JPH0599331A - Hydraulic control device for hydraulic transmission with direct coupling clutch for vehicle - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a hydraulic control device for a hydraulic transmission with a direct coupling clutch for a vehicle, which suppresses fluctuations in engine speed due to a response delay of a control valve at the start of slip control. [Structure] A third solenoid valve 50 and a clutch switching valve 52 for switching the engagement state of the lockup clutch 32.
Independently of the above, a linear solenoid valve 54 and a slip control valve 56 for slip control of the lockup clutch 32 are provided, so that, for example, when the vehicle state shifts from the release region to the slip control region, clutch switching is performed. At the completion of the switching of the lockup clutch 32 from the released state to the engaged state by the valve 52, or before that, the slip control valve 56 controls the output pressure P of the linear solenoid valve 54.
_{Since the lin} can output the hydraulic pressure suitable for the slip control operation in advance, the fluctuation of the engine rotation speed at the start of the slip control is eliminated and the drivability is not impaired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control system for a hydraulic transmission having a direct clutch for a vehicle.

[0002]

2. Description of the Related Art In a vehicle equipped with a hydraulic transmission with a direct coupling clutch, such as a torque converter with a lockup clutch and a fluid coupling with a lockup clutch, for example, periodic torque fluctuations of the engine during low speed running of the vehicle are suppressed. A hydraulic control device that slips a direct coupling clutch in order to absorb is proposed. For example, it is the hydraulic control device described in Japanese Patent Laid-Open No. 1-98759. According to the hydraulic control device of this type, for example, an electromagnetic valve that generates a signal pressure by being duty-driven, and an engagement-side oil chamber and a release-side oil chamber of the fluid transmission in accordance with the signal pressure. And a direct coupling clutch control valve for controlling the pressure difference between the direct coupling clutch control valve and the direct coupling clutch control valve for controlling the engagement and disengagement states of the direct coupling clutch, or for improving the fuel consumption. The slip control is executed between and.

[0003]

SUMMARY OF THE INVENTION In the conventional hydraulic control device for a hydraulic transmission with a direct coupling clutch for a vehicle as described above, the running state of the vehicle is preset between the release region and the engagement region of the direct coupling clutch. When the condition of being located within the slip control area provided in is satisfied by the direct coupling clutch control valve so that the deviation between the actual slip rotational speed of the direct coupling clutch and the predetermined target slip rotational speed is eliminated. The pressure difference between the side oil chamber and the release side oil chamber is adjusted. However, for example, when the running state of the vehicle changes from the release region of the direct coupling clutch to the slip control region, the pressure difference is adjusted by the direct coupling clutch control valve controlled by one solenoid valve so as to eliminate the above deviation. Although it is started, since the pressure difference at the start of slip control becomes unstable due to the release of the valve element in the direct coupling clutch control valve or the response delay from the engagement position to the slip control position,
There is a disadvantage that the engine speed fluctuates and the drivability is impaired. That is, when slip control is started during acceleration of the vehicle, an increase fluctuation of the engine rotation speed occurs, and when slip control is started during coasting of the vehicle, a decrease fluctuation of the engine rotation speed occurs.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluid type with a direct coupling clutch for a vehicle in which the fluctuation of the engine speed due to the response delay at the start of slip control is suppressed. It is to provide a hydraulic control device for a transmission.

[0005]

In order to achieve such an object, the gist of the present invention is to provide a vehicle in which a direct coupling clutch is operated according to a pressure difference between an engagement side oil chamber and a release side oil chamber. In a hydraulic power transmission device with a direct coupling clutch for hydraulics, a hydraulic control device of the type that adjusts the slip amount of the direct coupling clutch by controlling the hydraulic pressure in the release side oil chamber. In response, a clutch switching valve device that switches the engagement state of the direct coupling clutch by supplying working oil to one of the release side oil chamber and the engagement side oil chamber and discharging the working oil in the other side,
(b) In response to the operation of the electromagnetic solenoid for slip control,
A direction to increase the pressure difference and a direction to decrease the pressure difference in order to control the hydraulic pressure in the release side oil chamber in a state where the clutch switching valve is switched to a position for discharging the hydraulic oil from the release side oil chamber. And a slip control valve device that is moved toward and.

[0006]

With this configuration, the clutch switching valve device that is switched in response to the operation of the electromagnetic solenoid for switching switches between engagement and disengagement of the direct coupling clutch, and also responds to the operation of the electromagnetic solenoid for slip control. The slip amount of the direct coupling clutch is adjusted by the slip control valve device which is operated and controlled.

[0007]

As described above, since the slip control valve device for slip control of the direct coupling clutch is provided independently of the clutch switching valve device for switching the engagement state of the direct coupling clutch, for example, in a vehicle. When the state changes from the release region to the slip control region, the slip control valve device can be operated at an independent timing for slip control. Therefore, the slip control valve device can be brought into a state suitable for the slip control operation at the completion of the switching of the direct coupling clutch from the released state to the engaged state by the clutch switching valve device or prior to the completion of the switching. The fluctuation of the rotation speed is eliminated and the drivability is not impaired.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a skeleton view of a vehicle power transmission device to which an embodiment of the present invention is applied. In the figure, the power of the engine 10 is transmitted to the drive wheels via a torque converter 12 with a lockup clutch 12, a stepped automatic transmission 14 including three sets of planetary gear units, and a differential gear device (not shown). It has become so.

The torque converter 12 is the engine 1
Pump impeller 18 connected to zero crankshaft 16
And a turbine impeller 22 fixed to the input shaft 20 of the automatic transmission 14 and rotated by receiving oil from the pump impeller 18, and a housing 26 which is a non-rotating member via a one-way clutch 24. Stator wheel 28
And a lock-up clutch 32 connected to the input shaft 20 via a damper 30. When the hydraulic pressure in the disengagement side oil chamber 33 is higher than that in the engagement side oil chamber 35 in the torque converter 12, the lockup clutch 32 is disengaged, so that the input / output rotational speed ratio of the torque converter 12 is reduced. The torque is transmitted at a corresponding amplification factor. However, when the oil pressure in the engagement-side oil chamber 35 is higher than that in the disengagement-side oil chamber 33, the lock-up clutch 32 is engaged, so that the input / output members of the torque converter 12, that is, the crankshaft 16 and the input. The shaft 20 is directly connected.

The automatic transmission 14 has three coaxially arranged parts.
Set of single pinion type planetary gear units 34, 36, 38
And an input shaft 20, an output gear 39 that rotates together with a ring gear of the planetary gear device 38, and a counter shaft (output shaft) 40 that transmits power between the differential gear device. Some of the components of the planetary gear units 34, 36 and 38 are not only integrally connected to each other, but also selectively connected to each other by three clutches C ₀ , C ₁ and C ₂ . Further, the planetary gear units 34, 36, 3
Some of the eight components are four brakes B ₀ , B ₁ , B
₂ and B ₃ are selectively connected to the housing 26, and further, some of the components are engaged with each other or with the housing 26 by their rotational directions by three one-way clutches F ₀ , F ₁ and F ₂ . It is supposed to be done.

The clutches C ₀ , C ₁ and C ₂ and the brakes B ₀ , B ₁ , B ₂ and B ₃ are provided with, for example, a multi-plate type clutch or one band or two bands whose winding directions are opposite to each other. It is configured by a band brake or the like and is operated by hydraulic actuators, respectively, and the operation of these hydraulic actuators is controlled by an electronic control unit 42, which will be described later, and is shown in FIG. As described above, four forward gears and one reverse gear with different gear ratios I (= rotational speed of the input shaft 20 / rotational speed of the counter shaft 40) are obtained. In FIG. 2, “1st”,
“2nd”, “3rd”, and “O / D (overdrive)” represent the forward first gear, second gear, third gear, and fourth gear, respectively. The gear ratio gradually decreases from the first variable gear to the fourth gear. Since the torque converter 12 and the automatic transmission 14 are configured symmetrically with respect to the axis, the lower side of the rotation axis of the input shaft 20 and the upper side of the rotation axis of the counter shaft 40 are shown in FIG. It is omitted.

The hydraulic control circuit 44 includes a shift control hydraulic control circuit for controlling the gear stage of the automatic transmission 14 and an engagement control hydraulic control for controlling the engagement of the lockup clutch 32. And a control circuit. As is well known, the hydraulic control circuit for gear shift control includes a first solenoid valve 46 and a second solenoid valve 48 that are turned on and off by solenoid No. 1 and solenoid No. 2, respectively. Valve 46 and second solenoid valve 4
2, the clutch and the brake are selectively operated to establish any one of the first to fourth speed gear stages.

Further, the engagement control hydraulic control circuit is
For example, as shown in FIG.
The signal pressure P for switching is turned on and off more_swGenerate
Third solenoid valve 50 and its switching signal pressure P_swAccording to
And a release side position where the backup clutch 32 is released.
Engagement-side position for engaging the lockup clutch 32
And a clutch switching valve 52 for switching between
Drive current I supplied from the device 42_solSliding corresponding to
Control signal pressure P_linGenerating linear solenoid valve 5
4 and the slip output from the linear solenoid valve 54
Control signal pressure P _linAccording to the engagement side oil chamber 35 and release
Adjust the pressure difference ΔP in the side oil chamber 33 to
The slip control valve 56 for controlling the slip amount of the switch 32
I have it. In the present embodiment, the third solenoid valve 50 and
The clutch switching valve 52 constitutes a clutch switching valve device, and
The linear solenoid valve 54 and the slip control valve 56 are
It constitutes a slip control valve device.

The hydraulic control circuit 44 is provided with a pump 60 for sucking and pumping hydraulic oil that has flowed back to a tank (not shown) through a strainer 58, and the hydraulic pressure pumped from the pump 60 is An overflow type first pressure regulating valve 62 regulates the first line hydraulic pressure Pl ₁ . The first pressure regulating valve 62 generates a first line pressure Pl ₁ that increases in accordance with the throttle pressure output from a throttle valve opening detection valve (not shown), and outputs it via a first line oil passage 64. Second pressure regulating valve 66
Is an overflow type pressure regulating valve, and is a first pressure regulating valve 6
By adjusting the hydraulic oil flowed out from the No. 2 on the basis of the throttle pressure, the second line pressure Pl ₂ corresponding to the output torque of the engine 10 is generated. Third pressure regulating valve 6
Reference numeral 8 is a pressure reducing valve which uses the first line pressure Pl ₁ as a source pressure and generates a constant third line pressure Pl ₃ . Further, the manual valve 70 generates the R range pressure P _R when the shift operation lever 196 is in the R range. And 0
The R valve 72 selects and outputs the higher one of the pressure P _B2 for activating the brake B ₂ and the R range pressure P _R which are engaged when the gear is in the second speed or higher.

The clutch switching valve 52 is provided in the release side oil chamber 3
3, the release side port 80 communicating with 3, the engagement side port 82 communicating with the engagement side oil chamber 35, the input port 84 to which the second line pressure Pl ₂ is supplied, the engagement side oil chamber when the lockup clutch 32 is released. 35, a first discharge port 86 for discharging the hydraulic oil in 35, a second discharge port 88 for discharging the hydraulic oil in the release side oil chamber 33 when the lockup clutch 32 is engaged, a second
A supply port 90 to which a part of the hydraulic oil discharged from the pressure regulating valve 66 is supplied for cooling during the engagement period of the lockup clutch 32, a spool valve element 92 for switching the connection state of these ports, and its spool. A spring 94 for urging the valve element 92 toward the off-side position, a plunger 96 arranged so as to be capable of contacting the end of the spool valve element 92 on the spring 94 side, and end surfaces of the spool valve element 92 and the plunger 96. An oil chamber 98 provided therebetween for applying the R range pressure P _R , and an oil chamber 100 receiving the first line pressure Pl _{1 applied} to the end surface of the plunger 96.
And an oil chamber 102 that receives the switching signal pressure P _sw in order to apply the switching signal pressure P _sw from the third solenoid valve 50 to the end surface of the spool valve element 92 to generate thrust toward the ON side position. Is equipped with.

In the non-excited state (OFF state), the third solenoid valve 50 blocks the communication between the oil chamber 102 and the OR valve 72 by the spherical valve element and makes the oil chamber 102 a drain pressure, but in the excited state (ON state). (State), the oil chamber 102 and the OR valve 72 are communicated with each other, and the switching signal pressure P _sw is applied to the oil chamber 102. Therefore, when the third solenoid valve 50 is off, the oil chamber 1
No switching signal pressure P _sw from the third solenoid valve 50 is applied to 02, and the spool valve element 92 is turned off in accordance with the biasing force of the spring 94 and the first line hydraulic pressure Pl ₁ acting on the oil chamber 100. Since the input port 84 and the disengagement side port 80 are communicated with each other and the engagement side port 82 and the first discharge port 86 are communicated with each other, the oil pressure P _off in the disengagement side oil chamber 33 is equal to the engagement side oil. At the same time as the lockup clutch 32 is released by being raised above the hydraulic pressure P _on in the chamber 35, the working oil in the engagement side oil chamber 35 is transferred to the first discharge port 86, the oil cooler 104, and the check valve 106. It is discharged to the drain through.

On the contrary, when the third solenoid valve 50 is on, the switching signal pressure P _sw from the third solenoid valve 50 is set.
Is applied to the oil chamber 102 and the spool valve element 92 is positioned at the on-side position against the biasing force of the spring 94 and the first line hydraulic pressure Pl ₁ acting on the oil chamber 100. Since the engagement side port 82, the release side port 80 and the second discharge port 88, and the supply port 90 and the first discharge port 86 are made to communicate with each other, the hydraulic pressure P _on in the engagement side oil chamber 35 is the release side oil chamber. pressure P is also increased from _off the lock-up clutch 32 in 33 at the same time is engaged, the discharge hydraulic fluid in the release side oil chamber 33 into the drain through the second discharge port 88 and the slip control valve 56 To be done.

The linear solenoid valve 54 is a pressure reducing valve whose source pressure is a constant third line pressure Pl ₃ generated by the third pressure regulating valve 68. As shown in FIG. The slip control signal pressure P _lin is generated that decreases as the drive current I _sol increases, and the slip control signal pressure P _{lin is applied} to the slip control valve 56. The linear solenoid valve 54 includes a supply port 110 to which the third line pressure Pl ₃ is supplied, an output port 112 for outputting a slip control signal pressure P _lin , a spool valve 114 for opening and closing them, and a spool valve 114 thereof. 116 for urging the valve in the valve opening direction and the drive current I _sol
Slip control electromagnetic solenoid 118 for urging spool valve 114 in the valve closing direction in accordance with
An oil chamber 1 for receiving a feedback pressure (slip control signal pressure P _lin ) for generating thrust in the valve closing direction
20, the spool valve element 114 is operated so that the urging force in the valve opening direction by the spring 116 and the urging force in the valve closing direction by the slip control electromagnetic solenoid 118 and the feedback pressure are balanced.

The slip control valve 56 includes a line pressure port 130 to which the second line pressure Pl ₂ is supplied, a receiving port 132 for receiving the hydraulic oil in the release side oil chamber 33 discharged from the second discharging port, and its receiving port 132. A drain port 134 for discharging the hydraulic oil received in the receiving port 132
And the receiving port 132 and the drain port 134 are communicated with each other to discharge the hydraulic oil in the release side oil chamber 33, so that the pressure difference ΔP between the engagement side oil chamber 35 and the release side oil chamber 33.
The direction toward the first position (the lower position in FIG. 3) that increases (= P _on −P _off ) and the receiving port 132 and the line pressure port 130 are communicated with each other to make the second inside the release side oil chamber 33. The spool valve element 136 movably provided in the direction toward the second position (upper position in FIG. 3) that reduces the ΔP by supplying the line pressure Pl ₂ and the spool valve element 136 are A plunger 138 abuttable on the spool valve element 136 to urge the spool valve element 136 toward the position, and the plunger 138 and the spool valve element 136.
A signal pressure oil chamber 140 that receives the slip control signal pressure P _lin in order to generate a thrust in a direction in which the plunger 138 and the spool valve element 136 are separated from each other by causing the slip control signal pressure P _lin to act on The plunger 138 is acted upon by the hydraulic pressure P _off in the release side oil chamber 33 to cause the plunger 138 to move the spool valve element 136 to its first position.
The hydraulic pressure P in order to generate thrust in the direction toward the position
an oil chamber 142 for receiving the _off, hydraulic pressure P _on in order to the spool 136 by the action of pressure P _on the engaging oil chamber 35 generates a thrust in a direction toward its second position to spool 136 Oil chamber 144 for receiving the oil and the signal pressure oil chamber 140, and the spool valve element 136 is
And a spring 146 for urging in the direction toward the position.

Here, the plunger 138 is formed with a first land 148 and a second land 150 having cross-sectional areas A ₁ and A ₂ which become smaller from the oil chamber 142 side, and a spool valve element 136. Includes a third land 152 having a cross-sectional area A ₃ from the signal pressure oil chamber 140 side and a fourth land 15 having a cross-sectional area A ₄ smaller than the cross-sectional area A _3.
Fourth and fifth lands 156 are formed. The cross-sectional areas of those lands have a relationship of A ₃ > A ₁ (= A ₄ )> A ₂ . Therefore, when the slip control signal pressure P _lin is relatively small and the relationship shown in Formula 1 is established, the plunger 138 abuts the spool valve element 136 and operates integrally with each other, and the slip control signal pressure P _lin. A pressure difference ΔP having a magnitude corresponding to is formed. At this time, the pressure difference Δ
P changes relatively gently in accordance with the slope [(A ₃ −A ₂ ) / A ₁ ] according to Expression 2 with respect to the slip control signal pressure P _lin . In Equation 2, F _s is the spring 1
46 is a biasing force.

[0021]

[Equation 1]

[0022]

[Equation 2]

However, when the slip control signal pressure P _lin becomes larger than the predetermined value P _A , the relationship shown in the equation 3 is established. This predetermined value P _A is a value that is predetermined so as to obtain a change range ΔP _SLP of the pressure difference ΔP that is sufficient for slip control of the lockup clutch 32, and is a slip control signal. The respective cross-sectional areas and the like are set so that the relationship shown in Formula 3 is established when the pressure P _lin reaches this value P _A. For this reason, the plunger 138 and the spool valve 136 are separated from each other, and the spool valve 136 is operated so that the equation 4 is established. However, in the state where the spool valve element 136 is operated so as to satisfy the equation 4, the slip control valve 56
Is set so that the receiving port 132 and the drain port 134 are communicated with each other, the hydraulic pressure P _off in the release side oil chamber 33 further decreases to atmospheric pressure, and therefore ΔP = P _on , The pressure difference is sufficient to allow full engagement.

[0024]

[Equation 3]

[0025]

[Equation 4]

The solid line in FIG. 5 indicates the pressure difference ΔP obtained by the operation of the slip control valve 56 constructed as described above.
The change characteristic of the slip control signal pressure P _lin is shown. The broken line in FIG. 5 shows the change characteristic of the pressure difference ΔP with respect to the slip control signal pressure P _lin in the conventional direct-coupling clutch control valve, and the slope is steeper than the solid line.

Returning to FIG. 1, the electronic control unit 42 displays the CP
A so-called microcomputer including a U182, a ROM 184, a RAM 186, an interface (not shown), and the like, in which a throttle sensor 18 for detecting a throttle valve opening provided in an intake pipe of the engine 10 is provided.
8, an engine rotation speed sensor 190 that detects the rotation speed of the engine 10, an input shaft rotation sensor 192 that detects the rotation speed of the input shaft 20 of the automatic transmission 14, and the automatic transmission 14
From a counter shaft rotation sensor 194 that detects the rotation speed of the counter shaft 40 and an operation position of the shift operation lever 196, that is, an operation position sensor 198 that detects one of the L, S, D, N, R, and P ranges. , A signal indicating the throttle valve opening θ _th , a signal indicating the engine rotation speed N _e (pump impeller rotation speed N _P , that is, the input side rotation speed of the lockup clutch 32), an input shaft rotation speed N _in (turbine impeller Rotational speed N _T , that is, a signal representing the output side rotational speed of the lockup clutch 32, output shaft rotational speed N
A signal indicating _out , the operation position P of the shift operation lever 196
A signal representing _s is supplied to each.
The CPU 182 of the electronic control unit 42 has a RAM 186.
The first solenoid valve 46 for processing the input signal according to the program stored in advance in the ROM 184 while executing the shift control of the automatic transmission 14 and the engagement control of the lockup clutch 32 while utilizing the temporary storage function of 2 Solenoid valve 4
8, the third solenoid valve 50, and the linear solenoid valve 54 are controlled respectively.

In the above shift control, a shift diagram corresponding to an actual shift gear is selected from a plurality of shift diagrams stored in advance in the ROM 184, and the running state of the vehicle, for example, the throttle valve opening is selected from the shift diagram. The gear shift stage is determined based on the degree θ _th and the vehicle speed calculated from the output shaft rotation speed N _out, and the first solenoid valve 46 and the second solenoid valve 48 are driven so that the gear shift stage is obtained. As a result, the operation of the clutches C ₀ , C ₁ , C ₂ and the brakes B ₀ , B ₁ , B ₂ , B ₃ of the automatic transmission 14 is controlled so that one of the four forward gears is established. To be made. Note that FIG.
Shows the shift speed in each shift range of the shift operation lever 196 and the operating states of the solenoid, the clutch, the brake, and the one-way clutch when the shift speed is established. The “x” marks represent the excited state and the non-excited state, respectively. In the columns of clutch and brake, the mark "○" represents the engaged state, and the mark "no" represents the disengaged state.
Further, the mark "○" in the column of the one-way clutch indicates that the engagement state is obtained at the time of forward drive, and the non-mark indicates the non-engagement state.

In the engagement control of the lock-up clutch 32, from the relationship shown in FIG. 6 stored in the ROM 184 in advance, the running state of the vehicle, for example, the output shaft rotation speed (vehicle speed) N.
_It is determined whether the lockup clutch 32 is in the disengagement region, the slip control region, or the engagement region based on _out and the throttle valve opening θ _th . This relationship is selected from a plurality of relationships stored in advance according to the actual gear stage. In FIG. 6, on the release region side of the boundary line between the engagement region and the release region and on the low throttle valve opening side, the coupling effect is maintained to improve fuel efficiency as much as possible without impairing drivability. A slip control region that absorbs torque fluctuations of the engine 10 is provided.

When it is determined that the running state of the vehicle is within the engagement area shown in FIG. 6, the third solenoid valve 50 is excited and the clutch switching valve 52 is turned on, and at the same time, the linear solenoid valve 54 is turned on. The drive current I _sol for the lockup clutch 3 is set to the minimum drive current (rated value).
2 are engaged. Further, when it is determined that the traveling state of the vehicle is within the disengagement region shown in FIG. 5, the third solenoid valve 50 is de-energized, the clutch switching valve 52 is turned off, and at the same time the linear solenoid valve 54 is operated. Drive current I
_{Since sol} is set to the maximum drive current value, the lockup clutch 32 is released. When it is determined that the traveling state of the vehicle is within the slip control area shown in FIG. 6,
At the same time when the third solenoid valve 50 is excited and the clutch switching valve 52 is turned on, the drive current I _sol for the linear solenoid valve 54 is adjusted according to, for example, Equation 5. That is, for example, the deviation ΔN (=) between the target slip rotation speed N _slip ^T in the steady state and the actual slip rotation speed N _slip (= N _e −N _T ) determined from the relationship shown in FIG.
The drive current I _sol for the linear solenoid valve 54 is calculated so that (N _slip −N _slip ^T ), and the drive current I _sol is output.

[0031]

[Equation 5]

In the above control, when it is determined that the running state of the vehicle has shifted from the release region to the slip control region, the third solenoid valve 50 is excited and the clutch switching valve 52 is turned on. At the same time, the drive current I _sol for the linear solenoid valve 54 is adjusted according to, for example, Equation 5, so that the slip control valve 56 drives the drive current I _sol.
The pressure difference ΔP between the engagement side oil chamber 35 and the disengagement side oil chamber 33 is adjusted so that the slip rotation speed N _slip corresponding to _sol is _achieved . Drive current I for the linear solenoid valve 54
Strictly speaking, the supply timing of _sol does not have to be the same as the excitation of the third solenoid valve 50, but at least the clutch switching valve 5
It is determined that the spool valve element 136 of the slip control valve 56 is in the slip control operating position at the start of the slip control before the completion of the switching of No. 2.

As described above, the hydraulic control circuit 4 of the present embodiment.
4, the clutch control valve 52 controlled by the third solenoid valve 50 switches the engagement and release of the lockup clutch 32, and the slip control valve 5 controlled by the linear solenoid valve 54 operates.
6, the slip amount of the lockup clutch 32 is adjusted. Thus, the linear solenoid valve 54 and the slip control valve for slip control of the lockup clutch 32 are independent of the third solenoid valve 50 and the clutch switching valve 52 for switching the engagement state of the lockup clutch 32. Since 56 is provided, the slip control valve 56 can be operated at an independent timing for slip control when, for example, the vehicle state changes from the release region to the slip control region. Therefore, when the switching of the lock-up clutch 32 from the released state to the engaged state by the clutch switching valve 52 is completed, or prior to this, the slip control valve 56 can output the hydraulic pressure suitable for the slip control operation in advance, so that the slip control is started. Fluctuations in engine speed over time are eliminated, and drivability is not impaired.

Further, according to the present embodiment, when the linear solenoid valve 54 is broken or otherwise malfunctions, the slip control signal pressure P _lin becomes the maximum value P _linmax, and the spool valve element 136 of the slip control valve 56 is released. Since the receiving port 132 and the drain port 134 are brought into communication with each other at the first position, the lockup clutch 32
Does not hinder the engagement operation of. Therefore, even when the linear solenoid valve 54 is broken or otherwise broken, the slip control is simply disabled and the engagement control of the lockup clutch 32 is not affected.

Next, another embodiment of the present invention will be described. In this embodiment, the same members as those in the above-mentioned embodiments are designated by the same reference numerals and the description thereof will be omitted.

In the above embodiment, the running state of the vehicle is as shown in FIG.
In the case of shifting from the release region to the slip control region, the drive current I adjusted so that the linear solenoid valve 54 obtains the target slip rotation speed N _slip ^T at the same time as the third solenoid valve 50 is excited. _{Although sol} was supplied, in the present embodiment, as shown by the diagonal lines in FIG. 8, it is on the release region side and the high throttle valve opening side of the boundary line between the slip control region and the release region. By newly providing the slip control preparation area, the linear solenoid valve 54 in the slip control preparation area becomes the size at the start of the slip control before the excitation of the third solenoid valve 50 in the slip control area. _Adjusted drive current I _sol
Is being supplied.

The relationship shown in FIG. 8 is selected when the actual gear position among a plurality of types is overdrive. Taking this FIG. 8 as an example, the relationship of the lockup clutch 32 in this embodiment is shown. The total control will be described in detail with reference to the flowchart of FIG.

First, in step S1, when a signal indicating the vehicle state such as the throttle valve opening θ _th , the output shaft rotation speed N _out , and the gear stage is read, in the subsequent steps S2 to S4, the actual throttle valve opening θ _th is
_A reference opening θ _A (N _out ) for control region determination, which is determined based on the actual output shaft rotation speed N _out from the relationship of FIG.
Whether or not it is smaller than θ _B (N _out ) and θ _C (N _out ) is sequentially determined. The above three reference openings θ _A (N _out ), θ
_{Of B} (N _out ) and θ _C (N _out ), θ _A (N _out )
Is a value on the boundary line (broken line in FIG. 8) between the release area and the slip control preparation area, and θ _B (N _out ) is on the boundary line between the slip control preparation area and the slip control area (dotted line in FIG. 8). , Θ _C (N _out ) is a value on the boundary line (solid line) between the engagement region and the slip control region. Therefore, the vehicle is in the traveling state in the engagement region when the determination in step S2 is affirmative, and the vehicle is in the slip control region when the determination in step S2 is negative and the determination in step S3 is affirmative. In the state, and when the determinations in steps S2, S3, and S4 are all denied, it means that the lockup clutch 32 is in the corresponding state in the following steps S5, S6, and S7, because it is the traveling state in the release region. Controlled. That is, the third solenoid valve 50 and the linear solenoid valve 54 are controlled in the same manner as in the above-described embodiment, so that the lockup clutch 32 is in the engaged state in step S5, in the slip operating state in step S6, and in step S7. It is released.

If the determinations in steps S2 and S3 are negative and the determination in step S4 is affirmative, it is determined that the vehicle is in the slip control preparation region and the slip control preparation control is executed in the following step S8. It In this slip control preparation control, the third solenoid valve 50 is turned off, and the linear solenoid valve 54 is based on the throttle valve opening θ _th and the vehicle speed SPD based on the pre-stored relationship shown in FIG. 10, for example. Based on the drive current I _sol determined by the above or the prestored relationship shown in FIG. 11, the engine torque T _e [= f (θ _th , N
_in )], the drive current I _sol determined based on The relationship between FIG. 10 and FIG. 11 is such that the drive current I _sol for bringing the spool valve element 114 of the linear solenoid valve 54 to the desired operating position at the start of slip control by feedback control is obtained, in other words, slip control. It is obtained in advance in consideration of the engine torque so that the moving distance of the spool valve element 114 at the time of shifting from the preparation area to the slip control area is as small as possible. The relationship shown in FIG. 10 is one of a plurality of types stored in advance, and is selected according to the actual gear stage.

Therefore, in the present embodiment, when the vehicle state changes from the release region to the slip control region, the slip control preparation control is executed prior to the slip control, so that the third solenoid valve 50 is excited. Prior to, the drive current I adjusted to have the magnitude at the start of slip control
_{Since sol} is supplied to the linear solenoid valve 54, even if a slight response delay occurs in the linear solenoid valve 54 or the slip control valve 56 due to a change in the viscosity of the hydraulic oil, clogging of dust, or the like, When the slip control is started, the slip control valve 56 is surely set to the slip control position before the completion of the switching of the clutch switching valve 52. Therefore,
According to this embodiment, it is possible to reliably prevent the drivability from being impaired due to the fluctuation of the engine rotation speed at the start of the slip control.

The slip control preparation region of this embodiment is set to a relatively narrow region along the boundary of the slip control region on the release region side. As compared with the case where I _sol is constantly adjusted to a value in the slip control region, it is possible to preferably prevent the durability of the slip control electromagnetic solenoid valve 118 from decreasing and the inconvenience caused by heat generation.

Also, when the clutch switching solenoid valve and the slip control solenoid valve are simultaneously switched to the slip control operation when the state of the vehicle shifts from the release region to the slip control region, depending on the structure of the valve, The controllability may not be sufficiently obtained due to the response delay of the slip control solenoid valve. When the control of the present embodiment is applied to the hydraulic control circuit configured by the solenoid valve having such characteristics, as shown in FIG. 12, the conventional control in which the slip control preparation area is not provided is used. In comparison, since the response time from the start of the slip control to the actual slip state of the lockup clutch 32 by the slip control valve 56 is significantly shortened, high controllability of the slip control can be obtained. There are advantages.

Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other modes. For example, in the above-described embodiment, the clutch switching valve 52
Is operated by the switching signal pressure P _sw from the third solenoid valve 50 acting on the spool valve element 92, and the slip control valve 56 causes the spool valve element 154 to slip from the linear solenoid valve 54. Control signal pressure P
_The clutch switching valve 52 and the slip control valve 5 were operated by the action of the _lin.
6, the spool valve elements 92 and 114 may be configured to be directly driven by two electromagnetic solenoids, respectively.

In the above-described embodiment, the slip control signal pressure P _lin is output from the linear solenoid valve 54, but is connected to an oil passage for guiding the third line pressure Pl ₃ via a throttle, for example. It may be generated by providing an electromagnetic on-off valve that opens and closes between the drain and the downstream side of the throttle and by duty-driving the electromagnetic on-off valve.

Further, in the above-mentioned embodiment, the stepped planetary gear type automatic transmission 14 is provided at the rear stage of the torque converter 12, but it may be a continuously variable transmission.

Although the torque converter 12 with the direct coupling clutch has been described in the above embodiment,
It may be a fluid coupling with a direct coupling clutch.
In short, it is sufficient if it is a fluid transmission having a direct coupling clutch.

The above description is merely an embodiment of the present invention, and the present invention can be modified in various ways without departing from the spirit of the invention.

[Brief description of drawings]

FIG. 1 is a diagram showing a vehicle power transmission device to which a hydraulic control device according to an embodiment of the present invention is applied.

FIG. 2 is a table for explaining a relationship between a combination of operations of a first solenoid valve and a second solenoid valve and a shift speed obtained by the combination in the automatic transmission provided in the hydraulic transmission device of FIG.

FIG. 3 is a diagram illustrating a configuration of a main part of the hydraulic control circuit of FIG.

FIG. 4 is a diagram showing output characteristics of the linear solenoid valve of FIG.

5 is a characteristic of a slip control valve provided in the hydraulic control circuit of FIG. 3, illustrating a relationship between a pressure difference ΔP between an engagement oil chamber and a release oil chamber and a slip control signal pressure P _lin. FIG.

6 is a diagram showing a relationship between a running state of the vehicle and an engaged state of a lockup clutch, which is stored in the electronic control unit of FIG.

FIG. 7 is a diagram showing a relationship stored in the electronic control unit of FIG. 1 for determining a target slip rotation speed in a steady state.

FIG. 8 is a view corresponding to FIG. 6 in another embodiment of the present invention.

9 is a flowchart for explaining engagement control of the lockup clutch that is executed based on FIG.

FIG. 10 is a diagram showing relationships used during control according to FIG. 9.

FIG. 11 is a diagram showing relationships used during control according to FIG. 9.

FIG. 12 is a time chart for explaining the control response of slip control by the control of FIG. 9 in comparison with the related art.

[Explanation of symbols]

 12 torque converter (fluid type transmission device) 32 lock-up clutch (direct coupling clutch) 33 release side oil chamber 35 engagement side oil chamber 44 hydraulic control circuit (hydraulic control device) 49 switching solenoid solenoid 50 third solenoid valve (clutch switching) Valve device) 52 Clutch switching valve 54 Linear solenoid valve (slip control valve device) 56 Slip control valve 118 Electromagnetic solenoid for slip control

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryuji Ibaraki 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Yoshikazu Tanaka 1 Toyota Town, Aichi Prefecture, Toyota Motor Corporation ( 72) Inventor Katsumi Kono 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A fluid transmission device with a direct coupling clutch for a vehicle, wherein a direct coupling clutch is operated according to a pressure difference between an engagement side oil chamber and a release side oil chamber, by controlling a hydraulic pressure in the release side oil chamber. A hydraulic control device of the type for adjusting the slip amount of the direct coupling clutch, which supplies hydraulic oil to one of the release side oil chamber and the engagement side oil chamber in response to the operation of a switching electromagnetic solenoid and the other In response to the operation of the clutch switching valve device that switches the engagement state of the direct coupling clutch by discharging the hydraulic oil in the inside, and the operation of the slip control electromagnetic solenoid, the clutch switching valve causes the hydraulic oil to flow from the release side oil chamber. In order to control the hydraulic pressure in the release side oil chamber in a state of being switched to the discharge position, it is moved in the direction of increasing the pressure difference and in the direction of decreasing the pressure difference. Hydraulic control device for fluids with a vehicular direct clutch transmission which comprises a lip control valve device.