Experiment No.: 01
Aim of the Experiment: –
Study of different foundry tools and making a green sand mould of half bearing block/casting of bearing block.
Introduction: –
A foundry shop is the part of workshop which deals with the process of making casting in moulds prepared by patterns. Metals are cast into shapes by melting them into a liquid, pouring the metals into a mold and removing the mold materials after the metal has solidified as it cools. The whole process of producing casting may be classified into five stages: –
(i) Pattern making.
(ii) Moulding and core making.
(iii) Melting and casting.
(iv) Fettling.
(v) Testing and inspection
Except pattern making, all other stages to produce metal casting are done in foundry shop. The process of making pattern is done in Carpentry shop.
Tools used in foundry shop:
The common tools used in foundry shop are fairly numerous. A brief description of the following foundry tools used frequently by molder is given as following.
- Shovel.
- Hand Riddle.
- Hand Rammer.
- Trowels.
- Slicks.
- Lifter.
- Strike off bar.
- Bellows.
- Swab.
- Mallet.
- Sprue Pin.
- Vent Rod.
Shovel: It consists of an steel pan fitted with a long wooden handle. It is used in mixing, tempering and conditioning the foundry sand by hand. It is also used for moving and transferring the molding sand to the container and molding box as flask. It should always be kept clean.
Hand Riddle: It is consists of a screen of standard circular wire mesh equipped with circular wooden frame. It is generally used for clearing sand and for removing foreign materials such as nail, shot metal, splinters of wood, etc. from it. Even power operated riddles are available for riddling large volume of sand.
Hand Rammer: It is generally made up of wood or metal. It is small and on one end is carries a wedge type construction called pan and the other end processes a solid cylindrical shape known as butt. It is required for molding box to pack or compact it uniformly all around the pattern in bench molding work.
Trowels: Trowels are utilized for finishing flat surfaces and joints and parting lines of the mold. They consist of metal blade made of iron and equipped with a wooden blade. The common metal blade shapes of trowels may be pointed or contoured or rectangular oriented. the Trowels are basically employed for smoothing or slicking the surface of molds. They may also be used to cut in gate and repair the mold surface.
Slicks: Slicks are also recognized as small double ended mold finishing tool which are generally used for repairing and finishing the mold surfaces and their edges after withdrawal of the pattern. The commonly used slicks are of the types of heart and leaf, Square and heart, spoon and bead, and heart and spoon. The nomenclature of the slicks are largely due to their shapes.
Lifters: Lifter are also known as cleaners or finishing tool which are made up thin section of steel of various length and width with one end bent at right angle. They are used for cleaning, repairing and finishing the bottom and sides of deep and narrow openings are also used for removing loose sand mold cavity.
Strike off bar: Strike off bar is a flat bar having straight edge and is made of wood or iron. It is used to strike off or remove the excess sand from the top of molding box after its surface plane and smooth. Its one edge is made beveled and the other end is kept perfectly smooth and plane.
Bellows: bellows gun is operated. It is leather made device equipped with compressed air jet to blow or pump air when operated. It is used to blow away the loose or unwanted sand from the surface of mold cavities.
Swab: It is a small hemp fiber brush used for moistening the edges of sand mould which are in contact with the pattern. It is used for sweeping away the molding sand from the mold surface and pattern. It is also used for coating the liquid blocking on the mold faces in dry sand molds.
Mallet: Mallet is similar to a wooder hammer and is generally used as hammer in carpentry or sheet metal shop. I molding shop it is used for driving the draw spike into the pattern and then rapping it for separation from the mold surfaces so that pattern can be easily withdrawn leaving the mold cavity without damaging the mold surface.
Sprue Pin: Sprue pin is tapered rod of wood or iron which is placed or pushed in cope to join mold cavity while the molding sand on the cope is being rammed. latter its withdrawal from cope produces a vertical hole in molding sand called sprue through which the molten metal is poured into the mould using gating system.
Vent Rod: vent rod is a thin spiked steel rod or wire carrying a pointed edge at one end and a wooden handle or bent loop at the other end. After ramming and striking off the excess sand it is utilized to pierce series of small holes in the molding sand in the lope portion, to allow the exit of steam and gases during pouring mold and solidifying of the molten metal for getting a sound casting.
Tools used in pattern making process: (In carpentry shop)
- Steel Rule.
- Outside calliper.
- Scriber.
- Pencil.
- Carpentry Vice.
- Tenon Saw.
- Gauge chisel.
- Parting off tool.
- Wood turning lathe.
- Sand paper.
Steel Rule : It is made up of stainless steel. It is the simplest and most common measuring tool. The division marked on steel rule is inches or millimeters.
Outside caliper: It is used to measure the external diameter of cylindrical / spherical objects. It consists of two legs connected at one end by means of pivots or bolts. The edges are made to just touch the jobs legs are made up of medium carbon steel.
Scriber: It is used to scribe a line for marking on material. It is made up of high carbon steel.
Pencil : It is also used for marking the object for required dimension.
Carpentry Vice. : It is the common work holding device. It consists of one fixed jaw and one moveable jaws. Its one jaw is fixed to the side of the table while other is movable by means of screw and handle.
Tenon Saw : It is a kind of hacksaw that is used to cut straight lines in wood. It is a standard item in the carpentry toolkit. It is made out of high sped steel (HSS) and brass. The saw has a fine toothed cross-cut for sawing large joints
Gauge chisel : It serves to swive small pieces from wood the material, particularly in wood working, wood turning and sculpture. Gauges most frequently produced concave surface.
Parting off tool : Parting uses a blade like cutting tool plunged directly into the the work piece to cut off the workpiece at a specific length. It is normally used to remove the finished end of a workpiece from the bar stock that is clamped in the chuck.
Wood turning lathe : They are typically used to shape wood into cylindrical profiles. Objects made on wood Lathe include such items as furniture legs, lamp posts, base ball etc. wood lathe tooling consists of fixturing and securing devices for the workpiece a moveable tool rest and hand-held cutting tools in the form of long handled gauges, skews, scrapers and parting tools.
Sand paper : It is a stiff paper coated with powdered emery or sand. It is most often used to clear and smooth wood or metal in preparation for finishing or pointing. Sandpapers are commonly graded as Coarse (40 to 60 grit), medium (80 to 120grit), fine (150 to 180 grit), very fine (220 to 240 grit), extra-fine (288 to 320 grit) and super fine (360 to above).
