JP2007303401A - Ignition coil device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil device for an internal combustion engine excellent in waterproofness despite formability in small size. <P>SOLUTION: The ignition coil device for the internal combustion engine is provided with at least a coil case and a connector case, keeps the coil case inserted in a plug hole of a cylinder of the internal combustion engine, and is provided with a waterproofing sealant closing an opening of the plug hole. This device has an intake passage having the opening in a space part between the connector case and a cover covering the connector case 9 in the connector case by communicating with the plug hole closed by the waterproofing sealant 13, a projected part 20 on one of the connector case and the cover so as to surround the opening of the intake passage, and a top part of the projected part by abutting on the other of the connector case and the cover. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ignition coil device for an internal combustion engine, for example, an ignition coil device for an internal combustion engine that is mounted for each ignition plug of the internal combustion engine.

  An ignition coil device for an internal combustion engine includes at least a coil case and a connector case, and the coil case is inserted into a plug hole of a cylinder of the internal combustion engine and is electrically connected to the ignition plug.

  The ignition coil device for an internal combustion engine includes a waterproof seal material that is inserted into the plug hole and closes the opening of the plug hole, and the plug hole that is blocked by the waterproof seal material is substantially Sealed.

  In this case, since the air in the plug hole is expanded by the heat generated when the internal combustion engine is driven, the air needs to be discharged to the outside through the ignition coil device for the internal combustion engine.

  For this reason, the ignition coil device for an internal combustion engine has an intake passage (air vent passage) and is devised to prevent water from entering the plug hole through the intake passage.

In Patent Document 1 below, for example, an intake passage that communicates the inside and the outside of a plug hole is configured by a route of a first groove → a space portion → a second groove → a third groove, and the space portion is connected to the outside air side. Is configured to temporarily store moisture from the water and evaporate and drain the moisture to the outside through a first groove.
JP 2000-291523 A

  However, since the ignition coil device for an internal combustion engine having the above-described configuration has to form the intake passage with a complicated labyrinth structure as described above, the area occupied in the intake passage is increased, and the ignition for the internal combustion engine is increased. This was a factor that hindered miniaturization of the coil device.

  An object of the present invention is to provide an ignition coil device for an internal combustion engine that is excellent in waterproofness even though it can be formed small.

   Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

(1) An ignition coil device for an internal combustion engine according to the present invention includes, for example, at least a coil case and a connector case. The coil case is inserted into a plug hole of a cylinder of the internal combustion engine and closes an opening of the plug hole. An ignition coil device for an internal combustion engine comprising a waterproof seal material,
An air intake passage having an opening is formed in a space between the connector case and a cover covering the connector case in communication with the plug hole blocked by the waterproof seal material,
One of the connector case and the cover is formed with a protrusion so as to surround the opening of the intake passage, and the top of the protrusion is formed in contact with the other of the connector case and the cover. It is characterized by.

(2) The ignition coil device for an internal combustion engine according to the present invention is based on, for example, the configuration of (1), and a notch or a hole is provided in a part of the protrusion so as to communicate the opening side of the intake passage and the opposite side. It is formed.

(3) An ignition coil device for an internal combustion engine according to the present invention includes, for example, at least a coil case and a connector case. The coil case is inserted into a plug hole of a cylinder of the internal combustion engine and closes an opening of the plug hole. An ignition coil device for an internal combustion engine comprising a waterproof seal material,
An air intake passage having an opening is formed in a space between the connector case and a cover covering the connector case in communication with the plug hole blocked by the waterproof seal material,
An elastic member is interposed between the connector case and the cover so as to surround the opening of the intake passage.

(4) The ignition coil device for an internal combustion engine according to the present invention is based on the configuration of (3), for example, and at least one of the connector case and the cover is formed with a recess so as to cross the elastic member. It is characterized by.

(5) An ignition coil device for an internal combustion engine according to the present invention is characterized in that, for example, on the premise of the configuration of (1), a porous member is formed covering the opening of the intake passage in the connector case. To do.

  In addition, this invention is not limited to the above structure, A various change is possible in the range which does not deviate from the technical idea of this invention.

  The internal combustion engine ignition coil device configured as described above can be configured to be excellent in waterproofness although it can be formed in a small size.

  Embodiments of an ignition coil device for an internal combustion engine according to the present invention will be described below with reference to the drawings.

<Example 1>
FIG. 1 is a view showing an embodiment of an ignition coil device for an internal combustion engine according to the present invention, which is a portion exposed from a plug hole when inserted into a plug hole of a cylinder and having a built-in igniter or the like It is the figure which showed the case and its vicinity part. Further, in FIG. 1, the left half is depicted as a side view and the right half is depicted as a sectional view.

  First, a cylindrical coil case 3 having a slightly smaller diameter than the plug hole 2a is provided at a portion inserted into the plug hole 2a (see FIG. 2) of the cylinder 2 of the ignition coil device 1 for an internal combustion engine.

  Inside the coil case 3, a center core 4 extending along the central axis, a secondary coil bobbin 5 around which the secondary coil 5a is wound so as to surround the center core 4, and the secondary coil bobbin 5 are enclosed. Thus, the primary coil bobbin 6 around which the primary coil 6a is wound is disposed concentrically.

  Here, the center core 4 is formed by press laminating silicon steel plates, for example, and magnets 7 (only one magnet is shown in FIG. 1) are arranged at both ends thereof. The magnet 7 is arranged to obtain a large change in the amount of magnetic flux when the primary current is interrupted.

  The primary coil bobbin 6 and the secondary coil bobbin 5 are made of, for example, a thermoplastic synthetic resin. In the primary coil 6a, enameled wires having a wire diameter of 0.5 to 0.7 mm are laminated and wound 150 to 250 times over several tens of times per layer. In the secondary coil 5a, an enameled wire having a wire diameter of 0.03 to 0.05 mm is dividedly wound 15000 to 25000 times.

  A side core 7 formed by forming a cut and rounding a silicon steel plate into a tubular shape is disposed on the outer peripheral side of the coil case 3. The side core 8 is provided with the cut in order to prevent a so-called one-turn short circuit of the magnetic flux.

  The coil case 3 is integrally attached to the connector case 9 at a portion exposed from the plug hole 2a of the cylinder 2.

  The connector case 9 includes an igniter 10 and other electronic components, and is provided with a terminal portion 11 for supplying a signal or the like to the igniter 10 or the like on a part of its outer surface. The igniter 10 is configured to cut off the current to the primary coil 6a.

  Further, the inside of the connector case 9 and the inside of the coil case 3 are covered with the igniter 10, the center core 4, the secondary coil bobbin 5, the primary coil bobbin 6, etc., and filled with a synthetic resin material 12 made of, for example, epoxy resin or the like. Yes.

  Further, a portion of the coil case 3 adjacent to the connector case 9 is provided with a waterproof seal material 13 made of an annular seal rubber that is disposed by inserting the coil case 3.

  That is, the connector case 9 is formed with a large diameter in the radial direction with respect to the coil case 3, and the waterproof sealing material 13 contacts the outer peripheral surface of the coil case 3 on its inner peripheral surface. It arrange | positions so that the lower end surface in the figure of the said connector case 9 may contact in the upper end surface inside. In other words, the ignition coil device 1 for an internal combustion engine has a stepped portion between the coil case 3 and the connector case 9 in the axial direction thereof, and the waterproof sealing material 13 is disposed in contact with the stepped portion. .

  The waterproof sealing material 13 is formed with an annular groove 13a formed along the circumferential direction at the lower end surface in the drawing. The waterproof seal member 13 is secured to the cylinder 2 by the groove 13a.

  That is, as shown in FIG. 2, an annular protrusion 2b is formed on the surface of the cylinder 2 where the plug hole 2a is formed so as to surround the plug hole 2a, and the coil case 3 of the ignition coil device 1 for an internal combustion engine is mounted. When inserted into the plug hole 2 a, the protrusion 2 a is inserted into the groove 13 a of the waterproof seal material 13. In this case, convex portions 13b and 13c are formed on a part of each facing surface of the groove 13a of the waterproof seal material 13, so that the protruding portion 2b can be tightly sandwiched and pressed by the convex portions 13b and 13c. It has become.

  Further, as shown in FIG. 1, a protruding portion 9a is formed on the outer peripheral side of the waterproof sealing material 13 on the lower end surface of the connector case 9 in contact with the waterproof sealing material 13, and this protruding portion 9a and the coil case The waterproof sealing material 13 can be pressed between the three.

  And in order to avoid that the air in the insertion part of the said coil case 3 of the plug hole 2a is warmed and a pressure rises, the ignition coil device 1 for internal combustion engines is inserted in the connector case 9 from the said plug hole 2a. An intake passage called a so-called air vent hole is formed. This intake passage is configured as follows.

  First, as shown in FIG. 1, the connector case 9 has a recessed portion 15 formed adjacent to the coil case 3 so as to surround the coil case 3 on the lower end surface in the figure where the coil case 3 is attached. . FIG. 3 is a plan view seen from the direction of arrow III in FIG. 1 and shows that the recessed portion 15 is formed adjacent to the coil case 3 so as to surround the coil case 3.

  In addition, since this recessed part 15 is arrange | positioned so that the said waterproof sealing material 13 may cover the lower end surface of the connector case 9 in which it was formed, it is in the state which is not visually recognized by this waterproof sealing material 13. .

  Further, as shown in FIG. 1, a through hole 16 having an axis substantially parallel to the direction of the axis of the coil case 3 is formed in the side wall of the connector case 9, for example. One opening portion is provided in the portion, and the other opening portion communicates with the space portion 18 on the cover 17 side that closes the connector case 9. FIG. 3 shows that the through hole 16 is formed with an opening in a part of the recessed portion 15.

  Furthermore, as shown in FIG. 1, the outer surface of the coil case 3 has a groove 19 extending in the axial direction, and one end of the groove 19 reaches the recessed portion 15 provided in the connector case 9. The other end is formed so as to extend sufficiently beyond the region where the waterproof sealing material 13 is disposed. FIG. 3 shows that the groove 19 is formed up to the recessed portion 15.

  As a result, the plug hole 2a of the cylinder 2 to which the ignition coil device 1 for an internal combustion engine is mounted passes through the groove 19, the recessed portion 15, and the through hole 16, respectively, and the space portion 18 on the cover 17 side in the connector case 9. It is communicated to.

  The space portion 18 is at a level where air is sucked because a slight gap is formed in the fitting portion between the connector case 9 and the cover 18 covering the connector case 9 and sufficient airtightness is not ensured. The air is communicated with the atmosphere outside the cover 18.

  However, in some cases, water may enter into the connector case 9 through the gap between the connector case 9 and the cover 17 covering the connector case 9, and the water may pass through the through hole formed in the connector case 9. It is feared that the accumulation in 16 may hinder communication between the plug hole 2a of the cylinder 2 and the space 18 on the cover 17 side in the connector case 9.

  For this reason, in this embodiment, as shown in FIG. 4, the connector case 9 is provided with an annular protrusion 20 that surrounds the opening of the through hole 16, and the top of the protrusion 20 is the back surface of the cover 17. It is comprised so that it may contact | abut. 4 is a plan view of the connector case 9 as viewed from the direction of the arrow VI in FIG. 1, and the protrusion 20 is, for example, most of the center of the connector case 9 along the outer periphery of the connector case 9 (the penetration (Including the opening of the hole 16). As a result, the protrusion 20 prevents the intrusion of water from the gap in the fitting portion between the connector case 9 and the cover 17 to the through hole 16.

  In this case, as shown in FIG. 5 corresponding to FIG. 4, a notch 20 a that communicates the annular inner side and the outer side may be provided in a part of the protrusion 20. This is because the formation of the protrusion 20 avoids blocking the intake passage leading to the atmosphere from the through hole 16 through the fitting portion of the connector case 9 and the cover 17. From this point of view, the notch 20a is not limited to one, and a plurality of notches 20a may be formed at different locations. Moreover, it is not limited to the notch 20a, The through-hole formed from the side wall of the one side of the said projection part 20 to the side wall of the other side may be sufficient.

  In the embodiment described above, the protrusion 20 is formed on the connector case 9. However, it is not limited to this and may be provided on the case 17 side.

  In FIG. 1, a spark plug that is electrically connected to the secondary coil 5a is arranged at an end (not shown) of the coil case 3 opposite to the connector case 9. The spark plug electrode projects into the cylinder (combustion chamber).

<Example 2>
FIG. 6 is a view showing another embodiment of the ignition coil device for an internal combustion engine according to the present invention and corresponds to FIG.

  1 is different from the configuration of FIG. 1 in that, in the portion where the protrusion 20 is formed, the elastic member 21 made of, for example, rubber or the like is disposed instead of forming the protrusion 20. It is in.

  The elastic member 21 can block the intrusion of water from the gap between the fitting portion of the connector case 9 and the cover 17 to the through hole 16 in the same manner as the protruding portion 20. In this case, the elastic member 21 may or may not be bonded to the connector case 9 (or the cover 17). This is because the elastic member 21 can obtain an effect only by being restricted in position with respect to the connector case 9 (or the cover 17).

  FIG. 7A is a plan view of the connector case 9 viewed from the direction of arrow VII in FIG. The elastic member 21 is formed, for example, so as to surround most of the center of the connector case 9 (including the opening of the through hole 16) along the outer periphery of the connector case 9. Then, as shown in FIG. 7a, a recess 9a is formed on the connector case 9 (or cover 17) side so as to cross a part of the annular elastic member 21. As shown in FIG. 7B, which is a cross-sectional view taken along the line bb of FIG. 7A, the recessed portion 9a has a function of an air passage that connects the annular inner side and the outer side of the elastic member 21. It is.

  In this embodiment, instead of the elastic member 21, a porous member described later may be used. In this case, there is an effect that it is not necessary to form the above-described recessed portion 9a. This is because the porous member has a function of blocking the passage of liquid but allowing the passage of gas.

<Example 3>
FIG. 8 is a view showing another embodiment of the ignition coil device for an internal combustion engine according to the present invention and corresponds to FIG.

  1 differs from the configuration of FIG. 1 in that, for example, on the premise of the configuration shown in FIG. 1, a porous member 22 arranged so as to close the opening of the through hole 16 is provided.

  FIG. 9 is a plan view of the connector case 9 viewed from the direction of the arrow IX in FIG. It is shown that the porous member 22 is disposed so as to cover the opening of the through hole 16.

  The porous member 22 is made of, for example, a tetrafluoroethylene resin porous film having fine pores, and a member having a property that gas can pass but liquid cannot pass is selected.

  The porous member 22 with the opening of the through hole 16 blocked by itself can prevent water from entering the through hole 16. However, when foreign matter such as mud is mixed in the water, the foreign matter may block the micropores of the porous member 22, and there is a concern that the intake through the through-hole 16 is obstructed. Have. For this reason, in this embodiment, the protrusion 20 formed so as to surround the through hole 16 has a function of preventing foreign matters such as mud from entering the through hole 16.

  As the fixing of the porous member 22 to the connector case 9, bonding by double-sided tape, fixing by caulking, or fixing by welding is selected. When used in a temperature range of −40 ° C. to 150 ° C., fixing by caulking and fixing by welding are preferable, and welding fixing is preferable when downsizing is required.

  When the connector case 9 is made of a resin such as polybutylene terephthalate (PBT) or polyphenylene sulfide (PPS) and a porous tetrafluoroethylene resin film is selected as the porous member 22, the porous member 22 Can be welded at a temperature lower than the heat-resistant temperature, so that the porous member 22 can be firmly fixed without damaging it.

  Further, when the porous member 22 is welded to the connector case 9, the through hole 16 can only be formed in the range of φ0.5 to φ2 due to the space, so the connector case 9 closes the through hole 16. May deform in the direction. In this case, the above disadvantage can be avoided by forming a large warp on the side of the through hole 16 where the porous member 22 is welded.

  Each of the embodiments described above may be used alone or in combination. This is because the effects of the respective embodiments can be achieved independently or synergistically.

1 is a side view (sectional view) showing an embodiment of an ignition coil device for an internal combustion engine according to the present invention. It is explanatory drawing which showed the function of the waterproof seal material when the ignition coil device for internal combustion engines by this invention was inserted in the plug hole of a cylinder. It is the top view seen from the direction of arrow III of FIG. It is the top view seen from the direction of arrow IV of FIG. FIG. 6 is a plan view showing another embodiment of the ignition coil device for an internal combustion engine according to the present invention and corresponding to FIG. 4. It is a side view (sectional view) showing another embodiment of the ignition coil device for an internal combustion engine according to the present invention. It is the top view seen from the direction of arrow VII of FIG. It is a side view (sectional view) showing another embodiment of the ignition coil device for an internal combustion engine according to the present invention. It is the top view seen from the direction of arrow IX of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ignition coil device for internal combustion engines, 2 ... Cylinder, 2a ... Plug hole, 2b ... Projection part, 3 ... Coil case, 4 ... Center core, 5a ... Secondary coil, 5 ... Secondary Coil bobbin, 6a ... primary coil, 6 ... primary coil bobbin, 7 ... magnet, 8 ... side core, 9 ... connector case, 9a ... projecting part, 10 ... igniter, 11 ... terminal part, 12 ... Synthetic resin material, 13 ... waterproof seal material, 13a ... groove portion, 15 ... recessed portion, 16 ... through hole, 17 ... cover, 18 ... space portion, 19 ... groove, 20 ... projection, 20a: Notch, 21: Elastic member, 22: Porous member.

Claims (5)

An ignition coil device for an internal combustion engine comprising at least a coil case and a connector case, the coil case being inserted into a plug hole of a cylinder of the internal combustion engine and having a waterproof sealing material that closes an opening of the plug hole,
An air intake passage having an opening is formed in a space between the connector case and a cover covering the connector case in communication with the plug hole blocked by the waterproof seal material,
One of the connector case and the cover is formed with a protrusion so as to surround the opening of the intake passage, and the top of the protrusion is formed in contact with the other of the connector case and the cover. An ignition coil device for an internal combustion engine.   2. The ignition coil device for an internal combustion engine according to claim 1, wherein a notch or a hole is formed in a part of the protrusion so as to communicate the opening side of the intake passage and the opposite side. An ignition coil device for an internal combustion engine comprising at least a coil case and a connector case, the coil case being inserted into a plug hole of a cylinder of the internal combustion engine and having a waterproof sealing material that closes an opening of the plug hole,
An air intake passage having an opening is formed in a space between the connector case and a cover covering the connector case in communication with the plug hole blocked by the waterproof seal material,
An ignition coil device for an internal combustion engine, wherein an elastic member is interposed between the connector case and the cover so as to surround the opening of the intake passage.   The ignition coil device for an internal combustion engine according to claim 3, wherein a recess is formed in at least one of the connector case and the cover so as to cross the elastic member. 2. The ignition coil device for an internal combustion engine according to claim 1, wherein a porous member is formed covering the opening of the intake passage in the connector case.

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