JP3425700B2 - Control device for automatic transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission mounted on an automobile or the like, and more particularly to a control device for an automatic transmission provided with a lockup clutch in a torque converter for transmitting engine output to a transmission mechanism.

[0002]

2. Description of the Related Art A torque converter and a speed change mechanism are combined, and a power transmission path of the speed change mechanism is switched by selectively engaging a plurality of friction elements such as a clutch and a brake, so that a speed change step can be performed according to a driving state of the vehicle. In the automatic transmission in which the automatic transmission is automatically switched, in order to reduce the driving loss in the torque converter and improve the fuel efficiency, in the operating region where the torque increasing action and the shift shock absorbing action are not required, A lock-up clutch that directly connects the input side and the output side of the torque converter may be provided. In that case, for example, Japanese Patent Laid-Open No. 4-
As disclosed in Japanese Patent No. 140569, a shift valve for selectively supplying operating pressure to a hydraulic circuit of an automatic transmission of this type in a engagement chamber for engaging a lockup clutch and a release chamber for releasing an engaged state. A pressure regulating valve for adjusting the differential pressure between the engagement chamber and the release chamber, and an ON-OFF solenoid valve for controlling the control pressure for the shift valve so that the operating pressure is supplied to the engagement chamber in a predetermined state, A lockup clutch is released by providing a duty solenoid valve for adjusting the control pressure to the pressure regulating valve in a predetermined state of the shift valve and electrically controlling the ON-OFF solenoid valve and the duty solenoid valve, respectively. The so-called converter state and the so-called lock in which the lock-up clutch is completely engaged And-up state, there are those to select the three transmission modes between the slip state of being entered into the middle of the lock-up clutch.

On the other hand, in this type of automatic transmission, a plurality of shift valves are installed in the hydraulic control circuit, and these shift valves are selectively operated to selectively engage with a plurality of friction elements. by supplying pressure, but so as to form a desired gear position, depending on the type of the transmission if the gear position is changed by pressure ejection of the engagement pressure against the friction elements involved in the gear shift operation is there. In this case, generally, an orifice for gently releasing the fastening pressure is provided in the fastening oil passage for the friction element. However, depending on the situation such as the speed change, the one that releases the fastening pressure rapidly may be used. May be desirable.

In response to such a demand, as disclosed in, for example, Japanese Patent Laid-Open No. 63-186055, the first exhaust oil passage having an orifice in the hydraulic control circuit in this type of automatic transmission. And a second exhaust pressure oil passage having no orifice, and the operating state of the shift valve for shifting is made different so that the fastening oil passage communicating with a predetermined friction element is limited to the first exhaust pressure oil passage. A configuration is shown in which both a communication state and a state in which the fastening oil passage is in communication with both the first and second discharge pressure oil passages can be realized.
According to this, at the time of a gear shift in which a quick releasing operation of the friction element is required, the engagement oil passage communicating with the friction element is communicated with both the first and second discharge pressure oil passages, and the friction element is loosened. At the time of a gear shift that requires a releasing operation, it is possible to discharge the hydraulic oil appropriately corresponding to the gear shift situation such that the fastening oil passage is communicated only with the first drainage oil passage having the orifice. Become.

[0005]

However, in the prior art described in the above publication, the exhaust pressure pattern of the engaging pressure from the friction element is changed by using the shift valve for shifting, and therefore As such, it may not always be possible to answer the request.

That is, in this type of automatic transmission, a shift pattern is set in advance corresponding to, for example, the vehicle speed and the engine load, and the actual operating state (vehicle speed and engine load) constitutes the shift pattern. When the vehicle passes through, the shift control for downshifting or upshifting the shift stage is performed. One form of the shift control is so-called torque demand shifting. This is because when the driver's depression of the accelerator pedal increases the engine load and the operating state passes through the shift down shift line that constitutes the above shift pattern, the shift stage is automatically changed to the low shift stage. Downshifting is performed. By thus downshifting the shift speed when the engine load increases, the output torque of the automatic transmission increases and the vehicle accelerates. In that case, when the accelerator pedal is rapidly depressed such as during kickdown, a gear shift operation with good responsiveness is required even if some gear shift shock occurs, but when exiting from a corner When the accelerator pedal is slowly depressed as described above, a smooth gear shift operation with less shock is required even if the responsiveness is somewhat sacrificed. When such torque demand shifting is realized by exhausting the engagement pressure from the friction element, in the former case, the engagement pressure of the friction element must be quickly exhausted. ,
In the latter case, the fastening pressure has to be discharged rather gently.

However, since the shift valve switching operation is generally performed in accordance with a constant shift pattern for each shift operation during a shift operation, the shift pressure shift valve is used to discharge the engagement pressure from the friction element. If the pattern is changed, it may happen that the above requirements cannot be satisfied.

Further, the hydraulic oil used in the hydraulic circuit of this type of automatic transmission tends to have a higher viscosity as the oil temperature is lower. Therefore, when the oil temperature is low, such as immediately after the engine is started, the fluidity of the hydraulic oil is poor compared to when the oil temperature is high, and the hydraulic oil is less likely to be discharged from the friction element. There is also a problem that the operation time becomes excessively long and the shift feeling is deteriorated.

The present invention addresses the above-mentioned problems during gear shifting of an automatic transmission in which a gear-changing friction element is hydraulically engaged. The purpose is to release appropriately.

[0010]

[0011]

Means for Solving the Problems That is, the present application claims
A control device for an automatic transmission according to a first aspect of the invention (hereinafter referred to as the first aspect of the invention) is provided with a lockup clutch that directly connects the input side and the output side of a torque converter, and a hydraulic control circuit activates the lockup clutch. In an automatic transmission provided with a solenoid valve for controlling and a shift valve for switching supply and discharge of engagement pressure to and from a friction element for speed change, a plurality of engagement pressure discharge oil passages connected to the shift valve have different throttle amounts. A switching means for selectively communicating with the throttle means is provided, and the switching means is switched by the solenoid valve.

Further, the present invention of claim 2 (hereinafter, the second
The control device for an automatic transmission according to the invention) is provided with a lock-up clutch that directly connects the input side and the output side of the torque converter, and the hydraulic control circuit includes a solenoid valve for controlling the operation of the lock-up clutch, and a speed change gear. In the automatic transmission provided with a shift valve for switching the supply and discharge of the engaging pressure to and from the friction element, the pressure adjusted by the solenoid valve is installed in the oil passage for engagement of the friction element for other speed changes. A pressure regulating valve supplied as pressure, a switching valve similarly supplied with the pressure regulated by the solenoid valve as control pressure, and a fastening pressure exhaust pressure oil passage connected to the shift valve via the switching valve. And a plurality of throttle means having different throttle amounts that are selectively communicated with each other, and the switching valve is operated when the control pressure is equal to or higher than a predetermined value. And the switching state of the throttle means with respect to the engaging pressure exhaust oil passage from the shift valve is switched, and at the same time, the pressure adjusting operation is performed with respect to the pressure adjusting valve installed in the engaging oil passage of the other speed change friction element. It is characterized in that it is configured so as to supply a regulating pressure for inhibiting the pressure.

[0013]

According to the above construction, the following operation can be obtained.

That is, in both the first and second aspects of the invention, the throttle amount of the engagement pressure drainage oil passage connected to the shift valve for shifting is changed according to the operation of the solenoid valve for lockup control. Therefore, it becomes possible to appropriately discharge the engagement pressure from the friction element involved in the gear shift operation according to the mode of gear shift during shift, the oil temperature, etc., and the lockup control as the solenoid valve is performed. Since a solenoid valve for use in the hydraulic control circuit is used, it is not necessary to equip a dedicated solenoid valve, which reduces the number of parts and simplifies the configuration of the hydraulic control circuit.

According to the second aspect of the invention, the switching valve, to which the pressure adjusted by the solenoid valve for lock-up control is supplied as the control pressure, is operated when the control pressure is equal to or higher than a predetermined value, and the shift valve is shifted. At the same time as switching the communication state of the plurality of throttle means with respect to the fastening pressure drainage oil passage from the valve, at the same time, the pressure regulating operation of the pressure regulating valve installed in the fastening oil passage of the other speed change friction element is blocked. Since the pressure regulating blocking pressure is supplied, the number of parts is further reduced and the hydraulic control circuit is further simplified.

Moreover, at the time of gear shifting in which another friction element is engaged, the pressure regulating operation of the pressure regulating valve installed in the oil passage for coupling to the friction element is controlled by the control pressure supplied to the switching valve. Since it will be blocked when the value is above the specified value,
It becomes possible to set the adjustment range of the engagement pressure by the pressure adjustment valve to be small, and the engagement pressure at the time of the shift can be precisely controlled by reflecting the operating state by using the solenoid valve for lockup control. Even after the gear shift, the friction element is held in the state of being securely fastened.

[0017]

EXAMPLES Examples of the present invention will be described below.

First, the mechanical structure of the automatic transmission 10 according to the embodiment will be described with reference to FIG.
Is a torque converter 20 as a main component,
Transmission mechanism 30 driven by the output of the converter 20
And a plurality of friction elements 41 to 46 such as clutches and brakes for switching the power transmission path of the mechanism 30 and one-way clutches 51 and 52, by which the D, S, L and R ranges as a travel range are provided. And 1 to 4 speeds in the D range, 1 to 3 speeds in the S range, and 1 in the L range
You can get 2nd speed.

The torque converter 20 is a pump 2 fixed in a case 21 connected to the engine output shaft 1.
2 and the pump 22 disposed so as to face the pump 22.
A turbine 23 driven by hydraulic oil by means of a hydraulic fluid, and a stator 25 interposed between the pump 22 and the turbine 23 and supported by the transmission case 11 via a one-way clutch 24 to perform a torque increasing action. , Case 2 above
1 and the turbine 23, and is constituted by a lockup clutch 26 that directly connects the engine output shaft 1 and the turbine 23 via the case 21. The rotation of the turbine 23 is output to the transmission mechanism 30 side via the turbine shaft 27. Here, a pump shaft 12 penetrating the inside of the turbine shaft 27 is connected to the engine output shaft 1, and the oil pump 13 provided at the rear end portion of the transmission by the shaft 12
Are being driven.

On the other hand, the speed change mechanism 30 is constituted by a Ravigneaux type planetary gear device, and the turbine shaft 27
A small-sized small sun gear 31 loosely fitted on the upper side, and a turbine shaft 27 on the rear side of the sun gear 31
A large sun gear 32 having a large diameter loosely fitted above, a plurality of short pinion gears 33 meshed with the small sun gear 31, and a front half of the short pinion gear 33.
A long pinion gear 34 whose rear half is meshed with the large sun gear 32, a carrier 35 rotatably supporting the long pinion gear 34 and the short pinion gear 33, and a ring gear 36 meshed with the long pinion gear 34. It is composed of.

A forward clutch 41 and a first one-way clutch 51 are provided in series between the turbine shaft 27 and the small sun gear 31, and a coast clutch 42 is provided in parallel with the clutches 41 and 51. A 3-4 clutch 43 is provided between the turbine shaft 27 and the carrier 35, and the turbine shaft 27 and the large sun gear 3 are provided.
A reverse clutch 44 is interposed between the two. Further, between the large sun gear 32 and the reverse clutch 44, a 2-4 brake 45, which is a band brake for fixing the large sun gear 32, is provided, and
A second one-way clutch 52 that receives the reaction force of the carrier 35 and a low reverse brake 46 that fixes the carrier 35 are provided in parallel between the carrier 35 and the transmission case 11. The ring gear 36 is connected to the output gear 14, and the rotation is transmitted from the output gear 14 to the left and right wheels (not shown) via a differential device.

Here, the friction elements 41 to 46 such as the above-mentioned clutches and brakes and the one-way clutches 51 and 52.
Table 1 below summarizes the relationship between the operating state and the gear position.

[0023]

[Table 1] Next, a hydraulic control circuit that supplies and discharges hydraulic pressure to and from the actuators of the friction elements 41 to 46 will be described.
The automatic transmission 10 is provided with a hydraulic control circuit 60 as shown in FIG. Here, among the above actuators, the hydraulic actuator 4 of the 2-4 brake 45
5a is composed of a servo piston having an apply port 45b and a release port 45c.
When the hydraulic pressure is supplied only to 5b, the 2-4 brake 45 is engaged, and when the hydraulic pressure is not supplied to both ports 45b and 45c and when the hydraulic pressure is supplied to both ports 45b and 45c, 2 -4 The brake 45 is released. In addition, other friction elements 41 to 4
The actuators 4, 46 are composed of normal hydraulic pistons, and when the hydraulic pressure is supplied, the friction elements are engaged.

The hydraulic control circuit 60 has, as main components, a regulator valve 61 for adjusting the pressure of the hydraulic oil discharged from the oil pump 13 shown in FIG. 1 to the main line 110 to a predetermined line pressure, and a manual operation. A manual valve 62 for selecting a range by means of each of the friction elements (actuators) 41 to 4 which operates in accordance with a gear position.
First, second, and third shift valves 63, 64, and 65 for supplying and discharging hydraulic pressure to and from the engine 6 are provided.

The manual valve 62 includes D, S, L
Each forward range, R range, N range, and P range can be set. In the forward range, the main line 110 is connected to the forward line 111, and in the R range, it is connected to the backward line 112. It has become.

The first, second, and third shift valves 63, 64, 65 each have a control port 63 at one end.
a, 64a, 65a are provided. And the first,
Control ports 63a, 6 of the second shift valves 63, 64
The first and second control pressure lines 113 and 114 branched from the forward line 111 are connected to 4a,
Further, a third control pressure line 115 branched from the main line 110 is connected to the control port 65a of the third shift valve 65, and these control pressure lines 113, 114, 115 are respectively used for shifting. The first of
Second and third solenoid valves 66, 67, 68 are provided. Of these, the first and second solenoid valves 66,
67 is a control port 63 corresponding to each when ON
The control pressures of a and 64a are discharged, the spools of the first and second shift valves 63 and 64 are positioned on the left side in the drawing, and when the spools are off, the first and second control of the control ports 63a and 64a are performed. A control pressure is introduced from the pressure lines 113 and 114 to position the spools on the right side against the biasing force of the springs. Further, regarding the third solenoid valve 68, when it is ON, the control pressure of the corresponding control port 65a is exhausted, and the third shift valve 6
No. 5 spool is located on the right side in the drawing, and when it is OFF, the third control pressure line 115 is connected to the control port 65a.
The control pressure is introduced from the position so that the spool is positioned on the left side against the biasing force of the spring in this case as well.

Here, these solenoid valves 66 ...
68 is ON / OFF controlled based on a map preset according to the vehicle speed of the vehicle and the throttle opening degree of the engine by a signal from a controller described later,
Accordingly, the positions of the spools of the shift valves 63 to 65 are switched and the oil passages to the friction elements 41 to 46 are switched, so that the friction elements 41 to 46 are fastened in the combinations shown in Table 1 above. As a result, the shift speed can be switched according to the operating state. In this case, the relationship between each shift speed in the D, S, and L forward ranges and the ON / OFF combination pattern of the solenoid valves 66 to 68 is set as shown in Table 2 below.

[0028]

[Table 2] On the other hand, the spool of the manual valve 62 is set to D, S,
Main line 110 when set to each forward range of L
A line 116 is branched from a forward line 111 that is communicated with the line. The line 116 serves as a forward clutch line, and the orifice 69 and the one-way orifice 7 are connected.
It is guided to the forward clutch 41 via 0. Therefore, in the D, S, and L ranges, the forward clutch 4
1 will always be concluded. An ND accumulator 71 is connected to the forward clutch line 116 on the downstream side of the one-way orifice 70 via a line 117.

The forward line 111 is guided to the first shift valve 63, and the first solenoid valve 66 is turned on.
When the spool of the shift valve 63 becomes N on the left side, it communicates with the servo apply line 118 and reaches the apply port 45b of the servo piston 45a through the orifice 72. Therefore, when the first solenoid valve 66 is ON in the D, S, and L ranges, that is, the second, third, and fourth speeds in the D range, the second and third speeds in the S range, and the second speed in the L range, the apply port 45b is used. 2-4 when the hydraulic pressure (servo apply pressure) is introduced to the release port 45c and the hydraulic pressure (servo release pressure) is not introduced to the release port 45c.
The brake 45 will be engaged. A 1-2 accumulator 74 is connected to the apply port 45b via a line 119 and an accumulation cut valve 73.

The forward line 111 is also led to the third shift valve 65, and when the third solenoid valve 68 is OFF and the spool of the shift valve 65 is located on the left side, it communicates with the coast clutch line 120. .
The coast clutch line 120 reaches the coast clutch 42 via the coast reducing valve 75 and the one-way orifice 76. Therefore, D,
When the third solenoid valve 68 is OFF in the S and L ranges, that is, the coast clutch 42 is engaged in the D and S ranges of the third speed, the S and L ranges of the second speed, and the L range of the first speed.

Further, the forward line 111 is also led to the second shift valve 64. And the line 111
Is in communication with the 3-4 clutch line 121 when the second solenoid valve 67 is OFF and the spool of the second shift valve 64 is located on the right side. This line 121
Further, it reaches the 3-4 clutch 43 via the 3-4 control valve 77. Therefore, when the second solenoid valve 67 is OFF in the D, S, and L ranges, that is, the 3-4 clutch 43 is engaged in the 3rd and 4th speeds of the D range and the 3rd speed of the S range.

Here, the above 3-4 clutch line 121
The line 122 branched from is a servo release line that leads to the release port 45c of the servo piston 45a when the third solenoid valve 68 is OFF and the spool of the shift valve 65 is located on the left side. 123. Therefore, D,
Second and third solenoid valves 67 and 68 in the S and L ranges
Are both OFF, that is, in the third speed of the D range and the third speed of the S range, the servo release pressure is introduced into the release port 45c of the servo piston 45a, and the 2-4 brake 45 is released.

A line 124 is branched from the forward line 111, and this line 124 is also led to the first shift valve 63. The line 124 communicates with a line 125 that communicates with the second shift valve 64 when the first solenoid valve 66 is OFF and the spool of the first shift valve 63 is located on the right side. On the other hand, the second solenoid valve 67 is turned on to the second shift valve 64.
Then, when the spool of the valve 64 is located on the left side, a line 126 communicating with the line 125 is connected, and the line 126 is guided to the third solenoid valve 68 via the ball valve 79 and the line 127. Then, this line 127 is a low reverse brake line 128 that communicates with the low reverse brake 46 via the low reducing valve 79 when the third solenoid valve 68 is OFF and the spool of the third shift valve 65 is located on the left side. Communicate with. Therefore, in the D, S, and L ranges, the first, second, and third solenoid valves 66 to 68 are
Are OFF, ON, and OFF respectively, that is, L
The low reverse brake 46 is engaged at the first speed in the range.

Further, the retreat line 112 communicating with the main line 110 in the R range is the third shift valve via the line 129 branched from the line 112, the orifice 80, the one-way orifice 81, the ball valve 78 and the line 127. led to 65, the low reverse brake line 128 when the third solenoid valve 68 is a spool of the valve 6 8 is positioned to the left in OFF
Communicate with. In addition, the reverse line 112 serves as a reverse clutch line 130 and serves as a one-way valve 82.
The reverse clutch 44 is reached via. Therefore, in the R range, the third solenoid valve 68 is off.
While the low reverse brake 46 is engaged when
The reverse clutch 44 is always engaged. The one-way orifice 81 and the ball valve 78
An N-R accumulator 83 is connected to a line 131 branched from the line 129 between and.

The hydraulic control circuit 60 also includes a lockup clutch 2 in the torque converter 20 shown in FIG.
A fourth shift valve 84 for controlling 6 and a lockup control valve 85 are provided.

A converter line 132 led from the regulator valve 61 via a converter relief valve 86 is connected to the fourth shift valve 84 and the lockup control valve 85, and
Control port 8 provided at one end of the fourth shift valve 84
A control pressure line 134 communicating with the main line 110 via a line 133 is connected to 4a. A fourth solenoid valve 87 for lockup is connected to this line 134.
Is provided, and the spool of the fourth shift valve 84 is located on the left side when the solenoid valve 87 is OFF, so that the converter line 132 communicates with the release line 135 that communicates with the lockup release chamber 26a in the torque converter 20. As a result, the lockup clutch 26 is released, and the converter state is established.

On the other hand, the fourth solenoid valve 87 is turned off.
N and the control port 84a of the fourth shift valve 84
When the spool of the valve 84 moves to the right side in the drawing due to the discharge of the control pressure from the converter line 132, the converter line 132 communicates with the fastening line 136 leading to the lock-up fastening chamber 26b in the torque converter 20. Thus, the lockup clutch 26 is engaged. At this time, the release line 135 communicates with the lockup control valve 85 via the fourth shift valve 84 and the intermediate line 137, and the control valve 8
The operating pressure adjusted in 5 is supplied to the lockup release chamber 26a of the lockup clutch 26 as the lockup release pressure.

That is, the control pressure line 138 led from the main line 110 through the solenoid reducing valve 88 is connected to the control port 85a at one end of the lockup control valve 85, and the other end side thereof is connected. Forward line 11 is attached to the pressure regulation prevention port 85b.
A pressure regulation prevention line 139 leading to 1 is connected. The first duty solenoid valve 9 is provided downstream of the orifice 89 provided in the control pressure line 138.
0 is installed and this first duty solenoid valve 9
By adjusting the control pressure supplied to the control port 85a of the lock-up control valve 85 in accordance with the duty ratio given to 0, the pressure-adjustment prevention port 85b on the other end side is adjusted via the pressure-adjustment prevention line 139. on condition that the line pressure is not supplied, the lock-up release through the engagement pressure supplied to the lockup chamber 26 b through the converter cod in 132 and fastening line 136, the intermediate line 137 and disengagement line 135 It is adjusted differential pressure and release pressure supplied to the chamber 26 a, the lock-up clutch 26 is controlled to a predetermined slip state.

On the other hand, the lockup control valve 8
5 to the pressure regulation prevention port 85b
When the line pressure is supplied through the control valve 85, the spool of the control valve 85 is fixed with the spool positioned on the left side. Therefore, the operating pressure of the lockup release chamber 26a in the lockup clutch 26 is discharged from the drain port of the lockup control valve 85a via the release line 135, the fourth shift valve 84 and the intermediate line 137, The lockup clutch 26 is in the lockup state in which it is completely engaged. In that case, the drain port is provided with an orifice whose diameter is appropriately set, whereby the engagement chamber 2 of the lockup clutch 26 is connected via the engagement line 136.
Release chamber 26a in which the hydraulic oil supplied to 6b is in a communicating state
Even if it flows into, it will not be excessively discharged.

The operation characteristic of the first duty solenoid valve 90 is set so that the duty control pressure decreases as the duty ratio D increases. That is, when the duty ratio D is 100%, the drain port is always open and the orifice 89
The pressure level of the control pressure line 13 8 on the downstream side becomes 0. On the other hand, when the duty ratio D is 0,
The pressure level is maintained at the maximum pressure because the drain port is always shut off.

Further, the hydraulic pressure control circuit 60 includes a throttle modulator valve 91 and a second duty solenoid valve 92 for operating the valve for controlling the line pressure adjusted by the regulator valve 61.
Is provided.

A line 140 leading to the main line 110 is introduced to the throttle modulator valve 91 via the solenoid reducing valve 88, and a control port 91a on one end side is periodically opened and closed. The duty control pressure adjusted by the second duty solenoid valve 92 is introduced, and the throttle modulator pressure according to the duty ratio D of the duty solenoid valve 92 is generated. In that case, the duty ratio D is set according to, for example, the throttle opening of the engine, and the throttle modulator pressure corresponding to this is increased by the first increase of the regulator valve 61 via the line 141. Pressure port 61a
The line pressure adjusted by the valve 61 is increased in accordance with the increase of the throttle opening. On the other hand, a line 142 branched from the retreat line 112 is connected to the second pressure increasing port 61b provided in the regulator valve 61. This allows
In the R range, the line pressure will be further increased.

In this embodiment, the duty control pressure generated by the first duty solenoid valve 90 for adjusting the engagement force of the lockup clutch 26 is the control port 9 of the accumulator modulator valve 93.
3a is also supplied. This modulator valve 93 is connected from the main line 110 to the line 143.
A line pressure supplied via the first solenoid valve 66 is adjusted according to the duty control pressure from the first solenoid valve 66 to generate a modulator pressure, and the modulator pressure is supplied via a line 144 to the back of the N-R accumulator 83. The pressure chamber 83a and the like are supplied.

A line 145 branched from the line 144 is connected to the control port 77a of the 3-4 control valve 77 on the 3-4 clutch line 121. Therefore, if the duty control of the first duty solenoid valve 90 is performed, a modulator pressure according to the duty ratio D is generated by the accumulator modulator valve 93 and introduced into the control port 77a of the 3-4 control valve 77. As a result, the hydraulic pressure (3-4 clutch pressure) adjusted by the control valve 77 is also adjusted to a value corresponding to the duty ratio D.

On the other hand, this 3-4 control valve 77
Is provided with a pressure regulation blocking port 77b for blocking a pressure regulation (pressure reduction) operation at one end side thereof, and the pressure regulation blocking port 77b is connected to the main line 110 via the switching valve 94 and the line 146. The pressure blocking line 147 is connected. When the pressure regulation blocking line 147 communicates with the line 146 via the switching valve 94, the line pressure of the main line 110 is supplied to the pressure regulation blocking port 77b of the 3-4 control valve 77, The pressure regulating operation of the control valve 77 is blocked.

That is, the control port 94a at one end of the switching valve 94 has the orifice 89 and the first duty solenoid valve 90 in the control pressure line 138.
A line 148 branched from the control pressure line 138 is connected to the balance port 94b on the other end side, and a line 149 branched from the control pressure line 138 is connected to the balance port 94b on the other end side. Then, when the duty control pressure generated by the first duty solenoid valve 90 is equal to or higher than a predetermined value, the spool of the switching valve 94 is located on the left side in the drawing, and the pressure regulation blocking line 147 becomes the main line 110. Line 146 leading to
To the main line 110 through the line 146.
By supplying the line pressure of (3) to the pressure regulation blocking port 77b of the 3-4 control valve 77, the pressure regulation operation of the control valve 77 is blocked. On the other hand, when the duty control pressure generated by the first duty solenoid valve 90 falls below a predetermined value, the spool of the switching valve 94 overcomes the spring force and moves to the right side, whereby the pressure regulation blocking line 17 is generated.
7 is disconnected from the line 146.

Here, the switching valve 94 is connected with a line 150 which communicates with the pressure regulation blocking line 177 when the spool is located on the right side. This line 15
0 is led to the fourth shift valve 84 for lock-up control, and when the spool of the shift valve 84 is located on the right side, 0 is communicated with the line 151 communicating with the main line 110 via the line 133. There is. That is, when the fourth solenoid valve 87 is turned on and the engagement force of the lockup clutch 26 can be controlled, the line pressure of the main line 110 passes through the lines 133, 151, the fourth shift valve 84, and the line 150. Will be guided to the pressure regulation prevention line 177. In addition,
In the converter state in which the spool of the fourth shift valve 84 is located on the left side, the line 150 communicates with the drain port provided in the shift valve 84.

The switching valve 94 has a drain line 1 which communicates with the servo apply line 118 when the spool of the first shift valve 63 is located on the right side.
51 is connected. And this drain line 15
1 is selectively communicated with two drain ports having different throttle amounts.

Here, the first shift valve 63 has a 3-
When the line 152 branched from the pressure regulation blocking line 147 for the 4th control valve is connected, and the first solenoid valve 66 is turned on and the spool of the first shift valve 63 is located on the left side, A line 153 communicating with the second back pressure port 74b of the 1-2 accumulator 74, to which the line pressure of the main line 110 is constantly introduced from the pressure chamber 74a, is connected to the line 152. Therefore, the pressure regulation prevention line 147
When the line pressure is being supplied to the second accumulator 74, the line pressure is supplied via the lines 152 and 153 only when the spool of the first shift valve 63 is located on the left side. It will be introduced into the pressure chamber 74b.

Further, the servo apply line 118 leading to the apply port 45b of the servo piston 45a.
In the accumulation cut valve 73 installed on the line 119 leading to the 1-2 accumulator 74, the control port 73a on one end side is connected to the 3-4 clutch on the downstream side of the 3-4 control valve 77. A line 154 branched from the line 121 is connected to the accumulation cut prevention port 73b provided on the other end side for preventing pressure regulation of the lockup control valve 85 via a ball valve 95 and a line 155. The line 156 leading to the pressure regulation prevention line 139 is connected. And this accumulation cut valve 73
A line 157 branched from the line 126 connected to the second shift valve 64 is connected to the intermediate port 73c provided at the intermediate portion of the.

The ball valve 95 connected to the line 156 leading to the accumulation cut prevention port 73b of the accumulation cut valve 73 is connected to the ball valve 95 and the line 150 interposed between the switching valve 94 and the fourth shift valve 84. The line 158 branched from is also connected.

In addition to the above configuration, this hydraulic control circuit 6
0 is equipped with a fifth shift valve 96 mainly used for adjusting the shift timing. The fifth shift valve 96 includes a first bypass line 160 that bypasses the orifice 72 on the servo apply line 118.
And a second bypass line 161 that bypasses the one-way valve 82 on the reverse clutch line 130, and the pressure regulation blocking port 8 of the lockup control valve 85.
The control pressure line 162 branching from the main line 110 is introduced to the control port 96a on one end side while being installed so as to straddle the lockup pressure regulation prevention line 139 guided to 5b. Then, the fifth solenoid valve 97 installed in the control pressure line 162 is turned on,
When turned off, the fifth solenoid valve 97
The position of the spool is switched so that the first and second bypass lines 160 and 161 and the pressure regulation blocking line 139 are opened or closed.

That is, when the fifth solenoid valve 97 is OFF and the spool of the fifth shift valve 96 is located on the right side in the drawing, the first bypass line 160 and the pressure regulation blocking line 139 are opened while the first bypass line 160 and the pressure regulation blocking line 139 are opened. The second bypass line 161 is cut off. At this time, the downstream portion of the second bypass line 161 communicates with the line 129 provided with the orifice 80 and the one-way orifice 81, and then communicates with the reverse clutch line 130 or the reverse line 112 via the line 129. On the other hand, the fifth solenoid valve 97 is turned on, and the fifth solenoid valve 97 is turned on.
When the spool of the shift valve 96 moves to the left side in the drawing, the first bypass line 160 and the pressure regulation blocking line 139 are shut off, and the second bypass line 160 is opened.

Further, the first bypass line 160 is provided with a one-way orifice 98 located downstream of the fifth shift valve 96 for performing a throttling action in the hydraulic oil supply direction. A normal orifice 99 is provided on the upstream side of the shift valve 96. In the branch line 163 branched from the first bypass line 160 on the upstream side of the orifice 99, the orifice 100 having a smaller throttle amount than the orifice 99 and the passage of hydraulic oil in the supply direction are blocked. One-way valve 101 and
When the fifth solenoid valve 97 is turned on and the spool of the fifth shift valve 96 is located on the left side, the branch line 163 is joined to the first bypass line 160 downstream of the valve 96. Has become.

As shown in FIG. 3, the automatic transmission 10 includes first to third solenoid valves 66 to 68 for gear shift control and a fourth solenoid valve 8 for lockup.
The controller 200 controls the operations of the seventh and first duty solenoid valves 90, the second duty solenoid valve 92 for adjusting the line pressure, and the fifth solenoid valve 97. This controller 200
A signal from a vehicle speed sensor 201 that detects the vehicle speed of the automobile, a signal from a throttle opening sensor 202 that detects the throttle opening of the engine, and a position (range) of a shift lever included in the automatic transmission 10 are detected. A signal from the shift position sensor 203, a signal from an engine speed sensor 204 that detects an engine speed, a signal from a turbine speed sensor 205 that detects a turbine speed of the torque converter 20, and an oil temperature of hydraulic oil are detected. Signals and the like from the oil temperature sensor 206 are input, and the operation of each solenoid valve is controlled in accordance with the operating state indicated by these signals and the driver's request.

The automatic transmission 10 according to this embodiment has the above-mentioned configuration, but the 3-4 clutch 4 at the time of 2-3 shifts.
The engagement operation of No. 3 and the release operation of the 2-4 brake 45 at the time of 2-1 shift are performed as follows using the switching valve 94 whose operation is controlled by the first duty solenoid valve 90 for lockup control. It is properly controlled.

Now, in the second speed of the automobile, assuming that the operation mode of the lockup clutch 26 is set to the converter mode, the fourth solenoid valve 8 for controlling the operation of the lockup fourth shift valve 84.
7 is turned off, and as a result, the spool 84b of the shift valve 84 is located on the left side in the drawing, as shown in FIG. In this state, the line 150 led from the switching valve 94 to the fourth shift valve 84 is in communication with the drain port 84c provided in the shift valve 84.

At this time, assuming that the first duty solenoid valve 90 is at rest, the control pressure line 13
The pressure level of No. 8 is maintained at the maximum pressure, and the pressing force by the hydraulic pressure introduced from the control port 94a is superimposed on the spring force that acts on the spool 94c of the switching valve 94 from the right side in the drawing. Spool 94
c is held in the state of being positioned on the left side against the pressing force by the hydraulic pressure acting from the right side of the drawing. In this state, 3-4 control pressure regulating blocking lines 147 leading to the pressure regulating blocking port 77b of the valve 77, since it communicates with the line 146 leading to the main line 110, the line pressure of the main line 110, line 146 And the pressure regulation prevention port 7 through the pressure regulation prevention line 147.
7b is introduced. And by this line pressure 3-
4 The plug 77c built in the control valve 77 is pressed to the left side in the drawing, and the spool 77d also plugs 77
It will be held in the state of being pushed by c and positioned on the left side. As a result, the input port 77e and the output port 77f of the 3-4 control valve 77 are in complete communication.

In such a state, the operating state is changed to shift up the shift stage from the second gear to the third gear 2-3
If a shift command is issued, the second solenoid valve 67 that controls the operation of the second shift valve 64 is switched from ON to OFF according to the point shown in Table 2 above, and accordingly, the spool of the second shift valve 64 is changed. 64
b moves from the state shown in the figure to the right. At that time, the controller 200 sends the first duty control signal such that the duty control pressure of the first duty solenoid valve 90 becomes smaller than the predetermined value Po. It is output to the duty solenoid valve 90. Thereby, the balance port 94b in the switching valve 94
Pressure introduced from the relatively larger than the pressure introduced from the control port 94 a, the spool 94c of said changeover switching valve 94 is moved to the right against the urging force due to the spring force acting from the right side It will be.

Therefore, as shown in FIG.
4 through the pressure regulation blocking port 77b of the control valve 77
The pressure regulation prevention line 147 is connected to the main line 110.
4th shift valve, separated from the twisting line 146
It will be connected to the line 150 leading to 84. this
Therefore, the 3-4 control valve 77 pressure regulation prevention port
The line pressure supplied to 77b is the pressure regulation prevention line 1
47 and the line 150 of the fourth shift valve 84
The pressure will be exhausted from the drain port 84c.
Therefore, the plug 77 of the 3-4 control valve 77c
But the spring 77g placed between it and the spool 77d
Is pushed back by and moved to the right side,
The pressure adjustment (pressure reduction) operation of the rule valve 77 becomes possible. That
The first duty solenoid valve 90 to the specified duty.
If duty control is performed with the duty ratio D, the duty ratio
The modulator pressure according to D is the above model for accumulator.
It is generated by the regulator valve 93, and the 3-4 control is performed.
Is introduced into the control port 77a of the control valve 77.
And the line supplied to the input port 77e of the valve 77.
Pressure is adjusted to the pressure corresponding to the above modulator pressure.
Is supplied to the 3-4 clutch 43 as fastening pressure.
It becomes. In that case, the fastening pressure is the prescribed shelf pressure.
With the duty ratio D such that
If the id valve 90 is driven, the 3-4 class
Switch 43 for a short time without causing excessive fastening shock.
It will be in the complete fastening state during.

When the 3-4 clutch 43 is completely engaged and the 2-4 brake 45, which precedes the releasing operation, is completely released, the shift operation to the third speed is completed. A duty control signal is output to the 1-duty solenoid valve 90 so that the duty control pressure becomes equal to or higher than a predetermined value Po. Therefore, the spool 94c of the switching valve 94 located on the right side in the drawing
Moves to the left side, and accordingly, the line 146 communicating with the main line 110 communicates with the pressure regulation blocking line 147 again. Therefore, the line pressure of the main line 110 is supplied to the pressure regulation blocking port 77 b of the 3-4 control valve 77 via the line 146 and the pressure regulation blocking line 147, and thereby the plug of the valve 77. 77
As c moves to the left side, the input port 7
The spool 77d is held so that 7e and the output port 77f are in complete communication. Accordingly, the line pressure from the forward line 111 supplied from the second shift valve 64 to the 3-4 control valve 77 via the 3-4 clutch line 121 is supplied to the 3-4 clutch 43 without being reduced. I mean,
The clutch 43 is securely engaged.

Thus, the 3-4 control valve 7
Pressure regulation prevention line 14 leading to pressure regulation prevention port 77b of No. 7
7 and the line 146 leading to the main line 110, the switching valve 94 is provided when the duty control pressure from the first duty solenoid valve 90 introduced into the control port 94a is equal to or higher than the predetermined value Po. Since the pressure regulation blocking line 147 and the line 147 are configured to communicate with each other, the engagement pressure of the 3-4 clutch 43 is shown in FIG. 6 with respect to the duty control pressure adjusted by the first duty solenoid valve 90. The characteristics will change as shown. That is, the engagement pressure at the time of shifting is variably controlled in the range of the region X where the duty control pressure is smaller than the predetermined value Po, and the 3-4 control valve 77 is controlled in the region Y where the control pressure exceeds the predetermined value Po. By blocking the pressure regulating operation, the maximum fastening pressure equal to the line pressure can be obtained. Therefore, the control range R in the region X where the duty control pressure is smaller than the predetermined value Po can be set small, and the engagement pressure at the time of gear shift can be precisely controlled by reflecting the operating state.

On the other hand, when the accelerator pedal is depressed in the second speed state of the vehicle, a 2-1 shift command for downshifting the shift stage from the second speed to the first speed is generated, and the first shift valve 63 is actuated. First to control
The solenoid valve 66 is switched from ON to OFF as shown in Table 2 above. Therefore, as shown in FIG. 7, the spools 63a of the first and fifth shift valves 63, 94 are located on the right side, respectively, and the servo apply which communicates with the apply port 45b of the servo piston 45a via the orifice 72. Line 11
8 communicates with the drain line 151 leading to the switching valve 94, and the first bypass line 160, which joins the servo apply line 118 on the downstream side of the orifice 72, again applies servo on the upstream side of the orifice 72. It will communicate with the line 118.

Here, in this embodiment, drain ports 94d and 94e provided in the switching valve 94 are provided.
In the drawing, the drain port 94d located on the right side of the drawing has a smaller throttle amount than the drain port 94e on the left side. Therefore, when the rate of change of the throttle opening detected by the throttle opening sensor 202 is equal to or greater than a predetermined value, the duty control signal such that the duty control pressure of the first duty solenoid valve 90 becomes smaller than the predetermined value Po is set in the controller. 200 is output to the first duty solenoid valve 90. Therefore, the spool 94c of the switching valve 94 is located on the right side as shown in the figure, and the first shift valve 63
Drain line 151 communicates with the drain port 94d having a small throttle amount. As a result, the servo piston 45
The hydraulic oil supplied to the apply port 45b of a is
A part of the branch is branched to the first bypass line 160 on the downstream side of the orifice 72 on the servo apply line 118, then passes through the one-way orifice 98, and passes through the orifice 72 on the upstream side of the orifice 72. After merging with the rest of the discharged hydraulic oil, the hydraulic oil is discharged from the drain port 94d having a small throttle amount in the switching valve 94 via the servo apply line 118 and the drain line 151.

Therefore, at the time of rapid acceleration in which the accelerator pedal is rapidly depressed, the apply port 45 of the servo piston 45a as shown by the solid line in FIG.
The servo apply pressure of b is rapidly discharged, and the 2-4 brake 45 is quickly released.

On the other hand, the throttle opening sensor 20
When the rate of change of the throttle opening detected by 2 is less than or equal to a predetermined value, the first duty solenoid valve 90
Of the first duty control signal from the controller 200 such that the duty control pressure of the first duty control pressure becomes larger than the predetermined value Po.
It is output to the duty solenoid valve 90.
Therefore, the spool 94c of the switching valve 94 is now positioned on the left side as shown in FIG. 9, and the drain line 151 from the first shift valve 63 communicates with the drain port 94e having a large throttle amount. This allows
At the time of gentle acceleration in which the accelerator pedal is slowly depressed, as shown by the chain line in FIG. 8, the servo apply pressure of the apply port 45b in the servo piston 45a is gradually released, and the 2-4 brake 45 Will be released smoothly.

In such a slow acceleration state, 2-
Even during one gear shift, when the temperature of the hydraulic oil detected by the oil temperature sensor 206 is lower than the predetermined temperature, the servo apply pressure is discharged through the drain port 94d having a small throttle amount of the switching valve 94. Switching valve 94
The position of the spool 94d is switched.

In this embodiment, by switching the position of the spool 94c of the switching valve 94, the first
The throttle amount of the drain line 151 connected to the shift valve 63 is switched in two steps. For example, the drain line 151 is provided with a variable orifice for varying the throttle amount, and the throttle amount by this variable orifice is locked up. First duty solenoid valve 90 for vehicle
You may make it change continuously according to.

[0069]

As described above, according to the present invention, the amount of throttling of the engagement pressure drainage oil passage connected to the shift valve for shifting is
Since it is changed according to the operation of the solenoid valve for lock-up control, the engagement pressure is appropriately discharged from the friction element involved in the gear shift operation according to the mode of gear shift during shift and the oil temperature. In addition, since a solenoid valve for lock-up control is used as the solenoid valve, it is not necessary to equip a dedicated solenoid valve, and this reduces the number of parts and reduces the hydraulic control circuit configuration. It will also be simplified.

Moreover, as in the embodiment, a switching valve to which the pressure adjusted by the solenoid valve for lock-up control is supplied as the control pressure is provided, and this switching valve is used when the control pressure is equal to or higher than a predetermined value. It operates to switch the communication state of the plurality of throttle means with respect to the engagement pressure discharge oil passage from the shift valve, and at the same time, adjusts the adjustment pressure with respect to the pressure adjustment valve installed in the engagement oil passage of another speed change friction element. If it is configured to supply the pressure regulation blocking pressure that blocks the pressure operation,
The number of parts is further reduced, and the hydraulic control circuit is further simplified.

Moreover, at the time of gear shifting in which another friction element is engaged, the pressure regulating operation of the pressure regulating valve installed in the oil passage for coupling to the friction element is controlled by the control pressure supplied to the switching valve. Since it will be blocked when the value is above the specified value,
It becomes possible to set the adjustment range of the engagement pressure by the pressure adjustment valve to be small, and the engagement pressure at the time of the shift can be precisely controlled by reflecting the operating state by using the solenoid valve for lockup control. Therefore, even after the gear shift, the friction element can be held in a state of being securely fastened.

[Brief description of drawings]

FIG. 1 is a skeleton diagram of an automatic transmission according to an embodiment.

FIG. 2 is a circuit diagram showing a hydraulic control circuit of an automatic transmission according to an embodiment.

FIG. 3 is a control system diagram for each valve in the hydraulic control circuit of FIG.

FIG. 4 is an enlarged view of a main part of a hydraulic control circuit in a second speed state.

FIG. 5 is an enlarged view of a main part of a hydraulic control circuit during 2-3 shift.

FIG. 6 is a characteristic diagram showing a relationship between a duty control pressure by a first duty solenoid valve and a 3-4 clutch pressure.

FIG. 7 is an enlarged view of a main part of a hydraulic control circuit during 2-1 shift during sudden acceleration.

FIG. 8 is a time chart showing changes in the servo apply pressure of the 2-4 brake during the 2-1 shift.

FIG. 9 is an enlarged view of a main part of a hydraulic control circuit during 2-1 shift during slow acceleration.

[Explanation of symbols]

10 automatic transmission 20 Torque converter 26 Lockup clutch 43 3-4 Clutch 45 2-4 brake 45a Servo piston 45b Apply port 64 1st shift valve 77 3-4 Control valve 90 First duty solenoid valve 94 switching valve 94d drain port 94e drain port 118 Servo Apply Line 121 3-4 Clutch line 146 lines 147 Pressure regulation prevention line 151 drain line 200 controller

─────────────────────────────────────────────────── ─── Continuation of front page (72) Takuji Fujiwara, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Ichinori Enokido, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Da Incorporated (72) Inventor Ryori Mizobe 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) Reference JP-A-63-186055 (JP, A) JP-A-1-199060 (JP, A) JP 4-140569 (JP, A) JP 60-151447 (JP, A) JP 1-164848 (JP, A) JP 62-224763 (JP, A) (JP 58) Fields investigated (Int.Cl. ⁷ , DB name) F16H 59/00-61/24 F16H 61/38-61/64 F16H 63/40-63/48

Claims (2)

(57) [Claims] 1. A lock-up clutch for directly connecting an input side and an output side of a torque converter is provided, and a hydraulic control circuit is provided with a solenoid valve for controlling the operation of the lock-up clutch and a supply of engagement pressure to a friction element for shifting. A control device for an automatic transmission provided with a shift valve for switching the discharge, and a switching means for selectively communicating the fastening pressure exhaust pressure oil passage connected to the shift valve with a plurality of throttle means having different throttle amounts. A control device for an automatic transmission characterized in that the switching means is provided and is configured to be switched by the solenoid valve. 2. A lock-up clutch for directly connecting an input side and an output side of a torque converter is provided, and a hydraulic control circuit is provided with a solenoid valve for controlling the operation of the lock-up clutch and a supply of engagement pressure to a friction element for speed change. A control device for an automatic transmission provided with a shift valve for switching between discharge and discharge, the pressure being adjusted by the solenoid valve and supplied as a control pressure by being installed in an oil passage for fastening another friction element for gear shifting. And a switching valve to which a pressure regulated by the solenoid valve is supplied as a control pressure, and a coupling pressure exhaust pressure oil passage connected to the shift valve via the switching valve. A plurality of throttling means having different throttling amounts communicated with each other, and the switching valve is actuated when the control pressure is equal to or higher than a predetermined value. At the same time as switching the communication state of the throttle means to the fastening pressure drainage oil passage from the shift valve,
An automatic transmission characterized in that it is configured to supply a pressure regulating blocking pressure that inhibits the pressure regulating operation to a pressure regulating valve installed in a coupling oil passage of another gear shift friction element. Control device.