Module 1 AT (HỘP SỐ TỰ ĐỘNG (BẢN TIẾNG ANH)

Khóa học cơ bản Hệ Thống Điện Thân Xe bao gồm những thông tin chung. Nó sẽ là những kiến thức nền tảng để sửa chữa Hệ Thống Điện Thân Xe. Đặc biệt, phần 1.1.2. Hiểu về tín hiệu InputOutput, phương pháp điều khiển inputoutput cho hộp điều khiển Hệ Thống Điện Thân Xe. Nó là yêu cầu để thực hiện đào tạo thực hành cho việc kiểm tra và sửa chữa chung inputoutput trên một xe thực tế, ví thế bạn phải học chương này cận thận, kỹ càng. Mặc dầu bạn đã quen thuộc với những chi tiết này qua việc xem trước tài liệu online, chúng tôi khuyên bạn chú ý đến chương này để nâng cao khả năng sửa chữa

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LESSON

1.1 Overview 3

1.1.1 Introduction 3

1.1.2 Model Range 4

1.1.3 Specification 6

1.2 Layout 7

1.2.1 Main Feature 7

1.2.2 Input & Output Elements 8

1.3 Components 9

1.3.1 Mechanical Components 9

1.3.2 Hydraulic Control Components 13

1.3.3 TCU Input Components 16

1.3.4 TCU Output Components 19

1.4 Drive Train 23

1.4.1 Clutch & Brake Operation 23

1.4.2 Power Flow 24

1.5 Maintenance 29

1.5.1 Oil Level Adjustment 29

1.5.2 TCM Learning 31

1.5.3 Inhibitor Switch Cable Adjustment 33

[Learning Objectives]

▪ Explain the system mechanism by observing a transmission layout

▪ List the locations, mechanisms and functions of components

▪ Explain the power flow in each gear shift by observing the solenoid valve operation chart

▪ Take necessary actions after a part change and list the cautionary measures required for

maintenance

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▪ Increased driving force when starting off or driving uphill.

▪ Reduced engine rotation speed for increased rotary power.

▪ No load on the engine at startup.

▪ Reversing a vehicle, as an engine cannot reverse-rotate.

▪ High-speed rotation of wheels during high-speed driving.

An automatic transmission performs automatic clutch and transmission control, which is manuallyperformed with a manual transmission A torque converter, which functions as a clutch, a wet multi-plateclutch, which controls planetary gears, and a brake band make up an automatic transmission Becausethe engine and power transfer device are connected via a medium in fluid, vibration and shock areabsorbed, and gear shift appropriate for engine output can take place at all times Compared to themanual transmission, the automatic transmission consumes approximately 10% more fuel, but manydrivers prefer the automatic transmission for its convenience and ride comfort

▪ Model: A4AF3

It is the latest development among the alpha automatic transaxles (advanced alpha A/T) It is a 4-speedelectronic controlled front wheel driven transaxle produced by HMC Application: X -3, LC (Accent), TB(Getz), LD,C-car The vehicles equipped an alpha engine)

▪ Model: F4A series and F5A series

The F4A51 model is a HIVEC 4-speed electronic controlled front wheel driven automatic transaxleproduced by HMC and installed on the vehicle that has the engine volume of 2.0L or more The F5A51model is a 5-speed electronic controlled front wheel driven automatic transaxle produced by HMCand is based on the 4 speed version Depending on the actual vehicle there are several versionsavailable, such as the A5HF1 for the NF Sonata Also for the 4 speed transmissions several versionsare available

W4A51 is a kind of F4A51 HIVEC 4-speed A/T with a 4-wheel drive mechanism Application: santa Fe

▪ Model: AW30-40LE

The AW30-40LE model is a 4-speed electronic controlled rear wheel driven automatic transmission

▪ Model: F21-450

It is a 6-speed electronic controlled front wheel driven automatic transaxle produced by AISIN, Japan.The TCM is placed on top of the transaxle housing and all sensors are positioned inside the AT assembly.Application: EN (Veracruz)

▪ Model: A6LFx, A6MFx

It is a 6-speed electronic controlled front wheel driven automatic transmission developed by HyundaiMotor Company The speed sensors are integrated on the valve body Application: LM (Tucson, ix35),

YF (Sonata)

▪ Model: 6HP19

It is a 6-speed electronic controlled rear wheel driven automatic transmission by ZF The TCM and inputsensors are integrated on the valve body Application: BK (Genesis coupe) 3.8L

Component

An automatic transmission receives signals from various sensors and switches and controls the solenoidvalve, clutch and brakes for converting power received from the torque converter into planetary gear outputappropriate for different gear shifts.

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TCU processes signals received from sensors for optimal gear shifts, smoother shifts and improved fuelefficiency The input section receives various sensor signals, the control section determines the optimalgear selection based on sensor signals and controls the hydraulic pressure and the damper clutch, andthe output section executes controls based on TCM commands TCM functions as follows

▪ Determines the optimal gear selection using sensor data.

▪ Executes gear shift if the current gear is not the optimal gear (prevent gear shift shock).

▪ Determines the damper clutch activation – activates and deactivates accordingly.

▪ Regulates the line pressure based on current torque level.

▪ Performs automatic transaxle diagnosis.

1 Functions and Roles

A torque converter transfers engine power to a transmission and is made up of an impeller, turbineand stator Its functions are as follows

• Power transfer: Transfers engine power to the transmission

• Torque increase: Torque is increased by a stator to exceed engine-shaft torque

• Oil pump: Rotates the oil pump driver gear to pump oil

• Improved fuel efficiency: Engine RPM (power) is transferred to a transmission by a damper clutch

2 Mechanism

• Torque multiplication

Due to the application of the stator the engine torque can be multiplied The torque multiplication

is possible because the stator redirects the backflow stream so that it reaches the impeller vaneshaving the same direction that the impeller has and works as follows: during starting off the impellerturns with engine speed and the turbine is on halt The fluid driven by the impeller reaches theturbine and transfers the energy (engine torque) to it

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• Fluid clutch operation

When leaving the turbine again the fluid flow is redirected by the stator, so that the fluid streambecomes the same direction then the impeller (engine) is turning This creates a force which tries toturn the stator against the impeller (engine) turn direction Due to the one way clutch this movement

is restricted Therefore the oil flow is redirected into the engine turn direction This sharp change indirection causes a backblock of the fluid The force created by this acts as additional force on theturbine (within turning direction), so that its output torque is increased Another positive effect is thatthe fluid which is returned to the impeller reaches it in turning direction and nearly free of vortices

2) Damper Clutch

1 Functions and Roles

Due to the fact that a fluid coupling needs a minimum speed difference between the impeller andthe turbine (slippage) resulting in higher fuel consumption, modern torque converters incorporateadditionally a so called lock up clutch or damper clutch The lock up clutch avoids any slippage inthe torque converter during cruising by locking the turbine against the impeller (front cover), so thatthey turn together

2 Mechanism

Figure 1-1 Damper Clutch Applied (left) / Damper Clutch Released (right)

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• Damper clutch applied

Hydraulic pressure enters between the inner surface of the torque converter hub and the reactionshaft, bringing the plate (damper piston) and front cover together to connect the front cover andturbine

• Damper clutch released

Hydraulic pressure passes through the input shaft and applies the clutch plate in the oppositedirection, detaching the clutch plate from the front cover

3) Planetary Gear

▪ Functions and Roles

A simple planetary gear set consist of the following elements: ring gear (annulus gear), pinion gears(planetary gears), the planetary carrier and the sun gear

Hydraulic control is necessary to hold or connect specific parts of the planetary gear set (s), therebyallowing the power to be transmitted In order to transmit torque by an planetary gear set one elementmust be driven (input), one must be held stationery so that the third one is driven (output) depending onwhich part is held or connected the gear ratio is changed

4) Brake & Clutch

1 Functions and Roles

Figure 1-2 Multi-plate Brakes, Clutch (Plate & Disk) (left) / One Way Clutch (right)

As the names already indicate clutches and brakes are used to connect or hold mechanical parts

Figure 1-3 Clutch / Brakes Locations

2 Mechanism

• Clutch & Brake

Multiple disc types are consisting of a retainer holding the clutch discs and the clutch plates Theclutch plates are connected to the retainer, The clutch discs on the other hand are not connected tothe retainer

If the clutch is activated, pressure will be supplied behind the piston The piston then will move andpress clutch discs and plates against each other The retainer and the hub are connected in thiscase

If the pressure is released, the return spring will push back the piston, clutch plates and discs areagain separated The retainer and the hub are disconnected For brakes the basic construction isthe same , also the operation principle The difference is that clutches connect two rotating partsand the brake connects a part to the transmission housing, thereby holding it stationery

Clutch and brakes operation in different gears according to hydraulic pressure fluctuations will beexplained in Chapter 4 Drive Train

Figure 1-4 Not Applied (left) / Applied (right)

▪ Functions and Roles

It is driven by the torque converter and supplies pressurized fluid to the torque converter, the hydrauliccontrol system including the clutches and brakes, it delivers the necessary fluid quantity needed forlubrication and clutch and brake activation

Figure 1-5 Oil Flow

2) Valve Body

▪ Functions and Roles

The major feature of the valve body on the front wheel drive 6-speed A/T for small sized sedan is theapplication of the linear solenoid valve to improve stability and controllability of the hydraulic system Inaddition, the PCV pressure control screw is applied to minimize the pressure differences, which resulted

in enhanced shift quality, and various new technologies including dual reducing valves and damperclutch release control were applied And filter is added to each solenoid valve to improve durability andcleanliness

A VFS (Variable Force Solenoid) is installed for optimum line pressure control to suit different drivingconditions and improve fuel efficiency.

Figure 1-6 Regulator Valve

▪ PCV (Pressure Control Valve) & Solenoid Valve

A pressure control valve prevents a sudden drop in hydraulic pressure when clutch hydraulic pressure

is released to suppress an increase in input shaft revolutions A solenoid valve controls PCV to suitdifferent gear shifts, and indirectly controls the clutch and brakes

A TCU command increases/decreases currents in a solenoid valve, enabling hydraulic pressure supplythrough the pressure control valve The supplied hydraulic pressure is transferred to the clutch or brakesthrough the spring inside the PCV, enabling gear shifts The mechanism and operation of the solenoidvalve will be explain in greater detail in a section to follow

Figure 1-7 Pressure Control Valve (left) / Solenoid Valve (right)

▪ Manual Valve

A manual valve engages the gearshift lever of the driver seat and directs flow in each gear shift to supplyline pressure to valves

▪ Functions and Roles

An accumulator is installed in the hydraulic fluid channel of the clutch and brakes; temporarilyaccumulating hydraulic pressure supplied to the clutch at gear shift, it prevents sudden clutch/brakesapplication to allow smooth gear shifts An accumulator also absorbs pulsation created when a solenoidvalve operates, and prevents a sudden drop in hydraulic pressure when a solenoid valve stops

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1) Input & Output Speed Sensor

1 Functions and Roles

An input/output speed sensor enables TCM to produce optimum driving performance by detecting ATinput RPM and axle revolution speed and sending the data to TCM to be used to determine gear shifttiming

The conventional HIVEC AT is an external type, with a separate input shaft speed sensor and outputshaft speed sensor However, modern AT has an integrated input/output speed sensor built intothe transmission The input shaft speed sensor detects turbine revolution speed inside the torqueconverter, and the output shaft speed sensor detects the revolution speed of the transfer drive gear

• Gear Shift Control

TPS value received from the output shaft speed sensor and engine is used as a signal to controlgear shifts

• Damper Clutch Control

TCU uses input/output shaft speed and RPM to control the damper clutch

• Damper clutch operation range setting: Output shaft speed sensor, TPS, oil temperature

• Formula for calculating damper clutch slip: Engine RPM - input shaft speed sensor = damperclutch slip (You can check the current data)

2) Inhibitor Switch

▪ Functions and Roles

The inhibitor switch detects gear shift position (P-R-N-D) of the shift lever and sends operation data toTCM The inhibitor switch is installed on the transaxle case and connected with the manual control shaft.When the selector lever is not in position “P” or “N,” the electrical circuit for starting the engine is in theOFF state Therefore, the engine does not start in this condition, even if the ignition switch is turned tothe “START” position

Figure 1-9 Shift Lever Operation

• Sports mode: Manual mode is used to set a gear shift pattern that meets the driver's needs.

Up/down shift signals are analyzed to control gear shifts

▪ Mechanism

When the driver moves the shift lever, wires connect to the shaft protruding from the transmission andcauses the connector in the rotor to rotate and come in contact with the gear shift, producing 4 terminalsignals (S1, S2, S3, S4) P, R, N and D produce the signals shown in the table below

3) OTS (Oil Temperature Sensor)

1 Functions and Roles

Oil temperature sensor is installed directly in valve body as shown in the picture The sensor convertsoil temperature of inside A/T into electrical signal and transmits it to TCM

Oil temperature is a critical element of AT control The oil temperature sensor sends data to TCM,which is then used for important purposes including damper clutch operation/failure detection, oiltemperature variable control and hydraulic control during gear shifts

Figure 1-11 Oil Temperature Sensor

2 Mechanism

The oil temperature sensor uses a NTC thermistor, which changes its resistance level according tooil temperature changes TCM powers up the sensor and sensor output changes according to ATFtemperature changes

1 Functions and Roles

The solenoid valve is installed on the valve body of AT and acts as an actuator that functionsaccording to electric signals received from TCM Following TCM signals, PCV (Pressure ControlValve) is controlled to suit different gear shifts, resulting in indirect control of the clutch or brakeshydraulic pressure inside AT

For conventional HIVEC automatic transmissions, an independent solenoid valve for each clutch orbrake is installed However, the solenoid valve in the front-wheel drive 6-speed automatic transmissionuses more than two shift levers at the same time like the 35R clutch or 26 brake

NOTE

▪ VFS (Variable Force Solenoid): Line pressure variable solenoid

▪ N/H (Normally High): Supplies hydraulic pressure of 0-50mA when thesolenoid valve is not controlled

▪ N/L (Normally Low): Supplies hydraulic pressure of 850mA when thesolenoid valve is controlled

▪ SS-A (Shift Control Solenoid Valve-A): Directs the operating pressure ofOD/C & LR/B to LR/B when LR/B is operating

▪ SS-B (Shift Control Solenoid Valve-B): Guides flow direction to a target gearshift when 35R/C is operating