JP2012062998A - Lock-up clutch controller of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control the slipping amount of a lock-up clutch in lock-up clutch control performed when a vehicle in a deceleration state is re-accelerated.SOLUTION: When lock-up clutch command oil pressure which is instructed in accordance with the shift-up transmission control of an automatic transmission is learned, a reaching time from a shift control completion point of a time until a real slip ratio reaches a prescribed target value or a prescribed value close thereto is measured and the learned value of the command oil pressure is updated on the basis of the length of the reaching time. Original inertia phase control command pressure is corrected on the basis of the learned value and the control of the lock-up clutch accompanied by transition from the torque phase of shift control to an inertia phase is performed according to the corrected inertia phase control command pressure. Thereby, the slipping amount of the lock-up clutch upon shift-up under vehicle acceleration can be properly controlled and heat generation, the lowering of fuel efficiency, the generation of a shock and vibration or the like accompanied by the excessive generation of clutch slippage can be prevented.

Description

  The present invention relates to a lockup clutch control device for an automatic transmission that controls a slip amount of a lockup clutch. In particular, the lockup clutch command hydraulic pressure instructed in accordance with the shift-up shift control of the automatic transmission is learned during the lock-up clutch control performed when the vehicle is shifted up during acceleration, and the next time based on the learning result The present invention relates to a technique for appropriately controlling the slip amount of the lock-up clutch during the same control.

  Generally, in the engagement control of a lock-up clutch (LC) provided in a torque converter of an automatic transmission, a lock-up on / off mechanism that directly connects an engine output shaft and an automatic transmission mechanism input shaft. In addition to control for turning off, slip control for maintaining the lockup clutch in a slip state is performed for the purpose of improving fuel consumption and reducing fastening shock. In this slip control, the actual differential rotation (actual slip amount or actual slip ratio) between the engine output shaft and the input shaft of the automatic transmission mechanism is desired from the viewpoint of reducing engine vibration transmission and preventing fluctuations in LC transmission torque. It is preferable to control the slip amount by hydraulic control so that the target differential rotation (target slip amount or target slip ratio) is achieved, but especially when the accelerator operation by the driver is not constant and the engine torque fluctuates. In such cases, it is difficult to control the actual slip amount to the target slip amount only by simple feedback control.

  Therefore, not only the feedback control value is calculated based on the target slip amount and the actual slip amount, but also the feedforward control value corresponding to the engine torque is calculated, and the feedforward control value and the feedback control value are calculated. Conventionally, the slip control is performed using the added value. An example of such a technique is an apparatus disclosed in Patent Document 1, for example. In the conventional device described in Patent Document 1, the feedforward control value corresponding to the engine torque during slip control is learned and corrected according to the comparison result between the target slip amount and the actual slip amount, and the feed after the learning correction is corrected. A value obtained by adding the feedback control value to the forward control value is output as the lockup clutch command hydraulic pressure.

Japanese Patent No. 2985102

  However, in the conventional device as described above, the lock-up equivalent to the conventionally known feedback control that suddenly achieves a preset target slip ratio during the lock-up clutch control that is performed when the vehicle is shifted up during acceleration. Since the clutch command oil pressure (detailed below is the inertia phase control command pressure) is output, the target slip ratio is more tight (for example, the output shaft of the engine and the input shaft of the automatic transmission mechanism) for the purpose of, for example, improving fuel efficiency. The higher the lockup clutch command hydraulic pressure is, the more output is required, the closer the slip ratio is, for example, 90% to 100% with no differential rotation between Then, the lock-up clutch is suddenly engaged and a big shock is likely to occur. Occurs, there is a problem in that.

  The present invention has been made in view of the above points, and in a lock-up clutch control that is performed when the vehicle is shifted up during acceleration, a lock-up clutch command that is instructed in accordance with the shift-up shift control of the automatic transmission. By learning the hydraulic pressure and controlling the lock-up clutch according to the inertia phase control command pressure corrected based on the learning result (learned value), the slip amount of the lock-up clutch can be appropriately adjusted at the next control. An object of the present invention is to provide a lockup clutch control device for an automatic transmission that can be controlled.

  According to a first aspect of the present invention, there is provided a lockup clutch control device for an automatic transmission, wherein the lockup clutch (7) of the automatic transmission (1) is locked so that the actual slip ratio becomes a predetermined target value. In the lockup clutch control device (14) of the automatic transmission (1) for controlling the engagement pressure of the upclutch (7), detection means (3, 4, 11 for detecting engine torque, accelerator pedal opening, or throttle opening ), Determination means (E) for determining whether or not shift-up shift control has been started at the time of hydraulic pressure command for the lock-up clutch (7) in the automatic transmission (1), and during control of the lock-up clutch (7) Learning start determination means (A1) for determining whether or not a predetermined learning start condition is satisfied when the upshift control is started, and when the learning start condition is satisfied Further, learning means (A2) for learning a command oil pressure for instructing an engagement pressure of the lockup clutch (7), and the lockup clutch (7) according to a shift from the torque phase to the inertia phase of the shift-up shift control. Determining means (B) for determining an original inertia phase control command pressure for instructing an inertia phase control pressure at the time of control based on the detected engine torque, accelerator pedal opening or throttle opening; A correction means (B) for learning and correcting the determined original inertia phase control command pressure according to the learning result, and a control means for executing the control of the lockup clutch (7) according to the corrected inertia phase control command pressure ( 8), and the learning means (A2) is configured such that the actual slip ratio is a predetermined target value from the start of the upshift control. Stores the learned value of the command oil pressure for each learning region corresponding to the average value of the engine torque or accelerator pedal opening or throttle opening detected until reaching a predetermined value close to the predetermined value, and the shift-up shift control Measuring an arrival time until the actual slip rate reaches within a predetermined target value or a predetermined value close to the predetermined target value from the end of the step, and updating the learning value based on the length of the measured arrival time To do.

  According to the present invention, in lockup clutch hydraulic control performed when a vehicle in an acceleration state is shifted up, the lockup clutch command hydraulic pressure instructed in accordance with the shift up shift control of the automatic transmission (1) is learned. The time until the actual slip ratio reaches a predetermined target value or a predetermined value close to the predetermined target value from the end point of the shift-up shift control through a stepwise process between the torque phase and the inertia phase. The learning value is updated based on the length of the arrival time. Then, in order to instruct the inertia phase control pressure when controlling the lock-up clutch during cruise feedback control according to the shift from the torque phase to the inertia phase of the shift-up shift control, the engine torque, the accelerator pedal opening, or the throttle opening The original inertia phase control command pressure determined based on the degree is corrected based on the learned value, and the hydraulic control of the lockup clutch is executed in accordance with the shift to the inertia phase according to the corrected inertia phase control command pressure To do. In this way, by using the learning value based on the lockup clutch command hydraulic pressure instructed at the time of acceleration control, the slip amount of the lockup clutch at the time of lockup clutch control performed when the vehicle is shifted up during acceleration of the vehicle is obtained. It is possible to properly control, heat generation and fuel consumption deterioration due to excessive generation of clutch slip due to the inertia phase control command pressure being too low, shock due to excessive inertia phase control command pressure and Generation of vibrations can be prevented.

  According to a second aspect of the present invention, there is provided a lockup clutch control device for an automatic transmission, wherein the lockup clutch (7) of the automatic transmission (1) is locked so that the actual slip ratio becomes a predetermined target value. In the lockup clutch control device (14) of the automatic transmission (1) for controlling the engagement pressure of the upclutch (7), detection means (3, 4, 11 for detecting engine torque, accelerator pedal opening, or throttle opening ), Determination means (E) for determining whether or not shift-up shift control has been started at the time of hydraulic pressure command for the lock-up clutch (7) in the automatic transmission (1), and during control of the lock-up clutch (7) Learning start determination means (A1) for determining whether or not a predetermined learning start condition is satisfied when the upshift control is started, and when the learning start condition is satisfied Further, learning means (A2) for learning a command oil pressure for instructing an engagement pressure of the lockup clutch (7), and the lockup clutch (7) according to a shift from the torque phase to the inertia phase of the shift-up shift control. Determining means (B) for determining an original inertia phase control command pressure for instructing an inertia phase control pressure at the time of control based on the detected engine torque, accelerator pedal opening or throttle opening; A correction means (B) for learning and correcting the determined original inertia phase control command pressure according to the learning result, and a control means for executing the control of the lockup clutch (7) according to the corrected inertia phase control command pressure ( 8), and the learning means (A2) performs the shift-up shift control from the start of the shift-up shift control. The learning value of the command hydraulic pressure is stored for each learning region corresponding to the average value of the engine torque or accelerator pedal opening or throttle opening detected until the end of the shift, and the actual slip ratio at the end of the shift-up shift control and A deviation from a target value at the end of the upshift control is calculated, and the learning value is updated based on the calculated magnitude of the deviation. This also makes it possible to properly control the slip amount of the lock-up clutch during the lock-up clutch control that is performed when the vehicle is upshifted during acceleration of the vehicle. Or generation | occurrence | production of a shock, a vibration, etc. can be prevented now.

  Note that the reference numerals in the parentheses described above exemplify the corresponding constituent elements in the embodiments described later for reference.

  According to the present invention, the lockup clutch command hydraulic pressure instructed in accordance with the shift-up shift control of the automatic transmission performed during acceleration of the vehicle (more specifically, during cruise feedback control) is learned, and the learning result ( When the vehicle in the acceleration state is shifted up by correcting the original inertia phase control command pressure when controlling the lockup clutch in accordance with the transition from the torque phase to the inertia phase based on the learning value) The slip amount of the lock-up clutch at the next control to be performed is controlled appropriately. This prevents heat generation and fuel consumption deterioration caused by excessive clutch slippage due to the inertia phase control command pressure being too low, or shocks and vibrations caused by the inertia phase control command pressure being too high. There is an effect of being able to do.

1 is a schematic view showing an embodiment of an automatic transmission to which a lockup clutch control device for an automatic transmission according to the present invention is applied. It is a block diagram of a lockup clutch control device. It is a timing chart for explaining learning of lockup clutch command oil pressure. It is a flowchart which shows one Example of a lockup clutch command oil pressure learning process. It is a figure which shows one Example of a learning map. It is a flowchart which shows one Example of a lockup clutch command hydraulic pressure determination process. It is a flowchart which shows another Example of a lockup clutch instruction | command oil pressure learning process.

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

  FIG. 1 is a schematic view showing an embodiment of an automatic transmission to which a lockup clutch control device for an automatic transmission according to the present invention is applied. As shown in FIG. 1, an automatic transmission 1 connected to an engine 2 that is a power drive source is roughly divided into a torque converter (TC) having an automatic transmission mechanism (AT) 5 and a lock-up clutch (LC) 7. 6. A configuration comprising a hydraulic control circuit 8, wherein the torque converter 6 is interposed between the output shaft (not shown) of the engine 2 and the main shaft MS of the input shaft of the automatic transmission mechanism 5. It has become. That is, the driving force generated by the engine 2 is transmitted to driving wheels (not shown) of the vehicle via the torque converter 6 provided with the lock-up clutch 7, the automatic transmission mechanism 5, and the like. .

  The torque converter 6 performs torque transmission between the engine 2 and the input shaft of the automatic transmission mechanism 5 via a fluid in a state where the lock-up clutch 7 is released (lock-up off), while the lock-up clutch 7 is locked up. In a state where the clutch 7 is completely engaged (engaged) without slipping (lock-up on), torque is directly transmitted between the engine 2 and the main shaft MS of the input shaft. Such control for engaging / disengaging the lock-up clutch 7 (including slip control for maintaining the lock-up clutch 7 in a slip state), shift control in the automatic transmission mechanism 5 and the like are performed by hydraulic control by the hydraulic control circuit 8. Since the configuration of the automatic transmission mechanism 5 and the shift control of the automatic transmission mechanism 5 by the hydraulic control circuit 8 are well known, detailed description thereof will be omitted. However, the shift control of the upshift in the automatic transmission mechanism 5 is not limited to the torque phase and inertia. It is conventionally known that the process is performed by sequentially passing through each phase process (see FIG. 3 described later). In this specification, the engagement pressure for engaging and controlling the lockup clutch 7 when the shift control is in the torque phase process is referred to as torque phase control pressure, and the inertia when the shift control is shifted from the torque phase. The engagement pressure for controlling the engagement of the lock-up clutch 7 during the phase process is called inertia phase control pressure.

  As a hardware configuration of the hydraulic control circuit 8 for engaging / disengaging the lockup clutch 7, a well-known configuration may be employed as it is. As an example, a conventionally known hydraulic control circuit 8 that engages / releases the lockup clutch 7 using a lockup relay valve, a lockup control valve, a linear solenoid valve or the like will be briefly described. The lockup relay valve is a valve for switching the engagement / release of the lockup clutch 7, and the switching is performed depending on whether or not the control hydraulic pressure generated by the linear solenoid valve exceeds a predetermined threshold value. By gradually increasing or decreasing the control hydraulic pressure at the time of switching by means of a linear solenoid valve, the lockup relay valve, in combination with the lockup control valve, makes the lockup clutch 7 smooth (when shifting from lockup off to on). It can be fastened or released (while slipping).

  On the other hand, the lock-up control valve has an engagement pressure when the lock-up clutch 7 is engaged (or released), and its slip amount becomes a predetermined target value (target slip amount or target slip ratio, etc.). The fastening pressure is controlled by using a control hydraulic pressure generated by a linear solenoid valve as a control pilot pressure. Therefore, by controlling the control hydraulic pressure of the linear solenoid valve, the lockup clutch 7 can be (sliding) fastened with a necessary and sufficient hydraulic pressure corresponding to the output torque of the engine. Thus, the hydraulic control circuit 8 can perform not only the switching control for simply engaging / disengaging the lockup clutch 7, but also the slip control for maintaining the lockup clutch 7 in the slip state. It has become. Control of the lock-up clutch 7 such as the switching control and slip control by the hydraulic control circuit 8 is performed according to an instruction from the ECU 14.

  The ECU 14 includes a CPU, a ROM, a RAM, an input / output interface, and the like, and is a microcomputer that realizes a predetermined function according to various control programs stored in the ROM while using a temporary storage function of the RAM. In this embodiment, the ECU 14 functions as a lock-up clutch control device for an automatic transmission according to the present invention. A lock-up clutch command oil pressure learning process (see FIG. 4) and a lock-up clutch command oil pressure determination process described later. A lock-up clutch that is instructed in accordance with the shift-up shift control of the automatic transmission mechanism 5 in the lock-up clutch control performed when the vehicle is shifted up during vehicle acceleration by executing a computer program such as FIG. In addition to learning the command hydraulic pressure, the original inertia phase control command pressure is corrected based on the learning result (learned value), and the corrected inertia phase control command pressure is output at the next and subsequent lock-up clutch control. The operation of the hydraulic control circuit 8 is controlled. Details of such processing will be described later.

  In the ECU 14, for example, an engine torque signal from an engine torque sensor 3 that detects an output torque of the engine 2, a throttle, in order to reflect the load of the engine 2, the state of the engine 2 and the transmission 1, and the automatic transmission mechanism 5. The throttle opening signal from the throttle sensor 4 for detecting the opening degree, the LC transmission torque signal from the LC transmission torque sensor 9 for detecting the LC transmission torque transmitted from the lockup clutch 7 to the automatic transmission mechanism 5, and the automatic transmission mechanism 5 The main shaft rotational speed signal from the rotational speed sensor 10 for detecting the rotational speed of the main shaft MS, the accelerator pedal opening signal from the accelerator pedal sensor 11 for detecting the depression amount of the accelerator pedal, and the shift (shift stage) position are detected. Shift stage signal from the shift sensor 12 that performs automatic shift So that the various signals such as a shift torque signal from the shift torque sensor 15 for detecting the torque of the shift after the shift and torque of the transmission prior to shift is input at least upshift control configuration 5. As other signals, various signals such as a vehicle speed signal, an engine intake temperature, an engine cooling water temperature, an air conditioner on / off state, and a transmission lubricant oil temperature are input from other sensors 13 that can detect the signals. The Of course, signals other than those described here may be input.

  Note that the lockup clutch control device for an automatic transmission according to the present invention is not limited to one that executes a computer program such as the ECU 14 described above, and may be constituted by dedicated hardware. It is.

  Next, details of the ECU 14 will be described with reference to FIG. FIG. 2 is a block diagram of the lockup clutch control device (ECU 14). As shown in FIG. 2, in this embodiment, the ECU 14 includes a lockup clutch command hydraulic pressure learning means A, a lockup clutch command hydraulic pressure determination means B, a target slip ratio setting means C, an actual slip ratio detection means D, and a shift up control. It has start determination means E and learning value storage means F.

  The shift-up control start determination means E determines whether to perform hydraulic control of the lock-up clutch 7 according to the shift-up operation of the vehicle in the acceleration state based on the accelerator pedal opening signal, the vehicle speed signal, etc. In response to the start of the upshift control, it is determined whether or not to perform the lockup control corresponding to the shift control on the lockup clutch 7 during the cruise (acceleration) feedback control. When the lock-up control corresponding to the shift control is performed, a shift-up control start is output to the lock-up clutch command hydraulic pressure learning means A and the lock-up clutch command hydraulic pressure determining means B. The lockup clutch command oil pressure learning means A is for learning the lockup clutch command oil pressure for each gear stage (shift stage) after the shift specified by the shift stage signal. Do learning.

  The lockup clutch command hydraulic pressure learning means A includes a learning start determining means A1 and a learning means A2. The learning start determination means A1 determines whether a learning start condition for learning the lockup clutch command hydraulic pressure is satisfied. In the present embodiment, the engine intake air temperature, the engine coolant temperature, etc. are within a predetermined range, and the air conditioner is in an off state for a predetermined time or longer (engine-side stability condition), and the transmission The temperature of the lubricating oil 1 is within a predetermined range, and the hydraulic pressure for shifting control rises without delay (transmission side stability condition), and cruise (acceleration) ) The accelerator pedal opening (or engine) from before a certain time (see t0 to t1 shown in FIG. 3 to be described later) before the lockup clutch 7 in the feedback controlled state starts the control corresponding to the shift up shift control. (Torque or throttle opening) displacement is within a small range within a certain value. It only when satisfying all of (engine torque stability conditions) at the same time, it is determined that the learning start condition is satisfied. If the above three stability conditions are not satisfied after the start of learning and before the end of learning, the learning is terminated without reflecting the learning value.

  The learning means A2 learns the lockup clutch command hydraulic pressure during the learning period from the time when the control of the lockup clutch 7 is started to the cruise feedback control in accordance with the shift up shift control. This learning of the lockup clutch command oil pressure (reflection to the learning value) is performed each time the learning start condition is satisfied and the shift-up shift control is performed, and the learning result (learning value) at that time is stored in the learning value storage means F. It is reflected in the stored learning map (see FIG. 5 described later). Here, FIG. 3 is a timing chart for explaining learning of the lockup clutch command hydraulic pressure. Hereinafter, the learning timing of the lockup clutch command hydraulic pressure will be described with reference to the timing chart of FIG.

  It is determined by the learning start determination means A1 that the learning start condition that the engine side stability condition, the transmission side stability condition, and the engine torque stability condition are all satisfied at the same time is satisfied (here, all the flags corresponding to the respective conditions are “ 1), and when the control start determination (output) is made by the upshift control start determination means E, that is, during the cruise feedback control of the lockup clutch 7, the upshift control is started in the automatic transmission mechanism 5. Time t2 (shift control start time including the torque phase and inertia phase) is set as a learning start time. On the other hand, after the start of the upshift control, the time t5 when the cruise feedback control of the lockup clutch 7 is started (that is, the control corresponding to the shift control in each process of the torque phase and the inertia phase and the subsequent addition control are finished). Until the actual slip ratio approaches the target slip ratio within a certain value).

  Note that the start time of the upshift control (also referred to as the start time of the torque phase) is, for example, the time when it is detected that the shift stage has been changed and the torque of the changed speed stage N + 1 has started to be output. On the other hand, the end point of the shift-up shift control (also referred to as the end point of the inertia phase) is, for example, a point in time when it is detected that the rotation of the main shaft MS is synchronized with the rotation of the changed gear stage N + 1. Also, at the time of transition to the torque phase and the inertia phase from the start to the end of the shift control (that is, the end of the torque phase or the start of the inertia phase), for example, the clutch of the shift stage N before the change starts to slip. This is the point when it is detected.

  In this embodiment, for example, based on a lockup clutch command hydraulic pressure that fluctuates as shown in the figure, within the learning period from the learning start t2 to the learning completion t5, the shift speed N before the shift and the shift speed N + 1 after the shift are The actual slip ratio is within a certain value from the target slip ratio in accordance with the addition control of the lockup clutch 7 that is started after the shift control of the automatic transmission mechanism 5 is ended from the shift control end time t4 when the torque transfer is completed. The time until t5 (that is, the addition control time) is measured, and the lock-up clutch 7 is engaged and controlled according to the transition from the torque phase to the inertia phase in the next shift control according to the length of the measured addition control time. Learning to raise and lower the inertia phase control pressure is performed. In this embodiment, when the addition control time is short, negative learning for decreasing the inertia phase control pressure is performed, and when the addition control time is long, positive learning for increasing the inertia phase control pressure is performed. Learning value) is reflected in the learning map. A method of reflecting the learning value in such a learning map will be described later (see FIG. 5).

  The target slip ratio is determined by target slip ratio setting means C, and the actual slip ratio is determined by actual slip ratio detection means D. Since the method for determining each slip ratio by the target slip ratio setting means C and the actual slip ratio detection means D may be any known method, description thereof will be omitted.

  Returning to the explanation of FIG. 2, the lockup clutch command hydraulic pressure determining means B determines the lockup clutch command hydraulic pressure, and in this embodiment, in the lockup clutch control performed especially when the vehicle is shifted up during acceleration. As the shift control is shifted from the torque phase to the inertia phase, the inertia phase control pressure when the lockup clutch 7 is controlled to be engaged is determined and output to the hydraulic control circuit 8. The inertia phase control pressure depends on the accelerator pedal opening (or engine torque or throttle opening) at each shift stage with respect to the feedforward command hydraulic pressure that contributes to feedforward control determined according to the required LC transmission torque. The original inertia phase control pressure obtained by multiplying a predetermined correction coefficient determined in this way (simply referred to as the original command oil pressure to distinguish it from the corrected inertia phase control pressure) is stored in the learned value storage means F. It is determined by correcting according to the learned map.

  Next, the process of learning the lockup clutch command hydraulic pressure described above will be described with reference to FIG. FIG. 4 is a flowchart showing an embodiment of the lockup clutch command oil pressure learning process. As described above, when learning the lockup clutch command oil pressure or when determining the inertia phase control pressure in the lockup clutch engagement control, either the accelerator pedal opening, the engine torque, or the throttle opening is monitored. In order to make the explanation easier to understand, a case where the accelerator pedal opening is monitored as a representative will be described below as an example.

  In step S1, it is determined whether or not the engine-side stability condition flag is “1”. If it is determined that the engine-side stability condition flag is “1” (YES in step S1), it is determined whether the transmission-side stability condition flag is “1” (step S2). If it is determined that the transmission-side stability condition flag is “1” (YES in step S2), the displacement is predetermined and constant at the accelerator pedal opening (or engine torque or throttle opening, the same applies hereinafter). It is determined whether or not the value is within a value and continued for a certain period of time, that is, the engine torque is stable (step S3). On the other hand, when it is determined that the engine-side stability condition flag is not “1”, the transmission-side stability condition flag is not “1”, or the engine torque is not stable (any of steps S1 to S3 is NO). Then, the process ends. That is, the processes from the above steps S1 to S3 are processes for determining whether or not the engine-side stability condition, the transmission-side stability condition, and the engine torque stability condition are satisfied, and even one of these conditions is satisfied. If not, the process ends without learning the lockup clutch command hydraulic pressure.

  On the other hand, if all of the engine-side stability condition, the transmission-side stability condition, and the engine torque stability condition are satisfied (steps S1 to S3 are all YES), the engine torque is in a stable state and learning starts when the upshift is started. Time t2 is determined and learning is started. First, during the upshift control of the automatic transmission mechanism 5 or whether or not the engagement control of the lockup clutch 7 is being added, or during the upshift control of the automatic transmission mechanism 5 or the engagement control of the lockup clutch 7 It is determined whether or not a value obtained by subtracting the actual slip ratio from the target slip ratio is smaller than a predetermined value (that is, whether or not the actual slip ratio has reached a predetermined value from the target slip ratio) (step) S4). If the shift-up shift control or the addition control is being performed, or if it is determined that the value obtained by subtracting the actual slip ratio from the target slip ratio is smaller than the predetermined value during the shift-up shift control (YES in step S4) An average value of the accelerator pedal opening from the start of the shift control to the determination time is calculated (step S5). In step S6, the target addition control times T1 and T2 (in this case, T1 <T2 are used as references for the execution time of the addition control executed after the completion of the shift-up shift control based on the actually measured accelerator pedal opening. ) Is calculated. For the target addition control times T1 and T2, refer to, for example, data obtained by mapping the addition control time according to the accelerator pedal opening in advance obtained from an actual test result in which proper lockup clutch control is performed. It is required by doing.

  In step S4, neither the shift-up shift control nor the addition control is performed, or the lock-up clutch control is not in the engagement control corresponding to the shift control, and the value obtained by subtracting the actual slip ratio from the target slip ratio is not smaller than a predetermined value. When the determination is made and the learning completion time t5 is determined (NO in step S4), the target addition control time T1, T2 and the addition control time (actually measured value) required for the addition control in the lockup clutch control being executed. Are compared (step S7 and step S9), and different processes are executed according to the comparison results. When the actually measured addition control time is shorter than the target addition control time T1 (YES in step S7), the average value of the accelerator pedal opening obtained in step S5 in the learning map stored in the learning value storage means F ( The learning result is reflected by subtracting the learning value of the corresponding region based on the average accelerator pedal opening) (step S8). That is, the fact that the actual addition control time is shorter than the target addition control time T1 indicates that the actual slip ratio has reached the target slip ratio in a time shorter than the target, and such an operation is a rapid engagement. Therefore, in order to correct such an operation next time, more specifically, minus learning is performed to reduce the learning value so that the addition control is executed over a relatively long time so as not to cause the rapid fastening.

  On the other hand, when the actually measured addition control time is longer than the target addition control time T2 (which is naturally longer than the target addition control time T1) (step S7 is NO and step S9 is YES), the learned value storage means F The learning result is reflected by adding the learning value of the corresponding region based on the average value of the accelerator pedal opening (average accelerator pedal opening) obtained in step S5 in the learning map stored in step S10 (step S10). That is, the fact that the actually measured addition control time is longer than the target addition control time T2 indicates that the actual slip ratio has reached the target slip ratio in a longer time than the target, and such an operation causes a slip with heat generation. In order to correct such operation next time because it is a gradual fastening that can occur over a long period of time, more specifically, the learning value is added to end the addition control in a short period of time so as not to cause the above-mentioned slipping with heat generation. Do positive learning. Thus, the learning period is from the start of the upshift control of the automatic transmission mechanism 5 to the cruise feedback control of the lockup clutch 7, and the learning of the lockup clutch command hydraulic pressure is performed within the learning period. . When the actually measured addition control time is within the range of the target addition control times T1 and T2 (both steps S7 and S9 are NO), heat generation due to excessive clutch slippage, deterioration of fuel consumption, or engagement shock Assuming that appropriate lockup clutch control that does not occur is performed, learning of the lockup clutch command hydraulic pressure by the negative learning or the positive learning is not performed.

  Here, a method of reflecting the learning result (learning value) on the learning map will be described. FIG. 5 is a diagram illustrating an example of a learning map. This learning map is prepared for each shift stage. The learning map is data in which the relationship between the learning area based on the accelerator pedal opening (accelerator pedal opening area) and the learning value is mapped. In FIG. 5, the learning area is divided into nine areas (0/8 to 8/8). ) Shows what was divided. The reason why the learning area is divided into a plurality of areas in this manner is that, for example, variations in engine torque do not necessarily occur equally at each opening of the accelerator pedal opening. For example, if the engine torque fluctuates slightly only in the region where the accelerator pedal opening is in the vicinity of full open, if the learned value is reflected in the entire region of the accelerator pedal opening based on this, On the other hand, inappropriate learning is performed on the area. Therefore, the accelerator pedal opening is divided into nine, and the learning value of only the portion corresponding to this is updated based on the past addition control time corresponding to this.

  Note that if the number of divisions is set too large, the amount of information corresponding to the region for learning correction may be reduced, and there may be a region where learning correction is performed properly and a region where learning correction is not performed properly. It is not suitable, and too little is not suitable for the reasons described above. Therefore, 9 divisions are adopted in this embodiment.

  The learned value is reflected every time the lockup clutch command hydraulic pressure is learned, but the accelerator pedal opening range that reflects the learned value is determined based on the average accelerator pedal opening. When the average accelerator pedal opening is, for example, “1.5 / 8”, both the accelerator pedal opening areas “1/8” and “2/8” indicate that the average accelerator pedal opening area is, for example, “6.2 / In the case of “8”, both the accelerator pedal opening regions “6/8” and “7/8” (not shown) are determined as regions reflecting the learning value.

  On the other hand, the learning result (learned value) reflected in each region is determined according to a predetermined ratio based on the average accelerator pedal opening. Note that, in the learning map in the initial state where learning has not been performed once, all the learning values of all accelerator pedal opening regions are “0”. Specifically, when the average accelerator pedal opening is, for example, “1.5 / 8”, the learning value reflected in both the accelerator pedal opening regions “1/8” and “2/8” is “ When the average accelerator pedal opening is, for example, “6.2 / 8”, the learning values reflected in the region “6/8” and the region “7/8” are “0.8 ( 1-0.2) "and" 0.2 (1-0.8) ".

  When the learning result is reflected on the learning map, if the learning is negative, the learning value to be reflected is subtracted (see step S8 in FIG. 4). If the learning is positive, the learning value to be reflected is Add (see step S10 in FIG. 4). According to the above method, for example, when the first learning is performed and the average accelerator pedal opening at that time is “1.5 / 8” and the learning is negative, the area as shown in FIG. The learning value of “−0.5”, which is the learning result, is directly reflected on “1/8” and the region “2/8” (when the learning values of the learning map in the initial state are all “0”). When the second learning is continued and the average accelerator pedal opening at that time is “1.25 / 8” and the learning is positive learning, the same region “1/8” and region “2 /” as the first learning are performed. Since “+0.75 (1-0.25)” and “+0.25 (1-0.75)”, which are the second learning results, are reflected on the learning value of “8”, it is shown in FIG. Thus, at the end of the second learning, the region “1/8” is set to “−0.5 + 0.75 = 0.25”, and the region “2/8” is set to “−0.5 + 0.25 (1-0.75) = − 0.25”. The learning value is updated. In this way, when the learning of the lockup clutch command hydraulic pressure is repeated a plurality of times, a learning map in which learning values are recorded in all areas as shown in FIG. 5C, for example, is obtained.

  Next, processing for determining the lockup clutch command hydraulic pressure will be described. FIG. 6 is a flowchart showing an embodiment of the lockup clutch command hydraulic pressure determination process. In step S11, it is determined whether or not the shift control of the automatic transmission mechanism 5 is being performed (shift up). If it is determined that the shift control is being performed (YES in step S11), it is determined whether or not the initial process is being performed during the shift control (step S12). When it is determined that the process is the initial process during the shift control (YES in step S12), the feedforward command hydraulic pressure PFS is calculated with reference to the map based on the required LC transmission torque (step S13). Step S14 determines a shift start lockup latch command hydraulic pressure PCS.

  If it is determined that the process is not the initial process during the shift control (NO in step S12), the feedforward command hydraulic pressure PF is calculated according to a map prepared in advance based on the required LC transmission torque (step S15). In step S16, it is determined whether or not the shift control of the automatic transmission mechanism 5 is in the process of inertia phase. When it is determined that the shift control in the inertia phase is being performed (YES in step S16), the correction coefficient K is calculated based on the accelerator pedal opening (or engine torque or throttle opening, the same applies hereinafter) for each shift stage. (Step S17). In step S18, a learning pressure PS (correction pressure) is calculated for each shift stage based on the accelerator pedal opening actually measured at that time. A step S19 corrects the original inertia phase control pressure (original command hydraulic pressure) obtained by multiplying the calculated feedforward command hydraulic pressure PF by the correction coefficient K by the calculated learned pressure PS, so that the lockup clutch The command hydraulic pressure PC (inertia phase control pressure) is determined.

  Here, the calculation method of the learning pressure PS (correction pressure) will be specifically described with reference to FIG. An accelerator pedal opening range that refers to a learning value for calculating the learning pressure PS is determined based on the actually measured accelerator pedal opening. The determined learning value of each region is contributed when the learning pressure PS is calculated according to a predetermined ratio based on the accelerator pedal opening. Specifically, when the accelerator pedal opening is, for example, “1.25 / 8”, the accelerator pedal opening areas “1/8” and “2/8” both refer to the learned value. The contribution of the learning value in the region “1/8” is “−0.45 {(−0.6) × (1-0.25)}”, and the contribution of the learning value in the region “2/8” is “−0.125 {(−0.5) × (1−0.75)}”, and the total contribution to the learning pressure PS as a whole is “−0.575”. Alternatively, when the accelerator pedal opening is, for example, “2.75 / 8”, both the accelerator pedal opening areas “2/8” and “3/8” are the accelerator pedal opening areas that refer to the learned values. The contribution of the learning value of the region “2/8” is “−0.125 {(−0.5) × (1-0.75)}”, and the contribution of the learning value of the region “3/8” is “1.5 (2 X0.75) ", and the overall contribution that contributes to the learning pressure PS as a whole is" 1.375 (1.5-0.125) ". Based on the learning pressure specified based on the accelerator pedal opening, the control pressure corresponding to the total contribution is added (when the total contribution is positive) or subtracted (when the total contribution is negative). Thus, the learning pressure PS (correction pressure) is calculated.

  On the other hand, when it is determined that the shift control in the inertia phase is not being performed, that is, the shift control in the torque phase is being performed (NO in step S16), the calculated feed is calculated to the calculated shift start lockup latch command hydraulic pressure PCS. The lockup clutch command hydraulic pressure PC (torque phase control pressure) is determined by adding the forward command hydraulic pressure PF and further subtracting the feedforward command hydraulic pressure PFS calculated during the initial processing. Thus, the engagement pressure (torque phase control pressure) when starting the control of the lockup clutch 7 during the cruise feedback control in accordance with the start of the upshift control of the automatic transmission mechanism 5 is determined in accordance with the start of the shift control. This is determined by adding pressure increase / decrease to the shift start lockup latch command hydraulic pressure PCS by the difference (PF-PFS) of the feedforward value calculated based on the required LC transmission torque.

  If it is determined in step S11 that the shift control is not being performed, that is, the shift control has been completed and the control of the lockup clutch 7 is not performed in response to the torque phase and inertia phase of the shift control. When the addition control or cruise feedback control is being performed (YES in step S11), conventionally known addition control or cruise feedback control processing is executed (steps S21 to S29). That is, step S21 determines whether or not the absolute value of the difference between the target slip ratio and the actual slip ratio is greater than a predetermined value. If it is determined that the absolute value of the difference between the target slip ratio and the actual slip ratio is greater than the predetermined value (YES in step S21), it is determined whether the target slip ratio is greater than the actual slip ratio (step S22). ).

  If it is determined that the target slip ratio is greater than the actual slip ratio (YES in step S22), the added hydraulic pressure gradient P1 is calculated with reference to the map based on the accelerator pedal opening for each shift stage (step S23). . In step S24, the control pressure based on the calculated added hydraulic pressure gradient P1 is added to the current lockup clutch command hydraulic pressure PC to determine (update) the lockup clutch command hydraulic pressure PC. On the other hand, if it is determined that the target slip ratio is not greater than the actual slip ratio (NO in step S22), the subtraction hydraulic pressure gradient P2 is calculated with reference to the map based on the accelerator pedal opening for each shift stage ( Step S25). In step S26, the control pressure based on the calculated subtraction hydraulic pressure gradient P2 is subtracted from the current lockup clutch command hydraulic pressure PC to determine (update) the lockup clutch command hydraulic pressure PC.

  If it is determined in step S21 that the absolute value of the difference between the target slip ratio and the actual slip ratio is equal to or less than a predetermined value (NO in step S21), the feed forward is performed with reference to the map based on the required LC transmission torque. The command oil pressure PF is calculated (step S27). In step S28, a feedback command hydraulic pressure PFB that fills the difference between the target slip ratio and the actual slip ratio is calculated. In step S29, the calculated feedback command oil pressure PFB and the feedforward command oil pressure PF based on the calculated required LC transmission torque are added to determine (update) the lockup clutch command oil pressure PC.

  As described above, in the lockup clutch control device (ECU 14) for the automatic transmission according to the present invention, the actual slip ratio from the end of the shift control in the automatic transmission mechanism 5 to the target slip ratio in the control of the lockup clutch 7 is achieved. Measure the time to reach within a certain range (that is, the time when the addition control is performed), and negatively correct the inertia phase control pressure at the next lockup clutch control according to the length of the measured addition control time. The lockup clutch command oil pressure is learned by updating a learning value for determining a learning pressure PS (correction pressure) for positive correction.

  Specifically, when the addition control time is less than a certain value, the clutch is over-clutched, so learning to subtract the inertia phase control pressure during the next engagement control is performed, and the clutch is taken over an appropriate time. To be able to grab On the other hand, when the addition control time exceeds a certain value, the clutch slips easily and heat is likely to be generated, so learning to add the inertia phase control pressure during the next engagement control is performed and the clutch is grasped in a shorter time To be able to.

  In this way, the lockup clutch command hydraulic pressure instructed in accordance with the upshift is learned in the lockup clutch control performed when the upshift is performed during vehicle acceleration, and the cruise feedback control state is set based on the learned value. When the engagement control of a certain lock-up clutch is performed in accordance with the shift-up shift control, the slippage amount of the lock-up clutch at the time of the shift-up is corrected by correcting the original inertia phase control command pressure with the learning pressure PS (correction pressure). Control appropriately. As a result, heat generation and fuel consumption deterioration due to excessive generation of clutch slip due to the inertia phase control command pressure being too low, or shock and vibration due to the inertia phase control command pressure being too high, etc. Can be prevented.

  As mentioned above, although an example of embodiment was demonstrated based on drawing, this invention is not limited to this, It cannot be overemphasized that various embodiment is possible. In the above-described embodiment, as shown in FIG. 3, the learning period is from the shift control start t2 to the addition control end t5, and the next lock is performed according to the length of the addition control time (t4 to t5) within the learning period. Although learning to increase and decrease the inertia phase control pressure during up-clutch shift control has been shown, the present invention is not limited to this learning method. Such different learning methods will be described with reference to FIG.

  FIG. 7 is a flowchart showing another embodiment of the lockup clutch command hydraulic pressure learning process. In the processing shown in FIG. 7, the processing from step S31 to S33 is the same as the processing from step S1 to S3 in FIG.

  In step S34, it is determined whether or not the shift control is being performed. If it is determined that the shift control is being performed (YES in step S34), an average value of the accelerator pedal opening (or engine torque or throttle opening, the same applies hereinafter) is calculated (step S35). Step S36 refers to the map based on the accelerator pedal opening actually measured at that time, and calculates target slip differences D1 and D2 (where D1 <D2). The target slip differences D1 and D2 are target values for the deviation between the target slip ratio and the actual slip ratio at the end of the shift control t4.

  When it is determined that the shift control is not being performed, that is, when the shift control is finished (NO in step S34), the absolute value of the difference between the calculated target slip ratio and the actual slip ratio, that is, the actual slip at the shift control end time t4. It is determined whether or not the deviation (slip difference Y in the figure) between the ratio and the target slip ratio is smaller than the calculated target slip difference D1 (step S37). When it is determined that the absolute value (slip difference Y) of the difference between the target slip ratio and the actual slip ratio is smaller than the calculated target slip difference D1 (YES in step S37), the stored value is stored in the learning value storage means F. The learning result is reflected by subtracting the learning value of the corresponding region based on the average accelerator pedal opening in the learning map (step S38).

  When it is determined that the absolute value (slip difference Y) of the difference between the target slip ratio and the actual slip ratio is not smaller than the calculated target slip difference D1 (NO in step S37), the target slip ratio and the actual slip ratio. It is determined whether or not the absolute value of the difference (slip difference Y) is larger than the calculated target slip difference D2 (step S39). When it is determined that the absolute value (slip difference Y) of the difference between the target slip ratio and the actual slip ratio is larger than the calculated target slip difference D2 (YES in step S39), the stored value is stored in the learning value storage means F. The learning result is reflected by adding the learning value of the corresponding region based on the average accelerator pedal opening in the learning map (step S40). When it is determined that the absolute value (slip difference Y) of the difference between the target slip ratio and the actual slip ratio is not larger than the calculated target slip difference D2 (NO in step S39), the process is terminated.

  In the present embodiment, as shown in FIG. 3, the learning means A2 has a learning period from the shift control start time t2 (learning start) to the shift control end time t4 (learning completion), and the target slip at the end t4 of the learning period. The degree of achievement of the actual slip ratio with respect to the ratio (that is, the deviation between the target slip ratio and the actual slip ratio) is measured, and the inertia phase control pressure during the next lockup clutch control is raised or lowered according to the magnitude of the measured deviation. Do learning. In this embodiment, when the deviation is small, negative learning is performed to decrease the inertia phase control pressure, and when the deviation is large, plus learning is performed to increase the inertia phase control pressure, and these learning results (learned values) are Reflected in the learning map.

  Specifically, when the deviation at the end of the shift control is smaller than a certain value, the actual slip ratio and the target slip ratio are substantially the same, and there is a high possibility that the clutch will be excessively held in the subsequent addition control. Since it can be estimated, it is learned that the inertia phase control pressure is subtracted at the next engagement control, so that the actual slip ratio does not become too close to the target slip ratio at the end of the shift control. Correct the inertia phase control pressure appropriately so that the clutch can be properly held thereafter. On the other hand, when the deviation at the end of the speed change control is larger than a certain value, the actual slip ratio and the target slip ratio are greatly separated, and the clutch slippage is likely to generate heat easily even in the subsequent addition control. Since it can be estimated, it is learned that the inertia phase control pressure is added at the next engagement control, and the inertia phase control pressure at the time of lockup clutch control is adjusted so that the actual slip ratio approaches the target slip ratio at the end of the shift control. Correct so that the clutch can be properly held thereafter.

  In the above-described embodiments, the engine torque and the LC transmission torque are measured. However, the present invention is not limited to this. For example, the engine torque is estimated based on the throttle opening and the engine rotation speed. An estimation method may be used.

DESCRIPTION OF SYMBOLS 1 ... Automatic transmission 2 ... Engine 3 ... Engine torque sensor 4 ... Throttle sensor 5 ... Automatic transmission mechanism 6 ... Torque converter 7 ... Lock-up clutch 8 ... Hydraulic control circuit 9 ... LC transmission torque sensor 10 ... Speed sensor 11 ... Accelerator Pedal sensor 12 ... shift sensor 13 ... other sensor 14 ... ECU
15 ... Shift torque sensor A ... Lock-up clutch command oil pressure learning means A1 ... Learning start determination means A2 ... Learning means B ... Lock-up clutch command oil pressure determination means C ... Target slip ratio setting means D ... Actual slip ratio detection means E ... Shift Up control start determination means F ... learning value storage means MS ... main shaft

Claims (2)

In the lockup clutch control device for an automatic transmission that controls the engagement pressure of the lockup clutch so that the actual slip ratio of the lockup clutch of the automatic transmission becomes a predetermined target value,
Detection means for detecting engine torque or accelerator pedal opening or throttle opening;
Determining means for determining whether or not upshift control has been started at the time of a hydraulic command for a lockup clutch in the automatic transmission;
Learning start determination means for determining whether or not a predetermined learning start condition is satisfied when the upshift control is started during the control of the lockup clutch;
Learning means for learning a command hydraulic pressure that instructs an engagement pressure of the lockup clutch when the learning start condition is satisfied;
The detected engine torque or accelerator pedal opening is the original inertia phase control command pressure that instructs the inertia phase control pressure when controlling the lockup clutch according to the shift from the torque phase to the inertia phase of the shift-up shift control. Or a determining means for determining based on the throttle opening;
Correction means for learning and correcting the determined original inertia phase control command pressure according to the learning result of the command oil pressure;
Control means for executing control of the lock-up clutch according to the corrected inertia phase control command pressure,
The learning means sets the average value of the engine torque, the accelerator pedal opening, or the throttle opening detected until the actual slip ratio reaches a predetermined target value or a predetermined value close to the predetermined target value from the start of the upshift control. The learning value of the command oil pressure is stored for each corresponding learning region, and the arrival time until the actual slip ratio reaches a predetermined target value or a predetermined value close thereto is measured from the end of the upshift control. Then, the lockup clutch control device for an automatic transmission, wherein the learning value is updated based on the length of the measured arrival time. In the lockup clutch control device for an automatic transmission that controls the engagement pressure of the lockup clutch so that the actual slip ratio of the lockup clutch of the automatic transmission becomes a predetermined target value,
Detection means for detecting engine torque or accelerator pedal opening or throttle opening;
Determining means for determining whether or not upshift control has been started at the time of a hydraulic command for a lockup clutch in the automatic transmission;
Learning start determination means for determining whether or not a predetermined learning start condition is satisfied when the upshift control is started during the control of the lockup clutch;
Learning means for learning a command hydraulic pressure that instructs an engagement pressure of the lockup clutch when the learning start condition is satisfied;
The detected engine torque or accelerator pedal opening is the original inertia phase control command pressure that instructs the inertia phase control pressure when controlling the lockup clutch according to the shift from the torque phase to the inertia phase of the shift-up shift control. Or a determining means for determining based on the throttle opening;
Correction means for learning and correcting the determined original inertia phase control command pressure according to the learning result of the command oil pressure;
Control means for executing control of the lock-up clutch according to the corrected inertia phase control command pressure,
The learning means includes the command oil pressure for each learning region corresponding to an engine torque or an accelerator pedal opening or an average value of a throttle opening detected from the start of the upshifting control to the end of the upshifting control. And a deviation between an actual slip ratio at the end of the upshift control and a target value at the end of the upshift control, and the learned value based on the calculated magnitude of the deviation A lockup clutch control device for an automatic transmission.

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