the transmission input shaft 44, which is the input shaft of the automatic transmission 45, with amplified torque, or transmits the torque directly without amplification. The automatic transmission 45 includes the transmission input shaft 44, an output shaft 42 connected to the drive wheel 49 via a differential gear 48, a plurality of planetary gears, and a plurality of hydraulically driven friction engagement elements (clutch, brake). Each of the plurality of friction engagement elements has a hydraulic servo consisting of a piston, a plurality of friction engagement plates (friction plate and separator plate), an oil chamber to which hydraulic fluid is supplied, etc.

[0016] The high-voltage battery 60 is configured as, for example, a lithium-ion secondary battery or nickel-metal hydride secondary battery with a rated voltage of several hundred volts, and is connected to the high-voltage power line 61 together with the inverter 32. A system main relay 60a is installed on the high-voltage power line 61 to connect and disconnect the high-voltage battery 60. Electrical equipment 61a, such as the compressor of the air conditioning system that air-conditions the passenger compartment, is also connected to the high-voltage power line 61. The low-voltage battery 62 is configured as, for example, a lead-acid battery with a rated voltage of about 12V or 14V, and is connected to the low-voltage power line 63 together with the starter motor 25 and alternator 26. The DC / DC converter 64 is connected to the high-voltage power line 61 and the low-voltage power line 63. This DC / DC converter 64 supplies power from the high-voltage power line 61 to the low-voltage power line 63 with a voltage reduction.

[0017] Although not shown in the diagram, the HVECU70 is configured as a microcomputer centered around a CPU. The HVECU70 receives inputs such as the rotational speed Nin from the rotational speed sensor 41a attached to the input shaft 41 of the automatic transmission 40, the rotational speed Nmi from the rotational speed sensor 44a attached to the transmission input shaft 44 of the automatic transmission 40, the rotational speed Nout from the rotational speed sensor 42a attached to the output shaft 42 of the automatic transmission 40, the voltage Vbh of the high-voltage battery 60 from the voltage sensor attached between the terminals of the high-voltage battery 60, the current Ibh of the high-voltage battery 60 from the current sensor attached to the output terminal of the high-voltage battery 60, the voltage Vbl from the voltage sensor attached between the terminals of the low-voltage battery 62, the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 which detects the operating position of the shift lever 81, the accelerator opening Acc from the accelerator pedal position sensor 84 which detects the amount of depression of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 which detects the amount of depression of the brake pedal 85, and the vehicle speed V from the vehicle speed sensor 87.

[0018] HVECU70 can, for example, output control signals to the starter motor 25 and the alternator 26. It also outputs control signals to the clutch K0 and the automatic transmission 40 (hydraulic control device), and to the DC / DC converter 64. HVECU70 is connected to the engine ECU 24 and motor ECU 34 via a communication port.

[0019] Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way will be described, in particular, the operation when the system main relay 60a is turned on from a state in which the vehicle is running with the system main relay 60a turned off. Figure 2 is a flowchart showing an example of the system main relay switching process (SMR switching process) performed by the HVECU 70.

[0020] When the SMR switching process is executed, the HVECU 70 first determines whether the system main relay 60a is off and the vehicle is running (step S100). When it is determined that the vehicle is not running with the system main relay 60a off, that is, when it is determined that the vehicle is running with the system main relay 60a on, this process is unnecessary, so this process ends.

[0021] When it is determined in step S100 that the vehicle is running with the system main relay 60a off, it is determined whether there is a factor that requires the system main relay 60a to be turned off (step S110). That is, it is determined whether the factors that caused the vehicle to run with the system main relay 60a off, for example, factors such as the high-voltage battery 60 being in an extremely low temperature state or a failure of the high-voltage battery 60, have been resolved. When it is determined that there is a factor that requires the system main relay 60a to be turned off (the factor has not been resolved), it is judged that the state of running with the system main relay ingshould be continued, and this process ends without turning on the system main relay 60a.

[0022] When it is determined that there is no factor that requires turning off the system main relay 60a in step S110 (the factor has been resolved), the operation of high-voltage components such as the electrical equipment 61a connected to the high-voltage side power line 61 and the DC / DC converter 64 is stopped, and a rotational speed limit is imposed on the motor 30 (step S120). In the embodiment, the rotational speed limit for the motor 30 is set such that the reverse electromotive voltage generated by the motor 30 is not higher than the voltage of the high-voltage battery 60. Then, it is confirmed that the high-voltage components have stopped operating and the rotational speed Nm of the motor 30 is limited (step S130), and the system main relay 60a is turned on (step S140). That is, the system main relay 60a is turned on in an arcless state. By turning on the system main relay 60a in this arcless state, it is possible to avoid the inconvenience of excessive voltage acting or excessive current flowing when the system main relay 60a is turned on. Then, the operation of the high-voltage components that had stopped operating is resumed, and the rotational speed limit of the motor 30 is released (step S150), and this process is terminated.

[0023] In the hybrid vehicle 20 of the embodiment described above, when turning on the system main relay 60a from the state of running with the system main relay 60a turned off, the operation of the high-voltage components connected to the high-voltage side power line 61 is stopped, a rotational speed limit is imposed on the motor 30, and the system main relay 60a is turned on in an arcless state. Thereby, it is possible to avoid the inconvenience of excessive voltage acting or excessive current flowing when the system main relay 60a is turned on. As a result, it is possible to turn on the system main relay 60a without causing any inconvenience during the running with the system main relay 60a turned off.

[0024] In this embodiment, the present disclosure is applied to a hybrid vehicle 20 comprising an engine 22, a motor 30, an inverter 32, a clutch K0, an automatic transmission 40 having a torque converter 43 and an automatic transmission 45, and a high-voltage battery 60. However, it is not limited to this, and the present disclosure may be applied to any automobile having a configuration comprising a motor that inputs and outputs power for driving, a battery that exchanges power with the motor, and a system main relay that connects and disconnects the battery. For example, it may be applied to a hybrid vehicle comprising a planetary gear with three rotating elements connected to the output shaft of the engine, the rotation shaft of the first motor and the drive shaft, and a second motor that outputs power to the drive shaft. In this case, when the system main relay is turned off and the vehicle is driven, a portion of the power from the engine is generated by the first motor, and all of the power generated by the first motor is output by the second motor for driving.

[0025] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be explained. In the embodiment, motor 30 corresponds to "electric motor", high-voltage battery 60 corresponds to "energy storage device", system main relay 60a corresponds to "system main relay", and HVECU 70, engine ECU 24, and motor ECU 34 correspond to "control device".

[0026] Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.

[0027] Although embodiments for carrying out the present invention have been described above using examples, the present invention is not limited in any way to these embodiments, and can be carried out in various forms without departing from the spirit of the present invention. [Industrial applicability]

[0028] This invention can be used in industries such as the manufacturing of hybrid vehicles. [Explanation of Symbols]

[0029] 20 Hybrid vehicle, 22 Engine, 24 Engine ECU, 30 Motor, 34 Motor ECU, 40 Automatic transmission, 60 High-voltage battery, 60a System main relay, 61 High-voltage side power line, 61a Electrical equipment, 64 DC / DC converter, 70 HVECU.

Claims

[Claim 1] An electric motor that inputs and outputs power for propulsion, A power storage device that exchanges power with the aforementioned electric motor, A system main relay is attached to the power line to which the energy storage device is connected and is used to connect and disconnect the energy storage device. A control device for controlling the electric motor, A car equipped with, When the control device turns on the system main relay while the vehicle is running with the system main relay turned off, it stops the operation of electrical equipment receiving power from the power line and limits the rotational speed of the motor before turning on the system main relay. An automobile characterized by the following features.

Images