Weinig: "Complete Solutions for Machine Builders"
"Eaton automation systems and functional components offer an excellent price/ performance ratio”
Rainer Kurz und Benedikt Schneider
Weining’s semiautomatic "Cube" 4-sided planer produces precise workpieces in just one run. For the automation of the machine, the developers worked in close collaboration with the application engineers at Eaton.
Precise manufacturing, short run times and simple operation, even by untrained personnel – requirements like these also dominate the production plants of the woodworking sector. In order to meet these market requirements for straightening and planing, Weinig developed the "Cube" semiautomatic 4-sided planer that achieves outstanding production results with considerably higher quality in much less time. The developers of the machine, in close collaboration with Eaton, not only used their wide range of functional components but also their software expertise and extensive automation know-how. The semiautomatic machine now planes workpieces in one run with perfect dimensions, right angles and parallel lines and with a paintable surface finish.
The removal of chippings and the dimensions of the workpiece can be set at the push of a button on the touch screen installed directly above the tool support. In Jointing mode or Equalize mode the operator can set first of all whether all four sides are to be planed at right angles to each other, or whether only opposing sides are to be planed in parallel.
The workpiece sawn beforehand to the maximum rough dimensions of 160 by 260 millimeters is then placed against the rear edge jointing fence of the inclined straightening table. In the next step, the required height and width dimensions of the workpiece are set. Either fixed dimensions are entered on the touch screen or the planing rollers are moved to the fixed dimensions with an inching function.
The Moulder Preview System (MPV) projects the selected dimensions automatically with laser beams onto the workpiece; the laser is mechanically linked to the setting spindles of the planer rollers. The projecting of the finished dimensions on the unfinished workpiece optimizes the control of the result before feeding into the machine.
The machine processes the workpiece with four planing shafts simultaneously. The feed through the planing shafts has a considerable effect on the surface quality and can be changed by the operator at any time via the touch screen.
On machine startup, the first task of the controller is to check via the sensor data whether all safety conditions are fulfilled. A check is also made whether the protective guard is locked, whether the emergency-stop pushbutton actuator is functioning correctly and whether the safety lasers and mirrors are in the correct position. It must also ensure that there are no workpieces orforeign bodies in the machine and that the required system air pressure is present. If the planer is then switched on with the hardware start button, the first three spindle drives start up first of all and then the feed for the workpiece.
The "Wood ready" sensor registers the insertion of the workpiece and activates the safety laser at the outfeed opening and the mirrors at the infeed opening. The first feeding arm detects the inserted workpiece and transports it through the processing area of the four planing shafts, where it is transported further by the second feeding arm up to the outfeed opening. The machine is equipped with three LS-Titan safety position switches from Eaton. The first, opposite the left planing shaft prevents the feeding in of another workpiece whilst the previous one has not yet been finished. The second is installed behind the right-hand planer roller and third at the outfeed opening. Only after the end of the workpiece has passed the outfeed can the operator insert the next one.
The development and optimization of the automation concept, as well as the programming and commissioning, was carried out with close collaboration between the specialists at Weinig and the Automation Support and After Sales Service at Eaton. The XV-102 color 5.7" touch panel with its powerful 400 MHz Risc processor can even handle demanding PLC applications. It has a 128 MB onboard memory. It is connected via an RS485 interface with the four spindle positioning units, with which it exchanges positioning values, axis states etc. It also communicates via CANopen with the easy822 control relay which is connected via easyLink to an easy620. All sensor values are read in via digital inputs and processed by the HMI/PLC for controlling the individual actuators. easy822 also controls the feeding speed and defines the setpoint of the pulse width modulation, while easy620 switches the spindles and the feed on and off.
The controller processes the data of several sensors and actuators, including the four measuring lasers, mirror adjusting drives, parts recognition, four feed mechanisms, four planing shafts and the safety laser at the workpiece outfeed. PKZ high-performance compact starters and DILM contactors, FAZ miniature circuit-breakers and LS-Titan safety position switches are used in the application. With their with positively opening function to IEC/EN 60947 these are also approved for safety-related tasks. The developers based the safety engineering on Performance Level C in accordance with the EN ISO 13 849-1 standard, permitting a rate of one per 333,000 hours. The machine therefore meets the requirements of exceptionally high safety standards. Safety-related operating functions such as the manual on/off switching of the machine are implemented in compliance with the standards using RMQ-Titan pilot devices.
The example of Cube shows that Eaton is a competent partner for the development of customized solutions – from the concept design to component selection and programming, right through to commissioning and worldwide after-sales service. Rainer Kurz and Benedikt Schneider, wood technicians at Weinig, emphasize the fact that Eaton automation systems and functional components offer an excellent price/performance ratio. They also stress the competent support received in the selection of the most suitable products and the project implementation.