JPS6136544A - Automatic transmission for car - Google Patents

Abstract

PURPOSE:To obtain the proper driving power corresponding to traveling state by operating a subtransmission to a low speed stage when the working-oil temperature of a transmission is over a set value. CONSTITUTION:Each input signal of a car-speed sensor 501 for detecting car- speed V, oil-temperature sensor 602 for detecting the oil-temperature tx of working oil for a torque converter, shift-lever position sensor 603 for detecting the set position of a shift lever, throttle opening-degree sensor 604, and a mode switch 605 is read-out, and an automatic transmission is controlled by a shift-lever position signal, throttle opening-degree signal, and a car-speed signal. When the working-oil temperature is over a set value, a subtransmission is operated to a low speed stage. In other words, a proper driving power corresponding to traveling state can be obtained by detecting the shortage of the driving power of a car from the working-oil temperature and operating the subtransmission to a low speed stage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to an automatic transmission for a vehicle that includes a main transmission and an auxiliary transmission capable of switching between a high gear and a low gear.

[Prior Art] Conventionally, an automatic transmission for a vehicle includes a fluid transmission device such as a fluid coupling or a torque converter, a gear transmission mechanism having a plurality of gears, and the fluid transmission V4v! It consists of a main transmission with a control device that controls l and gear transmission mechanism at t/JIB, and an auxiliary transmission that can switch between high and low gears. The gears were set according to the driving force required by the auxiliary transmission.

[Problems to be Solved by the Invention] However, in such an automatic transmission for a vehicle, when the driving force is insufficient while traveling uphill, the main transmission is first automatically shifted to a lower gear, and the main transmission is If the driving force is still insufficient in the lowest gear, the driver's operation will set the first gear to the lower gear and generate the maximum driving force, but if the driver does not operate the sub-transmission to the lower gear. If this is not done, there will be a lack of drive horns and a large amount of slippage between the pump and turbine of the fluid transmission system.

In particular, when a torque converter is used as a fluid transmission device, the torque increases due to the slip even though a large amount of slip occurs, so the driver may not operate the auxiliary transmission to a low gear while the vehicle is running.

Driving with a large amount of slippage in the fluid transmission system not only reduces efficiency, but also causes the oil in the transmission to rise due to the heat generated by the slippage in the fluid transmission system, which has an adverse effect on parts. This may reduce the durability of the transmission.

A first object of the present invention is to provide an automatic transmission for a vehicle that can generate an appropriate drive horn depending on the vehicle running condition.

A second object of the present invention is to provide an automatic transmission for a vehicle that prevents an increase in hydraulic oil temperature, prevents adverse effects on transmission components due to the increase in oil temperature, and has excellent durability.

Means for Solving Problem E] The vehicle Kawaguchi O transmission of the present invention is an automatic transmission for a vehicle consisting of a main transmission and an auxiliary transmission capable of switching between a high gear and a low gear. The main transmission or the NJ transmission has hydraulic oil temperature detection means, and when the hydraulic oil temperature is equal to or higher than a set value, a control device is configured to shift the sub-transmission to a low gear. do.

[Operations and Effects of the Invention] With the above configuration, the Ii/L transmission for vehicles of the present invention has the following nine functions and effects.

b) By detecting insufficient driving force in the vehicle based on the concentration of hydraulic oil and shifting the sub-transmission to a low gear, it is possible to obtain an appropriate driving force depending on the driving condition.

口) When the hydraulic oil temperature is higher than the set value, the sub-transmission is shifted to a low gear by shifting MIm to reduce the fluid transmission fllIv.
Parts inside the Ru can be prevented from being adversely affected by a rise in the temperature of the hydraulic oil.

C Example J Next, the present invention will be explained based on embodiments shown in the drawings.

Figure 1 shows a four-wheel drive automatic transmission, and Figure 2 shows its gear train. 10 is a 4-speed automatic transmission with overdrive which is a main transmission, and 40 is 3!1 of the 4-speed automatic transmission 10.
A four-wheel drive transfer which is a sub-transmission connected to the output shaft 32 of the JJ gear transmission is shown.

The four-wheel drive transformer 40 is attached to the mounted four-speed automatic transmission 10, the first output shaft 42 is connected to the rear wheel drive propeller shaft C, and the second output shaft 5 is connected to the rear wheel drive propeller shaft C.
2 is connected to a propeller shaft B for driving the front wheels.

The 4-speed automatic transmission Iso 10 includes a hydraulic torque converter 11 overdrive mechanism oD, and an underdrive mechanism UD with three forward speeds and one reverse speed.

The torque converter T includes a pump 11 connected to the output shaft of the engine, a turbine 13 connected to the output shaft 12 of the torque converter T, a stator 15 connected to a fixed part via a one-way clutch 14, J3, and a direct coupling clutch. 1
From 6/j, the output axis 12 of the torque converter T is
It is the input shaft of the overdrive mechanism OD.

A-bird drive mechanism OD is I9! The multi-disc clutch CO1, the multi-disc brake Bo, and the one-way latch FO, which are the main threads of friction engagement, and the selective engagement of these friction engagement elements fix the component to a fixed member such as a transmission case, or A planetary gear set P that is y1 connected to the input shaft, output shaft, or other component, or is fixed or uncoupled.

It roars.

The planetary gear set PO includes a key rear 21 which is connected to the input shaft (12), a ring gear 22 connected to the output shaft 25 of the overdrive mechanism OD, and the input shaft 1.
A sun gear 23 rotatably fitted onto the carrier 21 and fixed to the transmission case via a brake Bo, and connected to the carrier 21 via a clutch C0J3 and a one-way latch FO parallel to the clutch CO; and rotatably supported by the carrier 21 and the sun gear 23
and a planetary pinion 2 meshed with the ring gear 22
4? - Growling.

The output shaft 25 of the A-bar drive mechanism 00 also serves as the input shaft of the underdrive mechanism LJD, which has three forward stages and one penetration stage.

The underdrive v/AV4UD includes multi-disc clutches C1 and C2, which are frictional engagement elements, and a multi-disc brake 31.
, [32 and B3 and one-way clutches F1 and F2
, a front planetary gear set P1, and a rear planetary gear set P2.

The rear planetary gear set P2 includes a ring gear 31 connected to the input shaft (25) via a clutch C1,
A carrier 33 connected to the output shaft 32 of the underdrive mechanism UD and the input shaft (25
), and the brake B1, 1m brake B
A sun gear J734 is fixed to the transmission case via a brake B2 parallel to the brake B2 and a one-way latch F1 connected in series with the brake B2, and a sun gear J734 is rotatably supported by the kit rear 33 and the sun gear 34 and ring gear 3
1 and a planetary onion 35 meshed with the other.

The front planetary gear set P1 is the brake B3 Jj
and a 4:I rear 3G fixed to the transmission case via a one-way latch 2 parallel to the brake B3;
IyI second stage planetary gear set P2 gear 34
It consists of a sun gear 31 formed integrally with the output shaft 32, a ring gear 38 connected to the output shaft 32, and a planetary pinion 39 rotatably supported by the kitria 36 and meshed with the sun gear 37 and the ring gear 38. .

This four-wheel drive automatic transmission has four through-hole M transmissions as shown in Fig. 3, and changes the engine throttle speed, vehicle speed, and Jf? ! Each of the clutches and brakes, which are the II engagement elements, is selectively engaged or released, and there is a self-help shift with 4 forward gears including overdrive (0/D), and a 1-gear penetration shift with only assisted shifting. will be done.

The shift lever (not shown) installed in the driver's seat to drive the manual valve of the hydraulic I+11i equipped [100] is
It has a shift position SP of each range (bark), R (reverse), neutral (N), D (drive), S (second), and low), and this shift position SP
and gears 4th gear (4), 3rd gear (3), 2nd gear (2),
Table 1 shows the operational relationship between the first speed (1) and the clutch and brake.

In Table 1, ○ indicates engagement of the frictional engagement element, × indicates disengagement, F(free) indicates free rotation of the one-way clutch, 1-(
Lock) indicates engagement of a one-way clutch.

4 speed white rib 2 speed 811 (M7) hbFEiJItillH
equipment 100c, hydraulic pump device 101, pressure regulating valve (regulator valve) 130, second pressure regulating valve 1501, cooler bypass valve 105, pledger relief valve 106, reverse clutch sequence valve 110, generates throttle pressure according to throttle opening. throttle valve 2001 cutback valve 145, direct clutch control piece 120, manual valve 21011-2 shift valve 220.2-3 shift valve 23
0.3-4 shift valve 240, said 1-2 shift valve 22
0 and 3-4 shift valve 240 IIJIII solenoid valve S1.2-3 shift valve 230 1illllll
solenoid valve S2. Direct connection clutch control valve 120
a solenoid valve 33 that adjusts the hydraulic pressure supplied to the brake B1, an intermediate coast modulator valve 245 that adjusts the hydraulic pressure supplied to the brake B1, a low coast modulator valve 250 that adjusts the hydraulic pressure supplied to the brake B3, and a clutch C1.
Accumulator 260 of Clutch C2, Accumulator 210 of Clutch C2, Accumulator 280 of Brake B2
, clutch C01C1, C2 and brake 80.81
．． The flow rate of pressure oil supplied to each of the 82 hydraulic servos is $11.
1 with check valve for 11! Control valve 301.302.30
3.304.305.30G, brake 80, B1.
82.83.84 hydraulic servo B-0, 3-1, B-'
2, 8-3.3-4, clutch C01C1, C2,
C3, C4 hydraulic servo C-o, c-1, C-2, c
-s, c-4, and oil passages that communicate between each valve and the hydraulic cylinders of the clutch and brake. The solenoid valves $1, B2, and B3 are electronically connected (not shown).
l ii 1ift turns ON according to vehicle driving conditions such as vehicle speed and engine load.

OFF, thereby 1-2 shift valve 220.2-3
Shift valve 230.3-4 Shift valve 240 Power M all
I get cked. These shift valves 220, 230, and 240 selectively communicate the hydraulic power source with the hydraulic servo of each gangway and brake according to the set position of the manual valve 210.

The manual valve 210 is connected to shift 1 to levers provided on the driver's seat, and is manually operated to switch between P (park), R (reverse), N (neutral), and D (depending on the range of the shift 1 lever). drive), S (second), L (
(low) position.

Table 2 shows the communication state between oil passage 1 and oil passages 2 to 5 in each shift range of the shift lever. 0 indicates a state where line pressure is supplied through communication, and x indicates a state where the pressure is exhausted.

Table 2 The transfer 40 in FIG. 2 has an output shaft 32 of a clutch C3, a brake B4, a clamp C4, which are RSM engagement elements, and a planetary gear set P1, P2 as input shafts, and is connected in series to the input shaft (32). The first output shaft 42 of the arranged transfer 40, the input shaft (32) and the first
A planetary gear set pr arranged between the output shaft 42
A four-wheel drive sleeve 51 is rotatably attached to the first output shaft 42, and a four-wheel drive sleeve 51 is installed parallel to the input shaft (32) in the opposite direction to the first output shaft 42. The second output shaft 52, the sleeve 51 and the second output shaft 5
The story between 2! It has a lJIm structure 53. The planetary gear set P" includes a sun gear 44 splined to the end of the input shaft (32), a planetary binion 45 that meshes with the cough sun gear 44, a ring gear 46 that meshes with the planetary binion 45, and The planetary nion 45 is rotatably held, and the first one of the transfer 40 is
It consists of a carrier 47 connected to the tip of the output shaft 42.

In this embodiment, as shown in FIG. 4, the brake B4 is a multi-plate friction brake for engaging the ring gear 4G with the transfer case 48. equipped@sarel
It is operated by a hydraulic servo 13-4 composed of a ζ piston 49P. The clutch C3 is arranged on the 4-through-opening dynamic transmission 10 side of the planetary gear set P', and is connected to the sun gear 44.
And Ki1? A hydraulic servo C is used to connect and disconnect the rear 41, and is composed of a cylinder 50 connected to the rear 41 and a piston 50P installed in the cylinder 50.
-3. Clutch C4 is Kitria 41
The first output shaft 42 and the second output shaft 52 of the transfer 40 connected to the drive 8'! It is a multi-disc friction clutch for connecting and disconnecting the sleeve 51 which is connected to one sprocket 56 of the transmission II structure 53 for transferring J', and is a transfer clutch. It is operated by a hydraulic servo C-4, which is composed of a cylinder 58 rotatably supported by the case 48 and a piston 58P mounted within the cylinder 58. Den 1i11 Mechanism 5
3 is a sprocket 5G spline-fitted to the sleeve 51, and a sprocket 55 formed on the second output shaft 52.
and a chain 57 stretched around these sprocket areas
Consisting of

A parking gear 59 is provided around the outer circumferential side of the cylinder 50 of the hydraulic servo C-3 of the clutch C3, and when the shift lever of the 4-port dynamic transmission 10 is selected to the parking position, the pawl engages the parking pawl (Fig. (not shown) to fix the first output shaft 42.

60 is a transfer valve body in which a is installed in the hydraulic control unit that supplies hydraulic pressure to the hydraulic servos C-3, C-4 and 3-4 of the clutches C3, C4 and brake B4 of the transfer 40, and 61 is its oil. It's bread. The pressure oil supplied to the hydraulic servos C-3, C-4 and B-4 of the clutches C3 and C4 and the brake B4 is connected to the transmission case 62 and the transfer case 62. The transfer valve body 6 in which the transfer III control device [400 is provided] is connected to the transfer valve body 6 through the oil passage 64 provided in the case 48
It leads to 0.

During normal driving, oil from the automatic transmission and line pressure supplied to the pressure control device are supplied to the hydraulic servo C-3, and the clutch C3
The brake B4 and the clutch C4 are released by discharging the hydraulic servos 3-4 and C-4. As a result, the sun gear 44 of the planetary gear hit P'' and the carrier 41 are connected 6, and the assist force is transmitted from the input shaft (32) to the first output shaft 42 at a reduction ratio of 1, allowing two-wheel A-shift running with only the rear wheels. At this time, the power from the input shaft (32) is transmitted from the carrier 47 to the first output shaft 42 via the clutch C3 without passing through the sun gear 44, planetary pinion 45, or ring gear 46, There is no load on the tooth surfaces of the gears, increasing the life of the gears.During this two-wheel drive driving, when four-wheel drive driving becomes necessary, manually shift the shift lever 401 installed on the driver's seat, etc. 1
By gradually supplying line pressure to the hydraulic servo C-4 of the i11 "@400" and smoothly engaging the clutch C4,
The first output shaft 42 and the sleeve 51 are connected, and power is also transmitted to the front wheels via the transmission mechanism 53, the second output shaft 52, and the front wheel drive propeller shaft B (shown in FIG. 1), and the input shaft (32) from the first output shaft 42 and the second output shaft 52
Power is transmitted at a reduction ratio of 1, and a four-wheel drive directly coupled driving state (high-speed four-wheel drive state) is obtained. During this 4-wheel drive driving, when the shift lever 401 is manually shifted when an increase in output torque is required, such as on a steep slope, the hydraulic pressure is applied to the hydraulic servo, which is a switching valve between high-speed 4-wheel drive state and low-speed 4-wheel drive state. Hydraulic servo B operates the inhibitor valve 440 and the accumulator control valve 460, which is a spool valve.
-4 and the oil pressure of hydraulic servo C-3 is applied to pressure IA" at an appropriate timing to gradually engage brake 84 and smoothly release clutch C3. This causes sun gear 44 and carrier 47
When the ring gear 46 is released, the ring gear 46 is fixed, and the power is decelerated from the human power shaft (32) via the sun gear 44, the planetary pinion 45, and the carrier 47, and is transferred to the first output shaft 4.
2113 and the second output shaft 52, and a four-wheel drive deceleration driving state (low-speed four-wheel drive state) with a large torque is obtained. Transf in Table 3? 40 shows the engagement and release of brake B4, clutches C3 and C4, and the running state of the vehicle.

Table 3 In Table 3, Q indicates the engaged state of the friction engagement element, and X indicates the released state. The reduction ratio (3.0 in the example) is the reduction ratio - (1 +
λ)/λ-3,0.

Transfer Mill for 4-wheel drive 1-Lanceforce 40
The device 400 includes a shift lever 401 provided in the driver's seat.
A transfer 1 manual valve 410 connected to via a link l181402, an inhibitor valve 440 for switching between high speed (direct connection) and low speed (deceleration) during four-wheel drive, and the inhibitor valve 440 and hydraulic servo C- 3
and the accumulator controller 1-[''-le valve 460, the accumulator 490J3 and the valve 491
The upshift (L4→]4 shift) timing mechanism 430, when the shift lever 401 is facing H4, changes H4→L4, H4 by turning on and off the solenoid valve S5.
1-L and 4, the input oil pressure of the inhibitor valve 440 (oil L1 related to the vehicle speed) is applied to the oil path 1M connected to the oil path 1, and when the vehicle speed exceeds the set value, Transfer automatic III control 4 to automatically switch between high and low speed of 64-wheel drive
11 Hydraulic oil supply to hydraulic cylinder 500 and oil pressure valve B-°4 Check valve number 520 provided in oil passage 1N, and hydraulic oil supply oil passage 1 to hydraulic servo C-4 In-line oil passage 1P between the throttle with a block valve 530, the inhibitor valve 440, and the upshift timing!14% 430 provided in the
It consists of a throttle with a check valve 540 provided in the.

The transfer manual valve 410 has a spool 420 connected to a shift lever 401 provided at the driver's seat via a link m mechanism 402, and is connected to line pressure generating oil of the hydraulic control circuit of the four-port auxiliary transmission 10. Inboat 411 that connects to Route 1, Outboat 413 that connects to Oil Route 6
, an outboat 415 and a drain boat 417 and 419 connected to the oil passage 1, and the spool 420 is a two-wheel drive (
H2) When set in position, connect oil passage 1 and oil passage 6, and connect oil passage 7 to drain boat 419,
When set to the wheel drive high gear (H4) position, oil passage 1 is connected to oil passage 6 and oil passage 1, and the four wheel drive low gear (L4) position is set.
), the oil passages 1 and 1 are connected, and the oil passage 6 is connected to the drain boat 417.

The inhibitor valve 440 is connected to a spring 450 from below in the figure.
The spools 441 have a sleeve-shaped land 445 at the lower end shown in the figure and a sleeve-shaped land 441 at the upper end shown in the figure, each having the same diameter and having a spring 450 installed on its back.
and an intermediate land 44G.

The plunger 442 has a lower end land 448 shown in the drawing having a larger diameter than the land of the spool 441, and an upper end land 449 having a larger diameter than the lower end land 448. These spools 44
1Jj and the plunger 442, the lower end oil chamber 451,
First and second intermediate oil chambers 452 and 453 between the sleeve-shaped land 445, intermediate land 446, and upper end land 447
, an oil chamber 45 between the spool 441 and the plunger 442
4, and an upper end oil chamber 456 are formed.

In this inhibitor valve 440, when the spool 441 is set upward in the figure, the lower end oil chamber 451 communicates with the vehicle speed pressure oil passage 1M via the cuff 443 of the sleeve-shaped land 445, and the first intermediate oil chamber 452 connects line pressure oil path 1 and deceleration oil path 1N, and connects line pressure oil path 1 to deceleration oil path 1N. i! 453 connects the direct connection oil path 1P and the drain boat 457, and connects the spool 411
1 is set downward in the figure, the upper end oil chamber 451 communicates with the drain boat 458 via the cuff 443 of the sleeve-shaped land 445, and the first intermediate oil chamber 452 connects to the deceleration oil path 1.
Contact N and drain boat 459, and move to the second intermediate oil room 45.
3 is in direct communication with the line pressure oil path 1, and the oil chamber 454 is a generation oil path IM for oil pressure related to constant heavy and high speeds.
The lower end oil chamber 456 is always in communication with the oil rji6.

The accumulator control valve 460 has a spool 471 on which a spring 470 is installed at the lower side in the figure, and the spool 411 has a lower end land 473j5, an intermediate land 475, and an upper end land with a diameter larger than these two lands 413 and 415 by a predetermined dimension. 471, and a lower end oil chamber 461, an intermediate oil chamber 463465, and a lower end oil chamber 4137 are formed from the bottom in the figure.

In this accumulator control valve 460, the lower intermediate oil chamber 463 always communicates with the oil passage 1Q which is connected to the hydraulic servo C-3, and the upper intermediate oil chamber 465 always communicates with the line pressure oil passages 1 and 3! [I] The oil pressure of the oil passage 1Q is fed back to the oil chamber 467 at the upper end, and the throttle 491 is fed back to the oil chamber 461 at the lower end.
Hydraulic pressure is supplied to the oil passage 1R, which communicates with the oil passage 1Q via an accumulator 490.

The 14-speed low-speed switching valve 480 has a spring 48 located downward in the figure.
1 is provided in front of the spool 482;
has a lower end land 4838 and an upper end land 484, and a lower end oil chamber 485, an intermediate oil chamber 486, and a lower end oil chamber 481 are formed from the bottom in the figure. The intermediate oil chamber 486 is always in communication with the E-end oil chamber 45G of the inhibitor valve 440 via the oil passage GΔ. Further, in the spool 482, when line pressure is supplied to the oil passage 1 and the solenoid valve S5 is ON, the line pressure is discharged from the lower end oil chamber 485.
When line pressure is supplied to 87 and set downward in the figure, and solenoid #85 is OFF, line pressure is supplied to the lower end oil chamber 485, and the spring 481 is supplied to the lower end oil chamber 481 regardless of whether line pressure is supplied or discharged. It is set upward as shown in the figure by force.

The transfer self-help νJva mechanism 500 includes a vehicle speed sensor 5
01, to detect the temperature of the hydraulic oil of the torque converter T, as shown in FIG.
00A cooler bypass valve 105 and oil cooler 1
Established between 07! ! 1dll that was done! l sensor 602,
Shift lever that detects the set position of shift lever 401
A position sensor 603, a throttle rotation sensor 604 that detects the throttle opening, and a throttle rotation sensor 604 are provided near the shift lever 401 and are turned on by the driver's operation.

A mode switch 605 that selects automatic switching between high speed and low speed in the H4 range that is turned off, a shift control circuit 600 that receives these outputs as input, a throttle 511 provided in the oil path 1M connected to the oil path 1, and a mm solenoid valve 34.55 which is turned on and off by the output of the speed change control circuit 600.

The solenoid valve S4 is turned off when the vehicle speed is above a set value (for example, 20 km/h), and the oil passage 1M is turned off.
generates line pressure in oil passage 1, and when it is below the set value, O
N, oil'/! Discharge 11M of hydraulic pressure. As a result, oil pressure related to the vehicle speed is generated in the oil path 1M. The solenoid valve 85 is turned OFF when the vehicle speed is above a set value 1i1'J (7, ie, 101u++/h) or when the temperature of the hydraulic oil is below a set value (for example, 100°C), and #I&! Lower end oil chamber 4 of high/low speed 1/7 switching valve 480
85 to generate line pressure, and when the skewer speed 1 is below the set value and the temperature of the hydraulic oil is above the set value, it is turned on and the oil pressure in the lower end oil chamber 485 is discharged. This results in lower end oil!
i! At 485, a hydraulic pressure is generated that is related to the vehicle speed and the temperature of the hydraulic fluid. ON/OFF of the solenoid valve S4
For example, if the fixed value is set to λ, the solenoid valve S is set according to the input signals from the vehicle speed sensor 501 and the oil temperature sensor 602.
The speed change control circuit 600 that controls
It is easy to make changes according to driving conditions.

Line pressure enters the intermediate oil chamber 465 from the oil passage 1, and the oil passage 7 is connected to the hydraulic servo C-4 via a throttle with a check valve 530. ,,.

Transf? The operation in each of the 40 setting ranges will be explained.

a) When the transfer manual valve 410 is set to the H2 range, the pressure in the oil passage 7 is exhausted, so the sleeve 51
No power is transmitted to the vehicle, and the two-wheel drive state is maintained. Also, since the oil passage 7 is depressurized, the solenoid valve ss it
>High/low speed switching valve 480 regardless of whether it is on or off
The spool 482 is set upward by the force of the spring 481, line pressure is supplied to the upper end oil chamber 456 of the inhibitor valve 440 via the intermediate oil chamber 48G and the oil path 6A, and the spool 441 and plunger 442 are set downward in the figure. The oil passage -1N is connected to the drain boat 459 and is evacuated, thereby the brake B4 is evacuated, and since the oil passage 1 is evacuated, the pressure of the clutch C4 is evacuated. Oil path 1P
is connected to the oil passage 1 and connected to the oil passage 1Q via the check valve-equipped throttle 540 and the accumulator control valve 460 to engage the clutch C3. Therefore, the transfer 40 becomes H2 (two-wheel drive directly connected state).

b) When transfer manual valve 410 is set to H4 range, line pressure is supplied to both oil passage 6 and oil passage 1. The line pressure supplied to oil path 7 is applied to clutch C.
4. This puts the transfer 40 in a four-wheel drive state.

b) When solenoid valve S5 is OFF, ^ speed low speed switching valve 4
Line pressure is supplied to the lower end oil chamber 485 of 80, and
The spool 482 is set upward by the force of the spring 481, and the line pressure passes through the intermediate oil chamber 486 and the oil path 6A.
The oil is supplied to the upper end oil chamber 456 of the inhibitor valve 440. The line pressure supplied to the upper end oil chamber 456 is transferred to the inhibitor valve 44.
The 0 spool 441 and the plunge 1v 442 are set at the lower side in the figure, and the oil passage 1N is connected to the drain boat 459 to exhaust the pressure, thereby discharging the brake BJL & pressure. As a result, the transfer 40 becomes H4 (four wheel parts vJ
directly connected state).

(mouth) When solenoid valve S5 is ON, high-speed and low-speed switching valve 48
When the line pressure is discharged from the lower end oil chamber 485 and the line pressure is supplied to the upper end oil chamber 481 from the oil passage 1, the spool 482 overcomes the force of the spring 481 and is set downward, and the oil passage 6A becomes the drain. It communicates with the boat 488, and the reline pressure is exhausted from the lower end oil chamber 456 of the inhibitor valve 440. The vehicle speed at which the solenoid valve S5 is turned on is set lower than the vehicle speed at which the solenoid valve S4 is turned on, so when the solenoid valve S5 is turned on, the solenoid valve S4 is turned on and the oil path 1M is drained. Since the spool 441 is pressurized, the spool 441 is set upward in the drawing by the action of the spring 450, and as a result, the oil passage 1 and the oil passage 1N are connected, hydraulic oil is supplied to the hydraulic servo B-4, and the oil passage 1P is connected to the drain boat. 451, and the hydraulic pressure of the hydraulic servo C-3 of the clutch C3 is discharged. As a result, the transfer y40 becomes L4 (four-wheel drive deceleration state).

C) When the transfer manual valve 410 is set to the L4 range, the pressure in the oil passage 6 is exhausted and the line pressure is supplied to the oil passage 1, so the high-speed and low-speed switching valve 480 is activated regardless of whether the solenoid valve S5 is ON or OFF. is set at the lower position in the figure by the line pressure supplied to the upper end oil chamber 451, the oil pressure in the upper end oil chamber 456 of the inhibitor valve 440 is discharged, and the plunger 442 is set at the upper position in the figure. Furthermore, since line pressure is supplied to the oil passage 1, the clutch C4 is engaged and the four-wheel drive state is maintained.

When the transfer manual valve 410 is set to the 14 range while the solenoid valve S4 is OFF, line pressure is supplied to the oil passage 1M. Therefore, the spool 441 of the inhibitor valve 440
remains set at the lower position in the figure due to the line pressure applied to the oil chamber 454, and the gears are not changed to prevent engine overrun.

Transfer manual valve 410 is set to the L4 range when the vehicle speed is below a set value and solenoid valve S4 is ON, or when the vehicle speed is above a predetermined value and solenoid valve S4 is OFF.
is in the L4 state and the vehicle speed goes from above the predetermined value to below the set value and the solenoid valve S4 is turned from OFF to ON, oil path 1
Since M is depressurized, the spool 441 is compressed by the spring 45.
0 is set upward in the figure, and as a result, oil passage 1 and oil passage 1N communicate with each other, and hydraulic oil is supplied to hydraulic servo B-4.
The oil passage 1P is connected to the drain boat 457 and the pressure is discharged, and the hydraulic pressure of the hydraulic servo C-3 of the clutch C3 is discharged. This puts the transfer 40 in a low-speed four-wheel drive state.

Once the vehicle enters the low-speed four-wheel drive state, even if the vehicle speed exceeds the set value and the solenoid valve S4 is turned off, the line pressure in the oil passage 1M is applied to the oil chamber 454 of the inhibitor valve 440 and the spool 441 is simultaneously applied. sleeve-like land 445
Since the oil is applied to the lower end oil chamber 451 through the cuff 443 of the spool 441, the spool 441 is not displaced and the low-speed four-wheel drive state is maintained.

first to fifth solenoid valves S1 depending on vehicle running conditions;
Shift control circuit that opens and closes S2, S3, S4, and S5 (
A computer) 600 includes a vehicle speed sensor 501 for detecting the vehicle speed as shown in FIG. 5, and a cooler bypass valve for the discharge oil passage 100A of the torque converter T as shown in FIG. 3 for detecting the temperature of the hydraulic oil of the torque converter T. Oil temperature sensor 60 arranged between 105 and oil cooler 107
2. A shift lever position sensor 603 that detects the set position of the shift lever 401; a throttle opening sensor 604 that detects the throttle opening degree;
Input port 10 for inputting a signal from mode switch 605 to select automatic switching between high speed and low speed in the range, automatic transmission gear change system 11i11tllll including solenoid valves 81 to S3 @ 612, solenoid valve S4,
H4→L4 including S5, output port 11 to H4-shi4 cutting device 613, central processing @*cpU, read-only memory ROM for storing preset vehicle speed and preset oil temperature, random access memory RAM Consisting of

Next, the operation of the speed change control circuit 600 according to the present invention will be explained based on the flowchart shown in FIG.

Turn the starter key ONL, start the engine, and set the transfer manual valve 410 to H4. 701)
, Next, the vehicle speed (V) is detected by a vehicle speed sensor 501, and the hydraulic oil 1 (tX) of the torque converter T is detected by an oil temperature sensor 602.
The set position of the shift lever 401 is read by input signals from the shift lever position sensor 603, throttle opening sensor 604, and mode switch 605 (702), and the automatic transmission 10 is controlled by the shift lever position signal, throttle opening signal, and vehicle speed signal. (703), and set the vehicle speed that can be manually shifted from H2 or H4 to L4 (■1) to R.
Read from OM (704), It is necessary to judge whether v < Vl or not. 705), When V < ■1 is not established (L4 shift impossible region by manual shift), solenoid valve S4 is set to 0F.
Continue running FL, H2 or H4 706),
After that, the process proceeds to (708). When V<Vl (L4 shift possible region by manual shift), solenoid valve S4 is turned ON to perform H4→L4 switching (707), and then the process proceeds to (70M).

Transfer manual valve 410 Due to m priority, only H4 range is valid in 9 in the flowchart below, and solenoid valve $5 is ON in H2 and H4 ranges.
Even if the OFF operation is performed, the gear will not be changed.

Next, it is necessary to judge whether the mode switch 605 is ON or not.
08) When the mode switch 605 is ON, it is determined whether the solenoid valve S5 is OFF or not. 709) When the mode switch 605 is ON, it is determined whether or not the solenoid valve S5 is OFF. V, and set oil temperature: (TI'
) - (T) 710) , v <V, t > T or not 711) , v <V, t>T, the gear shift from H4 to L4 is performed by turning on the solenoid valve S5. (712), then return. When the mode switch 605 is OFF, the solenoid valve S5 is turned OFF, the gear is changed from L4 to H4 (713), and then the process returns. When solenoid valve S5 is ON, vehicle speed during L4→H4 shift stored in ROM in advance: V3-V,
and set oil temperature: T2-T (714), proceed to its violation (711).

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of an automatic transmission for 4-wheel drive, Figure 2 is a schematic diagram of its gear train, Figure 3 is a hydraulic circuit diagram of a 4-port dynamic transmission, and Figure 4 is a diagram of a 4-wheel drive transfer. 5 is a block diagram of the speed change control circuit according to the present invention, and FIG. 6 is a flow chart of the speed change control circuit according to the present invention. In the figure 84...Multi-disc brake which is an 8111 engagement element for deceleration C3...Multi-disc clutch which is aI cool engagement IS for direct connection C4...Multi-disc clutch which is a friction damage element for four-wheel drive 1... Line pressure oil path 32... Transfer input shaft 42... First output shaft 51... 4
Wheel drive sleeve 52...Second output shaft 53...
Transmission mechanism P...Planetary gear set 410.
...Transfer manual valve 430...Upshift timing mechanism 440...Inhibitor valve 500
...Transfer intransitive W mechanism 501...Vehicle speed sensor 600...Shift control circuit 602...Oil temperature sensor CPU...Central processing unit ROM...Read-only memory RAM...Random access memory

Claims (1)

[Scope of Claims] 1) A vehicle automatic transmission comprising a main transmission and a sub-transmission capable of switching between a high speed gear and a low gear, comprising a hydraulic oil temperature detection means for the main transmission or the sub-transmission. An automatic transmission for a vehicle, comprising: a control device that shifts the sub-transmission to a low gear when the temperature of the hydraulic oil is equal to or higher than a set value. 2) The automatic transmission for a vehicle according to claim 1, wherein the hydraulic oil temperature detection means is an oil temperature sensor provided in a hydraulic oil discharge path.