JP2019173607A - Ignition coil device - Google Patents

Abstract

To connect a coil spring and an ignition plug accurately.SOLUTION: An ignition coil device 18 comprises: an ignition coil 20 that generates a voltage to be supplied to an ignition plug 17; a coil spring 22 that conducts the ignition plug and the ignition coil; and a casing 21 that has a holding part 21d holding the coil spring, and houses the coil spring. The coil spring has a small diameter part 22a having a first outer diameter and connected to the ignition plug, and a first large-diameter part 22b having a second outer diameter larger than the first outer diameter and disposed closer to the ignition plug than the holding part.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an ignition coil device.

  Patent Document 1 discloses an ignition device in which an ignition plug, an ignition coil, and a coil spring that electrically connects the ignition plug and the ignition coil are linearly arranged.

JP2013-204430A

  However, various components (for example, injectors, camshafts, cam caps, etc.) constituting the engine are provided around the ignition device. When the ignition device is linearly arranged, Interference with the ignition device may occur. When the ignition device interferes with these components, the ignition device is arranged in a curve by inserting the ignition plug into the ignition plug while bending (deforming) the casing. However, when the ignition device is arranged in a curve, the coil spring accommodated in the casing extends substantially linearly without following the bending of the casing, and the connection between the coil spring and the spark plug is normal. There was a case that could not be done.

  Accordingly, an object of the present invention is to provide an ignition coil device that can connect a coil spring and a spark plug with high accuracy.

  In order to solve the above-described problems, an ignition coil device according to the present invention holds an ignition coil that generates a voltage to be supplied to an ignition plug, a coil spring that electrically connects the ignition plug and the ignition coil, and the coil spring. And a casing for accommodating the coil spring, the coil spring having a first outer diameter, a small diameter portion connected to the spark plug, and a first larger diameter than the first outer diameter. A first large-diameter portion having two outer diameters and disposed closer to the spark plug than the holding portion.

  The coil spring has a third outer diameter that is larger than the first outer diameter, and has a second large-diameter portion that is disposed closer to the ignition coil than the holding portion. You may have a projection part which has an internal diameter larger than an outer diameter and smaller than the said 3rd outer diameter.

  The holding portion may have a protrusion formed integrally with the small diameter portion.

  The first large diameter portion may be provided between the holding portion and a separation position that is a predetermined distance away from a connection end of the coil spring connected to the ignition plug toward the ignition coil.

  According to the present invention, the coil spring and the spark plug can be accurately connected.

It is a front view of an engine. It is the schematic which shows the structure of an engine. It is the schematic which shows the structure of the ignition plug and ignition coil apparatus of this embodiment. It is the perspective view which looked at the ignition coil device attached to the cylinder head from above. FIG. 5 is a view taken in the direction of arrow V in FIG. 4. It is a figure for demonstrating attachment of an ignition coil apparatus. It is a schematic enlarged view of a coil spring and a terminal part. It is a schematic enlarged view which shows the state in which the coil spring and the terminal part were connected. It is the schematic which shows the structure of the ignition coil apparatus in a modification.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a front view of the engine 1. In the following, the traveling direction of the vehicle is the forward direction, the backward direction of the vehicle is the backward direction, the right side with respect to the traveling direction of the vehicle is the right direction, the left side with respect to the traveling direction of the vehicle is the left direction, The direction and the vertically downward direction will be described as the downward direction. In FIG. 1, the upper side is the upward direction of the vehicle, and the lower side is the downward direction of the vehicle. In FIG. 1, the cylinder head 2 in the right direction and the vicinity thereof are shown in cross section for easy understanding.

  As shown in FIG. 1, the engine 1 is a horizontally opposed engine. That is, the engine 1 is provided with cylinder blocks 4 in the left direction and the right direction with a crankshaft 3 extending in the front-rear direction of the vehicle as a boundary, and the axis of the cylinder bore 5 formed in the cylinder block 4 is horizontal. It is placed on the vehicle body so that Each cylinder block 4 is formed with two cylinder bores 5 in the front-rear direction. In addition, horizontal is not necessarily limited to only horizontal, but may be substantially horizontal.

  FIG. 2 is a schematic diagram showing the configuration of the engine 1. In FIG. 2, an injector 16 to be described later is shown by cross hatching, and the illustration of the internal structure is omitted. As shown in FIG. 2, a piston 6 is slidably disposed in the cylinder bore 5, and the piston 6 is connected to the crankshaft 3 via a connecting rod 7. In the engine 1, the space surrounded by the cylinder bore 5, the cylinder head 2, and the crown surface of the piston 6 becomes the combustion chamber 8.

  The cylinder head 2 is made of, for example, an aluminum alloy. An intake port 9 and an exhaust port 10 are formed in the cylinder head 2. In the cross section different from FIG. 2, the intake port 9 and the exhaust port 10 communicate with the combustion chamber 8. Further, the cylinder head 2 is provided with an intake valve 11 for opening and closing the intake port 9 and an exhaust valve 12 for opening and closing the exhaust port 10.

  The intake valve 11 is disposed in the cylinder head 2 so that the tip (umbrella) is positioned between the intake port 9 and the combustion chamber 8, and is moved by the cam mechanism 13 a to communicate the intake port 9 with the combustion chamber 8. And close. The exhaust valve 12 is disposed in the cylinder head 2 so that the tip (umbrella) is positioned between the exhaust port 10 and the combustion chamber 8, and is moved by the cam mechanism 13 b to communicate the exhaust port 10 with the combustion chamber 8. And close.

  Further, a hole 14 is formed in the cylinder head 2. An ignition device 15 and an injector 16 are accommodated in the hole 14. The ignition device 15 includes an ignition plug 17 and an ignition coil device 18. The spark plug 17 is disposed at a position (right side in FIG. 2) whose height in the vertical direction is lower than that of the injector 16. The hole 14 is provided with two communicating portions 14 a and 14 b that are holes communicating with the combustion chamber 8 at different positions in the vertical direction. The communication portion 14a whose position in the vertical direction is low is inclined to the cylinder head 2 so as to incline toward the exhaust port 10 (downward in the vertical direction) toward the direction away from the combustion chamber 8 (rightward) with respect to the horizontal direction. Formed. The communication portion 14b having a high vertical position is inclined to the cylinder head 2 so as to be inclined toward the intake port 9 side (vertical upper side) toward the direction away from the combustion chamber 8 (right direction) with respect to the horizontal direction. It is formed. The leading end of the spark plug 17 is inserted into the communicating portion 14a, and the leading end of the injector 16 is inserted into the communicating portion 14b. The tip of the injector 16 is located near the center of the combustion chamber 8 (so-called center injection).

  The fuel gallery 23 is a pipe through which fuel flows, and extends in the depth direction (front-rear direction) in FIG. The fuel gallery 23 is located on the rear end (end opposite to the combustion chamber 8) side of the injector 16. Further, the fuel gallery 23 is disposed at a position higher than the ignition coil device 18 and lower than the injector 16 in the vertical direction. A cap portion 24 is provided at the rear end of the injector 16. The cap part 24 has an insertion hole 24a through which the rear end of the injector 16 is inserted.

  The cap portion 24 is connected to the fuel gallery 23, and the insertion hole 24 a communicates with the inside of the fuel gallery 23. The injector 16 communicates with the inside of the fuel gallery 23 through the insertion hole 24 a of the cap portion 24, and fuel sent from a fuel pump (not shown) is supplied to the injector 16 through the fuel gallery 23.

  In the engine 1, after fuel is injected from the injector 16 at a predetermined timing, the fuel is ignited by the spark plug 17 and burned. Due to such combustion, the piston 6 reciprocates in the cylinder bore 5, and the reciprocating motion is converted into rotational motion of the crankshaft 3 through the connecting rod 7.

  FIG. 3 is a schematic diagram showing the configuration of the ignition plug 17 and the ignition coil device 18 of the present embodiment. The spark plug 17 has a pair of electrodes 17a at the distal end and a terminal portion (terminal portion) 17b at the proximal end. The terminal portion 17b has an upper surface 17e on the most proximal side. Moreover, the terminal part 17b has the hollow part 17c hollowed in the front end side from the upper surface 17e (base end side). The hollow portion 17c has a substantially truncated cone shape. As for the hollow part 17c, the terminal 17d is provided in the inner bottom face. Moreover, as for the hollow part 17c, the side wall around a bottom face (terminal 17d) is a taper shape. By making the side wall of the recess portion 17c into a tapered shape, when one end (hereinafter referred to as a connection end) of a coil spring 22 to be described later is introduced into the recess portion 17c, the connection end of the coil spring 22 and the terminal 17d are connected. Can be made easier.

  The ignition coil device 18 includes a connecting portion 19 and an ignition coil 20. The connecting portion 19 includes a casing 21 and a coil spring (conductive member) 22.

  The casing 21 has a substantially cylindrical shape. The casing 21 is formed of an insulating member such as rubber, and a through hole 21c that penetrates from one end 21a to the other end 21b is formed. A terminal portion 17b of the spark plug 17 (an end portion on the side opposite to the combustion chamber 8) is inserted into the through hole 21c from the one end 21a side of the casing 21. The other end 21 b of the casing 21 is connected to the ignition coil 20.

  In the present embodiment, as shown in FIG. 2, the central axis of the communication portion 14a is inclined downward in the vertical direction with respect to the horizontal direction. Therefore, the spark plug 17 inserted through the communication portion 14a is disposed so as to be inclined downward in the vertical direction with respect to the horizontal direction. Accordingly, the one end 21a of the casing 21 is inserted into the terminal portion 17b of the spark plug 17 inclined downward in the vertical direction with respect to the horizontal direction.

  Here, as shown in FIG. 2, a cam mechanism 13 b (for example, a cam cap or a cam shaft) is provided below the spark plug 17 in the vertical direction. Therefore, when the ignition coil device 18 is linearly arranged with respect to the ignition plug 17, the ignition coil device 18 and the cam mechanism 13b interfere with each other. Therefore, it becomes difficult to arrange the ignition coil device 18 linearly with respect to the spark plug 17.

  Therefore, in this embodiment, the ignition coil device 18 is assembled to the spark plug 17 by inserting the casing 21 into the spark plug 17 while bending (deforming) the casing 21. By bending the ignition coil device 18, interference between the ignition coil device 18 (ignition device 15) and the cam mechanism 13b can be avoided.

  A coil spring 22 is accommodated in the through hole 21 c of the casing 21, and a terminal (high voltage terminal) 20 a of the ignition coil 20 is connected to the coil spring 22. The casing 21 is formed with a holding portion 21d for holding the coil spring 22 on the inner peripheral surface. The through hole 21c has a constant inner diameter in the accommodating portion that accommodates the coil spring 22, but the holding portion 21d has an inner diameter that is smaller than the inner diameter of the accommodating portion. The holding portion 21d also functions as a positioning portion that determines the position of the coil spring 22 in the casing 21.

  As described above, in this embodiment, the ignition coil device 18 is bent and assembled to the spark plug 17. When the ignition coil device 18 is bent, the ignition coil 20 and the ignition plug 17 are not arranged linearly, so that the central axis of the terminal 20 a of the ignition coil 20 is different from the central axis of the ignition plug 17. At this time, the central axis of the terminal 20 a of the ignition coil 20 has an intersection that intersects the central axis of the spark plug 17. In addition, the casing 21 is formed with a bending point 21e that bends at the intersection where the central axis of the terminal 20a of the ignition coil 20 and the central axis of the ignition plug 17 intersect in the through hole 21c. In the present embodiment, the bending point 21e is formed at a position substantially equal to the holding portion 21d in the direction in which the central axis of the casing 21 extends (hereinafter simply referred to as the axial direction).

  The coil spring 22 has a small diameter portion 22a, a first large diameter portion 22b, and a second large diameter portion 22c. Further, the coil spring 22 has a connection end 22 d connected to the terminal 20 a of the ignition coil 20 and a connection end 22 e connected to the terminal 17 d of the ignition plug 17. The small diameter portion 22 a has a constant outer diameter (first outer diameter), and is connected to the terminal 17 d of the spark plug 17 and the terminal 20 a of the ignition coil 20. The first large diameter portion 22b has an outer diameter (second outer diameter) larger than that of the small diameter portion 22a, and is disposed closer to the spark plug 17 than the holding portion 21d. The second large diameter portion 22c has an outer diameter (third outer diameter) larger than that of the small diameter portion 22a, and is disposed closer to the ignition coil 20 than the holding portion 21d. Here, the outer diameter of the first large diameter portion 22b and the outer diameter of the second large diameter portion 22c may be the same diameter or different diameters.

  The holding portion 21d of the casing 21 has a protruding portion 21f having an inner diameter that is larger than the outer diameter of the small diameter portion 22a and smaller than the outer diameter of the second large diameter portion 22c. By making the inner diameter of the holding portion 21d smaller than the outer diameter of the second large diameter portion 22c by the protrusion 21f, the holding portion 21d restricts the movement of the coil spring 22 toward the spark plug 17 and the second large diameter. The part 22c (in other words, the coil spring 22) can be held.

  The ignition coil 20 is disposed on the other end 21 b side of the casing 21, and the terminal 20 a is connected to the connection end 22 d of the coil spring 22. The ignition coil 20 houses therein a primary coil, a secondary coil, an iron core, etc. (not shown). The secondary coil has more turns than the primary coil, and a high induced electromotive force is generated in the secondary coil when the magnetic field of the primary coil changes in accordance with a change in power supplied from a battery or the like. The induced electromotive force generated in the secondary coil is supplied to the spark plug 17 through the coil spring 22, and the spark plug 17 is sparked.

  FIG. 4 is a perspective view of the ignition coil device 18 attached to the cylinder head 2 as viewed from above. However, in FIG. 4, the left ignition coil device 18 shows a state after being attached to the cylinder head 2, and in FIG. 4, the right ignition coil device 18 shows a state in the middle of being attached to the cylinder head 2. . FIG. 5 is a view taken in the direction of arrow V in FIG. However, FIG. 5 shows the cylinder head 2 before the ignition coil device 18 is attached.

  As shown in FIG. 4, the cylinder head 2 is provided with a guide portion 25. The guide part 25 is a part of the cylinder head 2 and is made of, for example, an aluminum alloy, like the cylinder head 2. The guide portion 25 projects upward from the lower lower surface 14 c of the inner wall surface of the hole 14. Further, the guide portion 25 extends along the connecting portion 19 of the ignition coil device 18. That is, the guide portion 25 extends in the substantially horizontal direction, like the connecting portion 19.

  As shown in FIG. 5, the guide portion 25 is generally U-shaped when viewed from a substantially horizontal direction, and a guide groove 25 a is formed in the guide portion 25. The guide groove 25 a extends in a substantially horizontal direction, like the guide portion 25. The communication portion 14a is located at the back of the guide groove 25a of the guide portion 25, and the rear end of the spark plug 17 projects into the guide groove 25a (toward the front side in FIG. 5).

  FIG. 6 is a view for explaining attachment of the ignition coil device 18. In FIG. 6, the cylinder head 2 shows only the bottom surface side of the guide groove 25 a of the guide portion 25. After the ignition plug 17 is attached to the cylinder head 2, as shown in FIG. 6A, the casing 21 of the ignition coil device 18 is inserted into the guide groove 25a from the one end 21a side. The casing 21 is made of rubber or the like as described above and can be easily deformed. Therefore, as shown in FIGS. 6A and 6B, when the casing 21 is inserted obliquely from above into the guide groove 25a, the casing 21 is deformed along the guide groove 25a and is positioned by the guide groove 25a. Deviation is suppressed. Then, the terminal portion 17 b of the spark plug 17 is easily inserted into the through hole 21 c of the casing 21.

  When the casing 21 is bent as shown in FIG. 6B, the bending point 21e is formed inside the holding portion 21d. The coil spring 22 in the present embodiment has a first large-diameter portion 22b closer to the spark plug 17 than the holding portion 21d. When the casing 21 is bent, the first large diameter portion 22b comes into contact with the inner surface of the casing 21, and the small diameter portion 22a disposed between the holding portion 21d and the first large diameter portion 22b according to the deformation amount of the casing 21. Bend (deform). Thereby, even if the casing 21 deform | transforms, the small diameter part 22a by the side of the spark plug 17 from the 1st large diameter part 22b is maintained in the position of the central axis vicinity of the casing 21 separated from the inner peripheral surface of the casing 21.

  Thus, the coil spring 22 has the first large-diameter portion 22 b, so that the spark plug 17 side is deformed following the bending of the casing 21 with respect to the holding portion 21 d of the casing 21. Due to this deformation, the connection end 22 e of the coil spring 22 on the spark plug 17 side is disposed at a position near the central axis of the casing 21 that is separated from the inner peripheral surface of the casing 21.

  Therefore, the connection end 22e of the coil spring 22 is introduced into the recess 17c of the spark plug 17 when the casing 21 (ignition coil device 18) is attached to the spark plug 17 while being bent. As a result, the connection end 22 e of the coil spring 22 is connected to the terminal 17 d of the spark plug 17.

  Thus, the coil spring 22 of the present embodiment can be normally connected to the connection end 22e of the coil spring 22 and the terminal 17d of the spark plug 17 by being deformed following the bending of the casing 21. . Therefore, according to this embodiment, the coil spring 22 and the spark plug 17 can be accurately connected.

  FIG. 7 is a schematic enlarged view of the coil spring 22 and the terminal portion 17b. As described above, in the present embodiment, the outer diameter (second outer diameter) of the first large diameter portion 22b is set to a value larger than the outer diameter (first outer diameter) of the small diameter portion 22a. Here, as shown in FIG. 7, the outer diameter (second outer diameter) of the first large-diameter portion 22b is φ1, the outer diameter (first outer diameter) of the small-diameter portion 22a is φ2, and the inner diameter of the recess portion 17c. Is φ3, and the outer diameter of the terminal portion 17b is φ4. Note that φ1, φ2, φ3, and φ4 are all the outer diameters (inner diameters) of the outer diameters (inner diameters).

・・・ （１） In addition, a value derived by the following equation (1) (that is, a value half the difference between the outer diameter φ4 and the inner diameter φ3) is φ5. φ5 corresponds to the width of the upper surface 17e.

(1)

・・・ （２） At this time, the outer diameter φ1 has a value derived by the following formula (2) (that is, a value equal to or larger than the value obtained by adding the value φ5 to the outer diameter φ2). Here, φ1−φ2 corresponds to the difference between the outer diameter of the first large diameter portion 22b and the outer diameter of the small diameter portion 22a. Therefore, if φ1-φ2 is larger than φ5, it is possible to reduce the contact end 22e of the coil spring 22 from coming into contact with the upper surface 17e of the terminal portion 17b.

(2)

  When the outer diameter φ1 satisfies the above formula (2), when the ignition coil device 18 is mounted on the spark plug 17, the connection end 22e of the coil spring 22 is not introduced into the hollow portion 17c, and the terminal portion 17b The contact with the upper surface 17e can be reduced. If the connection end 22e of the coil spring 22 comes into contact with the upper surface 17e of the terminal portion 17b, it becomes difficult to bring the connection end 22e of the coil spring 22 into contact with the terminal 17d, and the ignition coil 20 and the ignition plug 17 are electrically connected. Cannot be connected automatically.

  FIG. 8 is a schematic enlarged view showing a state in which the coil spring 22 and the terminal portion 17b are connected. As described above, in the present embodiment, the first large diameter portion 22b is provided closer to the spark plug 17 than the holding portion 21d. Here, as shown in FIG. 8, in the direction in which the central axis of the spark plug 17 extends (hereinafter simply referred to as the axial direction), the space between the upper surface 17e of the terminal portion 17b and the bottom surface of the recess portion 17c (terminal 17d). Is the distance L1 (that is, the depth of the recess 17c). At this time, the first large-diameter portion 22b has the other end (ignition) from the separation position P separated from the connection end (one end) 22e of the coil spring 22 by the distance (predetermined distance) L1 from the connection end (other end) 22d side. Provided on the coil 20) side. That is, the first large diameter portion 22b is provided closer to the ignition plug 17 than the holding portion 21d and closer to the ignition coil 20 than the separation position P. In other words, the first large diameter portion 22b is provided in a range R between the holding portion 21d and the separation position P. By providing the first large diameter portion 22b between the holding portion 21d and the separation position P, it is possible to prevent the first large diameter portion 22b from coming into contact with the upper surface 17e of the terminal portion 17b. Further, by preventing the first large diameter portion 22b from coming into contact with the upper surface 17e of the spark plug 17, the connection between the connection end 22e of the coil spring 22 and the terminal 17d of the spark plug 17 is hindered. Can be avoided.

  Here, as a comparative example, a case where an ignition coil device 318 different from the present embodiment is attached to the spark plug 17 will be described. FIG. 6C is a view for explaining attachment of the ignition coil device 318 having the coil spring 322 in the comparative example. The coil spring 322 in the comparative example is different from the coil spring 22 in the present embodiment in that the first large diameter portion 22b is not provided. That is, the coil spring 322 is configured only by the small-diameter portion 22a having a constant outer diameter on the spark plug 17 side than the holding portion 21d. As shown in FIG. 6C, even if the casing 21 is bent, the coil spring 322 is not deformed on the side of the spark plug 17 relative to the holding portion 21 d of the coil spring 322 following the bending of the casing 21. Therefore, the connection end 22 e of the coil spring 322 is located on the inner peripheral surface side of the casing 21. Therefore, the connection end 22e of the coil spring 322 contacts the upper surface 17e of the ignition plug 17 (that is, the region outside the recess 17c) when the ignition coil device 318 is attached to the ignition plug 17. As a result, the connection end 22e of the coil spring 322 is not connected (contacted) with the terminal 17d of the spark plug 17. Thus, since the coil spring 322 does not deform following the bending of the casing 21, it is difficult to normally connect the connection end 22e of the coil spring 322 and the terminal 17d of the spark plug 17.

  As described above, the coil spring 22 of the present embodiment has the first large diameter portion 22b on the spark plug 17 side with respect to the holding portion 21d. Thereby, the coil spring 22 and the spark plug 17 can be accurately connected.

  FIG. 9 is a schematic view showing the configuration of the ignition coil device 118 in a modified example. The ignition coil device 118 according to this modification includes an ignition coil 20, a casing 210, and a coil spring 220. In the ignition coil device 118 of this modification, the configurations of the casing 210 and the coil spring 220 are different from the configurations of the casing 21 and the coil spring 22 of the ignition coil device 18 in the above embodiment.

  Specifically, the coil spring 220 of this modification has a small diameter portion 22a and a first large diameter portion 22b. The small diameter portion 22a and the first large diameter portion 22b have the same configuration as the small diameter portion 22a and the first large diameter portion 22b of the above embodiment. However, the coil spring 220 of this modification does not have the second large diameter portion 22c of the above embodiment. That is, the coil spring 220 of this modification is configured by only the small diameter portion 22a and the first large diameter portion 22b.

  Moreover, the casing 210 of this modification is a substantially cylindrical shape, and the through-hole 21c penetrated from the one end 21a to the other end 21b is formed. The terminal portion 17b of the spark plug 17 is inserted into the through hole 21c from the one end 21a side of the casing 210. The other end 21 b of the casing 210 is connected to the ignition coil 20. Moreover, the casing 210 of this modification is formed with a holding portion 210d that holds the coil spring 220 on the inner peripheral side. In addition, the casing 210 is formed with a bending point 210e that bends at the intersection where the central axis of the terminal 20a of the ignition coil 20 and the central axis of the ignition plug 17 intersect in the through hole 21c. In this modification, the bending point 210e is formed at a position substantially equal to the holding portion 210d in the axial direction of the casing 210.

  Here, the coil spring 220 of this modification does not have the second large diameter portion 22c as described above. Therefore, even if the casing 210 has the holding portion 21d of the above-described embodiment, it is difficult to hold the coil spring 220 because the second large diameter portion 22c is not formed in the coil spring 220. Therefore, when the casing 210 of this modification is molded with a mold, the casing 210 is integrally molded with the coil spring 220 by injection molding with the coil spring 220 disposed in the mold. Therefore, the holding portion 210d of the casing 210 of the present modification has a protrusion 210f formed integrally with the small diameter portion 22a of the coil spring 220 on the inner peripheral surface. By forming the protrusion 210f integrally with the small diameter portion 22a, the protrusion 210f holds the coil spring 220 even if the second large diameter portion 22c is not formed like the coil spring 22 of the above embodiment. can do.

  Also in this modification, the coil spring 220 has the first large-diameter portion 22b on the spark plug 17 side with respect to the holding portion 210d. Thereby, the coil spring 220 and the spark plug 17 can be accurately connected.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  In the embodiment and the modification described above, an example in which all of the first large diameter portion 22b is provided closer to the spark plug 17 than the holding portions 21d and 210d has been described. However, the present invention is not limited to this, and at least a part of the first large-diameter portion 22b may be provided closer to the spark plug 17 than the holding portions 21d and 210d. For example, in the above modification, the protrusion 210f (holding portion 210d) may be formed integrally with the first large diameter portion 22b of the coil spring 220. In that case, at least a part of the first large diameter portion 22b only needs to be provided closer to the spark plug 17 than the holding portion 210d.

  The present invention can be used for an ignition coil device.

17 Spark plug 18, 118 Ignition coil device 20 Ignition coil 21, 210 Casing 21d, 210d Holding part 21e, 210e Bending point 21f, 210f Projection part 22, 220 Coil spring 22a Small diameter part 22b First large diameter part 22c Second large diameter Part

Claims (4)

An ignition coil for generating a voltage to be supplied to the spark plug;
A coil spring for conducting the ignition plug and the ignition coil;
A casing that holds the coil spring, and a casing that houses the coil spring;
With
The coil spring is
A small diameter portion having a first outer diameter and connected to the spark plug;
An ignition coil device having a second outer diameter larger than the first outer diameter, and a first large-diameter portion disposed closer to the spark plug than the holding portion. The coil spring has a third outer diameter larger than the first outer diameter, and has a second large diameter portion arranged on the ignition coil side with respect to the holding portion,
2. The ignition coil device according to claim 1, wherein the holding portion has a protrusion having an inner diameter larger than the first outer diameter and smaller than the third outer diameter. The ignition coil device according to claim 1, wherein the holding portion includes a protrusion formed integrally with the small diameter portion. The first large diameter portion is
4. The device according to claim 1, wherein the coil spring is provided between the holding portion and a separation position that is separated from the connection end of the coil spring connected to the ignition plug by a predetermined distance toward the ignition coil. Ignition coil device.

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