JP2001355559A - Ignition coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-size and compact ignition coil. SOLUTION: This ignition coil is so constituted that a core 1 is fixed by resin as being erected from the bottom of a case 5, a bobbin 2 is disposed inside the case 5, a primary coil 3 is wound around inside the bobbin 2, a secondary coil 4 is wound around a flange portion 2a provided outside the bobbin 2, the tip of the secondary coil is connected to a high tension cord 6, and the core 1 has a yoke 7 connected thereto. This ignition coil is characterized in that the cylindrical projection 5a for inserting the high tension cord 6 is integrally formed inside the case 5 and the high-tension side of the secondary coil 4 is disposed oppositely to the insertion direction of the high tension cord 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a miniaturization of an ignition coil.

[0002]

2. Description of the Related Art An example of an ignition coil used for engine ignition or the like is disclosed in Japanese Utility Model Laid-Open No. 60-41031. Figure 2-4 of the present application shows
FIG. 1 of No. 1031 and FIG. 3 of the present application are shown in FIG. 10 of Japanese Utility Model Publication No. 60-41031. FIG. 2 is an overall perspective view of the ignition coil of Japanese Utility Model Publication No. Sho 60-41031, and FIG. 2 and 3, 1 is a core, 2
Is a bobbin, 3 is a primary coil, 4 is a secondary coil, 5 is a case, 5a is a cylindrical projection, 6 is a high tension cord, 7 and
7 'is a yoke.

Since the core 1 is formed by laminating a plurality of thin cores made of a silicon steel plate, the shape of the core 1 is three-dimensional and square.

[0004] The bobbin 2 has a hollow cylindrical shape, and is provided with a plurality of flange portions in the height direction. The flange portion has a plurality of recesses formed in the bobbin 2. A primary coil 3 is wound inside the bobbin 2, and a secondary coil 4 is wound outside the bobbin 2. Since the output voltage of the ignition coil reaches several tens of kV, the secondary coil 4 is wound separately in a dent formed by the flange to prevent the coil windings from contacting each other and causing insulation breakdown. ing. Therefore, the winding start and the winding end are always separated in the vertical direction, so that the windings do not come into contact with each other and do not cause dielectric breakdown. The high-pressure part at the tip of the secondary coil 4 is connected to the high tension cord 6.

[0005] The core 5 is formed integrally with the case 5 so that the core 1 stands upright at the bottom of the case 5. The bobbin 2 is disposed inside the case 5 so as to penetrate the core 1. The yokes 7 and
7 'is connected.

The core of the ignition coil needs to be firmly fixed to the case 5 in order to stabilize the operation of the ignition coil and to protect the core 1. In Japanese Utility Model Application Laid-open No. 60-41031, the core 1 is fixed by filling the inside of the case 5 with resin and performing insert molding, so that the insulation property that can withstand the output voltage of the secondary coil 4 is secured.

[0007] The case 5 has a core 1 in an upright shape at the bottom.
And a bobbin 2 in which a primary coil 3 is wound inside and a secondary coil 4 is wound outside. The case 5 has a front-rear circular shape when viewed from above, and a cylindrical projection 5a for accommodating the high tension cord 6 is provided on the bottom in a shape protruding downward from the bottom of the case 5.

Next, the operation of the ignition coil disclosed in Japanese Utility Model Publication No. Sho 60-41031 will be described. As the flywheel (not shown) rotates, magnetic flux passes through the core 1, the yoke 7, and the yoke 7 ', a voltage is generated between the primary coils 3, and an igniter (not shown) operates. By operating the igniter, the current of the primary coil 3 is rapidly cut off. When the current of the primary coil is suddenly cut off, a high voltage is induced in the secondary coil 4 by an electromagnetic induction effect. Then, the voltage induced in the secondary coil 4 is extracted as electric power for sparking the spark plug.

In Japanese Utility Model Application Laid-Open No. 60-41031, the core 1 is formed by laminating a plurality of thin cores made of a silicon steel sheet, so that the shape of the core 1 is three-dimensional and square.
However, the ignition coil of Japanese Utility Model No. 60-41031,
While the core 1 was square, the bobbin 2 was circular, and the case 5 was a front rear circular shape to match the bobbin 2. For this reason, a dead space was generated between the core 1 and the bobbin 2 and between the bobbin 2 and the case 5, and the entire ignition coil was enlarged.

Further, the cylindrical protrusion 5a protrudes from the bottom of the case 5, and the ignition coil tends to be large due to the spatial space from which the cylindrical protrusion 5a protrudes. Furthermore, since the cylindrical projection 5a is provided in a shape protruding from the bottom of the case 5, there is a risk that the assembly 5 may be broken or cracked when stress is applied.

[0011]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an ignition coil which is small in size, has a compact appearance, and has no danger of breaking the cylindrical projection 5a without lowering the output.

[0012]

According to the first aspect of the present invention, a cylindrical projection 5a for inserting the high tension cord 6 is integrally formed inside the case 5, and the high voltage side of the secondary coil 4 is high. By arranging the tension cord 6 on the side opposite to the insertion direction, the case 5 can be made smaller and more compact. The invention of claim 2 includes a core 1, a bobbin 2, a case 5
By unifying everything into a square shape, the entire ignition coil was reduced in size without creating dead space.

[0013]

FIG. 1 shows an embodiment of an ignition coil according to the present invention. In FIG. 1, 1 is a core, 2 is a bobbin, 3 is a primary coil, 4 is a secondary coil, 5 is a case, 5a
Is a cylindrical projection, 6 is a high tension cord, and 7 and 7 'are yokes.

The core 1 is made by laminating a plurality of thin cores made of a silicon steel sheet, so that the shape of the core 1 is three-dimensional and square.

The bobbin 2 has a rectangular cylindrical shape in accordance with the shape of the core 1. Multiple flanges 2a in the height direction of bobbin 2
Are provided, and a plurality of recesses are formed in the bobbin 2 by the flange portion 2a. Case 5 has a core 1 at the bottom of case 5.
The core 1 is integrally formed in a shape in which the core 1 stands upright. Also,
The bobbin 2 is arranged in the case 5 so as to penetrate the core 1. The yokes 7 and 7 ′ are provided at both ends in the long side direction of the core 1.
Is connected.

The core of the ignition coil must be firmly fixed to the case 5 to stabilize the operation of the ignition coil and to protect the core 1. In this embodiment, the core 1 is fixed by filling the inside of the case 5 with resin and performing insert molding.
The insulation property that can withstand the output voltage of the secondary coil 4 is ensured.

A primary coil 3 is wound inside the bobbin 2, and a secondary coil 4 is wound outside the bobbin 2.
Since the output voltage of the ignition coil reaches several tens of kilovolts, the secondary coil 4 is divided and wound around the dent formed by the flange 2a in order to prevent the coil windings from contacting each other and causing insulation breakdown. Have been. Therefore, the winding start and the winding end are always separated in the vertical direction, so that the windings do not come into contact with each other and do not cause insulation breakdown.

Since the secondary coil 4 is wound starting from the bottom of the bobbin 2 toward the upper part of the bobbin 2, the winding end of the secondary coil 4 comes to the upper part of the bobbin 2. The upper part of the bobbin 2 is also the upper part of the case 5. The high-pressure portion at the tip of the secondary coil 4 is connected to a high tension cord 6, and the high tension cord 6 is housed in a cylindrical projection 5a provided on the case 5.

The cylindrical projection 5a for accommodating the high tension cord 6 is provided inside the case 5 by being integrally formed with the case 5. Since the secondary coil 4 is wound from the bottom to the top of the case 5, the secondary coil
The high tension cord 6 to which the winding end of 4 is connected is housed in the cylindrical projection 5a from the top to the bottom of the case 5. For this reason, since the cylindrical projection 5a is not exposed to the outside of the case 5, there is no danger of the cylindrical projection 5a being broken even when stress is applied to the case 5. In addition, cylindrical projection
Since 5a does not protrude to the outside of the case 5, the appearance of the case 5 is made compact and downsizing can be realized.

In the case 5, the core 1 is formed in an upright shape at the bottom.
And a bobbin 2 in which a primary coil 3 is wound inside and a secondary coil 4 is wound outside. The case 5 has a square shape according to the shape of the bobbin 2. Therefore, dead space does not occur between the core 1, the bobbin 2, and the case 5, the case 5 can be reduced in size, and the ignition coil as a whole can be further reduced in size.

Next, the operation of the ignition coil according to the present invention will be described. With the rotation of the flywheel (not shown), magnetic flux passes through the core 1, the yoke 7, and the yoke 7 ',
A voltage is generated between the primary coils 3 and an igniter (not shown) operates. By operating the igniter, the current of the primary coil 3 is rapidly cut off. When the current of the primary coil is suddenly cut off, a high voltage is induced in the secondary coil 4 by an electromagnetic induction effect. Then, the electromotive force induced in the secondary coil 4 is extracted as electric power for sparking the spark plug.

[0022]

As described above, the cylindrical projection 5a for inserting the high tension cord 6 is integrally formed inside the case 5, and the high voltage side of the secondary coil 4 is inserted into the high tension cord 6. By arranging it on the side opposite to the direction, the cylindrical projection 5a is not exposed to the outside of the case 5, so that even if stress is applied to the case 5, there is no danger of the cylindrical projection 5a being broken. In addition, the cylindrical projection 5a is
Since it does not protrude to the outside of the case, the appearance of the case 5 is compact, and the size of the case 5 can be reduced.

Further, since the core, the primary coil, the secondary coil, and the case are all unified into a square shape, the outer shape of the case can be minimized without making useless space. Can be made smaller.

[Brief description of the drawings]

FIG. 1 shows an ignition coil according to the present invention.

FIG. 2 is an overall perspective view of the ignition coil of Japanese Utility Model Application Laid-Open No. 60-41031.

FIG. 3 is a side view showing the state where the ignition coil of Japanese Utility Model Application Laid-Open No. 60-41031 is installed. Core bobbin Primary coil Secondary coil Case 5a. Cylindrical projection high tension cord yoke 7 '. yoke

Claims (2)

[Claims] 1. A core 1 is fixed with resin so as to stand upright on the bottom of a case 5, a bobbin 2 is arranged inside the case 5, a primary coil 3 is wound inside the bobbin 2, and the bobbin 2 A secondary coil 4 is wound around a flange 2a provided on the outside, and a tip of the secondary coil is a high tension cord 6.
In the ignition coil in which the yoke 7 is connected to the core 1, the high tension cord 6 is connected to the core 1.
A cylindrical projection 5a for inserting the same is integrally formed inside the case 5, and the high voltage side of the secondary coil 4 is arranged on the side opposite to the insertion direction of the high tension cord 6. Characterized ignition coil. 2. The ignition coil according to claim 1, wherein all of the core 1, the bobbin 2, and the case 5 are square.