Infeed and centering system EV / EVP
At a glance
The infeed- and centering systems EV / EVP are installed in front of chipper canters. Their main task is the optimum alignment of logs which is particularly complex with logs that, despite their irregular shape, must be supplied to the chipper canter in a correct position. The arrangement and control of the rollers in the infeed- and centering systems allow a feeding of logs with large end first, small end first or mixed orientation with constant volume and accuracy. Various alignment functions and accurate centering guarantee maximum lumber recovery.
The infeed system for primary processing is equipped with two pairs of rollers for rotating the logs into their proper position. Two pairs of centering rollers and a hold-down roller then take and hold the log in position. The optional servo-hydraulic side adjustment of the roller pairs allows the sawing of asymmetrical cutting patterns and the usage of the infeed system in sawlines with merry-go-round system.
The infeed system for secondary processing feeds the two-sided cant centered and aligned to the secondary chipper canter. Alignment of the two-sided cant is done by two pairs of servo-hydraulically positioned centering rollers. Hold-down rollers hold the cant in position on the chain bed. Doors at the infeed systems facilitate the access to the chipper canter for tool change.
The roller units are directly mounted on supports which channel the arising forces directly into the steel support without any influence on the chain bed. The roller pairs can optionally be equipped with servo-hydraulic adjustment which allows the sawing of asymmetrical cutting patterns with primary processing and a diagonal cant alignment with secondary processing.
Decisive for an optimum lumber recovery is the rotating accuracy. The data from a 3D-scanner as well as the cutting pattern are used for determining the rotating angle which is then realised with an accuracy of S = ± 5°. Log rotation also considers negative influences resulting from the growth habit of the log.
Log Motion Control
An accurate log rotation before the first processing step is decisive to achieve high value recovery. With its optimization software, LINCK uses 3D-scanning data to generate a value-optimized cutting pattern and then determines the required angle for log rotation.
With Log Motion Control, LINCK presents a further step in the development of this technology. In addition to determining the log rotation angle, a Microtec Truespin scanner will be used where a camera records a characteristic pattern on the log surface and where the log position is transmitted to the LINCK Log Motion Control during the whole rotating process. The software determines the true log rotating position to be compared with the theoretical one. Any deviations will be compensated by immediately adjusting the position of the rotating rollers.
The log rotation process is therefore under the full control of the LINCK Log Motion Control software.
Split taper or full taper centering, diagonal alignment or active curve sawing can be used for feeding the two-sided cants to the following chipper canter. The sawline software makes the decision for the optimum alignment for each individual log by using the stored parameters. The required gap remains small no matter which alignment type is chosen.