CASING&

COMPRESSOR OF AIR CONDITIONER

INTRODUCTION

CASING OF AIR CONDITIONER (OUTDOOR UNIT)

Protection to the electric components inside the outdoor unit of an air conditioner

COMPRESSOR OF AIR CONDITIONER

Used to compress the refrigerant in the refrigerating cycle and increases energy and temperature of refrigerant.

CASING OF AIR CONDITIONER (OUTDOOR

UNIT)

1) CASING OF AN AIR CONDITIONER(OUTDOOR UNIT)

MATERIAL SELECTIONMaterial chosen: Aluminium alloyThis material is corrosion resistant.

MANUFACTURING PROCESSES FOR CASING OF AN AIR CONDITIONER

IDENTIFICATION

1) Die CastingIs a permanent-mold casting in which the molten metal is injected to the mold cavity under the high pressure.There are

types of die casting ; 1)Hot chamber 2)Cold chamber(more suitable)

2) Sheet metal workingSheet-metal processing is performed at room temperature (cold working).There are 3 majors categories of sheet-metal processes ; 1)Cutting 2)Bending 3)Drawing

Cutting Bending Drawing

DISCUSSION

1) The advantages and disadvantages die casting(cold chamber) are shown below:

2) The advantages and disadvantages of sheet metal working are shown below:

Advantages of sheet metal working

Disadvantages of sheet metal working

1) Higher strength

2) Good dimensional accuracy

3) Good surface finish

1) Time consuming

2) Higher tooling cost

3) Wasteful of material

4) Need high labor skill

Advantages of die casting (cold chamber)

Disadvantages of die casting (cold chamber)

1)Higher production rates

2)Economical for large production

3)Reasonable to good surface finish

4)Lower scrap

5)Lower tooling cost

1)Part produced has lower strength

than that produced by sheet-metal

working process

2)Poorer dimensional accuracy

JUSTIFICATION

1) Die casting (cold chamber) is chosen to produced outdoor unit casing of air conditioner.

2) Casing of an air conditioner is just a protecting shield which very high strength is not required.

3) This process involves lower tooling cost and higher production rate.

4) Die casting process involved less material waste which also contributes lower production cost.

COMPRESSOR OF AIR CONDITIONER

Example of compressor parts are:1) Piston2) Compressor Scroll3) Balance Plate4) Connecting Tube

1) PISTON OF AIR CONDITIONER COMPRESSOR

MATERIAL SELECTIONMaterial chosen: SiCp or Al-Si ( types of metal matrix composites materials).These materials have high strength, good wear resistance and light weight.

MANUFACTURING PROCESSES FOR PISTON OF AIR CONDITIONER COMPRESSOR

IDENTIFICATION

1) Hydrostatic extrusion followed by impression-die forgingBar is produced by hydrostatic extrusion. The extruded bar is warm-forged at temperature of 400oC to final shape by impression-die forging process.Flash is trimmed off to get final product.

2) Sand castingMolten alloy is poured into a sand mold having the shape of a piston.When alloy had solidified, it is removed from the mold.

DISCUSSION

1) The advantages and disadvantages of both hydrostatic extrusion and impression-die forging are shown below:

Advantages of hydrostatic extrusion and impression-die

forging

disadvantages of hydrostatic extrusion and impression-die

forging

1) Part produced is more ductile2) Higher strength3) Higher production rate

1) Higher tooling cost

2) The advantages and disadvantages of sand casting are shown below:

JUSTIFICATION

1) Hydrostatic extrusion followed impression-die forging are chosen as the manufacturing process for air conditioner compressor piston.

2) Piston of an air conditioner compressor required high ductility, strength to function without failure and both processes will increase the ductility and strength of the part produced.

3) These processes provide higher production rate and lead to reduction of production cost.

Advantages of sand casting Disadvantages of sand casting

1) Low tooling and production cost

2) Part produced is in net shape

1) Rough surface produced2) Close tolerances are difficult

to achieve3) Poor dimensional accuracy4) Low strength5) Time consuming

2) AIR COMPRESSOR SCROLL & BALANCE PLATE

MATERIAL SELECTIONAir compressor scrollMaterial chosen: Aluminium alloyThis material is light and corrosion resistant.

Balance plateMaterial chosen: No magnet stainless steel. This material is high strength.

MANUFACTURING PROCESSES FOR AIR COMPRESSOR SCROLL AND BALANCE

PLATE IDENTIFICATION

1) Flashless forgingCarried out in an elevated temperature which in between cold and hot forging.Warmed work piece is compressed between a punch and a die having the shape of the compressor scroll or balance plate until deformation occurs.

2) Sand castingMolten metal alloy is poured into the mold which has pattern of compressor scroll or balance plate and let to solidify. Casting is removed from the sand mold after solidified.

DISCUSSION

1) The advantages and disadvantages of flashless forging are shown below:

Advantages of flashless forging

Disadvantages of flashless forging

1)Part produced is more ductile2)Higher strength3)Higher production rate4)Little or no material is wasted5)Produced part are in net shape

1) Higher tooling cost due to complex die shape

2) The advantages and disadvantages of sand casting are shown below:

JUSTIFICATION

1) Flashless forging is chosen as the manufacturing process for air compressor scroll and balance plate.

2) High strength and ductility are important for these parts. This process will increase the ductility and strength of the part produced.

3) This process is also more economical due to higher production rate and less waste of material.

Advantages of sand casting Disadvantages of sand casting

1) Low tooling and production cost

2) Part produced is in net shape

1) Rougher surface produced2) Close tolerances are difficult

to achieve3) Poor dimensional accuracy4) Low strength5) Time consuming

3) CONNECTING TUBE

MATERIAL SELECTIONMaterial chosen: stainless steelThis material have very high corrosion and strength which needed for connecting tube production.

MANUFACTURING PROCESS FOR CONNECTING TUBE OF AIR CONDITIONER COMPRESSOR

IDENTIFICATION

1) Cold direct extrusion followed by machiningThe billet is place in the containerThe ram will push the billetThe shape of the final work is determine by the mandrel

2. Sand castingMolten alloy poured into sand mold After the casting had solidified, it is removed from the mold

DISCUSSION

1) The advantages and disadvantages of cold direct extrusion are shown below:

Advantages of cold direct extrusion

Disadvantages of cold direct extrusion

1) Higher strength2) Close tolerances3) Less material waste4) Good surface finish5) Higher production rate

1) Higher tooling and processing cost

2) The advantages and disadvantages of sand casting are shown below:

JUSTIFICATION

1) Cold direct extrusion is chosen as manufacturing process for connecting tube of air conditioner

2) Connecting tube require high strength to function

3) Cold direct extrusion more economical with less waste material and high production rate

Advantage of sand casting

Disadvantage of sand casting

1) Lower production cost2) Part produced is in net

shape

1) Lower strength2) Poor dimensional

accuracy3) Produced low surface

quality4) Lower production rate

CONCLUSION

1) Outdoor unit casing of an air conditioner - die casting process

2) Air conditioner compressor piston - hydrostatic extrusion followed by impressed-die forging.

3) Compressor scroll and balance plate - flashless forging

4) Connecting tube - cold direct extrusion.