Automatic Tool Changer

The full form of ATC is automatic tool changer it is used in CNC machines for changing tool automatically which helps to reduce the cycle time. If we think that tool will be changed manually then it will take more time and it is harmful to operator so in modern technology automatic tool changer is used the tools are fitted in the tool magazine as per the required operation the tool which change the tool from tool magazine and change it automatically so tool changing time will be reduced.

Mainly there are two types of ATC are:-

1) Drum Type

2) Chain Type

Drum Type:-

For holding small number of tools usually not more than 30, it is stored on the periphery of drum and tool search speed is faster in this type of ATC.

Chain Type:-

For more number of tools (40 or more), tools search speed will be less in this type of ATC. 

Advantages of ATC:-

1) Lines changed in seconds instead of hours

2) Increase operator safety by changing tool automatically

3) Changes the tool in seconds of time 

4) Increase flexibility

Figure of Automatic Tool Changer is shown below:-

Open loop & Closed loop system

Open loop system

As we know in CNC machine various operations are done the basic process is we give input like raw material then it will do various process on it and finally we will get the output here we will understand about open loop system in open loop system the process is same like Input, process & output in open loop system there is not a feedback device so if the output is ready and if it is accurate or not or any problem came in it we will not be able to know in open loop system because there is no feedback device this is known as open loop system. Figure of open loop system is shown below.

As shown in figure there is no feedback device this is known as open loop control system.

Closed loop system

The main thing in closed loop system is that there is a feedback device so if any problem during operation or in output the feedback device will give feedback to the error signal so we can make changes in it so now we we get the accurate product without any defect this is know as closed loop system. Figure of closed loop system is shown below.

In this figure we can see that there is a feedback device that goes to error signal so we are able to know that some problem is there and we can correct it this is known as closed loop systems.