JPS63133510A - Ignition coil - Google Patents

Abstract

PURPOSE:To improve the reliability of the entire coil as well as to contrive accomplishment of effective contribution on the miniatuarization of the title ignition coil by a method wherein at least secondary coil is formed by coaxially laminating a plurality of coil elements having a spiral conductive path formed by printing on a cylindrical plastic base. CONSTITUTION:Four cylindrical coil elements 30, for example, are axially laminated on a secondary coil 22. The coil elements 30 are formed by fixing the cylindrical base 31, consisting of a polyimide film, for example, is fixed to a roller 39, and by forming a copper leaf 32 of 10 microns-1 mm or thereabout in thickness on the base 31 as occasion demands. Then, photoetching is performed using a suitable mask while the rotary roller 39 is being rotated in B-direction, and a series of spiral conductive paths 33 which are continuous in a fixed direction are formed. An insulating film 34 is formed on the conductive circuit 33 as occasion demands, then the cylindrical base 31 is cut in the prescribed length, and four coil elements 30a-30d are obtained. Accordingly, a winding work is unnecessitated, a thickly formed member becomes unnecessary, and a coil itself can be thinly formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ignition coil used for ignition of a gasoline engine, and particularly to an ignition coil using novel components.

(Prior art) The ignition coil is, for example, as shown in FIG.
A primary coil (101) and a secondary coil (102) are wound around an iron core (100) and housed in a case filled with thermosetting resin. This primary coil (101) side is connected to an ignition circuit unit (
103), and the secondary coil (102) side is connected to a spark plug (105) via a high voltage cord (, 104). The ignition circuit unit (103) is configured, for example, to discharge electric charge stored in a capacitor via the primary coil (101) at a predetermined timing synchronized with engine rotation. At this time, the primary coil (101
), a large oscillating current is generated due to the inductance of 2
A high voltage can be induced in the secondary coil (102). The high voltage of the secondary coil (102) causes the spark plug (105) to ignite, thereby driving the engine.

The mechanical structure of such an ignition coil is disclosed in Reiko Gi' Utility Model Application No. 60-41031.

The primary and secondary coils of such an ignition coil are wound with painted conductor wire, and especially in the secondary coil, a thin conductor wire is wound many times (for example, with a diameter of 0.05 mm) in order to induce high voltage. 10,000 turns).

(Problems to be solved by the invention) However, when configuring such a coil, the thin conductor wire may be cut during the manufacturing process, or the insulation coating may peel off during the winding process, resulting in poor insulation. Such inconveniences were likely to occur. For this reason, the manufacturing work of the ignition coil requires careful attention, and the number of work and steps is large, resulting in a decrease in workability as a whole.

Therefore, an object of the present invention is to provide a highly reliable ignition coil that does not cause winding breakage or poor insulation, and can simplify the manufacturing process.

(Means and effects for solving the problem) In order to achieve this object, according to the present invention, the iron core (
20), in which at least the secondary coil (22) is formed by printing and molding on a cylindrical plastic base (31). A plurality of coil elements (30) each having a spiral conductive path (33) are coaxially stacked.

According to such a configuration, since the coil is formed by a printing technology process, there is no need for coil winding work, and it is possible to suppress the occurrence of accidents such as wire breakage and poor insulation caused by this. By the way, configuring windings on flexible insulating sheet plates using printing technology is beginning to be adopted in motors, etc.
- As in No. 186941, a sheet plate on which a spiral coil pattern is printed on an insulating sheet plate is bent into a cylindrical shape of an armature rotor, and arranged sequentially in the bending direction, so that the windings are connected to each other. It is configured to be connected continuously. A similar technique is also disclosed in JP-A-60-226731.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

In addition, the same reference numerals in each figure indicate similar objects.

FIG. 1 shows an ignition coil according to an embodiment of the present invention, in which a cylindrical case (1) with a U-shaped cross section includes a coil space (2), an ignition circuit unit space (3), and a high voltage It has a code space (4). Coil space (2
) is a semi-cylindrical wall surface (6), and a flat surface (6) continuous to both ends of the semi-cylindrical wall surface (6).
a), (61)), a space surrounded by a partitioning plane (6c) extending approximately at right angles to the plane (6a), and a small cylindrical curved surface (6d) connecting this plane (6c) and the plane (6b); and a cylindrical curved surface (7) integrally formed inside a closed curved surface composed of these surfaces. The circuit unit space (3) is a nearly rectangular parallelepiped space connected to the coil space (2), and has planes (6a), (6
b) and these planes (6a), (
6b) and the aforementioned partitioning plane (6c) and small curved surface (6d) arranged substantially parallel to this plane (6e). Coil space (2)
The small curved surface (6d) forming a part of the wall surface forming the space for the circuit unit (3) is the space for the high voltage cord (6d), respectively.
4) is a part of the cylindrical wall surface forming. The wall surface (6d) forming this high voltage cord space (4) projects downward in the longitudinal direction by a certain length D) from the bottom surface (la) of the case (1). A protruding portion (9) for forming a slit (8) is integrally formed on the plane (6e).

A primary coil (21) is wound around the cylindrical curved surface (7) of the coil space (2) using a conducting wire, and on top of this primary coil (21) is a conductive coil formed by printing technology. A secondary coil (22) consisting of a cylindrical coil element (described below) having a channel is arranged coaxially. The inside of the cylindrical curved surface (7) is hollow, and the iron core (20) is inserted and fixed therein. The iron core (20) is formed by laminating a plurality of thin steel plates (20a) to suppress the occurrence of iron loss. Further, the iron core (20) has a connecting piece (23) with a rivet (24) for connecting the ground side of the primary coil (21) and the secondary coil (22).
) is fixed. An ignition circuit unit (25) comprising, for example, a capacitor, a thyristor, etc. on a plastic substrate is inserted into the circuit unit space (3). Furthermore, the L-shaped bent portion (26a) of the primary terminal (26) pulled out from the primary coil (21) is inserted and fixed into the slit (8). A high voltage cord (not shown) is inserted into the high voltage cord space (4) from direction A and fixed by an appropriate method. These iron cores (2Q), primary coils (21
), secondary coil (22), circuit unit (25), terminal (26), etc., are covered with a case using a filler material (27) such as epoxy resin! Fixed inside.

The configuration of the secondary coil (22) explained above will be explained in more detail. FIG. 2 shows a secondary coil (22), in which four cylindrical coil elements (30) are coaxially stacked. In this case, the diameter of the coil element (30) would ideally be molded so that it becomes smaller toward the inside, but since the coil material is extremely thin, it is possible to insert pieces of the same diameter one after another, and in practice Generally speaking, the distortion during its insertion can be ignored.This coil element (30) is
Form as shown in the figure. That is, first, as shown in FIG. 3, a cylindrical base (31) made of, for example, a polyimide film is fixed to a rotating roller (39), and as shown in FIG. A copper foil (32) having a thickness of about 10 microns to 1 mm is formed depending on the conditions. Next, using an appropriate mask (not shown), photoetching is performed while rotating the rotary roller (39) in direction B, resulting in a series of spirals continuous in a certain direction, as shown in Figure 4(b). A shaped conductive path (33) is formed.

Ideally, the roller only needs to rotate once. The number of turns of this continuous spiral conductive path (33) is the number of turns of the secondary coil (
22) is the required number of turns, for example 10,000 turns. An insulating film (34) is formed on this spiral conductive path (33) if necessary. After this,
The cylindrical base (31) on which the conductive path (33) has been formed is cut into a predetermined length, for example, including 2500 turns, and four coil elements (30a) to (30a) as shown in FIG.
30d) is obtained.

In addition, when forming a series of conductive paths (33) on the rotating roller (39), at the same time, the first and last of the conductive paths (33),
It is also desirable to form connection pads, connection terminals, or leads (none of which are shown) in advance for each predetermined number of turns.

The coil elements (30) cut as described above are placed every other coil element in the opposite direction to the direction in which they were manufactured in series as shown in FIG. 3, and are successively inserted and laminated in a coaxial manner.

At this time, as schematically shown in FIG. 6(a), by electrically connecting the ends of the conductive paths (33) of adjacent coil elements (30) to each other, as shown in FIG. 6(b). As shown, a desired series of secondary coils (22) can be obtained. That is, the first coil element (3
The second coil element (30b) is connected to the winding start end (35a) of the conductive path (33a) of 0a).
3b) so that the winding end (36b) is located. The conductive path (33c) of the next third coil element (30c)
) is connected to the winding start end (37a) of the second coil element (30
The winding end end (36b) of the conductive path (33b) in b), that is, the winding start end (35a) of the first coil element (30a)
Insert it so that it corresponds to the same position as . Similarly, the first to fourth coil elements (30) to (30d) are sequentially inserted in alternate directions. At this time, one winding start end (35a) of the conductive path (33a) of the first coil element (3Oa) located at the outermost position is used as a secondary output terminal, and the other winding end end (36a) Connect to.

Further, the winding end end (311b) of the second coil element (30b) is connected to the winding start end (37a) of the third coil element (30C). In the same way, connect up to the fourth coil element (30d), and connect the fourth coil element (3od
) and the output terminal (35a) of the secondary coil (22) is connected to the terminal (26).
)'s earth side terminal (38b) is connected to the iron core (20)'s connection piece (
23).

FIG. 7 shows another embodiment of the present invention, in which both the primary coil (21) and the secondary coil (22) are thin cylindrical like the secondary coil (22) of the first embodiment. This shows an ignition coil manufactured using printing technology on PlusDeck film. In this case, the primary coil (21)
For example, as shown in FIG. 9, each coil element (43a)
, (43b), and (43C) in parallel, it is possible to configure a relatively small number of windings and a large current specification. In this embodiment, the ignition circuit unit is not built into the case.

In each of the above embodiments, the coil element (30) has a cylindrical shape, but it goes without saying that the coil element (30) may have a cylindrical shape as long as it is cylindrical, and is limited to the shape of the embodiments. It's not a thing. Similarly, the shape of the case is also arbitrary. Also, 2
In addition to the method of connecting four 500-turn coil elements (30) in series to obtain a 1000-turn coil, 20
00 turns of coil elements (30) may be stacked,
Of course, the total number of turns is not limited to 1000'0 turns.

(Effects of the Invention) According to the present invention, by forming the coil using the printing technique as described above, an ignition coil having the following effects can be obtained.

(1) Winding work using a winding machine or the like is eliminated, so there is no possibility of wire breakage, and there is no need to worry about poor insulation, so the reliability of the entire ignition coil is high.

(2) Because the coil base itself is an insulating material, and because the insulation coating during coil manufacturing can be easily thinned, materials such as insulating paper and bobbins that were conventionally used between the primary and secondary coils becomes unnecessary. Further, the coil itself can be made into a thin piece (approximately 1/2 of the conventional size). Therefore, it is possible to effectively contribute to downsizing of the entire ignition coil.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view (a) and a plan view (b) of an ignition coil according to an embodiment of the present invention, and FIGS.
The figure is an explanatory diagram of main parts of an ignition coil according to an embodiment of the present invention, FIG. 7 is a longitudinal cross-sectional view of an ignition coil according to another embodiment of the present invention, and FIG. 8 is a general electrical system of an ignition coil. It is a diagram. In the drawing, (1) is the case, (2) is the space for the coil, (3) is the space for the circuit unit, (4) is the space for the high voltage cord, (20) is the iron core, (21) is the primary coil, (22
) is the secondary coil, (27) is the filler, (3o) is the coil element, (31) is the cylindrical plastic base, (33) is the spiral conductive path, (35) to (38) (a, b) ) are connection terminals. Patent applicant: Honda Motor Co., Ltd. Agent
Person Patent Attorney 2 1) Part 1 Patent Attorney
Kuni Ohashi Patent Attorney Small
Yama Yuyuki Patent Attorney No 1)
Shigeru Figure 1 (b) Figure 2

Claims (3)

[Claims] (1) In an ignition coil consisting of a primary coil and a secondary coil coaxially wound around an iron core in a case, at least the secondary coil has a spiral conductive path printed and molded on a cylindrical plastic base. An ignition coil characterized by comprising a plurality of coil elements laminated in a coaxial manner. (2) In the ignition coil according to claim 1, the secondary coil includes a plurality of the coils cut from a single cylindrical base having a series of conductive paths wound in a fixed direction. An ignition coil characterized by having elements connected in reverse order. (3) An ignition coil according to claim 1 or 2, wherein the coil element has connection terminals formed at the same time as the conductive path.