JPH0320168A - Shift controller for sub transmission - Google Patents

Abstract

PURPOSE:To get rid of the worsening of a shift shock by connecting an accumulator to a control valve having each shift control hydraulic circuit of noth sub and main transmissions so as to make an accumulate chamber constitute a part of a working fluid hydraulic circuit of a friction element. CONSTITUTION:A multistage automatic transmission has each shift control hydraulic circuit of a sub transmission 4 and a main transmission 3 built-in a control valve C/V in a lump, attaching an accumulator 68, for example, a reduction brake accumulator to this valve. In addition, this accumulator 68 is connected so as to constitute a part of a working fluid hydraulic circuit 157 of a reduction brake RD/B or an accumulator chamber serves as a friction element, making working oil pressure in the friction element RD/B equal to internal pressure of the accumulator 68, and any rise in friction element working pressure is controlled as designed. Thus, such possible inconvenience such that interlocking is produced in the sub transmission and a shift shock is worsened is avoided in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a speed change control device for an auxiliary transmission used in a multi-stage automatic transmission.

(Prior Art) Examples of multi-stage automatic transmissions in which a main transmission and an auxiliary transmission are coupled in tandem include the rL4N 71B type, which was published by the applicant in 1982, and the I! 4N Type 71B Automatic Transmission Maintenance Instructions J (A261
There is a 4-speed automatic transmission described in CO4).

In this multi-stage automatic transmission, the speed change control device of the auxiliary transmission is constructed as shown in FIG. SFV is a shift valve (
3-4 shift valve), this shift valve shifts to a downshift position or an upshift position depending on the combination of throttle pressure PfH, which represents engine load, and governor pressure PG, which represents vehicle speed, and in the former position, line pressure PL is one-way. Supplied to direct clutch D/C via orifice 0-Ol and overdrive band brake 00/B
In the latter position, the engagement pressure of the direct clutch D/C is drained and the auxiliary transmission is brought into a directly connected state, and in the latter position, the working pressure of the direct clutch D/C is drained and the direct clutch D/C becomes inactive, and the line pressure PL is supplied via the one-way orifice O-02. By engaging this, the auxiliary transmission is brought into a speed increasing state.

In addition, in order to prevent shift shock when the direct clutch D/C is engaged, the direct clutch D/C
An accumulator ACC, which works together with the one-way orifice 0-01, is connected to the operating hydraulic circuit, and thereby controls the rising speed of the direct clutch operating hydraulic pressure at the time of rise so as not to cause a direct clutch engagement shock.

(Problem to be Solved by the Invention) However, in such a conventional speed change control device, the accumulator ACC was connected to the branch point Y above the operating hydraulic circuit C of the direct clutch D/C through the circuit C2.
When operating the direct clutch D/C, shift valve SPν
The shelf pressure generated in the direct clutch D/C due to the pressure drop that occurs in the oil path between accumulators 8 and 8 CC is assumed to be the sum of the above pressure drop and the accumulation shelf pressure that accompanies the stroke of accumulator ACC, resulting in the following problem. .

To explain the operating process of the direct clutch D/C in order, when the shift valve SFV is switched to the downshift position, first, the direct clutch D/C and the accumulator ACC are filled with hydraulic oil. However, during this time, no pressure is generated anywhere yet, and when the filling is completed, pressure is generated in the oil passages Ct, Ct. At the beginning of this pressure generation, it is not yet at a value that would cause the direct clutch D/C and accumulator ACC to stroke, so the circuit C
．． , no oil flow occurs in C2.

On the other hand, as shown in Fig. 5, the accumulator ^CC responds to the dropout of the high-speed selection pressure Psn (the engagement pressure of the band brake 00/B in the above conventional example) shown by the solid line at the time of power-on downshift (as the accelerator pedal is depressed). shift valve S
It is designed to obtain the target low speed selection pressure change PSL' (in the above conventional example, the working oil pressure change of the direct clutch D/C) in order to prevent shift shock during downshifting of Fv. Accumulator ACC
The instant t when the pressure in oil passage C2 reaches the stroke start pressure of
After that, accumulator ACC is stroked and PS
The internal pressure corresponds to the accumulation shelf on the L characteristic. By the way, during this time, the accumulator is stroking, so
An oil flow occurs in the oil passage Ct, causing a pressure drop JP, and the operating pressure of the direct clutch D/C is reduced to the pressure drop on the accumulation shelf, as shown by the dashed line in Fig. 5 as the low speed selection pressure psL. The pressure is the sum of AP. This shelf pressure is
It becomes a stroke shelf that accompanies the stroke that resists the set load of the return spring of Direct Clutch Ro/C.

This stroke shelf is short, and the engagement start pressure P2 of the friction element (here, the direct clutch D/C) is changed to the direct clutch D/C corresponding to the instant t2 when the stroke shelf is then switched to the accumulation shelf.
The pressure on C exceeds this and starts to engage this direct clutch.

Therefore, before the moment t3 when the corresponding brake 007B is released due to the release of the high-speed selection pressure psH, the low-speed selection pressure psL reaches the engagement start pressure P2 of the corresponding direct clutch D/C, and this element is activated at the moment t2. have already begun to conclude the contract. Therefore, between instants t2 and t, both frictional elements D
/C and 00/B are both engaged, putting the auxiliary transmission in an interlock state, and during this time the transmission output torque is momentarily pulled in as shown by the dashed line (indicated by TRI), and then the peak torque is increased due to reaction. The waveform becomes similar to that of TR2, leading to worsening of shift shock.

In particular, when the auxiliary transmission is arranged after the main transmission and housed in the rear extension connected to the rear of the main transmission case, the main transmission and auxiliary transmission's shift control hydraulic circuit (accumulator 800 and shift It is conceivable to incorporate all valves (including valve SFV) into a control valve and attach this control valve to the main transmission case, but as with the conventional example above, it was originally possible to construct an automatic transmission with only the main transmission. When adding an auxiliary transmission to multi-stage transmission, there is less freedom in the control valve layout, and if it is unavoidable that the oil path between the shift valve and the accumulator becomes longer, the above-mentioned pressure drop,!
! As IPs become larger, the above-mentioned problems become more prominent.

The present invention aims to solve this problem by devising an accumulator connection method.

(Means for Solving the Problems) For this purpose, the present invention provides a secondary system that can switch between high and low speeds by activating a friction element using hydraulic pressure whose rising speed is controlled by an accumulator, or by disabling this friction element. A transmission and a main transmission are coupled in tandem, and a control valve is attached to a case of the main transmission, and a control valve is installed in a case of the main transmission, and includes a built-in shift control hydraulic circuit for the auxiliary transmission and the main transmission. In a multi-stage automatic transmission in which the accumulator is attached to a valve, the accumulator is connected so that the accumulation chamber of the transmission mechanism constitutes a part of the hydraulic circuit for operating the friction element.

(Function) The auxiliary transmission is put into a low speed selection state or a high speed selection state by activating or deactivating the friction element by the transmission control hydraulic circuit in the control valve, and the transmission control hydraulic circuit in the control valve also operates the friction element in the low speed selection state or high speed selection state. Depending on the selected input gear of the main transmission, the multi-stage automatic transmission can be placed in various gear selection states.

On the other hand, when operating the friction element, an accumulator attached to the control valve controls the rising speed of the hydraulic pressure, thereby causing a tightening shock of the friction element,
In other words, shift shock can be prevented.

By the way, since this accumulator is connected so that its accumulator chamber covers a part of the hydraulic pressure circuit of the friction element, the hydraulic pressure of the friction element is made equal to the internal pressure of the accumulator, so that during the stroke of the accumulator, Even if a pressure drop occurs as described above, this pressure drop does not increase the working oil pressure of the friction element, and the design of the accumulator allows the increase in the friction element working oil pressure to be controlled as desired. Therefore, it is possible to eliminate the problem of the friction element starting to engage too early and causing the auxiliary transmission to momentarily interlock due to simultaneous engagement with other friction elements, resulting in deterioration of gear shift synchronization.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Fig. 1 shows the entire system of a multi-stage automatic transmission showing an embodiment of the present invention, Fig. 2 shows the shift control hydraulic circuit of this system, and Fig. 3 shows the gear transmission mechanism to be controlled by this system. Show each. First, to explain the entire system shown in FIG. 1 and the gear transmission mechanism shown in FIG. 3, 1 indicates an input shaft, and 2 indicates an output shaft.

These input and output shafts 1.2 are arranged in a coaxial butting relationship, and a main planetary gear transmission mechanism (main transmission) 3 is concentrically arranged on the input shaft 1, and a sub-planetary gear transmission mechanism (sub-planetary gear transmission) is arranged concentrically on the output shaft 2. Machine) 4
Place them respectively. The auxiliary transmission 4 is disposed after the main transmission 3 (on the side far from the torque converter T/C) and is housed in a rear extension R/B connected to the main transmission case M/C, and both transmissions 3.4 Common control valve C/
It is assumed that the speed change is controlled by a speed change control hydraulic circuit, which will be described later, built into the V.

The control valve C/V has a sub-planetary gear transmission mechanism 4.
A third shift valve 46 and a reduction accumulator 68 for controlling engagement and release of the internal reduction brake (friction element) RD/B are provided and are connected through an oil passage 157.

The main planetary gear transmission mechanism 3 is based on the "Automatic Transmission RHARO" published by the applicant in 1987.
IA type maintenance manual J (A261CO7) No. 1-53
It is the same as the transmission mechanism described on page 2, and has two first and second
A planetary gear set 5.6 is provided in tandem, each of which has a first
and second sangya 5s+6s, first and second ringya 5m. 6. A simple planetary gear set is made up of a pinion 5P16F meshing with these sun gear and ring gear, and first and second carriers 5c and 6c that rotatably support these pinions.

In addition to being able to fix the sun gear 58 with a band brake B/B, it can also be coupled to the input shaft 1 with a reverse clutch R/C. The carrier 5c can be connected to the input shaft 1 by a high clutch H/C, can be prevented from rotating in the opposite direction to the input shaft 1 by a low one-way clutch L/OWC, and can be fixed by a low reverse brake LR/B. do. Carrier 5c is further forward clutch F/C
This makes it possible to connect to the outer race of the forward one-way clutch F/OWC arranged in the same direction as the row one-way clutch L/OWC, and connect the inner race of the forward one-way clutch to the ring gear 6ll. Further, the ring gear 6 can be coupled to the carrier 5c by an overrun clutch OR/C, and the sangya 63 is coupled to the input shaft 1.

The auxiliary planetary gear transmission mechanism 4 includes a third planetary gear set 7, which is connected to a third sun gear 73, a third ring gear 7. , a pinion 7 that meshes with these, and a third carrier 7C that rotatably supports the pinion 7. Carrier 6c which is the output element of the main planetary gear transmission mechanism 3
Connect the ring gear 7II to the output shaft 2 and connect the carrier 7c to the output shaft
Join to. The ring gear 7l can further be coupled to a sangya 73 as appropriate by a direct clutch D/C, and this sangya 73 is connected to a reduction one-way clutch RD/O.
The WC prevents rotation in the opposite direction to the input shaft 1, and the reduction brake RD/B can be used to fix it as appropriate. The gear transmission system of the embodiment described above is capable of driving (D, III, II.
R) For each range, operate the clutches and brakes in the combinations shown in the table below (indicated by ○ marks) to achieve the first forward movement.
It is possible to obtain gears from 1st to 5th and reverse. However, if you do not wish to drive in neutral (N) range or park (P)
In the range, all friction elements (clutches and brakes) of the main planetary gear transmission mechanism are deactivated, making it impossible to transmit power to the auxiliary planetary gear transmission mechanism. ? First, to explain the operation of the main planetary gear transmission mechanism 3, when the forward clutch F/C is operated, the ring gear 68 is connected to the input shaft 1 via the forward one-way clutch F/OWC and the row one-way clutch L/OWCt. Rotation in the opposite direction is prevented. Therefore, the rotation from the input shaft 1 to the sun gear 63 causes the pinion 6F to rotate to the ring gear 6.
(2), the carrier 6c is decelerated in the same direction as the input shaft 1, and becomes in the l-speed state where it rotates forward. At this time, the gear ratio of the sun gear 6 and the ring gear 6R must be α2.

When forward clutch F/C and band brake B/B are operated, band brake B/B causes Sangya 5
3 is fixed and serves as a reaction force receiver, forward clutch F/C and forward one-way clutch F/OWC
Together with the operation of , the power from the input shaft 1 to the sangya 6s causes the carrier 6 to rotate forward at a higher speed than the first speed state, and the second speed state is obtained. The gear ratio at this time is α1, which is the gear ratio between the sangya 5 and the ring gear 5m.When the carrier 6c is reversely driven at high speed in the same direction as the input shaft 1 in the α2 state, the one-way clutches F/OWC, L/ Due to the opening of the OWC, no reverse driving force is transmitted to the input shaft l, and engine braking cannot be obtained. When engine braking is desired, use the overrun clutch OR/C as shown by the Δ mark in the table above.
The necessary force to operate the low bar brake LR/B and disengage the one-way clutches F/OWC and L/OWC does not reach input shaft 1 due to the release of the forward one-way clutch F/OWC, making it impossible to obtain engine braking. . When engine braking is desired, it is necessary to operate the overrun clutch OR/C to release the forward one-way clutch F/OWC, as indicated by the symbol Δ in the table above.

When the forward clutch F/C and the high clutch H/C are operated, the ring gear 6R rotates together with the input shaft 1, and the integral rotation of the sun gear 63 and the ring gear 6, I connected to the input shaft l causes A third speed (directly coupled) selection state in which the carrier 6c rotates in the same manner as the input shaft 1 is obtained.

In this state - also forward one-way clutch F/OW
Since C is released during reverse drive and engine braking cannot be obtained, it is necessary to operate overrun clutch OR/C to prevent forward one-way clutch F/OWC from being released when engine braking is required.

When the high clutch H/C and band brake B/B are activated, the carrier 5c rotates together with the input shaft 1 due to the activation of the high clutch H/C, and the sangya 5c is fixed due to the activation of the band brake B/B. Through the transfer of the pinion 52 on the sangya 5, the ring gear 5Rs and therefore the carrier 6 can obtain the speed increase 1 selection state. Note that in this 4th speed selection state, since there is a forward one-way clutch F/0WC, there is no support even if the forward clutch F/C is kept operating, and this forward clutch is kept in the operating state for convenience of shifting.

Reverse clutch R/C and low reverse brake LR
When /B is activated, the sun gear 53 rotates together with the input shaft 1 by the activation of the reverse clutch R/C, and the carrier 5 is fixed by the activation of the low reverse sprayer LR/B, so the ring gear 5l and therefore the carrier 6c are rotated. It is possible to reverse the rotation in the direction opposite to the input shaft 1 and obtain a reverse selection state with a gear ratio of 1. Next, to explain the operation of the sub-planetary gear transmission mechanism 4, when the reduction brake RD/B is operated, the sangya 7
3 is fixed, and the rotational power from the carrier 6c to the ring gear 7m is transferred to the carrier 7, and therefore to the output shaft 2, while moving the pinion 7F around the sangya 7, under deceleration, to obtain a deceleration state. Therefore, reduction brake R
The D/B functions as a low speed selection wear element for the auxiliary transmission.

At this time, the gear ratio is 1+α, where α is the gear ratio of the sangya 73 and ring gear 7R. When the direct clutch D/C is operated, the sangya 73 is transferred to the ring gear 78.
A direct connection state can be obtained in which the rotational power of the carrier 6c is directly transmitted to the carrier 7 and then to the output shaft 2.

Therefore, the direct clutch D/C functions as a high-speed selection friction element of the auxiliary transmission.

In addition, when switching the reduction brake RD/B from the operating state to the non-operating state, the sangya 7 and the carrier 6c and the ring gear 7R are connected to each other before the direct clutch D/C is activated.
If the direct clutch D/C rotates in the opposite direction, it will not only accelerate the wear of the direct clutch D/C, but also increase the shock when it is activated, causing shift shock. However,
The one-way clutch RD/OWC is useful for preventing the above-mentioned rotation of the ring gear 7ll and solving the above-mentioned problem.

Although there may be cases where it is not necessary to operate the one-way clutch RD/OWC and the reduction brake RD/B, it is possible to set the sub-planetary gear transmission mechanism to only the two states in which the direct clutch or the reduction brake is operated, and to change the high-low speed switching circuit. For simplicity, we decided to operate the reduction brake even when it is not needed.

As for the transmission system as a whole, as is clear from the table above, it is possible to obtain the first speed of the main transmission 3 and the deceleration state α2 (very low gear) of the auxiliary transmission 4, and the auxiliary transmission 4 is maintained as it is. By setting the main transmission 3 to the second speed and third speed (directly connected) states, the transmission ratios can be respectively set to the second speed and the third speed. Then, by keeping the main transmission 3 in the 3rd speed (directly connected) state and bringing the sub-transmission 4 into the directly connected state, the 4th speed (directly connected gear) with a gear ratio of 1 can be obtained. By keeping the auxiliary transmission 4 in the directly connected state and putting the main transmission 3 in the 4th speed (speed increase) state, the gear ratio is also changed, and the reverse gear is changed to the main transmission while the auxiliary transmission 4 is in the deceleration state. What can be gained by putting the transmission 3 in reverse? 1 Furthermore, the examples of the transmission ratios shown in the table above are the gear ratios α, . α■
α, is 0.44 within the range of 0.4 to 0.6, which is considered preferable in terms of strength and durability of the planetary gear sets 5 to 7, respectively.
1. 0.560. This is the value when the gear ratio is set to 0.384, but as is clear from this example gear ratio, an appropriate gear ratio can be obtained, and the lowest gear (1st gear) and highest gear (5th gear) It is possible to achieve a five-speed gear transmission in such a manner that the gear ratio range between Next, the hydraulic circuit shown in FIG. 2 that controls the speed change of the transmission train (main transmission 3 and auxiliary transmission 4) will be explained.

This hydraulic circuit is connected to the control valve C/V shown in Figure 6.
This is a built-in oil cylinder that is driven by the engine.
/P, regulator valve 20 during pressure, pilot valve 2
2. Duty solenoid 24, pressure modifier valve 26, modifier accumulator 28, accumulator control valve 30, torque converter relief valve 32, lock-up control valve 34, lock-up solenoid 36, manual valve 38, first shift solenoid A1 second Shift solenoid B1 Third shift solenoid 01 Overrun clutch solenoid 40, first shift valve 42, second shift valve 44, third shift valve 46
, 5-2 relay valve 48, 5-2 sequence valve 50
, 1-2 accumulator valve 52, N-D accumulator 54, 3rd and 4th speed servo release/reverse clutch accumulator 56, accumulator switching valve 58, 5th speed servo ablative accumulator 60, overrun clutch control valve 62, overrun Clutch pressure reducing valve 64
, a reduction tie ξ valve 66, a reduction brake accumulator 68, a direct clutch accumulator 70, and a range pressure reducing valve 72, which are interposed between the input shaft 1 in FIG. 3 and an engine (not shown). The inserted torque converter T/C, the forward clutch F/C, high clutch H/C, band brake B/B, reverse clutch R/C, low reverse brake LR/B, overrun clutch OR/C, direct clutch D /C and reduction brake RD/
Connect and configure B as shown. The torque converter T/C is a lock-up type that allows direct connection between input and output elements as appropriate, and when supplying hydraulic oil to the release chamber REL and discharging hydraulic oil from the apply chamber APL, the converter is in the above-mentioned disconnected state. The engine power is transferred to the input shaft l in Figure 3.
This is a well-known example in which engine power is transmitted to the input shaft 1 in Fig. 3 in a lock-up state in which the input and output elements are directly connected when the hydraulic oil is caused to flow in the opposite direction. Further, the band brake B/B is assumed to be appropriately engaged by a well-known servo according to Japanese Patent Application Laid-Open No. 62-159839, and is engaged when pressure is supplied only to the second speed servo apply chamber 23/A.3.
4-speed servo release chamber 3.4S/R is also released when pressure is supplied, and in addition, 5-speed servo release chamber 53/A
It is also re-fastened when pressure is supplied.

The pressure regulator valve 20 has a spring 20a. 20j
Basically, the oil pump O/P is equipped with a spool 20b elastically supported at the position shown in the figure and a plug 20c disposed opposite to the lower end surface of the spool in the figure. Although the pressure is regulated to a certain pressure determined by force, when the spring force of the spring 20j is increased by the plug 20c, the above pressure is increased by that amount to reach a predetermined line pressure. For this purpose, the pressure regulator valve 20 receives the pressure in the circuit 8l via the damping orifice 82 onto the pressure receiving surface 20d of the spool 20b, thereby biasing the spool 20b downward, and strokes the spool 20b. Boats 20e to 20h are provided which are opened and closed depending on the position. Boat 20e is connected to circuit 81 and is arranged so that as spool 20b descends from the position shown, it communicates with boats 20h and 20f. As the spool 20b descends from the illustrated position, the communication with the drain boat 20g is reduced, and at the point when the communication with the drain boat 20g is cut off, the port 20f is connected to the drain boat 20g.
Place it so that it begins to communicate with e. and boat 20f
is connected to the capacity control actuator 85 of the oil pump O/P via a circuit 84 with a bleed 83 in the middle,
A feedback accumulator 86 suppresses the pulsation to this. The oil pump 0/P is an engine-driven variable capacity vane pump, and the eccentricity is reduced when the pressure toward the actuator 85 exceeds a certain value, so that the capacity becomes smaller. The plug 20c of the pressure regulator valve 20 receives the modifier pressure from the circuit 87 on its lower end face in the figure, and receives the backward selection pressure from the circuit 88 on the pressure receiving surface 20i, and generates an upward force in the figure in response to these pressures. It is assumed that the spring 20j is added to increase the spring force.

The pressure regulator valve 20 is normally in the state shown in the figure, and when oil is discharged from the oil pump O/P, this oil flows into the circuit 81. At the illustrated position of the spool 20b, no oil in the circuit 81 is drained, and the pressure increases. This pressure passes through the orifice 82 and the pressure receiving surface 2
0d, and the springs 20a and 20j act on the Subur 20b.
20e to connect the port 20e to the boat 20h. As a result, the above pressure is partially drained from the port 20h and lowered, and the spool 20b is released from the spring 20a. 20j
pushed back. By repeating this action, the pressure regulator valve 20 basically reduces the pressure in the circuit 81 (
Line pressure) is set to a value corresponding to the spring force of the springs 20a and 20j. Incidentally, an upward force due to the modifier pressure from the circuit 87 is acting on the plug 20c, and the plug 20c increases the spring force of the spring 20j according to the modifier pressure, and the modifier pressure increases as described below. This occurs when the reverse is not selected and increases in proportion to the engine load (engine output torque), so the above line pressure increases as the engine load increases except when the reverse is selected.When the reverse is selected, the plug 20c has Instead of the above modifier pressure, an upward force from the reverse selection pressure (same value as the line pressure) from the circuit 88 acts, and this is applied to the Subur 20b, so the line pressure becomes a desired constant value when the reverse is selected.Oil Bomb 0/ When P reaches a certain number of revolutions or more (the engine reaches a certain number of revolutions or more), the oil discharge amount that increases accordingly becomes excessive, and the pressure in the circuit 81 becomes more than the pressure regulation value.

This pressure lowers the spool 20b further from the pressure regulating position, connects the boat 20f to the boat 20e, and connects the drain boat 20f to the drain boat 20e.
Cut off from 0g. As a result, some of the oil in the boat 20e is removed from the boat 20f and the lead 83, but
A feedback pressure is generated within circuit 84. This feedback pressure increases as the rotational speed of the oil pump O/P increases, and reduces the eccentricity (capacity) of the oil pump O/P via the actuator 85. In this way, the capacity of the oil pump 0/P is controlled so that the discharge amount remains constant while the rotational speed is above a certain value, thereby preventing an increase in power loss of the engine due to discharge of more than necessary oil.

The line pressure generated in the circuit 8l as described above is applied to the pilot valve 22, the manual valve 38, the third shift valve 46 and the 3.
It is supplied to a 4-speed servo release/reverse clutch accumulator 56.

The pilot valve 22 includes a spool 22b elastically supported in the illustrated position by a spring 22a, with the end face of the spool 22b farthest from the spring 22a facing the chamber 22c. Pilot valve 2
2 is further provided with a drain boat 22d, a pilot pressure circuit 90 having a filter 89 is connected between this and the line pressure circuit 81, and this circuit 90 is connected to the chamber 22c via an orifice 91.

Pilot valve 22 is normally in the state shown, where line pressure from circuit 81 is supplied to pilot pressure circuit 90 to create a pilot pressure in this circuit.

Then, the pilot pressure passes through the orifice 91 to the chamber 22c.
is fed back to push the spool 22b back against the spring 22a. When the pilot pressure reaches a value corresponding to the spring force of the spring 22a, the circuit 90 is switched and connected to the drain boat 22d, and the pilot pressure in the circuit 90 maintains a constant value corresponding to the spring force of the spring 22a. This pilot pressure is in circuit 9
0 leads to shift solenoids A, B, C and overrun clutch solenoid 40, as well as pressure modifier valve 26, orifice 92. 93, lockup control valve 34 and lockup solenoid 36
and further to the third shift valve 46. The duty solenoid 24 normally closes the drain port of the drain circuit 94 connected to the orifice 92, and the O
This drain boat shall be opened at N time. However, this lever solenoid 24 is controlled by a computer together with other solenoids described later, and as the ratio of ON time to a constant ON/OFF cycle (duty ratio) increases, the control pressure in the drain circuit 94 is decreased, and the duty is 0%. Set this control pressure to the same value as the pilot pressure, which is the source pressure, and set the control pressure to 0 with a duty of 100%. The duty ratio is decreased as the engine load (for example, engine throttle opening) increases except when the reverse range is selected, thereby increasing the above control pressure as the engine load increases. Also, when the reverse range is selected, the duty ratio is set to 100% and the above control pressure is set to 0. The pressure modifier valve 26 includes a spool 26b biased downward in the figure by a spring 26a and control pressure from the circuit 94, and the pressure modifier valve 26 further includes an output boat 26c connected to the circuit 87, and a pilot pressure Input port 26d and boat 26g to which circuit 90 is connected, and drain port 26e
will be established. Also, an orifice 26h for feeding back the modifier pressure in the circuit 87 is formed on the spool 26b into a chamber 26f facing the end face of the spool 26b far from the spring 26a. The spring force of the spring 26a is set to be larger than the force due to the pilot pressure from the port 26g, and the difference between the two forces causes the modifier pressure to be lower than the pressure regulating circuit 94.
Set the value to be an amplified value of the control pressure from . The spool 26b of the pressure modifier valve 26 directs the force of the spring 26a and the control pressure from the circuit 94 downward in the figure, and directs the force of the modifier pressure fed back to the chamber 26f and the force of the pilot chamber from the boat 26g. The spool 26b receives the force upward in the figure, and is stroked to a position where these forces are balanced. If the modifier pressure is insufficient to compensate for the downward force, the spool 26b connects the output boat 26c to the input boat 26d to increase the modifier pressure by replenishing the pilot pressure, and conversely, the modifier pressure is excessive. , the spool 26b connects the output boat 26c to the drain boat 26e to reduce the modifier pressure. By repeating this action, the pressure modifier valve 26 adjusts the modifier pressure in the circuit 87 to the sum of the difference between the force caused by the spring 26a and the force caused by the pilot pressure from the boat 26g, and the force caused by the control pressure from the circuit 94. Pressure regulator valve 2 adjusts the modifier pressure to the specified value.
0 plug 20c.

By the way, as mentioned above, the control pressure increases as the engine load increases except when reverse is selected, and since it is 0 when reverse is selected, the modifier pressure that amplifies this control pressure by the above difference also increases when the reverse is selected. It increases as the engine load increases, and becomes 0 when reverse is selected, enabling the above-mentioned line pressure control by the pressure + regulator valve 20. Note that the modifier pressure in the circuit 87 is suppressed from pulsating by the modifier accumulator 28 during the pressure regulating action.

The torque computer relief valve 32 includes a spool 32b elastically supported in the illustrated position by a spring 32a, and this spool receives the output boat 32c in the illustrated position.
, and as it rises in the figure, this communication is decreased and the output boat 32C is switched to be connected to the drain port 32e. A chamber 32f facing the spool end face far from the spring 32a to control the stroke of the spool 32b.
An orifice 32g that feeds back the output pressure of the spool 32c is connected to the spool 32b. The output port 32C is connected to the front lubricating section FR/ through the relief valve 95.
L U B and is connected to lock-up control valve 34 by circuit 96 . input boat 32
d is connected to the port 20h of the pressure regulator valve 20 by a circuit 97, and leads leakage oil from the pressure regulator valve 20 to the input port 32d as hydraulic oil for the torque converter T/C.

The torque converter relief valve 32 is normally in the state shown in the figure, and the pressure regulator valve 20 is connected to the input port 32.
The leaked oil to d is supplied to the lock-up control valve 34 and, therefore, the torque converter T/C via the circuit 96. When the torque converter supply pressure is generated here, this pressure is fed back from the orifice 32g to the chamber 32f, causing the spool 32b to rise in the figure against the spring 32a. When the torque converter supply pressure exceeds the set value corresponding to the spring force of the spring 32a, the spool 32b
2c to drain boat 32e to reduce the torque converter supply pressure and keep this pressure below a set value corresponding to the spring force of spring 32a. Note that even with this relief function, if the torque converter supply pressure exceeds the above set value, the relief valve 95 opens to release the excess pressure to the front lubricating part FR/LUB, thereby preventing deformation of the torque converter T/C.

The lock-up control valve 34 includes a spool 34a, a stepped plug 34b and a plug 34c coaxially abutted against each other at both ends of the spool 34a, and a spring 34d inserted between the spool 34a and the plug 34c. When the spool 34a is at the limit position opposite to the illustrated position, a circuit 96 is connected to a circuit 98 that communicates with the release chamber REL of the torque converter T/C, and a circuit 99 that communicates with the torque converter aberration chamber APL is connected to a drain circuit. Connect to 100. At this time circuit 96
The torque converter hydraulic oil flows through the torque converter T/C from the release chamber REL to the apply chamber APL to put the torque converter in the converter state. After flowing, the hydraulic oil is transferred from the drain circuit 100 to the oil cooler COOL.
is guided to the rear lubricating section RR/LU after being cooled here.
Head to B. When spool 34a is in the illustrated limit position, circuit 96 is connected to circuit 99 and circuit 98 is connected to drain boat 34e. At this time, the torque converter hydraulic oil in the circuit 96 flows from the apply chamber APL to the release chamber REL.
Flow through the torque converter T/C to lock up the torque converter. Note that in this lock-up state, the hydraulic oil that has passed through the torque converter is removed from the drain boat 34e, so it does not pass through the oil cooler COOL, but during this time it does not pass through the orifice 101. 1
02 bypasses the torque converter and guides the hydraulic oil to the oil cooler COOL, which cools it as well as the rear lubrication section R.
Compensate for R/L U B lubrication.

In order to control the stroke of the spool 34a, a drain circuit 103 is connected to the chamber 34f between the spool 34a and the plug 34c, and this circuit is connected to the orifice 93 of the pilot pressure circuit 90, and is normally connected to the drain boat of the circuit 103. is provided with a lock-up solenoid 36 that closes. The pressure in the torque converter release chamber circuit 98 is applied to the stepped plug 34b through the orifice 104, and the pressure in the pilot pressure circuit 90 is applied downward in the figure through the orifice 105.

The ON/OFF state of the lock-up solenoid 36 is controlled by a computer (not shown), and this computer determines whether the driving conditions are such that the torque converter T/C should be locked up. If lock-up is not to be expected, the lock-up solenoid 36 is turned OFF and closed to generate a pressure in the drain circuit 103 with the same value as the pilot pressure, which is the source pressure. This pressure reaches the chamber 34f and the spring 34
In cooperation with d, the subur 34a is connected to the orifice 104,
105 and acting on the stepped plug 34b, as shown in the figure, thereby bringing the torque converter T/C into the converter state as requested. If lock-up is to be performed, the lock-up solenoid 36 is turned ON and opened, and the drain circuit 103 is brought into a non-pressure state. At this time, the pilot pressure input from the orifice 105 lowers the stepped plug 34b along with the subur 34a against the spring 34d, thereby placing the torque converter T/C in the lock-up state as required. In this example, in order to prohibit lock-up when selecting the first forward speed and when selecting the reverse range, the chamber 34g facing the end face of the plug 34c far from the spool 34a is connected to the output port of the shuttle valve 107 by the circuit 106. The above-mentioned backward selection pressure circuits 88 are provided for each of the two seats of the shuttle valve.
and 1st speed selection pressure circuit 10B are connected. These circuits 88
Or, when selecting reverse or when selecting first speed in which pressure is generated at 108, the corresponding selection pressure reaches the chamber 34g from the shuttle valve 107, raising the subroutine 34a as shown in the figure via the plug 34c, and converting the torque converter T/C. state.
Note that the pilot pressure from the orifice 105 always urges the stepped plug 34b downward to prevent the stepped plug, spool 34a, and plug 34c from vibrating.

The manual valve 38 can be set to the parking (P) range, reverse (R) range, or neutral (N) range by the driver's manual selection operation.
) range, forward automatic transmission (D) range, third forward speed engine brake (III) range, and second forward speed engine brake (n) range (also used as first speed engine brake range). Depending on the selected range of the spool, the line pressure circuit 81 is connected to the boats 38D, 381.38, and 38R as shown in the following table. Note that in this table, ○ marks indicate boats that communicate with the line pressure circuit 81, and no marks indicate boats that are being drained.

The port 38D in Table 2 is connected to the D range pressure circuit 110 by the accumulator control valve 30, forward clutch F/C,
Accumulator switching valve 58, first shift valve 42, second shift valve 44, and overrun clutch control valve 6
Connect to 2. Also, port 38■ is ■range pressure circuit 11
1 connects to the shuttle valve 112 corresponding human power, and the boat 38 is connected to the range pressure reducing valve 7 by the range pressure circuit 113.
2, and the boat 38H is connected to the aforementioned reverse selection pressure circuit 8.
Connect 8. As described above, the circuit 88 is connected to the pressure regulator valve 20 and the shuttle valve 107, so that the pressure regulator valve 20 performs the line pressure adjustment function when the reverse is selected, and the lock-up control valve 34 performs the lock-up inhibiting function when the reverse is selected. One-way orifice 114 and shuttle valve 1
Low bar sprayer LR via 15 corresponding input ports
/B, and also connects to reverse clutch R/C via one-way orifice 117.

The accumulator control valve 30 is a stepped spool 30
a, and the chamber 30b facing the large diameter end is connected to the circuit 94.
The chamber 30c facing the small diameter end is opened to the atmosphere.
Therefore, the spool 30a is raised in the figure by the pressure in the circuit 94 which is regulated as described above by the duty solenoid 24, and the output boat 30d is raised by the drain boat 30e.
When the boat 30d is cut off from the D-range pressure circuit 110 and connected to the D range pressure circuit 110, the accumulator back pressure is output from the boat 30d. This pressure acts on the difference in pressure-receiving area between lands at both ends of the spool 30a, and urges the spool 30a downward in the figure, opposing the pressure within the chamber 30b. Then, the spool 30a strokes so that both are balanced, and the accumulator back pressure from the boat 30d changes depending on the pressure inside the chamber 30b. Therefore, the pressure inside the chamber 30b increases to the duty solenoid 24.
As mentioned above, it is adjusted to increase as the engine load increases outside the reverse range, and the source pressure D
The pressure of the range pressure circuit 110 is forward traveling (D, III
, II) Since it only occurs in the range, accumulator back pressure occurs only when the forward travel range is selected.
As the engine load increases, the capacity of the corresponding accumulator increases to match the engine load. Note that the accumulator back pressure is supplied to the 1-2 accumulator valve 52, the N-D accumulator 54, the 5-speed servo apply accumulator 60, the direct clutch accumulator 70, and the overrun clutch pressure reducing valve 64 through the circuit 116.

A one-way orifice 120 is inserted into the part of the D range pressure circuit 110 immediately before the forward clutch F/C, and this one-way orifice and the forward clutch F
/C, the N-D accumulator 54 and the accumulator switching valve 58 are sequentially connected via a one-way cup 121 which can be replaced with one having a different inner diameter.

The first shift valve 42 includes a spool 42b elastically supported in the illustrated position by a spring 42a, and this spool is in the illustrated position when the first shift solenoid A is turned ON (closed) to supply pilot pressure from the circuit 90 to the chamber 42c. shall be raised from D range pressure circuit 1 at the illustrated position of spool 42b
10 is connected to the second speed pressure circuit 122, the first speed pressure circuit 108 is connected to the drain port 42d, the range pressure circuit 124 is connected to the drain port 42f, and the circuit 125. 126 and also connects circuit 108 to circuit 12 in the raised position of spool 42b.
7 to lead to circuit 122 to circuit 128 to circuit 124.
is connected to circuit 129, and circuit 126 is connected to circuit 128.

The circuit 122 passes through the check valve 130 to the band brake B.
/B is connected to 2-speed servo apply chamber 2S/A, and circuit 1
24 to the corresponding input of shuttle valve 115 and circuit 12
5 to the 5-2 relay valve 48, and the circuit 126 to the 5-2 relay valve 48.
The circuit 127 is connected to the relay valve 48 and the overrun clutch control valve 62, and the circuit 127 is connected to the 5-2 sequence valve 50 on the one hand and the second shift valve 44 on the other hand.
8 and one-way orifices 131, 1 with mutually opposite directions.
32 to the high clutch H/C and to the second shift valve 44, and connects the circuit 129 to the second shift valve 44.

A bypass circuit 133 connected in parallel with a check valve 130 is provided in the second speed pressure circuit 122, and a 1-2 accumulator valve 52 is inserted into this bypass circuit. This 1-
The two-accumulator valve includes a spool 52a, and springs 52b and 52c act on its large diameter end face and small diameter end face, respectively. The spool 52a further has a circuit 1 at its stepped portion 52d.
The back pressure of the accumulator 16 is applied downward in the figure, and the spool 52a is assumed to be in a position further lower than the normally illustrated pressure regulating position due to this and the difference in spring force between the springs 52b and 52c. In this spool position, the spool 52a connects the output boat 52e to the input port 52f and connects the boat 52e to the input port 52f.
2e outputs the 2nd speed servo apply pressure to the 2nd speed servo aliquot chamber 2S/A. This pressure is fed back to chamber 52g via orifice 134, pushing back spool 52a.

When the second speed servo bridging pressure from the output port 52e' exceeds a value corresponding to the sum of the spring force difference and the accumulator back pressure acting on the stepped portion 52d, the spool 52a passes the output boat 52e to the drain boat 52h. The second speed servo apply pressure from the output port 52e is reduced by the excess amount, and this pressure is regulated to the above value.

By the way, the 2nd speed servo apply pressure is blocked by the check cup 135, acts on the piston cup 52i of the spring 52c through the orifice 136, and strokes it to gradually increase the spring force of the spring 52c. The pressure also increases with a predetermined time gradient. Also, the stepped portion 52
Since the accumulator back pressure acting on d is regulated by the duty solenoid 24 and the accumulator control valve 30 so as to increase as the engine load increases, the level during the change in the second speed servo apply pressure at the predetermined gradient is (commonly referred to as shelf pressure) can be increased as the engine load increases.

The second shift valve 44 includes a spool 44b elastically supported in the illustrated position by a spring 44a, and this spool is in the illustrated position when the second shift solenoid B is turned ON (closed) to supply pilot pressure from the circuit 90 to the chamber 44c. shall be raised from At the illustrated position of the spool 44b, the circuit 127 is connected to the drain port 44d, and between the circuits 1lO and 128,
The circuit 129 is connected to the drain boat 44e, and the spool 4
4b in the raised position of circuit 110. 127, the circuit 128 is connected to the drain boat 44e, and the circuit 129 is connected to the circuit 140. Circuit 140 is an I. II range pressure reducing valve 7
Connect to 2.

5-2 Relay valve 48 comprises a spool 48b elastically supported in the position shown by a spring 48a, and the spool 48b is connected to circuit 1.
When pressure is present in 26, this pressure shall force it into the raised position. Circuit 12 in the illustrated position of spool 48b
5 to drain boat 48C and circuit 125 in the raised position.
to circuit 141, which is connected to 5-2 sequence valve 50.

The 5-2 sequence valve 50 includes a spool 50b resiliently supported in the position shown by a spring 50a, which spool is forced into the lowered position when pressure is present in the circuit 142. In the illustrated position of the spool 50b, the circuit 141 is connected to the drain boat 50C, and in the lowered position, the circuit 141 is connected to the drain boat 50C.
41 to the circuit 127.

The circuit 142 is connected to a circuit 144 with a one-way orifice 143 that connects the 3rd and 4th speed servo release chambers 3 and 4S/R of the band brake B/B and the high clutch H/C, and a one-way orifice 143 is connected in the middle of the circuit 142. 145 and one-way cup 14 that can be replaced with one with a different inner diameter.
6 is connected to the accumulator switching valve 58 through a circuit 147 into which the accumulator switching valve 58 is inserted. This valve is further connected via circuit 14B to 3.
The 4-speed servo release/reverse clutch accumulator 56 is connected, and the reverse clutch R/C is connected via the circuit 149.

The accumulator switching valve 58 includes a spool 58b elastically supported in the position shown by a spring 58a, and this spool is D
It is assumed that when pressure exists in the range pressure circuit 110, it moves to the left in the figure. Circuit 148 at the location shown in Subur 58b
is connected to the circuit 149, and the accumulator 56 is used to control the pressure increase of the reverse clutch R/C. At the leftward position of the spool 58b, the circuit 148 is connected to the circuit 147, and the accumulator 56 is connected to the 3.4-speed servo release chamber 3, 4S/ Used for pressure rise control of R.

Band brake B/B 5-speed servo apply chamber 53/A
The circuit 150 to the 5-speed servo apply accumulator 6
0 and a one-way orifice 151, and is connected to an overrun clutch control valve 62. It is assumed that the overrun clutch control valve 62 includes a spool 62b elastically supported in the illustrated position by a spring 62a, and that this spool is raised in the figure by supplying pressure to the chamber 62c. room 6
2c is the overrun clutch solenoid 40 ON (
When the solenoid 40 is closed), pilot pressure is supplied from the circuit 90, and the pressure inside the chamber 62c is exhausted when the solenoid 40 is OFF. Overrun clutch pressure reducing valve 64 in the illustrated position of Subur 62b
from the circuit 152 to the circuit 110, the circuit 150 to the drain port 62d, and the raised position of the spool 62b, the circuit 152 to the drain port 62d, and the circuit 150 to the drain port 62d.
to circuit 126.

The third shift valve 46 includes a spool 46b elastically supported in the illustrated position by a spring 46a, and a chamber 46c facing both end surfaces of the spool.
46d, pilot pressure of circuit 90 and circuit 153, respectively.
supply pressure. Circuit 153 is connected to the output port of shuttle valve 154, and each of the two shuttle valves has a third
When the shift solenoid C is turned ON (closed), the pressure (same value as the pilot pressure of the circuit 90) and the reverse range pressure (described later) are selectively supplied to the circuit 155. When one of these pressures occurs, it passes through shuttle valve 154 and circuit 153 to chamber 46d, and in cooperation with spring 46a forces spool 46b into the position shown against the pilot pressure into chamber 46c, causing chamber While no pressure is supplied to chamber 46d, subur 46b is lowered in the figure against spring 46a by pilot pressure to chamber 46c. The circuit 156 is connected to the drain boat 46e at the position shown on the spool 46b, and the circuit 1
57 to line pressure circuit 8l, and in the lowered position of spool 46b, circuit 156 to line pressure circuit 8l, and circuit 1
57 to drain boat 46f.

A one-way orifice 158 is inserted into the circuit 156 and connected to the direct clutch D/C, and a direct clutch accumulator 70 is provided in the circuit 156 by connecting it through a one-way orifice 159. The circuit 157 also connects the reduction brake RD/
A reduction brake accumulator 68 is connected between the one-way orifice 160 and the reduction brake R D/B.

In making this connection, in light of the object of the present invention, the circuit 156 is separated, both separated parts are connected to the accumulation chamber 68c of the accumulator 68, and this chamber is made into a part of the hydraulic pressure circuit of the reduction brake RD/B. Eggplant. The accumulator 68 connects the circuit 161 from the accumulator back pressure chamber 68d to the output port of the shuttle valve 121, and connects one input of the shuttle valve 112 to the range pressure circuit 11.
Connect 1 and supply range pressure. Shuttle valve 112
A circuit 155 is connected to the other input of the shuttle valve 112, and this circuit is connected to the reverse selection pressure circuit 88 to supply the reverse selection pressure to the other input of the shuttle valve 112.

The pressure of the circuit 161 is also supplied to the chamber 66a of the reduction tie main valve 66,
This valve is constructed by elastically supporting a spool 66b at the position shown in the figure by a spring 66c. Spool 66b is in the position shown when there is no pressure in chamber 66a;
It is assumed that when pressure exists in , the pressure is raised against the spring 66c. The orifice 16 is parallel to the one-way orifice 160 at the position shown on the spool 66b.
The bypass circuit 163 with 2 is disconnected from the circuit 157 and communicates between the circuits 163.157 in the raised position of the subur 66a. The bypass circuit 163 bypasses the one-way orifice 160, and connects the end farthest from the reduction timing valve 66 to the reduction brake RD/B. Overrun clutch pressure reducing valve 64 is connected to circuit 15
2 is supplied to the overrun clutch OR/C, and includes a spool 64b that is brought to the illustrated position by a spring 64a and accumulator back pressure from the circuit 116. At this spool position, output port 64c is connected to circuit 1.
52, the boat outputs the operating pressure of the overrun clutch OR/C.

For this reason, boat 64c and overrun clutch OR/C
A circuit 165 in which an orifice 164 is inserted connects the two. Overrun clutch operating pressure is spool 6
It is fed back to the chamber 64e through an orifice 64d provided in the chamber 64b. Therefore, as the overrun clutch operating pressure increases, the spool 64b is lowered in the figure, and this pressure increases the accumulator back pressure from the circuit 116 and the spring 64.
When the value corresponding to the sum of the spring forces of a is exceeded, Subur 6
4b connects the output port 64c to the drain boat 64f to release excess pressure. As a result, the overrun clutch operating pressure is reduced to a value corresponding to the above sum value, but since the accumulator back pressure from the circuit 116 increases as the engine load increases, the overrun clutch operating pressure also increases as the engine load increases. The engagement capacity of the overrun clutch OR/C can be controlled to be appropriate for preventing engine brake shock, which will be described later. Note that the circuit 152 and the overrun clutch OR/C are connected by a circuit 167 into which a one-way valve 166 is inserted, and the one-way valve 166 and the orifice 164 constitute a one-way orifice.

■The range pressure reducing valve 72 reduces the ■range pressure from the circuit 113 and outputs it to the circuit 140. A spool 72b is elastically supported in the illustrated position by 2a. At this spool position, the circuit 140 is connected to the circuit 113 to generate pressure, and this pressure is applied to the orifice provided in the spool 72b. 2c feeds back to the right end surface of the spool to move the spool 72b to the left in the figure. Is the output pressure of circuit 140 a spring? If the value corresponding to the spring force of 2a is exceeded, the spool?
2b connects the circuit 140 to Drainboard 1-72d to release excess pressure and output pressure to the spring? The pressure is reduced to a constant value corresponding to the spring force of 2a.

The speed change action by the hydraulic circuit shown in FIG. 2 will now be explained. Prior to this explanation, the following table shows the ON/OFF combinations of shift solenoids A, B, and C to obtain the first to fifth forward speeds.

Table 3 If the driver does not wish to drive but wishes to park or stop and sets the manual valve 38 to the P or N range, the manual valve boat 380. 3811[. 38I1 and 38
All of R are drain boats as shown in Table 2 above, and line pressure is not output from these boats, so the forward clutch F/C and high clutch H are operated using the line pressure from these boats as source pressure. /C, band brake B/B, reverse clutch R/C, low reverse brake L R/B and overrun clutch OR/C
are all kept inoperative, and the main transmission 3 in the power transmission train shown in FIG. 3 can be kept in a neutral state in which power cannot be transmitted.

Therefore, regardless of the state of the sub-transmission 4, the multi-stage automatic transmission maintains a neutral state in which power cannot be transmitted; however, for the above-mentioned reasons, the sub-transmission 4 is set to a deceleration state as shown in Table 1 as described below. put. That is, by turning on and closing the third shift solenoid C, pilot pressure is supplied to the chamber 46d of the third shift valve 46 via the shuttle valve 154 and the circuit 153.

Therefore, the third shift valve 46 is in the state shown, and the circuit 15
6 to the drain boat 46e and direct clutch D
/C and connect the circuit 157 to the line pressure circuit 8l.
Reduction brake RD/B by line pressure
is engaged, and the sub-transmission 4 is brought into a deceleration state.

When the manual valve 38 is set to the D range with the desire to perform forward automatic shift driving in the D range, automatic shifts are performed between all gears and the first to fifth gears as follows.

(1st speed) That is, in the D range, the manual valve 38 outputs the line pressure of the circuit 8l as the D range pressure from only the port 38D as shown in Table 2 above, and this D range pressure is supplied to the circuit 110 to be applied to each part. reach The D range pressure heading towards the forward clutch F/C passes through the one-way orifice 120.
In conjunction with the function of the N-D accumulator 54, the forward clutch F/C is gradually engaged to alleviate the engagement shock.

On the other hand, when the car is stopped in the D range, the computer keeps the third shift solenoid C ON, and also turns both the first shift solenoid A and the second shift solenoid B ON.
, the spool 4 of the first shift valve 42 and the second shift valve 44
2b. 44b to the raised position. Therefore, the circuit 128 of the high clutch H/C is drained through the second shift valve boat 44e, releasing the high clutch H/C, and the circuit 14
The 3.4-speed servo release chambers 3 and 4S/R of the band brake B/B connected to the high clutch circuit 128 via 4 are also drained. Further, the second speed servo apply chamber 2S/A of the band brake B/B is also brought into a non-pressure state because its circuit 122 is connected to the drained circuit 128 by the first shift valve 42. Furthermore, regarding the 5-speed servo apply chamber 5S/A of the band brake B/B, its circuit 150
is drained as follows. That is, unless the driver performs an operation that requests engine braking, which will be described later, the computer will control the overrun clutch solenoid 40 to OIJ.
Lift the spool 62b of the overrun clutch control valve 62 as shown in the figure. Therefore, this valve is connected to circuit 15
2 to the drain boat 62d to release the overrun clutch OR/C, and at the same time connect the circuit 150 to the circuit 126.
Leads to. Since this circuit 126 is connected to the circuit 128 by the first shift valve 42, and the circuit 128 is connected to the drain boat 44e of the second shift valve as described above,
The fast servo apply chamber 5S/A is drained. The reverse clutch R/C and the low reverse brake LR/B are released because their circuits 88 are drained from the corresponding boat 38R of the manual valve 38.

Therefore, when the auxiliary transmission is decelerating due to the operation of the reduction brake RD/B, the main transmission is operated by the forward clutch F.
/C will be activated, and in combination with the operation of the forward one-way clutch F/OWC, each gear automatic transmission will be in the first speed selection state as shown in Table 1 above. However, at this time, the first shift valve 42 and the second shift valve 44 sequentially connect the circuit 108 to the circuit 127 and the D range pressure circuit 110, and the D range pressure circuit 110 from the circuit 110. Range pressure to circuit 127.
108, shuttle valve 107, and circuit 106 to the lockup control valve 34, and the torque converter T
Since /C is in the converter state, it is possible to maintain a stop by operating the brakes without stalling the engine in the first gear selection state. In addition, when the forward clutch F/C is operated, its operating hydraulic pressure is throttled by the one-way orifice 120, and the N-D accumulator 54 is stroked from the right half position to the left half position as it rises. is carried out slowly, and the forward clutch F/C engagement shock, that is, from N or P range to D
It can alleviate the N-D select shock when switching to range. When the engine output is increased by depressing the accelerator pedal in the first speed selection state, the vehicle is started.

(Second speed) When the vehicle speed increases after starting and the driving state becomes such that the second speed should be selected, the computer turns off the first shift solenoid A and switches the first shift valve 42 to the state shown in the figure, as shown in Table 3 above. . As a result, the first shift valve 42 switches and connects the circuit 126 to the circuit 125, but this circuit 125 is connected to the circuit 5-2.
Because the illustrated position of the relay valve 48 communicates with the drain boat 48C, it continues to drain the circuit 126 and therefore the 5th speed servo apply chamber 53/A. The first shift valve 42 further connects the lockup control valve 34 to the lockup solenoid 36 by connecting the circuit 10B to the drain boat 42d.
The torque converter T/C can be appropriately locked up under the computer control. The first shift valve 42 also connects the circuit 122 to the D range pressure circuit 110, and outputs the D range pressure from this to the circuit 122 as the second speed servo apply pressure. This pressure is passed through circuit 133 to 1-2
The pressure is regulated by the action of the accumulator valve 52 and is supplied to the second speed servo apply chamber 2S/A, and the band brake B/B is engaged. By the way, due to the pressure regulating action of the 1-2 accumulator valve 52, the engagement of the band brake B/B is 1.
- 2-shift is carried out in a manner that does not cause a shock, forward clutch F/C, forward one-way clutch F/C, forward clutch F/C, forward one-way clutch F/C
In conjunction with maintaining the operation of /OWC and reduction brake RD/B, it is possible to shift the multi-stage automatic transmission from the first speed to the second speed, as is clear from Table 1 above.

(3rd speed) After that, when the operating state becomes such that 3rd speed should be selected, the computer turns off the second shift solenoid B as shown in Table 3 above.
F L to switch the second shift valve 44 to the illustrated state. As a result, the circuit 128 is cut off from the drain boat 44e and communicated with the D range pressure circuit 110, and the D range pressure from this circuit passes through the circuit 128 and the one-way orifice 132, and reaches the high clutch H/C, which is then engaged. On the other hand, the pressure applied to engage the high clutch H/C reaches the 3rd and 4th speed servo release chamber 3.43/H via a circuit 144 branching from the high clutch circuit 12B, and reaches the band brake B/C.
Release B. The pressure to the servo release chamber 3.43/R is now D from the circuit 110 when the accumulator switching valve 58
Due to range pressure, circuit 147. 148, so after passing through the one-way orifice 145, the one-way cup 146, circuits 147, 148
and then reaches the accumulator 56. Therefore, the pressure in the servo release chambers 3, 4S/R gradually increases while the accumulator 56 is stroked from the right half position shown in the figure to the left half position shown in the figure. Therefore, the band brake B/B is released in a timely manner relative to the engagement of the high clutch H/C.

As a result of the above, the high clutch H/C is engaged and the band brake B/B is switched to disengaged. Together with maintaining the operation of the forward clutch F/C, forward one-way clutch F/OWC, and reduction brake RD/B, the above-mentioned As is clear from Table 1, the multi-speed automatic transmission is capable of upshifting from second speed to third speed. Note that during this upshift, the accumulator 56
can suppress shift shock by the above-mentioned action.

(4th speed) After that, when the operating state is reached in which 4th speed should be selected, the computer selects the first and second shift solenoids A as shown in Table 3 above.
, B are kept OFF, that is, the main transmission remains unchanged, and the third shift solenoid C is turned OFF L to lower the spool 46b of the third shift valve 46 in the figure. This results in
A circuit 157 connects to the drain port 46f to release the reduction brake RD/B, and a circuit 156 connects to the line pressure circuit 81 to engage the direct clutch D/C by the line pressure. Therefore, the sub-transmission is switched from the deceleration state to the direct connection state, and the multi-stage automatic transmission can be shifted from the 3rd speed to the 4th speed hair-down shift as is clear from Table 1 above.

During this upshift, the direct clutch D/
The working pressure of C is throttled by the one-way orifice 15B and increases while stroking the direct clutch accumulator 70 from the right half shown position to the left half shown position, so this rise is gradual and direct clutch D
/C engagement shock, that is, 3-4 gear shift shock can be alleviated.

(Fifth speed) After that, when the operating state is reached in which the fifth speed should be selected, the computer controller turns the first shift solenoid A ONL, thereby increasing the spool 42 of the first shift valve 42.
Raise b again in the figure. As a result, the second shift valve 4
The high clutch and servo release circuit 12B, which was connected to the D range pressure circuit 110 at 4, is connected to the circuit 126 at the first shift valve 42, and the D range pressure is supplied to this circuit 126. This pressure is supplied from the circuit 126 to the 5-speed servo apply chamber 53/A via the overrun clutch control valve 62 and the circuit 150, and is supplied to the band brake B/B.
conclude. On the other hand, the circuit 122 is cut off from the D range pressure circuit 110 by the switching of the first shift valve 42, but is switched to the circuit 128, so pressure continues to be supplied to the 2nd speed servo apply chamber 2S/A. . Therefore, the band brake B/B is engaged, and in conjunction with the forward clutch F/C, high clutch H/C, and direct clutch D/C maintaining operation, the multi-stage automatic transmission is clear from Table 1 above. As expected, from 4th gear to 5th gear (
It is possible to perform an upshift to overdrive (OD).

For this upshift, the 5th gear servo blazing chamber 5
The pressure to S/A is throttled by the one-way orifice 151 and gradually increases while the accumulator 60 is stroked from the right half shown position to the left half shown position, so the band brake B/B must be engaged accordingly. This can be done without shifting, and the shock of 4-5 gear shifting can be alleviated.

Furthermore, the above switching of the first shift valve 42 causes the circuit 108 to be cut off from the drain boat 42d and connected to the circuit 127, but this circuit is not connected to the drain boat 44d when the second shift valve 44 is in the illustrated state. Therefore, the lock-up control valve 34 is in the chamber 34g in the fifth speed selected state.
Torque converter T/
The lock-up control of C can continue to be left to electronic control by the solenoid 36.

(OD prohibition) If the driver does not wish to shift to 5th gear (OD) and has turned on an OD prohibition switch (not shown), the computer will shift to 5th gear as shown in Table 3 above. Do not select the ON/OFF combination of solenoids A, B, and C. Therefore, the multi-stage automatic transmission automatically changes gears between the 1st speed and the 4th speed, but at this time, the computer turns off the overrun clutch solenoid 40 when the engine throttle opening is below a predetermined value (for example, 1/16 opening). . This switches the overrun clutch control valve 62 to the state shown, and connects the circuit 152 to the D range pressure circuit 110. The D range pressure from this circuit is output to the circuit 152, and after being reduced as described above by the overrun clutch pressure reducing valve 64, it passes through the orifice 164 to the overrun clutch pressure reducing valve 64. Clutch OR/C is reached and engaged. By engaging the overrun clutch OR/C, the multi-stage automatic transmission enables engine braking in the second to fourth speeds, as is clear from Table 1 above. At this time, since the operating pressure of the overrun clutch is reduced by the valve 62 as described above,
It is possible to alleviate the shock when the overrun clutch OR/C is engaged.

The above switching of the overrun clutch control valve 62 connects the circuit 150 to the drain port 62d to drain the fifth speed servo brining chamber 5S/A, thereby compensating for the release of the band brake B/B. As a result, when overrun clutch OR/C is engaged, band brake B/B
is reliably released, and it is possible to prevent both from being engaged at the same time and interlocking the gear transmission train.

(4-3 Shift) The shift for switching the auxiliary transmission from the direct connection state to the deceleration state in the D range will be described below with respect to the 4-3 down shift shift.

During this shift, the computer shifts the main transmission (shift solenoids A and B) to the fourth shift as shown in Table 3 above.
While the speed is selected, the third shift solenoid C. @OF
F to ON to switch the third shift valve 46 to the state shown in the figure. As a result, the circuit 156 is connected to the drain boat 46e to exhaust the pressure, releasing the direct clutch D/C, and the circuit 157 is connected to the line pressure circuit 81 and the line pressure is introduced, thereby controlling the reduction brake RD/B as follows. As shown in Table 1 above, the multi-stage automatic transmission can be downshifted from the 4th speed to the 3rd speed.

When this reduction brake RD/B is engaged, the chamber 66a of the reduction timing valve 66 and the accumulator back pressure chamber 6 of the reduction brake accumulator 68 are
No pressure is supplied to the circuit 161 leading to 8d in the D range. The reason is that the manual valve boat 38m makes the circuit 111 unpressurized, and the manual valve boat 38R
This is to bring the circuit 155 into a no-pressure state through the circuit 88. Therefore, the reduction tying valve 66 is in the state shown and the circuit 157. 163, and the pressure of the circuit 157 cannot be supplied to the duction brake RD/B through the one-way orifice 160. Further, the back pressure of the reduction accumulator 68 is set to O, and the accumulator characteristics are determined only by the built-in spring 68a.

Therefore, the reduction brake engagement pressure is the solid line P in Figure 4.
．． As shown in , first the piston 68 of the accumulator 68
The spring force equivalent value P of the spring 68a which moves b to the right half position shown rises, and then the one-way orifice 16 is moved while the piston 68b is stroked to the left half position shown.
The piston 68 rises at a time gradient determined by the inner diameter of the piston 68.
At the moment t1 when b finishes its stroke, it further rises by the return spring force of the reduction brake RD/B,
Reduction brake RD/B loss stroke instant t
2, it becomes the same as the line pressure PL which is the source pressure.

By the way, the pressure value required to engage the reduction brake RD/B is P2, and the pressure value required to engage the reduction brake RD/B is P2.
/B is only concluded at the instant t2. However, the D range does not require engine braking and is intended for positive drive from the input shaft side to the output shaft side, and when the direct clutch D/C is released, the reduction one-way clutch RD/OWC (see Figure 3) ) can take over the power transmission, and the delay in engagement of the reduction brake RD/B will not affect the speed change. By delaying the engagement of the reduction brake, it is possible to prevent simultaneous engagement with the direct clutch D/C, and it is possible to reliably prevent shift shock caused by interlocking of the sub-transmission. ．． By the way, in the present invention, as shown in FIG. 2, the accumulator 68 is connected to the redux brake hydraulic circuit 157 in such a manner that the accumulator chamber 68c constitutes a part of the redux brake operating hydraulic circuit 157. can compensate for the pressure (po) control described above. Here, to explain the process of engaging the reduction brake RD/B, when changing the state of the third shift valve 46 for 4-3 downshift, first, the hydraulic fluid is transferred to the reduction brake RD/B and the accumulator 68 (accumulator 68). rate room 68c) is filled. However, during this time, no pressure is generated anywhere in the circuit 157, and when the filling is completed, the circuit 157
pressure is generated. At the beginning of this pressure generation, the pressure is not yet at a value that causes the reduction brake RD/B and the accumulator 68 to stroke, so no oil flow occurs in the circuit 157.

On the other hand, as shown in FIG.
The goal is to prevent shift shock during power-on downshifts (when downshifting due to depressing the accelerator pedal, when D range is selected) against the loss of sH (in this example, the engagement pressure of direct clutch D/C) shown by the solid line. Low speed selection pressure change PsL' (in this example, the beam brake RD/
It is designed to obtain the same pressure as shown by Pa in FIG. , while the accumulator 68 is being stroked, the internal pressure corresponds to the accumulator shelf on the pst' characteristic. By the way, during this time, accumulator 68
is stroking, an oil flow occurs in the oil passage between the third shift valve 46 and the accumulation chamber 68c, and a pressure drop AP occurs. However, the reduction brake R
Since D/B has not yet started to stroke and no oil flow is generated in the oil passage between the accumulation chamber 68c and the reduction brake RD/B, there is no pressure drop there. Therefore, the operating pressure of the reduction brake RD/H is the pressure in the accumulation chamber 68C, that is, the pressure in the accumulation chamber 68C.
The internal pressure of the accumulator 68 is maintained at the same level as the internal pressure of the accumulator 68, and is not affected by the pressure drop AP, as shown by the dotted line pst' in FIG. It has a stroke shelf that corresponds to the stroke of the reduction brake R/B, and p. It is possible to compensate for the pressure control shown by .

In this case, with reference to FIG. 5, the pressure PsL' (Pa
) exceeds P2, and the reduction brake RD/B starts to be engaged, preventing both from being engaged at the same time during the shift, that is, preventing the auxiliary transmission from interlocking, and changing the transmission output torque waveform to the first. As shown by the dotted line in FIG. 5, deterioration of shift shock can be avoided.

In the case of this embodiment, due to the structure of the sub-planetary gear mechanism 4, the reduction brake RI)/B is located at the rear of the transmission, and the accumulator 68 has a large diameter, so the torque converter has sufficient space. Although the direct clutch D/C is located as close as possible to the T/c, since the sub-planetary gear mechanism 4 also includes a direct clutch D/C, engagement and disengagement of this are also controlled at the same time. The third shift valve 46 cannot be disposed too far from the sub-planetary gear mechanism 4, and the third shift valve 46 has a duct, a ducting accumulator 68, and a ducting brake RD/B.
It is placed in between. Therefore, in these configurations, the accumulator 68 and the reduction brake R are simply
If the oil passages are connected to B/B in such a way that they are separated, the distance from the third shift valve to the accumulator 68 becomes longer, which worsens the shift shock as described above, but in this embodiment, this can be prevented. can.

■When a range driver desires engine braking driving in 3rd gear or lower, the manual valve 38 is set to ■range.

At this time, the computer outputs the O of shift solenoids A, B, and C.
The N and OFF combinations are determined so that the first, second, or third speed shown in Table 3 is selected depending on the driving condition, and a predetermined value of the engine throttle opening (for example, l/1
By turning off the overrun clutch solenoid 40 and engaging the overrun clutch OR/C when the opening degree is less than 6 degrees, as is clear from Table 1 above, the
Enables engine braking at high speeds.

By the way, if the manual valve 38 is set to the ■ range while driving in the 5th or 4th gear with the D range set, as is clear from Table 1 above, the auxiliary transmission is shifted as described above for the 4-3 downshift. Similarly, the direct connection state is switched to the deceleration state. However, in this lever range, the manual valve 38 also outputs the line pressure from the circuit 8l to the boat 381, and this pressure passes through the shuttle valve 112 and the circuit 161 to the chamber 66 of the reduction tie short valve 66.
a and the back pressure chamber 68d of the accumulator 68. Therefore, the reduction timing valve 66 is connected to the spool 6.
6b and passes between circuits 157 and 163, the pressure in circuit 157 is applied not only to one-way orifice 160 but also to reduction brake RD/
Supply to B. Further, the accumulation characteristics of the accumulator 68 are determined not only by the spring 68a but also by the line pressure from the circuit 161.

Therefore, the reduction brake engagement pressure first produces a reduction brake stroke shelf, as shown by the two-dot chain line Pt in FIG. rises to a higher value corresponding to the sum of the inner diameter of the one-way orifice 160 and the orifice 162.
The line pressure P rises at a steep slope determined by the sum of the inner diameters of the piston 68b, and reaches the line pressure P after the stroke of the achiemulator piston 68b is completed.

Therefore, the reduction brake engagement pressure is
The set value P2 is reached at an instant t0 earlier by the inner diameter of 2 and the back pressure of the accumulator 68, and the reduction brake RD
/B can be concluded early. By the way, this range ■ requests engine braking and operates the manual valve 38 by the driver, and is designed to reverse drive from the output shaft side to the input shaft side, and is timed to release the direct clutch D/C. If the reduction brake RD/B is not engaged quickly, there will be a delay in the effectiveness of the engine brake, and the requested engine brake will not be obtained. However, the early engagement of the reduction brake can eliminate this problem. On the other hand, t in Figure 4
Since the moment when the reduction brake engagement starts, which is indicated by 0, is during the stroke shelf time of the Akiemulator 68, the rate of change in the reduction brake engagement pressure is not such as to cause a reduction brake engagement shock (shift shock), and the shift at the time of the relevant shift is Shock can be alleviated.

1'' 5 Ren 2 When the driver desires to run with engine braking in 2nd gear or lower, he sets the manual valve 38 to the ■ range.

At this time, the computer outputs the O of shift solenoids A, B, and C.
The N and OFF combinations are determined so that the first speed or the second speed shown in Table 3 is selected depending on the driving condition, and a predetermined value of the engine throttle opening (for example, 1/l6 opening) is determined.
Turn off overrun clutch solenoid 40 with the following
L and engage overrun clutch OR/C. On the other hand, the manual valve 38 also outputs the line pressure of the circuit 81 from the port 381, and from this boat 38
The line pressure to 13 is reduced by valve 72 and supplied to circuit 140 as low reverse brake pressure.

At the first speed, the first and second shift valves 42. 44 is the spool raised in the figure, and the above pressure in circuit 140 is increased by circuit 12'lJ. 124 and the shuttle valve 115, the low reverse brake LR/B is reached and engaged.

Therefore, the multi-speed automatic transmission enables engine braking driving in the first gear. In addition, low bar sprayer LR/
If B is set to a large capacity so that it is engaged even when reversing is selected as described later, the engagement pressure of the neck is also reduced by the valve 72, which prevents the engagement shock of the low reverse sprayer LR/B from becoming large. be able to.

At the second speed, the first shift solenoid 42 is in the state shown, and the circuit 124 is connected to the low reverse brake engagement pressure circuit 129.
The low reverse brake LR/B is released to connect to the drain boat 42f, and with the 2nd gear selected and the overrun clutch O R/C engaged, the multi-speed automatic transmission applies engine braking in 2nd gear. enable running.

By the way, if the driver requests emergency engine braking and switches the manual valve 38 to the ■ range while driving in the 5th gear with the D range set, the jump from the 5th gear to the 2nd gear will occur due to the following action. and compensate for shifting.

Furthermore, as is clear from Table 1 above, this jump shifting is as follows:
Not only does the main transmission change gears, but the auxiliary transmission also switches from a direct-coupled state to a deceleration state, and the state change of the auxiliary transmission is the same as described for the effect when switching from D range to ■ range. Here, the first and second
Only the shift on the main transmission side by switching the shift solenoids A and B and the overrun clutch solenoid 40 will be described.

In 5th gear, the first shift solenoid A is ON as mentioned above.
to bring the first shift valve 42 into the spool up state and shift the second shift valve 42 to the spool up state.
When the shift solenoid B is OFF, the second shift valve 44 is placed in the state shown in the figure, and when the overrun clutch solenoid 40 is turned on, the overrun clutch control valve 62 is placed in the spool raised state, and the forward clutch F/C,
High clutch H/C, 2nd speed servo apply chamber 2S/A,
The 5th speed selection state of the multi-stage automatic transmission is obtained in which pressure is supplied to the 3.4-speed servo release chamber 3.43/R and the 5th-speed servo apply chamber 53/A. In this state, the 3rd and 4th speed servo release pressures reach the 5-2 sequence valve 50 via the circuit 144 and the circuit 142, and maintain this valve in the state in which the spool 50b is lowered in the figure. In addition, the 5th speed servo apply pressure is applied to the overrun clutch control valve 6 from the circuit 150.
2. The circuit 126 leads to the 5-2 relay valve 48, which is maintained in the state in which the spool 48b is raised in the figure.

Here, when the driver switches the manual valve 38 to the ■ range, the computer switches the first shift solenoid A to OFF, switches the first shift valve 42 to the state shown in the figure, switches the second shift solenoid B to ON, and switches the first shift solenoid A to the state shown in the figure. The shift valve 44 is switched to the spool up state, but the overrun clutch solenoid 40 is kept ON until the end of the 5-2 jump shift, and the overrun clutch control valve 62 is kept in the spool up state. Due to the above switching of the second shift valve 44, the pressure in the 3.4-speed servo release chamber 3.43/R is about to be drained together with the pressure in the high clutch H/C, but these pressures are drained through the one-way orifices 131, 143.
are narrowed down and not immediately eliminated. Therefore, during this time 3
, the pressure in the 4-speed servo release chamber 3, 4S/R keeps the 5-2 sequence valve 50 in the spool downward state, and the circuit 12
7. 141 are connected. Further, by the above switching of the second shift valve 44, the circuit 127 is connected to the D range pressure circuit 110, and the D range pressure from now on is transferred from the circuit 167 to 5-2.
Sequence valve 50, circuit 141, 5-2 relay valve 48
, circuit 125, the first shift valve 42 switched as described above, circuit l26, overrun clutch control valve 62, and circuit 150 to the 5th speed servo apply chamber 5S/
A is supplied to back up the 5th speed servo apply pressure in this chamber regardless of the ON/OFF combination of shift solenoids A and B for 2nd speed selection. This backup is
The 5th speed servo apply pressure acts on the lower end chamber of the 5-2 relay valve 48 to maintain the valve in the spool raised state, thereby self-maintaining.

After that, when the pressure in the 3.4-stroke servo apply chamber 3.4S/H is released, the spool 50b of the 5-2 sequence valve 50, which had been stroked, is returned to the raised position by the spring 50a, so that the circuit 141 drains. 50
．． Leads to c. Therefore, the 5th speed servo apply pressure backed up as described above is removed from the drain boat 50c, and due to this removal, the 5-2 relay valve 48 is also returned to the state shown in the figure. As a result of the above, the 3.4-speed servo apply chamber 3,
After the pressure of 43/R is released, the 5th speed servo brining chamber 53
/A will be released, and the band brake B/B will not be released at all and the pressure will continue to be supplied to the 2nd speed servo apply chamber 2S/A, thereby maintaining the engaged state. Therefore, when the pressure of the high clutch H/C released together with the pressure of the 3rd and 4th speed servo release chambers 3 and 4 S/R releases the high clutch, the multi-stage automatic transmission will be in the It is possible to shift from 5th gear to 2nd gear without passing through any intermediate gears.

After this jump shift, the computer switches the overrun clutch solenoid 40 to OFF, switches the overrun clutch control valve 62 to the state shown, connects the 5-speed servo apply pressure circuit 150 to the drain boat 62d, and connects the overrun clutch pressure circuit 152 to the drain boat 62d. is passed to the D range pressure circuit 110, and the overrun clutch O R/C is engaged with the upcoming D range pressure. By engaging this overrun clutch O R/C, the multi-speed automatic transmission can run with engine braking in 2nd gear, but it requires a large engine brake and switches from D range to ■ range while 5th gear is selected. At this time, the above-mentioned action makes it possible to reliably perform a jump shift from the fifth speed to the second speed, thereby ensuring the required engine braking.

The action of the 5-2 sequence valve 50 is as follows: Pressure exists in the 5-speed servo apply chamber 55/A, and this 5-speed servo apply pressure causes the 5-2 relay valve 48 to be in the spool up state. The existence of the 5-2 relay valve 48 can prevent malfunctions in which the backup of the 5th speed servo apply pressure is performed only during selection and is performed at other speeds.

When the ■ range driver requests engine braking driving in the first speed, he turns on the I range switch (not shown) with the manual valve 38 set to the ■ range.

At this time, the computer turns on the shift solenoids A, B, and C for selecting the first speed as shown in Table 3 above, and turns the overrun clutch solenoid 40 on when the engine throttle opening is below a predetermined value (for example, 1/16 opening). Turn off.

As a result, the multi-stage automatic transmission enters a state similar to that described above for the first speed in the (1) range, and maintains this state to enable first speed engine braking.

When the R range driver desires to drive in reverse and sets the manual valve 38 to the R range, the manual valve is set to the R range shown in Table 2 above.
The line pressure of circuit 81 is output only to 8R, and all other boats are used as drain boats. The line pressure output to the boat 38R is supplied to the circuit 88 as a backward selection pressure, while passing through the shuttle valve l07 and the circuit 106 to reach the chamber 34g of the lockup control valve 34. As a result, the valve 34 is stroked upward in the figure, and the torque converter T/
C is kept in the converter state as in the first speed selection.

The retraction selection pressure of circuit 88 is applied to one-way orifice 1 on the other hand.
14 to circuit 155, and then shuttle valve 154
and reaches the chamber 46d of the third shift valve 46 via the circuit 153 to bring this valve into the state shown, and direct clutch D/
By releasing C and engaging reduction brake RD/B, the auxiliary transmission is brought into a decelerating state. By the way, at this time, the reverse selection pressure passing through the circuit 155 is applied to the shuttle valve 112 and the circuit 1.
61 to the chamber 66a of the reduction tie valve 66 and the back pressure chamber 6 of the reduction brake emulator 68.
8d, and these valves and accumulators are made to function in the same manner as described for the range. As a result, the reduction brake RD/B is quickly engaged, and when the reverse rotation is selected, a reverse rotation output is intended, and since the transmission state is the same as the reverse drive (engine brake), the reduction one-way clutch RD/OWC (see Figure 3) Even if the sub-transmission is unable to function, the auxiliary transmission can be quickly brought into deceleration mode. Note that when the manual valve 38 is in the N or P range, the auxiliary transmission is in the deceleration state as shown in Table 1 above, and when the manual valve 38 is switched from the N or P range to the R range, the auxiliary transmission is also in the deceleration state. There is no change in the state, and the early engagement of the reduction brake RD/B by the above-mentioned functions of the reduction tying valve 66 and the reduction tying emulator 68 appears to be meaningless. However, when switching to the R range immediately after starting the engine in the N or P range, the auxiliary transmission is initially in a neutral state due to the delay in pressure generation immediately after the engine starts, and after switching to the R range, the sub-transmission is in a neutral state. The vehicle is switched to a deceleration state by engaging the reduction brake RD/B. By the way, if there is a delay in engagement of the reduction brake RD/B during this switching, the reduction one-way clutch RD/OWC cannot perform the substitute function as described above in this R range, so the neutral time of the auxiliary transmission will be delayed due to the above engagement delay. When switching from the N or P range to the R range immediately after starting the engine, there is a large time delay for the multi-stage automatic transmission to change from a neutral state to a state in which reverse rotation output is possible. This not only causes a delay in starting from the rear, but also causes the engine to run dry during that time, resulting in a large R range selection problem. Also, the above tendency is due to the high viscosity of the transmission hydraulic fluid when switching the manual valve 38 from the N or P range to the R range immediately after a cold start of the engine.
It becomes even more noticeable. However, in this R range, as described above, the reduction tie valve 66 and the reduction brake accumulator 68 quickly engage the reduction brake RD/B by the reverse selection pressure from the circuit 161, so there is no delay in starting backward or a large R range selection. Shock can be prevented.

The retraction selection pressure in circuit 88 also applies to one-way orifice 11.
4 and the low reverse brake L via the shuttle valve 115
It reaches the R/B and engages it, and also reaches the reverse clutch R/C via the one-way orifice 117 and engages it. Other friction elements related to the main transmission, forward clutch F/C, high clutch H/C, band brake B/B, and overrun clutch OR/C, all receive pressure from manual valve boats 38D, 381 [1, 38I1]. The boat is at working pressure, and since all of these boats have been drained, they will not be tied up. Therefore, low reverse brake LR/B, reverse clutch R/C
By engaging the reduction brake RD/B, the multi-stage automatic transmission can select reverse as is clear from Table 1 above. Shift solenoids A and B are used for this reverse selection.
, C and overrun clutch solenoid 40 are turned on,
Turning these off has no effect, but if these are turned off, the hydraulic oil will continue to drain and drive energy for the oil pump O/P will be lost. Program it to stay ONL.

Note that when the reverse is selected, the accumulator switching valve 58 is in the state shown in the figure because it does not receive pressure from the D range pressure circuit 110, and by connecting the circuit 148 to the circuit 149, the accumulator 56 functions as a reverse clutch accumulator as follows. let

In other words, as mentioned above, the pressure reaching the reverse clutch R/C is throttled by the one-way orifice 117 and then
9. It is also led to the accumulator 56 via the accumulator switching valve 58 and the circuit 148, and gradually rises while stroking this accumulator. Thereby, it is possible to reduce the engagement shock of the reverse clutch R/C, that is, the selection shock when the manual valve 38 is switched from the P or N range to the R range.

(Effects of the Invention) Thus, the speed change control device for the auxiliary transmission of the present invention has the following features as described above.
The accumulator 68 has an accumulation chamber 68c that is a friction element (in the illustrated example, a beam reduction brake RD/B).
Since a part of the hydraulic pressure circuit 157 of the friction element is connected in a cautious manner, the hydraulic pressure of the friction element is made equal to the internal pressure of the Achiemulator, and the pressure drop that occurs during the stroke of the Achiemulator increases the hydraulic pressure of the friction element. The design of the Akiemulator makes it possible to control the increase in the friction element operating pressure as desired. Therefore, it is possible to prevent the friction element from being engaged before the other elements are disengaged, and it is possible to eliminate the problem of interlocking the sub-transmission and worsening shift shock.

[Brief explanation of the drawing]

Fig. 1 is an overall system diagram of a multi-stage automatic transmission showing an embodiment of the present invention, Fig. 2 is a shift control hydraulic circuit diagram of the automatic transmission, and Fig. 3 is a power transmission train of the automatic transmission. 4 is a time chart illustrating changes over time in the reduction brake engagement pressure by the device of the present invention, and FIG. 5 is a comparison of the shift oil pressure of the auxiliary transmission between the device of the present invention and the conventional device. FIG. 6 is a conventional shift control hydraulic circuit diagram for an auxiliary transmission. 1... Input shaft 2... Output shaft 3... Main transmission 4... Sub-transmission D/C... Direct clutch RD/B... Reduction brake (friction element) RD
/OWC...Reduction one-way clutch 0/P
... Oil pump 20 ... Pressure regulator valve 22 ... Pilot valve 24 ... Duty solenoid 26 ... Pressure modifier valve 28 ... Modifier accumulator 30 ... Accumulator control valve T/C. ... Torque converter 32 ... Torque converter relief valve 34 ... Lockup control valve 36 ... Lockup solenoid 38 ... Manual valve A ... First shift solenoid B ... Second shift solenoid C ...Third shift solenoid 40...Overrun clutch solenoid 42...
First shift valve 44...Second shift valve 46...
Third shift valve 48...5-2 relay valve 50...
・5-2 sequence valve 52...1-2 accumulator valve 54...N-D accumulator 56...3.4 speed servo release/reverse clutch accumulator 58...Aki emulator switching valve 60...5 speed Servo apply accumulator 62...
・Overrun clutch control valve 64...Overrun clutch pressure reducing valve 66...Reduction tie ξ
68c... Accumulation chamber 70... Direct clutch accumulator 72...
・■ Range pressure reducing valve (Aki Fig. 4 Time (#) Fig. 6

Claims (1)

[Scope of Claims] 1. A sub-transmission capable of switching between high and low speeds by activating a friction element using hydraulic pressure whose rising speed is controlled by an accumulator or by disabling the friction element, and a main transmission. A control valve is attached to the case of the main transmission, and the accumulator is attached to the control valve. 1. A shift control device for an auxiliary transmission in an automatic transmission, characterized in that an accumulator is connected so that an accumulation chamber of the accumulator constitutes a part of a hydraulic pressure circuit for the friction element. 2. A shift control device for an auxiliary transmission according to claim 1, wherein the auxiliary transmission is disposed downstream of the main transmission. 3. In claim 1 or 2, the auxiliary transmission is provided with a direct clutch and a reduction brake as friction elements, the high speed selection state is set by hydraulic actuation of the direct clutch, and the low speed selection state is set by hydraulic actuation of the reduction brake,
A speed change control device for an auxiliary transmission in which a reduction brake accumulator is connected so that its accumulation chamber becomes part of the reduction brake operating hydraulic circuit.