JPH10122353A - Lock up control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release a lock up clutch device according to a speed shift and suppress generation of a shift shock when the device is again engaged thereafter. SOLUTION: This device has a lock up clutch device 24 for being engaged/ disengaged based on a pressure difference of engaging/disengaging side oil chambers RM2, RM1, hydraulic switch means for switching supply of hydraulic pressure to the engaging/disengaging side oil chamber RM2, RM1 based on a hydraulic control pressure setting a hysteresis region, hydraulic control pressure generation means generating a hydraulic control pressure, lock up control means 91 for adjusting the hydraulic control pressure to release the lock up clutch device 24 at the time of speed sift and engaging the lock up clutch device 214 after judging the shift end to set the hydraulic control pressure temporarily to a preset pressure out of a hysteresis region, and a delay means 93 for delaying switching of the oil pressure switch means. The lock up clutch device 34 is engaged in a completely released condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in an automatic transmission, rotation generated by an engine is transmitted to a transmission through a fluid transmission device, for example, a torque converter. To be communicated to. In the torque converter, a lock-up clutch device is provided, torque transmission is performed by fluid until the vehicle speed reaches a predetermined value, and when the vehicle speed reaches a predetermined value, the lock-up clutch device is engaged. Thus, the input side and the output side of the torque converter are directly connected, and the rotation of the engine is directly transmitted to the transmission.

For this purpose, an engagement-side oil chamber for engaging a lock-up clutch device in a torque converter,
A release-side oil chamber for releasing the lock-up clutch device is formed, and an on-pressure and an off-pressure are supplied to the engagement-side oil chamber and the release-side oil chamber, respectively. A lock-up relay valve is supplied to the lock-up control valve for switching between the on-pressure and the off-pressure, and a lock-up control valve for adjusting the secondary pressure to generate the on-pressure and the off-pressure. A linear solenoid valve is provided for each of the control hydraulic pressures.

When the vehicle is running with the lock-up clutch device engaged,
For example, in the case where the transmission shifts from the third speed to the fourth speed, a shift shock occurs due to a change in the engine speed associated with the shift, a vibration due to a torque fluctuation during the shift, and the like. Therefore, a lock-up control device for an automatic transmission is provided, and when performing a shift from the third speed to the fourth speed, the lock-up clutch device is not operated until the shift is started after the shift output of the 3-4 shift is generated. The engagement force is reduced, the lock-up clutch device is completely released from the time when the shift is determined to the time when the shift end is determined, and the lock-up clutch device is re-engaged after the shift is determined. I have.

Therefore, a change in the engine speed due to a gear shift, a vibration due to a torque fluctuation during the gear shift, and the like are absorbed by the torque transmission by the fluid, and the occurrence of a gear shift shock is suppressed (Japanese Patent Laid-Open No. 6-147309). Reference). Also, after the shift from the third gear to the fourth gear is completed,
There is provided a lock-up control device for an automatic transmission in which when the lock-up clutch device is re-engaged, the off-pressure is gradually reduced to suppress the occurrence of a shift shock (Japanese Patent Application Laid-Open No. H7-1995). -91533).

In this case, the lock-up relay valve is locked up in order to prevent a delay in response to switching of the lock-up relay valve and to effectively use the pressure adjustment region of the solenoid pressure of the linear solenoid valve. A hysteresis region is set for the solenoid pressure for switching between the engagement side and the release side of the clutch device. Then, after the shift is completed, in order to switch the lock-up relay valve to the engagement side, the linear solenoid valve is
The solenoid pressure is temporarily increased to a first set pressure outside the hysteresis area and switched to the engagement side, and the lock-up relay valve is reduced to a second set pressure in the hysteresis area where the lock-up relay valve does not switch to the release side. Then, the off-pressure is gradually reduced by gradually increasing the solenoid pressure from the second set pressure.

[0007]

However, in the conventional lockup control device for an automatic transmission, the time from when the shift start is judged to when the shift end is judged, that is, when the shift time is short, Due to the response delay of the lock-up relay valve, lock-up control valve, linear solenoid valve, etc., the lock-up clutch device cannot be released during the shift time,
The solenoid pressure is increased to the first set pressure in a state where the lock-up clutch device is not completely released.

As a result, an extremely large engagement force is generated in the lock-up clutch device, and a shift shock occurs. FIG. 2 is a time chart showing the operation of a conventional lockup control device for an automatic transmission. In Figure, T _O is the output torque of the automatic transmission, N _E is engine speed as the input side speed of the torque converter, N _C1 is input rotational speed of the output rpm of the torque converter, P _S linear target value of the solenoid pressure generated by the solenoid valve, P _oN is turned pressure supplied to the engagement side oil chamber of the torque converter, P _{oF F} off pressure supplied to the disengagement hydraulic pressure of the torque converter, [Delta] P is oN pressure This is the pressure difference between P _ON and OFF pressure P _OFF .

[0009] As shown, the target value P _S 100
[%], The off-pressure P _OFF becomes 0, and the lock-up clutch device generates an engagement force proportional to the differential pressure ΔP. After the shift output has been allowed to occur, when a predetermined time has elapsed, it is the shift start determination, in the shift time the target value P _S is the 0%. Subsequently, the shift time is that to shift end judgment lapse, the target value P _S to the solenoid pressure to the first set pressure is first set value x1 (%)
After the elapse of the time Δt, the target value P _S is set to the second set value x2 [%] in order to set the solenoid pressure to the second set pressure.
To be.

[0010] Thereafter, in order to gradually increase the solenoid pressure, the target value P _S is gradually increased, it is 100 [%]. The off-pressure P _OFF is generated by operating a lock-up relay valve, a lock-up control valve, a linear solenoid valve, etc., so that the lock-up relay valve, the lock-up control valve, the linear solenoid If the valve or the like has a response delay, as can be seen from the figure, the off pressure P _OFF cannot be made higher than the on pressure P _ON during the shift time. Therefore, the lock-up clutch device is gradually released as the differential pressure ΔP decreases,
The lock-up clutch device cannot be completely released during the shifting time.

[0011] Subsequently, when the shift end judgment is, the target value P _S is the first set value x1 (%), although the solenoid pressure is raised to a first set pressure, the solenoid pressure rises min Only the off-pressure P _OFF decreases, the differential pressure ΔP increases, and the lock-up clutch device is engaged. In this case, the lock-up clutch device is engaged in a state in which the lock-up clutch device is not completely released, so that the output torque T _O fluctuates greatly and a shift shock occurs.

The present invention solves the above-mentioned problems of the lock-up control device of the conventional automatic transmission, and releases the lock-up clutch device with the shift, and then causes the shift shock when the clutch is re-engaged. It is an object of the present invention to provide a lockup control device for an automatic transmission that can suppress occurrence of the lockup.

[0013]

For this purpose, in the lock-up control device for an automatic transmission according to the present invention, an engagement-side oil chamber, a release-side oil chamber, and a hydraulic pressure and a release-side oil of the engagement-side oil chamber are provided. To the engagement-side oil chamber and the release-side oil chamber based on a control oil pressure having a lock-up clutch device that is disengaged and disengaged based on a pressure difference from the oil pressure of the chamber and a hysteresis area. Hydraulic pressure switching means for switching between supply and discharge of the hydraulic pressure between the engagement side and the release side, control hydraulic pressure generation means for generating the control hydraulic pressure, adjusting the control hydraulic pressure, and releasing the lock-up clutch device with the shift. A lock-up control unit that temporarily sets the control oil pressure to a setting pressure outside the hysteresis region, switches a hydraulic pressure switching unit to an engagement side, and engages a lock-up clutch device after a shift end determination is made; And a delay means for delaying the switching of pressure switching means.

In another lockup control device for an automatic transmission according to the present invention, the delay means sets the control oil pressure to a set pressure after a delay time has elapsed since the completion of the shift determination. In still another automatic transmission lock-up control device of the present invention, the engagement-side oil chamber, the release-side oil chamber,
A fluid transmission device having a lock-up clutch device that is disengaged based on a differential pressure between the oil pressure of the engagement-side oil chamber and the oil pressure of the release-side oil chamber, and a control oil pressure in which a hysteresis area is set. Hydraulic pressure switching means for switching between supply and discharge of hydraulic pressure to the engagement-side oil chamber and release-side oil chamber between the engagement side and the release side; control hydraulic pressure generation means for generating the control hydraulic pressure; and adjusting the control hydraulic pressure. And a lock-up control unit for disengaging the lock-up clutch device with the shift and thereafter engaging the lock-up clutch device when it is determined that the shift has ended before the set time has elapsed.

In another lockup control device for an automatic transmission according to the present invention, the engagement side oil chamber, the release side oil chamber, and the difference between the oil pressure of the engagement side oil chamber and the oil pressure of the release side oil chamber. A hydraulic power transmission device having a lock-up clutch device disengaged based on pressure, and supply and discharge of hydraulic pressure to the engagement-side oil chamber and the release-side oil chamber based on a control hydraulic pressure in which a hysteresis area is set. Hydraulic pressure switching means for switching between the engagement side and the disengagement side; control hydraulic pressure generation means for generating the control hydraulic pressure; adjusting the control hydraulic pressure; By setting the differential pressure between the oil pressure and the oil pressure in the release-side oil chamber to be small,
Lock-up control means for engaging after a shift end determination is made.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 3 is a conceptual diagram of the automatic transmission according to the first embodiment of the present invention, and FIG. 4 is a diagram illustrating an operation table of the automatic transmission according to the first embodiment of the present invention. In the figure, A is an automatic transmission,
The automatic transmission A includes a torque converter 50, a four-speed transmission mechanism 1, a speed reduction mechanism 51, and a differential device 52 as a fluid transmission device having the lock-up clutch device 24. The four-speed transmission mechanism 1, the speed reduction mechanism 5
A transmission is constituted by 1 and the differential device 52.

The four-speed transmission mechanism 1 has a planetary gear unit 12 formed by connecting a single planetary gear 10 and a dual planetary gear 11. The single planetary gear 10 includes a sun gear S1, a pinion P1, and a ring gear R1. The planetary gear 11 includes a sun gear S2, pinions P1 'and P2, and a ring gear R2. The sun gear S1 of the single planetary gear 10 and the sun gear S2 of the dual planetary gear 11 constitute an integral sun gear S. The pinions P1 and P1 'meshing with the sun gears S1 and S2, respectively, and the pinion P2 meshing with the ring gear R2 are all supported by a common carrier CR.

The input shaft 15 connected to the output side of the torque converter 50 is connected to the connecting member 16 via the first clutch C1, and connected to the sun gear S via the second clutch C2. Further, a third clutch C3 and a second one-way clutch F0 are disposed in parallel between the connecting member 16 and the ring gear R1, and a fourth clutch C0 is disposed between the connecting member 16 and the ring gear R2. You.

Further, the first brake B1 has a brake band 62, and the sun gear S is connected to the drum 63 disposed inside the brake band 62. Then, the ring gear R2 and the transmission case 1
7, the second brake B2 and the first one-way clutch F1 are arranged in parallel with each other. In addition, the carrier CR and an output gear 13 located substantially at the center of the four-speed transmission mechanism 1 are connected.

The speed reduction mechanism 51 has a counter shaft 54 rotatably supported by the transmission case 17.
The small gear 55 is fixed, and the large gear 53 and the output gear 13 are meshed with the small gear 55 and the ring gear 61 of the differential device 52, respectively. The differential device 52 includes a differential carrier 60, a differential pinion 56 rotatably supported by the differential carrier 60, and side gears 57a and 57b meshing with the differential pinion 56 on the left and right sides, respectively, and the ring gear 61 is fixed to the differential carrier 60. Then, front axles 59a, 59b are fixed to the side gears 57a, 57b, respectively. The front axles 59a and 59b are respectively connected to left and right drive wheels (not shown).

Next, the operation of the automatic transmission A will be described. As shown in FIG. 4, in the automatic transmission A having the above configuration, at the first speed (1ST), the first clutch C1 and the third clutch C3 are engaged, and the first one-way clutch F1 and the second one-way clutch F0 is locked. At this time, the rotation of the input shaft 15 is transmitted to the ring gear R1 via the first clutch C1 and the second one-way clutch F0.
1, the rotation of the ring gear R2 is prevented, so that the sun gear S is rotated, the carrier CR is greatly reduced, and the reduced rotation of the carrier CR is output from the output gear 13 as the first-speed rotation.

The rotation output from the output gear 13 is further reduced by a speed reduction mechanism 51, and is transmitted to each of the front axles 59 a, 5 a through a differential device 52.
9b. Then, in 2nd gear (2ND),
Clutch C1, third clutch C3, and first brake B1
Are engaged, and the second one-way clutch F0 is locked.

At this time, the rotation of the input shaft 15 is transmitted to the ring gear R1 via the first clutch C1, the third clutch C3 and the second one-way clutch F0, but the rotation of the sun gear S is prevented by the first brake B1. Therefore, the ring gear R2 is idled, the carrier CR is decelerated, and the rotation of the reduced carrier CR is output from the output gear 13 as the second speed rotation.

Next, at the third speed (3RD), the first clutch C1, the third clutch C3, and the fourth clutch C0 are engaged, and the first brake B1 is released. At this time, the rotation of the input shaft 15 is transmitted to the ring gear R1 via the second one-way clutch F0 and the third clutch C3 and to the ring gear R2 via the fourth clutch C0. The whole unit rotates together, and 3 rotations at the same rotation speed as the input shaft 15
It is output from the carrier CR as high-speed rotation.

Next, at the fourth speed (4TH), the first clutch C1, the fourth clutch C0, and the first brake B1 are engaged, and the third clutch C3 is released. At this time, the rotation of the input shaft 15 is transmitted to the ring gear R2 via the fourth clutch C0, but the rotation of the sun gear S is prevented by the first brake B1, so that the rotation of the ring gear R2 is transmitted to the ring gear R1. Carrier CR while spinning
And the speed of the carrier CR is output from the output gear 13 as the fourth speed rotation.

Next, the lock-up control device will be described. FIG. 1 is a control block diagram of a lock-up control device for an automatic transmission according to a first embodiment of the present invention, FIG. 5 is a schematic diagram of a hydraulic circuit according to the first embodiment of the present invention,
FIG. 6 is a time chart showing the operation of the automatic transmission lock-up control device according to the first embodiment of the present invention.

As shown in FIG.
Are a pump impeller 21, a turbine runner 22 and a stator 2 which constitute a torus together with the pump impeller 21.
3. The lock-up clutch device 24 and a damper device (not shown). And the engine (E /
G) The rotation of 71 is transmitted to the front cover 26 via the crankshaft 73, and further, the front cover 26
Is transmitted to the pump impeller 21 fixed to the pump impeller 21. In this case, when the pump impeller 21 rotates, the oil in the torus rotates in the torque converter 50 and circulates between the pump impeller 21, the turbine runner 22, and the stator 23 by centrifugal force.

When the pump impeller 21 has just started to rotate, for example, when the vehicle starts moving, the pump impeller 2
1 and the turbine speed difference between the turbine runner 22 is large,
The oil flowing out of the turbine runner 22 flows in a direction that hinders the rotation of the pump impeller 21. Therefore, a stator 23 is provided between the pump impeller 21 and the turbine runner 22, and the stator 23 assists the rotation of the pump impeller 21 when the rotation speed difference between the pump impeller 21 and the turbine runner 22 is large. Convert the oil flow to

When the rotation speed of the turbine runner 22 increases and the difference in rotation speed between the pump impeller 21 and the turbine runner 22 decreases, the stator 2
The oil hitting the front side of the third blade comes to hit the back side, and the flow of oil is hindered. Therefore, in order to rotate the stator 23 only in a certain direction, a one-way clutch 27 is provided on the inner peripheral side of the stator 23. Therefore, the oil comes into contact with the back side of the blades of the stator 23, and the stator 23 rotates spontaneously, so that the oil circulates smoothly.

As described above, the torque converter 50
When the rotational speed difference between the pump impeller 21 and the turbine runner 22 is large, it is operated as a torque converter to amplify the transmission torque, and when the rotational speed difference is small, it is operated as a fluid coupling. Next, the lock-up clutch device 24 will be described.

When the vehicle speed v reaches a predetermined value after the start of the vehicle, the lock-up clutch device 24 is engaged.
When the lock-up clutch device 24 is engaged, the rotation of the engine 71 is directly transmitted to the input shaft 15 of the transmission 14 without the intervention of oil, so that fuel efficiency can be improved. The lock-up clutch device 24 is operated by switching the supply and discharge of hydraulic pressure between an engagement side and a release side by a lock-up (L-up) relay valve 77 as a hydraulic pressure switching means, and the clutch plate 31 is operated. By moving the clutch plate 31 and the front cover 26 in the axial direction, the friction material 3
It is made to come and go through 0.

A release-side oil chamber RM1 is formed between the clutch plate 31 and the front cover 26, and an engagement-side oil chamber RM2 is formed between the clutch plate 31 and the turbine runner 22. Therefore, the hydraulic circuit 7
When the oil is supplied from the hydraulic circuit 6 to the release-side oil chamber RM1, the lock-up clutch device 24 is released. When the oil is supplied from the hydraulic circuit 76 to the engagement-side oil chamber RM2, the lock-up clutch device 24 Engaged. Although the friction material 30 is fixed to the clutch plate 31 in the present embodiment, it can be fixed to the front cover 26.

The lock-up clutch device 2
When the clutch 4 is engaged, the rotation of the crankshaft 73 is directly transmitted to the input shaft 15 via the front cover 26, the clutch plate 31, and the damper device. Next, the hydraulic circuit 76 for disengaging the lock-up clutch device 24 will be described.

The hydraulic circuit 76 has a lock-up (L-
up) relay valve 77, lock-up (L-up) connector
Control valve 78, and a linear valve
Solenoid valve (SLU) 79 and lock-up
A modulator valve 86 is provided. The lock appli
The Rey valve 77 is a member of the lock-up clutch device 24.
Locks up the right half position during the slip and slip control
The left half position is taken when the clutch device 24 is released.
Therefore, when the lock-up clutch device 24 is engaged,
The secondary leg supplied via the oil passage L-1.
Pressure P_SECIs connected to the engagement side oil chamber R via the oil passage L-2.
ON pressure P for M2_ONSupplied as a lock-up
When the switch device 24 is released, the oil is supplied through the oil passage L-1.
Secondary regulator pressure P_SECIs the oil passage L-3
Pressure P to the release side oil chamber RM1 _OFFSupplied as
It is.

During the slip control of the lock-up clutch device 24, the oil pressure from the release-side oil chamber RM1 is applied to the lock-up control via the oil passage L-3, the lock-up relay valve 77, and the oil passage L-6. It is supplied to a valve 78. The lock-up control valve 78 receives a solenoid pressure P _SLU as a control oil pressure from a linear solenoid valve 79 via an oil passage L-8,
The communication between the oil passage L-6 and the drain port d is controlled. Accordingly, the hydraulic pressure in the release-side oil chamber RM1 is controlled in accordance with the solenoid pressure P _SLU from the linear solenoid valve 79, and as a result, the engagement-side oil chamber RM2 and the release-side oil chamber RM1
Is controlled to perform slip control.

The linear solenoid valve 79 receives a slip control command signal SG from the lock-up control means 91.
In response to 1, to adjust the solenoid modulator pressure P _MOD supplied from the lock-up modulator valve 86 generates a solenoid pressure P _SLU, the said solenoid pressure P _SLU
Through the oil passage L-8.
7 and the lock-up control valve 78, respectively.

Furthermore, the lockup modulator valve 86 generates a solenoid modulator pressure P _MOD to adjust the line pressure P _L which is generated by the primary regulator valve (not shown), the oil passage the solenoid modulator pressure P _MOD L- 21, and is supplied to the linear solenoid valve 79 via the strainer 87 and the oil passage L-22.

[0038] Then, the engine 71 is controlled by an engine control unit (ECM) 81, the engine control device 81, the engine speed N _E, a throttle opening theta, and the oil temperature t _m in the torque converter 50 An ignition signal SG2 is generated based on the ignition signal SG2, and the engine 71 is controlled based on the ignition signal SG2. For this purpose, an engine speed sensor and a throttle opening sensor (not shown) are provided on the engine 71, and an oil temperature sensor 83 is provided on the torque converter 50, respectively.

Reference numeral 84 is provided on the input shaft 15,
Input side rotation speed N of the transmission 14 _C1Input times to detect
A speed sensor 85 is provided on the transmission 14 and
Speed that detects the vehicle speed v that is the output side rotation speed of the speed device 14.
It is a sensor. Also, the shift start determination of the transmission 14 is performed.
And the shift end determination is based on the input side rotational speed N._C1And output side times
It is performed by the ratio (gear ratio) with the number of turns.

When the vehicle is running with the lock-up clutch device 24 engaged, for example, when the transmission 14 shifts from the third speed to the fourth speed, the speed change is performed. change in the engine rotational speed N _E, shift shock occurs due to vibration or the like due to torque variation at the time of shifting. Therefore, the automatic transmission control device 8
0, a lock-up control means 91 is provided. When performing a shift from the third speed to the fourth speed, the lock-up control means 91 determines that the shift is in progress, that is, that the shift start is determined and then the shift end is determined. By this time, the lock-up clutch device 24 is completely disengaged, and the lock-up clutch device 24 is re-engaged after the completion of the shift determination.

Therefore, the engine speed N associated with the shift
Changes in _E , vibrations due to torque fluctuations at the time of gear shifting, and the like are absorbed by the torque transmission by the fluid, so that the occurrence of gear shift shock can be suppressed. In this case, in order to gradually lower the off-pressure P _OFF , it is necessary to gradually increase the solenoid pressure P _SLU supplied to the lock-up relay valve 77.
When the hysteresis region to the solenoid pressure P _SLU when switching the 7 is set, even if gradually increasing the solenoid pressure P _SLU in the hysteresis region, the off pressure P
_OFF does not gradually decrease, but suddenly decreases when it exceeds the hysteresis region.

Therefore, the lock-up control means 91
When the lock-up clutch device 24 is re-engaged, the solenoid pressure P _SLU is temporarily increased to a first set pressure exceeding the hysteresis region, and then decreased to a second set pressure within the hysteresis region. And the pressure is gradually increased from the second set pressure. However, if the shift time from when the shift start is determined to when the shift end is determined is short, the linear solenoid valve 79, the lock-up control valve 78, the lock-up relay valve 7
Due to a response delay of 7 or the like, the lock-up clutch device 24 cannot be released during the shift time, and the solenoid pressure P _SLU is increased to the first set pressure in a state where the lock-up clutch device 24 is not completely released. Will be done.

As a result, the lock-up relay valve 77
With the solenoid pressure P_SLUIs temporary
Off pressure P_OFFThere is a sudden drain port
d from the lock-up clutch device 24
Large engaging force is generated, causing a shift shock.
Would. Therefore, the delay of the automatic transmission control device 80
Means 93 is provided for the solenoid pressure P _SLUTo the first setting
Delay to increase pressure, lock-up relay valve
Lock-up by delaying the switching of the
The switching of the pre-lay valve 77 is delayed.
You.

[0044] In FIG. 6, P _S is a solenoid pressure P to be generated by the linear solenoid valve 79 (FIG. 1)
The target value of the _SLU , P _ON, is the on-pressure supplied to the engagement-side oil chamber RM2 of the torque converter 50, and P _OFF is the off-pressure supplied to the release-side hydraulic pressure RM1 of the torque converter 50.
As shown, when the target value P _S is 100 [%], off pressure P _OFF becomes 0, the lock-up clutch device 24 to the differential pressure ΔP between the ON pressure P _ON and OFF pressure P _OFF Generates a proportional engagement force.

[0045] Then, after the shift output has been allowed to occur, when a predetermined time has elapsed, is the shift start determination, in the shift time the target value P _S is the 0%. Subsequently, the delay means 93 starts counting the time of the timer when the shift start is determined, and when the delay time T1 elapses after the shift time is determined and the shift end is determined, the solenoid pressure P is set. the target value P _S to the _SLU to the first set pressure first
When the set value x1 [%] is reached and the time Δt further elapses, the target value P is set in order to set the solenoid pressure P _SLU to the second set pressure.
_S is set to the second set value x2 [%].

Thereafter, the lock-up control means 91
In order to gradually increase the solenoid pressure P _SLU, gradually increasing the target value P _S to 100 [%]. In this case, the off pressure P _OFF is determined by the linear solenoid valve 7.
9. Since the lock-up control valve 78, the lock-up relay valve 77, and the like are generated by operating the linear solenoid valve 79, the lock-up control valve 78, the lock-up relay valve 77, etc., a response delay occurs. Even if there is, as shown in the figure, the OFF pressure P _OFF during the elapse of the delay time T1
Can be sufficiently high, the ON pressure P _ON can correspondingly be lowered. Therefore, the off-pressure P _OFF can be made higher than the on-pressure P _ON during the elapse of the delay time T1, so that the lock-up clutch device 24 can be completely released.

[0047] Subsequently, the delay time T1 has elapsed, the target value P _S is the first set value x1 (%), the solenoid pressure P
_{The SLU} is raised to the first set pressure. In this case, since the lock-up clutch device 24 is engaged in a completely disengaged state, the output torque does not fluctuate greatly, and a shift shock is generated. This can be suppressed.

Next, a second embodiment of the present invention will be described. FIG. 7 is a time chart showing the operation of the automatic transmission lock-up control device according to the second embodiment of the present invention. In Figure, P _S is a solenoid pressure P to be generated by the linear solenoid valve 79 (FIG. 1)
The target value of the _SLU , P _ON, is the on-pressure supplied to the engagement-side oil chamber RM2 of the torque converter 50, and P _OFF is the off-pressure supplied to the release-side hydraulic pressure RM1 of the torque converter 50.

[0049] In this case, the delay means 93, the time count of the timer starts when the shift time has been to shift end judgment lapse, the target value P _S when the delay time T2 by the timer of the timer has passed the 1 Set value x1 [%]. Therefore, even if there is a response delay in the linear solenoid valve 79, the lock-up control valve 78, the lock-up relay valve 77, and the like, as shown in the figure, the off-pressure P _OFF is sufficiently increased while the delay time T2 elapses. it can be, the on pressure P _oN can correspondingly be lowered. As a result, the OFF pressure P _OFF can be made higher than the _ON pressure P _ON during the elapse of the delay time T2, so that the lock-up clutch device 24 can be completely released.

[0050] Subsequently, the delay time T2 has elapsed, the target value P _S is the first set value x1 (%), the solenoid pressure P
_{The SLU} is raised to the first set pressure. In this case, since the lock-up clutch device 24 is engaged in a completely disengaged state, the output torque does not fluctuate greatly, and a shift shock is generated. This can be suppressed.

If the members such as the lock-up relay valve 77, the lock-up control valve 78, and the linear solenoid valve 79 deteriorate with time, the time required to release the lock-up clutch device 24 changes. Since the time measurement of the timer is started when the shift end is determined, it is possible to eliminate the influence of the deterioration over time.

Next, a third embodiment of the present invention will be described. FIG. 8 is a time chart showing the operation of the automatic transmission lock-up control device according to the third embodiment of the present invention. In Figure, P _S is a solenoid pressure P to be generated by the linear solenoid valve 79 (FIG. 1)
The target value of the _SLU , P _ON, is the on-pressure supplied to the engagement-side oil chamber RM2 of the torque converter 50, and P _OFF is the off-pressure supplied to the release-side hydraulic pressure RM1 of the torque converter 50.

In this case, the lock-up control means 91
The target value P when the shift start is determined_STo 0%
And starts the timing of a timer (not shown).
The shift end judgment is made before the set time T3 elapses by
Determine whether or not the connection has been made. And the set time T3
If the shift end is determined before
P_STo the first set value x1 [%] (FIG. 7),
It is set to the second set value x2 [%]. The set time T3 has passed.
If it is determined that the shift has ended after passing,
As with the form, the solenoid pressure P_SLUTo the first set pressure
Target value P_STo the first set value x1 [%], and
When the time Δt has elapsed, the solenoid pressure P _SLUTo the second setting
Target value P for constant pressure_STo the second set value x2 [%]
I do.

Therefore, the linear solenoid valve 7
9, the lock-up control valve 78, there is a response delay in the lock-up relay valve 77 and the like, as shown in the figure, when the shift end judgment is up to the elapse of the set time T3, the target value P _S is the Since it is not set to 1 set value x1 [%], the output torque does not fluctuate greatly, and the occurrence of a shift shock can be suppressed.

Next, a fourth embodiment of the present invention will be described. FIG. 9 is a time chart showing the operation of the automatic transmission lock-up control device according to the fourth embodiment of the present invention. In Figure, P _S is a solenoid pressure P to be generated by the linear solenoid valve 79 (FIG. 1)
The target value of the _SLU , P _ON, is the on-pressure supplied to the engagement-side oil chamber RM2 of the torque converter 50, and P _OFF is the off-pressure supplied to the release-side hydraulic pressure RM1 of the torque converter 50.

[0056] In this case, the target value P _S is 100 [%]
, The off-pressure P _OFF becomes zero, and the lock-up clutch device 24 applies a differential pressure Δ between the on-pressure P _ON and the off-pressure P _OFF.
An engagement force proportional to P is generated. After the shift output has been allowed to occur, when a predetermined time has elapsed, is the shift start determination, the lock-up control unit 91, the target value P _S in the shift time to x3 (%). At this time, the target value P _S in the range of lock-up relay valve 77 is not switched to the engagement side, the lock-up control valve 78
To minimize drain off pressure P _{OF F} by, on pressure P
The differential pressure ΔP between the _ON pressure and the OFF pressure P _OFF is reduced, and the lock-up clutch device 24 is placed in the pseudo release state. As a result, a change in the engine speed due to the shift, a vibration due to a torque fluctuation during the shift, and the like can be absorbed by the torque transmission by the fluid, and the occurrence of a shift shock can be suppressed.

[0057] Then, the speed change completion determination, when a predetermined time has elapsed, the lock-up control unit 91, in order to gradually increase the solenoid pressure P _SLU, gradually increasing the target value P _S 100 [% ]. Therefore, there is a response delay in the linear solenoid valve 79, the lock-up control valve 78, the lock-up relay valve 77, etc., and as shown in the figure, the off-pressure P _OFF must be sufficiently increased before the shift end is determined. Even if you can not
Target value P _S when shift end judgment is the first set value x
Since it is not set to 1 [%] (FIG. 6), the output torque does not fluctuate greatly, and the occurrence of a shift shock can be suppressed.

The present invention is not limited to the above embodiment, but can be variously modified based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

[0059]

As described above in detail, according to the present invention, in a lock-up control device for an automatic transmission,
A fluid transmission device including an engagement-side oil chamber, a release-side oil chamber, and a lock-up clutch device that is disengaged and disengaged based on a pressure difference between a hydraulic pressure of the engagement-side oil chamber and a hydraulic pressure of the release-side oil chamber; Hydraulic pressure switching means for switching between supply and discharge of hydraulic pressure to the engagement-side oil chamber and the release-side oil chamber between the engagement side and the release side based on the control hydraulic pressure in which the hysteresis area is set, and generating the control hydraulic pressure Control hydraulic pressure generating means, adjust the control hydraulic pressure, release the lock-up clutch device with the shift, and after the shift end determination is made, temporarily set the control hydraulic pressure to a set pressure outside the hysteresis area to reduce the hydraulic pressure. It has a lock-up control means for switching the switching means to the engagement side and engaging the lock-up clutch device, and a delay means for delaying the switching of the hydraulic pressure switching means.

In this case, the lock-up control means releases the lock-up clutch device with the shift, and thereafter,
After the control oil pressure is temporarily set to a set pressure outside the hysteresis region, the lock-up clutch device is engaged, so that a change in engine speed due to a shift, vibration due to a torque fluctuation at the time of a shift, etc. Absorbed by transmission. Therefore, occurrence of a shift shock can be suppressed.

After the control oil pressure is temporarily set to a pressure outside the hysteresis region, the lock-up clutch device is engaged in a completely disengaged state. In addition, the occurrence of a shift shock can be further suppressed. In another lockup control device for an automatic transmission according to the present invention,
Further, the delay means sets the control oil pressure to a set pressure after a delay time has elapsed since the shift end was determined.

In this case, even if the time required to disengage the lock-up clutch device changes due to the deterioration of each member such as the hydraulic pressure switching means and the control hydraulic pressure generating means with the passage of time, it is determined that the shift end is determined. Since the measurement of the delay time is started, the influence of the deterioration over time can be eliminated. In another lockup control device for an automatic transmission according to the present invention, the engagement side oil chamber, the release side oil chamber, and the pressure difference between the oil pressure of the engagement side oil chamber and the oil pressure of the release side oil chamber are determined. A fluid transmission device having a lock-up clutch device which is disengaged and disengaged,
Hydraulic pressure switching means for switching between supply and discharge of hydraulic pressure to the engagement-side oil chamber and the release-side oil chamber between the engagement side and the release side based on the control hydraulic pressure in which the hysteresis area is set, and generating the control hydraulic pressure Control hydraulic pressure generating means, adjusting the control hydraulic pressure, releasing the lock-up clutch device with the shift,
And a lock-up control unit for engaging the lock-up clutch device when it is determined that the shift is completed before the set time elapses.

In this case, if the shift end is determined before the set time elapses, it means that the lock-up clutch device has not been completely released at the time when the shift end determination is made. Therefore, the lock-up clutch device is engaged without setting the control oil pressure to the set pressure outside the hysteresis region even if it is determined that the shift is completed. As a result, the output torque does not greatly fluctuate, and the occurrence of a shift shock can be suppressed.

In another lockup control device for an automatic transmission according to the present invention, the engagement side oil chamber, the release side oil chamber, and the difference between the oil pressure of the engagement side oil chamber and the oil pressure of the release side oil chamber. A hydraulic power transmission device having a lock-up clutch device disengaged based on pressure, and supply and discharge of hydraulic pressure to the engagement-side oil chamber and the release-side oil chamber based on a control hydraulic pressure in which a hysteresis area is set. Hydraulic pressure switching means for switching between the engagement side and the disengagement side; control hydraulic pressure generation means for generating the control hydraulic pressure; adjusting the control hydraulic pressure; By setting the differential pressure between the oil pressure and the oil pressure in the release-side oil chamber to be small,
Lock-up control means for engaging after a shift end determination is made.

In this case, when the shift start is determined, the lock-up clutch device is placed in a pseudo-disengaged state in which the lock-up clutch device is slightly engaged with a small differential pressure. Vibration or the like due to the torque fluctuation is absorbed by the torque transmission by the fluid. Therefore, occurrence of a shift shock can be suppressed.

Even if the lock-up clutch device is not completely disengaged before the shift end determination is made, the control hydraulic pressure is not set to the set pressure outside the hysteresis region when the shift end determination is made, so that the output The torque does not greatly fluctuate, and the occurrence of a shift shock can be further suppressed.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a lock-up control device for an automatic transmission according to a first embodiment of the present invention.

FIG. 2 is a time chart showing an operation of a conventional lockup control device for an automatic transmission.

FIG. 3 is a conceptual diagram of the automatic transmission according to the first embodiment of the present invention.

FIG. 4 is a diagram showing an operation table of the automatic transmission according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram of a hydraulic circuit according to the first embodiment of the present invention.

FIG. 6 is a time chart illustrating an operation of the lock-up control device for the automatic transmission according to the first embodiment of the present invention.

FIG. 7 is a time chart illustrating an operation of a lock-up control device for an automatic transmission according to a second embodiment of the present invention.

FIG. 8 is a time chart showing an operation of a lock-up control device for an automatic transmission according to a third embodiment of the present invention.

FIG. 9 is a time chart illustrating an operation of a lock-up control device for an automatic transmission according to a fourth embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 24 Lock-up clutch device 50 Torque converter 77 Lock-up relay valve 79 Linear solenoid valve 80 Automatic transmission control device 91 Lock-up control means 93 Delay means A Automatic transmission P _SLU solenoid pressure RM1 Release hydraulic pressure RM2 Engagement oil chamber T1 , T2 delay time T3 set time ΔP differential pressure

Claims (4)

[Claims] An engagement-side oil chamber, a release-side oil chamber, and a lock-up clutch device that is disengaged based on a pressure difference between a hydraulic pressure of the engagement-side oil chamber and a hydraulic pressure of the release-side oil chamber. A fluid transmission device, and a hydraulic pressure switching unit that switches supply and discharge of hydraulic pressure to the engagement-side oil chamber and the release-side oil chamber between an engagement side and a release side based on a control oil pressure in which a hysteresis area is set; Control hydraulic pressure generating means for generating control hydraulic pressure, adjusting the control hydraulic pressure, releasing the lock-up clutch device with the shift, and after determining that the shift is completed, temporarily reducing the control hydraulic pressure outside the hysteresis region. An automatic transmission, comprising: lock-up control means for switching a hydraulic pressure switching means to an engagement side by setting a pressure to engage a lock-up clutch device; and delay means for delaying switching of the hydraulic pressure switching means. No Backup control device. 2. The lock-up control device for an automatic transmission according to claim 1, wherein said delay means sets said control oil pressure to a set pressure after a delay time has elapsed since the shift end was determined. 3. An engagement-side oil chamber, a release-side oil chamber, and a lock-up clutch device disengaged based on a pressure difference between a hydraulic pressure of the engagement-side oil chamber and a hydraulic pressure of the release-side oil chamber. A fluid transmission device, and a hydraulic pressure switching unit that switches supply and discharge of hydraulic pressure to the engagement-side oil chamber and the release-side oil chamber between an engagement side and a release side based on a control oil pressure in which a hysteresis area is set; A control oil pressure generating means for generating a control oil pressure, adjusting the control oil pressure, disengaging the lock-up clutch device with the shift, and then, when it is determined that the shift end is completed before a set time elapses, lock-up is performed. And a lock-up control unit for engaging the clutch device. 4. An engagement-side oil chamber, a release-side oil chamber, and a lock-up clutch device that is disengaged based on a differential pressure between a hydraulic pressure of the engagement-side oil chamber and a hydraulic pressure of the release-side oil chamber. A fluid transmission device, and a hydraulic pressure switching unit that switches supply and discharge of hydraulic pressure to the engagement-side oil chamber and the release-side oil chamber between an engagement side and a release side based on a control oil pressure in which a hysteresis area is set; A control oil pressure generating means for generating a control oil pressure, and adjusting the control oil pressure to reduce a pressure difference between the oil pressure of the engagement side oil chamber and the oil pressure of the release side oil chamber with the lock-up clutch device in accordance with a shift. And a lock-up control unit that is put into a pseudo-release state and is engaged after a shift end determination is made.