JPS648462B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition coil for an internal combustion engine, and particularly to a structure of a coil cap portion for eliminating an external resistor in an iron case type coil and inserting a resistor inside the coil.

In conventional well-known coils, coils with external resistors are mainly used due to the demand for improved ignition coil performance and startability. are improving.

However, in the conventional external resistor described above, the resistance wire used to produce the necessary resistance value is insulated with an insulator such as an insulator, and the resistance wire has two wires at each end: the wire coming from the power supply and the wire going to the coil. It consists of a resistor with a terminal to connect it to.When starting, this resistor is short-circuited, so a large current flows to the coil side only during starting, resulting in high performance. However, in addition to the coil itself, the above-mentioned external resistor is required, which increases the cost. There are drawbacks such as problems and restrictions on the installation space for the ignition coil due to the presence of this resistor.

In order to solve the above-mentioned drawbacks, the present invention provides flanges above and below the outer periphery of the cylindrical leg of the coil cap, winds the primary coil between these flange parts, and further provides a winding part on the cylindrical leg. A winding wire is wound here so that the magnetic flux does not interlink with the central core, and three terminals are provided at the top of the coil cap, and one end of the winding wire wound around the winding section is connected to one of them. Then, connect the other end of the winding wound around the winding section and one end of the primary coil wound between the upper and lower flanges to the other one, and By connecting the other end of the wound primary coil, the conventional external resistor and primary spool can be eliminated, and at the time of startup, the terminal to which the wound wire is connected can be connected to the winding section. By shooting, a large current flows through the same primary winding as during steady operation, and the purpose is to achieve high starting performance without the need for a conventional external resistor.

The present invention will be described below with reference to embodiments shown in the drawings. In Figures 1 to 4, 1 is a copper-shaped iron case, and 2 is a high pressure resistant case fixed to the case 1 by wrapping the open end of the case 1 and closing the open end of the case 1. A coil cap made of insulating resin, 3 a base made of an insulator placed on the inner bottom surface of the case 1, 4 a central core insulated by the base 3 and placed in the center of the case 1, 5 a core of the central core 4; A secondary coil placed on the outer periphery, 6 a primary coil placed on the outer periphery of the secondary coil 5, 7 a secondary terminal fixed at the center of the coil cap 2, 8a,
8b is two primary terminals fixed to the coil cap 2, and 8c is an intermediate terminal fixed to the coil cap 2 for starting. 9a and 9b are windings having a certain resistance, which replace conventional external resistors wound around the central core 4 so as not to interlink magnetic flux. The end of the primary coil 6 is
After being wrapped around the flange protrusion 2h and fixed, it is electrically connected to one of the primary terminals 8b, which serves as a negative electrode. The winding start of the primary coil 6, the winding end of the windings 9a and 9b having a certain resistance, which are wound so that the magnetic flux does not interlink with the central core 4, and the winding end of the secondary coil 5. The main winding is electrically connected to the intermediate terminal 8c. The beginnings of the windings 9a and 9b having a certain resistance, which are wound around the central core 4 so that the magnetic flux does not interlink with each other, are electrically connected to the other primary terminal 8a, which serves as a positive pole. The winding start of the secondary coil 5 is electrically connected to the secondary terminal 7 via the central core 4 and the plate spring 11. Reference numeral 10 denotes a screw for filling a screw hole provided in the secondary terminal 7 with insulating oil into the case 1 and then closing the screw hole.

The structure of the coil cap 2 is, as shown in FIG. 2, a cylindrical leg portion that extends toward the bottom of the case 1 and wraps around the secondary coil 5 and the central core 4 in an insulating manner. 2f, and extends toward the secondary coil 5 inside the cylindrical leg portion 2f, bites into the end portion of the secondary coil 5,
A small cylindrical portion 2c for fixing the secondary coil 5 within the case 1 is integrally molded. Flange portions 2d, 2e and radially extending protrusions 2a, 2b are integrally molded on the outer periphery of the cylindrical foot portion 2f, and a primary The coil 6 is wound thereon, and flange protrusions 2g and 2h for tightening the winding start and end of the primary coil 6 are integrally molded on the upper flange part 2d. Further, windings 9a and 9b having a certain resistance are wound around the protrusions 2a and 2b, and a catch portion is integrally formed at the tip of each of the protrusions 2a and 2b to prevent the windings from slipping.

In the above configuration, the cylindrical leg portion 2f of the cap 2
By providing the flange portions 2d and 2e on the outer periphery of the cap, the primary coil 6 can be directly wound on the cap 2, and the primary spool for winding the primary coil 6 can be eliminated. Since the secondary coil 6 is directly wound around the cap 2 fixed to the case 1, an ignition coil with excellent vibration resistance can be obtained. Next, by providing an intermediate terminal 8c in addition to the conventional primary terminals 8a and 8b on the upper side of the cap 2, a protrusion perpendicular to the central core 4 is provided between the primary terminal 8a and the intermediate terminal 8c. Part 2
Windings 9a and 9b having a certain resistance are wound around a and 2b so that the magnetic flux does not interlink with the central core 4, and when starting, by shorting between terminals 8a and 8c, the conventional external In the same way as shooting a resistor, high starting performance can be obtained by passing a large current through the same primary winding as during steady operation.

In addition, the part replacing the conventional external resistor between the primary terminal 8a and the intermediate terminal 8c of the present invention is as follows.
When this part is shot at startup, it is a part to obtain higher performance than during steady operation, so it may have a structure that does not easily affect the primary inductance as shown below.

(1) Above the flange 2d of the cylindrical leg 2f of the coil cap 2, protrusions 2a and 2b are protruded in a direction parallel to the central core 4, and the winding 9a and 2b having a certain resistance are attached to the protrusions 2a and 2b in a direction parallel to the central core 4. 9b.

(2) A winding part with a long winding width is formed on the outermost layer of the circumference with the central core 4 of the cylindrical leg part 2f as the central axis, and a winding wire with a certain resistance is wound on this winding part. In addition, the structure is such that magnetic flux is difficult to interlink with the central core 4.

As described above, in the present invention, the cylindrical leg of the coil cap is extended, and the secondary coil assembled around the central core is housed inside the cylindrical leg, and two flanges are attached to the outer periphery of the cylindrical leg. By providing a section and winding the primary coil between them, the primary spool that was conventionally used to wrap the primary coil can be eliminated, and an ignition coil with excellent vibration resistance and insulation can be obtained. effective.

Furthermore, an intermediate terminal is provided in addition to the primary terminal on the upper side of the coil cap, and these lead wires are electrically connected. By winding a winding with a certain resistance around the winding part formed in the main body, and by shooting this winding at startup, a larger current can flow through the same primary winding as during steady operation. This has the excellent effect of providing high starting performance without the need for conventional external resistors.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing an embodiment of the coil of the present invention, FIG. 2 is a perspective view showing a coil cap in the coil shown in FIG. 1, and FIG. 3 is a perspective view of the coil cap at the end of winding. FIG. 4 is an electrical circuit diagram of the coil of the present invention. 1... Iron case, 2... Coil cap, 2
a, 2b... Protrusion as a winding part, 2f... Cylindrical foot part, 4... Central core, 5... Secondary coil, 6
...Primary coil, 7...Secondary terminal, 8a,
8b...Primary terminal, 8c...Intermediate terminal, 9
a, 9b... windings with a certain resistance.

Claims (1)

[Claims] 1 center core and 2 arranged around the outer periphery of this center core
A secondary coil and a first coil placed around the outer circumference of this secondary coil.
It is equipped with a secondary coil, an iron case that houses these, a coil cap made of an insulator that is fixed by closing the open end of this iron case, and two primary terminals and a secondary terminal that are fixed to this coil cap. An ignition coil for an internal combustion engine, comprising: an intermediate terminal fixed to the coil cap; a cylindrical foot portion integrally formed with the coil cap and around which the primary coil is wound; and a winding formed on the cylindrical foot portion. and a winding having a certain resistance wound around the winding part, the primary coil is connected between one of the two primary terminals and the intermediate terminal, and the primary coil is connected between one of the two primary terminals and the intermediate terminal. An ignition coil for an internal combustion engine, characterized in that the winding having a certain resistance is connected between the other primary terminal of the ignition coil and the intermediate terminal.