Automatic tool changer

Last updated

An automatic tool changer (ATC) is used in computerized numerical control (CNC) machine tools to improve the production and tool carrying capacity of the machine. ATCs change tools rapidly, reducing non-productive time. They are generally used to improve the capacity of the machines to work with a number of tools. They are also used to change worn out or broken tools. They are one more step towards complete automation. [1]

Contents

Description

Simple CNC machines work with a single tool. Turrets can work with a large number of tools. But if even more tools are required, then an ATC is needed. The tools are stored in a magazine. This allows the machine to work with a large number of tools without operator intervention.

The main parts of an automatic tool changer are the base, the gripper arm, the tool holder, the support arm, and the tool magazines. [2]

Although the ATC increases the reliability, speed, and accuracy of a machine, it creates more challenges compared to manual tool change. For example, the tooling used must be easy to center, be easy for the changer to grab, and there should be a simple way to provide the tool's self-disengagement. Tools used in ATC are secured in tool holders specially designed for this purpose. [3]

A chain-type automatic tool changer with swiveling arm and two grippers, installed on a mill Chain type changer and arm with two grippers.jpg
A chain-type automatic tool changer with swiveling arm and two grippers, installed on a mill

Types of tool changers

Depending on the shape of the magazine, an ATC can be of two types: 1) Drum Type changers are used when the number of tools is lower than 30. The tools are stored on the periphery of the drum. 2) Chain type changers are used when the number of tools is higher than 30 (The number is different depending on the design and manufacturer. It is important to note that the number of tools for the drum type is fewer than the chain type). But the tool search speed will be lower in this case. [4]

Automatic tool changer mechanism

After receiving the tool change command, the tool to be changed will assume a fixed position known as the "tool change position". The ATC arm comes to this position and picks up the tool. The arm swivels between the machine turret and the magazine. It will have one gripper on each of the two sides. Each gripper can rotate 90°, to deliver tools to the front face of the turret. One will pick up the old tool from the turret and the other will pick up the new tool from the magazine. It then rotates 180° and places the tools into their needed position.

Tool changers on sheet metal working machinery

ATCs were first used on chip-removal machines, such as mills and lathes. Systems for automatic rearrangement of tools have also been used on sheet metal working machinery. Panel benders have an integrated CNC-controlled device that allows punches to be moved according to the size of the part. Automated tool changes on press brakes were limited to machines integrated on a robotic bending cell. Typically a 6-axis robot used for handling sheet metal blanks is also in charge of changing punches and dies between different batches.

Since the 2020s automatic tool changers have appeared on non-robotic press brakes. The most common configuration is a tool rack on the side of the press brakes, with a shuttle picking up tools and positioning them where needed. This reduces physical strain on the operator and increases overall productivity.

An Automatic Tool Changer for press brakes, used to set up, rearrange, and remove punches and dies. Tooling is stored in a motorized tool rack (right) and is placed in the desired position by the shuttle (blue/grey/white on center). Automatic tool changer for press brake.jpg
An Automatic Tool Changer for press brakes, used to set up, rearrange, and remove punches and dies. Tooling is stored in a motorized tool rack (right) and is placed in the desired position by the shuttle (blue/grey/white on center).

Functions of a tool changer

The use of automatic changers increases the productive time and reduces unproductive time. It provides the storage of the tools which are returned automatically to the machine tool after carrying out the required operations, increases the flexibility of the machine tool, makes it easier to change heavy and large tools, and permits the automatic renewal of cutting edges. [5]

See also

Related Research Articles

<span class="mw-page-title-main">Industrial robot</span> Robot used in manufacturing

An industrial robot is a robot system used for manufacturing. Industrial robots are automated, programmable and capable of movement on three or more axes.

<span class="mw-page-title-main">Automation</span> Use of various control systems for operating equipment

Automation describes a wide range of technologies that reduce human intervention in processes, namely by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines. Automation has been achieved by various means including mechanical, hydraulic, pneumatic, electrical, electronic devices, and computers, usually in combination. Complicated systems, such as modern factories, airplanes, and ships typically use combinations of all of these techniques. The benefit of automation includes labor savings, reducing waste, savings in electricity costs, savings in material costs, and improvements to quality, accuracy, and precision.

<span class="mw-page-title-main">Numerical control</span> Computer control of machine tools, lathes and milling machines, also used on 3D printers

Numerical control is the automated control of machining tools by means of a computer. A CNC machine processes a piece of material to meet specifications by following coded programmed instructions and without a manual operator directly controlling the machining operation.

<span class="mw-page-title-main">Cartesian coordinate robot</span> Robot with axes of control that are linear and orthogonal

A Cartesian coordinate robot is an industrial robot whose three principal axes of control are linear and are at right angles to each other. The three sliding joints correspond to moving the wrist up-down, in-out, back-forth. Among other advantages, this mechanical arrangement simplifies the robot control arm solution. It has high reliability and precision when operating in three-dimensional space. As a robot coordinate system, it is also effective for horizontal travel and for stacking bins.

<span class="mw-page-title-main">FANUC</span> Japanese robotics company

FANUC is a Japanese group of companies that provide automation products and services such as robotics and computer numerical control wireless systems. These companies are principally FANUC Corporation of Japan, Fanuc America Corporation of Rochester Hills, Michigan, USA, and FANUC Europe Corporation S.A. of Luxembourg.

<span class="mw-page-title-main">Punch press</span>

A punch press is a type of machine press used to cut holes in material. It can be small and manually operated and hold one simple die set, or be very large, CNC operated, with a multi-station turret and hold a much larger and complex die set.

<span class="mw-page-title-main">Metal lathe</span> Lathe machine

A metal lathe or metalworking lathe is a large class of lathes designed for precisely machining relatively hard materials. They were originally designed to machine metals; however, with the advent of plastics and other materials, and with their inherent versatility, they are used in a wide range of applications, and a broad range of materials. In machining jargon, where the larger context is already understood, they are usually simply called lathes, or else referred to by more-specific subtype names. These rigid machine tools remove material from a rotating workpiece via the movements of various cutting tools, such as tool bits and drill bits.

<span class="mw-page-title-main">Turret lathe</span> Metalworking lathe

The turret lathe is a form of metalworking lathe that is used for repetitive production of duplicate parts, which by the nature of their cutting process are usually interchangeable. It evolved from earlier lathes with the addition of the turret, which is an indexable toolholder that allows multiple cutting operations to be performed, each with a different cutting tool, in easy, rapid succession, with no need for the operator to perform set-up tasks in between or to control the toolpath. The latter is due to the toolpath's being controlled by the machine, either in jig-like fashion, via the mechanical limits placed on it by the turret's slide and stops, or via digitally-directed servomechanisms for computer numerical control lathes.

Lights-out manufacturing is the methodology of fully automating the production of goods at factories and other industrial facilities, such as to require no human presence on-site. Many of these factories are considered to be able to run "with the lights off," but few run exclusively lights-out production. For example, in computer numerical control machining, the presence of human workers is typically required for removing completed parts and setting up tombstones that hold unfinished parts. As the technology necessary for total automation becomes increasingly available, many factories are beginning to use lights-out production between shifts to meet increasing production demand or to save money on labor.

<span class="mw-page-title-main">Robotic arm</span> Type of mechanical arm with similar functions to a human arm

A robotic arm is a type of mechanical arm, usually programmable, with similar functions to a human arm; the arm may be the sum total of the mechanism or may be part of a more complex robot. The links of such a manipulator are connected by joints allowing either rotational motion or translational (linear) displacement. The links of the manipulator can be considered to form a kinematic chain. The terminus of the kinematic chain of the manipulator is called the end effector and it is analogous to the human hand. However, the term "robotic hand" as a synonym of the robotic arm is often proscribed.

<span class="mw-page-title-main">Agricultural robot</span> Robot deployed for agricultural purposes

An agricultural robot is a robot deployed for agricultural purposes. The main area of application of robots in agriculture today is at the harvesting stage. Emerging applications of robots or drones in agriculture include weed control, cloud seeding, planting seeds, harvesting, environmental monitoring and soil analysis. According to Verified Market Research, the agricultural robots market is expected to reach $11.58 billion by 2025.

A vision-guided robot (VGR) system is basically a robot fitted with one or more cameras used as sensors to provide a secondary feedback signal to the robot controller to more accurately move to a variable target position. VGR is rapidly transforming production processes by enabling robots to be highly adaptable and more easily implemented, while dramatically reducing the cost and complexity of fixed tooling previously associated with the design and set up of robotic cells, whether for material handling, automated assembly, agricultural applications, life sciences, and more.

<span class="mw-page-title-main">Fay automatic lathe</span> Machine tool

The Fay automatic lathe was an automatic lathe tailored to cutting workpieces that were mounted on centers. It could also do chucking work. Examples of workpieces included automotive steering knuckles and transmission gears, and such work done on mandrels as flanges, disks, and hubs. The machine tool was developed by F.C. Fay of Philadelphia and improved by Otto A. Schaum. It was originally manufactured by the Fay & Scott Machine Shop. James Hartness acquired manufacturing rights on behalf of the Jones & Lamson Machine Company and manufactured an improved version, developed under the management of Ralph Flanders.

LinuxCNC is a free, open-source Linux software system that implements numerical control capability using general purpose computers to control CNC machines. Designed by various volunteer developers at linuxcnc.org, it is typically bundled as an ISO file with a modified version of 32-bit Ubuntu Linux which provides the required real-time kernel.

<span class="mw-page-title-main">Automatic lathe</span>

In metalworking and woodworking, an automatic lathe is a lathe with an automatically controlled cutting process. Automatic lathes were first developed in the 1870s and were mechanically controlled. From the advent of NC and CNC in the 1950s, the term automatic lathe has generally been used for only mechanically controlled lathes, although some manufacturers market Swiss-type CNC lathes as 'automatic'.

A bar puller is a tool for automatically drawing in material on a CNC lathe. The machined part is cut off and new material has to be fed into the machine.

<span class="mw-page-title-main">Milling (machining)</span> Removal of material from a workpiece using rotating tools

Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece. This may be done by varying direction on one or several axes, cutter head speed, and pressure. Milling covers a wide variety of different operations and machines, on scales from small individual parts to large, heavy-duty gang milling operations. It is one of the most commonly used processes for machining custom parts to precise tolerances.

The history of numerical control (NC) began when the automation of machine tools first incorporated concepts of abstractly programmable logic, and it continues today with the ongoing evolution of computer numerical control (CNC) technology.

<span class="mw-page-title-main">Turret punch</span>


A turret punch or turret press is a type of punch press used for metal forming by punching.

CNC riveting is a CNC process used for obtaining permanent mechanical fastening of geometrical shapes, ranging from simple to complex shapes, such as aircraft fuselages. This is done in a shorter duration of time with a high riveting rate. The process is fast, robust, and is flexible in nature; thus improving its usage and providing reliability to the riveted joint along with the final product quality. CNC riveting can be used for a variety of operations ranging from riveting and fastening belts, skin panels, shear ties, and other internal fuselage components.

References

  1. OBREA, Claudiu Florin; PASCU, Marius; MIHAILA, Lucian; FUNARU, Marian (2012). "Design of an Automatic Tool Changer System for Milling Machining Centers" (PDF). Annals of DAAAM for 2012 & Proceedings of the 23rd International DAAAM Symposium. Vol. 23. DAAAM International. pp. 1139–1142. ISBN   978-3-901509-91-9 . Retrieved 23 March 2015.
  2. scribd. "Automatic tool changer". scribd. Rahul Singh. Retrieved 23 March 2015.
  3. Laboratory for Manufacturing Systems and Automation. "COMPUTER NUMERICAL CONTROL OF MACHINE TOOLS" (PDF). lms.mech.upatras.gr. Laboratory for Manufacturing Systems and Automation. Archived from the original (PDF) on 2 April 2015. Retrieved 23 March 2015.
  4. IGNOU. "Tooling for CNC machines" (PDF). ignou.ac.in. IGNOU. Retrieved 23 March 2015.
  5. NITC. "Tool Management in Advance Manufacturing Systems" (PDF). www.nitc.ac.in. Dept. of M.E. Retrieved 23 March 2015.