JP2011074926A - Trouble diagnosing device for oil temperature sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of fuel efficiency performance and deterioration of exhaust gas components by accurately determining a trouble wherein an oil temperature sensor outputs the only high temperature and by continuing running while the oil temperature sensor is still in trouble. <P>SOLUTION: This trouble diagnosing device for an oil temperature sensor includes a diagnosing means for setting a range of a gear ratio at a determination threshold temperature, which is computed based on a determination reference temperature of the operating fluid of an automatic transmission, or less as a diagnosis allowable region in a map setting the gear ratio, and for determining a trouble in the case wherein a plurality of parameters showing various conditions of a vehicle in running exist in the diagnosis allowable region and wherein the temperature of the operating fluid detected in running exceeds the determination reference temperature corresponding to the diagnosis allowable region and this condition has continued for a predetermined time or more. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a failure diagnosis device for an oil temperature sensor, and more particularly to an oil temperature related control of an automatic transmission, and more specifically, an oil temperature sensor for oil temperature related control in failure diagnosis control of a continuously variable transmission. The present invention relates to a failure diagnosis apparatus.

  An automatic transmission mounted on a vehicle includes a continuously variable transmission (CVT) including a primary pulley and a secondary pulley as a transmission mechanism and a belt wound between them, and a torque converter and a gear-type auxiliary transmission as a transmission mechanism. There is a stepped transmission (AT) equipped with a mechanism. These automatic transmissions perform shifting by controlling the hydraulic pressure of hydraulic oil supplied to the transmission mechanism by a shift control device, and the responsiveness changes when the oil temperature changes. The hydraulic pressure is controlled based on the detected temperature of the hydraulic oil. The transmission control device performs failure diagnosis of the hydraulic sensor because the transmission control is hindered when the hydraulic sensor fails.

In a conventional hydraulic sensor failure diagnosis device, after starting an engine and starting running, the vehicle runs for a first predetermined time at a low first predetermined vehicle speed or more and for a second predetermined time or more at a high second predetermined vehicle speed or more. When traveling, when the detected change amount of the temperature of the hydraulic oil is equal to or less than a predetermined value, there is one that determines that the hydraulic sensor is out of order (Patent Document 1).
A conventional hydraulic sensor failure diagnosis device includes a hydraulic sensor that is used when the temperature of the hydraulic oil detected by the oil temperature sensor is not within a predetermined range when the engine is started and the vehicle travels for a predetermined travel time. There is one that determines a failure (Patent Document 2).

JP-A-9-329222 JP 2006-177412 A

However, the oil temperature sensor failure diagnosis apparatus described in Patent Documents 1 and 2 is a hydraulic oil that is detected by the oil temperature sensor after a certain accumulated time has elapsed since the engine was started and the travel time in the forward travel range has elapsed. When the temperature of the engine does not rise from the temperature at the time of starting the engine to a temperature equal to or higher than a predetermined value, it is determined that the oil temperature sensor has failed.
However, these failure diagnosis devices can diagnose the oil temperature sensor on the low oil temperature side when starting the engine, but it is difficult to detect the failure on the high oil temperature side.
In addition, the oil temperature sensor failure diagnosis device described in Patent Document 1 is designed to cool the engine when the temperature of the hydraulic oil after a certain accumulated time has elapsed since the start of the engine exceeds a set value. The failure of the oil temperature sensor was judged by comparing with the degree of change in water temperature.
However, this failure diagnosis device can diagnose a failure on the high oil temperature side of the oil temperature sensor when the engine is started, but can diagnose a failure on the high oil temperature side of the oil temperature sensor during traveling. There wasn't.
Therefore, the conventional oil temperature sensor failure diagnosis device has a sticking in which the oil temperature sensor outputs only a high temperature within the operating temperature range of the control at high oil temperature during driving (region where the temperature of the operating oil decreases). In this case, there is a problem in that the fuel efficiency and exhaust gas components are deteriorated due to the inability to escape from the control at high oil temperature.

  The present invention makes it possible to detect a failure of an oil temperature sensor at an early stage, particularly to accurately determine a failure in which the oil temperature sensor outputs only a high temperature (adhering), and diagnosis from the start of the engine. In addition to being able to diagnose not only during traveling but also during traveling, it is also intended to prevent deterioration in fuel efficiency and exhaust gas components by continuing traveling while the oil temperature sensor has failed.

The present invention includes an oil temperature sensor that detects the temperature of hydraulic oil of an automatic transmission mounted on a vehicle, and determines whether or not there is a failure based on the temperature detected by the oil temperature sensor. A transmission ratio map for setting the transmission ratio of the automatic transmission based on the vehicle speed of the vehicle and the input rotational speed of the automatic transmission, and a determination threshold temperature from a predetermined determination reference temperature for the hydraulic oil. The range of the gear ratio that is calculated and is sandwiched between the gear ratio upper limit and the gear ratio lower limit of the gear ratio map and in which the temperature of the running hydraulic fluid is equal to or lower than the determination threshold temperature corresponds to the determination reference temperature. Is set as a diagnosis permission region, the vehicle speed and the input rotation speed are within the diagnosis permission region during traveling, and the temperature of the hydraulic oil detected during traveling exceeds the criterion temperature corresponding to the diagnosis permission region When holding the state has elapsed a predetermined time characterized in that it comprises determining diagnostic means a failure.
The present invention also includes an oil temperature sensor that detects the temperature of hydraulic oil of an automatic transmission mounted on a vehicle, and a failure of the oil temperature sensor that determines whether there is a failure based on the temperature detected by the oil temperature sensor. The diagnostic device includes a shift map that sets a gear ratio of the automatic transmission based on a vehicle speed and a throttle opening of the vehicle, calculates a determination threshold temperature from a predetermined determination reference temperature for the hydraulic oil, and A range of the speed change map in which the temperature of the hydraulic oil during traveling is equal to or lower than the determination threshold temperature is set as a diagnosis permission region corresponding to the determination reference temperature, and the vehicle speed and the throttle opening during the traveling are set. Is in the diagnosis permission area, and it is determined as a failure when a predetermined time elapses while maintaining a state where the temperature of the hydraulic oil detected during traveling exceeds the determination reference temperature corresponding to the diagnosis permission area You Characterized in that it comprises a diagnostic means.

  The failure diagnosis device for an oil temperature sensor according to the present invention determines not only a diagnosis from the start of the engine but also a failure in which the temperature of the hydraulic oil detected by the oil temperature sensor is always fixed to a high temperature while the vehicle is running. Can do. According to the oil temperature sensor failure diagnosis apparatus of the present invention, even if there is only one determination reference temperature set in advance, the diagnosis permission region can be set in detail, so that a failure can be accurately determined over a wide range of temperatures. The failure diagnosis device for an oil temperature sensor according to the present invention can detect a failure even if the oil temperature sensor can be fixed in a normal running state. Since the oil temperature sensor failure diagnosis device according to the present invention makes a diagnosis using a map for setting a gear ratio, it is possible to detect a failure with high accuracy even when the load changes, such as traveling at each gradient. is there. The failure diagnosis device for the oil temperature sensor of the present invention can detect failure at an early stage and can increase the chance of receiving services, so the deterioration of fuel consumption as a result of continuing running with the oil temperature sensor in failure, Deterioration of exhaust gas components can be suppressed.

It is a flowchart of the failure diagnosis of an oil temperature sensor. Example 1 It is a figure which shows the diagnosis permission area | region set to the gear ratio map based on a vehicle speed and input rotation speed. Example 1 It is a block diagram which shows the system configuration | structure of the failure diagnosis apparatus of an oil temperature sensor. Example 1 It is a figure which shows the some diagnosis permission area | region set to the gear ratio map based on a vehicle speed and input rotation speed. (Modification) It is a flowchart of the failure diagnosis of an oil temperature sensor. (Example 2) It is a figure which shows the diagnosis permission area | region set to the shift map based on a vehicle speed and throttle opening. (Example 2) It is a block diagram which shows the system configuration | structure of the failure diagnosis apparatus of an oil temperature sensor. (Example 2)

In the present invention, a speed ratio range that is equal to or lower than a judgment threshold temperature calculated from a judgment reference temperature of hydraulic oil for an automatic transmission is set as a diagnosis permission area in a map for setting the speed ratio, and various vehicle states are determined during traveling. If a plurality of parameters shown are within the diagnosis permission region and the temperature of the hydraulic oil detected during traveling exceeds the criterion temperature corresponding to the diagnosis permission region and a predetermined time has elapsed, a failure is indicated. Judgment.
Further, as a map for setting the gear ratio, a gear ratio map for setting the gear ratio of the automatic transmission based on the vehicle speed of the vehicle and the input rotational speed of the automatic transmission, or the vehicle speed and throttle opening of the vehicle A shift map for setting the gear ratio of the automatic transmission is provided.
Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. In FIG. 3, 1 is an engine mounted on a vehicle, and 2 is an automatic transmission. The automatic transmission 2 is a continuously variable transmission (CVT), and includes a primary pulley and a secondary pulley as a transmission mechanism, and a belt wound between them. The automatic transmission 2 composed of a continuously variable transmission (CVT) can shift a wide range from a lower speed ratio lower limit (pulley ratio lower limit) to a higher speed ratio upper limit (pulley ratio upper limit) by two pulleys and a belt, and continuously variable speeds. Alternatively, stepped speed change is possible. This automatic transmission 2 is a belt wound around each pulley by supplying hydraulic oil to the pulley chamber of the primary pulley and the pulley chamber of the secondary pulley by the control valve mechanism 3 to relatively expand and contract the groove width of each pulley. Shifting is performed by relatively increasing or decreasing the rotation radius of the.
The operation of the control valve mechanism 3 is controlled by the shift control device 4 of the automatic transmission 2. The speed change control device 4 is connected to a vehicle speed sensor 5 for detecting the vehicle speed of the vehicle and an input speed sensor 6 for detecting the input speed on the input side of the automatic transmission 2. The secondary rotational speed sensor 7 for detecting the secondary rotational speed on the side, the lockup solenoid 8 of the lockup clutch of the automatic transmission 2, the select solenoid 9 of the automatic transmission 2, and the like are connected. As shown in FIG. 2, the transmission control device 4 includes a transmission ratio map 10 that sets a transmission ratio based on the vehicle speed V of the vehicle and the input rotational speed R _in, and the vehicle speed V and the input that are actually detected. The operation of the control valve mechanism 3 is controlled based on the rotational speed R _in , and the hydraulic oil supplied to the primary pulley and the secondary pulley is adjusted to shift the automatic transmission 2.
Since the automatic transmission 2 performs an operation related to the shift by hydraulic pressure, the load applied to the hydraulic oil is large and the temperature becomes high. In particular, when the automatic transmission 2 includes a sub-transmission (including a planetary gear mechanism) in a continuously variable transmission, from a transmission gear ratio lower limit (pulley ratio lower limit) to a transmission gear ratio upper limit (pulley ratio upper limit). The dynamic range of can be very wide. In this case, not only the mechanism becomes complicated, but also the load applied to the hydraulic oil increases.
The shift control device 4 includes an oil temperature sensor 11 that detects the temperature of the hydraulic oil because the responsiveness changes when the temperature of the hydraulic oil of the automatic transmission 2 changes. The transmission control device 4 detects the temperature of the hydraulic oil by the hydraulic pressure sensor 11 and controls the hydraulic pressure by the control valve mechanism 3 based on the detected temperature of the hydraulic oil. The transmission control device 4 includes a failure diagnosis device 12 for the hydraulic sensor 11 because the transmission control is hindered if the hydraulic sensor 11 fails. Fault diagnosis functions such as various sensors including the oil temperature sensor 11 are provided as one function in the shift control device 4.

The failure diagnosis device 12 of the oil temperature sensor 11 includes the speed ratio map 10 that sets the speed ratio of the automatic transmission 2 based on the vehicle speed V of the vehicle and the input rotational speed R _{in of the} automatic transmission 2, and operates. The oil temperature sensor 11 for detecting the temperature of the oil is provided, and diagnostic means 13 for determining the presence or absence of a failure based on the temperature T _n of the hydraulic oil detected by the oil temperature sensor 11 is provided.
Diagnostic means 13 calculates a preset relative hydraulic oil determination reference temperature T from _th predetermined hysteresis temperature T _h a reduced determination threshold temperature (T _{th -T h),} as shown in FIG. 2, shift speed ratio upper limit of the specific map 10 (pulley ratio upper limit) and the gear ratio lower limit in the range sandwiched between (the pulley ratio lower limit) and the temperature T _n the determining threshold temperature of the working oil in the travel (T _th -T _h) The following speed ratio range is set as the diagnosis permission region α corresponding to the determination reference temperature _Tth .
The setting of the diagnosis permission region α is performed by measuring the input rotation speed R _in which is road load for each vehicle speed in the normal speed ratio map 10 traveling on a flat road and plotting it on the speed ratio map 10 in FIG. The connected piece is referred to as X-ray. Further, the vehicle speed temperature _{T n} of the hydraulic oil in the X line is equilibrated with _(T th -T _h) - input rotation number (speed ratio) to point A.
Furthermore, 5% gradient, 10% gradient, 15% gradient, even in the gradient of there loading 15% gradient, as well the temperature _{T n} of the hydraulic oil is equilibrated with _(T th -T _h) vehicle speed - input rotation speed (gear Ratio) points B, C, D, and E are measured, and the points connecting points A, B, C, D, and E are defined as Y curves. A range surrounded by the upper and lower limits (HIGH / LOW: transmission ratio upper limit / transmission ratio lower limit) line of these X-rays, Y curve, and pulley ratio is set as the diagnosis permission region α.
That is, as long as the vehicle travels within the diagnosis permission region α, the temperature T _{n at} which the hydraulic oil is in an equilibrium state is equal to or lower than the determination threshold temperature (T _th −T _h ).
The diagnostic means 13 has a current hydraulic oil temperature T _n detected by the oil temperature sensor 11 while the vehicle speed V and the input rotational speed R _in are within the diagnosis permission region α while the vehicle is traveling. However, if a predetermined time (failure determination condition time) t _f has elapsed while maintaining a state exceeding the determination reference temperature T _th corresponding to the diagnosis permission region α, it is determined as a failure. The failure diagnosis apparatus 12 includes a failure determination condition timer 14 that measures an elapsed time t ₁ for comparison with a predetermined time (failure determination condition time) t _f at the time of failure, and a predetermined time (normal determination condition time) t _t at normal time. and a normality determination condition timer 15 for measuring the elapsed time t ₂ for comparison with.

Next, the operation will be described with reference to FIG.
In FIG. 1,
• T _n [° C.]: Current hydraulic oil temperature • T _{n (t−1)} [° C.]: Temperature of hydraulic oil before one cycle • T _th [° C.] Criteria temperature for oil temperature sensor sticking failure T _h [° C.]: Hysteresis temperature of judgment reference temperature • t _f [sec]: Failure judgment condition time • t ₁ [sec]: Elapsed time measured by the failure judgment condition timer • t _t [sec]: Normal judgment condition time T ₂ [sec]: Elapsed time measured by the normal determination condition timer.

In Figure 1, the elapsed fault diagnosis apparatus 12 by the diagnostic means 13, fault When the diagnosis is started to (A01), failure determination condition timer 14 the elapsed time t ₁ and the normal determination condition timer 15 measured is the hydraulic sensor 11 is measured The time t ₂ is reset (t ₁ = 0, t ₂ = 0) (A02), the current hydraulic oil temperature T _n detected by the oil temperature sensor 11 is taken in (A03), diagnosis prerequisites 1 and assumptions 2 is determined (A04).

Precondition 1 is
-The oil temperature sensor 11 has not already failed due to other requirements-The oil temperature sensor 11 is not an electrical failure-The oil temperature sensor 11 is not a functional failure (function failure judgment at the existing low temperature side)
.

Precondition 2 is
・ The input value / function used for the precondition determination / diagnosis permission condition is normal. ・ The various sensors used for this control are not a GND disconnection failure. ・ The input rotational speed sensor 6 is not an electrical failure. ・ The input rotational speed sensor 6 is not a functional failure. The secondary speed sensor 7 is not an electrical failure. The secondary speed sensor 7 is not a functional failure. The lockup clutch is not a functional failure. The lockup solenoid 8 is not an electrical failure. The lockup solenoid 8 is not a functional failure. Is not a failure.

  If the determination (A04) is NO, the process returns to the process (A03). If the determination (A04) is YES, it is determined whether the diagnosis permission condition 3 and permission condition 4 are satisfied (A05).

Permission condition 3 is
The current input rotational speed R _in and the vehicle speed V point are within the diagnosis permission region α in which “the hydraulic oil temperature T _n is equal to or lower than the determination threshold temperature (T _th −T _h )”.

Permission condition 4 is
The lockup clutch is in the ON state. Control is being performed with the normal gear ratio map 10.

If the determination (A05) is NO, the process returns to the process (A03). If the determination (A05) is YES, it is determined whether the temperature T _{n of the} hydraulic oil has exceeded the determination reference temperature T _th (T _n > T _th ) (A06).
When determination (A06) is NO, it transfers to below-mentioned process (A11). If the determination (A05) is YES, whether the current hydraulic oil temperature Tn is _equal to the hydraulic oil temperature _{Tn (t-1)} one cycle before ( _Tn = _{Tn (t-1)} ) Judgment is made (A07).
When determination (A07) is NO, it transfers to the below-mentioned process (A11). If the determination (A07) is YES, the measurement of the elapsed time t ₁ by the failure determination condition timer 14 is continued (t ₁ = t ₁ +1), and the elapsed time t ₂ measured by the normal determination condition timer 15 is set to zero (t ₂ = 0) and (108), the elapsed time _{t 1} measured failure determination condition timer 14 failure determination condition time (predetermined time) or exceeds _{t f (t} 1> _{t f)} is determined (A09).
If the determination (A09) is NO, the process returns to the process (A03). If the determination (A09) is YES, it is determined that the oil temperature sensor 11 is malfunctioning (A10), and the process returns to the process (A02).
Meanwhile, the determination (A06) is NO, also in the case determination (A07) is NO, continue to measure the elapsed time _{t 2} by normal determination condition timer 15 _{(t 2 =} t 2 +1), the failure determination condition timer 14 The elapsed time t ₁ measured in step S1 is set to zero (t ₁ = 0) (A11), and the elapsed time t ₂ measured by the normal judgment condition timer 15 exceeds the normal judgment condition time (predetermined time) t _t (t ₂ > t _t ) is determined (A12).
If the determination (A12) is NO, the process returns to the process (A03). When judgment (A12) is YES, it determines with oil temperature sensor 11 being normal (A13), and returns to the above-mentioned processing (A02). Therefore, the failure diagnosis device 12 determines that the oil temperature sensor 11 is normal (the normal determination condition is satisfied) when the failure determination condition is not satisfied for a predetermined time (t _t ).

In this way, the failure diagnosis device 12 of the oil temperature sensor 11 determines the sticking failure determination reference temperature T _th on the high temperature side of the oil temperature sensor 11, travels normally on the normal gear ratio map 10, and is in an equilibrium state. The diagnosis permission region α (vehicle speed−input rotation speed) where the oil temperature T _n becomes equal to or lower than the determination threshold temperature (T _th −T _h ) (T _n ≦ (T _th −T _h )) is displayed on the transmission ratio map 10. Set. The failure diagnosis device 12 detects that the temperature T _{n of the} hydraulic oil detected by the oil temperature sensor 11 exceeds the determination reference temperature T _th while traveling within the diagnosis permission region α in the normal gear ratio map 10 (T _n > T _th ), and when the temperature T _{n of the} hydraulic oil does not change for a predetermined time t _f or more, a failure due to sticking of the oil temperature sensor 11 is detected.
Thereby, the failure diagnosis device 12 for the oil temperature sensor 11 not only performs diagnosis from the start of the engine 1 but also constantly increases the temperature T _{n of the} hydraulic oil detected by the oil temperature sensor 11 while the vehicle is running. It is possible to determine the failure that is stuck. In addition, the failure diagnosis device 12 of the oil temperature sensor 11 can finely set the diagnosis permission region α even if there is only one determination reference temperature T _th set in advance, so that the failure can be accurately determined over a wide range of temperatures. Further, since the failure diagnosis device 12 of the oil temperature sensor 11 performs diagnosis using the transmission ratio map 10 that sets the transmission ratio, the failure is highly accurate even when the load changes, such as traveling at each gradient. Detection is possible.
Further, the failure diagnosis device 12 of the oil temperature sensor 11 can detect a failure even when the temperature value that the oil temperature sensor 11 can take is fixed during normal running. Furthermore, since the failure diagnosis device 12 of the oil temperature sensor 11 can detect the failure at an early stage and increase the chance of receiving service, the fuel consumption is deteriorated as a result of the oil temperature sensor 11 continuing to run with the failure. In addition, deterioration of exhaust gas components can be suppressed.

In the failure diagnosis apparatus 12 of this embodiment, one diagnosis permission region α is set using one determination reference temperature T _th set in advance for hydraulic oil, but a plurality of determination reference temperatures are used. The diagnosis permission area can be set.
For example, as illustrated in FIG. 4, the diagnosis unit 13 of the failure diagnosis apparatus 12 sets a plurality of determination reference temperatures T _th 1, T _th 2, T _th 3 for hydraulic fluid in advance, and a plurality of determination reference temperatures. A plurality of determination threshold temperatures (T _th 1−T _h 1), (T _th 2−T _h 2), and (T _th 3−T _h 3) corresponding to T _th 1, T _th 2, and T _th 3 are calculated. To do. T _h 1, T _h 2, and T _h 3 are hysteresis temperatures of the determination reference temperatures T _th 1, T _th 2, and T _th 3, respectively.
The diagnosis means 13 is in a range between the gear ratio upper limit (pulley ratio upper limit) and the gear ratio lower limit (pulley ratio lower limit) of the gear ratio map 10, and the temperature T _n of the running hydraulic fluid is determined in a plurality of ways. A range of a gear ratio that is equal to or lower than each of the threshold temperatures (T _th 1−T _h 1), (T _th 2−T _h 2), and (T _th 3−T _h 3) is a plurality of determination reference temperatures T _th. 1, T _th 2, and T _th 3 are set as a plurality of diagnosis permission areas α, β, and γ, respectively.
The diagnostic means 13 is such that the vehicle speed V and the input rotational speed R _in are within one of a plurality of diagnosis permission regions α, β, γ, for example, within the diagnosis permission region γ during traveling of the vehicle and during traveling. holding temperature T _n of the detected hydraulic oil determination reference temperature corresponding to the diagnosis permission region of the vehicle speed V and the input rotation speed R _in, a state that exceeds the determination reference temperature T _{th 3} that corresponds to, for example, the diagnosis permission region γ and if the predetermined time has elapsed t _f and determines a failure.
Further, the diagnosis means 13 detects the vehicle speed V and the input rotation speed R _in within the diagnosis permission area β of the plurality of diagnosis permission areas α, β, γ during traveling of the vehicle and during traveling. If the hydraulic oil temperature T _n exceeds the determination reference temperature T _th 2 corresponding to the diagnosis permission region β with the vehicle speed V and the input rotational speed R _in and a predetermined time t _f has elapsed, a failure is assumed. judge.
Further, the diagnosis means 13 detects the vehicle speed V and the input rotation speed R _in within the diagnosis permission area α of the plurality of diagnosis permission areas α, β, γ during the traveling of the vehicle and during the traveling. If the hydraulic oil temperature T _n exceeds the determination reference temperature T _th 1 corresponding to the diagnosis permission area α with the vehicle speed V and the input rotational speed R _in and a predetermined time t _f has elapsed, a failure is assumed. judge.

In other words, the failure diagnosis apparatus 12 of the modified example has one permission condition 3 for diagnosis in the above-described embodiment.
The current input rotational speed R _in and the vehicle speed V point are within the diagnosis permission region α of “hydraulic oil temperature T _n is equal to or lower than the determination threshold temperature (T _th 1−T _h 1)” (permission condition 3-1 )
The current input rotational speed R _in and the vehicle speed V point are within the diagnosis permission region β of “the hydraulic oil temperature T _n is equal to or lower than the determination threshold temperature (T _th 2−T _h 2)” (permission condition 3-2 )
- current input rotational speed _{R in,} the vehicle speed V point is in the diagnosis permission region γ of the "hydraulic oil temperature _{T n} is determined threshold temperature _{(T th 3-T h 3} ) or less" (permission condition 3-3 )
The following three are set.
The failure diagnosis device 12 satisfies the precondition 1, the precondition 2 and the permission condition 4 in the above-described embodiment during the failure diagnosis, and the hydraulic oil detected during traveling when the permission condition 3-1 is satisfied. When a predetermined time t _f elapses while maintaining a state in which the temperature T _n of the vehicle exceeds a determination reference temperature T _th 1 corresponding to a certain diagnosis permission region α of the vehicle speed V and the input rotation speed R _in , it is determined as a failure. On the other hand, when the failure determination condition is not satisfied for a predetermined time (t _t ), it is determined that the oil temperature sensor 11 is normal.
In addition, the failure diagnosis device 12 is detected during traveling when the failure diagnosis is performed, when the prerequisite 1, the prerequisite 2, and the permission condition 4 in the above-described embodiment are satisfied and the permission condition 3-2 is satisfied. If the hydraulic oil temperature T _n exceeds the determination reference temperature T _th 2 corresponding to the diagnosis permission region β with the vehicle speed V and the input rotational speed R _in and a predetermined time t _f has elapsed, a failure is assumed. On the other hand, if the failure determination condition is not satisfied after a predetermined time (t _t ), the oil temperature sensor 11 is determined to be normal.
Furthermore, the failure diagnosis device 12 is detected during traveling when the prerequisite 1, the prerequisite 2, and the permission condition 4 in the above-described embodiment are satisfied and the permission condition 3-3 is satisfied during the failure diagnosis. If the hydraulic oil temperature T _n exceeds the determination reference temperature T _th 3 corresponding to the diagnosis permission region γ with the vehicle speed V and the input rotational speed R _in and the predetermined time t _f has passed, a failure is assumed. When the failure determination condition is not satisfied after a predetermined time (t _t ), the oil temperature sensor 11 is determined to be normal.

As described above, the failure diagnosis apparatus 12 according to the modified example sets a plurality of determination reference temperatures T _th 1, T _th 2, T _th 3, and has a plurality of operating oil temperatures T _n in an equilibrium state during traveling. A plurality of diagnosis permission regions α, β, and γ that are lower than any one of the determination threshold temperatures (T _th 1−T _h 1), (T _th 2−T _h 2), and (T _th 3−T _h 3). By setting, the range of the sticking detection of the oil temperature sensor 11 can be expanded, and sticking detection can be performed under a finer temperature condition.
As a result, the failure diagnosis device 12 for the oil temperature sensor 11 according to this modified example not only performs the diagnosis from the start of the engine 1 but also the temperature T _{n of the} hydraulic oil that is always detected by the oil temperature sensor 11 while the vehicle is traveling. It is possible to determine a failure that sticks to a high temperature. In addition, the failure diagnosis device 12 of the oil temperature sensor 11 can set not only a plurality of preset determination reference temperatures _Tth, but also finely set the diagnosis permission regions α, β, γ for each, so that it can be further set according to the temperature range. This gives you a wide range of choices and allows you to accurately determine failures over a wide range of temperatures. Furthermore, the failure diagnosis device 12 of the oil temperature sensor 11 of this modification can detect a failure even at a lower temperature even if the temperature value that the oil temperature sensor 11 can take is fixed during normal running.
In addition, since the failure diagnosis device 12 of the oil temperature sensor 11 performs diagnosis using the transmission ratio map 10 that sets the transmission ratio, the failure is highly accurate even when the load changes, such as traveling at each gradient. Detection is possible. Furthermore, since the failure diagnosis device 12 for the oil temperature sensor 11 can detect the failure at an earlier stage and increase the opportunity to receive service, the oil temperature sensor 11 continues to run with the failure. Deterioration of fuel consumption and exhaust gas components can be suppressed.

In the above-described embodiment, the automatic transmission 2 including the continuously variable transmission (CVT) including the primary pulley, the secondary pulley, and the belt wound between these pulleys has been described. As shown, automatic transmissions consisting of a torque converter and a gear-type auxiliary transmission mechanism can also be applied by setting the diagnosis permission area for the gear stage (fixed transmission ratio), vehicle speed, and throttle opening in the shift map. Is possible.
In FIG. 7, 101 is an engine mounted on the vehicle, and 102 is an automatic transmission. The automatic transmission 102 is a stepped transmission (AT) and includes a torque converter and a gear type auxiliary transmission mechanism as a transmission mechanism. The automatic transmission 102 including a stepped transmission includes a reverse speed and can be shifted from, for example, 1st speed to 4th speed by a torque converter and a gear-type auxiliary transmission mechanism. The automatic transmission 102 performs a shift by supplying hydraulic oil to the gear-type auxiliary transmission mechanism by the control valve mechanism 103 and switching the meshing body of each gear.
The operation of the control valve mechanism 103 is controlled by the shift control device 104 of the automatic transmission 102. A vehicle speed sensor 105 that detects the vehicle speed of the vehicle and a throttle opening sensor 106 that detects the throttle opening of the engine 101 are connected to the shift control device 104, and the input rotational speed on the input side of the automatic transmission 102 is further connected. An input rotational speed sensor 107 for detecting the output speed, an output rotational speed sensor 108 for detecting an output rotational speed on the output side of the automatic transmission 102, a lock-up solenoid 109 for a lock-up clutch of the automatic transmission 102, an automatic transmission 102 A select solenoid 110 or the like is connected.
As shown in FIG. 6, the shift control device 104 includes a shift map 111 that sets a gear stage (fixed gear ratio) based on the vehicle speed V and the throttle opening degree _Thr of the vehicle, and is actually detected. The operation of the control valve mechanism 103 is controlled based on the vehicle speed V and the throttle opening degree _Thr, and the hydraulic oil supplied to the gear-type auxiliary transmission mechanism is adjusted to shift the automatic transmission 102.
The shift map 111 is set based on the vehicle speed V and the throttle opening degree T _hr , and is divided into a plurality of shift lines, 1-2 shift lines, 2-3 shift lines, so as to be divided into each gear stage of the gear type auxiliary transmission mechanism. By delimiting by the 3-4 shift line, each gear stage (fixed gear ratio) is selectively set in the shift control. Each of the plurality of shift lines, the 1-2 shift line, the 2-3 shift line, and the 3-4 shift line is generally provided with hysteresis so as to be different in the case of upshifting and in the case of downshifting. Has been done.
Since the automatic transmission 102 performs an operation related to the shift by hydraulic pressure, the load applied to the hydraulic oil is large and the temperature becomes high. The shift control device 104 includes an oil temperature sensor 112 that detects the temperature of the hydraulic oil because the responsiveness changes when the temperature of the hydraulic oil of the automatic transmission 102 changes. The shift control device 104 detects the temperature of the hydraulic oil by the hydraulic sensor 112 and controls the hydraulic pressure by the control valve mechanism 103 based on the detected temperature of the hydraulic oil. The shift control device 104 includes a failure diagnosis device 113 for the hydraulic sensor 112 because the shift control is hindered if the hydraulic sensor 112 fails. Fault diagnosis functions such as various sensors including the oil temperature sensor 112 are provided as one function in the shift control device 104.

The failure diagnosis device 113 of the oil temperature sensor 112 includes the shift map 111 that sets the gear ratio of the automatic transmission 102 based on the vehicle speed V of the vehicle and the throttle opening _{Thr of the} engine 101, and the temperature of the hydraulic oil The oil temperature sensor 112 for detecting the oil temperature is provided, and the diagnostic means 114 for determining the presence or absence of a failure based on the temperature T _n of the hydraulic oil detected by the oil temperature sensor 112 is provided.
Diagnostic means 114 calculates a preset relative hydraulic oil determination reference temperature _T from _th predetermined hysteresis temperature _{T h} a reduced determination threshold temperature _(T th -T _h), as shown in FIG. 6, the shift The range of the gear ratio in the map 111 where the temperature T _n of the running hydraulic oil is equal to or lower than the determination threshold temperature (T _th −T _h ) is set as the diagnosis permission region α corresponding to the determination reference temperature T _th. It is set. As long as the vehicle travels within the diagnosis permission region α, the temperature T _{n at} which the hydraulic oil is in an equilibrium state is equal to or lower than the determination threshold temperature (T _th −T _h ).
The diagnosis permission region α basically has an upper limit on a curve Z that changes depending on the ratio of the heat generation amount and the cooling amount according to the vehicle speed V in the region corresponding to each gear stage (fixed gear ratio) of the shift map 111. Give as value. This curve Z is given as an upper limit value corresponding to the throttle opening degree _Thr , and a smaller range of the throttle opening degree _Thr is set as a diagnosis permission region α.
Moreover, the curve Z is compared with the area adjacent to each other about the region corresponding to the gear (fixed gear ratio), the higher the vehicle speed V is, the throttle opening T _hr Gayori larger value. In the vicinity of a shift line (1-2 shift line, 2-3 shift line, 3-4 shift line) that becomes a boundary between adjacent areas, a curve Z is continuously made with a slope so as to overlap the shift line, and diagnosis is performed. The permission area α is set.
The diagnosis permission region α is set in the shift map 111 in consideration of the lockup clutch operation provided in the torque converter in addition to the vehicle speed V, the throttle opening degree T _hr and the gear stage (fixed gear ratio). The lockup clutch is turned on and the input and output of the torque converter are mechanically coupled to reduce the load of hydraulic fluid flowing in the torque converter and suppress the temperature rise (heat generation). Set to widen α. Even if the shift line is in the vicinity, as shown in the figure, the diagnosis permission region α is set so as to expose a large step-like curve Z in a form that does not overlap the shift line. In the vehicle speed range where the lockup clutch is connected, the diagnosis permission region α can be widened regardless of the vicinity of the shift line.
The diagnostic means 114 has a current hydraulic oil temperature T _n detected by the oil temperature sensor 112 while the vehicle speed V and the throttle opening T _hr are within the diagnosis permission region α while the vehicle is traveling. However, if a predetermined time (failure determination condition time) t _f has elapsed while maintaining a state exceeding the determination reference temperature T _th corresponding to the diagnosis permission region α, it is determined as a failure. The failure diagnosis device 113 includes a failure determination condition timer 115 that measures an elapsed time t ₁ for comparison with a predetermined time (failure determination condition time) t _f at the time of failure, and a predetermined time (normal determination condition time) t _t at normal time. and a normality determination condition timer 116 for measuring the elapsed time t ₂ for comparison with.

Next, the operation will be described with reference to FIG.
In FIG.
• T _n [° C.]: Current hydraulic oil temperature • T _{n (t−1)} [° C.]: Temperature of hydraulic oil before one cycle • T _th [° C.] Criteria temperature for oil temperature sensor sticking failure T _h [° C.]: Hysteresis temperature of judgment reference temperature • t _f [sec]: Failure judgment condition time • t ₁ [sec]: Elapsed time measured by the failure judgment condition timer • t _t [sec]: Normal judgment condition time T ₂ [sec]: Elapsed time measured by the normal determination condition timer.

5, the elapsed fault diagnosis apparatus 113 by the diagnostic means 114, a failure diagnosis of the oil pressure sensor 112 starts to (B01), the failure determination condition timer 115 elapsed time is measured _{t 1} and normality determination condition timer 116 has measured The time t ₂ is reset (t ₁ = 0, t ₂ = 0) (B02), and the current temperature T _n of the hydraulic oil detected by the oil temperature sensor 112 is taken in (B03). 2 is judged (B04).

Precondition 1 is
-The oil temperature sensor 112 has not already failed due to other requirements-The oil temperature sensor 112 is not an electrical failure-The oil temperature sensor 112 is not a functional failure (function failure judgment on the existing low temperature side)
.

Precondition 2 is
・ The input value / function used for the precondition determination / diagnosis permission condition is normal. ・ The various sensors used for this control are not a GND disconnection failure. ・ The throttle opening sensor 106 is not an electrical failure. ・ The throttle opening sensor 106 is not a functional failure. The input speed sensor 107 is not an electrical failure. The input speed sensor 107 is not a malfunction. The output speed sensor 108 is not an electrical failure. The output speed sensor 108 is not a malfunction. The lockup clutch is not a malfunction. The lockup solenoid 109 is not an electrical failure. The lockup solenoid 109 is not a functional failure. The select solenoid 110 is not a failure.

  If the determination (B04) is NO, the process returns to the process (B03). When the determination (B04) is YES, it is determined whether the diagnosis permission condition 3 and the permission condition 4 are satisfied (B05).

Permission condition 3 is
The current throttle opening degree T _hr and the vehicle speed V point are within the diagnosis permission region α in which “the hydraulic oil temperature T _n is equal to or lower than the determination threshold temperature (T _th −T _h )”.

Permission condition 4 is
The lock-up clutch is in an ON state. Control is being performed with the normal shift map 111.

If the determination (B05) is NO, the process returns to the process (B03). If decision (B05) is YES, the temperature _{T n} of the hydraulic fluid to determine exceeds the determination reference temperature _{T th (T n> T th} ) (B06).
When determination (B06) is NO, it transfers to below-mentioned process (B11). If the determination (B05) is YES, whether the current hydraulic oil temperature Tn is _equal to the hydraulic oil temperature _{Tn (t-1)} one cycle before ( _Tn = _{Tn (t-1)} ) Judgment is made (B07).
When determination (B07) is NO, it transfers to the below-mentioned process (B11). If the determination (B07) is YES, the measurement of the elapsed time t ₁ by the failure determination condition timer 115 is continued (t ₁ = t ₁ +1), and the elapsed time t ₂ measured by the normal determination condition timer 116 is set to zero (t ₂ = 0) and (B08), the elapsed time _{t 1} measured failure determination condition timer 115 failure determination condition time (predetermined time) or exceeds _{t f (t} 1> _{t f)} is determined (B09).
If the determination (B09) is NO, the process returns to the process (B03). If the determination (B09) is YES, it is determined that the oil temperature sensor 112 has failed (B10), and the process returns to the process (B02).
On the other hand, when the determination (B06) is NO and the determination (B07) is NO, the measurement of the elapsed time t ₂ by the normal determination condition timer 116 is continued (t ₂ = t ₂ +1), and the failure determination condition timer 115 The elapsed time t ₁ measured in step S1 is set to zero (t ₁ = 0) (B11), and the elapsed time t ₂ measured by the normal judgment condition timer 116 exceeds the normal judgment condition time (predetermined time) t _t (t ₂ > t _t ) is determined (B12).
If the determination (B12) is NO, the process returns to the process (B03). When judgment (B12) is YES, it determines with oil temperature sensor 112 being normal (B13), and returns to the above-mentioned processing (B02). Therefore, failure diagnosis apparatus 113 determines that oil temperature sensor 112 is normal (normal determination condition is satisfied) when failure determination condition is not satisfied for a predetermined time (t _t ).

In this way, the failure diagnosis device 113 of the oil temperature sensor 112 determines the sticking failure determination reference temperature T _th on the high temperature side of the oil temperature sensor 112, performs steady running on the normal shift map 111, and reaches an equilibrium state. Further, a diagnosis permission region α (vehicle speed−throttle opening) in which the oil temperature T _n is equal to or lower than the determination threshold temperature (T _th −T _h ) (T _n ≦ (T _th −T _h )) is set on the shift map 111. . The failure diagnosis device 113 detects that the temperature T _{n of the} hydraulic oil detected by the oil temperature sensor 112 exceeds the determination reference temperature T _th while traveling within the diagnosis permission region α in the normal shift map 111 (T _n > T _th ) indicates, and if the temperature T _n of the hydraulic oil does not change more than a predetermined time t _f, to detect a failure due to sticking of the oil temperature sensor 112.
As a result, the failure diagnosis device 113 for the oil temperature sensor 112 not only performs diagnosis from the start of the engine 101, but also constantly increases the temperature T _{n of the} hydraulic oil detected by the oil temperature sensor 112 while the vehicle is traveling. It is possible to determine the failure that is stuck. In addition, the failure diagnosis device 113 of the oil temperature sensor 112 can finely set the diagnosis permission region α even if there is only one determination reference temperature T _{th to} be set in advance, so that the failure can be accurately determined over a wide range of temperatures. Furthermore, since the failure diagnosis device 113 of the oil temperature sensor 112 performs diagnosis using the shift map 111 for setting the gear ratio, it is possible to detect failure with high accuracy even when the load changes such as traveling at each gradient. Is possible.
Further, the failure diagnosis device 113 for the oil temperature sensor 112 can detect a failure even when the temperature value that the oil temperature sensor 112 can take is fixed during normal running. Furthermore, since the failure diagnosis device 113 of the oil temperature sensor 112 can detect the failure at an early stage and increase the chance of receiving service, the fuel consumption deteriorates as a result of the oil temperature sensor 112 continuing to run with the failure. In addition, deterioration of exhaust gas components can be suppressed.
In the second embodiment, one of the parameters of the shift map is the throttle opening, but it may be an accelerator opening (pedal operation amount).

  This invention can accurately determine a failure in which an oil temperature sensor of an automatic transmission outputs only a high temperature, and can prevent deterioration of fuel consumption performance and exhaust gas components by running in a failure state of the oil temperature sensor. Therefore, the present invention can be applied to various automatic transmissions that perform a shift by hydraulic pressure of hydraulic oil.

DESCRIPTION OF SYMBOLS 1 Engine 2 Automatic transmission 3 Control valve mechanism 4 Shift control apparatus 5 Vehicle speed sensor 6 Input rotation speed sensor 7 Secondary rotation speed sensor 8 Lockup solenoid 9 Select solenoid 10 Gear ratio map 11 Oil temperature sensor 12 Fault diagnosis device 13 Diagnosis means 14 Failure judgment condition timer 15 Normal judgment condition timer

Claims (5)

An oil temperature sensor that detects the temperature of hydraulic oil in an automatic transmission mounted on the vehicle,
In the oil temperature sensor failure diagnosis device that determines the presence or absence of a failure based on the temperature detected by the oil temperature sensor,
A gear ratio map for setting the gear ratio of the automatic transmission based on the vehicle speed of the vehicle and the input rotational speed of the automatic transmission;
Calculate a determination threshold temperature from a predetermined determination reference temperature for hydraulic oil,
Diagnosis permission corresponding to the determination reference temperature is a range between the transmission ratio upper limit and the transmission ratio lower limit of the transmission ratio map, and the range of the transmission ratio in which the temperature of the running hydraulic oil is equal to or lower than the determination threshold temperature Set as area,
The vehicle speed and the input rotational speed during traveling are within the diagnosis permission region, and a predetermined time is maintained while maintaining a state where the temperature of the hydraulic oil detected during traveling exceeds a determination reference temperature corresponding to the diagnosis permission region. An oil temperature sensor failure diagnosing device, comprising: a diagnosis unit that determines that a failure occurs when the time has elapsed. An oil temperature sensor that detects the temperature of hydraulic oil in an automatic transmission mounted on the vehicle,
In the oil temperature sensor failure diagnosis device that determines the presence or absence of a failure based on the temperature detected by the oil temperature sensor,
A gear ratio map for setting the gear ratio of the automatic transmission based on the vehicle speed of the vehicle and the input rotational speed of the automatic transmission;
Calculating a plurality of determination threshold temperatures according to a plurality of determination reference temperatures set in advance for the hydraulic oil;
The range of the gear ratio that is between the gear ratio upper limit and the gear ratio lower limit of the gear ratio map and in which the temperature of the running hydraulic fluid is equal to or less than each of the plurality of determination threshold temperatures is the plurality of determinations. Set as multiple diagnosis permission areas corresponding to the reference temperature,
The vehicle speed and the input rotation speed are within one of the plurality of diagnosis permission areas during traveling, and the temperature of the hydraulic oil detected during traveling is within the diagnosis permission area where the vehicle speed and the input rotation speed are present. An oil temperature sensor failure diagnosing device, comprising: a diagnosis unit that determines that a failure occurs when a predetermined time elapses while maintaining a state exceeding a corresponding determination reference temperature. An oil temperature sensor that detects the temperature of hydraulic oil in an automatic transmission mounted on the vehicle,
In the oil temperature sensor failure diagnosis device that determines the presence or absence of a failure based on the temperature detected by the oil temperature sensor,
A shift map for setting the gear ratio of the automatic transmission based on the vehicle speed and throttle opening of the vehicle is provided.
Calculate a determination threshold temperature from a predetermined determination reference temperature for hydraulic oil,
A range of the speed change map in which the temperature of the running hydraulic oil is equal to or lower than the determination threshold temperature is set as a diagnosis permission region corresponding to the determination reference temperature;
While maintaining the state where the vehicle speed and the throttle opening are within the diagnosis permission region during traveling and the temperature of the hydraulic oil detected during traveling exceeds the determination reference temperature corresponding to the diagnosis permission region, a predetermined time is maintained. An oil temperature sensor failure diagnosing device, comprising: a diagnosis unit that determines that a failure occurs when the time has elapsed. Set a curve according to the throttle opening that defines the diagnosis permission region,
The curve is set in accordance with the vehicle speed for each region corresponding to the gear stage in the shift map, and is set along the shift line at the boundary between the regions corresponding to the mutually adjacent gear stages. 4. The oil temperature sensor failure diagnosis apparatus according to claim 3, wherein the throttle opening is set to be larger than a value corresponding to the vehicle speed in a vehicle speed range to which is connected. An oil temperature sensor that detects the temperature of hydraulic oil in an automatic transmission mounted on the vehicle,
In the oil temperature sensor failure diagnosis device that determines the presence or absence of a failure based on the temperature detected by the oil temperature sensor,
A map for setting a gear ratio of the automatic transmission based on a plurality of parameters indicating various states in the vehicle;
Calculate a determination threshold temperature from a predetermined determination reference temperature for hydraulic oil,
A range of the map, where the temperature of the running hydraulic oil is equal to or lower than the determination threshold temperature is set as a diagnosis permission region corresponding to the determination reference temperature,
A plurality of parameters are both within the diagnosis permission area during traveling, and a predetermined time has elapsed while maintaining a state in which the temperature of the hydraulic oil detected during traveling exceeds the determination reference temperature corresponding to the diagnosis permission area An oil temperature sensor failure diagnosing apparatus, comprising: a diagnosis unit that determines that a failure has occurred.

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