JP2014169750A - Method for managing durability lifetime of friction fastening element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a durability lifetime of a friction fastening element while suppressing a reduction in performance when the friction fastening element is expected to reach the end of the durability lifetime before the assured travel distance is reached.SOLUTION: A method for managing a durability lifetime of a friction fastening element, comprises: an accumulative damage calculation step (Figs. 2 to 5); a durable life estimation step (step 2) of estimating a critical travel distance Lmax where the accumulative damage (f) of the friction fastening element reaches a use critical value 1; a life extension control starting step (Fig. 1) of starting life extension control for delaying progress of the accumulative damage when determining that the critical travel distance Lmax is shorter than an assured travel distance La; and a life extension control step (Figs. 12 and 13) of dividing a travel distance up to the assured travel distance La into a plurality of travel segments, delaying the progress of the accumulative damage in a stepwise manner every time the plurality of travel segments are changed over, and directing a changing characteristic of the accumulative damage (f) with respect to a travel distance L toward the assured travel distance La.

Description

  The present invention relates to a durable life management method for a frictional engagement element such as a friction clutch or a friction brake, which is provided in a driving force transmission system of a vehicle and whose engagement / release is controlled.

  Conventionally, the clutch life state is estimated by counting and accumulating the clutch damage state based on the minor rule, and the criteria for determining the clutch life (the critical use value of the clutch) are determined, and before the clutch reaches its life. 2. Description of the Related Art An alarm device for a clutch device that issues an alarm is known (for example, see Patent Document 1).

  Here, the “minor rule” refers to a technique in which when a fatigue limit exists, a stress amplitude below the fatigue limit is assumed to be infinite life and is not counted as damage. In the actual fatigue phenomenon, the stress amplitude below the fatigue limit also affects the damage. Therefore, a method in which correction is made so that the stress amplitude below the fatigue limit is also counted as damage is referred to as a “corrected minor rule”.

JP 2008-57670 A

  However, in the alarm device of the conventional clutch device, only the alarm is informed that the clutch is nearing the end of its life, so if the driver moves to a dealer etc. and leaves it without taking countermeasures, There has been a problem that the clutch reaches the endurance life and causes poor performance such as clutch seizure and judder.

  For example, an automatic transmission mounted on a vehicle has a guaranteed mileage (for example, 120,000 km) that allows the vehicle to travel while maintaining normal speed change performance. Believes that normal performance continuity is guaranteed. Therefore, even if an alarm is received before reaching the guaranteed travel distance, it is left without taking any immediate countermeasures and continues to ride up to the guaranteed travel distance.

  The present invention has been made paying attention to the above problems, and when it is predicted that the frictional engagement element will reach the endurance life before traveling to the guaranteed travel distance, the durability life of the frictional engagement element is reduced while suppressing the performance degradation. It is an object of the present invention to provide a durable life management method for a frictional fastening element that can extend the life.

In order to achieve the above object, the present invention is directed to a friction engagement element that is provided in a driving force transmission system of a vehicle and that is controlled to be engaged / released, and has a durability life until the friction engagement element reaches a use critical value. In the method for managing the durability life of the frictional engagement element that manages the above, the means includes a cumulative damage degree calculation procedure, a durability life prediction procedure, a life extension control start procedure, and a life extension control procedure.
The cumulative damage level calculation procedure calculates the cumulative damage level of the frictional engagement element in all travel sections after the vehicle starts to travel.
When the durable life prediction procedure reaches an initial determination timing at which the change in cumulative damage can be predicted after the vehicle starts running, the friction engagement element is maintained when the predicted change characteristic of the cumulative damage is maintained as it is. Predict the critical mileage at which the cumulative damage level reaches the use critical value.
In the life extension control start procedure, when it is determined that the critical travel distance is shorter than the guaranteed travel distance, the life extension of the cumulative damage degree is delayed compared to the normal control instead of the normal control of the friction engagement element. Start control.
In the life extension control procedure, when the life extension control is started, the travel distance from the current travel distance to the guaranteed travel distance is divided into a plurality of travel sections, and the cumulative damage degree progresses every time the plurality of travel sections are switched. Is delayed in stages, and the change characteristic of the cumulative damage degree with respect to the travel distance is directed to the guaranteed travel distance.
Here, the “guaranteed travel distance” refers to a travel distance guaranteed in advance that the vehicle can travel while maintaining normal engagement / release performance of the frictional engagement element.

Therefore, when it is predicted that when the vehicle reaches the initial judgment timing after the vehicle starts to travel, the normal life of the friction engagement element is not guaranteed until the guaranteed travel distance is maintained. Instead of the normal control of the fastening element, life extension control is started in which the progress of the cumulative damage degree is delayed compared to the normal control. In the life extension control, in the travel from the current travel distance to the guaranteed travel distance, the progress of the cumulative damage degree is delayed in stages each time the divided travel sections are switched, and the change characteristic of the cumulative damage degree with respect to the travel distance is guaranteed. Control is made to make it move toward the travel distance.
In other words, the durability of the frictional engagement element is not only evaluated based on the cumulative damage level, but the critical travel distance is used as a reference index, and when the initial judgment timing is reached, the critical damage is determined based on the cumulative damage level performance in the past travel section. The mileage is predicted. When the predicted critical mileage is shorter than the guaranteed mileage, life extension control is started, and the frictional engagement element is gradually increased while suppressing the performance degradation so that the driver does not notice in the mileage section toward the guaranteed mileage. Life extension control is performed to extend the durable life.
As a result, when it is predicted that the frictional engagement element will reach the endurance life before traveling to the guaranteed travel distance, it is possible to extend the durability life of the frictional engagement element while suppressing performance degradation.

It is a flowchart which shows the flow of the life extension control start process of the friction engagement element performed with the electronic controller of the automatic transmission in an Example. It is a figure which shows the physical strength line of Q (heat generation amount) -N (number of times of shift) used for calculation of the cumulative damage degree of the shift clutch in the durable life management method of the friction engagement element in the embodiment. It is heat generation explanatory drawing which shows the concept of the heat generation amount Q used for calculation of the cumulative damage degree of a transmission clutch in the durable life management method of the friction engagement element in an Example. It is a figure which shows the physical strength line of T (clutch temperature) -t (cumulative slip time) used for calculation of the cumulative damage degree of a slip clutch in the durable life management method of the friction engagement element in an Example. It is clutch temperature explanatory drawing which shows the concept of the clutch temperature T used for the cumulative damage degree calculation of a clutch used for the start fastened with a slip in the durable life management method of the friction engagement element in an Example. It is explanatory drawing which shows the prediction characteristic of the cumulative damage degree f with respect to the travel distance L in the initial determination timing in the life extension control start process of FIG. FIG. 7 is an explanatory diagram showing a prediction characteristic of an accumulated damage degree f with respect to a travel distance L when the number of shift / slip experiences n = 2 in the life extension control start process of FIG. 1. FIG. 6 is an explanatory diagram showing a prediction characteristic of an accumulated damage degree f with respect to a travel distance L when the number of shift / slip experiences n = n in the life extension control start process of FIG. 1. It is a flowchart which shows the flow of the required distance calculation process until repair and replacement | exchange of a friction engagement element are needed when life extension control performed with the electronic control apparatus of the automatic transmission in an Example is started. FIG. 10 is an explanatory diagram showing a relational characteristic of an accumulated travel distance with respect to the number of days when zzz <Now in the necessary distance calculation processing of FIG. FIG. 10 is an explanatory diagram showing a relational characteristic of an accumulated travel distance with respect to the number of days when zzz ≧ Now in the necessary distance calculation processing of FIG. 9. It is a flowchart which shows the flow of the life extension control process 1 of the friction engagement element performed with the electronic control apparatus of the automatic transmission in an Example. It is a flowchart which shows the flow of the life extension control process 2 of the friction engagement element performed with the electronic control apparatus of the automatic transmission in an Example. It is a figure which shows an example of the relationship characteristic of the cumulative damage degree with respect to the accelerator opening which varied the life extension level in the life extension control process of the friction engagement element. It is step explanatory drawing which shows the relationship characteristic of the cumulative damage degree f with respect to the travel distance L in the life extension control process of a friction engagement element. It is step explanatory drawing which shows the relationship characteristic of the cumulative damage degree f with respect to the travel distance L in the life extension control process of a friction engagement element. It is step explanatory drawing which shows the relationship characteristic of the cumulative damage degree f with respect to the travel distance L in the life extension control process of a friction engagement element. It is step explanatory drawing which shows the relationship characteristic of the cumulative damage degree f with respect to the travel distance L in the life extension control process of a friction engagement element. It is a figure which shows an example of the relational characteristic of the cumulative damage degree f of the clutch with respect to the travel distance L used in order to demonstrate the whole of the durable life management method of the friction engagement element in Example 1. FIG.

Hereinafter, the best mode for realizing the durable life management method for frictional engagement elements of the present invention will be described based on the embodiments shown in the drawings.
The present invention is suitable for durability life management of friction engagement elements involved in the shift of the automatic transmission for vehicles, and electronically controls engagement / release of the friction engagement elements and slip engagement at the start via a medium such as hydraulic pressure. The present invention can be applied to any vehicle automatic transmission controlled by the apparatus, for example, an automatic transmission for a hybrid vehicle as described in Japanese Patent Application Laid-Open No. 2010-77981 filed in the past by the present applicant. Also suitable.

First, the configuration will be described.
The method for managing the endurance life of the frictional engagement element in the embodiment is described as `` Detailed procedure of life extension control start processing of frictional engagement element '', `` Detailed procedure of necessary distance calculation processing until repair and replacement of frictional engagement element '', The description will be divided into “detailed procedure of the life extension control process of the frictional engagement element”.

[Detailed procedure for life extension control start processing of friction engagement element]
FIG. 1 shows a flow of a friction engagement element durability life management control process executed by an electronic control unit of an automatic transmission according to an embodiment. 2 to 5 show a calculation method of the cumulative damage degree, and FIGS. 6 to 8 show prediction characteristics of the cumulative damage degree. Hereinafter, the detailed procedure of the life extension control start processing of the frictional engagement element will be described based on the flowchart shown in FIG. 1 with reference to FIGS. 2 to 8 (life extension control start procedure).

  First, the “guaranteed mileage (La)” used in the description of the flowchart shown in FIG. 1 is a mileage (for example, 120,000 km) that is preliminarily guaranteed to be able to run while maintaining normal engagement / release performance of the frictional engagement element Or 190,000 km).

  In addition, in the cumulative damage degree calculation process different from that in FIG. 1, every time a shift / slip is experienced in the entire travel section after the vehicle starts running, the number of experiences and the cumulative damage degree f ( Dsft + Dslp) is calculated, and the data is read as needed (accumulation damage calculation procedure).

When the shift friction engagement element used for the shift is to be managed, as shown in FIG. 2 and FIG. 3, the heat generation amount Q generated by one shift using the shift friction engagement element is changed using the minor rule. The cumulative damage level Dsft is calculated. 2 is a diagram showing the relationship between the calorific value Q and the critical shift frequency N at which the frictional engagement element reaches the use critical value with respect to the calorific value Q. The higher the calorific value Q, the more critical shift frequency N becomes. Less. For example, when the amount of heat generated is Qi, the number of critical shifts intersecting with the Q-N physical force line is Ni, and if the same heat generation amount Qi is repeated, the friction engagement element reaches the use critical value due to the experience of Ni times of shifting. become.
As shown in FIG. 3, the heat generation amount Q generated by one shift from the shift start time t1 to the shift end time t2 is expressed as follows:
Q = ∫ {V / (P-RTN pressure) × C} dt
V: differential rotation, P: hydraulic pressure, RTN pressure: shift learning reflected value, C: calculated by a constant value formula. Then, using the current heat generation amount Qn and the QN body strength line shown in FIG. 2, the current limit shift number Nn corresponding to the calculated current heat generation amount Qn is obtained, and the cumulative damage degree Dsft due to the shift is calculated as
It is calculated by the equation Dsft = Σ (1 / Nn-1) + (1 / Nn).
However, Σ (1 / Nn−1) is the cumulative damage degree Dsft up to the previous time.

When the slip friction engagement element used for slip engagement (for example, the clutch CL2 in FIG. 1 of JP 2010-77981 A) is to be managed, the slip friction engagement element is used as shown in FIGS. The cumulative damage degree Dslp due to slip is calculated from the clutch temperature during one slip using the minor rule. That is, as shown in FIG. 5, the average clutch temperature T according to the slip time Δt is obtained between the engagement start time t1 and the engagement completion time t2. 4 is a graph showing the relationship between the clutch temperature T and the critical cumulative slip time t at which the friction engagement element reaches the use critical value. The higher the clutch temperature T, the higher the critical cumulative slip time. t becomes shorter. For example, when the clutch temperature Ti is reached, the critical cumulative slip time ti intersecting with the TT body force line is reached. If the slip at the same clutch temperature Ti is repeated, the friction engagement element reaches the use critical value when the cumulative slip time ti is reached. It will be.
Then, using the current average clutch temperature Tn and the T-t physical strength line shown in FIG. 4, the current cumulative slip time Stn based on the current average clutch temperature Tn is obtained, and the cumulative damage degree Dslp due to the slip is calculated as follows:
Dslp = Σ (Δtn−1 / Stn−1) + (Δtn / Stn).
However, Σ (Δtn−1 / Stn−1) is the cumulative damage degree Dslp up to the previous time.

  When the shift friction engagement element used for shifting is to be managed and the shift friction engagement element experiences not only the shift but also the slip engagement, the total number of experiences and the total cumulative damage degree Dsft + Dslp (= F) is calculated.

In step S1, it is determined whether or not the clutch to be managed has been shifted / slipped up to a set number of times (XXX times). If YES (shift / slip count ≧ set count), the process proceeds to step S2. If NO (shift / slip count <set count), the determination in step S1 is repeated.
Here, the set number of times is set to the number of shift / slip experience times that can be obtained by experiments and the like so that the change of the cumulative damage degree can be predicted after the vehicle starts running.

In step S2, following the determination in step S1 that the number of shifts / slips is equal to or greater than the set number of times, that is, the determination that the vehicle has started traveling and has reached the initial determination timing at which the cumulative damage degree can be predicted. The critical travel distance Lmax where the cumulative damage degree f of the frictional engagement element reaches the use critical value (f = 1) when the travel by the normal control that has been performed so far is continued is predicted, and the process proceeds to step S3 (endurance) Life prediction procedure).
Here, when predicting the critical travel distance Lmax, as shown in FIG. 6, in the change characteristic of the cumulative damage degree f with respect to the travel distance L, the intersection of the travel start point O, the initial determination travel distance Lxxx, and the cumulative damage degree fxxx. A line (linear) connecting p1 is calculated as a damage prediction line f1 (x). Then, when the damage prediction line f1 (x) is extended as it is, a travel distance at a point where the use critical value (f = 1) of the frictional engagement element intersects is predicted as a critical travel distance Lmax.

  In step S3, following the calculation of the damage prediction line in step S2, whether or not the predicted travel line has a guaranteed travel distance La is obtained by comparing the critical travel distance Lmax predicted in step S2 and the guaranteed travel distance La. Judging. If YES (La <Lmax, f1 (a) <1), the process proceeds to step S5. If NO (La ≧ Lmax, f1 (a) ≧ 1), the process proceeds to step S4. Note that La <Lmax and f1 (a) <1, and La ≧ Lmax and f1 (a) ≧ 1 are different depending on whether they represent a travel distance comparison or a cumulative damage degree comparison, and both are synonymous.

  In step S4, following the determination of La ≧ Lmax (f1 (a) ≧ 1) in step S3, that is, the determination that there is no guaranteed travel distance La according to the prediction line, the progress of the cumulative damage degree is delayed. The life extension control is started to extend the durable life of the clutch to be managed. When this life extension control is started, the necessary distance calculation processing until the clutch needs to be repaired or replaced in FIG. 9 is started, and further, the life extension control processing of the frictional engagement elements in FIG. 12 and FIG. 13 is started.

  In step S5, La <Lmax (f1 (a) <1) is determined in step S3, or F (L) + fn (La-Ln) <1 is determined in step S7, that is, a prediction line. Following the determination that the vehicle has the guaranteed travel distance La, the shift / slip in the normal control is performed, and the process proceeds to step S6.

  In step S6, every time a shift / slip is experienced following the execution of the shift / slip in step S5, as in step S2, the cumulative damage degree f of the friction engagement element is obtained when the shift / slip by the normal control is performed. Predicts the critical travel distance Lmax that reaches the use critical value (f = 1), and proceeds to step S7 (endurance life prediction procedure).

  When this critical travel distance Lmax is predicted, when shifting / slip is first experienced after the initial judgment timing (shift / slip experience number n = 2), as shown in FIG. In the change characteristic of f, the line (linear) connecting the intersection point p2 of the travel distance L1 and the cumulative damage degree f1 and the intersection point p3 of the travel distance L (xxx + 1) and the cumulative damage degree f (xxx + 1) is damaged. This is calculated as a degree prediction line f2 (x). Then, when the damage prediction line f2 (x) is extended as it is, a travel distance at a point where the use critical value (f = 1) of the frictional engagement element intersects is predicted as a critical travel distance Lmax. Then, when the shift / slip is experienced n times after the initial determination timing (shift / slip experience number n = n), as shown in FIG. A line (linear) connecting the intersection point p4 of L (n-xxx) and the cumulative damage degree f (n-xxx) and the intersection point p5 of the travel distance Ln and the cumulative damage degree fn as a damage degree prediction line fn (x) calculate. Then, when the damage prediction line fn (x) is extended as it is, a travel distance at a point where the use critical value (f = 1) of the frictional engagement element intersects is predicted as a critical travel distance Lmax. That is, in the damage degree prediction after the initial determination timing, the accumulated damage degree data from the previous XXX times is used every time a shift / slip is experienced without going back to the start of traveling.

  In step S7, following the calculation of the damage prediction line fn (x) in step S6, the shift / slip of the normal control is continued as it is by comparing the critical travel distance Lmax predicted in step S6 with the guaranteed travel distance La. Then, it is determined whether or not the vehicle has a guaranteed travel distance La. If YES (La <Lmax, F (L) + fn (La-Ln) <1), the process returns to step S5, and if NO (La≥Lmax, F (L) + fn (La-Ln) ≥1) Proceeds to step S4 and starts life extension control. Note that La <Lmax and F (L) + fn (La-Ln) <1, La ≧ Lmax and F (L) + fn (La-Ln) ≧ 1) represent mileage comparison or cumulative damage comparison Are different, and both are synonymous.

[Detailed procedures for calculating the required distance until the frictional engagement element needs to be repaired or replaced]
FIG. 9 shows a flow of a required distance calculation process until the frictional engagement element needs to be repaired or replaced when life extension control executed by the electronic control unit in the embodiment is started. Indicates the relational characteristic of the cumulative travel distance with respect to the number of days. Hereinafter, the detailed procedure of the required distance calculation processing until the frictional engagement element needs to be repaired and replaced will be described based on the flowchart shown in FIG. 9 with reference to FIGS. 10 and 11 (necessary distance calculation procedure).

  In step S41, when life extension control is started, the current number of days Now from the vehicle travel start date and time is calculated, and it is determined whether zzz days or more have elapsed from the vehicle travel start date and time to the current number of days Now. If YES (zzz <Now), the process proceeds to step S42. If NO (zzz ≧ Now), the process proceeds to step S43.

In step S42, following the determination in step S41 that zzz <Now, the required distance HZ until the frictional engagement element needs to be repaired or replaced is calculated by the following method.
As shown in FIG. 10, the average mileage of the day from the past zzz days to the present is
{Lnow-L (Now-zzz)} / zzz
It is calculated by the following formula. And, when the required number of days until the repair and replacement of the frictional engagement element is required is H, the required distance HZ until the repair and replacement is required,
HZ = H ・ {Lnow-L (Now-zzz)} / zzz
It is calculated by the following formula.

In step S43, following the determination that zzz ≧ Now in step S41, the necessary distance HZNow until the frictional engagement element needs to be repaired or replaced is calculated by the following method.
As shown in FIG. 11, the average daily mileage from the start of travel to the present
Lnow / Now
It is calculated by the following formula. And when the required number of days until repair and replacement of frictional engagement elements are required is H, the required distance HZNow until repair and replacement is required,
HZNow ＝ H ・ Lnow / Now
It is calculated by the following formula.

[Detailed procedure for life extension control processing of friction engagement elements]
12 and 13 show the flow of the life extension control process of the friction engagement element executed by the electronic control unit in the embodiment. FIG. 14 shows the relational characteristic of the cumulative damage degree with respect to the accelerator opening with different life extension levels. 15 to 19 show the relationship characteristics of the cumulative damage degree with respect to the travel distance. Hereinafter, the detailed procedure of the life extension control process of the frictional engagement element will be described based on the flowcharts shown in FIGS. 12 and 13 using FIGS. 15 to 19 (life extension control procedure).

First, when life extension control is started, the current travel distance is set to Lo and the current damage level is set to fo. In the life extension control process, as shown in FIG. 14, the relationship characteristic of the cumulative damage degree with respect to the accelerator opening with the life extension level varied in advance is set. Here, as a method for changing the life extension level, for example, the following (a) to (d) are used.
(a) Forcibly shorten the shifting time of the frictional engagement element. For example, when the normal shift time is 1, the shift time is gradually shortened according to the level.
(b) The shift line (up shift line, down shift line) of the shift map used for shift control of the automatic transmission is switched to a characteristic more dependent on the vehicle speed. As a result, the shift frequency due to the change in the accelerator opening APO is reduced.
(c) Increase the line pressure and increase the amount of lubricating oil during shifting. The amount of lubricating oil is determined by the amount of drain oil from the pressure regulator valve that regulates the line pressure.
(d) (c) is combined with (a) or (b).
Then, as the life extension level becomes level 1 → level 2 →… → level N → level End, any one of the above (a) to (d) is set so that the change gradient of the cumulative damage degree with respect to the travel distance becomes gentler. Select content.

  In step S401, it is determined whether or not the remaining travel distance (La-Lo) exceeds the required distance HZ or HZNow until the frictional engagement element needs to be repaired or replaced. If YES ((La-Lo)> HZ or HZNow), the process proceeds to step S403. If NO ((La-Lo) ≦ HZ or HZNow), the process proceeds to step S402.

  In step S402, following the determination that (La-Lo) ≦ HZ or HZNow in step S401, the shift of the clutch to be managed is set to level End, the emergency light is turned on, and the friction engagement element is given to the driver. Encourage repair or replacement. Or, make sure to repair or replace the parts at the time of inspection or vehicle inspection.

  In step S403, following the determination that (La-Lo)> HZ or HZNow in step S401 or n ≦ YY1 in step S406, the shift of the clutch to be managed is set to level 1. In step S404, the gear shift in the corresponding clutch is continued.

  In step S404, whether or not the remaining travel distance (La-Lo) exceeds the required distance HZ or HZNow until the frictional engagement element needs to be repaired or replaced following the gear shift in the corresponding clutch in step S403. Judging. If YES ((La-Lo)> HZ or HZNow), the process proceeds to step S406. If NO ((La-Lo) ≦ HZ or HZNow), the process proceeds to step S405.

  In step S405, following the determination that (La-Lo) ≦ HZ or HZNow in step S404, the shift of the clutch to be managed is set to level End, the emergency light is turned on, and the friction engagement element is given to the driver. Encourage repair or replacement. Or, make sure to repair or replace the parts at the time of inspection or vehicle inspection.

  In step S406, following the determination that (La-Lo)> HZ or HZNow in step S404, it is determined whether the shift / slip experience number n is n> YY1. If YES (n> YY1), the process proceeds to step S407. If NO (n ≦ YY1), the process returns to step S403.

  In step S407, following the determination that n> YY1 in step S406, it is determined whether or not the cumulative damage f (YY1_La) when the gear shift / slip is experienced only YY1 exceeds the use critical value 1. Judgment is made (see FIG. 15). If YES (f (YY1_La)> 1), the process proceeds to step S412 (see FIG. 16). If NO (f (YY1_La) ≦ 1), the process proceeds to step S408.

  In step S408, following the determination that f (YY1_La) ≦ 1 in step S407, or NO in steps S410, S411, and S416, the shift in the clutch to be managed is set to level 1. As the travel distance divided into a plurality becomes YY2, YY3,..., The level is changed to level 2, level 3,.

  In step S409, following the shift in the corresponding clutch in step S408, it is determined whether the remaining travel distance (La-Lo) exceeds the required distance HZ or HZNow until the frictional engagement element is repaired or replaced. . If YES ((La-Lo)> HZ or HZNow), the process proceeds to step S410. If NO ((La-Lo) ≦ HZ or HZNow), the process proceeds to step S405.

  In step S410, following the determination that (La-Lo)> HZ or HZNow in step S409, it is determined whether the shift / slip experience number n is n> YYN. If YES (n> YYN), the process proceeds to step S411. If NO (n ≦ YYN), the process returns to step S408.

  In step S411, following the determination that n> YYN in step S410, it is determined whether or not the cumulative damage f (YYN_La) when the gear shift / slip is experienced YYN times exceeds the use critical value 1. to decide. If YES (f (YYN_La)> 1), the process proceeds to step S420. If NO (f (YYN_La) ≦ 1), the process returns to step S408.

  In step S412, following the determination that f (YY1_La)> 1 in step S407, the difference between the travel distance LYY1 and the life extension control start distance Lo when the shift / slip experience is YY1 times is the guaranteed travel distance La. And whether or not the difference between the travel distance LYY1 is larger. If NO ((LYY1-Lo) ≦ (La-LYY1)), the process proceeds to step S417 (see FIG. 17), and if YES ((LYY1-Lo)> (La-LYY1)), the process proceeds to step S413 (FIG. 18).

  In step S413, following the determination that (LYY1-Lo)> (La-LYY1) in step S412, or the determination of NO in step S415, and the determination of YES in step S420, As the traveling distance divided into a plurality of clutches from level 1 becomes YY2, YY3,..., Shifts to level 2, level 3,... Are continued, and the process proceeds to step S414.

  In step S414, it is determined whether or not the remaining travel distance (La-Lo) exceeds the required distance HZ or HZNow until the frictional engagement element is repaired or replaced following the gear shift in the corresponding clutch in step S413. . If YES ((La-Lo)> HZ or HZNow), the process proceeds to step S415. If NO ((La-Lo) ≦ HZ or HZNow), the process proceeds to step S419.

  In step S415, following the determination that (La-Lo)> HZ or HZNow in step S414, it is determined whether the shift / slip experience number n is n> YYN. If YES (n> YYN), the process proceeds to step S416. If NO (n ≦ YYN), the process returns to step S413.

  In step S416, following the determination that n> YYN in step S415, whether or not the cumulative damage f (YYN_La) when experiencing a shift / slip only YYN times exceeds the use critical value 1 is determined. to decide. If YES (f (YYN_La)> 1), the process proceeds to step S420. If NO (f (YYN_La) ≦ 1), the process returns to step S408.

  In step S417, following the determination that (LYY1-Lo) ≦ (La-LYY1) in step S412 or the travel loop processing in step S418, the remaining travel distance (La-LNow) is determined by the friction engagement element. Judge whether or not the required distance HZ or HZNow for repair or replacement is exceeded. If YES ((La-LNow)> HZ or HZNow), the process proceeds to step S418. If NO ((La-LNow) ≦ HZ or HZNow), the process proceeds to step S419.

  In step S418, following the determination that (La-LNow)> HZ or HZNow in step S417, the remaining travel distance (La-LNow) becomes the required distance HZ or HZNow until the frictional engagement element is repaired or replaced. The clutch shift level in the running that is continued until it is reached is determined according to the current clutch shift level condition and the ignition off time condition, and the process returns to step S417 via the running loop. The method for determining the clutch shift level proceeds directly to the travel loop if the shift level at the clutch is level End. When the ignition off time is equal to or longer than the set time, the ignition is turned on, the shift level at the corresponding clutch is changed to the level End side, and the process proceeds to the traveling loop. When the ignition off time is less than the set time, the ignition is turned on and the traveling loop is advanced. Otherwise, the process proceeds to the travel loop with the clutch shift level at that time. Here, the traveling loop refers to a flow of repeating step S418 → step S417.

  In step S419, following the determination that (La-LNow) ≦ HZ or HZNow in step S417 or step S414 or step S421, the shift in the clutch to be managed is set to level End, the emergency light is turned on, Encourage the driver to repair or replace the frictional engagement element. Or, make sure to repair or replace the parts at the time of inspection or vehicle inspection.

  In step S420, following the determination that f (YYN_La)> 1 in step S411 or step S416, the travel distance LYYN when the shift / slip experience is YYN times and the travel distance L when YYN-1 times It is determined whether or not the difference of (YYN-1) is larger than the difference between the guaranteed travel distance La and the travel distance LYYN. If YES ({LYYN-L (YYN-1)}> (La-LYYN)), return to step S413, and if NO ({LYYN-L (YYN-1)} ≦ (La-LYYN)), step Proceed to S421.

  In Step S421, following the determination that {LYYN-L (YYN-1)} ≦ (La-LYYN) in Step S420, or the travel loop processing in Step S422, the remaining travel distance (La-LNow) Determines whether the required distance HZ or HZNow for repairing or replacing the frictional engagement element is exceeded. If YES ((La-Lo)> HZ or HZNow), the process proceeds to step S422. If NO ((La-Lo) ≦ HZ or HZNow), the process proceeds to step S419.

  In step S422, following the determination that (La-LNow)> HZ or HZNow in step S421, the remaining travel distance (La-LNow) becomes the required distance HZ or HZNow until the frictional engagement element is repaired or replaced. The clutch shift level in the running that is continued until it is reached is determined according to the current clutch shift level condition and the ignition off time condition, and the process returns to step S421 via the running loop. The method for determining the clutch shift level is the same as in step S418. Here, the traveling loop means a flow of repeating step S422 → step S421.

Next, the operation will be described.
The operation in the method for managing the durability life of the friction engagement element in the embodiment is divided into "the durability life management action of the friction engagement element not requiring life extension control" and "the durability life management action of the friction engagement element requiring life extension control". explain.

[Durability life management of friction engagement elements that do not require life extension control]
If it is predicted that the durability life of the frictional engagement element up to the guaranteed travel distance La will be ensured even if the normal control is maintained, it is preferable to continue the normal control because a good shift quality can be secured. Hereinafter, the durable life management action of the frictional engagement element that does not require life extension control reflecting this will be described.

  When the number of shift / slip experiences from the start of travel reaches the set number (XXX times), the process proceeds from step S1 to step S2 to step S3 in the flowchart of FIG. In step S2, a damage level prediction line f1 (x) is calculated following the determination that an initial determination timing at which a change in cumulative damage level can be predicted has been reached after the vehicle has started running. In the next step S3, it is determined whether or not the vehicle travels to the guaranteed travel distance La using the damage degree prediction line f1 (x) when the travel by the normal control that has been performed so far is continued.

  When it is determined in step S3 that the vehicle has the guaranteed travel distance La, the process proceeds from step S3 to step S5 → step S6 → step S7 in the flowchart of FIG. In step S5, shift / slip in normal control is performed, and in step S6, each time a shift / slip is experienced, a damage prediction line fn (x) is used using cumulative damage degree data from the previous XXX times. Is calculated. In the next step S7, it is determined whether or not the vehicle travels to the guaranteed travel distance La using the damage level prediction line fn (x) when the travel by the normal control that has been performed so far is continued. If it is determined in step S7 that the vehicle has the guaranteed travel distance La, the flow of steps S5 → step S6 → step S7 is repeated in the flowchart of FIG.

As described above, in the embodiment, as a method for managing the durability of the friction engagement element, when it is predicted that the durability of the friction engagement element up to the guaranteed travel distance La will be secured even if the normal control is maintained, The procedure for continuing normal control (the flow of repeating step S1 → step S2 → step S3 to step S5 → step S6 → step S7) was adopted.
For this reason, good shift quality is ensured in the entire traveling section until the frictional engagement element reaches the endurance life.

[Durability life management of friction fastening elements that require life extension control]
If it is predicted that the durable life of the frictional engagement element up to the guaranteed mileage La cannot be secured if the normal control is maintained, priority is given to securing the durable life over the shift quality to meet the user request. This is preferable. Hereinafter, the durable life management action of the frictional engagement element that requires life extension control reflecting this will be described.

  When the number of shift / slip experiences from the start of travel reaches the set number (XXX times), the process proceeds from step S1 to step S2 to step S3 in the flowchart of FIG. In step S2, a damage level prediction line f1 (x) is calculated following the determination that an initial determination timing at which a change in cumulative damage level can be predicted has been reached after the vehicle has started running. In the next step S3, it is determined whether or not the vehicle travels to the guaranteed travel distance La using the damage degree prediction line f1 (x) when the travel by the normal control that has been performed so far is continued. If it is determined in step S3 that the guaranteed travel distance La is not reached, the process proceeds from step S3 to step S4 in the flowchart of FIG. 1, and life extension control is started. Furthermore, even if it is determined in step S3 that the vehicle has the guaranteed travel distance La, in the flowchart of FIG. 1, the process proceeds from step S5 to step S6 to step S7, and in step S7, it is determined that the vehicle does not have the guaranteed travel distance La. In the flowchart of FIG. 1, the process proceeds from step S7 to step S4, and life extension control is started.

Life extension control is
(1) Have the frictional engagement element repaired or replaced before the cumulative damage f becomes “1 (use critical value)”.
(2) Ensure as much travel as possible up to the guaranteed travel distance La.
(3) The driver should be as unaware of the life extension control as possible.
As a technical philosophy, (1)>(2)> (3) is given priority.

  When the life extension control is started, in order to achieve the above (1), the necessary distance HZ or HZNow until the frictional engagement element is repaired or replaced is calculated using the flowchart of FIG. The calculation of the required distance HZ until repair or replacement proceeds from step S41 to step S42 in FIG. 9 when zzz <Now. In step S42, HZ = H · {Lnow-L (Now-zzz)} / Calculated by the zzz equation. On the other hand, calculation of the required distance HZNow until repair or replacement proceeds from step S41 to step S43 in FIG. 9 when zzz ≧ Now, and in step S43, it is calculated by the equation HZNow = H · Lnow / Now. .

  And in each step S401, S404, S409, S414, S417, S421 of the flowchart of FIG. 12 and FIG. 13, until the remaining travel distance (La-Lo) or (La-LNow) repairs or replaces the frictional engagement element. If it is determined that the required distance HZ or HZNow is less than or equal to step S402, step S405 or step S419, the shift in the clutch to be managed is set to level End, the emergency light is turned on, and the driver is rubbed. It is prompted to repair or replace the fastening element. Or, it is compulsory to repair or replace the relevant parts at the time of inspection or vehicle inspection. Therefore, even if the vehicle travels the required distance HZ or HZNow from receiving the warning until it is repaired or replaced, it is possible to arrive at the repair shop before the cumulative damage f becomes “1 (use critical value)”. The above (1) is achieved.

  When life extension control is started, life extension control is performed according to the flowcharts of FIGS. 12 and 13 in order to achieve the above (2) and (3). As shown in FIG. 19, the life extension control is divided into a plurality of travel sections (LYY1 to LYY2,..., L (YYN-1) to L in the travel distance from the travel distance LYY1 to the guaranteed travel distance La when the control is started. Each time (YYN)) is switched, the progress of the cumulative damage degree is delayed in stages (FIG. 14), and control is performed so that the change characteristic of the cumulative damage degree f with respect to the travel distance L is directed to the guaranteed travel distance La.

  That is, not only simply evaluating the endurance life of the frictional engagement element based on the cumulative damage level, but using the guaranteed mileage La as a reference index, when the initial judgment timing is reached, based on the cumulative damage level record in the past travel section Critical mileage Lmax is predicted. Then, when the predicted critical travel distance Lmax is shorter than the guaranteed travel distance La, life extension control is started (travel distance LYY1), and gradually, as shown in FIG. 19, in the travel section toward the guaranteed travel distance La. Life extension control is performed by a polygonal line characteristic that makes the slope of the cumulative damage degree gentle.

  Accordingly, as shown in FIG. 19, the travel section from the start of travel to the travel distance LYY1 where life extension control is started is set as the initial phase, and the travel section after the travel distance LYY1 is set as the life extension control phase. For this reason, the travel section in the life extension control phase becomes sufficiently long, and during this time, the life extension control with a high degree of freedom is performed, so that the travel up to the guaranteed travel distance La is ensured and the above (2) is achieved.

For example, when the slope of the cumulative damage degree is determined so as to go to the guaranteed mileage La from the start of life extension control, the speed change performance and slip performance due to life extension control change suddenly from the performance under normal control until then, and You will be noticed.
On the other hand, as shown in FIG. 19, life extension control is performed by a polygonal line characteristic that gradually reduces the slope of the cumulative damage degree until traveling to the guaranteed travel distance La is ensured. For this reason, changes in the speed change performance and the slip performance due to the life extension control become moderate, and even when the control is shifted from the normal control to the life extension control, the driver is not aware of the implementation of the life extension control, and the above (3) is achieved.

Next, the effect will be described.
In the durable life management method of the frictional engagement element of the embodiment, the effects listed below can be obtained.

(1) Durability of a frictional engagement element that is included in a vehicle driving force transmission system and that manages frictional engagement elements whose engagement / release is controlled and manages the durability life until the frictional engagement element reaches a use critical value In the life management method,
When the travel distance guaranteed in advance that the friction engagement element can travel while maintaining normal engagement / release performance is referred to as `` guaranteed travel distance La '',
A cumulative damage degree calculation procedure (FIGS. 2 to 5) for calculating a cumulative damage degree f of the frictional engagement element in all travel sections after the vehicle has started to travel;
When the vehicle reaches the initial determination timing at which the change in the cumulative damage level can be predicted after the vehicle starts running, the cumulative damage level f of the friction engagement element is used when the predicted change characteristic of the cumulative damage level is maintained as it is. A durability life prediction procedure (step S2) for predicting the critical travel distance Lmax reaching the critical value 1;
When it is determined that the critical travel distance Lmax is shorter than the guaranteed travel distance La, life extension control is started instead of normal control of the frictional engagement element, and life extension control is started with a delay in the cumulative damage degree compared to normal control. Control start procedure (FIG. 1);
When the life extension control is started, the travel distance from the travel distance LYY1 at that time to the guaranteed travel distance La is divided into a plurality of travel sections, and the progress of the cumulative damage degree is stepwise every time the plurality of travel sections are switched. A life extension control procedure (FIG. 12, FIG. 13) for delaying and directing a change characteristic of the cumulative damage degree f with respect to the travel distance L toward the guaranteed travel distance La;
Is provided.
For this reason, when it is predicted that the frictional engagement element will reach the endurance life before traveling to the guaranteed travel distance La, it is possible to extend the durability life of the frictional engagement element while suppressing performance degradation.

(2) When the life extension control is started, the required distance HZ or HZNow for repairing or replacing the frictional engagement element is calculated based on the average daily travel distance and the number of days required for repairing or replacing the frictional engagement element. A necessary distance calculation procedure (FIG. 14) for calculating is provided,
When the remaining travel distance (La-LNow) obtained by subtracting the current travel distance LNow from the guaranteed travel distance La falls below the required distance HZ or HZNow, the life extension control procedure (FIGS. 12 and 13) Switches to life extension control at a slow level (level End) and issues a warning to the driver.
For this reason, in addition to the effect (1), the frictional engagement element can be repaired or replaced before the cumulative damage f becomes “1 (use critical value)”.

(3) In the life extension control start procedure (FIG. 1), when it is determined that the critical travel distance Lmax predicted at the initial determination timing is longer than the guaranteed travel distance La, the friction engagement element is then engaged. The critical distance traveled Lmax is predicted each time the user experiences release / release, and life extension control is started when it is determined that the predicted critical distance Lmax is shorter than the guaranteed travel distance La (step S7 → step S4). ).
For this reason, in addition to the effect of (1) or (2), life extension control can be started at an early timing by continuously performing predictive monitoring of the durability life of the frictional engagement element after the initial determination timing. .

(4) In the life extension control start procedure (FIG. 1), when the critical travel distance Lmax is predicted after the initial determination timing, it is not the experience of all engagement / disengagement from the start of travel, but the engagement / release of a predetermined number of times in the past. A change characteristic of the cumulative damage degree f with respect to the travel distance L is predicted based on experience (step S6).
For this reason, in addition to the effect of (3), when a car user, a driver, or the like is changed, a change characteristic of the cumulative damage degree f with respect to the travel distance L can be accurately predicted in accordance with a change in driving personality.

(5) The cumulative damage degree calculation procedure (step S2) is performed when the management target is a shift friction engagement element used for a shift, and a minor amount is calculated from a calorific value Q generated in one shift using the shift friction engagement element. The cumulative damage degree Dsft is calculated using the law.
For this reason, in addition to the effects of (1) to (4), the cumulative damage degree Dsft of the shift friction engagement element that is engaged / released by the replacement control with high frequency, such as the friction engagement element of the automatic transmission, is accurately determined. Can be calculated.

(6) The cumulative damage degree calculation procedure (step S2) is based on the clutch temperature T during one slip time using the slip friction engagement element when the management target is a slip friction engagement element used for slip engagement. The cumulative damage degree Dslp is calculated using a minor rule.
For this reason, in addition to the effects of (1) to (4), the cumulative damage degree Dslp of the slip frictional engagement element that is slip-engaged frequently such as a start clutch of an automatic transmission or a lockup clutch of a torque converter is reduced. It is possible to calculate with high accuracy.

  As mentioned above, although the durable life management method of the friction engagement element of this invention has been demonstrated based on the Example, it is not restricted to this Example about a specific procedure, It concerns on each claim of a claim Design changes and additions are allowed without departing from the scope of the invention.

  In the embodiment, an example of calculating the cumulative damage degree Dsft of the shift friction engagement element and the cumulative damage degree Dslp of the slip friction engagement element is shown as the cumulative damage degree calculation procedure. However, the cumulative damage degree calculation procedure may be an example in which only the cumulative damage degree Dsft is calculated when the friction engagement element to be managed is a shift friction engagement element. Further, when the friction engagement element to be managed is a slip friction engagement element, only the cumulative damage level Dslp may be calculated.

  The durable life management method of the present invention can be applied not only to hybrid vehicles but also to various frictional engagement elements provided in the braking / driving system of other vehicles such as engine vehicles and electric vehicles. For example, in a torque converter of an engine vehicle, the durable life management method of the present invention can be applied to a lockup clutch that is slip-engaged. Further, in a vehicle equipped with a belt type continuously variable transmission, the durable life management method of the present invention can be applied to a forward clutch and a reverse brake.

  In addition, the present invention can sufficiently exert the effect of managing the durable life of the automatic transmission without being applied to all the frictional engagement elements provided in the automatic transmission, and is a frictional engagement that is less frequently involved in the shift. Elements such as a friction element that is fastened only during reverse travel or a friction element that is fastened only during high speed traveling may be excluded from the management target.

HZ or HZNow Required distance that requires repair or replacement of friction fastening elements
Lmax Critical distance
La Guaranteed mileage f Cumulative damage f = 1 Use critical value Dsft Cumulative damage degree of shift friction engagement element Dslp Cumulative damage degree of slip friction engagement element

Claims (6)

Durability life management method for a frictional engagement element, which is a management target of a frictional engagement element that is provided in a driving force transmission system of a vehicle and whose engagement / release is controlled, and manages the durability life until the frictional engagement element reaches a use critical value In
When the travel distance guaranteed in advance that the friction engagement element can travel while maintaining normal engagement / release performance is referred to as "guaranteed travel distance",
A cumulative damage degree calculation procedure for calculating a cumulative damage degree of the friction engagement element in all travel sections after the vehicle starts to travel;
When the initial judgment timing at which the change of the cumulative damage degree can be predicted after the vehicle starts running, the cumulative damage degree of the friction engagement element is used when the predicted change characteristic of the cumulative damage degree is maintained as it is. Endurance life prediction procedure to predict the critical mileage to reach the value,
When it is determined that the critical mileage is shorter than the guaranteed mileage, life extension control is started to start life extension control in which the progress of the cumulative damage degree is delayed compared to normal control instead of normal control of the friction engagement element. Procedure and
When the life extension control is started, the travel distance from the travel distance at that time to the guaranteed travel distance is divided into a plurality of travel sections, and the progress of the cumulative damage degree is delayed in stages each time the plurality of travel sections are switched, A life extension control procedure for directing the change characteristic of the cumulative damage degree with respect to the travel distance to the guaranteed travel distance;
A method for managing the durable life of a frictional engagement element, comprising: In the durable life management method of the frictional engagement element according to claim 1,
When the life extension control is started, a necessary distance calculating procedure for calculating a necessary distance until the frictional engagement element is repaired or replaced based on an average travel distance per day and a required number of days until the frictional engagement element is repaired or replaced. Provided,
In the life extension control procedure, when the remaining travel distance obtained by subtracting the current travel distance from the guaranteed travel distance is equal to or less than the required distance, the life extension control procedure is switched to the life extension control with a slow progress of the cumulative damage degree, and an alarm is issued to the driver. A method for managing a durable life of a frictional engagement element. In the durable life management method of the frictional engagement element according to claim 1 or 2,
When the critical travel distance predicted at the initial determination timing is determined to be longer than the guaranteed travel distance, the life extension control start procedure is performed each time the friction engagement element experiences engagement / release. A method for predicting a travel distance, and starting a life extension control when it is determined that the predicted critical travel distance is shorter than the guaranteed travel distance. In the durable life management method of the frictional engagement element according to claim 3,
In the life extension control start procedure, when the critical mileage is predicted after the initial judgment timing, the cumulative damage degree is calculated based on the past predetermined number of engagement / release experiences instead of all the engagement / release experiences from the start of traveling. A method for managing the durability life of a frictional engagement element, characterized by predicting a change characteristic with respect to a travel distance. In the durable life management method of the frictional engagement element according to any one of claims 1 to 4,
In the cumulative damage level calculation procedure, when the management target is a shift friction engagement element used for a shift, the cumulative damage level is calculated using a minor rule from the amount of heat generated in one shift using the shift friction engagement element. A method for managing a durable life of a frictional engagement element, characterized in that: In the durable life management method of the frictional engagement element according to any one of claims 1 to 4,
When the management target is a slip friction engagement element used for slip engagement, the cumulative damage degree calculation procedure uses the minor law from the clutch temperature during one slip time using the slip friction engagement element. A durability life management method for a frictional engagement element, characterized in that: