CNC PNEUMATIC AUTOFEED PUNCHING MACHINE

CNC PNEUMATIC AUTOFEED PUNCHING MACHINE-Mechanical project

SYNOPSIS
The pneumatic system has gained a large amount of importance in last few decades. This importance is due to its accuracy and cost. This convenience in operating the CNC pneumatic system has made us to design and fabricate this unit as our project.
This unit, as we hope that it can be operated easily with semi skilled operators. The CNC pneumatic auto feed punching machine has an advantage of working in low pressure, that is even a pressure of 6 bar is enough for operating the unit. The pressurized air passing through the tubes to the cylinder, forces the piston out whose power through the linkage is transmitted to the punch. The work piece thus got is for required dimensions and the piece can be collected through the land clearance provided in the die. The die used in this is fixed such that the die of required shape can be used according to the requirement. This enables us to use different type punch dies resulting in a wide range of products. Different types of punch as requirement can be thus got. According to the work material the operating pressure can be varied.

INTRODUCTION
The press is the punching machine tool designed to punch letter by applying mechanical force or pressure with the help of computer. The metal is punched to the desired requirement. The presses are exclusively intended for mass production and they represent the fastest and more efficient way to form a metal into a finished punched product. Press tools are used to form and cut thin metals. Press tools operation can be
simplified to a few simple operations involving a punch a die.
There are Nemours types of presses in engineering field, which are used to fulfill the requirements. We are interested to introduce pneumatic system in presses. The main function of machine is to form or cut thin sheet metals or non metals using pneumatic power. In this project we have used to punching process for simple application.

WORKING OPERATION

The air entering into the input goes out through the two outputs when the computer control signal is actuated. Due to the high air pressure at the bottom of the piston, the air pressure below the piston is more than the pressure above the piston. So these moves the piston rod upwards which move up the effort are, which is pivoted by computer unit. This force acting is passed on to punch which also moves downwards.

The punch is guided by a punch guide who is fixed such that the punch is clearly guided to the die. The materials are in between the punch and die. So as the punch comes down the materials are sheared to the required profile of the punch and the blank is moved downwards through the die clearance. When the piston is at the extreme point of the stock length, the exhaust valve is opened and the air is exhausted through it and the pressurized air come in at the top of the piston and it pushes the piston downwards. So the one side of the air is pulled downwards and the other side is lifted upwards. So the punch is therefore pulled upwards from the die. Now the piston reaches the bottom point of the required stroke length. Now the material is fed and the next stroke of the piston is made ready. When the material is correctly positioned then this machine is again actuated automatically. The time duration of the succeeding punching is adjusted with the help of computer.

ADVANTAGES AND APPLICATIONS
1. The outstanding advantage of pneumatic system is the control valve which consistently applies a specified load with minimum effort.
2. From thin foils to metal sheets can be pierced according to desirable shapes.
3. It can be modified to any extend to bring out the required effort.
4. Its outcome can be utilized properly in the extensive mechanical field.
5. Multiple cylinder systems can be put into action according to the need of pressing effort.
6. In modern payer plants this pneumatic system can be used for loading press roll.
7. Simple construction than the mechanical and hydraulic presses.
8. Compared to hydraulic and mechanical presses pneumatic press is economical.
9. It does not require current carrying cables.
10. No extra skill is required for operating this system.
11. Operation is very smooth and in this system we can get more output by applying less effort.
12. This system can be effectively used for punch mark in industrial materials such as industries name, address or number of product.

LIMITATIONS

1.  Hard and thick materials can not be punched
2.  Maintenance will be more due to the number of moving parts.
3.  Stroke length is fixed.