JPH066499Y2 - ignition coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an ignition coil used in a vehicle engine or the like, and more particularly to an ignition coil capable of achieving a lightweight and compact iron core.

[Prior Art] In order to increase the output of an ignition coil, it has already been proposed to insert a reverse biasing magnet in a closed magnetic circuit formed by an iron core and use this as a part of input energy ( French Published Patent No. 25
31751 and 2531752). According to this, the iron core can be made lighter and more compact in accordance with the decrease in the magnetic path cross-sectional area.

[Problems to be solved by the invention] However, in the above ignition coil, a part of the iron core is divided and the magnet is directly sandwiched between them. However, since the material of the magnet is generally fragile, if the magnet is repeatedly applied with a shock on the contact surface with the iron core for a long period of time due to the vibration of the engine, the magnet may be broken, and it is difficult to improve the durability. Further, when the magnet is damaged, the fragments may be scattered.

The present invention has been made in view of such circumstances,
An object of the present invention is to provide an ignition coil that protects a magnet to improve durability and prevents scattering of fragments when it is broken.

[Means for Solving Problems] The ignition coil of the present invention is an iron core that is formed by connecting a plurality of component pieces in a loop shape and is inserted in a part of a connecting portion between the component pieces to form an iron core. In the one provided with a magnet for applying a reverse bias to the closed magnetic circuit to be formed, and a primary coil and a secondary coil wound around an iron core,
The primary coil bobbin of the primary coil is a bottomed tubular resin member having one end opened and the other end formed in a closed portion, the magnet is integrally embedded in the wall thickness of the closed portion, and the iron core is A part of the constituent pieces to be configured is inserted into the primary coil bobbin and the tip thereof is brought into contact with the inner surface of the primary coil bobbin of the closed portion, and the other constituent piece of the iron core is brought into contact with the outer surface of the closed portion. Characterize.

[Operation of the Invention] The primary coil bobbin according to the present invention is a resin-made bottomed cylindrical member, and the magnet is integrally embedded in the wall thickness of the closed portion formed at one end thereof.

Therefore, a part of the iron core component is put in the cylindrical portion of the primary coil bobbin, the tip thereof is brought into contact with the inner surface of the primary coil bobbin of the closed portion, and the other component of the iron core is brought into contact with the outer surface of the closed portion. Then, if you connect multiple component pieces together,
The iron core forms a loop sandwiching the closed portion of the primary coil bobbin.

In this state, the magnet is reverse biased to the closed magnetic circuit formed in the iron core and is embedded in the wall thickness of the closed portion, so that the magnet does not fall off and the damage is effectively prevented. Moreover, even if it is broken, the fragments will not scatter.
Further, the positioning of the magnet becomes accurate and easy.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is a vertical sectional view of an ignition coil, and FIG. 2 is a sectional view of a primary coil bobbin.

A cylindrical bottomed primary coil bobbin 2 is housed in the center of a coil case 1 made of a suitable synthetic resin. The primary coil bobbin 2 is made of a suitable synthetic resin, and is a bottomed tubular member having one end open and the other end closed. The tubular portion forms the iron core passage 3 (see FIG. 2), and the magnet 5 is embedded and integrated by insert molding in the thickness of the bottom portion 4 corresponding to the closed portion of the present application.
The magnet 5 is a permanent magnet arranged so as to apply a reverse bias to a closed magnetic circuit formed in an iron core described later. However, it can be replaced with an electromagnet. A primary coil 6 is wound around this primary coil bobbin 2, and a secondary coil 7 is further wound around it. Also,
These are integrated by casting a suitable resin 8 such as an epoxy resin.

Further, one arm portion 11 of the C-shaped iron core 10 is inserted into the iron core passage 3 of the primary coil bobbin 2, and the tip end portion thereof is in contact with the inner side surface 4 a of the bottom portion 4. Further, one end of the I-shaped iron core 13 is in contact with the outer side surface 4b of the bottom portion 4, and I
The other end of the die core 13 is connected to the arm portion 12 of the C iron core 10. Therefore, the C-type iron core 10 and the I-type iron core 13
Form a loop sandwiching the bottom portion 4 of the primary coil bobbin 2. The C-shaped iron core 10 and the I-shaped iron core 13 respectively form constituent pieces of the iron core forming a loop as a whole, and are connected and integrated by a non-magnetic frame member (not shown).

In the ignition coil thus configured,
The C-shaped iron core 10 and the I-shaped iron core 13 form a closed magnetic circuit (in the direction of the arrow in FIG. 1) inside thereof, and a magnet 5 is interposed therebetween so as to apply a reverse bias. . Therefore, when the primary coil 6 is energized, a closed magnetic circuit is formed in the iron core as shown by the arrow in FIG. 1, but the magnet 5 applies a reverse bias to this.
As a result, the ignition coil can use the magnetic energy of the magnet 5 as the input energy and can reduce the magnetic path cross-sectional area, so that the iron core can be made lightweight and compact. Moreover, the wall thickness of the bottom portion 4 of the primary coil bobbin 2 functions as an air gap formed in the loop of the iron core. Since the thickness of the bottom portion 4 is formed according to the dimensional accuracy by in-mold molding, the air gap accuracy is relatively high.

In addition, since the magnet 5 is insert-molded on the bottom portion 4 of the primary coil bobbin 2 in the present embodiment, the magnet 5 is covered and protected by the resin of the primary coil bobbin 2, and when the primary coil bobbin 2 is mounted in the coil case 1. At the same time, its position is also accurately positioned. Therefore, positioning work and the like become easy. Moreover, since the magnet 5 is embedded in the thickness of the bottom portion 4, it can be stably interposed without dropping off.
And the damage is effectively prevented. Moreover, even if it is broken, the fragments will not scatter.

FIG. 3 shows another embodiment. In this embodiment, the E-shaped iron core 20 is used as the iron core. However, since the coil body side is common, if explained with the same reference numeral, the central arm portion 21 of the E-shaped iron core 20 is formed slightly shorter than the arm portions 22 and 23 on both sides. Enters the primary coil bobbin 2 and contacts the inner surface 4a of the bottom portion 4. Further, the I-shaped iron core 24 is connected and integrated so as to be in contact with the tip portions of the arm portions 22 and 23 and the outer surface 4b of the bottom portion 4 of the primary coil bobbin 2. The E-shaped iron core 20 and the I-shaped iron core 24 are components of the iron core that form a loop as a whole, and even with this structure, the same effect as that of the previous embodiment can be obtained. The magnet 5 is arranged so as to apply a reverse bias to the closed magnetic circuit formed in the iron core in the direction of the arrow.

[Advantage of the Invention] In the present invention, since the magnet is embedded and integrated in the wall thickness of the closed portion formed in the primary coil bobbin, the magnet can be stably interposed without dropping due to the wall thickness of the closed portion. Moreover, damage can be effectively prevented. Further, even if it is broken, it is possible to prevent scattering of the fragments. Therefore, the magnet can be surely protected. In addition, the positioning when mounting the magnet can be surely performed, which facilitates the positioning work and the like.

[Brief description of drawings]

1 and 2 show one embodiment, FIG. 1 is a longitudinal sectional view of an ignition coil, FIG. 2 is a sectional view of a main part, and FIG.
The figure is a longitudinal sectional view showing another embodiment. (Explanation of symbols) 1 ... Coil case, 2 ... Primary coil bobbin, 4 ...
Bottom, 5 ... Magnet, 6 ... Primary coil, 7 ... Secondary coil, 10 ... C-type iron core, 13, 24 ... I-type iron core, 20 ... E-type iron core.

Claims (1)

[Scope of utility model registration request] 1. An iron core formed by connecting a plurality of component pieces in a loop shape, and a magnet for interposing a reverse bias on a closed magnetic path formed in the iron core that is interposed in a part of a connecting portion between the component pieces. An ignition coil comprising a primary coil and a secondary coil wound around an iron core, wherein a primary coil bobbin of the primary coil is made of a resin having a bottomed tubular shape with one end open and the other end formed in a closed portion. As a member, while integrally embedding the magnet within the wall thickness of the closed portion,
Insert a part of the constituent pieces forming the iron core into the primary coil bobbin and bring the tip thereof into contact with the inner surface of the primary coil bobbin of the closing portion, and bring the other constituent pieces of the iron core into contact with the outer surface of the closing portion. Ignition coil characterized by that.