JP5846741B2 - Ignition coil for internal combustion engines - Google Patents

Description

The present invention relates to an ignition coil for an internal combustion engine.

2. Description of the Related Art Conventionally, in an ignition coil for an internal combustion engine that includes a primary coil, a secondary coil, and an iron core in a case, and a coil housing portion that is filled with mold resin in the case is disposed outside the plug hole, one of the primary coils. Several configurations have been proposed for the electrical connection between the next winding and the connecting portion for the purpose of improving the ease of connection and reliability. As a typical example of this, for example, Japanese Patent Application Laid-Open No. 09-317616 (hereinafter “Patent Document 1”) is known.

FIG. 11 is a side sectional view of the ignition device described in Patent Document 1. In FIG. 11, Patent Document 1 discloses a power switch in which a case 201, an ignition coil 221 housed in the case 201, and a power transistor and an integrated circuit for driving and controlling the power transistor are solid-sealed with resin by insert molding. 204, a low-voltage wiring body 222 as a wiring body in which a terminal 223 electrically connected to the power switch 204 and a terminal 207 electrically connected to the outside are insert-molded, and a tip 207a of the terminal 207 A connector case 225 for protection is provided.

The ignition coil 221 includes an iron core 209 that forms a magnetic circuit, a primary coil 210 that is provided around the iron core 209 and has a primary winding 210a wound around a primary bobbin 210b, and the primary coil 210. A secondary coil 211 is provided which is provided on the outer side and has a secondary bobbin 211b around which a secondary winding 211a is wound. The primary bobbin 210b and the low-voltage wiring body 222 are separate, and the primary bobbin 210b and the low-voltage wiring body 222 are separated by locking the locking portion of the primary bobbin 210b and the locked portion of the low-voltage wiring body 222. Integrated.

The low-voltage wiring body 222 has a through-hole through which the primary bobbin 210b passes. The through-hole has a small inner diameter along the insertion direction of the primary bobbin 210b. There has been proposed an ignition coil for an internal combustion engine in which the primary bobbin 210b and the low-voltage wiring body 222 can be temporarily fixed by pressing the inner wall surface.

JP 09-317616 A

However, the conventional ignition coil has the following problems. That is, in the ignition coil of Patent Document 1, the primary bobbin and the wiring body are connected and integrated to improve the ease of connection and reliability. There is a problem in that the ignition device is enlarged by providing the wiring body separately.

The present invention has been made in view of the above problems, and provides a small ignition coil that can be accommodated in a limited space in an engine room, and easily connects each terminal to a primary coil and a secondary coil. The aim is to provide a possible ignition coil.

In order to solve the above problems, the present invention has the following configuration of an ignition coil for an internal combustion engine. That is, an iron core composed of a central iron core and an outer iron core, a primary coil in which a primary winding is wound around a primary bobbin, and a secondary coil in which a secondary winding is wound around a secondary bobbin A case in which the iron core, the primary coil, and the secondary coil are housed, a connector provided on a side surface of the case, and a mold resin filled in a coil housing portion in the case. Prepared,
The connector is provided with at least a power connector terminal and a ground connector terminal. The power connector terminal has a slit formed at an end thereof, and the primary winding or the secondary coil. Any one of the secondary low-voltage terminals provided is press-fitted, and the ground connector terminal has an end portion of the terminal coinciding with the direction in which the iron core is inserted from the opening of the case. ,
The iron core has a recess that matches the direction in which the iron core is inserted from the opening of the case, and the end of the ground connector terminal is inserted into the recess.

As described above, the connector is provided with a power connector terminal, a slit is formed at the end of the power connector terminal, and the primary winding and the secondary low voltage terminal provided in the secondary coil are press-fitted into the slit to supply power. The connector terminal can be electrically connected to the primary coil and the secondary coil without welding or soldering. In addition, an igniter is provided in the case, a connection terminal for connecting the igniter and the primary coil is provided in the case, a slit is formed at an end of the connection terminal, and the primary winding is press-fitted into the slit, whereby the igniter and 1 The next coil can be electrically connected without welding or soldering. In addition, the connector is equipped with a grounding connector terminal, and a dent is formed in the central iron core. By inserting the grounding connector terminal into the dent, the central iron core and the grounding connector terminal are not welded or soldered. Electrical connection is possible.

In addition, the power connector terminal, connection terminal, and ground connector terminal protrude toward the opening of the case, so that only the coil portion combining the primary coil, the secondary coil, and the iron core is inserted into the case. Electrical connection with the other terminals can be performed simultaneously. As a result, a small ignition coil that can be accommodated in a limited space in the engine room can be realized, and an ignition coil that can be easily assembled can be realized.

1 is a perspective view of an ignition coil for an internal combustion engine according to an embodiment of the present invention. It is BB sectional drawing seen from the arrow (A) direction of FIG. It is the top view seen from the arrow (C) direction of FIG. It is EE sectional drawing seen from the arrow (D) direction of FIG. 1 is a circuit diagram of an ignition coil for an internal combustion engine according to an embodiment of the present invention. It is a perspective view of the connector terminal for power supplies of the ignition coil which is an Example of this invention. It is a figure shown with the connection state of the connector terminal for power supplies of the ignition coil which is an Example of this invention. It is a perspective view of the connection terminal of the ignition coil which is an Example of this invention. It is a figure which shows the connection state of the connection terminal of the ignition coil which is an Example of this invention. It is a perspective view of the connector terminal for earthing | grounding of the ignition coil which is an Example of this invention. It is side surface sectional drawing of the ignition device of patent document 1.

An example showing the embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view of an ignition coil for an internal combustion engine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line BB in the direction of the arrow (A) in FIG. 1, and FIG. 3 is a top view as seen from FIG. 3, FIG. 4 is a cross-sectional view taken along the line EE in FIG. 3, FIG. 5 is a circuit diagram of the ignition coil, and FIG. 6 is a diagram showing the connection state of the power connector terminal of the ignition coil, FIG. 7 is a perspective view of the connection terminal of the ignition coil, and FIG. 8 is a diagram showing the connection state of the connection terminal of the ignition coil. 9 is a perspective view of the grounding connector terminal of the ignition coil.

1 to 10, a case 40 forming the outer shape of the ignition coil 100 is formed by a box-shaped integral molding having an opening surface on the upper surface in the vertical direction. A case fixing portion 42 for attaching and fixing the ignition coil 100 to an engine head (not shown) is formed on the side surface of the case 40. Further, a high voltage tower 44 having a high voltage terminal 60 for supplying a secondary voltage to the spark plug 110 is formed on the outer bottom surface of the ignition coil 100 so as to protrude into a plug hole formed in the upper part of the engine. The high voltage tower 44 includes a protector (not shown) provided with a conductive member for supplying the secondary voltage output from the ignition coil 100 to the ignition plug 110 from the high voltage terminal 60.

Further, in the case 40, an iron core 36 composed of an I-shaped central iron core 30 formed by laminating a plurality of thin plates and a U-shaped outer peripheral iron core 32, and the central iron core 30 A primary coil 14 in which a primary winding 12 is wound about 100 turns around the outer periphery of a primary bobbin 10 formed of resin on the outer periphery, and a secondary bobbin 20 formed of resin on the outer periphery of the primary coil 14 It is composed of a coil portion of a secondary coil 24 in which a secondary winding 22 is wound around 8000 to 15000 turns on the outer periphery, and the outer peripheral iron core 32 has a magnetic path of the iron core 36 perpendicular to the opening surface of the case 40 It is arranged to be. Furthermore, a magnet 38 for generating a magnetic flux in the opposite direction to the magnetic flux generated by the primary coil 14 in the magnetic path is provided at one end of the connecting surface of the central iron core 30 and the outer peripheral iron core 32. .

A secondary high voltage terminal 26 is provided at one end of the secondary bobbin 20, and a secondary low voltage terminal 28 is provided at the other end of the secondary bobbin 20. Further, the secondary low voltage terminal 28 is provided with a diode 74 for preventing discharge to the spark plug 110 due to a back electromotive voltage when the ignition signal is ON.

Further, an igniter 70 for supplying an ignition signal to the primary coil 14 is provided in the case 40. Further, the igniter 70 is constituted by a switching element, and a substantially flat igniter terminal 72 formed of metal is provided on the base side, the collector side, and the emitter side of the switching element.

A connector 46 is formed on the side surface of the case 40, and the connector 46 includes a substantially flat power connector terminal 62, a ground connector terminal 63, and an ignition signal connector terminal formed of brass. .

The first end 62a of the power connector terminal 62 is connected to the battery 112, and the second end 62b of the power connector terminal 62 is connected to the igniter 70 for supplying a power voltage to the igniter 70. The third end 62c of the power connector terminal 62 is connected to the primary coil 14 and the secondary coil 24. Further, a first slit 66a and a third slit 66c are formed in the third end 62c of the power connector terminal 62, and the primary winding 14 on the low voltage side of the primary coil 14 is formed in the first slit 66a. The line 12a is press-fitted, and the secondary low-voltage terminal 28 is press-fitted into the third slit 66c. Further, the first slit 66a and the third slit 66c chamfer the low pressure side primary winding 12a and the pressure inlet of the secondary low voltage terminal 28, and the width of the third slit 66c is the secondary slit. It is formed narrower than the radial length of the low voltage terminal 28.

The width of the first slit 66a is narrower than the radial length of the primary winding 12, and the primary slit 12a is pressed into the first slit 66a when the low-voltage primary winding 12a is press-fitted into the first slit 66a. The insulating coating of the winding 12 is scraped to make an electrical connection. Further, the power connector terminal 62 is disposed along the inner wall of the case 40 on the same surface as the connector 46 and the inner bottom surface of the case 40, and the third end 62c of the power connector terminal 62 is Projecting toward the opening of the case 40.

Further, a connecting terminal 68 for connecting the igniter 70 and the primary coil 14 is provided in the case 40. Furthermore, one end 69a of the connection terminal 68 is connected to the igniter terminal 72 on the collector side, and the other end 69b of the connection terminal 68 is connected to the primary winding 12 on the high voltage side.

Further, a second slit 66b is formed at the other end 69b of the connection terminal 68, and the high voltage side primary winding 12b of the primary coil 14 is press-fitted into the second slit 66b. The second slit 66b chamfers the pressure inlet of the high-voltage side primary winding 12b, and the width of the second slit 66b is narrower than the radial length of the primary winding 12. When the high-voltage-side primary winding 12b is press-fitted into the two slits 66b, the insulating coating of the primary winding 12 is scraped and electrically connected. Further, the connection terminal 68 is disposed along the inner wall of the case 40 on the same surface as the connector 46 and the inner bottom surface of the case 40, and the other end 69b of the connection terminal 68 is directed toward the opening surface of the case 40. It protrudes.

The first end 63a of the ground connector terminal 63 is connected to an external ground, and the second end 63b of the ground connector terminal 63 is connected to the igniter terminal 72 on the emitter side. The third end 63c of the connector terminal 63 for use is connected to the central iron core 30. Further, a recess 35 is formed on the bottom side surface of the case 40 of the central iron core 30, and the recess 35 is formed so as to connect both ends in the radial direction of the central iron core 30, and the grounding is connected to the recess 35. The third end 63c of the connector terminal 63 is inserted.

Further, the third end portion 63c of the ground connector terminal 63 has an elastic force due to the bent elastic portion 64. Further, the ground connector terminal 63 is disposed along the inner wall of the case 40 on the same surface as the connector 46 and the inner bottom surface of the case 40, and the third end 63c of the ground connector terminal 63 Projecting toward the opening of the case 40.

One end of the ignition signal connector terminal is connected to the ECU, and the ignition signal connector terminal is connected to the igniter terminal 72 on the base side. Further, the ignition signal connector terminal is disposed along the same surface as the connector 46 of the case 40.

In addition, the coil portion is press-fitted into the case 40 from the above configuration, and at the same time, the secondary low-voltage terminal 28 and the primary winding 12 and the recessed portion 35 of the central iron core 30 are connected to the power connector terminal 62 and The connection terminal 68 and the ground connector terminal 63 are electrically connected.

The igniter terminal 72 is led out in a direction perpendicular to the opening surface of the case 40. Further, the igniter terminal 72 is electrically connected by a joining terminal 80 formed of a conductive member such as a metal having elasticity, and the igniter terminal 72 is simultaneously connected by a plurality of the joining terminals 80. .

Further, the igniter terminal 72 is formed with a groove portion for preventing the igniter terminal 72 from coming into contact with the joining terminal 80. Further, the joining terminal 80 is press-fitted into a holder 82 formed of PBT (polybutylene terephthalate), and the holder 82 has three holding portions for fixing the joining terminal 80.

Further, the periphery of the outer peripheral iron core 32 excluding the connection surface with the central iron core 30 and the magnet 38 is covered with a cover 50 that adheres to a mold resin formed of PBT.

A protrusion 56 is formed on the horizontal extension of the cover side coil facing surfaces 51a and 51b. Further, the protrusion 56 is formed at four locations along the curved portion 34 of the outer peripheral iron core 32, and the protrusion 56 has a length in the radial direction of the flange 21 formed on the secondary coil 24. It is formed to the same length.

The protrusion 56 is formed at a position where the flange 21 is hidden by the protrusion 56 when viewed from the upper surface of the case 40. Further, the case 40 is filled with a mold resin 90 that realizes electrical insulation of the ignition coil 100 and physical fixing of each member.

The mold resin 90 is filled to the vicinity of the opening surface of the case 40, and a resin surface 92 is formed in the vicinity of the opening surface.

Also, with the above configuration, when the ignition signal from the ECU is turned on, a current flows to the base of the igniter 70 and a primary current from the battery 112 flows to the primary coil 14. When the ignition signal from the ECU is turned off, the primary current of the primary coil 14 is cut off, a secondary current is generated in the secondary coil 24, and the spark plug 110 is discharged.

As a modification of the first embodiment, the shape and arrangement position of the power connector terminal 62 may be arbitrarily changed according to design circumstances, or may be formed at the third end 62c of the power connector terminal 62. The shape and width of the first slit 66a and the third slit 66c may be arbitrarily changed according to the design circumstances. Further, the low voltage side primary winding 12a and the secondary low voltage terminal 28 may be connected to either the first slit 66a or the third slit 66c. Further, the igniter 70 may not be directly supplied with power from the battery 112, and the secondary low voltage terminal 28 may be configured without the diode 74.

The power connector terminal 62 may be made of any material other than brass, as long as it is harder than the insulating coating of the primary winding 12 depending on the design circumstances. Further, the shape and arrangement position of the connection terminal 68 may be arbitrarily changed according to design circumstances, and the shape and width of the second slit 66b formed in the connection terminal 68 may be arbitrarily changed according to design circumstances. May be.

Further, the second slit 66b may be formed at the end of the igniter terminal 72, and the high-voltage side primary winding 12b may be press-fitted. Further, the connecting terminal 68 may be made of any material other than brass material as long as it is harder than the insulating coating of the primary winding 12 depending on design circumstances.

Further, the shape and arrangement position of the ground connector terminal 63 may be arbitrarily changed according to design circumstances. Further, the shape and position of the elastic portion 64 formed on the ground connector terminal 63 can be arbitrarily changed according to the design circumstances as long as the third end portion 63c of the ground connector terminal 63 has an elastic force. May be.

In addition, the shape and position of the indented portion 35 formed in the central iron core 30 may be arbitrarily changed according to design circumstances, and the indented portion 35 may be formed in the outer peripheral iron core 32. Further, the protruding direction of the third end 62c of the power connector terminal 62 and the other end 69b of the connection terminal 68 and the third end 63c of the ground connector terminal 63 are within the case 40. When the coil portion is press-fitted, the secondary low-voltage terminal 28 and the primary winding 12, and the recessed portion 35 of the central iron core 30 are connected to the power connector terminal 62 and the connection terminal 68, and the ground connector terminal 63. As long as it is a structure electrically connected to the terminal, it may be changed in any direction.

The low-voltage primary winding 12a is press-fitted into the first slit 66a, the high-voltage primary winding 12b is press-fitted into the second slit 66b, and the secondary slit is inserted into the third slit 66c. Although the low voltage terminal 28 is press-fitted, it may be changed to any configuration depending on the circuit configuration of the ignition coil.

10: 1 primary bobbin
12: Primary winding
12a: Low voltage side primary winding
12b: High voltage side primary winding
14: Primary coil
20: Secondary bobbin
21: Flange
22: Secondary winding
24: Secondary coil
26: Secondary high-voltage terminal
28: Secondary low voltage terminal
30: Central iron core
32: Outer iron core
33a, 33b: Outer iron core side coil facing surface
34: Music part
35: Recessed part
36: Iron core
38: Magnet
40: Case
42: Case fixing part
44: High-pressure tower
46: Connector
50: Cover that adheres to mold resin
51a, 51b: Cover side coil facing surface
56: Projection
60: High voltage terminal
62: Connector terminal for power supply
62a: first end
62b: second end
62c: third end
63: Connector terminal for grounding
63a: first end
63b: second end
63c: third end
64: Elastic part
66a: first slit
66b: Second slit
66c: Third slit
68: Connection terminal
69a: one end
69b: The other end
70: Igniter
72: Igniter terminal
74: Diode
80: Junction terminal
82: Holder
90: Mold resin
92: Resin surface
100: Ignition coil
110 spark plug
112: Battery

Claims (1)

An iron core composed of a central iron core and an outer iron core, a primary coil in which a primary winding is wound around a primary bobbin, a secondary coil in which a secondary winding is wound around a secondary bobbin, A case in which the iron core, the primary coil, and the secondary coil are housed, a connector provided on a side surface of the case, and a mold resin filled in a coil housing portion in the case;
The connector is provided with at least a power connector terminal and a ground connector terminal. The power connector terminal has a slit formed at an end thereof, and the primary winding or the secondary coil. Any one of the secondary low-voltage terminals provided is press-fitted, and the ground connector terminal has an end portion of the terminal coinciding with the direction in which the iron core is inserted from the opening of the case. ,
The iron core has a recessed portion that coincides with a direction in which the iron core is inserted from the opening of the case, and an end of the ground connector terminal is inserted into the recessed portion. Ignition coil.

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