Automobile front wall internal side sound insulation pad with multi-layer structure and manufacturing method thereof

The invention relates to an automobile front wall internal side sound insulation pad with a multi-layer structure and a manufacturing method thereof. The automobile front wall internal side sound insulation pad with the multi-layer structure has the multi-layer structure; the upper surface layer of the automobile front wall internal side sound insulation pad with the multi-layer structure is an injection-molded heavy layer; the bottom layer of the automobile front wall internal side sound insulation pad with the multi-layer structure is a sound absorbing material layer; the thickness of the heavy layer is changed according to the intensity of a noise source; according to product requirements, the thickness of a mold cavity of a mold is changed in areas; the heavy layer is injection-molded by using a large-sized injection molding machine; and the obtained heavy layer has different thicknesses in different areas. Compared with the prior art, the automobile front wall internal side sound insulation pad with the