Ignition coil

Abstract

In the ignition coil (2), the protector (16) is provided with a head part (28) exposed to the outside of the internal combustion engine (4), and a cylinder part (30) extending downward from the bottom surface of the head part (28) and inserted into a spark plug hole (6) of the internal combustion engine (4). The ignition coil (2) is provided with an air passage (64) which connects the outside with the spark plug hole (6) of the internal combustion engine (4). When a direction perpendicular to a central axis (Lf) of a mounting hole (20) of a flange portion (14) and a direction from the central axis (Lf) of the mounting hole (20) toward a central axis (Lp) of a protector (16) are taken as a reference direction, a first opening (50) of the air passage (64) is provided in a region on an outer surface of a coil assembly (8) or an outer surface of a head portion (28) located below the flange portion (14). The mounting hole (20) extends in the vertical direction, the center line of the mounting hole (20) when viewed from the reference direction overlaps the center axis (Lf) of the mounting hole (20), and the width of the mounting hole (20) when viewed from the reference direction is the same as the width of the mounting hole (20).

Description

Technical Field

[0001] This specification discloses an ignition coil for an internal combustion engine. Background Art

[0002] The ignition coil for an internal combustion engine includes a coil assembly having a coil generating a high voltage, a protector extending downward from the coil assembly, and a flange having a mounting hole. When the ignition coil is mounted on the internal combustion engine, the lower portion of the protector is inserted into the spark plug hole of the internal combustion engine. Furthermore, a bolt is inserted into the mounting hole of the flange, and the ignition coil is fixed to the internal combustion engine via the bolt.

[0003] When the internal combustion engine is used, the temperature inside the spark plug hole reaches a high temperature. The air inside the spark plug hole expands, and the pressure inside the spark plug hole increases. Japanese Patent Application Laid-Open No. 2010-287485 discloses an ignition device having a communication passage for discharging the air inside the spark plug hole to the outside. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-287485 Summary of the invention Problem that the invention aims to solve

[0005] Internal combustion engines, such as those mounted on vehicles, are sometimes exposed to rainwater or washing water. If such water enters the spark plug hole through the air passage connecting the outside and the inside of the spark plug hole, normal combustion may be impeded. It is required to suppress the intrusion of water into the ignition coil in the spark plug hole.

[0006] An object of the present invention is to provide an ignition coil having an air passage for suppressing water intrusion. Technical means of solving problems

[0007] An ignition coil for an internal combustion engine in one embodiment includes: a coil assembly including a primary coil and a secondary coil; an output portion extending downward from the coil assembly; a protector covering the outer periphery of the output portion and extending downward from the coil assembly; and a flange portion protruding rearward from the coil assembly and having a mounting hole extending vertically through the internal combustion engine. The protector includes a head portion exposed to the outside of the internal combustion engine when the ignition coil is mounted on the internal combustion engine, and a cylindrical portion extending downward from the bottom surface of the head portion and inserted into the spark plug hole of the internal combustion engine. An air passage connecting the outside and the spark plug hole of the internal combustion engine is provided on the ignition coil. When the direction perpendicular to the central axis of the mounting hole and the direction from the central axis of the mounting hole toward the central axis of the protector is taken as the reference direction, the first opening of the airway is arranged in an area on the outer surface of the coil assembly or the outer surface of the head located on the lower side of the flange portion, and is in an area extending in the up-down direction, whose center line when viewed from the reference direction overlaps with the central axis of the mounting hole, and whose width when viewed from the reference direction is the same as the width of the mounting hole. Effects of the Invention

[0008] In the ignition coil of this embodiment, an air passage connecting the outside and the spark plug hole of the internal combustion engine is provided. When the direction perpendicular to the central axis of the mounting hole of the flange portion and the direction from the central axis of the mounting hole toward the central axis of the protector is taken as the reference direction, the first opening of the air passage is provided in the following area: an area on the outer surface of the coil assembly located on the lower side of the flange portion or the outer surface of the head of the protector, and is an area extending in the up-down direction, the center line of which when viewed from the reference direction overlaps with the central axis of the mounting hole, and the width of which when viewed from the reference direction is the same as that of the mounting hole. When the ignition coil is mounted to the internal combustion engine, the bolt passes through the mounting hole. There is a bolt or a positioning portion for positioning the bolt on the front side of the area. Water from the outside is blocked by the bolt or the positioning portion and is difficult to reach the first opening. The ignition coil suppresses the intrusion of water into the air passage. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 (A) is a perspective view showing an ignition coil according to an embodiment. Figure 1 (B) is Figure 1 (A) Cross-sectional view of an ignition coil. Figure 2 It is magnified Figure 1 (B) is a cross-sectional view of a portion of. Figure 3 It is magnified Figure 1 Rear view of a portion of an ignition coil. Figure 4 (A) is Figure 1 Top view of the ignition coil protector. Figure 4 (B) is a bottom view of the protector. Figure 5 It is magnified Figure 2 Cross-sectional view of a portion of. Figure 6 (A) is a rear view showing a portion of an ignition coil according to another embodiment. Figure 6 (B) means Figure 6 (A) A perspective view of a portion of an ignition coil. Figure 7 It is magnified Figure 6 (A) A top view of a portion of an ignition coil protector. Figure 8 (A) is a perspective view showing a portion of an ignition coil according to another embodiment. Figure 8 (B) means Figure 8 (A) a perspective view of a portion of a coil assembly of an ignition coil, Figure 8 (C) means Figure 8 (A) A perspective view of a portion of an ignition coil protector. Fig. 9 This is a perspective view showing a portion of an ignition coil according to another embodiment. Fig.10 (A) is a perspective view showing a portion of an ignition coil according to another embodiment. Fig.10 (B) means Fig.10 (A) a perspective view of a portion of a coil assembly of an ignition coil, Fig.10 (C) means Fig.10 (A) A perspective view of a portion of an ignition coil protector. Fig.11 This is a perspective view showing a portion of an ignition coil according to another embodiment. DETAILED DESCRIPTION

[0010] Hereinafter, preferred embodiments will be described in detail with reference to appropriate drawings.

[0011] Figure 1 (A) is a perspective view showing an ignition coil 2 according to an embodiment. Figure 1 In the figure, arrow X indicates the front of the ignition coil 2. Arrow Y indicates the right direction of the ignition coil 2. Arrow Z indicates the top of the ignition coil 2. Arrow Z indicates the bottom of the ignition coil 2. In addition, the directions "front" and "top" are used in this specification to indicate the relative positional relationship between the components of the ignition coil 2 described later. As long as these relative positional relationships can be expressed, for example, Figure 1 The direction represented by "rear" can be set to "front" or "right".

[0012] Figure 1 (B) is cut perpendicular to the left and right directions Figure 1 (A) is a cross-sectional view of an ignition coil 2. Figure 1 In (B), an internal combustion engine 4 to which the ignition coil 2 is mounted is also shown. The internal combustion engine 4 has a spark plug hole 6, and a portion of the ignition coil 2 is inserted into the spark plug hole 6. Figure 2 In the middle, the enlarged Figure 1 The ignition coil 2 includes a coil assembly 8, a connector portion 10, an output portion 12, a flange portion 14, and a protector 16. Figure 1 (B) and Figure 2 In the figure, the internal structures of the coil assembly 8, the connector portion 10 and the output portion 12 are omitted.

[0013] The coil assembly 8 includes a primary coil, a secondary coil, and an iron core (not shown), and a housing for accommodating them. The primary coil is formed by winding a wire around the iron core, and the secondary coil is formed by winding a wire outside the primary coil. The number of turns of the wire of the secondary coil is much larger than the number of turns of the wire of the primary coil. Thus, by changing the current of the primary coil, a high voltage is generated in the secondary coil.

[0014] The connector 10 is located in front of the coil assembly 8. The connector 10 has an external terminal 18 for inputting a signal from the outside and an igniter (not shown). The igniter is a switch that controls the conduction and disconnection of the current of the primary coil according to the signal input to the external terminal 18. The operation of the ignition coil 2 is controlled according to the signal input to the external terminal 18.

[0015] like Figure 2 As shown, the output portion 12 is located below the coil assembly 8. The output portion 12 is in the shape of a tube extending downward from the coil assembly 8. The high voltage generated by the secondary coil is supplied to the spark plug mounted on the internal combustion engine 4 through the output portion 12.

[0016] The flange 14 protrudes toward the rear of the coil assembly 8. The flange 14 extends in a direction perpendicular to the direction in which the output portion 12 extends. The flange 14 is formed integrally with the housing of the coil assembly 8. A mounting hole 20 is provided in the flange 14 and passes through the flange 14. Figure 1 (B) and Figure 2 As shown, there is a positioning portion 22 of the internal combustion engine 4 at the lower side of the mounting hole 20. The positioning portion 22 has a mounting hole 24. When the ignition coil 2 is mounted on the internal combustion engine 4, the bolt 25 passes through the mounting hole 20 of the flange portion 14 and the mounting hole 24 of the positioning portion 22. Figure 1 The bolt 25 is also shown in (B). The ignition coil 2 is fixed to the internal combustion engine 4 by the bolt 25. Figure 2The bolt 25 is omitted.

[0017] In this embodiment, the connector portion 10 is located in front of the coil assembly 8, and the flange portion 14 is located behind the coil assembly 8. The flange portion 14 is opposite to the connector portion 10 across the coil assembly 8. The connector portion 10 and the flange portion 14 may also be arranged along mutually perpendicular sides of the coil assembly 8. For example, the connector portion 10 is located on the right side of the coil assembly 8, and the flange portion 14 is located behind the coil assembly 8. The connector portion 10 may also be located in other directions relative to the flange portion 14. In this specification, regardless of the positional relationship between the connector portion 10 and the flange portion 14, the shape of the coil assembly 8, etc., the direction in which the flange portion 14 exists relative to the coil assembly 8 is the "rear" of the ignition coil 2. The direction in which the output portion extends relative to the coil assembly 8 is the "below" of the ignition coil 2.

[0018] The protector 16 is located below the coil assembly 8. The protector 16 has a hole that penetrates the inside. The protector 16 covers the output portion 12. The protector 16 covers the outer periphery of the output portion 12. The protector 16 is made of a rubber composition. As a preferred material of the protector 16, silicone rubber can be exemplified. The protector 16 has a head 28 and a barrel 30.

[0019] The head 28 is annular. The head 28 has a hole 32 that passes through the center. The output portion 12 is inserted into the hole 32 of the head 28. The output portion 12 passes through the hole 32 of the head 28 and extends further downward from the head 28. The inner peripheral surface of the hole 32 of the head 28 is in contact with the outer peripheral surface of the output portion 12 without a gap. The upper surface 34 of the head 28 is in contact with the bottom surface 36 of the coil assembly 8.

[0020] like Figure 1 (B) and Figure 2 As shown, when the ignition coil 2 is mounted on the internal combustion engine 4, the head 28 is exposed to the outside from the internal combustion engine 4. The head 28 covers the opening of the spark plug hole 6 of the internal combustion engine 4. The outer diameter of the head 28 is larger than the inner diameter of the spark plug hole 6. The inner diameter of the head 28 is smaller than the inner diameter of the spark plug hole 6. Figure 2 As shown, a fitting groove 40 is provided on the bottom surface 38 of the head 28. The fitting groove 40 is annular (refer to Figure 4 (B)). An annular protrusion 42 is provided on the upper surface of the internal combustion engine 4. Figure 2 As shown, the protrusion 42 of the internal combustion engine 4 is fitted into the fitting groove 40 of the head 28. The head 28 functions as a cap that closes the opening of the spark plug hole 6.

[0021] The barrel 30 extends downward from the head 28. In this embodiment, the barrel 30 is formed integrally with the head 28. The barrel 30 and the head 28 may also be formed separately. The barrel 30 has a hole 44 that is continuous with the hole 32 of the head 28. The outer diameter of the barrel 30 is smaller than the outer diameter of the head 28. The outer diameter of the barrel 30 is smaller than the inner diameter of the spark plug hole 6. Figure 1 (B) and Figure 2 As shown, when the ignition coil 2 is mounted on the internal combustion engine 4, the cylindrical portion 30 is inserted into the spark plug hole 6. At this time, there is a gap between the outer peripheral surface 46 of the cylindrical portion 30 and the inner peripheral surface 48 of the internal combustion engine 4 forming the spark plug hole 6.

[0022] exist Figure 2 In FIG. 1 , a dashed line Lf indicates the center axis of the mounting hole 20. A dashed line Lp indicates the center axis of the protector 16. The center axis Lp of the protector 16 is a line that passes through the center of the hole 32 of the head 28 at a position on the bottom surface 38 of the head 28 and extends in the vertical direction. Figure 2 In FIG. 1 , arrow D indicates a direction perpendicular to the center axis Lf and from the center axis Lf toward the center line Lp. This direction is referred to as a reference direction D. In this embodiment, the reference direction D coincides with the direction X from the rear to the front of the ignition coil 2 .

[0023] Figure 3 FIG. 2 shows a portion of the ignition coil 2 viewed from a reference direction D. In this embodiment, Figure 3 2 is a rear view of the ignition coil 2. In this figure, the center axis Lf and the center axis Lp overlap. Figure 3 In FIG. 1 , symbol R represents an area on the outer surface of the coil assembly 8 and the outer surface of the head 28 located on the lower side of the flange 14. The area R extends from the lower end of the flange 14 to the lower end of the head 28 in the up-down direction. When viewed from the reference direction D, the center line Lr of the area R overlaps with the center axis Lf of the mounting hole 20, and the width of the area R is the same as the width of the mounting hole 20. The area R is referred to as a "configuration area R".

[0024] The ignition coil 2 has an opening 50 in the arrangement region R. Here, “having an opening in the arrangement region R” means that a part or all of the opening 50 is located in the arrangement region R. As described later, the opening 50 is the first opening 50 of the air passage of the ignition coil 2. Figure 3 In the embodiment of the present invention, the first opening 50 is located at the end of the coil assembly 8 of the head 28. Figure 3 In the embodiment, the first opening 50 is located on the center line Lr.

[0025] Figure 4 (A) is a top view of the protector 16. In this figure, the upper surface 34 of the head 28 is shown. Figure 4(B) is a bottom view of the protector 16. In this figure, the bottom surface 38 of the head 28 and the tube 30 are shown. Figure 5 It is a cross-sectional view showing the vicinity of the head 28 in an enlarged manner.

[0026] like Figure 4 (A) and Figure 5 As shown, the upper surface 34 of the head 28 is provided with a lead-out groove 52 extending from the first opening 50, a first annular groove 54 and a second annular groove 56. Figure 4 As shown in (A), a connecting groove 58 is also provided on the upper surface 34 of the head 28. The lead-out groove 52 connects the first opening 50 and the first annular groove 54. The connecting groove 58 connects the first annular groove 54 and the second annular groove 56. Figure 4 As shown in (A), an opening 59 of a hole is provided at the bottom of the second annular groove 56. Figure 4 As shown in (B), an opening 60 of a hole is provided on the bottom surface 38 of the head 28. Figure 5 As shown, there is a vent hole 62 that passes through from the bottom of the second annular groove 56 to the bottom surface 38 of the head 28. The opening 60 provided on the bottom surface 38 of the head 28 is the second opening 60 of the air passage. In other words, the ignition coil 2 has an air passage 64, which passes from the first opening 50 through the lead-out groove 52, the first annular groove 54, the connecting groove 58, the second annular groove 56 and the vent hole 62 to the second opening 60. Figure 4 (A) and Figure 5 In FIG. 6 , the airway 64 is indicated by a dotted line.

[0027] like Figure 4 As shown in (B), the fitting groove 40 provided on the bottom surface 38 of the head 28 is annular. The second opening 60 is provided on the inner side of the fitting groove 40 and on the outer side of the cylinder 30. Figure 5 As shown, the second opening 60 is located between the cylinder portion 30 and the inner peripheral surface of the internal combustion engine 4 constituting the spark plug hole 6. The second opening 60 is connected to the spark plug hole 6. That is, the air passage 64 of the ignition coil 2 connects the outside and the spark plug hole 6.

[0028] The effects of this embodiment will be described below.

[0029] In the ignition coil 2 of this embodiment, an air passage 64 is provided for connecting the outside and the spark plug hole 6 of the internal combustion engine 4. The first opening 50 of the air passage 64 is provided in the configuration area R. When the ignition coil 2 is mounted on the internal combustion engine 4, the bolt 25 passes through the mounting hole 20 of the flange portion 14. The positioning portion 22 of the positioning bolt 25 is located below the mounting hole 20. The outer diameter of the positioning portion 22 is larger than the inner diameter of the mounting hole 20. The positioning portion 22 is located on the front side of the configuration area R, and the flange portion 14 is located on the upper side of the configuration area R. Water from the outside is blocked by the positioning portion 22 and the flange portion 14, and therefore it is difficult to reach the first opening 50. In this ignition coil 2, the intrusion of water into the air passage 64 is suppressed.

[0030] In addition, sometimes the positioning portion 22 does not exist, and the bolt 25 passing through the mounting hole 20 extends to the upper surface of the internal combustion engine. In this case, the bolt 25 is located on the front side of the configuration area R. Water from the outside is blocked by the bolt 25. By locating the first opening 50 in the configuration area R, water from the outside is blocked by the positioning portion 22 or the bolt 25.

[0031] exist Figure 3 In FIG. 5 , the symbol Wr represents the width of the configuration area R. From the viewpoint of effectively suppressing the intrusion of water into the air passage 64, the distance between the center of the first opening 50 and the center line Lr is preferably 30% or less of the width Wr, more preferably 20% or less of the width Wr, and further preferably 10% or less of the width Wr. Most preferably, the center of the first opening 50 is located on the center line Lr.

[0032] Preferably, the first opening 50 is located at the end of the head 28 on the coil assembly 8 side in the configuration area R. In this way, the air passage 64 can be formed by a groove provided on the upper surface 34 of the head 28 and a vent hole 62 that penetrates from the bottom of the groove to the bottom surface 38 of the head 28. In this embodiment, the air passage 64 is formed by the lead-out groove 52, the first annular groove 54, the connecting groove 58 and the second annular groove 56, and the vent hole 62. The formation of the air passage 64 does not require the provision of a hole extending in the horizontal direction inside the head 28 or the coil assembly 8. This makes it easy to manufacture the ignition coil 2.

[0033] Preferably, the second opening 60 is located on the bottom surface 38 of the head 28. By locating the second opening 60 on the bottom surface 38 of the head 28, the length of the vent hole 62 can be shortened. This makes it easier to manufacture the ignition coil 2.

[0034] The position of the second opening 60 is not limited to the bottom surface 38 of the head 28. For example, the second opening 60 may be provided on the outer peripheral surface 46 of the barrel 30. In this case, for example, the opening of the second annular groove and the vent hole provided in the second annular groove is located above the barrel 30. The vent hole penetrates the head 28 from the bottom of the second annular groove, and then penetrates a part of the barrel 30, and extends to the outer peripheral surface 46 of the barrel 30. The second opening 60 only needs to be provided at a position connected to the spark plug hole 6.

[0035] Figure 6 (A) is a rear view showing a portion of an ignition coil 70 according to another embodiment. Figure 6 (B) is a perspective view showing a portion of the ignition coil 70. Figure 6 (A) and Figure 6 As shown in (B), the ignition coil 70 includes a coil assembly 72, a flange portion 74, and a protector 76. In the ignition coil 70, a protective member 80 is provided around the first opening 78. In addition to the protective member 80, the ignition coil 70 is Figure 1 The same as the ignition coil 2.

[0036] Figure 7 Yes means Figure 6 8 is a top view of a portion of the head 82 of the protector 76. In this embodiment, the protective member 80 protrudes from the side 83 of the head 82. The protective member 80 is located on both sides of the side of the first opening 78 (circumferential direction of the head 82). In this embodiment, the protective member 80 is composed of a first portion 80a located on one side of the first opening 78 and a second portion 80b located on the other side of the first opening 78. The first portion 80a and the second portion 80b are respectively columnar.

[0037] exist Figure 7 , a cross section 88 of the bolt 86 is also shown when a bolt 86 having an outer diameter equal to the inner diameter of the mounting hole 84 and extending to the bottom of the first opening 78 passes through the mounting hole 84 of the flange portion 74. In fact, a positioning portion 22 of the internal combustion engine 4 having an outer diameter larger than that of the bolt 86 exists on the front side of the mounting hole 84. That is, the cross section 88 is the smallest cross section of the member that can exist on the front side of the first opening 78. Figure 7In the figure, the dotted line V1 is a tangent to the outer peripheral surface of the bolt 86 passing through the corner of the first portion 80a on the first opening 78 side, and the dotted line V2 is a tangent to the outer peripheral surface of the bolt 86 passing through the corner of the second portion 80b on the first opening 78 side. Neither the tangent lines V1 nor V2 reaches the first opening 78. That is, at the same upper and lower positions as the first opening 78, when the ignition coil 70 is observed from any direction perpendicular to the upper and lower directions, the first opening 78 is hidden behind the bolt 86 or the protective member 80. In this specification, this is referred to as "the first opening 78 is in a hidden state". In other words, the height of the protective member 80 (in this embodiment, the height of each of the first portion 80a and the second portion 80b) is determined in such a way that the first opening 78 is in a hidden state.

[0038] The ignition coil 70 of this embodiment has guards 80 located on both sides of the first opening 78 and protruding from the side surfaces 83 of the head 82. The guards 80 effectively prevent water from the outside from reaching the first opening 78 from the side. In the ignition coil 70, the intrusion of water into the air passage is suppressed.

[0039] As described above, the height of the guard 80 is preferably determined so that the first opening 78 is hidden. Thus, the guard 80 more effectively prevents water from the outside from reaching the first opening 78. In the ignition coil 70, the intrusion of water into the air passage is suppressed.

[0040] The height of the guard 80 may not be determined so that the first opening 78 is hidden. The height of the guard 80 may be lower or higher than the height determined so that the first opening 78 is hidden. However, the height of the guard 80 must be determined so that it does not contact the positioning portion 22.

[0041] The shape of the protection member 80 is not limited to Figure 7 The shape shown. The thickness of the first part 80a and the second part 80b may also become thinner as they extend outward. The first part 80a and the second part 80b may be arc-shaped protruding from the side 83 of the head 82, respectively. The shield 80 may also have a third part protruding from the bottom of the first opening 78 and connecting the first part 80a and the second part 80b. The shield 80 may be an annular shape protruding from the side 83 of the head 82 and the side of the coil assembly 72 and surrounding the first opening 78. The shield 80 may also be other shapes. The shield 80 only needs to protrude from the side 83 of the head 82 on both sides of the side of the first opening 78.

[0042] Figure 8 (A) is a perspective view showing a portion of an ignition coil 90 according to another embodiment. Figure 8 (B) is a perspective view when the protector 94 is removed from the ignition coil 90. Figure 8 (C) is a perspective view of the protector 94 removed. Figure 8 (B) shows the coil assembly 92 and a part of the output portion 96 of the ignition coil 90 .

[0043] like Figure 8 As shown in (B) of FIG. 1 , in the ignition coil 90, a recessed portion 100 recessed upward is provided at the end portion of the side surface 99 of the bottom surface 98 of the coil assembly 92. Figure 8 As shown in (C), a protrusion 106 extending upward is provided at the end of the side surface 105 of the upper surface 104 of the head 102 of the protector 94. Figure 8 As shown in (A), when the coil assembly 92 and the protector 94 are assembled, the protrusion 106 is engaged with the recess 100. In addition to the recess 100 and the protrusion 106 engaged therewith, the ignition coil 90 is Figure 1 The same as the ignition coil 2.

[0044] In the ignition coil 90, the protrusion 106 of the head 102 is fitted into the recess 100 of the coil assembly 92, so that when the coil assembly 92 and the protector 94 are assembled, the protector 94 is prevented from rotating relative to the coil assembly 92. As a result, the first opening 108 can be positioned with high precision relative to the coil assembly 92. Since the shell and the flange portion 110 of the coil assembly 92 are formed as one body, the first opening 108 can be positioned with high precision relative to the center axis Lf of the mounting hole 112 of the flange portion 110. In the ignition coil 90, the first opening 108 can be arranged on the center line Lr of the arrangement area R with high precision. In the ignition coil 90, the intrusion of water into the air passage is suppressed.

[0045] Although not shown in the figure, in another embodiment of the ignition coil, a protrusion extending downward is provided at the end of the side side of the bottom surface of the coil assembly, and a recessed portion recessed downward is provided at the end of the side side of the upper surface of the head of the protector. When the coil assembly and the protector are assembled, the protrusion fits into the recess. In addition to the recess and the protrusion fitting therein, the ignition coil has a Figure 1 The same is true for the ignition coil 2. In this ignition coil, when the coil assembly and the protector are assembled, the protector is prevented from rotating relative to the coil assembly.

[0046] Fig. 91 is a perspective view showing a portion of an ignition coil 120 according to another embodiment. In this ignition coil 120, a protrusion 130 provided on the upper side of a head 128 of a protector 126 is engaged with a recess 124 on the bottom surface of a coil assembly 122. In this embodiment, the protrusion 130 of the head 128 and the recess 124 of the coil assembly 122 are provided in a configuration region R. A first opening 132 is provided on a side surface 131 of the protrusion 130 of the head 128. In this ignition coil 120, except that the protrusion 130 of the head 128 and the recess 124 of the coil assembly 122 are provided in a configuration region R and the first opening 132 is provided on a side surface 131 of the protrusion 130, Figure 8 The ignition coil 90 is the same.

[0047] In the ignition coil 120, a first opening 132 is provided on a side surface 131 of a protrusion 130 of a head 128 that fits into a recess 124 of a coil assembly 122. Therefore, the first opening 132 can be positioned with high precision relative to the coil assembly 122. The first opening 132 can be positioned with high precision relative to a center axis Lf of a mounting hole 136 of a flange portion 134. In the ignition coil 120, intrusion of water into the air passage is suppressed.

[0048] Fig.10 (A) is a perspective view showing a portion of an ignition coil 140 according to another embodiment. Fig.10 (B) is a perspective view when the protector 144 is removed from the ignition coil 140. Fig.10 (C) is a perspective view of the protector 144 removed. Fig.10 (B) shows the coil assembly 142 and a part of the output portion 146 of the ignition coil 140 .

[0049] like Fig.10 As shown in (A), in this embodiment, the first opening 148 is provided on the side 143 of the coil component 142. The first opening 148 is located at the end of the side 143 of the coil component 142 on the head 150 side of the protector 144. Fig.10 As shown in (B), a lead-out groove 154 extending from the first opening 148 is formed on the bottom surface 152 of the coil assembly 142. Although not shown in the figure, Figure 4 Similarly, a first annular groove, a connecting groove and a second annular groove are provided on the upper surface 156 of the head 150. In addition, a vent hole extending from the bottom of the second annular groove to the bottom surface 158 of the head 150 is provided. The lead-out groove 154 provided on the bottom surface 152 of the coil assembly 142 is connected to the first annular groove. In this embodiment, an airway is formed by the lead-out groove 154, the first annular groove, the connecting groove and the second annular groove, and the vent hole.

[0050] In this embodiment, the first opening 148 is located at the end of the head 150 side of the side surface 143 of the coil assembly 142 in the configuration region R. In this way, an air passage can be formed by the groove provided on the bottom surface 152 of the coil assembly 142, the groove provided on the upper surface 156 of the head 150, and the vent hole penetrating from the bottom of the groove to the bottom surface 158 of the head 150. To form the air passage, it is not necessary to provide a hole extending in the horizontal direction inside the head 150 or the coil assembly 142. This makes it easy to manufacture the ignition coil 140.

[0051] In this embodiment, the first opening 148 is provided on the side surface 143 of the coil assembly 142. The position of the first opening 148 relative to the central axis Lf of the mounting hole 162 of the flange portion 160 is not affected by the rotation of the protector 144 relative to the coil assembly 142. The first opening 148 can be positioned with high precision relative to the central axis Lf of the mounting hole 162 of the flange portion 160. In this ignition coil 140, the first opening 148 can be arranged on the center line Lr of the arrangement region R with high precision. In this ignition coil 140, the intrusion of water into the air passage is suppressed.

[0052] Although not shown in the figure, in another embodiment of the ignition coil, a protrusion extending downward is provided at the end of the side side of the bottom surface of the coil assembly, a recessed portion recessed downward is provided at the end of the side side of the upper surface of the head of the protector, and the first opening is provided on the side of the protrusion of the coil assembly. When the coil assembly and the protector are assembled, the protrusion is engaged with the recess. In addition to the recess and the protrusion engaged with the recess, and the first opening is provided on the side of the protrusion, the ignition coil and the protector are Fig.10 The ignition coil 140 is the same.

[0053] Fig.11 1 is a perspective view showing a portion of an ignition coil 170 according to another embodiment. In the ignition coil 170, the first opening is located at the end of the head 178 side of the protector 176 of the side surface 178 of the coil assembly 172 in the configuration region R. A guard 174 is provided around the first opening. In addition to the guard 174 being provided on the coil assembly 172, the ignition coil 170 is similar to the ignition coil 170. Fig.10 The ignition coil 140 is the same.

[0054] In this embodiment, the shield 174 protrudes from the side 178 of the coil assembly 172. The shield 174 is located on both sides of the first opening. In this embodiment, the shield 174 is composed of a first portion 174a located on one side of the first opening and a second portion 174b located on the other side of the first opening.

[0055] The shape of the protective member 174 is not limited to Fig.11The shape shown. The first part 174a and the second part 174b can be arc-shaped protruding from the side 178 of the coil assembly 172 respectively. The protective member 174 can also have a third part protruding from the top of the first opening and continuous with the first part 174a and the second part 174b. The protective member 174 can also be a ring-shaped protruding from the side 178 of the coil assembly 172 and the side 180 of the head 178 and surrounding the first opening. The protective member 174 can also be other shapes. The protective member 174 can protrude from the side 178 of the coil assembly 172 on both sides of the first opening.

[0056] In the above-mentioned embodiment, the first opening is arranged on any one of the side of the head and the side of the coil assembly. The first opening can be arranged across the side of the head and the side of the coil assembly. In this case, the upper surface of the head is provided with a lead-out groove extending from the first opening, and the lower surface of the coil assembly is provided with a lead-out groove extending from the first opening.

[0057] As described above, according to the present embodiment, the intrusion of water into the air passage of the ignition coil is suppressed. This clearly shows the superiority of the present embodiment.

[0058] [Public Project] The following items are disclosures of preferred embodiments.

[0059] [Project 1] An ignition coil is an ignition coil for an internal combustion engine, comprising: a coil assembly comprising a primary coil and a secondary coil; an output portion extending downward from the coil assembly; A protector covering an outer periphery of the output portion and extending downward from the coil assembly; and a flange portion, which protrudes rearward from the coil assembly and has a mounting hole penetrating vertically, The protector includes a head portion exposed to the outside of the internal combustion engine when the ignition coil is mounted on the internal combustion engine, and a cylindrical portion extending downward from a bottom surface of the head portion and inserted into a spark plug hole of the internal combustion engine. The ignition coil is provided with an air passage connecting the outside and the spark plug hole of the internal combustion engine. When a direction perpendicular to the central axis of the mounting hole and a direction from the central axis of the mounting hole toward the central axis of the protector is taken as a reference direction, The first opening of the airway is arranged in an area on the outer surface of the coil assembly or the outer surface of the head located on the lower side of the flange portion, and is an area extending in the up-down direction, wherein the center line when viewed from the reference direction overlaps with the center axis of the mounting hole, and the width when viewed from the reference direction is the same as the width of the mounting hole.

[0060] [Project 2] An ignition coil according to item 1, wherein A second opening of the airway is provided on the bottom surface of the head.

[0061] [Item 3] The ignition coil according to item 1 or 2, wherein: On both sides of the first opening, guards are provided that protrude from the side surfaces of the head or the side surfaces of the coil assembly.

[0062] [Item 4] The ignition coil according to item 3, wherein: The height of the protective member is determined as follows: when a bolt having an outer diameter identical to an inner diameter of the mounting hole and extending to the bottom of the first opening is installed in the mounting hole, when the ignition coil is observed from any direction perpendicular to the up and down directions at the same up and down positions as the first opening, the first opening is hidden behind the rod body or the protective member.

[0063] [Item 5] An ignition coil according to any one of items 1 to 4, wherein: A protrusion extending upward from the upper surface is provided at an end portion of a side surface of the upper surface of the head. A recessed portion into which the protrusion fits is provided on the bottom surface of the coil assembly.

[0064] [Item 6] The ignition coil according to item 5, wherein: The first opening is formed on a side surface of the protrusion.

[0065] [Item 7] An ignition coil according to any one of items 1 to 6, wherein: The first opening is provided at an end portion of a side surface of the head portion on the side of the coil assembly. The air passage is formed by a groove provided on the upper surface of the head and connected to the first opening, and a hole extending from the bottom of the groove to the second opening.

[0066] [Item 8] An ignition coil according to any one of items 1 to 7, wherein: The first opening is provided at an end portion of a side surface of the coil component on the head side.

[0067] [Item 9] The ignition coil according to item 8, wherein: A second opening of the airway is provided on the bottom surface of the head. The air passage is formed by a first groove provided on the bottom surface of the coil assembly and connected to the first opening, a second groove provided on the upper surface of the head and connected to the first groove, and a hole extending from the bottom of the second groove to the second opening.

[0068] [Item 10] A composite of an ignition coil and an internal combustion engine, comprising: An ignition coil according to any one of items 1 to 9, and an internal combustion engine having a spark plug hole into which the cylindrical portion of the protector of the ignition coil is inserted. Possibility of Industrial Application

[0069] The ignition coil described above is used in various internal combustion engines. Explanation of symbols

[0070] 2. 70, 90, 120, 140, 170… ignition coil 4…Internal combustion engine 6…Spark plug hole 8, 72, 92, 122, 142, 172…Coil assembly 10…Connector 12, 96, 146…output 14, 74, 110, 134, 160… flange 16, 76, 94, 126, 144, 176... Protector 20, 84, 112, 136, 162… Mounting holes on flange 22…Positioning unit 24…Mounting hole of positioning part 28, 82, 102, 128, 150, 178…head 30…Cylinder 32…Hole in the head 34, 104, 156… Upper surface of the head 36, 98… Bottom of coil assembly 38, 158… bottom of the head 40…fitting groove 42…Protrusion of internal combustion engine 44…Hole in the barrel 46…Outer circumference of the cylinder 48…Inner Surface 50, 78, 108, 132, 148…First opening 52, 154…lead out slot 54…First ring groove 56…Second ring groove 58…Connection slot 60…Second opening 62…Vent 64…Airway 80, 174…Protective parts 83, 105, 180…side of the head 25, 86…bolts 88…Section 99, 143, 178…Side view of coil assembly 100, 124… concave part 106, 130…protrusions on the head 131…side of the head protrusion.

Claims

1. An ignition coil, which is an ignition coil for an internal combustion engine, characterized in that: have: A coil assembly including a primary coil and a secondary coil; an output portion extending downward from the coil assembly; a protector covering the outer periphery of the output portion and extending downward from the coil assembly; and a flange portion protruding rearward from the coil assembly and having a mounting hole extending vertically therethrough, The protector includes a head portion exposed to the outside of the internal combustion engine when the ignition coil is mounted on the internal combustion engine, and a cylindrical portion extending downward from a bottom surface of the head portion and inserted into a spark plug hole of the internal combustion engine. The ignition coil is provided with an air passage connecting the outside and the spark plug hole of the internal combustion engine. When a direction perpendicular to the central axis of the mounting hole and a direction from the central axis of the mounting hole toward the central axis of the protector is taken as a reference direction, The first opening of the airway is arranged in an area on the outer surface of the coil assembly or the outer surface of the head located on the lower side of the flange portion, and is an area extending in the up-down direction, wherein the center line when viewed from the reference direction overlaps with the center axis of the mounting hole, and the width when viewed from the reference direction is the same as the width of the mounting hole.

2. The ignition coil according to claim 1, characterized in that: A second opening of the airway is provided on the bottom surface of the head.

3. The ignition coil according to claim 1 or 2, characterized in that: On both sides of the first opening, guards are provided that protrude from the side surfaces of the head or the side surfaces of the coil assembly.

4. The ignition coil according to claim 3, characterized in that: The height of the protective member is determined as follows: when a bolt having an outer diameter identical to an inner diameter of the mounting hole and extending to the bottom of the first opening is installed in the mounting hole, when the ignition coil is observed from any direction perpendicular to the up and down directions at the same up and down positions as the first opening, the first opening is hidden behind the rod body or the protective member.

5. The ignition coil according to any one of claims 1 to 4, characterized in that: A protrusion extending upward from the upper surface is provided at an end portion of a side surface of the upper surface of the head. A recessed portion into which the protrusion fits is provided on the bottom surface of the coil assembly.

6. The ignition coil according to claim 5, characterized in that: The first opening is formed on a side surface of the protrusion.

7. The ignition coil according to any one of claims 1 to 6, characterized in that: The first opening is provided at an end portion of a side surface of the head portion, on the side of the coil assembly. The air passage is formed by a groove provided on the upper surface of the head and connected to the first opening, and a hole extending from the bottom of the groove to the second opening.

8. The ignition coil according to any one of claims 1 to 7, characterized in that: The first opening is provided at an end portion of a side surface of the coil component on the head side.

9. The ignition coil according to claim 8, characterized in that: A second opening of the airway is provided on the bottom surface of the head. The air passage is formed by a first groove provided on the bottom surface of the coil assembly and connected to the first opening, a second groove provided on the upper surface of the head and connected to the first groove, and a hole extending from the bottom of the second groove to the second opening.

10. A composite of an ignition coil and an internal combustion engine, characterized in that: have: An ignition coil according to any one of claims 1 to 9, and an internal combustion engine having a spark plug hole into which the cylindrical portion of the protector of the ignition coil is inserted.

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