JPH0828414A - Attaching structure for generator of engine - Google Patents

Abstract

PURPOSE:To avoid the damage of a crankshaft by extending an end face on the large diameter side of the female tapered part of a flywheel magnet case nearer the inside of the crankshaft than a boundary part on the large diameter side of the male tapered part of the crankshaft. CONSTITUTION:A flywheel magnet case 22 is attached to a crankshaft 12 by fitting a female tapered part 22b formed in a boss part 22a on a male tapered part 12a formed at the upper end of the crankshaft, and locking both tapered parts 22b, 12a mutually with a Woodruff key and fastening them with a nut 26. An end face 22c on the large diameter side of the female tapered part 22b of the flywheel magnet case 22 is extended by the length L toward the inside of the crankshaft 12 from a boundary part (a) with the crarakshaft straight line part of the male tapered part 12a of the crankshaft 12. Thus stress concentration caused by the invasion of the edge of the end face of the flywheel magnet case 22 into the way of the tapered part 12a of the crankshaft 12 can be avoided for preventing the damage of the crankshaft 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a generator mounting structure for an engine used, for example, in an outboard motor.

[0002]

2. Description of the Related Art Conventionally, as a mounting structure for a magneto generator for an outboard engine, a flywheel magneto case (hereinafter referred to as a "flamag case") having a permanent magnet incorporated therein.
Is generally taper-fitted to the crankshaft. In this taper fitting, conventionally, as shown in FIG. 5, the female taper portion 80a of the flamag case 80 is formed to be slightly shorter than the male taper portion 81a of the crankshaft 81, and the larger diameter side of the female taper portion 80a is formed. Generally, the end surface 80b is located in the middle of the male taper portion 81a. FIG. 5 is a partial cross-sectional view schematically showing a main part of a conventional magneto-generator mounting structure.

[0003]

However, in the above-described conventional generator mounting structure, in the crankshaft 81, a crack occurs in the vicinity of the end surface 80b of the female taper portion 80a of the Flamag case 80, or in an extreme case, it breaks. There is a problem that sometimes.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a generator mounting structure for an engine capable of avoiding damage to the crankshaft.

[0005]

Means for Solving the Problems The present inventor has investigated the cause of the damage of the crankshaft and obtained the following findings.
For example, in the engine for an outboard motor, since the mass of inertia of the flamag case 80 is set large in order to improve the driving feeling in the low speed rotation range, the flamag case 8 is used.
0 largely swings at the resonance point of the crankshaft, so that the edge portion of the end surface 80b of the female taper portion 80a is the crankshaft 8
It is conceivable that the crankshaft 81 will be damaged by damaging the crankshaft 81. Therefore, the present invention is characterized in that, in the engine generator mounting structure, the large-diameter side end surface of the female taper portion of the above-mentioned Flamag case is extended to the inside of the crankshaft from the large-diameter side boundary portion of the male taper portion of the above crankshaft. I am trying.

[0006]

In the generator mounting structure for the engine according to the present invention,
Since the end surface of the female taper portion of the Flamag case is extended to the inside of the crankshaft from the boundary of the male taper portion of the crankshaft,
It is possible to prevent the end face edge portion of the Framag case from getting into the middle of the crankshaft taper portion, thereby preventing damage to the crankshaft.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 5 are views for explaining a generator mounting structure of an engine according to an embodiment of the present invention, FIG. 1 is a side view showing an outboard motor having the structure of this embodiment, and FIG. Figure 3 is a plan view of the outboard motor without the Flamag case.
FIG. 4 is a partial cross-sectional side view of the structure of the present embodiment, and FIG. 4 is a partial cross-sectional side view schematically showing the main part of the structure of the present embodiment.

In this embodiment, the engine for the outboard motor 2 is used.
A cycle 2-cylinder engine is used, and a crankshaft 12 is vertically arranged on the engine body 10, and a piston (not shown) horizontally arranged is connected to the crankshaft 12. Also, with respect to the engine body 10
The upper and lower intake manifolds 14, the upper and lower carburetors 16, and the intake box 18 corresponding to each cylinder are sequentially connected, and a cylinder head 19 is mounted on the opposite side of these, and a spark plug is attached to the cylinder head 19. Twenty is attached.

An ignition timing control device 1 is arranged on the upper surface of the engine body 10, and the sliding base 34 of the device 1 is rotated by a metal insert 36 in a cylindrical portion at the upper end of the engine body. It is mounted so that it can move freely. The lower portion of the sliding base 34 is held by the engine body 10 via a washer 38 for preventing wear. The upper portion of the sliding base 34 is held by a holding plate 40 formed by coating a metal plate with a resin, for example. The pressing plate 40 is attached to the upper end surface of the engine body 10 on which the sliding base 34 is mounted by the mounting bolts 4
It is fixed via 2, and the mounting portion of the pressing plate 40 is located radially inward of the outer peripheral edge of the sliding base 34. It should be noted that the upper end of the sliding base 34 is such that the upward protruding portion 35 contacts the lower surface of the pressing plate 40. Further, 44 is a bearing and 45 is a seal member.

An arm portion 48 integrally projects radially outward from a part of the annular sliding base 34, and a pulsar coil 50 is arranged on the arm portion 48 at a position outside the flamag case 22 described later. ing. Therefore, the pulsar coil 50 once faces the permanent magnet 28 of the flamag case 22 while the crankshaft 12 makes one revolution, and generates a pulse for ignition.

A control device 52 for correlatively controlling the throttle valve opening and the ignition timing is attached to the side surface of the engine body 10. In detail, as shown in FIG. 1, a first lever 54 is rotatably supported by a side surface of the engine body 10 via a mounting bolt 53, and a throttle wire 56 is connected to one end of the first lever 54. A cam 58 is connected to the other end via a link 57. The cam 58
Is configured to be rotatable about the mounting bolt 59,
It is in contact with a cam follower 62 of a lever 61 that rotates integrally with the throttle valve 60 in the carburetor 16. 6
Reference numeral 3 is a link for interlocking the lever 61 of each carburetor 16.

A second lever 65 is pivotally supported so as to be able to rotate coaxially with the first lever 54, and the second lever 65 and the first lever 54 are associated with each other to operate. A torsion spring 66 is provided. Second above
The end portion of the lever 65 is connected to the arm portion 48 of the sliding base 34 via a link 68.

The magneto generator 2 is mounted on the upper end of the crankshaft 12. This generator 2
On the inner surface of the Flamag case 22, as shown in FIG.
A plurality of permanent magnets 28 are fixedly attached, and a plurality of charge coils 30 are held on the sliding base 40 via brackets 31 so as to face the permanent magnets 28. Reference numeral 32 denotes a ring gear, which is fixed to the outer periphery of the flamag case 22 and receives a rotational force from a starter (not shown) when the engine is started.

The Flamag case 22 has a boss portion 22a.
By fitting the female taper portion 22b formed on the above into the male taper portion 12a formed at the upper end of the crankshaft 12, and by locking both taper portions 22b and 12a with the half-moon key 24 and tightening with the nut 26. , Crankshaft 1
It is attached to 2. As shown in FIG. 4, the large-diameter side end surface 22c of the female taper portion 22b of the flamag case 22 is located at the boundary portion a between the male taper portion 12a of the crankshaft 12 and the linear portion of the crankshaft 12a. It is extended inward by a length L.

Next, the operation of the above embodiment will be described.
For example, when the throttle wire 56 is moved in the fully open direction, the first lever 54 of the control device 52 rotates, and the throttle valve 6 of the carburetor 16 passes through the link and the cam mechanism.
0 is opened.

On the other hand, at the same time, the second lever 65 connected to the first lever 54 via a torsion spring 66 is also interlocked and rotated, whereby the sliding base 34 of the engine body 10 is moved via the arm portion 48. It is rotated around a predetermined angle. For example, when the ignition timing should be advanced, the sliding base 34 is rotated in the direction opposite to the rotation direction of the crankshaft 12. As a result, the start timing of the pulsar coil 50 due to the facing of the flamag case 22 with the permanent magnet 28 is advanced, and the ignition timing is advanced.

Since the flag magnet case 22 rotates with the crankshaft 12, the permanent magnet 28 rotates outside the charge coil, which causes the charge coil 3 to rotate.
AC is generated at 0. In this case, especially the crankshaft 12
In the conventional generator mounting structure, the edge of the end face of the taper portion of the flammag case is embedded in the taper surface of the crankshaft, and stress concentration occurs in the crankshaft because the flammage case 22 vibrates at the resonance point. There was a problem that the shaft was easily damaged.

On the other hand, in the present embodiment, the end surface 22c of the female taper portion 22b of the flamag case 22 is attached to the crankshaft 1.
Since it extends below the boundary portion a of the male tapered portion 12a of No. 2 (inside the crankshaft), the above-mentioned edge does not enter the crankshaft tapered surface, and the concentration of the above stress on the crankshaft tapered surface is prevented. Therefore, the crankshaft 12 can be prevented from being damaged.

It should be noted that, due to the extension of the female taper portion 22b of the Flamag case 22, the edge of the boundary portion a of the crankshaft 12 is hard to be inserted in the middle of the female taper portion 22b of the Flamag case 22, and the stress is concentrated on the Flamag case 22 side. However, even if a crack is generated on the flamag case 22 side, it does not cause a problem as in the case where a crack is generated on the crankshaft side.

[0020]

As described above, according to the generator mounting structure of the engine of the present invention, the end surface of the female taper portion of the flamag case is extended to the inside of the crankshaft from the large-diameter side boundary portion of the male taper portion of the crankshaft. Therefore, it is possible to avoid stress concentration on the tapered surface of the crankshaft and prevent damage to the crankshaft.

[Brief description of drawings]

FIG. 1 is a side view showing an outboard motor equipped with a generator mounting structure according to an embodiment of the present invention.

FIG. 2 is a plan view of the outboard motor without a part of a flamag case.

FIG. 3 is a partial cross-sectional side view of the structure of the embodiment.

FIG. 4 is a partial cross-sectional side view schematically showing a main part of the structure of the embodiment.

FIG. 5 is a partial cross-sectional side view of a conventional power generator for an outboard engine.

[Explanation of symbols]

 1 Generator 10 Engine 12 Crank Shaft 12a Male Tapered Part 22 Flamag Case 22b Female Tapered Part 22c Tapered End Face a Boundary

Claims (1)

[Claims] 1. A generator mounting structure for an engine in which a female taper portion of a flywheel magneto case is fitted to a male taper portion formed at one end of a crankshaft, wherein a female taper portion of the flywheel magneto case is provided. A generator mounting structure for an engine, characterized in that an end surface on the large diameter side is extended inward of the crankshaft from a boundary portion on the large diameter side of the male tapered portion of the crankshaft.