JPS5827066Y2 - Earth leakage prevention device at the ignition plug of a forced air-cooled engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an earth leakage prevention device in a spark plug of a forced air-cooled engine.

In conventional forced air-cooled engines, the high-voltage cord was connected to the spark plug outside the air guide cover, so the high-voltage cord was largely exposed outside the air guide cover, which was unsightly, and the terminal section could be damaged by rain or dust. It has the disadvantage of causing insulation deterioration.

In order to eliminate this drawback, the inventor of the present invention previously devised the device shown in FIG.

That is, a tool hole 3 is opened in the air guide cover 2 covering the cylinder head 1 in correspondence with the spark plug 4 fixed to the cylinder head 1, and a high voltage cord 6 is connected and fixed to the bolt-shaped terminal 5 of the spark plug 4 with a nut 9. And this high voltage cord 6
The terminal I is located inside the air guiding cover 2, and a fitting groove 10 on the outer periphery of a rubber cap 8 is removably fitted into and fixed to the tool hole 3.

However, with this structure, the high-voltage cord 6 wobbles due to engine vibration, the nut 9 loosens, and the cord terminal 7
There is a drawback that the wind guide cover 2 approaches the wind guide cover 2 and short-circuits occur.

The purpose of the present invention is to prevent such short-circuits from occurring, and for this purpose, the structure shown in FIG. 1 described above is used as is, and the improved structure shown in FIGS. It is characterized by □.

Hereinafter, an example of the present invention will be explained based on the drawings.

Figure 2 shows a sectional view of the main parts of an overhead valve type forced air-cooled engine, in which the air guide cover 2 is fixed so as to cover the cylinder head 1, and when the spark plug 4 screwed onto the cylinder head 1 is attached or detached, the plug is removed. A tool hole 3 into which a wrench is inserted is opened at a position corresponding to the spark plug 4 of the air guide case 2.

A high voltage cord 6 is connected to the bolt-shaped terminal 5 of the spark plug 4.
The terminal 7 is fixedly tightened by a nut 9 screwed onto the bolt-like terminal 5, and this high voltage cord 6 passes through the high voltage cord insertion hole provided in the side surface of the air guide case 2 and is inserted into the air guide case 2. It is now being incorporated into the

A fitting groove 10 on the outer periphery of a rubber cap 8 is removably fitted and fixed into a tool hole 3 opened in the air guide case 2.

Then, a circumferential protrusion 12 is formed on the lower inner surface of the cover cylinder 11 extending downwardly from the cap, and this protrusion 12
the circumferential groove 1 on the corrugated surface of the insulator 13 of the spark plug 4.
4 so that it can be inserted and removed externally.

The cord terminal 7 is fitted into the upper end of a fitting groove 15 that is cut upward from one location on the lower end of the cover cylinder 11 .

This cord terminal 7 is received by the upper end surface 16 of the insertion groove 15, and is also clamped by the groove's both side surfaces 17, so that it is securely fixed at a position a proper distance away from the air guide cover 2, and the cord terminal This prevents the nut 7 from bending toward the wind guiding cover 2 side or rotating to loosen the nut 9.

Since the present invention is configured as described above, the cord terminal 7 is firmly fixed and held to the plug insulator 13 via the cover tube 11 and the groove 15, and does not bend toward the wind guide cover 2 side. Since the cord terminal 7 is prevented from turning and coming loose from the plug terminal 5, it is possible to prevent the cord terminal 7 from shorting to the wind guide cover 2.

Furthermore, the structure for this purpose is simply to integrally form the cover cylinder 11 on the cap 8 and to form the groove 15 in the cover cylinder 11, so that the structure is simple and can be implemented at low cost.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of the main parts of an overhead valve type ■ type forced air-cooled engine showing the prior art, and Fig. 2 is a front view of the main parts of an overhead valve type
The figure corresponding to the figure, FIG. 3, is a sectional view taken along the line AA in FIG. 1... Cylinder head, 2... Wind guide cover 3... Tool hole, 4... Spark plug, 5, 7... Terminal , 6...
High voltage cord, 8... Cap, 11...
・Cover tube, 13... Insulator, 15...
·groove.

Claims (1)

[Scope of utility model registration request] In a forced air-cooled engine, a terminal 7 of a high-pressure cord 6 is fixed to a bolt-shaped terminal 5 of a spark plug 4 screwed onto a cylinder head 1 of a forced air-cooled engine by screwing a nut 9.
A tool hole 3 is opened in the air guide cover 2 that covers the cylinder head 1 in correspondence with the spark plug 4, the terminal 7 of the high voltage cord 6 is located inside the air guide cover 2, and a cap 8 can be attached or removed to the tool hole 3. A cover cylinder 11 extending integrally from the cap 8 toward the spark plug 4 is fitted and fixed externally to the insulator 13 of the spark plug 4 in a removable manner. A leakage prevention device for an ignition plug part of a forced air-cooled engine, characterized in that a terminal 1 of a high voltage cord is fixed with a steady rest in a groove 15 formed toward the end side.