Claims:We Claim:

1. A method (10) of assembly of a glow plug, the method (10) comprising:
caulking (105) a resistive coil (205) to a central electrode (210);
inserting (110) the resistive coil (205) with the central electrode (210) into a heating tube (215);
welding (115) the heating tube (215) to the coil (205);
stretching (120) the coil (205) by a pulling operation of the electrode (210);
dosing (125) Magnesium Oxide in a powder chamber (220) between the coil (205) and the heating tube (215);
sealing (130) the powder chamber (220);
conducting a swaging operation (135) on the assembly;
characterized in that:
mounting an electric interface (140) to the assembly to complete the glow plug assembly.

2. The method (10) as claimed in claim 1, wherein welding (115) the heating tube (215) to the coil (205) comprises Tig welding.

3. A method (30) of manufacturing an integrated pin terminal (140) for assembly of a glow plug, the method (30) comprising:
inserting (305) a sheet metal insert (350) into a machined pin (355), the pin (355) composed of any one of steel and brass;
overmolding (310) the pin (355) inserted with the sheet metal insert (350), the molding composed of polymer.

4. An integrated pin terminal (140) for assembly of a glow plug, the integrated pin terminal comprising:
a machined pin, the pin composed of any one of steel and brass;
a sheet metal insert adapted to be inserted into the machined pin;
an overmold over the machined pin inserted with the sheet metal insert, the mold composed of polymer.
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to an integrated pin terminal for a glow plug used in engines and a method of assembly of the glow plug.

Background of the invention
[0002] It is known that glow plugs are used in engines to provide cold start capability to the engine. There is a multitude of parts in the assembly of a glow plug, many parts being very small in size and intricate in shape, such that handling the same becomes difficult during assembly. Because of the above difficulty, some parts can be missed during the assembly resulting in rejection or undesirable usage of the glow plug. There is a problem that needs to be addressed.

Brief description of the accompanying drawings
[0003] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawings:

[0004] Figure 1 shows a schematic of steps involved in assembly of a glow plug;

[0005] Figure 2 shows a schematic of steps involved in assembly of an integrated pin terminal; and

[0006] Figure 3 shows a schematic of assembly of the integrated pin terminal with the heating tube to form the glow plug.

Detailed description of the embodiments
[0007] Figure 1 illustrates a schematic of steps involved in an assembly of a glow plug. The method 10 of assembly of a glow plug comprises a first caulking operation 105 of a resistive coil 205 to a central electrode 210, a second insertion operation 110 of the resistive coil 205 with the central electrode 210 into a heating tube 215, a welding operation 115 of the heating tube 215 to the coil 205, stretching operation 120 of the coil 205 by a pulling operation of the electrode 210, a dosing operation 125 of Magnesium Oxide in a powder chamber 220 between the coil 205 and the heating tube 215, a sealing operation 130 of the powder chamber 220, a swaging operation 135 on the assembly. The above is commonly understood by a person skilled in the art. The method 10 further comprises mounting an electrical interface 140 to the assembly to complete the glow plug assembly.

[0008] The welding operation 115 of the heating tube 215 to the coil 205 comprises Tig welding.

[0009] Figure 2 illustrates a schematic of steps involved in assembly of an integrated pin terminal 140. In the context of the instant specification, the electrical interface 140 and the integrated pin terminal is the same and is used interchangeably. The method 30 comprises an insertion step 305 of a sheet metal insert 350 into a machined pin 355, the pin 355 composed of any one of steel and brass, and an overmolding step 310 of the pin 355 inserted with the sheet metal insert 350, the molding composed of polymer. The pin 355 which is made of a metal, serves as one of the electrical interfaces for the glow plug.

[0010] Figure 3 illustrates a schematic of assembly of the integrated pin terminal 140 with the heating tube 215 to form the glow plug. This is the same as the last step in the method 10 of the assembly of the glow plug. This continues after the swaging operation 135 on the assembly. This is a press fitting operation for fitting the electrical interface 140 on the glow plug.

[0011] The assembly operations mentioned above are known in the industry and commonly understood by a person skilled in the art. The material used for injection overmolding is PA66GF35 which is a type of polymer.

[0012] The advantage of the above is that handling the electrical interface 140 is easier than handling all the individual smaller components that go into being assembled as the electrical interface of conventional glow plugs. This reduces the possibilities of components being missed resulting in the malfunction or rejection of the assembled glowplugs.

[0013] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.