| 摘要 |
The invention refers to a method and a device for forming concrete pipes (13) through subjecting concrete (4) in a mould (1) to vibration and pressure. The purpose of the invention is to ensure that the concrete pipe retains the aimed at quality and/ or predetermined length and according to the invention this is done through controlling the vibration frequency to be less during the last part of the mould (1) filling with concrete (4) and to again be greater during formation of a tapered end (14) in the concrete pipe (13). A simple and effective device for carrying out this method is comprised therein by a control tool (16) designed in order to reduce the vibration frequency in a vibrator (3) through reducing the rev count in a drive aggregate (6) for the vibrator (3) when the concrete (4) has reached a certain level under the upper edge of the mould (1) and that another control tool (19) is arranged in order to increase the vibration frequency in the vibrator (3) through increasing the rev count in the driver aggregate (6) when tapering (14) of the concrete pipe (13) occurs.<IMAGE> |
