JPS61231708A - Ignition coil - Google Patents

Abstract

PURPOSE:To reduce the thickness of the arm part and the outside leg part of the titled coil as well as to miniaturize the entire ignition coil by a method wherein the arm part is extended from the end part of the center leg part to the four quarters in radial direction. CONSTITUTION:The iron core 6, composed of cross-shaped iron cores 7 and 8, a cylindrical iron core 9 and a plate type iron core 10, is magnetically coupled to one end side of a center leg part 6a through the intermediary of an air gap. One end side arm part 6b extended in all directions radially other side arm part 6c extended in all directions radially from the other end side of the center arm part 6a are magnetically coupled by the outside leg part 6d. When the number of one end side or the other end side arm parts is set at 4, the thickness of the device can be reduced substantially when compared with the conventional one having two arm parts.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an ignition coil for generating high voltage for ignition of, for example, an internal combustion engine.

[Conventional technology]

An example of a conventionally known ignition coil for this dish will be explained with reference to FIGS. 5 and 6. In the figure, (1)
is a case made of synthetic resin material (2nd case (1)
) installed in a circle with one core and two figure-8-shaped laminated cores (
3) It is composed of I (4). (2a) is the central leg of the iron core (2), which has an air gap.

(2b) is a one-end leg extending in two directions from one end of the central leg (2a); (2C) is a leg portion extending in two directions from one end of the central leg (2a);
) the other end side leg portion extending in two directions from the other end side, (2d
) is the above one end side leg (2b>) and the above pond @ painting leg (2C)
(3J is the central leg (2)
(a) is a primary coil wound around the outer periphery of the primary coil (3); (5) is a secondary coil wound around the outer periphery of the primary coil (3); (5) is filled in the case (1); 1) This is a microwave oven in which the above-mentioned iron core (2), the above-mentioned primary coil AI (3), and the above-mentioned secondary coil (4) are impregnated.

In the configuration as described above, the primary carp IV
When the primary m flow flowing in 13) is varied, the iron core (2)
The magnetic flux (♂) interlinking with the secondary coil (4) works,
A screw pressure corresponding to the fine ore is induced in the secondary coil A/ (4) due to the magnetic flux (-), and is applied to, for example, a spark plug.

[The problem that the invention attempts to solve]

However, as mentioned above (in the case of this configuration,
The size of the ignition coil depends on the size of the iron core (2) and the legs (
2b), (2c) and the thickness t) of the outer leg (2d)
This iron core (
The cross-sectional area of 2) is set so that the magnetic flux density is the same in any cross-section due to magnetic properties.

That is, here, the central leg [2a], -@side arm (2b)
, the other end side arm portion (2c), and the outer leg portion (2d) have a cross-sectional area of Sa, Sb, and Sc%Sd, respectively, and must be set to have the following relationship.

Sa = 2Sb = 2Sd = 2Sc, 5b = S
d=Sc Here, Sa is necessarily determined due to the customization of the ignition coil, and therefore the cross-sectional areas Sb, Sc, and air are also determined accordingly. Furthermore, the arm portion (2b)
.

(2c) and the width e of the outer arm (2d) are
It is determined by the width e of a), and the cross sections asb, sc
The thickness t of the arm portions (2b), (2c) and the outer leg portion (2d) are determined as a result of the miniaturization of the iron core (2) and the overall size of the ignition coil. There are limits to miniaturization.

This invention was made in order to solve the above-mentioned problems, and aims at downsizing the iron core and, by extension, downsizing the entire ignition coil.

[Means for solving problems]

The ignition coil according to the present invention has one end side arm portion and the other end side arm portion extending in all directions, which are magnetically coupled to one end side or the other end side of the central arm portion of the core.

[Effect]

In this invention, since the one end side arm portion and the other end side arm portion extend in four directions Cζ in the radial direction, the magnetic paths are dispersed. The cross-sectional area of each arm and each outer leg can therefore be reduced and the thickness of each arm and each outer leg can be reduced because the magnetic flux through each arm and each outer leg is therefore reduced.

[Practical example]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, (6) is a cruciform iron core (7).

(8), an iron core composed of a cylindrical iron core (It) and a plate-shaped iron core CIQ, (6a) is the central leg of this iron core (6),
(6b) is an arm part on one end side which is magnetically coupled to one end side of the central leg part (6a) via an air gap and extends in all directions in the radial direction; (6c) is an arm part on one end side of the central leg part (6a); The other end side arm part (6d) extends from the other end side in all directions in the radial direction, and the outer leg (6d) magnetically couples the one end side arm part (6b) and the other end side arm part (6C). Department.

In the structure configured as described above, the central leg (8a
), arms (6b), (6c) and outer legs (6d
), the thickness t of the arms (6b), (6c) and the outer leg (6d) is calculated by the following formula.

t = (Sa/4)/e (Sa/4=Sb=Sc
= Sd) Here, 4 is the number of arms (6b) or (6c) on one end side or the other end side of the central leg (6a), and l is the number of arms (6b) or (6c) on one end side or the other end of the central leg (6a), The arm determined by (
6b), (6c) and the width of the outer leg (6d).

Hereinafter, arm parts (6b) when the shape and cross section d (Sa) of the central leg part (6a) are constant and the number of arms (6b) or (6C) on one end side or the other end side is odd-round. .

A comparison of the ratios of the thickness t of (6c) and the outer leg (6d) results in the following table.

In this way, when the number of arms on one end side or the other end side is 4, the thickness t can be significantly reduced compared to the conventional case where the number of arms is 2. Further, even if the number of arms is six or more, the thickness t will not be reduced even though the structure becomes complicated, and the most desirable number of arms is four.

In addition, as in the above embodiment, the members constituting the iron core (6) are the cruciform iron core (7), (s), and the cylindrical iron core (9).
, and a plate-shaped core αQ, as shown in FIG. 8, a cruciform core (7),
(8) and the plate-shaped core αq can be punched and formed at once, resulting in a very good material yield and low cost.

In addition, Figure 4 is another example of this tsumei, and in the figure,
(B) is a power distributor with a built-in dot large carp / I / (6), 4 is the housing of this power distributor (B), and the ignition coil (
6) is installed internally. 4 is the cap of the above Rt device aυ, α◆ is the rotation axis of the above-mentioned needle dispenser 4, which is inserted through the center leg (6a) of the ignition coil (6). A signal rotor fixed to 14, αQ is a magnetic pickup provided opposite to this signal rotor (6), and includes a stator (16a) made of a magnetic material,
A pickup coil tv (16b) wound around the stator (16a) and the stator (16a)
, a magnet (1
6c). aη is the magnetic pickup α
an ignition timing sub-unit that determines the ignition timing based on the output signal of Q and controls the primary surge of the ignition coil (6);
To) is the center vIIL where the secondary voltage of the ignition coil (6) is applied, and what is the rotor electrode (19a) that is in sliding contact with this center electrode (g)? The fixed power distribution rotor (E) is a peripheral electrode provided at several points around the entire circumference of the power distribution cap corresponding to the number of cylinders of the internal combustion engine.
19a) sequentially through the high voltage for ignition (point large carp A/ (
6) secondary voltage) is distributed. In this way, small 16
The dammed ignition coil may also be installed within other equipment, such as a power distribution device.

〔Effect of the invention〕

As described above, according to the present invention, the thickness of the arms and the outer legs can be reduced by a simple structure in which the arms extend in all directions in the radial direction from the end of the central leg. This has the effect of downsizing the iron core and, by extension, the entire ignition coil.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the present invention, Fig. 2 is a sectional view of Fig. 1, Fig. 8 is a plan view showing the molding process of Fig. 5 is a front view showing a conventional device, and FIG. 6 is a sectional view of FIG. 6. (6 in the figure, (3) is the primary coil, (4) is the secondary coil)
V, (6) C iron core, [6a] is the center leg, (6b) is -
MJ side arm part, (6c) is the other end side arm part, (6d) is the outer arm part. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A device comprising a primary coil and a secondary coil wound in an annular shape, and an iron core forming a common magnetic path of the primary coil and the secondary coil, wherein the iron core is connected to the primary coil and the secondary coil. is magnetically coupled to one end of the central leg in the axial direction,
an arm on one end extending in all directions in the radial direction; an arm on the other end that is magnetically coupled to the other end in the axial direction of the central leg and extending in all directions in the radial direction; An ignition coil characterized in that the ignition coil has an outer leg portion that magnetically couples the outer leg portion and the other end side arm portion. (2) The ignition coil according to claim 1, wherein the iron core is provided with an air gap.