JPH051864U - Internal combustion engine ignition device - Google Patents

Abstract

(57) [Abstract] [Object] In an ignition device including an ignition coil fixed to a cylinder head cover, a conductor is connected to the ignition coil so that the conductor can be easily and surely attached to and detached from an ignition plug. [Structure] A high tension cord 30 is integrally housed in an elastic holder 20 by insert molding, and a coil spring 27 is attached to the outer periphery. The holder 20 holds one end of the holder 20 on the ignition coil 10 and the other end of the ignition plug 40.
The high tension cord 30 can be reliably connected to the ignition plug 40 from any direction and can be removed from the ignition plug 40.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an ignition device for an internal combustion engine, and more particularly to an ignition device in which an ignition coil is arranged on a cylinder head cover and a high voltage is directly applied to the ignition coil.

[0002]

[Prior Art]

 The ignition device for an internal combustion engine interrupts the primary current of the ignition coil, applies a high voltage generated on the secondary side to the spark plug in response to changes in the magnetic flux in the coil, and ignites the mixture in the cylinder. . For this reason, in the past, a distributor was provided to distribute the high voltage generated in the ignition coil to the ignition plug of each cylinder. On the other hand, with the recent high performance of internal combustion engines, a technique of eliminating the distributor and connecting an ignition coil to each of the ignition plugs of each cylinder has been adopted, which is known as a coil distribution ignition system.

When such an ignition device is mounted on an internal combustion engine, an ignition coil may be directly connected to an ignition plug as described in, for example, Japanese Patent Application Laid-Open No. 63-116414. It cannot be applied to a multi-cylinder internal combustion engine equipped with a cylinder head cover. On the other hand, as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-157278, an ignition device has been proposed in which an ignition coil can be arranged between camshafts even for a DOHC engine having a narrow valve holding angle. There is. In the ignition device of the publication, the partition wall provided in the oil chamber is removed, the casing containing the ignition coil is directly disposed in the oil chamber, the cylinder head cover and the casing, and the ignition plug mounting hole and the casing. I try to seal between them. As the ignition coil used in the ignition device described in the publication, various ignition coils are known, for example, as disclosed in JP-A-2-37705.

[0004]

[Problems to be solved by the device]

 In the ignition device in which the ignition coil and the ignition plug are arranged apart from each other as described in JP-A-62-157278, a long connector member for connecting the ignition coil to the ignition plug is required. Becomes The connector member described in this publication is formed integrally with the casing body and is configured to be inserted into the spark plug mounting hole. The material of this connector member is not specified, but if it is an elastic body, the rigidity of the casing body becomes insufficient, so it is recognized as a rigid body.

Therefore, in order to connect the ignition coil to the ignition plug, the connector member must be inserted into the ignition plug mounting hole from directly above the internal combustion engine, and it is not possible to arrange parts and the like above the internal combustion engine. Can not. In view of the situation that the mounting space is decreasing with the increase in the number of parts of the internal combustion engine in recent years, such a restriction is not preferable, and it is necessary to allow connection even from the oblique direction.

On the other hand, if the connector member is formed of an elastic material separately from the casing body, it can be easily inserted into the ignition plug mounting hole, but the electrical characteristics of the ignition coil and the ignition plug are reduced. Connection is likely to be uncertain. For example, when a well-known high tension cord with a predetermined length is used as the connector member, even if the ignition coil is pressed in the direction of the ignition plug, the high tension cord bends in the middle and is formed inside the terminal of the high tension cord. It becomes difficult for the engaged portion to be fitted over the protruding portion formed on the outer periphery of the terminal of the spark plug. Even if the high tension cord terminal could be fitted into the spark plug terminal, the connection between the high tension cord and the ignition coil will come off when the ignition coil is removed due to the large coupling force of both terminals. However, a situation may occur in which the high tension cord is left in the spark plug mounting hole.

Therefore, the present invention is an ignition device for an internal combustion engine having an ignition coil fixed to a cylinder head cover, in which a conductor is connected to the ignition coil so that it can be easily and surely attached to and detached from a spark plug. The purpose is to

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is an internal combustion engine in which an ignition plug is mounted in an attachment hole formed in a cylinder head of the internal combustion engine, and an ignition coil for supplying power to the ignition plug is fixed to a cylinder head cover of the internal combustion engine. In the ignition device of the above, a flexible electric conductor for electrically connecting the ignition coil to the ignition plug and the electric conductor are integrally housed by insert molding, and one end is held by the ignition coil. At the same time, an elastic member holding the other end to the spark plug, and an elastic member attached to the outer periphery of the elastic member, have rigidity in the axial direction of the elastic member and have flexibility in the direction orthogonal to the axis of the elastic member. And a support member.

A high tension cord may be used as the conductor, the elastic member may be a silicon rubber cylinder, and the support member may be a coil spring fitted to the outer periphery of the cylinder.

[0010]

[Action]

 In the ignition device for an internal combustion engine of the present invention, an elastic member in which a conductor is integrally housed by insert molding and a supporting member having rigidity in the axial direction and flexibility in the direction orthogonal to the axis is attached to the outer periphery. First, one end of the elastic member is held by the ignition coil, and then the ignition coil is pressed toward the ignition plug to hold the other end of the elastic member by the ignition plug. As a result, the ignition coil and the spark plug are electrically connected via the conductor.

In this case, since the elastic member and the conductor have flexibility, they can be easily inserted even from a direction inclined with respect to the axis of the mounting hole of the ignition plug. In particular, the conductor is integrally housed in an elastic member, and one end of the elastic member is held by the ignition coil. Since the supporting member having flexibility is provided, the bending is prevented by the rigidity of the elastic member in the axial direction when connecting to the spark plug. Further, when detached from the ignition plug, since the conductor is integrally housed in the elastic member, only the conductor is taken out together with the elastic member without being left in the mounting hole.

In the ignition device configured as described above, when the primary current supplied to the ignition coil is intermittent, a high voltage is induced. This high voltage is applied to the spark plug through the conductor, and spark discharge occurs in the spark plug.

[0013]

【Example】

 Hereinafter, preferred embodiments of an ignition device of the present invention will be described with reference to the drawings. FIG. 2 shows the top of an internal combustion engine equipped with an ignition device according to an embodiment of the present invention. The internal combustion engine 50 in the present embodiment includes a plurality of cylinders arranged in series in parallel, and FIG. 2 shows a cross section of the cylinder head portion of one of the cylinders. The cylinder head 52 of the internal combustion engine 50 is integrally formed with an intake port and an exhaust port that open into the combustion chamber 51 in each cylinder, and a pair of intake valves 56 and exhaust valves 57 are attached to these, respectively. However, only one of these is shown in FIG. That is, in this embodiment, each cylinder is equipped with a pair of intake valve 56 and exhaust valve 57, a total of four valves, which is a so-called four-valve engine. It is a system.

In the internal combustion engine 50, a cylinder head cover 53 is joined above the cylinder head 52, and an oil chamber 55 is defined between the two. A mounting hole 54 is formed between the oil chamber 55 and the combustion chamber 51 between the intake valve 56 and the exhaust valve 57 of the cylinder head 52. The spark plug 40 is screwed into a small diameter hole of the attachment hole 54 on the combustion chamber 51 side, and the electrode portion of the spark plug 40 is fixed in an exposed state in the combustion chamber 51. As is well known, the spark plug 40 includes a terminal 41 shown in FIG. 1, and a screw thread portion 42 is formed following the terminal 41.

A mounting recess 53a is formed at the top of the cylinder head cover 53 so as to face the opening of the mounting hole 54 into the oil chamber 55, and an insertion hole 53b is provided at the bottom of the mounting recess 53a. Has been done. A cylindrical shielding cylinder 60 made of metal is inserted into the mounting hole 54, and one end thereof is fixed near the lower end of the mounting hole 54 by press fitting or the like. The other end of the shield cylinder 60 projects from the mounting hole 54 and extends to the insertion hole 53b of the mounting recess 53a.

The ignition coil 10 according to the present embodiment is small in size, and particularly has a thin main body portion so that it can be easily housed in the cylinder head cover 53. As shown in FIG. 1, the ignition coil 10 has a high-voltage terminal 11 incorporated in a secondary connector portion 10a by insert resin molding, and an annular engaging protrusion 10b is integrally formed on the outer periphery thereof. The high-voltage terminal 11 is a bottomed tubular body made of aluminum. The compression spring 12 of the conductor is housed in this, and one end of the high tension cord 30 is inserted into the tubular body of the high-voltage terminal 11 so as to come into contact therewith. Has been done.

The high tension cord 30 constitutes a conductor according to the present invention, and as is well known, the core wire 31 is covered with an insulator such as rubber capable of withstanding a high voltage. In this embodiment, one end of the core wire 31 is covered. The upper end (FIG. 1) is exposed and expanded, and then soldered to the terminal 32. The other end (lower end in FIG. 1) of the core wire 31 is connected to the terminal 33. The terminal 33 is a metal cylinder body that is caulked and joined to the outer periphery of the end of the high tension cord 30, and near the open end of the terminal 33, a locking portion 33a formed so as to project inward is provided. ing.

The high tension cord 30 is integrally housed in the holder 20 which is an elastic member according to the present invention by insert molding. That is, the holder 20 accommodates the high tension cord 30 by insert molding of silicon rubber having excellent heat resistance, has a flange portion 21 formed at one end, and has a plug attachment portion 22 having a tapered outer surface at the other end. Has been formed. The flange portion 21 of the holder 20 is formed with an annular seal projection 23 extending to the main body side, and several annular seal projections 24 (four in this embodiment) are arranged side by side on the outer periphery of the main body. Has been done. One end of the holder 20 has a stepped opening 26a formed on the flange portion 21 side, and the other end has an opening 26c that is fitted into the spark plug 40. An annular engagement groove 26b is formed in the stepped opening 26a.

A recess 25 is formed on the outer circumference between the seal projection 24 of the holder 20 and the plug mounting portion 22, and a coil spring 27 is fitted in the recess 25. The coil spring 27 is formed by closely winding a spring wire having a circular cross section in a spiral shape, and constitutes a supporting member according to the present invention. That is, as shown in FIG. 3, a coil spring 27 having rigidity in the axial direction of the holder 20 and flexibility in the direction orthogonal to the axis is wound around the outer surface of the central portion of the holder 20 in the axial direction, and It is in the form of being locked at both side steps of 25.

When the ignition coil 10 is connected to the ignition plug 40, the coil spring 27 is fitted in the recess 25 of the holder 20, and the stepped opening 26a of the holder 20 is first connected to the ignition coil. The secondary connector portion 10a of 10 is fitted. As a result, the engagement protrusion 10b formed on the outer periphery of the secondary connector portion 10a engages with the engagement groove 26b in the stepped opening 26a, the holder 20 is held by the ignition coil 10, and the core wire 31 And the terminal 32 are pressed against the compression spring 12, and the high tension cord 30 and the high voltage terminal 11 are electrically connected.

As described above, with the holder 20 having the high tension cord 30 connected to the ignition coil 10, the holder 20 is inserted into the shield cylinder 60 and the ignition coil 10 is pressed toward the ignition plug 40. Then, the plug mounting portion 22 of the holder 20 is fitted into the screw thread portion 42 of the spark plug 40. As a result, the holder 20 is held by the spark plug 40, and the locking portion 33a of the terminal 33 of the high tension cord 30 is locked by the terminal 41 of the ignition coil 40.

At this time, if other parts or the like are provided above the mounting recess 53 a of the cylinder head cover 53, the holder 20 is bent and inserted into the shield cylinder 60, and the plug mounting portion 22 is inserted. If the ignition coil 10 is pressed from above after contacting the ignition plug 40 and the coil spring 27 portion is housed in the shield cylinder 60, the holder 20 and the high tension cord 30 housed therein are respectively attached to the ignition plug 40. It is securely connected to the screw thread portion 42 and the terminal 41.

That is, since the holder 20 and the high tension cord 30 have flexibility, and the coil spring 27 has flexibility in the direction orthogonal to the axis of the holder 20, they are easily bent. After the coil spring 27 is housed in the shield cylinder 60, the holder 20 and the high tension cord 30 are kept in a linear state due to the rigidity in the axial direction, and even if the ignition coil 10 is pressed, they are not bent. It is securely connected to the ignition plug 40. In this way, the high voltage terminal 11 of the ignition coil 10 is electrically connected to one end of the high tension cord 30, and the other end of the high tension cord 30 is electrically connected to the ignition coil 40.

Then, the flange portion 10c of the ignition coil 10 is bolted to the cylinder head cover 53 to maintain the above-mentioned connected state and to secure a stable sealed state inside the shield cylinder 60. That is, since the seal projection 23 prevents water and the like from entering the shield cylinder 60, and the storage chamber and the oil chamber 55 in the shield cylinder 60 are completely separated by the seal protrusion 24, the oil chamber The oil droplets in 55 never enter the shielding cylinder 60.

Further, even when the ignition coil 10 is removed, the holder 20 and the like are bent in the same manner as described above, so that the holder 20 can be pulled out in any direction. At this time, since the high tension cord 30 is housed integrally in the holder 20, even if the coupling force between the terminal 41 of the ignition plug 40 and the terminal 33 of the high tension cord 30 is large, the high tension cord 30 can be easily attached together with the holder 20. Can be pulled out.

The operation of the ignition device of the present embodiment configured as described above will be described. The internal combustion engine 50 is started, and the intake valve 56 and the exhaust valve 57 are driven in a predetermined cycle. Then, the primary current of the ignition coil 10 is controlled by the ignition signal output in a predetermined order according to the rotation of the internal combustion engine 50, and a predetermined high voltage is generated in the secondary coil. This high voltage is directly applied to the ignition plug 40 through the high voltage terminal 11 and the high tension cord 30, spark discharge is generated at the electrode portion at the tip of the ignition plug 40, and the compressed air-fuel mixture in the combustion chamber 51 is ignited. ..

FIG. 4 shows another embodiment of the support member according to the present invention. In contrast to the coil spring 27 of FIG. 3 in which a spring wire having a circular cross section is closely wound, The coil 27a is formed by winding an elastic plastic band-shaped member in a spiral shape, and can be reduced in weight. Incidentally, the support member may have various modes other than this.

In the above embodiment, the high tension cord 30 is used as a conductor according to the present invention, but as shown in FIG. 5, the core wire 31 and the terminals 34 and 35 (each of the above are not provided with an insulating coating). (Corresponding to the terminals 32 and 33 in the embodiment) only. That is, in the embodiment shown in FIG. 5, terminals 34 and 35 are joined to both ends of the core wire 31 to form a conductor, and only the tips of both terminals 34 and 35 are exposed in the stepped opening 26a and the opening 26c, respectively. As described above, the holder 20 is formed by insert molding. Thus, like the above-described embodiment, the holder 20 and the terminal 35 can be easily and surely connected to the ignition plug 40 from any direction, and these can be removed from the ignition plug 40.

[0029]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects. That is, according to the ignition device of the present invention, since the elastic member and the conductor have flexibility, when connecting to the ignition plug, it can be easily inserted even from a direction inclined with respect to the axis of the attachment hole of the ignition plug. You can In particular, the conductor is formed integrally with the elastic member by insert molding, and this elastic member is held by the ignition coil. Moreover, the elastic member has an axial rigidity and is orthogonal to the axis. Since the supporting member having flexibility in the direction is attached, it can be securely attached to and detached from the spark plug.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an ignition device according to an embodiment of the present invention.

FIG. 2 is a sectional view of an internal combustion engine including an ignition device according to an embodiment of the present invention.

FIG. 3 is a perspective view of an embodiment of an elastic member and a supporting member according to the present invention.

FIG. 4 is a perspective view of another embodiment of the elastic member and the support member according to the present invention.

FIG. 5 is a partial cross-sectional view of an ignition device according to another embodiment of the present invention.

[Explanation of symbols]

 10 Ignition coil 10a Secondary connector part 11 High voltage terminal 20 Holder (elastic member) 27 Coil spring (supporting member) 30 High tension cord (conductor) 31 Core wire 32, 33 Terminal 40 Spark plug 50 Internal combustion engine 52 Cylinder head 53 Cylinder head cover 60 Shielding cylinder

Claims (1)

Claims for utility model registration 1. An internal combustion engine in which an ignition plug is attached to a mounting hole formed in a cylinder head of an internal combustion engine, and an ignition coil for supplying power to the ignition plug is fixed to a cylinder head cover of the internal combustion engine. In an engine ignition device, a conductor having flexibility and electrically connecting the ignition coil to the ignition plug, and the conductor are integrally housed by insert molding,
An elastic member having one end held by the ignition coil and the other end held by the ignition plug; and an elastic member mounted on the outer periphery of the elastic member and having rigidity in the axial direction of the elastic member and orthogonal to the axis of the elastic member. An ignition device for an internal combustion engine, comprising: a support member having flexibility in a direction.