Patent DE-102009011362-A1 (DE)
Title: Controlling and regulating a glass feeder having a glass melt container with an outlet opening for discharging glass gobs by an upwardly and downwardly movable piston such as a plunger, comprises determining a periodic distance-time curve
Inventor: HILBERT STEFAN
IPC: C03B7/00
Filed: 2009-03-05
Abstract: The method for controlling and regulating a glass feeder (2) having a glass melt container (21) with an outlet opening (21d) for discharging glass gobs by an upwardly and downwardly movable piston such as a plunger (22), comprises determining a periodic distance-time curve, where the movement of the plunger is controlled according to the periodic distance-time curve with n supporting points P ithat is equal to P i(s, t), where n is >= 3 and the distance coordinate s 1of the first supporting point P 1is equal to the distance coordinate s nof the last supporting point P n. The method for controlling and regulating a glass feeder (2) having a glass melt container (21) with an outlet opening (21d) for discharging glass gobs by an upwardly and downwardly movable piston such as a plunger (22), comprises determining a periodic distance-time curve, where the movement of the plunger is controlled according to the periodic distance-time curve with n supporting points P ithat is equal to P i(s, t), where n is >= 3 and the distance coordinate s 1of the first supporting point P 1is equal to the distance coordinate s nof the last supporting point P n. The plunger is connected with an electric drive motor and optionally a turntable (3) is directly or indirectly arranged in downstream to the glass melt container with glass molds (32) or other processing devices. A shearing device is arranged below the outlet openings of the glass melt container. The determination of the distance-time curve comprises fixing n supporting points, between which the plunger is moved with a constant speed, determining the speed v i+1of the plunger between two adjacent supporting points P iand P i+1, determining the acceleration a iin each of the n supporting points, determining a polynomial of (n-1)th order, which has n supporting points, integrating further m supporting points in the vicinity of the supporting points, in which the acceleration or pitch is higher than a fixed boundary value, where the further m supporting points lie on the polynomial of (n-1)th order, repeating the determination steps and integration step until the acceleration or pitch in each of the supporting points P iis smaller than the fixed boundary value, and changing the n supporting points P iduring the operation of the glass feeder. The speed, acceleration and/or pitch of the plunger are determined by calculations. In the fixing step, the distance-time curve is a distance-time curve formed from a straight line segment, where the supporting points, which are adjacent to a time axis, are connected by a straight line. In the speed determination step, the speed of the plunger between the two adjacent supporting points P iand P i+1is calculated as quotient from the distance s i+1-s iof the supporting points to the distance axis and from the distance t i+1-t iof the supporting points to the time axis. The conversion of the polynomial of (n-1)th order between the integrating and repeating steps in the distance-time curve formed from the straight line segment is provided with n+m supporting points, where two adjacent supporting points are connected by the straight line. In the acceleration determining step, the acceleration in the supporting point P iis calculated as quotient of the difference of the speed between the supporting points P iand P i+1and the speed between the supporting points P iand P i+1and a constant time difference, where the constant time difference is smaller than the least distance of the two adjacent supporting points P iand P i+1to the time axis. The constant time difference is 0.1-2% of the distance of the nth and 1st supporting points. The speed, acceleration and/or pitch of the plunger are determined at the base of measurements. The time-dependent distance of the plunger is continuously measured. The speed and the acceleration are calculated from the time-dependent distance. The acceleration of the plunger is continuously measured by an acceleration sensor. An independent claim is included for a glass feeder.