JPS632600Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mounting device for a cooling fan in an internal combustion engine, particularly a forced air-cooled general-purpose internal combustion engine.

In this type of internal combustion engine, a flywheel 2 is fitted onto a rotating shaft 1 such as a crankshaft with a key 3, etc., and a cooling fan 4 and a recoil starter 5 for starting the engine are attached to the side of the flywheel 2. It is known that a pulley 6 and a pulley 6 are stacked one on top of the other and fixed together by tightening with a nut 7 screwed into the rotating shaft (for example, see Japanese Patent Laid-Open No. 101642/1983).

The present invention provides a flywheel 2, a cooling fan 4, and a starting pulley 6 in an internal combustion engine as described above.
The purpose is to securely prevent rotation of the three parts.

In order to achieve this purpose, the following configuration has been adopted. That is, a metallic flywheel 2 is fitted to the rotating shaft 1 of an internal combustion engine so as not to rotate, and a cooling fan 4 made of synthetic resin and a starting pulley 6 of a recoil starter 5 are sequentially superimposed on the flywheel 2. In an internal combustion engine that is fixed together with a nut 7 screwed into the rotating shaft 1, the flywheel 2
and the cooling fan 4 at the periphery of the overlapped portion thereof by a plurality of protrusions 42 and a recess 24 that engages with the protrusions 42, and a distorted convex portion 22 formed on the flywheel 2 at the center and the cooling fan that engages therewith. 4 hole 4
1, the starting pulley 6 is engaged with the cooling fan 4 in the concave and convex portions 64 and 46 around the shaft hole 61, and the starting pulley 6 and the flywheel 2 are connected to the distorted convex shape. It is characterized by having concave and convex engagements 26 and 62 within the portion.

In the illustrated example, a protrusion 42 is formed on the peripheral edge of the overlapped portion of the cooling fan 4 with the flywheel 2, and a recess 24 that engages with the protrusion 42 is formed on the flywheel 2. Engaging recesses or holes may be formed in the cooling fan 4.

In addition, the distorted recess 22 of the flywheel 2 is located in the shaft hole 2.
It may be any shape as long as it has an eccentric portion with respect to 1, and it is not limited to the oval shape shown in the illustration, but may be any suitable shape such as an oval shape or a rectangular shape.

Since the present invention has the above-mentioned configuration, the flywheel 2 and the cooling fan 4 are formed by the protrusion 42 and the recess 24 on the periphery, and the distorted protrusion 22 and the hole 41 in the center.
The starting pulley 6 and the cooling fan 4 and the starting pulley 6 and the flywheel 2 are engaged with each other by concave and convex engagements 64, 46, 2, respectively.
6.62, the flywheel 2, cooling fan 4, and starting pulley 6 are firmly connected to each other to prevent rotation, and are prevented from rattling or shifting due to engine vibrations, etc., and from repetition thereof. This has the effect of reliably preventing the fixing nut 7 from loosening.

In FIG. 1, 8 is the crankcase, 9 is the cylinder, 10 is the fan cover, 11 is the rope reel of the recoil starter 5, 12 is the rope, 13 is the grip, and 14 is the connection between the rope reel 11 and the starting pulley 6. The clutch pawl 15 of the overrunning clutch provided therebetween indicates the engagement hole of the pawl 14.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a part of an internal combustion engine to which a cooling fan is attached using the mounting device of the present invention, and FIG. 2 is an exploded perspective view of the cooling fan and its surrounding parts. 1 is a rotating shaft (crankshaft), 2 is a flywheel, 4 is a cooling fan, 6 is a starting pulley, 7 is a nut, 42 is a protrusion, 24 is a recessed part, 22 is a distorted convex part, 41 is a hole, 64. 46, 26 and 62 are uneven engagements.

Claims (1)

[Scope of Claim for Utility Model Registration] A metal flywheel is fitted to the rotating shaft of an internal combustion engine in a non-rotating manner, and a cooling fan made of synthetic resin and a starting pulley of a recoil starter are sequentially superimposed on the flywheel. In an internal combustion engine that is fixed together with a nut screwed into a rotating shaft, the flywheel and cooling fan are connected to each other by a plurality of protrusions and a recess that engage with the protrusions on the periphery of their overlapping part, and to the flywheel in the center. The formed distorted convex portion and the hole of the cooling fan that engages with the convex portion prevent rotation, and the starting pulley is engaged with the cooling fan at the periphery of the shaft hole, and the starting pulley and the flywheel are engaged. A cooling fan mounting device for an internal combustion engine, characterized in that the above-mentioned distorted convex portions are engaged with each other in a concave-convex manner.