JPH0128653Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition coil mainly used in small internal combustion engines.

This type of ignition coil is constructed by placing two coils around the core in an insulating coil case with an opening at one end.
The secondary coil and the primary coil are arranged dually inside and outside, and the core, primary and secondary coils, and primary and secondary terminals are made of thermosetting synthetic resin that is cured inside the coil case. A device has been developed that allows it to be tied together.

An object of the present invention is to provide an ignition coil of this type that has a simple structure and allows for easy and accurate positioning of the core relative to the coil case before bonding with thermosetting synthetic resin. do.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes an insulating coil case made of synthetic resin and having an opening at one end. Both coils 2 and 3 are arranged so that the coils 3 are located concentrically. The inner end surface of the secondary coil 3 abuts against a plurality of protrusions 1a protruding from the bottom surface of the coil case 1, and the inner end surface of the primary coil 2 abuts against a stepped portion 4 formed on the inner peripheral surface of the coil case 1. is collided with. This causes the primary coil 2
is positioned so that it can be located in the middle of the secondary coil 3 in the generatrix direction. The secondary coil 3 is wound around a hollow bobbin 5 made of synthetic resin, and a ferrite core 7 as a core and a secondary terminal connecting plate 8 that overlaps with the ferrite core 7 are fitted into the rectangular center hole 6 of the secondary coil 3. The end of the connecting plate 8 on the side of the coil case opening is bent toward the end surface of the ferrite core 7.
A secondary terminal 9 passing through the bent portion is connected by soldering, and the secondary terminal 9 is attached to an insulating connection tube 10 for a high voltage cord made of synthetic resin by penetrating its bottom. . Further, the end of the connection plate 8 on the bottom side of the coil case is bent in the same way, and the winding start terminal 3 of the secondary coil 3 is attached to the bent part.
a is connected by soldering.

A pair of plate-like protrusions 16 that protrude in opposite directions are provided on the outer circumferential surface of the base end of the connecting tube 10 . Each protrusion 16 has a positioning protrusion 17 at its tip.
Moreover, each has a plurality of pressing protrusions 21 on the inner surface.

A pair of notch-shaped positioning recesses 15 are formed on the inner peripheral surface of the opening of the coil case 1 with a phase difference of 180°, and a connecting tube 10 is formed in both positioning recesses 15.
Both positioning protrusions 17 are engaged with each other. As a result, the connecting tube 10 is positioned at the opening of the coil case 1, and the ferrite core 7 is held and positioned by the both bent portions of the connecting plate 8. Furthermore, each pressing protrusion 21 abuts against the outer end surface of the secondary coil 3, and the inner end surface of the coil 3 is brought into contact with the coil case 1.
The secondary coil 3 is positioned because it is pressed against the protrusion 1a on the bottom surface.

Both primary terminals 11 have the same shape, and each terminal 11
consists of a low-voltage cord connecting portion 11a and a hook-shaped attachment portion 11b bent at the base end thereof. An elastic pawl 12 is formed at the tip of the attachment portion 11b that bends in the opposite direction to the connection portion 11a by cutting and bending the tip of the attachment portion 11b toward the connection portion 11a. A letter-shaped notch 13 is formed.

The winding start end 2a of the primary coil 2 is wound around the notch 13 of one of the primary terminals 11 and connected by soldering. Further, winding end terminals 2b and 3b of the primary coil 2 and the secondary coil 3 are wound around the notch 13 of the other primary terminal 11, and similarly connected by soldering.

A pair of terminal positioning holes 14 are formed in the coil case 1 with a phase difference of 180 degrees, and the ends of the mounting portions 11b of the pair of primary terminals 11 are located in the terminal positioning holes 14. The portions are forcibly inserted against the elastic force of the elastic claws 12, whereby both primary terminals 11 are positioned and fixed in the opening of the coil case 1.

After each component is arranged in the coil case 1 as described above, a thermosetting synthetic resin, such as an epoxy resin R, is injected into the coil case 1 through between the plate-like protrusions 16 of the connecting tube 10, and then vacuum removed. It is hardened by foam treatment. As a result, the primary coil 2, the secondary coil 3, the ferrite core 7, the connecting tube 10, and both primary terminals 11 are bonded to the coil case 1.
When this epoxy resin R is injected and degassed, it overflows from the opening of the coil case 1, but the overflow is received by the receiver 18 on the outer periphery of the opening of the coil case 1 and does not flow out to the outside. . This receiver 18 is cut off after the epoxy resin R is cured.

Each primary terminal 11 has an end of a low voltage cord 19,
Further, the ends of high voltage cords 20 are inserted into connection tubes 10 and connected to the secondary terminals 9, respectively.

As described above, according to the present invention, in an insulating coil case having an opening at one end, a secondary coil and a primary coil are arranged in a dual manner inside and outside with the core at the center.
In the ignition coil, the core, primary and secondary coils, and primary and secondary terminals are integrally bonded to the coil case using a thermosetting synthetic resin that is cured within the coil case. Insert the hollow bobbin to be wound into the coil case, fit the core and the connection plate for the secondary terminal that overlaps with the core into the hollow bobbin, and place both ends of the connection plate toward both end surfaces of the core. Connect the terminal of the secondary coil to one bent part located on the bottom side of the coil case, connect the secondary terminal to the other bent part located on the opening side of the coil case, and connect the terminal of the secondary coil to the other bent part located on the coil case opening side. Since the terminals are attached to the insulating connecting tube for the high voltage cord which is positioned in the opening of the coil case, the core can be positioned extremely easily and accurately with respect to the coil case via the connecting plate and the connecting tube.
Furthermore, since the connection plate that connects the secondary terminal and the secondary coil is also used for positioning and holding the core, there is no need to provide a special member for holding the core, and the structure is simplified.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional front view, Fig. 2 is a view taken along the line shown in Fig. FIG. 1 is an enlarged cross-sectional view of the section shown by arrows, and FIG. 4 is an exploded perspective view. R... Epoxy resin as thermosetting synthetic resin, 1... Coil case, 2... Primary coil, 3
... Secondary coil, 5 ... Hollow bobbin, 7 ... Ferrite core as core, 8 ... Connection plate, 9 ...
Secondary terminal, 10... Connection tube, 11... Primary terminal.

Claims (1)

[Scope of utility model registration request] Inside an insulating coil case with an opening at one end, a secondary coil and a primary coil are arranged double-layered inside and outside with the core at the center, and the core, primary, and secondary coils are connected to the primary and secondary terminals. In the ignition coil, the hollow bobbin around which the secondary coil is wound is inserted into the coil case. Then, fit the core and a connection plate for a secondary terminal that overlaps with the core into the hollow bobbin, bend both ends of the connection plate toward both end surfaces of the core, and position it on the bottom side of the coil case. Connect the terminal of the secondary coil to one bent part located on the coil case opening side, connect the secondary terminal to the other bent part located on the coil case opening side, and connect the secondary terminal to the coil case opening side. An ignition coil attached to an insulating connection tube for a positioned high voltage cord.