JP6193825B2 - Lock-up clutch abnormality detection device - Google Patents

Description

  The present invention relates to an abnormality detection device for a lockup clutch.

  In an automatic transmission equipped with a torque converter having a lock-up clutch, the engagement / release (non-engagement) of the lock-up clutch is controlled according to the driving state of the vehicle for the purpose of improving fuel consumption and drivability. Like to do. Therefore, when an abnormality occurs in the lockup clutch, it leads to deterioration of fuel consumption and drivability. Therefore, various techniques for detecting the abnormality of the lockup clutch have been proposed.

  For example, in the technique described in Patent Document 1, in a region where the engagement force of the lockup clutch is relatively high, that is, during acceleration driving or cruise driving of the vehicle, based on the difference between the engine speed and the transmission input speed. An abnormality of the lockup clutch is detected.

Japanese Patent No. 2928734

  By the way, recently, not only during vehicle acceleration or cruise, but also during deceleration, the lock-up clutch is engaged, and engine brakes are used and fuel (fuel) cut time is extended to improve fuel efficiency. Often configured to improve.

  However, according to the technique described in Patent Document 1, an abnormality of the lockup clutch can be detected while the vehicle is accelerating or cruising, while an abnormality of the lockup clutch is detected while the vehicle is decelerating. There is an inconvenience that cannot be done.

  In addition, as shown by the broken line in FIG. 6, when a characteristic abnormality occurs in the electromagnetic control valve that controls the operation of the lockup clutch, the characteristic value greatly deviates from the normal value during deceleration traveling. Nevertheless, since the characteristic value shows the same value as normal during acceleration traveling, the technology that detects the abnormality of the lockup clutch only during acceleration traveling detects this characteristic abnormality. There is a risk that the lockup clutch cannot be properly controlled during the deceleration traveling.

  Furthermore, in recent years, the demand for exhaust gas from vehicles has increased due to environmental considerations, and it is required to accurately detect abnormalities in equipment used for controlling and monitoring exhaust gas. Some of these devices perform an abnormality detection process when the vehicle is traveling at a reduced speed and the lockup clutch is engaged. It is necessary to accurately determine whether or not the two are securely engaged. However, since the conventional technology is configured to determine the abnormality of the lockup clutch only during acceleration traveling or cruise traveling, the abnormality determination result during acceleration traveling is determined for abnormality during deceleration traveling. This can only be estimated based on this, and there is a problem that a highly reliable determination result cannot be obtained.

  Accordingly, an object of the present invention is to solve the above-described problems and provide a lock-up clutch abnormality detection device that can accurately detect abnormality of the lock-up clutch even while the vehicle is decelerating.

In order to solve the above-described problem, according to a first aspect of the present invention, an output side of the internal combustion engine and an input side of the transmission are connected by being interposed between an internal combustion engine mounted on a vehicle and the transmission. In the abnormality detection device for a lockup clutch comprising an abnormality determination means for determining whether an abnormality has occurred in the possible lockup clutch, the abnormality determination means, when the transmission satisfies a predetermined determination condition, It is determined whether or not the vehicle performs a fuel cut of the internal combustion engine during deceleration travel and engages the lockup clutch, and determines whether or not the vehicle is performing the deceleration lockup travel. with abnormal-up clutch is determined whether or not occurred, it ends the deceleration lock-up running from the vehicle to start the deceleration lock-up running until Or a speed difference between a vehicle speed when the vehicle starts the deceleration lockup travel and a vehicle speed when the deceleration lockup travel ends is a predetermined value or more. In some cases, it is determined that no abnormality has occurred in the lockup clutch .

  In the lockup clutch abnormality detection device according to claim 2, the predetermined determination condition is that at least a clutch transmission torque of the lockup clutch is equal to or greater than a predetermined torque before the deceleration traveling is started, a torque converter The turbine speed of the engine is configured to be higher than the fuel-cut execution permission speed by a predetermined speed or more.

In the lockup clutch abnormality detection device according to claim 3 , the abnormality determination means includes a deceleration lockup time from when the vehicle starts the deceleration lockup travel to when the deceleration lockup travel ends. Is less than a predetermined time, and when the speed difference between the vehicle speed when the vehicle starts the deceleration lockup travel and the vehicle speed when the deceleration lockup travel ends is less than a predetermined value, the lockup It is configured to determine that an abnormality has occurred in the clutch.

According to a first aspect of the present invention, there is provided a lockup clutch abnormality detection device that determines whether or not an abnormality has occurred in a lockup clutch that can connect the output side of the internal combustion engine and the input side of the transmission. When the vehicle satisfies the above determination condition, it is determined whether or not the vehicle is performing a deceleration cut-up running with the fuel cut of the internal combustion engine and engaging the lock-up clutch during the deceleration running, and the vehicle is judged to be running the deceleration locking up. Determining whether or not an abnormality has occurred in the lockup clutch, and when the deceleration lockup time from the start of the deceleration lockup travel to the end of the deceleration lockup travel is a predetermined time or more, or The speed difference between the vehicle speed when the vehicle starts deceleration lockup and the vehicle speed when deceleration lockup travel ends is greater than or equal to a predetermined value. At one point, and configured for determining that no abnormality occurs to the lock-up clutch. Therefore, it is possible to accurately determine whether or not the lockup clutch is abnormal while the vehicle is decelerating. In particular, unlike the case where the abnormality of the lockup clutch is determined based on the ratio of the output rotational speed of the internal combustion engine to the rotational speed of the transmission, it is necessary to perform a desktop test in advance to determine a threshold value (predetermined ratio). Therefore, the cost can be reduced.

In the lock-up clutch abnormality detection device according to claim 2, at least the clutch transmission torque of the lock-up clutch is equal to or greater than a predetermined torque before the start of deceleration traveling, and the turbine speed of the torque converter is subjected to fuel cut. higher than the predetermined rotational speed than the allowed number of revolutions, it is arranged that consists of, it is possible to appropriately avoid erroneous determination that an abnormality has occurred in lock-up clutch, during deceleration of the vehicle Therefore, it is possible to accurately determine that an abnormality has occurred in the lockup clutch.

In the lockup clutch abnormality detection device according to claim 3 , the time from the start of deceleration lockup travel to the end thereof is less than a predetermined time, and the vehicle speed and end at the start of deceleration lockup travel when the speed difference between the vehicle speed when there is less than a predetermined value, the abnormality in the lock-up clutch is configured to determine to have occurred, during the deceleration of the vehicles, the abnormality in the lock-up clutch occurs It can be determined with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an entire lockup clutch abnormality detection device according to an embodiment of the present invention. FIG. 2 is a circuit diagram specifically illustrating a part of the configuration of the hydraulic pressure supply circuit illustrated in FIG. 1. It is a flowchart which shows the abnormality determination process of the lockup clutch which concerns on this Example. 3 is a sub-flow chart specifically showing a part of the processing shown in the flow chart. 3 is an explanatory diagram for explaining the threshold value used in the flow chart. It is explanatory drawing for demonstrating the characteristic abnormality of the electromagnetic control valve which controls a lockup clutch.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment for carrying out an abnormality detection device for a lockup clutch according to the invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic view showing an entire abnormality detection apparatus for a lockup clutch according to an embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a vehicle, and the vehicle 1 is equipped with an automatic transmission (hereinafter referred to as “transmission”) T. The transmission T is composed of a twin clutch type transmission having eight forward speeds and one reverse speed, and has a range such as P, R, N, and D.

  The transmission T is connected to a drive shaft 10a connected to a crankshaft of an engine (internal combustion engine) 10 via a torque converter 12, and is an even-stage input shaft (second input shaft) of 2, 4, 6 and 8 speeds. ) 14 and an odd-numbered input shaft (first input shaft) 16 of 1, 3, 5, and 7 speeds in parallel with the even-numbered input shaft 14. The engine 10 is composed of, for example, a spark ignition type internal combustion engine using gasoline as fuel.

  The torque converter 12 has a pump impeller 12b fixed to a drive plate 12a directly connected to a drive shaft 10a of the engine 10, a turbine runner 12c fixed to an even-numbered input shaft 14, and a lock-up clutch 12d. The driving force (rotation) of 10 is transmitted to the even-stage input shaft 14 via the torque converter 12.

  An idle shaft 18 is provided in parallel with the even-numbered input shaft 14 and the odd-numbered input shaft 16. The even-stage input shaft 14 is connected to the idle shaft 18 through gears 14a and 18a, and the odd-stage input shaft 16 is connected to the idle shaft 18 through gears 16a and 18a. The stage input shaft 16 and the idle shaft 18 rotate as the engine 10 rotates.

  Further, the first sub input shaft 20 and the second sub input shaft 22 are arranged coaxially and relatively rotatably on the outer circumferences of the odd-stage input shaft 16 and the even-stage input shaft 14, respectively.

  The odd-stage input shaft 16 and the first sub-input shaft 20 are connected via the first clutch 24 to transmit the rotation of the engine 10 via the first clutch 24, and the even-stage input shaft 14 and the second sub-input shaft 22 is connected via the second clutch 26 and transmits the rotation of the engine 10 via the second clutch 26. The first and second clutches 24 and 26 are both wet multi-plate clutches that operate when supplied with hydraulic oil pressure (hydraulic pressure).

  An output shaft 28 is disposed between the even-stage input shaft 14 and the odd-stage input shaft 16 in parallel with the even-stage input shaft 14 and the odd-stage input shaft 16. The even-numbered input shaft 14, the odd-numbered input shaft 16, the idle shaft 18, and the output shaft 28 are rotatably supported by bearings 30.

  A first-speed drive gear 32, a third-speed drive gear 34, a fifth-speed drive gear 36, and a seventh-speed drive gear 38 are fixed to the odd-numbered first auxiliary input shaft 20, and a second-numbered second-side input shaft 20 is fixed to the second-numbered second-side input shaft 20. A second speed drive gear 40, a fourth speed drive gear 42, a sixth speed drive gear 44, and an eighth speed drive gear 46 are fixed to the auxiliary input shaft 22.

  The output shaft 28 includes a 1-2 speed driven gear 48 that meshes with the 1st speed drive gear 32 and the 2nd speed drive gear 40, and a 3-4 speed driven gear 50 that meshes with the 3rd speed drive gear 34 and the 4th speed drive gear 42. A 5-6 speed driven gear 52 that meshes with the 5th speed drive gear 36 and the 6th speed drive gear 44 and a 7-8 speed driven gear 54 that meshes with the 7th speed drive gear 38 and the 8th speed drive gear 46 are fixed.

  The idle shaft 18 rotatably supports an RVS (reverse) idle gear 56 that meshes with a 1-2 speed driven gear 48 fixed to the output shaft 28. The idle shaft 18 and the RVS idle gear 56 are connected via an RVS clutch 58. Similar to the first and second clutches 24 and 26, the RVS clutch 58 is a wet multi-plate clutch that operates by being supplied with hydraulic pressure.

  A 1-3 speed gear fastening mechanism 60 (1-3) for selectively fastening (fixing) the 1st speed drive gear 32 and the 3rd speed drive gear 34 to the first auxiliary input shaft 20 on the odd-stage input shaft 16; A 5-7 speed gear fastening mechanism 60 (5-7) for selectively fastening (fixing) the high speed drive gear 36 and the 7th speed drive gear 38 to the first auxiliary input shaft 20 is disposed.

  A 2-4 speed gear fastening mechanism 60 (2-4) for selectively fastening (fixing) the 2nd speed drive gear 40 and the 4th speed drive gear 42 to the second auxiliary input shaft 22 on the even-stage input shaft 14; A 6-8 speed gear fastening mechanism 60 (6-8) for selectively fastening (fixing) the high speed drive gear 44 and the eighth speed drive gear 46 to the second auxiliary input shaft 22 is disposed. The four gear fastening mechanisms are collectively referred to by reference numeral 60.

  The driving force of the engine 10 is such that when the first clutch 24 or the second clutch 26 is engaged (engaged), the odd-numbered stage input shaft 16 to the first auxiliary input shaft 20 or the even-numbered stage input shaft 14 to the second auxiliary input shaft. 22 and further transmitted to the output shaft 28 via the drive gear and the driven gear described above.

  During reverse travel, the driving force of the engine 10 is applied to the output shaft 28 through the even-numbered input shaft 14, the gear 14 a, the gear 18 a, the idle shaft 18, the RVS clutch 58, the RVS idle gear 56, and the 1-2 speed driven gear 48. Communicated. The output shaft 28 is connected to a differential mechanism 64 via gears 28 a and 62, and the differential mechanism 64 is connected to wheels (drive wheels) 68 via a drive shaft 66. The vehicle 1 is indicated by wheels 68 or the like.

  All of the gear fastening mechanisms 60 operate by being supplied with hydraulic pressure (shift force). In order to supply hydraulic pressure to the gear fastening mechanism 60, the first and second clutches 24 and 26, the RVS clutch 58 and the torque converter 12, a hydraulic pressure supply circuit 70 is provided.

  FIG. 2 is a circuit diagram specifically showing a part of the configuration of the hydraulic pressure supply circuit 70, particularly a part related to control of the lockup clutch 12d.

  In the hydraulic pressure supply circuit 70, the hydraulic oil pumped up from the reservoir by the oil pump is regulated to a required pressure (LC engagement pressure) by a regulator valve and a torque converter pressure regulating valve (both not shown), It is supplied to the path 70a.

  The LC engagement pressure supplied to the oil passage 70a is sent to the LC shift valve 70b via the branch passage 70a1, and further supplied to the internal pressure chamber 12d1 of the torque converter via the oil passage 70c to engage the lockup clutch 12d. Press to the opposite side.

  On the other hand, the hydraulic pressure sent from the oil passage 70a to the LC control valve 70d via the branch passage 70a2 is appropriately adjusted here, and then the back pressure chamber 12d2 via the oil passage 70e, the LC shift valve 70b and the oil passage 70f. To press the lockup clutch 12d toward the release side.

  Here, the valve position (pressure adjustment point) of the LC control valve 70d changes according to the hydraulic pressure (LC control pressure) sent from the linear solenoid valve (electromagnetic control valve) 70g to the LC control valve 70d via the oil passage 70h. To do. The linear solenoid valve 70g is a hydraulic control valve, and has a characteristic that linearly changes (regulates) the output pressure (LC control pressure) from the output port by moving the spool in proportion to the energization amount, and is not energized. Is configured as an N / C (normally closed) type valve in which the spool moves to the closed position.

  The engagement force (slip amount) of the lock-up clutch 12d adjusts the hydraulic pressure difference between the LC engagement pressure supplied to the internal pressure chamber 12d1 and the hydraulic pressure supplied to the back pressure chamber 12d2, and more precisely to the linear solenoid valve 70g. It is controlled by appropriately adjusting the energization amount.

  As described above, the characteristic of the linear solenoid valve 70g can represent the energization amount and the output pressure (LC control pressure) by a linear function (linear relationship). However, as described with reference to FIG. 6, when an abnormality occurs in the characteristics of the linear solenoid 70g, particularly in the low output pressure range, the conventional technique cannot detect the abnormality of the lockup clutch 12d. There is concern about the inconvenience.

  Continuing the description of FIG. 2, a part of the hydraulic pressure supplied to the internal pressure chamber 12d1 of the torque converter 12 is supplied to each movable part of the transmission T as lubricating oil through the oil passage 70i.

  The operation of the LC shift valve 70b is controlled by on / off solenoid valves 70j and 70k. In this embodiment, when both the on / off solenoid valves 70j and 70k are demagnetized, the position of the LC shift valve 70b becomes the position shown in FIG. 2 and the above-described lockup clutch engagement circuit is formed. Configured to be

  On the other hand, when one or both of the on / off solenoid valves 70j and 70k are excited, the spool position of the LC shift valve 70b moves to the left side of the page, and no hydraulic pressure is supplied to the internal pressure chamber 12d1 of the lockup clutch 12d ( A circuit is formed in which the hydraulic pressure supply is cut off.

  That is, when one or both of the on / off solenoid valves 70j and 70k are excited and the spool position of the LC shift valve 70b moves to the left side of the page, the branch path 70a1 and the oil path 70f communicate with each other, while the oil path 70e It is blocked by the LC shift valve 70b. The oil passage 70c connected to the internal pressure chamber 12d1 communicates with the oil passage 70l, and the hydraulic pressure supplied to the internal pressure chamber 12d1 is discharged.

  Accordingly, in this state, the hydraulic pressure is supplied only to the back pressure chamber 12d2, and the lockup clutch 12d is released.

  Returning to the description of FIG. 1, the transmission T includes a shift controller 74. The shift controller 74 is configured as an electronic control unit (ECU) including a microcomputer. Further, an engine controller 76 composed of an electronic control unit equipped with a microcomputer is also provided for controlling the operation of the engine 10.

  The shift controller 74 is configured to be able to communicate with the engine controller 76, and acquires information such as the engine speed (output speed of the prime mover) NE, the throttle opening, and the accelerator opening AP from the engine controller 76.

  Further, the transmission T is provided with first, second, third, and fourth rotation speed sensors 82, 84, 86, and 90, which respectively indicate signals indicating the input rotation speed NM of the transmission T, first and second. A signal indicating the rotational speed of the auxiliary input shafts 20 and 22 and a signal indicating the rotational speed of the output shaft 28 (output rotational speed of the transmission T) NC (in other words, the vehicle speed V) are output.

  A plurality of hydraulic sensors 94 are disposed in the oil passages connected to the first and second clutches 24 and 26 and the lock-up clutch 12d of the hydraulic pressure supply circuit 70, and the first and second clutches 24 and 26 and the lock-up clutch. A signal indicating the hydraulic pressure of hydraulic oil supplied to 12d or the like is output.

  In addition, a range selector position sensor 102 is disposed near a range selector (not shown) disposed in the driver's seat of the vehicle 1 and is operated (selected) by the driver from a range such as P, R, N, and D. A signal indicating the range is output.

  All outputs from these sensors are input to the shift controller 74. The shift controller 74 excites and demagnetizes a linear solenoid valve (not shown) on the basis of information obtained by communicating with the engine controller 76 in addition to the outputs of these sensors, and the first, second, RVS clutches 24, 26, 58, The operation of the transmission T is controlled by controlling the operation of the gear fastening mechanism 60 and the lockup clutch 12d. In this specification, the shift controller 74 constitutes an abnormality detection device for the lockup clutch 12d.

  Based on the above, the abnormality determination process for the lockup clutch 12d according to the embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart showing the abnormality determination process according to this embodiment, FIG. 4 is a sub-flow chart specifically showing a part of the process, and FIG. 5 is a diagram for explaining threshold values used for the process. FIG.

  First, abnormality determination of the lockup clutch 12d according to the embodiment of the present invention will be described. As described above, according to the present invention, the vehicle is running at a reduced speed so that an abnormality detection process can be executed for equipment (for example, an oxygen sensor or an EGR (exhaust gas recirculation) valve) used to control or monitor the exhaust gas. Another object is to determine whether or not the lockup clutch 12d is engaged. In other words, it is an object to accurately determine that the state of the lock-up clutch 12d satisfies the condition for reliably executing the abnormality detection process of the device. Therefore, in the embodiment of the present invention, The abnormality determination of the lockup clutch 12d is performed based on whether or not the conditions necessary for executing the abnormality detection process are satisfied.

  In the following, in S10, it is determined whether or not the transmission T has an abnormality detection execution permission condition (predetermined determination condition) (S: processing step).

  The predetermined determination condition in S10 is locked when the vehicle 1 starts to decelerate based on the state before the vehicle 1 starts decelerating (that is, before the driver of the vehicle 1 releases the accelerator pedal (not shown)). This is a condition provided for confirming that the up clutch 12d is in a state where it should be reliably engaged. Specifically, before the vehicle 1 starts decelerating, the torque transmitted to the transmission T by the lockup clutch 12d (the clutch transmission torque of the lockup clutch 12d) is equal to or greater than a predetermined value, and the torque converter 12 The difference in rotational speed between the pump impeller 12b and the turbine runner 12c (slip ratio of the torque converter 12) is equal to or smaller than a predetermined slip ratio, the transmission T is not performing a speed change operation, and the rotational speed of the turbine runner 12c Is higher than the rotational speed that is the fuel cut control start condition, and there is no failure in the equipment that constitutes the lockup clutch 12d (for example, the LC control valve 70d) and the equipment that controls the engine 10. It consists of that.

  That is, in this embodiment, since the purpose is to determine the engagement abnormality of the lockup clutch 12d at the time of decelerating traveling, whether or not the lockup clutch 12d is sufficiently engaged before the decelerating traveling is started. Is confirmed based on the clutch transmission torque of the lockup clutch 12d and the slip ratio of the torque converter 12, and even after the start of the subsequent deceleration travel, it is estimated that the lockup clutch 12d is engaged for at least a certain time. It is decided to determine whether or not there is. Instead of the clutch transmission torque of the lockup clutch 12d, it is determined whether or not the lockup clutch 12d is sufficiently engaged based on the value of the LC control pressure that controls the engagement force of the lockup clutch 12d. May be. The LC control pressure can be obtained from the output of the hydraulic sensor 94. The rotational speed of the pump impeller 12b is calculated from the engine rotational speed NE, and the rotational speed of the turbine runner 12c is calculated from the output of the first rotational speed sensor 82 indicating the input rotational speed NM of the transmission T.

  Further, during the shifting operation of the transmission T, since it is generally performed to control the lock-up clutch 12d to slip positively in order to reduce the shift shock, the vehicle 1 is decelerated from this state. When started, there is a possibility that the engagement state necessary for accurately determining the abnormality of the lockup clutch 12d cannot be secured. Therefore, the fact that the speed change operation of the transmission T is not being performed is added to a predetermined determination condition.

  In addition, the engagement of the lockup clutch 12d during the deceleration traveling is originally intended to extend the fuel cut time and improve the fuel consumption. Therefore, at the time before starting the deceleration traveling or the deceleration traveling. Immediately after the transition, the engine run speed NE of the engine runner 12c is set so that the engine run speed of the engine 10 is less than the fuel cut control start permission revolution speed prohibiting the fuel cut and the fuel cut time cannot be sufficiently secured. It was added to the predetermined determination condition that it was higher than the specified rotational speed by the fuel cut control start condition.

If the result in S10 is negative, there is a possibility that the abnormality of the lockup clutch 12d may not be accurately determined. Therefore, the abnormality determination process described later is not executed, and the process proceeds from S12 to S18 to execute various flags (initial flag, deceleration LC end flag). ) And parameters T _LC and ΔV _LC (both will be described later), and the program is terminated. On the other hand, if the result in S10 is YES, the process proceeds to S20, calculates the deceleration LC time _{T LC} and deceleration LC speed difference [Delta] V _LC.

  FIG. 4 is a sub-flow chart for explaining the calculation process.

  First, in S100, it is determined whether or not the vehicle 1 is traveling at a deceleration lockup, that is, the vehicle 1 is traveling at a reduced speed, a fuel cut is being performed, and the lockup clutch 12d is engaged. It is determined whether or not all the requirements are satisfied.

  Whether or not the vehicle 1 is decelerating is determined based on the output of an accelerator pedal sensor that indicates the amount of depression of the accelerator pedal or an output of a throttle opening sensor that indicates the opening of a throttle valve that adjusts the intake amount to the engine 10. can do. Whether the lock-up clutch 12d is engaged can be determined based on the energization amount of the linear solenoid valve 70g that controls the lock-up clutch 12d and the slip ratio of the lock-up clutch 12d.

If the vehicle 1 has not yet started to decelerate, the determination in S100 is denied and the process proceeds to S102. In S102, it is determined whether or not the bit of the initial flag is 1. However, since the initial value of the bit of the initial flag is set to 0, the determination in S102 is also denied at the beginning, and the process proceeds from S104 to S108 and various parameters V _S (described later), ΔV _LC , and T _LC are initialized, and the sub-flow chart of FIG. 4 is terminated.

  On the other hand, when the result in S100 is affirmative and it is determined that the vehicle 1 is traveling in the deceleration lock-up, the program proceeds to S110 and determines whether or not the bit of the initial flag is 0. As described above, since the initial value of the bit of the initial flag is set to 0, the determination in S110 is first affirmed and the program proceeds to S112.

In S112, the current vehicle speed obtained from the output of the fourth rotation speed sensor 90 is set to V _S , the process proceeds to S114, and the value of the deceleration LC time _TLC indicating the duration of the deceleration lockup travel is reset.

  Next, the program proceeds to S116, and the bit of the initial flag is set to 1. That is, the initial flag is a flag for indicating that the first process (the processes of S112 and S114 described above) has been completed after the deceleration lock-up running is started.

Further, the program proceeds to S118, where the deceleration LC end flag indicating that the deceleration lockup travel has ended is reset and the program is terminated. In the next and subsequent program loops, while continuing the deceleration lock-up running, after an affirmative determination in S100 is the value of the deceleration LC time T _LC is gradually one by one incremented denied at the discretion of S110.

Thereafter, when it is determined that the deceleration lock-up travel has ended, the determination at S100 is denied and the determination at S102 is affirmed, so the program proceeds to S122. In S122, as the deceleration LC speed difference ΔV _LC , the difference between the vehicle speed V _S at the start of deceleration lockup travel and the current vehicle speed (at the end of deceleration lockup travel) stored in S112 is calculated. That is, the deceleration LC speed difference ΔV _LC means the amount of deceleration of the vehicle speed during deceleration lockup travel.

Furthermore the program proceeds to S124, with the value of the deceleration LC time T updates the value of the _LC and deceleration LC time T _LC is finally determined, after resetting the value of the bit of the first flag to 0 in S126, deceleration lock The bit of the deceleration LC end flag indicating that the up-travel has ended is set to 1, and the sub-flow chart in FIG.

Returning to the description of the flowchart of FIG. 3, the program then proceeds to S22 to determine whether or not the bit of the deceleration LC end flag is 1. When the result in S22 is negative, that is, when the deceleration lock-up running has not been finished yet, the following processing is skipped and the program is finished.

On the other hand, in S24 if the result is affirmative at S22, the deceleration LC time _{T LC} obtained in S124 of FIG. 4 it is determined whether less than the predetermined time _{T TH} (described later). If the result in S24 is affirmative, the process proceeds to S26, and it is determined whether or not a deceleration LC speed difference ΔV _LC (described later) obtained in S122 in FIG. 4 is less than a predetermined value. If this determination is also affirmed, the process proceeds to S28. It is determined that an abnormality has occurred in the lockup clutch 12d, and the program is terminated. On the other hand, when the result in S24 or S26 is negative, the program proceeds to S30, where it is determined that no abnormality has occurred in the lockup clutch 12d, and the program is terminated.

Here, the predetermined time T _TH and the predetermined value ΔV _TH will be described with reference to FIG. FIG. 5 shows that no abnormality has occurred in the lock-up clutch 12d, and therefore there are sufficient conditions for executing abnormality detection processing of equipment (for example, an oxygen sensor or an EGR valve) used to control exhaust gas. Indicates the secured situation. In FIG. 5, the hatched portion represents an area where the lockup clutch 12d is engaged when no abnormality has occurred in the lockup clutch 12d.

As shown, the reference time T1 the deceleration LC time T _LC when the vehicle 1 performs the normal deceleration, when the deceleration LC speed difference [Delta] V _LC at that time as the reference speed difference [Delta] V1, a threshold value predetermined time T _TH Is set to a value smaller than T1 and equal to or longer than the time (for example, about 10 msec) required to execute the device abnormality detection process. The predetermined value ΔV _TH is set to a speed difference that is decelerated at a predetermined time T _TH in normal deceleration. That is, the predetermined time T _TH and the predetermined value ΔV _TH do not need to be obtained by a desktop test or the like, and are set to values that are inevitably determined as conditions necessary for the abnormality detection processing of the device.

As a result, as shown by the one-dot chain line in FIG. 5, when the vehicle 1 performs strong deceleration (deceleration by sudden braking, etc.), the deceleration LC time T _LC is less than the predetermined time T _TH but the deceleration LC speed difference ΔV _LC Exceeds the predetermined value ΔV _TH , it is denied in S26 of FIG. 3 and it can be determined that no abnormality has occurred in the lockup clutch 12d.

Further, as indicated by a broken line in FIG. 5, when the vehicle 1 performs weak deceleration (deceleration by engine braking or inertia traveling without using a lot of foot brake), the deceleration LC speed difference ΔV _LC is less than a predetermined value ΔV _TH . However, as a result of the deceleration LC time T _LC exceeding the predetermined time T _TH , the result is negative in S24 of FIG. 3, and it can be determined that no abnormality has occurred in the lockup clutch 12d.

On the other hand, when an abnormality occurs in the lock-up clutch 12d, the lock-up clutch 12d is not engaged or is released early, so that the deceleration LC time T _LC falls below the predetermined time T _TH and the deceleration LC speed As a result, the difference ΔV _LC also falls below the predetermined value ΔV _TH , so that it is affirmed in the processing of S24 and S26 in FIG. 3 and it can be determined that an abnormality has occurred in the lockup clutch 12d.

Although illustration is omitted, the input rotation speed NM of the transmission T and the output rotation speed of the engine 10 are not used as in the prior art (Japanese Patent No. 2928734) without using the deceleration LC speed difference ΔV _LC and the deceleration LC time _LC. An NE ratio (ETR = NM / NE) can be calculated, and abnormality of the lockup clutch 12d can be determined based on the ratio.

  That is, if no abnormality has occurred in the lock-up clutch 12d and the lock-up clutch 12d is engaged during deceleration traveling, the ratio ETR is a value of about 1. However, if an abnormality has occurred in the lockup clutch 12d during deceleration travel (the lockup clutch 12d cannot be engaged), the engine speed NE is rapidly decreased by the fuel cut control, while the transmission input speed NM. Is gradually lowered under the influence of torque input from the wheel side, so the ratio ETR should exceed 1.

  Accordingly, it is possible to determine whether or not an abnormality has occurred in the lockup clutch 12d by monitoring the value of the ratio ETR for a certain period of time and comparing the value with a predetermined ratio set as appropriate. However, in this case, it is necessary to obtain a threshold value (predetermined ratio) for the ratio ETR in advance by a desktop test or the like.

  As described above, in the embodiment of the present invention, the output side of the engine 10 and the input of the transmission T are inserted between the engine (internal combustion engine) 10 mounted on the vehicle 1 and the transmission T. In the lockup clutch abnormality detection device (shift controller 74), the abnormality determination unit includes an abnormality determination unit that determines whether or not an abnormality has occurred in the lockup clutch 12d that can be connected to the transmission side. When T satisfies a predetermined determination condition (abnormality detection execution permission condition) (shift controller 74, S10), the vehicle 1 performs fuel cut of the engine 10 during deceleration traveling and engages the lockup clutch 12d. It is determined whether or not the vehicle is decelerating and locked up (shift controller S20, S100). When disconnection, abnormality is configured to determine whether or not occurred (the shift controller 74.S22～S30) to said lock-up clutch 12d. Therefore, it is possible to accurately determine whether or not an abnormality has occurred in the lockup clutch 12d while the vehicle 1 is traveling at a reduced speed.

  Further, the predetermined determination condition is that at least the clutch transmission torque of the lockup clutch 12d is equal to or greater than a predetermined torque before the start of the deceleration travel, and the turbine rotation speed (NE) of the torque converter is permitted to execute the fuel cut. In addition to the effects described above, it is possible to appropriately avoid erroneous determination that an abnormality has occurred in the lock-up clutch 12d, in addition to the above-described effects. It is possible to more accurately determine that an abnormality has occurred in the lock-up clutch 12d during the deceleration travel of 1.

  Further, when the abnormality determination means determines that the vehicle 1 is traveling in the deceleration lockup (S100), the ratio ETR of the output rotational speed NE of the engine 10 to the input rotational speed NM of the transmission T is determined. In addition to the above-described effects, in addition to the above-described effects, when the calculated ratio ETR is equal to or greater than a predetermined ratio, it is determined that an abnormality has occurred. It can be detected with higher accuracy that an abnormality has occurred in the lockup clutch 12d.

In addition, the abnormality determination unit is configured to detect the lock when a deceleration lockup time _TLC from when the vehicle 1 starts the deceleration lockup travel to the end of the deceleration lockup travel is _{equal to} or longer than a predetermined time _TTH. Since it is determined that no abnormality has occurred in the up-clutch 12d (S24, S30), in addition to the above-described effects, the presence or absence of abnormality of the lock-up clutch 12d is further accurately determined while the vehicle 1 is decelerating. Can be judged well.

  In particular, unlike the case where the abnormality of the lockup clutch 12d is determined based on the ratio ETR of the output speed NE of the engine 10 to the speed NM of the transmission T, a desktop test is performed in advance to set the threshold value (predetermined ratio). Since there is no need to define the cost, the cost can be reduced.

Further, the abnormality determination means is configured such that a speed difference ΔV _LC between a vehicle speed V _S when the vehicle 1 starts the deceleration lockup travel and a vehicle speed when the deceleration lockup travel ends is a predetermined value ΔV _TH or more. In some cases, it is determined that no abnormality has occurred in the lock-up clutch 12d (S26, S30). In addition to the above-described effects, the abnormality of the lock-up clutch 12d can be detected while the vehicle 1 is decelerating. Presence / absence can be determined with higher accuracy.

Further, the abnormality determination means is configured such that a deceleration lockup time _{TLC from} when the vehicle 1 starts the deceleration lockup travel to the end of the deceleration lockup travel is less than a predetermined time _TTH , and When the speed difference ΔV _LC between the vehicle speed V _S when the vehicle 1 starts the deceleration lock-up travel and the vehicle speed when the vehicle 1 ends the deceleration lock-up travel is less than a predetermined value ΔV _TH , the lock-up clutch 12d Since it is determined that an abnormality has occurred (S24-S28), in addition to the above-described effects, it can be determined with higher accuracy that an abnormality has occurred in the lockup clutch 12d while the vehicle 1 is traveling at a reduced speed. Can do.

  In the above-described embodiment, the twin clutch type transmission has been described as an example. However, it is merely an example, and a transmission having a lock-up clutch may naturally be a single clutch type or a CVT type. There may be.

  In the above description, the abnormality of the characteristic of the linear solenoid valve 70g has been described with reference to FIG. 6 as the abnormality of the lock-up clutch 12d. . That is, if the lock-up clutch 12d is not properly engaged during low-speed traveling, the occurrence of the abnormality can be determined regardless of the cause.

  T automatic transmission, 1 vehicle, 10 engine (internal combustion engine), 12 torque converter, 12d lock-up clutch, 68 drive wheel (wheel), 70 hydraulic supply circuit, 70b LC shift valve, 70d LC control valve, 70g linear solenoid valve 74 Shift controller (control means)

Claims (3)

An abnormality determination for determining whether or not an abnormality has occurred in a lockup clutch that is inserted between an internal combustion engine mounted on a vehicle and a transmission and that can connect an output side of the internal combustion engine and an input side of the transmission. In an abnormality detection device for a lockup clutch comprising means,
The abnormality determination means determines whether or not the vehicle is performing a deceleration lockup traveling that executes fuel cut of the internal combustion engine and engages the lockup clutch during deceleration traveling when the transmission satisfies a predetermined determination condition. When determining that the vehicle is in the deceleration lockup running, it is determined whether an abnormality has occurred in the lockup clutch, and the deceleration lockup is started after the vehicle starts the deceleration lockup running. The speed difference between the vehicle speed when the deceleration lockup time until the travel is finished is a predetermined time or more, or when the vehicle starts the deceleration lockup travel and the vehicle speed when the deceleration lockup travel is finished lock when is equal to or higher than the predetermined value, characterized in that determining that no abnormality occurs in the lock-up clutch Abnormality detection device of up clutch.   The predetermined determination condition is that at least the clutch transmission torque of the lockup clutch is equal to or greater than a predetermined torque before the start of the deceleration traveling, and the turbine rotation speed of the torque converter is a predetermined rotation speed than the execution permission rotation speed of the fuel cut. The abnormality detection device for a lock-up clutch according to claim 1, wherein the abnormality detection device is higher than a few.   The abnormality determination means is configured such that a deceleration lockup time from when the vehicle starts the deceleration lockup travel to the end of the deceleration lockup travel is less than a predetermined time, and the vehicle performs the deceleration lockup travel. 2. It is determined that an abnormality has occurred in the lockup clutch when a speed difference between a vehicle speed at the time of starting the vehicle and a vehicle speed at the time of ending the deceleration lockup travel is less than a predetermined value. Or the abnormality detection apparatus of the lockup clutch of 2.

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