JP2023056331A - Driving device - Google Patents

Abstract

To suppress inconvenience that is caused by unexpected excessive torque, which may be generated when charging an electric storage device with generated electric power obtained by driving a motor as a power generator in a state where an engine outputs power to a driving shaft, acting on the driving shaft.SOLUTION: A driving device comprises: an engine that outputs power to a driving shaft; a motor, connected to a crank shaft of the engine, which can generate electric power; an electric storage device that exchanges electric power with the motor; and a control device that controls the engine and the motor. The control device controls the engine and the motor so that required torque that is required in the driving shaft is outputted to the driving shaft, and target generated electric power, which is obtained by guarding generated electric power required based on an electric storage ratio of the electric storage device to an upper limit at an upper limit of power generation amounts based on a rotation speed of the driving shaft, is generated by the motor, so that the electric storage device is charged with the electric power.SELECTED DRAWING: Figure 2

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive system, and more particularly to a drive system having a motor capable of generating electricity coupled to the crankshaft of an engine.

Conventionally, this type of drive device has a drive mode in which the engine is driven by electric power supplied from a power storage device to start the engine, and a drive mode in which the power storage device is charged with power generated during normal operation of the engine. A technique for controlling a motor capable of generating power by using a power generation mode and a regenerative power generation mode in which power is generated regeneratively when the vehicle decelerates has been proposed (see, for example, Patent Document 1). In this device, in the regenerative power generation mode, when starting regenerative power generation, the field current of the motor is set to be the same as the maximum value in the drive mode that exceeds the maximum value of the field current in the power generation mode, and then the motor and each part of the motor By measuring the temperature of each part and reducing the field current when at least one of the temperatures of each part exceeds a predetermined threshold value, the amount of power generated during regeneration is increased and damage to the motor due to overheating is prevented. there is

JP 2010-081741 A

However, in the above-described drive system, when the power storage device is charged with power generated by driving the motor as a generator while the engine is outputting power to the drive shaft, the demand required for the drive shaft is reduced. The engine is controlled so that the engine outputs a torque obtained by adding the torque corresponding to the torque and the torque corresponding to the regenerative torque by the motor. At this time, if the regenerative torque is lost due to reasons such as motor failure, an unexpectedly large torque is output to the drive shaft. When the drive system is mounted on a vehicle, the unexpectedly large torque output causes the driver to feel uncomfortable.

In the drive system of the present invention, an unexpected excessive torque that can be generated when charging the power storage device with power generated by driving using the motor as a generator while the engine is outputting power to the drive shaft is prevented. The main purpose is to suppress inconvenience caused by acting on the drive shaft.

The driving device of the present invention employs the following means to achieve the above-mentioned main object.

The driving device of the present invention is
an engine that outputs power to a drive shaft;
a motor capable of generating electricity coupled to a crankshaft of the engine;
a power storage device that exchanges electric power with the motor;
a control device that controls the engine and the motor;
A drive device comprising:
The control device outputs the required torque required to the drive shaft to the drive shaft, and limits the required power generation based on the power storage ratio of the power storage device to a power generation amount upper limit value based on the rotation speed of the drive shaft. controlling the engine and the motor so that the target generated power obtained by guarding is generated by the motor and the power storage device is charged;
It is characterized by

In the drive system of the present invention, the required torque required for the drive shaft is output to the drive shaft, and the required power generation based on the power storage rate of the power storage device is guarded with the upper limit of the power generation amount based on the rotation speed of the drive shaft. The engine and the motor are controlled so that the motor generates the target power generated by the motor and charges the power storage device. The target generated power is guarded by the upper limit of the amount of power generated based on the number of revolutions of the drive shaft, so even if the regenerative torque of the motor is lost due to motor failure, etc., the output to the drive shaft is unexpected. Excessive torque magnitude can be suppressed. As a result, it is possible to suppress inconvenience caused by output of unexpected excessive torque to the drive shaft. When the drive system of the present invention is mounted on a vehicle, the sense of discomfort given to the driver due to the output of unexpectedly large torque to the drive shaft can be suppressed by suppressing the magnitude of the unexpectedly large torque. suppressed by As a result, when the motor is used as a generator to drive the motor while the engine is outputting power to the drive shaft, an unexpectedly large amount of torque that can be generated when charging the power storage device is applied to the drive shaft. Inconvenience caused by the action can be suppressed. It should be noted that the "upper limit of power generation" is preferably an upper limit that increases as the number of revolutions of the drive shaft increases. It is preferably the upper limit.

1 is a configuration diagram showing an outline of the configuration of an automobile 20 equipped with a driving device according to an embodiment of the present invention; FIG. 4 is a flowchart showing an example of torque control during power generation executed by a main ECU 70 of a vehicle 20 equipped with the drive system of the embodiment; FIG. 5 is an explanatory diagram showing an example of a power generation upper limit value setting map;

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing the outline of the configuration of an automobile 20 equipped with a drive system as one embodiment of the present invention. As illustrated, the automobile 20 of the embodiment includes an engine 22, a starter 25, a motor 30, an inverter 32, an automatic transmission 40, a high voltage battery 60, a low voltage battery 67, and a DC/DC converter. 68 and a main electronic control unit (hereinafter referred to as “main ECU”) 70 . The engine 22, the motor 30, the high-voltage battery 60, and the main electronic control unit 70 mainly correspond to the driving device.

The engine 22 is a multi-cylinder engine (4-cylinder, 6-cylinder, etc.) internal combustion engine. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 .

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU. In addition to the CPU, the engine ECU 24 includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Prepare. Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 via input ports, and various control signals for controlling the operation of the engine 22 are sent from the engine ECU 24 to the output port. is output via

A starter motor 25 for cranking the engine 22 is connected to a crankshaft 23 as an output shaft of the engine 22 . An input side of a damper 28 as a torsion element is also connected to the crankshaft 23 of the engine 22 . A pulley 23 b is attached to the crankshaft 23 of the engine 22 .

The motor 30 is configured as, for example, a synchronous generator motor. A pulley 30 b is attached to the rotation shaft of the motor 30 . A belt 31 is wound around the pulley 30b so as to rotate a pulley 23b attached to the crankshaft 23 of the engine 22. As shown in FIG. The inverter 32 is used to drive the motor 30 and is connected to the high voltage power line 61 . The motor 30 is rotationally driven by controlling the switching of a plurality of switching elements of the inverter 32 by the main ECU 70 .

The automatic transmission 40 includes a torque converter 43, a six-speed automatic transmission 45, for example, and a hydraulic circuit (not shown). The torque converter 43 is configured as a general hydraulic transmission device, and converts the power of the input shaft 41 connected to the rotating shaft of the motor 30 to the intermediate rotating shaft 44 which is the input shaft of the automatic transmission 45 . The torque is amplified and transmitted, or the torque is transmitted as it is without amplification. The automatic transmission 45 is connected to an output shaft 42 that is connected to an intermediate rotary shaft 44 and a drive shaft 46, and includes a plurality of planetary gears and a plurality of hydraulically driven friction engagement elements (clutches, brakes). have The drive shaft 46 is connected to rear wheels 55 a and 55 b via an axle 56 and a rear differential gear 57 . The automatic transmission 45 forms, for example, forward gears from first gear to sixth gear and reverse gears by engaging and disengaging a plurality of friction engagement elements, and power is transmitted between the intermediate rotary shaft 44 and the output shaft 42 . to communicate.

The high-voltage battery 60 is, for example, a lithium-ion battery or a nickel-metal hydride battery, and is connected to a high-voltage power line 61 connected to the inverter 32 . The low-voltage battery 67 is, for example, a lead battery having a lower rated voltage than the high-voltage battery 60 and is connected to a low-voltage power line 66 connected to the starter motor 25 . The DC/DC converter 68 is connected to the high voltage side power line 61 and the low voltage side power line 66 . The DC/DC converter 68 is controlled by the main ECU 70 to step down the power of the high voltage side power line 61 and supply it to the low voltage side power line 66 .

Although not shown, the main ECU 70 is configured as a microprocessor centered on a CPU. In addition to the CPU, the main ECU 70 includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Prepare. Signals from various sensors are input to the main ECU 70 through input ports. Signals input to the main ECU 70 include, for example, a rotational position φm of the rotor of the motor 30 from a rotational position sensor (not shown) that detects the rotational position of the rotor of the motor 30, and a rotational speed sensor attached to the drive shaft 46. The rotational speed Np of the drive shaft 46 from 46a can be mentioned. Further, a battery temperature Tb from a temperature sensor 60a attached to the high voltage battery 60, a voltage Vh of the high voltage battery 60 from a voltage sensor (not shown) attached between terminals of the high voltage battery 60, and a voltage Vh of the high voltage battery 60 The current Ih of the high voltage battery 60 from a current sensor (not shown) attached to the output terminal of , and the voltage Vb of the low voltage battery 67 from a voltage sensor (not shown) attached between the terminals of the low voltage battery 67 can also be mentioned. . Furthermore, the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83 , the brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, and the vehicle speed V from a vehicle speed sensor 88. The main ECU 70 calculates the power storage ratio SOC based on the voltage Vh of the high-voltage battery 60, the current Ih flowing through the high-voltage battery 60, and the like.

Various control signals are output from the main ECU 70 through an output port. Signals output from the main ECU 70 include, for example, a control signal to the starter motor 25, a control signal to the inverter 32, a control signal to the automatic transmission 40, and a control signal to the DC/DC converter 68. can be done. The main ECU 70 is connected to the engine ECU 24 via a communication port.

While the automobile 20 is running, the main ECU 70 sets a required drive shaft torque Td* required for the drive shaft 46 based on the accelerator opening Acc and the vehicle speed V, and outputs from the motor 30 Set the required motor torque Tm*. Then, the effective torque Teg* is calculated as the sum of the torque obtained by converting the required drive shaft torque Td* to the crankshaft 23 and the torque obtained by converting the required motor torque Tm* to the crankshaft 23, and the effective torque Teg* is sent to the engine ECU 24. Send. The engine ECU 24 executes intake air amount control, fuel injection control, and ignition control so that the received execution torque Teg* is output from the engine 22 . Further, the main ECU 70 performs switching control of the switching elements of the inverter 32 so that the motor required torque Tm* is output from the motor 30 . Further, the main ECU 70 controls the automatic transmission 40 so that the gear stage is determined by the gear shift map in which the gear stage is divided by the vehicle speed V and the drive shaft required torque Td*.

Next, the operation of the automobile 20 of the embodiment, in particular, the operation of charging the high voltage battery 60 while the vehicle is running will be described. FIG. 2 is a flowchart showing an example of torque control during power generation executed by the main ECU 70. As shown in FIG. This routine is repeatedly executed at predetermined time intervals.

When the power generation torque control is executed, the main ECU 70 first executes a process of inputting data necessary for control such as the power storage ratio SOC of the high-voltage battery 60, the vehicle speed V, and the required drive shaft torque Td* (step S100). ).

When the data is input, it is determined whether or not the power storage ratio SOC is less than the threshold value Sref (step S110). The threshold Sref is a threshold for determining whether or not charging of the high-voltage battery 60 is necessary, and for example, 50% or 40% can be used. When it is determined that the power storage ratio SOC is equal to or greater than the threshold Sref, it is determined that the high-voltage battery 60 does not need to be charged. 22, the torque to be output to the crankshaft 23 is calculated, and this torque is set as the effective torque Teg* and transmitted to the engine ECU 24 (step S120), and this process is terminated. As described above, upon receiving the execution torque Teg*, the engine ECU 24 executes intake air amount control, fuel injection control, and ignition control so that the execution torque Teg* is output from the engine 22 .

When it is determined in step S110 that the power storage rate SOC is less than the threshold value Sref, the required power generation Pin* for charging the high voltage battery 60 is set based on the power storage rate SOC (step S130). In the embodiment, the required power generation Pin* is determined by predetermining the relationship between the storage rate SOC and the required power generation Pin* and storing it as a required power generation setting map. It is set by deriving the required power generation Pin*. It is preferable to set the required electric power generation Pin* so that it tends to increase as the storage ratio SOC decreases, but it may be set to a constant value.

Subsequently, a power generation upper limit value Pinlim is set based on the vehicle speed V (step S140). In the embodiment, the upper limit value of power generation Pinlim is determined by predetermining the relationship between the vehicle speed V and the upper limit value of power generation Pinlim and storing it as a map for setting the upper limit value of power generation. is set by deriving FIG. 3 shows an example of a power generation upper limit value setting map. In the embodiment, the power generation upper limit value Pinlim tends to increase as the vehicle speed V increases. It is thought that the less the vehicle speed V is, the greater the driver's sense of discomfort due to unexpected excessive torque acting on the drive shaft 46 when the regenerative torque is lost from the motor 30 due to a failure of the motor 30 or the like. based on that. Since the vehicle speed V and the rotation speed Nd of the drive shaft 46 have a linear relationship, setting the power generation upper limit Pinlim based on the vehicle speed V is equivalent to setting the power generation upper limit Pinlim based on the rotation speed Nd of the drive shaft 46. I agree with what you set.

When the power generation upper limit Pinlim is set in this way, the required power generation Pin* is guarded by the power generation upper limit Pinlim (step S150), and the required power generation Pin* is adjusted to the rotation speed Nd of the drive shaft 46 and to the gear stage of the automatic transmission 40. The required motor torque Tm* is set by multiplying the corresponding conversion coefficient km by the conversion coefficient kp based on the pulleys 23b and 30b (step S160). When the motor required torque Tm* is set, the main ECU 70 controls switching of the switching elements of the inverter 32 so that the motor 30 outputs the motor required torque Tm*.

Then, the drive shaft demand torque Td* obtained by multiplying the drive shaft demand torque Td* by a conversion coefficient km corresponding to the gear stage of the automatic transmission 40 is converted to the crankshaft 23 torque, and the motor demand torque Tm* is added to the pulley torque. 23b and the pulley 30b by a conversion factor kp based on the conversion coefficient kp to set an effective torque Teg* as the sum of the torque converted to the crankshaft 23 and the torque converted to the crankshaft 23, and transmit it to the engine ECU 24 (step S170); End this process. As described above, upon receiving the execution torque Teg*, the engine ECU 24 executes intake air amount control, fuel injection control, and ignition control so that the execution torque Teg* is output from the engine 22 .

In the automobile 20 equipped with the drive system of the embodiment described above, the required power generation Pin* for charging the high voltage battery 60 is set based on the power storage rate SOC, and the required power generation Pin* is set based on the vehicle speed V. The upper limit is guarded by the set power generation upper limit Pinlim. Subsequently, the required power generation Pin* is divided by the product of the rotational speed Nd of the drive shaft 46 multiplied by the conversion coefficient km corresponding to the shift stage of the automatic transmission 40 and the conversion coefficient kp based on the pulleys 23b and 30b. to set the required motor torque Tm*. Then, the drive shaft demand torque Td* obtained by multiplying the drive shaft demand torque Td* by a conversion coefficient km corresponding to the gear stage of the automatic transmission 40 is converted to the crankshaft 23 torque, and the motor demand torque Tm* is added to the pulley torque. Execution torque Teg* is set as the sum of the torque converted to the crankshaft 23 and the motor required torque Tm* obtained by multiplying the conversion coefficient kp based on the pulley 30b and the pulley 30b. In this way, by setting the motor request torque Tm* and the execution torque Teg* while guarding the required power generation Pin* with the power generation upper limit Pinlim based on the vehicle speed V, the regenerative torque of the motor 30 due to failure of the motor 30, etc. Unexpected excessive torque acting on the drive shaft 46 when the torque is lost can be suppressed. As a result, it is possible to suppress inconveniences (for example, driver discomfort) caused by unexpected excessive torque acting on the drive shaft 46 .

In the automobile 20 equipped with the driving device of the embodiment, the required power generation Pin* for charging the high voltage battery 60 is set based on the power storage ratio SOC, and the required power generation Pin* is set based on the vehicle speed V. The upper limit is guarded by the power generation upper limit Pinlim, and the motor requested torque Tm* is set based on the guarded requested generated power Pin*, and the engine 22 is executed based on the motor requested torque Tm* and the drive shaft requested torque Td*. Torque Teg* shall be set. However, since it is sufficient that the required generated power Pin* is substantially guarded by an upper limit value based on the vehicle speed, the engine required torque calculated based on the required generated power Pin* and the drive shaft required torque Td* On the other hand, it is also possible to perform an upper limit guard based on an upper limit value based on the vehicle speed. In this case, the requested motor torque Tm* may be set by obtaining the requested generated electric power Pin* based on the requested engine torque and the requested drive shaft torque Td* with the upper limit guard applied. Further, an upper limit guard based on the vehicle speed is applied to the fuel injection amount necessary for outputting the engine required torque calculated based on the required generated electric power Pin* and the drive shaft required torque Td* from the engine 22. It may be processed. In this case, the engine torque is obtained from the fuel injection amount subjected to the upper limit guard, and the requested electric power Pin* is obtained based on this engine torque and the required drive shaft torque Td* to set the requested motor torque Tm*. Considering that the drive shaft required torque Td* is output to the drive shaft 46, the required generated power Pin An upper limit guard is applied to *.

In the automobile 20 equipped with the drive system of the embodiment, the motor 30 is attached to the crankshaft 23 of the engine 22 via the pulleys 23b and 30b. A motor may be attached to the shaft).

In the embodiment, the driving device is mounted on the automobile 20, but the driving device may be mounted on a vehicle other than the automobile, or may be mounted on a moving body other than the vehicle, or the driving device may be mounted on a vehicle. It is good also as what is incorporated in facilities, such as facilities. Even in these cases, it is possible to reduce unexpected excessive torque acting on the drive shaft when the regenerative torque of the motor is lost due to motor failure or the like.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the engine 22 corresponds to the "engine", the motor 30 corresponds to the "motor", the high voltage battery 60 corresponds to the "storage device", and the main electronic control unit 70 and the engine electronic control unit 24 Corresponds to "control device".

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the manufacturing industry of driving devices and the like.

20 automobile, 22 engine, 23 crankshaft, 23a speed sensor, 23b pulley, 24 engine ECU, 25 starter motor, 28 damper, 30 motor, 30b pulley, 31 belt, 32 inverter, 40 automatic transmission, 41 input shaft, 46a rotational speed sensor, 42 output shaft, 43 torque converter, 44 intermediate rotary shaft, 45 automatic transmission, 46 drive shaft, 55a rear wheel, 56 axle, 57 rear differential gear, 60 high voltage battery, 61 high voltage power line , 66 low-voltage power line, 67 low-voltage battery, 68 DC/DC converter, 70 main electronic control unit (main ECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor.

Claims (1)

an engine that outputs power to a drive shaft;
a motor capable of generating electricity coupled to a crankshaft of the engine;
a power storage device that exchanges electric power with the motor;
a control device that controls the engine and the motor;
A drive device comprising:
The control device outputs the required torque required to the drive shaft to the drive shaft, and limits the required power generation based on the power storage ratio of the power storage device to a power generation amount upper limit value based on the rotation speed of the drive shaft. controlling the engine and the motor so that the target generated power obtained by guarding is generated by the motor and the power storage device is charged;
A driving device characterized by:

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