摘要 |
Provided is a cover member (7) such as chain cover member for engines, configured to reduce significantly its own vibrations and noises generated or transmitted therefrom compared to other conventional cover members. On its central portion, the cover member (7) of the present invention is provided with circular compartments (17) each defined by a concave surface facing outward and a convex surface facing inward. At least, the concave surfaces facing outward jointly define a continuous curved surface. Therefore, the flat surfaces (flat portions) on the cover member (7) decrease, thereby reducing sound emission, and thus noises from the cover member (7). In addition, when the cover member (7) of the present invention has at least three circular compartments (17), in each three circular compartments (17) adjoining to each other, the three circular compartments (17) are arranged in a triangular pattern, and each one of them circumscribe the other two circular compartments (17). Therefore, the at least three circular compartments (17) can be arranged in the densest pattern on the cover member (7), and thus flat portions (18) each surrounded by three circular compartments (17) can be minimized, thereby reducing sound emission from the cover member (7).
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