JP2007162905A - Diagnosis device for automatic transmission of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent wrong diagnosis of abnormality of a gear ratio even when diagnosis is performed in a speed reducing operation where engine brake is not acted. <P>SOLUTION: An actual gear ratio GRR is operated on the basis of an input shaft rotating speed and an output shaft rotating speed of a transmission. A normal gear ratio GRD is determined on the basis of a gear shift stage at that time. The abnormality in gear ratio is judged when the actual gear ratio is deflected to a low side or a high side with respect to the normal gear ratio GRD under an acting condition of the engine brake, and the abnormality is judged when the actual gear ratio is deflected only to the low-side, under non-acting condition of the engine brake. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a diagnostic apparatus for diagnosing an abnormality in a gear ratio of a transmission in a vehicle automatic transmission having a condition for selectively operating an engine brake.

In Patent Document 1, an actual gear ratio is calculated based on the input rotation speed and output rotation speed of the transmission, and the actual gear ratio is compared with a normal gear ratio to diagnose a transmission failure. An apparatus is described.
Japanese Patent Laid-Open No. 01-172663

  By the way, in an automatic transmission that selectively operates the engine brake based on conditions such as the gear position and the accelerator opening, the output shaft rotational speed of the transmission is set to the idling of the one-way clutch during deceleration without the engine brake being operated. The actual gear ratio calculated based on the input / output rotational speed easily shifts to the high gear side (high speed gear side) with respect to the normal gear ratio.

For this reason, when the gear ratio abnormality is diagnosed at the time of deceleration in the same manner as at the time of acceleration, the shift to the high side may be erroneously diagnosed as being caused by an abnormality in the transmission.
Here, if the diagnosis of gear ratio abnormality is prohibited during deceleration and the diagnosis is performed only during acceleration, it is possible to prevent the occurrence of misdiagnosis associated with deceleration operation, but the diagnosis is performed only during acceleration. And there was a problem that there were fewer opportunities for diagnosis.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a diagnostic device that can avoid erroneously diagnosing an abnormality in the gear ratio even if diagnosis is performed during deceleration operation without operating the engine brake. And

  Therefore, a diagnostic device for an automatic transmission for a vehicle according to a first aspect of the invention detects an actual gear ratio of the transmission in an automatic transmission for a vehicle having a condition for selectively operating an engine brake, and A diagnostic apparatus for diagnosing an actual gear ratio abnormality, wherein the diagnostic characteristic of the gear ratio abnormality is switched according to whether or not the engine brake is operated.

According to such a configuration, the change characteristic of the gear ratio varies even if the transmission is normal depending on whether or not the condition for operating the engine brake is changed. Therefore, the diagnosis characteristic is switched to cope with the difference in the gear ratio characteristic. .
Therefore, it is possible to avoid the occurrence of misdiagnosis regardless of whether or not the conditions for operating the engine brake are satisfied.

According to the second aspect of the present invention, when it is not a condition for operating the engine brake, a shift to the high side of the actual gear ratio is less likely to be abnormally determined than when it is a condition for operating the engine brake. It is characterized by switching.
According to such a configuration, if the engine is decelerated when the engine brake is not operated, the actual gear ratio easily shifts to the high side. Accordingly, when the engine brake is not operated, the high gear is The shift is made so that it is difficult for the deviation to be determined as abnormal.

Therefore, even if the gear ratio shifts to the high side due to the deceleration operation when the engine brake is not activated, it is possible to prevent erroneous diagnosis of the gear ratio.
According to a third aspect of the present invention, there is provided a vehicular automatic transmission diagnostic apparatus that detects an actual gear ratio of a transmission in a vehicular automatic transmission having a condition for selectively operating an engine brake, and that detects the actual gear ratio. Diagnosing an abnormality in the gear ratio of the present invention, characterized in that it comprises a diagnostic means that is set such that a shift to the high side is harder to be judged as abnormal than a shift to the low side of the actual gear ratio.

According to such a configuration, in the transmission in which the gear ratio may shift to the high side due to the deceleration operation when the engine brake is not operated, the diagnostic means that is set so as to make it difficult to abnormally determine the shift to the high side is provided. Prepare.
Therefore, when the gear ratio is shifted to the high side due to the deceleration operation when the engine brake is not operated, it is possible to prevent erroneous diagnosis as an abnormal gear ratio.

In the invention according to claim 4, the setting that makes it difficult for the actual gear ratio shift to the high side to be abnormally determined is diagnosed as a shift of the gear ratio to the low side as abnormal, and the shift to the high side is regarded as normal. It is characterized by that.
According to this configuration, when the actual gear ratio shifts to the high side (high speed side), this is not diagnosed as an abnormal gear ratio, and the actual gear ratio shifts to the low side (low speed side). It is diagnosed that the gear ratio is abnormal.

Therefore, when the gear ratio is shifted to the high side due to the deceleration operation when the engine brake is not operated, it is possible to prevent erroneous diagnosis as an abnormality of the gear ratio.
According to the fifth aspect of the invention, the threshold value for determining the deviation between the actual gear ratio and the regular gear ratio is made different between the low side and the high side, so that the deviation to the high side is hardly determined abnormally. It is characterized by that.

According to such a configuration, by comparing the deviation between the actual gear ratio and the regular gear ratio and the threshold value, it is determined whether the actual gear ratio is different from the regular gear ratio so as to be recognized as abnormal. When making a diagnosis, an abnormality determination is not made unless the amount of shift to the high side is larger than the amount of shift to the low side.
Therefore, when the gear ratio is shifted to the high side due to the deceleration operation when the engine brake is not operated, it is possible to prevent erroneous diagnosis as an abnormality of the gear ratio.

The invention according to claim 6 is a configuration for diagnosing a gear ratio abnormality based on a duration of a state in which an actual gear ratio is different from a normal gear ratio, and a threshold for judging the duration is set to a low side. By making it different from the high side, the shift to the high side is made difficult to be abnormally determined.
According to such a configuration, the state where the actual gear ratio deviates from the normal gear ratio continues, and finally the gear ratio abnormality is diagnosed, but when it deviates to the high side, it deviates to the low side. If it does not continue for a longer time than when it is present, the final abnormality determination is not made, and as a result, the shift to the high side is hardly diagnosed as an abnormality.

  Therefore, when the gear ratio is shifted to the high side due to the deceleration operation when the engine brake is not operated, it is possible to prevent erroneous diagnosis as an abnormality of the gear ratio.

Embodiments of the present invention will be described below.
1 and 2 show an automatic transmission for a vehicle in the present embodiment.
The automatic transmission 102 connected to the engine 101 is electronically controlled to change the gear stage by a shift control controller 103 incorporating a microcomputer.
The shift controller 103 includes a shift position signal from the inhibitor switch 105 corresponding to the operation position of the shift lever 104, an accelerator position signal from an accelerator position sensor 106 that detects the depression amount of the accelerator pedal, and the automatic transmission. A vehicle speed signal from a vehicle speed sensor 107 that detects a vehicle speed from an output shaft rotation speed of 102, a turbine rotation signal from a turbine rotation sensor 108 that detects a turbine rotation speed that is an input shaft rotation speed of the automatic transmission 102, and the like are read. .

In the D range, a target shift stage is determined by referring to a shift map that stores the shift stage in advance according to the vehicle speed and the accelerator opening, and a friction described later is used to switch to the target shift stage. A control signal is output to various solenoids that control engagement / release of the engagement element.
The input shaft 2 of the automatic transmission 102 is connected to the output shaft 1 of the engine 101 via a torque converter 3 having a lock-up clutch 3L.

A space between the input shaft 2 and the output shaft 6 of the automatic transmission 102 is mainly composed of a first planetary gear mechanism 4 and a second planetary gear 5, and the power transmission of the first and second planetary gears 4 and 5 is performed. As a frictional engagement element for switching the path, a low and reverse brake L & R / B, an overrun clutch OVR / C, and the like are disposed as described later.
The first planetary gear 4 is a simple planetary gear composed of a carrier 4C that rotatably and revolvingly supports a pinion 4P that meshes with a sun gear 4S and a ring gear 4R, and the second planetary gear 5 is also a sun gear 5S, This is a simple planetary gear comprising a carrier 5C that supports a pinion 5P engaged with the ring gear 5R so as to be rotatable and revolved.

The carrier 4C of the first planetary gear 4 is selectively fastened to the input shaft 2 via a high clutch H / C, and the sun gear 4S can be selectively fixed via a band brake B / B. It is selectively fastened to the input shaft 2 via the scratch R / C.
Further, the carrier 4C of the first planetary gear 4 is provided with a low-and-reverse brake L & R / B that is selectively fixed to the casing side, and power from the input shaft 2 side to the output shaft 6 side only during acceleration. Is transmitted, while a low one-way clutch LO / C that prevents power transmission from the output shaft 6 side to the input shaft 2 side is interposed. The carrier 4C of the first planetary gear 4 is selectively fastened to the input shaft 2 via the high clutch H / C.

Further, the ring gear 4R of the first planetary gear 4 is coupled integrally with the carrier 5C and coupled to the output shaft 6.
On the other hand, the sun gear 5S of the second planetary gear 5 is coupled to the input shaft 2, and the ring gear 5R is selectively fastened to the carrier 4C side via the overrun clutch OVR / C, and the forward one-way clutch FO / C and forward When the clutch F / C is disposed and the forward clutch F / C is engaged, the forward one-way clutch FO / C is operated to transmit power from the input shaft 2 side to the output shaft 6 side only during acceleration, Power transmission from the output shaft 6 side to the input shaft 2 side is blocked.

Of the various frictional engagement elements, the high clutch H / C is engaged when the third speed or higher, and the band brake B / B is engaged when the second speed.
Here, as shown in FIG. 3, the various friction engagement elements 109 perform a fastening / release operation according to the hydraulic pressure supplied through the control valve 110, and the control valve 110 Drive control is performed by a lockup solenoid 111, a first shift solenoid 112, a second shift solenoid 113, an overrun clutch solenoid 114, and a line pressure solenoid 115.

The shift control controller 103 automatically controls the shift stage by controlling on / off of the various solenoids.
For example, in the D range, when the target shift speed is the first speed, both the first and second shift solenoids 112 and 113 are turned on, and only the forward clutch F / C is engaged. Only forward, and forward clutch F / C and band brake B / B are engaged. At the third speed, both the first and second shift solenoids 112 and 113 are turned off, and the forward clutch F / C, the high clutch H / C, and the band brake B / B are engaged.

In the D range, in addition to the forward clutch F / C being always engaged as described above, the overrun clutch OVR / C is selectively engaged and the engine brake is activated under a predetermined engine brake operating condition. Put it in a state.
When only the forward clutch F / C is engaged and the overrun clutch OVR / C is disengaged, the second planetary gear via the low one-way clutch LO / C and the forward one-way clutch FO / C only in the acceleration state Since the ring gear 5R is fixed, the driving force is transmitted from the sun gear 5S coupled to the input shaft 2 to the output shaft 6 via the carrier 5C that supports the pinion 5P.

On the other hand, when the driving force is input from the deceleration state, that is, from the output shaft 6 side, the forward one-way clutch FO / C and the low one-way clutch LO / C rotate idly, so that the ring gear 5R rotates according to the carrier 5C and is input. Power transmission to the shaft 2 side is not performed, and the engine brake does not operate.
On the other hand, for example, when the accelerator is in a predetermined low gear range at a predetermined gear position, the low and reverse brake L & R / B and the low and reverse brake L & R / B are over. When the run clutch OVR / C is selectively engaged, the ring gear 5 is fixed regardless of the acceleration / deceleration state, so that the driving force of the engine is transmitted from the input shaft 2 to the output shaft 6 and the carrier 5C, The engine brake can be operated by transmitting power from the output shaft 6 to the input shaft 2 via the pinion 5P.

As described above, the shift control controller 103 has a function of automatically controlling the shift speed of the transmission 102 and a function of selectively operating the engine brake under predetermined conditions, and diagnoses an abnormality in the gear ratio in the transmission 102. By doing so, it has a function of diagnosing an abnormality in the mechanical part of the transmission 102.
The flowchart of FIG. 4 shows a first embodiment of the diagnostic function.

The routine shown in the flowchart of FIG. 4 is executed every predetermined minute time. First, in step S101, the turbine rotation speed, which is the input shaft rotation speed Nin of the transmission 102, is detected based on a signal from the turbine rotation sensor 108. The output shaft rotational speed Nout of the transmission 102 is detected based on a signal from the vehicle speed sensor 107.
In the next step S102, the gear ratio GRR (GRR = Nin / Nout) of the transmission 102 is calculated from the input shaft rotational speed Nin and the output shaft rotational speed Nout.

The gear ratio GRR is preferably calculated on condition that the gear is not being changed.
In step S103, the normal gear ratio GRD is determined from the target gear position at that time.
Specifically, the gear ratio corresponding to each gear stage is stored in advance, and the gear ratio data corresponding to the target gear stage at that time is retrieved.
In step S104, it is determined whether the engine brake operating condition is satisfied.

For example, when a region for operating the engine brake is set in a map corresponding to the accelerator opening and the vehicle speed, it is determined whether or not the accelerator opening and the vehicle speed at that time are included in the engine brake operating region. To do.
If it is the engine brake operating condition, the process proceeds to step S105, where the actual gear ratio GRR is the normal gear ratio GRD + the predetermined value α, the upper limit value MAX, and the normal gear ratio GRD−predetermined value α. It is determined whether or not it is included in a normal gear ratio region sandwiched by the lower limit value MIN, that is, whether or not GRD−α ≦ GRR ≦ GRD + α (see FIG. 5).

If the transmission 102 is normal, the predetermined value α (threshold) is set so that GRD−α ≦ GRR ≦ GRD + α even if there is a rotational speed detection error.
Accordingly, if GRD−α ≦ GRR ≦ GRD + α, the process proceeds to step S106, where it is determined that the transmission 102 is normal, and if GRD−α> GRR or GRR> GRD + α, the mechanism portion of the transmission 102 is determined. Since some failure has occurred, it is determined that the gear ratio GRR indicates an abnormal value, and the process proceeds to step S107 to determine whether the transmission 102 is abnormal.

When an abnormality of the transmission 102 is determined, the driver is notified of a malfunction of the transmission by lighting a warning lamp provided near the driver's seat of the vehicle, lock-up or engine brake operation is prohibited, For example, the shift to the target shift stage where the abnormality is diagnosed is prohibited.
On the other hand, if it is determined in step S104 that the engine brake operating condition is not satisfied, the process proceeds to step S108.

In step S108, it is determined whether or not the actual gear ratio GRR exceeds the upper limit MAX that is the normal gear ratio GRD + the predetermined value α.
When GRR> GRD + α, it is determined that the gear ratio has shown an abnormal value because some failure has occurred in the mechanical part of the transmission 102, and the process proceeds to step S109 to determine whether the transmission 102 is abnormal. .

On the other hand, when GRR ≦ GRD + α, the routine proceeds to step S110, where it is determined that the transmission 102 is normal.
Therefore, when the engine brake operating condition is not satisfied, an abnormality is not diagnosed even if the actual gear ratio GRR is lower than the normal gear ratio GRD (shifted to the high side), and the actual gear ratio GRR is not the normal gear ratio. An abnormality is diagnosed only when the ratio GRD is exceeded (when shifted to the low side) (see FIG. 6).

When the engine is decelerated under the condition that the engine brake is not activated, the forward one-way clutch FO / C and the low one-way clutch LO / C are idled, so that the actual gear ratio GRR is higher than the regular gear ratio GRD (regular Easily shifts to a smaller side than the gear ratio GRD.
For this reason, as in the condition where the engine brake is operated, if the shift to the high side (GRD−α> GRR) is determined as abnormal, the transmission 102 is actually determined to be abnormal although it is normal. End up.

  Therefore, in the above embodiment, when the engine brake operating condition is not satisfied, it is determined that only the shift of the actual gear ratio GRR to the low side is abnormal, and the abnormality is not determined based on the shift to the high side. Even if the actual gear ratio GRR is shifted to a higher side than the normal gear ratio GRD during deceleration operation without engine braking, an abnormality of the transmission 102 is not erroneously diagnosed.

Note that the characteristic of judging only the shift to the low side as abnormal can be applied only when the engine brake is not operating and when the vehicle is decelerating.
The flowchart of FIG. 7 shows a second embodiment of the diagnostic function.
This second embodiment differs from the first embodiment only in the setting of the normal range of the gear ratio used for abnormality determination in step S208 when the engine brake is not operating condition, and other steps (S201 to S207, Steps S209 and S210 are processed in the same manner as the steps (S101 to S107, S109, and S110) of the first embodiment.

In step S208, the predetermined value β is used, and when GRR> GRD + α or GRD−β> GRR, an abnormality in the gear ratio is determined.
The predetermined values α and β are threshold values for determining a deviation between the actual gear ratio GRR and the normal gear ratio GRD. As shown in FIG. 8, the predetermined value β is sufficiently higher than the predetermined value α. It is set as a large value.

As a result, the engine is decelerated under the condition that the engine brake is not operated, and even if the actual gear ratio GRR is shifted to a higher side than the normal gear ratio GRD (a side smaller than the normal gear ratio GRD), this is diagnosed as an abnormality. It is hard to be done.
Therefore, even if the engine is decelerated under the condition that the engine brake is not operated and the actual gear ratio GRR shifts to the high side, it can be prevented from diagnosing this as an abnormality in the gear ratio.

The flowchart of FIG. 9 shows a third embodiment of the diagnostic function.
In the third embodiment, the final abnormality determination is performed when the continuation time when the gear ratio GRR is determined to be abnormal reaches a predetermined time.
In the flowchart of FIG. 9, in steps S301 to S303, the actual gear ratio GRR is calculated and the normal gear ratio GRD is set as in steps S101 to S103.

In step S304, whether or not the actual gear ratio GRR is abnormal is determined by determining whether or not GRD−α ≦ GRR ≦ GRD + α as in step S105.
Here, if it is determined that GRD−α ≦ GRR ≦ GRD + α and the actual gear ratio GRR indicates a normal value, the process proceeds to step S305, and a timer for measuring the duration of the abnormality determination is set to 0. Reset to.

The timer is also reset to 0 when a shift is performed.
On the other hand, if it is determined that GRD-α> GRR or GRR> GRD + α and the actual gear ratio GRR indicates an abnormal value, the process proceeds to step S306, where the timer is counted up to determine that the gear ratio is abnormal. The duration time T is measured.
In step S307, as in step S104, it is determined whether the engine brake operating condition is satisfied.

If it is determined that the engine brake operating condition is satisfied, the process proceeds to step S308, where a predetermined time T1 is set as the threshold Ts of the duration T.
On the other hand, if it is determined that the engine brake operating condition is not satisfied, the process proceeds to step S309, where a predetermined time T2 is set as the threshold Ts of the duration T. Here, the predetermined time T2 is set to a time longer than the predetermined time T1.

In step S310, the duration T measured by the timer is compared with the threshold Ts. If the duration T is equal to or less than the threshold Ts, the process proceeds to step S311 and it is determined that the gear ratio is normal.
On the other hand, if the duration T is longer than the threshold value Ts, the process proceeds to step S312 and it is determined that the gear ratio is abnormal.

According to the third embodiment, an abnormality is diagnosed in step S304 when the actual gear ratio GRR shifts to a higher side than the normal gear ratio GRD due to the deceleration operation, not the engine brake operating condition. Become.
However, the final abnormality determination is made after the duration T becomes equal to or greater than the threshold value Ts. However, when the engine brake is not in the operating condition, the threshold value Ts is set longer than in the operating condition. Therefore, even if the gear ratio GRR shifts to the high side when the engine brake is not applied, the final abnormality determination based on this is suppressed, and erroneous determination can be prevented.

Note that the threshold value Ts can be set to the predetermined time T2 on the condition that the engine brake operating condition is not satisfied and the gear ratio GRR is shifted to the high side.
The flowchart of FIG. 10 shows a fourth embodiment of the diagnostic function.
As in the third embodiment, the fourth embodiment is configured to perform a final abnormality determination when a duration time during which the gear ratio GRR is determined to be abnormal reaches a predetermined time, and The duration threshold value and the range of the gear ratio abnormality are switched depending on whether or not the engine brake operating condition is satisfied.

In the flowchart of FIG. 10, in steps S401 to S403, the actual gear ratio GRR is calculated and the normal gear ratio GRD is set as in steps S101 to S103.
In step S404, as in step S104, it is determined whether the engine brake operating condition is satisfied.

When the engine brake operating condition is satisfied, the process proceeds to step S405, where a predetermined time T1 (T1 <T2) is set as a threshold value Ts of the gear ratio abnormality continuation time T. In the next step S406, the same as step S15 described above. Whether or not the actual gear ratio GRR is abnormal is determined by determining whether or not GRD−α ≦ GRR ≦ GRD + α.
On the other hand, when the engine brake operating condition is not satisfied, the process proceeds to step S407, where a predetermined time T2 (T1 <T2) is set as the threshold value Ts of the gear ratio abnormality continuation time T. In the next step S408, as in step S208. By determining whether GRD−β ≦ GRR ≦ GRD + α (0 <α <β), it is determined whether there is an abnormality in the actual gear ratio GRR.

If it is determined in step S406 or step S408 that the gear ratio GRR is within the normal range, the process proceeds to step S409, and a timer for measuring the duration of the abnormality determination is reset to zero.
On the other hand, if it is determined in step S406 or step S408 that the gear ratio GRR is abnormal, the process proceeds to step S410, the timer is counted up, and the duration T during which the gear ratio GRR is determined to be abnormal is measured. .

Then, in the next step S411, the duration time T measured by the timer is compared with the threshold value Ts. When the duration time T is equal to or less than the threshold value Ts, the process proceeds to step S413 to determine that the gear ratio is normal. When the duration time T exceeds the threshold value Ts, the process proceeds to step S412 to determine that the gear ratio is abnormal.
According to the above embodiment, when the engine brake operating condition is not satisfied, the region where the gear ratio GRR is determined to be normal in step S408 is expanded to the high side, and a longer time T2 is set as the threshold Ts of the duration T. Therefore, even if the gear ratio GRR shifts to the high side in the deceleration operation where the engine brake does not act, it is possible to prevent the final abnormality determination from being made based on this.

  In the fourth embodiment, the actual gear ratio GRR and the regular gear ratio GRD are compared, and the duration of the gear ratio abnormality is further measured. As shown in FIG. If the normal range of the gear ratio is changed with the elapsed time after the gear ratio deviates from a relatively narrow reference range including the normal gear ratio, the abnormality is substantially the same as that of the fourth embodiment. Diagnosis can be performed.

  The normal region of the gear ratio shown in FIG. 11 is wide on both the low side and the high side immediately after the gear ratio is out of the reference range, so that the abnormality diagnosis is not substantially made. Is reduced to the vicinity of the normal gear ratio GRD immediately after the shift, while the normal region on the high side changes toward the normal gear ratio GRD later than the low side, and The normal range is set wider than the side.

  For this reason, if the gear ratio abnormality is diagnosed with the characteristics shown in FIG. 11 when the engine brake is not operating, the low side continues to slightly deviate from the normal gear ratio GRD for a relatively short time. Then, an abnormality determination is made because it corresponds to the abnormal region, and the abnormality determination is not made on the high side unless the state greatly deviating from the normal gear ratio GRD continues for a relatively long time.

That is, it is difficult for the high side to be determined abnormally with respect to the low side, and even if the actual gear ratio GRR shifts to the high side with respect to the normal gear ratio GRD due to the deceleration operation in which the engine brake does not act, It is possible to prevent erroneous diagnosis as a ratio abnormality.
Also, when the engine brake operating conditions are met, if the normal range of the gear ratio is changed with the characteristics shown in FIG. 12, the abnormality diagnosis is similarly performed on both the low side and the high side on the condition that the gear ratio abnormality continues. By doing this, a highly reliable diagnosis result can be obtained.

By the way, in each said embodiment, it was set as the structure which switches the diagnostic characteristic of gear ratio abnormality according to whether it is the operating condition of an engine brake, but, simply, whether it is an operating characteristic of an engine brake. Without making a determination, it is possible to execute a diagnosis with characteristics in which a shift to the high side is not likely to be abnormally determined with respect to a shift on the low side.
The flowchart of FIG. 13 shows a fifth embodiment in which the determination of whether or not the engine brake operating characteristics are omitted.

In the flowchart of FIG. 13, in steps S501 to S503, the actual gear ratio GRR is calculated and the normal gear ratio GRD is set as in steps S101 to S103.
In step S504, it is determined which of the normal region and the abnormal region of the characteristics shown in FIG.

  As described above, the normal region shown in FIG. 11 is wide on the low side and the high side immediately after the gear ratio deviates from a relatively narrow reference range including the normal gear ratio, so that substantially no abnormality diagnosis is made. However, the normal region on the low side is quickly reduced to the vicinity of the normal gear ratio GRD, whereas the normal region on the high side changes toward the normal gear ratio GRD. It is slower than the low side, and the normal range is set wider than the low side.

In step S504, the normal region / abnormal region in FIG. 11 is referred to based on the actual gear ratio GRR calculated in step S502 and the elapsed time after the shift.
In step S505, it is determined whether the actual gear ratio GRR is in the normal region or in the abnormal region.
If the actual gear ratio GRR is within the normal region, the process proceeds to step S506, where it is determined that the gear ratio is normal. If the actual gear ratio GRR is within the abnormal region, the process proceeds to step S507, where the gear ratio is determined. Is determined to be abnormal.

According to the above embodiment, even if the actual gear ratio GRR is shifted to the high side due to the deceleration operation in which the engine brake does not act, the high-side abnormality has a large deviation from the normal gear ratio GRD. In addition, since the abnormality is not judged unless it continues for a long time, it is possible to avoid erroneous diagnosis of the gear ratio abnormality.
Even when the engine brake is operating, since the diagnosis is performed based on the normal region / abnormal region of the characteristics shown in FIG. 11, the diagnosis characteristic is determined based on whether the engine brake is operating. Compared with the case of switching, a slight shift to the high side under the engine brake operating condition cannot be determined as abnormal.

Therefore, in order to ensure the reliability of the diagnosis, it is preferable to switch the diagnostic characteristics depending on whether or not the engine brake operating condition. However, according to the fifth embodiment, the engine brake operating condition is changed. Therefore, the versatility of the diagnosis function is high, and the diagnosis process can be simplified.
Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(A) In the vehicular automatic transmission diagnostic apparatus according to any one of claims 1 to 6,
A diagnostic apparatus for an automatic transmission for a vehicle, which determines whether or not a condition for operating an engine brake is based on an accelerator opening and / or a vehicle speed.

According to such a configuration, the gear position is determined from the accelerator opening and the vehicle speed, and in the automatic transmission that determines whether to operate the engine brake from the conditions of the gear position and the accelerator opening, the engine brake is operated. Whether or not can be accurately determined.
(B) In the diagnostic device for an automatic transmission for a vehicle according to claim 2 or 3,
A diagnostic device for an automatic transmission for a vehicle, wherein the normal region of the gear ratio is narrowed with time, and the speed of narrowing the normal region is slower on the high side than on the low side.

According to such a configuration, the normal region on the high side (high speed side) is not easily narrowed compared to the low side (low speed side), so the gear ratio abnormality is diagnosed relatively quickly on the low side. Even with the same degree of deviation, the deviation of the gear ratio to the high side is difficult to diagnose as an abnormality.
Accordingly, when the actual gear ratio is shifted to the high side by performing the deceleration operation without the engine brake acting, it is possible to prevent erroneous diagnosis as an abnormal gear ratio.
(C) In the automatic transmission diagnosis apparatus for a vehicle according to claim 3,
A diagnostic apparatus for an automatic transmission for a vehicle, wherein an abnormality in a gear ratio is diagnosed by the diagnostic means both when the engine brake is operated and when the engine brake is not operated.

According to such a configuration, by applying a characteristic that is difficult to diagnose as an abnormal shift to the high side regardless of whether or not it is a condition for operating the engine brake, a deceleration operation in which the engine brake does not act is performed. Thus, when the actual gear ratio GRR is shifted to the high side, the diagnosis process is simplified while preventing erroneous diagnosis of the gear ratio abnormality.
(D) In the diagnostic device for a vehicle automatic transmission according to claim 1,
A vehicle characterized by switching diagnosis characteristics of gear ratio abnormality depending on whether or not the engine brake is operated and whether the actual gear ratio is shifted to a high side or a low side Diagnostic device for automatic transmission.

According to such a configuration, when the engine brake is not operated, the actual gear ratio may be shifted to the high side instead of being abnormal. Therefore, the condition is limited to a condition in which the gear ratio is shifted even though it is normal. By switching the diagnostic characteristics, it is possible to prevent the gear ratio abnormality from being erroneously diagnosed while maintaining the diagnostic accuracy under other conditions.
(E) In the diagnostic device for an automatic transmission for a vehicle according to any one of claims 1 to 6,
A diagnostic apparatus for an automatic transmission for a vehicle, wherein the actual gear ratio is detected during non-shifting.

According to such a configuration, it is possible to prevent the actual gear ratio from being erroneously detected and the gear ratio abnormality being erroneously diagnosed when the gear ratio is changing while shifting.
(F) In the diagnostic device for an automatic transmission for a vehicle according to claim 1,
A diagnostic apparatus for an automatic transmission for a vehicle, wherein a diagnostic characteristic of a gear ratio abnormality is switched according to whether the engine brake is operated or not, and whether or not the vehicle is decelerating.

  According to this configuration, even under conditions where the engine brake is not activated (accelerator opening, vehicle speed), the gear ratio does not deviate during acceleration while the transmission is normal. Thus, diagnosis can be performed with high accuracy.

The system diagram of the automatic transmission for vehicles in an embodiment. 1 is a structural diagram of an automatic transmission according to an embodiment. The block diagram which shows the hydraulic control system of the automatic transmission in embodiment. The flowchart which shows 1st Embodiment of abnormality diagnosis of a gear ratio. The diagram which shows the abnormal area | region and normal area | region on the conditions which the engine brake in the said 1st Embodiment act | operates. The diagram which shows the abnormal area | region and normal area | region on the conditions which the engine brake in the said 1st Embodiment does not operate | move. The flowchart which shows 2nd Embodiment of abnormality diagnosis of a gear ratio. The diagram which shows the abnormal area | region and normal area | region on the conditions which the engine brake in the said 2nd Embodiment does not operate | move. The flowchart which shows 3rd Embodiment of abnormality diagnosis of a gear ratio. The flowchart which shows 4th Embodiment of abnormality diagnosis of a gear ratio. The diagram which shows the characteristic of the abnormal area | region and normal area | region when judging abnormality of a gear ratio from a gear ratio level and elapsed time. The diagram which shows the characteristic of the abnormal area | region and normal area | region when judging abnormality of a gear ratio from a gear ratio level and elapsed time. The flowchart which shows 5th Embodiment of abnormality diagnosis of a gear ratio.

Explanation of symbols

  3L ... Lock-up clutch, 4 ... first planetary gear mechanism, 5 ... second planetary gear, 101 ... engine, 102 ... automatic transmission, 103 ... shift control controller 103, 104 ... shift lever, 105 ... inhibitor switch, 106 ... Accelerator opening sensor, 107 ... Vehicle speed sensor, 108 ... Turbine rotation sensor, OVR / C ... Overrun clutch, L & R / B ... Low and reverse brake

Claims (6)

In a vehicular automatic transmission having a condition for selectively operating an engine brake, a diagnostic device for detecting an actual gear ratio of the transmission and diagnosing an abnormality in the actual gear ratio,
A diagnostic apparatus for an automatic transmission for a vehicle, wherein the diagnostic characteristic of the gear ratio abnormality is switched according to whether or not a condition for operating the engine brake is satisfied. When it is not a condition for operating the engine brake, switching is performed so that a shift to the high side of the actual gear ratio is not likely to be abnormally determined as compared with a condition for operating the engine brake. The diagnostic device for an automatic transmission for a vehicle according to claim 1. In a vehicular automatic transmission having a condition for selectively operating an engine brake, a diagnostic device for detecting an actual gear ratio of the transmission and diagnosing an abnormality in the actual gear ratio,
A diagnostic device for an automatic transmission for a vehicle, comprising diagnostic means that is set such that a shift to a high side is less likely to be abnormally determined than a shift to a low side of the actual gear ratio. The setting that makes it difficult for the deviation of the actual gear ratio to the high side to be abnormally determined is to diagnose the deviation of the gear ratio to the low side as abnormal and regard the deviation to the high side as normal. The diagnostic device for an automatic transmission for a vehicle according to claim 2 or 3. The threshold for determining the deviation between the actual gear ratio and the regular gear ratio is made different between the low side and the high side, so that the deviation to the high side is hardly determined abnormally. The diagnostic device for an automatic transmission for a vehicle according to claim 2 or 3. A configuration for diagnosing a gear ratio abnormality based on a duration time in which the actual gear ratio is different from a normal gear ratio, wherein a threshold value for judging the duration time is different between the low side and the high side. 4. The diagnostic apparatus for an automatic transmission for a vehicle according to claim 2, wherein a shift to the high side is difficult to be abnormally determined.

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