JP2004251222A - Start controller for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise in the case where an engine 1 is already warmed up when turning on a key switch 6 to start the engine 1 by solving a problem wherein noise caused by meshing of gears occurs when starting the engine by a starter 2. <P>SOLUTION: A warming-up situation of the engine 1 is detected, and engine start by the starter 2 is inhibited in the case where the engine is already warmed up to start the engine 1 by a motor generator 4 only. Noise caused when the key switch 6 is turned on to start the engine in the case where the engine 1 is already warmed up can be reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to control of an engine starting means in a hybrid vehicle having an engine and a motor in accordance with a warm-up state of the engine.
[0002]
[Prior art]
Conventionally, when the viscosity of the engine oil is higher than a predetermined value, there is a hybrid vehicle that improves the startability of the engine by using a motor generator as the second electric motor in combination with a starter motor as the first electric motor. It has been proposed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-161102
[Problems to be solved by the invention]
However, starting the engine with the starter motor has a problem of noise caused by gear engagement.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, attention is paid to the fact that a hybrid vehicle has a motor generator used for restarting an engine after an idle stop, and a means for detecting a warm-up state of the internal combustion engine is provided. At the time of possible warm-up, the start of the engine by the starter motor is prohibited, and the engine is started only by the motor generator.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a main configuration diagram of a hybrid vehicle incorporating an engine start control device according to an embodiment of the present invention. The hybrid vehicle of this embodiment has an engine 1 that is an internal combustion engine, a starter that is a first electric motor, and a motor generator (MG) 4 that is a second electric motor connected to the engine 1 via a belt 3.
[0007]
A hybrid control unit (HCU) 5 comprehensively controls the hybrid vehicle. The hybrid control system (HCU) 5 starts and stops the hybrid vehicle system in accordance with a signal from a key switch 6. To the control unit (PCU) 9 of the computer and the control unit (MCU) 10 of the MG 4. The power supply to the starter 2 is cut off by the HCU 5 so that the starter 2 can be prevented from being started by the starter 2 linked to the key switch 6.
[0008]
The MCU 10 has a built-in inverter, converts the electric energy of the battery 11 into an alternating current, and gives it to the MG 4 to generate a driving force, thereby starting the engine 1 connected via the belt 3 and driving the wheels.
[0009]
The battery 11 is different from a 12 V battery which is a power supply such as the HCU 5 and is 42 V in the present embodiment. The MG 11 is rotated by the kinetic energy of the wheels or the driving force of the engine 1 to generate electric power. Convert to DC and charge.
[0010]
The engine 1 is controlled by the PCU 9, the air flow rate (Qa) is controlled to a value obtained from the rotation speed (Ne) of the engine 1 and the torque command (PE) of the HCU 5, and the engine cooling water temperature (Tw) detected by the water temperature sensor 12. ) And the information of the oxygen concentration sensor on the exhaust side, etc., to control the fuel injection time.
[0011]
The operation of the hybrid vehicle will be described with reference to the software of FIG. This processing is executed every 10 ms.
[0012]
In step 101, operation signals for the key switch 6, the accelerator 7, and the brake 8 are input.
[0013]
In step 102, data such as an output command (PE, PM) and an operation mode are transmitted to the PCU 9 and the MCU 10, and the rotation speed of the MG 4, the voltage (42 V) of the battery 11, and the remaining amount (SOC) are transmitted from the MCU 10. From the PCU 9, an engine speed (Ne), an engine cooling water temperature (Tw), complete explosion determination information, and the like are received.
[0014]
In step 103, the operation mode is determined from the operation signals of the key switch 6, the accelerator 7, and the brake 8, the engine coolant temperature (Tw), and the complete explosion determination information. If the engine 1 has not completely exploded and the engine cooling water temperature (Tw) is low, the accelerator 7 is depressed, or the brake 8 is released, the "engine start mode" is set. When the engine cooling water temperature (Tw) is high, the accelerator 7 is released, and the brake 8 is depressed, the "idle stop mode" is set. In other cases, "running / power generation mode" is set.
[0015]
In step 104, a command for the engine 1 and the MG 4 is calculated.
[0016]
Details of step 104 are shown in FIG. In step 201, it is determined whether the operation mode is the "engine start mode", and if true, the process proceeds to step 202, in which the determination is made according to the engine cooling water temperature (Tw) according to the characteristics of FIG. If the temperature is high, the process proceeds to step 203, where the command to the MG 4 is a rotation speed command for starting the engine, the command to the PCU 9 is fuel injection after the predetermined rotation speed, and the engine start by the starter 2 is started. Ban. On the other hand, if the temperature is low, the process proceeds to step 204, where the command to the MG4 is turned off, the command to the PCU 9 is the start of the engine by the starter 2, and the start of the engine by the starter 2 is permitted.
[0017]
If the determination in step 201 is false, the process proceeds to step 205, where it is determined whether the operation mode is the "idle stop mode". If true, in step 206, a fuel injection stop instruction is issued to the PCU 9, and an idle stop control for stopping the MG 4 is issued to the MCU 10.
[0018]
If the determination in step 205 is false, the process proceeds to step 207, and the output commands (PE, PM) to the PCU 9 and the MCU 10 are determined according to the opening degree of the accelerator 7 and the vehicle speed.
[0019]
The software of FIG. 5 incorporated in the PCU 9 for controlling the engine will be described. This processing is executed every 10 ms.
[0020]
In step 301, signals from the engine rotation sensor, the water temperature sensor 12, and the like are input.
[0021]
In step 302, data such as the engine speed (Ne), the engine cooling water temperature (Tw) and the complete explosion determination information are transmitted to the HCU 5, and an output command (PE), an operation mode, a fuel injection permission / prohibition flag, etc. Receive data.
[0022]
In step 303, a necessary air amount (Qa) is calculated from the information given from the HCU 5 and the detected engine speed (Ne), and the throttle is controlled so as to obtain the Qa.
[0023]
In step 304, the fuel injection time of the fuel injection device corresponding to Qa is calculated and controlled.
[0024]
The software of FIG. 6 incorporated in the MCU 10 that controls the MG 4 will be described. This processing is executed every 10 ms.
[0025]
In step 401, the voltage of the battery 11 and the like are input.
[0026]
In step 402, the rotation speed of the MG4, the voltage (42V) and the remaining amount (SOC) of the battery 11 are transmitted to the HCU 5, and data such as the operation mode and the output command (PM) are received.
[0027]
In step 403, a current command to the MG4 corresponding to the command from the HCU 5 is calculated, and the current of the MG4 is controlled by a process (not shown) executed every 100 μsec.
[0028]
According to the present embodiment, when the engine 1 is warmed up, the start of the engine by the starter 2 is prohibited even when the engine is started by the key switch 6, so that the engine 4 can be started quietly by the MG4.
[0029]
【The invention's effect】
According to the present invention, when the engine 1 is warmed up and the starting torque is small, the engine start by the starter 2 is prohibited even when the key switch 6 is turned on. There is an effect that the engine 1 can be started quietly without noise.
[Brief description of the drawings]
FIG. 1 is a main configuration diagram of a hybrid vehicle incorporating a vehicle control device as an embodiment of the present invention.
FIG. 2 is a flowchart of software incorporated in a control device for a hybrid vehicle as an embodiment of the present invention.
FIG. 3 is a detailed flowchart of step 104 in FIG. 2;
FIG. 4 shows characteristics used for Tw determination in step 202 of FIG. 3;
FIG. 5 is a flowchart of software incorporated in the control device of the engine of the hybrid vehicle as the embodiment of the present invention.
FIG. 6 is a flowchart of software to be incorporated in the control device for the MG of the hybrid vehicle as the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Starter, 3 ... Belt, 4 ... Motor generator (MG), 5 ... Hybrid control unit (HCU), 6 ... Key switch, 7 ... Accelerator, 8 ... Brake, 9 ... Engine control unit (PCU) 10) MG control device (MCU), 11 ... battery.

Claims (2)

Start control of a hybrid vehicle including an internal combustion engine, a first electric motor coupled to the internal combustion engine to start the internal combustion engine, and a second electric motor coupled to the internal combustion engine and configured to generate power and start the internal combustion engine In the device,
Means for detecting a warm-up state of the internal combustion engine are provided, and when the internal combustion engine is in a warm-up state, starting of the internal combustion engine by the first electric motor is prohibited, and starting of the internal combustion engine by the second electric motor is started. A start control device for a hybrid vehicle. Start control of a hybrid vehicle including an internal combustion engine, a first electric motor coupled to the internal combustion engine to start the internal combustion engine, and a second electric motor coupled to the internal combustion engine and configured to generate power and start the internal combustion engine In the device,
A means for detecting a warm-up state of the internal combustion engine is provided, and when the internal combustion engine is in a warm-up state, use of the first electric motor is prohibited as a start-up means of the internal combustion engine when a key switch is turned on. A start control device for a hybrid vehicle, comprising starting the internal combustion engine by a second electric motor.

Images