JP3102122B2 - Hydraulic control device for automatic transmission for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art An automatic transmission having a fluid transmission with a lock-up clutch is provided, and the automatic transmission establishes a plurality of forward gears and a reverse gear by a combination of operations of a plurality of hydraulic friction engagement devices. A lock-up clutch switching valve for switching an engagement state of a lock-up clutch, and a common solenoid valve for supplying a signal to the lock-up clutch switching valve and generating a signal pressure for switching the lock-up clutch switching valve. Hydraulic control devices provided are known. For example, Toyota Motor Corporation A5
This is the hydraulic control circuit of the 40-type automatic transmission ("Toyota A540E, A540H Automatic Transaxle Hydraulic Circuit 1989 Model" 1988 Toyota Motor Corporation
(Issue No. ATH009U). In such a type of hydraulic control circuit, the engagement pressure is used as the base pressure of the solenoid valve by a hydraulic friction engagement device that is engaged when the automatic transmission is traveling forward at or above the second gear. Therefore, even if a failure occurs in the solenoid valve, the lock-up clutch is reliably released in the first gear of the automatic transmission, and the vehicle can be restarted.

[0003]

In the conventional hydraulic control apparatus as described above, the reverse gear for preventing the reverse gear from being established when the shift lever is operated to the reverse travel range during forward travel. It is conceivable to supply the control valve with a signal pressure from the solenoid valve controlled by the electronic control device, thereby controlling the reverse control valve to the blocking position. The electromagnetic valve used for controlling the engagement of the lock-up clutch can be shared for controlling the reverse control valve.

However, since the source pressure of the solenoid valve is the engagement pressure of the hydraulic friction engagement device that is engaged when the automatic transmission is traveling forward at or above the second speed, the shift lever moves backward. It is necessary to use other hydraulic pressure generated even when operated to the range as the base pressure of the solenoid valve in order to control the reverse control valve to the blocking position, and a relay valve for switching between two types of base pressure. However, there is a disadvantage that the configuration of the hydraulic control device becomes complicated and large. In particular, in the automatic transmission for FF driving, which has a lot of space restrictions, such inconvenience becomes remarkable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lock-up clutch for a lock-up clutch using a common solenoid valve without complicating the structure or increasing the size. An object of the present invention is to provide a hydraulic control device for an automatic transmission for a vehicle, which can perform joint control and control of a reverse control valve.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide an automatic transmission having a fluid transmission with a lock-up clutch, wherein the automatic transmission has a plurality of hydraulic friction devices. A lock-up clutch switching valve for switching an engagement state of the lock-up clutch in a vehicle in which a plurality of forward gears and a reverse gear are established by a combination of operations of an engagement device, and a lock-up clutch switching thereof A common solenoid valve that supplies a signal to the valve and generates a signal pressure for switching the valve. (A) The signal pressure from the solenoid valve causes the shift lever to move backward during forward running. A reverse control valve that is controlled to a position that prevents establishment of a reverse gear when operated to the travel range; and (b) the automatic transmission is at least First signal source pressure generating means for generating a first signal source pressure when the vehicle is in a forward gear or higher, and (c) a second signal source in a state where the automatic transmission is at least in a reverse gear. A second signal source pressure generating means for generating pressure, and (d) provided for controlling an operation timing of any one of the plurality of hydraulic friction engagement devices, wherein the automatic transmission is at a second gear or higher. (E) a timing control valve which is actuated in connection with switching to the forward gear
In response to a switching operation of the timing control valve, when the automatic transmission is at a forward gear speed equal to or higher than a second speed gear, the pressure is set as the source pressure supplied to the solenoid valve. Port switching means for selecting one signal source pressure and selecting the second signal source pressure as the source pressure when the automatic transmission is not at the forward gear or higher.

[0007]

With this configuration, the port switching means provided in the timing control valve responds to the switching operation of the timing control valve when the automatic transmission is in the forward gear higher than the second gear. The first signal source pressure is selected as the source pressure supplied to the solenoid valve, and when the automatic transmission is not in the forward gear stage higher than the second speed, the second signal source pressure is selected as the source pressure. Selected. For this reason,
The lock-up clutch switching valve, which is controlled to be switched when the vehicle is traveling forward, outputs from the solenoid valve a first signal source pressure generated when the automatic transmission is at least at the second forward speed or higher as a source pressure. It is controlled by the applied signal pressure.
The reverse control valve is controlled by a signal pressure output from the solenoid valve with the second signal source pressure generated at least in a state where the automatic transmission is in the reverse gear stage as a source pressure.

[0008]

As a result, even if a failure occurs in the solenoid valve, the lock-up clutch is reliably released in the first gear of the automatic transmission, and the vehicle can be restarted. Further, even if the shift lever is erroneously operated to the reverse range during forward running of the vehicle, establishment of the reverse gear is prevented by the reverse control valve. Thus, not only the lock-up clutch switching valve and the reverse control valve are controlled using the common solenoid valve, but also the port switching means for selecting the first signal source pressure and the second signal source pressure is provided by the existing timing control. Since it is provided on the valve, there is no need to newly install a relay valve for the selection, so that the hydraulic control circuit is simply configured and the increase in the size of the device is suitably suppressed. For this reason, it is particularly advantageous in an automatic transmission for FF drive, which has many space restrictions.

[0009]

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

[0010] The torque converter 12 is an engine 1
Pump wheel 18 connected to crankshaft 16
And a turbine wheel 22 fixed to the input shaft 20 of the automatic transmission 14 and rotated by receiving oil from the pump wheel 18, and fixed to 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 oil pressure in the release-side oil chamber 33 is higher than that in the engagement-side oil chamber 35 in the torque converter 12, the lock-up clutch 32 is disengaged. 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 release-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 is provided with a three-axis
Sets of single pinion type planetary gear sets 34, 36, 38
And a counter shaft (output shaft) 40 for transmitting power between the input shaft 20, an output gear 39 that rotates together with the ring gear of the planetary gear device 38, and the differential gear device. Some of the components of their planetary gear 34, 36, 38 is not only integrally connected to each other, are selectively connected to each other by three clutches _{C 0, C 1, C 2} . Further, the planetary gear units 34, 36, 3
Some of the eight components are the four brakes B ₀ , B ₁ , B
_2, B is selectively coupled to the housing 26 by _three further one-way clutch F ₀ part three components, F _1, mutually or housing 26 and engages by its rotational direction by the F ₂ It is made to be made.

The clutches C ₀ , C ₁ , C ₂ and the brakes B ₀ , B ₁ , B ₂ , B ₃ include, for example, a multi-plate clutch or one band or two bands whose winding directions are opposite to each other. It is constituted by band brakes and the like, and each of them is operated by a hydraulic actuator. The operation of each of the hydraulic friction engagement devices is controlled by the electronic control unit 42, and as shown in FIG. Speed ratio I (= rotational speed of input shaft 20 / counter shaft 4
Thus, four forward speeds and one reverse speed are obtained with different speeds. In FIG. 2, "1st", "2
"nd", "3rd", and "O / D (overdrive)" represent a first gear, a second gear, a third gear, and a fourth gear on the forward side, respectively. The gear ratio gradually decreases from the first gear stage to the fourth gear stage. 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 abbreviated. The electronic control unit 42 includes a CPU, ROM, RA
M, a so-called microcomputer comprising an interface (not shown), the throttle valve opening θ _th , the engine rotation speed _Ne (the pump wheel rotation speed N _P ), the input shaft rotation speed N _in (the turbine wheel rotation speed N _T ), based on the output shaft rotation speed N _out and the operating position P _sh of the shift lever 58, in addition to the above-described shift control for automatically shifting the shift gear, an accumulator back pressure control for reducing shift shock, a lock-up clutch. Lock-up clutch engagement control for switching the engagement state of the lock-up clutch 32, slip control of the lock-up clutch 32, and the like are executed.

A hydraulic control circuit 44 is provided for controlling the engagement of the lock-up clutch 32 and for controlling the gear position of the automatic transmission 14. As shown separately in FIGS. 3, 4, and 5, the hydraulic control circuit 44 includes a first solenoid valve 48 and a second solenoid valve which are turned on and off by solenoids No. 1 and No. 2, respectively. FIG. 2 is provided by a combination of the operations of the first solenoid valve 48 and the second solenoid valve 50.
As shown in FIG. 7, the clutch and the brake are selectively operated to establish any one of the first to fourth gears. The lock-up clutch 32 is opened or engaged by the operation of the third solenoid valve 52 driven by the solenoid No. 3. Also, the linear solenoid valve 5 driven by the linear solenoid SL.U
4, the slip control is executed in the half-engagement region of the lock-up clutch 32.
Then, by the linear solenoid valve 56 which is driven by a linear solenoid SL.N, the accumulator A _C1 of the clutch C ₁ backpressure of the accumulator A _C2 of the clutch C ₂ back pressure, the accumulator A _BO of the brake B ₀ back pressure, back pressure of the accumulator a _B2 of the brake B ₂ is adapted to be controlled respectively.

3, 4, and 5, the hydraulic oil pumped by a pump 60 rotated by the engine 10 is supplied by a first pressure regulating valve 62 of a relief valve type.
Based throttle pressure P _th which is supplied from the throttle opening degree detecting valve 64, a cutback pressure P _cb supplied from the cut-back valve 66, and a manual valve 68 interlocked with a shift lever 58 to the R range pressure P _R is supplied And the first line pressure P ₁₁ is generated. The first line pressure P _l1 is used as an engagement pressure of a hydraulic friction engagement device, and is controlled by a manual valve 68, a second solenoid valve 50, a 1-2 shift valve 70 and a 3-4 shift valve 74, First
The 2-3 shift valve 72 controlled by the solenoid valve 48, the S shift valve 76 that is switched in response to the operation of the shift lever 58 to the range below the S range, and the second gear stage below the S range is established. brake B ₂ of satisfied after brake B ₁ B1 orifice control valve 78 engaging pressure of the brake B ₂ is switched and increased in order to establish when to supply pressure in order to engage smoothly lock the brake B ₃ through such a low coast modulator valve 80, the second coast modulator valve 82 which applies regulating the supply pressure in order to engage smoothly lock the brake B ₁ for pressurizing the tone,
Each clutch C ₀ , C ₁ , C ₂ , brakes B ₀ , B ₁ , B
₂ and B ₃ . Reverse control valve 84
In order to prevent the establishment of the reverse gear when the shift lever 58 is erroneous to R range during forward traveling, intended for switching preferentially respectively to the side to release the clutch C ₂ and the brake B ₃ is there.

The manual valve 68 is switched in conjunction with the shift lever 58.
There in response to being operated R range, D range, S range, the L-range, R range pressure P _R, D range pressure P _D, S range pressure P _S, L range pressure P _L is generated. Among, the D range pressure P _D is caused to occur in the D range following the forward running range, S range pressure P _S is caused to occur in the S-range or less of the traveling range, L range pressure P _L is L
It is generated only when driving in the range.

The hydraulic oil flowing out of the first pressure regulating valve 62 is regulated by the second pressure regulating valve 86 in accordance with the throttle pressure P _th to generate a second line pressure P _l2 . This second
The line pressure P _l2 is supplied to the lock-up clutch switching valve 88 to operate the lock-up clutch 32. The lock-up clutch switching valve 88 causes the second line pressure P _l2 to act on the release-side oil chamber 33 in the torque converter 12 according to the signal pressure from the third solenoid valve 52, and to _operate in the engagement-side oil chamber 35. The clutch release side position (OFF side position in the figure) for draining the hydraulic oil through the oil cooler 90, the second line pressure P _{l2 is applied} to the engagement side oil chamber 35, and the hydraulic oil in the release side oil chamber 33 is removed. The position is switched to the clutch engagement side position (the ON side position in the drawing) to be drained through the slip control valve 92.

The slip control valve 92 is provided in a slip region provided between the engagement region and the release region to improve the fuel efficiency when the shift period of the automatic transmission 14 is within the shift period to reduce the shift shock. When the vehicle state enters,
By controlling the differential pressure between the release-side oil chamber 33 and the engagement-side oil chamber 35 according to the signal pressure from the linear solenoid valve 54, the slip amount of the lock-up clutch 32 is controlled to a predetermined amount.

The solenoid modulator valve 94, by regulating the first line pressure P _l1 a constant modulator pressure P _m, is supplied to the linear solenoid valves 54 and 56. Further, the modulator P _m is also supplied to the third solenoid valve 52 through the B1 orifice control valve 78. Accumulator control valve 9
6 adjusts the first line pressure P ₁₁ according to the signal pressure from the linear solenoid valve 56 as a base pressure,
Generate _b . The back pressure P _b is, the accumulator A _C1
, The back pressure chamber of the accumulator A _C2, the back pressure chamber of the accumulator A _BO , and the back pressure chamber of the accumulator A _B2 .

As shown in detail in FIG. 6, the B1 orifice control valve 78 is connected to the second coast modulator from the S shift valve 76 which is switched by the S range pressure P _S when the second gear stage below the S range is established. the hydraulic pressure P _B1S supplied to the brake B ₁ via the valve 82 and 2-3 shift valve 72 is intended to pass after the formation of the brake B _2, the brake B ₁ after engagement of the brake B ₂ It functions as a timing control valve to be engaged. B2 pressure P for actuating the brake B ₂ which is engaged in the second gear stage or more forward drive gear
_B2 is output from the 1-2 shift valve 70, is supplied to the brake B ₂ and the accumulator A _B2 through the aperture 100. In this supply process, when the differential pressure between the upstream side and the downstream side of the throttle 100 decreases, the B1 orifice control valve 78 is switched.

That is, as shown in detail in FIG.
The orifice control valve 78 is connected to the upstream port 1 connected to the upstream side of the throttle 100 in the oil passage for guiding the B2 pressure P _B2.
02 and the oil chamber 10 connected downstream of the throttle 100
4, an input port 106 to which the operating oil pressure P _B1S from the S shift valve 76 to be supplied to the brake B ₁ is input;
An output port 108 for outputting the operating oil pressure P _B1S toward the brake B ₁ , a spool valve 110 for opening and closing between the input port 106 and the output port 108, and a spool valve accommodated in the oil chamber 104. And a spring 112 for urging the valve 110 in the valve opening direction. As described above, the oil pressure on the upstream side and the downstream side of the throttle 100 is applied to both end surfaces of the spool valve element 110.
When the thrust in the valve closing direction based on the hydraulic pressure difference between the upstream side and the downstream side of 00 is greater than the thrust in the valve opening direction of the spring 112, the spool valve element 110 is positioned at the closed position. The valve 110 is now in its open position. Therefore, 1-2
Immediately after the shift valve 70 B2 pressure P _B2 is output, since between the input port 106 and output port 108 is closed, it engages the brake B ₂ is previously been operating oil supplied exclusively to the brake B ₂ but are engaged, the hydraulic pressure difference is small on the upstream side and the downstream side of the throttle 100 is increasing pressure within the brake B _2, engaged brake B ₁ and is opened between input port 106 and output port 108 It is done.

The B1 orifice control valve 78 has a plunger 11 provided so as to be in contact with a spool valve element 110.
And 4, R-range pressure port 116 R range pressure P _R for applying the end face of the plunger 114 is supplied
And the R range pressure P according to the position of the plunger 114.
_R and B2 pressure P _B2 to select the third solenoid valve 5
And a selection output port 118 for outputting to it as a source pressure of 2. The plunger 114, the R range pressure port 116, the selection output port 118, and the upstream port 102 serve to supply the source pressure of the third solenoid valve 52 to the B2 pressure P _B2 and R B in connection with the operation of the B1 orifice control valve 78.
It constitutes a port switching unit 120 for switching to any of the range pressure P _R. Therefore, the spool valve 11
When 0 is in the open position, the plunger 114 is not
, The B2 pressure P _B2 is selected as the source pressure of the third solenoid valve 52. But,
When the spool valve element 110 is in the closed position, the plunger 114 is so brought into a position below the position shown on the right side of FIG. 6, R range pressure P _R is selected as the source pressure of the third solenoid valve 52.

Therefore, when the automatic transmission 14 is at the second or higher gear during the forward running of the vehicle, the spool valve element 110 of the B1 orifice control valve 78 is moved to the open position. Since the plunger 114 is located at the upper position, the B2 pressure P _B2 is selected as the source pressure of the third solenoid valve 52. Thus, when a failure of the third solenoid valve 52 occurs, the first transmission of the automatic transmission 14
Lock-up clutch 3 in high gear and reverse gear
2 is reliably released, and the vehicle can be restarted.

[0023] However, while the shift lever 58 when it is operated to the R range, i.e. reverse drive range, the R range pressure P _R is supplied to the R-range pressure port 116, B
The 2 pressure P _B2 is not output from the 1-2 shift valve 70,
The upstream port 102 is set to the atmospheric pressure. Therefore, the plunger 114 is so moved to the lower side against the thrust based on the R range pressure P _R to the urging force of the spring 112, the R-range pressure port 116 and the selected output port 118 are communicated, R range pressure P _R is selected as the source pressure of the third solenoid valve 52. Accordingly, when the electronic control device 42 determines that the shift lever 58 has been operated to the R range during forward running of the vehicle, the electronic control device 42 turns on the third solenoid valve 52, and The output pressure P _sol3 of the third solenoid valve 52 is supplied to the oil chamber 122 of the reverse control valve 84. FIG. 7 shows the shift lever 58.
And the pressure at the selected output port 118 of the B1 orifice control valve 78. In the drawing, D ₁ , D ₂ , D ₃ and D ₄ are the first in the D range.
The first gear, the second gear, the third gear, and the fourth gear are shown.

The reverse control valve 84, as shown in FIG. 4, R range pressure P _R and R-range pressure port 124 is supplied, the clutch C ₂ for establishing the reverse gear and the R range pressure P _R and spool 128 for opening and closing the output port 126 to be supplied to the brake B _3, between them and the R-range pressure port 124 and the output port 126
A plunger 130 having a diameter larger than that of the spool valve element 128 and abutting on the spool valve element 128;
Spring 13 inserted between 8 and plunger 130
2, an oil chamber 134 provided between the spool valve element 128 and the plunger 130 to guide the D range pressure P _D, and an oil chamber 136 to guide the C2 pressure PC ₂ acting on the end face of the plunger 130. I have. For this reason, usually, regardless of the position of the plunger 130, the spool valve 128
, The R range pressure port 124 and the output port 126 are communicated with each other, and a state where the reverse gear can be established with the generation of the R range pressure is established. However, the output pressure P of the third solenoid valve 52 is applied to the oil chamber 122.
When _sol3 is supplied, spool valve element 128 is caused to position the position shown in the upper side of FIG. 4, the output port 126 is communicated with the drain port 138, the engagement of the clutch C ₂ and the brake B ₃ and the automatic transmission This prevents the reverse gear of the machine 14 from being established.

As described above, according to this embodiment, the port switching means 120 provided in the B1 orifice control valve 78 functioning as a timing control valve responds to the switching operation of the B1 orifice control valve 78, When the automatic transmission 14 is in the forward gear stage higher than the second gear stage, the B2 pressure P as the base pressure supplied to the third solenoid valve 52
_{When B2} (first signal source pressure) is selected and the automatic transmission 14 is in the reverse gear, the R range pressure P is used as the source pressure.
_R (second signal source pressure) is selected. For this reason, the lock-up clutch switching valve 88, which is controlled to be switched when the vehicle is traveling forward, uses the B2 pressure P _B2 generated when the automatic transmission 14 is in the forward gear speed higher than the second gear speed as the base pressure. It is controlled by the signal pressure P _sol3 output from the three solenoid valves 52. Also, reverse control valve 84, the automatic transmission 14 is controlled by the signal pressure P _SOL3 outputted from the third solenoid valve 52 as a source pressure to reverse gear and is caused to occur while the R range pressure P _R. In this embodiment, the B2 pressure P _B2
It is 1-2 shift valve 70 to generate a function as a first signal based on pressure generating means, the manual valve 68 to generate the R range pressure P _R is functioning as a second signal based on pressure generating means.

Therefore, even if a failure of the third solenoid valve 52 occurs, the lock-up clutch 3 remains in the first gear.
2 is reliably released, and the vehicle can be restarted.
Further, during forward running of the vehicle, the shift lever 58
Even if it is operated to the range, the electronic control unit 42 _supplies the signal pressure P _sol3 from the third solenoid valve 52 to the reverse control valve 84, thereby preventing the reverse gear from being established. Thus, not only the lock-up clutch switching valve 88 and the reverse control valve 84 is controlled using a common third solenoid valve 52, the port switching unit to select the B2 pressure P _B2 and R range pressure P _R 120 Is provided in the B1 orifice control valve 78 in the conventional hydraulic circuit, so there is no need to newly install a relay valve for the selection, so that the hydraulic control circuit is simply configured,
An increase in the size of the device is suitably suppressed.

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

8, 9, and 10, the reverse control valve 84 is configured in the same manner as in the above-described embodiment, but the oil chamber 136 is open to the atmosphere. Further, the B1 orifice control valve 78 of this embodiment is configured as shown in FIG. That is, the B1 orifice control valve 78 of this embodiment is connected to the input port 1 similarly to the above-described embodiment.
06, and a spool valve 110 that opens and closes between the output port 108 and the thrust force generated by the pressure difference between the upstream port 102 and the oil chamber 104 and the thrust of the spring 112. It is made to operate by.

However, the port switching means 120 provided in the B1 orifice control valve 78 is different from the above-described embodiment. That is, the modulator pressure port 140 constant modulator pressure P _m pressure regulated by the solenoid modulator valve 94 is supplied is provided newly, plunger 114, upstream port 1 in its upper position
02 to the selected output port 118
2 pressure P _B2 (the first signal source pressure) is outputted as the source pressure of the third solenoid valve 52, the modulator pressure P _m (second by communicating the modulator pressure port 140 to the selected output port 118 at its lower position Signal source pressure) to the third solenoid valve 5
Output as the original pressure of 2. In this embodiment, the solenoid modulator valve 94 functions as the second signal source pressure generating means.

When the electronic control unit 42 determines that the shift lever 58 has been operated to the reverse range during forward running of the vehicle, the reverse control is _performed by the signal pressure P _sol3 having the modulator pressure P _m as the original pressure. Valve 84
Is switched to the reverse blocking side, so that the same operation and effect as in the above-described embodiment can be obtained. Moreover, according to the present embodiment,
The relatively low modulator pressure P _m than in place of the R range pressure P _R, which is set at a higher pressure third solenoid valve 52
This is advantageous in that the pressure resistance structure of the third solenoid valve 52 does not need to be changed.

Although the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the above embodiment, the third
Although the B2 pressure P _B2 is used as the first signal source pressure of the solenoid valve 52, the port switching means 1 is switched when the automatic transmission 14 is in a forward gear higher than the second gear.
Since the original pressure is supplied to the third solenoid valve 52 through 20, a pressure generated when the automatic transmission 14 is at least in the second forward gear or higher, for example, the line pressure P ₁₁ is used. It may be.

Further, in the illustrated embodiments, the R range pressure P _R and the modulator pressure P _m is used as the second signal source pressure of the third solenoid valve 52, the automatic transmission 14 is at least a reverse gear The pressure generated when a stage is selected, for example the line pressure _P11, may be used.

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

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a vehicular automatic transmission to which an embodiment of the present invention is applied.

FIG. 2 is a table illustrating a shift operation of the automatic transmission of FIG. 1;

FIG. 3 is a diagram showing a hydraulic control circuit for controlling the automatic transmission shown in FIG. 1 together with FIGS. 4 and 5;

FIG. 4 is a diagram showing a hydraulic control circuit for controlling the automatic transmission of FIG. 1 together with FIGS. 3 and 5;

FIG. 5 is a diagram showing a hydraulic control circuit for controlling the automatic transmission of FIG. 1 together with FIGS. 3 and 4;

6 is a diagram showing the configuration of the B1 orifice control valve in FIG. 4 in detail.

FIG. 7 is a chart for explaining the operation of the B1 orifice control valve in FIG. 6;

8 is a diagram showing a hydraulic control circuit according to another embodiment of the present invention together with FIGS. 9 and 10, and is a diagram corresponding to FIG. 3;

FIG. 9 is a diagram showing a hydraulic control circuit according to another embodiment of the present invention, together with FIGS. 8 and 10, and is a diagram corresponding to FIG. 4;

FIG. 10 is a diagram showing a hydraulic control circuit according to another embodiment of the present invention, together with FIGS. 8 and 9, and corresponding to FIG. 5;

FIG. 11 is a diagram showing the configuration of the B1 orifice control valve of FIG. 9 in detail.

[Explanation of symbols]

Reference Signs List 14 automatic transmission 32 lock-up clutch 52 third solenoid valve (solenoid valve) 68 manual valve (second signal source pressure generating means) 70 1-2 shift valve (first signal source pressure generating means) 78 B1 orifice control valve ( Timing control valve) 84 reverse control valve 88 lock-up clutch switching valve 94 solenoid modulator valve (second signal source pressure generating means) 120 port switching means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Ryuji Ibaraki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References JP-A-2-212667 (JP, A) JP-A-2-296063 (JP, A) JP-A-2-138562 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00-63/48

Claims (1)

(57) [Claims] An automatic transmission having a fluid transmission with a lock-up clutch is provided, and the automatic transmission establishes a plurality of forward gears and a reverse gear by a combination of operations of a plurality of hydraulic friction engagement devices. A lock-up clutch switching valve for switching the engagement state of the lock-up clutch, a common solenoid valve for supplying the lock-up clutch switching valve and generating a signal pressure for switching the lock-up clutch switching valve. A reverse control controlled by a signal pressure from the solenoid valve to a position where a reverse gear is prevented from being established when a shift lever is operated to a reverse travel range during forward travel. A first signal source pressure generating means for generating a first signal source pressure when the automatic transmission is in a forward gear at least equal to a second speed. A second signal source pressure generating means for generating a second signal source pressure when the automatic transmission is at least in a reverse gear stage; and controlling an operation timing of one of the plurality of hydraulic friction engagement devices. The automatic transmission is provided with a second
A timing control valve that is operated in connection with being switched to a forward gear or higher, and a timing control valve that is provided in the timing control valve, and in response to the switching operation of the timing control valve, the automatic transmission Selecting the first signal source pressure as the source pressure supplied to the solenoid valve when the automatic transmission is not in the forward gear stage in the second speed or higher; And a port switching means for selecting a second signal source pressure as the source pressure.