Forced air-cooled engine

Abstract

To locate engine components including an engine body and an ignition coil to be compact to each other for making the engine small, and to prevent vibration of the engine body from being transmitted to the ignition coil so as to increase the life-span of the ignition coil. An engine 13 comprises an engine body 15 having a crankcase 18 which supports a crankshaft 17 and having a cylinder 19 extending from the crankcase 18; a spark plug 34 connected to the cylinder 19; a fan 37 coupled to the crankshaft 17; a shroud 38 for covering the engine body 15, the spark plug 34, and the fan 37 from their outside and for leading wind B from the fan 37 toward the cylinder 19 and spark plug 34; and an ignition coil 43 which can supply the spark plug 34 with current. The ignition coil 43 is located in an outer neighborhood of a portion 55 in the shroud 38 covering the outer face of the cylinder 19 in radial direction.

Description

technical field [0001] The present invention relates to a forced air-cooled engine in which an ignition coil is arranged outside a shroud covering a crankcase and a cylinder. Background technique [0002] Among the above-mentioned engines, conventionally, there is an engine disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 9-126109). According to this patent document 1, the above-mentioned engine is applied to a swing-type drive unit of a two-wheeled motorcycle, and the above-mentioned engine includes: an engine body having a crankcase supporting a crankshaft and a cylinder protruding from the crankcase, and an ignition plug mounted on the cylinder. , a centrifugal fan linked to the above-mentioned crankshaft, a shield that covers the above-mentioned engine body, ignition plug and fan from the outside and guides the wind from the fan to the above-mentioned cylinder and ignition plug, and can supply current to the above-...

AI Technical Summary

Problems solved by technology

[0004] Also, according to the above-mentioned patent document 1 image 3 , Figure 4 In the shown engine, although the above-mentioned ignition coil is installed on the outer surface of the crankcase, usually the outer dimension of the crankcase is larger than the cylinder, so at this time, the outer shape of the engine tends to become larger

Also, since the above-mentioned ignition coil is directly mounted on the crankcase, the vibration of the engine body is more directly applied to the above-mentioned ignition coil as it is, and at this time, there is a greater possibility that the ignition coil has a problem in life.

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