JPH0616984Y2 - Engine starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an engine starting device in which a starting ring gear is provided on a flywheel integrally formed with cooling fins.

(Prior art) In a small general-purpose engine, the crankshaft is projected outward from the crankcase, the load is connected to one of them, and the flywheel is attached to the other, and the flywheel is cooled on the side opposite to the crankcase. Fins are integrally formed, and an engine starting ring gear is provided on the crankcase side. The starter motor is mounted on the crankcase parallel to the crankshaft so that when the starter motor is energized, the pinion projects in the axial direction and meshes with the ring gear described above. (See the official gazette).

(Problems to be Solved by the Invention) In the above-mentioned conventional technique, since the shaft length of the starter motor is longer than the width dimension of the crankcase, if the pinion and the ring gear are properly arranged, the engine output shaft side ( The rear end of the starter motor will protrude to the side where the load is mounted, and the pulley for connecting the load must be installed at a distance from the end face of the crankcase by that amount, resulting in an overall large size. There was a problem.

Therefore, it is possible to move the mounting position of the starter motor to the flywheel side as much as possible. In this way, the rear end of the starter motor does not project from the output shaft side of the engine, but the area of the cooling fins is reduced by the amount of movement, which causes a problem that the cooling effect of the engine deteriorates.

The present invention has been made for the purpose of solving the above-mentioned problems.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a flywheel in which a cooling fin is integrally formed with a ring gear that meshes with a pinion of a starter motor. The ring gear is integrally formed on the outer peripheral portion of the fin, and an air passage is formed between the flywheel and the ring gear.

(Operation) With such a configuration, the above-mentioned problems of the conventional technique are solved. Further, in a magnet rotor in which a cooling fin and a ring gear are integrally formed on a flywheel by aluminum die casting, and a flywheel magnet in which an ignition coil is installed outside the ring, the ring gear is also formed on the crankcase side end of the flywheel. Therefore, the magnetic steel surface located on the outer periphery and the tapered surface of the hole through which the crankshaft is inserted cannot be chucked at the ring gear part, and the outer peripheral part of the fin is chucked. And the difficulty of obtaining concentricity of the ring gear will be solved.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.
In the figure, reference numeral 1 denotes a crankshaft, which is supported by bearings 2 and 3 and has both ends projected from a crankcase 4. Reference numeral 5 is a cylinder, 6 is a cylinder head, and the piston is not shown. A load (not shown) is directly connected to the left end of the crankshaft 1 in the figure,
Alternatively, they are connected via a pulley and a belt. A flywheel 14 and a drum 8 of the recoil starter, which will be described later, are attached to the nut protruding from the bearing 3 to the outside.
It is fixed by 10. The recoil starter is used when discharging a battery (not shown).

The flywheel 14 has a magnetic steel part (magnet) 11 and a balance weight 12 attached thereto, and a large number of cooling fins 15 are integrally formed in a radial shape where the attachment part is avoided,
A ring gear 16 is integrally formed on the outer peripheral portion of the cooling fin 15. Therefore, the air passage 13 is formed between the flywheel 14 and the ring gear 16. A ring gear 16 is integrally formed on the outer peripheral portion at the substantially center. A coil 17 is arranged outside the magnetic steel portion 11. A starter motor 18 is provided in the lower portion of the crankshaft 1, and a pinion 20 provided so as to move forward and backward with respect to an output shaft 19 of the crankshaft 1 is positioned so as to mesh with the ring gear 16 when protruding. Reference numeral 21 is a cooling cover, and 22 is a recoil starter cover, which are fixed to the cylinder 5, the cylinder head 6 and the like by bolts 23. The recoil starter cover 22 is provided with ventilation holes 24, 25 as shown in FIG.

In this device configured as described above, when the starter motor 18 is actuated to start the engine, the pinion 20 that projects and rotates meshes with the ring gear 16 and rotates the crankshaft 1 through the flywheel 14. This starts the engine. Needless to say, the pinion 20 retracts after the engine is started, and the meshing with the ring gear 16 is released. When the flywheel 14 rotates together with the crankshaft 1, the cooling fins 15 allow the outside air to flow through the ventilation holes 24 and 25 as shown by the arrow in FIG. 1 to cool the engine and the starter motor 18.

(Effect of the Invention) Since the present invention has the configuration and operation as described above, it has the following effects.

The starter motor having a long overall length can be accommodated without the rear end protruding to the load coupling side of the engine.

Since the passage of the engine cooling air can be widened and the flow thereof can be improved without reducing the cooling fin area, the cooling performance of the engine is improved.

When processing the magnetic steel surface and the tapered surface, it is possible to chuck the outermost ring gear portion,
If chucking is performed in this way, the above two processes can be performed at the same time, so that the concentricity of these can be enhanced.

The fin according to the present invention can be easily molded in a split mold.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an essential part of an embodiment of the present invention, and FIG.
The drawing is a right front view with a part of FIG. 1 omitted. 1 ... Crank shaft 13 ... Air passage, 14 ... Flywheel, 15 ... Cooling fin,
16 ... Ring gear 18 ... Starter motor, 20 ... Pinion 24, 25 ... Ventilation port

Claims (1)

[Scope of utility model registration request] 1. A flywheel in which a cooling fin is integrally formed with a ring gear that meshes with a pinion of a starter motor, wherein the ring gear is integrally formed on an outer peripheral portion of the cooling fin, and the flywheel is formed. An engine starting device, wherein an air passage is formed between the ring gear and the ring gear.