JP7223115B2 - AUTOMATIC TRANSMISSION AND METHOD OF DETERMINING VIBRATION LOCATION IN AUTOMATIC TRANSMISSION - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission and a method for determining vibration locations in an automatic transmission.

JP2017-78474A discloses an automatic transmission in which a torque converter, a variator, and a stepped transmission having at least two gear ratios are provided in series between a drive source for traveling and driving wheels. It is

In an automatic transmission, vibration (judder) may occur due to aged deterioration of frictional engagement elements and oil. When such vibration occurs, the frictional engagement elements and oil must be replaced, but it takes time to identify the location where the vibration occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic transmission capable of easily identifying the location where vibration occurs.

An automatic transmission according to one aspect of the present invention includes a torque converter provided on a power transmission path between a drive source and drive wheels, and a continuously variable transmission provided downstream of the torque converter in the power transmission path. a stepped transmission provided downstream in a power transmission path of the stepless transmission, a rotation speed detector for detecting the rotation speed of the output shaft side of the stepped transmission, a torque converter, a stepless transmission, and a control device for controlling the operation of the stepped transmission, wherein the control device calculates a vibration level in a predetermined frequency region of the vibration component of the rotational speed based on the rotational speed detected by the rotational speed detector. and a determination unit that determines the location of vibration based on the vibration level in the predetermined frequency range calculated by the calculation unit.

A method for determining a vibration location in an automatic transmission according to an aspect of the present invention includes a torque converter provided on a power transmission path between a drive source and drive wheels, and a torque converter provided downstream of the power transmission path in the power transmission path. a continuously variable transmission mechanism, a stepped transmission mechanism provided downstream in a power transmission path of the continuously variable transmission mechanism, a rotation speed detector for detecting the rotation speed of the output shaft side of the stepped transmission mechanism, a torque converter, A method for determining a vibration location in an automatic transmission comprising the continuously variable transmission mechanism and a control device for controlling the operation of the stepped transmission mechanism, wherein the rotation speed is detected by a rotation speed detector. A vibration level in a predetermined frequency range in the vibration component of the velocity is calculated, and the location where the vibration occurs is determined based on the calculated vibration level in the predetermined frequency range.

According to these aspects, it is possible to easily identify the location of vibration in the automatic transmission.

FIG. 1 is a schematic configuration diagram of an automatic transmission according to this embodiment. FIG. 2 is a block diagram of the controller according to this embodiment. FIG. 3 is a diagram for explaining the vibration level according to this embodiment. FIG. 4 is a time chart showing an example of shift control in the subtransmission mechanism according to this embodiment. FIG. 5 is a flow chart for explaining a method for determining a location where vibration occurs according to this embodiment. FIG. 6 is a flow chart for explaining the method of determining the location where vibration occurs according to the present embodiment, and is a continuation of FIG. FIG. 7 is a diagram for explaining the amplitude of pressure vibration according to the present embodiment. FIG. 8 is a diagram for explaining the μ-V characteristic of the friction engagement element according to this embodiment. FIG. 9 is a diagram showing the relationship between the travel distance and the oil base number in the torque converter according to the present embodiment. FIG. 10 is a flow chart for explaining a method for determining a location where vibration occurs according to a modification.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing the essential parts of a vehicle 100. As shown in FIG. A vehicle 100 includes an engine 1 , an automatic transmission T/M, an axle portion 4 , and drive wheels 5 .

The engine 1 is an internal combustion engine that uses gasoline, light oil, or the like as fuel, and functions as a drive source for running. The rotation speed, torque, etc. of the engine 1 are controlled based on commands from an ECU (not shown).

The automatic transmission T/M comprises a torque converter 2 provided on a power transmission path between the engine 1 and drive wheels 5, and an automatic transmission mechanism section 3 provided downstream of the torque converter 2 in the power transmission path. , a controller 10 as a control device for controlling operations of the torque converter 2 and the automatic transmission mechanism 3 , a hydraulic control device 50 , and an oil pump 6 .

The torque converter 2 transmits power through fluid. In the torque converter 2, the power transmission efficiency can be improved by engaging the lockup clutch 2a.

Based on a command from the controller 10, the automatic transmission mechanism 3 outputs the input rotational speed at a rotational speed corresponding to the gear ratio. The automatic transmission mechanism portion 3 includes a variator 20 as a continuously variable transmission mechanism provided downstream in the power transmission path of the torque converter 2, and a sub-transmission mechanism as a stepped transmission mechanism provided downstream in the power transmission path of the variator 20. a mechanism 30;

The axle part 4 is configured with a reduction gear, a differential, and a drive axle. The power of the engine 1 is transmitted to the drive wheels 5 through a power transmission path formed by the torque converter 2, the variator 20, the auxiliary transmission mechanism 30 and the axle portion 4.

The variator 20 has a primary pulley 21 , a secondary pulley 22 and a belt 23 . The variator 20 constitutes a belt-type continuously variable transmission mechanism that changes the winding diameter of the belt 23 by changing the groove widths of the primary pulley 21 and the secondary pulley 22, respectively. In the following, the primary will be referred to as PRI and the secondary as SEC.

The PRI pulley 21 has a fixed pulley 21a, a movable pulley 21b, and a PRI oil chamber 21c. A PRI pressure controlled by a hydraulic control device 50 is supplied through a passage 51 to the PRI oil chamber 21c. By supplying the PRI pressure, the movable pulley 21b is actuated, and the groove width of the PRI pulley 21 is changed according to the PRI pressure.

The SEC pulley 22 has a fixed pulley 22a, a movable pulley 22b, and an SEC oil chamber 22c. An SEC pressure controlled by a hydraulic control device 50 is supplied through a passage 51 to the SEC oil chamber 22c. By supplying the SEC pressure, the movable pulley 22b is actuated, and the groove width of the SEC pulley 22 is changed according to the SEC pressure.

A belt 23 is wound between the PRI pulley 21 and the SEC pulley 22 . Specifically, the belt 23 is formed by a V-shaped sheave surface formed by a fixed pulley 21a and a movable pulley 21b of the PRI pulley 21, and a fixed pulley 22a and a movable pulley 22b of the SEC pulley 22. It is wound around the V-shaped sheave surface.

The support of the belt 23 is ensured by a belt clamping force, which is a hydraulic supporting force generated by the PRI pressure and the SEC pressure supplied to the PRI oil chamber 21c and the SEC oil chamber 22c.

The auxiliary transmission mechanism 30 has two forward speeds and one reverse speed. The sub-transmission mechanism 30 has a first gear and a second gear having a smaller gear ratio than the first gear as forward gears. Auxiliary transmission mechanism 30 is provided in series on the output side of variator 20 (downstream side in the power transmission path).

The variator 20 and the auxiliary transmission mechanism 30 may be structurally configured as separate transmission mechanisms. In addition, the auxiliary transmission mechanism 30 may be directly connected to the variator 20, or may be indirectly connected to the variator 20 via another configuration such as a gear train.

The auxiliary transmission mechanism 30 includes a Low brake 31 as a first frictional engagement element, a High clutch 32 as a second frictional engagement element, and a reverse brake 33 as a third frictional engagement element. The low brake 31, high clutch 32, and reverse brake 33 are hydraulic clutches whose transmission torque capacity is controlled by the supplied hydraulic pressure and which can be engaged and disengaged. When the Low brake 31 is engaged and the High clutch 32 and the reverse brake 33 are released, the gear stage of the auxiliary transmission mechanism 30 becomes the 1st gear stage. When the High clutch 32 is engaged and the Low brake 31 and the reverse brake 33 are released, the gear stage of the auxiliary transmission mechanism 30 becomes the second gear stage having a smaller gear ratio than the first gear stage. Further, when the reverse brake 33 is engaged and the low brake 31 and the high clutch 32 are released, the gear stage of the auxiliary transmission mechanism 30 becomes the reverse gear. Furthermore, when the Low brake 31, High clutch 32, and reverse brake 33 are released, the auxiliary transmission mechanism 30 is put into a power cutoff state, and the automatic transmission mechanism portion 3 is put into a neutral state.

The oil pump 6 is driven by transmission of the rotation of the engine 1 via a belt (not shown), and discharges hydraulic oil sucked from a tank. Hydraulic oil discharged from the oil pump 6 is supplied to the torque converter 2 (lockup clutch 2a), the variator 20, the auxiliary transmission mechanism 30 and the like through the hydraulic control device 50 and the passage 51.

Hydraulic control device 50 includes a plurality of solenoid valves (not shown). The hydraulic control device 50 adjusts the pressure of hydraulic oil discharged by the oil pump 6 and supplies predetermined hydraulic pressure to each part of the variator 20 and the subtransmission mechanism 30 through the passage 51 . The hydraulic control device 50 adjusts the line pressure, the PRI pressure, the SEC pressure, and the engagement pressure of each friction engagement element (the lockup clutch 2a, the low brake 31, the high clutch 32, and the reverse brake 33). In this embodiment, the hydraulic control device 50 and the passage 51 constitute a hydraulic control circuit C. As shown in FIG.

A controller 10 is an ATCU that controls various operations of the automatic transmission T/M. The controller 10 is composed of a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM) and an input/output interface (I/O interface). The controller 10 can also be composed of a plurality of microcomputers. In addition to the ATCU, the controller 10 can also be configured to have functions such as an SCU that controls the shift range and an ECU that controls the engine 1 .

The controller 10 includes a first rotation speed sensor 41 for detecting the rotation speed of the input shaft side of the variator 20, and a rotation speed sensor for detecting the rotation speed of the input shaft side of the auxiliary transmission mechanism 30 (the output shaft side of the variator 20). Signals from the second rotation speed sensor 42 and the third rotation speed sensor 43 that detects the rotation speed Nout on the output shaft side of the auxiliary transmission mechanism 30 are input. The controller 10 also receives signals from an accelerator opening sensor 44, a brake sensor 45, an ignition switch 46, an inhibitor switch 47, an engine rotation speed sensor 48, a vehicle speed sensor 49, a pressure sensor 52, and the like.

An accelerator opening sensor 44 detects an accelerator opening APO representing the amount of operation of the accelerator pedal. The accelerator opening APO indicates the driver's request for acceleration. A brake sensor 45 detects whether or not the brake pedal is depressed. Depression of the brake pedal indicates a request for deceleration by the driver. The brake sensor 45 may detect a brake depression force representing the depression force of the brake pedal. The inhibitor switch 47 detects the position of the select lever. An engine rotation speed sensor 48 detects the rotation speed Ne of the engine 1 . The pressure sensor 52 detects the SEC pressure (pressure P) supplied to the SEC oil chamber 22c.

The controller 10 generates a shift control signal based on these signals and outputs the generated shift control signal to the hydraulic control device 50 . The hydraulic control device 50 controls the line pressure, the PRI pressure, the SEC pressure, and the engagement pressure of each frictional engagement element of the auxiliary transmission mechanism 30 and the torque converter 2 based on the shift control signal from the controller 10, and switches hydraulic paths. I do. As a result, hydraulic pressure corresponding to the shift control signal is supplied from the hydraulic control device 50 to each part of the lockup clutch 2a, the variator 20, and the subtransmission mechanism 30, and engagement control of the lockup clutch 2a of the torque converter 2 is performed. At the same time, the gear ratios of the variator 20 and the subtransmission mechanism 30 are changed to the gear ratio corresponding to the gear shift control signal, that is, the target gear ratio.

As shown in FIG. 2 , the controller 10 includes a shift control section 11 that controls the operations of the lockup clutch 2 a of the torque converter 2 , the variator 20 and the auxiliary transmission mechanism 30 , and the rotation speed detected by the third rotation speed sensor 43 . A calculation unit 12 for calculating a vibration level Lfn in a predetermined frequency range in the vibration component of the rotation speed Nout from Nout, and a vibration generation location based on the vibration level Lfn in the predetermined frequency range calculated by the calculation unit 12 a learning control unit 14 that learns the engagement pressure at which the Low brake 31 and High clutch 32 in the auxiliary transmission mechanism 30 begin to slip; and a storage unit 15 for storing. The shift control unit 11, the calculation unit 12, the determination unit 13, and the learning control unit 14 function to control the operation of the automatic transmission T/M in the controller 10 and generate vibration (judder), which will be described later. It is a virtual unit that has a function for specifying a location. Functions of the calculation unit 12, the determination unit 13, the learning control unit 14, and the storage unit 15 will be described later in detail.

Note that the vibration level Lfn is, as shown in FIG. It is a value corresponding to the difference.

Next, the shift control and learning control of the auxiliary transmission mechanism 30 will be described with reference to the time chart shown in FIG. FIG. 4 is an example of a time chart when the auxiliary transmission mechanism 30 is upshifted (that is, 1-2 shift). Note that the engagement pressure (hydraulic pressure) shown in FIG. 4 indicates the instruction pressure from the controller 10, and does not indicate the actual engagement pressure (hydraulic pressure).

As shown in FIG. 4, the shift control of the subtransmission mechanism 30 is composed of four phases, a preparation phase, a torque phase, an inertia phase, and an end phase, and upshifts are performed in this order. Furthermore, before and after the shift control of the auxiliary transmission mechanism 30, Low brake learning for learning the engagement pressure of the Low brake 31 and High clutch learning for learning the engagement pressure of the High clutch 32 are performed.

At time t1, more specifically, before the auxiliary transmission mechanism 30 shifts from 1st speed to 2nd speed, the controller 10 (learning control unit 14) executes Low brake learning. In Low brake learning, the engagement pressure at which the Low brake 31 starts to slip (hereinafter, the engagement pressure at which the Low brake 31 starts to slip is referred to as "first pressure PL") is learned. The controller 10 controls the hydraulic control device 50 to gradually decrease the hydraulic pressure (engagement pressure) supplied to the Low brake 31 . The controller 10 detects the rotational speed of the input shaft of the auxiliary transmission mechanism 30 detected by the second rotational speed sensor 42 and the rotational speed of the output shaft of the auxiliary transmission mechanism 30 detected by the third rotational speed sensor 43. When the rotational speed difference between Nout and Nout reaches a predetermined value or more, that is, the pressure when the Low brake 31 starts to slip is stored in the storage unit 15 as the first pressure PL (time t2).

At time t3, when the low brake learning ends, the controller 10 (transmission control unit 11) controls the hydraulic control device 50 to increase the hydraulic pressure (engagement pressure) supplied to the low brake 31 to the normal engagement pressure.

At time t4, when the shift control of the subtransmission mechanism 30 is started, as a preparatory phase, the high clutch 32 in the subtransmission mechanism 30 is precharged with hydraulic pressure, and the hydraulic pressure of the low brake 31 is reduced. Specifically, the controller 10 controls the hydraulic control device 50 to increase the hydraulic pressure supplied to the High clutch 32 and decrease the hydraulic pressure of the Low brake 31 . At this time, by temporarily supplying a high pressure to the High clutch 32 as a precharge, the engagement operation of the High clutch 32 can be started more quickly.

When the preparation phase ends, the shift control shifts to the torque phase (time t5). In the torque phase, the hydraulic pressure to the High clutch 32 is further increased, and the hydraulic pressure to the Low brake 31 is further decreased to shift the gear stage responsible for torque transmission from 1st to 2nd. The torque phase ends when a predetermined time has elapsed from the start (time t6).

At time t6, shift control shifts from the torque phase to the inertia phase. In the inertia phase, the gear ratio of the subtransmission mechanism 30 is smoothly changed from the gear ratio of 1st gear (pre-shift gear stage) to the gear ratio of 2nd gear (post-shift gear stage), and the variator 20 is moved to the gear ratio of the subtransmission mechanism 30. In this phase, the gear is shifted in the direction opposite to the shift direction (from the High side to the Low side).

When shifting to the inertia phase, the controller 10 (transmission control unit 11) controls the hydraulic control device 50 to further increase the hydraulic pressure to the High clutch 32 and further decrease the hydraulic pressure to the Low brake 31. At the same time, the speed change of the variator 20 is started. The speed change speed of the variator 20 is about the same as the speed change speed of the auxiliary transmission mechanism 30, and the speeds are changed in opposite directions.

When the shift of the subtransmission mechanism 30 ends (time t7), the inertia phase ends, and the shift to the end phase occurs. The end of the inertia phase, that is, the end of shifting of the auxiliary transmission mechanism 30 is based on, for example, the rotational speed detected by the second rotational speed sensor 42 and the rotational speed Nout detected by the third rotational speed sensor 43. is judged by

In the end phase, the controller 10 controls the hydraulic control device 50 to set the hydraulic pressure to the Low brake 31 to 0 to completely release the Low brake 31, and increases the hydraulic pressure to the High clutch 32 to completely close the High clutch 32. conclude. The end phase starts when the inertia phase ends (time t7), and ends when a predetermined time has passed since the start (time t8). As a result, the subtransmission mechanism 30 is completely switched to the 2nd speed.

At time t9, the controller 10 (learning control unit 14) executes High clutch learning. In high clutch learning, the engagement pressure at which the high clutch 32 begins to slip (hereinafter referred to as "second pressure PH") is learned. Specifically, the controller 10 controls the hydraulic control device 50 to gradually decrease the hydraulic pressure (engagement pressure) supplied to the high clutch 32 . The controller 10 detects the rotational speed of the input shaft of the auxiliary transmission mechanism 30 detected by the second rotational speed sensor 42 and the rotational speed Nout of the output shaft of the auxiliary transmission mechanism 30 detected by the third rotational speed sensor 43. , is stored in the storage unit 15 as the second pressure PH when the rotational speed difference of .

The first pressure PL and the second pressure PH stored in the storage unit 15 in this way are used as correction values in the shift control of the auxiliary transmission mechanism 30 from the next time onward.

Next, judder (vibration) occurring in the automatic transmission T/M will be described.

In the automatic transmission T/M, vibration may occur due to age deterioration of the friction engagement element (clutch plate) and oil. Specifically, the entire vehicle vibrates due to deterioration of the clutch plates in the low brake 31 and high clutch 32 of the auxiliary transmission mechanism 30 and the lockup clutch 2a of the torque converter 2 or changes in the composition of the lubricating oil. Judder may occur. Judder tends to occur when the frictional engagement element starts to be engaged or when the frictional engagement element starts to slip (see FIG. 4).

When such judder occurs, it is necessary to specify the location of the judder for replacement or the like. In order to specify the location where judder occurs, it is conceivable to specify it based on, for example, the vehicle speed or the engine rotation speed. However, the region in which judder occurs in subtransmission mechanism 30 and the region in which judder occurs in torque converter 2 overlap.

In addition, judder may occur due to hydraulic vibration generated in the hydraulic control circuit C. The region in which hydraulic vibration occurs in the hydraulic control circuit C also overlaps the region in which judder occurs in the auxiliary transmission mechanism 30 and the region in which judder occurs in the torque converter 2 .

Therefore, it is difficult to identify the location where judder occurs based on the vehicle speed and engine speed. Therefore, in the present embodiment, based on the rotation speed Nout on the output shaft side of the automatic transmission T/M (sub-transmission mechanism 30) detected by the third rotation speed sensor 43, judder (vibration) occurs at It is determined whether it is the sub-transmission mechanism 30 (the low brake 31 or the high clutch 32) or another part of the sub-transmission mechanism 30 (the torque converter 2 (the lockup clutch 2a) or the hydraulic control circuit C). .

Vibration characteristics differ between when judder occurs in the auxiliary transmission mechanism 30 (low brake 31 and high clutch 32) and when judder occurs in the torque converter 2 (lockup clutch 2a). The judder generated by the low brake 31, high clutch 32, and lockup clutch 2a is proportional to the mass from the torque converter 2 to the drive wheels 5 in the power transmission path. Therefore, the judder resonance frequency (about 25 to 35 Hz) in the auxiliary transmission mechanism 30 (low brake 31 and high clutch 32) is higher than the judder resonance frequency (about 5 to 10 Hz) in the torque converter 2 (lockup clutch 2a). also higher.

Therefore, the judder resonance frequency (first frequency region F1) in the auxiliary transmission mechanism 30 (low brake 31 and high clutch 32) is determined in advance based on experiments, etc., and the first frequency region F1 (for example, about 25 to 35 Hz) is determined. By determining whether or not the vibration level Lf1 is greater than or equal to the first predetermined value L1, it is determined whether or not the judder has occurred in the auxiliary transmission mechanism 30 (the low brake 31 and the high clutch 32). can do. Furthermore, the judder resonance frequency (second frequency region F2) in the torque converter 2 (lockup clutch 2a) is determined in advance based on experiments, etc., and the vibration level Lf2 within the second frequency region F2 (for example, about 5 to 10 Hz) is equal to or greater than the second predetermined value L2, it is possible to determine whether or not the judder has occurred in the torque converter 2 (lockup clutch 2a).

A method for determining a vibrating portion according to the present embodiment will be specifically described below with reference to FIGS. 5 and 6. FIG. 5 and 6 are flow charts showing the flow of the method for determining a vibrating location according to this embodiment.

In step S1, the rotational speed Nout is acquired. Specifically, the controller 10 acquires the rotational speed Nout detected by the third rotational speed sensor 43 .

In step S2, the rotational speed Nout is subjected to band-pass filter processing. Specifically, the calculation unit 12 performs band-pass filter processing on the rotation speed Nout detected by the third rotation speed sensor 43, and among the vibration components of the rotation speed Nout, the vibration component (waveform ). The first frequency region F1 is a region including the judder resonance frequency caused by the friction engagement elements (the low brake 31 and the high clutch 32) of the auxiliary transmission mechanism 30, and is, for example, 25 Hz to 35 Hz.

In step S3, the rotational speed Nout is subjected to band-pass filter processing. Specifically, the calculation unit 12 performs band-pass filter processing on the rotation speed Nout detected by the third rotation speed sensor 43, and determines that the vibration component (waveform) of the rotation speed Nout has a frequency higher than that in the first frequency region F1. A vibration component (waveform) in the small second frequency region F2 is extracted. The second frequency region F2 is a region including the judder resonance frequency caused by the lockup clutch 2a of the torque converter 2, and is, for example, 5 Hz to 10 Hz.

In step S4, the vibration level Lfn is calculated. Specifically, the calculation unit 12 calculates vibration levels Lf1 and Lf2 in each frequency region of the first frequency region F1 extracted in step S2 and the second frequency region F2 extracted in step S3.

In step S5, it is determined whether or not the vibration level Lf1 of the first frequency range F1 is equal to or greater than the first predetermined value L1. Specifically, the determination unit 13 determines whether or not the vibration level Lf1 of the first frequency region F1 calculated in step S4 is equal to or greater than the first predetermined value L1 for a predetermined period of time. By making the determination in step S5, it is possible to determine whether or not judder is occurring in the auxiliary transmission mechanism 30. FIG.

In step S5, if it is determined that the vibration level Lf1 of the first frequency region F1 is equal to or greater than the first predetermined value L1, the process proceeds to step S6, and the vibration level Lf1 of the first frequency region F1 is less than the first predetermined value L1. If it is determined that there is, the process proceeds to step S10.

In step S6, it is determined whether or not the traveling distance D of the vehicle 100 is equal to or greater than the first predetermined distance D1. If the traveling distance D is less than the first predetermined distance D1, there is a possibility that the frictional engagement elements (the low brake 31 and the high clutch 32) are not sufficiently used, and judder may occur due to this. have a nature. Therefore, a travel distance (first predetermined distance D1) that allows it to be determined that the friction engagement elements (Low brake 31 and High clutch 32) are sufficiently familiar is determined in advance by experiments or the like, and based on this travel distance (first predetermined distance D1) Judder caused by degradation of clutch plates in the low brake 31 and high clutch 32 or degradation of lubricating oil can be determined more accurately.

In step S7, it is determined whether or not the subtransmission mechanism 30 is being changed. If the subtransmission mechanism 30 is being changed, the process proceeds to step S9. In step S<b>9 , controller 10 stores travel distance D of vehicle 100 and the fact that judder (vibration) occurred during shifting of subtransmission mechanism 30 in storage unit 15 . The running distance D is divided into predetermined distances (for example, every 5000 km), and when judder occurs, the divided range and the number of occurrences of judder are counted and stored.

On the other hand, if it is determined in step S7 that the subtransmission mechanism 30 is not being changed, the process proceeds to step S8.

In step S8, it is determined whether or not learning control is being performed. The determination unit 13 determines whether the learning control of the auxiliary transmission mechanism 30 is being performed. If learning control is in progress, the process proceeds to step S9. If learning control is in progress, it is determined that the detected judder is not judder caused by the auxiliary transmission mechanism 30, and the process proceeds to END.

In step S<b>9 , the controller 10 stores the traveling distance D of the vehicle 100 and the occurrence of judder (vibration) during the learning control of the auxiliary transmission mechanism 30 in the storage unit 15 . Also in this case, the traveling distance D is divided into predetermined distances (for example, every 5000 km), and when judder occurs, the divided range and the number of occurrences of judder (vibration) are counted and stored. .

Next, the flow when it is determined in step S5 that the vibration level Lf1 of the first frequency region F1 is less than the first predetermined value L1 and the process proceeds to step S10 will be described.

In step S10, the pressure P is detected. Specifically, the pressure sensor 52 detects the SEC pressure (pressure P) supplied to the SEC oil chamber 22c. The detected pressure P is input to the controller 10 .

In step S11, the vibration width Pw is calculated. Specifically, the calculation unit 12 calculates a vibration width Pw (fluctuation width) from the input pressure P. As shown in FIG. The vibration width Pw is a value corresponding to the difference between the maximum value (positive peak) and the minimum value (minimum peak) in the waveform (fluctuation) of the pressure P, as shown in FIG.

In step S12, it is determined whether or not the gear stage of the auxiliary transmission mechanism 30 is on the Low side (first gear). If the gear stage of the sub-transmission mechanism 30 is on the Low side (1st speed), the process proceeds to step S13. Proceed to step S14.

In step S13, it is set to the fourth predetermined value P1. Specifically, the determination unit 13 sets the threshold used for the determination in step S15 to the fourth predetermined value P1, which is the threshold for the Low side (first gear). In step S14, it is set to the fifth predetermined value P2. Specifically, the determination unit 13 sets the threshold used for the determination in step S15 to the fifth predetermined value P2, which is the High side (2nd speed) threshold. The reason why the set value is changed according to the gear stage of the auxiliary transmission mechanism 30 is that the gear ratio differs between the low side (1st gear) and the high side (2nd gear), so there is a difference in the variation of the amplitude of vibration. It's for.

In step S15, it is determined whether or not the vibration width Pw is greater than or equal to the fourth predetermined value P1 or the fifth predetermined value P2. Specifically, the determination unit 13 determines whether the vibration amplitude Pw calculated in step S11 is equal to or greater than the fourth predetermined value P1 or the fifth predetermined value P2 set in either step S13 or step S14. judge.

If the amplitude of vibration Pw is greater than or equal to a predetermined value (fourth predetermined value P1 or fifth predetermined value P2), it is highly likely that hydraulic pressure vibration is occurring in the hydraulic control circuit C. Therefore, by making the determination in step S15, it is possible to determine whether the cause of the judder occurring in the automatic transmission T/M is the hydraulic vibration in the hydraulic control device 50 or not. can.

If the vibration width Pw is greater than or equal to the set predetermined value (the fourth predetermined value P1 or the fifth predetermined value P2), the process proceeds to step S16. On the other hand, if the vibration width Pw is less than the set predetermined value (fourth predetermined value P1 or fifth predetermined value P2), the process proceeds to step S19.

In step S16, it is determined whether or not the vibration level Lf2 of the second frequency range F2 is equal to or higher than the third predetermined value L3. Specifically, the determination unit 13 determines whether or not the vibration level Lf2 of the second frequency region F2 calculated in step S4 is equal to or higher than the third predetermined value L3 for a predetermined period of time.

In step S16, if it is determined that the vibration level Lf2 of the second frequency range F2 is equal to or greater than the third predetermined value L3, the process proceeds to step S17, and the vibration level Lf2 of the second frequency range F2 is less than the third predetermined value L3. If it is determined that there is, proceed to END.

In step S17, it is determined whether or not the hydraulic vibration detection condition is satisfied. Even if it is determined in step S15 that the vibration width Pw is equal to or greater than the fourth predetermined value P1 or the fifth predetermined value P2, no hydraulic vibration occurs in the hydraulic control circuit C, that is, the hydraulic vibration occurs due to another factor. It is also conceivable that Therefore, in step S17, it is determined whether or not the conditions (hydraulic vibration detection conditions) that are prerequisites for the generation of vibration in the hydraulic control circuit C are satisfied. Hydraulic vibration detection conditions are, for example, as follows.

(a): 25 [km/h] ≤ vehicle speed Vc ≤ 125 [km/h]
(b): 800 [rpm] ≤ engine speed Neng ≤ 4500 [rpm]
(c): 40 [°C] ≤ oil temperature T ≤ 100 [°C]
(d): Lockup clutch 2a is engaged

If all of the above conditions (a) to (d) are satisfied, the determination unit 13 determines that the hydraulic vibration detection condition is satisfied, and proceeds to step S18. On the other hand, if all of the above conditions (a) to (d) are not satisfied, the determination unit 13 determines that the hydraulic vibration detection condition is not satisfied, and proceeds to END. Note that when the vehicle 100 is in the coasting state (inertial running state), the condition (a) is changed to, for example, the following condition (a1).

(a1): 40 [km/h] ≤ vehicle speed Vc ≤ 120 [km/h]

In step S<b>18 , the controller 10 stores the travel distance D of the vehicle 100 and the occurrence of vibration (judder) in the hydraulic control circuit C in the storage unit 15 . In this case, the vehicle speed, oil temperature, etc. at the time when the judder occurred may also be stored.

In step S19, it is determined whether or not the traveling distance D of the vehicle 100 is equal to or greater than the second predetermined distance D2. If the traveling distance D is less than the second predetermined distance D2, there is a possibility that the lockup clutch 2a is not sufficiently engaged, resulting in judder. Therefore, a traveling distance (second predetermined distance D2) that can be determined to be sufficiently familiar with the lockup clutch 2a is determined in advance by experiments or the like, and a determination is made based on this traveling distance (second predetermined distance D2). It is possible to more accurately determine whether judder is caused by deterioration of the clutch plates of the up clutch 2a or deterioration of lubricating oil. The second predetermined distance D2 may have the same value as the first predetermined distance D1.

In step S20, it is determined whether or not the vibration level Lf2 of the second frequency range F2 is equal to or greater than the second predetermined value L2. Specifically, the determination unit 13 determines whether or not the vibration level Lf2 of the second frequency region F2 calculated in step S4 is equal to or higher than the second predetermined value L2 for a predetermined period of time.

In step S20, if it is determined that the vibration level Lf2 of the second frequency region F2 is equal to or greater than the second predetermined value L2, the process proceeds to step S17, and the vibration level Lf2 of the second frequency region F2 is less than the second predetermined value L2. If it is determined that there is, proceed to END. Although the second predetermined value L2 is set to be equal to or greater than the third predetermined value L3, the second predetermined value L2 and the third predetermined value L3 may be the same value.

In step S21, it is determined whether or not the lockup judder detection condition is satisfied. Even if it is determined in step S20 that the vibration level Lf2 of the second frequency region F2 is equal to or greater than the second predetermined value L2, the torque converter 2 (lockup clutch 2a) does not vibrate, that is, due to some other factor. Judder may also occur. Therefore, in step S21, it is determined whether or not a prerequisite condition (lockup judder detection condition) for judder (vibration) to occur in the torque converter 2 is satisfied. Lockup judder detection conditions are as follows.

(e): 8 [km/h] ≤ vehicle speed Vc ≤ 50 [km/h]
(f): The differential rotation Nd between the engine rotation speed Neng and the rotation speed Nt of the output shaft of the torque converter 2 is ≦300 [rpm]
(g): 40 [°C] ≤ oil temperature T ≤ 100 [°C]

If all of the above conditions (e) to (g) are satisfied, the determination unit 13 determines that the lockup judder detection condition is satisfied, and proceeds to step S22. On the other hand, if all of the above conditions (e) to (g) are not satisfied, the determination unit 13 determines that the lockup judder detection condition is not satisfied, and proceeds to END.

In step S<b>22 , the controller 10 stores the travel distance D of the vehicle 100 and the occurrence of vibration (judder) in the torque converter 2 in the storage unit 15 . In this case, the travel distance D is divided into predetermined distances (for example, every 5000 km), and when judder occurs, the divided range and the number of judder occurrences are counted and stored.

As described above, in the present embodiment, when judder occurs in the automatic transmission T/M, based on the vibration levels Lf1 and Lf2 in the predetermined frequency ranges (first frequency range F1, second frequency range F2) Since the location where vibration occurs can be determined, the location where judder occurs can be easily and more accurately specified. In addition, in the present embodiment, the storage unit 15 is made to store that judder has occurred. Therefore, at the time of maintenance, it is possible to easily identify the portion requiring repair from the information stored in the storage unit 15 .

Note that steps S10 to S18 may not be performed if judgment of judder by hydraulic vibration is unnecessary. A flowchart in this case is shown in FIG.

Next, factors that cause judder in the auxiliary transmission mechanism 30 will be described.

First, the μ-V characteristics of the Low brake 31 and High clutch 32 will be described. The μ-V characteristic is a change characteristic of the friction coefficient μ of the friction engagement elements (the clutch plates of the low brake 31 and the high clutch 32) with respect to the slip speed V (rotational speed difference). As shown in FIG. 8, judder does not occur if the μ-V characteristic maintains a positive gradient (solid line). However, when the μ-V characteristic of the friction engagement element has a negative slope (the friction coefficient μ decreases as the sliding speed V increases (dotted line)), judder may occur.

As factors for the negative slope of the μ-V characteristic, an increase in μ ₀ (maximum static friction coefficient, friction coefficient immediately before slipping) or a decrease in μ _d (dynamic friction coefficient) can be considered. Factors that increase μ ₀ (maximum coefficient of static friction) include deterioration of the oil, such as consumption of the anti-friction agent in the oil. In addition, deterioration of friction engagement elements (clutch plates of the low brake 31 and the high clutch 32) such as clogging of the friction material is one of the factors that cause the μ _d (dynamic friction coefficient) to decrease.

Furthermore, a situation in which judder occurs due to an increase in μ ₀ (maximum static friction coefficient) in the auxiliary transmission mechanism 30 is when the learning control is executed. As described above, the learning control learns the engagement pressure at which the Low brake 31 or High clutch 32 begins to slip. In other words, if judder occurs during execution of learning control, the _judder occurs when the low brake 31 or high clutch 32 begins to slip. It can be considered as a factor of judder.

As described above, the cause of the increase in μ ₀ (maximum coefficient of static friction) can be considered to be deterioration of the oil. Therefore, by storing in the storage unit 15 that judder has occurred during execution of learning control as in the present embodiment, it is possible to determine that oil replacement is necessary during maintenance.

Further, a situation in which judder occurs due to a decrease in μ _d (dynamic friction coefficient) in the subtransmission mechanism 30 is when the shift control in the subtransmission mechanism 30 is executed. As described above, the switching control switches transmission of torque while causing the Low brake 31 or High clutch 32 to slip. In other words, if judder occurs when the switching control is executed, it means that the _judder occurs when the low brake 31 or the high clutch 32 is slipping. can think.

As described above, the cause of the decrease in μ _d (dynamic friction coefficient) can be considered to be the deterioration of the friction engagement elements (the clutch plates of the low brake 31 and the high clutch 32) such as clogging of the friction material. . Therefore, by storing in the storage unit 15 that judder occurs during the execution of the switching control as in the present embodiment, it is possible to determine that the clutch needs to be replaced during maintenance. When you replace the clutch, you also need to replace the oil.

Next, the relationship between the travel distance D of the vehicle 100 and oil deterioration will be described. FIG. 9 is a diagram showing the relationship between the travel distance D of the vehicle 100 and the total base number of the oil in the torque converter 2. As shown in FIG. As shown in FIG. 9, the total base number of the oil decreases as the mileage D increases. That is, the oil deteriorates as the traveling distance D increases.

Therefore, in the present embodiment, the situation in which judder occurs is stored in the storage unit 15 together with the traveling distance D of the vehicle 100 . As a result, when performing maintenance, it is possible to more appropriately estimate the state of deterioration of the oil by taking the traveled distance D into consideration. The relation between the travel distance D of the vehicle 100 and the deterioration of the oil also approximates the characteristics shown in FIG.

The configuration, action, and effect of the embodiment of the present invention configured as described above will be collectively described.

The automatic transmission T/M includes a torque converter 2 provided on a power transmission path between a drive source (engine 1) and drive wheels 5, and a continuously variable torque converter 2 provided downstream of the torque converter 2 on the power transmission path. A transmission mechanism (variator 20), a stepped transmission mechanism (sub-transmission mechanism 30) provided downstream in the power transmission path of the continuously variable transmission mechanism (variator 20), and the output of the stepped transmission mechanism (sub-transmission mechanism 30) The rotation speed detector (third rotation speed sensor 43) that detects the rotation speed Nout on the shaft side, the torque converter 2, the continuously variable transmission mechanism (variator 20), and the stepped transmission mechanism (sub-transmission mechanism 30) are detected. and a control device (controller 10) for controlling.

Based on the rotational speed Nout detected by the rotational speed detector (third rotational speed sensor 43), the control device (controller 10) detects predetermined frequency regions (first frequency region F1, Vibration based on the vibration level Lfn in the predetermined frequency region (first frequency region F1, second frequency region F2) calculated by the calculation unit 12 that calculates the vibration level Lfn in the two frequency regions F2) and the calculation unit 12 and a judgment unit 13 for judging the occurrence location of .

In this configuration, the vibration level Lfn is calculated in a predetermined frequency range (first frequency range F1, second frequency range F2) in the vibration component of the rotational speed Nout, and the magnitude of the calculated vibration level Lfn is determined. , it is possible to specify the location where the vibration is generated in the automatic transmission T/M. As a result, it is possible to easily identify the location where the vibration is generated in the automatic transmission T/M. Therefore, there is no need to replace the entire unit, and appropriate maintenance can be performed.

In the automatic transmission T/M, the predetermined frequency range has a first frequency range F1 and a second frequency range F2 having a lower frequency than the first frequency range F1. When the vibration level Lf1 in the region F1 is equal to or greater than the first predetermined value L1, it is determined that vibration is occurring in the stepped transmission mechanism (sub-transmission mechanism 30), and the vibration level Lf2 in the second frequency region F2 exceeds the first predetermined value L1. 2 If it is equal to or greater than the predetermined value L2, it is determined that vibration is occurring in (the torque converter 2 or the hydraulic control circuit C) other than the stepped transmission mechanism (sub-transmission mechanism 30).

The judder frequency in the stepped transmission (sub-transmission mechanism 30) and the judder frequency in the torque converter 2 and the hydraulic control circuit C are different from each other. Therefore, by using the vibration levels Lf1 and Lf2 in the first frequency range F1 and the second frequency range F2 to determine the vibration component, it is possible to more finely determine the location where the vibration occurs in the automatic transmission T/M. .

In the automatic transmission T/M, when the vibration level Lf2 of the second frequency range F2 is equal to or greater than the second predetermined value L2, the determination unit 13 determines that the traveling distance D of the vehicle 100 is a predetermined value (second predetermined distance D2). If the above is the case, it is determined that the torque converter 2 is vibrating.

When determination based on hydraulic vibration is unnecessary, it is determined that vibration occurs in the torque converter 2 by determining whether the vibration level Lf2 of the second frequency range F2 is equal to or greater than the second predetermined value L2. can be done.

In the automatic transmission T/M, the stepped transmission mechanism (sub-transmission mechanism 30) includes a first friction engagement element (Low brake 31) for realizing the 1st speed and and a second frictional engagement element (High clutch 32) for realizing a second speed stage with a small gear ratio. When switching from one of the clutches 32) to the other of the first and second frictional engagement elements (the low brake 31 and the high clutch 32), the determination unit 13 detects vibration in the stepped transmission mechanism (sub-transmission mechanism 30). A storage unit 15 is further provided for storing the travel distance D of the vehicle 100 and the occurrence of vibration when it is determined that the vibration has occurred.

If it is determined that vibration has occurred while the stepped transmission mechanism (sub-transmission mechanism 30) is being switched, as described above, the first and second frictional engagement conditions such as clogging of the friction material may occur. It can be considered that the elements (the clutch plates of the low brake 31 and the high clutch 32) deteriorate. Therefore, by storing in the storage unit 15 that vibration has occurred during execution of the switching control, it can be determined that the clutch needs to be replaced during maintenance. As a result, proper maintenance can be performed without performing unnecessary replacement or work.

In the automatic transmission T/M, the control device (controller 10) sets the engagement pressure at which the first and second friction engagement elements (low brake 31 and high clutch 32) in the stepped transmission mechanism (sub-transmission mechanism 30) start to slip. A learning control unit 14 for learning is further provided, and when the determination unit 13 determines that vibration is occurring in the stepped transmission (sub-transmission mechanism 30) while the learning control unit 14 is learning. 2, the travel distance D of the vehicle 100 and the occurrence of vibration are stored in the storage unit 15 .

If vibration occurs during execution of learning control of the stepped transmission mechanism (sub-transmission mechanism 30), it can be considered that the oil has deteriorated, as described above. Therefore, by storing in the storage unit 15 that vibration has occurred during execution of learning control, it is possible to determine that oil replacement is necessary during maintenance. As a result, proper maintenance can be performed without performing unnecessary replacement or work.

In the automatic transmission T/M, a continuously variable transmission mechanism (variator 20) includes a primary pulley 21 having a primary oil chamber 21c, a secondary pulley 22 having a secondary oil chamber 22c, and wound around the primary pulley 21 and the secondary pulley 22. Hydraulic control circuit C (hydraulic control device 50, passage 51) for controlling the hydraulic pressure supplied to the belt 23, the primary oil chamber 21c and the secondary oil chamber 22c, and the hydraulic control circuit C (hydraulic control device 50, passage 51) and a pressure sensor 52 for detecting the internal pressure, and the determination unit 13 determines that the vibration width Pw of the pressure P detected by the pressure sensor 52 is equal to or greater than a predetermined value (fourth predetermined value P1 or fifth predetermined value P2). , and if the vibration level Lf2 of the second frequency region F2 is equal to or greater than the third predetermined value L3, it is determined that hydraulic vibration is occurring in the hydraulic control circuit C (hydraulic control device 50, passage 51). .

In this configuration, in addition to the vibrations caused by the auxiliary transmission mechanism 30 and the torque converter 2, the vibrations caused by the hydraulic control circuit C can also be determined.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. isn't it.

In the above embodiment, the pressure sensor 52 is configured to detect the SEC pressure (pressure P) supplied to the SEC oil chamber 22c. Hydraulic vibration may be determined based on the supplied PRI pressure or line pressure.

In the above-described embodiment, the case where each determination result is stored in the storage unit 15 has been described as an example.

This application claims priority based on Japanese Patent Application No. 2019-46140 filed with the Japan Patent Office on March 13, 2019, and the entire contents of this application are incorporated herein by reference.

Claims (6)

a torque converter provided on a power transmission path between the drive source and the drive wheels;
a continuously variable transmission provided downstream in the power transmission path of the torque converter;
a stepped transmission provided downstream of the power transmission path of the continuously variable transmission;
a rotational speed detector that detects the rotational speed of the output shaft side of the stepped transmission;
a control device that controls operations of the torque converter, the continuously variable transmission mechanism, and the stepped transmission mechanism;
The control device is
a calculation unit that calculates a vibration level in a predetermined frequency region in the vibration component of the rotation speed based on the rotation speed detected by the rotation speed detector;
a determination unit that determines a location where vibration occurs based on the vibration level in the predetermined frequency range calculated by the calculation unit;
The predetermined frequency range has a first frequency range and a second frequency range having a lower frequency than the first frequency range,
The determination unit
determining that vibration is occurring in the stepped transmission when the vibration level in the first frequency region is equal to or greater than a first predetermined value;
An automatic transmission that determines that vibration occurs in a lockup clutch or a hydraulic control circuit of the torque converter when the vibration level in the second frequency range is equal to or greater than a second predetermined value. In the automatic transmission according to claim 1,
When the vibration level in the second frequency region is equal to or greater than the second predetermined value, the determination unit is configured to vibrate in the lockup clutch of the torque converter when the travel distance of the vehicle is equal to or greater than a predetermined value. Automatic transmission that determines that is occurring. The automatic transmission according to claim 1 or 2,
The stepped transmission mechanism has a first frictional engagement element for realizing a first speed and a second frictional engagement element for realizing a second speed having a gear ratio smaller than that of the first speed. ,
The control device is
The judging unit judges that vibration is occurring in the stepped transmission mechanism when switching from one of the first and second frictional engagement elements to the other of the first and second frictional engagement elements. The automatic transmission further comprising a storage unit that stores the occurrence of vibration along with the mileage of the vehicle when the automatic transmission is set. In the automatic transmission according to claim 3,
The control device is
further comprising a learning control unit that learns engagement pressure at which the first and second frictional engagement elements in the stepped transmission mechanism begin to slip,
When the determination unit determines that vibration occurs in the stepped transmission mechanism while the learning control unit is performing learning, it is determined that the vibration has occurred along with the traveling distance of the vehicle. Automatic transmission memorized in memory unit. In the automatic transmission according to any one of claims 1 to 4,
The continuously variable transmission mechanism
a primary pulley having a primary oil chamber;
a secondary pulley having a secondary oil chamber;
a belt wound around the primary pulley and the secondary pulley;
the hydraulic control circuit for controlling hydraulic pressure supplied to the primary oil chamber and the secondary oil chamber;
a pressure sensor that detects the pressure in the hydraulic control circuit;
The determination unit
When the vibration amplitude of the pressure detected by the pressure sensor is equal to or greater than a predetermined value and the vibration level in the second frequency range is equal to or greater than a third predetermined value, hydraulic vibration occurs in the hydraulic control circuit. automatic transmission that is determined to be a torque converter provided on a power transmission path between the drive source and the drive wheels;
a continuously variable transmission provided downstream in the power transmission path of the torque converter;
a stepped transmission provided downstream of the power transmission path of the continuously variable transmission;
a rotational speed detector that detects the rotational speed of the output shaft side of the stepped transmission;
A method for determining a vibration location in an automatic transmission including the torque converter, the continuously variable transmission mechanism, and a control device that controls operations of the stepped transmission mechanism,
based on the rotational speed detected by the rotational speed detector, calculating a vibration level in a predetermined frequency region in the vibration component of the rotational speed;
Determining a location where vibration occurs based on the vibration level in the calculated predetermined frequency range,
The predetermined frequency range has a first frequency range and a second frequency range having a lower frequency than the first frequency range,
determining that vibration is occurring in the stepped transmission when the vibration level in the first frequency region is equal to or greater than a first predetermined value;
A method for determining a vibration location in an automatic transmission, comprising determining that vibration occurs in a lockup clutch or a hydraulic control circuit of the torque converter when the vibration level in the second frequency region is equal to or greater than a second predetermined value.

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