JP2887723B2 - Clutch control device for fluid coupling of automatic transmission for vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch control device for a fluid coupling of an automatic transmission for a vehicle.

[0002]

2. Description of the Related Art An automatic transmission of a type in which a clutch (hereinafter referred to as a damper clutch) for connecting and disconnecting an input side and an output side of a torque converter connected to an engine is known. . In a vehicle equipped with this type of automatic transmission, when predetermined operating conditions are satisfied, for example, when the operating condition that each of the throttle opening of the engine and the turbine speed of the torque converter is equal to or more than a predetermined value is satisfied, The damper clutch is directly connected to replace the fluid friction engagement of the torque converter with the mechanical friction engagement of the damper clutch, thereby improving fuel efficiency.

[0003]

On the other hand, during deceleration operation of the vehicle, the damper clutch is generally brought into a non-direct connection state. In this case, the rotational force acting on the engine from the drive wheels is transmitted through the torque converter in the fluid friction engagement state, and therefore, the effect of preventing the rotational force from lowering the engine speed is poor. For this reason, when the fuel supply to the engine is cut off due to the deceleration operation, the engine speed is rapidly reduced, and the fuel supply must be restarted to prevent engine stall. As a result, the fuel cut period is shortened, and it may not be possible to sufficiently improve the fuel efficiency.

[0004] Therefore, even during deceleration operation, the damper clutch is directly connected, and the function of preventing the engine speed from decreasing due to the rotational force acting on the engine from the driving wheels is effective, thereby extending the fuel cut period to improve fuel efficiency. Have been tried. When performing such direct control of the damper clutch, it is necessary to appropriately control the magnitude of the hydraulic pressure supplied to the damper clutch so that the damper clutch is engaged. Therefore, it has been attempted to learn about the clutch oil pressure to adjust the clutch supply oil pressure used in the next deceleration operation based on the result of monitoring the oil pressure supplied to the damper clutch during the deceleration operation.

On the other hand, if the brake is suddenly applied on a low μ road while performing the direct connection control of the damper clutch, there is a problem that the engine may be stalled. The reason for this is that if the clutch oil pressure is slightly excessive, the release of the direct connection state of the damper clutch is delayed at the time of sudden braking, and the engine speed sharply decreases as the axle speed rapidly decreases due to sudden braking.

Accordingly, an object of the present invention is to provide an automatic transmission for a vehicle in which the damper clutch is brought into a directly connected state and the learning for adjusting the clutch hydraulic pressure is performed during the deceleration operation of the vehicle. An object of the present invention is to provide a clutch control device for a fluid coupling of an automatic transmission for a vehicle, which can surely prevent an excessive increase, thereby preventing a delay in releasing a directly connected state of a damper clutch at the time of sudden braking, and thereby preventing an engine stall. Aim.

[0007]

SUMMARY OF THE INVENTION A pump is provided between an engine and an auxiliary transmission of an automatic transmission and connected to an output side of the engine, and a turbine is connected to an input side of the auxiliary transmission. In a fluid coupling of an automatic transmission for a vehicle, the clutch control device of the present invention includes a clutch capable of disconnecting and connecting a pump and a turbine, and controls a hydraulic pressure supplied to the clutch according to a vehicle operating state. And a deceleration engagement hydraulic pressure for supplying a deceleration engagement hydraulic pressure to the clutch when the driving state detection means detects that the vehicle has entered a deceleration state. Feedback control using the deceleration engagement oil pressure as an initial value so that the difference between the rotation speed of the pump and the rotation speed of the turbine detected by the supply means and the operation state detection means becomes a desired value. A feedback control means that, only when the vehicle speed change rate of the vehicle is detected to be within a predetermined range by operating condition detecting means, characterized by having a learning correction means for learning correction of the initial value.

[0008] Preferably, the deceleration range considered as a deceleration state is:
The range is set such that the engine load is low and the rotation speed of the turbine is equal to or higher than a predetermined low rotation speed.
Preferably, the clutch control device is configured to discharge the hydraulic pressure from the clutch when it is detected that the vehicle has entered the deceleration state, and to cause the pump and the turbine to be in a state immediately before engagement after the hydraulic pressure is discharged by the hydraulic pressure discharging means. As described above, the apparatus further includes a predetermined hydraulic pressure supply unit that supplies a predetermined hydraulic pressure to the clutch, and the deceleration engagement hydraulic pressure is supplied after the predetermined hydraulic pressure is output.

Preferably, the clutch control device is a timer for measuring an elapsed time from the start of the feedback control, and represents a hydraulic pressure value supplied to the clutch when a first predetermined time has elapsed from the start of the feedback control. A first oil pressure value detecting means for detecting the first oil pressure value; and a second oil pressure value supplied to the clutch when a second predetermined time set longer than the first predetermined time elapses from the start of the feedback control. A second oil pressure value detecting means for detecting the oil pressure value; and a hydraulic pressure difference calculating means for calculating a difference between the first oil pressure value and the second oil pressure value. Correct the oil pressure.

Preferably, the clutch control device further includes feedback control stopping means for stopping the feedback control when the oil pressure difference is outside the predetermined range and discharging the oil pressure from the clutch. Preferably, the operating state detecting means includes:
The vehicle includes at least one of a vehicle speed detecting unit, a lateral acceleration detecting unit, a wheel speed detecting unit, a longitudinal acceleration detecting unit, and a road surface gradient detecting unit, and the vehicle body speed change rate is obtained according to an output value from the at least one detecting unit. .

Preferably, the clutch control device further includes an electromagnetic valve for duty-controlling the hydraulic pressure supplied to the clutch, and the supply of hydraulic pressure to the clutch and the discharge of hydraulic pressure from the clutch are performed at a duty ratio given to the electromagnetic valve.

[0012]

When the deceleration state of the vehicle is detected by the driving state detection means, preferably, when the engine load is low and the turbine rotation speed is equal to or higher than a predetermined low rotation speed, the clutch is supplied from the deceleration engagement hydraulic pressure supply means. The deceleration engagement hydraulic pressure is supplied to. As a result, the pump of the fluid coupling of the automatic transmission and the turbine are connected by the clutch.

Preferably, prior to the supply of the engagement hydraulic pressure for deceleration, when the vehicle enters the deceleration state, the hydraulic pressure is first discharged from the clutch by the hydraulic pressure discharging means to bring the clutch into a non-direct connection state. The occurrence of a shock in the automatic transmission due to the transmission of the engine speed fluctuation to the automatic transmission is prevented. Next, the predetermined hydraulic pressure is supplied to the clutch by the predetermined hydraulic pressure supply means so that the pump and the turbine are brought into a state immediately before the engagement, and the non-coupled state for preventing the occurrence of a shock is promptly eliminated.

Next, the engagement hydraulic pressure supplied to the clutch is feedback-controlled by the feedback control means so that the difference between the pump rotation speed and the turbine rotation speed becomes a desired value. Here, the deceleration engagement hydraulic pressure is
It is used as an initial value of the engagement hydraulic pressure at the start of the feedback control. If the vehicle speed change rate during the feedback control is within a predetermined range and the vehicle is not decelerating due to a steep downhill or the like, the deceleration engagement hydraulic pressure as the initial value of the engagement hydraulic pressure is learned by the learning correction means. This is corrected so that the initial value of the engagement hydraulic pressure at the start of the next deceleration operation is optimized. On the other hand, if the vehicle speed change rate is outside the predetermined range and the vehicle is decelerating on a steep downhill or the like, learning correction of the initial value of the engagement hydraulic pressure is prohibited. As a result, excessive correction of the initial value of the engagement hydraulic pressure that occurs when the learning correction is performed on a steep downhill where the engagement oil pressure increases as compared with traveling on a flat road is prevented. Even when sudden braking is performed on a low μ road, an appropriate value is maintained so that engine stall does not occur.

Preferably, the rate of change in vehicle body speed is determined in accordance with an output value from at least one of vehicle speed detecting means, lateral acceleration detecting means, wheel speed detecting means, longitudinal acceleration detecting means, and road surface gradient detecting means. Accordingly, it is reliably detected whether the vehicle is being decelerated on a steep downhill or the like. Preferably, when it is determined from the start of the feedback control that the first and second predetermined times have elapsed from the start of the feedback control based on the measurement of the timer means, the first and the second indicating the supply hydraulic pressure values to the clutch at each of the determination times. A second oil pressure value is detected by the first and second oil pressure value detecting means, respectively, and a difference between the first oil pressure value and the second oil pressure value is calculated by the oil pressure difference calculating means;
The initial hydraulic pressure for deceleration is suitably corrected by the learning correction means according to the hydraulic pressure difference.

Preferably, when the oil pressure difference is out of the predetermined range, the feedback control stopping means stops the feedback control and discharges the oil pressure from the clutch, thereby correcting an excessive increase in the clutch supply oil pressure by the feedback control. , And engine stall due to sudden braking while feedback control started with an excessive initial clutch supply oil pressure is prevented.

Preferably, the supply of hydraulic pressure to the clutch and the discharge of hydraulic pressure from the clutch are performed at a duty ratio given to a solenoid valve of the clutch control device, and the duty of the hydraulic pressure supplied to the clutch is controlled by the solenoid valve. Clutch oil pressure control is performed properly.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic transmission for a vehicle equipped with a clutch control device according to one embodiment of the present invention will be described below. As shown in FIG. 1, the automatic transmission according to the present embodiment includes a casing 20A, a pump 23, a stator 24, and a turbine 25.
And a gear transmission 30 as an auxiliary transmission.

Drive shaft 21 in torque converter 20
Is connected to the internal combustion engine 1 via a flywheel 11.
0 is connected to the crankshaft 10A, and the pump 23 is connected to the drive shaft 21 via the casing 22 of the torque converter 20.
Is connected to the other end. Further, the stator 24 is connected to the casing 20A via a one-way clutch 24A, and the turbine 25 is connected to the input shaft 30A of the gear transmission 30.
It is connected to.

The gear transmission 30 includes, for example, a planetary gear mechanism (not shown) including a sun gear, a planetary carrier, and a ring gear as rotating elements, and a frictional engagement element (not shown) for allowing or preventing the rotating operation of these rotating elements. It has a multi-plate clutch and a brake (not shown) as a speed change element, and each speed change element has an engagement piston device or a servo device.

The torque converter 20 further includes a slip-type direct coupling clutch (hereinafter referred to as a damper clutch) 28 that allows the input shaft and the output shaft of the torque converter to be rigidly connected. The damper clutch 28 is interposed between the damper clutch input casing 22 and the turbine 25 and mechanically directly connects the pump 23 and the turbine 25 while allowing a required slip even during engagement (when directly connected). It has become.

The automatic transmission includes a storage device, a central processing unit,
A transmission control unit (hereinafter, referred to as an input / output interface, counter, etc.)
A TCU 16 and a hydraulic circuit 40 for driving and controlling the gear transmission 30 under the control of the TCU 16 are further provided. The hydraulic circuit 40 includes a manual valve (not shown) responsive to a select lever operation by a driver,
It has various control valves (not shown) for switching the line pressure supply path to the transmission element of the gear transmission 30 and controlling the magnitude of the supply hydraulic pressure.

The input side of the TCU 16 is connected to an electromagnetic pickup 14 as an engine speed sensor for detecting the internal combustion engine speed NE. The electromagnetic pickup 14 is fitted around the flywheel 11 and is connected to the starter 1.
Ring gear 1 having a predetermined number of teeth meshing with second pinion 12A
1A. The input side of the TCU 16 includes a turbine speed sensor 15 for detecting a turbine speed NT and a transfer drive gear speed N.
A transfer drive gear speed sensor 17 for detecting O is connected, and furthermore, a valve opening θ of a throttle valve (not shown) arranged in the intake passage of the internal combustion engine 10.
A throttle opening sensor 18 for detecting T, and a temperature TOIL of hydraulic oil discharged from a hydraulic pump (not shown).
And an oil temperature sensor 19 for detecting the oil temperature.

The automatic transmission further includes a damper clutch hydraulic control circuit 50 for performing direct connection, non-direct connection, slip direct connection, and deceleration direct connection control of the damper clutch 28. The damper clutch hydraulic control circuit 50 includes a damper clutch control valve 52 for switching a hydraulic oil supply oil path to the damper clutch 28 and controlling a hydraulic pressure applied to the clutch 28, and a damper clutch ON / OFF valve of a normally closed type. Clutch control solenoid valve 54
The solenoid 54A of the valve 54 is TCU1
6 is connected to the output side.

More specifically, the damper clutch control valve 52 includes a spool 52A, a left end chamber 52B for accommodating the left end of the spool, and a spring 52C for pressing the spool 52A rightward in FIG. A pilot oil passage 55 communicating with a pilot oil pressure source (not shown) is connected to 52B. A branch passage 55A connected to the pilot oil passage 55 and communicating with the drain side is provided with a damper clutch control solenoid valve 54.
The valve 54 is opened and closed to control the magnitude of the pilot hydraulic pressure supplied to the left end chamber 52B. Further, a hydraulic pressure is supplied from the pilot hydraulic pressure source to the right end chamber 52D into which the right end of the spool 52A can freely enter.

The damper clutch hydraulic control circuit 5 having the above configuration
At 0, when the pilot hydraulic pressure acts on the left end chamber 52B and the spool 52A moves to the extreme right position, the lubricating hydraulic pressure supplied to the torque converter 20 is supplied through the oil passage 56, the damper clutch control valve 52, and the oil passage 57. Is supplied to a hydraulic chamber defined by the input casing 22 and the damper clutch 28, whereby the engagement of the damper clutch 28 is released.

On the other hand, when the pilot hydraulic pressure is not supplied to the left end chamber 52B and the spool 52A moves to the left extreme position,
The line pressure from the hydraulic pump is supplied to a hydraulic chamber defined by the damper clutch 28 and the turbine 25 via an oil passage 58, a damper clutch control valve 52, and an oil passage 59, and thereby the damper clutch 28 22 is frictionally engaged.

When the duty control of the damper clutch control solenoid valve 54 is performed by the TCU 16, the pilot hydraulic pressure acting on the left end chamber 52B and the spring 5
The spool 52 is moved to a position where the resultant force of the spring force of 2C and the pilot oil pressure acting on the right end chamber 52C are balanced.
A moves and the hydraulic pressure corresponding to the spool movement position is supplied to the damper clutch 28, and the transmission torque via the damper clutch 28 is controlled to a required value.

The operation of the above-structured automatic transmission will be described below. When the engine 10 is started, the shift control and the clutch control by the hydraulic circuit 40 and the damper clutch hydraulic control circuit 50 that operate under the control of the TCU 16 are started. The shift control is performed as conventionally known. In brief, for this shift control, the TCU 16 sets NO
The optimum gear position is determined based on the transfer drive gear rotational speed NO detected by the sensor 17 and the vehicle speed NO indicating the vehicle speed, the throttle valve opening θT detected by the θT sensor 18, and the like. Is different from the optimal gear position, a shift command is sent to various control valves of the hydraulic circuit 40. The operation of the various control valves in response to the gearshift command switches the hydraulic pressure supply path to the gearshift element of the gear transmission 30 to switch the operating state of the rotating element of the gearbox, thereby establishing the optimal gear position. .

On the other hand, in connection with clutch control, TCU1
6 shows the current vehicle operation state represented by the turbine rotational speed NT detected by the NT sensor 15, the throttle valve opening θT detected by the θT sensor 18, and the like.
A clutch control area determination routine (not shown) for determining which of the divided clutch control areas falls as shown in FIG.

Referring to FIG. 2, the entire clutch control region is divided into four regions of a complete direct connection region, a non-direct connection region, a slip direct connection region, and a deceleration direct connection region according to the turbine rotational speed NT and the throttle valve opening θT. I have. If it is determined in the above determination routine that the current vehicle operation state is within the direct connection region, the TCU 16 sets the duty ratio of the normally closed damper clutch control solenoid valve 54 to 10
A control output for opening the valve 54 is sent to the solenoid 54A of the valve 54 as a value of 0% or a value close to 0%. As a result, the damper clutch control valve 52
The supply of the pilot hydraulic pressure to the left end chamber 52B is interrupted,
The spool 52A is in the left extreme position, whereby the line pressure from the oil passage 58 is supplied as an apply pressure to the damper clutch 28 via the oil passage 59, while the release-side hydraulic oil of the damper clutch 28 is It is discharged through 57. As a result, the damper clutch 28
, And the pump 23 and the turbine 25 are directly connected.

When the TCU 16 determines that the vehicle is operating in the non-direct connection area, the TCU 16 sets the duty ratio of the damper clutch control solenoid valve 54 to 0 to 30% and outputs a control output for closing the solenoid valve 54A.
To send to. As a result, the pilot hydraulic pressure is supplied to the left end chamber 52B of the damper clutch control valve 52, and the spool 52A assumes the right extreme position.
The line pressure from the oil passage 58 is supplied to the damper clutch 28 via the oil passage 57 as a release pressure, while the apply-side hydraulic oil of the damper clutch 28 is discharged via the oil passage 59. As a result, the mechanical friction engagement between the damper clutch 28 and the casing 22 and, consequently, the pump 23 and the turbine 2
5 is released, the pump 23 and the turbine 25
Are in fluid friction engagement.

When the TCU 16 determines that the vehicle operating state is in the slip direct connection area, the TCU 16 controls the duty of the clutch control solenoid valve 54 so that the required apply pressure and release pressure are applied to the damper clutch 28. Accordingly, the damper clutch 28 is directly connected to the casing 22 with a required slip state.
Also, in the deceleration direct connection area, the duty control of the clutch control solenoid valve 54 is performed by the TCU 16, and the apply pressure and the release pressure to the damper clutch 28 are adjusted.

Hereinafter, the deceleration direct connection control by the clutch control device of the present embodiment will be described in detail with reference to FIGS. During the operation of the vehicle, the TCU 16 determines that the current vehicle operation state represented by the turbine rotational speed NT and the throttle valve opening θT corresponds to any of the four clutch control areas shown in FIG. Is determined.

When the TCU 16 determines that the turbine rotation speed NT is equal to or higher than a predetermined rotation speed, for example, 1200 rpm, the throttle valve opening θT is equal to or higher than a predetermined angle, and the vehicle operating state is in the deceleration direct connection area, The deceleration direct connection control routine of FIG. 6 is started. In this deceleration direct connection control routine, the TCU 16 calculates the turbine rotation speed NT and the throttle valve opening θT at the time of the deceleration direct connection area determination by T
It is stored in a register (not shown) built in the CU 16, and then the damper clutch control solenoid valve 54
The control output for closing the valve 54 with the duty ratio of 0% is sent to the solenoid 54A of the valve 54 for t1 seconds (for example, one operation cycle time 655 ms) (step S2). As a result, in section A of FIG.
Apply pressure to the damper clutch 28 is 0% duty ratio
, The damper clutch 28 is brought into the non-coupled state, and the pump 23 and the turbine 25 are brought into the non-coupled state.

As described above, in step S2, T
The CU 16 cooperates with the valve 54 and the like to function as a means for discharging the hydraulic pressure from the damper clutch 28 when the vehicle enters the deceleration operation state, whereby the pump 23 and the turbine 25 immediately Since the non-direct connection state is established, the torque fluctuation of the engine 10 due to the return operation of the throttle valve is not directly transmitted to the gear transmission 30 via the pump 23 and the turbine 25. In other words, the engine output torque fluctuation at the start of the deceleration operation of the vehicle is absorbed by the working fluid interposed between the pump 23 and the turbine 25, so that the damper clutch 28 is in the directly connected state immediately before the vehicle enters the deceleration directly connected area. Even if there is, no shock or judder due to torque fluctuation transmission occurs.

When the transmission of the control output for t1 seconds to the solenoid 54A is completed, the TCU 16 determines whether or not the vehicle operation state is still in the deceleration direct connection area (step S3). If this determination result is negative, TCU1
6 resets flags F1, F2, and F3 having a control index function to be described later to a value “0”, respectively.
A control output for setting the duty ratio of No. 4 to 0% is sent to the solenoid 54A (step S4), whereby the control routine ends.

On the other hand, if it is determined in step S3 that the current vehicle operating state is in the deceleration direct connection area, the TCU 16 reads out the turbine rotational speed NT and the throttle valve opening θT stored in step S1 from the register, and stores the readout in the memory in advance. The duty ratio DG1 (%) for generating the hydraulic pressure corresponding to both the parameter values NT and θT is obtained with reference to the stored hydraulic pressure map (FIG. 8). A control output for setting the duty ratio of DG1 to DG1 is sent to the solenoid 54A for t2 seconds (for example, one operation cycle time 655 ms) (step S5). As a result, in the section B of FIG. 7, the apply pressure corresponding to the duty ratio DG1 is applied to the damper clutch 28, and the damper clutch 28 is directly connected.

As shown in FIG. 8, the hydraulic pressure map is realized in step S2 for 16 NT · θT regions divided by the turbine speed NT and the throttle valve opening θT. Duty ratios A1 to A16 (duty ratio DG1 for suddenly generating hydraulic pressure) are set so that the non-direct connection state can be quickly eliminated. In setting the duty ratios A1 to A16, the operating state of the damper clutch 28 immediately before entering the deceleration direct-connection area is considered. That is, the duty ratio A16 and the like used when shifting from the complete direct connection region where both the throttle valve opening θT and the turbine rotation speed NT are large are set to small values in consideration of the residual pressure on the damper clutch apply side. The duty ratio A1 and the like used when shifting from the non-direct connection region where the turbine rotation speed NT is low are set to larger values as the throttle valve opening θT is smaller.

In step S5, the TCU 16
Sends a control output to the solenoid 54A for t2 seconds, thereby functioning as a means for supplying a predetermined oil pressure (accumulation oil pressure) to the damper clutch 28 so that the pump 23 and the turbine 25 are brought into a state immediately before engagement. .
When the transmission of the control output is completed, the TCU 16 determines whether or not the vehicle driving state is still in the deceleration direct connection area (step S6). If the determination result is negative, the flags F1, F2, and F3 are respectively set. At the same time as resetting the value to "0", a control output for setting the duty ratio of the valve 54 to 0% is sent to the solenoid 54A (Step S).
4), the control routine ends.

On the other hand, if it is determined in step S6 that the current vehicle operation state is in the deceleration direct connection area, the TCU 16 reads out the turbine rotational speed NT and the throttle valve opening θT stored in step S1 from the register, and stores them in the memory in advance. Referring to the stored feedback start hydraulic pressure map (FIG. 9), duty ratio DG2 for generating feedback start hydraulic pressure corresponding to both parameter values NT and θT.
(%) Is set as an initial value of the variable duty ratio DG3 for feedback control, and a control output for setting the duty ratio of the valve 54 to DG3 is sent to the solenoid 54A. A timer (not shown) as a time measuring means for measuring the elapsed time is started (step S7).

As shown in FIG. 9, the feedback start hydraulic pressure map shows that the duty ratio of the valve 54 is controlled by feedback control for 16 NT · θT regions divided by the turbine speed NT and the throttle valve opening θT. Duty ratios B1 to B1 that make it possible to converge smoothly
B16 are set respectively. In the setting of the duty ratios B1 to B16, the operating state of the damper clutch 28 immediately before the vehicle enters the deceleration direct connection area is considered. That is,
The duty ratio B16 and the like used when shifting from the complete direct connection region where both the throttle valve opening θT and the turbine rotation speed NT are large are determined in consideration of the residual pressure on the damper clutch apply side in the non-connection region where the turbine rotation speed NT is low. The value is set to a value larger than the duty ratio B13 or the like used at the time of shifting from. Note that the duty ratios B1 to B16
Is increased or decreased by the learning correction described later, but initially,
Even when sudden braking is performed on a low μ road, a low value is set so as not to cause engine stall.

In step S7, the TCU 16 and the like
It starts functioning as a means for supplying the engagement hydraulic pressure for deceleration to the clutch damper 28, and also as a means for feedback-controlling the hydraulic pressure supplied to the clutch with the engagement hydraulic pressure for deceleration as an initial value. The feedback control in the C section 7 is started. In step S8,
The TCU 16 determines whether or not t3 seconds (for example, 1 second) as a first predetermined time has elapsed from the feedback control start time with reference to the timer output. Immediately after the start of the feedback control, the determination result in step S8 is negative. In this case, it is further determined whether or not t4 seconds (for example, 2.5 seconds) have elapsed from the start of the feedback control (step S9). Immediately after the start of the feedback control, the result of this determination is negative, so it is determined whether or not the vehicle operating state is still in the deceleration direct connection area (step S).
10).

If it is determined in step S10 that the area is not the area directly connected to deceleration, the TCU 16 resets the flags F1 to F3, and sends a control output to the solenoid 54A so that the duty ratio of the valve 54 is 0% ( Step S11). On the other hand, if it is determined that the area is directly connected to the deceleration, TC
U16 reads an output representing the vehicle speed V from the NO sensor 17 as a vehicle speed detecting means (step S12),
The NO sensor output stored in the first vehicle speed data area in the previous vehicle speed data storage cycle is transferred to the second vehicle speed data area and the N read in step S12 of the current cycle is stored.
The O sensor output is stored in the first vehicle speed data area (step S13), and the vehicle speed change rate ΔV is calculated from both NO sensor outputs.
Is calculated (step S14).

Next, the TCU 16 determines whether or not the vehicle speed change rate ΔV calculated in step S14 falls within a predetermined range, for example, larger than -10 km / h · s and smaller than 7 km / h · s. Then, if the result of this determination is negative, that is, if the vehicle is being decelerated on a steep downhill or steep uphill, the flag F3 is set to decelerate on a steep downhill or steep uphill. It is set to a value "1" (step S16).

In step S17 following step S15 or S16, the TCU 16 sets the engine speed NE.
The actual slip amount (NE-NT) in the damper clutch 28 is calculated from the output of the NE sensor 14 indicating the rotational speed NT and the output of the NT sensor 17 indicating the turbine rotational speed NT, and the target slip amount (for example, -5 rotations) during the deceleration operation is calculated. The value obtained by reading from the memory and then subtracting the target slip amount from the actual slip amount is the determination reference value “−a” (where a>
0) is determined.

If the result of the determination in step S17 is affirmative, that is, if the actual slip amount is smaller than the level lower than the target slip amount by the value "a", TCU is set.
16 judges that the apply pressure to the damper clutch 28 is too small, and updates the variable duty ratio DG3 to a value obtained by adding a predetermined value d1 to the variable duty ratio DG3 (step S18). As a result, the pressure applied to the damper clutch 28 increases. Next, it is determined whether or not the flag F1 is a value "1" (step S1).
9). If t3 seconds have not elapsed from the feedback control start time, the determination result in step S19 is negative, and in this case, the process returns to step S8.

On the other hand, if it is determined in step S17 that the value obtained by subtracting the target slip amount from the actual slip amount is not smaller than the determination reference value "-a", the TCU 16 subtracts the target slip amount from the actual slip amount. It is further determined whether or not the obtained value is larger than a determination reference value “b” (here, b> 0) (step S20). When the determination result is affirmative, that is, when it is determined that the apply pressure to the damper clutch 28 is excessive, the predetermined value d2 is subtracted from the variable duty ratio DG3, and the variable duty ratio DG3 is reduced so that the apply pressure decreases. Is updated (step S2
1). Next, it is determined whether or not the flag F1 is a value "1" (step S22). If the result of the determination is negative, the process returns to step S8.

In step S20, the value obtained by subtracting the target slip amount from the actual slip amount is not larger than the determination reference value "b", so that the actual slip amount and, consequently, the applied pressure to the damper clutch 28 are within the proper range. If it is determined that the value is within the range, it is determined in step S23 whether or not the flag F1 has the value "1". If the determination result is negative, the process returns to step S8.

As described above, the feedback control for increasing / decreasing or maintaining the duty ratio of the clutch control solenoid valve 54 is executed so that the slip amount in the damper clutch 28 falls within an appropriate range. After that, the first time from the start of the feedback control
When it is determined in step S8 that t3 seconds as the predetermined time has elapsed, the TCU 16 as the first oil pressure value detecting means determines the duty ratio DG3 that is being sent out as a control output to the valve 54 at that time to the first duty. The duty ratio D1 corresponding to the hydraulic pressure (first hydraulic pressure value) supplied to the clutch at the time when the predetermined time has elapsed is read and stored in the memory (step S24). To store the completion of detection of the oil pressure value, the flag F
1 is set to the value "1" (step S25), and the control processing after step S9 is executed.

During execution of this feedback control, if it is determined in step S19, S22 or S23 that the value of the flag F1 is "1", steps S26 and S27 are performed.
Alternatively, in S28, it is further determined whether or not the value of the flag F2 is "1". If t4 seconds as the second predetermined time has not elapsed from the feedback start point, the determination result in step S26, S27, or S28 is negative, and in this case, the control processing from step S9 is executed.

Thereafter, when it is determined in step S9 that t4 seconds as a second predetermined time has elapsed from the start of the feedback control, the TCU 16 as the second oil pressure value detecting means outputs a control output to the valve 54 at that time. The transmitted duty ratio DG3 is read as the duty ratio D2 corresponding to the hydraulic pressure (second hydraulic pressure value) supplied to the clutch at the time when the second predetermined time has elapsed, and is stored in the memory (step S29). Then, the flag F2 is set to the value "1" to store the lapse of the second predetermined time and the completion of the detection of the second hydraulic pressure value (step S30).

TCU1 as the hydraulic pressure difference calculating means
6 reads the duty ratios D1 and D2 as the first and second hydraulic pressure values from the memory and subtracts the duty ratio D1 from the duty ratio D2, thereby obtaining a duty ratio representing a difference between the first hydraulic pressure value and the second hydraulic pressure value. The rate change amount ΔD is calculated (step S31), and the duty rate correction amount β corresponding to the calculated duty rate change amount ΔD is obtained with reference to the duty rate change amount / duty ratio correction amount map (FIG. 10) ( Step S32).

As shown in FIG. 10, the duty ratio correction amount β is set so as to change stepwise in accordance with the increase or decrease of the duty ratio change amount ΔD. Specifically, when the duty ratio increases by 0% to 0.4% from the time point t3 seconds to the time point t4 seconds after the feedback control is started, the duty ratio is not corrected, and the duty ratio is 0.4%. When the duty ratio increases by 1.2%, the duty ratio is increased by 0.4%, and when the duty ratio increases by 1.2% to 1.6%, the duty ratio is increased by 1.2%. When the duty ratio increases by 1.6% or more, the duty ratio is corrected to increase by 1.6%. By setting the duty ratio correction amount β as described above, it is possible to prevent the duty ratio from being excessively increased and corrected, thereby preventing engine stall.

The same applies to the correction of the decrease of the duty ratio when the duty ratio decreases. Next, TC
U16 determines whether or not the value of the flag F3 is "1" (step S33), and the result of this determination is negative, that is, the vehicle body change rate ΔV is within a predetermined range, and therefore, the vehicle is suddenly moved. When it is determined that the vehicle is not traveling on a steep downhill or a steep uphill, the feedback start duty ratio DG2
(More specifically, the duty ratios B1 to B1 set in the map of FIG. 9 for each of the 16 NT · θT regions
The feedback start duty ratio DG2 is updated to a value obtained by adding the correction amount β obtained in step S32 to B16) (step S34). That is, T as learning correction means
The CU 16 learns the duty ratio DG2.

On the other hand, when the value of the flag F3 is "1",
If it is determined that the vehicle is traveling on a steep downhill or steep uphill (more generally, a road surface that may lead to improper learning correction), step S34 is skipped. The learning of the feedback start duty ratio DG2 on a steep downhill or the like is prohibited, and the duty ratio DG2 is reliably prevented from becoming excessive due to the learning of the duty ratio DG2 on a steep downhill or the like.

In step S35, it is determined whether or not the duty ratio change amount ΔD is greater than a determination reference value C (> 0). If the determination result is negative, the duty ratio change amount ΔD is determined by the determination reference value “D”. It is further determined whether it is smaller than "-f"(f> 0) (step S36). If the result of the determination in step S36 is negative, step S10
The subsequent control processing is executed.

On the other hand, if the decision result in the step S35 or S36 is affirmative, the TCU 16 as a feedback control suspending means resets the flags F1 to F3 and sets the control output such that the duty ratio of the valve 54 is set to 0%. Is sent to the solenoid 54A (step S3).
7), the control routine ends. That is, the determination result of step S35 is affirmative, and the duty ratio of the valve 54 is set to the determination reference value C from the time when t3 seconds elapse to the time when t4 seconds elapse from the start of feedback.
When the feedback control is continued, it is determined that if the feedback control is continued, the duty ratio of the valve 54 and, consequently, the applied pressure to the damper clutch 28 become excessive, and the feedback control is stopped. The reason for this is that if the feedback control is continued when the duty ratio increase change amount from the time point t3 seconds elapses to the time point t4 seconds elapses, the actual slip amount at a certain point (for example, 10 seconds after the start of the feedback control). This is because a sudden change in the actual slip amount such that the sign of the difference between the actual slip amount and the target slip amount suddenly reverses, which may cause a shock in the automatic transmission.

If the determination result in step S36 is affirmative and the duty ratio change amount ΔD from the lapse of t3 seconds to the lapse of t4 seconds is smaller than the determination reference value “−f”, the feedback start duty If the braking ratio is excessive and rapid braking is performed on a low μ road before the adjustment of the duty ratio by the decrease correction is not completed, engine stall is caused due to a delay in releasing the directly connected state of the damper clutch 28. There is a possibility that. Therefore, if the amount of decrease in the duty ratio is excessive, the feedback control is stopped to prevent such a problem.

The damper clutch 2 in the deceleration direct connection control
The appropriate range of the apply pressure (duty ratio of the valve 54) to 8 is relatively strict, and it is necessary to keep the applied pressure within the error range of, for example, about ± 5% with respect to the convergent apply pressure by the feedback control. That is, if sudden braking is performed on a low μ road in a state in which the applied pressure is higher than the converging applied pressure by, for example, 5% or more, engine stall occurs due to a delay in releasing the directly connected state of the damper clutch 28, while the applying pressure is Becomes smaller than the applied pressure by 5% or more, for example.
This is because the damper clutch 28 is in the non-coupled state, and the engine speed is likely to decrease rapidly. Therefore, the fuel cut is stopped in order to prevent the engine from stalling, so that it is not possible to improve the fuel efficiency by the direct coupling of the clutch. According to the clutch control device of the present embodiment, the feedback start duty ratio is appropriately learned and corrected, and the above requirement is satisfied.

The present invention is not limited to the above embodiment but can be variously modified. For example, in the embodiment, the vehicle speed change rate Δ obtained from the output of the NO sensor 17 as the vehicle speed detecting means.
V is detected as a vehicle speed change rate, and learning correction of the duty rate is selectively performed according to the detection result.
Instead of or in addition to the vehicle speed detecting means, at least one of a lateral acceleration detecting means, a wheel speed detecting means, a longitudinal acceleration detecting means and a road surface gradient detecting means is provided, and an output value from at least one of these detecting means is provided. The change rate of the vehicle body speed may be obtained according to the following.

In the embodiment, the feedback start hydraulic pressure map shown in FIG. 9 is used to start the feedback based on one of the feedback start duty ratios B1 to B16 set for each of the 16 NT · θT regions. The correction amount β is obtained in accordance with the duty ratio change rate ΔD detected during the execution of the feedback control, and all the duty ratios B1 to B16 are collectively learned and corrected with the correction amount β. B
Of 16, only one actually used at the start of the feedback control may be learned and corrected by the correction amount β.

[0063]

As described above, the pump disposed between the engine and the auxiliary transmission of the automatic transmission is connected to the output side of the engine and the turbine connected to the input side of the auxiliary transmission. In the fluid coupling for an automatic transmission for a vehicle, the clutch control device of the present invention has a clutch capable of connecting and disconnecting the pump and the turbine, and controls a hydraulic pressure supplied to the clutch according to a vehicle operating state. A deceleration engagement for supplying a deceleration engagement hydraulic pressure to the clutch when the driving state detection means detects that the vehicle has entered a deceleration state. Feedback control using the deceleration engagement oil pressure as an initial value so that the difference between the rotation speed of the pump and the rotation speed of the turbine detected by the oil pressure supply means and the operation state detection means becomes a desired value. Feedback control means, and learning correction means for learning and correcting the initial value only when the vehicle body speed change rate of the vehicle is within a predetermined range by the driving state detecting means. At the same time, the damper clutch can be directly connected, and learning to make the clutch oil pressure appropriate can be performed, and the learning can surely prevent the clutch oil pressure from becoming excessively large. The delay of the release of the direct connection state and the engine stall can be prevented. Therefore, fuel supply to the engine can be cut during deceleration operation of the vehicle without causing engine stall even during sudden braking on a low μ road, thereby improving fuel efficiency.

According to a specific mode of the present invention, the deceleration range regarded as the deceleration state is set to a range in which the engine load is low and the rotation speed of the turbine is equal to or higher than a predetermined low rotation speed. Direct connection control can be performed in an appropriate area. Further, according to a preferred aspect of the present invention, the clutch control device includes: a hydraulic discharge unit that discharges hydraulic pressure from the clutch when it is detected that the vehicle has entered the deceleration state; A predetermined hydraulic pressure supply means for supplying a predetermined hydraulic pressure to the clutch so as to bring the turbine into a state immediately before the engagement, so that the deceleration engagement hydraulic pressure is supplied after the predetermined hydraulic pressure is output; Can prevent the occurrence of a shock in the automatic transmission caused by the transmission of the fluctuation of the engine speed to the automatic transmission, and quickly cancel the non-coupled state of the clutch to prevent the occurrence of the shock and smoothly start the feedback control. It becomes possible.

According to a preferred aspect of the present invention, the clutch control device includes a timer for measuring an elapsed time from the start of the feedback control, and a clutch when the first predetermined time has elapsed from the start of the feedback control. First oil pressure value detection means for detecting a first oil pressure value representing a supply oil pressure value to
A second oil pressure value detecting means for detecting a second oil pressure value indicating a hydraulic pressure value supplied to the clutch when a second predetermined time set longer than the first predetermined time has elapsed from the start of the feedback control; There is further provided a hydraulic pressure difference calculating means for calculating a difference between the hydraulic pressure value and the second hydraulic pressure value, and the learning correction means corrects the initial hydraulic pressure for deceleration according to the hydraulic pressure difference, so that the learning correction can be appropriately performed.

According to the aspect including the feedback control stopping means for stopping the feedback control when the oil pressure difference is outside the predetermined range and discharging the oil pressure from the clutch, the shock caused by the excessive increase correction of the clutch supply oil pressure by the feedback control is provided. It is possible to prevent the occurrence of the engine stall due to the sudden braking during the continuation of the feedback control started with the excessive clutch supply hydraulic pressure initial value.

In a preferred aspect of the present invention, the driving state detecting means includes at least one of a vehicle speed detecting means, a lateral acceleration detecting means, a wheel speed detecting means, a longitudinal acceleration detecting means and a road surface gradient detecting means. Since the rate is obtained according to the output value from at least one of the detection means, it is possible to reliably determine whether the vehicle is being decelerated on a road surface where inappropriate learning correction may be performed, such as a steep downhill. Can be detected.

According to the aspect in which the solenoid valve for duty-controlling the hydraulic pressure supplied to the clutch is provided, and the hydraulic pressure is supplied to the clutch and the hydraulic pressure is discharged from the clutch at the duty ratio given to the solenoid valve, the clutch hydraulic pressure control is performed. Can be performed properly.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a main part of an automatic transmission for a vehicle equipped with a clutch control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a setting example of a complete direct connection area, a non-direct connection area, a slip direct connection area, and a deceleration direct connection area related to the operation control of the damper clutch in FIG. 1;

FIG. 3 shows a deceleration direct connection control of a damper clutch.
Transmission Control Unit (TCU)
5 is a flowchart showing a part of a deceleration direct connection control routine executed by the routine shown in FIG.

FIG. 4 is a flowchart showing another part of the deceleration direct connection control routine.

FIG. 5 is a flowchart showing still another part of the deceleration direct connection control routine.

FIG. 6 is a flowchart showing the rest of the deceleration direct connection control routine.

FIG. 7 is a graph showing a change in a duty ratio of a damper clutch control solenoid valve with time during a deceleration direct connection control of a damper clutch.

FIG. 8 is a diagram showing a setting example of a “sloppy hydraulic map” used for deceleration direct connection control of a damper clutch.

FIG. 9 is a diagram illustrating a setting example of a feedback start hydraulic pressure map used for deceleration direct connection control of a damper clutch.

FIG. 10 is a diagram showing a setting example of a duty ratio change amount / duty ratio correction amount map used for learning correction of a duty ratio of a damper clutch control solenoid valve.

[Explanation of symbols]

Reference Signs List 10 internal combustion engine 14 engine speed (NE) sensor 15 turbine speed (NT) sensor 16 transmission control unit (TC
U) 17 Transfer drive gear rotation speed sensor (vehicle speed sensor) 18 Throttle opening degree sensor 20 Torque converter 23 Pump 25 Turbine 28 Damper clutch 30 Gear transmission 40 Hydraulic circuit 50 Damper clutch hydraulic control circuit 52 Damper clutch control valve 54 Damper clutch control Solenoid valve

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshimasa Nagayoshi 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Toshinori Ishii 5-33-8 Shiba, Minato-ku, Tokyo No. Mitsubishi Motors Corporation (72) Inventor Yasuhiro Nakajima 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Youichi Furuichi 5-33 Shiba, Minato-ku, Tokyo No. 8 Inside Mitsubishi Motors Corporation (72) Inventor Toshimitsu Yamamoto 13-1, Sadamotocho, Himeji City, Hyogo Prefecture Mitsubishi Electric Control Software Co., Ltd. Himeji Works (56) References JP-A-7-42825 (JP, A) JP-A-2-46366 (JP, A) JP-A-3-260466 (JP, A) JP-A-1-141273 (JP, A) JP-A-5-172241 (JP, A) JP-A-6 −94121 (JP JP-A-6-185606 (JP, A) JP-A-6-331023 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 61/14

Claims (7)

(57) [Claims] 1. A vehicle, comprising a pump disposed between an engine and an auxiliary transmission of an automatic transmission and connected to an output side of the engine, and a turbine connected to an input side of the auxiliary transmission. A fluid coupling clutch control device for an automatic transmission, comprising: a clutch capable of connecting and disconnecting the pump and the turbine; and controlling a hydraulic pressure supplied to the clutch according to a vehicle operating state. An operating state detecting means for detecting a vehicle operating state; and a deceleration engaging member for supplying a decelerating engagement hydraulic pressure to the clutch when the driving state detecting means detects that the vehicle has entered a decelerating state. Combined hydraulic pressure supply means, and the deceleration engagement hydraulic pressure such that a difference between the rotation speed of the pump and the rotation speed of the turbine detected by the operation state detection means becomes a desired value. Feedback control means for performing feedback control as an initial value; learning correction means for learning and correcting the initial value only when the driving state detecting means detects that the vehicle body speed change rate is within a predetermined range. A clutch control device for a fluid coupling of an automatic transmission for a vehicle, comprising: 2. The deceleration range considered as the deceleration state is set to a range in which the load on the engine is low and the rotation speed of the turbine is equal to or higher than a predetermined low rotation speed. Item 2. A clutch control device for a fluid coupling of a vehicle automatic transmission according to item 1. 3. The clutch control device according to claim 1, further comprising: a hydraulic discharge unit configured to discharge the hydraulic pressure from the clutch when it is detected that the vehicle has entered the deceleration state. Predetermined hydraulic pressure supply means for supplying a predetermined hydraulic pressure to the clutch so as to be in a state immediately before engagement, wherein the engagement hydraulic pressure for deceleration is supplied after the output of the predetermined hydraulic pressure. Item 3. A clutch control device for a fluid coupling of a vehicle automatic transmission according to item 1 or 2. 4. The clutch control device according to claim 1, wherein the clutch control device measures time elapsed from the start of the feedback control, and a hydraulic pressure supplied to the clutch when a first predetermined time has elapsed from the start of the feedback control. A first oil pressure value detecting means for detecting a first oil pressure value representing a value; and a second oil pressure value detecting means for applying a pressure to the clutch when a second predetermined time set longer than the first predetermined time elapses from the start of the feedback control. A second oil pressure value detecting means for detecting a second oil pressure value representing the supplied oil pressure value; and a hydraulic pressure difference calculating means for calculating a difference between the first oil pressure value and the second oil pressure value, wherein the learning correction means The clutch control device for a fluid coupling of an automatic transmission for a vehicle according to any one of claims 1 to 3, wherein the controller corrects the initial hydraulic pressure for deceleration according to the hydraulic pressure difference. 5. The clutch control device according to claim 4, further comprising feedback control stopping means for stopping the feedback control when the hydraulic pressure difference is outside a predetermined range and discharging the hydraulic pressure from the clutch. The clutch control device for a fluid coupling of an automatic transmission for a vehicle according to claim 1. 6. The driving state detecting means includes at least one of a vehicle speed detecting means, a lateral acceleration detecting means, a wheel speed detecting means, a longitudinal acceleration detecting means, and a road surface gradient detecting means. The clutch control device for a fluid coupling of an automatic transmission for a vehicle according to any one of claims 1 to 5, wherein the clutch control device is determined in accordance with an output value from at least one detection means. 7. The clutch control device further includes an electromagnetic valve that duty-controls a hydraulic pressure supplied to the clutch, and a hydraulic pressure supplied to the clutch and a hydraulic pressure discharged from the clutch are controlled by a duty ratio applied to the electromagnetic valve. The clutch control device for a fluid coupling of a vehicle automatic transmission according to any one of claims 1 to 6, wherein the clutch control is performed.