Tool for measuring shrinkage rate of plastic part

Abstract

The invention relates to a tool for measuring the shrinkage rate of a plastic part. The tool comprises a tool body, a main rolling wheel, an auxiliary rolling wheel, an encoder, a single-chip microcomputer and a displayer, wherein the main rolling wheel is used for making contact with the surface of the plastic part; the auxiliary rolling wheel is used for making contact with the surface of the plastic part and is separated from the main rolling wheel; the encoder and the main rolling wheel are coaxial and are fixedly connected with each other, and the encoder outputs corresponding pulse signals along with rotation of the main rolling wheel; the single-chip microcomputer is arranged on the tool body, connected with the encoder and used for receiving the pulse signals, converting the pulse signals into actual measured sizes and comparing the actual measured sizes with preset theoretical measurement sizes to obtain the shrinkage rate of the plastic part; the displayer is arranged on the tool body and connected with the single-chip microcomputer. The tool has the advantages of improving measuring accuracy, and being light in weight, convenient to carry, free of spatial and regional influences and suitable for being used by various kinds of people in various environments.

Description

technical field [0001] The invention relates to a measuring tool for measuring shrinkage of plastic parts. Background technique [0002] In the automotive industry, exterior parts, especially bumper parts, are very important to give customers the first impression, so the requirements for vehicle matching are very high. In the injection molding process of such plastic parts, the shape and size of the part product will also change due to environmental changes such as temperature and pressure. In order to define this change, the industry defines the size of plastic parts at the molding temperature and the cooling of the mold. The percentage of the difference in size after reaching room temperature is the shrinkage rate of the plastic part, which reflects the degree of size reduction of the plastic part after it is taken out of the mold and cooled. Factors affecting plastic shrinkage include: plastic species, molding conditions, mold structure, etc. Different polymer materials...

AI Technical Summary

Problems solved by technology

[0008] However, the investment cost and post-maintenance cost of CMM measuring instruments are extremely expensive. A CMM equipment is worth more than 1 million, and requires professional operators to operate after strict training; at the same time, because this equipment is fixed, it is limited by the site. Large space impact, requiring a clean room, constant temperature and humidity environment

In addition, because each CMM measuring instrument can only measure the shrinkage degree of one plastic product at a time, and for manufacturers who develop many projects simultaneously, it is necessary to quickly obtain the shrinkage degree of each plastic product under development all the time, so , obviously the production capacity of one CMM measuring instrument is far from enough

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