JP2016048086A - Vehicular lockup clutch control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular lockup clutch control apparatus capable of improving the frequency of reengagement when a speed change instruction intervenes for increasing a target input rotation speed during lockup reengagement in a state of coasting.SOLUTION: A vehicle includes, between an engine 1 and a stepless transmission 6, a torque converter 4 including a lockup clutch 3. The vehicle further includes lockup control means (FIG. 4) for performing reengagement control of the lockup clutch 3 by means of fuel flow increase control for the engine 1 upon establishment of a reengagement start condition if the lockup clutch 3 is released in a coasting state as a result of a foot off the accelerator pedal. When a speed change instruction intervenes for increasing a target input rotation speed by the stepless transmission 6 during lockup reengagement, the lockup control means (FIG. 4) delays a speed change speed that includes zero.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicle lock-up clutch control device that performs re-engagement control of a lock-up clutch that is released in a coasting state.

  Conventionally, when re-engagement control of a lock-up clutch is performed after fuel supply cut due to accelerator release, a device is known that performs fuel supply that increases the engine speed and realizes clutch re-engagement in a coasting state ( For example, see Patent Document 1).

JP 7-279700 A

  However, in the conventional apparatus, fuel supply for increasing the engine speed is performed to re-engage the lockup clutch in the coasting state. In order to realize the lock-up re-engagement, the select operation and the automatic emblem control work during the operation of the engine torque-up control, and the turbine rotation speed may increase due to the intervention of the shift instruction. For this reason, there has been a problem that the engine rotation speed and the turbine rotation speed, which are the input / output rotation speeds of the lockup clutch, do not converge, and the lockup re-engagement frequency is reduced.

  The present invention has been made paying attention to the above-mentioned problem. When a gear shift instruction for increasing the target input rotational speed is intervened during lock-up re-engagement in a coasting state, the vehicle lock-up is intended to improve re-engagement frequency. An object is to provide a clutch control device.

In order to achieve the above object, the present invention includes a torque converter having a lock-up clutch between an engine and a transmission.
In this vehicle, when the lockup clutch is released in the coasting state by releasing the accelerator pedal, there is provided a lockup control means for performing the reengagement control of the lockup clutch by the fuel increase control of the engine when the reengagement start condition is satisfied. .
The lockup control means performs control to reduce the shift speed, including a shift speed of zero, when a shift instruction for increasing the target input rotational speed by the transmission intervenes during lockup re-engagement.

Therefore, the re-engagement control of the lock-up clutch in the coasting state is performed by the fuel increase control of the engine, and if a gear shift instruction for increasing the target input speed is intervened during this lock-up re-engagement, the gear shift including zero gear shift speed Control to reduce the speed is performed.
In other words, while the lockup is released in the coasting state, the engine speed decreases due to fuel cut or the like, the transmission input speed that is rotated by the drive wheels via the transmission increases, and the two speeds deviate. To do. On the other hand, when the fuel increase control of the engine is performed, the deviation width is narrowed due to the increase of the engine speed, but the transmission input speed (= clutch output speed) increases as the shift that increases the target input speed proceeds. To widen the gap. On the other hand, if control (including zero speed) is performed to reduce the shift speed, the increase in the transmission input speed is suppressed, and the frequency at which the two speeds converge (= re-engagement frequency) is improved.
As a result, it is possible to improve the re-engagement frequency when a gear shift instruction for increasing the target input rotation speed intervenes during the lock-up re-engagement in the coasting state.

1 is an overall system diagram showing an engine vehicle to which a lockup clutch control device of Embodiment 1 is applied. It is a shift map figure which shows an example of the shift map used by the shift control of a CVT control unit. It is a lockup map figure which shows an example of a lockup map used by the lockup clutch control of a CVT control unit. It is a flowchart which shows the flow of the lockup control processing performed in the CVT control unit of Example 1. FIG. Accelerator, shift instruction, rotation speed (engine rotation speed, turbine rotation speed), L / U release flag, shift difference between gear shifts, when performing lockup re-engagement control by delaying the shift speed during coasting in the first embodiment It is a time chart which shows each characteristic of a lockup command signal. Acceleration, shift instruction, rotation speed (engine rotation speed, turbine rotation speed), L / U release flag, gear shift difference when performing lockup re-engagement control with zero shift speed during coasting in Example 1 -It is a time chart which shows each characteristic of a lockup command signal. In the first embodiment, each of the accelerator, the shift instruction, the shift operation degree, the rotation speed (engine rotation speed, turbine rotation speed), the L / U release flag, and the lockup command signal when the lockup re-engagement control is finished during the coasting. It is a time chart which shows a characteristic.

  Hereinafter, the best mode for realizing a vehicle lock-up clutch control device according to the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
The configuration of the vehicle lockup clutch control device according to the first embodiment will be described by dividing it into an “overall system configuration” and a “lockup control configuration”.

[Overall system configuration]
FIG. 1 shows an engine vehicle to which the lockup clutch control device of the first embodiment is applied. The overall system configuration will be described below with reference to FIG.

  As shown in FIG. 1, the vehicle drive system includes an engine 1, an engine output shaft 2, a lock-up clutch 3, a torque converter 4, a transmission input shaft 5, and a continuously variable transmission 6 (transmission). The drive shaft 7 and the drive wheel 8 are provided.

  The lock-up clutch 3 is built in the torque converter 4 and connects the engine 1 and the continuously variable transmission 6 via the torque converter 4 when the clutch is released, and directly connects the engine output shaft 2 and the transmission input shaft 5 when the clutch is engaged. To do. The lockup clutch 3 is controlled to be engaged / slip engaged / released by an L / U actual oil pressure generated based on an L / U command oil pressure from a CVT control unit 12 described later.

  The torque converter 4 includes a pump impeller 41, a turbine runner 42 disposed to face the pump impeller 41, and a stator 43 disposed between the pump impeller 41 and the turbine runner 42. The torque converter 4 is a fluid coupling that transmits torque by circulating hydraulic oil filled therein through the blades of the pump impeller 41, the turbine runner 42, and the stator 43. The pump impeller 41 is connected to the engine output shaft 2 via a converter cover 44 whose inner surface is a fastening surface of the lockup clutch 3. The turbine runner 42 is connected to the transmission input shaft 5. The stator 43 is provided on a stationary member (transmission case or the like) via a one-way clutch 45.

  The continuously variable transmission 6 is a belt-type continuously variable transmission that continuously controls the gear ratio by changing the belt contact diameter to the primary pulley and the secondary pulley, and the output rotation after the shift is via the drive shaft 7. And transmitted to the drive wheel 8.

  As shown in FIG. 1, the vehicle control system includes an engine control unit 11 (ECU), a CVT control unit 12 (CVTCU), and a CAN communication line 13. As sensors for obtaining input information, an engine speed sensor 14, a turbine speed sensor 15 (= CVT input speed sensor), a CVT output speed sensor 16 (= vehicle speed sensor), an accelerator opening sensor 17, A secondary rotational speed sensor 18 and a primary rotational speed sensor 19 are provided. As other sensors, an inhibitor switch 20 for detecting a shift lever operation, a manual shift switch 21 that is switched by a shift operation in a manual mode, and other sensors and switches 22 are provided.

  The engine control unit 11 performs fuel cut control in which fuel injection to the engine 1 is stopped in a coasting state by releasing the accelerator pedal and fuel injection is restarted based on fuel recovery permission. This fuel cut control is performed by a fuel cut control unit 11a included in the engine control unit 11 and stops fuel injection by receiving a zero opening signal of an accelerator opening indicating an accelerator release from the CVT control unit 12. When the fuel injection is stopped, the fuel injection is resumed by receiving the fuel recovery permission from the CVT control unit 12.

  The CVT control unit 12 performs shift control for controlling the gear ratio of the continuously variable transmission 6, lockup clutch control for switching engagement / slip engagement / release of the lockup clutch 3, and the like.

  The basic control of the shift control is performed by a shift control unit 12 a included in the CVT control unit 12. For example, using the shift map shown in FIG. 2, when the operating point determined by the vehicle speed VSP and the accelerator opening APO moves to the low gear ratio side or the high gear ratio side, a gear shift instruction is issued and the target input speed (= target primary speed) The speed ratio is changed so as to obtain the rotation speed).

  The basic control of the lock-up clutch control is performed by the lock-up clutch control unit 12b included in the CVT control unit 12, and the lock-up map shown in FIG. 3 is used for the purpose of improving the fuel consumption in the driving state by depressing the accelerator. Done. That is, when the operating point determined by the vehicle speed VSP and the accelerator opening APO crosses the OFF → ON line in FIG. 3, an LU engagement request is issued and the unlocked lockup clutch 3 is engaged. On the other hand, when the operating point determined by the vehicle speed VSP and the accelerator opening APO crosses the ON → OFF line in FIG. 3, an LU release request is issued, and the lockup clutch 3 in the engaged state is released.

[Lockup control configuration]
FIG. 4 shows a flow of lockup control processing executed by the CVT control unit 12 of the first embodiment (lockup control means). Hereinafter, each step of FIG. 4 representing the lockup control processing configuration will be described.

In step S1, following the start of the lockup control, it is determined whether or not the lockup release state in which the lockup clutch 3 is released. If YES (lock-up released state), the process proceeds to step S2. If NO (other than the lock-up released state), the process returns to the start, and the determination in step S1 is repeated.
Here, in the lockup released state, the slip rotation speed (engine rotation speed-turbine rotation speed) of the lockup clutch 3 may be observed, or it may be determined that a predetermined time has elapsed from the lockup release command. Alternatively, it may be determined from a lockup differential pressure command value or the like.

  In step S2, following the determination that the lockup is released in step S1, the operating point based on the vehicle speed VSP and the accelerator opening APO is in the lockup engagement permission region in FIG. 3 (lockup ON region in FIG. 3). Judge whether there is. If YES (lockup fastening permission area), the process proceeds to step S3. If NO (lockup fastening permission area), the process returns to step S1.

In step S3, it is determined whether or not it is a coasting state (= coast state) by releasing the accelerator pedal, following the determination that it is the lockup fastening permission region in step S2. If YES (coast state), the process proceeds to step S4. If NO (other than the coast state), the process proceeds to step S7.
Here, the coast state may be determined using an idle switch signal or a signal related to engine torque (accelerator opening signal or the like).

  In step S4, following the determination that the coast state is in step S3 or the coasting in step S6, the lock-up engagement is exceptionally performed while the operating point is in the lock-up engagement permission region. Based on the operation of the lockup prohibition control to be prohibited, a lockup release instruction is output, and the process proceeds to step S5.

In step S5, following the output of the lockup release instruction in step S4, it is determined whether a control start condition for starting lockup re-engagement control of the released lockup clutch 3 is satisfied. If YES (control start condition is satisfied), the process proceeds to step S8. If NO (control start condition is not satisfied), the process proceeds to step S6.
Here, the control start condition of the lock-up re-engagement control can include, for example, that a predetermined time has passed in the coasting state. In addition, it may be a condition that the engine speed, the turbine speed, and the engine torque are in a stable state, or an elapsed time condition and a rotation / torque stabilization condition may be combined.

In step S6, following the determination that the control start condition is not satisfied in step S5, it is determined whether or not the vehicle is being driven by an accelerator depression operation. If YES (during driving), the process proceeds to step S7. If NO (coasting), the process returns to step S4.
Here, the determination of whether or not the vehicle is being driven may be made by looking at the accelerator operation or by using the throttle opening or the like. Alternatively, it may be determined from the relationship between the engine speed and the turbine speed (engine speed> turbine speed, etc.).

In step S7, following the determination in step S3 or step S6 that driving is in progress, normal lockup control is performed, and the process proceeds to the end.
Here, the normal lockup control refers to the engagement / release control of the lockup clutch 3 that is performed based on the lockup map of FIG.

  In step S8, the fuel increase amount of the engine 1 is determined based on the fuel recovery permission following the determination that the control start condition is satisfied in step S5 or the determination that the lockup engagement is impossible in step S15. Control (engine torque up) is performed, and the process proceeds to step S9.

In step S9, following the fuel increase control in step S8, it is determined whether or not there is a shift instruction for increasing the target input rotational speed of the continuously variable transmission 6. If YES (with a shift instruction), the process proceeds to step S10. If NO (without a shift instruction), the process proceeds to step S15.
Here, the presence / absence of a shift instruction for increasing the target input rotation speed of the continuously variable transmission 6 may be determined by a shift lever, a switch system operation (select operation, manual mode shift operation, etc.) by the driver, or the CVT control unit 12. This is determined by monitoring when the shift processing function is activated (such as a function that automatically increases the target input rotation speed for emblem). Note that the shift instruction for increasing the target input rotational speed is generally a down shift instruction. However, as shown in the characteristics of the coast target input speed in FIG. 2, for example, when the vehicle speed increases during downhill coast traveling, the target input speed is increased while the operating point moves to the upshift side. That is, the shift instruction for increasing the target input rotational speed includes a down shift instruction and an up shift instruction.

In step S10, following the determination that there is a shift instruction in step S9, it is determined whether or not the operation frequency of the driver's shift lever / switch or the shift operation frequency of the continuous operation is equal to or less than a threshold value. If YES (shift operation frequency ≦ threshold), the process proceeds to step S11. If NO (shift operation frequency> threshold), the lockup re-engagement is terminated and the process proceeds to the end.
Here, the threshold value of the shift operation frequency is variably set based on drivability.

In step S11, following the determination that the shift operation frequency is equal to or less than the threshold value in step S10, it is determined whether or not the step difference of the shift executed in accordance with the shift instruction in step S9 is equal to or less than the threshold value. If YES (difference between steps ≦ threshold), the process proceeds to step S11. If NO (difference between steps> threshold), the lockup re-engagement is terminated and the process proceeds to the end.
Here, the threshold value of the step difference between the shifts is variably set from the drivability.

In step S12, following the determination that the step difference in step S11 is equal to or less than the threshold value, it is determined whether or not the speed change speed zero condition is satisfied. If YES (shift speed zero condition is met), the process proceeds to step S13. If NO (shift speed zero condition is not met), the process proceeds to step S14.
Here, the shift speed zero condition is set from the viewpoint of drivability and the like, for example, when the difference between shift stages is very small or the change in the turbine speed is small. In addition, the predicted time required for shifting may be used as a condition. For example, the shift is stopped when the time required for the shift is short. If it is determined that the time required for the shift is long, the shift speed is decreased rather than zero. Alternatively, the originally set shift speed itself may be viewed, and the shift is stopped in a scene / area where the shift speed is set to be small from the beginning.

  In step S13, following the determination that the shift speed zero condition is satisfied in step S12, the shift executed in accordance with the shift instruction in step S9 is stopped (shift speed = zero), and the process proceeds to step S15.

In step S14, following the determination that the shift speed zero condition is not satisfied in step S12, the shift speed of the shift executed in accordance with the shift instruction in step S9 is delayed, and the process proceeds to step S15.
Here, when delaying the shift speed, the shift speed is given at a variable speed so that the predicted re-engagement time required from the start of lock-up re-engagement to the end of lock-up re-engagement does not exceed the set time. For example, the shift speed is changed according to a shift step difference, a shift operation degree, a re-engagement predicted time, and the like.

In step S15, it is determined whether there is no shift instruction in step S9, or the shift in step S13 is stopped, or the shift speed is delayed in step S14. Judging. If YES (state in which lock-up engagement is possible), the process proceeds to step S16. If NO (state in which lock-up engagement is not possible), the process returns to step S8.
Here, the determination that the lock-up engagement is possible is, for example, that the differential rotational speed between the clutch input rotational speed and the clutch output rotational speed is equal to or less than the differential rotational speed threshold set to a value that can suppress the engagement shock. Judge by.

  In step S16, following the determination in step S15 that the lockup engagement is possible, or the determination in step S17 that the lockup engagement has not been completed, a lockup engagement instruction is issued by operating the lockup solenoid. Output, and go to step S17.

In step S17, following the output of the lockup engagement instruction in step S16, it is determined whether or not the lockup engagement is complete. If YES (completion of lockup engagement), the process proceeds to step S18, and if NO (lockup engagement is not completed), the process returns to step S16.
Here, the determination of completion of lockup engagement may be performed by looking at the slip rotation speed (engine rotation speed-turbine rotation speed) or by determining that a predetermined time has elapsed from the lockup engagement command. Further, it may be determined from a lockup differential pressure command value or the like.

In step S18, following the determination in step S17 that the lock-up engagement has been completed, the shift speed is returned to the normal shift speed, and the gear speed is set to the turbine speed when the continuously variable transmission 6 is shifted according to the shift instruction. Resume and proceed to the end.
Here, the shift amount is an amount for correcting the deviation from the default shift line shown in FIG. 2 caused by delaying the shift speed (including zero shift speed) in response to the shift instruction in step S9.

Next, the operation will be described.
The operations of the lockup clutch control device of the first embodiment are as follows: “lockup control processing operation”, “lockup re-engagement control operation when a shift instruction is intervened”, “lockup re-engagement end when a shift instruction is intervened” This will be described separately in “Operation”.

[Lock-up control processing action]
Hereinafter, the lockup control processing operation of the first embodiment will be described based on the flowchart shown in FIG.
In a coasting scene where the vehicle speed VSP is high with the lock-up clutch 3 not fully engaged, the process proceeds from step S1 to step S2 to step S3 to step S4 in the flowchart of FIG. In step S4, a lockup release instruction is output based on the operation of the lockup prohibition control. When the control start condition for clutch re-engagement control is not established and the coasting state is maintained, the flow of steps S4 → S5 → S6 is repeated, and the lockup release instruction is output. Maintained. When the accelerator depression operation is intervened while the lockup release is maintained and the transition is made from the coasting state to the drive state, the process proceeds from step S6 to step S7, and the normal lockup control is returned.

  That is, if YES is determined in all of steps S1 to S3, the lockup release control is activated by the lockup prohibition control by the “coast running scene in a state where the lockup clutch 3 is not completely engaged” is activated. An instruction is output. In this case, when a lockup fastening instruction is continued in the lockup released state and the coasting state, a fastening shock or the like occurs at the time of lockup fastening. At this time, even if the fastening shock itself is small, the shock sensitivity of the occupant is high in the coasting state by the accelerator release operation. On the other hand, when the lock-up clutch 3 is released in the coasting scene, the uncomfortable feeling of driving operation can be eliminated.

  On the other hand, for example, when a predetermined time has elapsed since the lockup clutch 3 was released in the coasting state, it is determined in step S5 that the control start condition of the clutch reengagement control is satisfied, and the target input rotation speed Suppose that it is determined that there is no shift instruction to raise the speed. In this case, in the flowchart of FIG. 4, the process proceeds from step S5 to step S8 → step S9 → step S15. As long as it is determined in step S15 that lock-up engagement is impossible, the flow of steps S8 → S9 → S15 is repeated. In step S8, fuel increase control (engine torque up) of the engine 1 is performed. That is, when the lockup clutch 3 is re-engaged due to the establishment of the control start condition and there is no gear shift instruction intervention, fuel increase control (step S8) of the engine 1 is executed.

  In step S5, it is determined that the control start condition of the clutch re-engagement control is established, and there is a shift instruction, but the shift operation degree is less than or equal to the threshold, the shift step difference is less than or equal to the threshold, and the shift speed Assume that it is determined that the zero condition is not satisfied. In this case, in the flowchart of FIG. 4, the process proceeds from step S5 to step S8 → step S9 → step S10 → step S11 → step S12 → step S14 → step S15. As long as it is determined in step S15 that lock-up engagement is impossible, the flow of steps S8 → step S9 → step S10 → step S11 → step S12 → step S14 → step S15 is repeated. In step S8, fuel increase control (engine torque increase) of the engine 1 is performed, and in step S14, a shift based on the shift instruction is executed by delaying the shift speed. That is, when there is a shift instruction intervention while the lockup clutch 3 is re-engaged, the control end condition is not satisfied, and the shift speed zero condition is not satisfied, the fuel increase control ( Step S8) and a shift with a reduced shift speed are executed.

  In step S5, it is determined that the control start condition of the clutch re-engagement control is established, and there is a shift instruction, but the shift operation degree is less than or equal to the threshold, the shift step difference is less than or equal to the threshold, and the shift speed Assume that it is determined that the zero condition is satisfied. In this case, in the flowchart of FIG. 4, the process proceeds from step S5 to step S8 → step S9 → step S10 → step S11 → step S12 → step S13 → step S15. As long as it is determined in step S15 that lock-up engagement is impossible, the flow of steps S8 → step S9 → step S10 → step S11 → step S12 → step S13 → step S15 is repeated. In step S8, fuel increase control (engine torque increase) of the engine 1 is performed, and in step S13, the shift based on the shift instruction is stopped (the shift speed is zero). In other words, when there is a shift instruction intervention while the lockup clutch 3 is re-engaged, when the control end condition is not satisfied and the shift speed zero condition is satisfied, the fuel increase control ( Step S8) and shift standby control with zero shift speed are executed.

  When it is determined in step S15 that the differential rotation of the lockup clutch 3 has converged and the lockup engagement is possible, the process proceeds from step S15 to step S16 to step S17 in the flowchart of FIG. Then, as long as it is determined in step S17 that lock-up engagement has not been completed, the flow from step S16 to step S17 is repeated. In this step S16, a lock-up fastening instruction by the operation of the lock-up solenoid is output.

  If it is determined in step S17 that the lockup clutch 3 is not slipped and the engagement torque capacity is increased and the lockup engagement is completed, the process proceeds from step S17 to step S18 in the flowchart of FIG. In step S18, a shift is performed to correct the deviation from the default shift line shown in FIG. 2, which is caused by shifting the transmission speed by delaying the shift instruction in response to the shift instruction in step S9.

  On the other hand, suppose that it is determined in step S5 that the condition for starting the clutch reengagement control is satisfied, and there is a shift instruction, but it is determined that the shift operation degree exceeds the threshold value. In this case, in the flowchart of FIG. 4, the process proceeds from step S5 to step S8 → step S9 → step S10 → end, and the clutch reengagement control is terminated without reengaging the lockup clutch 3. In step S5, it is determined that the control start condition of the clutch reengagement control is satisfied, and there is a shift instruction, and the shift operation degree does not exceed the threshold, but the shift step difference exceeds the threshold. Suppose that it is determined. In this case, in the flowchart of FIG. 4, the process proceeds from step S5 to step S8 → step S9 → step S10 → step S11 → end, and the clutch reengagement control is terminated without reengaging the lockup clutch 3.

[Lock-up re-engagement control when a gear shift instruction is involved]
Hereinafter, the lock-up re-engagement control operation when the shift instruction of the first embodiment intervenes will be described based on the time charts shown in FIGS. 5 and 6.

  A lock-up re-engagement control operation when a shift instruction intervenes during the lock-up re-engagement control in the coasting state and the lock-up re-engagement control is performed by delaying the shift speed will be described with reference to a time chart shown in FIG. In FIG. 5, time t1 is a lock-up release time, time t2 is a re-engagement control start time, time t3 is a shift instruction generation time, time t4 is a lock-up re-engagement time, and time t5 is a shift completion time.

  That is, when the accelerator release operation is performed at time t1, the lock-up control prohibition condition is satisfied, the lock-up engagement instruction is switched to the lock-up release instruction, and the fuel cut of the engine 1 is performed and the lock-up is performed. The clutch 3 is released. When the lock-up clutch 3 is released at time t1, the engine speed of the engine 1 that has been fuel cut decreases due to a steep slope, whereas the CVT input that is rotated by the drive wheels 8 via the continuously variable transmission 6 The rotational speed (= turbine rotational speed) decreases due to a gentle gradient, and the turbine rotational speed and the engine rotational speed deviate toward time t2. When the start condition for the re-engagement control of the lockup clutch 3 is satisfied at time t2, the fuel supply amount increase control of the engine 1 is started, and the engine speed starts increasing from time t2.

  When a gear shift instruction is generated at time t3 during re-engagement of the lockup and the gear shift difference due to the gear shift instruction is smaller than the gear difference threshold value, the gear shift according to the gear shift instruction indicated by the broken line in FIG. The shift speed is delayed with respect to the turbine rotational speed locus. When the difference between the two rotational speeds converges at time t4 due to the engine rotational speed increase characteristic from time t3 and the turbine rotational speed characteristic that suppresses the increase in turbine rotational speed, the lockup is re-engaged at time t4. . Then, the shift is performed so as to coincide with the turbine rotational speed locus when the shift is performed according to the shift instruction from the time t4 to the time t5.

  A lock-up re-engagement control operation when a shift instruction intervenes during lock-up re-engagement control in the coasting state and lock-up re-engagement control is performed with the shift speed set to zero will be described with reference to a time chart shown in FIG. . In FIG. 6, time t1 is a lock-up release time, time t2 is a re-engagement control start time, time t3 is a shift instruction generation time, time t4 is a lock-up re-engagement time, and time t5 is a shift completion time. Further, until time t3, the time chart is the same as that shown in FIG.

  When a gear shift instruction is generated at time t3 during re-engagement of the lockup and the gear shift difference due to the gear shift instruction is smaller than the gear difference threshold value, the gear is shifted according to the gear shift instruction indicated by the broken line in FIG. The shift execution is temporarily stopped by setting the shift speed to zero with respect to the turbine rotational speed locus. When the difference between the two rotational speeds converges at time t4 due to the engine rotational speed increasing characteristic from time t3 and the turbine rotational speed horizontal characteristic, the lockup is re-engaged at time t4. Then, the shift is performed so as to coincide with the turbine rotational speed locus when the shift is performed according to the shift instruction from the time t4 to the time t5.

Thus, in the first embodiment, re-engagement control of the lockup clutch 3 in the coasting state is performed by fuel increase control of the engine 1. When a shift instruction for increasing the target input rotational speed is intervened during this lockup re-engagement, control is performed to reduce the shift speed including zero shift speed.
That is, while releasing the lockup in the coasting state, the engine speed decreases due to fuel cut, and the CVT input speed (= turbine speed) rotated by the drive wheels 8 via the continuously variable transmission 6 increases. Thus, the two rotational speeds deviate (time t2 in FIGS. 5 and 6). On the other hand, when the fuel increase control of the engine 1 is performed, the deviation width is narrowed due to the increase in the engine speed, but the deviation width is widened due to the increase in the turbine speed as the shift for increasing the target input speed proceeds. On the other hand, when the control for slowing the shift speed by slowing the ascending / descending slope of the shift hydraulic pressure, or the control for maintaining the shift hydraulic pressure and zeroing the shift speed, the increase in the turbine speed is suppressed, The frequency at which the two rotational speeds converge (= re-fastening frequency) is improved. Note that when a gear shift that lowers the target input rotation speed intervenes, the shift of the two rotation speeds is brought closer to the both, and is therefore excluded from the gear shift instruction to intervene.

  As a result, it is possible to improve the re-engagement frequency when a gear shift instruction for increasing the target input rotation speed intervenes during the lock-up re-engagement in the coasting state. Thus, the performance (drivability, fuel consumption, etc.) which is the original aim is implement | achieved by improving the lockup re-engagement frequency.

Further, when the shift is stopped at a shift speed of zero, priority is given to the engine rotation increase due to the fuel increase, and the lockup is re-engaged at an early stage, and then the shift is performed. On the other hand, when the shift speed is slowed down, shifting and lockup re-engagement can be realized at the same time without interrupting the shift control even during a shift intervention during the lock-up re-engagement control.
Therefore, in any case, since the increase in the turbine speed is suppressed, the required engine torque increase amount is suppressed when the shift is intervened during the lock-up re-engagement control compared with the case where the shift speed is not changed. Is done. As a result, the driver's shock can be reduced. Furthermore, fuel consumption can be increased by the amount that the required engine torque increase is suppressed.

The first embodiment includes a shift speed zero condition determining unit (S12) that determines that the condition is satisfied when the predicted time required for shifting is shorter than the set time. When a shift instruction for increasing the target input rotation speed by the continuously variable transmission 6 is intervened during the lock-up re-engagement, if it is determined that the condition for the shift speed zero is satisfied, the shift is stopped as a shift speed zero (S13), and the shift speed is zero. If it is determined that the condition is satisfied, the shift speed is decreased to change the speed (S14).
Here, the condition that the estimated time required for the shift is shorter than the set time may be indirectly determined based on, for example, a case where the gear difference between the shifts is very small or a change in the turbine speed is small. Alternatively, the time required for shifting may be predicted and directly determined.
Therefore, when it is determined that the shift speed zero condition is satisfied when the predicted time required for the shift is shorter than the set time, the shift speed is set to zero and the shift is stopped to give priority to the lock-up re-engagement control and perform the lock-up re-engagement early. Can be realized. On the other hand, when it is determined that the predicted time required for the shift is longer than the set time and the shift speed zero condition is not satisfied, it is possible to prevent a sense of incongruity that the user waits without shifting despite the shift instruction.

In the first embodiment, when a shift is performed at a lower speed, the shift speed is given at a variable speed so that the predicted re-engagement time required from the start of lock-up re-engagement to the end of lock-up re-engagement does not exceed the set time. It was.
For example, when shifting at a lower speed, if the speed is given at a slower constant speed, the progress of the speed change cannot be felt in response to the speed change instruction, which may give a sense of incongruity. On the other hand, if the shift speed is given at a fast constant speed, the increase in the turbine rotational speed is not effective, and the lockup re-engagement frequency may be reduced.
On the other hand, by providing the variable speed at a variable speed, it is easy to reduce the sense of incongruity and improve the lockup re-engagement frequency even in a driving scene that cannot be covered with a uniform speed.

In the first embodiment, after the re-engagement of the lock-up clutch by the shift control is completed, the continuously variable transmission 6 is shifted to the default shift line.
That is, as shown from time t4 to time t5 in FIGS. 5 and 6, the gear is shifted after the lockup clutch 3 is re-engaged and returned to the default shift line.
Therefore, by starting the shift that recovers the delay immediately after re-engagement of the lockup clutch 3 that performs the control for delaying the shift speed, the shift is quickly returned to the default shift line, and the original shift control performance by the continuously variable transmission 6 is improved. Can be secured.

[Operation to end lock-up re-engagement when a gear shift instruction is involved]
Hereinafter, the lock-up re-engagement end operation when the shift instruction of the first embodiment intervenes will be described based on the time chart shown in FIG.

  During the lockup re-engagement control in the coasting state, a gear shift instruction intervenes. For example, when the driver continuously operates the manual shift switch 21, the shift operation degree exceeds a threshold value and the lock-up re-engagement control is terminated. The lockup re-engagement termination action will be described with reference to the time chart shown in FIG. In FIG. 7, time t1 is a lockup release time, time t2 is a re-engagement control start time, time t3 is a shift instruction generation time, time t4 is a re-engagement control end time, and time t5 is a gear shift completion time. Further, until time t3, it is the same as the time charts shown in FIGS.

  When a shift instruction is generated at time t3 during re-engagement of the lockup and the shift operation degree according to the shift instruction is equal to or less than the threshold value, the turbine rotational speed trajectory when the shift is performed according to the shift instruction indicated by the broken line in FIG. On the other hand, the speed change is executed with the speed changed. When the shift operation degree exceeds the threshold value at time t4, the lockup re-engagement control is terminated at time t4. Then, from time t4, the fuel supply amount increase (torque up) is completed, and the normal shift control is resumed, so that it coincides with the turbine rotational speed trajectory when shifting is performed from time t4 to time t5 according to the shift instruction. Shifting is performed. Note that when a shift instruction is generated at time t3 during lock-up re-engagement and the shift difference due to the shift instruction exceeds a threshold value, the lock-up re-engagement control is similarly terminated.

The first embodiment includes a shift speed difference determining unit (S11) that determines whether or not the shift speed difference is equal to or less than a threshold value. Then, when a shift instruction for increasing the target input rotation speed by the continuously variable transmission 6 is intervened during the lock-up re-engagement, the lock-up re-engagement control is executed when it is determined that the difference between the gears is below the threshold value. To do. However, the lockup re-engagement control is terminated when it is determined that the step difference between the shifts exceeds the threshold value, and the shift according to the shift instruction is executed.
In other words, if the lockup re-engagement control is not executed when the shift difference is equal to or less than the threshold value, the lockup engagement frequency decreases. On the other hand, if the shift difference exceeds the threshold, the lockup re-engagement control gives a sense of incongruity that the shift following the shift instruction is not realized, and the engine accompanying the shift difference Increases torque.
Therefore, by determining the execution and end of the lockup reengagement control based on the difference between the shift speeds, it is possible to achieve both the improvement of the lockup reengagement frequency and the reduction of the uncomfortable feeling of not shifting. In addition, by causing the lockup re-engagement control to end when there is a gear difference, it is possible to prevent the occurrence of a shock accompanying an increase in fuel supply increase.

The first embodiment includes a shift operation degree determination unit (S10) that determines whether the shift operation degree is equal to or less than a threshold value. Then, when a shift instruction for increasing the target input rotation speed by the continuously variable transmission 6 is intervened during the lock-up re-engagement, the lock-up re-engagement control is executed if it is determined that the shift operation degree is equal to or less than the threshold value. However, the lockup re-engagement control is terminated when it is determined that the shift operation degree exceeds the threshold value.
That is, when the shift operation degree is equal to or less than the threshold value, the lockup engagement frequency is reduced unless the lockup reengagement control is executed. On the other hand, if the shift difference exceeds the threshold value, executing lock-up re-engagement control gives an uncomfortable feeling that the shift following the shift instruction is not realized, and increases the engine torque accompanying the shift operation degree. The amount becomes large.
Therefore, by determining the execution and end of the lockup reengagement control based on the shift operation degree, it is possible to achieve both the improvement of the lockup reengagement frequency and the reduction in the uncomfortable feeling of not shifting. In addition, by causing the lockup re-engagement control to end when the shift operation degree is high, it is possible to prevent the occurrence of a shock accompanying an increase in the fuel supply increase.

Next, the effect will be described.
In the lockup clutch control device of the first embodiment, the effects listed below can be obtained.

(1) In a vehicle provided with a torque converter 4 having a lock-up clutch 3 between an engine 1 and a transmission (continuously variable transmission 6),
When the lock-up clutch 3 is released in the coasting state by releasing the accelerator pedal, the lock-up control means for performing the re-engagement control of the lock-up clutch 3 by the fuel increase control of the engine 1 when the re-engagement start condition is satisfied (FIG. 4). )
The lock-up control means (FIG. 4) slows down the shift speed including zero shift speed when a shift instruction for increasing the target input rotational speed by the transmission (continuously variable transmission 6) is intervened during lock-up re-engagement. Control is performed (FIG. 5).
For this reason, it is possible to improve the re-engagement frequency when a shift instruction for increasing the target input rotation speed intervenes during the lock-up re-engagement in the coasting state.

(2) The lockup control means (FIG. 4) includes a shift speed difference determining unit (S11) that determines whether or not the shift difference is equal to or less than a threshold value. When a shift instruction for increasing the target input rotational speed by the (continuously variable transmission 6) is intervened, if it is determined that the shift step difference is equal to or less than the threshold value, lock-up re-engagement control is executed, When it is determined that the difference exceeds the threshold value, the lockup re-engagement control is terminated, and the shift according to the shift instruction is executed.
For this reason, in addition to the effect of (1), the execution and termination of the lockup reengagement control is judged from the difference in gear speed, thereby improving the lockup reengagement frequency and reducing the uncomfortable feeling of not shifting. , Can be made compatible. In addition, by causing the lockup re-engagement control to end when there is a gear difference, it is possible to prevent the occurrence of a shock accompanying an increase in fuel supply increase.

(3) The lockup control means (FIG. 4) has a shift operation degree determination unit (S10) that determines whether or not the shift operation degree is equal to or less than a threshold value. When a shift instruction for increasing the target input rotational speed by the transmission 6) intervenes, if it is determined that the shift operation degree is below the threshold value, lockup re-engagement control is executed, and the shift operation degree exceeds the threshold value If it is determined, the lock-up re-engagement control is terminated, and the shift according to the shift instruction is executed (FIG. 7).
For this reason, in addition to the effect of (1) or (2), the execution and termination of lockup re-engagement control is judged from the degree of shifting operation, so that the frequency of lockup re-engagement is improved, and there is a sense of incongruity of not shifting. Reduction can be achieved at the same time. In addition, by causing the lockup re-engagement control to end when the shift operation degree is high, it is possible to prevent the occurrence of a shock accompanying an increase in the fuel supply increase.

(4) The lockup control means (FIG. 4) has a shift speed zero condition determination unit (S12) that determines that the condition is satisfied when the estimated time required for the shift is shorter than the set time, and shifts during the lockup re-engagement. When the shift instruction for increasing the target input rotational speed by the machine (the continuously variable transmission 6) intervenes, if it is determined that the shift speed zero condition is satisfied, the shift is stopped as the shift speed is zero (S13), and the shift speed zero condition is satisfied. If it is determined, the speed is changed at a lower speed (S14).
For this reason, in addition to the effects (1) to (3), the lockup re-engagement control can be prioritized when the zero condition is satisfied, and the lock-up re-engagement can be realized at an early stage. Regardless, it is possible to prevent a sense of incongruity of waiting without shifting.

(5) The lock-up control means (FIG. 4) ensures that the estimated re-engagement time required from the start of lock-up re-engagement to the end of lock-up re-engagement does not exceed the set time when shifting at a lower speed. The shift speed is given at a variable speed (S14).
For this reason, in addition to the effect of (4), it is possible to easily reduce the sense of incongruity and improve the lockup re-engagement frequency even in a driving scene that cannot be covered at a uniform speed.

(6) The lockup control means (FIG. 4) performs a shift to return the transmission to the default shift line after completion of re-engagement of the lockup clutch by the shift control (S18).
For this reason, in addition to the effects (1) to (5), the shift to the default shift line can be quickly returned by starting the shift to recover the delay immediately after re-engagement of the lockup clutch 3 that performs the control to delay the shift speed. Thus, the original shift control performance by the transmission (the continuously variable transmission 6) can be ensured.

  As mentioned above, although the lockup clutch control apparatus for a vehicle according to the present invention has been described based on the first embodiment, the specific configuration is not limited to the first embodiment, and in each claim of the claims Design changes and additions are allowed without departing from the gist of the invention.

  In the first embodiment, the lockup control means includes step S12 that determines that the condition is satisfied when the predicted time required for the shift is shorter than the set time. Then, when a shift instruction for increasing the target input rotational speed by the continuously variable transmission 6 is intervened during the lock-up re-engagement, if it is determined that the shift speed zero condition is satisfied, the shift is stopped as the shift speed is zero (S13). On the other hand, an example is shown in which when it is determined that the shift speed zero condition is satisfied, the shift speed is decreased and the shift is performed (S14). However, the lockup control means does not have a shift speed zero condition determination unit, and may be an example of performing control to stop the shift at a shift speed of zero with respect to the shift instruction intervention, or against the shift instruction intervention. Alternatively, an example of performing shift control with a reduced shift speed may be used.

  In the first embodiment, as the lockup control means, when the shift speed is decreased and the shift is performed, the shift speed is set so that the predicted re-engagement time required from the start of lock-up re-engagement to the end of lock-up re-engagement does not exceed the set time. An example of giving the variable speed is shown. However, the lock-up control means may be an example in which a shift is performed at a predetermined delay speed when a shift is performed at a lower shift speed.

  In the first embodiment, as the lockup control means, when it is determined that the shift difference between gears exceeds the threshold value, the lockup re-engagement control is terminated, and the shift operation degree is determined to exceed the threshold value. Then, the example which complete | finishes lockup re-engagement control was shown. However, the lock-up control means may be an example in which conditions other than the shift step difference and the shift operation degree, such as a time condition, are set as end conditions for stopping the lock-up re-engagement. Further, the shift step difference or the shift operation degree threshold value may be given as a constant value or a variable value.

  In the first embodiment, the lock-up clutch control device of the present invention is applied to an engine vehicle equipped with a continuously variable transmission. However, the lock-up clutch control device according to the present invention can be applied to a hybrid vehicle as long as the engine is mounted on a drive source, and a stepped automatic shift is performed as a transmission. A stepped transmission may be used. In short, it can be applied to any vehicle provided with a torque converter having a lock-up clutch between the engine and the transmission.

1 Engine 2 Engine output shaft 3 Lock-up clutch 4 Torque converter 5 Transmission input shaft 6 Continuously variable transmission (transmission)
7 Drive shaft 8 Drive wheel 11 Engine control unit (ECU)
12 CVT control unit (CVTCU)
13 CAN communication line 14 Engine speed sensor 15 Turbine speed sensor (= CVT input speed sensor)
16 CVT output speed sensor (= vehicle speed sensor)
17 Accelerator opening sensor 18 Secondary rotational speed sensor 19 Primary rotational speed sensor 20 Inhibitor switch 21 Manual shift switch

Claims (6)

In a vehicle provided with a torque converter having a lock-up clutch between an engine and a transmission,
When the lockup clutch is released in a coasting state by releasing the accelerator pedal, a lockup control means is provided for performing reengagement control of the lockup clutch by fuel increase control of the engine when a reengagement start condition is satisfied,
The lockup control means performs a control to reduce the shift speed, including a shift speed of zero, when a shift instruction for increasing the target input rotation speed by the transmission intervenes during lockup re-engagement. Lockup clutch control device. In the vehicle lock-up clutch control device according to claim 1,
The lockup control means includes a shift speed difference determining unit that determines whether or not a shift speed difference is equal to or less than a threshold value, and increases a target input rotation speed by the transmission during lockup re-engagement. When the shift instruction is intervened, lockup re-engagement control is executed if it is determined that the gear difference between shifts is less than or equal to the threshold value, and lockup is restarted if it is determined that the gear difference between gears exceeds the threshold value. A lockup clutch control device for a vehicle, wherein the engagement control is terminated and a shift according to a shift instruction is executed. In the vehicle lock-up clutch control device according to claim 1 or 2,
The lockup control means includes a shift operation degree determination unit that determines whether or not the shift operation degree is equal to or less than a threshold value, and a shift instruction for increasing the target input rotation speed by the transmission during lockup re-engagement. When intervening, it is determined that the shift operation degree is less than or equal to the threshold value, and lockup re-engagement control is executed. If it is determined that the shift operation degree exceeds the threshold value, the lockup re-engagement control is terminated and A vehicle lock-up clutch control device, characterized by executing a gear shift as instructed. In the vehicle lock-up clutch control device according to any one of claims 1 to 3,
The lockup control means has a shift speed zero condition determining section that determines that the condition is satisfied when the estimated time required for shifting is shorter than the set time, and increases the target input rotation speed by the transmission during lockup re-engagement. When it is determined that the shift speed zero condition is satisfied, the shift is stopped at the shift speed zero condition, and when it is determined that the shift speed zero condition is satisfied, the shift speed is decreased and the shift is performed. Vehicle lock-up clutch control device. In the vehicle lock-up clutch control device according to claim 4,
The lockup control means, when performing a shift at a lower shift speed, changes the shift speed to a variable speed so that the predicted re-engagement time required from the start of lock-up re-engagement to the end of lock-up re-engagement does not exceed the set time. A vehicle lock-up clutch control device. In the vehicle lock-up clutch control device according to any one of claims 1 to 5,
The lockup control device for a vehicle, wherein the lockup control means performs a shift to return the transmission to a default shift line after completion of re-engagement of the lockup clutch by shift control.