JP2012069613A - Ignition device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device having high reliability obtained by improving filling properties of a mold resin, even if a space between a primary coil and a secondary coil is narrow in the ignition device.SOLUTION: A flange 16 is formed at least at one end in the axial direction of a bobbin 10 of the coil, out of the primary coil 14 and the secondary coil 24, disposed in the inner side, and a resin inflow part 18 is formed at a part of the flange 16, thereby capable of surely filling the mold resin even if the space between the primary coil outer periphery and the secondary coil inner periphery is narrow.

Description

The present invention relates to an internal combustion engine ignition device.

2. Description of the Related Art Conventionally, an internal combustion engine ignition device is configured to include an iron core, a primary coil, and a secondary coil in a coil housing portion of a case, and each member is insulated and fixed by filling the case with an insulating resin. Yes. However, it is known that in the pen-type ignition coil in which the coil housing portion is inserted into the plug hole of the engine, the interval between the members is narrowed and the filling property of the mold resin is deteriorated. In such a situation, for example, it is known to have a configuration as disclosed in JP-A-11-186080 (hereinafter “Patent Document 1”).

A side view of the secondary spool described in Patent Document 1 is shown in FIG. In Patent Document 1 shown in FIG. 7, in an ignition coil in which a winding wound around a cylindrical spool 210 is housed in a cylindrical coil case and an insulating filler is filled, A filling groove 310 for filling the filler is formed in at least a portion on the high voltage terminal side of the outer peripheral surface so as to extend in the axial direction. The filling groove 310 is formed at least in the spool 210 of the secondary winding. Further, the filler 310 is made of a resin having a low linear expansion coefficient.

Further, there has been proposed an ignition device in which a rod-shaped central core is housed in the spool 210 and a cushion member is disposed at least at the upper end of the central core, and the cushion member is formed in a non-circular shape. Yes.

Japanese Patent Laid-Open No. 11-186080

However, the above conventional ignition device has the following problems. That is, in the ignition coil disclosed in Patent Document 1, a filling groove for filling a filler is formed in at least a portion on the high voltage terminal side of the outer peripheral surface of the bobbin so as to extend in the axial direction, and is disposed at least at the upper end of the iron core. By forming the cushion member in a non-circular shape, the filling property of the resin into the lower end direction of the ignition coil and the gap between the secondary bobbin and the iron core is improved. It is difficult to obtain a structure such as 1, and there is a possibility that the interval becomes narrower and the filling property is deteriorated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly reliable ignition device in which the filling property of the mold resin is improved even when a portion where the interval between the members is narrow occurs.

In order to solve the above problems, the present invention is configured as follows. That is, in the invention of claim 1, a case, a primary coil in which the primary winding is wound around the primary bobbin in the case, a secondary coil in which the secondary winding is wound around the secondary bobbin, and the iron In an ignition device having a core, the primary coil and the secondary coil being coaxially wound around the iron core, the coil disposed inside the primary coil and the secondary coil An internal combustion engine ignition device is characterized in that a flange is formed at least at one end in the axial direction of the bobbin and a resin inflow portion is formed at least at a part of the flange.

In the above configuration, the resin inflow portion may be formed in a shape that opens in one direction, or a slit that covers one side may be formed instead of the resin inflow portion. Moreover, you may form the said resin inflow part in the bobbin of the coil arrange | positioned outside among the said primary coil and the said secondary coil. In addition, the case includes two primary coils each having a primary winding wound around a primary bobbin, two secondary coils each having a secondary winding wound around a secondary bobbin, and two ignition coils. May be.

As described above, a flange is formed at least one end in the axial direction of a bobbin of a coil disposed on the inner side of the primary coil and the secondary coil, and a resin inflow portion is formed at a part of the flange, thereby forming the primary. Even when the interval between the outer periphery of the coil and the inner periphery of the secondary coil is narrow, a highly reliable ignition device capable of reliably filling the mold resin can be realized. In addition, there are limited ignition devices that have two ignition coils in the case to ignite multiple ignitions in order to prevent misfire caused by variations in the air-fuel ratio in lean combustion and stratified combustion and ignition plug smoldering. It is necessary to reduce the size of the case in order to mount it in the space, and since the number of windings wound around each bobbin is reduced, each bobbin becomes smaller, and the distance between the primary coil outer periphery and the secondary coil inner periphery is the case. Since it becomes narrower than the ignition device having one ignition coil inside, the above-described configuration can provide the same or higher effect.

1 is a perspective view of an ignition device according to an embodiment of the present invention. It is BB sectional drawing seen from the arrow (A) direction of the ignition device of FIG. It is a perspective view before the assembly of the primary coil and secondary coil which are the Examples of this invention. It is the perspective view after the assembly of the primary coil and secondary coil which are the Examples of this invention. It is the figure seen from the arrow (C) direction of FIG. It is a perspective view of the primary coil made into the modification of this invention. It is a side view of the secondary spool made into patent document 1. FIG.

Example 1 and Example 2 showing an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view of an ignition device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line BB of the ignition device of FIG. FIG. 3 is a perspective view before assembling the coil and the secondary coil, FIG. 4 is a perspective view after assembling the primary coil and the secondary coil according to the embodiment of the present invention, and FIG. FIG. 5 shows a perspective view, and FIG. 6 shows a perspective view of a primary coil as a modification of the present invention.

1 to 6, the case 50 forming the outer shape of the ignition device 70 is formed by integral molding in a box shape having one opening surface. Further, the case 50 is formed with two case fixing portions 52 for attaching and fixing the ignition device 70 to an engine head (not shown) at two locations, that is, an opening surface of the case 50 and a substantially vertical surface. Further, a high voltage tower 54 for providing a high voltage terminal for supplying a secondary voltage to the ignition plug is formed on the bottom surface of the case 50 so as to protrude into a plug hole formed in the upper part of the engine.

The coil housing portion of the case 50 includes a first ignition coil 80 and a second ignition coil 90, and each of the first ignition coil 80 and the second ignition coil 90 individually includes a plurality of thin plates. An iron core 30 formed by laminating a core, a primary coil 14 in which a primary winding 12 is wound around the outer periphery of a primary bobbin 10 formed of resin on the outer circumference of the iron core 30, and about 50 turns, and The primary coil 14 includes a secondary coil 24 in which a secondary winding 22 is wound around 3000 turns on the outer periphery of a secondary bobbin 20 formed of resin on the outer periphery. Further, flanges 16 for preventing the primary winding 12 from collapsing are formed at both axial ends of the primary bobbin 10.

The flange 16 is formed with a resin inflow portion 18 for improving the filling property of the mold resin 60 filled between the outer periphery of the primary coil 14 and the inner periphery of the secondary bobbin 20, and the resin inflow portion 18 is It is formed in a shape having an open direction, and is formed at four locations on the outer periphery of the flange 16 at intervals of 90 degrees. Further, the resin inflow portion 18 is formed in the flange 16 at both ends of the primary bobbin 10.

A secondary low voltage terminal 46 is provided on the low voltage side of the secondary coil 24, and the primary coil 14 of the first ignition coil 80 and the second ignition coil 90 is electrically connected to the secondary low voltage terminal 46. It is connected to the. Further, a secondary high voltage terminal 48 is provided on the high voltage side of the secondary coil 24, and a case side secondary high voltage terminal 38 is provided on each of the first ignition coil 80 and the second ignition coil 90 on the inner bottom surface of the case 50. The secondary high-voltage terminal 48 of the first ignition coil 80 and the case-side secondary high-voltage terminal 38 are electrically connected, and the secondary high-voltage terminal 48 of the second ignition coil 90 and the case The side secondary high voltage terminal 38 is electrically connected.

In the case 50, an igniter 34 for supplying an ignition signal to the first ignition coil 80 and the second ignition coil 90 is provided in each of the first ignition coil 80 and the second ignition coil 90. In preparation, the igniter 34 is electrically connected to the primary coil 14 of the first ignition coil 80 and the second ignition coil 90. Further, a battery and an ECU, and a connector 32 for supplying a primary voltage or an ignition signal from the ignition device control unit are provided on the side surface of the case 50, one for each of the first ignition coil 80 and the second ignition coil 90. I have.

The connector 32 on the first ignition coil 80 side is electrically connected to the primary coil 14 and the igniter 34 of the first ignition coil 80, and the connector on the second ignition coil 90 side. 32 is electrically connected to the primary coil 14 and the igniter 34 of the second ignition coil 90. Further, a diode group 40 for preventing the secondary voltage of one of the first ignition coil 80 and the second ignition coil 90 from flowing to the other ignition coil is provided on the inner bottom surface of the case 50. Are provided in each of the first ignition coil 80 and the second ignition coil 90.

The diode group 40 includes three diodes, each of which includes a lead wire 44. The lead wires 44 are connected by soldering to electrically connect the respective diodes. is doing. Further, the lead wires 44 on the anode terminal side of the diode group 40 of the first ignition coil 80 and the second ignition coil 90 are coupled together and electrically connected to the high voltage terminal.

The lead wire 44 on the cathode terminal side of the diode group 40 on the first ignition coil 80 side is electrically connected to the case side secondary high voltage terminal 38 on the first ignition coil 80 side, and The lead wire 44 on the cathode terminal side of the diode group 40 on the second ignition coil 90 side is electrically connected to the case side secondary high voltage terminal 38 on the second ignition coil 90 side. Further, a groove portion 56 for embedding the diode group 40 of the first ignition coil 80 and the second ignition coil 90 is formed on the inner bottom surface of the case 50.

In addition, a substantially U-shaped lead wire fixing portion 58 for fixing the lead wire 44 of the diode group 40 of the first ignition coil 80 and the second ignition coil 90 to the groove portion 56 is provided in the groove portion 56. The diodes 40 are formed and fixed at twelve positions in total, one at each end of each diode constituting the diode group 40, and the lead wire 44 insertion opening of the lead wire fixing portion 58 is chamfered. Further, the groove portion 56 is formed to such a depth that the diode group 40 and the lead wire fixing portion 58 do not protrude from the bottom surface of the case 50.

An outer peripheral groove 57 is formed on the inner bottom surface of the case 50. The outer peripheral groove 57 includes the groove portion 56 in which the diode group 40 and the lead wire fixing portion 58 are embedded, the case side secondary high voltage terminal 38, The high voltage terminal is formed so as to surround the entire outer periphery of the lead wire 44. Further, the outer peripheral groove 57 is formed with a width of about one third of the width of the groove portion 56, and the outer peripheral groove 57 is formed with a depth equal to the groove portion 56.

Further, in the case 50, a first partition wall 55a is formed in the first ignition coil 80 in order to prevent the spread of cracks generated between the first ignition coil 80 and the second ignition coil 90, A second partition wall 55b is formed in the second ignition coil 90. Further, the first partition 55a and the second partition 55b are formed on a straight line connecting the first ignition coil 80 and the second ignition coil 90.

Further, the first partition wall 55a seals the iron core crack of the first ignition coil 80 and positions the iron core 30 of the first ignition coil 80 in order to position the iron core 30 of the first ignition coil 80. The second partition wall 55b is disposed so as to be in contact with the outer peripheral surface of the iron core 30, so that the iron core crack of the second ignition coil 90 is sealed and the iron core 30 of the second ignition coil 90 is positioned. The second ignition coil 90 is disposed so as to be in contact with the outer peripheral surface of the iron core 30. Further, the first partition wall 55a and the second partition wall 55b are formed at a height equal to the vertical height of the iron core 30 from the bottom surface of the case 50.

The case 50 is filled with a thermosetting mold resin 60 so as to realize electrical insulation of the ignition device 70 and physical fixation of each member. Further, the secondary voltage output from the first ignition coil 80 and the second ignition coil 90 is supplied from the high voltage terminal to the ignition plug through a conductive member accommodated in the plug hole.

As a modification of the first embodiment, the resin inflow portion 18 may be formed on a bobbin disposed inside one of the primary bobbin 10 and the secondary bobbin 20. The flange 16 may be formed only at one end in the axial direction of the primary bobbin 10 or the secondary bobbin 20. Further, the shape of the resin inflow portion 18 may be arbitrarily changed according to design circumstances such as a shape constituted by a curve, and the formation position and the number of the resin inflow portions 18 may be arbitrarily changed according to design circumstances. Also good.

Further, the resin inflow portion 18 may be formed on one of the flanges 16 formed at both axial ends of the primary bobbin 10 or the secondary bobbin 20. Further, the flange 16 and the resin inflow portion 18 may be formed in either the first ignition coil 80 or the second ignition coil 90 depending on design circumstances.

The shape of the flange 16 may be arbitrarily changed as long as it can prevent the primary winding 12 or the secondary winding 22 from being collapsed. Further, instead of the resin inflow portion 18, a slit 19 that covers one side may be formed, and the shape, number, and position of the slit 19 may be arbitrarily changed according to design circumstances.

Further, the resin inflow portion 18 may be formed on a bobbin of a coil disposed on the outer side of the primary coil 14 and the secondary coil 24. Further, in the first embodiment, a multi-ignition type ignition device having two ignition coils each including the primary coil 14, the secondary coil 24, and the iron core 30 in the case 50 is used. The case 50 may be implemented in an ignition device having one ignition coil in the case 50, or may be implemented in a pen-type ignition device in which the coil housing portion in the case 50 is inserted into the plug hole. .

10: 1 primary bobbin
12: Primary winding
14: Primary coil
16: Flange
18: Resin inflow section
19: Slit
20: Secondary bobbin
22: Secondary winding
24: Secondary coil
30: Iron core
32: Connector
34: Igniter
38: Secondary high-voltage terminal on the case side
40: Diode group
44: Lead wire
46: Secondary low voltage terminal
48: Secondary high-voltage terminal
50: Case
52: Case fixing part
54: High pressure tower
55a: first partition
55b: Second partition
56: Groove
57: Outer groove
58: Lead wire fixing part
60: Mold resin
70: Ignition system
80: First ignition coil
90: Second ignition coil

Claims (5)

A case, a primary coil in which the primary winding is wound around the primary bobbin, a secondary coil in which the secondary winding is wound around the secondary bobbin, and an iron core in the case;
In the ignition device in which the primary coil and the secondary coil are coaxially wound around the iron core,
A flange is formed at least at one end in the axial direction of the bobbin of the coil disposed inside the primary coil and the secondary coil,
An internal combustion engine ignition device characterized in that a resin inflow portion is formed in at least a part of the flange. The ignition device for an internal combustion engine according to claim 1, wherein the resin inflow portion is formed in a shape opened in one direction. The internal combustion engine ignition device according to claim 1 or 2, wherein a slit covering one side is formed instead of the resin inflow portion. The internal combustion engine ignition device according to any one of claims 1 to 3, wherein the resin inflow portion is formed on a bobbin of a coil disposed outside of the primary coil and the secondary coil. The case is provided with two primary coils each having a primary winding wound around a primary bobbin, two secondary coils each having a secondary winding wound around a secondary bobbin, and two ignition coils. The ignition device for an internal combustion engine according to any one of claims 1 to 4.

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