JP2737352B2 - Control device for vehicle lock-up clutch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for a lock-up clutch for a vehicle.

2. Description of the Related Art In a vehicle in which the output of an engine is transmitted to a transmission via a fluid coupling with a lock-up clutch, the lock-up clutch is released after the lock-up clutch is released in connection with the operation of the acceleration operating member being returned. 2. Description of the Related Art A control device for a vehicle lock-up clutch for re-engaging a lock-up clutch in connection with re-operation of an acceleration operation member is known.
For example, a lock-up clutch control device disclosed in Japanese Patent Application Laid-Open No. 61-119870 is one example. According to this, when the operation amount of the accelerator pedal is increased again after the operation amount of the accelerator pedal becomes zero when the lock-up clutch is engaged, the release depending on the change amount (operation speed) of the operation amount at the time of the re-operation is performed. The time is determined, and when the release time has elapsed, the lock-up clutch is re-engaged.

SUMMARY OF THE INVENTION Incidentally, in the above-described conventional lock-up clutch control device for a vehicle, the engagement timing is determined according to the operation amount at the start of re-operation of the accelerator pedal. If the acceleration operation member is further operated after the start of the operation, the engagement is performed in a state where the input / output rotation speed difference of the lock-up clutch is greatly increased, and the inconvenience that an engagement shock occurs is caused. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress the engagement shock of the lock-up clutch after the re-operation of the acceleration operation member regardless of the operation state. It is an object of the present invention to provide a control device for a vehicle lock-up clutch that can be used.

Means for Solving the Problems The gist of the present invention to achieve the above object is to provide a vehicle in which the output of an engine is transmitted to a transmission via a fluid coupling with a lock-up clutch while the vehicle is running. A vehicle lock-up clutch for re-engaging the lock-up clutch in connection with re-operation of the acceleration operation member after the lock-up clutch is released in connection with the return of the operation of the operation member (A) operation speed detection means for sequentially detecting the operation speed of the acceleration operation member; (b) determination means for determining that the operation speed has changed below a predetermined value; c) During the period in which the operation speed is equal to or higher than the predetermined value, the engagement time determination variable that is lower than the operation amount by the predetermined value is repeatedly calculated, and the calculated value is a value equal to or larger than the previously calculated value. An engagement time determination variable increasing unit that updates the engagement time determination variable only when there is a certain time and the operation speed is lower than the predetermined value, and increases the engagement time determination variable at a predetermined constant speed. (D) engagement control means for engaging the lock-up clutch when the operation speed is lower than a predetermined value by the determination means and the operation amount and the engagement time determination variable intersect. , To include.

In this way, the lock-up clutch is engaged when the operation speed at the time of re-operation of the acceleration operation member becomes lower than the predetermined value and the operation amount intersects with the engagement time determination variable. Be combined. After the operating speed at the time of re-operation of the acceleration operating member changes below the predetermined value, the engine rotational speed value or its increasing rate tends to decrease, and the engine output torque value or its increasing rate also decreases. At this time, the inertia torque at the stage preceding the fluid coupling is becoming smaller, so the operation amount of the acceleration operation member and the engagement time determination variable increasing means were increased at such time. The engagement shock can be reduced by engaging the lock-up clutch when the engagement time determination variable intersects, and the operation amount is indicated by disturbance of the operation amount of the acceleration operation member, noise, and the like. Engage the lock-up clutch at the right time based on overall peaks, even in operating conditions where multiple peaks are formed in the curve It can be. In addition, the engagement of the lock-up clutch is performed at a time when the engine rotation speed value or the rate of increase thereof tends to decrease, so that a change in the engine rotation speed due to the engagement is reduced, giving a sense of incongruity to the driver. Therefore, the engagement shock can be suppressed also in the sense.
In the present invention, as described above, the control is performed so that the lock-up clutch is engaged after the operation speed at the time of re-operation of the acceleration operation member changes below a predetermined value. After the start of the re-operation, the lock-up clutch is not engaged at a time when the operation is being further increased.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 schematically shows a main configuration of an embodiment of the present invention. In the figure, the operation speed Δθ _th of the acceleration operation member 4 detected by the operation speed detection means 2 is supplied to the determination means 6. In decision unit 6, whether the manipulation speed [Delta] [theta] _th is changed lower than a predetermined criterion value C _B is determined. In the engagement timing determining parameter increasing means 7, the period operating speed [Delta] [theta] _th is the criterion value C _B above, the predetermined value C _S lower engagement timing decision variable A is repeatedly calculated from the throttle valve opening theta _th with its only when calculated value a is a value of more than the calculated value of the previous engagement timing decision variables theta _thb is updated, lower period than the operating speed [Delta] [theta] _th judgment reference value C _B, the engaging timing decision variables theta _thb is increased at a constant rate C _D determined in advance. The operating speed [Delta] [theta] _th the determination unit 6 becomes lower than the criterion value C _B, and when the throttle valve opening theta _th engages timing decision variables theta _thb intersect, the lock-up by the engagement control means 8 The clutch is adapted to be engaged.

Next, the main configuration diagram will be described in more detail. Second
In the figure, the power of an engine 10 is a fluid coupling 12 with a lock-up clutch corresponding to the fluid coupling,
Belt-type continuously variable transmission corresponding to the transmission (hereinafter referred to as CVT
14, a drive theory 24 connected to a drive shaft 22 via a forward / reverse switching device 16, an intermediate gear device 18, and a differential gear device 20.
To be transmitted to

Fluid coupling 12 is the crankshaft of engine 10
26 and the pump shaft 28 of the CVT 14
0, a turbine impeller 32 that is rotated by receiving an oil flow from a pump impeller 28, a lock-up clutch 36 fixed to the input shaft 30 via a damper 34, and an engagement-side oil passage 37. An engagement-side oil chamber 33 and a release-side oil chamber 35 connected to the release-side oil passage 39 are provided. The inside of the fluid coupling 12 is always filled with hydraulic oil, and when the hydraulic oil is supplied to the engagement-side oil chamber 33 and the hydraulic oil flows out of the release-side oil chamber 35, the lock-up clutch 36 is engaged. As a result, the crankshaft 26 and the input shaft 30 are directly connected. Conversely, when the hydraulic oil is supplied to the release-side oil chamber 35 and the hydraulic oil flows out of the engagement-side oil chamber 33, the lock-up clutch 36 is released.

The CVT 14 has a primary variable pulley 40 and a secondary variable pulley 42 provided on its input shaft 30 and output shaft 38, respectively.
And a transmission belt 44 wound around the variable pulleys 40 and 42. The variable pulleys 40 and 42 are fixed rotating bodies fixed to the input shaft 30 and the output shaft 38, respectively.
46 and 48, and movable rotators 50 and 52 provided on the input shaft 30 and the output shaft 38 so as to be movable in the axial direction and not to rotate relatively around the axis, respectively.
Is moved by the primary hydraulic cylinder 54 and the secondary hydraulic cylinder 56 functioning as a hydraulic actuator, thereby changing the V-groove width, that is, the hanging diameter (effective diameter) of the transmission belt 44, and changing the speed ratio γ (= The rotation speed N _in of the input shaft 30 / the rotation speed N _out of the output shaft 38) are changed.

The forward / reverse switching device 16 is a well-known double pinion type planetary gear mechanism, and includes a pair of planetary gears 62 and 64 rotatably supported by a carrier 60 fixed to an output shaft 58 thereof and meshing with each other. Planetary gear 6 fixed to the input shaft (output shaft of CVT 14) 38 of the
2, a sun gear 66 meshing with 2, a ring gear 68 meshing with the planetary gear 64 on the outer peripheral side, a reverse brake 70 for stopping rotation of the ring gear 68, the carrier 60 and the input shaft 38 of the forward / reverse switching device 16 are connected. And a forward clutch 72 to be driven. The reverse brake 70 and the forward clutch 72 are friction engagement devices of a type operated by hydraulic pressure.
Is set to a neutral state, and power transmission is interrupted. However, when the forward clutch 72 is engaged, the output shaft 38 of the CVT 14 is
And the output shaft 58 of the forward / reverse switching device 16 are directly connected to transmit power in the forward direction of the vehicle. When the forward brake 70 is engaged, the output shaft 38 of the CVT 14 and the forward / reverse switching device 16
The rotation direction is reversed between the output shaft 58 and the output shaft 58, so that the power in the vehicle backward direction is transmitted.

A hydraulic pump 74 that is driven to rotate by the engine 10 is a hydraulic source of a hydraulic control circuit 76 shown in FIG. The hydraulic control circuit 76 is for controlling the vehicle power transmission device. For example, JP-A-62-196449, JP-A-64-49749, Japanese Patent Application No. 1-78784, Alternatively, the configuration is the same as that of the hydraulic control circuit described in Japanese Patent Application No. 1-333141. The hydraulic control circuit 76 includes a first solenoid valve 80 for controlling a shift direction control valve (not shown) and a second solenoid valve 82 for controlling a shift speed control valve (not shown). CV related to the ON / OFF operation state of the first solenoid valve 80
The change direction of the speed ratio γ of T14 is switched, and the second solenoid valve 8
Since the speed of change of the gear ratio γ is switched in relation to the on / off operation state of the second solenoid valve 2, the first solenoid valve 80 and the second solenoid valve 82
Depending on the combination of the operating states of, the rapid increase mode in which the gear ratio γ is quickly changed to the speed increasing side, the rapid deceleration mode in which the gear ratio γ is quickly changed to the reduced speed side, and the gear ratio γ is gradually changed to the increased speed side The slow acceleration mode and the slow deceleration mode for gradually changing the speed ratio γ to the deceleration side are respectively established, and between the rapid acceleration mode and the slow acceleration mode, and between the rapid deceleration mode and the slow deceleration mode. Target mode is 2nd
This is established by the duty drive of the solenoid valve 82.

Further, the hydraulic control circuit 76 is provided with a third solenoid valve 84 for controlling the engagement state of the lock-up clutch 36. Normally, when a predetermined condition in consideration of fuel efficiency and drivability is satisfied, for example, the vehicle speed v, the input shaft rotation speed
When it is determined that at least the vehicle speed v of N _in and the throttle valve opening θ _th is within a predetermined range, a lock-up operation command signal is output and the third solenoid valve 84 is output.
Is actuated to supply hydraulic oil to the engagement-side oil chamber 33 and to allow hydraulic oil to flow out of the release-side oil chamber 35. As a result, the lock-up clutch 36 is engaged, and the crankshaft 26 and the input shaft 30 are directly connected. Conversely,
When the vehicle speed v or the like becomes equal to or less than a predetermined value, the hydraulic oil is supplied to the release-side oil chamber 35 and the hydraulic oil flows out of the engagement-side oil chamber 33, so that the lock-up clutch 36 is released.

The electronic control unit 90 controls the first control in the hydraulic control circuit 76.
By driving the solenoid valve 80, the third solenoid valve 82, and the third solenoid valve 84, the gear ratio γ of the CVT 14 and the lock-up clutch 3
Control 6 and so on. The electronic control unit 90 includes a CPU 92, a ROM 94, an R
A so-called microcomputer comprising an AM96, an interface circuit (not shown), etc.
Vehicle speed sensor 102 that detects 24 circuit speeds, input shaft of CVT14
An input shaft rotation sensor 104 and an output shaft rotation sensor 106 for detecting rotation speeds of the output shaft 30 and the output shaft 38, respectively, are provided in an intake pipe of the engine 10 in a state of being mechanically connected to an accelerator pedal 107 as an acceleration operation member. A throttle valve opening sensor 108 for detecting the opening of the throttle valve, an operation position sensor 110 for detecting the operation position of the shift lever 100,
From a brake switch 112 for detecting operation of a brake pedal, a signal representing the vehicle speed v, a signal indicative of an input shaft rotational speed N _in the signal representing the output shaft speed N _out, a signal indicative of the throttle opening theta _th, signal representing the operating position P _s of the shift lever 100, a signal representative of a brake operation are supplied. The CPU 92 in the electronic control unit 90 processes an input signal in accordance with a program pre-stored in the ROM 94 while utilizing a temporary storage function of the RAM 96, and processes the first solenoid valve 80, the second solenoid valve 82, and the third solenoid valve. It outputs signals for driving 84 respectively.

The electronic control unit 90 executes gear ratio control for controlling the gear ratio γ of the CVT 14 and also executes lock-up clutch control for controlling the lock-up clutch 36.

The gear ratio control is executed, for example, according to a flowchart shown in FIG. In FIG. 3, after initialization is performed in a step (not shown), input signals and the like from the respective sensors are read in step S1, and the vehicle speed v and the rotation of the input shaft 30 are determined based on the read signals. Speed N _in , rotation speed N _{out of} output shaft 38
Is calculated. In the following step S2, the ROM 94
, The target input shaft rotation speed N _in ^* based on the actual throttle valve opening θ _th and the vehicle speed v ^.
Is calculated. This relationship is obtained in advance to operate the engine 10 on an optimal curve in consideration of fuel efficiency and drivability, for example. In the following step S3, the difference between the actual rotation speed N _in of the input shaft 30 and the target input shaft rotation speed N _in ^* , that is, the control deviation ΔN _in (= N _in ^* −N _in ) is calculated, and in step S4. In the above, the control deviation Δ
A control mode for eliminating N _in is selected. That is, the deviation ΔN _in the feedback control of the speed ratio γ
Becomes zero, in other words, the target input shaft rotation speed N _in
^* And actual input shaft speed N _in (= engine speed
N _e ) so that the transmission mode and duty ratio match
D _s2 is determined. Then, in step S5, such that the shift mode or the duty ratio D _s2 is obtained,
The first solenoid valve 80 and the second solenoid valve 82 is driven, it is the actual input shaft speed a rotational speed N _in to match the target rotational speed N _in ^* ratio γ is adjusted.

The engagement control of the lock-up clutch 36 is executed, for example, according to a flowchart in FIG. In FIG. 4, the latest throttle valve opening θ _th , the input shaft rotation speed N _in , and the vehicle speed v are read in a step (not shown), and _in step ST1, a flag XF
Is determined as to whether or not the content is “1”. This flag
XF indicates that the lock-up clutch 36 has been once engaged when the content is “1”. Initially, the content of the flag XF has been cleared to "0", so it is determined in steps ST2 and ST3 whether or not the engagement condition is satisfied. That is, in step ST2, the input shaft rotation speed N _in is determined in advance as the reference rotation speed f ₁ (θ
_th ) is determined, and in step ST3, it is determined whether the vehicle speed v is greater than or equal to a predetermined reference vehicle speed _Cv1 . If at least one of the determinations in steps ST2 and ST3 is denied, the process proceeds to step ST
7 is performed to maintain the disengagement state of the lock-up clutch 36, but if the determinations in steps ST2 and ST3 are both affirmative, the flag X is determined in step ST4.
After the content of F is set to “1” and the content of the engagement timing determination variable θ _thb is reset to zero in step ST14, the third solenoid valve 84 is switched to the lock-up clutch operating side in step ST15. The lock-up clutch 36 is engaged.

As described above, once the content of the flag XF is set to "1", in the next cycle, steps ST5 and subsequent steps are executed after step ST1. First, step 5 and S
At T6, it is determined whether the release condition is satisfied. That is, in step ST5, it is determined whether or not the input shaft rotation speed N _in is equal to or higher than a predetermined reference rotation speed f ₂ (θ _th ), and in step ST6, the vehicle speed v is set to a predetermined determination reference vehicle speed C. It is determined whether it is _v2 or more. If at least one of the steps ST5 and ST6 is negative, the content of the flag XF is reset to "0" in step ST7, and the lock-up clutch 36 is released in step ST19. The judgment reference rotation speeds f ₁ (θ _th ) and f ₂ (θ _th ) and the judgment reference vehicle speeds C _v1 and C _v2 are obtained in advance in consideration of fuel efficiency and drivability. Rotational speed f ₁ (θ _th ), f ₂ (θ
_th ) is, for example, a function shown in FIG.
C _v1 is a constant value of, for example, about 40 km / h, and C _v2 is a constant value of about 35 km / h.

However, if the determination in step ST5 and ST6 is affirmative together, whether the throttle valve opening theta _th is a predetermined release criterion value C _T or more in step ST8 is determined. This release determination reference value _CT is a determination reference value for releasing the lock-up clutch 36,
It is set to a small value close to 0%. Accelerator pedal
Since 107 is not yet re-operation, when the throttle valve opening theta _th is not greater than the release determination reference value C _T in step ST8, the lock-up clutch 36 is caused to release at step ST19. However, due to the re-operation of the accelerator pedal 107, as shown at point B in FIG.
When the throttle valve opening theta _th exceeds the release criteria value C _T,
When the determination in step ST8 is affirmed, the engagement shock prevention routine of step ST9 and subsequent steps is executed.

First, in step ST9, it is determined whether or not the lock-up clutch 36 is engaged (on). If the lock-up clutch 36 is in the engaged state, the steps S14 and subsequent steps are executed, and the engaged state of the lock-up clutch 36 is maintained. However, if it is determined not to be engaged in the lock-up clutch 36 in step ST9, at step ST10, the change rate [Delta] [theta] _th of the throttle valve opening theta _th is calculated from the following equation (1). Since the change speed Δθ _th of the throttle valve opening θ _th is the acceleration operation speed of the accelerator pedal 107, the above step ST10 corresponds to the operation speed detection means 2.

^{_{Δθ th = θ th -θ th -1}} ··· (1) Then, in step ST11, whether the change rate [Delta] [theta] _th of the throttle valve opening theta _th is equal to or less than the predetermined criterion value C _B is Is determined. The criterion value C _B is the inflection point of the throttle valve opening theta _th consecutive, is used to detect the upper peak point in the present embodiment, negative close to zero (C _B <
0) is used. Therefore, the above step ST11
Is of being judged that the operation speed of the accelerator pedal 107 ([Delta] [theta] _th) is changed lower than a predetermined criterion value C _B, corresponds to the decision means 6.

Immediately after re-operation start of the accelerator pedal 107 is, for example, as shown in FIG. 6, the rate of change of the throttle valve opening theta _th delta
Since _θth is a positive value, the determination in step ST11 is determined. Therefore, in step ST16, the initial value A of the engagement timing determination variable _θthb is calculated according to the following equation (2).

A = θ _th −C _s (2) where C _s is a constant value.

Next, in step ST17, it is determined whether or not the initial value A calculated in step ST16 is larger than the already determined engagement timing determination variable θ _thb . If the initial value A is equal to or _smaller than the engagement time determination variable θ _thb , step ST19 is executed to maintain the disengagement state of the lock-up clutch 36, but if the initial value A has already been determined, If it is determined that the _{value is} larger than the variable θ _thb , the content of the engagement timing determination variable θ _thb is updated to the initial value A in step ST18, and then the above-mentioned step ST19 is executed.
Therefore, in the peaks after the maximum peak, step ST
The determination in step 17 is denied, and the engagement timing determination variable θ _thb is not reset, and engagement control is performed based on the maximum peak value. That is, in the present embodiment, in step ST12 and steps ST16 to ST18, the operation speed Δθ _th is determined by the determination reference value C _B
During the above period, the throttle valve opening degree θ _th is a predetermined value
The engagement time determining variable A that is lower than C _s is repeatedly calculated, and the engagement timing determining variable θ _thb is updated only when the calculated value A is equal to or greater than the previous calculated value, and the operation speed Δθ _th becomes the determination reference value. lower period than C _B, the engaging timing determining variable θ
_thb corresponding to the engaging timing determining parameter increasing means 7 increases at a constant rate C _D defined in advance.

The operation amount of the accelerator pedal 107 when reducing a peak a predetermined value, the judgment of step ST11 is change rate [Delta] [theta] _th of the throttle valve opening theta _th is a negative value is positive. Point C in FIG. 6 shows this state. Therefore, step ST12 is executed, and the engagement timing determination variable θ _thb
Constant increment value C _D is added to. As a result, the engagement timing determination variable θ _thb is increased linearly as the control cycle is repeated. In step ST13, the curve representing the curved engaging timing decision variables theta _thb showing the throttle valve opening theta _th is whether it is greater than the engagement timing decision variables theta _thb, the throttle valve opening theta _th other words It is determined whether or not has crossed. Since still throttle opening theta _th just after the throttle valve opening theta _th showed a peak value is greater than the engagement timing decision variables theta _thb, the steps ST13
Is affirmative, the step ST19 is executed, and the disengagement state of the lock-up clutch 36 is maintained.

However, when the throttle valve opening theta _th is the time after a predetermined time has elapsed and a peak value, since the throttle valve opening theta _th is equal to or less than the engagement timing decision variables theta _thb, the determination in step ST13 is negative Therefore, step ST14 and subsequent steps are executed, and the lock-up clutch 36 is engaged. Point D in FIG. 6 shows this state. Also, the sixth
As shown by the two-dot chain line in the figure, after the time when the throttle valve opening _θth shows the peak value, even if the value at that time is substantially maintained, the lock operation is performed at the point E in FIG. The up clutch 36 is engaged. Thus the step ST13 is in the engagement of the lock-up clutch 36 after the [Delta] [theta] _th is determined to have changed less than the criterion value C _B in step ST11, in response to the engagement control means 8 I have.

As described above, according to the present embodiment, the accelerator pedal 10
After the [Delta] [theta] _th corresponding to the operation speed at the time of re-operation of the 7 that has changed less than a predetermined criterion value C _B is determined in step ST11, the lock-up clutch 36 is engaged. After the operation speed at the time of such re-operation of the accelerator pedal 107 is changed below a predetermined value, the engine
If the rotation speed value of 10 or its increase rate is on the decline,
Since the output torque value of the engine 10 or the rate of increase thereof is also in a period of decreasing tendency, the inertia torque in the preceding stage of the fluid coupling 12 is in a state of being reduced.
Is performed, the engagement shock is reduced. Further, since the engagement of the lock-up clutch 36 is performed at a time when the engine rotational speed value or the rate of increase thereof tends to decrease, the change in the engine rotational speed due to the engagement is reduced, and the driver feels uncomfortable. Since it is less likely to be given, it is possible to suppress the engagement shock also in the sense.

In the present embodiment, as described above, after the operation speed at the time of re-operation of the accelerator pedal 107 ([Delta] [theta] _th) is changed lower than a predetermined criterion value C _B, so the lock-up clutch 36 is engaged Therefore, the lock-up clutch 36 is not engaged at a time when the accelerator pedal 107 is being operated further after the re-operation of the accelerator pedal 107, and the engagement shock is suppressed at this point as well. .

Further, according to this embodiment, even if a plurality of peaks as shown in FIG. 7 a curve showing a throttle valve opening theta _th at the time of re-operation is formed, as described above, in ST17 and ST18, only when the contents of the engaging timing decision variables theta _thb is a value greater than the initial value a, since the engagement timing decision variables theta _th is updated, resetting the engagement timing decision variables theta _thb is the largest peak after peak _However , the engagement timing determination variable θ _thb determined based on the maximum peak value and the throttle valve opening θ _th
The engagement of the lock-up clutch 36 is performed at the intersection with the curve indicating. Therefore, even if a plurality of peaks are formed on the curve indicating the throttle valve opening degree θ _th due to disturbances in the operation amount, noise, and the like, the engagement control of the lock-up clutch 36 is appropriately performed based on the overall peak. It can be performed. In each section of FIG. 7, the conditions shown in FIG. 8 are satisfied, and the engagement timing determination variable θ _thb is determined. The engagement updated to the initial value A at the maximum peak time The engagement of the lock-up clutch 36 is determined based on the timing determination variable θ _thb .

Further, according to the present embodiment, since the engagement timing determination variable θ _thb is determined so as to be increased with time, the accelerator pedal 10 as shown by the two-dot chain line in FIG.
Even after the re-stepping of step 7, the engagement control of the lock-up clutch 36 can be appropriately performed even in an operation state in which the value is maintained.

Further, according to the present embodiment, the engagement of the lock-up clutch 36 is determined based on the intersection of the curve indicating the throttle valve opening degree θ _th and the curve indicating the engagement timing determination variable θ _thb as described above. Therefore, the more quickly the accelerator pedal 107 is returned, the sooner the lock-up clutch 36 is engaged, and the more slowly the accelerator pedal 107 is returned, the later the engagement timing of the lock-up clutch 36 is delayed, and Extremely desirable control can be obtained in terms of shock or discomfort given to the driver.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Criterion value C _B which is used in step ST11 in the foregoing example was negative, but than may be positive values are used. In this case, as shown in FIG.
Even if the slope after the inflection point of Δθ _th corresponding to the operation speed of the accelerator pedal 107 has a positive slope, the lock-up clutch 36
Can be performed. In this case, the engagement control of the lock-up clutch 36 is performed when the operation speed is decreased, not when the operation of the accelerator pedal 107 is returned, but this also provides the primal effect of the present invention. it can. Further, according to this embodiment, since the lock-up clutch 36 can be engaged relatively early, the fuel efficiency can be improved.

As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.

For example, in the above-described embodiment, the opening degree _{θth of the} throttle valve mechanically connected to the accelerator pedal 107 is used as the operation amount of the accelerator pedal 107, and the throttle valve opening rate is used as the operation amount speed of the accelerator pedal 107. Degree change rate Δθ _th was used, but the accelerator pedal 107
Replaced with an operation amount sensor for detecting an operation amount A _cc may be directly is used the operation amount A _cc and the operation speed .DELTA.A _cc, corresponding to the operation amount of the accelerator pedal 107, such as fuel injection amount Other amounts may be used.

In the above-described embodiment, the normal engagement control of the lock-up clutch 36 (steps ST1 to ST6) and the engagement control for eliminating the engagement shock (steps ST8 to ST18).
Are independently provided, but both the engagement condition of the lock-up clutch 36 in the normal engagement control and the engagement condition of the lock-up clutch 36 in the engagement control for canceling the engagement shock are both set. The lock-up clutch 36 may be configured to be engaged when satisfied. With this configuration, the effect of reducing the engagement shock can be obtained even when lock-up is executed for the first time after the vehicle starts moving.

The determination of the engagement or disengagement of the lock-up clutch 36 in step ST1 to ST6 of FIG. 4 described above has been performed based on the input shaft rotational speed N _in and the vehicle speed v, starting throttle valve theta _th and Other determination methods, such as making a determination based on the vehicle speed v, may be used.

Although the fluid coupling 12 with a lock-up clutch is used in the above-described embodiment, a torque converter with a lock-up clutch may be used.
In short, any fluid coupling with a lock-up clutch that transmits power via fluid may be used.

In the above embodiment, the target input shaft rotation speed N _in ^*
Actual Although the gear ratio as the input shaft rotational speed N _in is matched γ has been controlled, always such may not be feedback braking, the above target input shaft rotational speed N when
An open-loop control may be employed in which a control amount for obtaining _in ^* is determined according to a control expression stored in advance, and the speed ratio γ is adjusted in accordance with the control amount.

In the above embodiment, the target input shaft rotation speed N _in ^*
While feedback control of the gear ratio gamma has been performed by making a match the actual input shaft rotation speed N _in, γ ^*
= Because it is N _in ^{* /} N _out, determines a target gear ratio to replace the target input shaft rotational speed N _in ^{* γ *,} the target gear ratio gamma ^* the actual gear ratio transmission ratio to match the gamma gamma The control for adjusting is substantially the same.

The above is merely an example of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a main configuration diagram of an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the embodiment of FIG. 1 in detail. FIG. 3 is a flowchart illustrating a shift control operation of the electronic control device of FIG. FIG. 4 is a flowchart illustrating a lock-up clutch engagement control operation of the electronic control device of FIG. FIG. 5 is a diagram showing the relationship used in FIG. 6 and 7 are time charts showing the engagement operation obtained by the control operation of FIG. 4, respectively. FIG. 8 is a table showing the conditions for establishing each section in the time chart of FIG. FIG. 9 is a view corresponding to FIG. 6 in another embodiment of the present invention. 2: Operation speed detection means 4: Acceleration operation member 6: Judgment means 7: Engagement timing decision variable increasing means 8: Engagement control means 10: Engine 12: Fluid coupling (fluid coupling) 14: CVT (transmission) 36 : Lock-up clutch 107: Accelerator pedal (acceleration operating member)

Claims (1)

(57) [Claims] In a vehicle in which the output of an engine is transmitted to a transmission via a fluid coupling with a lock-up clutch, the lock-up clutch is released in response to the operation of the acceleration operation member being returned during traveling. A vehicle lock-up clutch control device for re-engaging the lock-up clutch in connection with the re-operation of the acceleration operation member, wherein the operation speed of the acceleration operation member is sequentially detected. Speed detecting means; determining means for determining that the operation speed has changed below a predetermined value; and a period in which the operation speed is equal to or higher than the predetermined value is lower than the operation amount of the acceleration operation member by a predetermined value. While repeatedly calculating the engagement time determination variable, the engagement time determination variable is updated only when the calculated value is equal to or greater than the previous calculation value,
During a period in which the operation speed is lower than the predetermined value, engagement time determination variable increasing means for increasing the engagement time determination variable at a predetermined constant speed; and And an engagement control means for engaging the lock-up clutch when the operation amount and the engagement time determination variable intersect with each other. Control device.