JPH08320068A - Speed change controller for automatic transmission - Google Patents

Abstract

PURPOSE: To make response of speed change and decrease of a shock compatible with each other at a high level by making a structure for performing electronic control of operating pressure of respective friction elements and switching control of the friction elements regardless of the correlation. CONSTITUTION: Speed change is performed by switch-controlling supply of D-range pressure of an oil passage 116 to any one of clutches C3, C2 or a brake B2 by the combination of the shift positions of shift valves 6, 7, to be determined of ON or OFF of solenoids SOL1, SOL2, and operating pressure of the clutches and the brake to which the D-range pressure is to be supplied is controlled by control valves 8, 9, 10 to be operated in response to respective duty solenoids SOL3, SOL4, SOL5. Switching of operation of the clutches C3, C2 and the brake B2 and electronic control of operating pressure can be performed regardless of the correlation, and response of speed change and decrease of shock can be compatible with each other at a high level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission, and more particularly to a shift control device for an automatic transmission adapted to individually control operating pressures associated with a plurality of friction elements that determine a shift stage. Is.

[0002]

2. Description of the Related Art An automatic transmission selects a corresponding shift speed by selectively hydraulically operating (engaging) a plurality of friction elements (friction clutches and friction brakes) and changes the operating friction element to change to another shift speed. It is configured to shift.

As disclosed in Japanese Patent Laid-Open No. 1-299351, a shift control device for controlling the shift of the automatic transmission has been conventionally provided by individually electronically controlling the operating pressures of a plurality of friction elements. There has been proposed a shift control device adapted to perform the shift. This kind of shift control device is advantageous in that the structure of the hydraulic circuit can be simplified, and that the operating pressure of the friction element can be finely controlled to be suitable for all running conditions.

In an automatic transmission, it is inevitable that there is an operating combination of friction elements that mechanically locks the gear transmission mechanism (interlock state). It is absolutely necessary to prevent it from being activated. Naturally, the shift control device of the above-described type has some countermeasures for it, and the countermeasures are as shown in FIG.

In the figure, the clutch C-1 is in the first speed range.
It should be operated in 3rd speed, clutch C-0
Is to be operated in 3rd and 4th speed. The operating pressures of these clutches C-1 and C-0 are based on the forward travel range pressure from the manual valve M / V, and are duty-controlled by the individual solenoid valves S-1 and S-0. Further, the brake B-1 adjusts the forward travel range pressure from the manual valve M / V by electronically controlling the solenoid valve S-3, and the pressure from the relay valve R / V to the servo release chamber S / R. Is supplied to each of the servo apply chambers S / A, and when pressure is supplied only to the servo apply chamber S / A, the servo release chamber S /
When the pressure is also supplied to R, it is inactivated regardless of the pressure in the servo apply chamber S / A, and it should be activated in the second speed and the fourth speed.

Here, not only the second speed and the fourth speed at which the brake B-1 should be operated, but also the second speed at which the brake B-1 should be inactive should be taken into consideration for convenience of hydraulic control in the servo apply chamber S.
/ A is to be supplied with pressure, so that the servo apply chamber S / A is continuously supplied with pressure from the second speed to the fourth speed.

Thus, the solenoid valve S-3 is the brake B.
In order to explain the speed change action of the second speed to the fourth speed that continues to supply the pressure to the servo apply chamber S / A of No.-1, the solenoid valve S-1 supplies the pressure to the clutch C-1 at the second speed. Actuating it, solenoid valve S-0 does not supply pressure to clutch C-0, deactivating it. At this time the relay valve R
/ V reaches the rightward position in the lower half of the drawing, and connects the servo release chamber S / R to the clutch C-0 to which no pressure is supplied, and activates the brake B-1. Therefore, the second speed can be obtained by the operation of the clutch C-1 and the operation of the brake B-1.

When shifting from the second speed to the third speed, the solenoid valve S-1 supplies pressure to the clutch C-1 and continues to operate the clutch C-1, while the solenoid valve S-0 is operated.
Supplies pressure to the clutch C-0 to operate it. At this time, since the relay valve R / V receives the same pressure on both ends, the stroke position is not decided, but the clutch C
Since pressure is supplied to both -1 and C-0,
Either one of the pressures goes through the relay valve R / V and the brake B-
The servo release chamber S / R of No. 1 is reached, and this is surely deactivated. Therefore, the third speed can be obtained by operating the clutches C-1 and C-0.

Further, when shifting from the third speed to the fourth speed, the solenoid valve S-0 supplies pressure to the clutch C-0 and continues to operate it, and the solenoid valve S-1
Deactivates clutch C-1 and deactivates it. At this time, the relay valve R / V is set to the leftward position in the upper half of the figure, and the servo release chamber S / R is communicated with the clutch C-1 that is no longer supplied with pressure to activate the brake B-1. Therefore, the fourth speed can be obtained by the operation of the clutch C-0 and the operation of the brake B-1.

From the above, the relay valve R / V is connected to the clutch C.
-1 and C-0 are both actuated at the third speed, the pressure is reliably supplied to the servo release chamber S / R to brake B-
The function of ensuring the non-operation of No. 1 is ensured, and it is ensured that the automatic transmission is mechanically locked by the simultaneous operation of the three clutches C-1, C-0 and the brake B-1. Can be prevented.

[0011]

However, in such a conventional interlock prevention measure, the relay valve R / V is
There is also no need to set the switching timing between the operation and non-operation of the friction elements to be changed at the time of gear shift, and this switching timing causes the operating pressure of the clutches C-1 and C-0 to increase due to the solenoid valves S-1 and S-0. Since it depends on the reduction control, these switching timings and the operating pressure increase / decrease control correlate with each other, and the following problems were confirmed.

That is, the operation and non-operation of the friction elements to be replaced at the time of gear shifting are promptly performed so that the responsiveness of gear shifting is emphasized, and the solenoid valves S-1 and S-0 satisfying this are satisfied. When the duty ratio is changed, the frictional elements that are to be actuated at the time of gear shifting are rapidly engaged, resulting in a large gear shift shock. However, if a well-known accumulator is connected to the working pressure circuit of the friction element to prevent the shift shock, and the working pressure is smoothly raised, the relay valve R /
The switching of V is delayed, causing a delay in switching between the frictional elements and non-operating, which causes an extension during the shift.

On the contrary, when the duty ratios of the solenoid valves S-1 and S-0 are changed smoothly with the aim of preventing a large shift shock, this time, the friction element to be changed during the shift is changed. Switching between operation and non-operation is not performed promptly, and the responsiveness of the shift is reduced.

Therefore, in the conventional measures to prevent the interlock of the automatic transmission by adding the relay valve, no matter how the solenoid valve duty ratio change ratio is decided, the response of the speed change is obtained. It was difficult to achieve both high performance and reduction of shift shock at a high level.

Further, in the conventional measures against interlock, if the relay valve added for that purpose is not installed downstream of the solenoid valve for individually controlling the operating pressure of the friction element, a predetermined interlock preventing action cannot be performed. Since the frictional element operating pressure supplied through the relay valve is still low at the beginning of the ascending control by the solenoid valve, it is greatly affected by the resistance due to the relay valve, and in this respect also the deterioration of the shift response is unavoidable.

According to the present invention, the switching of the friction elements is performed independently rather than the conventional switching of the friction elements by electronically controlling the operating pressures of the friction elements. Therefore, the main purpose is to propose a shift control device for an automatic transmission that does not cause the above-mentioned problems, and an interface of the automatic transmission is provided in a functional portion for switching between operation and non-operation of the friction element. The subordinate purpose is to implement interlock prevention measures by also providing a lock prevention function.

[0017]

SUMMARY OF THE INVENTION For the above-mentioned main purpose, a shift control device for an automatic transmission according to a first aspect of the present invention is configured to selectively actuate a plurality of friction elements by fluid pressure to selectively shift gears of a shift gear mechanism. In the automatic transmission adapted to determine the speed, between the pressure source of the fluid pressure and the plurality of friction elements, a plurality of switching valves that determine which of the friction elements the fluid pressure is directed to, , An operating pressure electronic control valve for individually electronically controlling the operating pressures of the plurality of friction elements, and the switching valve individually according to the selected gear stage,
It is characterized in that switching valve electronic control means for controlling switching so that the fluid pressure is directed to the friction element for achieving the selected shift speed is provided.

Further, in the shift control device of the automatic transmission according to the second aspect of the present invention, for the above-described object, the plurality of switching valves are mechanically locked by any combination of switching positions. It is characterized in that it is configured so that the fluid pressure is not directed to the friction element of the combination that causes the.

Furthermore, a shift control device for an automatic transmission according to a third aspect of the present invention is characterized in that the operating pressure electronic control means is arranged on the downstream side closer to the friction element than the plurality of switching valves.

[0020]

In the first aspect of the invention, the automatic transmission determines the selected shift speed of the speed change gear mechanism by selectively operating a plurality of friction elements with fluid pressure. By the way, at the time of shifting, a plurality of switching valves are electronically controlled by individual switching valve electronic control means, and among the plurality of friction elements,
A fluid pressure can be directed to the friction element to achieve the selected gear, and the fluid pressure actuation of the friction element can achieve the selected gear. On the other hand, at this time, the operating pressure electronically controlled valve is
The operating pressures of the plurality of friction elements are individually electronically controlled.

Therefore, the individual control of the plurality of friction element operating pressures by the operating pressure electronic control valve and the operation / non-operation switching of the friction elements by the plurality of switching valves can be independently performed without any correlation. It is possible to reduce the shift shock due to and the shift responsiveness due to the latter at a high level.

In the shift control device for an automatic transmission according to the second aspect of the present invention, the plurality of switching valves are fluid pressure applied to a friction element of a combination which causes a mechanical locked state of the transmission gear mechanism by any combination of switching positions. Therefore, even if any failure occurs, therefore, even if a plurality of switching valves are left in any switching position, a mechanical lock state of the transmission gear mechanism is generated. Therefore, in addition to the effect of the first invention, the effect of preventing interlock can be achieved.

In the shift control device for the automatic transmission according to the third aspect of the present invention, the operating pressure electronic control means is arranged on the downstream side closer to the friction element than the plurality of switching valves. The fluid pressure after passing through is controlled by the operating pressure electronic control valve and becomes the operating pressure to the friction element, so that the operating pressure toward the friction element is not affected by the resistance of the switching valve, It is possible to eliminate the adverse effect that the shift responsiveness deteriorates.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a speed change gear mechanism that forms a power transmission train of an automatic transmission to which a shift control device according to an embodiment of the present invention is applied, and FIG. 2 is a fastening logic table of a plurality of friction elements in the power transmission train. Indicates. The transmission train of the transmission gear mechanism shown in FIG. 1 was developed by the applicant of the present application and is in practical use.
N Maxima New Car Manual, "Introduction of Changes to J30 Type Cars" 1
The input shaft I / S to which the rotational power is transmitted from the crankshaft C / S of the engine ENG via the torque converter T / C and the input shaft I / S similar to those described in August 991 (FOO7671) It comprises an output shaft O / S arranged coaxially, and comprises a first planetary gear set G1 and a second planetary gear set G2 coaxially provided on these input / output shafts, and various friction elements described later.

The torque converter T / C has a lockup clutch L / C, and when the working fluid is passed through the torque converter T / C, the working fluid is passed from the apply chamber AP to the release chamber RE. When the lockup clutch L / C is engaged, the torque converter T / C enters a lockup state in which the input and output elements are directly connected, and the working fluid flows in the opposite direction.
Is released, the torque converter T / C enters a converter state in which the direct connection between the input and output elements is released.

The first planetary gear set G1 includes a sun gear S1, a ring gear R1, a pinion P1 meshing with these, and a pinion carrier PC1 rotatably supporting the pinion P1.
A normal planetary gear set consisting of a second planetary gear set G
2 is also a simple planetary gear set including a sun gear S2, a ring gear R2, a pinion P2, and a pinion carrier PC2.

Next, the first to third clutches C1, C2 and C3, which are various friction elements that control the shift control, and the first and second clutches.
Brake B1, B2, and one-way clutch OWC
Will be explained. The carrier PC1 can be appropriately connected to the input shaft I / S via the second clutch C2, the sun gear S1 can be appropriately fixed by the second brake B2, and can be appropriately connected to the input shaft I / S by the first clutch C1. And The carrier PC1 can be further appropriately fixed by the first brake B1 and prevents reverse rotation (rotation in the direction opposite to the engine) via the one-way clutch OWC. The ring gear R1 is integrally connected to the carrier PC2 and drivingly connected to the output shaft O / S, and the sun gear S2 is connected to the input shaft I / S. The ring gear R2 can be appropriately coupled to the carrier PC1 via the third clutch C3.

First to third clutches C1, C2 and C3,
The first and second brakes B1 and B2 are actuated by the supply of hydraulic pressure to perform the appropriate coupling and fixing, respectively. However, the power transmission train of FIG. 1 includes the first to third clutches C.
1, C2, C3 and first and second brakes B1, B2
2 are operated in various combinations (shown by circles) as shown in the table of FIG. 2 in combination with the appropriate operation (engagement) of the one-way clutch OWC to constitute the planetary gear sets G1 and G2. Of the input shaft I / S
By changing the rotation speed ratio of the output shaft O / S with respect to the rotation speed of, the forward four speeds and the reverse first speed can be obtained. The first brake B1 is operated at the first speed when engine braking is required at the first speed, and when the first brake B1 is not operated, the one-way clutch OWC receives a reaction force. Although the first speed is achieved, engine braking is impossible due to idling of the one-way clutch OWC.

First to third clutches C as shown in FIG.
1 and C2 and C3 are operated and deactivated, and the first and second brakes B1 and B2 are operated and deactivated to select a predetermined shift speed. Four
The configuration is shown in. Here, in FIG. 3 and FIG. 4, due to space limitations, the hydraulic circuit of the gear shift control device in this example has the oil passage portion A. It is divided and shown in B, C, and D. This shift control device includes an oil pump O / P, a pressure regulator valve 1, a manual valve 2, a torque converter relief valve 3, a lockup control valve 4, and a pilot valve 5.
A first shift valve 6 and a second shift valve 7 that form a plurality of switching valves in the present invention, a third clutch control valve 8, a second brake control valve 9 that forms an operating pressure electronic control valve in the present invention, and The two-clutch control valve 10, the L-range pressure reducing valve 11, the first shift solenoid SOL1 and the second shift solenoid SOL2 that form the switching valve electronic control means in the present invention, and the third clutch solenoid SOL.
3, second brake solenoid SOL4, second clutch solenoid SOL5, line pressure solenoid SOL6
And a lockup solenoid SOL7 and an accumulator ACC.
C2, C3, first and second brakes B1, B2, and torque converter T / C are connected as shown in the figure.

The oil pump O / P supplies the discharge oil to the oil passage 10.
1 through port 201 of pressure regulator valve 1
Supply to. Here, the pressure regulator valve 1
The spool 301 is set to the upper limit position shown by the regulator spring 302, and the port 201 is connected to the port 2
The pressure of the hydraulic oil from the oil passage 101 to the port 201 is increased without being connected to either 05 or 206, and the line pressure P _L is generated. This line pressure P _L is fed back to the port 202 via the oil passage 102, and acts on the pressure receiving area difference between the lands 301a and 301b set on the spool 301 to lower the spool 301 as the line pressure P _L increases. Thereby reducing the increase in line pressure P _L via the port 201 is a port 205, for the rise of a further line pressure P _L, that the port 201 is communicated to port 206, increase of the line pressure P _L Prevent. Therefore, the pressure regulator valve 1 regulates the line pressure P _L to a value corresponding to the spring force of the regulator spring 302.

By the way, the regulator spring 302
Is seated on the plug 303, and the plug 303
The stroke position of is due to the solenoid pressure for controlling the line pressure supplied from the line pressure solenoid SOL6 to the port 203 via the circuit 103, and the reverse travel range pressure supplied from the manual valve 2 to the port 204 via the oil passage 104. Since it is determined, the line pressure P _L can be arbitrarily controlled according to the operating state via the line pressure solenoid SOL6, and can be set to a special value during reverse traveling. Here, when traveling backward, port 204
The backward traveling range pressure to the plug 303 acts on the pressure receiving area difference between the lands 303a and 303b set in the plug 303.
In order to increase the spring force of the regulator spring 302 by making 03 stroke upward in the figure, the line pressure P _L is made particularly high when traveling backward.

The pilot valve 5 includes a spool 310 elastically supported by a spring 311 at a position shown in the drawing, and an input port 220 communicates with an output port 221 at this spool position.
Therefore, the pilot pressure P _p, which is the output pressure from the port 221 to the oil passage 106, increases with the line pressure P _L input from the oil passage 105 to the port 220. This pilot pressure P
_p is fed back to the circuit 222 through the oil passage 107, and as the pilot pressure P _p rises, the spool 310 is lowered against the spring 311 in the figure, and finally the output port 22.
Connect 1 to the drain port. Therefore, the pilot valve 5
The pilot pressure P _p is controlled to a constant value corresponding to the spring force of the spring 311.

This pilot pressure P _p passes through the oil passage 108 to the lockup solenoid SOL7, and also to the oil passage 10
9 and 110 to the first shift solenoid SOL1 and further oil passages 109 and 111 to the second shift solenoid SO1.
L2, through the oil passages 109 and 112 to the third clutch solenoid SOL3, further through the oil passages 109 and 113 to the third brake solenoid SOL4, and the oil passages 109 and 1
In addition to reaching the second clutch solenoid SOL5 via 14, the line pressure solenoid SOL7 is reached via the oil passage 115.

The line pressure solenoid SOL7 reduces the constant pilot pressure P _p input through the oil passage 115 according to the drive duty to create a solenoid pressure for controlling the line pressure, which is supplied via the oil passage 103. It is supplied to the pressure regulator valve 1 to help control the line pressure P _L. Therefore, by controlling the duty of the line pressure solenoid SOL7, it is possible to generate a line pressure P _L suitable for the operating state in the oil passage 101, and to supply this to the input port 210 of the manual valve 2 and to the accumulator ACC. Supply as pressure.

During the adjustment of the line pressure P _L by the pressure regulator valve 1 described above, the surplus oil discharged from the port 205 flows into the port 230 of the torque converter relief valve 3 through the oil passage 120, and the surplus oil is discharged. Flows into the end chamber 231 of the torque converter relief valve 3 through the oil passage 121 provided in the spool 320 of the torque converter relief valve. The oil that has flowed into this chamber 231 acts on the corresponding end surface of the spool 320, and
0 is pushed upwards in the figure against the spring 321 and the spring 32
Pressurized with a reaction force of 1. The hydraulic pressure generated by this is output from the port 232 to the oil passage 122, and the spool 320 is raised in the figure as the pressure rises. When the spool 320 communicates the port 230 with the drain port 233, the hydraulic pressure output from the port 232 to the oil passage 122 is
It cannot be higher than that, and the oil pressure is at this time the spring 321.
The pressure is adjusted to a constant value corresponding to the spring force of.

Here, the constant hydraulic pressure to the oil passage 122 is set to a value at which the torque converter T / C is not destroyed, and the torque converter relief valve 3 has a function of preventing the torque converter T / C from being destroyed. . The constant hydraulic pressure to the oil passage 122 thus regulated by the torque converter relief valve 3 is supplied to the lockup control valve 4.

Next, to explain the lockup control system of the torque converter T / C, this lockup control is performed by the lockup solenoid SOL7 via the lockup control valve 4 as follows.

The lockup solenoid SOL7 is described above.
As shown in FIG.
Pilot pressure P_pHas been supplied by this pilot
Pressure P _pIs regulated by the drive duty according to the running condition.
From the oil passage 123 to the end chamber 24 of the lockup control valve 4.
Supply to 0. Lockup control valve 4 is a valve spool
330, the spool 330 to the end chamber 240
It is urged to the left in the figure by the solenoid pressure. On the other hand, oil passage
The hydraulic pressure introduced to 122 causes oil passages 124 and 125 to flow.
Is introduced into the port 241 of the lockup control valve 4 via
The oil introduced through this port 241 is
Of the land 330 between the lands 330a and 330b.
It acts on the pressure area difference, and the spool 330 is also leftward in the drawing.
Urge to.

On the contrary, the lockup control valve spool 3
The force for urging 30 in the right direction in the figure is introduced into the port 242 of the lockup control valve 4 from the oil passage 122 through the oil passage 126 through the spring force of the spring 331 in the lockup control valve 4. The generated hydraulic pressure is generated by acting between the lands 332a and 332b of the plug 332 arranged so as to face the spool 330 in the lockup control valve 4.

When it is determined that the torque converter T / C should be in the lockup state from the running state and a lockup command is issued, the lockup solenoid SOL7 is activated.
The solenoid pressure from the oil passage 123 to the oil passage 123 is maximized. At this time, the force for urging the valve spool 330 and the plug 332 to the left in the drawing overcomes the force for urging them to the right, and the spool 330 in the lockup control valve 4 is reversed.
And the plug 332 is shifted to the left in the drawing. Therefore, the release chamber RE of the torque converter T / C is
7 and the port 244 of the lock-up control valve 4 and the drain port 243 are opened to the atmosphere, and the apply chamber AP of the torque converter T / C passes through the oil passage 128 and the port 245 of the lock-up control valve 4 to the port 242.
Lead to Therefore, the oil introduced from the torque converter relief valve 3 into the oil passages 122 and 126 is supplied to the torque converter apply chamber AP via the ports 242 and 245 and further via the oil passage 128.

At this time, the torque converter T / C allows the working fluid to flow from the apply chamber AP to the release chamber RE, and the power is transmitted in the lockup state in which the lockup clutch L / C shown in FIG. 1 is engaged. It can be performed.

During the passage through the oil passage 128, the hydraulic oil is
Although it is supplied to the rear lubrication portion of the power transmission mechanism and the differential gear device through the oil passage 129 and the orifice and used for lubrication thereof, although not shown in the drawings,
It shall also be supplied to the front lubrication part of the power transmission mechanism.

Next, the torque converter T /
When it is determined that C should be in the converter state and the lockup command is erased, the lockup solenoid SO
Solenoid pressure from L7 to oil passage 123 is minimized.
At this time, the force that urges the valve spool 330 and the plug 332 to the left in the figure is reduced, and as a result, the force that urges the valve spool 330 and the plug 332 to the right becomes the force that urges to the left. Overcome and shift the valve spool 330 and the plug 332 to the right in the drawing. At this time, the release chamber RE of the torque converter T / C communicates with the oil passage 125 via the oil passage 127 and the ports 244 and 241.
P communicates with oil passage 130 via oil passage 128 and ports 245, 246.

At this time, the torque converter T / C allows the working fluid to flow from the release chamber RE to the apply chamber AP, and the power is transmitted in the converter state in which the lockup clutch L / C shown in FIG. 1 is released. It can be carried out.

The hydraulic oil that has reached the oil passage 130 after flowing through the torque converter is supplied to the rear lubrication portion of the power transmission mechanism and the differential gear device through the orifice, and is used for lubrication thereof. Although not shown in the figure, it is assumed that the power is also supplied to the front lubrication part of the power transmission mechanism.

The manual valve 2 is manually operated via a select lever and a shift linkage (not shown) in accordance with the traveling mode desired by the driver. The selectable traveling modes include parking (P) range and backward traveling ( The R) range, the stop (N) range, the forward automatic shift travel (D) range, and the first speed engine brake (L) range are set. On the other hand, in the manual valve 2, as described above, the line pressure P _L of the oil passage 101 regulated by the pressure regulator valve 1 is introduced into the input port 210, and the line pressure P _L to the input port 210 depends on the selected range. _L is output port 2D, 2L,
2R is selectively led to drain all the output ports that are not supplied with the line pressure P _L.

In the P and N ranges of the manual valve 2, all the output ports 2D, 2L and 2R are connected to the drain, and in the D range, the line pressure P _{L of the} port 210.
Is supplied to the port 2D as D range pressure, in the L-range, supplied as L range pressure line pressure P _L of the port 210 to the port 2D and 2L, the R-range, the port of the line pressure P _L of the port 210 It shall be supplied to 2R as R range pressure.

Here, the manual valve output port 2R is
It is connected to the oil passage 104 from the pressure regulator valve 1 and is connected to the first clutch C1 via the one-way orifice 212 and the accumulator ACC via the oil passages 118 and 119, and is also connected to the first via the oil passage 118 and the shuttle valve 211. Connect to brake B1. Also,
The manual valve output port 2D passes through the oil passage 116 and reaches the second
The oil passage 11 is connected to the port 281 of the shift valve 7.
It is also connected to the ports 261 and 262 of the first shift valve 6 via the oil passages 132 and 133 branched from 6. Further, the manual valve output port 2L is connected to the input port 250 of the L range pressure reducing valve 11 via the oil passage 117.

The L range pressure reducing valve 11 supplies the L range pressure output from the port 2L in the L range of the manual valve 2 to the input port 250. Here, L range pressure reducing valve 1
Since the spool 340 of No. 1 is pushed downward in the figure by the spring force of the spring 341, the input port 250 and the output port 251 are in communication with each other, and the L range pressure to the port 250 is the output port 251. The output pressure of the oil passage 130 connected to is increased. And oil passage 130
Is fed back to the end chamber 252 of the L range pressure reducing valve 11 via the oil passage 131, and the spool 340 is caused to stroke upward in the drawing as the output pressure increases. When the output pressure of the oil passage 130 reaches a value corresponding to the spring force of the spring 341, the spool 340 changes to the output port 2
51 to the drain port 253, and the oil passage 13
Do not raise 0 output pressure. Therefore, L range pressure reducing valve 11
Reduces the L range pressure (the same value as the line pressure P _L ) output from the port 2L in the L range of the manual valve 2 to a value corresponding to the spring force of the spring 341 and outputs it to the oil passage 130. Is supplied to the port 263 of the first shift valve 6 via the oil passage 130.

Next, the first shift valve 6 and the second shift valve 7 will be described. In these shift valves, the D range pressure output from the port 2D in the D range of the manual valve 2 is as follows. Supplied. In other words, the D range pressure is
It is introduced into the ports 261 and 262 of the first shift valve 6 through the oil passages 116 and 132 and also through the oil passages 116 and 133, and is also introduced into the port 281 of the second shift valve 7 through the oil passage 116. To be done. Further, when the L range pressure is output from the port 2L to the oil passage 117 in the L range of the manual valve 2, the D range pressure is introduced to the first shift valve 6 and the second shift valve 7 as described above. In addition to being done,
The pressure in the oil passage 130 obtained by reducing the L range pressure in the oil passage 117 with the L range pressure reducing valve 11 is additionally introduced into the port 263 of the first shift valve 6.

The first shift valve 6 has a spool 350 elastically supported by a spring 351 at a position shown in the figure. When the first shift solenoid SOL1 is turned on (closed), the pilot pressure P _p of the oil passage 110 is passed through the oil passage 134. When the solenoid pressure is output to the end chamber 264, the solenoid pressure switches the spool 350 to the opposite stroke position against the spring 351. Also, the second shift valve 7
When the spool 360 is elastically supported by the spring 361 at the position shown in the figure, and when the second shift solenoid SOL2 is turned on (closed), the pilot pressure P _p of the oil passage 111 is output as solenoid pressure to the end chamber 282 via the oil passage 135. It is assumed that the solenoid pressure switches the spool 360 to the opposite stroke position against the spring 361.

Here, the shift solenoids SOL1, SO
It is assumed that L2 selects a desired gear stage by turning ON and OFF based on the logic shown in FIG. 5, and ON and OFF of these shift solenoids are electronically controlled by a microcomputer or the like. In other words, the microcomputer or the like determines the traveling state from the vehicle speed and the throttle opening degree, calculates the shift stage suitable for this traveling state, and shift solenoids SOL1, SOL to achieve this shift stage.
2 shall be ON / OFF controlled.

The first shift valve 6 has the port 26 when the spool 350 is in the position shown by the spring 351.
Between 2 and 265, drain port 267 and port 268
The ports 261 and the confinement ports 266, and the ports 263 and 269, respectively.
0 is the spring 3 due to the solenoid pressure to the end chamber 264.
When the stroke is reversed from the position shown in the figure against 51, the port 265 and the drain port 267, the ports 261 and 268, the ports 263 and 266, and the port 269 and the drain port 270 are connected to each other. To

The second shift valve 7 has a port 2 when the spool 360 is in the position shown by the spring 361.
83, 284, the ports 281, 285, the drain port 286, and the port 288 are communicated with each other, and the spool 360 is stroked from the illustrated position to the opposite position against the spring 361 by the solenoid pressure applied to the end chamber 282. Port 281,284, drain port 286 and port 285, ports 287,28
8 are connected to each other.

Here, between the first shift valve 6 and the second shift valve 7, the ports 265, 283 are connected by the oil passage 136, and the ports 269, 287 are connected by the oil passage 140. Then, the port 268 of the first shift valve 6
Is connected to the input port 401 of the second brake control valve 9 by an oil passage 137, and the port 284 of the second shift valve 7 is connected by an oil passage 138 to the input port 291 of the third clutch control valve 8.
And connect the port 285 of the second shift valve 7 to the oil passage 139.
Is connected to the input port 411 of the second clutch control valve 10, and the port 287 of the second shift valve 7 is connected to the input port of the shuttle valve 211 by the oil passage 141.

The third clutch control valve 8 controls the input pressure to the port 291 to the port 293 according to the solenoid pressure supplied from the output oil passage 141 of the third clutch solenoid SOL3 to the end chamber 292. The spool 370, which outputs pressure, responds to the solenoid pressure in the end chamber 292.
Then, the spring 371 is caused to act in the direction opposite to the solenoid pressure. Here, the third clutch pressure from the port 293 is fed back to the end chamber 294 in which the spring 371 is accommodated via the oil passage 142 on the one hand, and is supplied to the third clutch C3 via the oil passage 143 on the other hand.

The third clutch solenoid SOL3 supplies the solenoid pressure according to the drive duty from the oil passage 141 to the end chamber 292 of the third clutch control valve 8 using the pilot pressure P _p from the oil passage 112 as the original pressure. Then, the drive duty is arbitrarily determined by the microcomputer according to the traveling state. The third clutch control valve 8 is
As the solenoid pressure rises to the end chamber 292, the spool 3
70 is stroked from the position shown in the figure against the spring 371, and the port 293 is largely communicated with the port 291 as the solenoid pressure increases, thereby increasing the third clutch pressure from the port 293. This third clutch pressure is applied to the end chamber 2
As it is fed back to 94, as it rises, the spool 370 is pushed back and the port 293 is communicated with the drain port 295, so that the third clutch pressure is applied to the end chamber 2
It does not rise above the value corresponding to the solenoid pressure to 92,
The third clutch pressure can be arbitrarily controlled by the drive duty of the third clutch solenoid SOL3.

The second brake control valve 9 controls the input pressure to the port 401 to the second brake to the port 403 according to the solenoid pressure supplied from the output oil passage 144 of the second brake solenoid SOL4 to the end chamber 402. The spool 380, which outputs the pressure, responds to the solenoid pressure in the end chamber 402.
Then, the spring 381 is actuated in the direction opposite to the solenoid pressure. Here, the second brake pressure from the port 403 is fed back to the end chamber 404 in which the spring 381 is accommodated via the oil passage 145 on the one hand, and is supplied to the second brake B2 via the oil passage 146 on the other hand.

The second brake solenoid SOL4 supplies the solenoid pressure corresponding to the drive duty from the oil passage 144 to the end chamber 402 of the second brake control valve 9 using the pilot pressure P _p from the oil passage 113 as the original pressure. Then, the drive duty is arbitrarily determined by the microcomputer according to the traveling state. The second brake control valve 9 is
When the solenoid pressure is increased to the end chamber 402, the spool 3
80 is stroked from the position shown in the figure against the spring 381 to cause the port 403 to largely communicate with the port 401 as the solenoid pressure rises, thereby increasing the second brake pressure from the port 403. This second brake pressure is applied to the end chamber 4
04, the spool 380 is pushed back as it rises, causing the port 403 to communicate with the drain port 405, so that the second brake pressure is applied to the end chamber 4
It does not rise above the value corresponding to the solenoid pressure to 02,
The second brake pressure can be arbitrarily controlled by the drive duty of the second brake solenoid SOL4.

The second clutch control valve 10 extends from the output oil passage 147 of the second clutch solenoid SOL5 to the end chamber 412.
In accordance with the solenoid pressure supplied to the port 411, the input pressure to the port 411 is controlled and output to the port 413 as the second clutch pressure. The spool 390 is provided which responds to the solenoid pressure in the end chamber 412.
Then, the spring 391 is applied in the direction opposite to the solenoid pressure. Here, the second clutch pressure from the port 413 is fed back to the end chamber 414 in which the spring 391 is accommodated via the oil passage 148 on the one hand, and is supplied to the second clutch C2 via the oil passage 149 on the other hand.

The second clutch solenoid SOL5 supplies the solenoid pressure according to the drive duty from the oil passage 147 to the end chamber 412 of the second clutch control valve 10 using the pilot pressure P _p from the oil passage 114 as the original pressure. Then, the drive duty is arbitrarily determined by the microcomputer according to the traveling state. Second clutch control valve 10
Is stroked against the spring 391 from the position shown in the drawing by the increase of the solenoid pressure to the end chamber 412, causing the port 413 to largely communicate with the port 411 as the solenoid pressure increases, and the second clutch from the port 413. Increase pressure. Since this second clutch pressure is fed back to the end chamber 414, as it rises, the spool 390 is pushed back to cause the port 413 to communicate with the drain port 415, so that the second clutch pressure corresponds to the solenoid pressure to the end chamber 412. Does not rise above the specified value, and the second clutch pressure is set to the second clutch solenoid SOL5.
Can be arbitrarily controlled by the drive duty of.

The shifting operation of the above embodiment will be described below. (P, N range) If the driver wants to park or stop,
When the manual valve 2 is set to the P range or the N range, the manual valve 2 does not supply the line pressure P _L of the input port 210 to any of the output ports 2L, 2D, 2R and the output ports 2L, 2D, 2R. Drain all. Therefore, on the hydraulic circuits of FIG. 3 and FIG. 4, all the friction elements C1, C2, C3, B1, B2 whose operating hydraulic pressure is the pressure from the manual valve output ports 2L, 2D, 2R are deactivated. The gear transmission mechanism shown in FIG. 1 is in a neutral state in which power is not transmitted and enables parking or stopping.

(D range) When the driver desires the automatic forward variable speed running and sets the manual valve 2 to the D range, the manual valve 2 sets the line pressure P _L of the input port 210 to the port 2D as the D range pressure. It is output and this D range pressure is supplied to the corresponding ports of the first and second shift valves 6 and 7.

D-range first speed When the microcomputer determines from driving conditions that the first speed should be selected, the first shift solenoid SOL1 is turned off and the second shift solenoid SOL is turned on as shown in FIG.
Turn on 2. Therefore, the solenoid pressure of SOL1 is not generated, but the solenoid pressure of SOL2 is generated. At this time,
The first shift valve spool 350 is at the position shown in the figure, which is pushed upward by the spring force of the spring 351.
The second shift valve spool 360 moves from SOL2 to the oil passage 13
The solenoid pressure supplied to the end chamber 282 via 5 causes the spring 361 to be pushed downward against the spring force of the spring 361.

As a result, the port 262 of the first shift valve 6
And 265 are in communication with each other, and through the oil passage 133 to port 2
The D range pressure introduced to 62 is introduced to the oil passage 136 via the port 265, and further to the port 283 of the second shift valve.
Will be introduced to. However, since the second shift valve spool 360 shifts downward and blocks the port 283,
The D range pressure from the route does not contribute to the shift. On the other hand, through the oil passage 132, the port 2 of the first shift valve 6
The D range pressure introduced into 61 reaches the containment port 266, but since the port 266 itself is not connected to any oil passage, the D range pressure from that passage does not contribute to the gear shifting. Further, since the drain port 268 of the first shift valve 6 communicates with the drain port 267 to eliminate the original pressure of the second brake control valve 9, the operating pressure of the second brake B2 is not generated.

On the other hand, the D range pressure introduced into the port 281 of the second shift valve 7 via the oil passage 116 is equal to the second range pressure.
Since the spool 360 of the shift valve 7 shifts downward and communicates between the ports 281 and 284, it is introduced into the oil passage 138 through these ports 281 and 284,
Further, it is introduced into the input port 291 of the third clutch control valve 8. As described above, the third clutch control valve 8 can control the third clutch pressure for engaging the third clutch C3 by the solenoid pressure from the solenoid SOL3.
Under the control, the third clutch C3 can be engaged at the first speed. On the other hand, the spool 3 of the second shift valve 7
Since 60 is shifted downward, the port 285 of the second shift valve 7 communicates with the drain port 286, and the source pressure of the second clutch control valve 10 communicating with the port 285 does not exist. Become. Therefore, the engagement operating pressure of the second clutch C2 is not generated, and as a result, the second clutch C2 is not engaged in the first speed.

As described above, when the first speed is selected, only the third clutch C3 of the friction elements is engaged, and the other clutches and brakes are not engaged. Therefore, as is apparent from FIG. 2, the first speed selection state can be obtained as required. In this case, in FIG. 2, the mark ◯ in the column B1 (OWC) means the operation of the one-way clutch OWC, and therefore the D range first
Engine braking does not work at high speeds.

D range second speed When the microcomputer determines from driving conditions that the second speed should be selected, the first shift solenoid SOL1 is turned on and the second shift solenoid SOL2 is turned on as shown in FIG.
Turn ON. Therefore, the solenoid pressure of SOL1 is generated, and the solenoid pressure of SOL2 is also generated. At this time the first
The shift valve spool 350 is shifted downward in the figure against the spring force of the spring 351 by the solenoid pressure supplied from the SOL 1 to the end chamber 264 via the oil passage 134, and the second shift valve spool 360 is also the above-mentioned. As in the case of the first speed, the position is shifted downward in the figure.

As a result, the ports 261 and 268 of the first shift valve 6, which were blocked at the first speed, are brought into communication with each other, and the D range pressure introduced through the oil passage 132 is applied to these ports 261 and 268 and the oil passage. It is introduced into the input port 401 of the second brake control valve that controls the engagement hydraulic pressure of the second brake B2 via 137. Second brake control valve 9
As described above, the engagement operating pressure of the second brake B2 can be arbitrarily determined by the duty control of the solenoid SOL4, and the second brake B2 can be engaged and operated at the second speed.

Further, since the spool 360 of the second shift valve 7 is at the same downward stroke position as in the case of the first speed, the D range pressure introduced into the port 281 of the second shift valve 7 via the oil passage 116. Is introduced into the input port 291 of the third clutch control valve 8 via the port 284 and the oil passage 138, and is used for engaging operation of the third clutch C3. On the other hand, since the spool 360 of the second shift valve 7 is at the same downward stroke position as in the first speed, the port 285 and the drain port 286 of the second shift valve 7 are in communication with each other, and as a result, the second speed is established. Even when is selected, the D range pressure is not supplied to the second clutch C2, and the second clutch C2 is not engaged.

Therefore, the third clutch C3 is engaged and the second brake B2 is engaged, and the other clutches and brakes are not engaged. As is apparent from FIG. 2, the second speed selection is performed as required. You can get the status.

When the D range third speed microcomputer determines from driving conditions that the third speed should be selected, both the first shift solenoid SOL1 and the second shift solenoid SOL2 are turned off as shown in FIG. Therefore, the solenoid pressure of SOL1 is not generated and the solenoid pressure of SOL2 is not generated. At this time, the first shift valve spool 350 is in the position shown in the figure pushed upward by the spring force of the spring 351, and the second shift valve spool 360 is also pushed upward in the figure by the spring force of the spring 361. It is in the illustrated position.

As a result, the first shift valve 6 has the port 262.
And 265 are brought into communication with each other, and the D range pressure introduced through the oil passage 133 is introduced into the port 283 of the second shift valve 7 via these ports 262 and 265 and the oil passage 136. By the way, since the second shift valve spool 360 shifts upward and makes the ports 283 and 284 communicate with each other, the D range pressure to the port 283 passes through the port 284 and the oil passage 138 and becomes the port of the third clutch control valve 8. 29
1 to enable the engagement operation of the third clutch C3.

On the other hand, the D range pressure introduced into the port 261 of the first shift valve 6 via the oil passage 132 is caused by the upward shift position of the first shift valve spool 350, and thus the port of the first shift valve 6 is caused. 266, but since the port 266 itself is not connected to any oil passage, the D
Range pressure does not contribute to shifting. Further, due to the upward shift position of the first shift valve spool 350,
The port 268 of the shift valve 6 communicates with the drain port 267, drains the input port 401 of the second brake control valve 9, and inhibits the engagement operation of the second brake B2.

On the other hand, the D range pressure introduced into the port 281 of the second shift valve 7 through the oil passage 116 is caused by the upward shift of the second shift valve spool 360, and the ports 281 and 285 and the oil. It is introduced into the input port 411 of the second clutch control valve 10 via the path 139 and enables the engagement operation of the second clutch C2. On the other hand, due to the upward shift of the second shift valve spool 360, the port 288 of the second shift valve 7 communicates with the drain port 286, and the first brake B1 that communicates with the port 288.
The operating pressure oil passage 141 is drained, resulting in the first
The engagement operation of the brake B1 is prohibited.

Therefore, when selecting the third speed, the third speed is selected.
Only the clutch C3 and the second clutch C2 are engaged, and the other clutches and brakes are not engaged, and as is apparent from FIG. 2, the third speed selection state can be obtained as required.

D range 4th speed When the microcomputer determines from driving conditions that the 4th speed should be selected, the first shift solenoid SOL1 is turned on and the second shift solenoid SOL2 is turned on as shown in FIG.
Turn off. Therefore, the solenoid pressure of SOL1 is generated and the solenoid pressure of SOL2 is not generated. At this time, the first shift valve spool 350 moves from SOL1 to the oil passage 134.
The solenoid pressure supplied to the end chamber 264 via
It is shifted downward in the figure against the spring force of the spring 351, and the second shift valve spool 360 is in the position shifted upward in the figure by the spring force of the spring 361.

As a result, the port 26 of the first shift valve 6
The D range pressure introduced through the oil passage 132 is supplied to the input port 401 of the second brake control valve 9 via the ports 261 and 268 and the oil passage 137. Therefore, the engagement operating pressure of the second brake B2 can be generated under the duty control by the solenoid SOL4, and the engagement operation of the second brake B2 can be performed.

Further, due to the downward shift of the first shift valve spool 350, the port 265 becomes the drain port 26.
7 and the ports 283, 2 due to the upward shift of the second shift valve spool 360.
84 are communicated with each other, and as a result, the input port 291 of the third clutch control valve 8 is drained. As a result, the engagement operation of the third clutch C3 can be prohibited. On the other hand, due to the upward shift of the second shift valve spool 360, the ports 281 and 285 of the second shift valve 7 are communicated with each other. As a result, the port 2 is connected via the oil passage 116.
The D range pressure introduced into 81 is introduced into the input port 411 of the second clutch control valve 10 via the port 285 and the oil passage 139, so that the second clutch C2 can be engaged.

Therefore, when selecting the fourth speed, the second speed is selected.
Only the clutch C2 and the second brake B2 are engaged, and the other clutches and brakes are not engaged, and as is apparent from FIG. 2, the fourth speed selection state can be obtained as required.

(L range) When the driver desires engine braking at the first speed and sets the manual valve 2 to the L range, the manual valve 2 causes the line pressure P to the port 210 to reach P.
_L, and the addition to also output to the port 2D as in the D range, the line pressure port 210 to port 2L P _L
Is output as L range pressure. The L range pressure output from the port 2L reaches the L range pressure reducing valve 11 from the oil passage 117, is reduced to a predetermined pressure, and then is supplied to the port 263 of the first shift valve 6 by the oil passage 130.

In the L range, the microcomputer turns off the first shift solenoid SOL1 and turns on the second shift solenoid SOL2 as in the case of the D range first speed. Therefore, as in the case of the first speed in the D range, the first shift valve 6 strokes the spool 350 to the upper position in the figure, and the second shift valve 7 moves the spool 36 to the upper position.
0 is stroked to the lower position in the figure,
The first speed selection state can be achieved by engaging the clutch C3.

At the same time, since the upper stroke position of the first shift valve spool 350 passes between the ports 263 and 269 and the lower stroke position of the second shift valve spool 360 passes between the ports 287 and 288, the L range pressure reducing valve 11 The pressure reduced by the
It is supplied to the first brake B1 via 9, 287, 288, the oil passage 141, and the shuttle valve 211, and the first brake B1 can be engaged and operated.

Therefore, in the L range, the D range first
Similar to the case of the speed, the first brake B1 is engaged in addition to the engagement operation of the third clutch C3, which enables the engine brake traveling at the first speed.

(R range) When the driver desires backward traveling and sets the manual valve 2 to the R range, the manual valve 2 outputs the line pressure P _L to the port 210 to only the port 2R as the R range pressure, Drain all other output ports 2D and 2L. The R range pressure from the port 2R reaches the first brake B1 via the oil passage 118 and the shuttle valve 211 on the one hand to engage the same, and on the other hand, the oil passage 11
It is supplied to the first clutch C1 via 8, 119, the one-way orifice 212, and the accumulator ACC, and engages the first clutch C1. By thus engaging the first clutch C1 and the first brake B1 as shown in FIG.
As can be seen from FIG. 2, the gear transmission mechanism of 1 can be in the reverse gear selection state as required.

(Interlock Preventing Function) The interlock preventing function for preventing the gear transmission mechanism shown in FIG. 1 from becoming mechanically locked will be described below.

Due to a failure of the solenoids SOL1 and SOL2 or its control system, or a stick of the shift valves 6 and 7, the first shift valve 6 is left in the upper shift position of FIG. When there is a failure in which the No. 4 downward shift position is maintained, the third clutch C3 is engaged in the same state as when selecting the first speed. At this time, the first shift valve 6 is in the port 2
68 to the drain port 267 to mechanically drain the operating pressure system of the second brake B2 related to the port 268,
The second brake B2 is never engaged. Further, the second shift valve 7 allows the port 285 to communicate with the drain port 286 to mechanically drain the operating pressure system of the second clutch C2 related to the port 285, never engaging the second clutch C2. Therefore, the second brake B2 and the second clutch C2 are not engaged when the third clutch C3 is engaged, and the interlock of the gear transmission mechanism can be prevented.

With respect to the first clutch C1, since the manual valve 2 drains the output port 2R, it is not engaged and the interlock preventing action can be realized. Also, for the first brake B1, in the L range from the port 2L of the manual valve 2 to the L
When the range pressure is output, it is engaged by this L range pressure, but the first brake B is engaged when the third clutch C3 is engaged.
When 1 is engaged, the gear transmission mechanism does not enter the interlock state, and there is no problem.

Due to the malfunction of the solenoids SOL1 and SOL2 or its control system or the sticking of the shift valves 6 and 7, the first shift valve 6 is left in the lower shift position of FIG. 4, and the second shift valve 7 is also shown. When there is a failure in which the fourth downward shift position is maintained, the third clutch C3 and the second brake B2 are engaged in the same state as when the second speed is selected. At this time, the second shift valve 7 communicates the port 285 with the drain port 286 to mechanically drain the operating pressure system of the second clutch C2 related to the port 285, and never engage the second clutch C2.

Also, in the L range, port 2 of manual valve 2
Even if the L range pressure is output from L, the first shift valve 6 does not direct the L range pressure to the first brake B1 because it is contained in the port 266 by the downward shift position of FIG. B1 is never concluded.
Therefore, when the third clutch C3 and the second brake B2 are engaged, the second clutch C2 and the first brake B1 are
Is not fastened, and the interlock of the gear transmission mechanism can be prevented.

Due to the malfunction of the solenoids SOL1 and SOL2 or its control system or the sticking of the shift valves 6 and 7, the first shift valve 6 is left in the upper shift position of FIG. 4, and the second shift valve 7 is also shown. When there is a failure in which the No. 4 upper shift position is maintained, the third clutch C3 and the second clutch C2 are engaged in the same state as when the third speed is selected. At this time, the first shift valve 6 is moved to the port 26 by the upper shift position of FIG.
8 is connected to the drain port 267 to mechanically drain the operating pressure system of the second brake B2, so that the first brake B2 is never engaged. In addition, the second shift valve 7 communicates the port 288 to the drain port 286 to mechanically drain the operating pressure system of the first brake B1 related to the port 288, so that the L range pressure from the port 2L of the manual valve 2 to the L range pressure is increased in the L range. Even if it is output, the first brake B1 is never activated. Therefore, the third clutch C
Since the second brake B2 and the first brake B1 are not engaged when the third clutch C2 and the third clutch C2 are engaged, interlock of the gear transmission mechanism can be prevented.

Due to a failure of the solenoids SOL1 and SOL2 itself or the control system thereof, or a stick of the shift valves 6 and 7, the first shift valve 6 is left in the lower shift position of FIG. 4, and the second shift valve 7 is turned on. In the event of a failure in which the fourth upper shift position is maintained, the second clutch C2 and the second brake B2 are engaged in the same state as when selecting the fourth speed. At this time, the first shift valve 6 moves to the port 26 due to the downward shift position of FIG.
5 to the drain port 267, and the second shift valve 7 passes between the ports 283 and 284 in the upper shift position of FIG. 4, so that the operating pressure system of the third clutch C3 is connected to these ports 284, 283, 265, 267. And mechanically drain it to never engage the third clutch C3.

The second shift valve 7 connects the port 288 to the drain port 286 at the lower shift position shown in FIG.
The operating pressure system of the first brake B1 relating to the port 288 is mechanically drained, and the port 2 of the manual valve 2 is operated in the L range.
Even if the L range pressure is output from L, the first brake B
Never activate 1. Therefore, the third clutch C3 and the first brake B1 are not engaged when the second clutch C2 and the second brake B2 are engaged, and the interlock of the gear transmission mechanism can be prevented.

As described above, in the present embodiment, even if the shift valves 6 and 7 remain in any combination of shift positions, a plurality of friction elements are simultaneously engaged with a combination that causes an interlock of the gear transmission mechanism. There is no.

(Advantages of Embodiment) The gear shifting action and the interlock preventing action in this embodiment have been described above. However, as in the present embodiment, each friction element, that is, the third clutch C3, the second brake B2, Of the two clutches C2, when determining which frictional element the operating pressure is directed to, the first and second shift solenoids SOL1, SO
The determination is made by the first and second shift valves 6 and 7 that respond to L2, and the third clutch C is used at the time of shifting.
3, the engagement operating pressures of the second brake B2 and the second clutch C2 are set to the individual duty solenoids SOL3, SOL4,
With the configuration in which the SOL 5 is individually controlled via the individual control valves 8, 9 and 10, the following operational effects can be achieved.

In other words, in the case of the configuration like this example,
Switching the operating pressure to the friction element by turning ON / OFF the shift solenoids SOL1 and SOL2, the solenoid SO
It is possible to independently perform the operation pressure control of the friction element by the duty control of L3, SOL4, and SOL5. Therefore, when changing control of frictional elements such as engaging a certain clutch (or brake) and disengaging another clutch (or brake) at the time of shifting, variations in environmental conditions (oil temperature, voltage, etc.) On the other hand, according to the configuration of the present example, it is possible to realize the high-dimensional compatibility depending on the traveling condition and the environmental condition even in the region where it is difficult to achieve both the timing of engaging / disengaging the clutch and the shift shock.

Further, in this embodiment, since the first and second shift valves 6 and 7 for switching the operating pressure are installed upstream of the operating pressure control valves 8, 9 and 10, especially the engagement of the friction element.・ Even when the operating pressure is low, such as when controlling the operating pressure immediately before releasing, it is possible to reduce the flow resistance of hydraulic oil, improve the engagement / release response, and improve the gear shifting performance.

[0098]

As described above, according to the first aspect of the present invention, there is provided a shift control device for an automatic transmission, wherein a plurality of friction elements are selectively actuated by fluid pressure to select a shift stage of a shift gear mechanism. In determining the above, the plurality of switching valves directs the fluid pressure to the friction element for achieving the selected shift stage among the plurality of friction elements under the electronic control of the individual switching valve electronic control means. On the other hand, at this time, since the operating pressures of the plurality of friction elements are electronically controlled individually by the operating pressure electronic control valves, the individual control of the plurality of friction element operating pressures by the operating pressure electronic control valves is performed. The actuation and non-actuation of friction elements by a plurality of switching valves can be independently performed without any correlation, which reduces the shift shock by the former and the shift responsiveness by the latter at a high level. It can be.

According to a second aspect of the present invention, there is provided a shift control device for an automatic transmission, comprising:
Since the fluid pressure is not directed to the friction element of the combination that causes a mechanical lock state of the speed change gear mechanism by any combination of the switching positions, no matter what kind of failure occurs, a plurality of switching valves are accordingly arranged. No mechanical lock state of the speed change gear mechanism is generated even when any failure occurs in which the switching position remains in the switching position, and in addition to the function and effect of the first invention, the function and effect of interlock prevention can be achieved. You can

According to the third aspect of the present invention, in the shift control device for the automatic transmission, the operating pressure electronic control means is arranged on the downstream side closer to the friction element than the plurality of switching valves. , The fluid pressure after passing through the plurality of switching valves is controlled by the operating pressure electronic control valve and becomes the operating pressure to the friction element, so that the operating pressure toward the friction element is not affected by the resistance of the switching valve. ,
It is possible to eliminate the adverse effect that the shift responsiveness deteriorates due to the switching valve.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing a power transmission train of an automatic transmission to which a shift control device according to an embodiment of the present invention is applied.

FIG. 2 is an explanatory diagram showing a relationship between an engagement logic table of various friction elements in the power transmission train shown in FIG. 1 and a selected shift speed.

FIG. 3 is a hydraulic circuit diagram showing a part of a shift control hydraulic circuit applied to the transmission train shown in FIG.

FIG. 4 is a hydraulic circuit diagram showing the rest of the shift control hydraulic circuit.

FIG. 5 is an explanatory diagram showing a relationship between ON / OFF of a shift solenoid and a selected shift stage in the same shift control hydraulic circuit.

FIG. 6 is a circuit diagram showing only a main part of a shift control hydraulic circuit in a conventional automatic transmission.

[Explanation of symbols]

 T / C Torque converter I / S Input shaft O / S Output shaft G1 1st planetary gear set G2 2nd planetary gear set C1 1st clutch (friction element) C2 2nd clutch (friction element) C3 3rd clutch (friction element) ) B1 1st brake (friction element) B2 1st brake (friction element) OWC One-way clutch 1 Pressure regulator valve 2 Manual valve 3 Torque converter relief valve 4 Lockup control valve 5 Pilot valve 6 1st shift valve (switching valve) 7 2nd shift valve (switching valve) 8 3rd clutch control valve (operating pressure electronic control valve) 9 2nd brake control valve (operating pressure electronic control valve) 10 2nd clutch control valve (operating pressure electronic control valve) 11 L range Pressure reducing valve SOL1 1st shift solenoid (switching valve electronic control means) SOL2 2nd shift solenoid (switching valve electronic control means) SOL3 3rd clutch solenoid SOL4 2nd Rake solenoid SOL5 the second clutch solenoid SOL6 line pressure solenoid SOL7 lock-up solenoid ACC accumulator

Claims (3)

[Claims] 1. An automatic transmission in which a plurality of friction elements are selectively operated by fluid pressure to determine a selected gear stage of a transmission gear mechanism, wherein a pressure source of the fluid pressure and a plurality of friction elements are provided. In between, a plurality of switching valves that determine which of the friction elements the fluid pressure is directed to, and an operating pressure electronic control valve that individually electronically controls the operating pressures of the plurality of friction elements are provided. The automatic shift control device further includes switching valve electronic control means for controlling switching of the switching valves individually according to the selected shift speed so that the fluid pressure is directed to the friction element for achieving the selected shift speed. Gear shift control device. 2. The fluid pressure control device according to claim 1, wherein the plurality of switching valves do not direct fluid pressure to friction elements of a combination that causes a mechanical locked state of the transmission gear mechanism by any combination of switching positions. A shift control device for an automatic transmission characterized by being configured. 3. The shift control device for an automatic transmission according to claim 1, wherein the operating pressure electronic control means is arranged on the downstream side closer to the friction element than the plurality of switching valves.