JP5703945B2 - Ignition coil and method of manufacturing ignition coil - Google Patents

Description

  The present invention relates to an ignition coil that generates a voltage that causes spark discharge in an ignition plug, and a method for manufacturing the same.

  2. Description of the Related Art Conventionally, an ignition coil that is connected to an ignition plug and generates a high voltage that causes a spark discharge in the ignition plug by boosting a voltage that energizes a primary coil by a secondary coil is known. As a kind of such an ignition coil, for example, Patent Document 1 discloses a secondary spool around which a secondary conductor forming a secondary coil is wound, and a resin that covers the secondary spool by covering the periphery of the secondary spool. And a diode comprising a diode connected to the secondary conductor.

  In the ignition coil of Patent Document 1 having the above configuration, a current that causes spark discharge in the spark plug is induced in the secondary coil when the energization of the primary coil is changed from the on state to the off state. On the other hand, when the energization of the primary coil is changed from the off state to the on state, a current is induced in the secondary coil. The current at the time of energization is a reverse current that tends to flow through the secondary coil in a direction opposite to the current that causes spark discharge in the spark plug. The diode connected to the secondary coil exhibits an effect of regulating the reverse current induced in the secondary coil. Since the reverse current regulation makes it difficult for electric power to be accumulated in the secondary coil, the voltage generated in the secondary coil when the energization of the primary coil is changed from the off state to the on state is suppressed. This makes it possible to avoid spark discharge that occurs in the spark plug due to the reverse current.

  Such an electronic component such as a diode is generally connected to an external configuration such as a secondary conductor forming a secondary coil via a metal member such as a terminal. For example, Patent Document 2 discloses an electronic component connection structure characterized by a lead connection portion connected to a lead terminal of an electronic component in a metal electrode portion corresponding to a terminal. Specifically, in the connection structure of Patent Document 2, a recess for facilitating the fixation of the lead terminal to the electrode part is provided in the lead connection part (see, for example, FIG. 2 of Cited Document 2).

JP 2009-283909 A JP 2008-19005 A

  Now, the ignition coil as disclosed in Patent Document 1 is generally exposed to intense fluctuations in ambient temperature. Cracks may occur in the resin covering the secondary spool due to thermal stress that repeatedly acts due to such fluctuations in ambient temperature. For example, it is assumed that a crack is generated in a portion covering the lead connecting portion as described above inside the resin. Then, it is assumed that such a crack starting from the vicinity of the lead connection portion extends toward the conductor connection portion connected to the secondary conductor at the terminal. When the extension of the crack reaches the vicinity of the conductor connecting portion, the crack may cause the secondary conductor to be disconnected in the resin covering the secondary conductor.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an ignition coil having a configuration capable of avoiding disconnection of a conductive wire forming a secondary coil, and a manufacturing method thereof.

  In order to achieve the above object, according to the first aspect of the present invention, a voltage that is connected to the spark plug and boosts the voltage for energizing the primary coil by the secondary coil is generated to cause spark discharge in the spark plug. An ignition coil that has a lead wire forming a secondary coil and a lead portion, and regulates a reverse current induced in the secondary coil when energization of the primary coil is switched from the off state to the on state A bobbin member having a winding portion around which a conducting wire forming the secondary coil is wound in a cylindrical shape, a conducting wire connecting portion connected to the conducting wire forming the secondary coil, and a lead portion of the diode. A connecting member having a lead connecting portion, an insulating resin covering the conductor, the diode, and the connecting member by covering the periphery of the bobbin member, and the connecting member penetrating inside the insulating resin. It has a through portion, and a partition wall separating the said conductor connecting portion and the lead connecting portion by penetrating the connecting member to the through portion.

  According to the present invention, it is assumed that a crack has occurred in the insulating resin covering the lead connecting portion of the connecting member due to the repeated action of thermal stress. And this crack is going to extend toward the conducting wire connection part of the connecting member connected with the conducting wire which forms a secondary coil. However, the extension of the crack is hindered by the partition wall that separates the lead wire connecting portion and the lead connecting portion by passing the connecting member through the penetrating portion inside the insulating resin. As described above, the partition wall exhibits an action of blocking the extension of cracks. Therefore, it is possible to avoid a situation in which the conductive wires are broken in the portions of the insulating resin covering the conductive wires due to cracks generated in the insulating resin.

  In general, in the bobbin member, a flange portion that protrudes in a hook shape on the outer peripheral side of the winding portion is formed between the support portion that supports the diode and the winding portion. Therefore, the conducting wire wound around the winding portion has a lead wire portion led out from the winding portion side at the conducting wire connecting portion of the connecting member located on the support portion side with respect to the flange portion. Here, the crack which arises in the insulating resin of the part which has coat | covered the lead connection part can be extended toward a leader line part.

  Therefore, in the invention according to claim 2, the bobbin member is located between the support portion that supports the diode, and the support portion and the winding portion, and the flange that protrudes in a bowl shape on the outer peripheral side of the winding portion. And the lead wire has a lead wire portion led out from the winding portion side of the collar portion at the conductor wire connection portion located on the support portion side of the collar portion, and the partition wall portion is a conductor connection portion. A partition wall main body part that separates the lead connection part and the lead connection part, and a partition wall extension part that separates the lead connection part and the lead wire part by extending from the partition wall main body part between the lead connection part and the lead wire part. It is characterized by having.

  That is, in this invention, the partition extending portion extends from the partition body portion separating the lead connection portion and the lead connection portion toward the space between the lead connection portion and the lead wire portion. Therefore, the extension of the crack toward the leader line portion is hindered by the partition wall extending portion of the partition wall portion. As described above, since the partition wall extending portion of the partition wall functions to block the extension of cracks toward the lead wire portion, the lead wire portion is cracked in the insulating resin covering the portion of the lead wire portion. It is possible to avoid the situation of disconnection due to.

  In the invention according to claim 3, the bobbin member has a lead-out part for pulling out the lead-out line part from the winding part side to the support part side across the collar part, and the partition wall extending part extends along the collar part. And extending from the bulkhead main body portion to a position beyond the lead-out portion, and the lead-out wire portion and the lead connection portion drawn through the lead-out portion are separated from each other.

  In the present invention, the lead wire portion of the conducting wire is drawn from the winding portion side to the support portion side through the lead portion through the collar portion, and is connected to the conducting wire connecting portion of the connecting member. In this form, the position where the leader line portion is drawn is defined as the position where the leader portion is provided in the collar portion. Therefore, by extending the partition wall extending portion from the partition wall main body portion to the position beyond the lead portion along the collar portion, it is possible to reliably separate the entire leader line portion from the lead connection portion by the partition wall portion. . As described above, since the extension of the crack from the insulating resin near the lead connection portion toward the lead wire portion can be severely blocked by the partition wall, the certainty of exhibiting the effect of suppressing the disconnection of the lead wire portion caused by the crack However, it will improve.

  The invention according to claim 4 is characterized in that, in the connection member, the outer wall surface of the extending portion extending from the through portion on the side opposite to the diode of the partition wall portion is cylindrical.

  As in the present invention, in the connection member, the insulating resin covering the extending portion extending from the through portion on the side opposite to the diode of the partition wall (hereinafter referred to as “outside of the partition wall”) is also cracked. May occur. Therefore, the outer wall surface of the extending portion extending outside the partition wall is formed into a cylindrical surface. Thereby, since the insulating resin which coat | covers the extension part becomes a shape which supplements a cylindrical surface outer wall surface, the rapid shape change in the said insulating resin is suppressed. As described above, since the insulating resin covering the extended portion is less likely to become a starting point of crack generation, the occurrence of cracks on the outside of the partition wall portion is reduced. Therefore, the certainty of exhibiting the effect of suppressing the disconnection of the leader line portion due to the crack is improved.

  In addition, if the extended portion of the connecting member is bent outside the partition wall, the insulating resin that covers the bent portion may exhibit a shape that serves as a starting point of crack generation. Accordingly, in the invention described in claim 5, the connection member has an extending portion that extends linearly from the through portion on the opposite side of the partition wall from the diode. Thereby, since the insulating resin which coat | covers the extension part is formed in the linear form which complements a cylindrical-shaped outer wall surface, the rapid shape change in the said insulating resin is suppressed. As described above, since the insulating resin covering the extended portion is less likely to become a starting point of crack generation, the occurrence of cracks on the outside of the partition wall portion is reduced. Therefore, the certainty of exhibiting the effect of suppressing the disconnection of the leader line portion due to the crack is improved.

  In a sixth aspect of the present invention, the bobbin member has a support portion that supports the diode, and the partition wall portion is formed integrally with the bobbin member.

  According to the present invention, the bobbin member has the support portion on which the diode is placed and integrally forms the partition wall portion. In this embodiment, the connection member is connected to the diode supported by the support portion, and the position is defined by the bobbin member. Further, since the partition wall is formed integrally with the bobbin member, the position is defined by the bobbin member. As described above, even if the bobbin member is covered with the resin insulation for covering, the relative positions of the connecting member and the partition wall portion, the positions of which are defined by the bobbin member, are difficult to shift. Therefore, the partition wall portion is reliably positioned between the conductor connection portion and the lead connection portion inside the insulating resin, and can exert an action of blocking the extension of cracks. Therefore, the effect of suppressing the disconnection obtained by providing the partition wall portion can surely be exhibited.

  The invention according to claim 7 is a method for manufacturing the ignition coil according to any one of claims 1 to 6, wherein the lead connection step of connecting the lead connection portion of the connection member to the lead portion of the diode. And a supporting step of supporting the diode connected to the connecting member by the lead connecting step on the supporting portion of the bobbin member so that the conductive wire connecting portion of the connecting member extends from the partition wall, and the supporting step. A conducting wire connecting step of connecting the conducting wire to the conducting wire connecting portion of the connecting member.

  In the present invention, the connection between the lead portion of the diode and the lead connection portion of the connection member is performed in a step before the connection between the lead wire and the lead connection portion of the connection member. Therefore, it is possible to avoid a situation in which the force acting on the connecting member when connecting the lead portion to the lead connecting portion acts as a pulling force on the lead wire, causing the lead wire to break. Therefore, the disconnection of the conducting wire at the time of manufacturing the ignition coil is reduced together with the disconnection of the conducting wire due to the crack.

It is a longitudinal cross-sectional view for demonstrating the state which the ignition coil by one Embodiment of this invention was connected with the ignition plug, and was attached to the engine. It is a longitudinal cross-sectional view for demonstrating the structure of the ignition coil by one Embodiment of this invention. It is a top view for demonstrating the structure of the ignition coil by one Embodiment of this invention. It is an enlarged view which expands and shows the principal part of the ignition coil shown in FIG. FIGS. 4A and 4B are diagrams for explaining a process for manufacturing the ignition coil shown in FIG. 3, wherein FIG. (C) is a figure for demonstrating a secondary copper wire connection process. It is a figure which shows the some modification of a connection member.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view for explaining the configuration of an ignition coil 100 according to an embodiment of the present invention. The ignition coil 100 is connected to the spark plug 10 and used for a spark ignition engine such as a gasoline engine. The ignition coil 100 is inserted together with the ignition plug 10 into a plug hole 23 formed in the cylinder head 20 of the gasoline engine, and is attached to a cylinder head cover 21 constituting the cylinder head 20. The connector 48 provided in the ignition coil 100 is connected to a power source such as a battery and an external connector (not shown) for connecting the engine control device to the ignition coil 100.

  As shown in FIGS. 1 to 3, the ignition coil 100 includes a central core 70, an outer peripheral core 75, a primary coil 60, a secondary coil 65, a diode 55, an igniter 50, a housing 40, and a plug mounting portion 80. ing. In the ignition coil 100 according to the present embodiment, the axial directions of the primary coil 60 and the secondary coil 65 are orthogonal to the axial direction of the plug hole 23 in a state where the ignition coil 100 is attached to the cylinder head cover 21.

  The central core 70 is formed in a cylindrical shape as a whole by, for example, pressure-molding a powder of a soft magnetic material such as iron, cobalt, and nickel. The center core 70 has a winding part 71 and a flange part 72. The winding part 71 is a main body part of the central core 70 and has a cylindrical shape. A primary coil 60 is formed on the outer side of the winding portion 71 in the radial direction. The collar portion 72 is formed at one end portion in the axial direction of the winding portion 71. The flange portion 72 protrudes in a hook shape on the outer peripheral side of the outer peripheral surface of the winding portion 71. The collar portion 72 suppresses the collapse of a primary copper wire 61 (described later) that forms the primary coil 60.

  The outer peripheral core 75 forms a magnetic circuit of the ignition coil 100 together with the central core 70 and the like. As with the central core 70, the outer peripheral core 75 is formed in a square cylindrical shape by press-molding soft magnetic powder. In the space surrounded by the four side surfaces forming the outer peripheral core 75, the central core 70, the primary coil 60, and the secondary coil 65 are accommodated. In this way, the axial direction of the outer peripheral core 75 surrounding the elements 70, 60, 75 in a frame shape is along the axial direction of the plug hole 23 and is orthogonal to the axial direction of the central core 70. The outer peripheral core 75 has a pair of end surface facing portions 77 and a pair of outer peripheral portions 76.

  The end surface facing portions 77 are a pair of side surfaces facing the both end surfaces of the central core 70 in the axial direction among the four side surfaces of the outer peripheral core 75. A magnetic circuit formed by the outer peripheral core 75 and the central core 70 is disposed between one of the pair of end surface facing portions 77 and the axial end surface of the central core 70 facing the one end surface facing portion 77. Permanent magnets and a core gap for improving magnetic properties are formed. The other of the pair of end surface facing portions 77 is in contact with the axial end surface of the central core 70 facing the other end surface facing portion 77. The outer peripheral portion 76 is a pair of side surfaces that extend along the axial direction of the central core 70 among the four side surfaces of the outer peripheral core 75 and connect the end surface facing portions 77. Each outer peripheral portion 76 is positioned on the outer peripheral side of the central core 70, and positions the outer peripheral core 75 with respect to the housing 40 by contacting the inner wall surface of the housing 40.

  The central core 70 and the outer peripheral core 75 may be formed by laminating soft magnetic electromagnetic steel plates such as silicon steel plates instead of pressure forming.

  The primary coil 60 is formed by winding a primary copper wire 61 around a winding portion 71 of the central core 70 in a cylindrical shape. The primary copper wire 61 is an enameled wire formed by baking an insulating paint on a wire formed of a conductive material such as copper. The diameter of the primary copper wire 61 is set to about 0.3 to 0.8 mm. The primary coil 60 is electrically connected to an external power source and can be energized with power supplied from the power source.

  The secondary coil 65 includes a bobbin 68 and a secondary copper wire 66. The bobbin 68 is formed in a cylindrical shape from a resin material, and houses the primary coil 60 and the central core 70. The secondary coil 65, the primary coil 60, and the central core 70 are disposed so as to be concentric with each other. The bobbin 68 has a flange portion 68b, a winding portion 68a, a support portion 69, and a drawing groove 68c. The flange portion 68b is formed at one end portion close to the support portion 69 among both axial end portions of the secondary coil 65, and protrudes in a hook shape on the outer peripheral side of the outer peripheral surface of the winding portion 68a. . The winding part 68a is located on the opposite side to the support part 69 of the collar part 68b, and is formed in a cylindrical shape. The secondary coil 65 is formed by winding the secondary copper wire 66 around the winding portion 68a in a cylindrical shape. In the secondary coil 65 of this embodiment, the secondary copper wire 66 is wound obliquely around the winding portion 68a. Similar to the primary copper wire 61, the secondary copper wire 66 is an enameled wire formed by baking an insulating paint on a wire formed of a conductive material such as copper. The diameter of the secondary copper wire 66 is smaller than that of the primary copper wire 61 and is set to about 40 to 50 micrometers. In addition, the number of times that the secondary copper wire 66 is wound around the winding portion 68 a is larger than the number of times that the primary copper wire 61 is wound around the winding portion 71. The collapse of the secondary copper wire 66 wound around the winding portion 68a is suppressed by the flange portion 68b.

  The support portion 69 is formed on the opposite side of the winding portion 68a with the collar portion 68b interposed therebetween, and has a configuration for supporting the excreted diode 55. The lead-out groove 68c is provided by denting the outer peripheral portion of the flange portion 68b located between the support portion 69 and the winding portion 68a inward in the radial direction. The secondary copper wire 66 is drawn out from the winding portion 68a side to the support portion 69 side through the drawing groove 68c with the flange portion 68b interposed therebetween. A portion of the secondary copper wire 66 that is led out toward the support portion 69 through the lead-out groove 68 c is referred to as a lead-out portion 67.

  The diode 55 is an electronic element having a rectifying action, and is placed on the support portion 69 of the bobbin 68. The diode 55 has a pair of lead portions 56 for connection to the outside. The lead part 56 is formed of copper or the like having excellent conductivity. The outer surface of the lead portion 56 is plated with silver, tin, nickel, or the like. One of the pair of lead portions 56 is connected to a lead wire portion 67 of a secondary copper wire 66 drawn to the support portion 69 side from the flange portion 68b through a connecting member 90 described later. The other of the pair of lead portions 56 is connected to the igniter 50. The diode 55 allows a current from the leader line 67 to the igniter 50 and regulates a current from the igniter 50 to the leader line 67.

  The igniter 50 controls energization to the primary coil 60 of electric power supplied from an external power source based on an ignition signal from the engine control device. The igniter 50 is formed by molding a circuit board on which a switching element such as an insulated gate bipolar transistor (IGBT) is mounted with an insulating resin material. The igniter 50 has a mold resin portion 51 formed of an insulating resin as described above and a plurality of igniter terminals 52.

  The mold resin portion 51 is formed in a rectangular box shape, and is disposed in the housing 40 along one end surface facing portion 77 of the outer peripheral core 75. The plurality of igniter terminals 52 extend from the inside of the mold resin portion 51 to the outside in a strip shape. Each igniter terminal 52 is fixed to the circuit board inside the mold resin portion 51. One of the plurality of igniter terminals 52 is a ground terminal to which a ground voltage is applied by being connected to the outer core 75. The ground terminal is electrically connected to the emitter of the IGBT inside the mold resin portion 51. Another one of the plurality of igniter terminals 52 is an ignition signal terminal to which an ignition signal from the engine control device is input. The ignition signal terminal is electrically connected to the base of the IGBT inside the mold resin portion 51. Still another one of the plurality of igniter terminals 52 is a power supply terminal connected to a power supply through the primary coil 60. The power supply terminal is electrically connected to the collector of the IGBT inside the mold resin portion 51.

  The igniter 50 having the above configuration energizes between the collector and the emitter when the ignition signal from the engine control device is input to the base of the IGBT. As a result, a current based on the power supplied from the power supply flows through the primary coil 60 connected between the collector of the IGBT and the power supply.

  The housing 40 includes a main case 41, a sub case 44, an insulating resin 45, and the like. The housing 40 accommodates the central core 70, the outer peripheral core 75, the primary coil 60, the secondary coil 65, the diode 55, and the igniter 50.

  The main case 41 is formed in a rectangular parallelepiped shape with a thermoplastic resin such as polybutylene terephthalate (PBT). The main case 41 is provided with a cylindrical portion 42 and a fixing portion 43. In the main case 41, the cylindrical portion 42 projects from the bottom wall 41a placed on the cylinder head cover 21 in a cylindrical shape in a direction orthogonal to the bottom wall 41a. The cylindrical portion 42 is a part of the plug mounting portion 80. The fixing portion 43 is formed on one of the side walls of the main case 41. The fixing portion 43 is configured to fix the ignition coil 100 to the cylinder head cover 21 with a bolt (not shown) or the like. In the main case 41, an opening 41b is formed at a portion facing the bottom wall 41a.

  The sub case 44 is integrally formed with the main case 41 by an insulating resin material or the like. The sub case 44 is formed with the connector portion 48 described above. A plurality of terminals 47 are exposed inside the connector portion 48. One of the plurality of terminals 47, which is connected to the engine control device by fitting the external connector into the connector portion 48, is connected to an ignition signal terminal that is one of the igniter terminals 52. Another terminal of the plurality of terminals 47 that is connected to the power source is connected to the primary coil 60. Another terminal among the plurality of terminals 47, which is connected to the ground of the vehicle, is connected to the outer core 75 and grounds the outer core 75.

  The insulating resin 45 is a thermosetting resin such as an epoxy resin. The insulating resin 45 is filled through the opening 41b into the integrated elements of the main case 41 and the sub case 44 that accommodate the elements 70, 75, 60, 65, 55, and 50 in a flowable state before curing. Is done. Thereby, the insulating resin 45 covers the periphery of each element 70, 75, 60, 65, 55, 50 inside the housing 40, thereby filling the gap between these elements, It is fixed to the housing 40. In addition, the insulating resin 45 covers the primary copper wire 61 of the primary coil 60, the secondary copper wire 66 of the secondary coil 65, the diode 55, the connecting member 90 described later, and the like to insulate the elements from each other. ing. By such filling of the insulating resin 45, the opening 41b of the main case 41 is sealed in a watertight manner.

  A spark plug 10 is mounted on the plug mounting portion 80. The spark plug 10 ignites the working gas compressed in the combustion chamber of the gasoline engine by spark discharge. The spark plug 10 includes a plug terminal portion 13, an electrode portion 15, and an insulator portion 11. The plug terminal portion 13 is a portion to which a voltage necessary for spark discharge is applied from the outside. The electrode portion 15 is exposed in the combustion chamber of the gasoline engine, and spark discharge is generated by the voltage applied to the plug terminal portion 13. The insulator part 11 is made of alumina or the like, and insulates the plug terminal part 13 and the electrode part 15 from the housing or the like of the plug mounting part 80.

  The plug mounting portion 80 includes a cylindrical portion 42 formed in the main case 41, a plug cap 82, a coil terminal portion 81, a spring 83, and the like. The plug cap 82 is formed in a cylindrical shape by a material having high elasticity such as phenol resin. One end of the plug cap 82 in the axial direction is fitted on the cylindrical portion 42. The other end of the plug cap 82 in the axial direction is externally fitted to the lever portion 11 of the plug mounting portion 80. The coil terminal portion 81 is formed in a disk shape from a conductive material. The coil terminal portion 81 is electrically connected to the secondary copper wire 66 of the secondary coil 65. The spring 83 is formed by winding a metal wire in a spiral shape. The spring 83 is disposed between the plug terminal portion 13 of the spark plug 10 and the coil terminal portion 81 in a state where the spring 83 is compressed in the axial direction. The plug terminal portion 13 and the coil terminal portion 81 are electrically connected. I am letting.

  An operation in which the ignition coil 100 having the above configuration generates a voltage for causing the spark plug 10 to generate a spark discharge will be described below.

  Based on the ignition signal from the engine control device, the IGBT of the igniter 50 switches the energization of the primary coil 60 from the on state to the off state. Then, the magnetic flux generated in the magnetic circuit composed of the central core 70 and the outer peripheral core 75 due to the current flowing through the primary coil 60 disappears. The secondary coil 65 is induced with a current that cancels out the disappearance of the magnetic flux. Due to such mutual induction action, the secondary coil 65 having more turns than the primary coil 60 boosts the voltage of the current flowing through the primary coil to, for example, about 30 to 50 kV. The voltage boosted by the secondary coil 65 is guided to the spark plug 10, and spark discharge is generated at the electrode portion 15 of the spark plug 10.

  Now, in the ignition coil 100 that operates as described above, the function of the diode 55 connected to the secondary coil 65 will be described in detail.

  Based on the ignition signal from the engine control device, the energization of the primary coil 60 must be switched from the off state to the on state by the IGBT of the igniter 50. At this time, a magnetic flux is formed in the magnetic circuit by the current that starts flowing through the primary coil 60. Then, a current (hereinafter referred to as “reverse current”) that prevents the formation of the magnetic flux is induced in the secondary coil 65. As described above, even when the energization is on, the secondary coil 65 tends to flow a reverse current in a direction opposite to the above-described current causing the spark discharge due to the mutual dielectric action. This reverse current may cause a spark discharge in the spark plug 10.

  The diode 55 is connected to the secondary coil 65 in a direction that regulates the reverse current. Therefore, when the energization of the primary coil 60 is switched from the off state to the on state, the reverse current from the outside toward the secondary coil 65 through the igniter 50 or the like is regulated by the diode 55. In this way, the supply of electric power to the secondary coil 65 is restricted, so that the secondary coil 65 is difficult to store electric power. Therefore, the voltage generated in the secondary coil when the energization of the primary coil 60 is changed from the off state to the on state is suppressed. Therefore, the spark discharge generated in the spark plug 10 due to the reverse current can be avoided.

  The connection member 90 that is provided in the ignition coil 100 described so far and connects the diode 55 to the secondary coil 65 and the partition wall portion 30 that is formed so as to surround the diode 55 will be described in detail with reference to FIG. To do.

  The connection member 90 is formed of a wire material such as phosphor bronze having excellent conductivity and a melting point lower than that of the secondary copper wire 66. The connection member 90 penetrates the partition wall 30 in the wall thickness direction of the partition wall 30. The connection member 90 has a lead connection portion 91 and a secondary copper wire connection portion 96.

  The lead connection portion 91 is provided at one end portion of both end portions in the axial direction of the connection member 90. In the connection member 90, a portion that is located closer to the diode 55 than the partition wall 30 (hereinafter referred to as “inside of the partition wall 30”) and that forms the lead connection portion 91 is referred to as an isolation portion 92. . The lead connection portion 91 is formed by winding one end portion of the connection member 90 into a cylindrical coil shape. When the lead portion 56 is press-fitted inside the cylindrical coil shape, the lead connecting portion 91 is externally fitted to the lead portion 56.

  The secondary copper wire connecting part 96 is provided at the other end located on the opposite side of the lead connecting part 91 from both ends of the connecting member 90 in the axial direction. In the connection member 90, a portion that extends to the opposite side of the partition wall portion 30 from the diode 55 (hereinafter referred to as “outside of the partition wall portion 30”), and that is a portion that forms the secondary copper wire connection portion 96. , An extended portion 94. The extending portion 94 extends linearly from the partition wall portion 30. In addition, the outer wall surface 95 of the extending portion 94 is formed in a cylindrical surface shape. In the secondary copper wire connecting portion 96, an end portion of the lead wire portion 67 drawn through the lead groove 68c is tangled. And the edge part of the leader line part 67 entangled with the secondary copper wire connection part 96 is reliably connected to the said secondary copper wire connection part 96 by micro arc welding etc., for example.

  With the recent lead-free of the diode 55, a high melting point material such as nickel may be used for the plating material of the lead portion 56 in some cases. Therefore, it is difficult to weld the end portion of the lead wire portion 67 to the lead portion 56. However, in the present embodiment, the connecting member 90 made of a material having a lower melting point than the secondary copper wire 66 is interposed between the lead portion 56 and the end portion of the lead wire portion 67. The secondary copper wire 66 is reliably connected to the secondary copper wire connecting portion 96 by melting the secondary copper wire connecting portion 96.

  The partition wall portion 30 is formed integrally with the bobbin 68 and, specifically, is provided on the bobbin 68 so as to surround the support portion 69. The partition wall portion 30 is configured to separate the lead connection portion 91 of the connection member 90 from the lead wire portion 67 of the secondary copper wire 66 inside the insulating resin 45 (see FIG. 2 and the like). It has a partition body portion 31 and a partition extending portion 33. The through groove 32 is a groove formed in the partition wall main body portion 31 along the wall thickness direction and penetrating the partition wall main body portion 31 in the wall thickness direction. By allowing the connecting member 90 to pass through the through groove 32, the partition wall main body portion 31 is positioned between the secondary copper wire connecting portion 96 and the lead connecting portion 91, and the secondary copper wire connecting portion 96 and the lead connecting portion 91 Separate. The partition wall extending portion 33 extends from the end portion of the partition wall main body portion 31 adjacent to the flange portion 68 b toward the space between the lead connecting portion 91 and the lead wire portion 67. The partition extending portion 33 extends to a position exceeding the extraction groove 68c along the flange portion 68b. Thus, an accommodation groove 68 d that accommodates the leader line portion 67 and guides the leader line portion 67 to the vicinity of the outer wall surface 95 is formed between the partition wall extending portion 33 and the flange portion 68 b. With the above configuration, the partition wall extending portion 33 separates the lead wire portion 67 and the lead connection portion 91.

  The extending direction of the extraction groove 68 c is inclined with respect to the axial direction of the secondary coil 65. Thereby, the lead-out groove 68c approaches the secondary copper wire connection part 96 as it goes from the winding part 68a side to the support part 69 side across the flange part 68b. Such a shape of the lead-out groove 68c reduces the bending that occurs in the lead-out line portion 67 between the lead-out groove 68c and the accommodation groove 68d.

  Of the plurality of steps for manufacturing the ignition coil 100 having the above-described configuration, the steps relating to the connection of the diode 55 and the arrangement on the support portion 69 will be described in detail with reference to FIG.

  In the lead connection process shown in FIG. 5A, one lead portion 56 of the diode 55 is press-fitted into the lead connection portion 91 of the connection member 90. Thereby, the lead connection part 91 is connected to the lead part 56.

  In the support step shown in FIG. 5B, the diode 55 connected to the connection member 90 in the lead connection step is disposed on the support portion 69 of the bobbin 68 and supported by the support portion 69. At this time, the connecting member 90 is fitted into the through groove 32 of the partition wall main body portion 31, so that the extending portion 94 including the secondary copper wire connecting portion 96 extends from the partition wall portion 30.

  In the secondary copper wire connecting step shown in FIG. 5C, the end portion of the lead wire portion 67 is connected to the secondary copper wire connecting portion 96 of the connecting member 90 disposed together with the diode 55 by the supporting step. I can get lost. Then, the secondary copper wire connecting portion 96 and the lead wire portion 67 entangled with the secondary copper wire connecting portion 96 a plurality of times are connected to each other by micro arc welding or the like.

  The result of the above secondary copper wire connecting process is accommodated in a space within the integrated element of the main case 41 and the sub-case 44 as shown in FIGS. 2 and 3, and the insulating resin 45 is filled in the space. To do. The ignition coil 100 is manufactured by such a manufacturing method.

  In the present embodiment described so far, cracks are generated in the insulating resin covering the lead connection portion 91 due to the repeated action of thermal stress, and an attempt is made to extend toward the secondary copper wire connection portion 96. And However, the extension of cracks is hindered by the partition wall 30 that separates the secondary copper wire connection part 96 and the lead connection part 91 inside the insulating resin 45. As described above, the partition wall portion 30 exhibits an action of blocking the extension of cracks in the vicinity of the secondary copper wire connecting portion 96. Therefore, due to a crack generated in the insulating resin 45, the situation in which the secondary copper wire 66 is broken in the portions of the insulating resin 45 covering the secondary copper wire 66 in the vicinity of the secondary copper wire connecting portion 96, It can be avoided.

  In addition, according to the present embodiment, the extension of the crack toward the lead line portion 67 located in the vicinity of the lead groove 68c is hindered by the partition extending portion 33 extending from the partition main body portion 31. As described above, the partition wall extending portion 33 exerts an action of blocking the extension of the crack toward the lead wire portion 67, so that the lead wire portion 67 is cracked in the insulating resin 45 in the portion covering the lead wire portion 67. It is possible to avoid the situation of disconnection due to.

  Further, according to the present embodiment, the position where the lead line portion 67 is drawn is defined as the position where the lead groove 68c is provided in the flange portion 68b. Therefore, the extended partition wall extending portion 33 can separate the entire lead wire portion 67 from the lead connecting portion 91 up to a position beyond the lead groove 68c. As described above, the extension of the crack from the insulating resin in the vicinity of the lead connection portion 91 toward the lead wire portion 67 can be blocked by the partition wall portion 30, so that the effect of suppressing the disconnection of the lead wire portion 67 due to the crack is achieved. The certainty of performance is improved.

  Furthermore, according to the present embodiment, the extending portion 94 extends linearly outside the partition wall portion 30 and forms a cylindrical outer wall surface 95. In the insulating resin 45 that covers the extended portion 94 and has a shape that complements the extended portion 94, rapid shape changes such as corners and bends are suppressed. As described above, since the insulating resin 45 covering the extended portion 94 is unlikely to become a starting point of crack generation, generation of cracks on the outside of the partition wall portion 30 is reduced. Therefore, the certainty of exhibiting the effect of suppressing the disconnection of the leader line portion 67 due to the crack is improved.

  In addition, according to the present embodiment, since the support portion 69 and the partition wall portion 30 are formed integrally with the bobbin 68, the connection member 90 supported by the support portion 69 together with the diode 55, and the partition wall portion 30. Are both defined by a bobbin 68. Therefore, even if the bobbin 68 is covered with the insulating resin 45, the relative positions of the connecting member 90 and the partition wall portion 30 are not easily displaced. Thus, the partition wall portion 30 is reliably positioned between the secondary copper wire connection portion 96 and the lead connection portion 91 inside the insulating resin 45, and can exert an action of blocking the extension of cracks. Therefore, the effect of suppressing the disconnection obtained by providing the partition wall portion 30 can be surely exhibited.

  Furthermore, according to the present embodiment, the connection between the lead portion 56 of the diode 55 and the lead connection portion 91 of the connection member 90 is before the connection between the secondary copper wire 66 and the secondary copper wire connection portion 96. Implemented in the process. Therefore, it is possible to avoid a situation where the force acting on the connecting member 90 when the lead portion 56 and the lead connecting portion 91 are connected acts as a pulling force on the secondary copper wire 66 to break the conducting wire 66. It becomes possible. Therefore, the disconnection of the secondary copper wire 66 caused by the cracks as well as the disconnection of the secondary copper wire 66 during the manufacture of the ignition coil 100 are reduced.

  In the present embodiment, the through groove 32 corresponds to the “through portion” in the claims, the secondary copper wire 66 corresponds to the “conductive wire” in the claims, and the bobbin 68 corresponds to the claims. It corresponds to a “bobbin member”, the winding portion 68a corresponds to the “winding portion” in the claims, the flange portion 68b corresponds to the “rib portion” in the claims, and the drawing groove 68c is claimed. The secondary copper wire connecting portion 96 corresponds to the “conducting wire connecting portion” in the claims, and the secondary copper wire connecting step corresponds to the “leading wire connecting portion” in the claims. It corresponds to “Process”.

(Other embodiments)
As mentioned above, although one embodiment by the present invention was described, the present invention is not interpreted limited to the above-mentioned embodiment, and can be applied to various embodiments within the range which does not deviate from the gist.

  In the above embodiment, the lead connecting portion 91 of the connecting member 90 is formed by winding one axial end of the wire forming the connecting member 90 in a coil shape. However, the form of the lead connection portion 91 is not limited to that of the above embodiment. For example, as shown in FIG. 6A, the connection member 290 may be a tubular member made of a conductive material. The lead connection portion 291 is connected to the lead portion 56 by press-fitting the lead portion 56 into the cylindrical hole of the lead connection portion 291 of the connection member 290.

  Alternatively, like the connection member 390 shown in FIG. 6B, the lead connection portion 391 is formed in a tube shape, and the portions other than the lead connection portion 91 are the same as the connection member 90 of the above embodiment. It may be formed in a solid line shape. The lead connecting portion 391 is connected to the lead portion 56 by press-fitting the lead portion 56 into the cylindrical hole of the lead connecting portion 391 of the connecting member 390.

  Alternatively, like the connection member 490 shown in FIG. 6C, the lead connection portion 491 may be formed by bending the end of the wire so that the lead portion 56 can be sandwiched. . The lead connection portion 491 is connected to the lead portion 56 by press-fitting the lead portion 56 between the wires forming the lead connection portion 491.

  The extending portion 94 in the embodiment and the above-described modification example has a linear shape and has a cylindrical outer wall surface 95. However, the extension portion may be bent as long as it is formed so as to suppress cracking of the insulating resin covering the extension portion. In addition, the cross-sectional shape of the extended portion may not be a circular shape as described above, but may be a polygonal shape with chamfered corners, for example.

  In the said embodiment, the partition extending part 33 extended | stretched from the partition main-body part 31 blocked | interrupted the extension of the crack toward the leader line part 67 of the extraction groove | channel 68c vicinity. However, the form of the partition wall is not limited to that of the above embodiment. For example, in the said embodiment, the extending | stretching direction of the partition main-body part and the partition extending part crossed. However, for example, a partition wall having an arc shape and integrally forming the partition wall main body portion and the partition wall extending portion may be erected on the support portion. Or the part corresponded to the partition extending part may be abbreviate | omitted from the partition part.

  In the said embodiment, the through-groove 32 formed in the partition main-body part 31 corresponded to the "penetration part" as described in a claim. However, the “penetrating portion” is not limited to the groove-like configuration like the through groove 32. For example, the “through portion” may be a through hole that penetrates the partition wall main body portion in the wall thickness direction.

  In the above embodiment, the lead wire portion 67 is drawn from the winding portion 68a side to the support portion 69 side through the lead groove 68c with the flange portion 68b interposed therebetween. However, the structure provided in the collar part for drawing out the leader line part may be a drawer hole or the like penetrating the collar part in the axial direction. Or the structure corresponding to the "drawer part" as described in a claim may be abbreviate | omitted, and the leader line part may straddle the outer peripheral side of a collar part.

  In the above embodiment, the support portion 69 is formed integrally with the bobbin 68 together with the partition wall portion 30. However, if the relative position of the support part and the partition part can be reliably maintained in the insulating resin, the support part and the partition part are formed as separate structures, for example, even if assembled to a bobbin. Good.

  In the above embodiment, in order to reduce the disconnection of the secondary copper wire 66 at the time of manufacture, the lead connection step of connecting the lead portion 56 and the lead connection portion 91 is performed by connecting the secondary copper wire 66 to the secondary copper wire connection portion. It was implemented before the secondary copper wire connecting process connecting to 96. However, if consideration is given to reducing the disconnection of the secondary copper wire, the lead connection step may be performed after the secondary copper wire connection step.

DESCRIPTION OF SYMBOLS 10 Spark plug, 11 Insulator part, 13 Plug terminal part, 15 Electrode part, 20 Cylinder head, 21 Cylinder head cover, 23 Plug hole, 30 Bulkhead part, 31 Bulkhead body part, 32 Through groove (penetrating part), 33 Bulkhead extending part , 40 housing, 41 main case, 41a bottom wall, 41b opening, 42 cylindrical part, 43 fixing part, 44 sub case, 45 insulating resin, 47 terminal, 48 connector part, 50 igniter, 51 mold resin part, 52 igniter Terminal, 55 Diode, 56 Lead part, 60 Primary coil, 61 Primary copper wire, 63 Primary bobbin, 65 Secondary coil, 66 Secondary copper wire (conductive wire), 67 Leader part, 68 Bobbin (bobbin member), 68a winding Rotating part, 68b collar part, 68c drawer groove (drawer part), 68d receiving groove, 69 support part , 70 Central core, 71 Winding part, 72 Hook part, 73 Secondary bobbin, 75 Outer core, 76 Outer part, 77 End face facing part, 80 Plug mounting part, 81 Coil terminal part, 82 Plug cap, 83 Spring, 90 , 290, 390, 490 Connection member, 91, 291, 391, 491 Lead connection part, 92 Isolation part, 94 Extension part, 95 Outer wall surface, 96 Secondary copper wire connection part (conductor connection part), 100 Ignition coil

Claims (7)

An ignition coil that is connected to the spark plug and generates a voltage that causes a spark discharge in the spark plug by boosting a voltage that energizes the primary coil by a secondary coil;
A conductive wire forming the secondary coil;
A diode having a lead portion and restricting a reverse current induced in the secondary coil when energization of the primary coil is switched from an off state to an on state;
A bobbin member having a winding portion around which the conducting wire forming the secondary coil is wound in a cylindrical shape;
A connecting member having a conductor connecting portion connected to the conductor forming the secondary coil, and a lead connecting portion connected to the lead portion of the diode;
By covering the periphery of the bobbin member, an insulating resin that covers the conductive wire, the diode, and the connection member;
A partition part that penetrates the connection member inside the insulating resin, and partitions the lead wire connection part and the lead connection part by penetrating the connection member through the penetration part;
An ignition coil comprising: The bobbin member is
A support for supporting the diode;
It is located between the support part and the winding part, and has a flange part protruding in a hook shape on the outer peripheral side of the winding part,
The conducting wire has a lead wire portion that is led out from the winding portion side of the flange portion on the conductor connection portion located on the support portion side of the flange portion,
The partition wall is
A bulkhead body portion separating the lead wire connecting portion and the lead connecting portion;
2. A partition extending portion that separates the lead connecting portion and the lead wire portion by extending from the partition main body portion toward the space between the lead connecting portion and the lead wire portion. Ignition coil according to. The bobbin member has a lead-out part for pulling out the lead-out line part from the winding part side to the support part side across the collar part,
The extending portion of the partition wall extends from the partition wall main body portion to a position beyond the lead-out portion along the flange portion, and separates the lead wire portion and the lead connection portion that are led out through the lead-out portion. The ignition coil according to claim 2.   4. The connection member according to claim 1, wherein an outer wall surface of an extension portion extending from the through portion on the opposite side of the partition wall from the diode is cylindrical. The ignition coil according to item.   5. The connection member according to claim 1, wherein the connection member includes an extending portion that linearly extends from the through portion on a side opposite to the diode of the partition wall portion. Ignition coil. The bobbin member has a support portion for supporting the diode,
The ignition coil according to claim 1, wherein the partition wall is formed integrally with the bobbin member. A method for producing the ignition coil according to any one of claims 1 to 6,
A lead connection step of connecting the lead connection portion of the connection member to the lead portion of the diode;
A support step of supporting the diode connected to the connection member by the lead connection step on a support portion of the bobbin member such that the conductor connection portion of the connection member extends from the partition portion;
A conducting wire connecting step of connecting the conducting wire to the conducting wire connecting portion of the connecting member disposed by the supporting step;
An ignition coil manufacturing method comprising:

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