JPH02220418A - Ignition coil for firing internal-combustion engine - Google Patents

Abstract

PURPOSE:To easily connect primary and secondary terminals to primary and secondary coils with soldering by forming a primary connector so that it is integral with a primary bobbin; besides, by forming a secondary connector which extends axially from one side of axial end faces of a secondary bobbin so that its secondary connector is integral with the secondary bobbin. CONSTITUTION:Primary and secondary connectors 15c and 16c are formed to be integral with primary and secondary bobbins 15 and 16 respectively. Further, primary and secondary coils 13 and 14 are wound on junction parts 21c and 21d. Then a prescribed soldering-junction is completed by performing only soldering works to these junction parts 21c and 21d. After winding the primary and secondary coils 13 and 14, soldering-junction is performed as it is to primary terminals 21a and 21b as well as a secondary terminal 22. The soldering works are thus performed to the primary and secondary bobbins 15 and 16 as a unit work prior to incorporation into an ignition coil. Then several steps of the conventional process are reduced.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an ignition coil for an internal combustion engine, and in particular to a primary bobbin around which a primary coil is wound, a primary bobbin that accommodates the primary bobbin, and a secondary coil that is divided and wound. The present invention relates to an ignition coil that includes a rotating secondary bobbin, and is equipped with a connector for a primary terminal connected to the primary coil and a connector for a secondary terminal connected to the high voltage side of the secondary coil.

[Prior Art] An ignition coil for an internal combustion engine consists of a core wound with a primary coil and a secondary coil.Recently, multilayer split winding has been adopted for the insulation structure of the secondary coil where high voltage is induced. There is.

This method divides the secondary coil into multiple layers to suppress the voltage between the eyebrows to below the partial discharge voltage. Multiple grooves are formed on the outer surface of the secondary bobbin of the cylindrical body, and the secondary coil is inserted into these grooves. It is divided and wound, for example, as disclosed in Japanese Patent Application Laid-Open No. 61-25261.
It is disclosed in Publication No. 8.

Furthermore, in Japanese Utility Model Application Publication No. 59-9524, the first
A secondary bobbin has been proposed in which the groove, the second groove, and the first groove on the winding end side are narrower than the groove width of the intermediate groove. Further, Japanese Patent Application Publication No. 1988-500152 discloses a technique in which the insulation interval between the secondary coil and the primary coil is increased as the potential of the secondary coil increases.

[Problems to be Solved by the Invention] Regarding the above-mentioned prior art, the first publication does not specifically explain the terminals connected to the primary coil and the secondary coil, and according to the drawings, the terminals are connected to the ignition coil. It is spaced apart from the bobbin on a plane perpendicular to the axis.

The second publication discloses a primary terminal and a secondary terminal arranged in the axial direction, but the primary connector including the primary terminal is provided apart from the primary bobbin, and this primary connector is covered with an exterior housing along with each component. It is constructed so that it is integrally molded with molded resin and a secondary connector portion is formed at the same time.

In the technique described in the third publication, each connector including the primary and secondary terminals is attached in the axial direction, but each connector is placed apart from each bobbin.

In this way, in the above-mentioned conventional technology, both the primary connector and the secondary connector are distinguished from the bobbin.
When soldering the primary and secondary terminals to each coil, each connector must be held or temporarily secured, making soldering difficult and creating gaps between each connector and the bobbin. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ignition coil in which a primary bobbin is housed in a hollow portion of the secondary bobbin, with a structure in which a primary terminal and a secondary terminal can be easily soldered to the primary coil and the secondary coil.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a primary bobbin which is made up of a cylindrical body having flanges on the side surfaces of both ends, and in which a primary coil is wound between the flanges; It is comprised of a cylindrical body formed with a plurality of annular grooves, and includes a secondary bobbin in which a secondary coil is divided and wound around each of the plurality of grooves, and the primary coil is wound in a hollow part of the secondary bobbin. An ignition coil for an internal combustion engine, which houses the primary bobbin, and has a core inserted into the hollow part of at least the primary bobbin and is molded with synthetic resin. A primary connector extending axially from one flange of the bobbin is integrally formed with the primary bobbin, and includes a secondary terminal connected to the secondary coil, and extends from one axial end surface of the secondary bobbin. A secondary connector extending in the axial direction is integrally formed with the secondary bobbin.

[Function] In the above ignition coil, the primary connector including the primary terminal connected to the primary coil is formed integrally with the primary bobbin, and the secondary connector including the secondary terminal connected to the secondary coil is formed integrally with the secondary bobbin. It is formed integrally with the next bobbin. After the primary coil and the secondary coil are wound around the primary bobbin and the secondary bobbin, respectively, the primary bobbin is housed in the hollow part of the secondary bobbin. Therefore, the primary connector and the secondary connector are arranged in close proximity to the primary coil and the secondary coil,
The primary coil and the secondary coil are directly soldered to the primary terminal and the secondary terminal.

The core is inserted into the hollow part of the primary bobbin to form an ignition coil, and the primary current supplied to the primary coil via the primary terminal is controlled intermittently.

This causes a magnetic flux change in the core, and a high voltage is induced in the secondary coil, which is output from the secondary terminal to the high voltage cable.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Figures 1 and 2 show an embodiment of the ignition coil of the present invention. The ignition coil 1 is a closed magnetic circuit core 11 wrapped around a primary coil 13 and a secondary coil 14, and is made of a synthetic resin cylinder with a bottom. It is housed in a housing 1a of the body. The closed magnetic circuit core 11 has a cylindrical peripheral core lla, and a hollow cylindrical central core flb extends in the axial direction of the central portion thereof. The peripheral core lla and the central core 11b are formed by laminating a plurality of cylindrical magnetic bodies having different diameters in the radial direction to form a cylindrical body.

An annular end face core llc is press-fitted between one end of the central core llb and one end of the peripheral core lla, and are magnetically coupled. Then, the other end of the peripheral core lla and the center core l
An end face core lid of an annular lid body that magnetically couples the other ends of the lb is press-fitted into the peripheral core 11a and is magnetically coupled.

As shown in FIG. 1, the end face cores llc and lid are formed by laminating a plurality of annular magnetic bodies to form a flat plate body. A non-oriented or oriented silicon steel plate is used as the magnetic material constituting these end cores llc, lid, the peripheral core lla and the central core llb.

Note that an annular micro-gap, ie, an air gap 18, is formed between the center core 1.1b and the end core lld in order to reduce the hysteresis of the magnetic flux and obtain a large change in the effective magnetic flux.

Central core ll of the closed magnetic circuit core 11 configured as described above
A primary coil 13 is installed between the outer surface b and the inner surface of the peripheral core lla.
and a secondary coil 14 are housed therein. That is, a part of the bobbin 15, which is a cylindrical body made of synthetic resin, around which the coil 13 is partly wound, is placed in a hollow part of a secondary bobbin 16, which is a cylindrical body made of synthetic resin, around which the secondary coil 14 is wound. The central core Ilb is inserted into the hollow portion of the primary bobbin 15.

A part of the bobbin 15 has a flange formed at both ends, and a part of the coil 13 is wound between these flange parts. As shown in FIG. 2, one collar portion of the primary bobbin 15 is formed with an arm portion 15a that extends in the radial direction, and this arm portion 15a has a cylindrical shape that extends in the axial direction and passes through the housing 1a. A portion of the connector 15C is integrally molded.

A pair of primary terminals 21a, 21 are provided inside the connector 15c.
b is buried, and these primary terminals 21a, 21b
partially extend in the axial direction inside the connector 15c, and each base extends outward from the side surface of the arm portion 15a to form joint portions 21c and 21d. Further, pins 15p and 15q are integrally formed and erected on the arm portion 15a of the primary bobbin 15. After the winding start of the primary coil 13 is wound around the pin 15p several times, the joint portion 21c&: of the primary terminal 21a is wound and soldered. Similarly,
The end of the winding of the primary coil 13 is wound several times around the pin 15q, and then wound around the joint portion 21d of the primary terminal 21b and soldered.

On the other hand, a plurality of annular grooves are formed on the side surface of the cylindrical body of the secondary bobbin 16, and the secondary coil 1 is inserted into each of these grooves.
4 is divided and wound. The outer periphery of the high-voltage side secondary bobbin 16, which is the end of winding of the secondary coil 14, is reduced and a stepped portion is formed in the axial direction. Therefore, the number of turns of the coil in this part is smaller than in other parts.

The secondary coil 14 is integrally molded with a bottomed cylindrical secondary connector 16ch that extends in the axial direction and extends in the axial direction. It is extending. A portion of the outer peripheral portion of the bottom surface of the secondary connector 16c is in contact with the end surface of the peripheral core 11a. Inside the secondary connector 16C is a secondary terminal 2 made of a metal cylinder with a bottom.
2 are integrally provided, and a projection 22a having an abbreviated cross section formed at the bottom of the secondary terminal 22 penetrates the bottom of the secondary connector 16c and extends into the housing la. A pin tap is integrally formed on the bottom surface of the secondary bobbin 16, and a notch 16a is formed in the radial direction.

As shown in FIG. 1, the end of the winding of the secondary coil 14 is wound around the protrusion 22a of the secondary terminal 22 and soldered. The winding start of the secondary coil 14 is taken out from the notch 16a of the secondary bobbin 16 as shown in FIG.
After being wound several times around the primary terminal 21b, it is wound around the joint 21d of the primary terminal 21b and soldered. Incidentally, this solder bonding is partially performed simultaneously with the bonding at the end of winding of the coil 13. In this way, the secondary terminal 22 extends in the axial direction of the ignition coil 1 and is open, and a terminal of a high voltage cable (not shown) is fitted into the open end of the secondary terminal 22.

These parts including the closed magnetic circuit core 11 are housed in a housing la, and a thermosetting synthetic resin, such as an epoxy resin, is filled into the gap in the housing ia and hardened to form a resin portion 17. Thereby, the primary coil 13 and the secondary coil 14 are impregnated and fixed, and the insulation that can withstand the high voltage output from the secondary coil 14 is ensured.

As described above, in the ignition coil 1, the first layer connector 15c and the secondary connector 16c are integrally molded on the primary bobbin 15 and the secondary bobbin 16, respectively, and the primary coil 13
Since the secondary coil 14 is wound around the joint parts 21c and 21d, a predetermined solder joint is completed by simply soldering the joint parts 21c and 21d. Furthermore, there is of course no gap between the primary connector 15c and the first layer bobbin 15, and between the secondary connector 16c and the secondary bobbin 16, and therefore the device is smaller than the conventional device.

The ignition coil 1 having the above configuration is attached to a power distributor (not shown) of an internal combustion engine, and the primary current supplied to the coil 13 is controlled intermittently by an ignition circuit (not shown). This causes a magnetic flux change in the closed magnetic circuit core 11. Then,
A predetermined high voltage is generated in the secondary coil 14, is supplied to a power distributor (not shown), and is sequentially distributed to each spark plug (not shown).

In the above embodiment, the first layer connector 15c is integrally molded on the first layer bobbin 15, and the secondary connector 16c is integrally molded on the secondary bobbin 16, but by forming these separately and fitting or joining them, they can be integrated. In the case of this configuration, a process of joining the connector and bobbin is required, but good workability can be ensured with respect to solder joints, and it is also easier than conventional methods. Can be formed into a small size.

[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below.

That is, according to the ignition coil of the present invention, the primary connector and the secondary connector are integrally formed on the bobbin and the secondary bobbin, respectively, and after the primary coil and the secondary coil are wound, they can be connected to the primary terminal and the secondary terminal as they are. Since the bobbin and the secondary bobbin can be soldered together, the bobbin and the secondary bobbin can be soldered as a unit before being assembled into the ignition coil, which reduces the number of man-hours and therefore the manufacturing cost. Furthermore, since the primary connector and the secondary connector are integrated with the primary bobbin and the secondary bobbin, respectively, and unlike conventional ignition coils, they are not separated from each other, the overall structure can be made compact.

Furthermore, by integrally molding the primary connector and the single-layer bobbin, and similarly integrally molding the secondary connector and the secondary bobbin, the number of parts can be reduced and manufacturing costs can be further reduced.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing one embodiment of an ignition coil for an internal combustion engine according to the present invention. FIG. 2 is a bottom view of the primary bobbin and secondary bobbin. 18c...Secondary connector. 21a, 21b --- Primary terminal. 22...Secondary terminal

Claims (1)

[Claims] (1) A primary bobbin consisting of a cylindrical body having flanges on the side surfaces of both ends, around which a primary coil is wound between the flanges, and a cylindrical body having a plurality of annular grooves formed on its side surfaces, each of the plurality of grooves a secondary bobbin on which a secondary coil is divided and wound; the primary bobbin with the primary coil wound thereon is accommodated in a hollow part of the secondary bobbin; In an ignition coil for an internal combustion engine, which is formed by inserting a core and molding it with synthetic resin, the primary connector includes at least a primary terminal connected to the primary coil and extends in the axial direction from one flange of the primary bobbin. A secondary connector is integrally formed with the primary bobbin and includes a secondary terminal connected to the secondary coil and extends in the axial direction from one of the axial end surfaces of the secondary bobbin. An ignition coil for an internal combustion engine, characterized in that it is formed as follows.