JPS62113959A - Lock-up control device for automatic transmission - Google Patents

Abstract

PURPOSE:To improve the fuel consumption at a lock-up time, by decreasing the load of a charging pump, at the lock-up time. CONSTITUTION:A main regulating valve 70 is installed in a hydraulic circuit, which controls a torque converter 10 and a speed change gear 12. This main regulating valve 70 closes routes 73, 77, at a lock-up time. At the same time, the pressure receiving face I of a main spool 76 is pressed, a part of pressure oil sent from an inflow port 70a4, is circulated toward a charging pump 25, and the line pressure of a route 71a is lowered. With this constitution, the fuel consumption at the lock-up time, can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lock-up control device for an automatic transmission equipped with a so-called pressurized piston type lock-up mechanism suitable for low-speed, high-torque vehicles such as construction machinery. be.

(Prior art and its problems) The lock-up mechanism normally used in automatic transmissions for passenger cars uses the internal pressure of the torque converter directly to connect the output shaft and engine with a friction material fixed to one side of the lock-up piston. It has a structure that is directly connected.

However, in the lock-up mechanism for passenger cars, the number of friction surfaces is 1, and the internal pressure of the torque converter is 2.
It is not suitable for construction machinery, industrial vehicles, or commercial vehicles equipped with low-speed, high-torque engines because the pressure must be kept to a low pressure of about 4 to 9/cIA.

Therefore, between the lock-up piston and the front cover of the torque converter, it must be rubbed on both sides! A so-called pressurized piston type lock-up mechanism has been developed in which a disk equipped with II is provided and a lock-up piston presses the disk against the front cover.

In the conventional piston-type lockup mechanism, the line pressure of the hydraulic gear shift control device of the M star gear transmission installed after the torque converter is guided to the lockup piston to connect the lockup piston and the front cover. ing.

For this reason, during lock-up operation, the torque input to the transmission is not amplified by the torque converter, so high oil pressure is supplied from the charging pump even though very high line pressure is not required. There is a problem in that the engine power required to drive the pump is lost.

On the other hand, in order to reduce the loss of engine power during lock-up, the following three points are important.

(1) Since the engine torque is transmitted from the lock-up mechanism, it is possible to reduce the line pressure of the hydraulic gear shift control device by the torque ratio of the torque converter.

(2) Draining the hydraulic oil in the torque converter will reduce drag losses.

(3) Since the engine speed is relatively high, reducing the amount of lubricating oil supplied to the friction elements of the planetary gear transmission will reduce drag and lower the temperature of the hydraulic oil.

Therefore, there is a need for a lock-up control device for an automatic transmission that has a simple structure that satisfies the above three items.

(Objectives of the Invention) The present invention aims to improve fuel efficiency by (1) lowering the line pressure of the hydraulic gear shift control device during lock-up operation; (2) reducing the drag of hydraulic oil inside the torque converter during lock-up operation: (3) It is an object of the present invention to provide a lock-up control device for an automatic transmission that can reduce the drag and lower the temperature of the hydraulic oil by reducing the amount of lubricating oil supplied to the planetary gear transmission during lock-up operation.

(Structure of the Invention) (1) Technical Means The present invention provides a method for installing a transmission capable of switching between a plurality of gears at the rear stage of a torque converter with a pressurized piston lock-up mechanism that transmits engine power using fluid. In an automatic transmission equipped with a hydraulic gear speed control device that switches gears of the transmission based on an operating status signal (using an electronic control circuit and controls the lock-up mechanism), pressurized oil from the charging pump A lock-up control valve for lock-up switching is provided downstream of the main regulating valve for regulating the flowing pressure, and when the lock-up control valve is switched to the lock-up state by a signal from the electronic control circuit, the main regulating valve is switched to the lock-up state. The pressure receiving surface of the spool of the main regulating valve is formed with a difference in area so that the main regulating valve operates in a low pressure state, and in the lock-up state, the pressure oil is guided to the piston of the lock-up mechanism, and the pressure oil inside the torque converter is drained. A lock-up control device for an automatic transmission is characterized in that the lock-up control valve is formed as described above, and a lubricating oil throttle mechanism is provided for reducing the amount of lubricating oil supplied to the transmission when in the lock-up state.

(2) Operation The lock-up control valve drains the hydraulic oil in the torque converter during lock-up to reduce drag caused by the hydraulic oil in the torque converter.

During lock-up, the lock-up pressure applies a load to the main regulating valve spool, lowering the line pressure.

A lubricant squeezing mechanism reduces the amount of lubricant supplied to lubricating points within the transmission during lockup.

(Embodiment) In FIG. 1 showing an embodiment in which the present invention is applied to an automatic transmission for a commercial vehicle such as a truck, 10 is a four-element two-stage torque converter. A transmission 12 with three forward speeds and one reverse speed is connected to the rear stage of the torque converter 10. The transmission 12 includes a clutch F3 or brakes Fl, F2 . It has R.

The transmission 12, the torque converter IO, and a hydraulic gear speed control device, which will be described in detail later, constitute an automatic transmission.

The torque converter 10 includes a pump 14, a turbine 16, a fixed stator 18, a reverse rotation speed data 20, and a lock-up clutch 21.
The structure is such that the power of the engine is transmitted to the engine.

A piston 21a is slidably provided between the lock-up clutch 21 and the front cover 22, and when the histone 21a slides toward the lock-up clutch 21 by hydraulic pressure, both sides of the lock-up clutch 21 It is a so-called pressurized piston type that serves as a torque transmission surface.

The turbine 16 is connected to a turbine shaft 16a, and the reversing stator 20 is connected to a stator shaft 20a. The fixed stator 18 is fixed to the housing 12a by a shaft 18a,
The pump 14 is connected to a pump shaft 14a. A ring gear 141) is provided at the transmission side end of the pump shaft 14a, and the number of teeth of the ring gear 14b is set to Z611.

The ring gear 14'b meshes with a gear 24b (number of teeth Zez) of an intermediate shaft 24a disposed at the upper part of the housing 12a, and the gear +24t) engages with a PTO shaft 24c (
It meshes with gear 24d of PowerTake Off. A hydraulic pressure source is located at the bottom of the housing 12a. A charging pump 25 is provided, and the charging pump 25 is slid by a sliding gear 25a that meshes with the ring gear 141).

A clutch disk 26a of a third clutch F3 is fixed in the middle of the turbine shaft 16a.

The clutch cap 22b of the clutch F3 is attached to the stator shaft 20.
Connected to a. A second continuous brake F2 is arranged outside the clutch force of -221), and the brake F2 is fixed to the housing 12a.

A second sun gear 28a (number of teeth za!) is fixed to the end of the stator shaft 20a, and a first sun gear 30a (number of teeth Zax) is fixed to the end of the turbine shaft 16a.

The $1 sun gear 30a meshes with the first planetary gear 30b,
The second sun gear 28a meshes with the second planetary gear 28b.

A first ring gear 300 is located outside the first planetary gear 301).
(number of teeth Zrx), and the first ring gear 300 and the first planetary gear 301) are in mesh with each other. Further outside the first ring gear 300, a first speed brake Fl fixed to the housing 12a is arranged.

On the outside of the second planetary gear 281) is a second ring gear 28C.
(number of teeth Zrz) are in mesh with each other, and a brake R for reversing is arranged further outward of the second ring gear 28Q. Brake R is fixed to housing 12a.

As shown in FIG. 2, the first planetary gear 30b and the second planetary gear 28b are held on a carrier 32 in a rotatably engaged state.

An output shaft 34 is connected to the carrier 32.

The above transmission 12 includes a clutch Fl and a brake Fl.

F2. By selectively turning on R, the reduction ratios shown in Table 1 below can be generated. Note that the ○ mark in the table indicates the ON operation of the clutch and brake.

Table 1 Next, as shown in Table 1, the hydraulic pressure from the charging pump 25 is applied to the clutch F3 and the brake Fl.

F2. A hydraulic gear speed control device that controls ON and OFF of R will be explained.

In FIG. 3, 39 is a selection position display panel of a select lever (not shown) that is manually operated by the driver. The P range of this selection position display panel 39 displays the parking state, and the R1/
The N range indicates the reverse state, and the N range indicates the neutral state.

The D range displays the 1st, 2nd, and 3rd automatic gear shift statuses by the microcomputer 40 (child control circuit), the 2nd range displays the 2nd gear fixed status, and the L range displays the 1st gear selection status. . The microcomputer 40 has a vehicle speed signal 42, an accelerator opening signal 44, and an engine rotation speed signal 46.
etc. (all driving status signals) are input, and based on these signals 42, 44, 46, the microcomputer 40 compares the pre-stored automatic shift schedule with the signals 42, 44, 46 and determines the driving state. The gear stage that is most suitable for the situation is determined and an output signal 48 is output.

Output signal 48 is solenoid pulp SL, S+, St, S
R and each solenoid pulp SL.

31, S2. SR is O only when output signal 48 is input.
N operation. Solenoid pulp S
L is for the lock-up clutch 21, solenoid pulps St and S2 are for 1st speed and 2nd speed, respectively, and SR is for fin pressure control.

The select lever is connected to a spool 52 of a manual pulse 50 via a link mechanism (not shown),
A passage 54 through which pressure oil from the charging pump 25 flows is connected to the inflow port 50a of the manual pulp 50. In addition, the manual pulp 50 has D range ports 50D and 2 that are opened and closed by sliding the spool 52.
Range port 50S, L range port 50L, R range boat 50R.

A drain port 501) is formed.

Each of these ports is open when the Nuveu/I/52 Dv range is selected (D range port 50D), and when 2 range is selected, the D range port 50D and 2 range port 5 are open.
08 are both open, and when L range is selected, D range boat 50D, 21/:/shibaud) 508. L range bow)
50L is arranged in a position where all of them are open.

In Figure 3, 60 is the 1st shift valve, and 62 is the 2nd shift valve.
It is nα nft pulp. Both sheadopa~pro0.62 are provided in series on the same axis. 1st shifudopa μ
A single return spring 68 is interposed between the pro 0's sprue/L'64 and the 2nd and the sead pug's sprue A/66, and the return spring 6B connects both sprues A/64.66. Both ends are energized.

The first shift pulp 60 has an inflow port 60al.

5Qaz, outflow port 60b, solenoid port) 6
08L.

Drainpau) 60Ct, 60cz are formed. 2 times Seadopa μ Pro 2 has inflow port) 60a,
Outflow port 62b2.62b2, solenoid port 62
1L, drain ports 6201, and 62Qz are formed. Further, a 1-2 shift lever 61 is provided which communicates both shift pulps 60 and 62.

The area of the pressure-receiving surface formed at both Sday/L'64.66 is A, the area of the pressure-receiving surface corresponding to 628L is A, the area of the pressure-receiving surface corresponding to 62a is B, the inflow port). If the area of the pressure receiving surface corresponding to 60at is 01 and the area of the pressure receiving surface corresponding to solenoid port 5QSL is D, then the relationship of ADD%C>B, k>0-B, B>D...fil is satisfied. It is set as follows.

In FIG. 3, 70 is a main regulating pulp for oil pressure adjustment, and 72 is a lock-up control pulp for lock-up.

Main regulating pulp 70 has main Sday 1v
76 and the auxiliary scale μ78 are arranged on the same axis, and a pressure regulating spring 80.8 is installed between both scales L'76.78.
2 is interposed.

Main spout of main regulating pulp 70 /I/
76, three pressure receiving surfaces E, F,
■ is formed.

The main regulating pulp 70 has five inflow ports 70al, 70az, 70ELs,
70a4.7Qas is provided and outflow port) 7
0b, Drenpo) 70c+, 70Q! is formed.

Matarotsu Kuag Control Pulbu 72KG-! Sday/l/84 is slidably provided in a state where it is biased to the left in the figure by a return spring 86.

The lock-up control pulp 72 has an inflow boat 7.
2a+, 72az, outflow bow) 72bx,
72bz, drain boat 7201, and 72C2 are formed.

The piping system for each of the above pulps will be explained. First, the R range boat 50R of the manual pulp 50 communicates with the brake RK for reverse movement through a passage 51, and one end of an auxiliary passage 71 is branched and connected in the middle of the passage 51.

The other end of the auxiliary passage 71 is in communication with the main regulating pulp 70 (inflow bow) 70as, and when moving backward, the auxiliary spool 78 is pushed to the left in the figure by the hydraulic pressure from the auxiliary passage 71, and the main regulating pulp 70 is ~The set pressure of Gua 0 is increased.

A passage 53 communicates between the D range boat 50D and the inflow boat 60a2, a passage 55 communicates between the 2V range port 50S and the inflow boat 62a, and a passage connects the L range port 1-5OL and the inflow boat 5Qax. 57.

1st shift valve 60 outflow bow) 60b communicates with the brake F+ for 1st speed via the passage 63, and 2n(
1 shift valve 62 outflow port) 62bl is the passage 65
The outflow boat 6 is connected to the brake F2 for 2nd speed through
2bt communicates with the third speed clutch F1 via a passage 67.

One end of a passage 59 is branched in the middle of the passage 53, and the other end of the passage 59 is branched into three branches, which communicate with the respective solenoid valves St, St, and S2. aisle 59
A throttle 59a is formed at the branching portion of the solenoid pulp, and a drain boat 59b is formed in each solenoid pulp.

Solenoid boat 62s of the above 2na shift pad ρ pro 2
One end of the passage 69s2 is connected to the passage 69s2, and the other end of the passage 69s2 is connected to the passage 59 near the solenoid pulp S2.
branch is connected to. Similarly, one end of the passage 6981 is connected to the solenoid boat (5Q3L) from 1st shift pump to pro 0, and the other end of the passage 69s1 is branched and connected to the passage 59 near the solenoid pulp S1. A passage 59i1L is provided between the passage 59 and the lock-up control pulp 72.

Inflow port 70 of main regulating pulp 7o
A passage 71a communicates between al~70a4 and the passage 54, and a throttle 71b for preventing chattering of the main slide/v76 is formed near the inlet bows 70al~70as. The inlet bow) 7Qas communicates with a passage 710, and a solenoid t<
A/7" SR is provided.The solenoid valve) is formed with a Drainbow) 71 (l).

Further, a passage 73 communicates between the outflow boat 70b and the inflow boat (7Qaz) of the lockup control pulp 72. Furthermore, a passage 75 communicates between the drain boat 7001 and the vicinity of the suction port of the char sink pump 25.

Lockup control pulp 72 outflow boat 72
b! A passage 77 communicates between the oil chamber 88 and the oil chamber 88 of the torque converter 10, and a passage 79 connected to the outflow bow 72bz communicates with the torque converter flow passage 10a of the torque converter 10.

One end of a discharge passage 81 communicates with the torque converter flow path 10a, and the other end of the discharge passage 81 communicates with the torque converter flow path 10a. Part of the hydraulic oil is supplied as lubricating oil to the friction members of R and clutch F3. A check valve 90 and an oil cooler 74 are interposed in the middle of the discharge passage 81. A drain passage 8 is provided near the downstream side of the check valve 90.
3 is branched and connected, and a safety valve 9 is installed in the drain passage 83.
2 is interposed.

Further, one end of a bypass passage 85 is branched and connected near the drain passage 830 on the downstream side, and the other end of the bypass passage 85 is branched and connected to the middle of the passage 77. A lubricating oil throttle mechanism 98 consisting of an orifice 94 and a check valve 96 is provided in the middle of the bypass passage 85 . The flow path area of the orifice 94 is such that the brake Fl
, F3. R, is set to a small area that allows the minimum necessary amount of lubricating oil to flow to the friction member of clutch F3.

Next, the effect will be explained. First, in the transmission 12 shown in Fig. 1, when shifting to the first gear by turning on only the brake Fl and turning off the other brakes and clutches, only the first ring gear 300 is connected to the housing 12a, and the engine The power is input from the pump 14 to the turbine 16 via fluid, and from the turbine shaft 16a to the first sun gear 30a, and the reaction force due to the fact that the first ring gear 300 is fixed via the first planetary gear 30b. At the same time, the reversing force is outputted to the carrier 32 from the pump 14 via the fluid from the turbine 16 to the reversing stator 20, and then from the stator shaft 20a to the second sun gear 28a. The direction is similarly changed to the carrier 32 via the gear 28b and the first planetary gear 30b, and the signal is decelerated and output.The reduction ratio at this time can be set to an arbitrary value of 2 or more.

When shifting to second gear with only the brake F2 being turned ON and the other brakes and clutches being turned OFF, only the Kufutsu force par 26d is connected to the housing 12a, and the reverse rotation of the stator shaft 20a is stopped, so that the torque converter lO
The power from the turbine shaft 16a is the first sun gear 30a.
is input to the first planetary gear 30b and the second planetary gear 28b.
It is decelerated and output to the carrier 32 as a reaction force due to the second sun gear 28a being fixed. The reduction ratio at that time can be set to any value between 1 and 2.

During the third speed shift when only clutch F3 is turned ON, stator shaft zOa and shaft 261) rotate together, so sun gear 28a of transmission 12 connected to these shafts
, 30b also rotate integrally, all idle gear trains rotate integrally, and the reduction ratio is set to 1.

When only brake R is turned on, second ring gear 2
80 is fixed to the housing, and the power of the engine is transferred from the pump 14 to the turbine 16 via fluid to the turbine shaft 16a.
is input to the first sun gear 30a from the first planetary gear 30a.
b% second ring gear 28 via second planetary gear 281)
Since C is fixed, the direction of rotation is converted and output to the carrier 32, and at the same time, the fluid is transferred from the pump 14 to the turbine 16 to the reversing stator 20, and from the stator shaft 20a to the second sun gear 28a. The reversing force input to the carrier 32 is similarly decelerated and outputted to the carrier 32 via the second planetary gear 28b.

As mentioned above, each clutch Fs, brake Ft, F
The electronically controlled hydraulic gear speed control device that selectively turns on Z and R, that is, supplies hydraulic pressure, operates as follows.

First, when the N range shown in FIG. 3 is selected, the manual pulp 50 is closed, so the manual valve 50 is closed.
Therefore, the EE oil from the charging bond 25 does not flow to each clutch Fs, brake F1°Fz, and R side.

On the other hand, the torque converter 10 is constantly supplied with pressure oil from the passage 71a, which is regulated by the main regulator valve 70 and which has passed through the passages 71b10, the pickup control valve 72, and 73a.

Next, when the N range is selected, the spoo/v52 of the manual valve 50 moves to the left in the figure, and the inflow boat 50a and the R range boat 50R communicate with each other. In this state, pressure oil from the charging pump 25 flows from the passage 54 to the passage 51.
Flows to and applies hydraulic pressure to the reverse brake R, turning the brake R ON.

In addition, in this R range, pressure oil is supplied from the passage 71 to the main regulator pulp 70, and the pressure of the main regulator valve 70 is adjusted to the high pressure side to generate the high pressure oil pressure necessary for reversing.

In the P range, the spool 52 moves further to the left, and the spool 52 closes the inflow port 50a, engages the parking gear (not shown), and locks the output shaft 34 (FIG. 1).

Next, when the D range is selected, the gear stage is automatically selected according to the automatic shift program stored in the microcomputer 40.

In this D range, the spool 52 of the manual valve 50
moves to the right, inflow port) 50a and D range port)
50D is connected. In this state, the pressure oil from the charging pump 25 flows from the passage 54 to the passage 53.
From the inflow port 1-60a2 of the st shift valve 60 to the 1-2 shifted pipe port 61, the 2nd shift valve 60
Toha/l/g62 outflow Bo Toro 2b2 to 1lfi
I paid a bribe to 67 to make the triple clutch F5 ON#1. Therefore, when the output signal 48 from the microcomputer 40 stops, the gear is shifted to third speed.

In addition, each solenoid pulp Ss, S2 from the passage 59
, SL is supplied to each pulp S+, Sz.

When the valve Sh is opened, water is drained from the drain port 59'b.

When the D range is selected and the vehicle is stopped, the vehicle speed signal 42 is not at zero level, the microcomputer 40 determines that it is in the starting state, and sends an output signal 48 to the solenoid pulp SL for the L series. .

In this state, the drain port 59 of the solenoid pulp S1
1) is closed, and the pressure oil supplied from the passage 59 flows into the IS't shear pump parlenoid port 5QSL through the passage 69S1. solenoid port) 60S
The spool 64 is moved by the hydraulic pressure from L to the return spring 6.
Move to the left in the figure against the spring force of 8, and press the sprue/L/
The right end of 66 collided with the left end of Sude/L'64, and the 1st
Inflow boat 60a2 and outflow port 6 of shift pulp 60
0b is connected.

On the other hand, 1-2 shift pulp boat 61 is drain ho)
60t3z, and the pressure oil from the passage 67 is drained from the drain port 60C2. Therefore, the clutch F3 is turned OFF, and the brake F+ is turned ON by the hydraulic pressure from the passage 63, thereby shifting to the first speed.

When the vehicle speed increases and reaches the second speed region, the microcomputer 40 outputs only the output signal 48 to the second speed solenoid pulp S2, and opens the solenoid pulp S1. In this state, the pressure oil from the passage 59 flows through B69S.
z and flows into the solenoid boat 623'L of the 2nd shift pump μPro 2. The spool 66 is moved to the right by the hydraulic pressure from the solenoid boat 621L against the spring force of the return spring 68, pushing the spool 1v64 to the right. When both spools μ64 and 66 move as one and the right end of the spool 64 collides with the right wall, l-2
The shift is connected to the outflow port (61) and the outflow port (62bx), and the pressure oil from the passage 53 is transferred to the l-2 shift pulp port (1-2).
61, and is supplied to the dual brake F2 through a passage 65.

On the other hand, the outflow port 60b and the drain port 6001 are connected, the brake F1 is turned off, and the shift from 1st speed to 2nd speed) 0 operation is completed.

When the vehicle speed further increases and reaches the third speed region, all output signals 48 from the microcomputer 40 become zero level, and the aforementioned third speed shift state is entered.

Under normal driving conditions, there is no problem with driving in the D range above, but if you want to constantly exert high driving force, such as when climbing a steep hill, or if you want to apply engine braking when descending, use 2.
Select the range and drive with so-called power shift.

In the 2nd range, the sleeve 52 of the manual pulp 50 moves further to the right, and the inflow port 50a communicates with the D range boat 50D and the 2nd range port 509. In this state, pressure oil is supplied to both passages 53 and 55, and 13t
Pressure oil flows into the inflow port ωa2 of the shift pulp 62 and the inflow port 62a of the 2nd shift pulp 62.

The spoo/I/66 is pushed to the right by the oil pressure from the inflow port 62a, and the 1-2 shift valve port 61 and the outflow port 62bs are connected, and the inflow port 60a2 and the 1-2 shift valve port 61 are connected to each other.
2 shift valve port) 61 is in communication, so the pressure oil from passage 53 passes through 1-2 shift valve port) 61, and then passes through w! It flows to r65 and only brake F2 is turned ON.

In this two-range state, the area of each pressure receiving surface of Sday/l/64.66 is set as B>D as shown in equation (1) above, so in the unlikely event that the microcomputer 40 malfunctions, the solenoid Even when hydraulic pressure is applied from 60SL, the spools 64 and 66 do not move from the above-mentioned 2nd speed shift state and maintain the 2nd speed fixed state.

If the driving force is insufficient even in the 2-range state, select the L range. In the L range state, the subu/1152 of the manual pulp 50 moves to the far right, and the inflow boat 50a
, D range port 50D, 2 range port 509% L range port) and 50L communicate.

In this state, pressure oil flows through the three passages 53, 55, and 57, and is supplied to the inflow boats 60as, 60az, and 62a.

Therefore, tin=/I'66 is pushed to the right, and sugu-/
l/64 is pushed to the left, but spoo A/64, 66
Since the area of the pressure-receiving surface of is set as C>B as in equation (1) above, Sday/l/64 moves to the leftmost position together with spoo/L/66 due to the difference in pressing force. do.

In this first speed shift state, since the inflow port (60a2) and the outflow port (60b) are in communication, pressure oil flows from the passage 53 to the passage 63, and the brake F1 is turned on.

By the way, in the L range, a so-called foo μ groove mechanism is provided to prevent the engine from overheating when the driver selects the L range while maintaining high speed.

In the unlikely event that the L range is selected at such a high speed that the engine will overrun when shifted to L speed, the output signal 48 from the microcomputer 40 is sent to the solenoid pulp S2, so the solenoid pulp S2 turns ON. f7:,.

Therefore, pressure oil flows into the passage 69S2, and pressure oil is supplied to the solenoid valve 628L of the 2ncl shift pulp 62. The area of the pressure receiving surface of the spool 64 and 66 is the area of the F
As shown in equation 11, since A+B>C is set, the spool 1v66 moves to the right against the leftward pressure from the spool 64, and is shifted to the 2nd speed shift state described above.

Therefore, even if the driver selects L range while maintaining high speed, there is no risk of the engine overrunning, υ,
There is no need to incorporate a single one-way clutch into the transmission 12, the transmission 12 is downsized, and engine braking also works during a speed shift. The line pressure is appropriately controlled by the microcomputer 40 which detects the opening degree of the slot μ and the running condition, and operates the solenoid pulp SR in response to the signal 48.

Next, the operation during lock-up, which is the gist of the present invention, will be explained. When the microcomputer 40 detects a lock-up state, an output signal 4 is sent to the solenoid pulp St.
Send 8. When the solenoid pulp SL is turned on by the output signal 48, pressure oil first flows from the passage 59SL to the inflow port of the lock-up control pulp 72).
Supplied to a+.

At this time, the sprue)v84 slides to the right in the figure by the hydraulic pressure from the inflow port 72a1, and the inflow port)72a2 and the outflow port)721)l communicate with each other, and the outflow port)
72b2,! : Drain port 72 (32 is in communication.

Therefore, the pressure oil flowing from the charging bond 25 to the inflow port 72a2 via the passage 71a, the main regulating pulp 70, and the passage 73 flows through the outflow hole.
2'bt, the oil is supplied to the oil chamber 88 of the torque converter 10 through the passage 77. When the hydraulic pressure pull-up piston 21a of the oil chamber 88 is pushed, the lock-up clutch 21 connects the front cover 22, the turbine 16, and the turbine shaft X6a (FIG. 1) with both surfaces serving as torque transmitting parts.

Further, the hydraulic oil in the torque converter flow path 10a is discharged from the passage 79 to the drain boat 72C2, the hydraulic oil in the torque converter flow path 10a gradually flows out, and the drag (flow path resistance) in the torque converter flow path 10a is significantly reduced.

Simultaneously with the above lock-up operation, the main regulating pulp 70 lowers the fin pressure in the passage 71a as follows. That is, the passage 73 and the passage 77 are communicated with each other, and the passage 77 is a closed circuit except for the orifice 94, so that the oil pressure of the passage 73 and the passage 77 is above at, and that of the main spool 76 of the main Regini reading pump 70. Press the pressure receiving surface. With this hydraulic pressure, the main speed/I/76 has a pressure regulating spring of 80.8
It slides to the right in the figure against the spring force shown in step 2 and enters the inflow port) 7
0a4 and drain port) 7001 are connected. Inflow port) 70a4 is also connected to outflow port) 70b ￥87
The line pressure of 1a decreases, and the lockup pressure and fin pressure become the same pressure.

As described above, when the fin pressure in the passage 71a is reduced, the load acting on the charging pump 25 is also significantly reduced, so the engine power required to drive the charging pump 25 is reduced, and the fuel consumption during lock-up is reduced. will improve.

Further, during lockup when pressure oil is supplied from the passage 77, the pressure oil flows through the passage 85 into the passage 81 as lubricating oil. At this time, the flow rate of the passage 85 is the same as that of the orifice 9.
4, the brakes of the transmission 12 are F+, F2, and R.

The flow rate of lubricating oil supplied to clutch F3 is significantly reduced, and an increase in oil temperature is prevented.

(Effects of the Invention) As explained above, in the lockup control device for an automatic transmission according to the present invention, the lockup control device for an automatic transmission according to the present invention has a lockup control system for the hydraulic circuit that controls the torque converter 10 and the transmission 12, which are provided with a so-called pressurized piston type lockup mechanism. At times aisle 7
3 and the passage 77, and push the pressure receiver of the main sprue/L/76 into the inflow bow) A part of the pressure oil from 70a4 flows from the drain port 70C2 to the passage 75, and part of the pressure oil is transferred to the charging bond 25. Since the main regulating pulp 70 is provided to circulate the pulp to the fins and reduce the fin pressure in the passage 71a, the load on the charging pump 25 is reduced during lock-up, and the engine power required to drive the charging bonde 25 is greatly reduced. It is possible to reduce fuel consumption during lock-up and improve fuel efficiency.

Also, during lockup, the inflow port 72az and outflow port 72b of the lockup control pulp 72! Since the lockup control pulp 72 is formed so that the outflow port 72b2 and the drain port 72C2 are communicated with each other, the oil chamber 8 is connected to the oil chamber 8 from the passage 77 at the time of lockup.
Pressure oil can be supplied to the torque converter flow path 8, and at the same time, the hydraulic oil in the torque converter flow path 10a can be discharged from the passage 79, and the drag caused by the hydraulic oil in the torque converter flow path 10a can be reduced.

Furthermore, at the time of lock-up, the orifice 94 of the lubricating oil squeezer (498) can adjust the flow rate of the lubricating oil flowing from the passage 77 through the bypass passage Vi!r85 to the passage 81 to the minimum necessary level, preventing drag and operating Can prevent oil temperature from rising.

[Brief explanation of drawings]

Claims (1)

[Claims] A transmission that can freely switch between multiple gears is installed after the torque converter with a pressurized piston type lockup mechanism that transmits engine power using fluid. In an automatic transmission equipped with a hydraulic gear speed control device that performs switching and controls the lock-up mechanism, lock-up switching is performed downstream of a main regulating valve for pressure regulation through which pressure oil from a charging pump flows. A spool of the main regulating valve is provided so that the main regulating valve operates to a low pressure state when the lock-up control valve is switched to the lock-up state by a signal from the electronic control circuit. The lock-up control valve is formed with a difference in area on the pressure receiving surface of the torque converter, and the lock-up control valve is formed so as to guide pressure oil to the piston of the lock-up mechanism in a lock-up state and drain pressure oil inside the torque converter. A lock-up control device for an automatic transmission, comprising a lubricant squeezing mechanism that reduces the amount of lubricant supplied to the transmission in a lock-up state.