JP2017089809A - Control device of lockup clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a lockup clutch which can suppress that necessary torque cannot be secured when an inertia phase is finished.SOLUTION: In switching processing, when timing for switching a control system to an acceleration flexible control system from a hydraulic direct indication system is superimposed on an inertia phase, a control device 10 sets an initial value of target hydraulic pressure in the acceleration flexible control system to target hydraulic pressure except for a correction amount ΔP of inertia torque during a gear change. By this constitution, since the initial value of the target hydraulic pressure in the acceleration flexible control system is set at the target hydraulic pressure except for the correction amount of the inertia torque, it can be suppressed that the target hydraulic pressure is lowered by the correction amount of the inertia torque after a finish of the inertia phase, and necessary feedforward torque cannot be secured.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for a lockup clutch.

  In general, a vehicle is known that includes a shift control device capable of switching a control method between feedback control and feedforward control. In such a vehicle, a shift shock may occur due to a step in the target hydraulic pressure when the control method is switched. For this reason, in Patent Document 1, when switching the control method from feedback control to feedforward control, the integral term of feedback control is applied to the initial value of feedforward control, and when the control method is switched from feedforward control to feedback control. An invention has been proposed in which the torque shift correction amount of feedforward control is applied to the initial value of the integral value of feedback control.

Japanese Patent No. 3446613

  According to the invention described in Patent Document 1, since the initial value of the control value can be smoothly connected when the control method is switched, the occurrence of a step in the target hydraulic pressure can be suppressed. However, when the control system switching timing overlaps with the inertia phase, if the initial value is calculated in consideration of the correction amount of the inertia torque during the shift, the target hydraulic pressure is increased by the correction amount of the inertia torque when the inertia phase is completed. There is a possibility that the torque that is originally required cannot be secured.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a lock-up clutch capable of suppressing that a necessary torque cannot be secured when an inertia phase is completed. .

  A lockup clutch control device according to the present invention is mounted on a vehicle including a torque converter that transmits output torque of an engine to a transmission, and a lockup clutch that can directly connect an engine side and a transmission side of the torque converter. And controlling the target oil pressure of the lockup clutch based on the first control method for controlling the oil pressure of the lockup clutch to a predetermined target oil pressure and the oil pressure obtained by feedforward control having an integral term. A lockup clutch control device capable of switching a control method to and from a second control method, wherein the timing for switching the control method from the first control method to the second control method overlaps with the inertia phase, Set the initial value of the target oil pressure in the 2-control method to the target oil pressure excluding the correction of the inertia torque during shifting. Characterized in that it comprises a control means for.

  According to the torque converter control device of the present invention, the initial value of the target hydraulic pressure in the second control method is set to the target hydraulic pressure excluding the correction amount of the inertia torque, so that the correction amount of the inertia torque is completed after the inertia phase is completed. As a result, it is possible to suppress the target hydraulic pressure from being lowered and the necessary torque from being secured.

FIG. 1 is a schematic diagram showing a configuration of a lockup clutch control device and a vehicle to which the control device is applied, which is an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the lockup clutch control apparatus according to the embodiment of the present invention. FIG. 3 is a flowchart showing the flow of switching processing according to an embodiment of the present invention. FIG. 4 is a timing chart for explaining the switching process according to the embodiment of the present invention.

  A lockup clutch control device according to an embodiment of the present invention will be described below with reference to the drawings.

[Vehicle configuration]
First, a configuration of a vehicle to which a lockup clutch control device according to an embodiment of the present invention is applied will be described with reference to FIG.

  FIG. 1 is a schematic diagram showing a configuration of a lockup clutch control device and a vehicle to which the control device is applied, which is an embodiment of the present invention. As shown in FIG. 1, a vehicle 1 to which a lockup clutch control device according to an embodiment of the present invention is applied includes an engine 2, a transmission 3, a torque converter 4, and a lockup clutch 5 as main components. As prepared.

  The engine 2 is an internal combustion engine such as a gasoline engine or a diesel engine that generates a driving force by combustion of fuel injected into a cylinder, for example. In addition, the code | symbol ne and Te in a figure represent the rotation speed (henceforth, engine speed) and output torque of the engine 2, respectively.

  The transmission 3 shifts the output torque Tt, which is the sum of the output torque Tc of the torque converter 4 and the output torque Tlu of the lockup clutch 5, and then transmits it to drive wheels (not shown). Examples of the transmission 3 include an automatic transmission (AT) and a continuously variable transmission (CVT). In addition, the code | symbol nt in a figure represents the turbine rotational speed which is the rotational speed of the input shaft (output shaft of the torque converter 4) of the transmission 3. FIG.

  The torque converter 4 includes a pump impeller 4a corresponding to an input rotating member connected to the crankshaft 2a of the engine 2 and a turbine impeller 4b corresponding to an output rotating member connected to the transmission 3 via the turbine shaft 3a. And a fluid power transmission device that transmits power through a fluid. Note that the symbol Te <b> 1 in the drawing represents the input torque of the torque converter 4.

  The lock-up clutch 5 mechanically directly connects the input side and the output side of the torque converter 4 when engaged, and disables the fluid power transmission function of the torque converter 4 by the pump impeller 4a and the turbine impeller 4b. It is to make it. The lock-up clutch 5 is configured to be driven and controlled between an engaged state, a released state, and a slip state (half-engaged state) under the control of the control device 10. Here, the engaged state means a state where the input side and the output side of the torque converter 4 are directly engaged, and the released state means a state where such an engaged state is released. The slip state is an intermediate state between the engaged state and the released state, that is, a state in which the relative rotation between the input side and the output side of the torque converter 4 is allowed to some extent and both are partially engaged. means. A symbol Te <b> 2 in the drawing represents an input torque of the lockup clutch 5.

[Configuration of control device]
Next, with reference to FIG. 2, the structure of the control apparatus of the lockup clutch which is one Embodiment of this invention is demonstrated. FIG. 2 is a block diagram showing the configuration of the lockup clutch control apparatus according to the embodiment of the present invention.

  As shown in FIG. 2, the lockup clutch control device 10 according to an embodiment of the present invention includes a feedforward control unit 11, a feedback control unit 12, a target torque capacity calculation unit 13, a torque / hydraulic conversion unit 14, and A packing control unit 15 is provided. The control device 10 locks up on the basis of the hydraulic pressure obtained by the hydraulic direct indication method (constant pressure standby method) for controlling the hydraulic pressure of the lockup clutch 5 to a predetermined target hydraulic pressure and the feedforward control having an integral term. The control method of the lockup clutch 5 can be switched between the control method for controlling the target hydraulic pressure of the clutch 5.

  The feedforward control unit 11 includes a subtractor 11a, a multiplier 11b, a multiplier 11c, an integrator 11d, a gain multiplication unit 11e, and a TC model 11f.

  The subtractor 11a calculates a difference value between the estimated differential rotation speed of the lockup clutch 5 estimated by the torque converter model (TC model) 11f and the target differential rotation speed of the lockup clutch 5, and calculates the calculated difference value. It outputs to the multiplier 11b and the multiplier 11c.

  Multiplier 11b multiplies the difference value between the estimated differential rotational speed and the target differential rotational speed by inertia torque I of engine 2 and torque converter 4. The multiplier 11b outputs the multiplication value to the gain multiplication unit 11e.

  Multiplier 11c multiplies the difference value between the estimated differential rotational speed and the target differential rotational speed by a slope a of a characteristic line indicating the relationship between the engine rotational speed at the current engine rotational speed and the torque capacity of torque converter 4. The multiplier 11c outputs the multiplication value to the integrator 11d.

  The integrator 11d calculates an integral value of the multiplication value of the multiplier 11c, and outputs the calculated integration value to the gain multiplication unit 11e.

The gain multiplication unit 11e calculates a value obtained by multiplying the sum of the multiplication value output from the multiplier 11b and the integration value output from the integrator 11d by the feedforward gain _kpi as the torque capacity of the lockup clutch 5. The gain multiplication unit 11 e outputs the calculated torque capacity of the lockup clutch 5 to the TC model 11 f and the target torque capacity calculation unit 13.

  The feedback control unit 12 includes a subtracter 12a, a multiplier 12b, a multiplier 12c, an integrator 12d, and a gain multiplication unit 12e.

  The subtractor 12a calculates a difference value between the actual differential rotation speed of the lockup clutch 5 and the target differential rotation speed of the lockup clutch 5, and outputs the calculated difference value to the multiplier 12b and the multiplier 12c.

  Multiplier 12b multiplies the difference value between the actual differential rotational speed and the target differential rotational speed by inertia torque I of engine 2 and torque converter 4. The multiplier 12b outputs the multiplication value to the gain multiplication unit 12e.

  The multiplier 12c multiplies the difference value between the actual differential speed and the target differential speed by a slope a of a characteristic line indicating the relationship between the engine speed and the torque capacity of the torque converter 4 at the current engine speed. The multiplier 12c outputs the multiplication value to the integrator 12d.

  The integrator 12d calculates an integral value of the multiplication value of the multiplier 12c, and outputs the calculated integration value to the gain multiplication unit 12e.

The gain multiplication unit 12e calculates a value obtained by multiplying the sum of the multiplication value output from the multiplier 12b and the integration value output from the integrator 12d by the feedback gain k _fb as the torque capacity of the lockup clutch 5. The gain multiplication unit 12 e outputs the calculated torque capacity of the lockup clutch 5 to the target torque capacity calculation unit 13.

  The target torque capacity calculator 13 calculates the sum of the torque capacity output from the gain multiplier 11e and the torque capacity output from the gain multiplier 12e as the target torque capacity Tlu, and calculates the calculated target torque capacity as torque / Output to the hydraulic pressure conversion unit 14.

  The torque / hydraulic conversion unit 14 converts the target torque capacity of the lockup clutch 5 calculated by the target torque capacity calculation unit 13 into the hydraulic pressure of the lockup clutch 5, and a control signal indicating the converted hydraulic pressure (indicated pressure). The data is output to the packing control unit 15.

  The pack control unit 15 controls the hydraulic pressure of the lockup clutch 5 in accordance with the control signal output from the torque / hydraulic conversion unit 14.

  The lockup clutch control device 10 having such a configuration implements the necessary feedforward torque by executing the switching process shown below to reduce the target hydraulic pressure of the lockup clutch 5 after the inertia phase is completed. Suppresses being unable to do so. Hereinafter, with reference to FIG. 3 and FIG. 4, the operation of the lockup clutch control device 10 when executing the switching process according to the embodiment of the present invention will be described.

[Switching process]
FIG. 3 is a flowchart showing the flow of switching processing according to an embodiment of the present invention. 4A and 4B are timing charts for explaining the switching process according to the embodiment of the present invention. The flowchart shown in FIG. 3 starts at the timing when the driving of the control device 10 is started, and the switching process proceeds to the process of step S1.

  In the process of step S1, the control device 10 determines whether or not the state of the lock-up clutch 5 is a direct hydraulic pressure instruction state (constant pressure standby state) for controlling to a predetermined target hydraulic pressure. As a result of the determination, when the current state of the lockup clutch 5 is not the hydraulic pressure direct instruction state (step S1: No), the control device 10 advances the switching process to the process of step S4. On the other hand, when the current state of the lock-up clutch 5 is the hydraulic pressure direct instruction state (step S1: Yes, time t = t1 to t2 shown in FIG. 4), the control device 10 performs the switching process in step S2. Proceed to

  In the process of step S2, the control device 10 is locked in the acceleration flex control state in which the differential rotation speed of the lockup clutch 5 is controlled to a positive value when the torque converter 4 is in the driving state (differential rotation speed> 0). It is determined whether or not an acceleration flex control process (differential rotation control) for controlling the state of the up clutch 5 has been started. As a result of the determination, when the acceleration flex control process has not been started (step S2: No), the control device 10 ends the series of switching processes. Thereafter, while the control device 10 is being driven, the control device 10 executes the switching processing every time a predetermined time elapses after the switching processing is completed. On the other hand, when the acceleration flex control process is started (step S2: Yes, time t = t3 shown in FIG. 4), the control device 10 advances the switching process to the process of step S3.

  In the process of step S3, the control device 10 converts the target hydraulic pressure in the hydraulic direct instruction state into torque capacity, and the torque capacity output from the feedforward control unit 11 when the acceleration flex control process is started is converted into torque. The initial value of the integral term calculated by the integrator 11d of the feedforward control unit 11 is calculated and set so as to have a capacity. Thereby, the process of step S3 is completed and the switching process proceeds to the process of step S4.

  In step S4, the control device 10 determines whether or not the lockup clutch 5 is in the acceleration flex control state. As a result of the determination, when the lockup clutch 5 is not in the acceleration flex control state (step S4: No), the control device 10 ends the series of switching processes. Thereafter, while the control device 10 is being driven, the control device 10 executes the switching processing every time a predetermined time elapses after the switching processing is completed. On the other hand, when the lockup clutch 5 is in the acceleration flex control state (step S4: Yes, after time t = t3 shown in FIG. 4), the control device 10 advances the switching process to the process of step S5.

  In the process of step S5, the control device 10 performs an inertia phase (time t = t2 shown in FIG. 4) in which the shift control process transitions from the state before the shift to the state after the shift based on the engine speed ne and the turbine speed nt. ~ T4) is determined. As a result of the determination, when the shift control process is not in the inertia phase (step S5: No), the control device 10 ends the series of switching processes. Thereafter, while the control device 10 is being driven, the control device 10 executes the switching processing every time a predetermined time elapses after the switching processing is completed. On the other hand, when the shift control process is in the inertia phase (step S5: Yes), the control device 10 advances the switching process to the process of step S6.

  In the process of step S6, the control device 10 calculates the integrator 11d of the feedforward control unit 11 so that the initial value of the target hydraulic pressure of the lockup clutch 5 becomes the target hydraulic pressure excluding the correction amount ΔP of the inertia torque that is being changed. The initial value of the integral term is set (time t = 3 to t4 shown in FIG. 4). According to such a process, as shown in FIG. 4B, the hydraulic pressure of the lockup clutch 5 indicated by the solid line becomes larger by the correction amount ΔP of the inertia torque than the hydraulic pressure obtained from the target differential rotation speed indicated by the dotted line. . As a result, after the inertia phase is completed, it can be suppressed that the oil pressure indicated by the solid line is lower than the oil pressure obtained from the target differential rotation speed indicated by the dotted line by the correction amount ΔP of the inertia torque, and the necessary feedforward torque cannot be secured. Thereby, the process of step S6 is completed and a series of switching processes are complete | finished. Thereafter, while the control device 10 is being driven, the control device 10 executes the switching processing every time a predetermined time elapses after the switching processing is completed.

  As is clear from the above description, in the switching process according to an embodiment of the present invention, when the timing for switching the control method from the hydraulic direct instruction method to the acceleration flex control method overlaps with the inertia phase, the control device 10 causes the acceleration flex The initial value of the target hydraulic pressure in the control method is controlled to the target hydraulic pressure excluding the correction amount ΔP of the inertia torque during shifting. As a result, the initial value of the target hydraulic pressure in the acceleration flex control method is set to the target hydraulic pressure excluding the correction amount of the inertia torque, so that the target hydraulic pressure is reduced by the correction amount of the inertia torque after the inertia phase is completed. It can suppress that it becomes impossible to ensure feedforward torque.

  The embodiment to which the invention made by the present inventors is applied has been described above, but the present invention is not limited by the description and the drawings that constitute a part of the disclosure of the present invention. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the present embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Transmission 4 Torque converter 5 Lock-up clutch 10 Control apparatus 11 Feed forward control part 11a, 12a Subtractor 11b, 11c, 12b, 12c Multiplier 11d, 12d Integrator 11e, 12e Gain multiplication part 11f TC model 12 Feedback Control Unit 13 Target Torque Capacity Calculation Unit 14 Torque / Hydraulic Conversion Unit 15 Packing Control Unit

Claims (1)

A torque converter that transmits engine output torque to a transmission, and a lockup clutch that can directly connect the engine side and the transmission side of the torque converter are mounted on a vehicle, and the hydraulic pressure of the lockup clutch is predetermined. The control method is switched between the first control method for controlling the target oil pressure and the second control method for controlling the target oil pressure of the lock-up clutch based on the oil pressure obtained by feedforward control with an integral term. Possible lock-up clutch control device,
When the timing for switching the control method from the first control method to the second control method overlaps with the inertia phase, the initial value of the target oil pressure in the second control method is set to the target oil pressure excluding the correction amount of the inertia torque that is being changed. The control apparatus of the lockup clutch characterized by including the control means to do.

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