| 摘要 |
<p>PROBLEM TO BE SOLVED: To avoid the vacuum pressure deterioration influence on a glass plate difficult of vacuum suction by once switching off valve means to stop feeding of the vacuum pressure to a suction part if specified value of the vacuum pressure to this part is not reached. SOLUTION: A controller 4 once switches off an electromagnetic valve 2 to stop feeding of the vacuum pressure to a suction part 1 and shuts off this part 1 from a main pipe line 10 to wait for specified time, if specified value of the vacuum pressure to this part is not reached after specified time lapsed from the start of a sucking operation. As the result, the main line 10 recovers the vacuum pressure, the controller switches on the valve 2 to try the sucking operation, thereby obtaining a higher suction pressure enough to suck and hold a glass plate 20 being forced to warp. Thus it is possible to avoid the vacuum pressure deterioration influence on the glass plate difficult of vacuum suction.</p> |
