JP2016012599A - Ignition coil for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine which enables a protruding length of a connector part from a contour of a case to be reduced without shortening the connector part.SOLUTION: An ignition coil 1 for an internal combustion engine includes: a primary coil 21 and a secondary coil 22 which are magnetically coupled to each other; a core 3 which forms a magnetic path of magnetic flux generated by an electric current flowing through the primary coil 21; a case 4 which houses the primary coil 21, the secondary coil 22, and the core 3; and a connector part 11 for connecting an external connector. The connector part 11 protrudes from the case 4 and is formed so that the external connector is connected thereto so as to be covered by an outer periphery of the connector part 11. The case 4 includes a caved part 61, which is caved further than other portions, in a periphery of the connector part 11.

Description

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

  As an ignition coil used for an internal combustion engine, a primary coil and a secondary coil that are magnetically coupled to each other, a core that forms a magnetic path of a magnetic flux generated by energization of the primary coil, a primary coil, a secondary coil, and a core And a connector portion for connecting an external connector (Patent Document 1). In such an ignition coil, the connector portion protrudes from the case, and the external connector is configured to fit into the connector portion in a state of covering the connector portion from the outer periphery.

JP 2009-188364 A

  However, in recent years, with the downsizing of the engine and the like, the arrangement space of the ignition coil has been reduced, so that the ignition coil is required to be downsized. In particular, from the viewpoint of improving the mountability of the ignition coil to the engine, it is desired to minimize the protruding amount of the connector portion from the case.

  However, if the length of the connector portion is simply reduced, when the connector portion and the external connector are fitted together, the fitting length between the two becomes short, and the connection reliability between the ignition coil and the external connector is reduced. There is a fear. Therefore, it is desired to reduce the protruding amount of the connector part from the outer shape of the case without reducing the length of the connector part.

  The present invention has been made in view of such a background, and provides an ignition coil for an internal combustion engine that can reduce the amount of protrusion of the connector portion from the outer shape of the case without shortening the length of the connector portion. It is something to try.

One aspect of the present invention includes a primary coil and a secondary coil that are magnetically coupled to each other;
A core constituting a magnetic path of magnetic flux generated by energizing the primary coil;
A case for housing the primary coil, the secondary coil, and the core;
An ignition coil for an internal combustion engine having a connector portion for connecting an external connector,
The connector portion protrudes from the case, and is configured to be connected to the external connector so as to be covered from the outer periphery.
The case is an ignition coil for an internal combustion engine, characterized by having a depressed portion that is depressed more than the other portion around the connector portion.

  In the ignition coil for an internal combustion engine, the case has a depressed portion that is depressed more than the other portion around the connector portion. That is, since the connector part protrudes from the recessed part of a case, even if it does not shorten a connector part, the protrusion amount of the connector part from the external shape of a case can be made small.

  As described above, according to the present invention, it is possible to provide an ignition coil for an internal combustion engine that can reduce the amount of protrusion of the connector portion from the outer shape of the case without reducing the length of the connector portion.

FIG. 3 is a cross-sectional view of the ignition coil in the first embodiment. 1 is a perspective view of an ignition coil in Embodiment 1. FIG. FIG. 3 is a top view of the ignition coil in the first embodiment. The perspective view explaining the process of assembling the sub assembly in the 1st case body in Example 1. FIG. Sectional drawing explaining the process in which the subassembly in Example 1 is assembled | attached to a 1st case body. Sectional drawing of the ignition coil in Example 2. FIG. The perspective view of the ignition coil in Example 2. FIG.

(Example 1)
Examples of the ignition coil for the internal combustion engine will be described with reference to FIGS.
As shown in FIG. 1, the ignition coil 1 for an internal combustion engine of this example constitutes a primary coil 21 and a secondary coil 22 that are magnetically coupled to each other, and a magnetic path of magnetic flux generated by energizing the primary coil 21. The case 3 includes a core 3, a primary coil 21, a secondary coil 22, and the core 3, and a connector portion 11 for connecting an external connector. As shown in FIGS. 1 to 3, the connector portion 11 protrudes from the case 4 and is configured to be connected to an external connector so as to be covered from the outer periphery. The case 4 has a depressed portion 61 that is depressed more than the other portions around the connector portion 11.

  As shown in FIG. 1, the primary coil 21 and the secondary coil 22 are arranged so as to overlap each other on the inner and outer circumferences. The core 3 includes a central core 31 disposed on the inner peripheral side of the primary coil 21 and the secondary coil 22 and an outer peripheral core 32 disposed on the outer peripheral side of the primary coil 21 and the secondary coil 22. The case 4 is provided with a tower portion 53 in which the conduction terminal 13 connected to the secondary coil 22 is arranged inside in a direction orthogonal to the axial direction of the primary coil 21 and the secondary coil 22. The connector portion 11 is formed so as to protrude from one end side in the axial direction X of the primary coil 21 and the secondary coil 22 in the case 4. A gap formed in the case 4 is filled with a filling resin 12 having electrical insulation.

  In this example, the primary coil 21 and the secondary coil 22 have the same winding axis, and the direction of these winding axes is referred to as the axial direction X. Further, the protruding direction of the tower portion 53 is referred to as a vertical direction Z, and a direction orthogonal to both the axial direction X and the vertical direction Z is referred to as a horizontal direction Y. In the vertical direction Z, the side from which the tower portion 53 projects may be referred to as “lower side”, and the opposite side may be referred to as “upper side”. Note that the upper and lower expressions do not determine the vertical direction.

  As shown in FIG. 1, the primary coil 21 is formed by winding a primary wire around a primary spool 101 disposed on the outer periphery of the central core 31, and the secondary coil 22 is formed on the outer peripheral side of the primary coil 21. A secondary wire that is thinner than the primary wire is wound around the secondary spool 102 more times than the primary wire. Thereby, when the current supplied to the primary coil 21 is cut off, a high voltage current is generated in the secondary coil 22 by mutual induction. The primary spool 101 and the secondary spool 102 are made of resin. In this example, the primary wire is wound around the primary spool 101. However, the primary wire may be wound directly around the central core 31 without using the primary spool 101. it can.

  The center core 31 has a substantially quadrangular prism shape formed by laminating a plurality of magnetic steel plates in the vertical direction Z. The central core 31 is arranged such that the longitudinal direction thereof is the axial direction X.

  The outer core 32 is a substantially rectangular frame that opens in the vertical direction Z. The outer peripheral core 32 is also formed by laminating a plurality of magnetic steel plates in the vertical direction Z. A magnet body 103 is disposed between the center core 31 and the outer core 32.

  The case 4 includes a side wall portion 51 that surrounds the primary coil 21, the secondary coil 22, the core 3, and the magnet body 103 from the axial direction X and the lateral direction Y and opens upward, and the side wall portion 51. And a bottom wall portion 52 that closes the lower end thereof. As shown in FIG. 3, the side wall 51 has a rectangular outer shape when viewed from the vertical direction Z, and the longitudinal direction of the rectangular shape is the axial direction X. As shown in FIGS. 1 and 2, a tower portion 53 is formed on the bottom wall portion 52, and the tower portion 53 is formed to protrude downward from the bottom wall portion 52. The tower portion 53 is fitted inside a plug cap (not shown).

  As shown in FIGS. 1 to 3, the case 4 includes a first case body 5 and a second case body 6 assembled to the first case body 5, and the connector portion 11 is formed of the second case body 6. Configured as part. The first case body 5 and the second case body 6 are separate parts and are combined together to form the case 4. Case 4 (the 1st case body 5 and the 2nd case body 6) consists of resin.

  As shown in FIG. 4, the first case body 5 includes a part of the side wall portion 51 and a bottom wall portion 52. That is, the 1st case body 5 has the notch part 512 formed by notching a part of the side wall part 51 below from an opening direction. The cutout portion 512 is formed on one side of the side wall portion 51 in the axial direction X. The second case body 6 is disposed in the cutout portion 512 of the first case body 5 and is engaged with the edge of the side wall portion 51 adjacent to the cutout portion 512.

  As shown in FIGS. 1 to 3, the second case body 6 includes a groove 62 that engages with an edge of the side wall portion 51 adjacent to the notch 512 of the first case body 5 in the second case body 6. At the lower end and at both ends in the lateral direction Y. The second case body 6 includes a reference surface 63 that is a part of the outer surface on one side in the axial direction X of the case 4 and a recessed portion 61 that is recessed from the reference surface 63. That is, the depressed portion 61 is located inside the outer shape of the case 4.

  As shown in FIGS. 1 and 2, the depressed bottom surface 611 that is the bottom surface of the depressed portion 61 is a flat surface, and is inclined so as to be directed toward the inside of the case 4 in the axial direction X toward the upper side.

  The connector portion 11 is formed so as to protrude from the approximate center of the depressed bottom surface 611 in the lateral direction Y. That is, a part of the connector part 11 is located inside the outer shape of the case 4. The connector portion 11 protrudes perpendicularly to the depressed bottom surface 611, and the protruding direction is inclined with respect to the axial direction X. That is, the connector part 11 inclines so that it may go to the opposite side (upper side) of the protrusion direction of the tower part 53 as it goes to the protrusion front end side. Further, the connector part 11 protrudes at an obtuse angle with respect to the lower side surface 631 of the connector part 11 on the reference surface 63.

  By connecting the external connector so as to be covered from the outer periphery of the connector part 11, the external device and the ignition coil 1 are electrically connected. That is, the connector portion 11 is a so-called male connector, and the external connector is a so-called female connector.

  An attachment portion 54 is formed on the opposite side of the case 4 in the axial direction X from the connector portion 11. As shown in FIGS. 2 and 3, the attachment portion 54 has a through hole 540 for inserting a bolt for attaching the ignition coil 1 to the engine.

  As shown in FIG. 1, the case 4 houses an igniter 7 that is disposed on one end side in the axial direction X of the primary coil 21 and the secondary coil 22 and energizes and shuts off the primary coil 21. . The depressed portion 61 is disposed adjacent to a position (upper side) opposite to the protruding direction of the tower portion 53 in the igniter 7. The igniter 7 is arranged so that the upper surface thereof is located below the upper surface of the outer peripheral core 32.

  The igniter 7 has an igniter terminal 71 protruding upward. A conductive pin 111 (control signal transmission terminal) for transmitting a switching signal to the igniter 7 is arranged in the connector portion 11, and the conductive pin 111 (control signal transmission terminal) is connected to the igniter terminal 71. It is connected.

  As shown in FIG. 2, three conductive pins 111 are arranged in the connector portion 11. These conductive pins 111 are respectively a grounding terminal for grounding the outer peripheral core 32, a terminal for transmitting a control signal from an external control device that controls on / off of the switching element in the igniter 7, and a terminal for connecting an external power source It is.

  The central core 31, the primary coil 21, the secondary coil 22, the outer core 32, the magnet body 103, and the igniter 7 disposed in the case 4 are embedded in the thermoplastic filling resin 12.

Next, the assembly process of the ignition coil 1 of this example will be described.
As shown in FIGS. 4 and 5, the central core 31, the primary coil 21, the secondary coil 22, the outer peripheral core 32, the magnet body 103, the igniter 7, and the second case body 6 (including the connector portion 11) are assembled. As a result, the sub-assembly 10 is formed. That is, the subassembly 10 is formed before the second case body 6 is assembled to the first case body 5.

  In the first case body 5, the conduction terminal 13 is disposed inside the tower portion 53. Then, the subassembly 10 is inserted into the first case body 5 from the opening direction. At this time, the notch 512 of the first case body 5 is engaged with the groove 62 of the second case body 6.

And in the state which assembled | attached the sub assembly 10 to the 1st case body 5, as shown in FIG. 1, the filling resin 12 is poured in in the case 4, and the sub assembly 10 is sealed by hardening this.
The ignition coil 1 for the internal combustion engine of this example can be obtained by the above assembly process.

Next, the function and effect of this example will be described.
In the ignition coil 1 for an internal combustion engine, the case 4 has a recessed portion 61 that is recessed from the other portions around the connector portion 11. That is, since the connector part 11 protrudes from the recessed part 61 of the case 4, even if it does not shorten the connector part 11, the protrusion amount of the connector part 11 from the external shape of the case 4 can be made small. In addition, since the external connector can be inserted into the depressed portion 61 and fitted into the connector portion 11, contact reliability between the connector portion 11 and the external connector can be ensured.

  In addition, since the recessed portion 61 is provided around the connector portion 11 of the case 4, the external connector can be inserted into the recessed portion when the external connector is fitted to the connector portion 11. Therefore, it is possible to sufficiently secure the fitting length between the connector portion and the external connector.

  The case 4 includes a first case body 5 and a second case body 6, and the connector portion 11 is configured as a part of the second case body 6. Thereby, the assembly | attachment of the ignition coil 1 can be made easy.

  The connector portion 11 is formed so as to protrude from one end side in the axial direction X of the case 4. Thereby, size reduction of the ignition coil 1 in the axial direction X can be achieved while preventing the ignition coil 1 from increasing in size in the lateral direction Y.

  The depressed portion 61 is disposed adjacent to a position on the igniter 7 opposite to the protruding direction of the tower portion 53. Therefore, as the wide space above the igniter 7 in the case 4 can be reduced, the filling resin 12 disposed in the space can be reduced. Thereby, the thermal stress applied to the components in the case 4 such as the igniter 7 can be reduced.

  Moreover, the connector part 11 inclines so that it may go to the opposite side to the protrusion direction of the tower part 53, as it goes to the protrusion front end side. Therefore, it is easy to attach an external connector to the connector portion 11.

  As described above, according to this example, it is possible to provide an ignition coil for an internal combustion engine that can reduce the protruding amount of the connector part from the outer shape of the case without reducing the length of the connector part.

(Example 2)
In this example, as shown in FIGS. 6 and 7, the protruding direction of the connector portion 11 is the axial direction X. The depressed bottom surface 611 is formed perpendicular to the axial direction X. Further, the depressed bottom surface 611 is formed on the entire circumference of the proximal end portion of the connector portion 11. A portion of the recessed bottom surface 611 above the connector portion 11 is an inclined surface 612 that is inclined so as to be directed toward the inside of the case 4 in the axial direction X as it goes upward.

Others are the same as in the first embodiment. Of the reference numerals used in this example or the drawings relating to this example, the same reference numerals as those used in the first embodiment denote the same components as in the first embodiment unless otherwise specified.
Also in this example, it has the same effect as Example 1.

  In the above-described embodiment, the example in which the connector portion is formed so as to protrude from one end side in the axial direction of the case is shown. However, for example, a configuration in which the connector portion is formed so as to protrude from the lateral side in the case. It is also good. Also in this case, the protrusion amount of the connector part from the outer shape of the case can be reduced by providing the depressed part around the connector part.

DESCRIPTION OF SYMBOLS 1 Ignition coil for internal combustion engines 11 Connector part 21 Primary coil 22 Secondary coil 3 Core 4 Case 61 Recessed part

Claims (5)

A primary coil (21) and a secondary coil (22) magnetically coupled to each other;
A core (3) constituting a magnetic path of magnetic flux generated by energization of the primary coil (21);
A case (4) for housing the primary coil (21), the secondary coil (22) and the core (3);
An ignition coil (1) for an internal combustion engine having a connector portion (11) for connecting an external connector,
The connector portion (11) protrudes from the case (4) and is configured to be connected to the external connector so as to be covered from the outer periphery.
The ignition coil (1) for an internal combustion engine, wherein the case (4) has a depressed portion (61) that is depressed more than the other portions around the connector portion (11).   The case (4) includes a first case body (5) and a second case body (6) assembled to the first case body (5), and the connector portion (11) includes the second case. 2. The ignition coil (1) for an internal combustion engine according to claim 1, characterized in that it is configured as part of the body (6).   The primary coil (21) and the secondary coil (22) are arranged on the inner and outer circumferences, and the core (3) is composed of the primary coil (21) and the secondary coil (22). ) And a peripheral core (32) disposed on the outer peripheral side of the primary coil (21) and the secondary coil (22), and the case ( 4) includes a tower portion (53) in which a conduction terminal (13) connected to the secondary coil (22) is arranged on the inner side, and a shaft of the primary coil (21) and the secondary coil (22). The connector portion (11) is provided in one direction in the axial direction (X) of the primary coil (21) and the secondary coil (22) in the case (4). Projected from the side, the gap formed in the case (4) Ignition coil for an internal combustion engine according to claim 1 or 2 filling resin having gas insulation (12) is characterized in that it is filled (1).   In the case (4), the primary coil (21) and the secondary coil (22) are arranged on one end side in the axial direction (X) to energize and shut off the primary coil (21). The igniter (7) to be performed is accommodated, and the depressed portion (61) is disposed adjacent to a position opposite to the protruding direction of the tower portion (53) in the igniter (7). An ignition coil (1) for an internal combustion engine according to claim 3.   5. The internal combustion engine according to claim 3, wherein the connector portion (11) is inclined so as to be directed to a side opposite to a protruding direction of the tower portion (53) toward the protruding tip side. Ignition coil for engine (1).

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