7.GENERAL DESCRIPTION of AUXILIARY GADGETS and PARTS

7-1 FUEL INJECTION PUMP MECHANISM

It is not too much tosay that the fuel injection pumpis the heart of thediesel engine, and it must beprecise enough t o sat- isfy the following functions.

Function

Injecting fuel, starting withhigh pressure and ending with low pressure. Injecting the predetermined amount of fuel accurately at each stroke. Injecting fuelat specified time within a specified time interval.

Quantity being injected is closely vaned by thegovernor to suit to varying load.

This engine has no automatic advancing device,but in starting (maxdelivery),. the injection timeingis to be delayed.

Theory of the injection pumpmechanism

The plunger of the injection pumpis pushed u p by the cam of the camshaft, and itis pushed down by the plunger spring. By this up and down motion in a stroke, suction and forced supplyof fuel are conducted. (See Fig. 54.)

Suction of fuel

Through the filter in the fuel tank, fuel is supplied and is in full around the intake port of the plunger barrel. When the top of the cam lobe passed the tappet and cam function ended,plunger spring pushes down the plunger.

When the plunger is pushed down passing the fuel intake, fuelis sucked into the barrel, and suctionis continued until arrival of the plunger at the bottom of its strokeThis. is on thestage of "suction."

Forced supply offuel.

The camshaft rotates and pushes up the plunger. Forced supply of the fuel is started only when the upper partof the plunger closed the fuel intake in the course of being pushed up by the cam rotation. The fuel in the barrelis pressur- ized by a,very strong force (100 kg/cm2 and up), andas a result, the force of thefuel pushes up the delivery valve and the dampingvalve, and then it injects thefuel into combustion chamber.This is on the stage of "pressurized supply."

DAMPING VALVE

D E L I V E R Y V A L V E

VERTICAL HOLE

PLUNGERBARREL

PLUNGER

INTAKE PORT (EXHAUST PORT)

L E A D

EFFECTIVE STROKE

Fig. 54

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Subaru Robin Power Products DY30, DY35 General Description of Auxiliary Gadgets and Parts, Fuel Injection Pump Mechanism

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.