JPS6154980B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for controlling selective engagement of a plurality of hydraulically operated friction engagement devices in a vehicle automatic transmission.

Conventionally, vehicle speed and engine load are detected electrically, and a computer determines when to switch the gear ratio, and in order to switch oil passages to multiple frictional engagement devices, multiple systems are used to control oil passage switching. Some shift valves are operated directly by a solenoid, while others have a solenoid for holding or discharging control hydraulic pressure that acts on a pressure receiving surface formed at one end of the shift valve via a fixed orifice.

However, in these conventional devices, in order to control a plurality of shift valves, the same number of solenoids as the shift valves or a similar number are required.
As the number of gear ratios increases, the number of solenoids increases accordingly, which complicates the structure and is disadvantageous in terms of both cost and space.

The present invention has been proposed to solve the above-mentioned drawbacks, and is a vehicle in which a plurality of gear ratios are achieved between input and output shafts by selectively engaging a plurality of hydraulically operated friction engagement devices. In the automatic transmission for use in the automatic transmission, a plurality of shift valves that switch the oil passage of the hydraulic pressure applied from the hydraulic source to the plurality of frictional engagement devices by supplying and discharging the control hydraulic pressure, and a plurality of shift valves that supply the control hydraulic pressure to each of the plurality of shift valves. Supply oil to a control oil passage, the plurality of control oil passages, or an oil passage that applies hydraulic pressure to a specific frictional engagement device among the plurality of frictional engagement devices, or drain oil from the oil passage depending on the position of the valve body. a solenoid valve that hydraulically controls the position of the valve body of the shift control valve; a potentiometer that detects the position of the valve body of the shift control valve; a target position of the valve body of the shift control valve determined according to the driving state of the vehicle detected by the driving detection device; and a position of the valve body detected by the potentiometer. and a computer that controls the solenoid valve by generating an electric signal so that the position of the valve body is always at the target position by comparing the values, and controlling the plurality of speeds according to the detected driving state of the vehicle. The gist of the present invention is a control device for an automatic transmission for a vehicle, characterized in that it is configured to achieve one of the following ratios.

In the present invention, a plurality of shift valves for controlling selective engagement of a plurality of hydraulically operated friction engagement devices are integrated into one.
Control can be performed using individual solenoid valves, which is extremely advantageous in terms of cost and space, and also has the effect of simplifying the structure of the shift valve.

Further, in the present invention, since the hydraulic pressure for controlling the plurality of shift valves is controlled by two-stage switching between zero and high hydraulic pressure, the responsiveness of the shift valves is good and the shift position is also reliable.

Furthermore, in the present invention, the target position of the valve body of the shift control valve according to the operating state is stored in the computer, the position of the valve body is directly detected by the potentiometer, and feedback control is performed by the solenoid valve. Valve operation is not affected by external disturbances such as changes in oil amount or oil pressure, and the desired gear ratio is reliably achieved according to the operating condition.
Moreover, there is no unexpected hysteresis in the shift control valve, and gear changes are achieved smoothly.

In addition, since the control hydraulic pressure of the shift valve can be set to line pressure, it is possible to supply the control hydraulic pressure directly to the friction engagement device without going through the shift valve, and it is also possible to reduce the number of shift valves. In this respect as well, it is advantageous in terms of cost and space.

Next, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6.

In the illustrated embodiment, the present invention is applied to an automatic transmission that provides a gear ratio of four forward speeds and one reverse speed.

In the power train diagram shown in FIG. 1, a crankshaft 2 of an engine 1 serving as a power source for the vehicle is directly connected to a pump 4 of a torque converter 3. The torque converter 3 includes a pump 4, a turbine 5, a stator 6, and a one-way clutch 7. The stator 6 is connected to a case 8 via the one-way clutch 7.
The one-way clutch 7 allows the stator 6 to rotate in the same direction as the crankshaft 2, but is not allowed to rotate in the opposite direction. A direct coupling clutch 9 is provided between the crankshaft 2 and the turbine 5, and the clutch 9 is directly coupled with a predetermined slip ratio when engaged.

Therefore, the output of the engine 1 is the output of the direct coupling clutch 9.
Alternatively, the torque is transmitted to the turbine 5 via the torque converter 3.

The torque transmitted to the turbine 5 is transmitted by an input shaft 10 to a transmission gear train 100 disposed at the rear thereof that achieves four forward speeds and one reverse speed.

The transmission gear train 100 includes three sets of clutches 11, 1
2, 13, two sets of brakes 14, 15, one set of one-way clutch 16, and one set of Ravigneau type planetary gear set 17.

The planetary gear set 17 includes an annulus gear 18, a reverse sun gear 19, a forward sun gear 20, a long pinion 21, a short pinion 22, and a carrier 23.

The annulus gear 18 is fixed to the output shaft 24,
Reverse sun gear 19 is a kick down drum 25
The drum 25 is fixed to the case 8 via the kickdown brake 14, and is also integrated to the input shaft 10 via the front clutch 11, while the forward sun gear 20 is connected to the input shaft via the rear clutch 12. integrated into the shaft 10, and
The carrier 23 that holds the long pinion 21 and short pinion 22 is a one-way clutch 16.
It is fixed to case 8 through Ru. One-way clutch 16 is provided to prevent reverse rotation of carrier 23.

The three sets of clutches 11, 12, 13 and the two sets of brakes 14, 15 are hydraulic friction engagement devices, and the oil pressure supplied to each hydraulic piston that operates these friction engagement devices is supplied to an oil pump 26. occurs in

The output passing through the speed change gear train 100 is transmitted to the output shaft 24.
The transmission is transmitted from the transfer drive gear 27 fixed to the transfer idle gear 28 to the transfer driven gear 29, and further to the transfer shaft 30 integrated with the driven gear 29.
The signal is transmitted from the helical gear 31 to the differential gear 32 .

The driver's seat select lever (not shown) and the
Depending on the operation of the auxiliary switch that selects D ₄ and D ₃ and the driving state of the vehicle detected by various driving detection devices described later, each of the frictional engagement devices described above is selectively engaged, and various speed changes are performed. step is achieved.

Select patterns are P (parking), R (reverse),
N (neutral), D ₄ (4 forward automatic transmission), D ₃ (3 forward automatic transmission), 2 (2 forward automatic transmission), L (1
(fixed speed), and the select levers P, R,
It has 6 positions: N, D, 2, and L, and if you select the auxiliary switch with the same lever in the D position,
The structure is such that D ₃ or D ₄ is selected.

How each friction engagement device works when the select lever and auxiliary switch are placed in each position of the above select pattern is as shown in the operating element diagram in Figure 2. By selectively combining the coupling devices, a gear ratio of four forward speeds and one reverse speed can be obtained.

In this figure, the O mark indicates a friction engagement device that is engaged by hydraulic operation, the ● mark indicates that the carrier 23 is stopped by the action of the one-way clutch 16, and the select lever and auxiliary switch position is D. ₄ , D ₃ , 2, 1st, 2nd, 3rd in the L column,
4th indicates the first speed, second speed, third speed, and fourth speed, respectively.

Next, the direct coupling clutch 9 will be explained with reference to FIG.

This direct coupling clutch 9 is a slip type clutch that transmits power while constantly slipping. When the clutch 9 is in operation, the power from the engine 1 is mainly transmitted to the input shaft 10 via the clutch 9, and some of the power is transmitted to the input shaft 10. is transmitted via the torque converter 3,
As a result, the slip of the torque converter 3 is reduced, thereby improving fuel efficiency, and this slip also has the effect of alleviating the impact torque from the engine 1 (damping effect).

The torque converter 3 and the direct coupling clutch 9 are integrally formed, and a drive plate 33 is fixed to the crankshaft 2, and the drive plate 33 is connected to the outer shell 34 of the pump 4 of the torque converter 3 and the friction plate 35 of the direct coupling clutch 9. The turbine 5 is spline-fitted to the input shaft 10 and rotates integrally with the input shaft 10, and is also connected to the piston 38 via a torsion spring 37 so as to rotate integrally with the input shaft 10. 3
8 is fitted to be slidable and rotatable in the axial direction with respect to the input shaft 10, and has a friction surface 39 that is disposed opposite to the plate 36 and comes into contact with the friction plate 35, so that the piston 38 and the plate 36 A hydraulic chamber 41 is formed therebetween, and a hydraulic chamber 42 is formed between the outer peripheral surface of the outer shell 40 of the turbine 5 and the piston 38.

Friction plate 35 and friction surface 39 of the direct coupling clutch 9
The coefficient of dynamic friction is set so that the rate of change due to speed difference is small. A plurality of grooves are appropriately provided on the surface of the friction plate 35 along the radial direction, circumferential direction, or a combination of the two, and the friction plate 35 and the friction surface 39 are formed by oil passing through the grooves. Overheating is prevented.

Oil is supplied to the torque converter 3 and the direct coupling clutch 9 with oil pressure regulated by hydraulic control, which will be described later. As shown by the arrow in FIG. 3, the oil is guided into the torque converter 3 through an oil passage 43 formed on the inner surface of a sleeve 43 fitted externally to the input shaft 10 of the pump 4, and is circulated, and is further introduced into a hydraulic chamber 42. After that, the hydraulic chamber 41 passes through the gap between the friction plate 35 and the friction surface 39 of the direct coupling clutch 9.
The oil is guided to the input shaft 10, and is discharged through an oil passage 45 formed in the input shaft 10, or is circulated in the opposite direction.

Next, hydraulic control and computer control of the frictional engagement device will be explained with reference to FIG.

The hydraulic control device is connected to the oil filter 4 from the oil sump 46.
7. The oil discharged from the oil pump 26 through the oil passage 402 is transferred to the torque converter 3, the direct coupling clutch 9, the front clutch 11, the rear clutch 12,
In order to operate the hydraulic pistons of the kickdown brake 14, low reverse brake 15, and 4-speed clutch 13, the hydraulic pressure supplied to each hydraulic chamber is controlled according to the operating state, and is mainly controlled by the pressure regulating valve 50 and torque converter control valve. 70, direct coupling clutch control valve 9
0, pressure reducing valve 110, shift control valve 130, manual valve 150, 1st-2nd speed shift valve 170, 2nd-3rd speed shift valve 190, 3rd-4th speed shift valve 210, hydraulic control valve 250 during gear shifting, Orifice control valve 27
0 and 4 solenoid valves 300, 310, 32
The main component is a potentiometer 340 provided in the shift control valve 130, and each component is connected by an oil path. The solenoid valves 300, 310, 320, and 330 each have the same structure, and each orifice 30 is activated by an electric signal from the computer 290.
1, 311, 321, 331 is a duty control solenoid valve of the non-energized closed type that controls the opening and closing of solenoids 302, 312, 322, and 3.
32, each orifice 3 arranged in the same solenoid
Valve body 3 that opens and closes 01, 311, 321, 331
01, 313, 323, and 333, springs 304, 314, 3 that bias the valve body in the closing direction
24 and 334.

The computer 290 detects the driving state of the vehicle and the signal from the potentiometer 340 and operates the solenoid valves 300, 310, 320, 330.
It controls the stop and single pulse current width of the 35Hz pulse current supplied to the solenoid valve, changes the valve opening time, and controls the oil pressure.The main input element is the engine 1 (not shown). An engine load detection device 350 that detects the throttle valve opening or intake manifold negative pressure, a rotation speed detection device 351 of the engine 1, a rotation speed detection device 352 of the kickdown drum 25 shown in FIG. 1, and a rotation speed detection device of the output shaft 24. from a rotational speed detection device 353 of the transfer driven gear 29, an oil temperature detection device 354 that detects lubricating oil temperature, a select lever selection position detection device 355, an auxiliary switch selection position detection device 356, etc. It is completed. Oil discharged from the oil pump 26 passes through an oil passage 401 to a pressure regulating valve 50, a manual valve 150, a direct clutch control valve 90, a pressure reducing valve 110, and a shift control valve 13.
0, is guided to the orifice 311 of the solenoid valve 310.

The pressure regulating valve 50 has a spool 53 and a spring 54, which have pressure receiving surfaces 51 and 52, and the manual valve 150 has the N, D ₄ , D ₃ , 2, and L positions selected on the pressure receiving surface 51 by operating a select lever. At the same time, the oil pressure in the oil passage 401 is applied to the oil passage 4 through the manual valve 150.
03 through an orifice 404, and as a result, the oil pressure in the oil passage 401 is regulated to a constant pressure (line pressure) of 6 kg/cm ² , and a manual valve 150 is installed on the pressure receiving surface 52.
is in the R position, the oil passage 4 passes through the manual valve 150.
The oil pressure of 01 acts from the oil passage 405 through the orifice 406, and as a result, the oil pressure of the oil passage 401 becomes 17
The pressure is regulated to Kg/ ^cm2 .

Note that the relief valve 40 provided in the oil passage 401
7 is a relief valve when high pressure oil is discharged from the oil pump 26.

The oil led to the pressure reducing valve 110 through the oil passage 401 is regulated to 2.3 kg/cm ² by the same valve 110 and is led to the oil passages 409 and 410.

The pressure reducing valve 110 has a spool 111 and a spring 1.
12 and an adjustment screw 113, the spool 111
The pressure is regulated by the balance between the hydraulic pressure due to the area difference between the pressure receiving surfaces 114 and 115 formed opposite to each other and the spring 112, and the hydraulic pressure is adjusted to 2.3 kg/cm ² by the adjusting screw 113. are doing.

The hydraulic pressure led to the shift control valve 130 through the oil passage 401 is transferred to the oil passages 408 and 41 depending on the operating state.
1,412,413 and the oil path 408 operates the 1st-2nd speed shift valve 170, and the oil pressure led to the oil path 411 operates the 2nd-3rd speed shift valve 190. The hydraulic pressure led to the oil passage 412 engages and operates the clutch 13, and the oil pressure led to the oil passage 413 operates the 3rd-4th speed shift valve 210.

The shift control valve 130 includes a valve body 133 having pressure receiving surfaces 131 and 132 having different pressure receiving areas, and a hydraulic chamber 1.
34, 135, and the pressure receiving surface 131 has an oil passage 40.
1 acts directly on the pressure receiving surface 132, and oil pressure controlled by the solenoid valves 310 and 320 acts on the pressure receiving surface 132. The solenoid valve 310 controls the amount of oil that guides the oil in the oil passage 401 to the hydraulic chamber 135 via the orifice 311.
The amount of oil drained through the orifice 321 is controlled.

Next, the control of both solenoid valves 310 and 320 by the computer 290 will be described.

Potentiometer 340 is shift control valve 130
A voltage that changes depending on the position of the valve body 133 is transmitted as a signal to the computer 290, and the computer 290 detects the voltage of the valve body 133 set according to the position of the valve body 133 detected by the signal and the driving state of the vehicle.
The valve body 133 is electrically compared with the target position of the valve body 133.
solenoid valve 31 so that the position becomes the target position.
Controls 0,320.

When moving the valve body 133 to the right in FIG.
In order to increase the opening time of the orifice 311 by the solenoid valve 310, close the solenoid valve 320 and increase the opening time of the orifice 311 by the solenoid valve 310, close the solenoid valve 310 and move the valve body 133 to the left. 133, both solenoid valves 31
Just close 0,320.

Further, when the distance between the position of the valve body 133 detected by the potentiometer 340 and the target position stored in the computer 29 is large, the opening time width of the solenoid valve 310 or 320 that is controlled to open is set to be large, If the valve opening time width is controlled to become proportionally smaller as the distance approaches, fine adjustment can be made without hunting, and smooth position control can be achieved.

The 1st-2nd speed shift valve 170 has a spool 171 and a spring 172, and the hydraulic force acting on the left end pressure receiving surface 173 of the spool 171 and the spring 1
By comparison with the biasing force 72, the spool 171 is selectively switched between the left end position shown in FIG. 4 and the right end position (not shown).

Similarly, the 2nd speed-3rd speed shift valve 190 and the 3rd speed-4th speed shift valve 210 are connected to the spools 191 and 2, respectively.
11 and springs 192, 212, a pressure receiving surface 193, 213 is provided at the left end of each spool, and each spool can be selectively switched between the left end position shown in FIG. 4 and the right end position (not shown). .

Next, shift control based on selective engagement of each frictional engagement device will be explained.

When the manual valve 150 is switched from N to D, 6
The oil in oil passage 401 whose pressure is regulated to Kg/cm ² is transferred to oil passage 414.
and 415.

The oil in the oil passage 414 flows through the orifice 41 arranged in parallel.
6. The oil passes through the 3rd-4th speed shift valve 210 via the check valve 417, and is further led from the oil passage 418 to the hydraulic chamber of the rear clutch 12 through the orifice 419 and the orifice control valve 270, and when the rear clutch 12 is engaged. 1st gear is achieved.

At this time, the accumulator 420, orifice 416, and check valve 4 installed in the oil passage 414
17 prevents a sudden rise in hydraulic pressure in the hydraulic chamber of the rear clutch 12 and prevents a shock. When the accelerator is depressed and the vehicle speed increases from the state where the first speed is achieved, the computer 290 issues a command to the solenoid valves 310 and 320 to achieve the second speed, and the valve body 1 of the shift control valve 130
33 is moved to the right in FIG. 4, oil passage 401 is communicated with oil passage 408, and oil passages 411, 412, 41
3 is stopped at a position where it is cut off, high line pressure (6 kg/cm ² ) is introduced to the oil passage 408, and the 1st speed - 2nd speed
The spool 171 of the speed shift valve 170 is switched to the right end.

Due to this switching, the oil in the oil passage 415 is transferred to the oil passage 421.
The oil is guided to the oil passage 422 through the oil pressure control valve 250 and supplied to the engagement side oil pressure chamber 423 of the kickdown brake 14, and the rod 424 is connected to the spring 4.
25 to the left to engage a brake band (not shown) with the kickdown drum 25, and second speed is achieved.

The hydraulic control valve 250 responds to the hydraulic control of the solenoid 330 to reduce the hydraulic pressure in the oil passage 422 only during a gear shift, thereby preventing a shift shock.

That is, the pressure regulating oil by the solenoid valve 330 between the orifice 426 interposed in the oil passage 409 and the solenoid valve 330 is applied to the pressure receiving surface 427 at one end of the hydraulic control valve 250, and the solenoid valve 330 is not operated except when changing gears. Then, the orifice 331 is normally closed to increase the oil pressure acting on the pressure receiving surface 427, and the pressure regulating oil of 6 kg/cm ² by the pressure regulating valve 50 is directly sent to the oil path 4.
22.

In order to achieve third speed according to a command from the computer 290, the valve body 133 of the shift control valve 130 is further moved to the right in FIG.
8 and 411, and the oil passage 41
When line pressure is also supplied to the gear shift valve 1, the spool 191 of the second-to-third gear shift valve 190 is switched to the right end. At this time, the oil passage 421 is communicated with the oil passage 428, and the oil passage 422 is communicated with the oil passage 429.

Oil passage 428 leads to orifice control valve 270.

The orifice control valve 270 has a spool 271 and a spring 272, and controls opening and closing of the bypass passage 431 of the orifice 419 in the oil passage 418 by hydraulic pressure acting on two pressure receiving surfaces 273 and 274 of the spool 271.

The oil passage 429 passes through the 3rd-4th speed shift valve 210 and the oil passage 423 to the release side hydraulic chamber 433 of the kickdown brake 14 and the orifice control valve 270.
It communicates with the pressure receiving surface 274 and the switching valve 434
It communicates with the hydraulic chamber of the front clutch 11 via.

During this shift from 2nd speed to 3rd speed, the hydraulic control valve 250 operates and the oil passage 4 is operated for a short period of about 1 second.
22 supply oil pressure is kept low. An orifice 444 is installed in the oil passage 432, and by the action of the orifice 444, the oil pressure in the oil pressure chamber 433 and the oil pressure chamber of the front clutch 11 is maintained at the same low oil pressure while the oil pressure control valve 250 is operating. The kickdown brake 14 is released and the hydraulic control valve 2
When the operation of the front clutch 11 is stopped, the hydraulic pressure is increased to 6 kg/cm ² and the engagement of the front clutch 11 is completed.
speed is achieved.

When the third speed is achieved, the planetary gear set 17 is integrated, and this moment is detected by the two rotation speed detection devices 33.
2, 333, the solenoid valves 310, 320 are controlled by the command from the computer 290, and the valve body 133 of the shift control valve 130 is further activated.
The oil passage 401 is moved to the right side of the figure and the oil passage 408, 4
11, 412, and the oil passage 4
When line pressure is also supplied to the clutch 12, the four-speed clutch 13 is supplied with hydraulic pressure and is held in an engaged state.
With the auxiliary switch D ₄ selected, the solenoid valves 310 and 320 are operated in order to achieve 4th speed according to the command from the computer 290, and the valve body 133 of the shift control valve 130 is moved to the rightmost position, and the oil is When line pressure is also supplied to line 413, 3
The spool 211 of the speed-4 speed shift valve 210 is switched to the right end, and the oil in the oil passages 418 and 432 is drained.

At this time, the oil in the hydraulic chamber of the rear clutch 12 is pumped through the check valve 44 installed in parallel with the orifice 419.
7, the rear clutch 12 is immediately released, and the front clutch 11 is also released after the oil in the hydraulic chamber is released, but the hydraulic control valve 250 is activated in the same way as when shifting from 2nd to 3rd speed. As a result of the supply oil pressure 422 being reduced for a short time during gear shifting, the engagement oil pressure acting on the oil pressure chamber 423 of the kick-down brake 14 is also low, and the engagement oil pressure of the brake 14 is reduced due to deactivation of the oil pressure control valve 250. 6
When the pressure reaches Kg/cm ² , engagement is achieved and 4th gear is completed.

Next, to explain a downshift, the switching of the hydraulic pressure operating path is the opposite of the above-mentioned upshift. First, in order to shift from 4th gear to 3rd gear based on a command from the computer 290, the shift control valve
Move the valve body 133 to the left in FIG.
When this is communicated with the oil drain path 446, the spool 211 of the 3rd-4th speed shift valve 210 is switched to the left end, and hydraulic pressure is supplied to the oil paths 418 and 432. At this time, the orifice control valve 270 closes the bypass oil passage 431 by the hydraulic pressure acting on the pressure receiving surface 273, and the oil flows into the hydraulic chamber 43 of the kick-down brake 14.
3 and the front clutch 11 are smoothly supplied via the orifice 444, and the rear clutch 12's hydraulic chamber is gradually supplied via the orifice 419 with a sufficient delay compared to the front clutch 11. .

At this time, the kick-down brake 14 is immediately released, but even during this deceleration shift, the hydraulic pressure control valve 250 operates for a short period of time during gear shifting, and the hydraulic pressure supplied to the oil passage 432 is maintained at a low pressure enough to provide a light initial engagement. During a power-off downshift, the operation of the hydraulic control valve 250 is stopped after a set time of about 1 second has elapsed, and during a power-on downshift, the two rotational speed detection devices 332 and 333 detect the integration of the planetary gear set 17. The hydraulic control valve 25 detects the gear train condition of this integrated 3rd speed drive ratio.
0 operation is stopped and the hydraulic pressure supplied to the oil passage 432 is increased to 6 kg/cm ² , so that the front clutch 11 is completely engaged with a slight delay in the release of the kick-down brake 14. carrier 2
3 and the input shaft 10 is completed, the oil passage 43
The hydraulic pressure increased to 6 kg/cm ² of 2 acts on the pressure receiving surface 274 of the orifice control valve 270 as a synchronization detection signal.

When the hydraulic pressure acting on the pressure receiving surface 274 of the orifice control valve 270 increases, the spool 271 moves to the left end position as shown in the figure, opening the previously closed bypass oil passage 431, and the hydraulic pressure is no longer supplied to the hydraulic chamber of the rear clutch 12. This occurs immediately through the bypass oil passage 431, and engagement of the rear clutch 12 is achieved. This is done in order to prevent a shift shock caused by engagement from the rear clutch 12, which has a large torque capacity.

When shifting from 3rd speed to 2nd speed, the valve body 133 of the shift control valve 130 further moves to the left in FIG.
The spool 191 of the 2nd-3rd speed shift valve 190 moves to the left end, the 4th speed clutch 13 is immediately disengaged, the front clutch 11 is disengaged, and the kick-down brake 14 is disengaged. Hydraulic control valve 250 similar to the above shift from 4th to 3rd speed
The shift is carried out gradually and smoothly by the operation during gear shifting.
speed is achieved.

When shifting from 2nd speed to 1st speed, the valve body 133 of the shift control valve 130 moves to the leftmost end and closes the oil passage 40.
8 is also communicated with the oil drain passage 446, the spool 171 of the 1st-2nd speed shift valve 170 moves to the left end, the oil in the hydraulic chamber of the kick-down brake 14 is discharged, and the engagement of the brake 14 is released. 1st gear is achieved.

By operating the select lever and auxiliary switch
When D ₃ or 2 positions are selected, manual valve 15
The oil passage is not switched at all by 0, but the position is detected by the select lever selection position detection device 355 and the auxiliary switch selection position detection device 356, and a signal is given to the computer 290.
The solenoid valves 310 and 320 are controlled so that the speed change is not performed at the third or third speed or higher.

When the manual valve 150 is selected to the L position, the position is detected by the selection lever selection position detection device 355, and if the vehicle speed is above a predetermined value such as 40 km/h at the initial stage of selection, the vehicle is held at 2nd gear, and thereafter the vehicle speed is increased. When the value falls below a predetermined value, the first speed is fixed by controlling the solenoid valves 310 and 320, and the oil passage 414 and the oil passage 448 are communicated with each other, and the oil flows into the oil passage 448.
The hydraulic pressure of the low reverse brake 15 is guided to the 1st-2nd speed shift valve 170 through an orifice 449 and a check valve 450, which are installed in parallel with each other. is supplied to the chamber and first speed is achieved.

In addition, the spool 1 of the 1st speed-2nd speed shift valve 170
71 is provided with an orifice 454, the orifice 454, the orifice 449 and the check valve 4.
Due to the action of 50, the hydraulic pressure supplied at the time of switching is maintained at a low pressure and a shock is prevented.

When the manual valve 150 is selected to the R position, the oil passage 4
01 is connected to an oil passage 455, and the oil passage 455 is connected to an orifice 456 and a check 457 installed in parallel.
The oil is connected to the switching valve 452 via the orifice 456 with a delay.
2. The oil passage 453 leads to the low reverse brake 15, while the oil passage 455 is connected to the switching valve 434 via an oil passage 458, and the front clutch 1
1 hydraulic chamber is also supplied with oil, and both clutches 11,
Retraction is achieved by engagement of 15.

By the way, the oil led to the torque converter control valve 70 from the oil passage 459 through the pressure regulating valve 50 is
The pressure is regulated to 2.5 Kg/cm ² and the oil passes through the oil passage 460 to the direct clutch control valve 90 . Further, the oil in the oil passage 460 is supplied to the lubrication system on the engine 1 side of the transmission from an oil passage 467 and an oil cooler 462 via an orifice 461, and is supplied to the lubrication system on the side opposite to the engine 1 via an orifice 463. Supplied. The pressure is regulated to 2.3Kg/cm ² by the pressure reducing valve 110 and the oil passage 41
The oil guided to zero is passed through the orifice 464 to the orifice 30, which is controlled to open and close by the solenoid valve 300.
It reaches 1.

The direct clutch control valve 90 has a spool 91 and a spring 92, and is operated by a solenoid 300.
The control hydraulic pressure regulated between 0.3 and 2.3 kg/cm ² acts on the pressure receiving surface 93 at one end of the spool 91, and the pressure receiving surface 9
The flow direction of oil supplied to the torque converter 3 and the linear clutch 9 and its oil pressure are controlled by the balance between the hydraulic pressure acting on the torque converter 3 and the biasing force of the spring 92.

The oil passage 44 following the torque converter 3 is an oil passage 46
5 and continues to the direct coupling clutch 9.
By switching control of the direct coupling clutch control valve 90, the oil passage 465 is selectively communicated with the supply oil passage 401 or the discharge oil passage 467 via an orifice 468 that reduces oil pressure pulsation, and the oil passage 466 is connected to the supply oil passage 401 or the discharge oil passage 467. It is selectively communicated with passage 460 or discharge oil passage 467.

When a command to engage the direct coupling clutch 9 is given to the solenoid 300 by the computer 290, oil whose pressure is regulated by the direct coupling clutch control valve 90 is supplied from the oil passage 401 to 465 as shown by the solid line arrow in FIG. The direct coupling clutch 9 is connected to the hydraulic chamber 4.
The piston 38 is pushed leftward by the hydraulic pressure acting on the piston 2 and is engaged with a predetermined amount of slip.

If the hydraulic pressure acting on the piston 38 is controlled by a computer to provide a slip amount that is slightly below the range of speed fluctuations of the crankshaft 2 caused by the fluctuating torque of the engine 1, most of the fluctuating torque of the crankshaft 2 can be transmitted. This results in highly efficient power transmission and improved fuel efficiency.

By the way, when starting or suddenly accelerating, it is necessary to remove the direct coupling clutch 9 in order to utilize the characteristics of the torque converter 3 due to the feeling. At this time, the computer 290 stops the power supply to the solenoid valve 290, and the direct coupling clutch control valve 90 is switched so that the oil flows in the opposite direction to that shown by the dashed arrow in FIG.

In other words, the low oil pressure of 2.5Kg/cm ² by the torque converter control valve 110 is lower than the oil pressure of 460 compared to the oil pressure of 460.
6, the piston 38 of the direct coupling clutch 9 moves to the right by the hydraulic pressure acting on the hydraulic chamber 41, and its engagement is released.

According to the above embodiment, two solenoid valves 31
Clutches 11, 12, 13 are a plurality of frictional engagement devices that achieve four forward speeds through control of 0,320 degrees.
The three shift valves 170, 190, and 210 that switch the oil passages of the hydraulic pressure applied to the brakes 14 and 15 are switched and controlled. Therefore, the number of valves provided in the hydraulic circuit is reduced compared to the past, and the structure of each individual valve is reduced. Since it can be easily performed, it is extremely advantageous in terms of cost and space.

Furthermore, among the select lever positions, D ₄ ,
Control according to the D ₃ and 2 positions can be easily performed by commands from the computer 290 to the solenoids 310 and 320 without the need for a separate control valve.

Next, a modification of the above embodiment shown in FIG. 5 will be described. In this modification, the shift control valve 130 is controlled by one solenoid valve 360 instead of the two solenoid valves 310 and 320 in the above embodiment, and the oil passage 401 of the above embodiment is connected to the hydraulic chamber of the shift control valve 130. 134 via an oil passage 469, and from an oil passage 472 through an oil passage 471 in which an orifice 470 is installed.
5, and the oil passage 471 is connected to the solenoid valve 36.
0 orifice 361.

The solenoid valve 360 adjusts the amount of deviation between the position of the valve body 133 of the shift control valve 130 corresponding to the gear ratio set in advance in the computer 290 according to the operating state and the position of the valve body 133 detected by the potentiometer 340. Accordingly, the opening/closing time of the orifice 361 is controlled by changing the pulse width using duty control at 35 Hz, and the hydraulic chamber 135 is
The valve body 133 is always moved to a target position set in the computer 290 by adjusting the amount of oil drained therein.

It should be noted that the present invention is not limited to the above-described embodiments and modifications, but is effective for use in automatic transmissions for vehicles having a plurality of automatic gears.

[Brief explanation of the drawing]

Fig. 1 is a power train diagram of an automatic transmission for a vehicle showing an embodiment of the present invention, and Fig. 2 shows the engagement state of each frictional engagement device in the above automatic transmission in relation to the select lever position. Working element diagram,
Fig. 3 is a sectional view of the torque converter and direct coupling clutch of the same embodiment, Fig. 4 is a system diagram showing the hydraulic control device of the automatic transmission, and Fig. 5 is a main part system diagram showing a modification of the above embodiment. It is. 1...Engine, 10...Input shaft, 11,1
2, 13...Clutch, 14, 15...Brake, 17...Ravigniot type planetary gear set, 24...Output shaft, 50...Pressure regulating valve, 110...Pressure reducing valve, 13
0...Shift control valve, 150...Manual valve, 170
...1st speed - 2nd speed shift valve, 190 ... 2nd speed - 3rd speed shift valve, 210 ... 3rd speed - 4th speed shift valve, 29
0...computer, 300, 310, 320,
330, 360... Solenoid valve, 340... Potentiometer, 350... Engine load detection device, 351, 352, 353... Rotation speed detection device, 354... Oil temperature detection device, 355... Select lever selection Position detection device, 356... Auxiliary switch selection position detection device, 470... Orifice.

Claims (1)

[Claims] 1. In an automatic transmission for a vehicle in which a plurality of gear ratios are achieved between input and output shafts by selectively engaging a plurality of hydraulically operated frictional engagement devices, a hydraulic power source is connected to the plurality of frictional engagement devices from a hydraulic source. A plurality of shift valves that switch oil passages for applied hydraulic pressure by supplying and discharging control hydraulic pressure, a plurality of control oil passages that supply control oil pressure to each of the plurality of shift valves, a plurality of control oil passages, or a plurality of frictional engagements as described above. A shift control valve that controls oil supply to an oil passage that applies hydraulic pressure to a specific frictional engagement device in the device, or oil drainage from the oil passage, depending on the position of the valve body, and the position of the valve body of the shift control valve. hydraulically controlled solenoid valve,
A potentiometer that detects the position of the valve body of the shift control valve, a driving detection device that electrically detects the driving state of the vehicle, including at least the vehicle speed, and a driving state determined according to the driving state of the vehicle detected by the driving detection device. A target position of the valve body of the shift control valve detected by the potentiometer is compared with the position of the valve body detected by the potentiometer, and an electric signal is generated so that the position of the valve body is always at the target position. control of an automatic transmission for a vehicle, comprising a computer that controls the solenoid valve, and is configured such that one of the plurality of speed change ratios is achieved according to the detected driving state of the vehicle. Device.