Industrial Engineering Knowledge Center: Machine Tools - Industrial Engineering and Productivity Aspects

Friday, July 26, 2024

Machine Tools - Industrial Engineering and Productivity Aspects - Facilities Industrial Engineering

Lesson 51 of Industrial Engineering ONLINE Course.

Machine is an important variable in productivity improvement effort. At the time of facilities planning or capacity planning the most productivity machine has to be identified and acquired. The process plan for a job has to utilize the full potential of the machine. OEE calculation needs to be modified to accounting for the utilization of maximum potential of the machine. As the machine is in operation, it has to be studied to identify further improvement opportunities related to the machine that prevent wastes and improve productivity. Industrial engineers have to know the machines under their responsibility for productivity improvement and process improvement thoroughly. Selection of machine tools, replacement of machine tools, and improvement of machine tools comes under facilities industrial engineering task.

Industrial engineers have to monitor the developments in machine tools and accessories to identify machines and accessories that can increase productivity in the processes of their organization.

Classification of Machine Tools

1. General purpose machine tools.
2. Production machine tools
3. Special purpose machine tools
4. Single purpose machine tools

In the number 1 type, the machine tool can do many different machining operations, but rate of production is less.

In the number 4 type, only single machining operation is possible, but rate of production is quiet high, as all accessories are specially designed to minimize handling time of workpieces and tools.

Industrial engineers have to know the possibilities of employing special purpose machines that can give very low cost of production. Industrial engineers have one focus, productivity improvement or cost reduction and one major limitation or constraint that is not to deteriorate effectiveness of design, both product and process. They are free to explore all engineering alternatives for technical feasibility and select the one based first on economic analysis and then the agreement among stakeholders. Multicriteria decision making can be employed whenever there are disagreements among large number of stakeholders.

https://books.google.co.in/books?id=9rNldaV3FwcC&pg=RA1-SA3-PA1#v=onepage&q&f=false

https://books.google.co.in/books?id=3sS5a4jqzS8C&pg=PA73#v=onepage&q&f=false

2009, P.N. Rao, Professor, University of Northern Iowa.

New Machine Tools - Some Illustrations

2024

SMV -1050 High-Performance Vertical Machining Center

FEELER友嘉實業 YouTube Channel

27 May 2024

The SMV-1050 vertical machining center, known for its high flexibility, precision, performance, and productivity.

Target markets include general (automotive) parts, precision molds, and high-efficiency components.

https://www.youtube.com/watch?v=uDOGMXVauUc

2022

Machine Tool 4.0

Machine Tool 4.0 is a recent research topic in machine tools and also various companies are coming out with machine tools with various smart features.

IJaw - Intelligent clamping

https://www.pressebox.de/pressemitteilung/coretigo/Roehm-CoreTigo-Exhibit-Smart-Machine-Tooling-for-IT-OT-Convergence-at-May-2022-Events/boxid/1113590

Machine Tool 4.0 in the Era of Digital Manufacturing

September 2020

Conference: The 32nd European Modeling & Simulation Symposium

Authors: Dimitris Mourtzism University of Patras Lab. For Manufacturing Systems and Automation (LMS)

https://www.researchgate.net/publication/347077906_Machine_Tool_40_in_the_Era_of_Digital_Manufacturing

Machine Tool Transition from Industry 3.0 to 4.0. MDPI

by S Ilari · 2021 · — With a smart retrofitting process it is possible to extend the service life of machinery, avoiding wasting material and money on new machines

https://www.mdpi.com/2071-1050/13/18/10441/pdf?version=1632362738

2021

TNC 640 contouring control

The smart solution for demanding requirements

24 control loops (22 with functional safety), including up to 4 spindles

Version with multi-touch screen

Milling, turning, and grinding operations

User-friendly programming in HEIDENHAIN Klartext or with G codes

Extensive machining and touch-probe cycle packages

Fast block processing time (0.5 ms)

High-end performance for perfect surfaces and exceptional accuracy

Dynamic collision monitoring for greater safety and reliability

Complete machining

The TNC 640 features an extensive package of cycles for milling, drilling, boring, grinding, and turning operations. It also provides special cycles for complex applications such as interpolation turning and hobbing. All of this functionality can be programmed with Klartext functions and cycles.

Optimal machining

The OCM option optimizes roughing processes, using special trochoidal milling cycles to machine any contour with high efficiency. Productivity is significantly increased, while tool wear is considerably reduced. The optimal cutting data are determined by an integrated cutting-data calculator.

Exceptional availability

Dynamic Collision Monitoring (DCM) monitors the work envelope during all operating modes and stops traversing movements before a pending collision. DCM therefore allows optimal use of the machine envelope, preventing machine damage and costly downtime.

Efficient workstation

Extended Workspace seamlessly brings PCs and external applications to the control's screen. The comfort version adds an additional display to the work area, while the compact version offers an extra application window inside the 24-inch widescreen.

Dynamic Efficiency

The Dynamic Efficiency package of functions is well matched to the requirements of roughing operations. Various functions offer enormous potential for optimizing process reliability, machining time, and idle time, making production more effective, stable, and predictable.

Dynamic Precision

Dynamic Precision includes multiple functions that improve the contouring accuracy of machine tools, even during high feed rates and complex movements. Precise parts can be efficiently manufactured in short machining times without manual rework.

https://www.heidenhain.com/products/cnc-controls/tnc-640

2020
HYPERTURN 65 Powermill – For Increased Productivity in Complex Complete Machining
February, 2020
https://www.cnctimes.com/editorial/hyperturn-65-powermill-for-increased-productivity-in-complex-complete-machining

2019

Mazak to Spotlight High-productivity Machine Tool Technology at CMTS 2019
8/2/2019

FLORENCE, Ky., – For machine shops looking to boost productivity as well as profitability, Mazak will demonstrate several high-capability machining systems at the Canadian Manufacturing Technology Show (CMTS) from September 30-October 3 in booth #2560. These advanced systems – under full power and processing real-world parts – will include the VTC-300C Vertical Traveling Column machine, HCR-5000S Horizontal Machining Center, QUICK TURN 250MSY and INTEGREX i-100 BARTAC-S Multi-Tasking Machines, and VC-500A/5X Vertical Machining Center.

Mazak VTC-300C

For effective production of extremely long and heavy workpieces or of multiple smaller parts at one time, the Mazak VTC-300C features a full traveling-column design and fixed table along with a powerful 40 taper, 15,000 rpm spindle. An optional table center partition transforms the machine work envelope into two separate areas so the machine can be in cycle in one work area during part setup in the other. At CMTS, the Kentucky-built VTC-300C will be machining a flange/coupling part and large mold component.

Mazak HCR-5000S

As a 5-axis, single-table (S) machine processing an aluminum satellite component during CMTS, the Mazak HCR-5000S features a 40-tool Auto Tool Changer that is expandable to a 160-tool capacity. Mazak also offers the machine in a range of high-speed spindle options, from a standard 12,000 rpm spindle up to 30,000 rpm one, and each features an integral spindle/motor and ballscrew core cooling that minimizes vibrations for higher accuracy. Linear roller guides allow the HCR-5000S to achieve 60 m/min rapid traverse rates as well as 1G acceleration/deceleration rates in the X and Y axes and 0.8G in its Z axis to significantly shorten overall machining cycle times.

Mazak’s QUICK TURN 250MSY

Mazak’s QUICK TURN 250MSY will show its Multi-Tasking productivity prowess by machining a sophisticated shaft component during CMTS. The machine sports several productivity-enhancing features that include a direct-drive turret design, high-torque main spindle, a powerful milling spindle and Mazak’s MAZATROL SmoothG CNC control. The Kentucky-built machine has two turning spindles, a rotary tool milling spindle and Y-axis capabilities for single-setup DONE IN ONE precision part-processing operations. The machine’s 12-position, direct-drive turret eliminates the use of belts for improved part surface finishes and reduced maintenance. It accepts both VDI and bolt-on tooling.

Mazak’s INTEGREX i-100 BARTAC-S

In addition to the QUICK TURN model, Mazak’s INTEGREX i-100 BARTAC-S will highlight the Multi-Tasking capabilities that make it possible to process complete powertrain part sets at CMTS. The demonstration will underscore all the features of the machine, including 5-axis milling, heavy rough milling, turning, threading, hobbing and more. When processing small high-precision parts in single setups as well as machining bar material up to 4" in diameter, the machine offers even higher levels of productivity with its two turning spindles and milling spindle for DONE IN ONE operation.

Through its Intelligent Bar Loader System, the INTEGREX i-100 BARTAC-S brings advanced tactics to bar workpiece machining. The system automatically feeds out the material the required distance from the machine’s chuck and minimizes the bar remnant. An optional chuck-pressure management system automatically changes by part program for a wide variety of workpieces. It maintains not only the set chuck pressure per workpiece, but also the same pressure when changing material.

VC-500A/5X

For its Kentucky-built VC-500A/5X, Mazak will showcase the machine cutting a 5-axis mold component in Mastercam reseller In-House Solutions' booth, #2536. With a trunnion-style rotary/tilt table, the machine allows for the accurate, cost-effective processing of small complex parts via full 5-axis machining and features the MAZATROL SmoothX CNC that allows for easier programming and faster part cycle times, in either EIA/ISO or MAZATROL conversational language.

https://www.mazakusa.com/news-events/press-releases/mazak-to-spotlight-high-productivity-machine-tool-technology-at-cmts-2019/

Labour Productivity Improvement in an Automobile Component Manufacturer Machine Shop using Lean Tools

by A.Pradeep, A.Manimaran, P.Arunkumar, K.Balaji
The paper discusses replacement of existing one-axis machines with new 3-axis machines.
International Journal of Innovative Technology and Exploring Engineering (IJITEE)
ISSN: 2278-3075, Volume-8 Issue-11, September 2019

PRODUCTION MACHINE TOOLS

Most parts have a number of machined features and require processing on a series of machine tools. For parts required in high volumes, a number of specially designed machine tools may be grouped to work on jobs held on a common work table. As an alternative automated materials handling can be employed to transfer the work piece from machine to machine. Such machine tool groups or systems featuring automated part transfer between stations are called transfer machines.

There are two basic classes of such machines: rotary transfer machines and in-line or conventional transfer machines. In rotary transfer machine is the rotary indexing system, in which parts are mounted on a horizontal table or dial and transferred by rotation through various machining stations arranged around the table. The stations doing same operation repeatedly are often numerically controlled. In a dial system, rotations are of a standard length. Dial systems provide two access The European rotary type provides three access planes. A prism system composed of fixtures that advance in a horizontal plane between workstations. Prism systems allow the rotation of individual pallets so that parts can be machined on multiple surfaces.

Center column systems have rotary indexing system but have machining stations mounted on a central column. They have a small footprint and can accommodate more operations than conventional rotary indexing systems as additional spindles or slides can be mounted around the periphery. In this configuration, they provide three access planes. Generally, rotary indexing systems are used for small or light parts, while center column machines are favored for heavy parts.

Conventional or in-line transfer machines are designed to produce a single part in large volumes (e.g., >25,000/year). The investment cost per part is relatively low, even though initial investment is high. They utilize automated part transfer system. There are three conventional types of part transfer: sliding transfer, palletized transfer, and walking-beam or lift-and-carry transfer. The dimensions and utility connections of components of transfer machines have been standardized in both the United States and Europe so that machines can, in principle, be assembled modularly from basic components.

Conventional transfer machines are well suited for manufacturing products with long market cycle lives (greater than 5 years). To operate economically, transfer machines require accurate preplanning of the product design. A major disadvantage of conventional transfer machines is that they are serial systems, and thus do not run when any of the stations need repair or a tool change. Due to this limitation, many systems are often operating roughly 60% of the time. One strategy to improve machine utilization is to break large systems up into smaller subsystems with intermediate parts buffers, but this increases in-process inventory.

In recent years, a number of technologies have been applied to in-line automated production systems to improve flexibility. A convertible transfer line is designed to accept a defined range or family of parts (e.g., iron and aluminum versions of an engine block, or six and eight cylinder versions of an engine head). Convertible systems can typically be switched over from one part to another in a few days. A convertible system requires additional initial investment and accurate preplanning. It is especially desirable to use a common locating scheme for all parts to minimize fixture rework and to standardize hole diameters so that common tooling can be used.

A flexible transfer line (FTL) is capable of producing a family of similar parts with unplanned changes or additional machined content. There has to demand for this flexible system to fully utilize the system for 10–15 years. Such systems allow new products of the same family to be introduced quickly without major retooling. The changeover time between different products is usually a few hours, depending on the number of workstations involved and the available flexibility. Flexible transfer lines require a significant initial investment premium compared to conventional transfer machines and still require accurate part planning. Currently, flexibility is commonly accomplished by using machining stations with indexable heads (turrets) or shuttle heads, each fitted with a number of different tools. CNC machines have also been used in FTLs. Product design is much more critical for FTLs than for conventional lines. Part features should be grouped and commonized so that a large number of features can be machined with single spindles. This means, for example, that the holes in the part should all have the same diameter so that they can be drilled using the same tool to reduce the number of tool changes. Other methods for increasing the production rate of an FTL include the use of multiple independent spindles for machining to minimize machining time or the use of multiple spindles with multiple part loading (e.g., twin spindles with dual part loading).

Automatic lathes, such as screw machines, bar chuckers, drum- and Swiss-style automatics, and vertical turret lathes comprise another class of production machine tools still encountered in older operations. These machines, have been replaced in many recent applications by the CNC turning centers. CNC Swiss machines are still widely used in the manufacturing of small parts.

CNC Machine Tools

Machining Centers

Machining centres are designed to work with a pallet transfer systems, for the rapid handling of parts between machines and stations.

CNC turning centers perform turning, boring, facing, threading, profiling, and cutoff operations. CNC machining centers are used primarily for milling, boring, drilling, and tapping.

In most CNC turning centers, tools are held in a turret, which rotates to bring a specific tool to bear. The turret is commonly mounted on a slant bed slide, which sheds chips into the bottom of the machine.

All CNC turning centers have a headstock with spindle, and most have a tailstock. Turning centers usually used quick-change modular tooling. In addition to standard CNC turning centers, there are a number of advanced types with additional capabilities.

CNC automatics are similar to turning centers but include more axes, rotating tooling (live tooling), and multiple slides and spindles. These machines are also called multifunctional machines or mill-turn machines when they are equipped with live spindles in the turret. On CNC automatics, a job can be divided into segments so that many tools can work on different areas of a workpiece simultaneously. Cycle times can thus be shorter than on CNC lathes, and idle time for part setup and handling is often reduced. They are especially useful for finishing smaller parts with limited machined content in a single setup. However, they often cannot be used to produce highly precise parts because they generally do not have fine controller resolution.

Machining centers are usually classified by spindle orientation (vertical or horizontal) and the number of axes controlled. On a vertical spindle machine, the workpiece is mounted on a horizontal bed;

on a horizontal spindle machine, the workpiece is usually mounted on a vertical fixture or table. Vertical machines are preferred for large workpieces, flat parts, and especially for contoured surfaces in dies so that the thrust force is absorbed directly by the bed of the machine.

Vertical gantry or bridge-type milling machines are used for very large workpieces because their

two-column design gives greater stability to the cutting spindle(s).

Horizontally configured machines are more versatile because four sides of the workpiece can be machined without re-fixturing if a rotary indexing worktable is available. Horizontals are finding increasing use in surface machining, since they provide increased access on larger complex parts and have less restriction on vertical height of the workpiece. Horizontal machines are preferred for untended use since they allow for easy chip and coolant evacuation. Horizontal machines are often preferred in high-volume applications for increased ease and safety of maintenance. Horizontal machines are also often preferred for dry or minimum quantity lubrication (MQL) applications since they can be adapted to eliminate chip accumulations in the work zone more easily. Universal machines have heads that rotate to act as a horizontal or a vertical machine. The combination of tilts and swivels available in the spindles and tables allows the workpieces to be addressed at various compound angles.

Common nomenclature for axes and rotations. The primary axis directions on the machine are designated by the Cartesian coordinates X, Y, and Z. The corresponding rotary axes are A, B, and C. Secondary linear axes aligned to X, Y, and Z, often on a table, are called U, V, and W or X′, Y′, and Z′.

The Z-axis is commonly aligned with the spindle, whether the spindle is horizontal or vertical. On a horizontal machine, the Z-axis may correspond to motion of a spindle carried in a column, and the W-axis may refer to motion of a table toward a stationary spindle or the extension of a quill from a stationary spindle.

Conventional three-axis machines most commonly have a vertical spindle and three linear axes (X, Y, Z) but may have two linear and one rotational axis. Horizontal spindle three-axis machines are sometimes used for drilling, milling, and tapping large workpieces.

Four-axis machines typically have three linear axes and a rotational axis on the work table. Horizontal spindle machines often have a B-axis table. Horizontal spindle four-axis machines with A-axis tables or trunnions are used in dry and MQL machining applications since they permit the part to be machined upside down to clear chips by gravity . Vertical spindle four-axis machines commonly have an A-axis trunnion.

Five-axis machining centers are used for contour surface machining on components such as molds, dies, and airfoils and for positioning on workpieces requiring machining on multiple sides or at compound angles. Five-axis machining is essential for the first class of applications and often provides reduced cycle times and increased accuracy for the second. Five-axis machines have three linear and two rotational axes, with rotations being performed by a table, the spindle, or both. They are often built up by adding rotary axes to three-axes horizontal or vertical machines. Common configurations include a B-axis table mounted on an A-axis trunnion (B over A), and a C-axis table mounted on a B-axis table (C over B). These configurations are well suited to machining smaller parts, and the choice of a particular configuration depends on the workpiece dimensions and orientation, the required axis motions, fixturing, and the available base machine tools. Axes may also be added to the spindle, using a fork and swivel mechanism or a nutating head. This approach is common on large machines, since it is often not practical to precisely rotate large workpieces.

Hybrid machining centers combine the functions of turning centers and conventional machining

centers, providing the ability to complete all machining operations for many classes of parts in a

single setup. This type of machine can perform turning, milling, drilling, contouring with the C-axis, off-center machining with the Y-axis, milling of angled surfaces with the B-axis, grinding, and other operations.

Such machines may be called multitasking turning centers because in addition to the traditional X- and Z-axes, they incorporate the Y-axis and rotary C- and B-axis for tilting the turret.

These machines can reduce cycle/lead times and work-in-process inventory, save up setup and queue time, and potentially improve part quality by eliminating refixturings.

The capabilities of machining centers are characterized by maximum spindle RPM, power, and torque versus speed curves, spindle size, and toolholder adaption, axis drive motor power, rapid feed rate, fastest cutting feed rate, structural properties (stiffness, damping, etc.), workspace size, and support for networking.

https://www.mmsonline.com/zones/machining-centers

Special Purpose Machine Tools

SPM is designed specifically for exact requirement of component to be processed or machined. SPM tools are designed to perform special machining operations, usually for production purposes. Examples include gear-cutting and gear-grinding machines, broaching machines, lapping and honing machines, and boring machines.

Generally there are two layouts for SPMs;  Single-station  Multi-station. In single station the workpiece is held in a fixed position where machining and sliding units are positioned around it such that they can process the part from different directions. In the case of multiple machining units they may process the part simultaneously or in sequence depending on the geometry of the workpiece and machining features.

Different layouts for SPMs; (a) Single-station, (b) Special application, (c) Transfer machine, (d) rotary machine, and (e) In-line operation machine.

Special purpose machines are in demand because they do the job they are created for more efficiently when compared against mass produced machines available in the market. This efficiency can be measured in two ways.

1. The first is to save money. Leads to a considerably less amount of units of cost of production.

2. The second reason is the aspect of time

An engineer job in the special purpose machinery industry would be to optimize a process as much as is logically possible with the help of the machine.

Various types of SPM - Examples:  SPM for metal cutting.  Special purpose CNC machine.  SPM for vertical turning machine.  Rotary Indexing Drilling & Tapping SPM.  SPMs for multi and simultaneous operations such as Drilling, Milling, Boring etc.

Special purpose CNC machine:  Machining Process  Component Handling & Holding System  Particular Fixture For Particular Component Holding  Component's Measuring

SPM for vertical turning machine: SPM for vertical turning machine are designed in three configurations to suit specific requirement-  VT- turning machines  VM- multi tasking turn-mill machines  VU- 5-axis universal turn-mill machines

SPM for vertical turning machine.

Advantages:  Increase in productivity.  Less machining time  Less complicated operation.  Effective in mass production.

Limitations:  High initial investment.  Less flexible.

High speed Machines and Special Purpose Machines
https://www.slideshare.net/gauravshukla3511041/high-speed-machines-and-special-purpose-machines

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Flexible Manufacturing System- Introduction

https://nraoiekc.blogspot.com/2019/06/flexible-manufacturing-system.html

Flexible Manufacturing System (FMS) - Books, Course Pages - Bibliography

https://nraoiekc.blogspot.com/2020/08/flexible-manufacturing-system-fms-books.html

Digital Twins of Machine Tools

https://nraoiekc.blogspot.com/2020/12/digital-twins-of-machine-tools.html

Digital Twins of CNC Machines - Bibliography