摘 要

近年来随着国家经济的不断发展，汽车工业也不段发展，节能、环保、安全、轻量化将成为未来汽车的主要发展方向。植物纤维复合材料与传统相比，具有刚性打、强度高、质量轻等特点。其有效引领着世界汽车逐步趋向轻量化和低成本化，是未来汽车制造业发展的必然趋势。也正是因为汽车轻量化的趋势使得汽车饰品中运用大量的薄壳类注塑制件，然而薄壳类注塑制件也有一些缺点，其中主要缺陷就是翘曲变形，严重情况下会使产品尺寸产生偏差，影响产品装配质量。因此需要采用改进的浇注系统和优化的工艺参数，来降低汽车门内饰板的翘曲变形程度。本文通过moldflow软件对汽车门内饰板进行翘曲分析，并通过优化工艺参数来减少翘曲变形程度以及优化熔接痕的位置分布。

现有大部分植物纤维复合材料汽车制品均为压制成型产品。汽车内饰产品造型结构复杂，采用压制工艺难以实现，一般塑料内饰产品均采用注塑成型工艺制备而成。植物纤维复合材料由于植物纤维的加入，其热、力、流动性能均与普通塑料存在较大差别，导致模具设计与工艺存在差异。因而，本文针对具体植物纤维复合材料内饰产品，采用CAE分析方法研究工艺参数、模具结构等对产品的注塑成型性能的影响。

关键词：植物纤维复合材料、汽车门内饰板、注塑成型、翘曲

Abstract

In recent years, with the continuous development of the national economy, the automobile industry has also developed, and energy saving, environmental protection, safety, and light weight will become the main development direction of the automobile in the future. Compared with traditional, plant fiber composite material has the characteristics of rigidity, high strength and light weight. It effectively leads the world's autos to gradually become lighter and lower cost, which is an inevitable trend for the future development of the automotive manufacturing industry. It is precisely because of the trend of lightweight vehicles that a large number of thin shell injection molded parts are used in automotive accessories. However, thin shell injection molded parts also have some shortcomings. The main defect is warpage, which will cause product size in severe cases Deviations affect product assembly quality. Therefore, it is necessary to adopt an improved pouring system and optimized process parameters to reduce the degree of warpage of interior trim panels of automobile doors. In this paper, the mold flow software is used to analyze the warpage of the interior door panel of the car, and the process parameters are optimized to reduce the degree of warpage and optimize the position distribution of the weld line.

Most of the existing plant fiber composite automotive products are press-formed products. The shape structure of automobile interior products is complicated, which is difficult to achieve by the pressing process. The general plastic interior products are prepared by injection molding. The plant fiber composite material has a large difference in heat, force and flow performance from ordinary plastics due to the addition of plant fibers, resulting in differences in mold design and process. Therefore, for the specific plant fiber composite interior products, this article uses the CAE analysis method to study the impact of process parameters, mold structure, etc. on the injection molding performance of the product.

Keyword：Plant fiber composite materials、automotive door interior panels、injection molding、warpage

Contents

Abstract in Chinese I

Abstract II

Chapter 1 Introduction 1

1.1 Subject research background and significance 1

1.2 Development status of plant fiber composite automotive interior parts 1

1.2.1 Development status of foreign automobile fiber composite interior trim parts 1

1.2.2 Development status of domestic plant fiber composite automotive interior parts..........................................................................................................................................2

1.3 The main content of the research 2

Chapter 2 Design and manufacture of interior trim panels for car doors 3

2.1 Structure of automobile door interior panel and common materials 3

2.2 The molding process of automobile door interior trim 3

2.2.1 Filling stage of injection molding process..............................................................4

2.2.2 Pressure holding stage of injection molding process..............................................4

2.2.3 Cooling stage of injection molding process............................................................5

2.2.4 Demoulding stage of injection molding process.....................................................6

Chapter 3 Plant Fiber Composite Materials 7

3.1 Characteristics of plant fiber composite materials 7

3.2 Classification of plant fiber composite materials 7

3.3 Application of plant fiber composite materials in the automotive industry..................8

Chapter 4 Numerical Simulation Analysis of Injection Molding of Automobile Door Interior Panel 9

4.1 Introduction to Autodesk Moldflow Software 9

4.2 Autodesk Moldflow basic flow of mold flow analysis 10

4.3Confirmation of Molding Simulation Scheme for Automotive Door Interior Panels Based on Moldflow............................................................................................................ ...11

4.3.1 Establishment of finite element model1...............................................................12

4.3.2 Preliminary determination of pouring scheme.....................................................13

4.3.3 Selection of main materials for interior trim panels of automobile doors............18

4.4 Analysis of the numerical simulation results of the main body of the door trim panel.......................................................................................................................................20

4.4.1 Filling time analysis...............................................................................................20

4.4.2 Analysis of welding marks.....................................................................................21

4.4.3Cavitation analysis..................................................................................................22

4.4.4 Warpage analysis...................................................................................................23