General information

Design of typical AT (1 of 2)

Design of typical AT (2 of 2)

For a complete set of cars considered in the real Management can be used 4-step (including raising transfer) automatic transmissions (AT) of a series 03-72LE of production of the Aisin Warner company (AW372LE).

Playing a role of ordinary coupling at the moment of a car troganiye from a place, during movement AT performs work on gear shifting.

The AT main components are the being blocked hydrotransformer (the rotation converter), a three-row step planetary reducer and an electronic and hydraulic control system. Hydrodriving multidisk brakes (4 pieces), obgonny couplings (3 pieces) and multidisk friction clutches (3 pieces) are applied to gear shifting without a rupture of a stream of capacity in a planetary reducer.

Management of switching of all transfers, and also blocking of the hydrotransformer carries out the special electronic module (TCM) which is working in close connection with the module of engine management (ECM) and continuously communicating with last.

Possibility of blocking of the hydrotransformer at movement in a cruiser mode about the speed, exceeding some threshold value allows to increase essentially profitability of fuel consumption at the expense of decrease in working turns of the engine.

The liquid cooler of ATF is built in a radiator of system of cooling of the engine, one more, an external air cooler is established directly ahead of a radiator of system of cooling.

TCM supervises functioning of all AT executive mechanisms (klapanny assembly, couplings, brake assemblies) taking into account a choice of one of three set modes of transmission: ECONO (a normal mode), POWER or HOLD, - see. Head Governing bodies and operation receptions). On the basis of the analysis of the data arriving from various information sensors (not necessarily directly related to functioning actually transmissions), TCM chooses optimum from the point of view of profitability, smoothness of switchings and so forth a mode of functioning of AT. A component of a control system of AT is the self-diagnostics subsystem, - at detection of serious malfunction the module of management switches transmission in a special emergency (safe) operation with a limited range of switchings. Switching in emergency operation allows to drive away the car under the own steam on car repair shop for performance of detailed diagnostics and necessary regenerative repair. On the basis of the data arriving from gas traditionally established under a pedal of the sensor switch of activation of the mode kickdown, TCM carries out transmission switching on adjacent being used at the moment transfer at complete squeezing of a pedal that allows to raise essentially dynamic characteristics of the car, for example during overtaking commission. Thanks to use of the special N/R sensor switch start of the engine can be carried out only when the lever of the AT selector is in the situation "R" or "N" that allows to prevent a casual troganiye of the car in start attempt.

The unique procedure of service of AT which performance should be made on a regular basis, check of level of the working liquid (ATF) which order of performance is stated in Head the Current leaving and service is. Need for regular replacement of ATF is absent.

In the present chapter the general procedures of service AT lying within qualification of the average amateur mechanic are considered only most. Information on a design and principles of functioning of the AT separate executive elements below is provided.

Klapanny assembly

Klapanny assembly is located in the pallet of a case of transmission and under control of TCM exercises administration of ATF streams in a box. A part assemblies liquids supervising pressure valves are connected among themselves by internal channels. Cleaning taken away of the pallet of a case of transmission liquid (ATF) is provided with the mesh filter which has been built in in a maslozabornik of pump assembly.

Design of klapanny assembly of AT

Hydroaccumulators

The main function of the accumulator is ensuring absence of stress of switchings of transmission towards transfer increase at the expense of smoothing of operation of friction clutches. In considered transmission three relatives on an accumulator design are used: friction clutches of forward transfers and direct perception and a disk brake of transfers from the 2nd and above.

The accumulator consists of the valve and a spring. To the podpruzhinenny party of the valve the main pressure, whose action плюсуется is constantly attached to effort developed by a spring and presses the valve when assembly is in an inactive condition.

Accumulator design

When giving operating pressure upon the corresponding executive mechanism (a friction clutch or a multidisk brake) the same pressure (from the valve of manual switching) is put to the working party of the valve of the corresponding accumulator. Under the influence of this pressure the valve starts to be wrung out down, overcoming antipressure and the effort developed by a spring. On filling of working volume the accumulator needs some time by the time of which end the executive mechanism appears completely included, - this delay and provides smoothness of operation of an under control friction clutch/brake and, respectively, absence of stress of switching of AT.

Hydrotransformer blocking

The blocking coupling provides possibility of transfer of a torque from a cranked shaft of the engine to directly entrance shaft of O/D of transmission.

Operation of blocking occurs only in a cruiser mode at movement with a speed over 69 km/h (43 miles/h) and at temperature of cooling liquid not less 50°С. At delay of speed of movement is lower than a threshold of inclusion of raising (O/D) of transfer (69 km/h), no less than at decrease in temperature of cooling liquid is lower 50°С, the blocking coupling automatically is disconnected.

Blocking inclusion

At delivery by the module of management (TCM) of the corresponding team during car movement on 2nd, 3rd or 4th (O/D) to transfer operation of the electromagnetic valve of the blocking coupling leads to opening of drainage channels and, as a result, dumping of the main pressure from the spring party of the operating zolotnikovy valve of the hydrotransformer. Under the influence of the main pressure (from the valve of switching 1-2), a zolotnik brought from the opposite side, there is its switching to supply of the transmission liquid which was under the pressure of the hydrotransformer via the turbine on the back party of the blocking coupling, - forced out from the opposite side of the ATF coupling via the operating valve is deduced in the case pallet (the stream of the transmission liquid banished through a cooler of ATF, at the included blocking of the hydrotransformer is reduced). As a result blocking coupling nestles on a forward cover, mechanically with it being blocked. As the coupling has shlitsevy landing on the turbine, from this point a forward cover, the coupling and the turbine start to rotate as a unit, providing torque transfer from a cranked shaft of the engine directly on an entrance shaft of O/D of transmission.

Principle of inclusion of blocking of the hydrotransformer

Blocking shutdown

At delivery by the module of management (TCM) of command for shutdown of blocking there is a closing of the electromagnetic valve under the influence of effort developed by its spring. As a result of a perekryvaniye of drainage channels and pressure alignment from both parties of the operating valve of the hydrotransformer, the last under the influence of effort developed by a spring is switched, providing giving being under the pressure of the ATF hydrotransformer on the forward party of the blocking coupling. As a result blocking coupling is wrung out from a forward cover, deducing the last from gearing with the block the coupling turbine, - surplus of volume of the liquid being under the pressure of the hydrotransformer, is deduced via the operating valve in a cooler of ATF and further in the case pallet.

Principle of shutdown of blocking of the hydrotransformer

ATF cooler

At the switched-off blocking of the hydrotransformer transmission generates a large number of heat which main part accumulates transmission liquid.

For heat selection from ATF the special two-level okhladitelny path is organized. The first step of cooling is organized by means of laying of tubes of a transmission contour in the bottom tank of a radiator of system of cooling. After return of a part of heat of cooling liquid of the engine in a radiator of system of cooling, ATF goes in a maslookhladitel. The heat exchanger of a cooler of ATF is established ahead of a radiator of system of cooling and is blown by a running stream of air which selects the remained superfluous heat at ATF. Pressure of ATF is supported at constant level in 1.9 atm at the expense of inclusion to the okhladitelny highway of transmission of the special perepuskny valve.

The main source of a thermal emission in AT is the hydrotransformer. As at inclusion of blocking of the hydrotransformer turbulence of a stream of ATF in it decreases, the capacity of a thermal emission of transmission is considerably reduced also. Taking into account this factor, in a design of AT function of reduction of a stream of transmission liquid through ATF cooler for the period of turning on of the blocking coupling is put. If there is an overheat, TCM develops special command for shutdown of blocking of the hydrotransformer for the purpose of restoration of intensity of circulation of ATF via the cooler heat exchanger.

Purpose of the AT separate executive elements

Card of operation of the AT actuation mechanisms

The card is presented in the table.

Device Mode		Ø/m C. And	Ø/m C. In	O/D friction clutch	Friction clutch of forward transfers
R		•	—	•	—
R		•	—	•	—
N		•	—	•	—
D	1st transfer	•	—	•	•
	2nd transfer	•	•	•	•
	3rd transfer	—	•	•	•
	O/D	—	—	—	•
2	1st transfer	•	—	•	•
	2nd transfer	•	•	•	•
L	1st transfer	•	—	•	•

Device Mode		Friction clutch of direct perception	O/D brake	Mode "2" brake	Brake of transfers from the 2nd and above
R		—	—	—	—
R		•	—	—	—
N		—	—	—	—
D	1st transfer	—	—	—	—
	2nd transfer	—	—	—	•
	3rd transfer	•	—	—	•
	O/D	•	•	—	•
2	1st transfer	—	—	—	—
	2nd transfer	—	—	•	•
L	1st transfer	—	—	—	—

Device Mode		Brake of modes "L" and "R"		Обг. O/D coupling	Обг. coupling No. 1	Обг. coupling No. 2
		Vnutr. piston	Plank beds. piston
R		—	—	•	—	—
R		•	•	•	—	—
N		—	—	•	—	—
D	1st transfer	—	—	•	—	•
	2nd transfer	—	—	•	•	—
	3rd transfer	—	—	•	—	—
	O/D	—