JP2005083329A - Structure for mounting flywheel magneto - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress temperature-elevation in a stator in a flywheel. <P>SOLUTION: At a tip-end 1a of a crankshaft 1, a hole 2c of a boss part 2b of a flywheel 2 is fit with an opening 2a faced to the outside. A rotor 4 is constituted by mounting a permanent magnet 3 on the inside periphery of a cylindrical part 2d of the flywheel 2. A stator 8 provided in the cylindrical part 2d is fixed by means of a stator cover 10 to a crankcase 11. A recoil cup 13 fit in the tip-end of the crankshaft 1 is secured together with the flywheel 2 to the crankshaft 1. A vent hole 17 is made on the bottom 2e of the flywheel 2, and a vent hole 18 is made oppositely to the vent hole 17 in the crankcase 11. Fan-shaped parts 21 with vent holes 22 are provided in the recoil cup 13. Vent holes 23 are made oppositely to the vent holes 22 in the part of the stator cover 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flywheel magneto mounting structure mounted on an internal combustion engine such as a snow vehicle.

  As shown in FIG. 5, a conventional flywheel magneto mounting structure of this type has a flywheel 2 with an opening 2a at the tip (shaft side fitting portion) 1a of the crankshaft 1 of the internal combustion engine. A hole (boss-side shaft fitting portion) 2c of the boss portion 2b is fitted in a state in which the tip is directed toward the tip, and a permanent magnet 3 such as a rare earth magnet is attached to the inner periphery of the cylindrical portion 2d of the flywheel 2. Thus, the rotor 4 is configured. A stator 8 is obtained in which a power generation coil 7 is wound around a convex pole portion 5a of a stator iron core 5 facing the permanent magnet 3 via an insulating bobbin 6 to obtain an electrical output. The stator 8 is fitted in the flywheel 2 to the outer periphery of the boss portion 2b via a gap 9. Such a stator 8 is fixed to the crankcase 11 via an annular stator cover 10. A recoil cup 13 for starting the internal combustion engine is fitted via a spacer 14 to the tip of the crankshaft 1 that protrudes outside through the central hole 12 of the stator cover 10, and is bolted to the crankshaft 1 together with the flywheel 2. 15 is fastened together. Reference numeral 13 a denotes a recoil claw provided on the cylindrical portion 13 b of the recoil cup 13. A washer 16 is interposed between the bottom 13c of the recoil cup 13 and the head 15a of the bolt 15. A ventilation hole 17 is provided in the bottom 2 e of the flywheel 2, and a ventilation hole 18 is provided in a portion of the crankcase 11 that can face the ventilation hole 17.

In addition, a reluctator 19 made of a protrusion is provided on the outer periphery of the cylindrical portion 2 d of the flywheel 2, and a pulsar coil 20 is installed at a position that can face the reluctor 19. A trigger signal for ignition is obtained (for example, see Patent Document 1).
Japanese Utility Model Publication No. 62-61926

  However, such a flywheel magneto mounting structure in which the stator 8 is mounted on the crankcase 11 via the stator cover 10 is close to a sealed state, and there is a concern that the temperature of the stator 8 will increase due to power generation.

  In particular, as shown in this example, the flywheel magneto mounting structure using a rare earth magnet as the permanent magnet 3 is small, light, and has a high output. There is a problem that the temperature rise of the coil 7 becomes more severe.

  The objective of this invention is providing the attachment structure of the flywheel magneto which can suppress the temperature rise of the stator in a flywheel.

  Another object of the present invention is to provide a flywheel magneto mounting structure capable of ventilating a flywheel using a recoil cup.

  In the present invention, the hole of the boss portion is fitted to the tip of the crankshaft of the internal combustion engine in a state where the opening of the flywheel faces in the direction toward the tip of the crankshaft, and the permanent magnet is provided on the inner periphery of the cylinder portion of the flywheel. Is attached to the rotor, and a stator coil is formed by winding a power generating coil around a convex pole portion of the stator core facing the permanent magnet. The stator is a crankcase through a stator cover that covers the opening side of the flywheel. The recoil cup is fitted to the tip of the crankshaft that is fixed to the center of the stator cover and protrudes to the outside through the hole in the center of the stator cover, and is fastened together with the flywheel together with the crankshaft. Installation of flywheel magneto in which a ventilation hole is provided in a portion of the crankcase that can face the ventilation hole To target structure.

  In the flywheel magneto mounting structure according to the present invention, the recoil cup is provided with a fan-shaped portion with a vent hole, and the stator cover is opposed to the fan-shaped portion with the vent hole. It is characterized by.

  In this case, it is preferable that the fan-shaped portion with the vent hole is configured by a notch shape by press extrusion.

  In the flywheel magneto mounting structure according to the present invention, the recoil cup is provided with a fan-shaped portion with a vent hole, and the stator cover portion facing the fan-shaped portion with the vent hole is provided with a vent hole. The ventilation hole is connected to the ventilation hole at the bottom of the flywheel and the ventilation hole of the crankcase, and ventilation is performed in the flywheel by the action of the fan-shaped portion of the recoil cup, so that the stator can be cooled. For this reason, the temperature rise of the stator in a flywheel can be suppressed.

  In this case, if the fan-shaped portion with the vent holes is formed by a notched shape by press extrusion, it is possible to blow air at a low cost without increasing the number of parts.

  1 to 3 show a first example of the best mode of the flywheel magneto mounting structure according to the present invention. FIG. 1 is a longitudinal sectional view of the flywheel magneto mounting structure of this example, and FIG. The recoil cup used in this example is shown, (A) is a rear view of the recoil cup used in this example, (B) is a longitudinal sectional view of the recoil cup, and (C) is a view of the recoil cup. Front view, (D) is a cross-sectional view taken along line AA of (C), FIG. 3 shows a stator cover used in this example, and (A) is a vertical cross section of the stator cover used in this example. (B) is a front view of the stator cover used in this example. Note that portions corresponding to those in FIG. 5 described above are denoted by the same reference numerals.

  In the flywheel magneto mounting structure of this example, a fan-shaped portion 21 with a vent hole 22 is provided at a corner portion near the bottom portion 13c of the recoil cup 13. The fan-shaped portion 21 with the ventilation holes 22 is formed into a fan shape by forming a U-shaped notch shape in the recoil cup 13 by press extrusion, and extruding the notch shape into the recoil cup 13. Ventilation holes 22 are provided in the corner portion near the bottom 13c of the recoil cup 13 by the notch extrusion of the fan-shaped portion 21. In this example, the fan-shaped portion 21 with the ventilation hole 22 is configured to be able to blow air toward the stator cover 10 side by the rotation of the recoil cup 13.

  A ventilation hole 23 is provided in the portion of the stator cover 10 that faces the fan-shaped portion 21 with the ventilation hole 22.

  As described above, when the fan-shaped portion 21 with the ventilation hole 22 is provided in the recoil cup 13 and the ventilation hole 23 is provided in the portion of the stator cover 10 facing the fan-shaped portion 21 with the ventilation hole 22, the ventilation holes 22, 23 is connected to the ventilation hole 17 of the bottom portion 2e of the flywheel 2 and the ventilation hole 18 of the crankcase 11, and the ventilation passage 24 is formed. The ventilation action of the fan-shaped part 21 of the recoil cup 13 causes the ventilation to occur in the flywheel 2. This is done and the stator 8 can be cooled. For this reason, the temperature rise of the stator 8 in the flywheel 2 can be suppressed.

  In this case, if the fan-shaped part 21 with the ventilation hole 22 is configured by a notch shape by press extrusion, it is possible to blow air at a low cost without increasing the number of parts.

  FIG. 4 is a partial cross-sectional view showing a second example of the best mode of the flywheel magneto mounting structure according to the present invention, corresponding to the portion P in FIG.

  In the flywheel magneto mounting structure of this example, the structure of the fan-shaped portion 21 with the ventilation hole 22 provided in the recoil cup 13 is formed so as to blow air in the direction opposite to that in FIG.

  If it becomes like this, the ventilation with respect to the inside of the flywheel 2 will be performed so that it may enter from the crankcase 11 side, and may come out from the recoil cup 13 side.

  Even in such a direction, the stator 8 can be cooled as in the first example.

  In this case, if the fan-shaped portion with the vent holes is formed by a notched shape by press extrusion, it is possible to blow air at a low cost without increasing the number of parts.

  Moreover, in the figure of the said example, although the front-end | tip (shaft side fitting part) 1a of the crankshaft 1 was described in the taper shape, the hole (boss side shaft fitting part) 2c of the boss | hub part 2b was also described in the taper shape, These may be straight.

It is the longitudinal cross-sectional view which showed the 1st example of the best form in the attachment structure of the flywheel magneto which concerns on this invention. The recoil cup used in this example is shown, (A) is a rear view of the recoil cup used in this example, (B) is a longitudinal sectional view of the recoil cup, and (C) is a view of the recoil cup. A front view and (D) are the sectional views on the AA line of (C). The stator cover used by this example is shown, (A) is a longitudinal cross-sectional view of the stator cover used by this example, (B) is a front view of the stator cover used by this example. It is the fragmentary sectional view which showed the 2nd example of the best form in the attachment structure of the flywheel magneto which concerns on this invention. It is a longitudinal cross-sectional view of the conventional flywheel magneto mounting structure.

Explanation of symbols

1 Crankshaft 1a Tip (Shaft side fitting part)
2 Flywheel 2a Opening 2b Boss 2c Hole (Boss side shaft fitting part)
2d cylinder part 2e bottom part 3 permanent magnet 4 rotor 5 stator iron core 5a convex pole part 6 insulating bobbin 7 power generation coil 8 stator 9 gap 10 stator cover 11 crankcase 12 hole 13 recoil cup 13a recoil claw 13b cylinder part 14 spacer 15 bolt 15a head Portion 16 Washer 17, 18 Ventilation hole 19 Retractor 20 Pulsar coil 21 Fan shape portion 22, 23 Ventilation hole 24 Ventilation passage

Claims (2)

The hole of the boss portion is fitted to the tip of the crankshaft of the internal combustion engine with the opening of the flywheel facing the tip of the crankshaft, and a permanent magnet is attached to the inner periphery of the cylinder portion of the flywheel A rotor is formed, and a stator coil is formed by winding a power generation coil around a convex pole portion of a stator core facing the permanent magnet, and the stator is interposed via a stator cover that covers the opening side of the flywheel. A recoil cup is fitted to the tip of the crankshaft that is fixed to the crankcase and protrudes to the outside through the center hole of the stator cover, and is fastened together with the crankshaft together with the flywheel, and the bottom of the flywheel Ventilation holes are provided on the crankcase, and ventilation holes are provided in the crankcase portion that can face the ventilation holes. In the mounting structure of the flywheel magneto which is,
A flywheel magneto mounting structure, wherein the recoil cup is provided with a fan-shaped portion with a vent hole, and the stator cover is opposed to the fan-shaped portion with the vent hole. .   2. The flywheel magneto mounting structure according to claim 1, wherein the fan-shaped portion has a notch shape formed by press extrusion. 3.

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