JPH029529Y2 - - Google Patents

Description

[Detailed description of the invention] This invention electromagnetically interconnects multiple unit ignition coils through a common magnetic path in order to cause spark discharge to the spark plugs of each cylinder of a multi-cylinder internal combustion engine without using a power distributor. This invention relates to an integrated ignition coil.

Traditionally, a single ignition coil and a power distributor were combined to distribute power to the spark plugs of each cylinder of a multi-cylinder internal combustion engine, causing spark discharge, but recently advances in electronic advance and electronic intermittent systems have made this possible. As a result, it has come to be used as a simple power distribution mechanism by eliminating the advance part and interrupter provided inside the power distribution device. Additionally, in order to prevent a decrease in output and the generation of noise due to flying sparks between the rotor and the fixed segment, which is the mechanical power distribution mechanism in the power distribution device, the mechanical power distribution mechanism was removed and a non-power distribution system came to be used. Ta.

In this case, generally, an integrated ignition coil is used, which is composed of a plurality of unit ignition coils that are electromagnetically coupled to each other through a common magnetic path, and each unit ignition coil simultaneously causes spark discharge to two spark plugs.

Figure 1 shows a conventional centralized ignition coil with two E
The legs 2 and 2', 3 and 3', and 4 and 4' of the shaped iron cores 1 and 1' are butted against each other, and the center legs 2 and 2' are butted against each other, and the left and right side legs 3 and 3', 4 and 4' are connected to the bobbin The primary coil 5- wound above is inserted from each end into a coil assembly fitted into the bobbin of the secondary coil 5-, and arranged to face each other by maintaining a gap in the coil assembly, As a result, the common magnetic path of the central legs 2 and 2' that are butted together, the leg magnetic path 6a that includes the side legs 3 and 3' and faces in a U-shape on one side of the common magnetic path, and the coil assembly 5a. One unit ignition coil A is constituted by a common magnetic path, a leg magnetic path 6b including side legs 4 and 4', and facing in a U-shape on the other side of the common magnetic path, and a coil assembly 5b. Another unit ignition coil B
Configure. Therefore, the beginning of the winding of the primary coil of each unit ignition coil assemblies 5a and 5b is connected to the battery 7.
and connect the winding ends to mechanical or electronic interrupters 8a and 8b, respectively, and coil assembly 5.
The secondary coil 5- of the coil assembly 5-a is connected to each spark plug 9a, 10a of the two cylinders, and the secondary coil 5- of the coil assembly 5b is connected to each spark plug 9b of the other two cylinders.
10b, for example, when the circuit breaker 8a connected to the primary coil of unit ignition coil A is closed, current flows from the battery 7 to the primary coil, and the leg magnetic path 6a including the side legs and the center leg are connected to each other. 2,2'
A loop-shaped magnetic flux φa is formed between the common magnetic paths of
When the interrupter 8a opens, the magnetic flux φa suddenly disappears, a high voltage is generated in the secondary coil, and the spark plugs 9a and 1
A spark discharge occurs at 0a, igniting the air-fuel mixture in the two cylinders. However, in this case, the leg magnetic path including the side legs 4, 4' of the other unit ignition coil B is the center leg 2,
If the central leg 2' has a much higher magnetic resistance than the common magnetic path, a loop-shaped magnetic flux φa' will not be generated between the two leg magnetic paths 6a and 6b when the interrupter 8a is closed. , 2' have a high magnetic path resistance, so the above-mentioned magnetic flux φa' is generated between the two leg magnetic paths, and when the interrupter 8a opens, the secondary coil of the other unit ignition coil B In some cases, a high voltage is induced in the spark plug 9b, which should not be ignited.
10b may also have the problem of discharge occurring.

Therefore, in the present invention, the common magnetic path is composed of an I-shaped core, and the leg magnetic paths facing each side of the common magnetic path are composed of C-shaped cores, and high magnetic path resistance is provided between each C-shaped core and each side of the I-shaped core. This eliminates the above-mentioned problem by eliminating magnetic interference between the multiple unit ignition coils.

FIG. 2 and subsequent figures each show some embodiments of the present invention, and components functionally the same as those used in FIG. 1 are given the same reference numerals.

In either embodiment, the common magnetic path is composed of an I-shaped iron core 11, and the leg magnetic paths facing each side of the common magnetic path in a U-shape are for a four-cylinder internal combustion engine with one spark plug in each cylinder. are two C-shaped cores 12a, 12
b. For a 4-cylinder internal combustion engine with two spark plugs in each cylinder or an 8-cylinder internal combustion engine with one spark plug in each cylinder, four C-shaped iron cores 12a, 12b,
13a and 13b, and the primary and secondary coil assemblies are each fitted into one leg of the C-shaped core facing the common magnetic path.

In the embodiment shown in FIG. 2, a gap is maintained between each side of the I-shaped core and the end of each leg of the opposing C-shaped cores 12a and 12b, and the entire body is insulated with plastic 14 in this state. The gap is filled with plastic 14 to provide high magnetic path resistance.

In addition, in the embodiment shown in FIG. 3, a plate-shaped insulating spacer 15 is sandwiched between each side of the I-shaped core and the end of each leg of the C-shaped cores 12a, 12b opposing this to provide high magnetic path resistance. , and then the whole is insulated and made into one piece with plastic 14. Of course, instead of the plate-shaped insulating spacer 15, the I-shaped core 11 can be placed in a cylindrical insulating spacer of the required thickness, or an insulating layer of the required length can be formed around the I-shaped core 11 by insert molding. Then, each C
The shaped iron core may be placed opposite each side of the spacer or insulating layer and insulated with plastic and integrated.In this case, it is better to maintain the gap and prevent the gap from forming when the plastic is insulated, or the plate When sandwiching the shaped insulating spacer 15 and insulatingly covering it with the plastic 14, it is possible to prevent the spacer from shifting and moving and making it impossible to obtain the required high magnetic path resistance.

From this point of view, the embodiments shown in FIGS. 4 and 5 are insulating spacers 1 in which the I-shaped iron core is formed into a cylindrical shape with a required wall thickness.
6, or an insulating layer 16 of a required thickness is formed of plastic around the I-shaped core by insert molding. In the case of an 8-cylinder internal combustion engine, two Cs facing each other on one side of the I-type iron core are used.
Type iron cores 12a and 13a, two C facing each other on the other side
Since it is necessary to maintain a high magnetic path resistance between the I-shaped cores 12b and 13b, the insulating layer 16 is formed around the I-shaped core when forming the cylindrical insulating spacer 16 or by insert molding, as shown in the figure. At this time, it is preferable to simultaneously form insulating plates 16a and 16b separating the iron cores 12a and 13a and 12b and 13b. This greatly simplifies the process of arranging four C-shaped cores, two I-shaped cores, facing each other on each side and insulatingly covering them with plastic 14 to integrate them.

The ignition coil of the present invention has a common magnetic path as described above.
The leg magnetic path facing each side of the I-shaped core 11 is composed of C-shaped cores 12a, 12b, 13a, and 13b.
A high magnetic path resistance made of an insulating material such as plastic is provided between each side of the core and the legs of each C-type core, so that the I-type core 11, which is a common magnetic path, and the C-type core 12a and its legs, for example, are connected to the common magnetic path. The interrupter 8a to which the primary coil of the unit ignition coil A made up of the coil assembly 5 attached above is connected is closed and current flows, thereby generating a loop-shaped magnetic flux φa, but the same I-shaped iron core has a common magnetic path Since the C-shaped cores 12b, 13a, and 13b of the other unit ignition coils have a high magnetic path resistance made of plastic or the like between the leg tips and each side of the I-shaped core, a loop-shaped magnetic flux φa' is not generated. Therefore, when the interrupter 8a opens and the magnetic flux φa suddenly disappears, and a high voltage is generated in the secondary coil to cause spark discharge in the spark plugs 9a and 10a, the other unit ignition coils are No high voltage is generated in the secondary coil. This is true not only for unit ignition coil A but also for other unit ignition coils.

Thus, according to the present invention, it is possible to prevent magnetic interference between a plurality of unit ignition coils by using the I-shaped iron core 11 as a common magnetic path, and to provide an integrated ignition coil that does not malfunction.

In the figure, 17 and 17 are primary terminals for connecting the winding start side and winding end side of the primary coil of each coil assembly to the battery 7 and the interrupter 8, and 18 and 18 are the winding start side of the secondary coil. This is a high voltage terminal for connecting the end of the winding of the spark plug of one cylinder to the spark plug of another cylinder.These terminals are electrically connected to each coil when insulating with plastic 15, and Fixed in 14 layers.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional centralized ignition coil, Fig. 2 is a sectional view of a first embodiment of the integrated ignition coil of the present invention, Fig. 3 is a sectional view of the second embodiment, and Fig. 4 is a cross-sectional view of another embodiment, and FIG. 5 is a perspective view of the I-shaped core, in which 11 is an I-shaped core, 12a, 12b, 13a, and 13b are C-shaped cores, and 14 is a high-magnetic core. Plastic with road resistance, 15
Similarly, 16 indicates a plate-shaped insulating spacer, and 16 similarly indicates a cylindrical insulating spacer or an insulating layer formed by insert molding.

Claims (1)

[Claims for Utility Model Registration] A common magnetic path, and leg magnetic paths located on one side and the other side of the common magnetic path in the transverse direction, respectively facing the common magnetic path, In a centralized ignition coil in which the leg magnetic path is equipped with a coil assembly consisting of a concentric primary coil and a secondary coil, the common magnetic path is an I-type iron core, each leg magnetic path is a C-type iron core, and each C-type An integrated ignition coil characterized by providing a high magnetic path resistance between the iron core and each side of the I-type iron core.