JP4888440B2 - Sensor abnormality diagnosis device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine the presence or absence of anomaly in an engagement/disengagement sensor which detects an engagement/disengagement state of a power transmission passage between an engine side and a wheel side on a vehicle, by using existing sensors provided on the vehicle without adding any new sensor for that purpose. <P>SOLUTION: When a clutch lower switch 18 and a neutral switch 19 are normal while an engine 1 is inertially rotating (at an engine speed of 2,000-4,000 rpm) with an accelerator operation amount of "0" and with the power transmission passage connected between the engine 1 side and the wheel 4 side, both of the switches output an OFF signal (corresponding to a connection state of the power transmission passage). If the switch 18 or 19 continuously outputs an ON signal in such cases, the switch 18 or 19 outputting the ON signal is determined to have an ON anomaly. Then the accelerator operation amount and engine speed used for this determination are detected by the existing sensors provided on the vehicle. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a sensor abnormality diagnosis device.

  In vehicles such as automobiles, the connection / disconnection state of the power transmission path between the engine side and the wheel side where the driving force is adjusted based on the amount of accelerator operation is detected by a clutch or transmission. 2. Description of the Related Art A sensor having a connection / disconnection sensor that outputs a corresponding signal depending on whether it is in a connected state or not is known. For example, in a vehicle that automatically stops and restarts an engine as shown in Patent Document 1, when the engine is automatically stopped and restarted based on the connection / disconnection state of the power transmission path, The connection / disconnection sensor is provided for the purpose of realizing accurate automatic stop / restart of the engine.

By the way, regardless of the actual connection / disconnection state of the power transmission path, the connection / disconnection sensor continues to output a signal corresponding to the disconnection state of the same path or outputs a signal corresponding to the connection state of the same path. There is a possibility of anomalies such as continuing. In order to determine whether or not there is an abnormality in such a connection / disconnection sensor, for example, it is conceivable to provide another connection / disconnection sensor that detects the connection / disconnection state of the power transmission path and outputs a signal corresponding to the connection / disconnection state. In this case, if an abnormality occurs in the connection / disconnection sensor, the signal output from the connection / disconnection sensor and the signal output from the other connection / disconnection sensor do not coincide with each other. It becomes possible to judge.
JP 2000-170568 A (paragraph [0003])

  As described above, by providing another connection / disconnection sensor for recognizing an abnormality, the presence / absence of abnormality in the connection / disconnection sensor can be determined. However, this increases the cost associated with the provision of the other connection / disconnection sensor for recognizing an abnormality, and requires time and labor for installing the other connection / disconnection sensor.

  The present invention has been made in view of such a situation, and the object thereof is to check whether there is an abnormality in the connection sensor for detecting the connection state of the power transmission path between the engine side and the wheel side in the vehicle. Therefore, it is an object of the present invention to provide a sensor abnormality diagnosis apparatus that can perform the above determination using an existing sensor provided in a vehicle without providing a new sensor.

In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, according to the first aspect of the present invention, there is provided an engine side of a vehicle including an accelerator position sensor for detecting an accelerator operation amount used for engine driving force adjustment and a rotation speed sensor for detecting engine rotation speed. Detects the connection / disconnection state of the power transmission path with the wheel side, and diagnoses the abnormality of the connection sensor that outputs a corresponding signal depending on whether the connection / disconnection state is a disconnected state or a connected state. In the sensor abnormality diagnosis device to be performed, when the accelerator operation amount is “0”, the engine rotation speed higher than the idle rotation speed continues for a predetermined time or more, and the connection sensor is connected to the power transmission path during the predetermined time. Based on the fact that the signal corresponding to the shut-off state continues to be output, it comprises a judging means for judging that the connection / disconnection sensor is abnormal, and the predetermined time is Necessary for lowering the engine speed from the maximum value of the engine speed to the idle speed when the engine is blown by increasing the amount of accelerator operation under the condition where the force transmission path is interrupted. The gist is that it is set to a value longer than the set time.

  As a situation where the engine rotation speed becomes higher than the idle rotation speed when the accelerator operation amount is “0”, for example, the following situations [1] and [2] are conceivable. [1] During inertial rotation of the engine with the power transmission path connected between the engine side and the wheel side during vehicle deceleration or the like. [2] When the engine is blown by the accelerator operation of the driver in a state where the power transmission path between the engine side and the wheel side is interrupted. In the situation of [1] above, since the power transmission path is in a connected state, if the connection / disconnection sensor for detecting the connection / disconnection state of the power transmission path is normal, the power transmission path is connected from the sensor. A signal corresponding to the state is output.

  According to the above configuration, it is determined whether or not a signal corresponding to the disconnection state is output from the connection / disconnection sensor under the situation [1] through the determination means, and the above signal is output based on the output of the signal. It is determined that the connection / disconnection sensor is abnormal. Here, the accelerator operation amount and the engine rotation speed used for making such a determination are detected by an accelerator position sensor and a rotation speed sensor provided in a vehicle on which the engine is mounted. Therefore, the determination of the presence / absence of an abnormality in the connection / disconnection sensor for detecting the connection / disconnection state of the power transmission path between the engine side and the wheel side in the vehicle is provided in the vehicle without providing a new sensor. It can be performed using existing sensors such as an accelerator position sensor and a rotation speed sensor.

  According to a second aspect of the present invention, in the first aspect of the present invention, the vehicle includes a clutch pedal operated by a vehicle driver to connect and disconnect a clutch provided on the power transmission path, and the power. A shift lever that is operated by a vehicle driver to switch a transmission provided on the transmission path between a predetermined shift speed and a neutral position. A clutch lower switch that outputs an on signal only when the clutch is in a position for disengaging the clutch, and a neutral switch that outputs an on signal only when the shift lever is in a position for neutralizing the transmission. The determination means has a predetermined engine rotation speed higher than the idle rotation speed when the accelerator operation amount is “0”. The switch that continues to output the ON signal is abnormal on based on the fact that at least one of the clutch lower switch and the neutral switch continues to output the ON signal during the predetermined time. The gist was to judge.

  According to the above configuration, the power transmission path between the engine side and the wheel side is connected / disconnected by the clutch or the transmission. In the situation of [1] above, that is, during inertial rotation of the engine with the power transmission path connected between the engine side and the wheel side when the vehicle is decelerated, the clutch lower switch and the neutral switch are If normal, an off signal that is a signal corresponding to the connection state of the power transmission path is output from the switches. Therefore, it is determined whether or not an ON signal, which is a signal corresponding to the cutoff state of the power transmission path, is output from the clutch lower switch and the neutral switch under the condition [1] through the determination means. Based on the output of the signal, it is determined that the switch outputting the ON signal among the two switches is ON abnormal. As described above, whether or not there is an abnormality in the clutch lower switch and the neutral switch is determined by using existing sensors such as an accelerator position sensor and a rotational speed sensor provided in the vehicle without providing a new sensor. Will be able to.

  According to a third aspect of the present invention, in the second aspect of the present invention, the engine is configured such that an ON signal is output from the neutral switch and an OFF signal is output from the clutch lower switch by the control device. Is automatically stopped based on the establishment of an automatic stop condition including, and is restarted based on the establishment of a restart condition including a condition that an ON signal is output from the clutch lower switch during the automatic stop, The determining means, when it is determined that at least one of the neutral switch and the clutch lower switch is abnormally on, issues a prohibition instruction to prohibit the control device from automatically stopping the engine. It was.

  Since the automatic stop condition and restart condition of the engine include conditions such as an ON signal output from the neutral switch and an ON signal output from the clutch lower switch, if the switch is abnormally turned ON, the control device The engine may be automatically stopped or restarted through The switch on abnormality is an on signal which is a signal corresponding to the cut off state of the power transmission path from the switch even though the power transmission path between the engine side and the wheel side is in a connected state. Is an error that is output. According to the above configuration, when it is determined that at least one of the clutch lower switch and the neutral switch is on abnormally, a prohibition command for prohibiting the automatic stop of the engine is issued to the control device, and the engine Automatic stop is prohibited. Accordingly, the automatic stop of the engine is performed in a state in which the clutch lower switch or the neutral switch is on, so that the automatic stop or restart of the engine can be prevented from being erroneously performed.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the determination means has a duration of the engine speed higher than the idle speed in a state where the accelerator operation amount is "0" for less than a predetermined time, The gist is to determine that the connection / disconnection sensor is abnormal when the connection / disconnection sensor continues to output a signal corresponding to the connection state of the power transmission path during the time less than the predetermined time.

  The situation in which the engine speed is higher than the idle speed when the accelerator operation amount is “0” is the situation [2], that is, the power transmission path between the engine side and the wheel side is interrupted. There is also a situation in which the engine is blown by the driver's accelerator operation in a wet state. In such a situation, the time when the engine speed is higher than the idle speed when the accelerator operation amount is “0” is shorter than the predetermined time used by the judging means, and the connection / disconnection is during that time. If the sensor is normal, a signal corresponding to the cutoff state is output from the sensor.

  According to the above configuration, whether or not a signal corresponding to the connection state is output from the connection / disconnection sensor for a time shorter than the predetermined time under the situation [2] is determined through the determination unit. Based on the output of the signal, it is determined that the connection / disconnection sensor is abnormal. Therefore, in the connection / disconnection sensor, it is possible to determine whether or not an abnormality has occurred so as to continue outputting a signal corresponding to the connection state regardless of the actual connection / disconnection state of the power transmission path without adding a new sensor. it can.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the vehicle includes a clutch pedal operated by a vehicle driver to connect and disconnect a clutch provided on the power transmission path, and the power. A shift lever that is operated by a vehicle driver to switch a transmission provided on the transmission path between a predetermined shift speed and a neutral position. A clutch lower switch that outputs an off signal is provided except when the clutch is in a disengaged position, and the judging means is operated to a position where the shift lever sets the transmission to a predetermined gear position. When the accelerator operation amount is “0” and the engine rotation speed higher than the idle rotation speed is less than a predetermined time, The clutch lower switch during less time when continues to output an OFF signal, and summarized in that determining that the clutch lower switch is off abnormal.

  According to the above configuration, the power transmission path between the engine side and the wheel side is connected / disconnected by the clutch or the transmission. The situation of [2] above, that is, when the engine is blown by the accelerator operation of the driver in a state where the power transmission path between the engine side and the wheel side is interrupted, This occurs when the power transmission path is cut off by the clutch or the transmission. When the engine rotational speed is higher than the idle rotational speed under the situation [2], the high engine rotational speed state is maintained only for a time shorter than the predetermined time. For this reason, when the amount of time that the accelerator is depressed is “0” and the duration of the engine speed higher than the idle speed is less than the predetermined time, in other words, when the engine is idle, When the machine is operated to a position where a predetermined gear position is set, an ON signal is output from the switch if the clutch lower switch is normal. Note that the ON signal here is a signal corresponding to a state in which the clutch pedal is operated to a position where the clutch is disengaged. The determination means is the time when the engine is emptied while the transmission is at a predetermined gear position, and during the time when the engine speed is higher than the idle speed, the clutch lower sensor It is determined whether or not an off signal, which is a signal corresponding to the connected state of the power transmission path (clutch), is output. Then, based on the output of the off signal, it is determined that the clutch lower switch is off abnormally. As described above, it is possible to determine whether or not there is an abnormality in the clutch lower switch.

  According to a sixth aspect of the present invention, in the first or fourth aspect of the present invention, the engine is configured such that a signal corresponding to a cut-off state of the power transmission path is output from the connection sensor by the control device. Of the restart condition including the condition that the automatic stop condition is satisfied based on the establishment of the automatic stop condition including the condition that the automatic stop condition is in progress and a signal corresponding to the cutoff state of the power transmission path is output from the connection / disconnection sensor. The determination means restarts upon establishment, and when the determination means determines that the connection / disconnection sensor is abnormal, the determination means instructs the control device to prohibit the automatic stop of the engine. The summary.

  The engine automatic stop condition and restart condition include a condition of signal output corresponding to the power transmission path interruption state from the connection / disconnection sensor, so if there is an abnormality in the connection / disconnection sensor, There is a possibility that the automatic stop or restart of the engine is erroneously performed through the control device. Note that, as an abnormality of the connection / disconnection sensor, a signal corresponding to the cutoff state of the power transmission path is output from the switch even though the power transmission path between the engine side and the wheel side is in a connected state. Can be given. According to the above configuration, when it is determined that the connection / disconnection sensor is abnormal, a prohibition instruction is issued to prohibit the automatic stop of the engine from the control device, and the automatic stop of the engine through the device is prohibited. Become. Therefore, it is possible to avoid the automatic stop and restart of the engine from being erroneously performed by automatically stopping the engine in a state where the connection sensor is abnormal.

[First Embodiment]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is embodied in a sensor abnormality diagnosis device for an automobile in which an engine is automatically stopped and restarted will be described with reference to FIGS.

  In the automobile shown in FIG. 1, an engine 1 whose driving force is adjusted through an operation of an accelerator pedal 7 by a driver is mounted as a power source. The driving force of the engine 1 is adjusted so as to increase as the operation amount (accelerator operation amount) of the accelerator pedal 7 is increased from “0”, and from the output shaft 1a of the engine 1 to the clutch 2 and the gear shift. It is transmitted to the wheel 4 via the machine 3 or the like.

  The clutch 2 changes between the disconnected state and the connected state through the operation of the clutch pedal 5 by the driver, thereby connecting and disconnecting the power transmission path between the engine 1 side and the wheel 4 side. 1 is connected to the output shaft 1a of the transmission 3 and the input shaft 3a of the transmission 3. The clutch 2 operates so that the power transmission path is cut off (clutch disconnection) when the driver depresses the clutch pedal 5, and the power transmission path is connected when the depression of the clutch pedal 5 is released. Operates to make a state (clutch engagement).

  The transmission 3 has a plurality of shift stages having different speed ratios, which are ratios of rotational speeds between the engine 1 side and the wheel 4 side, and shifts by a shift operation of the shift lever 6 by the driver. The gear ratio is made variable by operating so as to switch the gears. The transmission 3 can be switched to a neutral state in which the power transmission path between the engine 1 side and the wheel 4 side is cut off, as well as the shift speed. Is switched to the neutral state by switching to the neutral position. Therefore, when the shift lever 6 is operated to a position corresponding to a predetermined shift stage and the transmission 3 is switched to the same shift stage, the power transmission path between the engine 1 side and the wheel 4 side is connected, When the position of the shift lever 6 is switched to the neutral position and the transmission 3 is in the neutral state, the power transmission path is cut off.

  In addition, a starter 8 is connected to the output shaft 1a of the engine 1 to forcibly rotate (crank) the engine 1 so that the engine 1 can be operated independently when starting the operation of the engine 1 in a stopped state. Further, the output shaft 1 a of the engine 1 is also connected to various auxiliary machines 9 such as an air conditioner compressor, and an alternator 11 that generates power for charging the battery 10.

  The alternator 11 is electrically connected to the battery 10 through the power control unit 12 and is controlled to operate through the unit 12. When power is generated by the alternator 11 based on the rotation of the output shaft 1 a of the engine 1, the generated AC electricity is converted to DC electricity through the power control unit 12 and stored in the battery 10. At this time, the power generation amount is adjusted by adjusting the voltage applied to the exciting coil of the rotor of the alternator 11 through the power control unit 12. By generating electricity by such an alternator 11, power is supplied to various electric devices 13 mounted on the automobile. In other words, the various electric devices 13 of the automobile are supplied with power from the alternator 11 and power from the battery 10 through the power control unit 12, and the various electric devices 13 are driven based on the power supply.

  An automobile is equipped with an electronic control unit 14 that performs various controls such as operation control of the engine 1. The electronic control unit 14 includes a CPU that executes arithmetic processing related to the above-described various controls, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores arithmetic results of the CPU, and an external interface. The input / output port for inputting / outputting the signal is provided.

Various sensors shown below are connected to the input port of the electronic control unit 14.
An accelerator position sensor 15 that detects the amount of operation of the accelerator pedal 7 (accelerator operation amount).

A rotational speed sensor 16 that outputs a signal associated with the rotation of the output shaft 1a of the engine 1 and is used to detect the engine rotational speed.
A vehicle speed sensor 17 that detects the vehicle speed based on the rotation of the output shaft 3b of the transmission 3 or the like.

  -Outputs an on signal when the clutch pedal 5 is depressed to bring the clutch 2 into the disconnected state, and outputs an off signal when the clutch pedal 5 is released to bring the clutch 2 into the engaged state. Clutch lower switch 18 to perform.

  -An ON signal is output when the shift lever 6 is being operated neutrally so that the transmission 3 is in the neutral state, and the shift lever 6 is in a position corresponding to the same gear to switch the transmission 3 to a predetermined gear. A neutral switch 19 that outputs an off signal when operated.

  The clutch lower switch 18 and the neutral switch 19 detect the connection / disconnection state of the power transmission path between the engine 1 side and the wheel 4 side of the automobile, and whether the connection / disconnection state is a disconnection state or a connection state. As a connection / disconnection sensor that outputs a signal corresponding to each of them, it is provided in an automobile.

  In addition to the power control unit 12 being connected to the output port of the electronic control unit 14, drive circuits for various devices such as a fuel injection valve and a spark plug for operating the engine 1, a starter 8, an auxiliary machine 9, and A drive circuit such as the electric device 13 is connected.

  Then, the electronic control unit 14 grasps the driving state of the automobile and the engine 1 based on the detection signals input from the various sensors, and sends command signals to various driving circuits connected to the output port according to the grasped driving state. Is output. In this way, various controls such as operation control of the engine 1 and drive control of the starter 8, the auxiliary machine 9, the alternator 11, and the electric device 13 are performed through the electronic control unit 14.

Next, connection / disconnection of the power transmission path between the engine 1 side and the wheel 4 side related to the traveling of the automobile will be described.
When starting the engine 1 in a stopped state, the shift lever 6 is operated to the neutral position to set the transmission 3 to the neutral state, and the clutch pedal 5 is depressed to bring the clutch 2 to the disconnected state. The power transmission path between the four sides is turned off. After the power transmission path is cut off as described above, the engine 1 is forcibly rotated by driving the starter 8, and the self-sustained operation of the engine 1 is started. Thus, even if the engine 1 starts a self-sustaining operation, the driving force of the engine 1 is not transmitted to the wheel 4 side because the power transmission path is cut off by the clutch 2 and the transmission 3. .

  After the self-sustained operation of the engine 1 is started, the shift lever 6 is operated to a position corresponding to a predetermined shift stage to switch the transmission 3 to the shift stage and release the depression of the clutch pedal 5 to connect the power transmission path. As a result, the driving force on the engine 1 side is transmitted to the wheel 4 side, and the vehicle travels. When the vehicle is accelerating, the driving force of the engine 1 is adjusted to a value corresponding to the accelerator operation amount, and the driving force is transmitted to the wheels 4 via the clutch 2, the transmission 3, etc. Is self-propelled. Further, when the vehicle is coasting, the accelerator operation amount is set to “0” and the driving force of the engine 1 is set to the minimum value. In this state, the frictional force between the road surface and the wheels 4 is the driving force. Is transmitted to the engine 1 through the transmission 3, the clutch 2, and the like, and the engine 1 rotates by inertia.

  Depending on the driver of the automobile, the power transmission path between the engine 1 side and the wheel 4 side may be cut off, and the accelerator pedal 7 may be operated in that state to rapidly increase the engine rotation speed. There is a case of performing an occultation. As shown in FIG. 2 (a), the engine 1 is operated in the neutral state by operating the shift lever 6 in the neutral state while the vehicle speed is "0", or the clutch pedal 5 This is realized by stepping on and releasing the clutch 2 and then depressing and releasing the accelerator pedal 7 in a short time under these conditions.

  That is, when the accelerator pedal 7 is depressed / released, as shown in FIG. 2B, the accelerator operation amount rapidly increases from “0” and then returns to “0”. According to the change in the amount, the driving force of the engine 1 suddenly increases from the value corresponding to the idle operation and then returns to the value corresponding to the idle operation. As a result, as shown in FIG. 2 (c), the engine rotation speed when the engine 1 is idling rapidly increases from the idle rotation speed to the maximum value, and then rapidly decreases to the idle rotation speed. Will show the movement. Incidentally, when the engine 1 is idle, the time Tr is required as shown in FIG. 2 in order to reduce the engine rotation speed from the maximum value of the engine rotation speed to the idle rotation speed.

Next, automatic stop / restart of the engine 1 shown in FIG. 1 will be described.
The automatic stop / restart of the engine 1 is performed for the purpose of improving the fuel consumption of the engine 1, and the operation of the engine 1 is automatically performed when there is no output request of the engine 1 such as a driving request of an automobile. This is realized by restarting the engine 1 during the automatic stop and before the output request of the engine 1 is made.

  Here, examples of the automatic stop condition that is an execution condition of the automatic stop in the engine 1 include those shown in the following (a) to (e), and all of these conditions (a) to (e) are mentioned. When established, the automatic stop condition is established, and the engine 1 is automatically stopped based thereon.

(A) The vehicle speed is “0”.
(B) The output request of the engine 1 is made due to a shortage of the charge amount of the battery 10, an increase in the drive load of the engine 1 due to the drive of the electric device 13, and an increase in the drive load of the engine 1 due to the drive of the auxiliary machine 9. Not that.

(C) The accelerator operation amount is “0”, in other words, there is no request for driving the automobile by the driver.
(D) It can be determined that the transmission 3 is in the neutral state and the power transmission path between the engine 1 side and the wheel 4 side is in the cutoff state, for example, an ON signal is output from the neutral switch 19.

  (E) The depression of the clutch pedal 5 is not performed, and it can be determined that the driver does not intend to drive the vehicle, for example, an off signal is output from the clutch lower switch 18.

  On the other hand, examples of the restart condition that is the restart execution condition of the engine 1 that is automatically stopped include those shown in the following (f) and (g), and each of these (f) and (g) The restart condition is satisfied when any one of the conditions is satisfied, and the engine 1 is restarted based on the restart condition.

  (F) It can be determined that the transmission 3 is in the neutral state and the depression of the clutch pedal 5 has been performed, for example, an ON signal is output from the neutral switch 19 and an ON signal is output from the clutch lower switch 18 .

  (G) An ON signal is output from at least one of the neutral switch 19 and the clutch lower switch 18, and in this state, the amount of charge of the battery 10 is insufficient, the driving load of the engine 1 increases due to driving of the electric device 13, and An output request of the engine 1 caused by an increase in driving load of the engine 1 accompanying the driving of the auxiliary machine 9 is made.

  Incidentally, the connection / disconnection sensors such as the clutch lower switch 18 and the neutral switch 19 are connected to the on signal, that is, the power transmission path between the engine 1 side and the wheel 4 side regardless of the position of the clutch pedal 5 or the position of the shift lever 6. There is a possibility that an abnormality such as continuing to output a signal corresponding to the interruption state (hereinafter referred to as an ON abnormality) may occur. When trying to determine the presence or absence of an abnormality with such a connection / disconnection sensor, a separate connection / disconnection sensor is provided to duplicate the same sensor, and the presence / absence of an abnormality is determined based on whether there is a difference in the output signals from both. It is possible.

  For example, regarding the clutch lower switch 18, a clutch lower switch different from the switch 18 may be provided, and it may be determined that an abnormality has occurred in the clutch lower switch 18 based on a difference in output signals from the switches. Is possible. Further, with respect to the neutral switch 19, a neutral switch different from the switch 19 is provided, and it is possible to determine that an abnormality has occurred in the neutral switch 19 based on the difference in the output signals from these switches. . However, as described above, providing another connection / disconnection sensor to identify the presence / absence of an abnormality in the connection / disconnection sensor increases the cost associated with it and also takes time and labor for installing the other connection / disconnection sensor. It becomes like this.

  Therefore, in the present embodiment, the accelerator position sensor 15 and the rotational speed sensor 16 that are provided for use in the operation control of the engine 1 in an automobile equipped with the engine 1 are used, and the accelerator operation detected by the sensors 15 and 16 is used. The occurrence of ON abnormality in the connection / disconnection sensor is determined based on the amount and the engine speed. Thus, it is necessary to provide a new sensor for the determination by determining occurrence of abnormality in the connection / disconnection sensor using the existing sensors such as the accelerator position sensor 15 and the rotation speed sensor 16 provided in the automobile. This eliminates the cost increase associated with the provision of the sensor and saves the labor required for installing the sensor.

  FIG. 3 showing an on-abnormality diagnosis routine for the procedure for determining the occurrence of an on-abnormality in the connection / disconnection sensor in this embodiment, that is, the procedure for determining the occurrence of an on-abnormality in the clutch lower switch 18 and the neutral switch 19 This will be described with reference to the flowchart of FIG. This on-abnormality generation routine is periodically executed through a time interrupt every predetermined time T (for example, every 16 ms) through the electronic control unit 14.

  In this routine, first, whether or not the engine rotation speed is a value within a determination range (for example, 2000 to 4000 rpm) determined as a range higher than the idle rotation speed (S101 in FIG. 3), the accelerator operation amount is “0”. Is determined (S102). Here, the situations shown in the following [1] and [2] can be considered as the situations in which affirmative determination is made in step S101 and step S102.

  [1] During inertial rotation of the engine 1 with the power transmission path connected between the engine 1 side and the wheel 4 side during deceleration of the automobile or the like. [2] When the engine 1 is blown by the driver's accelerator operation in a state where the power transmission path between the engine 1 side and the wheel 4 side is interrupted. In the situation [1], since the power transmission path is in the connected state, if the clutch lower switch 18 and the neutral switch 19 for detecting the connection / disconnection state of the power transmission path are normal, they are Both switches 18 and 19 output a signal (off signal) corresponding to the connection state.

  Subsequently, processing (S104 to S108) for determining whether or not the neutral switch 19 is turned on is performed. In this series of processing, it is first determined whether or not an ON signal is output from the neutral switch 19 (S104). If the determination is affirmative, the counter C1 is incremented by "1" (S105). The counter C1 represents the time during which the ON signal is continuously output from the neutral switch 19 in the state where the accelerator operation amount is “0” and the engine rotation speed is within the above-described determination range (2000 to 4000 rpm). Is. When the counter C1 becomes equal to or greater than the predetermined value a (S106: YES), it is determined that the neutral switch 19 is abnormally on (S107).

  With respect to the predetermined value “a”, the allowance α is greater than the time Tr (FIG. 2) required to reduce the engine rotation speed from the maximum value to the idle rotation speed when the engine 1 is idled. Is set to a value corresponding to a longer time (Tr + α). Specifically, the predetermined value a is set to a value {(Tr + α) / T} obtained by dividing the time (Tr + α) by a time T that is a time interval in which the ON abnormality occurrence routine is executed. Therefore, when the counter C1 is equal to or greater than the predetermined value a, the accelerator operation amount “0” indicates that the engine rotation speed is a value within the determination range (2000 to 4000 rpm). It means that the situation is [1]. Incidentally, the allowance α used for setting the predetermined value a means that when the counter C1 becomes equal to or larger than the predetermined value a as described above, it is in the situation [1] above. Thus, an optimum value determined in advance through experiments or the like is employed. Under the condition [1], if the neutral switch 19 is normal, an off signal is output from the switch 19 as described above. Therefore, when the ON signal continues to be output from the neutral switch 19 for the time corresponding to the predetermined value a under the condition [1], an ON abnormality has occurred in the switch 19. In the on-abnormality diagnosis routine, it is determined that an on-abnormality has occurred in the neutral switch 19 at this time through the processing of steps S106 and S107.

  As for the counter C1, when it is determined that an ON abnormality has occurred in the neutral switch 19 (after S107), and before the determination is made, an off signal is output from the neutral switch 19 (S104). : NO), the initial value is reset to “0” (S108). Further, when the engine speed changes outside the determination range (2000 to 4000 rpm) before the above determination is made (S101: NO), and when the accelerator operation amount is larger than “0” (S102: NO) ), The counter C1 is reset to the initial value “0” (S103).

  After the processing of the above steps S104 to S108, that is, the processing for determining whether or not the neutral switch 19 is turned on has been performed, it is determined whether or not the clutch lower switch 18 has been turned on. The process (S109-S113 of FIG. 4) for performing is performed. In this series of processing, it is first determined whether or not an ON signal is output from the clutch lower switch 18 (S109). If the determination is affirmative, the counter C2 is incremented by "1" (S110). The counter C2 indicates the time during which the ON signal is continuously output from the clutch lower switch 18 in the state where the accelerator operation amount is “0” and the engine speed is within the above-described determination range (2000 to 4000 rpm). It represents. When the counter C2 becomes equal to or greater than the predetermined value a (S111: YES), it is determined that the clutch lower switch 18 is abnormally on (S112).

  Since the predetermined value a is set to the above-described value {(Tr + α) / T}, that the counter C2 is equal to or greater than the predetermined value a means that the accelerator operation amount is “0” and the engine speed is within the above-described determination range (2000 It means that it is the situation of [1] among the situations of the above [1] and [2] which become a value within .about.4000 rpm). Under the condition [1], if the clutch lower switch 18 is normal, an off signal is output from the switch 18 as described above. Therefore, when the ON signal is continuously output from the clutch lower switch 18 for the time corresponding to the predetermined value a under the condition [1], the ON abnormality has occurred in the switch 18. In the on-abnormality diagnosis routine, it is determined that an on-abnormality has occurred in the clutch lower switch 18 at such a time through the processing of steps S111 and S112.

  As for the counter C2, when it is determined that an ON abnormality has occurred in the clutch lower switch 18 (after S112), and when the OFF signal is output from the clutch lower switch 18 before the determination is made. (S109: NO), the initial value is reset to “0” (S113). In addition, when the engine speed changes outside the determination range (2000-4000 rpm) before the above determination is made (S101: NO in FIG. 3), and when the accelerator operation amount becomes larger than “0” ( Also in S102: NO), the counter C2 is reset to the initial value “0” (S103).

  Here, if an ON abnormality has occurred in the clutch lower switch 18 and the neutral switch 19, the automatic stop / restart may be erroneously performed in the engine 1 that is automatically stopped / restarted. This is an execution condition for restarting the engine 1 during the automatic stop, in which the automatic stop condition that is an execution condition for the automatic stop of the engine 1 includes the condition (d) related to the ON signal of the neutral switch 19. This is because the restart conditions include the above conditions (f) and (g) related to the ON signals of the clutch lower switch 18 and the neutral switch 19. In order to avoid the above-described problem that the automatic stop / restart of the engine 1 is erroneously performed, in this embodiment, when it is determined that at least one of the clutch lower switch 18 and the neutral switch 19 is on abnormally, the engine 1 The automatic stop of 1 is prohibited.

  FIG. 5 is a flowchart showing an automatic stop prohibiting routine for prohibiting the automatic stop of the engine 1. This automatic stop prohibition routine is periodically executed through a time interrupt such as every 16 ms through the electronic control unit 14. In this routine, it is determined whether or not the neutral switch 19 is abnormally turned on in step S201, and whether or not the clutch lower switch 18 is abnormally turned on is determined in step S202. If a negative determination is made in both step S201 and step S202, that is, if neither the neutral switch 19 nor the clutch lower switch 18 is abnormally on, automatic stop of the engine 1 is permitted (S204). In addition, when a negative determination is made in either step S201 or step S202, that is, when either the neutral switch 19 or the clutch lower switch 18 is abnormal on, the automatic stop of the engine 1 is prohibited. For this reason, an automatic stop of the engine 1 is prohibited through the electronic control unit 14 (S203).

  Finally, the abnormality diagnosis of the connection / disconnection sensors such as the clutch lower switch 18 and the neutral switch 19 will be summarized with reference to the time chart of FIG. In the figure, (a) to (g) are vehicle speed, accelerator operation amount, engine rotation speed, neutral switch 19 output signal, clutch lower switch 18 output signal, counter C1, and switches 18, 19 respectively. It shows changes over time about the presence or absence of abnormalities.

  When the vehicle starts to travel, the clutch pedal 5 is depressed to disengage the clutch 2, and the output signal from the clutch lower switch 18 changes from an off signal to an on signal as shown in FIG. 6 (e). (Timing T1). Further, the shift lever 6 is operated from the neutral position to a position corresponding to a predetermined gear position to switch the transmission 3 to the gear position. At that time, an output signal from the neutral switch 19 is shown in FIG. Thus, the on signal changes to the off signal (timing T2). Thereafter, by releasing the depression of the clutch pedal 5 while depressing the accelerator pedal 7, the clutch 2 is switched from the disconnected state to the connected state while increasing the driving force of the engine 1. Is transmitted. As a result, the vehicle starts to travel. Further, at this time, as shown in FIG. 6 (b), the accelerator operation amount increases from “0”, and accordingly, the driving force of the engine 1 increases and the engine rotation speed is shown in FIG. 6 (c). As shown in FIG. 6E, the output signal from the clutch lower switch 18 is switched from the on signal to the off signal (timing T3).

  When the vehicle is running and the power transmission path between the engine 1 side and the wheel 4 side is in the connected state, the depression of the accelerator pedal 7 is released and the accelerator operation amount becomes “0” (timing T4). When the driving force of the engine 1 decreases to a value corresponding to idle operation, the frictional force between the road surface and the wheels 4 is transmitted to the engine 1 side as the driving force, and the engine 1 rotates inertially. As a result, the engine rotation speed and the vehicle speed gradually decrease as shown in FIG. 6C and FIG. 6A, respectively. As a result, the engine speed increases due to the decrease speed in the process of decrease. Therefore, with respect to the time during which the engine rotational speed that decreases as described above is within the determination range (2000 to 4000 rpm), the engine rotational speed is reduced in the process of decreasing the engine rotational speed that has increased due to the engine 1 being blown away. It becomes longer than the time existing within the determination range. In other words, the time that the engine rotational speed that falls is within the above-described determination range is longer than the same time when the engine 1 is vacated, indicating that the engine rotational speed is determined by the accelerator operation amount “0”. The situation of being within the range means that the situation occurred due to the situation of [1] above.

  In the situation [1], since the power transmission path is in the connected state, if the clutch lower switch 18 and the neutral switch 19 for detecting the connection / disconnection state of the power transmission path are normal, the switches 18 , 19 output an off signal (a signal corresponding to the connection state of the power transmission path) as indicated by a solid line in FIGS. 6 (e) and 6 (d). Here, for example, if an ON abnormality has occurred in the neutral switch 19, an ON signal is output from the switch 19 as shown by a two-dot chain line in FIG. 6 (d). In this case, when the engine speed is within the determination range (timing T5) and within the determination range, the counter C1 shown in FIG. It is counted up every time interval (time T) in which the routine is executed. When the ON signal continues to be output from the neutral switch 19 until the counter C1 becomes equal to or greater than the predetermined value a, the ON signal is output from the neutral switch 19 for the time corresponding to the predetermined value a under the condition [1]. Based on this, it is determined that an ON abnormality has occurred in the switch 19 (timing T6 in FIG. 6G).

According to the embodiment described in detail above, the following effects can be obtained.
(1) In the situation of [1] above, that is, during inertial rotation of the engine 1 with the accelerator operation amount “0” and the power transmission path between the engine 1 side and the wheel 4 side connected, If the switch 18 and the neutral switch 19 are normal, an off signal is output from both the switches 18 and 19. In such a case, the time during which the engine speed is in the determination range (2000 to 4000 rpm) is equal to or longer than the time corresponding to the predetermined value a, and during that time, the clutch lower switch 18 and the neutral switch 19 output an ON signal. In the case of continuing, it is determined that an ON abnormality has occurred in the switch that outputs the ON signal. The accelerator operation amount and the engine rotation speed used for making such a determination are detected by the accelerator position sensor 15 and the rotation speed sensor 16 provided in the vehicle on which the engine 1 is mounted. Therefore, existing sensors such as the accelerator position sensor 15 and the rotational speed sensor 16 provided in the automobile are used for determining whether the clutch lower switch 18 and the neutral switch 19 are on or not, without providing new sensors. Can be done. For this reason, while suppressing the cost increase accompanying providing the said new sensor, the effort which the installation operation | work of the sensor, etc. require can be saved.

  (2) When it is determined that at least one of the clutch lower switch 18 and the neutral switch 19 is on abnormally, the automatic stop of the engine 1 is prohibited. For this reason, the engine 1 is not automatically stopped when the switches 18 and 19 are abnormally turned on, and the engine 1 is automatically stopped by executing the automatic stop of the engine 1 in such a state. And restarting can be avoided.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In this embodiment, in addition to the first embodiment, the presence / absence of an abnormality (hereinafter referred to as “off abnormality”) in which the connection / disconnection sensor continues to output a signal corresponding to the connection state (off signal) is also determined. . Specifically, in the present embodiment, it is determined whether or not there is an off abnormality in which the clutch lower switch 18 continues to output a signal (off signal) corresponding to the engaged state (clutch engagement). Note that when it is determined that an off abnormality has occurred in the clutch lower switch 18, as in the case where it is determined in the first embodiment that the neutral switch 19 or the clutch lower switch 18 has an on abnormality, the engine 1 It is preferable to prohibit automatic stop.

  FIG. 7 is a flowchart showing a clutch lower switch off abnormality diagnosis routine for determining whether or not the clutch lower switch 18 has an off abnormality. This clutch lower switch-off abnormality diagnosis routine is periodically executed through a time interrupt every predetermined time T through the electronic control unit 14.

  In this routine, first, it is determined whether or not the engine speed is a value within the determination range (2000 to 4000 rpm) (S301) and whether or not the accelerator operation amount is “0” (S302). Here, as the situation in which affirmative determination is made in both step S301 and step S302, the situation shown in [1] and [2] described above can be considered. In the situation [2], that is, when the engine 1 is idle, the time during which the engine rotational speed is within the determination range in the process of decreasing the engine rotational speed is from the time corresponding to the predetermined value a. Will also be shorter. If the transmission 3 is not in the neutral state and the clutch lower switch 18 is normal during the time when the engine speed is within the above-described determination range due to the idling of the engine 1, the switch 18 is turned on. The signal will continue to be output.

Subsequently, processing (S303 to S311) for determining whether or not the clutch lower switch 18 is off abnormally is executed.
In this series of processes, it is determined whether an off signal is output from the clutch lower switch 18 on the condition that the transmission 3 is not in the neutral state (S303: YES) (S304). Regarding the determination that the transmission 3 is not in the neutral state in step S303, for example, there is no abnormality in the neutral switch 19 and an off signal is output from the neutral switch 19, in other words, a shift lever This is based on the fact that 6 is other than neutral and is operated to a position corresponding to a predetermined gear position. If it is determined in step S304 that an off signal is output from the clutch lower switch 18, the flag F is set to "1" (S305), and then the counter C3 is incremented by "1". (S306).

  The flag F can continue to output a signal (off signal) corresponding to the clutch engagement in the state where the transmission 3 is not in the neutral state despite the engine 1 being idle. This is for determining whether or not there is a possibility that the clutch lower switch 18 has an off abnormality. As described above, the flag F is set to “1 (possibility of off abnormality)” based on the positive determination in step S304. In addition, the counter C3 is a clutch lower when the accelerator operation amount is “0” and the engine speed is within the above-described determination range (2000 to 4000 rpm) and the transmission 3 is not in the neutral state. This represents the time during which the OFF signal is continuously output from the switch 18.

  On the other hand, in the above-described series of processing (S303 to S311), when the engine speed is not within the determination range (2000 to 4000 rpm) (S301: NO), the flag F is set to “1 (possibility of off abnormality)”. It is determined whether it is set (S307). The affirmative determination here means that the accelerator operation amount is “0”, the engine speed is within the above-described determination range, and the clutch lower switch 18 is operated under the condition that the transmission 3 is not in the neutral state. This means that the engine rotation speed has deviated from the determination range to the lower side in the state where the off signal has been output from the engine.

  If an affirmative determination is made in step S307, it is determined whether or not the counter C3 is greater than the initial value “0” and less than the predetermined value a (S308). Here, the affirmative determination means that the time when the accelerator operation amount is “0” and the engine rotation speed is within the above-described determination range is the same as that in the above-mentioned situation [1], that is, the vehicle This means that it is shorter than the same time during inertial rotation of the engine 1 during deceleration traveling or the like. Therefore, the situation where the accelerator operation amount is “0” and the engine rotational speed becomes a value within the determination range (2000 to 4000 rpm) is the situation [2] among the situations [1] and [2], that is, the engine. It was caused by 1 sky. In addition, the affirmative determination in step S308 means that the engine speed is within the determination range due to the idling of the engine 1 (a time shorter than the time corresponding to the predetermined value a). During this time, it also means that the clutch lower switch 18 continued to output an off signal (a signal corresponding to the clutch engagement). Therefore, if an affirmative determination is made in step S308, it is determined that the clutch lower switch 18 is off abnormally based on the determination (S309).

  The counter C3 is reset to the initial value “0” (after S309) after it is determined that the clutch lower switch 18 has an off abnormality (S309), and the flag F has an off abnormality in the clutch lower switch 18. Is determined to occur (after S309), it is set to "0" (S311). The resetting of the counter C3 to the initial value “0” (S310) and the setting of the flag F to “0” (S311) are also executed in the following situation.

When the accelerator pedal 7 is depressed by the driver and the accelerator operation amount is no longer “0” (S302: NO).
When the shift lever 6 is operated to neutral by the driver and the transmission 3 is switched to the neutral state (S303: NO).

When an ON signal (signal corresponding to clutch disengagement) is output from the clutch lower switch 18 (S304: NO).
-All conditions that the accelerator operation amount is "0" and the engine speed is within the above-mentioned determination range and that the transmission 3 is not turned off from the clutch lower switch 18 under the condition that the transmission 3 is not in the neutral state. When there is no opportunity to be established at the same time and the flag F remains “0” (S307: NO).

  -It is caused by the situation of [1] above that the engine speed becomes a value within the determination range (2000-4000 rpm) when the accelerator operation amount is "0", and the counter C3 exceeds the predetermined value a. When (S308: NO).

  Next, the determination of the presence / absence of the off abnormality in the clutch lower switch 18 will be summarized with reference to the time chart of FIG. In the figure, (a) to (g) are vehicle speed, accelerator operation amount, engine speed, neutral switch 19 output signal, clutch lower switch 18 output signal, counter C3, and clutch lower switch 18 respectively. The change with time about the presence or absence of off abnormality is shown.

  When the transmission 3 is in a state other than the neutral state, that is, when the engine 1 is idled while being switched to a predetermined gear position, the clutch pedal 5 is depressed and the clutch 2 is disengaged. At the same time, the shift lever 6 is operated to a position corresponding to the gear position. As a result, the neutral switch 19 outputs an off signal as shown in FIG. 8 (d), and the clutch lower switch 18 outputs an on signal as shown by a solid line in FIG. 8 (e). . In this state, the accelerator pedal 7 is depressed such that the accelerator operation amount is rapidly increased from “0” and then returned to “0” as shown in FIG. 8B. At this time, since the power transmission path between the engine 1 side and the wheel 4 side is cut off by the clutch 2, the driving force is adjusted in the engine 1 whose driving force is adjusted in accordance with the change in the accelerator operation amount. Increases rapidly from a value corresponding to idle operation, and then decreases to a value corresponding to idle operation. As a result, the vehicle speed remains “0” as shown in FIG. 8 (a), and the engine rotational speed temporarily increases rapidly from the idle rotational speed as shown in FIG. 8 (c) to the maximum value. After that, so-called idling of the engine 1 is carried out, in which the engine speed rapidly decreases to the idle rotation speed.

  In the process of lowering the engine speed during the engine break, that is, the process of lowering the engine speed in the situation [2], the engine speed is reduced in the situation [1]. Compared to the same time when the speed decreases, it becomes faster. For this reason, in the process of decreasing the engine speed in the idling of the engine 1, the time during which the engine speed is within the determination range (2000 to 4000 rpm) is determined under the condition [1]. Since the speed is shorter than the time existing in the determination range, the speed is shorter than the time corresponding to the predetermined value a. Further, in the process of lowering the engine speed during the idling of the engine 1, if the clutch lower switch 18 is normal when the transmission 3 is not in the neutral state, the switch 18 is shown by a solid line in FIG. As shown, an ON signal (a signal corresponding to the clutch disengagement) is output.

  Here, if an off abnormality has occurred in the clutch lower switch 18, an off signal is output from the switch 18 as shown by a two-dot chain line in FIG. 8 (e). In this case, the counter C3 shown in FIG. 8 (f) is turned off from the clutch lower switch 18 while the engine rotation speed is within the determination range from when the engine rotation speed enters the determination rotation speed (timing T7). Is counted up from the initial value “0” at each time interval (time T) in which the clutch lower switch-off abnormality diagnosis routine is executed. When the engine speed deviates from the determination range (timing T8) and the counter C3 is less than the predetermined value a, the time corresponding to the predetermined value a under the condition [2] above. For a shorter period of time, the clutch lower switch 18 continues to output the off signal. Based on this, it is determined that the clutch lower switch 18 has an off abnormality (timing T8 in FIG. 8G).

According to the embodiment described in detail above, the following effects can be obtained.
(3) In the situation [2] above, that is, when the engine 1 is blown away, the power transmission path between the engine 1 side and the wheel 4 side is interrupted by the clutch 2 or the transmission 3. Occurs when in a state. Under the condition [2] above, the time during which the engine speed is within the determination range is shorter than the time corresponding to the predetermined value a. Therefore, when the accelerator depression amount is “0” and the engine speed is within the determination range is shorter than the time corresponding to the predetermined value “a”, the engine 1 is blown. It is possible to determine that the situation described in [2] is present. When the transmission of the engine 1 is performed, if the transmission 3 is not in a neutral state, in other words, if the shift lever 6 is operated to a position where the transmission 3 is set to a predetermined gear position, the clutch lower If the switch 18 is normal, an ON signal (signal corresponding to the clutch disengagement) is output from the switch 18. Therefore, when the transmission 3 is in a state where the transmission 3 is set to the predetermined gear position, the time during which the engine speed is within the determination range (the time corresponding to the predetermined value a) It is determined that the clutch lower switch 18 is abnormally off based on the fact that the OFF signal continues to be output from the clutch lower switch 18 for a shorter time. As described above, it can be determined whether or not the clutch lower switch 18 is turned off. It should be noted that the determination of whether or not the clutch lower switch 18 has an off abnormality is also made by using existing sensors such as the accelerator position sensor 15 and the rotation speed sensor 16 provided in the automobile without providing a new sensor. Can do. For this reason, while suppressing the cost increase accompanying providing the said new sensor, the effort which the installation operation | work of the sensor, etc. require can be saved.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS.
In this embodiment, a clutch upper switch 20 shown in FIG. 9 is provided as a connection / disconnection sensor in addition to the clutch lower switch 18 and the neutral switch 19 of the first embodiment. The clutch upper switch 20 is in a state where the power transmission path between the engine 1 side and the wheel 4 side is cut off with respect to the electronic control unit 14 when the clutch pedal 5 is depressed so as to put the clutch 2 into a cut-off state. A signal (off signal) corresponding to (clutch disengagement) is output. Further, when the clutch pedal 5 is released to bring the clutch 2 into the engaged state, the clutch upper switch 20 sends a signal (ON) to the electronic control unit 14 corresponding to the connection state (clutch engagement) of the power transmission path. Signal).

  In this embodiment, the clutch upper switch 20 has an on abnormality that continues to output an on signal regardless of whether the clutch pedal 5 is depressed, and an off abnormality that continues to output an off signal regardless of whether the clutch pedal 5 is depressed. It is determined whether or not the clutch upper switch 20 is abnormal. Note that when it is determined that the clutch upper switch 20 has an off abnormality or an on abnormality, as in the case where it is determined that the neutral switch 19 or the clutch lower switch 18 is on abnormal in the first embodiment, It is preferable to prohibit the automatic stop of the engine 1.

  FIG. 10 and FIG. 11 are flowcharts showing a clutch upper switch abnormality diagnosis routine for determining whether or not an off abnormality or an on abnormality has occurred in the clutch upper switch 20. This clutch upper switch abnormality diagnosis routine is periodically executed through a time interrupt every predetermined time T through the electronic control unit 14.

  In this routine, first, it is determined whether or not the engine speed is within a determination range (2000 to 4000 rpm) (S401 in FIG. 10) and whether or not the accelerator operation amount is “0” (S402). The Here, as the situation in which affirmative determination is made in both step S401 and step S402, the situations shown in [1] and [2] described above can be considered.

  In the situation [1], that is, during inertial rotation of the engine 1 with the power transmission path connected, the power transmission path is in the connected state. If the clutch upper switch 20 that detects the state is normal, an ON signal is output from the switch 20. Further, in the situation [2] above, that is, when the engine 1 is idle, the time during which the engine rotational speed is within the determination range in the process of decreasing the engine rotational speed is from the time corresponding to the predetermined value a. Will also be shorter. If the transmission 3 is not in the neutral state and the clutch upper switch 20 is normal during the time that the engine speed is within the above-described determination range due to the idling of the engine 1, the switch 20 is turned off. The signal will continue to be output.

  Subsequently, processing (S403 to S408 in FIG. 11) for determining whether or not an abnormality of the clutch upper switch 20 has occurred is executed. In this series of processing, it is determined whether or not the transmission 3 is not in a neutral state (S403) and whether or not an off signal is output from the clutch upper switch 20 (S404). If both the determinations in steps S403 and 404 are affirmative, the counter C4 is incremented by "1" (S405). The counter C4 indicates that the accelerator operation amount is “0” and the engine rotation speed is within the above-described determination range (2000 to 4000 rpm), and the time during which the OFF signal is continuously output from the clutch upper switch 20 in this state. It represents. When the counter C4 becomes equal to or greater than the predetermined value a (S406), it is determined that the clutch upper switch 20 is off abnormally (S407).

  Since the predetermined value a is set to the above-described value {(Tr + α) / T}, the fact that the counter C4 is equal to or larger than the predetermined value a can be affirmative in both steps S401 and S402 in FIG. ] And [2] means that the situation is [1]. Under the condition [1], if the clutch upper switch 20 is normal, an ON signal is output from the switch 20 as described above. Therefore, when the OFF signal is continuously output from the clutch upper switch 20 for the time corresponding to the predetermined value a under the condition [1], an OFF abnormality has occurred in the switch 20. In the clutch upper switch abnormality diagnosis routine, it is determined through the processes in steps S406 and S407 that the clutch upper switch 20 has an off abnormality at such a time.

The counter C4 is reset to the initial value “0” in the following situation.
After it is determined that the clutch upper switch 20 is off abnormally (after S407 in FIG. 11).

When an ON signal is output from the clutch upper switch 20 before the above determination is made (S404: NO)
When the engine speed changes outside the determination range (2000 to 4000 rpm) (S401 in FIG. 10: NO).

When the accelerator pedal 7 is depressed by the driver and the accelerator operation amount becomes larger than “0” (S402: NO).
When the shift lever 6 is operated to neutral by the driver and the transmission 3 is switched from the predetermined gear position to the neutral state (S403 in FIG. 11: NO).

When an ON signal is output from the clutch upper switch 20 (S404: NO).
In the clutch upper switch abnormality diagnosis routine, processing (S411 to S415) for determining whether or not the clutch upper switch 20 is turned on is also executed. In this series of processing, the flag F is set to “1” on condition that the transmission 3 is not in the neutral state (S403: YES) and the ON signal is output from the clutch upper switch 20 (S404: NO). Then, the counter C5 is incremented by “1” (S412).

  The flag F indicates that the clutch upper switch 20 has output a signal corresponding to the clutch engagement (ON signal) under the condition that the transmission 3 is not in the neutral state, even when the engine 1 is idle. This is for determining whether or not there is a possibility that an ON abnormality has occurred in the clutch upper switch 20. As described above, the flag F is set to “1 (possibility of ON abnormality)” based on the negative determination in step S404. Further, the counter C5 is a clutch upper in a situation where the accelerator operation amount is “0” and the engine rotation speed is within the above-described determination range (2000 to 4000 rpm) and the transmission 3 is not in the neutral state. This represents the time during which the ON signal is continuously output from the switch 20.

  In the above series of processing (S411 to S415), when the engine speed is not within the determination range (2000 to 4000 rpm) (S401: NO in FIG. 10), the flag F is “1 (possibility of ON abnormality)”. Is determined (S413 in FIG. 11). Here, the affirmative determination means that the accelerator operation amount is “0”, the engine speed is within the above determination range, and the clutch upper switch 20 is in a state where the transmission 3 is not in the neutral state. Means that the engine speed has deviated from the determination range to the lower side.

  If an affirmative determination is made in step S413, it is determined whether or not the counter C5 is greater than the initial value “0” and less than the predetermined value a (S414). Here, the affirmative determination means that the time when the accelerator operation amount is “0” and the engine rotation speed is within the above-described determination range is the same as that in the above-mentioned situation [1], that is, the vehicle This means that it is shorter than the same time during inertial rotation of the engine 1 during deceleration traveling or the like. Therefore, a situation where the accelerator operation amount is “0” and the engine rotational speed becomes a value within the above-described determination range (2000 to 4000 rpm) (a situation where both the determination in steps S401 and S402 in FIG. 10 are affirmative) is the above [1]. And [2], that is, the situation of [2], that is, caused by the engine 1 being blown away. In addition, the affirmative determination is made in step S414 in FIG. 11 means that the engine speed is within the above-described determination range due to the idling of the engine 1 (shorter than the time corresponding to the predetermined value a). This also means that the ON signal (the signal corresponding to the clutch engagement) has been continuously output from the clutch upper switch 20 during the time). Therefore, if an affirmative determination is made in step S414, it is determined that the clutch upper switch 20 is abnormally on based on the determination (S415).

  The counter C5 is reset to the initial value “0” (S416) after it is determined that an ON abnormality has occurred in the clutch upper switch 20 (after S415), and the flag F has an ON abnormality in the clutch upper switch 20. Is determined to occur (after S415), it is set to “0” (S417). The resetting of the counter C5 to the initial value “0” (S416) and the setting of the flag F to “0” (S417) are also executed in the following situation.

When the accelerator pedal 7 is depressed by the driver and the accelerator operation amount is no longer “0” (S402 in FIG. 10: NO).
When the shift lever 6 is operated to neutral by the driver and the transmission 3 is switched from the predetermined gear position to the neutral state (S403 in FIG. 11: NO).

  ・ All the conditions that the accelerator operation amount is “0” and the engine rotation speed is within the above-described determination range, the transmission 3 is not in the neutral state, and the ON signal is output from the clutch upper switch 20 are satisfied simultaneously. When the flag F remains “0” (S413: NO).

  The situation where the engine speed becomes a value within the determination range (2000 to 4000 rpm) when the accelerator operation amount is “0” (a situation in which affirmative determination is made in all steps S401 to S403) is caused by the situation [1] above. Has occurred and the counter C5 is greater than or equal to the predetermined value a (S414: NO).

  Further, when an off signal (a signal corresponding to the clutch disengagement) is output from the clutch upper switch 20 (S404: YES), the counter C5 is reset to the initial value “0” (S409), and the flag F “ Setting to “0” (S410) is performed.

  Next, the determination of whether or not the clutch upper switch 20 is off will be described in detail with reference to the time chart of FIG. In the figure, (a) to (g) are vehicle speed, accelerator operation amount, engine rotation speed, neutral switch 19 output signal, clutch upper switch 20 output signal, counter C4, and clutch upper switch 20 respectively. The change with time about the presence or absence of off abnormality is shown.

  When the vehicle starts to run, the clutch pedal 5 is depressed to disengage the clutch 2, and the output signal from the clutch upper switch 20 changes from an on signal to an off signal as shown in FIG. 12 (d). (Timing T9). Further, the shift lever 6 is operated from the neutral position to a position corresponding to a predetermined gear position to switch the transmission 3 to the gear position. At that time, an output signal from the neutral switch 19 is shown in FIG. Thus, the on signal changes to the off signal (timing T10). Thereafter, by releasing the depression of the clutch pedal 5 while depressing the accelerator pedal 7, the clutch 2 is switched from the disconnected state to the connected state while increasing the driving force of the engine 1. Is transmitted. As a result, the vehicle starts to travel. At this time, as shown in FIG. 12B, the accelerator operation amount increases from “0”, and accordingly, the driving force of the engine 1 increases and the engine speed is shown in FIG. 12C. As shown in FIG. 12E, the output signal from the clutch upper switch 20 is switched from the off signal to the on signal (timing T11).

  When the vehicle is running and the power transmission path between the engine 1 side and the wheel 4 side is connected, the depression of the accelerator pedal 7 is released and the accelerator operation amount becomes “0” (timing T12). When the driving force of the engine 1 decreases to a value equivalent to idle operation, the frictional force between the road surface and the wheels 4 is transmitted to the engine 1 side as the driving force, and the engine 1 rotates inertially. As a result, the engine speed and the vehicle speed gradually decrease as shown in FIG. 12C and FIG. 12A, respectively, and the engine speed decreases at this time. As a result, the engine speed increases due to the decrease speed in the process of decrease. Therefore, with respect to the time during which the engine rotational speed that decreases as described above is within the determination range (2000 to 4000 rpm), the engine rotational speed is reduced in the process of decreasing the engine rotational speed that has increased due to the engine 1 being blown away. It becomes longer than the time existing within the determination range. In other words, the time that the engine rotational speed that falls is within the above-described determination range is longer than the same time when the engine 1 is emptied. This means that the power transmission path to the side is in a connected state, that is, the situation [1].

  In the situation [1], since the power transmission path is in the connected state, if the clutch upper switch 20 that detects the connection / disconnection state of the power transmission path is normal, the switch 20 starts from FIG. An ON signal (a signal corresponding to the clutch engagement) is output as indicated by a solid line in (e). Here, if an off abnormality has occurred in the clutch upper switch 20, an off signal is output from the switch 20 as shown by a two-dot chain line in FIG. In this case, the counter C4 shown in FIG. 12F changes from the initial value “0” to the clutch upper switch while the engine speed is within the determination range from the time when the engine rotation speed enters the determination range (timing T13). It is counted up every time interval (time T) in which the abnormality diagnosis routine is executed. If the off signal is continuously output from the clutch upper switch 20 until the counter C4 becomes equal to or greater than the predetermined value a, the off signal is output from the clutch upper switch 20 for the time corresponding to the predetermined value a under the situation [1]. Is output, and based on this, it is determined that the switch 20 has an off-state abnormality (timing T14 in FIG. 12G).

  Next, the determination of the presence or absence of ON abnormality in the clutch upper switch 20 will be described in detail with reference to the time chart of FIG. In the figure, (a) to (g) are vehicle speed, accelerator operation amount, engine rotation speed, neutral switch 19 output signal, clutch upper switch 20 output signal, counter C5, and clutch upper switch 20 respectively. The change with time about the presence or absence of ON abnormality is shown.

  When the transmission 3 is in a state other than the neutral state, that is, when the engine 1 is idled while being switched to a predetermined gear position, the clutch pedal 5 is depressed and the clutch 2 is disengaged. At the same time, the shift lever 6 is operated to a position corresponding to the gear position. As a result, an off signal is output from the neutral switch 19 as shown in FIG. 13 (d), and an off signal is output from the clutch upper switch 20 as shown by a solid line in FIG. 13 (e). . In this state, the accelerator pedal 7 is depressed such that the accelerator operation amount is rapidly increased from “0” and then returned to “0” as shown in FIG. At this time, since the power transmission path between the engine 1 side and the wheel 4 side is cut off by the clutch 2, the driving force is adjusted in the engine 1 whose driving force is adjusted in accordance with the change in the accelerator operation amount. Increases rapidly from a value corresponding to idle operation, and then decreases to a value corresponding to idle operation. As a result, the vehicle speed remains “0” as shown in FIG. 13 (a), and the engine rotational speed temporarily increases rapidly from the idle rotational speed as shown in FIG. 13 (c) to the maximum value. After that, so-called idling of the engine 1 is carried out, in which the engine speed rapidly decreases to the idle rotation speed.

  In the process of lowering the engine speed during the engine break, that is, the process of lowering the engine speed in the situation [2], the engine speed is reduced in the situation [1]. Compared to a similar decrease rate when the speed decreases, it becomes faster. For this reason, in the process of decreasing the engine speed in the idling of the engine 1, the time during which the engine speed is within the determination range (2000 to 4000 rpm) is determined under the condition [1]. Since the speed is shorter than the time existing in the determination range, the speed is shorter than the time corresponding to the predetermined value a. In addition, if the clutch upper switch 20 is normal when the transmission 3 is not in the neutral state in the process of lowering the engine speed during the idling of the engine 1, the solid line shown in FIG. The off signal (the signal corresponding to the clutch disengagement) is output as shown in FIG.

  Here, if an ON abnormality has occurred in the clutch upper switch 20, an ON signal is output from the switch 20 as shown by a two-dot chain line in FIG. In this case, the counter C5 shown in FIG. 13 (f) is turned on from the clutch upper switch 20 while the engine rotational speed is within the determination range from when the engine rotational speed enters the determination rotational speed (timing T15). Is counted up from the initial value “0” at every time interval (time T) in which the clutch upper switch abnormality diagnosis routine is executed. When the engine speed deviates to the lower side with respect to the determination range (timing T16), when the counter C3 is less than the predetermined value a, the time corresponding to the predetermined value a under the condition [2] above. For a shorter time, the off signal is continuously output from the clutch upper switch 20. Based on this, it is determined that an ON abnormality has occurred in the clutch upper switch 20 (timing T16 in FIG. 13G).

According to the embodiment described in detail above, the following effects can be obtained.
(4) In the situation of [1] above, that is, during inertial rotation of the engine 1 with the accelerator operation amount “0” and the power transmission path between the engine 1 side and the wheel 4 side connected, If the switch 20 is normal, an ON signal is output from the switch 20. Accordingly, the time during which the accelerator operation amount is “0” and the engine rotational speed is in the determination range (2000 to 4000 rpm) is equal to or longer than the time corresponding to the predetermined value a, and during that time, an off signal is output from the clutch upper switch 20. Based on what has been continued, it is determined that the switch 20 has an off abnormality. The accelerator operation amount and the engine rotation speed used for making such a determination are detected by the accelerator position sensor 15 and the rotation speed sensor 16 provided in the vehicle on which the engine 1 is mounted. Therefore, it is possible to determine whether the clutch upper switch 20 is off or not using existing sensors such as the accelerator position sensor 15 and the rotation speed sensor 16 provided in the automobile without providing a new sensor. it can. For this reason, while suppressing the cost increase accompanying providing the said new sensor, the effort which the installation operation | work of the sensor, etc. require can be saved.

  (5) In the situation [2] above, that is, when the engine 1 is blown, the power transmission path between the engine 1 side and the wheel 4 side is interrupted by the clutch 2 or the transmission 3. Occurs when in a state. Under the condition [2] above, the time during which the engine speed is within the determination range is shorter than the time corresponding to the predetermined value a. Therefore, when the accelerator depression amount is “0” and the engine speed is within the determination range is shorter than the time corresponding to the predetermined value “a”, the engine 1 is blown. It is possible to determine that the situation described in [2] is present. When the transmission of the engine 1 is performed, if the transmission 3 is not in a neutral state, in other words, if the shift lever 6 is operated to a position where the transmission 3 is set to a predetermined gear position, the clutch upper If the switch 20 is normal, an off signal (a signal corresponding to the clutch disengagement) is output from the switch 20. Therefore, when the transmission 3 is in a state where the transmission 3 is set to the predetermined gear position, the time during which the engine speed is within the determination range (the time corresponding to the predetermined value a) Based on the fact that the ON signal continues to be output from the clutch upper switch 20 for a shorter time), it is determined that the clutch upper switch 20 is ON abnormal. As described above, it is possible to determine whether or not the clutch upper switch 20 is on abnormally. It should be noted that the determination of whether or not the clutch upper switch 20 is turned on is also made using existing sensors such as the accelerator position sensor 15 and the rotation speed sensor 16 provided in the automobile without providing a new sensor. Can do. For this reason, while suppressing the cost increase accompanying providing the said new sensor, the effort which the installation operation | work of the sensor, etc. require can be saved.

[Other Embodiments]
In addition, each said embodiment can also be changed as follows, for example.
-You may apply this invention to the motor vehicle by which the engine in which automatic stop and restart are not performed is mounted.

  -Although the range of 2000-4000 rpm which is a rotational speed range higher than an idle rotational speed was illustrated as a determination range, the other range higher than an idle rotational speed may be employ | adopted.

  A determination may be made as to whether or not there is an off abnormality in which the neutral switch 19 continues to output an off signal regardless of the operation position of the shift lever 6. In this case, it is possible to apply the method of determining whether or not there is an off abnormality in the clutch lower switch 18 in the second embodiment. That is, if the clutch 2 is in the connected state and the neutral switch 19 is normal during the time when the engine speed is within the determination range (2000 to 4000 rpm) due to the idling of the engine 1, the switch 19 From the fact that the ON signal continues to be output from, it is determined whether or not the neutral switch 19 has an OFF abnormality. Specifically, the time during which the accelerator operation amount is “0” and the engine rotational speed is within the determination range is shorter than the time corresponding to the predetermined value a, and the clutch 2 is in the engaged state during that time. On the basis of the fact that the neutral switch 19 continues to output the OFF signal, it is determined that an OFF abnormality has occurred in the switch 19. As described above, it is possible to determine whether or not the neutral switch 19 is off. It should be noted that the determination of the presence / absence of an off abnormality in the neutral switch 19 can also be performed using existing sensors such as the accelerator position sensor 15 and the rotation speed sensor 16 provided in the automobile without providing a new sensor. it can. For this reason, while suppressing the cost increase accompanying providing the said new sensor, the effort which the installation operation | work of the sensor, etc. require can be saved.

  The present invention may be applied to an automobile equipped with an automatic transmission instead of the transmission 3. In such a car, the clutch 2, the clutch pedal 5, the clutch lower switch 18, the clutch upper switch 20, and the like are not provided, and an ON signal is output only when the shift lever 6 is switched to the neutral state in which the automatic transmission is in the neutral state. A neutral switch 19 is provided. Then, the presence or absence of an abnormality such as an ON abnormality or an OFF abnormality of the neutral switch 19 is determined using an existing sensor without providing a new sensor.

  The determination of whether or not the clutch lower switch 18 is off abnormally in the second embodiment and the determination of whether or not the clutch upper switch 20 is on abnormal and off abnormal in the third embodiment may be performed. .

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows schematic structure of the motor vehicle to which the sensor abnormality diagnosis apparatus of 1st Embodiment is applied. (A)-(c) is a time chart which shows transition of the vehicle speed, accelerator operation amount, and engine speed when engine idling is performed. The flowchart which shows the procedure which judges the presence or absence of ON abnormality of a clutch lower switch and a neutral switch. The flowchart which shows the procedure which judges the presence or absence of ON abnormality of a clutch lower switch and a neutral switch. The flowchart which shows the procedure which prohibits an engine automatic stop. (A) to (g) are vehicle speed, accelerator operation amount, engine rotation speed, neutral switch output signal, clutch lower switch output signal, counter C1, and abnormality of each of the above switches from the start to the stop of the vehicle. The time chart which shows the change about the presence or absence of. The flowchart which shows the procedure which judges the presence or absence of the OFF abnormality of the clutch lower switch in 2nd Embodiment. (A) to (g) are vehicle speed, accelerator operation amount, engine rotation speed, neutral switch output signal, clutch lower switch output signal, counter C3, and off of the clutch lower switch when the engine is idling. The time chart which shows the change about the presence or absence of abnormality. The schematic diagram which shows the clutch upper switch of 3rd Embodiment. The flowchart which shows the procedure which judges the presence or absence of ON abnormality of a clutch upper switch, and OFF abnormality. The flowchart which shows the procedure which judges the presence or absence of ON abnormality of a clutch upper switch, and OFF abnormality. (A) to (g) are vehicle speed, accelerator operation amount, engine rotation speed, neutral switch output signal, clutch upper switch output signal, counter C4, and clutch upper switch OFF from the start to the stop of the vehicle. The time chart which shows a change about the presence or absence of abnormality. (A) to (g) are vehicle speed, accelerator operation amount, engine rotation speed, neutral switch output signal, clutch upper switch output signal, counter C5, and clutch upper switch on abnormality during engine idling The time chart which shows the change about the presence or absence of.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 1a ... Output shaft, 2 ... Clutch, 3 ... Transmission, 3a ... Input shaft, 3b ... Output shaft, 4 ... Wheel, 5 ... Clutch pedal, 6 ... Shift lever, 7 ... Accelerator pedal, 8 ... Starter , 9 ... Auxiliary machine, 10 ... Battery, 11 ... Alternator, 12 ... Power control unit, 13 ... Electric equipment, 14 ... Electronic control device (determination means), 15 ... Accelerator position sensor, 16 ... Rotational speed sensor, 17 ... Vehicle speed Sensor 18 ... Clutch lower switch 19 ... Neutral switch 20 ... Clutch upper switch

Claims (6)

Detects the connection / disconnection state of the power transmission path between the engine side and the wheel side of the vehicle including an accelerator position sensor for detecting an accelerator operation amount used for engine driving force adjustment and a rotation speed sensor for detecting engine rotation speed. In the sensor abnormality diagnosis device that performs abnormality diagnosis of the connection sensor that outputs a signal corresponding to each connection state according to whether the connection state is a cutoff state or a connection state,
In the state where the accelerator operation amount is “0”, the engine rotation speed higher than the idle rotation speed continues for a predetermined time or more. During the predetermined time, the connection / disconnection sensor outputs a signal corresponding to the cut-off state of the power transmission path. Based on the fact that it continues to output, it has a judging means for judging that the connection / disconnection sensor is abnormal,
The predetermined time is the same as the engine rotation speed from the maximum value of the engine rotation speed to the idle rotation speed when the engine is blown by an increase in the amount of accelerator operation with the power transmission path cut off. A sensor abnormality diagnosis device characterized in that it is set to a value longer than the time required for speed reduction. The vehicle includes a clutch pedal operated by a vehicle driver to connect and disconnect a clutch provided on the power transmission path, and a transmission provided on the power transmission path with a predetermined gear position and a neutral position. And a shift lever operated by a vehicle driver to switch between
The connection / disconnection sensor includes a clutch lower switch that outputs an ON signal only when the clutch pedal is in a position for disengaging the clutch, and ON only when the shift lever is in a position for setting the transmission to neutral. And a neutral switch that outputs a signal.
The determination means has an engine rotation speed higher than an idle rotation speed in a state where the accelerator operation amount is “0” for at least the predetermined time, and at least of the clutch lower switch and the neutral switch during the predetermined time. The sensor abnormality diagnosis device according to claim 1, wherein one of the switches that continues to output the ON signal determines that the switch that continues to output the ON signal is ON abnormal. The engine is automatically stopped by the control device based on the establishment of an automatic stop condition including a condition that an ON signal is output from the neutral switch and an OFF signal is output from the clutch lower switch. And restarted based on the establishment of a restart condition including a condition that an ON signal is output from the clutch lower switch.
The determination means, when determining that at least one of the neutral switch and the clutch lower switch is on abnormal, makes a prohibition instruction for prohibiting the automatic stop of the engine to the control device. 2. The sensor abnormality diagnosis device according to 2. In the state where the accelerator operation amount is “0”, the determination means has a duration of engine rotation speed higher than the idle rotation speed for less than a predetermined time, and the connection sensor transmits the power transmission during the time less than the predetermined time. The sensor abnormality diagnosis device according to claim 1, wherein when the signal corresponding to the connection state of the path is continuously output, it is determined that the connection / disconnection sensor is abnormal. The vehicle includes a clutch pedal operated by a vehicle driver to connect and disconnect a clutch provided on the power transmission path, and a transmission provided on the power transmission path with a predetermined gear position and a neutral position. And a shift lever operated by a vehicle driver to switch between
As the connection / disconnection sensor, a clutch lower switch that outputs an off signal is provided except when the clutch pedal is in a position for disengaging the clutch,
The determination means has a predetermined period of time during which the engine rotation speed is higher than the idle rotation speed when the shift lever is operated to a position where the transmission is set to a predetermined gear position and the accelerator operation amount is “0”. The sensor abnormality diagnosis device according to claim 4, wherein when the clutch lower switch continues to output an off signal during a time less than the predetermined time, the clutch lower switch is judged to be off abnormally. The engine is automatically stopped by the control device based on the establishment of an automatic stop condition including a condition that a signal corresponding to the cutoff state of the power transmission path is output from the connection / disconnection sensor. And is restarted based on the establishment of a restart condition including a condition that a signal corresponding to the cutoff state of the power transmission path is output from the connection / disconnection sensor,
5. The sensor abnormality diagnosis device according to claim 1, wherein when the determination unit determines that the connection / disconnection sensor is abnormal, the control unit issues a prohibition instruction to prohibit the automatic stop of the engine.

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