4-15 COMBUSTION SYSTEM

For lower fuel consumption and easy starting of the engine,

/INTAKE

VALVE

thedirectinjectionsystemisadoptedinthecombusition

INTAKE PORT

chamber.

 

 

 

4-15-1FORMING of COMBUSTION GAS and COMBUS-

SWIRL

 

TION

 

 

 

SWIRL (Inspiring swirl)

 

CYLINDER

In order to promotemixing injected fuel andair under

PISTON

 

thedirectinjectionsystem, swirl flow is utilizedfor

 

 

 

good Combustion. Swirl is spiral flow of air generated

 

 

in the cylinder duringinspiring stroke, and itdecreases

 

 

during compressing stroke but it still remains and pro-

 

 

motes mixing of fuel and air toward ignition timing.

 

 

Spiral flow of air (swirl) is generated by the shape of

 

 

intake port, which is called helical port or spiral port.

 

 

Tail end of intake port,i.e. upper part of intakevalve

Fig. 13

 

seat, is madein the spiral form; andwhile the inspired

 

 

air is passing throughthispart,

swirl is generated

 

 

around the intakevalve. Thus, intake portplays an im- portant role in generating swirl. (See Fig. 13.)

SQUISH (Squished air flow) Inthepiston,combustionchamber(dishtypecom- bustionchamber) is formed. When the piston comes up toTDC (top dead center), air in thegaps is squished in the combustion chamber and air flow is generated, which iscalled “squish.” (See Fig. 14.)

FORMING of COMBUSTION GAS and COMBUSTION

Fig. 14

For igniting quickly the fuel injected from the nozzle, it is essential to atomize very fine oil particles for distributing evenly in the combustion chamber. For t h s purpose, fuel should be injected through hole type nozzle by very high pressure, i. e. 195 kg/cm2. The fue!, thus injected, is mixed with air by the flow of swirl and squish while piston is Coming Up. Accompanying crimb of the piston, combustiongas compressed further and finally it automatically begins igniting and while piston is going down, “squish” functions and promotes combustion.

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Subaru Robin Power Products DY41, DY35, DY30 manual Combustion System
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DY41, DY30, DY35 specifications

Subaru Robin Power Products have built a solid reputation in the realm of portable engines and generators, particularly with their DY35, DY30, and DY41 models. These engines are extensively used for various applications, ranging from construction to agricultural equipment, owing to their reliability and efficiency.

The Subaru DY35 engine exemplifies performance with a displacement of 35cc. Its lightweight design ensures easy portability, while its robust construction provides durability in demanding environments. Featuring a two-stroke cycle, the DY35 offers a high power-to-weight ratio, making it ideal for handheld equipment and compact machinery. Key characteristics include its advanced electronic ignition system that promotes easy starting and reliable operation. The DY35 also boasts superior fuel efficiency, which translates to lower operational costs over time.

Moving on to the DY30, this engine is designed with versatility in mind. It has a slightly smaller displacement of 30cc, making it a great choice for various power tools and smaller machinery. The DY30 is known for its excellent torque delivery, which allows users to tackle challenging tasks without the need for frequent refueling. One of its standout features is the automatic lubrication system that keeps the engine running smoothly while minimizing wear and tear. This feature significantly extends the engine’s life, making it a favorite among users looking for long-term performance.

The DY41 takes a step up in power with a displacement of 41cc, making it suitable for heavier-duty applications. Designed for larger equipment, the DY41 is renowned for its high torque and robust construction. It also includes an innovative cooling system that effectively dissipates heat, ensuring optimal engine performance in prolonged usage scenarios. The DY41 is equipped with advanced vibration-dampening technology, which enhances user comfort and reduces fatigue during operation.

Each of these Subaru Robin engines incorporates fuel-efficient technologies that reduce emissions and comply with environmental regulations. They are built to withstand the rigors of demanding work environments while providing reliable power. With their distinct features and durable designs, the DY35, DY30, and DY41 engines continue to be sought-after choices for professionals and hobbyists alike, underscoring Subaru's commitment to innovation and quality in power products.
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