JP2004207581A - Iron core/coil assembly for internal combustion engine ignition coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems arising when interposing a thin permanent magnet between one end of the linear iron core making a closed magnetic path iron core in the inner periphery of a bobbin of a primary coil and the inner periphery of an outer annular iron core of the closed magnetic path iron core surrounding the primary coil in order to improve the performance of an ignition coil. <P>SOLUTION: A side L<SB>1</SB>between right-angled two sides of a thin rectangular permanent magnet 9 interposed between one end of a linear iron core 3' and the inner periphery of an outer annular iron core 3 is made longer than the laminate thickness (t) or the width (w) of the linear iron core. Another side L<SB>2</SB>is made shorter than the width (w) or the laminate thickness (t) of the linear iron core. In the middle of the terminal of a flange 11' on one end of a primary coil 1, notches 12, 12 are provided while being opposed for accepting terminal portions of the one side L<SB>1</SB>between two right-angled sides of which the depth is equal to the thickness of the thin permanent magnet. The terminals of the one side L<SB>1</SB>in the right-angled two sides of the slice 9 of permanent magnet are engaged to the notches 12, 12, and the thin permanent magnet 9 is abutted to one terminal of the linear iron core 3' and held immovably on the terminal portion of the flange on the one end of the primary coil. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a core-coil assembly of an ignition coil for an internal combustion engine for supplying a high voltage to an ignition plug of an internal combustion engine such as an automobile engine to generate a spark discharge.
[0002]
[Prior art]
As shown in FIG. 2, a mold-type ignition coil for an internal combustion engine usually has a secondary coil 2, a primary coil 1 penetrating the inner periphery of the secondary coil, and a straight line penetrating the inner periphery of the primary coil. An outer ring core 3 of a closed magnetic circuit core including an iron core 3 ′ is housed inside an insulating case 4, and the insulating case houses a high-voltage terminal 6 that houses a high-voltage terminal 6 that partially enters the inside of the insulating case. And an elastic pin 7 for connecting the winding end side of the secondary winding is attached to the bobbin of the secondary coil, and this elastic pin is brought into elastic contact with the protruding end portion 6 'in the insulating case of the high voltage terminal. The secondary coil 2, the primary coil 1, the closed magnetic circuit core, the elastic pins 7, and the high voltage terminals 6 are fixed in the insulating case by the insulating resin layer 8 cast and solidified in the insulating case. Then, in order to increase the output of the ignition coil, a permanent magnet as shown in the drawing is provided between one end of the linear core 3 ′ of the closed magnetic circuit core and the inner periphery of the outer ring core 3 opposed to the one end. A square thin piece 9 may be interposed.
[0003]
In this case, the magnetic pole on the surface of the thin piece 9 of the permanent magnet facing the one end of the linear core portion 3 'and the magnetic pole on the opposite surface facing the inner periphery of the outer ring core portion 3 were energized to the primary coil. A thin piece of permanent magnet is arranged in series with the closed magnetic circuit in a direction that generates a magnetic flux opposite to the magnetic flux that is sometimes created, a magnetic bias is applied to the closed magnetic circuit core, and when the current is interrupted to the primary coil, the closed magnetic circuit core is The amount of change in magnetic flux is increased, and the output is increased.
[0004]
[Problems to be solved by the invention]
The thin section of the conventional permanent magnet is a rectangle having the same size as the end face of the linear core portion 3 ', and is attracted to the end face of one end portion of the linear core portion by magnetic force and located outside the flange at one end of the primary coil. Therefore, when assembling into a closed magnetic circuit core in combination with the outer ring core 3, the inner ring of the outer ring core moves out of contact with the inner periphery of the straight ring core, protrudes from the end face of one end of the linear core, and does not function properly. It takes time and effort to push the protruding portion back to the correct position, which causes a problem of reducing productivity. Furthermore, since the size of the square of the thin piece 9 of the permanent magnet is the same as that of the end face of the straight core portion 3 ', the size becomes large and the cost of the permanent magnet increases.
[0005]
[Means for Solving the Problems]
The present invention has been developed in order to solve the above-mentioned problem, and the length of one side of the two perpendicular sides of the rectangular thin piece of the permanent magnet is larger than one of the lamination thickness and the width of the straight core portion. In addition, the length of the other side is smaller than the other of the width of the straight core portion and the lamination thickness, and the thickness of the permanent magnet thin section is set at the center of the end of the flange at one end of the primary coil. Notches that are equal in thickness and receive the respective ends of one side of the perpendicular two sides are provided to face each other, and each end of one side of the perpendicular two sides of the thin piece of the permanent magnet is engaged with the above notches, It is characterized in that a thin piece of a permanent magnet is brought into contact with one end of a linear iron core and is fixedly held at one end of a flange of one end of a primary coil.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Figure 1 shows an embodiment of the present invention, larger than the laminated thickness t of the linear core portion 3 'of the closed magnetic circuit core length of one side L ₁ of the perpendicular two sides of the square of the permanent magnet flakes 9 to (hereinafter also referred to as long side to side), the length of the other side L ₂ are the smaller than the width w of the linear core portion 3 '(hereinafter, also referred to as the other side short side).
[0007]
And at the center of an end portion of one end of the flange 11 of the bobbin 11 of the primary coil ', the thickness and depth of the foil 9 of the permanent magnet is the same, each end of the long side L ₁ of the flakes 9 (long side L provided a notch 12, 12 for receiving a half addressed) length of minus the laminate thickness t of the linear core portion from the length of ₁ to face the long side of the slice of the permanent magnet in this cut-out 12, 12 Each end of L1 is engaged.
[0008]
Of course, during the bobbin 11 of the primary coil Yes inserted linear core portions 3 ', flakes 9 of the end portion and the permanent magnet are mutually attracted by a magnetic force, the end of the long side L ₁ of the flakes 9 Since it is engaged with the notches 12, 12, it is held without moving.
[0009]
Also, when assembling the outer ring core 3 and the primary coil having a linear core 3 'on the inner periphery to assemble a closed magnetic core, the thin pieces of the permanent magnet rub against the inner periphery of the outer ring core. It does not move and sticks to its inner circumference. The magnetic pole on the side facing the straight core portion 3 ′ of the thin piece of the permanent magnet and the magnetic pole on the side facing the inner periphery of the outer ring core portion are connected to the primary coil as described in the above paragraph 0003. When the current is interrupted, the amount of change in the magnetic flux of the closed magnetic core is increased to increase the output of the ignition coil.
[0010]
Illustrated embodiment the large west from laminated thickness t of the linear core portions 3 a length of one side L ₁ of the closed magnetic circuit iron core of the perpendicular two sides of the lamina 9 of the permanent magnet ', straight line length of the other side L ₂ 'it was to be smaller than the width w of the reverse smaller than the laminated thickness t of the linear core portion the length of one side L ₁ to west, straight core portion 3 the length of the other side L _2' core portion 3 the width of the It may be larger than w, in which case a pair of notches 12, 12 corresponding to this may be formed at the end of the collar at one end of the bobbin of the primary coil.
[0011]
【The invention's effect】
Since the size of the permanent magnet flakes used in the present invention is smaller than before, the absolute output performance of the ignition coil is lower than before, but the cost is reduced due to the small size of the permanent magnet, and furthermore, Since the permanent magnet flakes do not move when assembling the closed magnetic core, there is no trouble in assembling, and the permanent magnet flakes are positioned and held at the center of the end face of one end of the linear core, so the permanent magnet demagnetizing field Variation in the manner of application can be minimized. Further, since the demagnetizing field directly applied to the permanent magnet is reduced due to the increase in the fringing magnetic flux accompanying the downsizing of the thin pieces of the permanent magnet, thermal demagnetization becomes difficult, and the thermal stability of the permanent magnet is enhanced.
[Brief description of the drawings]
FIG. 1A is a perspective view of a disassembled state of a primary coil, a thin piece of a permanent magnet, a linear core portion and an annular core portion of a closed magnetic circuit core, and FIG. FIG. 4 is a partial cross-sectional view showing a state in which a thin piece of a magnet is held, and FIG. 4C is a front view seen from the direction of arrow A in FIG.
FIG. 2 is a general sectional view of a conventional ignition coil.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Primary coil 3 Outer ring core part 3 'of a closed magnetic circuit core Linear core part 9 of a closed magnetic circuit core 9 Thin piece of permanent magnet 11 Bobbin 11' of a primary coil 11 'One end of a bobbin 12 A flange of one end of a bobbin Notch L ₁ provided _One side L ₂ Other side t Laminated thickness w Width

Claims (1)

A flange is provided at both ends, and a linear core portion of a closed magnetic circuit core is laminated and inserted into the inner periphery of the primary coil fitted to the inner periphery of the secondary coil, and at one end of the linear core portion, In an iron-coil assembly for an ignition coil for an internal combustion engine, a rectangular thin piece of a permanent magnet is interposed in contact with the inner periphery of an outer ring core portion of a closed magnetic circuit core surrounding both primary and secondary coils. The length of one side of the two perpendicular sides of the thin section is made larger than one of the lamination thickness and the width of the straight core portion, and the length of the other side is one of the width and the lamination thickness of the straight core portion. At the center of the end of the flange at one end of the primary coil, a notch having a depth equal to the thickness of the thin piece of the permanent magnet and receiving each end of one of two perpendicular sides is provided at the center of the end of the flange. Each end of each of two perpendicular sides of the thin piece of the permanent magnet is engaged with the notch. Iron core of the ignition coil for an internal combustion engine, characterized in that is held immovably on the end of the flange at one end of the primary coil is brought into contact with the flakes of the permanent magnet at one end of the linear core portions - coil assembly.

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