DE102012102044A1 - Starter control device for internal combustion engine, has two starter control circuits with current path for supplying current to starter, where switching unit has relay switches, relay coil and switching element - Google Patents

Abstract

The starter control device has two starter control circuits (14,15) with current paths (32,33) for supplying a current to the starter. A switching unit has relay switches (24,26,29), a relay coil (25,27,31) and a switching element. An energization control unit (40) for controlling the energization of the relay coil of the switching unit by the switching element. A switch sensing unit is provided for detecting a change of state of the switching unit between an on state and an off-state.

Description

BACKGROUND OF THE INVENTION

1 , Field of the invention

The present invention relates to a starter drive device.

2. Description of the Related Art

There is known an engine control system with a so-called idle-stop function for detecting the operation of a driver of a vehicle for stopping or starting a vehicle, such as the operation of an accelerator pedal or a brake pedal, automatically to the internal combustion engine of a vehicle stop or restart. The idle-stop function is used to reduce fuel consumption.

To restart a combustion engine of a vehicle, the output shaft (crankshaft) of the engine is initialized by a starter, as otherwise by the operation of the driver of an ignition key to start the engine of the vehicle. More specifically, the pinion of the starter is pushed out in the axial direction thereof to engage with the ring gear of the crankshaft. Thereafter, the motor of the starter is energized to rotate the pinion. This will crank up the engine and restart it.

Here, a starter drive system including a drive circuit for driving a starter in response to the operation of an ignition key by the driver, and a drive circuit for driving the starter in response to an engine restart request are known. However, such a system has a drawback that even if the driving circuit provided for the operation of the ignition key by the driver is normal, the engine is in response to the operation of the ignition key by the driver can be started, it is not possible to restart the machine after the machine has been automatically stopped, if the drive circuit, which is provided for a restart request of the machine, has a so-called off-abnormality, in which a switching means, such as For example, a relay can not be switched from off to on. Accordingly, it is common to perform an abnormality diagnosis to determine whether the drive circuit provided for the restart request of the engine is normal before the engine is automatically stopped.

However, it is difficult to predict a timing at which an automatic restart request of the engine occurs, which may cause an automatic restart request of the engine to occur just before or during an abnormality diagnosis. In this case, if the engine is automatically stopped after waiting for the completion of an abnormality diagnosis, the effect on the reduction of fuel consumption by the idle-stop function becomes inappropriate because a time lag between the occurrence of an automatic stop request and the occurrence of an automatic stop request Time, when the machine is actually stopped, gets big.

SUMMARY OF THE INVENTION

The present invention relates to a starter drive apparatus for an engine configured to be automatically stopped when a predetermined engine stop condition is satisfied, and to be automatically restarted by cranking by a starter when a predetermined engine restart condition is satisfied after being automatically performed wherein the starter drive device is configured to power the starter to crank the engine, the starter drive device comprising:
a first starter drive circuit including a first current path for conducting a first current to be supplied to the starter, and first switching means arranged and configured in the first current path by the operation of a driver of the vehicle for supplying the first current to the starter of FIG to be changed from an off-state to an on-state;
a second starter drive circuit including a second current path for conducting a second current to be supplied to the starter and a second switching means including a relay switch, a relay coil and a first switching element, the relay switch being arranged in the second current path and is configured to be changed from an open state to a closed state when the first switching element is turned on to energize the relay coil to supply the second current to the starter;
an excitation control means for controlling the energization of the relay coil of the second switching means by the first switching element,
switch detection means for detecting a state change of the first switching means between an on-state and an off-state; and
an abnormality diagnosing means for performing, by energizing the relay coil by the first switching element via the energizing means, when the changeover detection means detects the state change of the first switching means Abnormality diagnosis to determine whether there is an off-abnormality in the second switching means in which the relay switch remains in an opened state.

According to the present invention, there is provided a starter drive apparatus by which an abnormality diagnosis of a starter can be performed without preventing a machine from being automatically stopped by an idle stop control.

Further advantages and features of the invention will become more apparent from the following description including the drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings show:

1 a diagram illustrating the electrical structure of an engine control system according to an embodiment of the invention;

2 FIG. 10 is a flowchart illustrating steps of a process flow for determining whether to perform an abnormality abnormality diagnosis in the engine control system; FIG.

3 FIG. 10 is a flowchart illustrating steps of a transistor-off abnormality diagnosis performed in the engine control system; FIG.

4 FIG. 10 is a flowchart illustrating steps of relay contact abnormality diagnosis performed in the engine control system; and FIG

5 Fig. 10 is a timing chart explaining an example of the abnormality abnormal diagnoses.

PREFERRED EMBODIMENTS OF THE INVENTION

An embodiment of the invention will be described with respect to an engine control system for a vehicle.

The engine control system including an ECU (Electronic Control Unit) as its main component performs fuel injection amount control, ignition timing control, and idling stop control. 1 shows a diagram illustrating the electrical structure of the engine control system.

In 1 denotes reference numeral 10 a starter with a pinion (not shown), a solenoid 11 for pushing out the pinion and a motor 12 to drive the pinion, so that this turns. The starter 10 is with a motor switch 17 including a relay coil and a relay switch for switching the motor 12 between the powered state and the non-powered state.

The starter 10 has a dual function that allows it to push both the pinion and the pinion using the torque of the motor 12 can rotate independently. That is, the excitement of the solenoid 11 and the excitement of the engine 12 by power from a battery 13 can be controlled independently. The engine control system includes a first starter drive circuit 14 and a second starter drive circuit 15 Serving as independent power source paths to the solenoid 11 and the engine 12 function.

The first starter drive circuit 14 is a power supply path through which the starter 10 supplied with power (electricity) when a starter switch 16 is turned on by the operation of a switch (or a key) by a driver of a vehicle. The starter switch 16 is on or on a first rung 32 provided in the first starter drive circuit 14 included is the starter 10 powered. The first starter drive circuit 14 also contains a relay 18 that is between the starter switch 16 and the solenoid 11 is provided to the solenoids 11 to switch between the excited and non-energized states, being a relay 19 between the starter switch 16 and the engine 12 is provided to the engine 12 switch between the powered and the non-driven state.

When the starter switch 16 is turned on by the operation of an ignition key of the vehicle, the relays 18 and 19 turned on, causing the solenoid 11 and the engine 19 Power is supplied. If the relay 18 is turned on, the solenoid is 11 is energized, whereby the pinion is pushed out in the axial direction and meshes with the ring gear (not shown) of the machine. If the relay 19 is turned on, is also the engine switch 17 turned on, causing the engine 12 is powered, that is, activated. This starts the engine 12 to rotate, which also rotates the pinion. When the pinion is rotated, the machine is also cranked, causing the initial rotation to take place.

The machine control system is with a delay circuit 21 provided between the starter switch 16 and the relay 19 is arranged such that the engine 12 is turned on to rotate the pinion, after the pinion and the ring gear are engaged with each other.

The second starter drive circuit 15 is a power supply path through which the starter 10 according to a command from the ECU 40 is powered by the driver of the vehicle regardless of an operation of a switch or an ignition key. The second starter drive circuit 15 has a second current path 33 with a branched path 33a that to the solenoid 11 leads, and a branched path 33b that to the engine 12 leads, on. The branched path 33a is with a pinion drive relay 22 connected to the solenoid 11 , according to one of the ECU 40 received control signal to switch between the excited and non-energized state. The branched path 33b is with the motor drive relay 23 for switching the engine 12 , according to one of the ECU 40 received control signal, connected between the on and off state.

The pinion drive relay 22 contains a relay switch 24 and a relay coil 25 , The relay switch 24 is in a current path 33a provided that to the solenoid 11 leads. When the relay coil 25 is energized, the relay switch 24 closed (the pinion drive relay 22 is turned on), causing the solenoid 11 is excited. As a result, the pinion is pushed out in the direction of the sprocket and combed with the sprocket.

The relay switch 26 is in the branched path 33b that to the engine 12 leads, provided. When the relay coil 27 is energized, the relay switch 26 closed, causing the motor drive relay 23 is energized, causing the engine 12 is powered and is driven to rotate.

An upstream relay 28 is in a section of the rung 33 between the battery 13 and the starter 10 arranged, with the section on one side closer to the battery 13 as the pinion drive relay 22 and the motor drive relay 23 provided and not branched off. The upstream relay 28 contains a relay switch 29 and a relay coil 31 , When the relay coil 31 is energized, the relay switch 29 closed to the starter 10 to supply electricity.

The engine control system further includes a voltage sensor 37 that is halfway between the upstream relay 28 and the drive relay 22 and 23 for detecting a voltage therebetween as the intermediate point voltage Vp. The voltage sensor 37 is with a power source 39 connected to the Abnormalitätserfassung for a connection of the power source 39 on the side of the battery 13 what is determined by a resistance 38 on the side opposite to the battery 13 is grounded. Accordingly, the intermediate point voltage Vp drops when the pinion drive relay 22 or the motor drive relay 23 is turned on while the upstream relay 28 Off, and rises when the upstream relay 28 is turned on while the pinion drive relay 22 and the motor drive relay 23 Off are.

The engine control system is also equipped with an ignition switch 34 as the engine start switch operated by the driver of the vehicle, a crank angle sensor 41 which is configured to output a crank angle signal in a right angle waveform at intervals of a predetermined crank angle and a switch sensor (not shown) for detecting on / off of the starter switch 16 , intended.

The ECU 40 , which is a microcomputer-based electronic control unit, receives detection signals from various sensors, and performs various engine control including an intake air amount control, a fuel injection amount control and an idling stop control, and a starter drive control 10 by.

The idling stop control is provided to automatically stop the engine by stopping the combustion of the engine when a predetermined engine stop condition is satisfied, and to restart the engine by continuing the combustion of the engine when a predetermined engine restart condition is satisfied. The engine stop condition includes at least one of conditions that an operation value of the accelerator pedal becomes 0 (the engine is in the idle state), and that the brake pedal has been depressed. The engine restart condition includes that the accelerator pedal has been depressed and that an operation value of the brake pedal has become 0.

The ECU 40 includes first to fourth transistors TR1 to TR4 and controls these transistors on / off to supply a current to the starter 10 by the second starter drive circuit 15 to control. More specifically, the first transistor TR1 has its low side terminal through an output terminal P1 of the ECU 40 with the high side terminals of the relay coils 25 and 27 connected. The second transistor TR2 has its high side terminal connected through an output terminal P2 of the ECU 40 with the low-side connection of the relay coil 25 connected. Of the third transistor TR3 is connected to its high-side terminal through an output terminal P3 of the ECU 40 with the low-side connection of the relay coil 27 connected. The fourth transistor TR4 is its high side terminal through an output terminal P4 of the ECU 40 with the low-side connection of the relay coil 31 and connected.

The first transistor TR1 is connected at its high-side terminal to a sensor power source (+ IG), and connected at its low-side terminal to a shunt resistor R1, and the second to fourth transistors TR2 to TR4 are connected at their high-side terminals through shunt terminals. Resistors R2 to R4 connected to the sensor power source accordingly. Accordingly, when one of the transistors TR1 to TR4 is switched from an off-state to an on-state while its associated relay is off, a voltage of an intermediate point between the transistor and the shunt resistor becomes the microcomputer (not shown) of the ECU 40 indicated as element detection voltage Vm (Vm1 to VM4).

The starter drive control is operated, for example, such that when the engine restart condition is satisfied after the engine stop condition is satisfied, the fourth transistor TR4 is turned on and then the first and second transistors TR1 and TR2 are turned on. As a result, the pinion is pushed out to the ring gear as the pinion drive relay 22 is turned on, causing the solenoid 11 is excited. Further, the motor drive relay 23 when the third transistor TR3 is turned on while the fourth transistor TR4 is turned on. This starts the engine 12 to turn and crank the machine.

In the above operation, if there is an off-abnormality in the second starter drive circuit 15 occurs in which one of the relays operating in the second starter drive circuit 15 are included (one of the pinion drive relay 22 , Motor drive relay 23 and the upstream relay 28 ) can not be changed from an off state to an on state, not possible, the solenoid 11 or the engine 12 excite even if the first starter drive circuit 14 and the starter 10 are normal, and thus it would not be possible to start the engine by the operation of the ignition key by the driver of the vehicle. In this case, since it is not possible to provide an initial rotation of the machine, the machine can not be restarted after the machine is automatically stopped. The situation in which the engine should be restarted when the engine restart condition is met may be that the vehicle waiting for a change in a traffic light circuit needs to be started. Such a condition that the machine can not be started, however, must be prevented or avoided.

Thus, the present embodiment is configured to perform an off-abnormality diagnosis to determine whether the second starter drive circuit 15 is normal after the ignition switch 34 switched on and before the machine is stopped automatically.

One possible cause of an abnormality in the second start drive circuit 15 is a malfunction of one of the transistors TR1 to TR4 or the relay 22 . 23 and 28 due to a cable break.

In this embodiment, an abnormality diagnosis is performed for each of the transistors TR1 to TR4, and if the result of the diagnosis shows that all the transistors TR1 to TR4 are functioning normally, an abnormality abnormality diagnosis is made for each of the relays 22 . 23 and 28 carried out.

Next, out-abnormality diagnoses for the transistors TR1 to TR4 will be explained. To determine whether the transistors TR1 to TR3 are connected to the pinion drive relay 22 or with the motor drive relay 23 are connected, normal, is the element detection voltage Vm, which occurs when the transistor is energized when the upstream relay 28 Off is measured for each of these transistors. Based on the element detection voltage Vm, it is determined whether there is an off-abnormality in which the diagnosed transistor remains in an off-state.

To determine if the transistor TR4 is connected to the upstream relay 28 is connected, is in a normal state, the element detection voltage Vm, which occurs when the transistor TR4 is energized, while the pinion drive relay 22 and the motor drive relay 23 Are out, measured. Based on the element detection voltage Vm, it is determined whether there is an off-abnormality in which the transistor TR4 remains in an off-state.

For example, when the first transistor TR1 is under investigation, the element detection voltage Vm1, which occurs when the first transistor TR1 is energized while the fourth transistor TR4 is off, is measured. If the measured element detection voltage Vm1 is greater than a predetermined positive value, it is determined that there is an off-abnormality, that is, the first transistor TR1 is in an off-state. Condition remains. It is preferable that the second and third transistors TR2 and TR3 are held off while the first transistor TR1 is being diagnosed.

Next, out-abnormality diagnoses for the contacts of the above relays will be explained. To determine if the pinion drive relay 22 and / or the motor drive relay 23 are normal or are in a normal state, is determined by the voltage sensor 37 detects the intermediate point voltage Vp that occurs when the relay coil of the pinion drive relay 22 or the motor drive relay 23 is energized while the upstream relay 28 Is over. Based on this intermediate point voltage Vp, it is determined whether there is an off-abnormality affecting the contact of the driving relay 22 or 23 stops on. Here, it is determined that the diagnosed relay is normal if an increase in the intermediate point voltage Vp has been detected, and in another case, it is determined that there is an abnormality in the diagnosed relay.

To determine if the upstream relay 28 is normal or is in a normal state, the intermediate point voltage Vp, which occurs when the relay coil 31 of the upstream relay 28 is energized while the pinion drive relay 22 and the motor drive relay 23 Are out, measured. Based on this intermediate point voltage Vp, it is determined whether there is an off-abnormality at which the contact of the upstream relay 28 is held off. This determines that the upstream relay 28 is normal, if an increase has been detected with respect to the intermediate point voltage Vp, otherwise it is determined that at the contact of the upstream relay 28 there is an off-abnormality.

Since the out-abnormality diagnoses for the relay contacts are made after the transistors TR1 to TR4 have been detected as normal, if the diagnosed relay can not be turned on, when the associated transistor is turned on, it may be determined that the cause the off-abnormality is in the relay.

At this time, it is difficult to predict a timing when the automatic stop request of the engine occurs. It can occur before the off-abnormality diagnoses are made or while one of the abnormality diagnoses is being performed. In this case, the machine can not be automatically stopped immediately and it is necessary to wait for the off-abnormality diagnoses to be completed. Thus, the effect of reducing the fuel consumption by the idling stop control becomes inappropriate or unusable.

In this embodiment, the off abnormality diagnoses for the relays of the second starter control circuit become 15 in view of the fact that an automatic engine stop request is unlikely to occur during or shortly after a start of the engine, after an operation by the ignition key by the driver of the vehicle, during a predetermined engine start period. More specifically, if detected, the starter switch is detected 16 is changed from an on-state to an off-state, each of the first to fourth transistors TR1 to TR4 is energized to perform the abnormality abnormality diagnosis for each of the relays 22 . 23 and 28 perform.

Next, the out-of-abnormality diagnoses performed in this embodiment will be described with reference to FIG 2 to 4 explained in detail. 2 FIG. 12 is a flowchart showing steps of a process flow for determining whether the abnormality abnormal diagnoses are allowable to be performed. FIG. 3 FIG. 12 is a flowchart showing steps of abnormality diagnosis of the transistors. FIG. 4 FIG. 12 is a flow chart showing steps of abnormality diagnosis of the relay contact. FIG. These processes are performed periodically by the microcomputer of the ECU 40 executed.

First, the operation for determining whether the off-abnormality diagnoses are allowed to be performed will be made with reference to the flowchart of FIG 2 explained. This process flow starts in step S11 to determine whether the starter switch is based on the sensor detection signal 16 switched from on to off or not. If the determination result in step S11 is affirmative, the process flow proceeds to step S12 to determine whether or not the engine speed NE has reached a combustion speed NE1 (500 to 600 rpm in this embodiment), which means that the engine performs a combustion. If the determination result in step S12 is affirmative, the process flow proceeds to step S13, where an abnormality diagnostic execution flag f1 is turned on, and an ISS approval flag f3 is turned off. Thereafter, this process is terminated. The ISS approval flag f3 is a flag indicating permission or prohibition of execution of the automatic engine stop or restart. If the flag f3 of the ISS permission is On, the automatic engine stop or restart is allowed to be performed. The flag f3 of the ISS permission is reset to off when the ignition switch 34 is switched off in this embodiment. The flag f3 of the ISS permission is turned off in step S13 for safety.

Next, a diagnostic process flow of an abnormality of a transistor with respect to 3 explained.

This process flow starts in step S21 to determine whether an execution abnormality diagnostic flag f1 is on or not. If the determination result in step S21 is affirmative, the process flow proceeds to step S22 to determine whether abnormality diagnosis of the second transistor TR2 has been performed or not, and otherwise proceeds to step S23.

In step S23, the second transistor TR2 is energized while the fourth transistor TR4 is not energized. Thus, the element detection voltage Vm2 occurring in this state is detected in step S24. In subsequent step S25, it is determined whether or not the element detection voltage Vm2 is less than or equal to a predetermined value. If the determination result in step S25 is affirmative, the process flow proceeds to step S26, in which the determination that there is an off-abnormality in the second transistor TR2 is performed, this determination being stored in non-volatile memory as abnormality information, and then proceeds to step S27. If the determination result in step S25 is negative, the process flow proceeds directly to step S27. In step S27, the power supply to the second transistor TR2 is stopped.

After completing the abnormality diagnosis of the second transistor TR2 and after making a corresponding positive determination in step S22, the process flow proceeds to step S28. In step S28, it is determined whether or not an abnormality diagnosis of the third transistor TR3 has been performed. If the determination result in step S28 is negative, the process flow proceeds to step S29.

In step S29, the third transistor TR3 is energized while the fourth transistor TR4 is not energized. Thereafter, the element detection voltage Vm3 occurring in this state is detected in step S30. In subsequent step S31, it is determined whether the element detection voltage Vm3 is less than or equal to a predetermined value. If the determination result in step S31 is affirmative, the process flow proceeds to step S32, where it is determined that there is an off-abnormality in the third transistor TR3, this determination being stored in non-volatile memory as abnormality information, and then proceeds to step S33. If the determination result in step S31 is negative, the process flow proceeds directly to step S33. In step S33, the power supply to the third transistor TR3 is stopped.

After completion of the abnormality diagnosis of the third transistor TR3 and a corresponding positive determination in step S28, the process flow proceeds to step S34. In step S34, it is determined whether or not an abnormality diagnosis of the first transistor TR1 has been performed. If the determination result in step S34 is negative, the process flow proceeds to step S35.

In step S35, the first transistor TR1 is energized while the fourth transistor TR4 is not energized. Thereafter, the element detection voltage Vm1 occurring in this state is detected in step S36. In subsequent step S37, it is determined whether the element detection voltage Vm1 is less than or equal to a predetermined value. If the determination result in step S37 is affirmative, the process flow proceeds to step S38, where it is determined that there is an off-abnormality in the first transistor TR1, this determination being stored in the non-volatile memory as abnormality information, and the process flow proceeds Step S39 proceeds. If the determination result in step S37 is negative, the process flow proceeds directly to step S39. In step S39, the power supply to the first transistor TR1 is stopped.

After completion of the abnormality diagnosis of the first transistor TR1 and a corresponding positive determination in step S34, the process flow proceeds to step S40. In step S40, it is determined whether or not an abnormality diagnosis has been made for the fourth transistor TR4. If the determination result in step S40 is negative, the process flow proceeds to step S41.

In step S41, the fourth transistor TR4 is energized while the first, second and third transistors TR1, TR2 and TR3 are not energized. Thereafter, the element detection voltage Vm4 occurring in this state is detected in step S42. In subsequent step S43, it is determined whether the element detection voltage Vm4 is less than or equal to a predetermined value. If the determination result in step S43 is affirmative, the process flow proceeds to step S44, where it is determined that there is an off-abnormality in the fourth transistor TR4, this determination being stored in nonvolatile memory as abnormality information, and then the processing flow proceeds to step S45. If the determination result in step S43 is negative, the process flow proceeds directly Step S45 ahead. In step S45, the power supply to the fourth transistor TR4 is stopped.

When the abnormality diagnosis for the first to fourth transistors TR1 to TR4 is completed and a corresponding positive determination is made in step S40, the process flow advances to step S46. In step S46, by referring to the stored abnormality information, it is determined whether or not all of the first to fourth transistors TR1 to TR4 are normal. If the determination result in step S46 is affirmative, the process flow proceeds to step S47 to turn on a transistor normality determination flag f2, and this process is thereafter terminated.

Next, a diagnostic process flow of the abnormality of the relay contact with respect to 4 explained.

This process flow starts in step S51 to determine whether the transistor normality determination flag f2 is on and the ISS permission flag f3 is off. If the determination result in step S51 is negative, the process flow is ended because it means that at least one of the transistors is abnormal, and the automatic engine stop is prevented.

If the determination result in step S51 is affirmative, the process flow proceeds to step S52 to determine whether an abnormality diagnosis for the pinion drive relay 22 has been carried out or not. If the determination result in step S52 is negative, the process flow proceeds to step S53.

In step S53, currents are supplied to the transistors TR1 and TR2. In subsequent step S54, the intermediate point voltage Vp which occurs in this state and by the voltage sensor 37 is measured. In subsequent step S55, it is determined whether or not the detected intermediate point voltage Vp is greater than or equal to a first determination threshold. If the determination result in step S55 is affirmative, the process flow proceeds to step S56, where a determination is made that an off-abnormality in the pinion drive relay 22 is present, this determination is stored in the non-volatile memory as abnormality information. Thereafter, in step S57, the power supply to the second transistor TR2 is stopped. The power supply to the first transistor TR1 is maintained for an abnormality diagnosis to be subsequently performed for the first transistor TR1.

If the abnormality diagnosis for the pinion drive relay 22 is completed and a corresponding positive determination has been made in step S52, the process flow proceeds to step S58 to determine whether an abnormality diagnosis of the motor drive relay 23 has been carried out or not. If the determination result in step S28 is negative, the process flow proceeds to step S59.

In step S59, the third transistor TR3 is supplied with power. In subsequent step S60, the intermediate point voltage Vp that occurs in this state and by the voltage sensor 37 is measured. In subsequent step S61, it is determined whether the detected intermediate point voltage Vp is greater than or equal to a second determination threshold. The first determination threshold and the second determination threshold may be equal to each other or different from each other.

If the determination result in step S61 is affirmative, the process flow proceeds to step S62, where it is determined that in the motor drive relay 23 there is an off-abnormality, and this determination is stored in the nonvolatile memory as abnormality information. Thereafter, in step S63, the current supplied to the first and third transistors TR1 and TR3 is stopped.

After completing the abnormality diagnosis for the motor drive relay 23 and a correspondingly positive determination in step S58, the process flow proceeds to step S64, and determines whether or not the upstream relay 28 an abnormality diagnosis has been made or not. If the determination result in step S64 is negative, the process flow proceeds to step S65.

In step S65, power is supplied to the fourth transistor TR4. In subsequent step S66, the intermediate point voltage Vp that occurs in this state and by the voltage sensor 37 is measured. In subsequent step S67, it is determined whether or not the intermediate point voltage Vp is greater than or equal to a third determination threshold. If the determination result in step S67 is affirmative, the process flow proceeds to step S68, where it is determined that an off-abnormality in the upstream relay 28 is present, this determination is stored in the non-volatile memory as abnormality information.

If the abnormality diagnoses for all relays 22 . 23 and 28 are completed and positive determinations were made in step S64, the flow of the process proceeds to step S69 to refer to FIG stored abnormality information to determine if the relay 22 . 23 and 28 are normal or not. If the determination result in step S69 is affirmative, the process flow proceeds to step S70 to stop the power supply to the fourth transistor TR4. Thereafter, the abnormality diagnosis execution flag f1 and the transistor normality determination flag f2 are reset to off in step S71, and then this process flow is ended. If the determination result in step S69 is negative, the process flow proceeds to step S72 to set the ISS permission flag from off to on and to maintain the power supply to the fourth transistor TR4. Thereafter, the process flow proceeds to step S71 to reset the execution abnormality diagnostic execution flag f1 and the transistor normality determination flag f2 to off. Thereafter, this process is terminated.

In this embodiment, the fourth transistor TR4 is held in the on state when all the transistors TR1 to TR4 and the relays 22 . 23 and 24 are diagnosed as normal. Thus, if the restart condition is satisfied after the engine stop condition has been met and the engine has been stopped, the engine may be stopped by the starter in a further process flow (not shown) 10 , only by changing the pinion drive relay 22 and the motor drive relay 23 from off to on, be cranked.

5 FIG. 12 is a timing chart showing an example of abnormality diagnosis of the relay. FIG. In 5 Range a) provides a transition from the on state to the off state of the ignition switch 34 the region b) is a transition from the on state to the off state of the starter switch 16 , the range c) a transition of the engine speed, the range d) a transition of the on state to the off state of the execution flag f1 with respect to the abnormality diagnosis, the region e) a transition from the on state to the off state an operation of the brake pedal, the range f) a transition of the vehicle speed and the range g) a transition from the on-state to the off-state in the flag f3 with respect to the ISS approval.

In the in 5 shown example, the ignition switch 34 and the starter switch 16 at the time t11 by the operation of a driver of the vehicle is turned on, causing the starter 10 Power is supplied to start an initial rotation of the machine. After that, when the starter switch 16 is turned off at a time t12 by the driver of the vehicle, the abnormality diagnosis execution flag f1 is turned on at this time, whereby the abnormality abnormal diagnoses shown in FIG 3 and 4 are shown performed.

After completing the abnormality abnormalities, the abnormality diagnosis execution flag f1 is turned off. If the results of off-abnormality diagnoses show that all transistors TR1 to TR4 and the relays 22 . 23 and 28 are normal or in a normal state, the flag f3 of the ISS permission is turned on as by the solid line in the area g) to allow the automatic engine start and stop to be performed thereafter. If the results of the abnormality diagnoses indicate that at least one of the transistors TR1 to TR4 and the relays 22 . 23 and 28 is abnormal, the flag f3 of the ISS permission, as shown by the solid line in the area g), is held off to prevent the subsequent automatic engine start / stop.

By the embodiment described above, the following advantages are provided.

The above embodiment is configured to be during an engine startup period after an on-operation of the starter switch 16 Off-abnormality diagnostics for the pinion drive relay 22 , the motor drive relay 23 and the upstream relay 28 in the second starter drive circuit 15 are included. According to this embodiment, since a restart request for automatic engine start is unlikely to occur during the engine start time set in response to the operation by an ignition key or switch by the driver of the vehicle, it is possible to avoid a situation where a request for automatic engine startup is made Machine stop occurs before or while the relay's abnormality diagnostics are running. According to this embodiment, therefore, it is possible to obtain the full benefits from the idling stop control while preventing a situation that the vehicle is due to a malfunction of the starter 10 can not be started.

The above embodiment is configured 15 shortly after completion of driving or driving the starter 10 an abnormality diagnosis for the second starter drive circuit by the first starter drive circuit 14 to start. Since the abnormality diagnosis of the second starter drive circuit 15 is performed after it has been confirmed that the starter 10 is normal, therefore, the occurrence of an abnormality in the second starter drive circuit can be reliably detected.

At the off-abnormality diagnoses of the upstream relay 28 and the drive relay 22 and 23 is a power supply to the relay coil of the upstream relay 28 Maintained, last diagnosed. Thus, if the restart condition is satisfied after the engine has been automatically stopped by the idle-stop control, the engine can only be changed by changing the drive relays 22 and 23 be quickly restarted in the on state.

Further embodiments

According to the embodiment described above, as shown below, other modifications are conceivable.

In the present embodiment, a system may also be provided which automatically stops by the idle-stop control based on the condition that the vehicle speed reaches a predetermined speed (for example, several km / h or several tens of km / h) the machine allowed. In this case, since the automatic stop of the engine is not allowed until the engine has reached the predetermined speed after the starter switch 16 On, a small chance that the engine was not automatically stopped while the engine was being started in response to the actuation by the ignition key or the switch by the driver of the vehicle. According to this modification, a situation in which an automatic stop of the engine is prevented can be prevented from occurring because the abnormality diagnoses of the relays 22 and 23 not be carried out.

In the embodiment, the off-abnormality diagnoses of the relay start at a time when the starter switch 16 from On to Off. However, the timing is not limited to if the abnormality abnormalities of the relay are made in response to an operation for changing the starter switch from on to off.

For example, the embodiment may be modified such that at least one of the transistors TR1 to TR4 at a timing (time t11 in FIG 5 ) when the starter switch 16 is changed from off to on, powered on, and the off-abnormality diagnoses of the relay are then performed. Furthermore, the embodiment may be modified such that at a time between a time t11 and a time t12 in FIG 5 at least one of the transistors TR1 to TR4 is energized, and the off-abnormality diagnoses are then performed. Further, the embodiment may be modified such that at a time point after a predetermined time from a time point t12 in FIG 5 has passed, at least one of the transistors TR1 to TR4 is energized, and the off-abnormality diagnoses of the relay are then performed.

According to the above embodiment, both the transistors TR1 to TR4 and the relays 22 . 23 and 28 Items of abnormality diagnoses. However, only the transistors TR1 to TR4 or the relays 22 . 23 and 24 be determined as objects of aus-abnormality diagnoses. Further, only some of the transistors TR1 to TR4 or some of the relays may be used 22 . 23 and 28 be determined as objects of aus-abnormality diagnoses.

The above embodiment may be configured to supply power to the starter 10 by on / off control of the pinion drive relay 22 and the motor drive relay 23 without using the upstream relay 28 to control.

In this case, the element detection voltage Vm for each of the transistors is measured in a state in which no power is supplied to one of the transistors at the high side of the associated relay and at another of the transistors of the low side of this relay is measured to one To detect abnormality for each of the transistors TR1 to TR4, and it is determined whether the transistor on the low side of this relay is normal or not based on the measured element detection voltage Vm. Accordingly, the element detection voltage Vm is measured in a state where no power is supplied to the transistor at the low side of the relay, and current is applied to the transistor at the high side of this relay, and it is determined based on the measured element detection voltage Vm the transistor on the high side of this relay is normal or not.

For diagnosing the first transistor TR1, for example, the element detection voltage Vm1 is measured in a state in which the second transistor TR2 but not the first transistor TR1 is energized. If the measured element detection voltage Vm1 is greater than a predetermined voltage, it is determined that the first transistor TR1 is normal, and it is otherwise determined to be abnormal.

A detection of an abnormality of a contact in the upstream relay 28 and the drive relay 22 and 23 may be performed such that an abnormality diagnosis for the upstream relay 28 followed by abnormality diagnostics for the drive relays 22 and 23 , By maintaining a power supply to the drive relays 22 and 23 If all of the relays have been diagnosed as normal, the machine can be restarted quickly if the restart condition is met after the machine has been automatically stopped.

In the above embodiment, the upstream relay 28 closer to the battery 13 as the pinion drive relay 22 and the motor drive relay 23 intended. The upstream relay 28 but also closer to the starter 10 as the pinion drive relay 22 and the motor drive relay 23 be arranged.

In the above embodiment, the starter is 10 a double-acting starter for pushing out the pinion 12 and turning the pinion 12 using a torque of the motor 12 , independently of each other. However, the present invention is also applicable to a conventional starter in which its motor is driven when the pinion is pushed out.

In the above embodiment, the engine is a gasoline engine. However, the present invention can also be applied to a diesel engine.

The preferred embodiments explained above are exemplified for the invention of the present application, which is defined by the following claims. It should be understood that modifications of the preferred embodiment may be made in accordance with the skill of one of ordinary skill in the art.

Claims (3)

Starter drive device ( 14 . 15 ) for an internal combustion engine configured to be automatically stopped when a predetermined engine stop condition is satisfied, and by cranking by a starter ( 10 ) is automatically restarted when a predetermined engine restart condition is satisfied after it has been automatically stopped, wherein the starter drive device is configured to power the starter to crank the engine, the starter drive device comprising: a first starter Control circuit ( 14 ) including a first current path ( 32 ) for conducting a first current to be supplied to the starter, and a first switching means ( 18 . 19 ) disposed in the first current path and configured to be changed from an off state to an on state by the operation of a driver of a vehicle to supply the first current to the starter; a second starter drive circuit ( 15 ) including a second current path ( 33 ) for conducting a second current to be supplied to the starter, and a second switching means ( 22 . 23 . 28 ), which has a relay switch ( 24 . 26 . 29 ), a relay coil ( 25 . 27 . 31 ) and a first switching element ( 16 ), wherein the relay switch is disposed in the second current path and configured to be changed from an open state to a closed state when the first switching element is turned on to energize the relay coil to supply the second current to the starter; an excitation control means ( 40 ) for controlling the energization of the relay coil of the second switching means by the first switching element; a change-over detection means ( 37 . 40 ) for detecting a state change of the first switching means between an on-state and an off-state; and an abnormality diagnostic agent ( 40 ) for performing, by energizing the relay coil by the first switching element via the excitation control means when the changeover detection means detects the state change of the first switching means, an abnormality diagnosis for determining whether the second switching means has an off-abnormality in which the relay switch in an open state remains. The starter drive apparatus according to claim 1, wherein the abnormality diagnosing means is configured to perform the abnormality diagnosis by turning on the first switching element via the energization control means shortly after the switching detection means detects that the first switching means has been changed from an on-state to an off-state. A starter drive apparatus according to claim 1 or 2, wherein said second starter drive circuit further comprises third switching means (12). 17 ), which includes a relay coil, a second switching element and a relay switch, which is connected in series with the relay switch of the second switching means in the second current path, wherein the excitation control means is configured, the energization of the relay coil of third switching means by the second switching element to switch the relay switch of the third switching means between an open state and a closed state, wherein the abnormality diagnosing means is configured to perform an abnormality diagnosis to determine whether the third switching means has an off-abnormality by energizing the relay coil of the third switching means by the second switching element via the energization control means after the switch detection means detects that the first switching means has changed from an on-state to an off-state, the excitation-control means being configured to configure the relay Switch of the second n switching means or the third switching means, whichever has been diagnosed last, to keep in the closed state, when the second switching means and the third switching means have been diagnosed as normal by the abnormality diagnostic means.

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