基于电阻应变片的称重传感器设计 本科学位论文

毕业设计说明书基于电阻应变片的称重传感器设计

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2014年 6 月

基于电阻应变片的称重传感器设计

摘要

随着技术的进步,由称重传感器制作的电子衡器已广泛地应用到各行各业,实现了对物料的快速、准确的称量，特别是随着微处理机的出现，工业生产过程自动化程度化的不断提高，称重传感器已成为过程控制中的一种必需的装置。目前，称重传感器几乎运用到了所有的称重领域。

本文设计了一个电阻应变式的称重传感器。电阻应变式称重传感器是基于这样一个原理：弹性体（弹性元件，敏感梁）在外力作用下产生弹性变形，使粘贴在他表面的电阻应变片（转换元件）也随同产生变形，电阻应变片变形后，它的阻值将发生变化（增大或减小），再经相应的测量电路把这一电阻变化转换为电信号（电压或电流），从而完成了将外力变换为电信号的过程。本设计的称重传感器就是利用应变片阻值的变化量来确定弹性元件的微小应变，从而利用力，受力面积及应变之间的关系来确定力的大小，进而求得产生作用力的物体的质量。应变片阻值的变化可以通过后续的处理电路求得。

关键词：称重传感器，弹性体，电阻应变片

Based on the design of resistance strain gauge load cell

Abstract

With the progress of technology, electronic weighing apparatus made by the weighing sensor is widely used in all walks of life, to realize the rapid and accurate for material weighing, especially with the emergence of microprocessor, the constant improvement of the industrial production process automation, weighing sensor has become a necessary device in the process control. At present, apply to almost all weighing weighing sensors.

In this paper, the design of a resistance strain type weighing sensor. Resistance strain type weighing sensor is based on the principle that elastomer (elastic element, sensitive beam) elastic deformation under the action of external force, the resistance strain gauge on the surface of the paste in his (cell) also along with the deformation and deformation resistance strain gauge, its value will change (increase/decrease), and then through the corresponding measurement circuit convert the resistance to electrical signals (voltage or current), so as to complete the process of external force transform into electrical signals. The design of the weighing sensor is the change of resistance strain gauge is used to determine the small strain of elastic element, so as to use force, stress and strain the relationship between the area to determine the size of the force, then the force of the mass of the body. The change of the resistance strain gauge can be obtained through the subsequent processing circuit.

Keywords: Weighing sensors, elastomer, resistance strain gauge

目录

1 绪论 (1)

1.1 课题研究的背景 (1)

1.2 国内外发展动态 (1)

2 传感器的相关知识 (3)

2.1 传感器概念 (3)

2.2 传感器的工作原理 (3)

2.3 传感器的组成结构 (5)

3 电阻应变片的相关知识 (7)

3.1 电阻应变片的结构和工作原理 (7)

3.2 电阻应变效应 (8)

3.2.1 金属材料的电阻应变效应 (8)

3.2.2 电阻—应变特性 (8)

3.2.3 应变片测试原理 (9)

3.3 电阻应变片的种类及材料 (10)

3.3.1 电阻应变片的种类 (10)

3.2.2 电阻应变片的材料 (12)

3.4 金属应变片的主要特性 (13)

4 电阻应变式力传感器的设计 (19)

4.1 柱形应变式力传感器 (19)

4.1.1 利用拉伸与压缩应力的称重传感器 (20)

4.1.2 柱式称重传感器的误差来源 (22)

4.2 梁式力传感器 (23)

5 粘贴技术及稳定处理 (27)

5.1 应变片粘贴技术 (27)

5.1.1 粘结剂的选择 (27)

5.1.2 应变计的粘贴 (27)

5.2 弹性元件材料的稳定处理 (28)

6 电阻应变式传感器的信号处理电路 (31)