Method and device for measuring thickness of slab of medium density fiberboard

Abstract

The invention relates to a method and device for measuring the thickness of a slab of a medium density fiberboard. An incremental rotary encoder is arranged on an encoder bracket with an adjustable height. An oscillating bar is fixed on a rotor shaft of the rotary encoder. A roller is arranged at the other end of the oscillating bar; the oscillating bar has the length of R. An initial position of the oscillating bar is regulated to a vertical state by regulating the height of the encoder bracket; the lowermost point of the roller is just in contact with the surface of a conveyor belt; an angular displacement output by the rotary encoder in the state is set to be zero; when the roller is pushed by the slab to drive the oscillating bar to swing by an angle alpha, the rotor shaft of the rotary encoder rotates along with the oscillating bar, an angular displacement pulse signal is output, is acquired by a data acquisition card, is input into a computer and is processed by data processing software, and the thickness H of the slab is calculated by utilizing the formula H=R(1-cos alpha); and the thickness value of the slab is displayed and output in real time. The device has the advantages of high measurement accuracy and low cost and is convenient to use.

Description

technical field [0001] The invention belongs to the technical field of object thickness measurement, and relates to a method and a device for measuring the thickness of a plate, in particular to a method and a device for measuring the thickness of a medium-density fiberboard slab. Background technique [0002] Medium density fiberboard is a kind of raw material processed by using small diameter wood, branch wood and wood processing residues through chipping, hot grinding, sizing, drying, forming, pre-pressing, hot pressing, trimming, sanding and other processes. Plates have a wide range of uses. The forming process is to pave the fibers after sizing and drying into a continuous slab belt with a certain width and thickness by mechanical or air-flow forming method. The formed slab is very fluffy, thick and low density, which affects transportation and slabs. The billet enters the hot press. Therefore, it is necessary to pre-press the slab before hot pressing, increase the de...

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Problems solved by technology

[0009] For the contact measurement method using a linear displacement sensor, the linear displacement sensor is installed perpendicular to the surface of the measured plate, and the displacement of the measuring rod is equal to the thickness of the plate, so the thickness of the plate can be directly measured. Since the measuring rod needs to be in contact with the measured plate, The plate to be tested is required to have greater hardness and a smoother surface. In the early days, it was mainly used to measure the thickness of the finished plate. It is difficult to measure the thickness of the relatively soft and thick slab. It is still in the experimental research stage. , has not been practically applied

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