JP2008187026A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To present a structure for connecting a terminal and fixing a coil, and to provide a highly reliable ignition coil for internal combustion engine not contaminating the earth environment. <P>SOLUTION: The ignition coil for internal combustion engine has a secondary bobbin terminal connected with a secondary wire and provided in a secondary bobbin, and a high voltage lead terminal connected electrically with the secondary bobbin terminal and arranged in a route for distributing the high voltage of a secondary coil to the outside of an ignition coil wherein the secondary bobbin terminal and the high voltage lead terminal are arranged to be fitted when the secondary coil is contained in a case. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ignition coil for an internal combustion engine, and more particularly to a terminal connection structure for an ignition coil.

  In recent internal combustion engines for automobiles, an ignition coil having a configuration that does not use solder in consideration of the environment is presented. However, there is a demand for a smaller and more easily assembled ignition coil. FIG. 7 is a longitudinal sectional view of a conventional ignition coil for an internal combustion engine. FIG. 8 is an enlarged view of part B of FIG.

  7 to 8, the ignition coil 10 to which the prior art is applied has a primary coil 20 in which a primary conductor is wound around a primary bobbin 21 and a secondary conductor is wound around a secondary bobbin 31 on the outer periphery thereof. A secondary coil 30 is disposed, and a coil assembly including the primary coil 20 and the secondary coil 30 is housed in a case 40. Inside the primary bobbin, a central core 81 formed by laminating a thin sheet of silicon steel sheet, an outer peripheral core 82 formed by laminating a thin sheet of silicon steel sheet on the outer periphery, and a coil assembly are embedded, and an insulating material is used. It is integrated by injection-curing a certain epoxy resin. The high-voltage side of the secondary coil 30 is connected to a secondary bobbin terminal 32 having a cylindrical protrusion at the tip and formed of a conductive material. The secondary bobbin terminal 32 is a plate made of a conductor. Both ends are electrically connected to a high-voltage terminal 70 that is a screw via a high-voltage lead terminal 60 provided with through holes at both ends. In order to connect the high-voltage lead terminal 60 and the high-voltage terminal 70, one through hole of the high-voltage lead terminal 60 is subjected to a drawing process in which a pilot hole is drilled and stretch-flanged into a cylindrical shape. , Mechanically screwed. The case 40 integrally has a high voltage tower 41 that distributes a high voltage generated by the secondary coil 30 on the opposite side of the opening surface. The high-voltage terminal 70 is electrically connected.

  The secondary bobbin terminal 32 and the high-voltage lead terminal 60 are connected to each other by projecting a cylindrical protrusion at the tip of the secondary bobbin terminal 32 through a through-hole provided in the high-voltage lead terminal and projecting from the through-hole. Next, the bobbin terminal is bent to form a bent portion 32a, and then the bent portion 32a is electrically and mechanically connected by soldering.

  A plug boot 91 that holds an ignition plug (not shown) made of an elastic material such as rubber is attached to the outside of the high-pressure tower portion 41, and the ignition coil 10 is fixed to the engine head 99.

In Japanese Patent Laid-Open No. 6-251964 (Patent Document 1), the secondary coil terminal is inserted into the case while being guided by the guide concavo-convex portion formed on the case, and the secondary coil terminal and the high-voltage terminal are electrically connected without misalignment. A connected and configured ignition coil is disclosed. Japanese Patent Application Laid-Open No. 2002-033230 (Patent Document 2) discloses an ignition coil having a configuration in which a terminal pin is brought into contact with a high-voltage terminal by housing a secondary coil in an insulating case.
JP-A-6-251964 JP 2002-033230 A

  However, in the above configuration, since the high-voltage lead terminal and the high-voltage terminal are connected by screw connection, burring to the high-voltage lead terminal and screw connection man-hours are required, and many man-hours are increased. Furthermore, the connection between the secondary bobbin terminal and the high-voltage lead terminal requires a large number of assembly steps as described above, and also contaminates the global environment by using solder. Japanese Patent Laid-Open No. 6-251964 (Patent Document 1) increases the design man-hours because the case is processed with a guide uneven portion. Japanese Patent Laid-Open No. 2002-033230 (Patent Document 2) does not consider the coil fixing after connection. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an ignition coil for an internal combustion engine that solves the above-described problems and presents a terminal connection and a coil fixing structure and has good reliability that does not pollute the global environment.

  In order to solve the above problems, the present invention is configured as follows. That is, in claim 1, a primary coil in which a primary conductor is wound around a primary bobbin and a secondary coil in which a secondary conductor is wound around a secondary bobbin are arranged. These primary coil and 2 An ignition coil for an internal combustion engine in which a coil assembly composed of a secondary coil is housed in a case, the secondary coil having a secondary bobbin terminal connected to the secondary conductor and provided in a secondary bobbin, A high-voltage lead terminal electrically connected to the terminal and disposed in a path for distributing the high voltage of the secondary coil to the outside of the ignition coil, and the secondary bobbin terminal and the high-voltage lead when the secondary coil is housed in a case An ignition coil for an internal combustion engine, characterized in that the terminal is disposed so as to be fitted.

  In addition, one of the secondary bobbin terminal and the high-voltage lead terminal is a terminal formed of a plate-like or linear conductive material and having a fitting portion having an elastic force, and the other The terminal may be formed of a conductive material and may include a through hole that contacts and fits to the outer periphery of the one terminal. In addition, the contact area of the inner periphery of the through hole may be expanded by drawing.

  Further, at least one of the secondary bobbin terminal and the high-voltage lead terminal is a terminal made of a plate-like or linear conductive material and having an elastic force, and the other terminal is connected to the secondary bobbin terminal or the high-voltage by the elastic force. You may comprise the terminal which processed the tip of the terminal into the shape of a cone or the thin plate which reduces width so that a lead terminal may contact and fit. Further, the secondary bobbin terminal and the high-voltage lead terminal are made of a rod-shaped wire made of a conductor, and one terminal is formed with a substantially conical spiral portion having a diameter larger than the center toward the tip, You may comprise by the terminal which a front-end | tip diameter reduces gradually so that it may fit inside the cone of a conical spiral part with an elastic force.

  A primary coil in which a primary conducting wire is wound around a primary bobbin and a secondary coil in which a secondary conducting wire is wound around a secondary bobbin are arranged, and the coil is composed of the primary coil and the secondary coil. An ignition coil for an internal combustion engine, in which an assembly is housed in a case, has a secondary bobbin terminal that is connected to the secondary conductor and provided in a secondary bobbin, and is electrically connected to the secondary bobbin terminal And a high voltage lead terminal arranged in a path for distributing the high voltage of the secondary coil to the outside of the ignition coil, and the secondary coil is arranged so that the secondary bobbin terminal and the high voltage lead terminal are fitted when the case is accommodated. Thus, when the coil assembly is housed in the case, the high-voltage lead terminal on the case side and the secondary bobbin terminal of the coil assembly are electrically connected and mechanically automatically fitted, and soldering, etc. Connection work is not good To become.

  In addition, one of the secondary bobbin terminal and the high-voltage lead terminal is a terminal formed of a plate-like or linear conductive material and having a fitting portion having an elastic force, and the other These terminals are formed of a conductive material and are provided with a through hole that contacts and fits the outer periphery of the one terminal with an elastic force, so that the two terminals can be reliably connected by the elastic force.

  The through-hole is configured to widen the contact area of the inner periphery of the hole by drawing, and at least one of the secondary bobbin terminal and the high-voltage lead terminal is made of a plate-like or linear conductive material and has an elastic force. The other terminal is constituted by a terminal whose tip is processed into a conical shape or a thin plate with a reduced width so that the secondary bobbin terminal and the high-voltage lead terminal are brought into contact with each other by the elastic force. The secondary bobbin terminal and the high-voltage lead terminal are made of a rod-like wire rod made of a conductor, and a terminal having a substantially conical spiral portion whose one end is larger in diameter than the center toward the tip, A more reliable electrical and mechanical connection between the terminals is achieved by configuring the terminals with the diameter of the tip gradually decreasing so as to fit into the cone of the conical spiral portion by an elastic force.

  FIG. 1 is a longitudinal sectional view of an ignition coil for an internal combustion engine according to the technique of the present invention. FIG. 2 is an enlarged view of a portion A in FIG. FIG. 3 is an enlarged view showing a terminal having a U-shaped portion of an ignition coil for an internal combustion engine according to the present invention and a terminal fitted on the outer periphery of the U-shaped portion. FIG. 4 is an enlarged view showing a terminal having a U-shaped portion of the ignition coil for an internal combustion engine according to the present invention and a terminal fitted to the inner periphery of the U-shaped portion. FIG. 5 is an enlarged view showing a terminal having a U-shaped portion of an ignition coil for an internal combustion engine according to the present invention and a terminal fitted to the outer periphery of the U-shaped portion. FIG. 6 is an enlarged view showing a terminal having a substantially conical spiral portion of the ignition coil for an internal combustion engine according to the present invention and a terminal fitted inside the cone of the substantially conical spiral portion.

  The ignition coil 100 of the present invention shows only the difference from the prior art. 1 and 2, the ignition coil 100 for an internal combustion engine according to the first embodiment of the present invention includes a primary coil 120 in which a primary conductor is wound around a primary bobbin 121 and a secondary bobbin 131 on the outer periphery thereof. A coil assembly including a secondary coil 130 around which a conductive wire is wound is housed in a case 140. The case 140 has an opening 147, and a primary bobbin engagement hole 142 that engages with a part of the primary bobbin 121 is provided on the opposite side of the opening 147. Further, the high-voltage tower 141 for distributing the high voltage generated in the secondary coil 130 is separately configured and disposed below the case 140. The case 140 has a high-pressure tower insertion opening for inserting and fitting the high-pressure tower 141, and the high-pressure tower 141 has an insertion 145 having a diameter slightly larger than the inner diameter of the opening. The high-voltage tower unit 141 has a conduction hole formed below the insertion unit 145, and has a cylindrical shape that reduces radio noise during coil operation, and radio noise formed at both ends by conductors 194a and 194b. The lower end of the conductor 194b of the reducing resistor 194 is fixed so as to be exposed from the end of the conduction hole, and the upper end of the conductor 194a is connected to a high voltage lead terminal 163 described later. . Therefore, the high voltage lead terminal 163 is fixed inside the high voltage tower unit 141. The high voltage side of the secondary coil 130 is connected to a secondary bobbin terminal 132 formed of a conductive material, and the secondary bobbin terminal 132 is connected to a radio noise reduction resistor 194 via the high voltage lead terminal 163. It is connected and electrically connected to a spark plug (not shown) via a spring 195.

  Next, the assembly of the ignition coil will be described. First, the insertion portion 145 is inserted toward the high-pressure tower insertion opening, whereby the high-pressure tower portion 141 and the case 140 are fitted and assembled. Next, when the coil assembly is housed from the opening 147 of the case 140, a part of the rear end of the primary bobbin 121 is guided and fitted into the primary bobbin engagement hole 142, and the secondary bobbin terminal Easily advances linearly toward the high-voltage lead terminal 163 and is automatically electrically connected. The secondary bobbin terminal 132 is a terminal made of a conductive material having a U-shaped portion 132a described later. The high-voltage lead terminal 163 is a plate-like conductive material having a through-hole 163a having a diameter smaller than the outer periphery of the U-shaped portion 132a provided at one end of the high-voltage lead terminal 163 for fitting with the U-shaped portion 132a. It is a configured terminal. Further, in order to improve the contact area between the through hole 163a and the U-shaped portion 132a, the through hole 163a is drawn around the through hole 163a in the direction in which the U-shaped portion 132a is fitted into the through hole 163a. What comprises the shape which has the protrusion part 163b protruded by this is preferable. Accordingly, the secondary bobbin terminal and the high-voltage lead terminal 163 are fixed by fitting the inner periphery of the through hole 163a to the outer periphery of the U-shaped portion 132a by the spring elastic force of the U-shaped portion 132a. The coil assembly is fixed to the case 140. After that, it is integrated by injecting and curing an epoxy resin as an insulating material.

  FIG. 3 is an enlarged view of a portion representing the fitting between the secondary bobbin terminal and the high-voltage lead terminal in FIG. 4 to 6 are enlarged views showing another embodiment showing the fitting between the secondary bobbin terminal and the high-voltage lead terminal. As shown in FIG. 3, the secondary bobbin terminal 132 is a conductor having a U-shaped portion 132a and a rod-shaped wire rod processed into a self-letter shape. The high-voltage lead terminal 163 is a plate-like conductive member having a through-hole 163a having a diameter smaller than the outer periphery of the U-shaped portion 132a provided at one end so as to fit and contact the outer periphery of the U-shaped portion 132a. A terminal made of a material. The connection between the secondary bobbin terminal 132 and the high voltage lead end 163 is such that when the coil assembly is housed in the case 140, the U-shaped part 132a of the secondary bobbin terminal 132 is connected to the high voltage tower part 141. It goes straight to the through hole 163a of the high-voltage lead end 163 installed on the outer periphery of the U-shaped portion 132a, and the outer periphery of the U-shaped portion 132a is automatically fitted into the inner periphery of the through hole 163a by spring elastic force. Electrically connected. Thus, the coil assembly is fixed to the case 140. Further, a part of the rear end of the primary bobbin 121 is guided and fitted in the primary bobbin engagement hole 142, but the through hole 163a secures a contact area so that it can cope with some blurring. The center diameter of the penetration portion is desirable.

  As a first modification, as shown in FIG. 4, the secondary bobbin terminal 133 is a terminal having a U-shaped part 133a made of a conductor and processed into a self-shaped rod-shaped wire. The high-voltage lead terminal 164 is made of a plate-like conductive material having a through-hole 164a processed into a thin plate shape whose one end is reduced in width so as to fit and contact the inner periphery of the U-shaped portion 133a. Terminal. At this time, the connection between the secondary bobbin terminal 133 and the high voltage lead end 164 is such that when the coil assembly is housed in the case 140, the U-shaped portion 133a of the secondary bobbin terminal 133 is connected to the high voltage tower. It is linearly directed to the through hole 164a of the high-voltage lead end 164 installed in the portion 141, and the inner periphery of the U-shaped portion 133a is automatically fitted by the spring elastic force to the outer periphery of the through hole 164a. Is electrically connected. Thus, the coil assembly is fixed to the case 140.

  Although not shown, the high-voltage lead terminal 164 is a terminal made of a conductive material having a through hole whose one end is processed into a conical shape so as to fit and contact the inner periphery of the U-shaped portion 133a. There may be. Also in this case, the inner periphery of the U-shaped portion 133a is electrically connected by fitting to the outer periphery of the through hole.

  As a second modification, as shown in FIG. 5, the secondary bobbin terminal 134 is a conductor having a U-shaped portion 134 a and a rod-shaped wire processed into a five-letter shape. The high-voltage lead terminal 165 is a terminal made of a plate-like conductive material having a through hole 165a provided at one end so as to fit and contact the outer periphery of the U-shaped portion 134a. At this time, the connection between the secondary bobbin terminal 134 and the high voltage lead end 165 is such that when the coil assembly is housed in the case 140, the U-shaped portion 134a of the secondary bobbin terminal 134 is connected to the high voltage tower. The U-shaped portion 134a is linearly directed to the through hole 165a of the high-voltage lead end 165 installed in the portion 141, and the outer periphery of the U-shaped portion 134a is automatically engaged with the inner periphery of the through hole 165a by a spring elastic force. Electrically connected. Thus, the coil assembly is fixed to the case 140. Further, in order to improve the contact area between the through-hole 165a and the U-shaped portion 134a, the through-hole 165a is drawn around the through-hole 165a in the direction in which the U-shaped portion 134a is fitted into the through-hole 165a. What comprises the shape which has the protrusion part 165b protruded by this is preferable.

  As a third modification, as shown in FIG. 6, the secondary bobbin terminal 135 is a terminal that has a tip portion 135 a and is formed by processing a rod-shaped wire rod into a U shape with a conductor. The high-voltage lead terminal 166 is a terminal that is made of a conductor and has a substantially conical spiral portion 166a with one end portion having a diameter larger than the center toward the tip end. At this time, the connection between the secondary bobbin terminal 135 and the high voltage lead end 166 is such that when the coil assembly is housed in the case 140, the tip 135a of the secondary bobbin terminal 135 is connected to the high voltage tower 141. The U-shaped portion 135a is linearly directed to the substantially conical spiral portion 166a of the high-voltage lead end 166 installed on the inner periphery of the substantially conical spiral portion 166a by a spring elastic force. Electrical connection is established by fitting. Thus, the coil assembly is fixed to the case 140. Further, it is preferable that the tip portion 135a is configured so that the tip diameter gradually decreases so as to fit into the cone of the substantially conical spiral portion 166a.

  By adopting the above configuration, when the coil assembly is housed in the case 140, the secondary bobbin terminal advances linearly toward the high-voltage lead terminal 161 and is automatically electrically connected. . Thus, the coil assembly is fixed to the case 140 by connecting the terminals. Therefore, it is possible to provide an electrical connection structure that does not use solder, to reduce the number of assembly steps, and to provide an ignition coil for an internal combustion engine that has good reliability without polluting the global environment.

  As described above, the embodiments have been described based on the gist of the present invention.However, as long as the number of assembling steps can be reduced, and an ignition coil for an internal combustion engine with good reliability that does not pollute the global environment can be provided, The combination, size, position, and material of the present invention are not particularly limited. That is, various modifications can be made without departing from the spirit of the present invention.

Explanation of symbols

10, 110 Ignition coil 20, 120 Primary coil 21, 121 Primary bobbin 30, 130 Secondary coil 31, 131 Secondary bobbin 32, 132, 133, 134, 135 Secondary bobbin terminal 40, 140 Case 41, 141 High voltage Tower part 60, 163, 164, 165, 166 High voltage lead terminal 70 High voltage terminal 81, 181 Center side core 82, 182 Outer side core 91, 199 Protector 95, 195 Spring 99 Engine head 132a, 133a U-shaped part,
134a U-shaped portion 135a Tip portion 142 Primary bobbin engagement hole 147 Case openings 163a, 164a, 165a Through holes 163b, 165b Protruding portion 166a Substantially conical spiral portion 194 Radio noise reduction resistors 194a, 194b Conductor

It is a longitudinal cross-sectional view of the ignition coil for internal combustion engines of the technique of this invention. It is the A section enlarged view of FIG. It is an enlarged view showing the terminal which has the U-shaped part of the ignition coil for internal combustion engines of the technique of this invention, and the terminal fitted to the outer periphery of a U-shaped part. It is an enlarged view showing the terminal which has the U-shaped part of the ignition coil for internal combustion engines of the technique of this invention, and the terminal fitted to the inner periphery of a U-shaped part. It is an enlarged view showing the terminal which has a U-shaped part of the ignition coil for internal combustion engines of the technique of this invention, and the terminal fitted to the outer periphery of a U-shaped part. It is an enlarged view showing the terminal which has the substantially conical spiral part of the ignition coil for internal combustion engines of the technique of this invention, and the terminal fitted inside the cone of a substantially conical spiral part. It is a longitudinal cross-sectional view of the ignition coil for internal combustion engines of a prior art. It is the B section enlarged view of FIG.

Claims (5)

  A primary coil in which a primary conducting wire is wound around a primary bobbin and a secondary coil in which a secondary conducting wire is wound around a secondary bobbin are arranged, and the coil is composed of the primary coil and the secondary coil. An ignition coil for an internal combustion engine, in which an assembly is housed in a case, has a secondary bobbin terminal that is connected to the secondary conductor and provided in a secondary bobbin, and is electrically connected to the secondary bobbin terminal And a high voltage lead terminal arranged in a path for distributing the high voltage of the secondary coil to the outside of the ignition coil, and the secondary coil is arranged so that the secondary bobbin terminal and the high voltage lead terminal are fitted when the case is accommodated. An ignition coil for an internal combustion engine.   Either one of the secondary bobbin terminal and the high-voltage lead terminal is a terminal formed of a plate-like or linear conductive material, and the fitting portion has an elastic force, and the other terminal. 2. The ignition coil for an internal combustion engine according to claim 1, further comprising a through hole formed of a conductive material and in contact with and fitted to the outer periphery of the one terminal by an elastic force.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the through hole has a contact area on the inner periphery of the hole increased by drawing.   At least one of the secondary bobbin terminal and the high-voltage lead terminal is a terminal made of a plate-like or linear conductive material and having an elastic force, and the other terminal is a secondary bobbin terminal or a high-voltage lead terminal by the elastic force. 2. The ignition coil for an internal combustion engine according to claim 1, wherein the terminal is formed of a terminal whose tip is processed into a conical shape or a thin plate with a reduced width so as to come into contact with each other.   The secondary bobbin terminal and the high-voltage lead terminal are made of a rod-shaped wire made of a conductor, one end of which is formed with a substantially conical spiral portion having a diameter larger than the center toward the tip, and the substantially conical shape 2. The ignition coil for an internal combustion engine according to claim 1, wherein the ignition coil is constituted by a terminal whose tip diameter is gradually reduced so as to be fitted into the cone of the spiral portion by an elastic force.

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