JP3340246B2 - Engine generator mounting structure - Google Patents

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 an outboard motor, for example.

[0002]

2. Description of the Related Art Conventionally, as a mounting structure for a magneto generator for an outboard engine, a flywheel magneto case incorporating a permanent magnet (hereinafter referred to as a "flamag case").
Is generally taperedly 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 large diameter side of the female taper portion 80a is formed. Generally, the end face 80b is located in the middle of the male tapered portion 81a. FIG. 5 is a partial cross-sectional view schematically showing a main part of a mounting structure of a conventional magneto generator.

[0003]

However, in the above-described conventional generator mounting structure, cracks occur near the end face 80b of the female tapered portion 80a of the flamag case 80 in the crankshaft 81, or breakage occurs in an extreme case. There is a problem that sometimes.

The present invention has been made in view of such circumstances, and has as its object to provide a generator mounting structure for an engine that can avoid damage to a crankshaft.

[0005]

The inventor of the present invention has studied the cause of the damage to the crankshaft and obtained the following findings.
For example, in the engine for an outboard motor, the inertia mass of the flamag case 80 is set to be large in order to improve the driving feeling in the low speed rotation range.
0 greatly fluctuates at the resonance point of the crankshaft, so that the edge of the end face 80b of the female tapered portion 80a
It is considered that the crankshaft 81 is damaged by biting into the crankshaft 81. Therefore, the present invention provides an engine generator mounting structure 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. The large-diameter end surface of the female tapered portion and the edge of the large-diameter end surface are extended so as to be located inside the crankshaft from the large-diameter boundary portion of the male tapered portion of the crankshaft.

[0006]

In the engine generator mounting structure according to the present invention,
Since the large-diameter end face of the female tapered portion of the flamag case and the edge of the end face are located on the crankshaft inner side from the boundary portion of the male tapered portion of the crankshaft, the edge of the end face of the flamag case is the tapered portion of the crankshaft. It is possible to avoid getting stuck halfway, 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 for an engine according to an embodiment of the present invention. FIG. 1 is a side view showing an outboard motor having the structure of the embodiment, and FIG. Plan view of the outboard motor excluding a part of the flamag case, FIG.
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 illustrating a main part of the structure of the present embodiment.

In this embodiment, an outboard motor 2 is used as an engine.
A cycle two-cylinder engine is used. A crankshaft 12 is vertically arranged on the engine body 10, and a piston (not shown) arranged horizontally with respect to the crankshaft 12 is connected to the crankshaft 12. Also, for the engine body 10,
The upper and lower intake manifolds 14, the upper and lower carburetors 16, and the intake boxes 18 corresponding to the respective cylinders are connected in order, and a cylinder head 19 is mounted on the other side thereof. 20 are attached.

An ignition timing control device 1 is disposed on an upper surface of the engine main body 10, and a sliding base 34 of the device 1 is turned around a cylindrical portion at an upper end of the engine main body via a metal insert 36. Mounted movably. The lower portion of the sliding base 34 is held by the engine main 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, for example, coating a sheet metal with a resin. The holding plate 40 is provided with mounting bolts 4 on the upper end surface of the engine body 10 on which the sliding base 34 is mounted.
2, and the mounting portion of the holding plate 40 is located radially inward of the outer peripheral edge of the sliding base 34. The upper end of the sliding base 34 is configured such that the upwardly projecting portion 35 contacts the lower surface of the holding plate 40. 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 disposed on the arm portion 48 at a position outside the flamag case 22, which will be described later. ing. Therefore, the pulsar coil 50 once faces the permanent magnet 28 of the flamag case 22 during one rotation of the crankshaft 12, and generates a pulse for ignition.

A control device 52 for correlating and controlling the throttle valve opening and the ignition timing is mounted on a side surface of the engine body 10. More specifically, as shown in FIG. 1, a first lever 54 is rotatably supported on 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 able to rotate around the mounting bolt 59,
It is in contact with a cam follower 62 of a lever 61 that rotates integrally with a throttle valve 60 in the carburetor 16. Note that 6
Reference numeral 3 denotes a link for linking the lever 61 of each carburetor 16.

A second lever 65 is pivotally supported so as to rotate coaxially with the first lever 54. Between the second lever 65 and the first lever 54, the two levers are operated in association with each other. A torsion spring 66 is provided. The second
The end of the lever 65 is connected to the arm 48 of the sliding base 34 via a link 68.

On the upper end of the crankshaft 12, a magneto generator 2 is mounted. This generator 2
Is provided on the inner surface of the flamag case 22, as shown in FIG.
A structure in which a plurality of permanent magnets 28 are fixed 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 includes a boss 22a.
The female taper portion 22b formed at the upper end of the crankshaft 12 is fitted to the male taper portion 12a formed at the upper end of the crankshaft 12, and the taper portions 22b and 12a are prevented from rotating with the half-moon key 24 and tightened with the nut 26. , Crankshaft 1
2 attached. As shown in FIG. 4, the large-diameter end face 22 c of the female tapered portion 22 b of the flamag case 22 is separated from the boundary portion a of the male tapered portion 12 a of the crankshaft 12 with the straight portion of the crankshaft. 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 is connected via the link and the cam mechanism.
0 is opened.

At the same time, the second lever 65, which is connected to the first lever 54 via a torsion spring 66, is also rotated in conjunction therewith, whereby the sliding base 34 is connected to the engine body 10 via the arm 48. It is turned around by a predetermined angle. For example, when the ignition timing is to be advanced, the sliding base 34 is rotated in the direction opposite to the rotation direction of the crankshaft 12. Accordingly, the start timing of the pulsar coil 50 due to the opposition of the flamag case 22 to the permanent magnet 28 is advanced, and the ignition timing is advanced.

Since the flamag case 22 rotates together with the crankshaft 12, the permanent magnet 28 rotates outside the charge coil.
AC is generated at zero. In this case, in particular, the crankshaft 12
In the conventional generator mounting structure, the edge of the end face of the tapered portion of the flamag case gets into the tapered surface of the crankshaft, and stress concentration occurs in this portion, so that the crankshaft is cranked. 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 tapered portion 22b of the flamag case 22 is
2 extends downward (inside the crankshaft) from the boundary portion a of the male tapered portion 12a, so that the edge does not penetrate into the crankshaft taper surface and the stress is prevented from concentrating on the crankshaft taper surface. Thus, damage to the crankshaft 12 can be avoided.

The extension of the female tapered portion 22b of the flamag case 22 causes the edge of the boundary a of the crankshaft 12 to enter the middle of the female tapered portion 22b of the flamag case 22 and stress is concentrated on the flamag case 22 side. However, even if the crack occurs on the side of the flamag case 22, the problem does not occur as in the case where the crack occurs on the side of the crankshaft.

[0020]

As described above, according to the engine generator mounting structure of the present invention, the end face and the edge of the female tapered portion of the flamag case are located on the inner side of the crankshaft from the large diameter side boundary of the male tapered portion of the crankshaft. , Stress concentration on the tapered surface of the crankshaft can be avoided, and damage to the crankshaft can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a plan view of the outboard motor excluding 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 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]

 DESCRIPTION OF SYMBOLS 1 Generator 10 Engine 12 Crankshaft 12a Male taper part 22 Flamag case 22b Female taper part 22c Tapered end surface a Boundary part

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02P 1/02 F02P 1/06 F16D 1/06

Claims (1)

(57) [Claims] 1. A generator mounting structure for an engine which is adapted to fit the female taper portion of the crank shaft flywheel magnet case the male tapered portion formed at one end of the female taper portion of the flywheel magnet case , The female
The engine according to claim 1, wherein the large-diameter side end surface of the tapered portion and the edge of the large-diameter side end surface extend so as to be located inside the crankshaft from the large-diameter side boundary portion of the male tapered portion of the crankshaft. Generator mounting structure.