JPS6214659Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention penetrates the primary coil into the bobbin of the secondary coil, and inserts one end of the bobbin of the primary coil that protrudes outside from one end of the secondary coil into a hole in the bottom of the case. Both coils are housed concentrically in a case, thermosetting resin is poured into the case, filled and hardened between both coils and between the secondary coil and the inner surface of the case, and an iron core is placed in the primary coil bobbin. This relates to a penetrating molded ignition coil, and its purpose is to completely prevent thermosetting resin from flowing into the primary coil bobbin from the upper end, especially during casting.

Figure 1 shows a coil assembly that has passed through the primary coil 1 into the bobbin of the secondary coil 2 and is attached to a thermosetting synthetic resin 3.
This shows an exterior mold type ignition coil in which a case 4 buried inside and an iron core 5 penetrating through the bobbin 1' of the primary coil are covered with a coating layer 6 of thermoplastic synthetic resin, and the top surface is open. Insert the lower end of the primary bobbin 1' protruding from the lower end of the secondary coil into the hole at the bottom of the case 4, stand the secondary coil 2 concentrically with respect to the primary coil in the case, and pour the thermosetting resin 3. After molding, a thermosetting resin is filled between the outer periphery of the primary coil and the secondary coil bobbin, and between the outer periphery of the secondary coil and the inner surface of the case, and both coils are buried in the case and hardened.

The high-voltage terminal 7 has a cylindrical portion 8 having a holding hole for the high-voltage terminal integrally protruding downward from one end of the bottom of the case 4, so the tip portion 7 is inserted into the holding hole before casting. ′ into the case and connect it to the high voltage end of the secondary coil at the end of the winding, but the high voltage end of the secondary coil is pulled out through the small hole at the bottom of the case, cast, and exterior molded. Before connecting the high voltage end of the secondary coil and the tip of the high voltage terminal outside the case,
Sometimes the case, core, and high-voltage terminal are integrally covered with a coating layer.

Conventionally, the upper surface of the collar 9 at the upper end of the bobbin 1' of the primary coil is approximately at the same level as the open upper surface of the case 4, so when the thermosetting resin 3 is cast into the case, a portion of the collar 9 is placed on the bobbin 1'. The resin tends to flow into the interior from above, hardens while adhering to the inner periphery, and then it takes time to remove the adhering resin when passing through the iron core. In addition, it takes time to cast the mold without allowing it to flow in, which hinders productivity improvement.

Therefore, the present invention has a cylindrical wall projecting upward on the upper surface of the collar 9 at the upper end of the primary bobbin to prevent the thermosetting resin from flowing into the inner circumference of the bobbin during casting. This solves the problem. Fig. 2 shows the state before casting using a primary bobbin according to one implementation of the present invention, and the primary terminals 10, 10 are inserted from above on the collar 9 at the upper end, extending to one side. In addition to temporarily fixing the terminal, a block 11 is provided to hold the lead wire at the start end of the primary coil connected to this terminal, and both lead wires at the end of the winding and the other end of the secondary coil. A U-shaped wall 12 connected to one side and surrounding the inner periphery of the bobbin is integrally erected, and this wall 12 and the side surface of the block 11 constitute a cylindrical wall 13. This primary coil bobbin may be molded from a suitable synthetic resin, and the block 11 and wall 12 may be provided integrally during molding.

The cylindrical wall 13 only needs to have a height that allows the upper end to be located above the level of the upper surface of the thermosetting synthetic resin cast into the case, but it is sufficient to ensure that the resin does not flow into the primary bobbin. It is desirable for the wall 12 to protrude considerably above the upper surface level L of the resin, and in this case, the thickness of the wall 12 is as shown in the figure in order to cut and remove it from the upper surface of the collar 9 prior to inserting the core. It is best to keep it as thin as possible.

This reliably prevents the resin from flowing into the primary bobbin during casting.

The cylindrical wall 13 of the embodiment shown in FIG. 4 does not need to be removed from the upper surface of the collar later (of course, it may be removed).
The height has been reduced. Therefore, in this case, the wall thickness is somewhat thick, but as shown in the figure, only the corner 13' is made extremely thin, so that when inserting the core, the wall thickness at the corner 13' is made extremely thin.
If 3' is torn, the work of inserting the core will not be obstructed.

In this embodiment as well, a block 11 is integrally provided on the collar, and this block connects the lead wire 1a at the winding start end of the primary coil, and the lead wires 1b and 2a at the winding end and the secondary coil winding start end. An E-shaped frame part 11a on the collar that is held separately, a primary terminal that connects to the central leg of the E-shaped frame part and extends outside the collar and connects the lead wire at the starting end of the primary coil winding, and a primary terminal that connects the lead wire at the starting end of the primary coil winding. The two primary terminals that connect both lead wires at the beginning of the winding of the secondary coil can be placed side by side as shown in the figure, or in a terminal mounting part 11b equipped with a blind hole into which they can be inserted from above in an approximately T-shaped arrangement. This can prevent the lead wire from loosening when leading during casting or exterior molding, causing contact between 1a, 1b, and 2a and causing the wire to shoot, or from coming into contact with the iron core or coming out of the exterior coating layer 6. Insulation failure caused by exposure is eliminated, and since both primary terminals are positioned, workability during insertion is greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of an example of a molded ignition coil, Fig. 2 is a sectional view of an embodiment of the bobbin according to the present invention before casting, and Fig. 3 is a main part of the same primary coil. 4 is a perspective view of the main parts of the primary coil of another embodiment. In the figure, 1 is the primary coil, 1' is the bobbin, 2 is the secondary coil, and 3 is the thermosetting synthetic resin. , 4 is a case, 5 is an iron core, 9 is a collar at the upper end of the primary bobbin, and 13 is a cylinder wall.

Claims (1)

[Claim for Utility Model Registration] The coil assembly is assembled by inserting one end of the primary coil bobbin that protrudes outside the secondary coil into the hole in the bottom of the case. In the molded ignition coil, the thermosetting resin is poured into the case and hardened, and the iron core is passed through the primary coil bobbin.A primary terminal is attached to the flange at the upper end of the primary coil bobbin. A block for holding the primary lead wire and a U-shaped wall connected at both ends to this block protrude above the level of the top surface of the thermosetting resin cast into the case and extend above the inner periphery of the bobbin. A molded ignition coil characterized by comprising a surrounding cylinder wall.