TWI763448B - Method for stabilizing idle speed of engine - Google Patents

Abstract

The present invention relates to a method for stabilizing the idle speed of an engine, which is applied to a vehicle. The vehicle includes an engine, an integrated starter-generator system, a battery, and an engine management system. The integrated starter-generator system includes a starter-generator controller, a starter-generator motor, and a motor phase sensor. The battery is electrically connected to the starter-generator controller. The engine management system detects the crankshaft angle with a crankshaft angle sensor and executes fuel injection and ignition function. As such, through the integrated starter-generator system actively provides torque by grasping the timing of performing stable rotation speed in order to stabilize the engine rotation speed at idling speed and reduce vehicle emissions. The method can effectively prevent the vehicle from stalling due to unstable idling speed and maintain the constancy of the system.

Description

How to stabilize engine idle speed

The present invention relates to a method for stabilizing the idling speed of an engine, especially a method for stabilizing the idling speed of an engine suitable for a power vehicle.

In order to maintain the stability of the idling speed and keep the characteristics of idling that is not easy to flame out, the fuel locomotive will increase the concentration of fuel injection and increase the kinetic energy of the engine explosion and combustion to stabilize the idling speed, especially when the vehicle is cold or At the beginning, the conditions for maintaining a stable idle speed will be more severe.

However, if the concentration of the injection fuel supply is increased, the environmental pollution will increase and the fuel supply will be lost. The inventor is due to this, and in the spirit of active invention, it is urgent to think of a vehicle with an integrated drive and power generation system. The method for stabilizing the idle speed of the engine which can solve the above problems has finally been completed in the present invention after several researches and experiments.

The main purpose of the present invention is to provide a method for stabilizing the idling speed of an engine. By grasping the timing of executing the driving at a stable rotational speed to stabilize the rotational speed of the engine during idling and reduce vehicle pollution, the engine can be effectively prevented from stalling due to unstable idling. the predicament.

In order to achieve the above objects, the method for stabilizing engine idle speed of the present invention is applied to a power vehicle. The power vehicle includes an engine, an integrated drive and power generation system, a battery and an engine management system. The engine has a crankshaft; the integrated drive and power generation system includes a drive power generation controller, a drive power generation motor and a motor phase sensor, the drive power generation motor is arranged coaxially with the crankshaft; the battery is electrically connected to the drive power generation controller; the engine management system A crankshaft angle sensor detects the crankshaft angle and executes the fuel injection ignition function. Wherein, the method for stabilizing the idle speed of the engine includes the following steps: (A) when the engine is running, perform step (B); (B) judging whether the engine speed is in the idle state, if so, execute step (C), otherwise return to step (A); (C) Judgment Check whether the key switch of the power vehicle is turned on, if so, go to step (D), if not, turn off the engine; (D) judging whether the engine speed is less than a first specific speed, if so, execute step (E), if otherwise, drive the power generation controller to maintain normal power generation, and return to step (A); (E) Execute a steady speed drive, calculate the accumulated time of executing the steady speed drive and the crankshaft angle accumulated by executing the steady speed drive, and execute step (F); (F) judging whether the engine speed is greater than a second specific speed or whether the accumulated time for performing the stable speed driving reaches a specific time or whether the accumulated crankshaft angle for performing the stable speed driving reaches a specific angle, if so, perform step (G), If otherwise, go back to step (C); (G) Stop the steady speed drive.

With the above design, if the power vehicle uses the method for stabilizing the idle speed of the engine of the present invention, the power vehicle can be cooled without increasing the fuel supply. When the engine combustion is unstable and the speed is lower than a certain speed, the integrated The drive and power generation system actively provides torque to stabilize the idle speed of the engine without stalling, maintaining the constancy of the system.

The above step (C) may further include a step (C1) judging whether the engine management system sends an idling stop indication signal to the drive generator controller, if not, perform step (D), and if so, execute the engine idling stop. In this way, the method can additionally judge the system according to the presence or absence of the idling stop indication signal. If the engine management system does send an idling stop indication signal to the drive generator controller, it can directly stop the fuel injection and ignition, so that the engine stops naturally. That's it.

The above step (C) may further include a step (C2) judging whether the battery voltage is less than a specific voltage, if otherwise, perform step (D), if so, drive the power generation controller to maintain normal power generation, and return to step (A). Therefore, when the battery voltage is too low, the integrated drive and power generation system may not be able to provide enough torque to help stabilize the idle speed. Therefore, the engine is selected to continue to generate electricity normally, the battery is charged, and the stable speed drive is not performed.

After the above step (C), it may further include a step (C1) judging whether the engine management system sends an idling stop indication signal to the drive generator controller, if otherwise, execute the step (C2), if so, execute the engine idling stop; and a step ( C2) Determine whether the battery voltage is less than a specific voltage, if not, execute step (D), if so, drive the power generation controller to maintain normal power generation, and return to step (A). In this way, the present invention can also combine the above steps (C1) and (C2) for judgment at the same time, so that the process is more complete.

The above-mentioned idling stop indication signal can be an analog signal, a digital signal, a frequency signal or a communication signal transmitted by the controller area network (CANbus) or K-Line (K-Line).

The above-mentioned specific voltage can be 10 volts, that is, when the battery voltage is greater than 10 volts, the stable speed driving can be performed.

The first specific speed may be 1300RPM, and the second specific speed may be 1500RPM, that is, when the engine speed is less than 1300RPM, the stable speed driving can be performed, and when the engine speed is greater than 1500RPM, the stable speed driving will be stopped.

The above-mentioned specific time may be 1 second, that is, when the accumulated time for executing the steady-speed driving reaches 1 second, the steady-speed driving will be stopped.

The above-mentioned specific angle may be 7200 degrees, which is 10 times the engine running cycle.

The above-mentioned battery can be a 12-volt or 48-volt battery. Therefore, the battery can be a 12-volt or 48-volt lead-acid battery, a lithium battery or an energy capacitor, which is used to store electrical energy and is not limited to a specific battery type.

Both the foregoing summary and the following detailed description are exemplary in nature and are intended to further illustrate the scope of the present invention. The other objects and advantages of the present invention will be explained in the following descriptions and drawings.

Please refer to FIG. 1 , which is a system configuration diagram of the power vehicle of the present invention. The figure shows a power vehicle 1 , which mainly includes an engine 2 , an integrated drive and power generation system 3 , a battery 4 and an engine management system 5 .

In this embodiment, the engine 2 has a crankshaft 21 , and the integrated drive-generator system 3 includes a drive-generator controller 31 , a drive-generator motor 32 and a motor phase sensor 33 . The drive-generator motor 32 is connected to the crankshaft 21 . Coaxial setup. The motor phase sensor 33 enables the drive generator controller 31 to detect the phase of the drive generator motor 32 , and can determine the crankshaft angle of the engine 2 according to the phase and rotational speed changes of the drive generator motor 32 , and can determine the crankshaft angle of the engine 2 according to the motor phase sensor 33 . The signal time difference of the commutation frequency is converted into the current speed and the speed change rate of the engine 2 . When the drive generator controller 31 drives the engine 2 to run, according to the signal of the motor phase sensor 33, the power source of the battery 4 is converted into an appropriate phase current and sent to the drive generator motor 32 to generate torque to drive the engine 2 to start or run. 2. During normal operation, the crankshaft 21 can drive the generator motor 32, and when the generator motor 32 is used as a generator, the generator can also be properly switched according to the phase detected by the signal of the motor phase sensor 33 to generate electricity, and can receive the power vehicle 1 The key switch signal S3 is used to determine whether the power vehicle 1 is in an on or off state. The battery 4 is electrically connected to the power generation controller 31, which is a 12-volt or 48-volt lead-acid battery, a lithium battery or an energy capacitor, and is not limited to a specific battery type. 2 The battery 4 can be charged when generating electricity.

The engine management system 5 (Engine Management System, EMS) detects the angle of the crankshaft 21 with a crankshaft angle sensor 51, and can send an engine control signal S1 to perform the fuel injection ignition function to manage and control the combustion state of the engine. On the other hand, the engine management system 5 can also send an idling stop indication signal S2 to the drive generator controller 31 to determine whether the engine 2 is about to idling and stop. In this embodiment, the idling stop indication signal S2 is an analog signal, a digital signal, a frequency signal, or a communication signal transmitted by the controller area network (CANbus) or K-Line (K-Line), and is based on the engine management system 5 Detecting engine 2's own cylinder head temperature, idling time, idling speed, vehicle speed and other conditions or judging by other items whether idling can be turned off, and can adjust the fuel supply (injection) amount by detecting the engine temperature and the above parameters , ignition angle, idle speed establishment conditions and other engine performance.

Based on the above configuration of the power vehicle, the following method for stabilizing the engine idling speed can be realized. The function is that when the power vehicle 1 is started in cold, the power generation controller 31 receives the electric energy of the battery 4, converts it into three-phase alternating current and sends it to the drive power generation The motor 32 drives the generator motor 32 to drive the crankshaft 21 to operate the engine 2 . When the engine speed (about 300~600rpm or more) that engine 2 can operate with fuel injection and ignition is reached, fuel injection and ignition will be performed according to the current conditions of the engine, but since the engine temperature does not reach the ideal working conditions, it may be difficult to maintain a stable idle speed. Therefore, in general design, it is necessary to increase the fuel supply by setting to stabilize the idle speed, but this will cause increased pollution and loss of fuel supply. Therefore, the present invention uses the power vehicle 1 with the integrated drive and power generation system 3. Under the setting of not increasing the fuel supply in the cold car, when the combustion of the engine 2 is unstable and the speed is lower than a certain speed, the drive power generation controller 31 can control The generator motor 32 is driven to output torque to assist the engine 2, so that the idle speed is stable and does not stall.

Please refer to FIG. 2 , which is a flowchart of the method for stabilizing the idle speed of the engine according to the first embodiment of the present invention. As shown in the figure, the method for stabilizing the engine idling speed of the present invention includes the following steps: (A) when the engine 2 is in a running state, execute step (B); (B) determine whether the rotational speed of the engine 2 is in an idling state, and if so, execute step ( C), if otherwise, go back to step (A); (C) determine whether the key switch of the power vehicle 1 is turned on, if so, execute step (D), if otherwise, turn off the engine, that is, when the key switch of the vehicle is in the off state At this time, the power vehicle is really going to be turned off. At this time, the speed drop does not need to drive the generator controller 31 to provide additional torque to stabilize the idle speed. Therefore, the engine management system 5 stops fuel injection and ignition, and the engine 2 is naturally turned off to stop. (D) Determine whether the rotational speed of the engine 2 is less than a first specific rotational speed, if so, execute step (E), if otherwise, drive the power generation controller 31 to maintain normal power generation, and return to step (A). In this embodiment, the first The specific rotational speed is 1300 RPM, that is, when the engine rotational speed is less than 1300 RPM, the stable rotational speed driving can be performed. (E) Execute a steady speed driving, calculate the accumulated time of executing the steady speed driving and the crankshaft angle accumulated by executing the steady speed driving, and execute step (F). (F) judging whether the engine speed is greater than a second specific speed or whether the accumulated time for performing the stable speed driving reaches a specific time or whether the accumulated crankshaft angle for performing the stable speed driving reaches a specific angle, if so, perform step (G), Otherwise, go back to step (C), in this embodiment, the second specific speed is 1500RPM, the specific time is 1 second, and the specific angle is 7200 degrees, that is, when the engine speed is greater than 1500RPM or when the stable speed driving is performed When the accumulated time reaches 1 second or when the accumulated crankshaft angle of the steady-speed driving reaches 7200 degrees, step (G) will be executed to stop the steady-speed driving.

In addition, when the condition for deviating from the stable speed driving is reached (when the engine speed is greater than 1500RPM or the accumulated time for performing the stable speed driving reaches 1 second or the accumulated crankshaft angle for performing the stable speed driving reaches 7200 degrees), you can also wait for a while Time does not generate electricity. The waiting time in this embodiment is set to 3 seconds. After the engine speed is stabilized, normal electricity generation is performed to charge the battery 4 .

Please refer to FIG. 3 , which is a flowchart of a method for stabilizing the idle speed of an engine according to the second embodiment of the present invention. As shown in the figure, the basic process of the method for stabilizing the engine idle speed of this embodiment is the same as that of the first embodiment, but the difference is that after step (C), a step (C1) is included to determine whether the engine management system 5 sends An idling stop indicating signal S2 is sent to the drive generator controller 31 , if otherwise, step (D) is performed, and if so, the engine idling stop is performed. In this way, the method can additionally perform system judgment according to the presence or absence of the idling stop signal. If the engine management system 5 does send an idling stop signal S2 to the drive generator controller 31, it can directly stop the fuel injection and ignition, so that the engine 2 Naturally turn off the flame to stop.

Please refer to FIG. 4 , which is a flowchart of a method for stabilizing the idle speed of an engine according to the third embodiment of the present invention. As shown in the figure, the basic process of the method for stabilizing the engine idle speed of this embodiment is the same as that of the first embodiment, but the difference is that after step (C), a step (C2) is included to determine whether the voltage of the battery 4 is less than a The specific voltage, if otherwise, perform step (D), if yes, the drive power generation controller 31 maintains normal power generation, and returns to step (A), in this embodiment, the specific voltage is 10 volts, that is, when the battery voltage Greater than 10 volts, only stable speed drive can be performed. Therefore, when the voltage of the battery 4 is too low, the integrated drive and power generation system 3 may not be able to provide enough torque to help stabilize the idle speed. Therefore, the engine 2 is selected to continue to generate electricity normally, the battery 2 is charged, and the stable speed drive is not performed.

Please refer to FIG. 5 , which is a flowchart of a method for stabilizing the idle speed of an engine according to the fourth embodiment of the present invention. As shown in the figure, the basic process of the method for stabilizing the engine idle speed of this embodiment is the same as that of the first embodiment, but the difference is that after step (C), a step (C1) is included to determine whether the engine management system 5 sends An idling stop indicating signal S2 is sent to the drive power generation controller 31, if otherwise, execute step (C2), if so, execute engine idling stop; and a step (C2) determine whether the voltage of the battery 4 is less than a specific voltage, if otherwise, execute step (D ), if so, drive the power generation controller 31 to maintain normal power generation, and return to step (A). In this way, the present invention can also combine the above steps (C1) and (C2) for judgment at the same time, so that the process is more complete.

Please refer to FIG. 6A and FIG. 6B , which are respectively a current-time diagram and an engine speed-time diagram of the present invention for performing stable rotation speed driving. As shown in Figure 6B, the engine speed in the normal idle mode will basically remain above 1300RPM. Once the idle speed is unstable and the engine speed is lower than 1300RPM, it will start to stabilize the engine idle speed. At this time, as shown in Figure 6A, the drive The generator controller 31 will control and drive the generator motor 32 to output torque to assist the engine 2, so that the engine speed will return to 1500 RPM again, and the engine 2 will not be turned off by driving at a stable speed.

The above-mentioned embodiments are only examples for convenience of description, and the scope of the claims claimed in the present invention should be based on the scope of the patent application, rather than being limited to the above-mentioned embodiments.

1: Powered Vehicles 2: Engine 21: Crankshaft 3: Integrated drive and power generation system 31: Drive generator controller 32: Drive generator motor 33: Motor Phase Sensor 4: battery 5: Engine Management System 51: Crankshaft angle sensor S1: Engine control signal S2: idling stop indicator signal S3: key switch signal A-G: Steps

FIG. 1 is a system configuration diagram of a powered vehicle of the present invention. FIG. 2 is a flowchart of a method for stabilizing the idle speed of an engine according to the first embodiment of the present invention. FIG. 3 is a flowchart of a method for stabilizing the idle speed of an engine according to the second embodiment of the present invention. FIG. 4 is a flowchart of a method for stabilizing the idle speed of an engine according to the third embodiment of the present invention. FIG. 5 is a flowchart of a method for stabilizing the idle speed of an engine according to the fourth embodiment of the present invention. FIG. 6A is a current-time diagram of the present invention for performing stable rotational speed driving. FIG. 6B is a speed-time diagram of the engine in which the present invention performs stable speed driving.

A-G: Steps

Claims (10)

A method for stabilizing the idle speed of an engine is used in a powered vehicle, the powered vehicle comprising: an engine having a crankshaft; an integrated drive and power generation system, comprising a drive power generation controller, a drive power generation motor and a motor phase sensor, the drive power generation motor is coaxially arranged with the crankshaft; a battery electrically connected to the drive power generation controller; and An engine management system detects the crankshaft angle with a crankshaft angle sensor, and executes a fuel injection ignition function; Wherein, the method for stabilizing the idle speed of the engine includes the following steps: (A) when the engine is running, perform step (B); (B) judging whether the engine speed is in the idle state, if so, execute step (C), otherwise return to step (A); (C) determine the Check whether the key switch of the power vehicle is turned on, if so, go to step (D), if not, turn off the engine; (D) judging whether the engine speed is less than a first specific speed, if so, execute step (E), if otherwise, the drive and power generation controller maintains normal power generation, and returns to step (A); (E) executing a stable speed driving, calculating the accumulated time of executing the stable speed driving and the accumulated crankshaft angle of executing the stable speed driving, and executing step (F); (F) judging whether the engine speed is greater than a second specific speed or whether the accumulated time of executing the stable speed driving reaches a specific time or whether the accumulated crankshaft angle of executing the stable speed driving has reached a specific angle, if so, execute step ( G), otherwise return to step (C); and (G) Stop the steady rotational speed driving. The method for stabilizing the idle speed of an engine according to claim 1, wherein the step (C) may further include a step (C1) judging whether the engine management system sends an idling stop signal to the drive generator controller, if not Go to step (D), if yes, go to idling and stop the engine. The method for stabilizing the idle speed of an engine according to claim 1, wherein after the step (C), a step (C2) may be further included to determine whether the battery voltage is less than a specific voltage, if not, perform step (D), and if so, the The drive power generation controller maintains normal power generation and returns to step (A). The method for stabilizing the idle speed of an engine according to claim 1, wherein the step (C) may further include a step (C1) judging whether the engine management system sends an idling stop signal to the drive generator controller, if not Step (C2) is performed, and if so, the engine is idling and turned off; and a step (C2) is performed to determine whether the battery voltage is less than a specific voltage, if otherwise, step (D) is performed, if so, the drive and power generation controller maintains normal power generation, and Return to step (A). The method for stabilizing engine idling according to claim 2 or claim 4, wherein the idling stop indication signal is an analog signal, a digital signal, a frequency signal or a controller area network (CANbus) or K-line (K- Line) the communication signal transmitted. The method for stabilizing engine idle speed as claimed in claim 3 or claim 4, wherein the specific voltage is 10 volts. The method for stabilizing engine idle speed as claimed in claim 1, wherein the first specific rotational speed is 1300 RPM, and the second specific rotational speed is 1500 RPM. The method for stabilizing engine idle speed as claimed in claim 1, wherein the specific time is 1 second. The method for stabilizing engine idle speed as claimed in claim 1, wherein the specific angle is 7200 degrees. The method for stabilizing engine idle speed as claimed in claim 1, wherein the battery is a 12-volt or 48-volt battery.

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