JP2019100473A - Lock-up clutch controller of vehicle - Google Patents

Abstract

To provide a lock-up clutch controller of a vehicle, capable of suppressing shock in a case where a multistage transmission downshifts during coast traveling.SOLUTION: A lock-up clutch controller has a transmission controller 12 in which an engine 1, a torque converter 2 comprising a lock-up clutch 2c, a sub-transmission 30 capable of attaining forward two stages and backward one stage by changing over a Low brake 32, a High clutch 33 and a Rev brake 34, and a drive wheel 7 are arranged in a transmission path, and which controls an engagement state of the lock-up clutch 2c according to a vehicle speed VSP. The transmission controller 12, during coast traveling in the engagement state of the lock-up clutch 2c, when D-L select operation from a driver is detected, delays release of the lock-up clutch 2c compared to a case where the D-L select operation is not detected.SELECTED DRAWING: Figure 1

Description

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

  Patent Document 1 discloses an automatic transmission provided with a stepped transmission that changes its speed by switching a clutch and a brake.

JP, 2010-209946, A

In the above-described prior art, during coasting, during engine downshifting caused by the release of the lock-up clutch during downshifting of the stepped transmission accompanying selection operation from the D range to the L range by the driver, the engine There is a scene where fuel cut recovery that resumes fuel supply occurs. At this time, the transfer torque capacity of the low brake during the shift change of the stepped transmission is determined according to the absolute value of the input torque of the stepped transmission, so when the engine torque rises due to fuel cut recovery, There is a possibility that a shock (deceleration loss) may occur due to the rapid change of the transfer torque capacity of the brake from an increase to a decrease.
One of the objects of the present invention is to provide a lockup clutch control device for a vehicle that can suppress a shock when the stepped transmission downshifts during coasting.

  In the lockup clutch control device for a vehicle according to one embodiment of the present invention, during coasting with the lockup clutch engaged, the input rotation speed of the stepped transmission is higher than the first travel range to the first travel range. When the driver's select operation to the second travel range is detected, the release of the lockup clutch is delayed compared to the case where the driver's select operation is not detected.

  Therefore, it is possible to suppress a shock when the stepped transmission downshifts during coasting.

FIG. 1 is a schematic configuration view of a vehicle equipped with a continuously variable transmission according to a first embodiment. FIG. 2 is a view showing an internal configuration of a transmission controller according to Embodiment 1. It is a figure which shows an example of the speed change map stored in the memory | storage device of the transmission controller. It is a figure which shows an example of the lopup control map stored in the memory | storage device of a transmission controller. It is a time chart of conventional lockup control. It is a flow chart which shows a flow of lock up control at the time of coast lock up. 5 is a time chart of lockup control of the first embodiment.

Embodiment 1
Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In the following description, the "gear ratio" of a certain transmission mechanism is a value obtained by dividing the input rotational speed of the transmission mechanism by the output rotational speed of the transmission mechanism. Further, "lowest gear ratio" means the largest gear ratio of the transmission mechanism, and "highest gear ratio" means the smallest gear ratio of the transmission mechanism.

FIG. 1 is a schematic configuration diagram of a vehicle equipped with a continuously variable transmission according to the first embodiment. This vehicle is equipped with an engine 1 as a power source. The output rotation of the engine 1 includes the torque converter 2, the first gear train 3, the variator 20, and the auxiliary transmission 30 (hereinafter, the variator 20 and the auxiliary transmission 30 are simply referred to as "transmission 4"), the second. It is transmitted to the drive wheel 7 via the gear train 5 and the final reduction gear 6. The second gear train 5 is provided with a parking mechanism 8 which mechanically locks the output shaft of the transmission 4 in a non-rotatable manner during parking.
Further, in the vehicle, each part of the transmission 4 by adjusting the hydraulic pressure from the oil pump 10 and the oil pump 10 driven by utilizing an engine controller 1a that controls the engine 1, a part of the power of the engine 1 An oil pressure control circuit 11 for supplying the pressure control valve 11 and a transmission controller 12 as a control device for controlling the oil pressure control circuit 11 are provided.

  Each configuration will be described. The torque converter 2 has a pump impeller 2a, a turbine runner 2b and a lockup clutch 2c. The pump impeller 2 a is connected to the engine 1. The turbine runner 2 b is coupled to the first gear train 3. The lockup clutch 2c can connect the pump impeller 2a and the turbine runner 2b integrally. The transmission 4 includes a variator 20 and an auxiliary transmission 30 provided in series with the variator 20. "To be provided in series" means that the variator 20 and the auxiliary transmission 30 are provided in series in the same power transmission path. The auxiliary transmission 30 may be directly connected to the output shaft of the variator 20 as in this example, or may be connected via another transmission or power transmission mechanism (for example, a gear train).

  The variator 20 is a belt type continuously variable transmission including a primary pulley 21, a secondary pulley 22, and a V-belt 23 wound around the pulleys 21 and 22. The pulleys 21 and 22 each have a fixed conical plate, a movable conical plate disposed with the sheave surface facing the fixed conical plate and forming a V-groove between the fixed conical plate, and the movable conical plate The hydraulic cylinders 23a and 23b are provided on the rear surface of the cylinder to displace the movable conical plate in the axial direction. When the hydraulic pressure supplied to the hydraulic cylinders 23a and 23b is adjusted, the width of the V groove changes to change the contact radius between the V-belt 23 and the pulleys 21 and 22, and the transmission ratio vRatio of the variator 20 changes steplessly. Do.

  The auxiliary transmission 30 is a transmission mechanism having two forward gears and one reverse gear. The auxiliary transmission 30 is connected to a Ravigneaux-type planetary gear mechanism 31 connecting carriers of two planetary gears, and a plurality of rotating elements constituting the Ravigneaux-type planetary gear mechanism 31, and a plurality of frictions that change the linkage state thereof. A fastening element (Low brake 32, High clutch 33, Rev brake 34) is provided. When the oil pressure supplied to each friction engagement element 32-34 is adjusted, and the engagement / release state of each friction engagement element 32-34 is changed, the gear position of the auxiliary transmission 30 is changed. For example, when the Low brake 32 is engaged and the High clutch 33 and the Rev brake 34 are released, the gear position of the auxiliary transmission 30 becomes the first gear. If the High clutch 33 is engaged and the Low brake 32 and the Rev brake 34 are released, the gear position of the auxiliary transmission 30 will be the second gear whose gear ratio is smaller than the first gear. In addition, if the Rev brake 34 is engaged and the Low brake 32 and the High clutch 33 are released, the shift position of the sub transmission 30 is reverse. In the following description, it is expressed that "the transmission 4 is in the low speed mode" when the gear position of the auxiliary transmission 30 is the first speed, and "the transmission 4 is in the high speed mode" when the second gear is. Express.

FIG. 2 is a diagram showing an internal configuration of the transmission controller according to the first embodiment. As shown in FIG. 2, the transmission controller 12 includes a CPU 121, a storage device 122 including a RAM and a ROM, an input interface 123, an output interface 124, and a bus 125 interconnecting these components.
The input interface 123 includes an output signal of an accelerator opening sensor 41 for detecting an opening of the accelerator pedal (hereinafter referred to as "accelerator opening APO"), an input rotational speed of the transmission 4 (= rotational speed of the primary pulley 21). Hereinafter, the output signal of the rotational speed sensor 42 for detecting "primary rotational speed Npri", the output signal of the vehicle speed sensor 43 for detecting the traveling speed of the vehicle (hereinafter referred to as "vehicle speed VSP"), transmission 4 An output signal of the oil temperature sensor 44 which detects the oil temperature of the above, an output signal (range signal) of the inhibitor switch 45 which detects the position of the select lever, and the like are input. The driver can select each range (P, R, N, D, S, L) of the transmission 4 by operating the select lever. The S range is a so-called two-speed range, and only a shift at a speed ratio lower than the D range (first travel range) is permitted. The L range (second travel range) is a so-called first speed range, and only a shift at a transmission gear ratio lower than the S range is permitted.

The storage device 122 stores a shift control program of the transmission 4 and a shift map (FIG. 3) used in the shift control program. The CPU 121 reads out and executes the transmission control program stored in the storage device 122, performs various arithmetic processing on various signals input through the input interface 123, and generates a transmission control signal, thereby generating the generated transmission. The control signal is output to the hydraulic control circuit 11 via the output interface 124.
The hydraulic control circuit 11 is composed of a plurality of flow paths and a plurality of hydraulic control valves. The hydraulic control circuit 11 controls a plurality of hydraulic control valves based on the transmission control signal from the transmission controller 12 to switch the supply path of the hydraulic pressure, and prepares the necessary hydraulic pressure from the hydraulic pressure generated by the oil pump 10 Is supplied to each part of the transmission 4. As a result, the transmission ratio vRatio of the variator 20 and the shift position of the auxiliary transmission 30 are changed, and the transmission 4 is shifted.

  FIG. 3 is a diagram showing an example of a shift map stored in the storage device of the transmission controller. On this shift map, the operating point of the transmission 4 is determined based on the vehicle speed VSP and the primary rotational speed Npri. The slope of the line connecting the operating point of the transmission 4 and the zero point of the lower left corner of the shift map is the transmission ratio of the transmission 4 (the overall transmission ratio obtained by multiplying the transmission ratio v Ratio of the variator 20 by the transmission ratio sub Ratio of the auxiliary transmission 30 Hereinafter, it is referred to as “through gear ratio Ratio”. In this shift map, a shift line is set for each accelerator opening APO, similarly to the shift map of a conventional belt-type continuously variable transmission, and the shift of the transmission 4 is selected according to the accelerator opening APO. Following the shift line. In FIG. 3, for the sake of simplicity, all load lines in the D range (shift line when the accelerator opening APO is 8/8), partial lines (shift line when the accelerator opening APO is 4/8) Only the coast line (the shift line when the accelerator opening APO is 0) is shown.

  When the transmission 4 is in the low speed mode, the low speed mode Lowest line obtained by maximizing the transmission ratio v Ratio of the variator 20 and the low speed mode Highest line obtained by minimizing the transmission ratio v Ratio of the variator 20 It is possible to change the speed in the area between the two. At this time, the operating point of the transmission 4 moves in the A area and the B area. On the other hand, when the transmission 4 is in the high speed mode, the transmission 4 can obtain the high speed mode Lowest line obtained by maximizing the transmission ratio v Ratio of the variator 20 and the high speed mode highest obtained by minimizing the transmission ratio v Ratio of the variator 20. It is possible to change the speed in the area between the lines. At this time, the operating point of the transmission 4 moves in the B area and the C area.

  The gear ratio of each gear of the auxiliary transmission 30 is the gear ratio corresponding to the low speed mode Highest line (low speed mode Highest gear ratio) corresponds to the high speed mode Lowest line (high speed mode Low gear ratio) It is set to be smaller than that. Thereby, the low speed mode ratio range which is the range of through transmission ratio Ratio of transmission 4 which can be taken in the low speed mode and the high speed mode ratio range which is the range of the through transmission ratio Ratio of transmission 4 which can be taken in the high speed mode are partially When the operating point of the transmission 4 is in the range B between the high speed mode lowest line and the low speed mode highest line, the transmission 4 can select either the low speed mode or the high speed mode. ing.

  The transmission controller 12 sets the through transmission ratio Ratio corresponding to the vehicle speed VSP and the accelerator opening APO as a final through transmission ratio DRatio with reference to the shift map. The final through speed ratio DRatio is a target value that the through speed ratio Ratio should finally reach in the operating state. Then, the transmission controller 12 sets a target through speed ratio t Ratio, which is a transient target value for causing the through speed ratio Ratio to follow the ultimate through speed ratio DRatio with desired response characteristics, and the through speed ratio Ratio is a target. The variator 20 and the sub transmission 30 are controlled to match the through transmission ratio t Ratio. On the shift map, the low speed mode Highest line functions as a shift line for determining the switching from 1st speed to 2nd speed of the auxiliary transmission 30, and the high speed mode Lowest line is 2nd speed of the auxiliary transmission 30. It functions as a shift line for determining the switch from 1st gear to 1st gear. The transmission controller 12 performs shift control of the auxiliary transmission 30 when the operating point of the transmission 4 changes across the shift line. At this time, the transmission controller 12 coordinates the shift control of the variator 20 with the shift control of the auxiliary transmission 30. In FIG. 3, the L range high limiter line corresponds to the coast line in L range (a shift line when the accelerator opening APO is 0), and defines the Highest gear ratio (minimum gear ratio) in L range. . Similarly, the S range high limiter line corresponds to the coast line in the S range, and defines the Highest transmission ratio of the through transmission ratio DRatio in the S range.

The engine controller 1a injects a predetermined amount of fuel from each injector provided for each cylinder to a predetermined cylinder according to the operating state of the engine 1 based on each input information such as the accelerator opening APO. In addition, when the driver releases the accelerator pedal and releases the accelerator pedal, fuel cut is performed to stop fuel supply in order to prevent waste of fuel consumption during coasting.
Further, the engine controller 1a ignites the spark plug of a predetermined cylinder at a predetermined timing via an igniter provided for each cylinder based on each input information according to the operating state of the engine 1. As a result, the engine 1 is operated as prescribed, and fuel cut is performed as prescribed during coasting. Furthermore, the engine controller 1a prevents the engine stall by performing fuel cut recovering, which reinjects a predetermined amount of fuel from each injector to a predetermined cylinder when the engine rotation decreases to a predetermined recovery threshold or less.

  Next, lockup control will be described. The lockup clutch 2c is configured to control the engaged state by supplying and discharging the oil pressure to both the apply side and the release side oil chambers, and it is brought into the engaged state by supplying the engaging pressure to the apply side. It is in the released state by supplying to the release side. FIG. 4 is a view showing an example of the drop-up control map stored in the storage device of the transmission controller. On this lockup control map, engagement / release of the lockup clutch 2c is determined based on the operating point corresponding to the vehicle speed VSP and the accelerator opening APO. The transmission controller 12 engages or releases the lockup clutch 2c with reference to the lockup control map from the vehicle speed VSP and the accelerator opening APO. In the lockup control map, a torque converter area (L / U OFF area) for releasing the lockup clutch 2c and a lockup area (L / U ON area) for engaging the lockup clutch 2c are defined. In the lock-up control map, the L / U ON line is determined by the broken line, and the L / U ON line of the operation point is determined to determine the movement from the L / U OFF area to the L / U ON area (switching from release to engagement) in the operation point. The L / U OFF line for determining the movement from the area to the L / U OFF area (switching from fastening to release) is indicated by a solid line for each range (D range, S range, L range). The L / U ON line and the L / U OFF line are set with hysteresis to avoid lock-up hunting.

  In the lockup control map, the L / U ON area is set wider in the order of D range, S range, and L range. In other words, the L / U OFF region is set wider in the order of the L range, the S range, and the D range. In the L range, the gear ratio of the variator 20 is at or near maximum, so when the lockup clutch 2c is engaged in the middle to high vehicle speed range, the powerup resonance can not be suppressed with the lockup damper of the lockup clutch 2c. A so-called "sway vibration" occurs in which the vehicle body vibrates in the front-rear direction. As a countermeasure, in the L range, the L / U OFF vehicle speed (the first lockup off vehicle speed) for determining the switching from the engaged state to the released state of the lockup clutch 2c is higher than in the D and S ranges. The L / U OFF line is set to Further, the L / U OFF vehicle speed (second lockup off vehicle speed) of the D range is a vehicle speed that receives a release request of the lockup clutch 2c from the engine controller 1a. The engine controller 1a requests the transmission controller 12 to release the lockup clutch 2c when the vehicle speed VSP decreases to a certain vehicle speed to prevent an engine stall.

FIG. 5 is a time chart of conventional lockup control. As a premise, the driver has released his foot from the accelerator pedal, and the lockup clutch is in the engaged state (hereinafter referred to as "coast lockup"). Also, since the engine is under fuel cut and is rotated by the drive wheels, the engine torque has a negative value. The vehicle speed VSP immediately before time t1 is a vehicle speed between the L / U OFF vehicle speed for the S range and the L / U OFF vehicle speed for the L range.
At time t1, the driver selects the select lever from the D range to the L range, thereby crossing the high speed mode Lowest line from the point on the coastline for the D range where the operating point on the shift map is in the C range. , Move to a point on the coast line for L range (L range high limiter line) in the A area. The transmission controller starts downshifting the variator so that the through transmission ratio Ratio matches the target through transmission ratio tRatio, and reduces the auxiliary transmission from second gear to first by switching the High clutch and Low brake. Shift shift (hereinafter referred to as “2-1 shift”) is started. At time t1, the driver's select operation causes the L / U OFF vehicle speed on the lockup control map to be for D range to L range In order to switch, the transmission controller releases the lockup clutch when the vehicle speed VSP falls below the L / U OFF vehicle speed First, in the case of the 2-1 shift, the commanded capacity of the High clutch (commanded value of transmission torque capacity) After performing reduction (preparatory control) to reduce the capacity to the specified capacity and at the same time increase the indicated capacity of the Low brake to the last state where the transmission torque capacity is generated, the Low brake In torque phase control, the command capacity of the Low brake is adjusted according to the absolute value of the input torque of the auxiliary transmission The absolute value of the input torque is the gear ratio of the variator The transmission controller increases the indicated capacity of the Low brake in order to increase in response to the increase of.

At time t2, since the engine rotation has become equal to or less than the predetermined recovery threshold value, the engine controller performs fuel cut recovery (FCR) to restart fuel supply to the engine. As a result, the engine torque rises in a step-like manner to near zero, and the input torque of the auxiliary transmission is rapidly reduced, so the transmission controller sharply reduces the indicated capacity of the Low brake. At this time, a shock (deceleration loss) and a judder are generated as the transmission torque capacity of the Low brake rapidly changes from an increase to a decrease. In addition, the release of the lockup clutch reduces the moment of inertia, which weakens the effectiveness of the engine brake. These phenomena are very uncomfortable for the driver who is expecting the engine brake effect to be enhanced by the downshift operation.
At time t3, the transmission controller increases the transfer torque capacity of the Low brake as inertia phase control, and advances the 2-1 shift. At this time, the transmission controller upshifts the variator such that the through transmission ratio Ratio matches the target through transmission ratio t Ratio.
At time t4, the through gear ratio Ratio matches the final through gear ratio DRatio. The transmission controller raises the instructed capacity of the Low brake to the full engagement capacity as the termination control.

As described above, in the conventional lockup control, the driver performs a select operation from the D range to the L range (hereinafter referred to as “DL select operation”) during coast lockup in the fuel cut state. When the lockup clutch is released during the 2-1 shift when the transmission 30 performs a 2-1 shift, the transmission torque capacity of the Low brake changes suddenly, causing a shock or the like, which gives the driver a sense of discomfort. was there.
In the lock-up control of the first embodiment, therefore, the shock is to be suppressed, and when the driver performs the DL select operation while coasting with the lock-up clutch 2c engaged, locking is performed more than when not detected. The release of the up clutch 2c is delayed. The specific method is shown below. FIG. 6 is a flowchart showing the flow of lockup control at the time of coast lockup. This flowchart is repeatedly executed at a predetermined cycle at the time of coast lockup during fuel cut.
In step S1, it is determined whether there is a request for L / U OFF delay based on whether one of the following condition 1 or condition 2 is satisfied. In the case of YES, the process proceeds to step S6, and in the case of NO, the process proceeds to step S2.

The satisfaction condition of Condition 1 is assumed to satisfy all the following three conditions.
(1) The vehicle speed VSP is higher than a predetermined vehicle speed. Here, the predetermined vehicle speed is assumed to be the L / U OFF vehicle speed for D range.
(2) I am driving on the coast. Whether or not coasting is in progress is determined based on whether or not the accelerator opening APO = 0. It should be noted that whether or not coasting is to be performed may be determined from engine torque <0.
(3) A 2-1 shift of the auxiliary transmission 30 is in progress.
A cancellation condition of Condition 1 (a condition where it is determined as NO after the condition 1 is satisfied in S1) is assumed to be the case where the 2-1 shift is completed.

Condition 2 is satisfied when all the following three conditions are satisfied.
(1) I am driving on the coast.
(2) The remaining time of the timer is greater than zero. The transmission controller 12 starts a timer countdown when it detects the driver's DL select operation from the range signal. The initial value of the timer is set to a value such that the remaining time becomes zero when it is possible to predict that the downshift of the sub transmission 30 has ended since the detection of the DL select operation.
(3) It is not during the 2-1 shift of the auxiliary transmission 30.
The cancellation condition of Condition 2 (condition where it is judged as NO after the judgment of YES by the satisfaction of Condition 2 in S1) is assumed that the remaining time of the timer is zero.

In step S2, it is determined whether the range signal is in the L range. In the case of YES, the process proceeds to step S4, and in the case of NO, the process proceeds to step S3.
In step S3, it is determined whether the range signal is S range. In the case of YES, the process proceeds to step S5, and in the case of NO, the process proceeds to step S6.
In step S4, the L / U OFF line on the lockup control map referred to in the lockup control is set as the L / U OFF line for L range.
In step S5, the L / U OFF line on the lockup control map referred to in the lockup control is set as the L / U OFF line for the S range.
In step S6, the L / U OFF line on the lockup control map referred to in the lockup control is set as the L / U OFF line for D range.

In step S7, it is determined whether the operating point on the lockup control map is in the L / U OFF region determined by the L / U OFF line for L range (vehicle speed VSP is less than L / U OFF vehicle speed for L range) Or not). In the case of YES, the process proceeds to step S10, and in the case of NO, the process returns to step S1.
In step S8, whether the operating point on the lockup control map is in the L / U OFF region determined by the L / U OFF line for the S range (if the vehicle speed VSP is less than the L / U OFF vehicle speed for the S range) Or not). In the case of YES, the process proceeds to step S10, and in the case of NO, the process returns to step S1.
In step S9, whether the operating point on the lockup control map is in the L / U OFF region determined by the L / U OFF line for D range (vehicle speed VSP is less than L / U OFF vehicle speed for D range) Or not). In the case of YES, the process proceeds to step S10, and in the case of NO, the process returns to step S1.
In step S10, the lockup clutch 2c is released, and the present control is ended.

FIG. 7 is a time chart of lockup control of the first embodiment. The premise is the same as in FIG.
At time t1, the operating point on the shift map moves from area C to area A due to the driver's DL select operation, so the transmission controller 12 changes variator 20 such that the through transmission ratio Ratio matches the target through transmission ratio tRatio. In addition to the start of the downshift gear shift, the secondary gear shift 30 of the auxiliary transmission 30 is started by switching between the High clutch 33 and the Low brake 32. Further, at time t1, in the flowchart of FIG. 6, since condition 1 of step S1 is satisfied, it is determined that the L / U OFF delay request is present, and the L / U OFF vehicle speed is for L range to D range at step S6. Switch. Therefore, although the vehicle speed VSP is lower than the L / U OFF vehicle speed for the L range, the lockup clutch 2c is not released, and the engine rotation is maintained at a rotation higher than the recovery threshold. Thus, the fuel cut continues and the engine torque is kept constant. As a result, the effect of the engine brake can be prevented from being reduced immediately after the DL select operation. In the 2-1 shift, after performing rattling (preparation control), it shifts to torque phase control. In torque phase control, the indicated displacement of the low brake 32 is adjusted in accordance with the absolute value of the input torque of the auxiliary transmission 30. The absolute value of the input torque of the transmission 30 increases in the form of a ramp as the transmission ratio of the variator 20 increases. The transmission controller 12 increases the indicated displacement of the Low brake 32 according to the absolute value of the input torque as torque phase control.

At time t5, the transmission controller 12 increases the transfer torque capacity of the Low brake as inertia phase control, and advances the 2-1 shift. At this time, the transmission controller 12 upshifts the variator such that the through speed ratio Ratio matches the target through speed ratio tRatio.
At time t6, the through gear ratio Ratio matches the final through gear ratio DRatio. The transmission controller 12 pulls up the instructed capacity of the Low brake 32 to the full engagement capacity as the termination control. At the end of the 2-1 shift, it is determined in step S1 that there is no request for L / U OFF delay, and in step S4, the L / U OFF vehicle speed is set to the L range. At this time, since the vehicle speed VSP is already lower than the L / U OFF vehicle speed for L range, the transmission controller 12 releases the lockup clutch 2c.
At time t7, since the engine rotation has become equal to or less than the predetermined recovery threshold value, the engine controller 1a performs fuel cut recovery (FCR), and restarts the fuel supply to the engine 1. As a result, the engine torque rises stepwise to near zero. At this time, since the 2-1 shift of the auxiliary transmission 30 has already been completed, the indicated displacement of the Low brake 32 is a completely engaged displacement and is not affected by the input torque of the auxiliary transmission 30. Therefore, since the sudden change of the transfer torque capacity of the Low brake 32 caused by the fuel cut recovery as shown in FIG. 5 does not occur, the shock and the judder can be suppressed.

Next, the case where the operating point on the shift map moves from the C area to the B area by the driver's DL select operation, that is, the case where the auxiliary transmission 30 does not perform the 2-1 shift will be described. In this case, in the flowchart of FIG. 6, since the condition 2 is satisfied in step S1, it is determined that the L / U OFF delay request is present, and the L / U OFF vehicle speed is used for the D range in step S6. After that, when the remaining time of the timer becomes zero, it is determined in step S1 that there is no L / U OFF delay request, and in step S4, the L / U OFF vehicle speed is used for the L range.
That is, when the transmission controller 12 detects the DL select operation, the L / U OFF vehicle speed is switched from the L range use to the D range use even when the auxiliary transmission 30 does not perform the 2-1 shift. This is because the vehicle speed VSP at which the lockup clutch 2c is released depending on the presence or absence of the 2-1 shift if the release of the lockup clutch 2c is delayed until the end of the downshift only when the auxiliary transmission 30 performs the 2-1 shift This is because the difference is large and the driver feels uncomfortable. Therefore, even when the 2-1 shift is not performed, the L / U OFF vehicle speed is used for the D range until the time when the 2-1 shift can be predicted to end, which gives the driver a sense of discomfort. It can be reduced.

In the first embodiment, the following effects are achieved.
(1) The engine 1, the torque converter 2 having the lockup clutch 2c, the auxiliary transmission 30 and the drive wheels 7 which realize two forward gears and one reverse gear by switching the low brake 32, high clutch 33 and Rev brake 34 A lockup clutch control device for a vehicle having a transmission controller 12 that arranges transmission paths in accordance with the vehicle speed VSP and controls the engagement state of the lockup clutch 2c. The transmission controller 12 includes a lockup clutch 2c. During coasting in the engaged state, when the driver's DL select operation is detected, the release of the lockup clutch 2c is delayed more than when not detected.
This makes it possible to suppress the release of the lockup clutch 2c during the 2-1 shift of the auxiliary transmission 30. As a result, a scene where the transfer torque capacity of the Low brake 32 suddenly changes due to the fuel cut recovery can be reduced, so that shock and judder can be suppressed. In addition, it is possible to prevent the engine brake from becoming weak immediately after the DL select operation.
In addition, even when the auxiliary transmission 30 does not perform the 2-1 shift, the release of the lock-up clutch 2c is delayed, so the release timing of the lock-up clutch 2c largely differs depending on the presence or absence of the 2-1 shift. Can be suppressed, and the discomfort given to the driver can be reduced.

(2) The transmission controller 12 determines that the lockup clutch 2c is released based on the L / U OFF vehicle speed set to a higher vehicle speed as the input rotation speed of the sub transmission 30 increases. During coast driving with the clutch 2c engaged, when the driver's DL select operation is detected, the L / U OFF vehicle speed is switched from the L range use to the D range use.
Thereby, the delay of the release of the lockup clutch 2c when the driver's DL select operation is detected can be realized by a simple method. Further, even during the 2-1 shift of the auxiliary transmission 30, if the vehicle speed VSP falls below the L / U OFF vehicle speed for the D range, the lockup clutch 2c is released to suppress a shock or the like. At the same time, the occurrence of engine stall can be avoided.

(3) The transmission controller 12 sets the L / U OFF vehicle speed as the L / U OFF vehicle speed for the L range when the shift of the sub transmission 30 is completed.
That is, when the shift of the auxiliary transmission 30 is finished, the transmission torque capacity of the Low brake 32 which is a factor such as a shock does not change suddenly. In this case, by setting the L / U OFF vehicle speed to L range, It is possible to achieve both suppression of shock etc. and suppression of shaking vibration.

(4) The transmission controller 12 detects a DL select operation, and when a predetermined time has elapsed (when the remaining time of the timer becomes zero), the L / U OFF vehicle speed is L / L for L range U Turn off the vehicle speed.
As a result, it is possible to suppress the wobbling vibration while preventing the release timing of the lockup clutch 2c from being largely different depending on the presence or absence of the 2-1 shift.

(5) A variator 20 is interposed between the lockup clutch 2c on the transmission path and the auxiliary transmission 30. That is, the transmission 4 includes the variator 20 and the auxiliary transmission 30.
As a result, compared with the ratio coverage that can be obtained with either one of the variator 20 and the auxiliary transmission 30, an expanded ratio coverage can be obtained.

Other Embodiments
As mentioned above, although the form for implementing this invention was demonstrated based on drawing, the specific structure of this invention is not limited to embodiment, The design change of the range which does not deviate from the summary of invention etc. The present invention is included in the present invention.
For example, in step S1 of FIG. 6, it may be determined from only condition 1 or only condition 2 whether or not there is a request for L / U OFF delay. When the determination is made based only on the condition 2, of the three conditions constituting the satisfaction condition of the condition 2, “(3) Not being switched to the auxiliary transmission 30” is deleted. As a result, the L / U OFF vehicle speed is switched from the L range use to the D range use until the remaining time of the timer becomes zero regardless of the presence or absence of the 2-1 shift. -1 Release of the lockup clutch 2c during the shift can be suppressed.
The present invention is applicable to a vehicle in which a stepped transmission capable of achieving a plurality of shift speeds by switching friction engagement elements on a transmission path between a torque converter and drive wheels. That is, the present invention can be applied to a vehicle having no variator.
The L / U OFF line and the L / U ON line of the S range may be the same as the L range.

1 Engine
2 Torque converter
2c lockup clutch
7 drive wheels
12 transmission controller
20 Variator (CVT)
30 auxiliary transmission (geared transmission)
32 Low brake (friction fastening element)
33 High clutch (friction engaging element)
34 Rev Brake (Friction Fastening Element)

Claims (5)

Engine, torque converter with lock-up clutch, geared transmission that realizes multiple shift speeds by switching friction engagement elements, and drive wheels in the order of transmission path arrangement, the lock-up clutch engaged state according to the vehicle speed Lock-up clutch control device for a vehicle having a controller for controlling
The controller is configured to move from the first travel range to the second travel range in which the input rotation speed of the stepped transmission is higher than the first travel range during coasting with the lockup clutch engaged. A lockup clutch control device for a vehicle, which delays release of the lockup clutch when detection operation is detected than when detection operation is not detected. The vehicle lockup clutch control device according to claim 1, wherein
The controller
In determining the release of the lock-up clutch based on the lock-up off vehicle speed set to a higher vehicle speed as the travel range of the stepped transmission increases.
During coasting with the lockup clutch engaged, when a select operation from the first travel range to the second travel range is detected, the lockup off vehicle speed is determined by the stepped shift by the select operation. The vehicle is switched from a first lockup off vehicle speed corresponding to the first gear position after gear shift of the machine to a second lockup off vehicle speed corresponding to the second gear position lower in the input rotational speed than the first gear position. Lock-up clutch control device. The vehicle lockup clutch control device according to claim 2, wherein
The lockup clutch control device for a vehicle, wherein the controller sets the lockup off vehicle speed to the first lockup off vehicle speed when the shift of the stepped transmission is completed. The vehicle lockup clutch control device according to claim 2 or 3, wherein
The controller sets the lockup off vehicle speed to the first lockup off vehicle speed when a predetermined time has elapsed after detecting the select operation from the first travel range to the second travel range. Lock-up clutch control device. The lockup clutch control device for a vehicle according to any one of claims 1 to 4, wherein
A lockup clutch control device for a vehicle in which a continuously variable transmission is interposed between the lockup clutch on the transmission path and the stepped transmission.

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