Automobile steering wheel with dual-density EPP (Expanded Polypropylene) structure and manufacturing process thereof

Abstract

The invention provides two manufacturing processes of an automobile steering wheel with a dual-density EPP (Expanded Polypropylene) structure. Both the two processes adopt the dual-density EPP material structure, so that on one hand, the comfort of using the steering wheel is ensured, and on the other hand, the difficulty in product processing is avoided; in order to ensure the tight combination of the EPP material structure and a metal framework, low-temperature PP (Propene Polymer) resin is adopted, so that the metal framework, the EPP material and the low-temperature PP resin are firmly combined; and regarding to the other process, a PUR (Poly Urethane Resin) layer is covered on the outermost layer of the steering wheel, so that not only are the use of PUR materials and environment pollution reduced, but also the advantages of the PUR materials are retained.

Description

technical field [0001] The invention relates to the processing and manufacturing of automobile parts, in particular to an automobile steering wheel with double-density EPP structure and its manufacturing process. Background technique [0002] At present, there are two kinds of steering wheels commonly used in automobiles. The first structure is that the metal skeleton directly wraps the skin. This structure steering wheel feels hard, poor operating comfort, heavy product quality, and low safety factor. The second structure is a metal skeleton with PUR hair. Foam structure, this structure has improved comfort, but the PUR material itself and its processing technology are not environmentally friendly and will pollute the environment. In addition, although the weight of the steering wheel parts made of PUR material is reduced, the weight of the PUR material is in the The foam area is still very heavy, and the steering wheel parts made of the whole piece of PUR foam feel poor. ...

AI Technical Summary

Problems solved by technology

[0002] At present, there are two kinds of steering wheels commonly used in automobiles. The first structure is that the metal skeleton directly wraps the skin. This structure steering wheel feels hard, poor operating comfort, heavy product quality, and low safety factor. The second structure is a metal skeleton with PUR hair. Foam structure, this structure has improved comfort, but the PUR material itself and its processing technology are not environmentally friendly and will pollute the environment. In addition, although the weight of the steering wheel parts made of PUR material is reduced, the weight of the PUR material is in the The foam area is still very heavy, and the steering wheel parts made of the whole piece of PUR foam feel poor

[0003] In the steering wheel manufacturing process, EPP materials are often used, and most of them are single-density EPP materials. There are often the following problems: the EPP material itself cannot be tightly combined with the metal skeleton during molding. The particles are closely combined. In the finished product test, the torsion force of the handle is too small, and the sound of EPP particles breaking will be heard when twisted lightly, which cannot pass the torsion test; when using single-density EPP material, if low-density EPP material is used After the outer skin is covered, sharp corners and sharp edges will be formed. Due to the large change in the size of the outer skin, after the steering wheel is assembled with other parts such as horn buttons, there will be a large gap, which will affect the appearance. Dimensional control is very difficult and product processing is difficult. , if high-density EPP is used to cover the outer skin, the ring handle of the steering wheel will be too hard, which will affect the comfort of customers

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