JPH10174328A - Method for tightening flywheel damper of flywheel magneto - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for tightening the flywheel damper of a flywheel magneto which allows tightening torque to be easily controlled on a production line. SOLUTION: The method uses as a hexagon head bolt a bolt 11 for torque control to the top of the bolt head 11b of which the head 11d of the bolt 11 for bolt torque control is connected through a constriction 11c and which is so set that the constriction 11c will be broken under a specified torque. Rotational force for tightening is applied to the head 11d of the bolt for torque control by means of the bolt 11 for torque control, and a flywheel damper is thereby fastened to a flywheel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flywheel damper tightening method for a flywheel magneto.

[0002]

2. Description of the Related Art In a flywheel magneto which is a magnet generator mounted on an engine such as an outboard motor, a boss portion 2 of a flywheel 1 as shown in FIGS. Are fitted concentrically, and a nut is screwed into a threaded portion at the tip of an engine shaft (not shown) that has passed through the boss portion 2. The flywheel 1 has a structure having a cylindrical portion 1a and an annular bottom portion 1b.
A permanent magnet 3 is mounted on the inner periphery of the cylindrical portion 1a.
The inner circumference of the bottom 1b of the flywheel 1 is fixed to the outer circumference of the boss 2 by caulking or the like. The flywheel 1 and the permanent magnet 3 constitute a flywheel magneto rotor. Although not shown, flywheel 1
Inside, a flywheel magneto stator is arranged, and the rotor and the stator constitute a flywheel magneto.

A ring gear 4 to which a rotational force from a starter (not shown) is applied is fixed to the outer periphery of the flywheel 1, and the engine shaft is rotated at the time of starting by the rotational force applied through the ring gear 4. It has become.

A flywheel damper 5 is fastened to the outer surface of the flywheel 1 with a plurality of hexagon bolts 7. That is, the flywheel damper 5 includes a damper cover 6 having a cylindrical portion 6a and an annular bottom portion 6b, and the damper cover 6 overlaps the bottom portion 6b with the bottom portion 1b of the flywheel 1 to form a plurality of hexagon bolts 7. Has been concluded. An annular vibration ring 8 made of a weight having a natural frequency is disposed in the cylindrical portion 6a of the damper cover 6, and the vibration ring 8 is connected to the cylindrical portion of the damper cover 6 via a vibration absorbing material 9 such as rubber. 6a. A flange 6c is continuously provided on the outer periphery of the distal end of the cylindrical portion 6a of the damper cover 6, and a hook 10 for hooking a knot of a starting rope is provided on the outer periphery of the flange 6c. The starting rope hooked on the hook 10 is
The damper cover 6 is wound around the outer periphery of the cylindrical portion 6a.

In the flywheel magneto having such a structure, the engine vibration is large, the moment of inertia and the weight of the flywheel 1 are large, and the force due to the engine vibration and the rotation of the flywheel 1 excessively acts on the engine shaft. However, at the resonance point where the vibration of the flywheel 1 increases, the vibration is transmitted to the vibration ring 8
Thus, the engine shaft can be prevented from being broken.

In the flywheel 1 provided with such a flywheel damper 5, since it is a rotating body, the flywheel 1 and the damper 5 which are separate parts at the time of manufacture are particularly viewed from the viewpoint of safety. Must be securely fastened with hexagon bolts 7.

[0007] For this purpose, the tightening torque of the hexagon bolt 7 must be controlled within a prescribed control range in terms of quality (particularly, from the viewpoint of safety).

Conventionally, the tightening torque of the hexagon bolt 7 has been managed by measuring the torque with a torque wrench.

[0009]

However, when this torque management is performed on a production line, the torque management is a manual operation, and there is a problem that much man-hour is required for the management. In particular, in the case of a large flywheel 1, if there are six tightening points per unit and the specified tightening torque is large (for example, 235 kg-cm or more), manual torque management is more inefficient. There was a problem.

An object of the present invention is to provide a method for tightening a flywheel damper of a flywheel magneto which can easily control a tightening torque on a production line.

[0011]

SUMMARY OF THE INVENTION The present invention is directed to an improvement in a method of fastening a flywheel damper to a flywheel magneto in which a flywheel damper is fastened to a flywheel of the flywheel magneto with a plurality of hexagon bolts.

According to the present invention, the hexagonal bolt is provided with a torque control bolt head connected to the top of the bolt head via a constricted portion, and the constricted portion is set to break at a specified torque. Use management bolts.

The flywheel damper is fastened to the flywheel by applying a tightening torque to the head of the torque management bolt with the torque management bolt.

Using such a torque management bolt,
When a tightening rotational force is applied to the head of the torque management bolt to fasten the flywheel damper to the flywheel, the neck portion is broken at a specified torque, so that the torque can be managed without using a torque wrench. According to such torque management, it is possible to easily manage the tightening torque on the production line.

The present invention also provides a flywheel in which the bottom of a damper cover of a flywheel damper is overlapped with the bottom outer surface of the flywheel of a flywheel magneto, and the bottom of the damper cover is fastened to the bottom of the flywheel with a plurality of hexagon bolts. An object of the present invention is to improve a method of tightening a flywheel damper of Magneto.

In the present invention as well, the hexagonal bolt is provided with a torque management bolt head connected to the top of the bolt head via a constricted portion, and the constricted portion is set so as to break at a specified torque. Use management bolts.

The torque management bolt applies a tightening torque to the head of the torque management bolt to fasten the damper cover of the flywheel damper to the flywheel.

In this case, when the flywheel damper is fastened to the flywheel by applying a tightening torque to the head of the torque management bolt, the constricted portion is broken at a specified torque, so that the torque management can be performed without using a torque wrench. It can be performed. Therefore, according to such torque management, the tightening torque can be easily managed on the production line.

[0019]

FIG. 1 shows an embodiment of a torque management bolt used in the present invention.

[0020] The torque management bolt 11 is
An ordinary hexagonal bolt head 11b is provided at the base end of 1a, and a hexagonal torque management bolt head 11d is continuously provided at the top of the bolt head 11b via a constricted portion 11c, and the constricted portion 11c is provided. The structure is set to break at the specified torque.

FIG. 2 shows a process of fastening the damper cover 6 of the flywheel damper 5 to the flywheel 1 of the flywheel magneto using the torque management bolt 11. Parts corresponding to those in FIGS. 4 and 5 described above are denoted by the same reference numerals.

In this embodiment, the torque management bolt head 11 shown in FIG. 2 is used by using the torque management bolt 11 shown in FIG.
d to give flywheel damper 5
Is fastened to the flywheel 1. When the fastening operation using the torque management bolt 11 is performed in this manner, the constricted portion 11c is broken at a specified torque, and the torque management bolt head 11d is cut off. In this state, it can be seen that the fastening operation has been performed at the specified torque. Therefore, torque management can be performed without using a torque wrench. According to such torque management, it is possible to easily manage the tightening torque on the production line.

Further, according to this method, even if the bolt tightening operation is automatically performed, the bolts that do not reach the specified tightening torque can be easily visually confirmed because the torque management bolt head 11d remains. It is advantageous in terms of quality control.

Further, the torque management bolt 11 is
Since the shape after cutting off the torque management bolt head 11d is the same shape as a normal bolt, it can be applied to the place where the normal bolt was used, and after tightening such as "loosening" or "retightening" Can be handled in exactly the same way as ordinary bolts.

[0025]

According to the flywheel damper tightening method for a flywheel magneto according to the present invention, a torque management bolt head is provided as a hexagonal bolt at the top of the bolt head via a constricted portion, and the constricted portion is formed. Uses a torque management bolt that is set to break at the specified torque, and applies a torque to the head of the torque management bolt with the torque management bolt to fasten the flywheel damper to the flywheel. In addition, the constricted portion is broken at the specified torque, so that torque management can be performed without using a torque wrench. According to such torque management, it is possible to easily manage the tightening torque on the production line.

According to this method, even if the bolts are automatically tightened, the bolts that do not reach the specified tightening torque can be easily visually checked because the torque management bolt head remains. It is advantageous from the aspect of quality control.

Furthermore, since the torque management bolt has the same shape as the ordinary bolt after the head of the torque management bolt is cut off, it can be applied to the place where the ordinary bolt was used. There is an advantage that handling after tightening such as "loosening" and "retightening" can be handled exactly the same as a normal bolt.

[Brief description of the drawings]

FIGS. 1A and 1B are a plan view and a side view showing an example of an embodiment of a torque management bolt used in the present invention.

FIG. 2 is a longitudinal sectional view showing a process of fastening a damper cover of a flywheel damper to a flywheel of a flywheel magneto using the torque management bolt shown in FIG.

FIG. 3 is a bottom view of a main part of the flywheel with a flywheel damper after the fastening in FIG. 2 is completed.

FIG. 4 is a longitudinal sectional view of a flywheel with a flywheel damper of a conventional flywheel magneto.

FIG. 5 is a bottom view of the flywheel magneto shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flywheel 1a Cylindrical part 1b Bottom part 2 Boss part 2a Tapered hole 3 Permanent magnet 4 Ring gear 5 Flywheel damper 6 Damper cover 6a Cylindrical part 6b Bottom part 6c Flange part 7 Hexagon bolt 8 Vibration ring 9 Vibration absorber 10 Hook part 11 Torque management bolt 11a Screw part 11b Bolt head 11c Narrow part 11d Torque management bolt head

Claims (2)

[Claims] 1. A method for tightening a flywheel damper to a flywheel of a flywheel magneto with a plurality of hexagon bolts, wherein the hexagonal bolt has a constricted portion at the top of the bolt head. A torque management bolt head is connected to the torque management bolt head, and the neck portion is set so as to break at a specified torque. A flywheel damper for fastening the flywheel damper to the flywheel by applying a turning torque to the flywheel. 2. A flywheel magneto, wherein a bottom of a damper cover of a flywheel damper is overlapped on an outer surface of a bottom of the flywheel of the flywheel magneto, and the bottom of the damper cover is fastened to a bottom of the flywheel with a plurality of hexagon bolts. In the flywheel damper tightening method, as the hexagonal bolt, a torque management bolt head is continuously provided via a constricted portion at a top of the bolt head, and the constricted portion is set to break at a specified torque. A flywheel, wherein the torque management bolt is used to apply a torque to the head of the torque management bolt to fasten a damper cover of the flywheel damper to the flywheel. Tightening method of flywheel damper for wheel magneto.