JPH0514173B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the shape of a spark plug for spark discharge necessary for igniting gas appliances and the like.

Prior Art The structure of a conventional spark plug is shown in FIG. In general, a spark plug includes an insulator 10 and a core wire 11 for discharging inserted through the insulator in order to guide ignition energy that generates high voltage (10 Kv or more) to a burner flame.
and a core wire 11 and an insulator 10.
is bonded to the insulator 10 with a ceramic 12 or the like of the same quality to maintain the size and strength of the spark plug.

Problems to be Solved by the Invention However, due to the nature of the adhesive in the manufacturing process of such spark plugs, spark plugs are held in a high-temperature furnace at 300°C using jigs, etc. in order to maintain their dimensions. It requires a sintering (baking hardening) manufacturing process.
Furthermore, a drying process for the adhesive is required before sintering, and despite the shape and configuration, there are problems in secondary manufacturing costs, dimensional control in the furnace, and work time control. Furthermore, in practice, in the case where the ignition plug is mounted close to the gas burner flame, a certain distance is required between the discharge portion 11a of the core wire 11 and the insulator 10 so that the burner flame does not directly hit the insulator 10. Therefore, core wire 1
Since positioning is generally performed by processing a part of the core wire, the cost of dimensional control required for positioning the core wire is also high. Also, core wire 11 and insulator 10
Because of the adhesive, when used in the stove part of a gas appliance, it was not possible to completely prevent water spray, boiling liquid, etc. from entering from the usage environment.

The present invention aims to solve these conventional problems, and maintains the dimensions of the insulator and the discharge part of the core wire only by mechanical assembly without using adhesives. The present invention provides a spark plug that is inexpensive to manufacture.

Means for Solving the Problems The spark plug of the present invention has a ring interposed between the discharge part of the core wire and the insulator to maintain a constant distance and apply a biasing force to the core wire to maintain the distance. .

Effects The spark plug of the present invention brings the discharge part of the core wire, the ring, and the insulator into close contact with each other due to the biasing force applied to the core wire, thereby eliminating the need for adhesion of the core wires used in the past. prevent water from entering the area,
In addition, the burner flame should not come into direct contact with the insulator, and the temperature of the insulator should not become high enough to cause cracks or the like.

Embodiment A spark plug according to an embodiment of the present invention will be described below with reference to the drawings. As shown in Fig. 1, a fixing spring 3 is fixed to the lower end of the heat-resistant, electrically insulating insulator 2 using a speed nut, etc., which acts in the direction that applies a force that always brings the core wire 1 inserted through the insulator 2 into close contact with the insulator 2. It is fixed with a ring 4. 2a is a recessed portion for eliminating displacement of the fixed spring 3. On the other hand, a convex portion 7 is integrally formed at the upper end of the insulator 2 to guide the core wire 1. Reference numeral 5 denotes a cylindrical ring that fits into the convex part 7 of the insulator 2, and also fits into the concave part 6a of the circular discharge part 6 attached to the upper end of the core wire 1, so that the biasing force of the core wire 1 by the fixed spring 3 is reduced. The discharge part 6 and the insulator 2 are brought into close contact with each other, and a constant distance is maintained between the insulator 2 and the discharge part 6. In this embodiment, the fixed spring 3 is an insulator 2 which is not affected by the burner flame 8 shown in FIG.
Because it is located at the lower end of the spark plug, the spring force does not change due to heat, making it as effective as or better than a spark plug fixed with adhesive. Further, a groove 9 is provided at the lower end of the core wire 1, and a fixing ring 4 engaged with this groove 9 is designed to prevent the spring 3 from coming off. However, as shown in FIG. 3A and B, the core wire 1 may be provided with a screw 1a and the nut 1b may be screwed into this, or the end of the core wire 1 may be flattened 1c to have a diameter larger than the outer diameter of the spring 3. The same effect can be obtained even if processed in such a way.

Effects of the Invention As described above, the spark plug of the present invention has a cylindrical ring interposed between the insulator and the discharge part of the core wire, and the ring is brought into close contact with and fixed to the insulator and the discharge part by the biasing force. Since there is no need for conventional adhesives, it is possible to shorten working time, reduce manufacturing costs, and improve component precision. In addition, it has an extremely advantageous configuration in practice because it can secure a distance from the burner flame and prevent the infiltration of boiling liquid, etc., which were difficult points in practical use.

[Brief explanation of the drawing]

FIG. 1A is a cross-sectional view of a spark plug according to an embodiment of the present invention, FIG. 1B is an exploded perspective view thereof, FIG. , B are a sectional view of a main part of another embodiment showing the attachment of the fixing spring, and FIGS. 4A and 4B are a sectional view and an exploded perspective view of a conventional spark plug. 1... Core wire, 2... Insulator, 3... Fixed spring, 4
...Fixed ring, 5...Ring.

Claims (1)

[Scope of Claims] 1. An insulator, a core wire that is inserted into the insulator and has a discharge portion at its upper end, and a cylindrical ring that is interposed between the discharge portion of the core wire and the insulator and that is brought into close contact with these by biasing force. Spark plug with. 2. The spark plug according to claim 1, wherein the core wire and the insulator are always brought into close contact with each other through a spring at the lower end of the core wire.