Pneumatic-free pick & place
Mechatronic handling modules are a successful newcomer to the field of production automation, which score highly compared to conventionally powered components as regards versatility, communication ability, and energy efficiency. SCHUNK is currently expanding its mechatronics program, and is launching an electrical universal gripper, whose features put even the classic SCHUNK PGN-plus flagship product in the shade.
Under the motto "Improving tried and tested", the innovative family-owned company is bringing a new generation of its pneumatic universal grippers to the market, and also applying their performance package to the area of electrical handling. The SCHUNK PGN-plus-E is the world's first digitally controlled mechatronic gripper with patented multi-tooth guidance. Like its pneumatic counterpart, it has modified multi-tooth guidance, in which the support dimensions between the six load-bearing shoulders have been significantly increased, so that increased torques, and thus longer fingers, can be used. In order to ensure a perfect accuracy of fit, each individual base jaw of the PGN-plus-E was carefully manually ground and fitted to its casing individually.
Permanent lubrication through continuous lubrication pockets in the control contour ensures that, for short strokes in particular, lubricant is distributed especially rapidly and evenly. Moreover, the tried and tested diagonal pull kinematics ensure high surface coverage in all stroke positions. The universal gripper is powered by a brushless DC servomotor, and its gripping force can be adjusted between four different levels. Combined, all of these features ensure permanent high process stability and a long life with minimal maintenance costs.
Conversion especially simple
The SCHUNK PGN-plus-E makes the change from pneumatic to electrical components especially simple - for one, the universal 24 V gripper has an identical screw connection pattern to its pneumatic counterpart, and it is also easily controlled via digital I/O. In addition, up to two gripping positions can be monitored via an additional M8 standard connection. The required control and power electronics are already completely integrated into the compact module, so that no space is taken up in the control cabinet. This means that the SCHUNK PGN-plus-E significantly differs from most mechatronic modules on the market, whose control units require a lot of space, and sometimes even additional control cabinets. Neither in-depth mechatronical expertise nor additional programming are required for start-up.
High-speed picker for small components
Ralf Steinmann, Business Unit Manager for Gripping Systems at SCHUNK, believes that this will play a decisive role in the acceptance of mechatronic handling modules: "Components that can be easily integrated into processes, reliably function, which do not require a lot of effort to install them or during the ongoing process, are the key to the mechatronization of handling systems", emphasizes Steinmann. SCHUNK has therefore continuously been expanding its mechatronic program in this area for some years now. For example, with the SCHUNK EGP they succeeded in establishing an electrically powered high-speed picker in addition to the classic MPG-plus gripper for small components. "Users can select the ideal drive from application to application, without having to be change the entire periphery", explains Steinmann. This is aided by the fact that the sensor systems - regardless of the drive - are mostly identical.
Pioneering assembly applications
High-performance assembly in particular recognized the potential of mechatronic handling early. The bigger the range of parts, the higher the number of cycles, and the more gripping processes there are, the greater the benefit that is obtained from the use of mechatronic components. If the module is then highly compatible with mechanical and electrical interfaces, as well as regulator designs, the change is especially simple. For example, the servo-electrically powered pick & place units of the SCHUNK PPU-E series can be controlled using a wide variety of fieldbuses, and are therefore particularly easy to integrate into automated systems.
The fastest high-performance assembly units currently on the market also impress mechanically. They are powered by a wear-free direct drive instead of a tolerance and wear-prone movement transmission system. This minimizes maintenance costs, increases permanent repeatability, and simplifies the programming. Intelligent controllers can control both the cantilever arm as well as the actuators without a higher-level control unit. The software required for this purpose is already integrated. Alternatively, the units can be simply and quickly integrated into automated systems in a process-reliable way using standard controllers from Bosch Rexroth.
Minimum maintenance costs
Highly compatible mechatronic components also confer significant advantages for modular pick & place systems. The SCHUNK ELB linear motor axis, designed for precise and dynamic strokes, can therefore also be controlled via Bosch Rexroth IndraDrive or Siemens Sinamics converters. In addition, the sine-cosine, SSI and Hiperface sensor interfaces available as standard allow all standard controllers on the market to be used. Using the motor controller bus interfaces (such as Profinet IO, EtherNet/IP, EtherCat, Profibus), the module can be quickly and easily integrated into higher-level control systems. The combination of a powerful linear motor drive with a particularly smooth running, pre-loaded junction roller guide, makes the module extremely compact, rigid and dynamic.
Relatively high loads may be positioned with a continuous excellent repeat accuracy of 0.01 mm. The maximum acceleration amounts to 100 ms-2 and the maximum speed 4 ms-1. Since the driving force (maximum 150 N) is transmitted directly and without gears to the slide by the play-free junction roller guide, operators benefit from outstanding precision, extremely short cycle times as well as high productivity and process stability when used in demanding joining and placement processes. In addition, the modules have almost no wearing parts, so that maintenance costs and unplanned downtimes are almost nonexistent and you can count on particularly long service lives. The module can be equipped with an optional incremental stroke measuring system (sine or cosine interface) or with an absolute stroke measuring system (Hiperface or SSI interface).
With an absolute-value transducer, inconvenient reference movements during system start-up and after emergency stops are no longer necessary. In addition, the modules require neither end nor reference sensors, which decrease investment costs, programming effort and the number of cables in the cable set.