Features Of Azfe Engine

The 2AZ-FE engine has achieved the following performance through the use of the items listed below.

(1) High performance and reliability

(2) Low noise and vibration

(3) Lightweight and compact design

(4) Good serviceability

(5) Clean emission and fuel economy

Section

Item

(1)

(2)

(3)

(4)

(5)

Engine Proper

A cylinder block made of aluminum alloy along with a magnesium alloy die-cast cylinder head cover is used.

o

A taper squish shape is used for the combustion chamber.

o

o

A resin gear balance shaft is used.

o

o

Mechanism

A timing chain and chain tensioner are used.

o

o

o

The shim-less type valve lifters are used.

o

o

The VVT-i system is used.

o

o

Intake and

Exhaust

System

A chacoal filter is used in the air cleaner cap.

o

Intake manifold made of plastic is used.

o

The linkless-type throttle body is used.

o

o

A thin-wall ceramic TWC (Three-Way Catalytic converter) is used.

o

Fuel System

The fuel returnless system is used.

o

o

o

Quick connectors are used to connect the fuel hose with the fuel pipe.

o

o

o

12-hole type fuel injectors with high atomizing performance are used.

o

o

Ignition System

Iridium-tipped spark plugs are used.

o

o

Charging System

The segment conductor type generator is used.

o

o

o

Starting System

PS (Planetary reduction-Segment conductor motor) type starter is used.

o

o

Engine Control System

The ETCS-i is used.

o

o

The DIS (Direct Ignition System) makes ignition timing adjustment unnecessary.

o

o

o

The non-contact type sensor is used in the throttle position sensor.

o

The planar type air-fuel ratio sensor is used.

1. Cylinder Head Cover

• A lightweight magnesium alloy die-cast cylinder head cover is used.

• Acrylic rubber, which excels in heat resistance and reliability, is used for the cylinder head cover gasket.

Cylinder Head Cover

Cylinder Head Cover

Cylinder Head Cover Gasket dr011eg20

Cylinder Head Cover Gasket dr011eg20

2. Cylinder Head Gasket

A steel-laminate type cylinder head gasket is used. A shim has been added around the cylinder bore to increase the sealing surface, thus improving the sealing performance and durability.

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Cylinder

Outer

Front

Shim

Cylinder

Outer

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A - A Cross Section

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3. Cylinder Head

• Through the adoption of the taper squish combustion chamber, the engine knocking resistance and fuel efficiency have been improved.

• An upright intake port is used to improve the intake efficiency.

• Installing the injectors in the cylinder head enables the injectors inject fuel as close as possible to the combustion chamber. This prevents the fuel from adhering to the intake port walls, which reduces HC exhaust emissions.

• The routing of the water jacket in the cylinder head has been optimized to realize the high cooling performance. In addition, a water bypass passage has been provided below the exhaust ports to reduce the number of parts and the weight.

Exhaust Side A

Injector

Spring Word Search Puzzles Printable

Intake Side

Injector

Combustion Chamber Rav4

Bypass Passage

Taper Squish

Bypass Passage

Taper Squish

A - A Cross Section

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4. Cylinder Block

• Lightweight aluminum alloy is used for the cylinder block.

• By producing the thin cast-iron liners and cylinder block as a unit, compaction is realized.

• Air passage holes are provided in the crankshaft bearing area of the cylinder block. As a result, the air at the bottom of the cylinder flows smoother, and pumping loss (back pressure at the bottom of the piston generated by the piston's reciprocal movement) is reduced to improve the engine's output.

• The oil filter and the air conditioning compressor brackets are integrated into the crankcase. Also, the water pump swirl chamber and thermostat housing are integrated into the cylinder block.

^ Air Flow During Engine Revolution ^

Water Pump Swirl Chamber I?

Crankshaft Bearing Cap

Plastic Region Tightening Bolts

Water Pump Swirl Chamber I?

Crankshaft Bearing Cap

2az Engine Timing Cover Full

Thermostat Housing

Air Conditioning Compressor Brackets

Plastic Region Tightening Bolts

Thermostat Housing

Air Passage Holes

0/

/

/ o :

Air Flow

Air Conditioning Compressor Brackets

Air Flow

NOTICE

Never attempt to machine the cylinder because it has a thin liner thickness.

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• The liners are the spiny-type, which have been manufactured so that their casting exteriors form large irregular surfaces in order to enhance the adhesion between the liners and the aluminum cylinder block. The enhanced adhesion helps heat dissipation, resulting in a lower overall temperature and heat deformation of the cylinder bores.

Car Water Jacket

• Water jacket spacers are provided in the water jacket of the cylinder block.

• They suppress the water flow in the center of the water jackets, guide the coolant above and below the cylinder bores, and ensure uniform temperature distribution. As a result, the viscosity of the engine oil that acts as a lubricant between the bore walls and the pistons can be lowered, thus reducing friction.

Water Jacket Spacer

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5. Piston

• The piston is made of aluminum alloy and skirt area is made compact and lightweight.

• The piston head portion uses a taper squish shape to improve the fuel combustion efficiency.

• The piston skirt has been coated with resin to reduce the friction loss.

Resin Coating

Taper Squish Shape

Taper Squish

Taper Squish Shape

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6. Connecting Rod

The connecting rods and caps are made of high-strength steel for weight reduction.

Nut-less type plastic region tightening bolts are used on the connecting rod for a lighter design.

The connecting rod bearings are reduced in width to reduce friction.

Toyota Piston Skirt Resin Coating

Plastic Region Tightening Bolts

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7. Crankshaft

• The forged crankshaft has 5 journals and 8 balance weights.

• The crankshaft is made of forged steel.

• Pin and journal fillets are roll-finished to maintain adequate strength.

• The balance shaft drive gear is provided for the crankshaft.

- Balance Shaft Drive Gear

No.1 Journal

No.1 Journal

Cat 789 Brake
Balance Weight

i

Oil Hole

8. Balance Shaft

General

• A balance shaft is used to reduce vibrations.

• The crankshaft directly drives the No. 1 balance shaft.

• In addition, a resin gear is used on the driven side to suppress noise and offer lightweight design.

Crankshaft

Balance Shaft Drive Gear

Balance Shaft No.2

Balance Shaft Drive Gear

Balance Shaft No.2

2azfe Balance Shaft Timing

Balance Shaft No.1

Balance Shaft No.1

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Balance Shaft Housing

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Operation

In the in-line 4-cylinder engine, the crankshaft angle for cylinders No.1 and No.4 are exactly at the opposite (180°) position of cylinders No.2 and No.3. Therefore, the inertial force of the pistons and the connecting rods of the former 2 cylinders and of the latter 2 cylinders almost cancel each other. However, because the position at which the piston reaches its maximum speed is located toward the top dead center from the center of the stroke, the upward inertial force is greater than the downward inertial force. This unbalanced secondary inertial force is generated twice for each rotation of the crankshaft.

Wankelmotor

Inertial Force of Cylinders No.2 and No.3

Combined Inertial Force of All Cylinders Unbalanced Secondary Inertial Force

Inertial Force of Cylinder No.1 and No.4

Force / Inertial force that cannot be canceled

Force / Inertial force that cannot be canceled

Combined Inertial Force of All Cylinders Unbalanced Secondary Inertial Force

Dagram Direction Car
Crankshaft Angle

Inertial Force Generated by the In-line 4 Cylinders

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To cancel the unbalanced secondary inertial force, 2 balance shafts are rotated twice for each rotation of the crankshaft and generate inertial force in the opposite direction. Also, in order to cancel the inertial force generated by the balance shaft itself, the balance shaft actually consists of 2 shafts rotating in opposite directions.

Cylinder Engine With Balance Shafts

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Responses

  • Azzeza
    How to time balance shafts on 2azfe?
    8 years ago
  • nebay
    Does 2002 RAV4 have an aluminum block?
    3 years ago

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