KR20060118590A - Controller controlling electric machine operated to start internal combustion engine - Google Patents

Abstract

outputting a start command signal to a starter (S100); determining whether an engine has been ignited (S200); if the engine is not ignited (NO at S200), detecting the engine's rate of rotation (S300) and when the engine's rate of rotation attains an upper limit or more (YES at S400), then outputting a stop command signal to the starter (S500); and after the stop command signal has been output to the starter when the engine is inertially rotating before the engine's rate of rotation attains a lower limit or less (NO at S700), continuing a process for igniting the engine, and determining whether the engine has been ignited (S800).

Description

CONTROLLER CONTROLLING ELECTRIC MACHINE OPERATED TO START INTERNAL COMBUSTION ENGINE}

BACKGROUND OF THE INVENTION The present invention generally relates to an electric machine operated to start an internal combustion engine mounted on a vehicle, and more particularly to a control device for controlling the electric machine.

Once the vehicle began to operate, the vehicle was equipped with an internal combustion engine that could continue to operate with automatically generated kinetic energy. However, in order to start an engine, an air fuel mixture must be sucked in and compressed, and thus the engine needs external kinetic energy. Thus, a starter device called a starter motor is introduced.

The starter motor is provided with a pinion gear (outer gear) at one end. Furthermore, the engine has a crankshaft provided at one end with a flywheel surrounded by an external gear. The pinion gear of the starter motor and the external gear of the flywheel are meshed using an electromagnetic switch, and since a secondary battery is used as a power, the engine is operated by rotating (or cranking) the crankshaft by operating the starter motor. Will start.

There is also a starter motor that allows the pulley for the crankshaft of the engine without the pinion gear and the pulley for the rotational shaft of the starter motor to be connected to the belt. To start the engine, a secondary battery supplies power to operate the starter motor, and the belt transfers power from the pulley for the rotational shaft of the starter motor to the pulley for the crankshaft of the engine to rotate (or crank) the crankshaft. Ranking) to start the engine.

The prior art for such an engine starter is disclosed in the publications as described below.

Japanese Patent Laid-Open Publication No. 1-88076 discloses a gas that has been expanded in a warm start to remove poor starting capability due to fuel leaking from an injector, a carburetor, or the like of a fuel injection engine. An engine starter control device is disclosed that avoids the defects associated with initially setting the starter motor at high rotation rate for scavenge. The engine starter control device causes the starter motor to be connected to the engine through a switching mechanism, and operates to switch the switching mechanism by the temperature of the engine in response to a temperature sensor detecting the temperature of the engine and an output of the temperature sensor. Control means for starting the engine by changing the cranking rotation rate.

In such an engine starter control device, the control means can be driven to change the cranking rotation rate to an optimum rotation rate by the temperature of the engine, so that the battery voltage is not good due to the high cranking rotation rate at the start of the engine. To prevent it from decreasing. More specifically, at warm start, the control means controls the switching means to increase the cranking rotation rate. This immediately scavengs the overly dense air fuel mixture filling the intake duct, thus providing improved starting capability. At other start-ups in which the intake pipe is not filled with an excessively rich air fuel mixture, the control means controls the switching means so that the cranking rotation rate is not increased so as to avoid a reduced battery voltage.

Japanese Patent Laid-Open Publication No. 5-133309 discloses preventing an overload on a starter motor powered by a battery for starting an engine, and also preventing excessive discharge from the battery to properly start the engine. An engine starter is disclosed. An engine starter provided with a battery which is operated to supply power to operate the starter motor to start the engine, has a predetermined time period when the starter motor is operated for at least a predetermined time period so that the engine does not reach a predetermined rotation rate. A first process for stopping the starter motor for a longer time, and a second process for setting the engine to a non-startable state when the first process is repeated at least a predetermined number of times and the engine has not yet reached a predetermined turnover rate; It includes a control device to perform.

In the engine starter when the starter motor is operated for a predetermined period of time and the engine has not yet reached a predetermined rotation rate, the control device performs a first process for stopping the starter motor longer than the predetermined period of time. Perform. Conventionally, when the engine is not started even though the starter motor is operated, the starter motor is restarted immediately after the operation of the starter motor is stopped. Alternatively, the control device disclosed above may prevent the starter motor from being overloaded and prevent the battery from being excessively discharged. If the first process is repeated at least a predetermined number of times and the engine has not yet reached a predetermined turn rate, the control device performs a second process for setting the engine to an unstartable state. This condition forces inspection, repair, or other similar work to eliminate the cause of the failure and prevents the engine from being started indiscriminately.

However, the engine starter control device disclosed in Japanese Patent Laid-Open No. 1-88076 has the following disadvantages: For example, during cranking by the starter motor, the oil pump of the engine functions insufficiently. In this way, increasing the cranking rotation rate may damage the engine, the transmission, and the like in durability, because the gear, the bearing, and the like are insufficiently lubricated. In this case, in order to provide not only the starting capability but also the durability to the engine, the cranking rotation rate by the starter motor must be precisely controlled within a narrow range. However, it is known that the cranking rotation rate depending on the starter motor is significantly changed by being influenced by the availability of the battery, the variation in the rolling resistance of the engine, and the like. Therefore, it is difficult to control within a narrow range. Furthermore, the cost for mounting the control device for controlling the cranking rotation rate according to the starter motor for this control also increases.

The engine starter disclosed in Japanese Patent Laid-Open No. 5-133309 has the following disadvantages: If the engine has not yet reached a predetermined rotation rate even though the starter motor is operated for a predetermined time period, the control device A first process of stopping the starter motor for longer than a predetermined time period is performed. Whether the engine has not reached a predetermined rate of rotation or the rotation has been stopped completely, the control for starting the engine will be stopped. As such, once entering the first process, the engine will not start even though it is rotating inertia.

As mentioned above, providing higher cranking turnover improves engine starting capability for a number of reasons. Accordingly, if the cranking by the starter motor is stopped, there is a time period in which the engine rotates inertia above the rotation rate that enables engine starting. If control to start the engine is interrupted during this time period and the engine is not ignited, the engine will not start even though it is rotating at a rotation rate that enables engine starting.

The present invention has devised a control device for controlling an electric machine which is operated to start an internal combustion engine that can realize a satisfactory starting capability without a specific device causing an increase in cost.

The control device of the present invention controls an electric machine that is operated to start an internal combustion engine. The electric machine receives power from an electricity storage mechanism. The control device includes a detection unit for detecting a rotation rate of the internal combustion engine; A start detector for detecting whether the internal combustion engine is started; And power supplied to the electric machine when the electric machine cranks the internal combustion engine so that the internal combustion engine achieves at least a predetermined rotation rate, but nevertheless the start detection unit does not detect that the internal combustion engine has started. It is characterized in that it comprises a control unit for interrupting and continuing the process of starting the internal combustion engine.

According to the present invention, the electric machine includes a starter motor, a starter generator and the like (hereinafter simply referred to as a "starter"), which is mounted on a vehicle and cranks the internal combustion engine through a belt, a gear or the like. The starter is powered by a secondary battery corresponding to the power storage mechanism. As the starter cranks the engine, the detector detects an increasing turnover of the engine. The increasing turnover reaches a predetermined turnover and the starter is cranked to protect the durability of the engine, transmission, etc. when the engine is not started because the air fuel mixture in the combustion chamber of the engine does not ignite. The upper limit of the set rotation rate. When the upper limit is achieved and the start detection unit has not yet detected that the engine has started, the power supplied to the starter is cut off. The start detection unit detects that the engine is started, for example, from a rapidly increased engine turnover rate. A shortening of the starter activation time can be achieved, which extends the life of the sliding portion of the starter's motor brush or the like, prevents the output from temporarily decreasing due to the starter's own heat generation, and keeps the power constant. Contributes to If the power to the starter is cut off, the engine will not stop immediately. More specifically, a flywheel or the like connected to the crankshaft of the engine causes the engine to rotate inertia for a predetermined period of time. If the power to the starter is cut off, the control still continues the process of starting the engine. More specifically, the process continues to ignite the air fuel mixture introduced into the combustion chamber of the engine. If the engine that is rotating inertia has a predetermined rotation rate or more, the engine can be started. As described above, by continuing the ignition process for a range of engine revolutions (i.e., below a predetermined revolution and at least a predetermined revolution that allows engine starting), the engine starts if the power supplied to the starter is cut off. Can be. A reduced cranking turnover can be provided to prevent problems with the durability of the engine, transmission, etc. due to the starter, and furthermore, when the power supplied to the starter is cut off and the engine is still rotating inertia, the engine The air fuel mixture in the combustion chamber of may be ignited to start the engine. As a result, it is possible to provide a control device for controlling an electric machine that is operated to start an internal combustion engine that realizes satisfactory engine starting capability without providing a specific device causing an increase in cost.

It is more preferable that the control unit may control to continue the process of starting the internal combustion engine when the power supplied to the electric machine is cut off but nevertheless the internal combustion engine is rotated inertia.

For example, even if the power supplied to the starter is cut off, if the engine is still rotating inertia, the controller can provide control to continue the process for starting (or igniting) the engine. The engine can be started while it is rotating inertia.

The control unit may also control to continue the process of starting the internal combustion engine when the internal combustion engine is inertia rotated at least at a predetermined rotation rate.

For example, the predetermined rate of rotation includes the minimum rate of rotation necessary to start the engine and the minimum rate of rotation that allows the engine to satisfactorily ignite. If the engine is rotating inertia at least at a predetermined rate of rotation, the process for starting or igniting the engine continues. Therefore, the engine can be started when the power supplied to the starter is cut off.

Further, the process of starting the internal combustion engine is preferably a process for igniting an air fuel mixture in the internal combustion engine.

The process of igniting the air fuel mixture introduced into the combustion chamber of the engine to start the engine may continue after the power supplied to the starter is cut off. Therefore, the engine can be started even after the power supplied to the starter is cut off.

1 is a block diagram of control for a vehicle including an ECU, a starter control device according to an embodiment of the present invention;

2 is a flowchart illustrating a control configuration of a program executed by the ECU of FIG. 1; And

3 is a diagram illustrating how the rotation rate of an engine changes with time as a vehicle in which the control of FIG. 1 is started;

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the detailed description below, like elements are designated by like reference numerals, and names and functions are also the same.

1 shows a block diagram of control for a vehicle comprising an ECU, a starter control device according to an embodiment of the invention. It should be noted that the present invention is not limited to the belt driven starter shown in FIG. 1. Magnetic switches, pinion gears, etc. may be used rather than the belt. Furthermore, the starter is not limited to an engine for starting the engine, but may be a starter generator for starting and regeneratively generating the engine. These are referred to as electric machines. Furthermore, the vehicle may be a vehicle equipped only with an engine, or may be a hybrid vehicle equipped with an engine, a motor generator, and a motor for driving the vehicle. Alternatively, the vehicle may be a vehicle which automatically stops the engine, for example, to prevent idling when the vehicle is temporarily stopped by a red light.

As shown in FIG. 1, the vehicle includes an engine 100 serving as an internal combustion engine, a transmission 200 connected to an output shaft of the engine 100, and a starter 300 for starting the engine 100, for example, a secondary vehicle. A power source 400 in the form of a battery, a capacitor or similar power supply mechanism for supplying power to the starter, an electrical control unit (ECU) 500 for controlling the starter 300, and a power source 400 to the starter 300. It includes a starter relay 350 that operates in response to the command signal output from the ECU 500 to supply and cut off the power provided.

The ECU 500 receives the rotation rate of the engine from the sensor 600 that detects the engine start signal and the rotation rate of the engine 100 based on a signal of, for example, an ignition switch operated by the driver of the vehicle. Further, the ECU 500 stops (starting to supply power from the power source 400 to the starter 300) and stops (for stopping power supplied from the power source 400 to the starter 300). The command signal is output to the starter relay 350.

The starter 300 has a relay 310 and a belt drive starter 320. The relay 310 has a switch terminal 360 connected to the starter relay 350 to receive power when the starter relay 350 is closed. When the switch terminal 360 receives power, the relay 310 closes the path for sending power supplied from the power source 400 to the belt drive starter 320 to transfer power from the power source 400 to the belt drive starter 320. ). The belt drive starter 320 has a rotating shaft provided with a pulley 330 for the starter to transfer power through the belt 340 to the pulley 110 for the crankshaft of the engine 100.

Note that starter 300 and power source 400 have sufficient ability to provide cranking to reach a turnover that satisfactorily ignites engine 100 for illustrative purposes. More specifically, if the availability of the power supply 400, the variation in the rotational resistance of the engine 100, etc., causes the cranking turn rate to change, it has a high enough lower limit for illustrative purposes.

Further, the ECU 500 stores in the memory an upper limit of the cranking rotation rate that does not affect the engine 100 and the transmission 200 in durability when lubrication is poor. Furthermore, the ECU 500 also stores in the memory a lower limit of the rotation rate of the engine that starts the engine 100 when the engine 100 is rotating inertia.

During the cranking of the engine 100 when it is started (or when the air fuel mixture introduced into the combustion chamber of the engine 100 is ignited), the ECU 500 cuts off the power supplied to the starter 300. However, it should be noted that if the cranking turnover has reached the upper limit and the engine 100 has not yet started (or ignited), the ECU 500 cuts off the power supplied to the starter 300. Thus, while the ECU 500 cuts off the power supplied to the starter 300, the ECU 500 still continues the process of igniting the air fuel mixture in the combustion chamber of the engine 100. The ECU 500 implements such control by a program.

Hereinafter, a control configuration of a program executed by the ECU 500 will be described with reference to the flowchart of FIG. Note that this flowchart illustrates the process performed after the ECU 500 receives the engine start signal.

In step S100, the ECU 500 outputs a start command signal to the starter 300. More specifically, the ECU 500 outputs a start command signal to the starter relay 350, the relay contact is turned on, and power is supplied from the power source 400 to the belt drive starter 320 through the relay 310. Supplied.

In S200, the ECU 500 determines whether the air fuel mixture in the combustion chamber of the engine 100 has been ignited. This determination is made, for example, from signal output from a separately provided temperature sensor that detects the rate of rotation of the rapidly increased engine 100 detected by the engine speed sensor 600 and / or the temperature of the gas exhausted from the engine 100. When the air fuel mixture is ignited (if YES in S200), the process ends. Otherwise (if NO in S100), the process moves to S300.

In S300, the ECU 500 detects the rotation rate of the engine 100 from the signal output from the sensor 600. In S400, the ECU 500 determines whether the rotation rate of the engine 100 has reached or exceeded the upper limit stored in the memory of the ECU 500. If so (YES at S400), the process moves to S500. Otherwise (NO in S400), the process returns to S200.

In S500, the ECU 500 outputs a stop command signal to the starter 300. More specifically, the ECU 500 stops outputting the start command signal to the starter relay 350. The relay contact is turned off to cut off power supplied from the power source 400 to the belt drive starter 320 through the relay 310.

In S600, the ECU 500 detects the rotation rate of the engine 100 from the signal output from the sensor 600. In S700, the ECU 500 determines whether the rotation rate of the engine 100 is equal to or less than the lower limit stored in the memory of the ECU 500. If so (YES in S700), the process returns to S100. Otherwise (if NO in S700), the process moves to S800.

In S800, the ECU 500 determines whether the combustion chamber of the engine 100 has an ignited air fuel mixture. If so (YES in S800), the process ends. Otherwise (if NO in S800), the process returns to S600.

According to the above-described configuration and flowchart, the engine 100 of the vehicle equipped with the ECU 500 corresponding to the control device for the starter 300 operates when the engine is started, which will be described later.

For example, when the engine 100 is temporarily stopped while the condition for temporarily stopping the engine is not established, when the driver of the vehicle puts the ignition switch in the starting position, or when control for stopping idling is performed, The ECU 500 receives the engine stop signal.

The ECU 500 outputs a start command signal to the starter relay 350 (S100), and the power supply 400 supplies power to the belt drive starter 320, and the power is supplied from the belt drive starter 320 to the starter pulley ( 330, belt 340, and crankshaft pulley 110, and the engine 100 is cranked.

If the engine 100 is not ignited (NO in S200), the rotation rate of the engine 100 is detected (S300). If the rotation rate of the engine 100 is greater than or equal to the upper limit (YES in S400), the ECU 500 outputs a stop command signal to the starter relay 350 (S500) and the belt drive starter 320 from the power source 400. The power supplied to the unit will be interrupted. In this state, the engine 100 is rotating inertia. In this state, the process for igniting the engine 100 still continues (NO in S700) until the rotation rate of the engine 100 reaches below the lower limit.

This state is shown in FIG. 3 shows how the rotation rate of engine 100 changes over time when the engine is started. As described above, the memory of the ECU 500 has upper and lower limits set therein.

When cranking, if the engine 100 is ignited at a rotation rate falling to a range lower than the upper limit (if YES in S200), the rotation rate is changed as indicated by the thick dotted rule in FIG. More specifically, the engine 100 is ignited and started before the power supplied to the starter 300 is cut off.

When the engine 100 does not ignite and reaches an upper limit (YES in S400), the power supplied to the starter 300 is cut off (S500), and the rotation rate of the engine 100 is indicated by a thin dotted ruled line in FIG. 3. Gradually decrease as shown. Until the rotation rate falls below the lower limit (NO in S700), the ignition process of the engine 100 continues, as indicated by the thick solid line in FIG. 3, as the engine 100 rotates inertia, the engine 100 ) Is ignited (YES in S800).

In Fig. 3, the alternately long and short dotted ruled lines indicate how the rotation rate of the engine 100 changes when the rotation rate reaches the upper limit but nevertheless the power supplied to the starter 300 is not cut off. Note that

Therefore, the starter control device of the present invention cuts off the power supplied to the starter when cranking when the engine is started (or when the air fuel mixture introduced into the combustion chamber of the engine is ignited). If the engine does not start (or does not ignite) despite the engine's rotation rate reaching the upper limit of the cranking rotation rate, the power supplied to the starter is cut off. Thus, while the power supplied to the starter is interrupted, the process for igniting the air fuel mixture in the combustion chamber of the engine still continues. If the power to the starter is cut off, when the ignition process can be performed to start the engine, the engine will not stop immediately and will continue to rotate inertia. This can prevent excessively increased engine turnover due to cranking which causes problems of durability of the engine, transmission, and the like. Furthermore, a reduced starter activation time can be achieved, can provide an increased lifetime of the sliding portion of the starter's motor brush, etc., prevent temporary loss of output due to heat generation of the starter itself, and provide constant power Contribute to maintaining

While the present invention has been described and illustrated in detail, the present invention has been described by way of example only, and is not intended to be limiting thereof, and the spirit and scope of the present invention are limited only by the terms of the appended claims. It is self-evident.

Claims (8)

In the control device for controlling the electric machine 300 is operated to start the internal combustion engine 100, The electric machine 300 receives power from the electrical storage device 400, Detection means (600) for detecting a rotation rate of the internal combustion engine (100); Starting detecting means (500) for detecting whether the internal combustion engine (100) has been started; And The electric machine 300 cranks the internal combustion engine 100 so that the internal combustion engine 100 achieves at least a predetermined rate of rotation, but nevertheless the start detection means indicates that the internal combustion engine 100 has been started. And control means (500) for interrupting the power supplied to the electric machine (300) and for continuing the process of starting the internal combustion engine (100) if not detected. The method of claim 1, The control means 500 continues the process of starting the internal combustion engine 100 when the power supply to the electric machine 300 is cut off but nevertheless the internal combustion engine 100 is rotated inertia. And means for controlling. The method of claim 2, The control means 500 comprises means for controlling to continue the process of starting the internal combustion engine 100 when the internal combustion engine 100 is inertia rotated at least at a predetermined rotation rate. Controller. The method according to any one of claims 1 to 3, And said process of starting said internal combustion engine (100) is a process for igniting an air fuel mixture in said internal combustion engine (100). In the control device for controlling the electric machine 300 is operated to start the internal combustion engine 100, The electric machine 300 receives power from the electrical storage device 400, A sensor (600) for detecting a rotation rate of the internal combustion engine (100); And If the electric machine 300 cranks the internal combustion engine 100 so that the internal combustion engine 100 achieves at least a predetermined rotation rate, but nevertheless does not detect that the internal combustion engine 100 has started, the And an electric control unit (500) for controlling power to interrupt electric power supplied to the electric machine (300) and to continue the process of starting the internal combustion engine (100). The method of claim 5, The electric control unit 500 continues the process of starting the internal combustion engine 100 when the power supply to the electric machine 300 is cut off but nevertheless the internal combustion engine 100 is rotated inertia. A control apparatus, characterized in that for performing a control for. The method of claim 6, The electric control unit 500 controls to continue the process of starting the internal combustion engine 100 when the internal combustion engine 100 is inertia rotated at least at a predetermined rotation rate. Device. The method according to any one of claims 5 to 7, And said process of starting said internal combustion engine (100) is a process for igniting an air fuel mixture in said internal combustion engine (100).

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