JP2008117865A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil for cylinder type internal combustion engine, which is attached to the inside of a plug hole of an engine to supply a high voltage to the ignition plug and accordingly high in reliability while having utility that the same is mounted on many kinds of various engines or the like and which is capable of obtaining an output of the best ignition performance. <P>SOLUTION: The ignition coil for internal combustion engine is constituted of a coil unit, comprising a central core made of electromagnetic steel sheets, a primary coil connected to the central core through electromagnetic coupling and arranged at the outer peripheral side of the center core, a secondary coil and an external peripheral core arranged at the outer peripheral side of both of the primary and secondary coils while being made of the electromagnetic steel sheets. In this case, the coil unit is received in a case having electric insulating property and is sealed by an insulating material. In such an ignition coil for internal combustion engine, the winding layers of the primary coil are constituted of odd number layers and a primary side electric conduction passage is arranged at the outer peripheral side of the primary coil. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides an internal combustion engine that supplies a high voltage to an ignition plug, in particular accommodated in a plug hole of an engine head or mounted on or near an engine head cover and connected to the ignition plug directly or via a plug boot or plug cord. The present invention relates to an engine ignition coil.

  The internal combustion engine ignition coil used in a recent automobile internal combustion engine has conflicting demands for downsizing and high output to cope with a lean combustion engine in consideration of the global environment.

  The cylindrical internal combustion engine ignition coil that directly supplies a high voltage to the engine spark plug is housed in a part or most of the engine head plug hole, so that the space on the engine head can be reduced and the high voltage can be reduced. Since there is no need for a conducting wire to the spark plug such as a high tension cable because it is supplied directly to the spark plug, the occurrence of noise during ignition that adversely affects the electrical components is small, and the propagation loss of ignition energy to the spark plug is also low. It is used in many engines because of its advantages such as being small.

  In recent years, the diameter of the plug hole has been reduced due to the expansion of the water jacket, the angle of the valve, and the diameter of the spark plug. In order to maintain the performance of the ignition coil for a cylindrical internal combustion engine, the diameter can be reduced. It is essential to improve the efficiency of the coil part.

  The ignition coil for a cylindrical internal combustion engine is configured by electromagnetically coupling a primary coil, a secondary coil, and an iron core, and is subjected to intermittent control by a switching element such as an igniter (semiconductor switch) at the timing of ignition. By cutting off the secondary coil current, a high voltage obtained by boosting the battery power supply voltage of the automobile from 30 to 40 kV is distributed to the spark plug. The approximate value of the energy of the ignition coil for a cylindrical internal combustion engine can be obtained from the product of the number of turns of the primary coil, the cross-sectional area of the iron core, and the cutoff current of the primary coil. In other words, if each of them is increased, a large ignition energy can inevitably be obtained. However, in practice, the primary coil cutoff current value depends on the performance of the igniter that performs the intermittent operation. As an automobile ignition system, a cylinder internal combustion engine ignition coil of about 8 to 10 A is generally used. It was.

  In recent years, an igniter that can be intermittently controlled at 15 A or more can be used. Here, in the case of an ignition coil for a cylindrical internal combustion engine that has obtained an ignition energy of about 40 mJ with a primary coil breaking current value of 8 A and a primary coil winding number of 200 turns, If the secondary current value is doubled to 16A, the number of turns of the primary coil can be halved.

  A conventional example will be described with reference to FIGS. FIG. 10 is a longitudinal sectional view of an ignition coil for an internal combustion engine to which a conventional technique is applied. FIG. 11 is a coil diagram of an ignition coil for an internal combustion engine to which a conventional technique is applied. FIG. 12 is a schematic circuit diagram of FIG.

  10 to 12, the conventional ignition coil for a cylindrical internal combustion engine includes a central iron core 70 made of an electromagnetic steel plate such as a silicon steel plate, and a plurality of ones from one end to one end on the outer periphery of the central iron core 70. Each section is provided with a section, and a secondary coil 20 in which a secondary copper wire is wound around a secondary bobbin 22 in which each section is laminated, and a coaxial arrangement with the secondary coil 20, and polybutylene terephthalate (Hereinafter referred to as “PBT”), a primary coil 10 in which a primary copper wire is wound around a primary bobbin 11, and a cylindrical shape formed outside these coils and cut into a part of its circumference. The outer peripheral iron core 60 having a notch, the central iron core 70, the primary coil 10, and the secondary coil 20 form the coil part 2, and an upper storage part having a large opening in the upper part for storing the coil part 2 30 A cylindrical internal combustion engine ignition coil 1 having a cylindrical case 3 formed of a flame-retardant insulating resin material of polyphenylene sulfide (hereinafter referred to as “PPS”) having good electrical insulation characteristics, 3 is mounted with a primary current input unit 32 for supplying a battery power supply voltage to the primary coil 10, and in some cases, an igniter 80 for turning on and off the primary current is stored in the upper storage unit 30. An epoxy insulating material is injected into the case 3 as an insulating material and cured to form a cylindrical internal combustion engine ignition coil 1.

  The electrical connection between the primary coil 10 and the primary current input unit 32 for supplying a power supply voltage to the primary coil 10 or the igniter 80 accommodated in some cases is performed in the shortest electrical conduction path. The primary coil 10 and the primary current input unit 32 to the igniter 80 are concentrated on the upper portion of the case 3, and the primary coil 10 is connected to the collector side (C) of the igniter 80 and the B + of the battery power source. (Battery +) is electrically connected to one end side of the primary coil 10. Thus, it is required to design the winding layer of the primary coil with a plurality of layers.

  In the circuit diagram of FIG. 12, the igniter 80 has outputs on the base side (B), collector side (C), and emitter side (E). The base side (B) is an ignition signal generating circuit and collector side ( C) is connected to the primary coil and the emitter side (E) is grounded. The ignition coil is electrically connected to the primary coil 10 at the low voltage side 24 of the secondary coil 20. The primary side electric conduction path is an electric path from B + (battery +) to the primary coil 10 and the collector side (C) of the igniter 80 to the emitter side (E). When an ignition signal is input to the base side (B) of the igniter 80 from the ignition signal generation circuit, a current flows from B + (battery +) to the primary coil to generate a magnetic field, and the generated magnetic field is held on the iron core. . Next, when the ignition signal on the base side (B) of the igniter 80 is cut off, the current flowing in the primary coil 10 is also cut off, and a high voltage corresponding to the turn ratio of the primary coil 10 and the secondary coil 20 is obtained. Is excited by the secondary coil 20 and distributed to a spark plug (not shown) electrically connected to the secondary coil 20.

  Specifically, the primary coil 10 is a copper wire with an insulating film having a wire diameter of about φ0.5 mm to φ1 mm and is wound around the primary bobbin 11 in about 75 to 100 turns, and the resistance is 100 to 300 mΩ, The total volume is two layers of a round trip. The first layer 13a, which is the forward path, is wound in a dense winding and occupies most of the primary winding number, and the second layer 13b, which is the return path, turns back the primary copper wire of the first layer 13a in about 5 turns. From the point approaching the return path, it is wound in a rough roll toward the winding start end side.

  Further, at both ends or one end of the central iron core 70, only the magnet 72 and the yoke core 73 or the magnet 72 for generating a magnetic flux in the opposite direction to the magnetic flux generated in the primary coil 10 in order to suppress the saturation of the magnetic flux of the iron core. In some cases, the ignition energy during operation is increased.

  Further, a lower portion of the coil portion 2 is provided with a high voltage tower portion 34. The high voltage tower portion 34 is provided with a secondary high voltage terminal 22, and a spring 40 for transmitting a high voltage generated in the secondary coil to an ignition plug (not shown). Electrically coupled. Further, the high voltage tower portion 34 includes a plug boot 50 formed by covering an electrically conductive member (not shown) with an insulating elastic material such as rubber so that a high voltage does not leak into a metal portion such as a plug hole. It is closely fitted with the spark plug.

The operation of the above-described ignition coil for a cylindrical internal combustion engine will be described. The current input from the primary current input unit 32 generates a magnetic flux through the primary coil 10, facilitates the magnetic flux to pass through the central iron core 70 and the outer peripheral iron core 60, and the current is supplied from the ECU by the igniter 80. A high voltage is generated in the secondary coil 20 by being interrupted by the ignition signal. The high voltage generated in the secondary coil 20 passes through the secondary high voltage terminal 22 attached to the high voltage tower section 34 and is applied to a spark plug (not shown) via the spring 40.
European Patent Publication No. 1557849

  Conventionally, in the case of 16A in which the primary breaking current is doubled than in the case of an ignition coil having a primary coil winding number of two layers of 200 turns and a primary breaking current of 8A, the above-mentioned is necessary to generate an equivalent ignition performance. The required number of turns of the primary coil can be constituted by half of 100 turns, and the winding layer of the primary coil that has been conventionally constituted by two layers of the reciprocating path can be constituted by one layer of the forward path. Due to such a structure, it is required that the winding layer of the primary coil is composed of a plurality of layers. In this case, it cannot be composed of one layer of the forward path, and two layers of the round-trip path are necessary. Thus, the effect of reducing the outer diameter of the coil due to halving the number of turns could not be obtained.

  Further, as described in European Patent Publication No. 1557849 (Patent Document 1), the primary coil starts from the point where the second layer primary copper wire of the return path starts to return to the return path of the return path. It can be pulled straight up to the winding start end in the axial direction perpendicular to the winding direction of the layer, and this second layer can be placed in the gap in the slit part of the outer iron core, but it is placed in the gap and straight at the winding start end. There are problems that positioning for pulling up is difficult, and that the effect of reducing the diameter cannot be obtained sufficiently when the primary copper wire diameter is large relative to the laminated thickness of the outer peripheral iron core.

  In view of the above problems, the present invention pays attention to a method of configuring a primary coil electric circuit of an ignition coil for a cylindrical internal combustion engine, and is installed in a plug hole of the engine to supply a high voltage to the ignition plug. In the ignition coil for a cylindrical internal combustion engine, it is possible to obtain an output with the best and most versatile ignition performance, such as mounting the ignition coil for a cylindrical internal combustion engine on a wide variety of engines with a small diameter and high reliability. An object is to provide an ignition coil for a cylindrical internal combustion engine.

  In order to solve the above-mentioned problems, claim 1 of the present invention includes a central iron core made of an electromagnetic steel sheet, and a primary coil connected to the central iron core by electromagnetic coupling and disposed on the outer peripheral side of the central iron core. A coil part is constituted by a secondary coil, the primary coil, and an outer peripheral iron core made of an electromagnetic steel plate disposed on the outer peripheral side of both of the secondary coils, and the coil part is electrically insulative. An ignition coil for an internal combustion engine sealed in an insulating material, wherein the winding layer of the primary coil is formed of an odd number layer, and a primary-side electric conduction path is formed on the outer peripheral side of the primary coil. Is an ignition coil for an internal combustion engine.

  Further, in claim 2, the ignition coil for an internal combustion engine according to claim 1, wherein a part of the primary side electric conduction path is constituted by the outer peripheral iron core; To do.

  According to a third aspect of the present invention, in the ignition coil for an internal combustion engine according to the first aspect, the outer peripheral iron core is electrically connected between one end of the primary coil and an igniter (collector side). An ignition coil for an internal combustion engine is provided.

  According to a fourth aspect of the present invention, in the ignition coil for an internal combustion engine according to the first aspect, the outer peripheral iron core is electrically connected between one end of the primary coil and B + (battery +). An ignition coil for an internal combustion engine is provided.

  The ignition coil for an internal combustion engine according to any one of claims 1 to 4, wherein the coil portion is disposed in the engine plug hole and directly connected to the ignition plug. And

  According to a sixth aspect of the present invention, in the ignition coil for an internal combustion engine according to the first to fourth aspects, the coil portion is mounted on an engine head cover or in the vicinity of a spark plug, and the coil portion is an electric connected to the coil portion. The internal combustion engine ignition coil is electrically connected to the spark plug through a high-voltage conductor having an electrically conductive member covered with an insulating material.

  Further, according to claim 7, in the internal combustion engine ignition coil according to claims 1 to 6, the outer peripheral iron core is made of an electromagnetic steel plate obtained by rounding a thin plate into a cylindrical shape. Ignition coil.

  According to an eighth aspect of the present invention, in the ignition coil for an internal combustion engine according to any one of the first to sixth aspects, the outer peripheral iron core is formed of a laminated electromagnetic steel sheet having a B shape or an O shape. It is set as the ignition coil for internal combustion engines.

  According to a ninth aspect of the present invention, a central iron core made of an electromagnetic steel plate, a primary coil connected to the central iron core by electromagnetic coupling and disposed on the outer peripheral side of the central iron core, a secondary coil, and the primary A coil part is comprised with the coil and the outer periphery iron core which consists of an electromagnetic steel plate arrange | positioned at the outer peripheral side of both of the said secondary coils, The said coil part is stored in the case which has electrical insulation, and insulation In the internal combustion engine ignition coil sealed with a material, the winding layer of the primary coil is formed of an odd number layer, and a primary electric conduction path is disposed on the inner peripheral side of the primary coil. An ignition coil for an internal combustion engine is used.

  According to a tenth aspect of the present invention, there is provided an ignition coil for an internal combustion engine according to the ninth aspect, wherein a part of the primary side electric conduction path is constituted by the central iron core.

  According to claim 11, in the ignition coil for an internal combustion engine according to claim 9, the central iron core is electrically connected between one end of the primary coil and an igniter (collector side). An ignition coil for an internal combustion engine is provided.

  According to claim 12, in the ignition coil for internal combustion engine according to claim 9, the central iron core is electrically connected between one end of the primary coil and B + (battery +). An ignition coil for an internal combustion engine is provided.

  The internal combustion engine ignition coil according to claim 9, wherein the coil portion is disposed in the engine plug hole and directly connected to the ignition plug. And

  According to a fourteenth aspect of the present invention, in the ignition coil for an internal combustion engine according to the ninth to twelfth aspects, the coil portion is mounted on an engine head cover or in the vicinity of a spark plug, and the coil portion is electrically connected to the coil portion. The internal combustion engine ignition coil is electrically connected to the spark plug through a high-voltage conductor having an electrically conductive member covered with an insulating material.

  Further, in the fifteenth aspect of the present invention, in the internal combustion engine ignition coil according to the first to twelfth aspects, the outer peripheral iron core is formed of an electromagnetic steel plate obtained by rounding a thin plate into a cylindrical shape. Ignition coil.

  According to a sixteenth aspect of the present invention, in the ignition coil for an internal combustion engine according to the ninth to twelfth aspects, the outer peripheral iron core is formed of a laminated electromagnetic steel sheet having a B shape or an O shape. It is set as the ignition coil for internal combustion engines.

  Further, in claim 17, the ignition coil for an internal combustion engine according to any one of claims 1 to 16, wherein the outer peripheral iron core and the central iron core are electrically connected. A coil.

  According to claim 18, in the internal combustion engine ignition coil according to claim 1 to claim 6, or claim 9 to claim 14, wherein one or both of the central iron core and the outer peripheral iron core are insulated. An ignition coil for an internal combustion engine, characterized in that it is a powder iron core formed by pressure-molding the magnetic powder subjected to the above.

  Further, in the nineteenth aspect of the present invention, in the ignition coil for an internal combustion engine according to the first to eighteenth aspects, the connecting portion between the igniter (collector side) of the primary coil and B + (battery +) An ignition coil for an internal combustion engine is provided on one end side.

  According to claim 20, in the internal combustion engine ignition coil according to claims 1 to 19, the central iron core and the outer peripheral iron core form a closed magnetic circuit magnetic circuit. An ignition coil for an engine, and in claim 21, in the ignition coil for an internal combustion engine according to claims 1 to 19, an open magnetic circuit magnetic circuit is constituted by the central iron core and the outer peripheral iron core. An ignition coil for an internal combustion engine is provided.

  In Claim 22, the central iron core which consists of an electromagnetic steel plate, the primary coil which is connected with the said central iron core by electromagnetic coupling, and is arrange | positioned at the outer peripheral side of the said central iron core, the secondary coil, and the said primary coil And an outer peripheral iron core made of an electromagnetic steel plate disposed on both outer peripheral sides of the secondary coil, and a coil part is configured, and the coil part is housed in a case having electrical insulation, In the ignition coil for an internal combustion engine sealed with a primary coil, the winding layer of the primary coil is an even layer, and a primary electrical conduction path is disposed on the outer peripheral side of the primary coil and An ignition coil for an internal combustion engine, characterized in that a primary-side electrical conduction path is disposed on the circumferential side.

  With the above configuration, when the winding layer of the primary coil of the ignition coil for a cylindrical internal combustion engine fits in an odd number layer, it is necessary to provide a final even number layer that has been conventionally set as a return path conduction path by using the above solution. The coil part can be reduced in size.

  By making the configuration of the present invention, the diameter of the coil main body can be reduced. If the wire diameter of the primary copper wire is 0.7 mm, the effect of downsizing on the outer diameter of the coil body is 0.7 mm × 2 = 1.4 mm.

  This is because if the coil has a conventional structure and the coil body has an outer diameter of 24 mm, it can be rolled to 24 mm−1.4 mm = 22.6 mm by using the configuration of the present invention. A high ignition coil for a cylindrical internal combustion engine can be provided.

  In addition, it is possible to improve the performance of the ignition coil for a cylindrical internal combustion engine by maintaining the outer diameter of the coil body and allocating the effect of downsizing to the enhancement of the magnetic circuit, that is, the expansion of the cross-sectional area of the iron core. .

  Next, the embodiment to which the technique of the present invention is applied will be described only for the different parts of the ignition coil for a cylindrical internal combustion engine according to the background art. An embodiment according to the present invention will be described with reference to FIGS. 1 is a longitudinal sectional view of an ignition coil for a cylindrical internal combustion engine according to a first embodiment to which the technology of the present invention is applied. FIG. 2 is a coil part view of the ignition coil for the cylindrical internal combustion engine of the first embodiment. FIG. 3 is a longitudinal sectional view of an ignition coil for a cylindrical internal combustion engine according to a third embodiment to which the technology of the present invention is applied. FIG. 4 is a schematic circuit diagram of the first embodiment to which the technology of the present invention is applied. FIG. 5 is a schematic circuit diagram of Embodiment 2 to which the technology of the present invention is applied. FIG. 6 is a schematic circuit diagram of Example 3 to which the technology of the present invention is applied. FIG. 7 is a schematic circuit diagram of Example 4 to which the technology of the present invention is applied. FIG. 8 is a longitudinal sectional view of a rectangular internal combustion engine ignition coil according to a fifth embodiment to which the technology of the present invention is applied. FIG. 9 is a transverse sectional view of the ignition coil for a rectangular internal combustion engine of the fifth embodiment. FIG. 10 is a coil part diagram of the ignition coil for a rectangular internal combustion engine of the fifth embodiment.

In the present embodiment, only differences from the background art will be described. As shown in FIGS. 1, 2, and 4, the first embodiment of the present invention is the same as that of the ignition coil 101 for a cylindrical internal combustion engine. 120, a primary coil 110 coaxially disposed on the outer periphery of the secondary coil 120, and an outer peripheral iron core 160 formed in a cylindrical shape outside the coils and having a notch at a part of the circumference thereof. A cylindrical internal combustion engine for an internal combustion engine having an upper storage portion 130 having a large opening in the upper portion for storing the coils, and a cylindrical case 104 formed of a flame-retardant insulating resin material. A primary current input unit 132 for supplying a battery power supply voltage to the primary coil 110 is mounted on the upper portion of the case 104, and the primary current is turned on and off in the upper storage unit 130 in some cases. Igna Housing the motor 180, the in case 104 injected to cure the epoxy insulating material as the insulating material to form an ignition coil 101.

  Specifically, the primary coil 110, the secondary coil 120, the primary coil 110, and the outer peripheral iron core 160 made of an electromagnetic steel plate disposed on the outer peripheral side of both of the secondary coils 120, In the ignition coil for an internal combustion engine, which constitutes a coil part 102 and is housed in a case 104 having electrical insulation and sealed with an insulating material, the primary coil 110 and the primary coil The primary coil 110 and the primary current input unit 132 to the igniter 180 are electrically connected to the primary current input unit 132 for supplying a power supply voltage to the 110 and the igniter 180 accommodated in some cases. The primary coil 110, which is concentrated on the upper part of the case 104, is electrically connected to the collector side (C) of the igniter 180 and one end 110 a of the primary coil 110. Which is connected to the structure. Further, the winding layer of the primary coil 110 is composed of an odd-numbered layer 113a, and a part of the primary-side electrical conduction path is composed of the outer peripheral iron core 160.

  The primary coil 110 is a copper wire with an insulation film having a wire diameter of about φ0.5 mm to φ1 mm, and is wound around a primary bobbin in about 75 to 100 turns, the resistance is 100 to 300 mΩ, and the total winding is It is wound in one layer of the outward path. The outer peripheral iron core 160 is provided with electrical connection portions 160a and 160b at the ends, and the electrical connection portion 160a is electrically connected to one end portion 110a of the primary coil 110, and the electrical connection portion 160b The igniter 180 is electrically connected to the collector side (C). The primary coil end portion 110a and the electrical connection portion 160a may be connected to the high-voltage tower portion 134 via a primary terminal 115 formed in an annular shape. When the primary breaking current is 16 A, the ignition is equivalent to the conventional case. Performance can be generated.

  Further, according to FIG. 5, the second embodiment of the present invention is different from the first embodiment in that the outer peripheral iron core is electrically connected between the end 10a of the primary coil and the battery power source B + (battery +). It is connected to the. As described above, when the primary cutoff current is 16 A, it is possible to generate an ignition performance equivalent to the conventional one.

  Moreover, according to FIG. 3 or FIG. 6, Example 3 of this invention is an electromagnetic steel plate arrange | positioned at the outer peripheral side of both a primary coil, a secondary coil, the said primary coil, and the said secondary coil. A coil part, and the coil part is housed in a case having electrical insulation and sealed with an insulating material. The primary coil 111 and the primary current input unit 133 are electrically connected to the primary current input unit 133 that supplies the battery power supply voltage to the primary coil 111 and the igniter 181 that is accommodated in some cases. The igniter 181 is concentrated on the upper portion of the case 105, and the central iron core 171 is electrically connected to the collector side (C) of the igniter 181 and one end 111a of the primary coil 111. It has become the structure. Further, the winding layer of the primary coil 111 is composed of an odd number layer 114 a, and a part of the primary side electrical conduction path is composed of the central iron core 171. As in the first embodiment, the winding layer of the primary coil 111 is wound around one layer of the forward path. When the primary cut-off current is 16 A, it is possible to generate ignition performance equivalent to the conventional one.

  Further, according to FIG. 7, in the fourth embodiment of the present invention, as a difference from the third embodiment, the central iron core 170 is electrically connected between one end of the primary coil 111 and B + (battery +). ing. As described above, when the primary cutoff current is 16 A, it is possible to generate an ignition performance equivalent to the conventional one.

  Furthermore, the present invention can be applied to a closed magnetic circuit. 8 to 10, according to the fifth embodiment of the present invention, in an ignition coil 201 for an internal combustion engine, a central iron core 271 and a primary coil 211 coaxially with the outer periphery of the central iron core 271 are arranged. A secondary coil 221 arranged coaxially on the outer periphery of the secondary coil 211, an outer peripheral iron core 261 that forms a magnetic circuit in pairs with the central iron core 271 outside these coils, and an opening for housing the aforementioned coils An ignition coil 201 for an internal combustion engine having a case 205 of a flame-retardant insulating resin material having a primary current input portion 233 for supplying a battery power supply voltage to the primary coil 211 on the case 205. In some cases, an igniter 281 for turning on and off the primary current is housed in the upper housing portion 231, and an epoxy insulating material is injected into the case 205 as an insulating material and cured. Forming a part 203.

  Specifically, the outer periphery iron core 261 and the outer periphery iron core which consist of the electromagnetic steel plates arrange | positioned at the outer peripheral side of both the primary coil 211, the secondary coil 221, the said primary coil 211, and the said secondary coil 221. 261 and a central iron core 271 that constitutes a magnetic circuit in a pair form a coil part 203. The coil part 203 is housed in an electrically insulating case 205 and sealed with an insulating material. In the ignition coil, the winding layer of the primary coil 211 is composed of an odd-numbered layer 213a, and a part of the primary-side electrical conduction path is composed of the outer peripheral iron core 261.

  The primary coil 211 is a copper wire with an insulation film having a wire diameter of about φ0.5 mm to φ1 mm and is wound around a primary bobbin in about 75 to 100 turns, the resistance is 100 to 300 mΩ, and the winding layer is It is wound in one layer of the outward path. The outer peripheral iron core 261 is electrically connected between the primary terminal 216 at one end of the primary coil 211 and the collector side (C) of the igniter 281. When the primary cut-off current is 16 A, it is possible to generate ignition performance equivalent to the conventional one.

  Further, in the sixth embodiment of the present invention, as a difference from the fifth embodiment, the outer peripheral iron core 261 is electrically connected between the end portion 210a of the primary coil 211 and B + (battery +) (not shown). Yes. As described above, when the primary cutoff current is 16 A, it is possible to generate an ignition performance equivalent to the conventional one.

  Although the first to fourth embodiments have been described, the ignition coil for the cylindrical internal combustion engine is arranged with the secondary coil 120 and the primary coil 110 in order coaxially with the central iron core 170. The primary coil 110 and the secondary coil 220 may be arranged in order in a coaxial manner. In this case, in particular, when the central iron core 170 is used as a primary electrical passage, when the primary coil 110 is disposed outside the secondary coil 220, the primary path is distributed so as to cross the vicinity of the high voltage portion of the secondary coil 220. Although necessary, since the primary coil 110 and the central iron core 170 can be brought close to each other, the insulation design can be facilitated.

  In addition, although the fifth to sixth embodiments have been described, the ignition coil for an internal combustion engine is formed by press-molding magnetic powder in which at least one of or both the central iron core 271 and the outer peripheral iron core 261 is provided with an insulating film. It may be a pressed iron core. In this case, the dust core has an advantage that it is easy to simplify the connecting portion because it is possible to easily produce a partial projection shape or the like that was difficult with an iron core made of an electromagnetic steel plate.

  Further, in the ignition coil for an internal combustion engine of the above embodiment, the central iron core and the outer peripheral iron core constitute an open magnetic circuit magnetic circuit, or the central iron core and the outer peripheral iron core are closed magnetized. The present invention can also be applied to those constituting a path magnetic circuit.

  Here, the open magnetic circuit is defined as a magnetic circuit composed of a cylindrical outer core disposed coaxially on the outer periphery of a rod-shaped (I-type) central core.

  The closed magnetic circuit is composed of two C-type cores, or two E-type cores, or one I-type central core and one C-type outer core, two L-type outer cores, or one O-type. The magnetic cores are defined as a magnetic circuit formed in close contact except for an air gap portion of about 0.5 to 1.5 mm, which is called an air gap portion.

  As mentioned above, although the Example of this invention was described concretely, the concrete description content does not specifically limit this invention. That is, the present invention is one in which the winding layer of the primary coil is wound by an odd number layer and can conduct a part of the primary-side electric conduction path, and exhibits the same effect as the above-described embodiment. If it can do, the material and form will not be specifically limited. According to the present invention, the winding layer of the primary coil is wound in an odd number layer, and the return path of the primary side electric conduction path can be conducted to the primary current input unit mounted on the upper part of the case or the igniter accommodated in some cases. It is intended to provide a thing, and various modifications can be made without departing from the spirit. In addition, the winding layer of the primary coil is an even layer, and a primary-side electrical conduction path is disposed on the outer peripheral side of the primary coil and a primary-side electrical conduction path is provided on the inner peripheral side of the primary coil. You may arrange.

It is a longitudinal cross-sectional view of the ignition coil for cylindrical internal combustion engines of Example 1 to which the technique of this invention is applied. It is a coil part figure of the ignition coil for cylindrical internal combustion engines of the Example 1. FIG. It is a longitudinal cross-sectional view of the ignition coil for cylindrical internal combustion engines of Example 3 to which the technique of this invention is applied. It is a schematic circuit diagram of Example 1 to which the technology of the present invention is applied. It is a schematic circuit diagram of Example 2 to which the technology of the present invention is applied. It is a schematic circuit diagram of Example 3 to which the technology of the present invention is applied. It is a schematic circuit diagram of Example 4 to which the technology of the present invention is applied. It is a longitudinal cross-sectional view of the ignition coil for rectangular internal combustion engines of Example 5 to which the technique of this invention is applied. It is a cross-sectional view of the rectangular internal combustion engine ignition coil of the fifth embodiment. It is a longitudinal cross-sectional view of the ignition coil for internal combustion engines to which the conventional technique is applied. It is a coil part figure of the ignition coil for internal combustion engines to which the prior art is applied. It is a schematic circuit diagram of FIG.

Explanation of symbols

1,101 Cylindrical internal combustion engine ignition coil 10, 110, 111, 211 Primary coil
10a, 110a, 111a, 211a Primary coil end 11 Primary bobbins 13a, 113a, 114a, 213a Primary coil densely wound portion (first layer)
13b Primary coil rough winding (second layer)
15, 115, 116, 216 Primary terminals 160a, 160b, 161a, 161b Electrical connection portions 2, 102, 103, 203 Coil portions 20, 120, 121, 221 Secondary coil 201 Ignition coil 22 for internal combustion engine Secondary bobbin 23 , 123, 223 High voltage terminal 24 Secondary coil terminal (low voltage side)
3, 104, 105, 205 Case 30, 130, 131, 231 Upper storage part 32, 132, 133, 233 Primary current input part 34, 134, 234 High-voltage tower part 40, 140 Spring 50, 150 Plug boot 52 Rain cover 60, 160, 161, 261 Outer iron core 61 Primary coil end connection
62, 162, 262 Igniter connection 70, 170, 171, 270 Center iron core 72, 172 Magnet 73, 173 Yoke core 74, 174 Core cap 80, 180, 181, 281 Igniter 82, 182, 282 B + of battery power source (battery +)
90, 190, 290 filler

Claims (22)

  A central iron core made of an electromagnetic steel sheet, a primary coil connected to the central iron core by electromagnetic coupling and disposed on an outer peripheral side of the central iron core, a secondary coil, the primary coil, and the secondary The coil part is composed of an outer iron core made of an electromagnetic steel plate disposed on both outer peripheral sides of the coil, and the coil part is housed in a case having electrical insulation and sealed with an insulating material. An ignition coil for an internal combustion engine, wherein a winding layer of the primary coil is formed of an odd number layer, and a primary electrical conduction path is disposed on an outer peripheral side of the primary coil.   2. The ignition coil for an internal combustion engine according to claim 1, wherein a part of the primary side electric conduction path is constituted by the outer peripheral iron core.   The ignition coil for an internal combustion engine according to claim 1, wherein the outer peripheral iron core is electrically connected between one end of the primary coil and an igniter (collector side). .   2. The ignition coil for an internal combustion engine according to claim 1, wherein the outer peripheral iron core is electrically connected between one end of the primary coil and B + (battery +). .   5. The internal combustion engine ignition coil according to claim 1, wherein the coil portion is disposed in the engine plug hole and directly connected to the ignition plug.   5. The ignition coil for an internal combustion engine according to claim 1, wherein the coil portion is mounted on an engine head cover or in the vicinity of a spark plug, and the coil portion is an insulating material connected to the coil portion. An ignition coil for an internal combustion engine, wherein the ignition coil is electrically connected to a spark plug through a high-voltage conductor covered with.   7. The ignition coil for an internal combustion engine according to claim 1, wherein the outer peripheral iron core is composed of an electromagnetic steel plate obtained by rounding a thin plate into a cylindrical shape.   The ignition coil for an internal combustion engine according to any one of claims 1 to 6, wherein the outer peripheral iron core is made of a laminated electromagnetic steel sheet having a U-shape or an O-shape. coil.   A central iron core made of an electromagnetic steel sheet, a primary coil connected to the central iron core by electromagnetic coupling and disposed on an outer peripheral side of the central iron core, a secondary coil, the primary coil, and the secondary The coil part is composed of an outer iron core made of an electromagnetic steel plate disposed on both outer peripheral sides of the coil, and the coil part is housed in a case having electrical insulation and sealed with an insulating material. The ignition coil for an internal combustion engine according to claim 1, wherein a winding layer of the primary coil is formed of an odd number layer, and a primary side electric conduction path is disposed on an inner peripheral side of the primary coil.   The ignition coil for an internal combustion engine according to claim 9, wherein a part of the primary side electric conduction path is constituted by the central iron core.   The ignition coil for an internal combustion engine according to claim 9, wherein the central iron core is electrically connected between one end of the primary coil and an igniter (collector side). .   The ignition coil for an internal combustion engine according to claim 9, wherein the central iron core is electrically connected between one end of the primary coil and B + (battery +). .   13. The ignition coil for an internal combustion engine according to claim 9, wherein the coil portion is disposed in the engine plug hole and directly connected to the ignition plug.   13. The ignition coil for an internal combustion engine according to claim 9, wherein the coil portion is mounted on an engine head cover or in the vicinity of a spark plug, and the coil portion is an insulating material connected to the coil portion. An ignition coil for an internal combustion engine, wherein the ignition coil is electrically connected to a spark plug through a high-voltage conductor covered with.   The ignition coil for an internal combustion engine according to any one of claims 1 to 12, wherein the outer peripheral iron core is made of an electromagnetic steel plate obtained by rounding a thin plate into a cylindrical shape.   13. The ignition coil for an internal combustion engine according to claim 9, wherein the outer peripheral iron core is composed of a laminated electromagnetic steel sheet having a U shape or an O shape. coil.   The internal combustion engine ignition coil according to any one of claims 1 to 16, wherein the outer peripheral iron core and the central iron core are electrically connected.   15. An internal combustion engine ignition coil according to claim 1, wherein either one or both of the central iron core and the outer iron core are provided with an insulating film. An ignition coil for an internal combustion engine, characterized in that it is a powder iron core that has been pressure-molded.   The ignition coil for an internal combustion engine according to any one of claims 1 to 18, wherein a connection portion between an igniter (collector side) and B + (battery +) of the primary coil is disposed on one end side with respect to a winding segment. An ignition coil for an internal combustion engine.   The ignition coil for an internal combustion engine according to any one of claims 1 to 19, wherein the central iron core and the outer peripheral iron core constitute a closed magnetic circuit magnetic circuit.   20. The internal combustion engine ignition coil according to claim 1, wherein the central iron core and the outer peripheral iron core constitute an open magnetic circuit magnetic circuit.   A central iron core made of an electromagnetic steel sheet, a primary coil connected to the central iron core by electromagnetic coupling and disposed on an outer peripheral side of the central iron core, a secondary coil, the primary coil, and the secondary The coil part is composed of an outer iron core made of an electromagnetic steel plate disposed on both outer peripheral sides of the coil, and the coil part is housed in a case having electrical insulation and sealed with an insulating material. In the internal combustion engine ignition coil, the winding layer of the primary coil is an even layer, and a primary-side electric conduction path is disposed on the outer peripheral side of the primary coil and the primary is disposed on the inner peripheral side of the primary coil. An ignition coil for an internal combustion engine, wherein a side electric conduction path is arranged.

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