JP2011085150A - Oil temperature sensor breakdown detection device of automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil temperature sensor breakdown detection device of an automatic transmission which can detect a breakdown of a temperature sensor without requiring time in all temperature areas. <P>SOLUTION: The device calculates a quantity of heat Qa required to change only temperature ▵T set in advance for each initial oil temperature Ti detected by a temperature sensor when starting breakdown diagnosis and a calorific value Qb for each unit time acquired by employing engine rotation speed and automatic transmission input rotating speed varying from a timing of detecting the initial oil temperature Ti, sums the calculated calorific values Qb, continues the summation until the summed calorific values ΣQb exceeds a determination value acquired in accordance with the quantity of heat Qa, and determines the breakdown of the oil temperature sensor when the summed calorific values ΣQb is determined to be in the determination timing and the detected oil temperature Tm detected by the oil temperature sensor is not included within the determination oil temperature range. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oil temperature sensor failure detection device for an automatic transmission, and more particularly to an oil temperature sensor failure detection device for an automatic transmission that quickly detects an oil temperature sensor failure in all temperature ranges.

A vehicle equipped with an automatic transmission is provided with an oil temperature sensor that detects the temperature of hydraulic oil of the automatic transmission, and a failure detection device that detects a failure of the oil temperature sensor.
In this failure detection device, a failure is determined when the temperature of the hydraulic fluid of the automatic transmission at the time of starting the engine does not rise to a temperature equal to or higher than a specified value after a certain cumulative time has elapsed in the forward drive range. .

JP-A-9-49564 JP 2006-177412 A JP 2007-162664 A

The automatic transmission failure diagnosis device according to Patent Document 1 takes into account the determination conditions in addition to the temperature of the hydraulic oil, so that a failure of the automatic transmission can occur even under special driving conditions such as high-load driving and traffic on congested roads. Is to diagnose.
The oil temperature sensor failure detection device for an automatic transmission according to Patent Document 2 sets a predetermined travel time shorter as the temperature of the hydraulic oil when the engine is started is higher, and sets the temperature of the hydraulic oil when the engine is started. This is determined based on the temperature of the atmosphere around the vehicle derived from the detection result of at least one of the engine coolant temperature sensor and the engine intake air temperature sensor, and the detection frequency is increased.
The failure detection device for an oil temperature sensor according to Patent Document 3 suppresses erroneous detection of a failure of the oil temperature sensor while suppressing failure detection from being delayed or the detection frequency from being reduced.

  By the way, conventionally, in an oil temperature sensor failure detection device for an automatic transmission, it takes a long time until the failure of the oil temperature sensor is determined, or a detectable temperature range is limited. For example, it is not possible to diagnose the failure of the oil temperature sensor if the environment always exceeds the specified hydraulic fluid temperature or if the hydraulic fluid temperature at engine startup exceeds the specified value. was there.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an oil temperature sensor failure detection device for an automatic transmission that can quickly detect an oil temperature sensor failure in all temperature ranges.

  The present invention provides an oil temperature sensor failure diagnosis device that detects the temperature of hydraulic oil in an automatic transmission mounted on a vehicle, and uses the temperature of the hydraulic oil detected by the oil temperature sensor at the start of failure diagnosis as an initial oil temperature. A calorific value calculating means for calculating a calorific value required to change from the initial oil temperature value by a preset temperature for each detected initial oil temperature; and an engine that changes from the timing at which the initial oil temperature is detected. A calorific value calculating means for calculating a calorific value per unit time calculated using the rotational speed and the input speed of the automatic transmission; and a calorific value integrating means for integrating the calorific value calculated by the calorific value calculating means; The determination timing detection continues to be integrated until the heat generation amount integrated by the heat generation amount integration means exceeds the determination value calculated in accordance with the heat amount calculated by the heat amount calculation means. And the temperature of the hydraulic oil detected by the oil temperature sensor when it is determined that the amount of heat integrated by the determination timing detection means is the determination timing, and the detected oil temperature is preset. Failure determination means for determining that the oil temperature sensor has failed when not included in the determined oil temperature range.

  The oil temperature sensor failure detection device for an automatic transmission according to the present invention can quickly detect an oil temperature sensor failure in all temperature ranges.

FIG. 1 is a system configuration diagram of an oil temperature sensor failure detection apparatus. (Example) FIG. 2 is a flowchart of the oil temperature sensor failure detection. (Example) FIG. 3A shows the movement of ΣQb when ΣQb> 0. FIG. 3B is a diagram illustrating failure determination when ΣQb> 0. (Example) FIG. 4A shows the movement of ΣQb when ΣQb ≦ 0. FIG. 4B is a diagram illustrating failure determination when ΣQb ≦ 0. (Example) FIG. 5 is a diagram showing a table for calculating the heat amount correction value (Qc). FIG. 6 is a diagram showing a table for calculating Tdmin, Tumin, Tdmax, Tumax.

The purpose of this invention is to detect the temperature of the hydraulic oil detected by the oil temperature sensor when it is determined that the integrated heat generation amount is the determination timing for the purpose of quickly detecting the failure of the oil temperature sensor in all temperature ranges. This is realized by determining that the oil temperature sensor is malfunctioning when the detected oil temperature is not included in the preset determination oil temperature range.
Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings.

1 to 4 show an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a vehicle, 2 denotes an engine mounted on the vehicle 1, and 3 denotes an automatic transmission connected to the engine 2.
In the vehicle 1, a radiator 4 that cools cooling water of the engine 2 is disposed in front of the engine 2.
The automatic transmission 3 includes a torque converter 5 directly connected to the engine 2 and a transmission gear device 6 connected to the torque converter 5.
An oil cooler 7 that cools the hydraulic oil of the automatic transmission 3 is attached to the lower portion of the torque converter 5.

In the automatic transmission 3, as shown in FIG. 1, a heat generation amount and a heat dissipation amount are generated at each location.
That is, in the torque converter 5, a heat generation amount (Qtc) is generated due to the automatic transmission input rotation speed, the differential rotation between the engine rotation speed and the automatic transmission input rotation speed, and the like.
Further, in the transmission gear device 6, a heat generation amount (Qmc) is generated due to mechanical loss or the like, and a heat dissipation amount (Qair) is generated due to cooling with outside air.
Further, in the oil cooler 7, a heat radiation amount (Qoc) is generated by the oil cooler 7.

The vehicle 1 is provided with an oil temperature sensor failure detection device 8 for the automatic transmission 3.
The oil temperature sensor failure detection device 8 includes an oil temperature sensor 9 that is attached to the automatic transmission 3 and detects the temperature (oil temperature) of hydraulic oil, and an engine rotation that is attached to the engine 2 and detects the engine speed. A number sensor 10 and an automatic transmission input speed sensor 11 attached to the automatic transmission 3 and detecting the automatic transmission input speed are in communication.

The oil temperature sensor failure detection device 8 sets the temperature of the hydraulic oil detected by the oil temperature sensor 9 at the start of failure diagnosis as the initial oil temperature (Ti), and the initial oil temperature for each detected initial oil temperature (Ti). An amount of heat calculating means 12 for calculating the amount of heat (Qa) required to change from the value of (Ti) by a preset temperature (ΔT), and an engine that changes from the timing at which the initial oil temperature (Ti) is detected. A calorific value calculating means 13 for calculating a calorific value (Qb) per unit time calculated using the rotational speed and the automatic transmission input rotational speed, and a calorific value (Qb) calculated by the calorific value calculating means 13 And the calorific value (ΣQb) accumulated by the calorific value integrating means 14 exceeds the determination value calculated according to the calorie (Qa) calculated by the calorific value calculating means 12. The detection timing detection means 15 that continues to accumulate at the time, and the temperature of the hydraulic oil detected by the oil temperature sensor 9 when the calorific value (ΣQb) accumulated by the determination timing detection means 15 is determined as the determination timing is detected. A failure determination means 16 for determining that the oil temperature sensor 9 has failed when the detected oil temperature (Tm) is not included in a preset determination oil temperature range. . This is because it is possible to detect the failure of the oil temperature sensor 9 in all temperature ranges, regardless of whether the temperature of the hydraulic oil rises or falls.
Further, the oil temperature sensor failure detection device 8 includes a calorific value correcting unit 17 that corrects the calorific value (Qa) based on the sign of the calorific value (ΣQb) accumulated by the calorific value accumulating unit 14. This is because it is possible to detect the failure of the oil temperature sensor 9 with high accuracy.
Further, the oil temperature sensor failure detection device 8 includes a temperature range correction unit 18 that corrects the determination oil temperature range based on the sign of the heat generation amount (ΣQb) integrated by the heat generation amount integration unit 14. This is to prevent the oil temperature sensor 9 from being erroneously determined as a failure.

In the oil temperature sensor failure detection device 8, the following calculation is executed.
The amount of heat (Qa) required to increase ΔT ° C is
Qa = Tmc × ΔT
Is calculated by
here,
Tmc: Theoretical value considering the amount of heat required for the hydraulic oil temperature to rise by 1 ° C. not only in the safety factor and hydraulic oil but in the entire automatic transmission assy (safety factor x specific heat of the entire automatic transmission assy) × mass)
ΔT: A value that takes into account the point at which the temperature is difficult to change for each temperature of the initial temperature (Ti), etc., is a value set in the table.
Qb = Acons * A_TC * TC_capacity * EGrpm2 * absolute (EGrpm- (inRpm * TC_trqRatio))-T_Cool
here,
Acons × A_TC × TC_capacity × EGrpm2 × absolute (EGrpm− (inRpm × TC_trqRatio)) = Qtc + Qmc
T_Cool = Qoc + Qair
Acons: Coefficient for unit alignment A_TC: Coefficient TC_capacity: Capacity of torque converter 5 (calculated from speed ratio (automatic transmission input rotational speed / engine rotational speed))
TC_trqRatio: Torque ratio (calculated from speed ratio (automatic transmission input rotational speed / engine rotational speed))
T_Cool: Heat dissipation amount EGrpm: Engine rotation speed inRpm: Input rotation speed Further, the heat amount correction value (Qc) has a table for each hysteresis and initial temperature (Ti) with respect to the heat amount (Qa) (see FIG. 5).
Further, the Tm lower limit threshold (Tdmin) when ΣQb is lowered, the Tm lower limit threshold (Tumin) when ΣQb is raised, the Tm upper threshold (Tdmax) when ΣQb is lowered, and the Tm upper limit threshold (Tumax) when ΣQb is raised are the amount of heat (Qa ) And a table for each Ti temperature (see FIG. 6).
Tm: measured oil temperature ΣQb: calorific value obtained by integrating Qb

Next, failure detection according to this embodiment will be described based on the flowchart of FIG.
As shown in FIG. 2, when the program starts (step A01), first, a change of ΔT ° C. from the initial oil temperature (Ti), which is the temperature of the hydraulic oil at the time of engine start (current oil temperature), is increased (increased). Calculates the required amount of heat (Qa) and calculates the amount of heat generated (Qb) from the heat generated by the automatic transmission input speed, the difference between the engine speed and the automatic transmission input speed, and the heat released from cooling. Further, a calorific value correction value (Qc) is set, and a Qc threshold value (Qcd) when ΣQb is lowered and a Qc threshold value (Qcu) when ΣQb is raised are calculated, and the integrated calorific value (ΣQb) is calculated. In consideration of calculation errors and the like, the lower threshold (Tmin) and the upper threshold (Tmax) are calculated as the failure threshold after the change of ΔT ° C. from the initial oil temperature (Ti) (Ti + ΔT). Threshold (Tma ) Is divided into positive and negative values of ΣQb, similarly to the calorie correction value (Qc), Tm lower limit threshold (Tdmin) when ΣQb is lowered, Tm upper limit threshold (Tdmax) when ΣQb is lowered, and Tm lower limit threshold when ΣQb is raised (Tumin), Tm upper limit threshold value (Tumax) when ΣQb rises is calculated (step A02).
As a result, the failure determination time can be shortened, and in the past, it could be detected only on the temperature rise side, but in this embodiment, the failure occurred both in the temperature rise and fall in all oil temperature regions. Judgment is possible.
Then, a calorific value (ΣQb) obtained by integrating the calorific value (Qb) is calculated (step A03), and it is determined whether ΣQb ≦ 0 (step A04).
When this step A04 is YES, the heat amount correction value (Qc) is set as Qc = Qcd (heat amount correction value used when Qb is negative) (see FIG. 4A), and whether ΣQb ≦ Qa + Qcd is satisfied. Is determined (step A05). The actual temperature when ΣQb ≦ Qa + Qcd is assumed to be Tm.
If step A05 is NO, the process returns to step A03.
If step A05 is YES, it is determined whether Tdmin <Tm <Tdmax (step A06).
When this step A06 is NO, it is determined as a failure (step A07) (see FIG. 4B).
If step A06 is YES, it is assumed that normality is detected, the accumulated heat generation amount is reset (step A08), and the process returns to step A02.
On the other hand, when the step A04 is NO, the heat amount correction value (Qc) is set as Qc = Qcu (heat amount correction value used when Qb is positive) (see FIG. 3A), and ΣQb ≧ Qa + Qcu. (Step A09). The actual temperature when ΣQb ≧ Qa + Qcu is assumed to be Tm.
If step A09 is NO, the process returns to step A03.
If this step A09 is YES, it is determined whether Tumin <Tm <Tumax (step A10).
When this step A10 is NO, it determines with it being a failure (step A07) (refer FIG. 3 (B)).
If step A10 is YES, it is determined that normality is detected, the accumulated heat generation amount is reset (step A08), and the process returns to step A02.

As a result, in the oil temperature sensor failure detection device 8, the temperature of the hydraulic oil detected by the oil temperature sensor 9 at the start of failure diagnosis is set as the initial oil temperature (Ti), and for each detected initial oil temperature (Ti). A calorific value calculating means 12 for calculating a calorific value (Qa) required to change from the value of the initial oil temperature (Ti) by a preset temperature (ΔT), and a timing at which the initial oil temperature (Ti) is detected. The calorific value calculation means 13 for calculating the calorific value (Qb) per unit time calculated using the engine speed and the automatic transmission input rotational speed that change from the above, and the calorific value calculated by the calorific value calculation means 13 The calorific value integrating means 14 for integrating the quantity (Qb), and the calorific value (ΣQb) accumulated by the calorific value integrating means 14 are calculated according to the calorie (Qa) calculated by the calorific value calculating means 12. Determination timing detection means 15 that continues to accumulate until the determination value exceeds, and the operation detected by the oil temperature sensor 9 when it is determined that the calorific value (ΣQb) accumulated by the determination timing detection means 15 is the determination timing. A failure determination that determines that the oil temperature sensor 9 has failed when the detected oil temperature (Tm) is not included in a predetermined determination oil temperature range, with the oil temperature being the detected oil temperature (Tm). Means 16.
As a result, in all temperature ranges, it is possible to detect a failure of the oil temperature sensor 9 without taking time, regardless of whether the temperature of the hydraulic oil rises or falls.
In other words, since the amount of heat necessary for increasing (or decreasing) ΔT ° C. is obtained, it is possible to detect a failure even when the temperature increases and decreases (when heat dissipation exceeds heat generation) in all temperature ranges. In addition, since the calorie correction value (Qc) can be divided into the threshold value Qcd and the threshold value Qcu, each of the temperature ΔT depends on the outside air temperature, the cooling water temperature, the intake air temperature, the heat generation amount, and the heat release amount. The threshold range can be changed (eg, it is stricter on the rising side of the temperature and looser on the lowering side. It is changed when the outside air temperature is high or low. Cold start, warm start, etc.) Furthermore, since the Tm allowable ranges Tmin and Tmax after the change of ΔT ° C. are set, it is possible to prevent erroneous diagnosis even when a failure occurs during diagnosis, the measured temperature suddenly changes, and is fixed.

  In addition, the oil temperature sensor failure detection device 8 includes a calorific value correcting unit 17 that corrects the calorific value (Qa) based on the sign of the calorific value accumulated by the calorific value accumulating unit 14. Thereby, the failure detection of the oil temperature sensor 9 can be performed with high accuracy.

  Further, the oil temperature sensor failure detection device 8 includes a temperature range correction unit 18 that corrects the determination oil temperature range based on the sign of the heat generation amount integrated by the heat generation amount integration unit 14. This prevents the oil temperature sensor 9 from being erroneously determined as a failure.

  The oil temperature sensor failure detection device of the present invention can be applied to various vehicles.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Automatic transmission 5 Torque converter 6 Transmission gear device 8 Oil temperature sensor failure detection device 9 Oil temperature sensor 10 Engine rotation speed sensor 11 Automatic transmission input rotation speed sensor 12 Heat quantity calculation means 13 Heat generation amount calculation means 14 Heat generation Quantity integration means 15 Determination timing detection means 16 Failure determination means 17 Heat quantity correction means 18 Temperature range correction means

Claims (3)

In an oil temperature sensor failure diagnosis device that detects the temperature of hydraulic oil of an automatic transmission mounted on a vehicle,
The temperature of the hydraulic oil detected by the oil temperature sensor at the start of failure diagnosis is set as the initial oil temperature, and it is necessary to change only the preset temperature from the value of the initial oil temperature for each detected initial oil temperature. A calorific value calculating means for calculating a calorific value;
A calorific value calculation means for calculating a calorific value per unit time calculated using the engine speed and the automatic transmission input speed that change from the timing at which the initial oil temperature is detected;
A calorific value integrating means for integrating the calorific value calculated by the calorific value calculating means;
A determination timing detection unit that continues to accumulate until the heat generation amount integrated by the heat generation amount integration unit exceeds a determination value calculated according to the heat amount calculated by the heat amount calculation unit;
The hydraulic oil temperature detected by the oil temperature sensor when the calorific value integrated by the determination timing detection means is determined to be the determination timing is set as the detected oil temperature, and the detected oil temperature is set in advance. An oil temperature sensor failure detection device for an automatic transmission, comprising: failure determination means for determining that the oil temperature sensor has failed when not included in a temperature range.   The calorific value correcting means for correcting a calorific value required to change by the preset temperature based on whether the calorific value accumulated by the calorific value integrating means is positive or negative. Oil temperature sensor failure detection device for automatic transmission.   2. The oil temperature sensor failure of the automatic transmission according to claim 1, further comprising a temperature range correction unit that corrects the determination oil temperature range based on whether the heat generation amount integrated by the heat generation amount integration unit is positive or negative. Detection device.

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