Tomislav Skračić, MA

Undergraduate English Course for MARINE ENGINEERS

4th Semester

Essential reading:

SPINČIĆ, A., PRITCHARD, B,

An English Textbook For Marine Engineers 2

, Pomorski fakultet, Rijeka 2009.

LUZER, J., SPINČIĆ, A.,

Gramatička vježbenica engleskog jezika za pomorce

, Pomorski fakultet, Rijeka 2003.

LESSON 6

CYLINDER HEAD AND VALVES

Lesson 6 Cylinder Head and Valves

KEY WORDS

cylinder head cylinder cover outer cylinder cover - glava cilindra - glava / poklopac cilindra - vanjska glava cilindra (velika) [1] cylinder cover-insert - unutarnja glava (mala) valve stud (n.) firing loads metallic joint shim (n.) borehole (n.) - ventil usadni vijak, "pržunjer" opterećenja izgaranja / ekspanzije - metalni spoj / brtva podloška, "bajlaga" izvrtani / izbušeni otvor [1] Na starijim Sulzerima, danas većina motora ima 1 glavu.

Lesson 6 Cylinder Head and Valves

VALVES

starting v.

- uputni ventil, v. uputnog zraka air starter / starting air v.

- ventil uputnog zraka injector / fuel injection v.

safety v. = relief v.

v. goriva, ubrizgač sigurnosni, odušni ventil, "šigureca" indicator v.

exhaust v.

- indikatorski v. / pipac ispušni v.

air inlet v. = intake v. - usisni ventil

Lesson 6 Cylinder Head and Valves

tension (n.) tension stud clamp down cylinder cover stud with the aid of sealing ring control bore in turn sequence (n.) bring down - napon, napetost - pritezni vijak - pritegnuti, stisnuti vijak glave cilindra, "pržunjer" uz pomoć, pomoću - brtveni prsten - kontrolni kanal / otvor - naizmjenice, redom - redoslijed, slijed - sjesti, prilegnuti, spustiti (se)

Lesson 6 Cylinder Head and Valves

tightening (n.) stretch of a stud - stezanje crosswise tightening - unakrsno stezanje torque wrench - moment ključ - rastezanje / vlak vijka nozzle (n.) tangentially - mlaznica, sapnica - tangencionalno, pod kutem inspection of the cooling water spaces - pregled, nadzor circumference (n.) via conducting pipe insert (n.) outlet pipe - obujam, opseg, periferija - putem (e.g. Split - umetak - ispusna cijev –Šibenik via Boraja / news via satellite) - provodna cijev

1. DEFINITION

 Cylinder head is a casting that covers the top of a cylinder

2. FUNCTION

  to close tightly

/

seal off the top of cylinders.

to form the combustion chamber, together with the piston crown or, in some cases, with the liner itself.

 to carry the injector and the valves

3. VALVES

All internal combustion engines (2- or 4-stroke) have:  an

air starting valve

which admits compressed air into the cylinder for starting purposes;  a

safety

or

relief valve

is a spring loaded valve set to a safe limit which releases excessive pressure;  an

indicator cock

which is used as a point of the indicator mechanism attachment.

 4-stroke engines have

inlet

and

exhaust

valves.

Spring loaded non-return safety valve

Exercise 1 – Name the parts of the cylinder head:

4. STRESSES

 High pressure and temperature due to combustion

5. REQUIREMENTS

 Strong, sturdy construction / manufacture  Carefully cooled

6. COOLING

 Is executed by F.W. circulation, as excessive temperature may give rise to damage by cracking

7. MATERIAL

 Cast or forged steel

Cooling of the cylinder head

Cooling of the cylinder head

8. DESIGN

passages.

–

not simple. It has valve bores and o o

RND-M

One piece steel block with cooling bores.

B & W

(K-GF Type) Two parts: outer cover and inner insert. The head is a solid steel plate with radial cooling water bores. The insert contains a bore for the exhaust valve cage and mountings for fuel valves, a safety valve and an indicator valve.

o

B & W

(K-GF Type) cooling water drillings.

One piece of forged steel with o

Sulzer

Z40 The double bottom water cooled cylinder head made of special cast iron. It has two inlet and two exhaust valves as well as a centrally arranged fuel valve.

9. HEAD SECURING

 By

studs

made of alloyed steel with close-pitch thread.

 The heads are held in place / held against the cylinder liner top collar by:    studs screwed into the cylinder block studs attached to the cylinder frame studs tightened by hydraulic tools.

Studs are made of special steel alloyed with 0.8% of carbon

Exercise 2 – Answer the following questions:

1.

2.

3.

4.

5.

6.

7.

8.

9.

Name the valves that may be accommodated in the cylinder head.

Are the cylinder heads fitted with inlet and exhaust valves in all marine engines?

What is the purpose of the relief valve?

What is the function of the studs?

Why should the studs be tightened evenly?

How are the studs tightened?

What is the purpose of the control bore?

How can the injector be arranged?

What else does the cylinder head accommodate?