Thickness measuring device for thickness measurements of plates in the course of the production of chipboards (pressboards), fibreboards and the like

摘要

The invention relates to a thickness measuring device for thickness measurements of plates in a measurement gap between a probe and a plate support in the production of chipboards, fibreboards and the like, which are supported in the process on a plate support which defines the zero point. The thickness measuring device consists in its basic design of a displacement sensor which is preferably designed as an inductive displacement sensor, and a probe with a tracing roller. The probe with the tracing roller is guided in a holder such that it can move up and down, and operates the displacement sensor. The probe is designed in this arrangement as a two-part probe. It consists of a probe lower part, which is guided in the holder and provided with the tracing roller, and of a probe upper part, which can be adjusted in the holder in order to set a measurement gap with respect to the support. A cylinder/plunger arrangement which is coaxial with the probe is interposed between the probe lower part and probe upper part. Said arrangement has, on the one hand, a lower cylinder chamber with, guided therein, a gas spring plunger which seals the probe lower part, and on the other hand an upper cylinder chamber, which is separated from the lower cylinder chamber and has, guided therein, a compensating and adjusting plunger which seals the probe upper part. The lower cylinder chamber above the gas spring plunger can be pressurised by a pressure medium in order to set the pressure force of the tracing roller. The upper cylinder chamber above the compensating and adjusting plunger can be pressurised by a pressure medium in order to keep open the cylinder chamber, while a portion of the upper cylinder chamber below the compensating and adjusting plunger can be pressurised by a pressure medium for the purpose of adjusting the zero point. The pressure above the compensating and adjusting plunger can be decreased for the purpose of adjusting the zero point or in the case of the adjustment of the zero point. IMAGE