|
|
 |
|
|
In Focus - Archive July 2011
|
| |
|
|
 |
Quick-Change Systems provide more flexibility in manufacturing,handling and assembly
|
|
|
01.07.2011 -
In dealing with industrial robot efficiency cycle rate and process reliabilty largely depend on their front ends, the grippers and other tools, but also from the effectors’ interfaces to the robot arm. Robot accessories have a great influence on the robot’s performance, flexibility and fields of application. Latest developments of quick-change systems, driven tools, compensation units, and power sensors show that the potentials of modern accessory components are enormous. Experts assume that their importance for handling, assembly and manufacturing will continuously increase.
|
 |
|
The SWS-1210 from SCHUNK with three locking systems
|
 |
|
SWS-1210 from SCHUNK
|
 |
|
The SWS-L Heavy Load Change System from SCHUNK
|
|
|
Quick-change systems provide speed in production
Grippers, tools, and other effectors can be quickly exchanged by means of quick-change systems. This reduces machine down-time, and increases the flexibility of the robot. While an experienced operator requires between 10 to 30 minutes for the manual exchange without using a changing system, a quick-change system can reduce the same operation to less than 10 to 30 seconds. The use of a quick-change system makes always sense in areas, where new products or product variants have to be regularly exchanged, where various effectors for handling or machining are required, and where downtimes due to maintenance of components and tools need to be minimized.
Quick-change systems usually consist of two components: a quick-change head, mounted on the robot arm, and a quick-change adapter, which is connected with the tool. During a tool change, both components are automatically or manually coupled, as well as all the electric, pneumatic, and hydraulic feed-throughs. Ideally this is done pneumatically via a self-retaining locking system, and is controlled via integrated sensors. Since alignment of the effectors is already defined by the quick-change system, no time is lost due to re-adjustment.
When selecting a quick-change system, customers and system integrators should pay attention to compact dimensions, a low weight/force-ratio, short change times and exactly dimensioned energy transfer modules. Modular systems are particularly economic, where various electronic and fluid modules can be combined with each other according to the application. Force-free locking and unlocking with a so-called no-touch-locking-system would be ideal, since it also ensures safe locking, if the clearance between head and adapter amounts to several millimeters.
Since industrial robots are becoming more powerful, and weights of several kilograms can be handled, special heavy-load systems are gaining importance. They are suitable for handling heavy workpieces, but also for jobs with heavy grippers, vacuum gripping systems, hydraulically, pneumatically or electrically driven machining spindles, riveting applications, welding tongs, or stud welding applications with automatic materal feeding. Moreover, they can be used in the automotive industry for assembly or for presses. Due to their high payload, they can be used for the set-up of flexible production lines, where light-weight and heavy workpieces are alternately machined.
|
 |
|
Integrated Micro Valves: With the SWS-I from SCHUNK the consumption of compressed air reduced by up to 90%.
|
|
|
Integrated valves are the energy-efficient pace-makers
If the energy-efficiency of a plant needs to be increased, quick-change systems are also playing an important role. Micro valves which are integrated in a quick-change system can replace a complete valve terminal. At every cycle, the piston area of the actuator is filled with compressed air, too, which saves a lot of time. If you are using a three meter long feeding hose with a 4 mm diameter, the integrated valves will reduce the air consumption by 90%. At the same time, the cycle time increases, since the compressed air is directly actuating. Instead of cable and wire bundels, just one pneumatic line for compressed air and power supply is required. Both lines can usually be fed through the center bore with a diameter of 12 mm, and can be integrated in the arm of a SCARA robot.
|
 |
|
The MFT Material Finishing Tool from SCHUNK
|
 |
|
The FDB deburring spindle from SCHUNK is working with up to 65.000 rpm.
|
|
|
Bending tools for grinding, polishing and deburring
Besides handling, robots are also used in defined machining processes, such as drilling or milling. During grinding, polishing, brushing, and deburring however, they usually reached their limits, since it is impossible to replace experience, sense of proportion, and the sure instinct of a human being compared to a robot. There has always been the risk that burr residues are left, or that more material has been removed than required. Moreover, tools quickly wore out, or was broken. Now the robots are trying their luck in this field of application.
Their secret are driven tools, which are axially or radially seated, and are compensating deviations between the robot path and the workpiece contour. In order to machine surfaces of metals and plastics with a robot, the grinding wheels or polishing brushes are clamped in air-driven finishing tools. The slowly running special tools generate a high torque. Since they bend in axial direction, a uniform contact pressure is also given for uneven surfaces. It can be controlled via air pressure and ranges between 14 N and 74 N. The tools are very rigid crosswise to the surface, in machining direction however, they have a defined flexiblility. Tool wear, inaccuracies in workpiece position, as well as slight deviations of the robot arm from the given robot path are compensated. This improves the quality of the machining results, the tool service life of the used tools, and programming time is reduced by up to 75%.
Chamfering spindles follow a similar concept. They try to imitate the manual chamfering operation as accurately as
possible. In contrast to the finishing tools, high frequency spindles work at speeds of up to 65,000 rpm. Their spindle and motor system is flexibly seated on a self-aligning bearing. Several pneumatic pistons assure that the spindles can offset radially or axially up to nine millimeters. Therefore the compressed air motor can move relative to the housing, and deviations between the tool path and the actual workpiece contour are compensated. Even in case of components with an irregular shape, a uniform result can be achieved. The rigidity of the deburring spindle can be controlled via a separate air connection, and clean-cut deburring edges can be assured in every installation position. Depending on the adjusted air pressure, forces between 3.1 N and 42.3 N are acting on the milling cutter’s cut surface, and depending on the material, working speeds of up to 0.3 ms-1 are possible. Since less fixed-points have to be defined during robot path’s programming, the programming time is reduced, if deburring spindles are used.
|
 |
|
The TCU Compensation Unit is using elastomer elements for compensation.
|
|
|
Compensation Units without pneumatics
In order to avoid problems during joining, assembly or insertion, compensation units ensure the necessary compliance between effector and robot arm. They avoid plant malfunctions and damages, and increase process reliability. The youngest generation of this flexible module is working without pneumatics. Compliance in two directions are adjusted via springs with adjustment screws, in three directions via elastomer elements. Since the units are working without pneumatic elements, they are very flat and particularly suitable for the use in confined areas. Smooth running roller guides can compensate smaller compensation forces without stick-slip effects. Spring-actuated return pistons ensure a high repeat accuracy.
|
 |
|
FTNet Force-Torque-Sensor from SCHUNK
|
 |
|
Intelligent sensors such as the FTNet from SCHUNK, measures exactly occuring forces and moments during maching.
|
|
|
Force-Torque-Sensors provides more sensitivity to the robots
There is no doubt that pneumatically and mechanically compensating accessory products can be helpful, and in many cases are perfectly suitable. However, extremely precise result cannot be achieved with them. According to SCHUNK, the competence leader for clamping technology and gripping systems, the future trend goes towards intelligent force-torque sensors, which help to provide the robots with the necessary sensitiveness. Today, they are being used to record the occuring process forces, and to transfer them to the control unit. The robot path can be precisely readjusted, and as a result, consistent forces and machining results are obtained.
For industrial automation, the most versatile force-torque sensor is the FTNet from SCHUNK. It measures the forces and moments in all 6 degrees of freedom. For the first time, a sensor is provided with an interface to the robot control unit, and connection is greatly simplified. The high-precision sensor disposes of a high-speed data output of up to 7.000 Hz. There are four possible communication protocols (Ethernet, Ethernet/IP, DeviceNet and a CAN-Bus Interface), remote control via LAN, and a configuration via web interface and therefore offers a unique interface compatibility for numerous applications. It can be used for product tests, robot assemblies, or machining tasks such as grinding and polishing, but also for robot surgery, applications in the field of rehabilitation, in neurology, and inmany more areas. With this sensor, even difficult assembly, machining, and finish-machining tasks can be automated, which have so far been done manually, or with a complex special machine. With the FTNet even highly dynamic control concepts can be implemented. The sensor is available for payload ranges between 12 N and 40.000 N.
|
World’s largest range of options
SCHUNK the competence leader for clamping technology and gripping systems, is a leading manufacturer of robot accessories all over the world. The company recognized early on the potentials of quick-change systems and compensation units, and developed standardized modular systems. Today the innovative family-owned company offers the world’s largest range of options of quick-change systems. The robot accessory program from SCHUNK comprises changing systems for grippers, rotary feed throughs, compensation units, driven tools and various sensors. The company also offers a long history of experience for customized solutions: Since 1999 SCHUNK has implemented more than 800 customized quick-change systems.
|
|
|
| |
|
| |
|
|
|
| |
|
|
12.2011
Clamping solutions for automated mass production
Efficient manufacturing means automated manufacturing. This particularly applies if large series are machined. This is when the clamping vises, which are the direct interface to the workpiece, playing an important role. In only a few seconds, they have to mount the components, safely and precisely align them, clamp them with-out deformation, and after machining they have to be reliably released. In view of the several million clamping cycles, which have to be carried out by many clamping vises being exposed to chips and coolant, process reliability is one of the decisive factors of success.
 more...
|
| |
|
|
11.2011
Modularity the factor of success
When designing gripping systems for handling and assembly applications, standardized modular systems will play an increasingly important role in the future. They reduce the necessary time for project planning and commissioning, and lower the investment costs. Due to the standardization, they offer optimum preconditions for stable processes. Since modular designed units can be flexibly modified and enlarged, they can be re-configurated for any changes that come up in the future.
more...
|
| |
|
|
10.2011
Producing more efficient
For a number of years, everybody was talking about the energy efficiency issue. Increasing energy costs, a growing environmental awareness, and the political guidance were all triggers for many companies to highlight the energy consumption of machines and components in their communication with the public. Efficiency is much more than simple energy efficiency now, especially when considering the
time- and cost aspects in regards to efficiency. When all these factors have been considered in a holistic way, the full potentials for modern machining and production become visible. The modern clamping devices and gripping systems make it clear how complex the possibilities are.
more...
|
| |
|
|
09.2011
Welding demanding materials crack- and pore-free
Laser welding technology is second-to-none, regardless of whether you are dealing with gears and injection molds or delicate and challenging welding works. When conventional cw lasers and many Nd:YAG-lasers reach their limits, modern process strategies can help to machine demanding welding metallurgies, different types of materials, or micro components process reliably and efficiently. Laser welding is particularly used if components have to be joined at a high welding speed, because slim welding seams, and a low thermal distortion are required. Compared with other welding techniques, the energy during laser welding fully penetrates into the material.
more...
|
| |
|
|
08.2011
More than a "Stopgap":
Intermediate sleeves ensure safe clamping and precision
They appear to be unimposing - but they are located at a decisive interface in the chain of the metal cutting process. Between toolholder and workpiece, the intermediate sleeves influence reliability and precision of the clamping operation. The thin-walled, mostly slotted precision sleeves cover the difference between the clamping diameter of the toolholder, and the workpiece which has to be clamped. Functioning like reduction inserts, they multiply the fields of application of the toolholders or arbors, compensate tolerances, and ensure safe and gentle clamping of gear wheels. The newest sleeve design can do even more. Intermediate sleeves with nozzle effect extend the tool service life and increase the volume machining.
more...
|
| |
|
|
07.2011
Changing, machining, compensating -
current trends in robot accessories
In dealing with industrial robot efficiency cycle rate and process reliabilty largely depend on their front ends, the grippers and other tools, but also from the effectors’ interfaces to the robot arm. Robot accessories have a great influence on the robot’s performance, flexibility and fields of application. Latest developments of quick-change systems, driven tools, compensation units, and power sensors show that the potentials of modern accessory components are enormous. Experts assume that their importance for handling, assembly and manufacturing will continuously increase.
more...
|
| |
|
|
06.2011
Deformation-free clamping:
From the plastic chuck jaw to the hybrid chuck
In case of rings, housings and other workpieces which are highly deformable dur-ing processing, conventional 3-jaw chucks quickly reach their limits. If the clamping forces are too low, there is no secure hold. If they are increased, workpieces de-form, and precision is reduced. A comparison shows the alternatives, the differ-ence between them, and how users can achieve an optimum result.
more...
|
| |
|
|
05.2011
Service robotics is the future key market
Insiders are convinced that golden times lie ahead for service robotics. Around the world companies and institutes have recognized the potential of robots as helpers for humans, and are working on everyday solutions. All different kinds of businesses are interested in service robotics, from large companies, to innovative startups, and also conventional manufacturers of industrial robots, electronic and automation components.
more...
|
| |
|
|
04.2011
Having set-up times under control
You cannot earn money with a turned off machine. However, in many companies the workpieces are still set-up in a complicated and time-consuming way on a grooved table while the plant is turned off. But solutions exist, which optimize the machine tool load. Modern quick-change pallet systems demonstrably accelerate the machining process, and at the same time, ramp up the precision and process reliability score. This leads to a reduction of set-up costs of up to 90%.
more...
|
| |
|
|
03.2011
Toolholders for micro cutting
Clamping tools used for micro cutting have their own rules. The subtle tools, the high spindle speeds, and the extreme precision requirements are a challenge for every tool manufacturer and user. Those who want to achieve continuously precise results, need mountings with a high run-out accuracy and balancing grade. Moreover, they should be as slim as possible and resistant to dirt. Furthermore, they have to assure that even small tools can be precisely adjusted and exchanged.
more...
|
| |
|
|
02.2011
Leight-weight design increases efficiency of Gripping Systems
Light-weight modules are now playing an increasing role in the area of gripping systems. Integrated into the system, they are saving energy at the same efficiency, or achieve a considerably higher efficiency at the indentical energy consumption. In both cases, the efficiency of the whole system is increasing. This is why the lightweights are so interesting for plant manufacturers, system integrators, and users. Since light-weight solutions had the reputation of being overly expensive in the past, recent developments now show that efficiency and cost control can go hand-in-hand. Modern designs, materials and techniques are paving the way to lighter solutions, which are rigid and robust, too. This also offer many more advantages.
more...
|
| |
|
| |
|
|
|
| |
In Focus - 2013
In Focus - Archive 2012
In Focus - Archive 2011
In Focus - Archive 2010
In Focus - Archive 2009
In Focus - Archive 2008
In Focus - Archive 2007
|
|
