JP2002349694A - Automatic transmission direct-coupled clutch controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutch controller to reliably control shocks and judders that may occur, when a direct-coupled or slip direct-coupled state shifts to a deceleration direct-coupled state. SOLUTION: The clutch control means can switch among a non-coupled state, where the clutch is not directly coupled, a completely direct-coupled state where it is firmly coupled or a slip direct-coupled state, where it is under a feedback control so as to have desirable slippage, and a deceleration direct- coupled state where it is under a feedback control, so as to have desirable slippage during decelerating operation; when the slip direct-coupled state shifts to the deceleration direct-coupled state, the clutch control means maintains the oil pressure level supplied to the clutch, as it is, until the slippage lowers below a predetermined value; and when it has lowered below the value, temporarily drops the oil pressure and then holds the clutch under a feedback control so that desirable deceleration slippage is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In an automatic transmission of an automobile, a transmission mechanism using a planetary gear is generally used, and the planetary gear is connected or fixed by a hydraulic friction engagement element such as a hydraulic clutch or a brake to set a desired gear. I'm trying to get. Further, a torque converter is interposed between the engine and the transmission to increase the engine torque at the time of starting and transmit the torque to the transmission, or to absorb a shock at the time of shifting or sudden acceleration / deceleration. .

In an automatic transmission having such a torque converter, since the torque converter transmits power through a fluid, a loss due to slip occurs and fuel efficiency is poor. Therefore, at present, a clutch is provided inside this torque converter, and in a predetermined operating region such as a certain speed or higher, the output shaft of the engine and the input shaft of the transmission are directly connected by connecting the clutch without passing through the torque converter. A lock-up mechanism is adopted. In this lockup mechanism, a torque converter input shaft (output shaft of the engine) and an output shaft (input shaft of the transmission) are rigidly connected to each other during power-on traveling at a relatively high speed to completely prevent the slip loss from occurring. Slip direct coupling area where the input and output shafts are coupled while slipping about several tens of revolutions during power-on traveling at relatively low speed, making it difficult for engine torque fluctuations to be transmitted to the transmission, and power-off traveling During deceleration operation, the input shaft and output shaft are coupled together with a small slip to prevent engine stall and perform fuel cut, and the non-direct connection region where the input shaft and output shaft are not directly connected. have.

[0004] This clutch is controlled by the hydraulic pressure (apply pressure) controlled by a control valve. In a completely directly connected area, a high apply pressure acts on this clutch so that the clutch does not slip. In the slip direct connection area and the deceleration direct connection area, the apply pressure adjusted to the target slip amount acts on this clutch. In this case, a spool valve is used as the control valve, and is operated by control hydraulic pressure duty-controlled by an electromagnetic valve.

In such an automatic transmission, when the vehicle shifts from a complete direct connection area or a slip direct connection area to a deceleration direct connection area, the traveling state changes from power-on (engine is driven) to power-off (engine is driven). Switch to. Therefore, the engine torque fluctuates at the time of this transition, and this torque fluctuation is transmitted to the transmission via the clutch in the directly connected state, and a shock or judder is generated. Therefore, when shifting to the deceleration direct connection area, the solenoid valve is stopped for a predetermined time to release the apply pressure by the control valve, thereby temporarily setting the clutch to a non-direct connection area to avoid shocks and judder, and thereafter, applying the desired application. The pressure was supplied to perform deceleration direct connection control. Such a direct-coupled clutch control device for an automatic transmission is disclosed, for example, in Japanese Patent No. 29
No. 24624.

[0006]

However, in the above-described conventional direct-coupled clutch control apparatus for an automatic transmission, when the shift to the deceleration direct-coupled region is performed, the apply pressure is reduced to temporarily disengage the clutch to reduce shocks and judder. Avoiding,
In contrast to the clutch control that temporarily disengages the clutch when shifting to the deceleration direct connection area, the engine side has a delay in lowering the engine output due to factors such as dashpot control and smoothing control, and the load from the transmission side There is a problem that the engine speed temporarily increases due to the fact that the decrease in the engine speed precedes the decrease in the engine output.

FIG. 6 is a time chart showing an operation state of the automatic transmission at the time of deceleration direct connection control by the conventional automatic transmission direct connection clutch control device. As shown in the figure, when the driver returns the accelerator pedal to reduce the accelerator opening θ _TH (%) and closes, the solenoid valve is stopped for a predetermined time (duty ratio is 0 (%)) and the apply pressure is reduced. (Section A).
Then, after a lapse of a predetermined time, the duty ratio of the solenoid valve is set to 100 (%) and the predetermined duty ratio is set from (B section) to a desired slip amount (C section).
Section). However, when the driver releases the accelerator pedal, the engine rotation speed Ne (rpm) despite the duty ratio being set to 0 in accordance with the decrease in the accelerator opening θ _TH.
Does not decrease at the same time due to factors such as dashpot control that suppress sudden changes in engine output. On the other hand, the engine speed temporarily increases slightly due to a reduction in the load due to decoupling from the transmission. At this time, a change in the longitudinal acceleration G occurs, and the driver feels a shock.

The present invention has been made to solve the above-mentioned problem, and it is an object of the present invention to provide a direct-coupled clutch control for an automatic transmission in which the occurrence of a shock or a judder when shifting from a directly coupled state or a slip directly coupled state to a deceleration directly coupled state is reliably suppressed. It is intended to provide a device.

[0009]

According to a first aspect of the present invention, there is provided a direct-coupled clutch control device for an automatic transmission, wherein the clutch control means includes: a non-direct-coupled state in which the clutch is not directly coupled; A completely connected state in which the clutch is connected and / or a slip directly connected state in which the clutch is feedback-controlled so as to have a desired slip amount; Switching is possible, and the hydraulic pressure supplied to the clutch is held until the slip amount becomes equal to or less than a predetermined value when the state is shifted from the complete direct connection state or the slip direct connection state to the deceleration direct connection state.

Therefore, when the driver shifts from the complete direct connection state or the slip direct connection state by the torque converter to the deceleration direct connection state by returning the accelerator pedal, a sudden change in the engine output such as a dashpot is suppressed after the accelerator opening is reduced. Even if the decrease in the engine output is delayed due to this factor, the hydraulic pressure supplied to the clutch is maintained until the slip amount falls below a predetermined value, that is, until the engine output falls below an appropriate value. As a result, the hydraulic pressure supplied to the clutch decreases after the engine output drops below the appropriate value, so that shocks and judders that occur at the time of shifting to the deceleration direct connection state can be reliably avoided. Of the longitudinal acceleration G due to the increase in the engine output can be prevented.

In the direct clutch control apparatus for an automatic transmission according to a second aspect of the present invention, when shifting from the slip directly connected state to the deceleration directly connected state, the hydraulic pressure supplied to the clutch is maintained until the slip amount becomes a predetermined value or less. Like that. Since the hydraulic pressure supplied to the clutch is lower in the slip direct connection state than in the full direct connection state, the clutch release is faster and the engine speed tends to increase when shifting to the deceleration direct connection state. By keeping the clutch oil pressure until the slip amount becomes equal to or less than the predetermined value at the time of transition to the state, it is possible to effectively prevent a temporary increase in the engine speed.

In the direct-coupled clutch control device for an automatic transmission according to the third aspect of the invention, when the slip amount becomes equal to or less than a predetermined value, the hydraulic pressure is once reduced, and then feedback control is performed so that the desired deceleration slip amount is obtained. I have. Therefore,
The transition can be made smoothly from the complete direct connection state or the slip direct connection state to the deceleration direct connection state without generating any shock or judder.

In the direct-coupled clutch control device for an automatic transmission according to a fourth aspect of the present invention, when the hydraulic pressure supplied to the clutch is maintained for a predetermined time or longer, the clutch is shifted to a deceleration directly-coupled state. Therefore, in a situation where the slip amount does not readily decrease even when the supply hydraulic pressure of the clutch is maintained, it is possible to avoid the situation where the maintenance of the clutch supply hydraulic pressure is uselessly continued and the shift to the deceleration direct connection state is delayed. it can.

In the direct clutch control apparatus for an automatic transmission according to a fifth aspect of the present invention, the hydraulic pressure supplied to the clutch is maintained for a predetermined minimum time at the time of transition from the complete direct connection state or the slip direct connection state to the deceleration direct connection state. At the same time, the oil pressure is maintained until the slip amount becomes equal to or less than a predetermined value. Therefore, even if the slip amount in the state before the shift to the deceleration direct connection state is small, the clutch supply oil pressure is maintained for the predetermined minimum time, and the decrease in the load from the transmission side causes the decrease in the engine output. It is possible to more reliably prevent the vehicle from moving ahead, and to more reliably prevent the engine speed from rising.

[0015]

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

FIG. 1 is a schematic configuration of a direct-coupled clutch control device for an automatic transmission according to a first embodiment of the present invention, FIG. 2 is a map showing a control range of a clutch, and FIG. A flow chart and FIG. 4 are time charts showing the operating state of the automatic transmission during the direct reduction control.

In the direct-coupled clutch control device for an automatic transmission according to the present embodiment, as shown in FIG.
Is transmitted to the drive wheels via the automatic transmission 12. The automatic transmission 12 includes a torque converter 13, a transmission main body 14, a hydraulic controller 15, and the like.
U) 16 is driven and controlled. The transmission main body 14 includes a plurality of sets of planetary gears, hydraulic clutches, hydraulic brakes, and other hydraulic friction engagement elements. The hydraulic controller 15 has a plurality of solenoid valves duty-driven by the ECU 16 in addition to a hydraulic circuit formed integrally.

On the other hand, the ECU 16 includes an input / output device (not shown) and a storage device (RO) storing a large number of control programs.
M, RAM, nonvolatile RAM, etc.), central processing unit (CP
U), an engine speed sensor 1 for detecting the engine speed Ne via a ring gear 17 provided on the engine output shaft on the input side thereof.
8, a turbine speed sensor 19 for detecting a turbine speed Nt of the torque converter 13, a drive gear speed sensor 20 for detecting a speed No of a transfer drive gear (not shown), and an opening degree θ of a throttle valve (not shown)
A throttle position sensor 21 for detecting _TH and an oil temperature sensor 22 for detecting the oil temperature of hydraulic oil discharged from an oil pump (not shown) in the torque converter 13 are connected. The ECU 16 is connected to an inhibitor switch for detecting the position of the gear selector lever of the automatic transmission 12, an idle switch for detecting the closed state of the throttle valve, and the like.

The torque converter 13 includes a housing 2
3, a casing 24, a pump 25, a stator 26, a turbine 27, and the like. The pump 25 is connected to a drive shaft 28 as an input shaft via the casing 24. And the stator 26 is a one-way clutch 29
And the turbine 27 is connected to the input shaft 30 of the transmission body 14 as an output shaft.
It is connected to. In the torque converter 13, a direct coupling clutch (hereinafter, referred to as a damper clutch) 31 is interposed between the casing 24 and the turbine 27. The engagement of the damper clutch 31 drives the drive shaft 28.
And the input shaft 30 can be directly connected.
The damper clutch 31 is driven by hydraulic oil supplied from a clutch hydraulic control circuit 34 via oil passages 32 and 33.

A control valve 35, which is the center of the clutch hydraulic pressure control circuit 34, is driven by a closed electromagnetic valve 36 to control the hydraulic pressure supplied to the damper clutch 31, and is provided at both ends of the spool valve 37. A left end chamber 38 and a right end chamber 39 are located, oil passages 40 and 41 for introducing pilot pressure to the respective chambers 38 and 39, and a spring 42 for urging the spool valve 37 rightward in FIG. The oil passage 40 to the left end chamber 38 is a branch oil passage 43
The solenoid valve 36 is connected to the
Is in the closed state (OFF position), the pilot pressures of the left end chamber 38 and the right end chamber 39 are balanced, and the spool valve 37 biased by the spring 42 moves rightward. On the other hand, when the solenoid valve 36 is in the open state (ON position), the left end chamber 3
The pilot pressure on the 8 side is released, and the spool valve 37 moves to the left by being urged by the pilot pressure on the right end chamber 39 side.
The orifices 44 and 45 are formed in the oil passage 40 and the branch oil passage 43, respectively, to prevent a sudden change in pilot pressure.

When the spool valve 37 moves rightward, a torque converter lubricating oil pressure (release pressure) is supplied between the casing 24 and the damper clutch 31 via the oil passage 32, and at the same time, via the oil passage 33. Casing 2
Hydraulic oil is discharged from 4. Then, damper clutch 3
1 is opened, and the rotation of the drive shaft 28 is transmitted to the input shaft 30 via the pump 25 and the turbine 27. On the other hand, when the spool valve 37 moves to the left, the hydraulic oil between the casing 24 and the damper clutch 31 is discharged via the oil passage 33, and at the same time, the control valve 35 is adjusted into the casing 24 via the oil passage 30. Apply pressure based pressure is provided. Then, the damper clutch 31 is brought into a connected state (completely connected state), and the rotation of the drive shaft 28 is directly transmitted to the input shaft 30.

The connection / disconnection of the damper clutch 31 and the supply hydraulic pressure are determined by the position of the spool valve 37, that is, the pressure difference between the pilot pressure supplied to the left end chamber 38 and the pilot pressure supplied to the right end chamber 39. It is controlled by duty driving the solenoid valve 36. For example, when the ECU 16 drives the solenoid valve 36 at a duty ratio of about 80%, the pilot pressure in the left end chamber 38 is discharged through the branch oil passage 43 and the solenoid valve 36, and the spool valve 37 moves to the left end, and Due to the action of the pressure, the damper clutch 31 is completely connected. On the other hand, when the ECU 16 drives the solenoid valve 36 at a duty ratio of 0% (that is, does not drive it at all), the spool pressure is applied by the spring 42 to balance the pilot pressures in the left end chamber 38 and the right end chamber 39. 37 moves to the right end, and the damper clutch 31 is brought into a non-direct connection state by the action of the release pressure. Then, when the ECU 16 drives the electromagnetic valve 36 at a predetermined duty ratio (for example, 25 to 35%), a low apply pressure state can be formed, and the damper clutch 31 is in a deceleration direct connection state or a slip direct connection state.

In the thus-configured direct-coupled clutch control device for an automatic transmission according to the present embodiment, when the driver turns on the ignition key to drive the engine 11, the ECU 16 sets each initial value. , And reads and stores detection signals of various sensors. Then, the ECU 16
Determines the speed to be established by the transmission body 14 from the throttle opening θ _TH and the transfer drive gear rotation speed No, and outputs a shift signal of the determined speed. To control the shift.

The ECU 16 controls the driving of the damper clutch 31 based on the control range map of the direct coupling clutch shown in FIG. In this control range map, the horizontal axis is the output shaft (transfer drive gear) rotation speed No (or turbine rotation speed Nt), and the vertical axis is the throttle opening θ _TH . As shown in FIG. 2, the region where the output shaft rotation speed No is relatively low is a non-direct connection region where the damper clutch 31 is completely released, and the output shaft rotation speed No is relatively high.
In a region where the throttle opening θ _TH is larger than the power online L, a slip direct connection region and a complete direct connection region on a higher rotation side than the slip direct connection region are set. In the slip connection area, the slip amount of the damper clutch 31 is, for example, 50
Feedback control is performed so that the target slip amount becomes about rpm. On the other hand, in the completely connected region, the damper clutch 31 is controlled to be completely directly connected.

That is, in the slip direct connection area and the complete direct connection area, the apply pressure is supplied from the control valve 35 into the casing 24, while the release pressure is discharged from between the damper clutch 31 and the casing 24. The duty ratio of the solenoid valve is feedback-controlled so that the damper clutch 31 is completely engaged and in the slip-directly-coupled region, the target slip amount is achieved. On the power online L, the engine speed Ne and the turbine speed Nt (transfer drive gear speed N
Although the acceleration and the deceleration are not performed in accordance with o), the acceleration and the deceleration may be slightly increased due to the variation in the output of the engine 11 in practice.

When the throttle opening θ _TH is smaller than the power online L, a predetermined region (for example, 3000 rpm) from a region where the output shaft rotational speed No is slightly higher than the idle rotational speed (for example, 1500 rpm) is directly connected to the deceleration region. And the region beyond that is a non-direct connection region. In this deceleration direct connection area, the duty ratio of the solenoid valve 36 is feedback-controlled so as to attain the target deceleration slip amount, so that the minimum required apply pressure is supplied to the damper clutch 31 and the engine 11 and the transmission body 14 With a predetermined target deceleration slip amount (for example, -10 rpm), the damper clutch 31 is directly engaged with the slip, while at the time of sudden braking, the damper clutch 31 is quickly released to avoid engine stall. In the deceleration direct connection area, fuel supply can be stopped (fuel cut) while maintaining the rotation of the engine 11 to improve fuel efficiency.

In this embodiment, when the driver shifts from the completely connected state or the slip directly connected state to the deceleration directly connected state by returning the accelerator pedal, the damper clutch is operated until the slip amount becomes equal to or less than a predetermined value. The hydraulic pressure supplied to 31 is maintained.
Hereinafter, this deceleration direct connection control will be described based on the flowchart shown in FIG. 3 and the time chart in FIG.

As shown in FIG. 3, in step S11,
Based on the throttle opening θ _TH and the output shaft rotation number No, it is determined from the map of FIG. 2 whether or not the driving state of the vehicle is in the deceleration operation range. If the routine exits from this routine without being in the deceleration operation range, the deceleration direct connection start condition is determined in steps S12 and S13. That is, in step S12, it is determined whether or not the engine speed Ne is equal to or higher than a predetermined speed.
If the engine rotation speed Ne is lower than the predetermined rotation speed, there is a possibility that the engine will be stalled due to fuel cut.
Move to 3. In this step S13, it is determined whether or not the power-on is directly connected before the predetermined time, that is, whether the power-on is in the completely directly connected state or the slip directly connected state. If the power-on is not directly connected before the predetermined time, the process exits this routine without doing anything. On the other hand, if the power-on is directly connected before the predetermined time, the process proceeds to step S14.

Then, in step S14 and thereafter, the control of the shift to the direct connection to the deceleration is performed. That is, in step S14, first, the previous duty ratio (DCC duty) is held, and in step S15, it is determined whether the slip amount of the damper clutch 31 is equal to or more than a predetermined rotation speed (for example, 10 rpm). I do. Here, if the slip amount is higher than the predetermined rotation speed, it is determined that the engine output (engine rotation speed Ne) is not sufficiently reduced due to factors such as dashpot control even though the driver releases the accelerator pedal. The process proceeds to step S16, where it is determined whether the duty ratio is maintained for a predetermined time α (for example, about 300 msec) or more. At first, since the predetermined time is not reached, steps S11 to S16 are repeated. Then, when the slip amount becomes lower than the predetermined rotation speed in step S15, the direct deceleration control is executed in step S17 and thereafter. If it is determined in step S17 that the duty ratio has been maintained for the predetermined time α or longer, it is determined that the slip amount does not decrease even if the duty ratio is maintained, and the control for deceleration direct control is performed. In order to avoid a delay in shifting, deceleration direct connection control is executed in step S17 and subsequent steps.

That is, in step 17, the ECU 16
The solenoid valve 3 at a predetermined time before the start point of the deceleration direct connection control
6 and the slip amount of the damper clutch 31, a solenoid valve drive stop time is set from a preset map, and the solenoid valve 3 is stopped over this solenoid valve drive stop time.
6, the drive duty ratio is set to 0, the apply pressure is discharged while the release pressure is supplied, and the damper clutch 31 is brought into a non-direct connection state (section A in FIG. 4). Therefore, when the apply pressure in the torque converter 13 is high, the solenoid valve drive stop time is set to be long, the direct connection state is avoided, and the torque fluctuation of the engine 11 is not transmitted to the automatic transmission 12 side. Can be prevented. On the other hand, when the apply pressure in the torque converter 13 is low, the solenoid valve drive stop time is set to be short, the time of the non-direct connection state does not become unnecessarily long, and the fuel injection is restarted due to a decrease in the engine speed. Fuel consumption can be reduced.

Then, at step 18, the ECU 16
Is used to set the rattling duty ratio and rattling time from a preset map from the throttle opening θ _TH and the output shaft rotational speed No immediately before entering the deceleration direct connection area, and to set the electromagnetic gap over this rattling time. The valve 36 is driven at a predetermined rattling duty ratio to supply an apply pressure to the damper clutch 3.
1 is filled (section B in FIG. 4). In addition, this rattling duty ratio is such that when the throttle opening θ _TH is large and the output shaft rotational speed No is high, the shift from the complete direct connection region is as follows.
It is set small because the applied pressure residual pressure is high, and set large because the applied pressure residual pressure is low in the transition from the non-direct connection area or the like.

Further, in step 19, the ECU 16
A feedback start duty ratio is set from a preset map based on the throttle opening θ _TH and the output shaft speed No just before the vehicle enters the deceleration direct connection area, and the solenoid valve 36 is driven at a predetermined feedback start duty ratio. Performs feedback control so that the slip amount becomes the target deceleration slip amount (section C in FIG. 4). Note that the feedback start duty ratio has a large throttle opening θ _TH and an output shaft speed No.
Is set to a small value because the residual pressure of the apply pressure is high in the transition from the fully connected region where the pressure is high, and is set large in the transition from the non-direct coupled region and the like because the residual pressure of the apply pressure is low. Thereafter, the feedback control is continued until the driving state of the vehicle is changed to another driving range.

As described above, in the present embodiment, when the driving state of the vehicle shifts to the deceleration direct connection state, the hydraulic pressure supplied to the damper clutch 31 is maintained until the slip amount becomes equal to or less than a predetermined value. The feedback control is performed such that the desired amount of deceleration slip is obtained after reducing the engine speed, and it is possible to prevent the occurrence of longitudinal acceleration due to the increase in engine speed at this time.

That is, as shown in FIG. 4, when the driver releases the accelerator pedal to reduce the throttle opening θ _TH , the engine speed Ne does not immediately decrease due to factors such as dashpot control. D
Holds CC duty. Then, when the slip amount becomes lower than the predetermined rotation speed after the predetermined time elapses, the drive duty ratio of the solenoid valve 36 is set to 0 over the solenoid valve drive stop time, and the damper clutch 31 is in the non-direct connection state over the section A. Then, after the elapse of the solenoid valve driving stop time, the solenoid valve 36 is driven at the backlash duty ratio for the backlash time, and the apply pressure is supplied to the damper clutch 31 over the B section to be backlashed. After the elapse of the play time, the solenoid valve 36 is driven at the feedback start duty ratio for the period C, and thereafter, feedback control is performed so that the slip amount becomes the target deceleration slip amount.

As described above, when the torque converter 13 shifts from the slip direct connection state to the deceleration direct connection state, even if the decrease in the engine output is delayed due to the driver's return operation of the accelerator pedal due to factors such as dashpot control, the slip amount is reduced. Until the engine output falls below the predetermined value, that is, until the engine output falls below the appropriate value, the oil pressure that has been supplied to the damper clutch 31 is maintained. It is possible to reliably avoid the occurrence of the longitudinal acceleration G due to the increase in the engine speed at this time.

FIG. 5 is a flow chart of the deceleration direct connection control by the direct clutch control device of the automatic transmission according to the second embodiment of the present invention. Note that members having the same functions as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

In the present embodiment, as shown in the flowchart of FIG.
And the other controls are the same. That is, in this step S20, the holding time of the duty ratio is a predetermined minimum time β (for example, 100 msec, β <
α) or more. If the duty ratio holding time is less than the minimum time β, the process returns to step S11. If the duty ratio holding time is more than the minimum time β, the process proceeds to step S15. By the processing in step S20, the duty ratio is maintained during the minimum time β regardless of the slip amount. Accordingly, for example, even when the state is changed from the complete direct connection state or the minimum slip direct connection state to the deceleration slip direct connection state (when the slip amount is originally small),
The transition to the deceleration direct connection state can be delayed. For this reason, it is possible to more reliably prevent a decrease in load from the transmission side from leading to a decrease in engine output, and to more reliably prevent an increase in the engine speed and the occurrence of longitudinal acceleration.

In each of the above-described embodiments, in the torque converter 13 of the automatic transmission 12, when shifting from the slip directly connected state to the deceleration directly connected state, the torque is supplied to the damper clutch 31 until the slip amount becomes a predetermined value or less. Although the hydraulic pressure is maintained, the hydraulic pressure supplied to the damper clutch 31 is maintained until the slip amount becomes equal to or less than a predetermined value at the time of transition from the complete direct connection state to the deceleration direct connection state. Almost the same operation and effect can be obtained.

[0039]

As described in detail in the above embodiment, according to the direct-coupled clutch control device for an automatic transmission according to the first aspect of the present invention, the clutch control means controls the non-direct-coupled state in which the clutch is not directly coupled. A complete direct connection state in which the clutch is rigidly connected and / or a slip direct connection state in which the clutch is feedback-controlled so as to have a desired slip amount, and a deceleration direct connection in which the clutch is feedback-controlled so that the clutch has a desired deceleration slip amount during deceleration operation of the vehicle. State, and the hydraulic pressure supplied to the clutch is maintained until the slip amount becomes equal to or less than a predetermined value at the time of transition from the complete direct connection state or the slip direct connection state to the deceleration direct connection state. Or, when the driver returns to the accelerator pedal from the slip direct connection state to shift to the deceleration direct connection state, It is delayed reduction of the engine output due to factors such as the dashpot from decreased cell opening,
Until the slip amount falls below a predetermined value, that is, until the engine output falls below an appropriate value, the hydraulic pressure that has been supplied to the clutch is held. As a result, the shock and judder generated when shifting to the deceleration direct connection state can be reliably avoided, and
At this time, the occurrence of the longitudinal acceleration G due to the increase in the engine speed can be prevented.

According to the direct-coupled clutch control device for an automatic transmission according to the second aspect of the present invention, when shifting from the slip directly-coupled state to the deceleration directly-coupled state, the hydraulic pressure supplied to the clutch until the slip amount becomes equal to or less than a predetermined value is reduced. Because it is held, the hydraulic pressure supplied to the clutch is lower than in the complete direct connection state, and the clutch is released quickly when shifting to the deceleration direct connection state, and the occurrence of shock is likely to be noticeable. During the transition, a temporary increase in the engine speed can be effectively prevented.

According to the direct-coupled clutch control device for an automatic transmission according to the third aspect of the invention, when the slip amount becomes equal to or less than a predetermined value, the hydraulic pressure is once reduced, and then the feedback control is performed so that the desired deceleration slip amount is obtained. As a result, a smooth transition can be made from the complete direct connection state or the slip direct connection state to the deceleration direct connection state without generating any shock or judder or the like.

According to the direct-coupled clutch control device for an automatic transmission according to the fourth aspect of the present invention, when the hydraulic pressure supplied to the clutch is maintained for a predetermined time or longer, the clutch is shifted to the deceleration direct-coupled state. In a situation where the slip amount does not readily decrease even if the supply hydraulic pressure of the clutch is maintained, the maintenance of the supply hydraulic pressure of the clutch can be wastefully continued to avoid a situation in which the shift to the deceleration direct connection state is delayed.

According to the direct-coupled clutch control device for an automatic transmission according to the fifth aspect of the present invention, the hydraulic pressure supplied to the clutch is reduced for a predetermined minimum time when the state is shifted from the completely directly-coupled state or the slip directly-coupled state to the deceleration directly-coupled state. Since the hydraulic pressure is maintained until the slip amount becomes equal to or less than the predetermined value, the clutch supply hydraulic pressure is maintained for the predetermined minimum time even if the slip amount in the state before the shift to the deceleration direct connection state is small. As a result, it is possible to more reliably prevent a decrease in the load from the transmission side from leading to a decrease in the output of the engine, and to more reliably prevent an increase in the engine speed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a direct-coupled clutch control device for an automatic transmission according to a first embodiment of the present invention.

FIG. 2 is a map showing a control range of a clutch.

FIG. 3 is a flowchart of deceleration direct connection control by a direct connection clutch control device.

FIG. 4 is a time chart illustrating an operation state of the automatic transmission during a direct reduction control.

FIG. 5 is a flowchart of deceleration direct coupling control by a direct coupling clutch control device for an automatic transmission according to a second embodiment of the present invention.

FIG. 6 is a time chart showing an operation state of the automatic transmission during deceleration direct connection control by a conventional direct transmission clutch control device for an automatic transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Engine 12 Automatic transmission 13 Torque converter 14 Transmission body 15 Hydraulic controller 16 Electronic control unit (ECU) 18 Engine speed sensor 19 Turbine speed sensor 20 Drive gear speed sensor 21 Throttle position sensor 28 Drive shaft (input shaft) Reference Signs List 30 input shaft (output shaft) 31 damper clutch 34 clutch oil pressure control circuit 35 control valve

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiro Hamano 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation F-term (reference) 3J053 CA03 CB14 CB26 DA02 DA06 DA14 EA02

Claims (5)

[Claims] 1. A torque converter connected to an engine, a clutch attached to the torque converter so that an input shaft and an output shaft of the torque converter can be rigidly connected, and clutch control means for controlling the clutch. Deceleration of the vehicle, wherein the clutch control means does not directly connect the clutch, a completely connected state in which the clutch is rigidly connected, and / or a slip directly connected state in which the clutch is feedback-controlled so as to have a desired slip amount. In an automatic transmission that switches to a deceleration direct-coupled state in which the clutch is feedback-controlled so that the clutch has a desired deceleration slip amount during operation, the shift is performed when the complete direct-coupled state or the slip direct-coupled state is shifted to the deceleration direct-coupled state. The hydraulic pressure supplied to the clutch is maintained until the amount falls below a predetermined value. A direct-coupled clutch control device for an automatic transmission characterized by having 2. The direct-coupled clutch control device for an automatic transmission according to claim 1, wherein the clutch is supplied to the clutch until the slip amount becomes equal to or less than a predetermined value at the time of transition from the slip directly-coupled state to the deceleration directly-coupled state. A direct-coupled clutch control device for an automatic transmission, characterized in that it maintains a high hydraulic pressure. 3. The direct-coupled clutch control device for an automatic transmission according to claim 1, wherein when the slip amount is equal to or less than a predetermined value, the hydraulic pressure is temporarily reduced and then feedback control is performed so as to attain a desired deceleration slip amount. A direct-coupled clutch control device for an automatic transmission. 4. The direct-coupled clutch control device for an automatic transmission according to claim 1, wherein if the time for which the hydraulic pressure supplied to the clutch is held for a predetermined time or more, the state is shifted to the deceleration directly-coupled state. Direct transmission clutch control device for automatic transmission. 5. The direct-coupled clutch control device for an automatic transmission according to claim 1, wherein a hydraulic pressure supplied to the clutch is changed by a predetermined value when the state is shifted from the completely directly-coupled state or the slip directly-coupled state to the deceleration directly-coupled state. A direct-coupled clutch control device for an automatic transmission, wherein a minimum time is maintained and the hydraulic pressure is maintained until the slip amount becomes a predetermined value or less.