JP2012189162A - Failure diagnosis control device of oil temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a determination of a failure diagnosis, without requiring a travel condition, by making the travel condition of limiting the performing timing for determining the possibility of performing the diagnosis unimportant, in a failure diagnosis control device of an oil temperature sensor.SOLUTION: A control means (12) determines failure of the oil temperature sensor (10), by storing the oil temperature detected by the oil temperature sensor (10) as the stopping oil temperature when stopping operation of an internal combustion engine (3), storing the water temperature detected by a water temperature sensor (5) as the stopping water temperature, storing the oil temperature detected by the oil temperature sensor (10) as the starting oil temperature when starting the internal combustion engine (3), storing the water temperature detected by the water temperature sensor (5) as the starting water temperature, calculating a difference between the stored stopping oil temperature and the starting oil temperature, and comparing this difference with a determining value determined under a predetermined condition based on the stored any water temperature.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil temperature sensor failure diagnosis control device, and more particularly to an oil temperature sensor for detecting a failure of an oil temperature sensor for detecting a temperature of hydraulic oil used in a power transmission mechanism such as a transmission used in a power train of a vehicle. The present invention relates to a failure diagnosis control device for a temperature sensor.

The vehicle includes an oil temperature sensor for detecting the temperature of hydraulic oil used in a power transmission mechanism such as a transmission used in the power train, and a failure diagnosis control for diagnosing the failure of the oil temperature sensor. Equipment.
In such an oil temperature sensor failure diagnosis control device, a stack having an oil temperature of 20 ° C. or less (state in which the output signal is fixed to a certain value) is detected, and the driving condition is satisfied by a predetermined accelerator opening condition or the like. When the oil temperature has not changed over a predetermined time, it is determined that the stack has failed.

Japanese Patent No. 3189701 Japanese Patent No. 4072199 Japanese Patent No. 4459965 JP 2010-15182 A JP 2010-116994 A JP 2006-177412 A JP 2008-25468 A

An abnormality determination device for a temperature sensor for a vehicle according to Patent Document 1 measures an elapsed time in which the temperature of a drive system part of the vehicle is continuously included in a predetermined temperature region, and the measured elapsed time reaches the predetermined temperature. In this case, it is determined that the temperature sensor is abnormal.
In the automatic transmission failure diagnosis apparatus according to Patent Document 2, when it is determined that the shift position is other than the travel range position and the voltage value of the oil temperature signal is equal to or lower than the set value, the timer reaches the set time. In such a case, a failure of the oil temperature sensor and its warning are performed.
The oil temperature sensor defect detection method for an automatic transmission according to Patent Document 3 detects the oil temperature of the automatic transmission, accurately determines other failures due to the oil temperature sensor defect, and is estimated in each operation mode of the vehicle. The oil temperature is used to calculate the alternative oil temperature at the time of sensor failure to reduce the shift control.
The hydraulic oil temperature sensor abnormality determination device according to Patent Document 4 determines that the oil temperature sensor is abnormal when the difference between the water temperature of the internal combustion engine and the oil temperature of the transmission is equal to or greater than a threshold value.
In the control device and the control method according to Patent Document 5, when the difference between the water temperature of the internal combustion engine and the oil temperature of the transmission is equal to or less than a third threshold value that is smaller than the first predetermined value, the oil temperature sensor is temporarily abnormal. When the determination is made and this temporary abnormality is determined a predetermined number of times or more, it is determined that the oil temperature sensor is this abnormality.
An oil temperature sensor failure detection device for an automatic transmission according to Patent Document 6 determines a failure of an oil temperature sensor by changing a predetermined traveling time of a vehicle according to an oil temperature when the engine is started. is there.
The temperature sensor failure determination device according to Patent Document 7 determines that a temperature sensor failure occurs after a certain period of time has elapsed after the engine is stopped when the engine is stopped after being operated and the failure determination condition is satisfied. Is.

However, since the oil temperature sensor failure is detected conventionally using the oil temperature rise, the failure detection in the region where the oil temperature is saturated (for example, detection only when the oil temperature is 20 ° C. or lower, 140 ° C. or higher) ) Was difficult. Further, since a failure of the oil temperature sensor is detected when the vehicle is traveling, the detection area is limited by traveling conditions and the like. For these reasons, it has become a cause of failure detection failure and frequency reduction.
Moreover, there is a tendency that it takes a long time until the failure of the oil temperature sensor is determined. In addition, when determining the diagnostic judgment value, it is necessary to confirm the oil temperature temperature rise performance, which requires a lot of confirmation and conformity man-hours. Furthermore, when the cooler performance is changed due to a change in vehicle parts (bumper change, oil amount change, cooler change, etc.), there is a disadvantage that the number of confirmation man-hours increases.

  Therefore, the object of the present invention is to enable failure diagnosis in a wider detection area, increase the frequency of performing failure diagnosis, shorten the time required to determine a failure, improve detection accuracy, The oil temperature that reduces the computational load on the control means involved in the failure diagnosis, and in particular, extends the detection area to the area where the oil temperature saturates, and further expands the area that is extremely limited by the running conditions. An object of the present invention is to provide a sensor fault diagnosis control device.

  The present invention provides an oil temperature sensor that detects the temperature of hydraulic oil used in a power transmission mechanism of a vehicle equipped with an internal combustion engine, and includes a water temperature sensor that detects a water temperature as a temperature of cooling water of the internal combustion engine, A failure determination unit that determines an abnormal state of the oil temperature sensor based on the oil temperature detected by the oil temperature sensor, a time measuring unit that measures elapsed time, and a storage unit that stores at least the detected oil temperature and water temperature are provided. In the oil temperature sensor failure diagnosis control apparatus provided with the control means, the control means stores the oil temperature detected by the oil temperature sensor when the operation of the internal combustion engine is stopped as the stop oil temperature and the water temperature sensor The detected water temperature is stored as a stop water temperature, the oil temperature detected by the oil temperature sensor at the start of the internal combustion engine is stored as the start oil temperature, and the water temperature detected by the water temperature sensor is started. Storing as a water temperature, calculating a difference between the stored stop oil temperature and the starting oil temperature, and comparing the difference with a determination value determined under a predetermined condition based on any one of the stored water temperatures. The failure determination of the oil temperature sensor is performed by the following.

  The failure diagnosis control device for the oil temperature sensor of the present invention enables failure diagnosis in a wider detection area, increases the frequency of performing failure diagnosis, shortens the time required to determine the failure, and increases detection accuracy, The calculation load on the control means related to the failure diagnosis is suppressed to a small level. In particular, the detection region is expanded to a region where the oil temperature is saturated, and the region that is extremely limited by the running conditions is further expanded to enable diagnosis.

FIG. 1 is a flowchart of failure diagnosis control. (Example) FIG. 2 is a control block diagram of the failure diagnosis control apparatus. (Example) FIG. 3 is a schematic plan view of a vehicle equipped with a power train. Example 1 FIG. 4 is a time chart of an operation example of the stall release timer. (Example) FIG. 5 is a diagram illustrating conditions for determining deviation. (Example) FIG. 6 is a time chart of an operation example of soak timer active. (Example) FIG. 7 is a diagram showing preconditions when starting the internal combustion engine in the thermal damage environment determination. (Example) FIG. 8 is a diagram showing conditions for determining the heat damage environment. (Example) FIG. 9 is a diagram illustrating conditions that are regarded as vehicle stop and internal combustion engine start in the thermal damage environment determination. (Example) FIG. 10 is a diagram showing the storage timing of each temperature. (Example) FIG. 11 is a diagram showing a concept of time at start-up. (Example) FIG. 12 is a diagram showing failure determination values (eight patterns). (Example) FIG. 13 is a diagram showing a confirmed state of an oil temperature function failure. (Example) FIG. 14 is a diagram showing soak failure diagnosis. (Example) FIG. 15 is a diagram showing temperature rising failure diagnosis. (Example) FIG. 16 is a time chart in a normal state in the first detection example of failure detection. (Example) FIG. 17 is a time chart at the time of failure of oil temperature and high temperature fixation as a first detection example of failure detection. (Example) FIG. 18 is a time chart in a normal state in a second detection example of failure detection. (Example) FIG. 19 is a second detection example of failure detection and is a time chart at the time of failure of oil temperature and low temperature fixation. (Example) FIG. 20 is a time chart in a normal state in a third detection example of failure detection. (Example) FIG. 21 is a time chart at the time of failure when oil temperature is fixed at room temperature in a third detection example of failure detection. (Example)

  The present invention enables failure diagnosis in a wider detection area, increases the frequency of failure diagnosis, shortens the time required to determine a failure, increases detection accuracy, and relates to the diagnosis Stored stop for the purpose of minimizing the computational load on the control means and, in particular, expanding the detection area to the area where the oil temperature saturates and enabling the diagnosis by further expanding the area that is extremely limited by the driving conditions This is realized by determining the failure of the oil temperature sensor by comparing the difference between the oil temperature and the starting oil temperature with a determination value determined under a predetermined condition based on one of the stored water temperatures.

1 to 21 show an embodiment of the present invention.
In FIG. 3, 1 is a vehicle, and 2 is a power train mounted on the vehicle 1.
The power train 2 includes an internal combustion engine 3 and a transmission (automatic transmission) 4 as a power transmission mechanism connected to the internal combustion engine 3.
The internal combustion engine 3 is provided with a water temperature sensor 5 that detects the water temperature as the temperature of the cooling water.
The transmission 4 includes first to fourth solenoids 6 to 9 as a plurality of solenoids that actuate each valve, and an oil temperature sensor 10 that detects the temperature of the working oil of the first to fourth solenoids 6 to 9. Is provided.

As shown in FIG. 2, the vehicle 1 includes a failure diagnosis control device 11 for the oil temperature sensor 10.
This failure diagnosis control device 11 stores the water temperature, oil temperature, and air temperature when the internal combustion engine is stopped, and diagnoses the failure of the oil temperature sensor 10 by examining the correlation between the temperatures at the next start of the internal combustion engine. By determining the situation when the vehicle 1 is traveling, when the internal combustion engine is stopped, and when the internal combustion engine is started, diagnosis is prohibited, and a determination value (threshold value) suitable for each situation is used.
The failure diagnosis control apparatus 11 is provided with a control means (TUC) 12.
A water temperature sensor 5, first to fourth solenoids 6 to 9, and an oil temperature sensor 10 are in communication with the control means 12.
The control means 12 includes an intake air temperature sensor 13 that is an air temperature sensor that can detect the intake air temperature to the internal combustion engine 3 as the temperature of the environment in which the internal combustion engine 3 is placed (hereinafter referred to as “air temperature”), and an accelerator. An accelerator opening sensor 14 that detects the amount of pedal depression as an accelerator opening, a vehicle speed sensor 15 that detects the vehicle speed, an engine speed sensor 16 that detects the engine speed, and a battery voltage detection sensor that can detect the battery voltage. 17, an ignition switch 18, a shift position switch 19 capable of detecting a shift position, and an internal combustion engine start / stop detection sensor 20 capable of detecting when the internal combustion engine 3 is started or stopped are in communication.

As shown in FIG. 2, the control unit 12 includes a failure determination unit 12A that determines an abnormal state of the oil temperature sensor 10 based on the oil temperature detected by the oil temperature sensor 10, a time measurement unit 12B that measures elapsed time, And storage means 13C for storing at least the detected oil temperature and water temperature.
Then, the control means 12 stores the oil temperature detected by the oil temperature sensor 10 when the operation of the internal combustion engine 3 is stopped as a stop oil temperature, stores the water temperature detected by the water temperature sensor 5 as a stop water temperature, and starts the internal combustion engine 3. Sometimes the oil temperature detected by the oil temperature sensor 10 is stored as the starting oil temperature, the water temperature detected by the water temperature sensor 5 is stored as the starting water temperature, and the difference between the stored stop oil temperature and the starting oil temperature is calculated. At the same time, the failure of the oil temperature sensor 10 is determined by comparing the difference with a determination value determined under a predetermined condition based on any one of the stored water temperatures.
Note that the water temperature, oil temperature, and air temperature, which are the detected values of the current temperature, are immediately calculated, and can be stored even temporarily (volatile), so that they may not be stored in the nonvolatile memory. Is possible.

  Further, as a failure determination of the oil temperature sensor 10, the control means 12 calculates a first oil temperature difference between the stop oil temperature at the previous stop and the start oil temperature at the current start, and based on any one of the stored water temperatures. Soak failure determination (see FIG. 14) of the oil temperature sensor 10 performed by comparing the determination value determined under predetermined conditions with the first oil temperature difference, the starting oil temperature at the previous start and the stop oil at the previous stop A temperature difference failure determination of the oil temperature sensor is performed by calculating a second oil temperature difference from the temperature and comparing a determination value determined under a predetermined condition based on any one of the stored water temperatures with the second oil temperature difference One or more determinations are made (see FIG. 15).

  Furthermore, the control means 12 performs two determinations, the soak failure determination and the temperature rising failure determination. In the soak failure determination, the first of the stop oil temperature at the previous stop and the start oil temperature at the current start is determined. An oil temperature difference is calculated, and the judgment value determined in a predetermined map is compared with the first oil temperature difference based on the stop water temperature, and the temperature rise failure judgment determines that the start oil temperature at the previous start and the previous stop The second oil temperature difference with the stop oil temperature at the time is calculated, and the determination value determined in a predetermined map based on the start water temperature is compared with the second oil temperature difference.

Furthermore, the control means 12 communicates with an intake air temperature sensor 13 as an air temperature sensor that can detect the temperature of the environment in which the internal combustion engine 3 is placed, and performs three determinations to determine the determination value. Two judgments are taken into account: a deviation determination considering the degree of deviation between the oil temperature and the water temperature; a soak determination considering the soak time of the internal combustion engine measured by the time measuring means; and a temperature detected by the temperature sensor. 8 patterns of determination values used for the two failure determinations of the soak failure determination and the temperature rising failure determination are set (see FIG. 12), and the deviation determination, the soak determination and the heat damage determination are performed. One pattern is selected based on the three determination results.
In addition, as an air temperature sensor, sensors, such as an external air temperature sensor which detects the atmospheric temperature of an engine room or the internal combustion engine 3, are also possible.

  Moreover, the control means 12 makes the said divergence determination the binary determination which determines the difference of the said stop oil temperature and the said stop water temperature by the determination value based on water temperature, The soak determination time which set the said soak determination as an eigenvalue previously The thermal damage determination is a binary determination in which the temperature measured by the temperature sensor when the internal combustion engine is started is determined by a determination value based on the water temperature.

  Further, the control means 12 provides three types of predetermined maps for determining the determination values used for the soak failure determination, and these three types of maps are used to determine failures on the side where the oil temperature difference is low as shown in FIG. A low-side map that provides a determination value for performing a determination, a high-side map that provides a determination value for determining a failure on the high oil temperature difference side, and a range in which the oil temperature difference correlates with the water temperature of the internal combustion engine. A core map is used.

Next, failure diagnosis of the oil temperature sensor 10 according to this embodiment will be described based on the flowchart in FIG.
As shown in FIG. 1, when the program of the control means 12 is started (step A01), it is first determined whether or not a precondition (running) condition for failure diagnosis of the oil temperature sensor 10 is established (step A02). That is, the DC (driving cycle) traveling immediately before the diagnosis is performed is monitored to determine whether or not the failure diagnosis is performed.
This failure diagnosis is performed when the traveling condition is satisfied and the uphill (stall) condition is not satisfied.
The running conditions are: oil temperature is set range, water temperature is set range, air temperature is set range, internal engine 3 ON time is longer than set time, internal combustion engine 3 idle operation time is longer than set time, accelerator opening integrated time is set It is established when all the conditions that the vehicle speed is equal to or greater than the set time and the travel time is equal to or greater than the set time are satisfied.
The uphill (stall) condition is satisfied when the stall determination is satisfied and the stall release timer is equal to or greater than zero (0).
Stall judgment is all conditions when the accelerator opening is equal to or greater than the set opening, the transmission 4 is not in a lock-up / slip state, and the shift position is other than the parking range (P) or neutral range (N). Is satisfied if The set opening of the accelerator opening is determined according to the vehicle speed.
In the operation example of the stall release timer, as shown in FIG. 4, when the stall determination is satisfied (diagnostic condition is stopped), and when the stall determination is not satisfied (denoted as “stall confirmation”), The stall decay time (sec) is set by the stall release timer, the stall decay time is attenuated, and when the stall decay time becomes zero (0), the diagnosis condition is restored.

  If step A02 is NO, the fault diagnosis is terminated (step A03), and the process returns to step A02.

When step A02 is YES, whether the condition is satisfied (Kairi = 1) or not satisfied (Kairi = 0) is set in the deviation (Kairi) determination when the internal combustion engine 3 is stopped (Step A04). That is, each temperature is monitored when the DC internal combustion engine is stopped immediately before the diagnosis is performed, and an optimal failure determination value that matches the diagnosis execution and conditions is selected.
In this deviation determination, one of the conditions that the engine speed is equal to or lower than the set speed and the ignition switch 18 is off, the battery voltage is equal to or higher than the set voltage, and the INP (input) speed is equal to or lower than the set speed, When the vehicle speed is less than the set vehicle speed, the shift position is the parking range (P) or the neutral range (N), and the accelerator opening is all less than the set opening, the vehicle is considered to be stopped and the internal combustion engine is stopped, and the stop water temperature The filtered values of the stop oil temperature and stop temperature are stored. This filter can be adapted with a constant.
Moreover, the preconditions when the internal combustion engine is stopped are satisfied when the stop water temperature satisfies all the conditions of the set range, the stop oil temperature of the set range, and the stop air temperature of the set range.
The deviation determination is performed based on the stored water temperature and the stored oil temperature. When the deviation degree is large, a dedicated determination value set according to the water temperature is used for the failure determination.
As shown in FIG. 5, when the stop water temperature (EngWaFin) is equal to or higher than the stop oil temperature (TftFin), the difference state is obtained by subtracting the stop oil temperature (TftFin) from the stop water temperature (EngWaFin). KaiTb1) or more conditions, or when the stop oil temperature (TftFin) is larger than the stop water temperature (EngWaFin), the value obtained by subtracting the stop water temperature (EngWaFin) from the stop oil temperature (TftFin) is the second judgment value ( It is determined when the above condition is satisfied. Here, the first determination value (KaiTb1) and the second determination value (KaiTb2) are determined according to the water temperature.

  After the process of step A04, the internal combustion engine 3 is started (step A05).

After the internal combustion engine 3 is started, whether the condition is satisfied (soak = 1) or not satisfied (soak = 0) is set in the soak determination (step A06). That is, control is performed to improve accuracy by performing diagnosis in a region where the temperature is stable by using soak determination (for example, determination for 5 hours).
For example, as shown in FIG. 6, when vehicle soak determination is performed (denoted as “soak”) and sufficient soak is performed within the soak determination time, another determination is made to improve diagnosis accuracy. Diagnosis is performed using the value, and whether it is established (soak = 1) or not established (soak = 0) is set.

After that, whether the condition is satisfied (hot = 1) or not established (hot = 0) is set (step A07) in the determination of the heat damage environment at the time of starting the internal combustion engine (permitted diagnosis when the internal combustion engine is stopped). In other words, each temperature at the time when the DC internal combustion engine to be diagnosed is stopped is monitored, and a diagnosis determination and an optimal failure determination determination value that meets the conditions are selected.
In this thermal damage environment determination, as shown in FIG. 7, the preconditions for starting the internal combustion engine are as follows: the starting oil temperature (TftSta) is in the range between the low side oil temperature (TftSTAL) and the high side (TftStah), and the starting water temperature (EngWaSta). ) Is satisfied when the conditions of the low-side water temperature (EngWaSTAL) and the high-side water temperature (EngWaSTAH) and the starting air temperature (EngArSta) satisfy the conditions of the range of the low-side air temperature (EngArSTAL) and the high-side air temperature (EngArSTAH).
Further, as shown in FIG. 8, the heat damage is determined when the starting air temperature (EngArSta) is equal to or higher than a determination value (HotTbl) set according to the water temperature.
In this thermal damage environment determination, when each temperature at the start of the internal combustion engine is stored, as shown in FIG. 9, the battery voltage is equal to or higher than the set voltage (VbSto), the engine speed is equal to or higher than the set speed (EngSto), All the cases where the INP speed is equal to or higher than the set speed (InpSto), the vehicle speed is equal to or lower than the set vehicle speed (VholSto), the shift position is equal to the parking range (P) or the neutral range (N), When the condition is satisfied, each temperature is stored assuming that the vehicle is stopped and the internal combustion engine 3 is started. Since this temperature is used in the next 2DC (second operating state and time), it can be stored twice or more. That is, the starting water temperature, the starting oil temperature, and the starting air temperature are stored as the current DC stored data and the previous DC stored data (see FIG. 10).
As for the value for storing each temperature, the average value of each temperature from the diagnosis start time to the diagnosis end time is calculated and stored (see FIG. 11), and it is determined for a certain time in consideration of communication noise and the like. It is preferable to store the temperature when it has passed, to store the value after filtering for each temperature, and to be able to adapt with a constant for the filter.
In addition, since the temperature transition is not stable when the air temperature is high, this heat damage environment determination uses a determination value for heat damage determination according to the water temperature for failure determination, and when the starting air temperature is larger than the determination value, To establish.

Then, correlation diagnosis for failure determination is performed (step A08).
The determination value of this failure determination is diagnosed using each pattern (determination value 1 to determination value 8) of the failure determination value of FIG. 12 based on each determination result (step A08). In FIG. 12, establishment of divergence determination (kairi) (Kairi = 1) / non-establishment (Kairi = 0), establishment of soak determination (soak) (soak = 1) / non-establishment (soak = 0), and determination of thermal environment A pattern of each determination value (1 to 8) is set by combining (hot) establishment (hot = 1) and non-establishment (hot = 0).
This failure determination has two types of diagnosis: a soak failure determination (see FIG. 14) and a temperature rising failure determination (see FIG. 15). In FIG. 14, a low side map, a high side map, and a core map (a map that defines a range having a correlation with the water temperature) that can be set for each stop water temperature and start water temperature correspond to the water temperature and the oil temperature. Is set within a predetermined range.
By combining the above fault diagnosis according to the settings, it is possible to arbitrarily select A to C with each determination value as shown in FIG. To do.
In the soak failure determination, when the value obtained by subtracting the start oil temperature from the stop oil temperature is smaller than the determination value determined by the low side map (see FIG. 14), the value obtained by subtracting the start oil temperature from the stop oil temperature is the high side map. The absolute value obtained by subtracting the starting oil temperature from the stop oil temperature is greater than the determination value determined in the core map (see FIG. 14). If all conditions are satisfied, a soak failure is assumed.
In the temperature increase failure determination, a temperature increase failure is determined when the absolute value obtained by subtracting the stop oil temperature from the previous DC start oil temperature satisfies a condition larger than the determination value in the oil temperature increase temperature map.

If step A08 is YES, a failure is assumed (step A09).
On the other hand, when step A08 is NO, it is assumed to be normal (step A10).
Then, after the process of step A09 or after the process of step A10, the program is ended (step A11).

Examples of detection of failure detection of the oil temperature sensor 10 according to this embodiment include those shown in FIGS. In FIGS. 16 to 21, “1DC” means the first operating state and time. “Soak” means a stop state and time until the internal combustion engine 3 is restarted. “2DC” means the second operating state and time.
16 and 17 show a first detection example when the internal combustion engine 3 is stopped in a state where both the water temperature and the oil temperature are completely warm, and the internal combustion engine 3 is started after complete cooling. In FIG. 16, although it is normal, in FIG. 17, it becomes a failure state by oil temperature high temperature fixation.
18 and 19 show a second detection example when the internal combustion engine 3 is stopped and the internal combustion engine 3 is started immediately when both the water temperature and the oil temperature are completely warm. Although it is normal in FIG. 18, in FIG. 19, it will be in a failure state by oil temperature low temperature fixation.
20 and 21 show a third detection example when the internal combustion engine 3 is stopped in a state where both the water temperature and the oil temperature are completely warm, and the internal combustion engine 3 is started after complete cooling. Although it is normal in FIG. 20, in FIG. 21, it will be in a failure state by oil temperature normal temperature fixation. In FIG. 21, a soak diagnosis and a temperature rise diagnosis are combined to detect a failure in the normal temperature range.

Although the embodiments of the present invention have been described above, the configuration of the above-described embodiments will be described for each claim.
First, in the first aspect of the invention, the control means 12 stores the oil temperature detected by the oil temperature sensor 10 when the operation of the internal combustion engine 3 is stopped as the stop oil temperature, and the water temperature detected by the water temperature sensor 10 is the stop water temperature. And the oil temperature detected by the oil temperature sensor 10 at the start of the internal combustion engine 3 is stored as the start oil temperature, the water temperature detected by the water temperature sensor 5 is stored as the start water temperature, and the stored stop oil temperature and the While calculating the difference from the starting oil temperature, the failure determination of the oil temperature sensor 10 is performed by comparing this difference with a determination value determined under a predetermined condition based on any one of the stored water temperatures.
As a result, the driving conditions that limit the execution timing of the diagnosis feasibility determination can be made unimportant, and the determination of the failure diagnosis can be performed without requiring the driving conditions. Further, the determination value (threshold value) can be changed according to the state of the water temperature, and the determination accuracy can be improved. Furthermore, since the judgment is basically made only by the detected oil temperature and water temperature, the control is simple, the calculation load of the control means 12 is small, and adaptation to individual vehicles can be easily performed.
In the invention according to claim 2, the control means 12 calculates the first oil temperature difference between the stop oil temperature at the previous stop and the start oil temperature at the current start as the failure determination of the oil temperature sensor 10, and stores the memory Soak failure determination of the oil temperature sensor 10 performed by comparing the first oil temperature difference with the determination value determined under a predetermined condition based on any one of the water temperatures, the starting oil temperature at the previous start and the previous stop The temperature increase of the oil temperature sensor 10 is performed by calculating a second oil temperature difference from the stop oil temperature and comparing the second oil temperature difference with a determination value determined under a predetermined condition based on any one of the stored water temperatures. Make one or more determinations with a failure determination.
As a result, even if the judgment is based only on the temperature lowering performance when the internal combustion engine is stopped or the temperature raising performance during operation, it is impossible in the past as a larger temperature range (normal temperature range where the internal combustion engine 3 is operated). (Including the entire range of 20 ° C. to 140 ° C.).
In the invention according to claim 3, the control means 12 performs two determinations, the soak failure determination and the temperature rising failure determination. In the soak failure determination, the stop oil temperature at the previous stop and the current start time are determined. The first oil temperature difference from the starting oil temperature is calculated, and the judgment value determined in a predetermined map is compared with the first oil temperature difference based on the stop water temperature. The second oil temperature difference between the starting oil temperature and the stopping oil temperature at the previous stop is calculated, and the determination value determined in a predetermined map based on the starting water temperature is compared with the second oil temperature difference.
Thereby, since the determination is based on both the temperature lowering performance when the internal combustion engine is stopped and the temperature increasing performance during operation, the accuracy is high, and the failure diagnosis can be performed in a larger temperature range.
In the invention according to claim 4, the control means 12 communicates with an intake air temperature sensor 13 as an air temperature sensor capable of detecting the temperature of the environment where the internal combustion engine 3 is placed, and determines three determination values to determine the determination value. The three determinations are made as follows: a divergence determination that considers the degree of divergence between the oil temperature and the water temperature; a soak determination that considers the soak time of the internal combustion engine 3 measured by the time measuring means 12B; and an intake air temperature sensor 13 The heat damage determination taking into account the temperature detected by the above, and eight patterns of determination values used for two failure determinations of the soak failure determination and the temperature rising failure determination are set, and the deviation determination, the soak determination and the heat damage are set One pattern is selected based on the three determination results.
Thereby, since the determination value can be set finely by 8 patterns in consideration of the environment in which the vehicle 1 is placed and the driving state of the vehicle, the accuracy can be extremely increased and erroneous determination can be reduced. In addition, considering the correlation with the water temperature of the internal combustion engine 3, it is divided into 8 patterns by three judgments that take into account the environment in which the vehicle is placed and the driving state of the vehicle, so that the setting of each judgment value can be optimized. The gray zone can be reduced.
In the invention according to claim 5, the control unit 12 sets the deviation determination as a binary determination in which a difference between the stop oil temperature and the stop water temperature is determined based on a determination value based on a water temperature, and the soak determination is performed in advance. The binary determination is determined by the soak determination time set as the eigenvalue, and the thermal damage determination is a binary determination in which the air temperature measured by the intake air temperature sensor 13 at the start of the internal combustion engine 3 is determined by a determination value based on the water temperature.
Thereby, the selection (pattern determination) about 8 patterns in consideration of the environment where the vehicle 1 is placed and the driving state of the vehicle can be simplified, and the calculation load of the control means 12 can be reduced.
In the invention according to claim 6, the control means 12 provides three types of predetermined maps for determining determination values used for the soak failure determination, and these three types of maps are used to determine failures on the low oil temperature difference side. A low-side map that provides a determination value for performing a determination, a high-side map that provides a determination value for determining a failure on the higher oil temperature difference, and a range in which the oil temperature difference is correlated with the water temperature of the internal combustion engine 3 A core map is used.
As a result, as shown in the schematic diagram of soak determination, an optimal determination value can be given over a wide temperature range and at each temperature, and highly accurate failure diagnosis is possible.

In the present invention, the same diagnosis can be performed for temperature sensors (water temperature, oil temperature, etc.) having a lifting / lowering property other than the oil temperature sensor.
In addition, regarding two oil temperature sensors, two oil temperature sensors can be diagnosed with each other.
Furthermore, by using the temperature, even with respect to a pattern in which the temperature drop such as heat damage is not stable, it is possible to make a more accurate diagnosis by dividing the determination value.

  The failure diagnosis control apparatus according to the present invention can be applied to various internal combustion engines.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Powertrain 3 Internal combustion engine 4 Transmission 5 Water temperature sensor 10 Oil temperature sensor 11 Fault diagnosis control device 12 Control means 12A Abnormality judgment means 12B Timekeeping means 12C Storage means 13 Intake temperature sensor (temperature sensor)
14 Accelerator opening sensor 15 Vehicle speed sensor 16 Engine speed sensor 17 Battery voltage detection sensor 18 Ignition switch 19 Shift position switch 20 Internal combustion engine start / stop detection sensor

Claims (6)

  An oil temperature sensor for detecting a temperature of hydraulic oil used in a power transmission mechanism of a vehicle equipped with an internal combustion engine is provided, a water temperature sensor for detecting a water temperature as a cooling water temperature of the internal combustion engine is provided, and the oil temperature sensor Control means comprising failure determination means for determining an abnormal state of the oil temperature sensor based on the detected oil temperature, time measuring means for measuring elapsed time, and storage means for storing at least the detected oil temperature and water temperature In the oil temperature sensor failure diagnosis control apparatus, the control means stores the oil temperature detected by the oil temperature sensor when the operation of the internal combustion engine is stopped as a stop oil temperature and the water temperature detected by the water temperature sensor. Stored as a stop water temperature, stores the oil temperature detected by the oil temperature sensor at the start of the internal combustion engine as a start oil temperature, and uses the water temperature detected by the water temperature sensor as a start water temperature The difference between the stored stop oil temperature and the starting oil temperature is calculated, and the difference is compared with a determination value determined under a predetermined condition based on any one of the stored water temperatures. An oil temperature sensor failure diagnosis control device characterized by performing failure determination of an oil temperature sensor.   The control means calculates a first oil temperature difference between the stop oil temperature at the previous stop and the start oil temperature at the current start as a failure determination of the oil temperature sensor, and is predetermined based on any one of the stored water temperatures. The soak failure determination of the oil temperature sensor, which is performed by comparing the determination value determined under the conditions of the above and the first oil temperature difference, and the second oil temperature difference between the starting oil temperature at the previous start and the stop oil temperature at the previous stop One or more determinations of the temperature rise failure determination of the oil temperature sensor performed by comparing the determination value determined under a predetermined condition based on any one of the stored water temperatures and the second oil temperature difference The failure diagnosis control apparatus for an oil temperature sensor according to claim 1, wherein:   The control means performs two determinations, the soak failure determination and the temperature rising failure determination. In the soak failure determination, the first oil temperature difference between the stop oil temperature at the previous stop and the start oil temperature at the current start is determined. Is calculated by comparing the determination value determined in a predetermined map with the first oil temperature difference based on the stop water temperature, and in the temperature increase failure determination, the start oil temperature at the previous start and the previous stop The second oil temperature difference from the stop oil temperature is calculated, and the determination value determined by a predetermined map based on the starting water temperature is compared with the second oil temperature difference. Oil temperature sensor failure diagnosis control device.   The control means communicates with an air temperature sensor capable of detecting the temperature of the environment in which the internal combustion engine is placed, makes three determinations to determine the determination value, and determines the three determinations as the oil temperature and the oil temperature. A divergence determination that takes into account the degree of divergence of water temperature, a soak determination that takes into account the soak time of the internal combustion engine measured by the time measuring means, and a thermal damage determination that takes into account the air temperature detected by the temperature sensor, Eight determination values used for two failure determinations, ie, a failure determination and a temperature rising failure determination, are set, and one of these patterns is determined based on the three determination results of the divergence determination, the soak determination, and the thermal damage determination. 4. The oil temperature sensor failure diagnosis control apparatus according to claim 2, wherein the oil temperature sensor failure diagnosis control apparatus is selected.   The control means determines the divergence as a binary determination in which a difference between the stop oil temperature and the stop water temperature is determined based on a determination value based on a water temperature, and the soak determination is determined based on a soak determination time set in advance as an eigenvalue. 5. The binary determination according to claim 4, wherein the thermal damage determination is a binary determination in which the temperature measured by the temperature sensor when the internal combustion engine is started is determined by a determination value based on a water temperature. Oil temperature sensor failure diagnosis control device.   The control means provides three types of predetermined maps for determining determination values used for the soak failure determination, and these three types of maps provide a determination value for determining a failure on the low oil temperature difference side. A map, a high-side map that provides a determination value for determining a failure on a side with a high oil temperature difference, and a core map that defines a range in which the oil temperature difference correlates with the water temperature of the internal combustion engine. The failure diagnosis control device for an oil temperature sensor according to any one of claims 3 to 5.

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