JP2008144607A - Electronic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent cutoff of processing for writing data such as an abnormality diagnostic result in a nonvolatile memory, when a battery is removed when an electronic control device is in operation. <P>SOLUTION: This electronic control device has the battery arranged in an engine room having a hood, a nonvolatile storage means capable of holding the data without receiving supply of a power source, and a writing-in means for writing the data in the nonvolatile storage means by receiving the power source supply from the battery. The electronic control device is characterized in that the writing-in means prohibits writing of the data in the nonvolatile storage means when the hood is opened. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic control device that writes control data to a memory, and more particularly to electronic fuel injection control that writes control data of an electronic fuel injection control device mounted on a vehicle to a non-volatile memory that can be retained even when the power is cut off. Relates to the device.

  Conventionally, for example, in an electronic fuel injection control apparatus (Electronic Fuel Injection-Electronic Controlled Unit (hereinafter referred to as “ECU”)) that performs fuel injection control to an in-vehicle engine, a control section that performs various processes and operations for engine control. Various electronic circuits centering on a microcomputer (hereinafter referred to as “microcomputer”) are provided.

  As shown in FIG. 1, the microcomputer provided in the ECU is configured such that electric power is supplied (for example, 12 V) from a battery 100 installed in the engine room via a power supply circuit 102. The microcomputer acquires control information of the engine 101 via the input / output circuit 103, adds a calculation in a CPU 104 (Central Processing Unit), and outputs the result to the engine 101 as a control value. At the time of calculation by the CPU 104, the control value is temporarily stored in a RAM (Random Access Memory) 105, transferred to an EEPROM (Electronically Erasable and Programmable Read Only Memory) 106 at a predetermined timing, and stored and held. The EEPROM 106 is non-volatile, and requires power when writing or erasing data, but can keep stored information even after the power supply is cut off. The data stored in the EEPROM 106 is read when the microcomputer is activated next time, and is used for calculations for controlling the engine 101.

  The ECU 1 is installed in the vehicle 34 as shown in FIG. 2, and is connected to the engine 21 disposed in the engine room 31 that is closed by the hood 33. And while electric power is supplied from the battery 13, the abnormality diagnosis of the apparatus in the vehicle and the sensor 24 is performed, and the diagnosis result is stored in the nonvolatile memory.

  On the other hand, some abnormality diagnosis control of these devices and sensors is performed while the vehicle is stopped. In other words, it is possible to improve the accuracy of diagnosis by making a diagnosis while the vehicle is stationary and stable, and because the diagnosis takes a long time, the vehicle is stopped so as not to affect the drive control of other devices. Some of them also diagnose abnormalities. For example, in abnormality diagnosis relating to fuel gas such as a fuel transpiration prevention device, abnormality diagnosis is executed while the vehicle is stopped and liquid fuel such as gasoline is stable without moving in the tank. In addition, in the abnormality diagnosis of the water temperature sensor, there is a diagnosis performed by operating the heater and variously changing the water temperature. In this case, the diagnosis time is long. During this time, the engine or the like based on the water temperature cannot be controlled, so the diagnosis is performed while the vehicle is stopped.

  Such abnormality diagnosis control is performed by starting the ECU at regular intervals by a soak timer after the vehicle is stopped, that is, after the ignition switch is turned off, and executing abnormality diagnosis of the apparatus. The soak timer is a timer that measures a time (hereinafter referred to as “soak time”) after substantial operating power is not supplied to the ECU due to an ignition switch being turned off or the like. Then, the soak timer supplies power to the microcomputer of the ECU every certain soak time (for example, every few hours to every several days), thereby executing abnormality diagnosis of devices and sensors in the vehicle. A flag which is an abnormal or normal diagnosis result is temporarily stored in a volatile memory. Since the temporary storage memory is a volatile memory composed of a RAM or the like, the stored data is erased when the ignition switch is turned off. For this reason, when the abnormality diagnosis process is completed, the diagnosis result data stored in the RAM is written and stored in a predetermined address of the nonvolatile memory, and then the abnormality diagnosis control is terminated.

  This nonvolatile memory is composed of an EEPROM or the like, and can store stored data even when the power is cut off. For example, data can be stored for about 10 years since the last data storage. Data writing can be repeated about 100,000 times. Then, after the abnormality diagnosis control is completed, the microcomputer and power supply of the ECU are shut off again, and the soak timer starts counting again.

  The abnormality diagnosis control includes, for example, a perforated inspection (leak check) for detecting leakage of vaporized fuel from a fuel transpiration prevention device (evaporator) that prevents transpiration of fuel from the fuel tank. The fuel transpiration prevention device consists of a fuel tank, a fuel adsorption tank (canister) that adsorbs fuel gas with activated carbon, etc., a communication pipe that connects both tanks, an air blocking valve that leads from the canister to the atmosphere, and an intake pipe adjustment valve that leads to the intake pipe Mainly composed. Then, the vaporized fuel such as gasoline evaporated and vaporized in the fuel tank is adsorbed to the canister through the communication pipe to prevent release to the atmosphere. The fuel adsorbed by the canister is appropriately introduced into the intake pipe and burned in the engine by adjusting the opening of the valve according to the operating state of the engine.

  In the leak check, in order to prevent air pollution and fire due to fuel leakage, after the ignition switch is turned off, the ECU is started after several hours measured by the soak timer, and the pressure in the evaporator is kept for several tens of minutes (for example, 30 minutes) The degree of leakage is checked by controlling and measuring (Patent Document 1).

  A pipe made of special rubber or the like is used for the communication pipe through which the evaporated fuel passes from the fuel tank to the evaporator. Since such a tube comes into contact with an alcohol component, there is a possibility that cracks or holes may be generated due to deterioration such as corrosion.

JP 2003-315474 A

  However, although the ECU is powered and activated for about 30 minutes after detecting fuel evaporation, the battery cord may be disconnected from the battery for vehicle maintenance such as battery replacement. This is because the vehicle owner or the maintenance staff may recognize that the ECU is not activated because the ignition switch is off. Further, during the diagnosis, even if the ECU is activated, the engine is not operating, so it is impossible for an operator to tell whether the ECU is operating.

  When the battery code is removed from the battery, if the result of the abnormality diagnosis is in the middle of being written to the nonvolatile memory or the like, there is a risk that diagnostic data consisting of a plurality of bits will be written and stored halfway. For example, when diagnosis data consists of a storage area of multiple bits and an abnormality or normal flag for one sensor or device is stored for each bit, the abnormality flag diagnosed in the past is used as the normal flag for the latest diagnosis. If the power is shut off before rewriting and the writing is interrupted, the abnormal flag may remain in the diagnostic data, which is a problem. In this case, the next time the engine is started, the engine is controlled based on the erroneously stored diagnosis data, so that a failure warning is issued even if no abnormality has occurred, and the engine is not properly controlled. There is a risk of deterioration of fuel consumption and poor purification of exhaust gas.

  For example, if the fuel transpiration prevention device becomes abnormal, the amount of transpiration fuel introduced into the intake pipe cannot be calculated accurately. Therefore, if the device is determined to be abnormal, the intake pipe adjustment valve is closed and the transpiration fuel is used. Without engine control. For this reason, when an erroneous diagnosis result is stored that is not abnormal but stored as abnormal, the intake pipe adjustment valve is closed and the vaporized fuel that should be introduced into the intake pipe is not introduced. This will cause unnecessary fuel consumption deterioration.

  Further, when it is determined that the water temperature sensor is abnormal, the value obtained from the water temperature sensor is not used for control, and the engine control is performed using a value (fail safe value) in which the water temperature is fixed at 90 ° C. or the like. In this case, even if the engine control itself can be continuously performed until the sensor is repaired, the fuel injection control cannot be performed properly, and the air-fuel ratio is not stabilized. For this reason, if an erroneous diagnosis result indicating that the water temperature sensor is not abnormal is stored, but the fuel injection control based on the actual water temperature should be possible, the fuel injection control using the fail-safe value is performed. For this reason, the air-fuel ratio is not stable, and unnecessary purification of exhaust gas is caused.

  The present invention has been made paying attention to the above-mentioned problems, and an object of the present invention is to provide an electronic fuel capable of accurately performing a nonvolatile memory writing process and appropriately controlling a vehicle-mounted engine. To provide an injection control device.

  In order to achieve the above object, the present invention provides an electronic control device comprising a writing means for receiving power from a power supply means installed in a hangar equipped with an opening / closing mechanism and writing data to a nonvolatile storage means. When the opening / closing mechanism is opened, the writing means prohibits writing of data into the nonvolatile storage means.

  According to the electronic control device of the first aspect of the present invention, when the opening / closing mechanism provided in the hangar in which the power supply means is installed is opened, the writing means is prohibited from writing data into the nonvolatile storage means. . For this reason, after the opening / closing mechanism is opened, the execution of the write control can be stopped or suspended before the power supply means is operated and the power supply to the electronic control device is interrupted. Therefore, it is possible to prevent the possibility that the diagnosis result originally intended to be written to the nonvolatile storage means is stored differently during the control of writing data to the nonvolatile storage means. Further, unnecessary fuel consumption deterioration and exhaust gas purification failure due to fuel injection control based on an erroneous diagnosis result can be prevented.

  According to the second aspect of the present invention, the writing unit stores the data in a temporary storage unit that is constantly supplied with power from the power source unit when the writing is prohibited.

  According to the second aspect of the present invention, when the writing unit prohibits writing, the latest data that was about to be written, that is, data that is prohibited from being written to the nonvolatile storage unit, is temporarily received from the power source unit. It memorize | stores in a memory | storage means. For this reason, even if the power supply to the electronic control device is terminated after the write is prohibited, the data can be stored in the temporary storage means that receives the power supply independently. Therefore, the latest data created can be used for control without erasing the data created for writing with the termination of power supply to the electronic control unit.

  According to the third aspect of the present invention, the writing unit permits writing of data in the nonvolatile storage unit when the opening / closing mechanism is closed after prohibiting writing of the data.

  According to the third aspect of the present invention, the writing means is configured to permit writing of data to the nonvolatile storage means when detecting closing of the opening / closing mechanism after prohibiting data writing. For this reason, even if the opening / closing mechanism is opened and data writing is prohibited, if the opening / closing mechanism is closed later, data can be written in the nonvolatile storage means. Therefore, data created for writing can be safely written in a state in which the opening / closing mechanism is closed, that is, in a state where there is no possibility that the power supply is shut off.

  According to a fourth aspect of the present invention, the writing unit includes a writing mode for writing data to the nonvolatile storage unit regardless of the open / close state of the opening / closing mechanism.

  The electronic control device according to the fourth aspect of the present invention has a write mode for writing data to the nonvolatile storage means regardless of the open / close state of the open / close mechanism. For this reason, even when the opening / closing mechanism is opened, if there is no fear of power interruption, data can be written to the nonvolatile storage means by setting to this mode. Accordingly, since the electronic control device can be operated by writing the latest data, it is possible to check the latest operation of the electronic control device and the connected device.

  According to the fifth aspect of the present invention, there is provided a battery installed in an engine room having a bonnet, a non-volatile storage means capable of holding data without receiving power supply, and a non-volatile storage means receiving power supply from the battery. In the electronic control device provided with the writing means for writing data to the memory, when the bonnet is opened, the writing means prohibits data writing to the nonvolatile storage means.

  The electronic control device according to the fifth aspect of the invention is configured such that when the bonnet provided in the engine room in which the battery is installed is opened, the writing unit is prohibited from writing data into the nonvolatile storage unit. did. For this reason, after the bonnet is opened, the execution of the write control can be suspended or suspended before the battery is operated and the power supply to the electronic control device is interrupted. Therefore, it is possible to prevent the possibility that the diagnosis result originally intended to be written to the nonvolatile storage means is stored differently during the control of writing data to the nonvolatile storage means. Further, unnecessary fuel consumption deterioration and exhaust gas purification failure due to fuel injection control based on an erroneous diagnosis result can be prevented.

  According to a sixth aspect of the present invention, there is provided an electronic fuel injection control device that operates by receiving power supply from a battery installed in an engine room provided with a bonnet and performs fuel injection control of an engine mounted on a vehicle. A timer for measuring the time after the power supply is stopped, an abnormality diagnosis means for performing abnormality diagnosis of at least one of the fuel transpiration prevention device and the water temperature sensor every predetermined time by the timer, and a diagnosis result of the abnormality diagnosis Non-volatile memory for storing and writing means for writing the diagnostic result to the nonvolatile memory, and the writing means prohibits writing of the diagnostic result to the nonvolatile memory when the hood is opened. It is characterized by that.

  According to the electronic fuel injection control device of the sixth aspect of the present invention, when the bonnet is opened, the storage contents of the nonvolatile memory are prohibited from being written with the diagnosis result of the abnormality diagnosis. For this reason, after the bonnet is opened, the execution of the write control can be stopped or suspended before the battery is operated and the power supply to the electronic fuel injection control device is shut off. Accordingly, it is possible to prevent the possibility that the diagnosis result originally intended to be written in the nonvolatile memory is stored differently during the control of writing data to the nonvolatile memory. Moreover, unnecessary fuel consumption deterioration and exhaust gas purification failure caused by performing fuel injection control of the engine based on an erroneous diagnosis result can be prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 3 is a block diagram showing a configuration example of an ECU to which the present invention is applied.
The ECU 1 performs control necessary for engine control such as fuel injection control, ignition timing control, and idling speed control of the vehicle engine 21. The input / output circuit 9 receives information acquired by the engine 21 or various sensors provided in the vehicle, and transmits a control signal such as a fuel injection time to the engine 21 to each actuator for engine control, and an input The CPU 2 that performs a predetermined calculation based on the obtained information and a memory are provided. The CPU 2 also functions as a writing unit that performs control to write predetermined data of the calculation result into the memory.

  This memory temporarily stores the fuel injection control program executed by the CPU 2, the ROM 5 for storing the program for executing the functions of the present invention, the calculation results of the CPU 2 controlling the fuel injection, etc., and the power supply is cut off. Volatile RAM 6 in which stored data disappears, nonvolatile EEPROM 8 for storing variables necessary for engine control, learning values, vehicle-specific information, and the like, and backup RAM 7.

  The backup RAM 7 is a volatile memory that can hold stored data even when the ignition switch 11 is turned off because it is connected to the battery 13 and is always supplied with power without passing through the ignition switch 11. However, when the battery connector 12 is removed, the power is cut off and the stored data is erased due to its volatile nature. Further, the CPU 2 and these memories are connected by a data bus 10 for inputting / outputting data to / from each other.

  The CPU 2 and the like are connected to the battery 13 via the battery connector 12 and are supplied with power. The battery 13 stably outputs a voltage of 12V to the ECU or the like. In addition, it is installed in an engine room that is closed by a bonnet so that rain, dust, and the like are not attached. Therefore, the battery 13 can be provided in a hangar configured in a vehicle such as a trunk or a dashboard in addition to the engine room. Any place can be used as long as it can be installed in a place having a lid that acts as an opening / closing mechanism, such as a bonnet, so that the lid can be closed to avoid rain and dust, and can be opened to maintain the battery 13. In the present invention, an engine room closed by a bonnet is taken as an example.

  The battery connector 12 is provided between the ECU 1 and the battery 13. By connecting the battery 13, power is supplied to the ECU 1, and when the connection is removed, the power supply is cut off. For this reason, it is possible to reset the CPU 2 and RAM 6 of the ECU 1 by disconnecting the connection. Further, when performing maintenance such as replenishment of battery fluid, it is possible to prevent accidents such as electric shock during work by disconnecting the battery connector 12.

  When the ignition switch 11 is turned on, the power supply circuit 3 is supplied with power from the battery 13 and supplies a stabilized voltage of 5V to each part of the ECU such as the CPU 2. Then, so-called power-on reset control is performed in which a reset signal, which is an activation signal, is transmitted to the CPU 2 when power supply is started. The CPU 2 starts the activation process by receiving this activation signal. Further, the power supply circuit 3 may transmit an activation signal to the CPU 2 by receiving power supply from the soak timer IC even when the ignition switch 11 is off.

  The soak timer IC 4 is connected to the battery 13 and can operate even when the ignition switch 11 is turned off. And the time after substantial operating electric power is no longer supplied to ECU1 is measured. When the preset time is reached, the power of the battery 13 is supplied to the power supply circuit 3. The power supply circuit 3 receives a power supply from the soak timer IC 4 and transmits a signal for starting the CPU 2. The CPU 2 that has received the activation signal from the soak timer IC 4 cannot receive power directly from the battery 13 because the ignition switch 11 is off, and the activation power is also input via the soak timer IC 4. The CPU 2 outputs a holding signal indicating that the CPU 2 is operating during operation to the soak timer IC 4 and stops outputting the holding signal when the control is finished. When the CPU 2 finishes the control, the holding signal to the soak timer IC 4 is interrupted, so the soak timer IC 4 ends the power supply control by detecting the interruption of the holding signal. Thereafter, time measurement is started again.

  The bonnet switch 27 is a switch that detects opening and closing of the bonnet. While the bonnet is closed, the bonnet and the electrodes provided on the vehicle body are short-circuited, so that the current is absorbed by the ground provided on the body side, and no current flows through the input / output circuit 9. When the bonnet is opened, the bonnet switch 27 is disconnected from the ground and energized, whereby a current flows through the input / output circuit 9. Accordingly, the CPU 2 can determine whether the bonnet is opened or closed by detecting the conduction state of the current supplied to the input / output circuit 9. In addition, this switch can detect the opening / closing by applying it to not only the bonnet but also an opening / closing mechanism such as another door or trunk of the vehicle.

  A pressure sensor 15 is disposed in the fuel tank 14. A semiconductor element that reacts to atmospheric pressure is used, and a predetermined voltage is output in accordance with the atmospheric pressure in the fuel tank 14. By measuring this output, the atmospheric pressure in the tank can be detected.

  The fuel tank 14 is provided with a relief valve 16 for releasing the pressure when the pressure exceeds −40 mmHg to 150 mmHg, and is connected to the canister 17 via the communication pipe 20. Therefore, the section from the fuel tank 14 to the canister 17 is always kept below the pressure fluctuation within this relief pressure range. Therefore, it is sufficient to employ a pressure sensor 15 having a structure that can withstand this relief pressure range.

  The canister 17 includes activated carbon and is configured to adsorb the fuel gas evaporated from the fuel tank 14. The adsorbed fuel gas is appropriately introduced into the intake pipe 30 and combusted in the engine 21 by adjusting the opening of the intake pipe adjustment valve 19 according to the operating state of the engine 21. Further, when the adsorption limit is exceeded, the fuel gas may be released to the atmosphere by opening the air blocking valve 18.

  The air blocking valve 18 is an electromagnetic on-off valve that communicates the canister 17 body with the atmosphere. The intake pipe adjusting valve 19 is an electromagnetic on-off valve that is opened when the vaporized gas in the canister 17 is introduced into the intake pipe 30. The communication pipe 20 that connects the fuel tank 14 and the canister 17 and allows the vaporized gas to pass therethrough is formed entirely of a flexible material such as a rubber hose or a nylon hose.

  The external operation tool 28 is connected to the input / output circuit 9 of the ECU 1 and the power supply circuit 3 of the CPU 2 and is connected via the connector 32 when the CPU 2 is to be set in the maintenance mode. The maintenance mode is a mode that is set so that data can be written even when data writing is prohibited. The external operation tool 28 can also read data stored in the backup RAM 7 via the input / output circuit 9 during the operation of the CPU 2.

  The sensor connected to the ECU 1 includes a temperature sensor 24 for detecting the temperature of the radiator liquid and detecting the temperature of the engine 21, a throttle valve opening sensor 22 for detecting the throttle valve angle, and an air-fuel ratio of the exhaust gas. There are various sensors and devices, such as an A / F sensor 26 that performs knocking, a knock sensor 25 that determines whether or not the engine 21 is knocked, and a fuel injection valve 23 that injects fuel into the engine 21 based on the output of the ECU 1. is there.

  The battery 13, the engine 21, the fuel tank 14, and the like are installed in an engine room 31 serving as a storage. The engine room 31 is configured to be closed by a bonnet (not shown) that functions as an opening / closing mechanism.

  FIG. 4 is a flowchart showing a control flow of the soak timer IC4. This control is executed at predetermined time intervals by the soak timer IC 4 measuring time.

  The soak timer IC 4 operates by receiving power supply from the battery 13 even when the ignition switch 11 is off. When the output of the hold signal from the CPU 2 is interrupted, that is, when the end of the operation of the CPU 2 is detected, time measurement is started, and it is determined whether or not the time count has reached 6 hours (step 100). Note that the end of the operation of the CPU 2 may be due to the ignition switch 11 being turned off, or the CPU 2 is activated by the soak timer IC 4, the predetermined processing is terminated, and the CPU 2 ends the operation itself. If the result corresponds to 6 hours later, power is supplied to the power supply circuit 3 (step 110). On the other hand, if the CPU 2 does not correspond after 6 hours from the end of the operation, this flow ends.

  While the power is being supplied, it is determined whether a holding signal is input from the CPU 2 (step 120). If it is determined that the input has been made, power supply to the power supply circuit is continued because the CPU 2 is under control. If it is determined that the holding signal has been interrupted, the supply of power is terminated (step 130). Thereafter, time measurement is started (step 140), and this flow is ended.

  FIG. 5 is a flowchart showing a control flow of the CPU 2 provided in the ECU 1. The processing according to this flowchart is executed when the CPU 2 receives an activation signal via the power supply circuit 3. That is, when the ignition switch 11 is turned on and when the soak timer IC measures a predetermined time.

  When the CPU 2 receives power supply from the soak timer IC 4 via the power supply circuit 3 and receives the activation signal output from the circuit 3, the CPU 2 executes activation processing (step 200). At this time, initialization processing of the RAM 6 and the like is executed. The initialization is controlled according to the flowchart of FIG. When the initialization process is completed, it is detected from the signal of an ignition switch detection circuit (not shown) whether the ignition switch is off (step 205). If the ignition switch is off, the process proceeds to step 210. On the other hand, if the ignition switch is turned on, this flow is terminated and the routine proceeds to normal control (not shown). Therefore, the control from step 210 to step 340 in this flow is executed when the ignition switch is OFF, that is, when the CPU 2 is activated by the soak timer IC4.

Next, the CPU 2 receives a signal from the bonnet switch 27 and determines whether the bonnet is closed, that is, the open / closed state of the bonnet (step 210).
When it is determined that the bonnet is not closed, that is, opened, the termination process is controlled without performing the abnormality diagnosis and the writing process to the EEPROM 8 after step 220 (step 340). That is, when the hood is opened, there is a possibility that the battery 13 may be removed. Therefore, the CPU 2 can be immediately terminated to avoid power interruption during the control process. Even if the control processing is continued, if the battery 13 is removed before the processing result is stored in the EEPROM 8, the processing result up to that point cannot be saved, resulting in useless processing. By immediately ending the CPU 2 as described above, it is possible to prevent wasteful consumption of battery power required for control.

  On the other hand, when it is determined in step 210 that the bonnet is closed, the CPU 2 performs abnormality diagnosis of the transpiration prevention device (step 220). The output value of the pressure sensor 15 is taken in via an input / output circuit. When diagnosing other sensors, the output values of the water temperature sensor 24, the throttle sensor 22, and the A / F sensor 26 are taken in via an input / output circuit. In addition to the sensor, other electronic control devices such as an electronic control device for an electronic control transmission may be subject to abnormality diagnosis.

  If the evaporator is taken as an example, the abnormality diagnosis method is performed as to whether there is an abnormality in the leakage of the vaporized gas from the fuel tank 15 and the canister 17 and the communication pipe 20 connecting the two. First, the intake pipe adjustment valve 19 of the canister 17 is closed, and the air blocking valve 18 is opened so that the inside of the fuel tank 14 and the canister 17 becomes atmospheric pressure. Next, the open air closing valve 18 is closed to seal the fuel tank 19 and the canister 17. The pressure rises according to the amount of fuel gas generated in the fuel tank 14. It is measured for 10 minutes by a timer provided in the CPU 2. A pressure increase rate (P1) for 10 minutes from atmospheric pressure is detected and stored by a pressure sensor 15 provided in the fuel tank 14.

  Next, the intake pipe adjustment valve 19 of the canister 17 is opened, and the atmospheric block valve 18 is closed. In this state, an engine start motor (not shown) is rotated to operate the piston 31 of the engine 21, thereby generating a negative pressure in the intake pipe 30. Since the intake pipe adjusting valve 19 is opened, a negative pressure is generated in the fuel tank 14 and the canister 17. This is detected by a pressure sensor 15 provided in the fuel tank 14, and when a predetermined pressure, for example, −20 mmHg, is reached, the intake pipe adjustment valve 17 is closed to seal the fuel tank 14 and the canister 17. Here, the pressure increase rate (P2) for 10 minutes from the negative pressure state is detected and stored by the pressure sensor 15.

  If the detected pressure increase rates P1 and P2 do not match, it can be determined that there is a possibility that a vaporized gas leakage abnormality has occurred in the evaporator. In other words, if there is an abnormality such as a hole in the evaporator, the rate of increase of P1 that has increased in pressure from the positive pressure state is low because of gas outflow. On the other hand, the increase rate of P2, which has increased in pressure from the negative pressure state, is increased because of the inflow of outside air. Therefore, if there is an abnormality in the evaporator, the outflow of gas or the inflow of outside air occurs and P1 and P2 do not match.

  Note that a sensor such as the water temperature sensor 24 may be an abnormality diagnosis target. In this case, the diagnosis is made by determining whether or not the sensor output value is in a normal range. For example, the water temperature sensor 24 outputs 0.1 V to 5.0 V when it is normal, but if there is no output within this range, it can be diagnosed that there is some abnormality in the sensor. In addition, in order to determine whether the temperature can be detected without abnormality from normal temperature to high temperature, a wide range of water temperature detection may be performed by operating a heater (not shown) and increasing the water temperature. In this case, the water temperature is detected over several tens of minutes due to the heating time by the heater.

  Next, when abnormality diagnosis is performed, it is determined whether or not a predetermined abnormality diagnosis process is completed (step 230). If it is determined that the bonnet is not completed, it is determined again in step 210 whether or not the hood is closed, and the abnormality diagnosis is continued.

  If it is determined that the abnormality diagnosis has been completed, it is determined whether an abnormality has been detected by the diagnosis (step 240). If an abnormality is detected, “1” is set to the evaporator diagnosis flag (step 250). If no abnormality is detected, “0” is similarly set (step 260).

  Next, “1” is set in the write request flag. The fact that 1 is set in this write request flag is an execution condition of control for writing diagnostic data to the EEPROM 8.

  Next, it is determined whether the voltage supplied from the soak timer IC 4 through the power supply circuit 3 is 10 V or more and 12 V or less (step 280). The reason why the voltage applied to the CPU 2 is detected is that about 11V is normally applied during the operation of the CPU 2 and normal operation is possible within a voltage fluctuation range of about + 1V to −1V. However, if the voltage is 10V or less or 12V or more, it is impossible to write data to the EEPROM 8 using an appropriate voltage. Therefore, even if it is stored, the data may be erased immediately, or erroneous data contents are stored in the memory. There is a fear of letting you. For this reason, before the diagnostic data is written into the EEPROM 8, it is determined whether or not the voltage value applied to the CPU 2 is 10V or more and 12V or less.

  If it is determined in step 280 that the voltage is not less than 10 V and not more than 12 V, the process proceeds to step 340 and the program is terminated. Then, the process of this flow is terminated, and the process is started again from step 200 at the next flow start timing.

  If the voltage value is appropriate, the open / close state of the bonnet is determined again (step 290). By making the determination before the writing process to the EEPROM 8, the writing process can be performed while there is no fear that the battery connector 12 is removed, so that erroneous data contents are not written.

  If it is determined that the bonnet is closed, diagnostic data is written into the EEPROM (step 300).

  When the diagnostic data writing process is executed, the write request flag is set to “0” to indicate that the diagnostic data writing process has ended normally (step 320), and the control program end process is performed (step 340). ).

  On the other hand, if it is determined in step 290 that the hood is open, the diagnostic data and the write request flag stored in step 250 or 260 and step 270 are stored in the backup RAM 7 (step 310 and step 330). By this step, the control program end processing is performed without going through the diagnostic data writing processing to the EEPROM 8 in step 300 and the write request flag “0” setting processing in step 320 (step 340).

  As described above, in the present embodiment, when the hood is open, the data writing process is prohibited by avoiding the writing process to the EEPROM 8. Further, since the backup RAM 7 is connected to the battery 13 without passing through the ignition switch 11, data can be retained even when the ignition switch 11 is turned off. For this reason, unless the battery connector 12 is removed, the write request flag remains 1 when the CPU 2 is activated at the next control, so that it is stored in the backup RAM 7 when there is no risk of the battery connector 12 being removed. Diagnostic data can be written to the EEPROM 8.

  According to the embodiment described above, the opening / closing of the hood is determined before the diagnostic data writing process to the EEPROM 8 is executed. If the bonnet is open, the battery connector 12 may be removed by maintenance personnel or the like. Therefore, by prohibiting the writing process of diagnostic data to the EEPROM 8, the connector is disconnected during the writing process. Therefore, it is possible to prevent the EEPROM 8 from being properly stored.

  Further, according to the present embodiment, the opening / closing of the bonnet is determined before or during the execution of the abnormality diagnosis process for the vehicle device or sensor. When the bonnet is opened, the battery connector may be removed by maintenance personnel or the like, and therefore, after the bonnet opening is detected, the program termination process is executed immediately. Thereby, it is possible to prevent the connector from being disconnected during the control process, and to eliminate the consumption of battery power consumed in the control process until the connector is disconnected.

Next, the activation process of the CPU 2 in step 200 will be described with reference to FIG.
First, in step 400, initialization processing is performed. Here, first, a control program is acquired from the ROM 5 and control data is acquired from the EEPROM 8. Subsequently, the input / output circuit 9 is initialized. That is, when an output that turns off each port of the circuit is performed, the contents of the RAM 6 are all cleared to 0 and the initial value of the RAM 6 is set by the control data read from the ROM 5 or the EEPROM 8. As a result, the CPU 2 is provided for arithmetic processing in controlling the engine 21 and the in-vehicle device.

  When the initialization process ends, it is determined whether or not the write request flag is 1 (step 410). In this step, the fact that the write request flag is set to 1 means that the diagnostic data is stored in the backup RAM 7 which is a temporary storage means in steps 310 and 330. That is, in the process when it was previously activated by the soak timer IC4, the diagnostic process of step 240 to step 270 is completed, but the bonnet is opened and the storing process to the EEPROM 8 is not performed, and the diagnostic data is stored and saved in the backup RAM 7. Means the state. Therefore, if the write request flag is 1 in this step, writing to the EEPROM 8 is executed as processing that continues from the previous processing.

  Next, it is determined whether or not the voltage applied to the CPU 2 is 10V or more and 12V or less (step 420). On the other hand, if the flag is 0, that is, if there is no request for writing diagnostic data, the process of this flow ends, and the process proceeds to step 210.

  The reason why the voltage applied to the CPU 2 is detected is that about 11 V is normally applied during the operation of the CPU 2 and normal operation within a voltage fluctuation range of about 1 V above and below is possible. However, if the voltage is lower than 10V or higher than 12V, the storage process cannot be performed using an appropriate voltage for the EEPROM 8, and there is a risk of storing wrong data contents, or the data is immediately stored even if stored. There is a risk of disappearing. Therefore, before the diagnostic data writing process is performed, it is determined whether or not the voltage value applied to the CPU 2 is 10 V or more and 12 V or less.

  If it is determined in step 420 that the voltage is not lower than 10 V and not higher than 12 V, the process of this flow is terminated. If it is determined that the voltage is not lower than 10 V and not higher than 12 V, is the hood closed? It is determined whether or not (step 430). If it is determined that the hood is closed, the diagnostic data stored in the backup RAM 6 in step 440 is written into the EEPROM 8 (step 440). On the other hand, if it is determined that the bonnet is open, the battery connector 12 may be removed, and thus this flow is terminated without writing diagnostic data. As described above, the writing prohibition process is performed by not executing the writing of the diagnostic data in response to the open state of the hood.

  Instead of writing the diagnostic data in the EEPROM 8, the diagnostic data can be transmitted to an abnormality management center outside the vehicle (not shown), a portable terminal of the vehicle owner, or the like by sending it from the input / output circuit 9 to the transmitter 29. Further, it is possible to transmit diagnostic data simultaneously with the writing.

  The diagnostic data written here is read from the EEPROM 8 to the CPU 2. When the CPU 2 reads that the abnormality data is set in the diagnostic data, the CPU 2 turns on a warning lamp (not shown) to warn the driver that an abnormality has occurred in the vehicle device or the like. When the vehicle is transported to a maintenance factory or the like, the contents of the diagnostic data can be referred to by using an external operation tool, so that the diagnostic data can be used for vehicle repair or the like.

  When the writing of diagnostic data to the EEPROM 8 is completed, the write request flag is set to 0 (step 450), and the processing according to this flow is terminated.

  As described above, in the present embodiment, if diagnostic data is stored in the backup RAM 7 in the startup process of the CPU 2, this is written into the EEPROM 8. That is, if the bonnet is opened at the timing after diagnosis of the abnormality and before the diagnosis data is stored, the CPU 2 can be immediately terminated, and sufficient processing time is secured at the next startup to write the diagnosis data to the EEPROM 8. Therefore, the data acquired by the abnormality diagnosis can be used effectively.

  As described above in detail, according to the present invention, when the power supply may be cut off, the diagnostic data writing process is prohibited, so that the power supply is being controlled during the data writing control to the nonvolatile storage means. Therefore, it is possible to prevent the diagnosis result originally written in the nonvolatile storage means from being stored differently.

  In the above embodiment, the case of an electronic control device that performs fuel injection control of the engine has been described as an example. However, the present invention is not limited to a specific embodiment, and other electronic control devices are also described. Can be applied similarly. Further, in the above embodiment, the engine room is shown as the storage place for the power supply device, and the bonnet is shown as the lid, but the invention is not limited to this, and the present invention is applied to other storage places where the power supply device can be installed. May be applied.

  Next, a second embodiment of the present invention will be described with reference to FIG. In addition, in this process, about the step which performs the same process as a 1st embodiment, since the same code | symbol as the 1st embodiment was attached | subjected, the description is abbreviate | omitted. Therefore, only steps different from the first embodiment will be described.

  As shown in FIG. 7, in the control of the startup process of the CPU 2, if it is determined that the hood is open, it is determined whether or not the maintenance mode is set (step 500). The maintenance mode is a mode that is set when data stored in the EEPROM 8 or the backup RAM 7 is read by the external operation tool 28. A vehicle mechanic can read out the stored data to grasp the vehicle state and perform appropriate maintenance.

  When the external operation tool 28 is connected to the connector 32 provided in the input / output circuit 9 of the ECU 1 and a start signal is transmitted to the power supply circuit 3, the CPU 2 performs an initialization process and enters a start state. Here, this mode is set by transmitting a maintenance mode setting command by the external operation tool 28.

  When the maintenance mode is set, since it is premised on the data read from the EEPROM 8 or the like by the maintenance personnel, there is no possibility that the battery will be removed even if the hood is opened. Therefore, in this case, diagnostic data is stored in the EEPROM 8 (step 440). On the other hand, when not in the maintenance mode, the diagnosis data storage process is avoided and the process ends.

  In the second embodiment described above, when the maintenance mode is set, the data temporarily stored in the backup RAM 7 is used to control the writing of diagnostic data to the EEPROM 8 regardless of whether the hood is opened or closed. It can be immediately written to the EEPROM 8. As a result, the latest diagnostic data can be stored and stored even if the battery is removed for vehicle maintenance.

  In addition, although the maintenance mode was demonstrated in the 2nd embodiment, it is also possible to apply this mode with respect to a 1st embodiment. That is, if it is determined in step 290 of FIG. 3 that the hood is open, it is determined whether or not the maintenance mode is set. If it is set, the process proceeds to step 300 and the diagnosis flag is stored in the EEPROM 8. On the other hand, if it is determined that the maintenance mode is not set, the process proceeds to step 310 where the diagnostic flag is stored in the backup RAM. As described above, by applying the maintenance mode to the first embodiment, even if the hood is opened immediately before the storing process of the diagnostic flag, the diagnostic flag is transferred to the EEPROM 8 if the maintenance mode is set. Since it is stored, the latest diagnostic data can be stored and saved even if the battery is removed for vehicle maintenance.

It is a block diagram which shows the prior art example of this invention. It is a figure which shows the prior art example of this invention. It is a block diagram which shows the structural example of ECU to which this invention is applied. It is a flowchart which shows the flow of a process of a soak timer. It is a flowchart which shows the flow of a process of CPU. It is a flowchart which shows the flow of a starting process among the process flows of CPU. It is a flowchart which shows the flow of a process of CPU in a 2nd embodiment.

Explanation of symbols

1 ECU (electronic fuel injection control device)
2 CPU (Central Processing Unit)
3 Power supply circuit 4 Soak timer IC
6 RAM (volatile memory)
7 Backup RAM (volatile memory)
8 EEPROM (nonvolatile memory)
DESCRIPTION OF SYMBOLS 9 Input / output circuit 10 Data bus 11 Ignition switch 12 Battery connector 13 Battery 14 Fuel tank 17 Canister 18 Atmospheric block valve 19 Intake pipe adjustment valve 27 Bonnet switch 28 External operation tool 29 Transmitter 30 Intake pipe 31 Engine room 33 Bonnet 34 Vehicle

Claims (6)

In an electronic control device comprising a writing means for receiving power supply from a power supply means installed in a hangar equipped with an opening / closing mechanism and writing data to a nonvolatile storage means,
The electronic control device according to claim 1, wherein when the opening / closing mechanism is opened, the writing means prohibits writing of data into the nonvolatile storage means.
2. The writing means, when prohibiting the writing, stores data prohibited to be written to the nonvolatile storage means in a temporary storage means that is constantly supplied with power from the power supply means. The electronic control apparatus as described in.
3. The electronic device according to claim 1, wherein the writing unit permits writing of data to the nonvolatile storage unit when the opening / closing mechanism is closed after prohibiting the writing of the data. 4. Control device.
4. The electronic control device according to claim 1, wherein the writing unit includes a writing mode in which data is written to the nonvolatile storage unit regardless of an open / close state of the opening / closing mechanism.
A battery installed in the engine room with a bonnet;
Non-volatile storage means capable of holding data without receiving power supply;
In an electronic control device comprising a writing means for receiving power supply from the battery and writing data to the nonvolatile storage means,
The electronic control device according to claim 1, wherein when the bonnet is opened, the writing means prohibits writing of data into the nonvolatile storage means.
In an electronic fuel injection control device that operates by receiving power supply from a battery installed in an engine room equipped with a bonnet and performs fuel injection control of an engine mounted on a vehicle,
A timer for measuring the time after power supply from the battery is stopped;
An abnormality diagnosis means for performing abnormality diagnosis of at least one of the fuel transpiration prevention device and the water temperature sensor every predetermined time by the timer;
A non-volatile memory for storing a diagnosis result of the abnormality diagnosis;
Writing means for writing the diagnostic result to the nonvolatile memory;
The electronic fuel injection control device according to claim 1, wherein when the bonnet is opened, the writing means prohibits writing of the diagnostic result to the nonvolatile memory.

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