Базовый двигатель 4B40. Общая информация. Устройство и описание
CYLINDER HEAD RELATION
1. CYLINDER HEAD COVER. A plastic cylinder head cover has been adopted.
2. PCV VALVE
3. CAMSHAFT BEARING CAP. The inlet camshafts is supported by 5 bearings.
The exhaust camshafts is supported by 6 bearings.
4. OIL FEEDER CONTROL VALVE
5. CYLINDER HEAD. The cylinder head is made of aluminium alloy, which is lightweight and has an excellent cooling efficiency. The inlet and exhaust ports are arranged in a cross-flow construction. Each cylinder has a pair of inlet ports on one side and a pair of exhaust ports on the other side.
6. CYLINDER HEAD GASKET. A multiple layers, metal type cylinder head gasket that excels in heat resistance and sealing performance has been adopted.
7. VALVE GUIDE. Valve guides that are common to both the inlet and exhaust have been adopted.
8. VALVE SEAT. Sintered alloy valve seats have been adopted.
9. CAMSHAFT POSITION SENSOR
CYLINDER BLOCK
A cylinder block is made of aluminium alloy has been adopted for weight reduction.
Five bearings are provided for the crankshaft journals and the No. 4 bearing sustains the thrust load of the crankshaft.
The water jacket is the full Siamese type.
1. CYLINDER BLOCK. The cylinder block is made of lightweight aluminium alloy. The water jacket is of a full-seamless design.
Specifications
Overall height mm 279.59
Bore mm 75.0
Bore pitch mm 83.0
Stroke mm 84.8
2. CRANKSHAFT BEARING CAP. The crankshaft journal is supported by four bearings. The crankshaft thrust load is supported by No. 4 bearing.
3. OIL JET. The oil jet cooling the piston is placed on the cylinder block lower plane which is the main bearing among cylinders.
PISTON RELATION
1. PISTON. The pistons are made of special aluminium alloy. Their weight has been reduced by lowering their overall height and increasing the depression at each end of the piston pin. The piston pin hole centre is offset 0.5 mm towards the thrust side of the piston centre. The skirt portion along the perimeter of the piston is finished with streaks that excel in oil retention and seizure resistance.
2. PISTON PIN. The full floating type of piston pin is used to improve the reliability by reducing the friction.
3. CONNECTING ROD. The connecting rod is made of highly rigid, forged carbon steel. The rod portion has an H-shaped cross section. The connecting rod big end bearing is lubricated through an oil passage running from the main journal to the crankshaft pin.
4. PISTON RING. Each piston is provided with No. 1 and No. 2 compression rings and an oil ring.
5. CONNECTING ROD BEARING. Adopted resin coating for upper connecting rod. The connecting rod bearing is equipped with back metal. While the bearing itself is made of aluminium alloy, the back metal is normally made of steel sheet. The connecting rod bearing is narrower than the bearing cap, this is to minimize wear.
CRANKSHAFT RELATION
1. CRANK SHAFT. A forged crankshaft is used for the crankshaft. The crankshaft consists of five main bearings and eight balance weights. The crankshaft pins are arranged at 180° intervals. The oil hole supplies lubrication oil from the journal to the crank pin.
2. CRANKSHAFT BEARING. The upper crankshaft bearing (with oil groove) is located on the cylinder block side while the lower bearing (without oil groove) is held by the bearing cap.The crankshaft bearing is equipped with back metal. While the bearing itself is made of aluminium alloy, the back metal is made of steel sheet. A molybdenum disulfide layer (shot treatment) is added on the sliding surface to reduce friction.
3. THRUST BEARING. A thrust bearing is installed on both sides of the No. 3 crankshaft bearing. The resin coat is adopted to reduce friction on the same sliding surface of the thrust bearing.
4. CRANKSHAFT PULLEY. The crankshaft pulley is made of cast-iron and rubber. The pulley has grooves to engage with a V-ribbed belt (six ribs), which drives an alternator and a water pump and an A/C compressor. An ignition timing mark (notch) is stamped on the flange of the pulley. The crankshaft pulley is equipped with a torsional damper to minimize the torsional vibration of the crankshaft as well as substantially reduce noise and vibration at the high speed range.
5. CRANKSHAFT SENSING RING. The crankshaft is also fitted with a crankshaft sensing ring.
6. FLEXIBLE FLYWHEEL. A steel gear is a shrink fit in the flexible flywheel made of cast iron and steel sheet. The steel Plate is installed to the crankshaft by tightening bolts. Enhance quietness by isolating vibration transmission and resonance between engine and transmission.
7. DRIVE PLATE. A cast iron ring gear is a shrink fit in the steel plate of the drive plate. The drive plate is installed by tightening six bolts.
8. ADAPTER PLATE
TIMING CHAIN RELATION
1. OIL SEAL. A front crankshaft oil seal is press-fit into the case.
2. TIMING CHAIN CASE. The engine support bracket, the oil pump and the relief valve are integrated as well as water chamber of the water pump.
3. TIMING CHAIN. Two camshafts are driven by the timing chain via the respective sprockets. The timing chain, consisting of 180 links, is an endless chain, connecting the crankshaft sprocket with the camshaft and V.V.T. sprockets. The timing chain is equipped with three mark link plates (blue) to correctly time the two sprockets with each other. The timing chain is tensioned by the timing chain tensioner, which has a built-in plunger with plunger springs.
4. TIMING CHAIN TENSIONER. The plunger in the timing chain tensioner directly pushes the tension lever, and the pressure automatically adjusts the timing chain tension. A cam is provided to lock the plunger in place after the engine stops. This helps to prevent the timing chain from wobbling just after the engine starts. With the timing chain tensioner installed, do not crank the engine in the reverse direction. This will force the plunger to overcome the cam, or even cause other problems.
5. TENSION LEVER ASSEMBLY
6. CHAIN GUIDE ASSEMBLY
7. CAMSHAFT SPROCKET EXHAUST
8. V.V.T. CAMSHAFT SPROCKET
VALVE RELATION
The valve mechanism is based on a 4-valve DOHC (Double Over Head Camshaft) design having the camshaft on the upper valve. Each cylinder has two inlet valves and two exhaust valves, arranged in a V-shape pattern.
Camshaft rotation is transmitted via valve tappets to the respective valves which open and close accordingly.
1. CAMSHAFT
2. VALVE TAPPET. Valve tappets are available in 31 thicknesses, at 0.020 mm intervals between 5.100 mm and 5.700 mm, to ensure the correct valve clearance.
3. VALVE. The valves have heat-resistance. The entire valve surface is treated with nitriding.
4. VALVE STEM SEAL. The valve stem seal portion excels in sealing performance and is equipped with a spring to prevent oil from descending.
5. VALVE SPRING. The valve spring has a dual pitch spring to prevent surging in the high speed range.
MIVEC (MITSUBISHI INNOVATIVE VALVE TIMING ELECTRONIC CONTROL SYSTEM) RELATION
MIVEC (Mitsubishi Innovative Valve timing Electronic Control system) consists of the components illustrated above.
The valve timing is optimally controlled (continuously variable) under the changing driving conditions to improve performance in the entire speed range.
V.V.T. SPROCKET (VARIABLE VALVE TIMING SPROCKET)
Oil from the oil feeder control valve is sent to the V.V.T. sprocket, moving the vane rotor and thus regulating the valve timing.
CAMSHAFT
The lightweight camshaft is achieved by the hollow design.
Oil channels run through the camshaft, through which oil is sent from the oil feeder control valve to the V.V.T. sprocket.
A cam position sensing ring is press-fitted onto the rear portion of the camshaft.
OIL FEEDER CONTROL VALVE (OCV)
The oil feeder control valve is essentially a solenoid valve, regulated by the engine-ECU signals to feed oil to the V.V.T. sprocket assembly to move the vane rotor.
By adopting a filter-equipped oil feeder control valve, a filter is added to each port to improve reliability.