JPH0624997Y2 - Trance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a transformer used as an ignition coil for supplying a high voltage to an ignition plug, which is provided at a rod-shaped portion and one axial end of the rod-shaped portion. A core having a brim portion is inserted into the bobbin on which the coil is wound from one end in the axial direction of the inner diameter hole of the bobbin to be combined therein, and a connector for connecting an ignition plug to the end face opposite to the insertion direction of the core, By mounting the spark plug in a direction that is substantially coincident with the coil winding direction, the connecting direction of the spark plug is matched with the coil winding direction of the transformer, and the overall shape is made smaller and simpler. The lowering of the efficiency is compensated by the collar portion provided at one end in the axial direction to improve the magnetic efficiency.

<Prior Art> A general configuration of a conventional transformer of this type is such that two or more coils are combined with a closed magnetic circuit type core made of an EE type, an EI type, a UU type, a UI type, or the like in the winding axis direction. The structure was such that a connector for mounting a spark plug was provided in a direction orthogonal to each other. FIG. 5 is a front partial sectional view of a conventional transformer of this type in use, and FIG. 6 is a side view of the same. 1, 2 are E-shaped cores made of a magnetic material such as ferrite, 3 is a low voltage input coil, Reference numeral 4 is a high-voltage output coil, and 5 is an insulating cover that covers the whole. 6 is a bobbin around which the low voltage input coil 3 is wound, 7 is a bobbin around which the high voltage output coil 4 is wound, and 8 is an ignition plug.

The bobbin 7 has a coil winding portion defined by a collar portion 71 provided at an appropriate interval along the axial direction, and the high voltage output coil 4 is continuously wound around each coil winding portion. Then, the inner diameter hole 7 of the bobbin 7 around which the high-voltage output coil 4 is wound.
The bobbin 6 around which the low-voltage input coil 3 is wound is coaxially inserted and arranged in the inside of 2, and passes through the inner diameter hole 61 of the bobbin 6,
Two EE type, EI type, UU type, UI from both sides in the axial direction
A closed magnetic circuit is formed by combining cores 1 and 2 of a mold or the like.

A connector 9 for connecting a spark plug is provided on the outer peripheral portion of the insulating cover 5 in a direction orthogonal to the coil winding axis direction, and the spark plug 8 is mounted on the connector 9.
Therefore, the spark plug 8 is connected in the direction orthogonal to the coil winding axis.

<Problems to be solved by the invention> As described above, in the case of the conventional transformer, the EE type and the EI type are used.
Since the closed magnetic circuit is formed by the cores 1 and 2 of U-type, UU-type, UI-type, etc., the magnetic coupling of the coils 3 and 4 becomes high.
However, there are the following problems.

(B) This type of transformer is used as an ignition coil or the like that supplies high voltage to an automobile ignition plug,
Since there is usually no space for installation, downsizing and simplification of shape are important issues. However, since the spark plug 8 is connected in a direction orthogonal to the winding axis direction of the coils 3 and 4, the overall shape becomes complicated, the occupied area becomes large, and the mounting work becomes difficult. There was a problem.

(B) The cores 1 and 2 of EE type, EI type, UU type, UI type, etc. are exposed to the outside of the insulating cover 5 so that the overall shape is inevitably large, which makes it difficult to miniaturize and the outer shape. The shape becomes complicated.

(C) An attempt was made to use an open magnetic circuit type core such as an I type for downsizing and simplification of the shape, but the magnetic coupling between the coils deteriorates and the efficiency of the transformer decreases. There was a problem.

<Means for Solving Problems> In order to solve the above-mentioned conventional problems, the present invention has a low voltage input coil and a high voltage output coil that are coaxially arranged, and a core that magnetically couples the both coils. In the transformer, the core has a rod-shaped portion and a flange portion provided at one end portion in the axial direction of the rod-shaped portion, and extends from one end in the axial direction of the inner diameter hole of the bobbin wound with the coil to the inside thereof. , The rod-shaped portions are inserted and combined, and a connector for connecting a spark plug is attached to an end surface of the core opposite to the insertion direction so that the connection direction substantially coincides with the coil winding axis direction. .

<Operation> When the core of the transformer according to the present invention is coupled to the bobbin, the rod-shaped portion forming the majority of the core comes to be located inside the bore of the bobbin, and the overall shape of the transformer is reduced. . Moreover, since the rod-shaped portion can be assembled by inserting it into the bobbin inner diameter hole from one end side without the brim portion,
Assembly work becomes easy.

Further, since the collar portion is provided at one end portion in the axial direction of the rod-shaped portion, the collar portion can compensate for the decrease in the magnetic efficiency due to the open magnetic path of the rod-shaped portion and improve the magnetic efficiency.

Further, a connector for connecting an ignition plug is attached to the end surface on the side opposite to the insertion direction of the core so that the connection direction is substantially the same as the coil winding axis direction. , The work of connecting the spark plug is facilitated, the overall shape of the spark plug with the spark plug attached is downsized and simplified, and the occupied area required for mounting on the automobile is reduced.

<Embodiment> FIG. 1 is an exploded perspective view of a transformer according to the present invention, and FIG. 2 is a sectional view of the same in an assembled state. In the figure, the same reference numerals as those in FIGS. 5 and 6 denote the same components. 10 is a core made of a ferrite magnetic material, 11
Is a shield case. The core 10 includes a rod-shaped portion 101,
The rod-shaped portion 101 has a T-shaped cross-section having a collar portion 102 provided so as to project from one end portion in the axial direction of the rod-shaped portion 101.
It is inserted and assembled in the inner diameter hole 61. Therefore, most of the core 10 is located in the inner diameter hole 61 of the bobbin 6, so that the overall shape is reduced and simplified. In addition, from the end side without the brim portion 102, the rod-shaped portion 1
Since 01 can be inserted and assembled in the inner diameter hole 61 of the bobbin 6, the assembling work becomes easy.

The brim portion 102 has substantially the same shape as the outer diameter of the bobbin 7, and is arranged along the axial end surface of the bobbin 7. The shape of the collar portion 102 may be another shape such as an arc shape. As described above, in the case of the open magnetic circuit with the I-shaped core, the magnetic efficiency is deteriorated. However, in the present invention, the collar portion 102 compensates for the decrease in the magnetic efficiency due to the open magnetic circuit of the I-shaped core to improve the magnetic efficiency. Can be improved. 31, 3
Reference numeral 2 is a coil end of the coil 3, and 103 and 104 are notches for leading out the coil ends 31 and 32.

The axial end surface 7 of the bobbin 7 on the side opposite to the insertion side of the core 10
A connector 9 whose connection direction matches the coil winding axis direction is attached to 3 by an appropriate means such as adhesion or screwing. One end of the high voltage output coil 4 is connected to this connector 9.

The insulating cover 5 is coaxially inserted so as to cover the outside of the bobbin 7, and the end face side facing the connector 9 is an opening 51, and an ignition plug is inserted through the opening 51.
It can be connected to the connector 9. Although illustration is omitted, it is also possible to adopt a structure in which the insulating cover 5 is filled with an insulating resin and sealed.

The shield case 11 is provided in order to prevent electromagnetic noise generated from the connecting portion when the spark plug is connected to the connector 9, and is a magnetic conductive material such as iron or nickel or a nonmagnetic conductive material such as copper. Is used to form a tubular shape with both ends open, and is attached to the insulating cover 5 so as to surround at least the portion of the connector 9. A plurality of spring pieces 112 divided by slits 111 are formed at the tip of the shield case 11.

FIG. 3 is a sectional view showing a state in which an ignition plug is connected to the transformer according to the present invention. As shown in the figure, the spark plug 8 can be directly inserted and connected to the connector 9 in the coil winding axis direction. Therefore, the connecting direction of the ignition plug 8 becomes substantially coincident with the coil winding axis direction of the transformer, and the connecting work of the ignition plug 8 becomes easy and
The overall shape with the spark plug 8 attached is downsized and simplified, and the occupied area required for attachment is reduced.

Further, in this embodiment, since the connecting portion between the connector 9 and the spark plug 8 is surrounded by the shield case 11,
Electromagnetic noise generated from the connection part can be blocked. When the entire transformer is covered with the shield case 11 as shown in the figure, noise generated from the transformer can also be blocked.
Moreover, since the spring piece 112 of the shield case 11 is pressed against and supported by the outer peripheral surface of the spark plug 8, the support stability of the spark plug 8 is enhanced, and the transformer is prevented from falling off. Can be prevented.

FIG. 4 is an electric circuit diagram in use. In the conventional general ignition circuit, a resistor for limiting current change is inserted between the spark plug 8 and one end of the high voltage output coil 4, or a spark plug with a built-in resistor is used to suppress noise generation. It is normal to do. According to the present invention, since the shield case 11 surrounding the spark plug 8 and the connector of the transformer can provide a noise blocking effect, as shown in FIG. It is possible to use a circuit in which the spark plug 8 is directly connected.

<Effect of the Invention> As described above, according to the present invention, the following effects can be obtained.

(A) The core has a rod-shaped portion and a flange portion provided at one end portion in the axial direction of the rod-shaped portion, and the core is provided from one end in the axial direction of the inner diameter hole of the bobbin wound with the coil to the inside thereof. Since the rod-shaped portions are inserted and combined, it is possible to provide a simple ignition coil transformer having a small overall shape.

(B) It is possible to provide an ignition coil transformer that can be easily assembled.

(C) Since the collar portion is provided at one end portion in the axial direction of the rod-shaped portion, it is possible to provide the ignition coil transformer having improved magnetic efficiency by compensating for the decrease in magnetic efficiency due to the open magnetic path.

(D) Since the connector for connecting the ignition plug is attached to the end surface on the side opposite to the insertion direction of the core so as to be substantially coincident with the coil winding axis direction from the connection direction, the connecting direction of the ignition plug is the coil winding axis of the transformer. It is possible to provide a transformer for an ignition coil which has a substantially same shape, is easy to connect the spark plugs, and has a small overall shape with the spark plugs attached, which is simple and has a small installation area.

(E) Since the overall shape is small and simple, high-voltage noise can be easily prevented by the shield, a resistance for noise prevention is not required, and an ignition coil transformer with a small discharge energy loss can be provided.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a transformer according to the present invention, FIG. 2 is a sectional view in the same assembled state, and FIG. 3 is a partial sectional view with a spark plug connected to the transformer according to the present invention.
FIG. 5 is an electric circuit diagram in use, FIG. 5 is a partial front sectional view of a conventional transformer of this type in use, and FIG. 6 is a side view of the same. 3, 4 ... Coil, 5 ... Insulation cover 6, 7 ... Bobbin, 9 ... Connector 10 ... Core, 101 ... Rod portion 102 ... Collar portion

Continuation of the front page (72) Inventor Kunihiro Sato 1-13-1 Nihonbashi, Chuo-ku, Tokyo Within TDK Corporation (56) Reference JP-A-57-173922 (JP, A)

Claims (2)

[Scope of utility model registration request] 1. A transformer having a low-voltage input coil and a high-voltage output coil coaxially arranged, and a core for magnetically coupling the both coils, wherein the core has a rod-shaped portion and one axial end of the rod-shaped portion. With the collar portion provided,
From the axial end of the inner diameter hole of the bobbin wound with the coil, into the inside thereof, the rod-shaped portion is inserted and combined, and on the end face opposite to the insertion direction of the core, a connector for ignition plug connection, A transformer characterized in that it is mounted so that the connection direction is substantially the same as the coil winding axis direction. 2. A transformer according to claim 1, further comprising a shield covering at least the periphery of the connector for connecting the spark plug.