Skip to main content

Cold Bending of Metal in Manufacturing

Bending is the process by which a straight length is transformed into a curved length. It is one of the most widely used forming process for changing plates (or sheets) into drums, curved channels etc. Bars, rods, wires, tubing and structural shapes as well as sheet metal are bent to many shapes in cold conditions through dies. In all metal bending, the metal stressed beyond the elastic limit is in tension on the outside and in compression on the inside of  the bend. Stretching of the metal on the outside makes the stock thinner. Bending a flat strip of metal is commonly done by roll forming.

Roll forming - There are two main types of roll forming ; one uses continuous -strip material for high - production work ; the other uses sheet and plate stock. Materials used for roll forming include carbon steel, stainless steel, bronze, brass, copper, zinc, and aluminum. Among its many products are metal window and screen frame members, bicycle wheel rims, furnace, Jacked rings, trolley rails. Much of the present day tubing is roll-formed cold and then resistance welded.

Continuous roll forming utilizes a series of  rolls to gradually change the shape of the metal. As the metal passes between the rolls in a fast-moving continuous strip, the cross-sectional shape is changed to the desired shape. The forms are almost limitless in variation. The intricacy of the shape, the size of the section, the thickness, and the type of material will determine the number of rolls required. 

Bending rolls are used for bending sheet and plate stock into cylindrical shapes. A roll-bending machine is made up of  three rolls of  the same diameter, two of them being held in fixed position and one being adjustable. As a metal plate enters and goes through the rolls, its final diameter is determined by the position of the adjustable rolls. After the part is removed from the rolls, it is placed in fixture to close the gap prior welding. Bending - roll machines range in size from those that are able to roll heavy steel plate 25 mm thick, to small bench models used for light - gauge sheet metal work. 


Cold bending of Metal


check out other cold working processes

Labels:

Comments

Post a Comment

Popular posts from this blog

Advantages And Disadvantages Of Air Refrigeration System :

 Advantages Of  Air Refrigeration : 1. The refrigerant used namely air is cheap and easily available. 2. There is no danger of fire or toxic effects due to leakages. 3. The weight to ton of refrigeration ratio is less as compared to other systems. Disadvantages Of Air Refrigeration : 1. The quantity of  Refrigerant used per ton of refrigeration is high as compared to other systems. 2. The COP of the system is very low. Therefore running cost is high. 3. The danger of frosting at the expander valves is more as the air contains moisture content. 
Post a Comment
Read more

ELECTRICAL COMPARATORS AND ITS WORKING

Electrical Comparators are used as a means of  detecting and amplifying small movements of a work contacting elements. An electrical comparator consists essentially of  a pick-up head or transducer for converting a displacement into a corresponding change in current and a meter or recorder connected in the circuit to indicate the electrical change, calibrated to show in terms of displacement. Generally, an amplifier is needed to provide the requisite sensitivity and to match the characteristics of different parts of  the circuit. Electrical comparators can be classified according to the electrical principle used in the pick-up head. Most of the comparators use either a differential transformer, an inductance bridge, a strain gauge or a capacitor as a means of detecting movement of the gauging element. There are different types of  electrical comparators. One kind called an electrolimit gauge is used to check or measure the outside diameter of a  roll. The objec...
Post a Comment
Read more

SIMPLE CARBURETOR - CONSTRUCTION AND WORKING

CONSTRUCTION OF SIMPLE CARBURETOR :  The main Components of Simple Carburetor are : Float Chamber, float, nozzle, venturi, throttle valve, inlet valve, and metering jet . In the float chamber, a constant level of petrol is maintained by the float and a needle valve.  The float chamber is ventilated to atmosphere.  This is used to maintain atmospheric pressure inside the chamber. The float which is normally a metallic hollow cylinder rises and closes the inlet valve as the fuel level in the float chamber increases to certain level. The mixing chamber contains venturi, nozzle and throttle valve. The venturi tube is fitted with the inlet  manifold. This tube has a narrow opening called venturi. A nozzle is provided just below the centre of this venturi. The nozzle keeps the same level of petrol as that of the level in the float chamber. The mixing chamber has two butterfly valves.  One is to allow air into the mixing chamber known as choke valve. The other is to al...
Post a Comment
Read more