JP2009097373A - Method for diagnosing battery voltage short detection and vehicle operation control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure stable vehicle operation without causing overcurrent of a fuel pressure-feed metering valve even if an ignition switch is turned on again during a process for diagnosing detection whether it is in a failure state that voltage of a section at a power source side of the fuel pressure-feed metering valve is always battery voltage or not, which is executed as one of after-run processes of an automobile. <P>SOLUTION: In the vehicle operation control device, difference between target current calculated with a predetermined operation formula and actual current of the fuel pressure-feed metering valve determined through feed back control for controlling current supplied to the fuel pressure-feed metering valve is forcibly set to zero to put the feed back control into a stop state when the process for diagnosing detection of battery voltage short is started. Consequently, overcurrent of the fuel pressure-feed metering valve at a time when the ignition switch is turned on again is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a short-circuit detection diagnosis of a battery voltage of a fuel pressure adjustment valve used in a common rail fuel injection control device, and more particularly to a device for further ensuring the stability of the operation of the device.

The so-called common rail fuel injection control device pressurizes fuel with a high-pressure pump, pumps the fuel to a common rail that is an accumulator, accumulates the pressure, and supplies the accumulated high-pressure fuel to the injector. It is known and known as a fuel injection enabled.
In the high-pressure pump of the common rail fuel injection control device, a fuel pressure adjustment valve, which is an electromagnetic proportional control valve, is used as means for adjusting the amount of fuel supplied to the high-pressure plunger.

  By the way, in the motor vehicle, after the ignition switch is turned off (disconnected), various operation diagnosis and the like are performed, and if necessary, the diagnosis result and the like are stored and stored in the nonvolatile storage element, and then the control device Is generally performed, and a series of diagnostic processing after such an ignition switch is turned off is generally referred to as after-run processing (for example, Patent Document 1). , See Patent Document 2).

As one of such after-run processes, there is a fuel pressure metering valve in the previous high-pressure pump that is configured to perform a battery voltage short-circuit detection diagnosis in its drive circuit.
The drive circuit of the fuel pressure adjustment valve is, for example, a field effect transistor from the power source side to the high side, an electromagnetic coil of the fuel pressure adjustment valve, and a field effect transistor on the low side side in series between the power source and the ground. A connected configuration is common. In such a circuit, the high-side field effect transistor and the low-side field effect transistor are driven by duty ratio control, so that the energization amount to the fuel pressure adjusting valve, that is, the fuel to the high-pressure plunger is in other words. The supply amount can be adjusted.

  In such a configuration, the connection portion between the high-side field effect transistor and the fuel pressure adjustment valve is in a state where the power supply voltage, that is, the battery voltage of the vehicle battery is normally applied for some reason. That is, in a state called a battery voltage short circuit (VB short circuit), even if the high-side field effect transistor is turned off, the application of the battery voltage to the fuel pressure adjustment valve cannot be cut off. Therefore, in this state, if the connection point between the fuel pressure adjustment valve and the low-side field effect transistor is shorted to the ground for some reason, the fuel pressure adjustment valve Current flows, and in the worst case, the electromagnetic coil of the fuel pressure adjustment valve is seized, and there is a possibility that normal fuel injection operation cannot be secured.

  The battery voltage short-circuit detection diagnosis in the after-run process is based on the fact that the connection between the high-side field effect transistor and the fuel pressure adjustment valve is not It is for diagnosing whether or not there is a voltage.

JP 2006-57455 A (page 3-7, FIGS. 1 to 9) JP 2001-304025 A (page 2-4, FIG. 1 and FIG. 2)

However, in the conventional battery voltage short-circuit detection diagnosis process, it is rare, but when the ignition switch is turned on again during the process, the fuel pressure adjustment amount is caused by the following reasons. There is a risk of overcurrent flowing through the valve.
That is, first, during the execution of the battery voltage short detection diagnostic process, normally, the above-described high-side and low-side field effect transistors are both turned off. It is determined whether or not the voltage at the connection point between the transistor and the fuel pressure adjustment valve has reached the battery voltage.

  By the way, the energization amount to the fuel pressure adjusting valve by the on / off control of the high-side and low-side field effect transistors is controlled by the duty ratio as described above. Is based on the difference between the actual current value of the fuel pressure adjustment valve and the target current value calculated by a predetermined calculation process. That is, the difference between the actual current value of the fuel pressure adjusting valve and the target current value calculated by a predetermined calculation process is obtained, and a calculation coefficient for determining the duty ratio is determined in proportion to the difference, The duty ratio is determined according to the magnitude of the calculation coefficient.

Normally, the calculation coefficient for determining the above-described duty ratio increases in proportion to the difference between the actual current value of the fuel pressure adjustment valve and the target current value calculated by a predetermined calculation process, and reaches a predetermined value. In this case, the predetermined value is set.
For this reason, when the battery voltage short detection detection process is started, the actual current value of the fuel pressure adjustment valve becomes zero, while the calculation of the target current value by the predetermined calculation process is continued. Therefore, in response to the actual current value becoming zero, the target current value increases with time, and accordingly, the calculation coefficient for determining the above-described duty ratio also increases, and finally the regulation value Will be reached.

  The above-mentioned re-ignition of the ignition switch is performed when the calculation coefficient for determining the duty ratio is increasing as described above or when the regulation value has been reached. At the same time as energization is started, an excessive current flows.

In addition, in the conventional battery voltage short detection diagnostic processing, in addition to the problem that an overcurrent of the fuel pressure adjusting valve occurs when the ignition switch as described above is turned on again, as described below. There is a risk that the relief valve will open due to a sudden rise in rail pressure.
That is, in the battery voltage short-circuit detection diagnosis process, as already described, both the high-side and low-side field effect transistors are turned off, and the energization current to the fuel pressure adjustment valve becomes zero. Yes. On the other hand, the relative relationship between the energization amount of the fuel pressure adjusting valve and the fuel pressure amount from the high pressure plunger to the common rail is generally an inversely proportional relationship. Therefore, the energization current to the fuel pressure adjustment valve is zero, and the engine speed that is asymptotic to nearly zero increases for some reason, so-called rotation. If this happens, the current flow to the fuel pressure metering valve is zero, so the fuel discharge by the high pressure plunger will be in the full pressure feed state, causing the rail pressure to rise inadvertently. There is a possibility that the relief valve provided in the valve will be opened.

  The present invention has been made in view of the above circumstances, and during the battery voltage short-circuit detection diagnosis process in the drive circuit of the fuel pressure metering valve, which is executed as one of the after-run processes in an automatic vehicle in which electronic control is performed. Even when the ignition switch is turned on again, it is possible to reliably avoid overcurrent of the fuel pressure adjustment valve and the sudden increase in rail pressure due to the fluctuation of the engine speed. A battery voltage short-circuit detection diagnosis method and a vehicle operation control device for a fuel pressure adjustment valve capable of ensuring vehicle operation are provided.

In order to achieve the above object of the present invention, a battery voltage short detection diagnostic method according to the present invention comprises:
A high-pressure pump that pumps fuel to the common rail; an electromagnetic proportional control valve that adjusts a fuel supply amount to the high-pressure pump; and an electronic control unit, wherein the electromagnetic proportional control valve is connected to a vehicle battery and a ground. And the drive transistor based on the difference between the actual current flowing through the electromagnetic proportional control valve and the target current calculated by a predetermined arithmetic expression. In a vehicle operation control device configured to perform current governor control that allows feedback control of the fuel and to adjust the fuel supply amount to the high-pressure pump by the electromagnetic proportional control valve, the ignition switch is turned off. After that, whether or not the driving transistor is in an off state and the power supply side of the electromagnetic proportional control valve is at a battery voltage. A battery voltage short detection diagnostic method for determining,
The current governor control is stopped at the start of execution of the battery voltage short detection diagnostic method, and the current governor control is restarted at the end of the battery voltage short detection diagnostic method.
In order to achieve the above object of the present invention, a vehicle operation control device according to the present invention includes:
A high-pressure pump that pumps fuel to the common rail; an electromagnetic proportional control valve that adjusts the amount of fuel supplied to the high-pressure pump; and an electronic control unit, wherein the electromagnetic proportional control valve includes And the drive transistor based on the difference between the actual current flowing through the electromagnetic proportional control valve and the target current calculated by a predetermined arithmetic expression. And the current governor control that enables adjustment of the fuel supply amount to the high-pressure pump by the electromagnetic proportional control valve is executed, and after the ignition switch is turned off, A battery that determines whether or not the driving transistor is off and the power supply side of the electromagnetic proportional control valve is at a battery voltage. A vehicle motion control apparatus comprising is configured to voltage short detection diagnostics run,
The electronic control unit is configured to stop the current governor control at the start of execution of the battery voltage short detection diagnostic method, and to restart the current governor control at the end of the battery voltage short detection diagnostic method. It will be.

According to the present invention, detection and diagnosis of a failure state in which the power supply side portion of the electromagnetic proportional control valve that adjusts the fuel supply amount to the high-pressure pump is constantly at the battery voltage regardless of whether the driving transistor is on or off. Since the feedback control for controlling the energization current of the electromagnetic proportional control valve does not function during the battery voltage short detection diagnosis process, the voltage on the power supply side of the electromagnetic proportional control valve is not Even if the ignition switch is turned on again during detection diagnosis, unlike the conventional case, it is possible to reliably avoid an overcurrent from flowing at the start of energization of the electromagnetic proportional control valve, ensuring stable vehicle operation startup, It can contribute to the improvement of reliability.
In addition, it is possible to drive a driving transistor that controls energization of an electromagnetic proportional control valve that adjusts the fuel supply amount to the high-pressure pump at the end of the battery voltage short detection diagnosis process without waiting for the end of the after-run process. Therefore, even if there is a so-called rebound of engine rotation between the end of the battery voltage short detection diagnosis process and the end of the after-run process, unlike the conventional case, the high-pressure pump can be prevented from being fully pumped. Generation | occurrence | production of the rapid rise of rail pressure can be prevented, and more reliable apparatus operation | movement can be provided.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6.
The members and arrangements described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.
First, a configuration example of a common rail fuel injection control device as a vehicle operation control device that realizes a battery voltage short-circuit detection diagnosis method for a fuel pressure adjustment valve according to an embodiment of the present invention will be described with reference to FIG. To do.

The common rail fuel injection control device includes a high pressure pump device 50 that pumps high pressure fuel, a common rail 1 that stores the high pressure fuel pumped by the high pressure pump device 50, and a high pressure fuel supplied from the common rail 1 to diesel engine ( Hereinafter, a plurality of fuel injection valves 2-1 to 2-n that inject and supply to three cylinders, and an electronic control unit ("ECU" in FIG. 1) that performs fuel injection control and the like as will be described later. 4) as a main component.
Such a configuration itself is the same as the basic configuration of this type of fuel injection control apparatus that has been well known.

The high-pressure pump device 50 has a known and well-known configuration with the supply pump 5, the fuel pressure adjustment valve 6, and the high-pressure pump 7 as main components.
In this configuration, the fuel in the fuel tank 9 is pumped up by the supply pump 5 and supplied to the high-pressure pump 7 through the fuel pressure-feeding metering valve 6. A known and well-known electromagnetic proportional control valve is used as the metering valve 6, and the amount of current supplied to the high-pressure pump 7 is controlled by the electronic control unit 4. The discharge amount of the pump 7 is adjusted.
A return valve 8 is provided between the output side of the supply pump 5 and the fuel tank 9 so that surplus fuel on the output side of the supply pump 5 can be returned to the fuel tank 9. .

  The fuel injection valves 2-1 to 2-n are provided for each cylinder of the engine 3, and are supplied with high-pressure fuel from the common rail 1, and perform fuel injection by injection control by the electronic control unit 4. Yes.

The electronic control unit 4 has, for example, a microcomputer (not shown) having a known and well-known configuration, a storage element (not shown) such as a RAM and a ROM, and a fuel injection valve 2- A drive circuit (not shown) for driving 1 to 2-n and an energization circuit (not shown), which will be described later, for energizing the fuel pressure adjusting valve 6 are configured as main components. It has become.
The electronic control unit 4 includes a sensor corresponding to an engine speed, an accelerator opening, a rail pressure of the common rail 1, an intake air amount (air mass), and the like detected by a sensor (not shown) for operation control of the engine 3 and the like. An output signal is input.

FIG. 2 shows a schematic configuration example of an energization circuit for energizing the fuel pressure adjusting valve 6, and the configuration of the energization circuit will be described below with reference to FIG.
The energization circuit of the fuel pressure adjusting valve 6 has a configuration conventionally used as this type of circuit. A power supply (not shown) for supplying the power supply voltage VB, that is, a vehicle battery (see FIG. The field effect transistor 11 for energization drive, the electromagnetic coil 6a of the fuel pressure adjusting valve 6, and the field effect transistor 12 for energization drive are connected in series between the power source side and the ground. It has been made. In FIG. 2, the field effect transistors 11 and 12 are represented as switch elements.

In general, the field effect transistor 11 whose drain (or source) is connected to the power supply and arranged on the power supply side is arranged on the high side, and the electric field which is arranged on the earth side with the drain (or source) connected to ground. The effect transistors 12 are distinguished from each other on the low side.
In such a configuration, the high-side field effect transistor 11 and the low-side field effect transistor 12 are configured such that a repetitive pulse is applied to their gates as a drive control signal, and the duty ratio of the repetitive pulse is By controlling, the energization amount to the fuel pressure adjusting valve 6 is controlled, and the fuel supply amount to the high pressure pump 7 can be adjusted. As a result, the amount of fuel pumped to the common rail 1 of the high-pressure pump 7 is adjusted.

  In the embodiment of the present invention, the energization current of the fuel pressure adjusting valve 6 and the amount of fuel supplied to the high pressure pump 7, in other words, the flow rate of fuel pumped from the high pressure pump 7 to the common rail 1, For example, as schematically shown in FIG. 3, the correlation is substantially in an inversely proportional relationship in which the flow rate decreases as the energization current increases.

FIG. 4 is a flowchart showing the overall processing procedure of the after-run process executed by the electronic control unit 4, and the contents thereof will be described below with reference to FIG.
This series of processing is for diagnosing confirmation of vehicle operation or the like, generally called after-run processing. That is, in an electronically controlled automatic vehicle, when an ignition switch (not shown) is cut off and the vehicle is stopped, failure history confirmation and storage during traveling for a predetermined time, various sensors Various processes such as diagnosis of the presence or absence of a failure of the electronic control unit 4 are executed, and thereafter, a process for completely turning off the power of the electronic control unit 4, that is, a process generically called an after-run process is executed. . This is performed from the standpoint of further improving the reliability and stability of the vehicle operation by reflecting the result of the operation control of the vehicle at the next time the vehicle is started. Is.

  Thus, when processing is started by the electronic control unit 4, it is first determined whether or not the engine 3 is in a stopped state, that is, whether or not the engine speed NE is zero (step of FIG. 4). If it is determined that the engine speed NE is not yet zero (in the case of NO), a series of processes are terminated, and the process returns to the main routine (not shown). It becomes.

  On the other hand, if it is determined in step S100 that the engine speed NE is zero (in the case of YES), the after-run process is started (see step S200 in FIG. 4). The drive is stopped (see step S300 in FIG. 4). Here, as an actuator, for example, there is an actuator that is provided at an appropriate position of an intake passage for controlling intake air amount of a so-called internal combustion engine and used for opening and closing the passage.

Next, a diagnostic process for determining whether or not the output level offset amount fluctuates in an air mass sensor (not shown) for detecting the intake air amount (see step 400 in FIG. 4), and a rail pressure sensor for detecting rail pressure ( A determination process of whether or not the offset amount fluctuates is not performed (see step 500 in FIG. 4).
After these processes are completed, the battery voltage short-circuit detection diagnosis process (VB diagnosis process) of the fuel pressure adjustment valve 6 is executed (see step S600 in FIG. 4).

  After the VB diagnosis process is completed, predetermined data is stored and stored in a non-volatile memory element (not shown) (see step S700 in FIG. 4), the main relay (not shown) is turned off, and a series of operations are performed. The process ends (see step S800 in FIG. 4). Here, the main relay is inserted in series in a power supply line between the electronic control unit 4 and the vehicle battery (not shown), and is normally disconnected when the after-run process is completed, The power supply to the electronic control unit 4 is completely cut off.

FIG. 5 shows a subroutine flowchart showing a more specific processing procedure of the VB diagnosis processing in step S600 of FIG. 4, and the contents thereof will be described below with reference to FIG.
When the process is started, first, it is determined whether or not a start condition for the high-side battery voltage short detection diagnosis process is satisfied (see step S602 in FIG. 5). Here, the start condition of the high side battery voltage short detection diagnosis process (high side VB short detection diagnosis process) is determined to be in an operating state suitable for starting the high side battery voltage short detection diagnosis process. Therefore, there are usually a plurality of predetermined conditions.

  For example, conditions such that the engine speed is zero, the vehicle speed is zero, there are no other errors that hinder the processing, and the low-side field effect transistor 12 is not short-circuited to the ground side. Is satisfied as a starting condition. Of course, these are merely examples, and the present invention is not limited thereto.

In step S602, when it is determined that the start condition for the high-side VB short detection diagnosis process has not yet been established (in the case of NO), the series of processes are terminated while the start condition is established. If YES (YES), the high-side field effect transistor (FET) 11 is turned off, and after a predetermined time has elapsed, the process proceeds to step S606 (step in FIG. 5). (See S604).
Here, waiting for the elapse of a predetermined time after the high-side field effect transistor 11 is turned off reduces the current transient that occurs after the high-side field effect transistor 11 is turned off, This is because it is desirable to perform the next processing after the current becomes zero and the circuit state becomes stable.

Next, in step S606, a high-side VB short detection diagnosis is performed. That is, in the electronic control unit 4, as described above with reference to FIG. 2, the voltage at the connection portion between the high-side field effect transistor 11 and the fuel pressure adjustment valve 6 is read. In step S606, it is determined whether or not the voltage is the battery voltage VB.
Then, the current governor control is stopped together with the VB short detection diagnosis (see step S608 in FIG. 5).
That is, the low-side field effect transistor 12 is turned off, and as described below, the actual current value of the fuel pressure adjustment valve and the target of the fuel pressure adjustment valve 6 calculated by a predetermined calculation process The difference from the current value is forced to be zero.

  Here, the current governor control is a method for controlling the energization amount of the fuel pressure adjusting valve 6 which has been conventionally performed. That is, in the current governor control, first, the difference between the actual current value of the fuel pressure adjustment valve and the target current value of the fuel pressure adjustment valve 6 calculated by a predetermined calculation process is obtained. Next, a calculation coefficient (current governor factor) that determines the duty ratio of the drive control signal of the gate of the high-side field effect transistor 11 and the low-side field effect transistor 12 is determined in proportion to the above-described difference. The duty ratio is determined according to the magnitude of the current governor factor, and feedback control is performed in which the high-side field effect transistor 11 and the low-side field effect transistor 12 are driven at the duty ratio.

  In the embodiment of the present invention, the energization of the fuel pressure adjustment valve 6 is determined as described above with the high-side field effect transistor 11 turned on and the low-side field effect transistor 12 as described above. It is driven at a duty ratio.

  Conventionally, such current governor control is performed in a state where high-side VB short detection diagnosis (see step S606 in FIG. 5) is performed in the after-run processing, and both the field effect transistors 11 and 12 are forcibly turned off. The software itself was supposed to be executed regardless of the state. Accordingly, since the actual current value of the fuel pressure adjustment valve 6 is zero, the difference from the target current value increases with time, the current governor factor increases, and finally the upper limit regulation It was in a situation that would be value.

  As described above, the high-side VB short detection diagnosis (see step S606 in FIG. 5) is performed, and the ignition switch is a rare timing in the state where the current governor factor is increasing or reaches the upper limit regulation value. When (not shown) is turned on again, the low-side field effect transistor 12 is driven with a very large duty ratio from the start of driving, and the fuel pressure adjusting valve 6 is started to start. At the same time, there is a risk of overcurrent flowing.

  However, in the embodiment of the present invention, during the high-side VB short detection diagnosis, the current governor control is stopped, that is, the difference between the actual current value of the fuel pressure adjustment valve and the target current value is forcibly Since it is zero, the duty ratio of the drive control signal for the field effect transistor 12 on the low side is zero. Therefore, unlike the conventional case, the current governor factor is inadvertently increased, and finally, reaching the upper limit regulation value is surely avoided, and the ignition switch is restarted during the high-side VB short detection diagnosis process. Even when the vehicle is turned on and the vehicle is started, unlike the conventional case, an overcurrent does not flow through the fuel pressure adjustment valve 6 at the time of startup, and stable startup is ensured.

Accordingly, in step S610, based on the determination result of whether or not the voltage at the connection portion between the high-side field effect transistor 11 and the fuel pressure adjustment valve 6 obtained in the previous step S606 is VB. Thus, it is determined whether or not the high-side field effect transistor 11 is in a disconnected state.
That is, in a state where no VB short-circuit occurs, that is, in a normal state of the circuit, in this case, the high-side field effect transistor 11 is turned off. The voltage at the connection portion with the fuel pressure adjusting valve 6 does not become VB and is almost zero v, and the high-side field effect transistor 11 can be determined to be in an off state, in other words, a disconnected state. .

On the other hand, although the high-side field effect transistor 11 is in the OFF state as described above, the voltage at the connection portion between the high-side field effect transistor 11 and the fuel pressure adjusting valve 6 is the battery voltage VB. In some cases, it is determined that the high-side field effect transistor 11 is not disconnected.
That is, in this case, for some reason, the connection portion between the high-side field effect transistor 11 and the fuel pressure adjustment valve 6 is short-circuited with the vehicle battery (not shown) and is in the state of the battery voltage VB. Conceivable.

In this way, when it is determined in step S610 that the high-side field effect transistor 11 is in a disconnected state (in the case of YES), the high-side field effect transistor 11 is not in a high-side VB short state. Therefore, the normal state is assumed (see step S612 in FIG. 5), and the process proceeds to step S616.
On the other hand, if it is determined in step S610 that the high-side field effect transistor 11 is not disconnected (in the case of NO), the high-side field effect transistor 11 is assumed to be in a VB shorted state (FIG. 5 (see step S614 of FIG. 5), and the process proceeds to step S616.

In step S616, a flag is set according to the execution of step S612 or S614 described above.
That is, in the embodiment of the present invention, a high-side VB short error state flag is provided, and when it is determined in step S612 that the circuit operation is not normal but the circuit operation is in a normal state. The high side VB short error state flag is set to a predetermined value indicating that the circuit operation is normal, for example, “zero”. On the other hand, if it is determined in step S614 that the high-side VB short-circuit state is present, the high-side VB short error state flag is set to a predetermined value indicating that the high-side VB short-circuit has occurred, for example, “1”. Will be.

Next, the high-side VB short diagnosis completion flag is set to a predetermined value indicating the completion of the high-side VB short detection diagnosis process, for example, “1” (see step S618 in FIG. 5).
Then, the current governor control that has been stopped is started (see step S620 in FIG. 5). In the embodiment of the present invention, at the start of the current governor control, first, the actual current value (actual current value) of the fuel pressure adjusting valve 6 and the fuel pressure adjusting valve 6 calculated by a predetermined arithmetic processing are used. The state where the difference from the target current value is forcibly made zero is canceled. At the same time, the actual current value of the fuel pressure adjustment valve is forcibly replaced with the target current value at this time (initialization of the actual current with the target current), and the fuel pressure adjustment valve 6 at the target current is supplied to the fuel pressure adjustment valve 6. Energization is started. By initializing the actual current with the target current, a relatively large current is transiently increased due to the difference between the actual current and the target current at the start of the current governor control. It will be prevented from flowing into.

Next, the high-side field effect transistor 11 and the low-side field effect transistor 12 are brought into a driving start state, a series of processing is ended, and the routine returns to the routine shown in FIG. 4 (FIG. 5). Step S622).
Here, in the embodiment of the present invention, the drive start state of the field effect transistors 11 and 12 is specifically, the high side field effect transistor 11 is kept on, while the low side side The field effect transistor 12 is in a state where on / off control (duty ratio control) according to the duty ratio is started.

Next, the operation when the ignition switch is turned on again during the after-run process, particularly the VB diagnosis process, will be described generally with reference to FIGS.
First, when an ignition switch (not shown) is turned off and after-run processing is started, the current of the fuel pressure adjustment valve 6 decreases toward zero (see FIG. 6A). In FIG. 6, “time t1” is the time when the ignition switch (not shown) is turned off, and “time t2” is the time when the ignition switch is turned on during the VB diagnosis processing. It is.

Then, as one of the after-run processes, the current governor control is stopped (see step S608 in FIG. 4) by starting the VB diagnostic process (see step S600 in FIG. 3 and FIG. 4), and the current The governor factor is held at a constant value (see the solid characteristic line in FIG. 6B).
On the other hand, unlike the embodiment of the present invention, the current governor factor is indicated by a dotted line in FIG. 6B because the current governor control has been executed even during execution of the VB diagnosis process. As it was done, it increased with the start of the after-run process, and finally reached a predetermined maximum regulation value.

  For example, if the ignition switch (not shown) is turned on again during the VB diagnosis process, the current governor factor is increasing as described above or the predetermined maximum regulation is applied to the conventional device. Since the value has reached the value, there is a possibility that an overcurrent may flow in the fuel pressure adjustment valve 6 at the moment when the ignition switch is turned on (see the characteristic line in FIG. 6A).

  On the other hand, in the embodiment of the present invention, as described above, the current governor factor is held at the value immediately before the current governor control is stopped by stopping the current governor control, and the ignition switch is turned on again. In this case, since the actual current value of the fuel pressure adjusting valve 6 is initialized with the target current value and energized, unlike the conventional case, the current is started with the target current without causing an overcurrent when energization is started. (Refer to the solid characteristic line in FIG. 6A.)

  Further, in the embodiment of the present invention, unlike the conventional case, as described above, the high-side field-effect transistor 11 and the low-side transistor 11 and the low-side transistor at the time when the VB diagnosis processing is completed before the after-run processing is completed. The field effect transistor 12 on the side is returned to the driving state (see step S622 in FIG. 5). Therefore, conventionally, before the after-run process is completed, if the engine 3 rotates for some reason, both the high-side field effect transistor 11 and the low-side field effect transistor 12 are not driven. Since the energization current of the fuel pressure adjusting valve 6 is zero, the maximum amount of fuel is supplied to the high-pressure pump 7 (see FIG. 3), and the high-pressure pump 7 may be in a full-pressure feeding state. . However, in the embodiment of the present invention, the high-side field effect transistor 11 and the low-side field effect transistor 12 are driven before the after-run process is completed (see step S622 in FIG. 5). Even if the engine 3 rolls back, unlike the conventional case, the high-pressure pump 7 is in a fully pumped state, and it is possible to prevent the rail pressure from rapidly increasing.

It is a block diagram which shows the structural example of the common rail type | mold fuel injection control apparatus by which the battery voltage short circuit detection diagnostic method in embodiment of this invention is implement | achieved. It is a block diagram which shows the schematic structural example of the electricity supply circuit which supplies electricity to the fuel pressure adjustment valve in the common rail type fuel injection control apparatus shown by FIG. It is a characteristic diagram which shows an example of the correlation with the energizing current of a fuel pressure adjustment valve, and the flow volume of the fuel pumped from a high pressure pump to a common rail. It is a flowchart which shows the whole process sequence of the after-run process performed by the electronic control unit in the common rail type | mold fuel-injection control apparatus shown by FIG. 6 is a subroutine flowchart showing a more specific processing procedure of the VB diagnosis processing in FIG. 4. FIG. 6 is a characteristic diagram for explaining the operation when the ignition switch is turned on again during the VB diagnosis process, and FIG. 6 (A) is a characteristic diagram showing the change over time of the energization current of the fuel pressure adjustment valve; FIG. 6B is a characteristic diagram showing a time change of the current governor factor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Common rail 3 ... Engine 4 ... Electronic control unit 6 ... Fuel pressure adjustment valve 11 ... Field effect transistor (high side side)
12. Field effect transistor (low side)

Claims (8)

A high-pressure pump that pumps fuel to the common rail; an electromagnetic proportional control valve that adjusts a fuel supply amount to the high-pressure pump; and an electronic control unit, wherein the electromagnetic proportional control valve is connected to a vehicle battery and a ground. And the drive transistor based on the difference between the actual current flowing through the electromagnetic proportional control valve and the target current calculated by a predetermined arithmetic expression. In a vehicle operation control device configured to perform current governor control that allows feedback control of the fuel and to adjust the fuel supply amount to the high-pressure pump by the electromagnetic proportional control valve, the ignition switch is turned off. After that, whether or not the driving transistor is in an off state and the power supply side of the electromagnetic proportional control valve is at a battery voltage. A battery voltage short detection diagnostic method for determining,
The battery governor control is stopped at the start of execution of the battery voltage short detection diagnostic method, and the current governor control is restarted at the end of the battery voltage short detection diagnostic method. Diagnostic method. 2. The battery voltage short circuit according to claim 1, wherein the current governor control is stopped by forcing the difference between the actual current flowing through the electromagnetic proportional control valve and the target current calculated by a predetermined arithmetic expression to be zero. Detection diagnostic method.   3. The battery voltage short detection diagnostic method according to claim 2, wherein at the end of the battery voltage short detection diagnostic method, the actual current of the electromagnetic proportional control valve is initialized with the target current.   4. The battery voltage short detection diagnostic method according to claim 3, wherein at the end of the battery voltage short detection diagnostic method, the driving of the driving transistor is resumed together with the start of the current governor control. A high-pressure pump that pumps fuel to the common rail; an electromagnetic proportional control valve that adjusts a fuel supply amount to the high-pressure pump; and an electronic control unit, wherein the electromagnetic proportional control valve is connected to a vehicle battery and a ground. And the drive transistor based on the difference between the actual current flowing through the electromagnetic proportional control valve and the target current calculated by a predetermined arithmetic expression. And the current governor control that enables adjustment of the fuel supply amount to the high-pressure pump by the electromagnetic proportional control valve is executed, and after the ignition switch is turned off, A battery that determines whether the driving transistor is off and the power supply side of the electromagnetic proportional control valve is at battery voltage. A vehicle motion control apparatus comprising is configured to voltage short detection diagnostics run,
The electronic control unit is configured to stop the current governor control at the start of execution of the battery voltage short detection diagnostic method, and to restart the current governor control at the end of the battery voltage short detection diagnostic method. A vehicle operation control device comprising:   6. The vehicle operation control according to claim 5, wherein the current governor control is stopped by forcing the difference between the actual current flowing through the electromagnetic proportional control valve and the target current calculated by a predetermined arithmetic expression to be zero. apparatus.   The vehicle operation control device according to claim 6, wherein the electronic control unit is configured to initialize the actual current of the electromagnetic proportional control valve with the target current at the end of the battery voltage short detection diagnostic method.   The vehicle operation control device according to claim 7, wherein the electronic control unit is configured to resume driving of the driving transistor at the end of the battery voltage short detection diagnostic method together with the start of the current governor control.

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