JPS6134271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition coil for an internal combustion engine, and particularly to the structure of a coil cap portion in an iron case type coil.

Conventionally known ignition coils for internal combustion engines mainly use coils with external resistors to improve performance and startability, and when the ignition coil is started, this external resistor is short-circuited to improve the startability of the ignition coil. Ta.

However, with this external resistor, the resistance wire to produce the necessary resistance value is insulated with an insulator such as an insulator, and both ends of the resistance wire are connected to terminals that connect the wire coming from the power supply and the wire going to the coil. By using a circuit that shorts this resistor during starting, a large current flows through the coil only during starting, resulting in high performance and greatly improving starting performance. However, since the above-mentioned external resistor is required in addition to the coil body, the manufacturing cost is high, and problems caused by cracks in the insulation of this external resistor and There were disadvantages such as restrictions on the installation space for the ignition coil due to the presence of the ignition coil.

The present invention overcomes the above-mentioned drawbacks.

The object of the present invention is to wrap the secondary coil and the central core inside the cylindrical leg of the coil cap so as to insulate it from the ground body such as the case, and to wrap the coil cap around the upper, lower and outer periphery of the cylindrical leg. A flange part is provided in between, and the main primary coil and auxiliary primary coil are wound between them, and the end of the auxiliary primary coil and the winding of the main primary coil are connected to the primary terminal at the top of the coil cap. The winding end of the main primary coil is connected to the primary terminal side, and the winding start of the auxiliary primary coil fixed to the protrusion of the intermediate flange is connected to the winding end of the secondary coil on the low voltage side. The primary spool, which is the base of the primary winding, can be eliminated by creating a shape that has a battery terminal for connecting to the lead wire, and by winding half of the total number of turns of the auxiliary primary coil in opposite directions. At the same time, by short-circuiting between the coil's battery terminal and the terminal, even without the need for a conventional external resistor, only the main primary coil is connected between the terminals, and a large Current flows, high performance can be obtained without energy absorption, starting performance can be improved, and external resistors are not required.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ignition coil for an internal combustion engine according to the present invention will be described in detail below according to embodiments.

FIG. 1 is a partial sectional view of an embodiment of an ignition coil for an internal combustion engine according to the present invention, FIGS. 2A and B are a partial sectional front view and a plan view of the coil cap portion of FIG. 1, and FIG. FIG. 4 is a front view showing the state of the coil shown in the figure before being stored in the case, and FIG. 4 shows an ignition circuit diagram using the coil shown in FIG. 1.

In Figures 1 to 3, 1 is an iron case, and 2 is a coil cap made of high-voltage insulating resin fixed to the case 1 by closing the open end of the case 1 by wrapping the open end of the case 1. , 3 is a secondary bobbin made of high-voltage insulating resin having a plurality of winding grooves 3a on its outer periphery and a closed portion 3b at its lower end, and the closed portion 3b is in contact with the inner bottom surface of the case 3. A central core 4 is inserted into the secondary bobbin 3 and is insulated by the closed portion 3b of the secondary bobbin 3, and is disposed at the center of the case 1. 5 is a secondary coil that is dividedly wound around each winding groove 3a of the secondary bobbin 3; 6;
is a primary coil placed around the outer periphery of the secondary coil 5;
8b and 8c are the secondary terminals fixed at the center of the coil cap 2, respectively.
8a is the primary terminal fixed to the primary coil 6.
This is the battery terminal. The primary coil 6 is divided into a main primary coil 6a and an auxiliary primary coil 6b.
The end of the winding of the secondary coil 5 and the auxiliary primary coil 6
At the beginning of winding b, connect the lead wire 11 to the battery terminal 8a.
a, 11b, and the winding start of the secondary coil 5 is connected to the central core 4 and the plate spring 9.
The winding end of the main primary coil 6a is electrically connected to the secondary terminal 7 through the terminal 8 of the other primary terminal.
b via a lead wire 11c. Further, the winding end line of the auxiliary primary coil 6b and the winding start line of the main primary coil 6a are the primary terminal terminal 8c.
electrically connected to. Reference numeral 10 denotes a screw for filling the case 1 with insulating oil through a screw hole provided in the secondary terminal 7, and then closing the screw hole.

The structure of the roll cap 2 includes a cylindrical foot 2a that extends toward the bottom of the case 1 and wraps around the secondary coil 5 and the central core 4 insulatingly inside the case 1; A small cylinder part 2b extends toward the secondary bobbin 3 inside the foot part 2a, and fits into the outer periphery of the tower part 3c at the upper end of the secondary bobbin 3 to fix the secondary bobbin 3 inside the case 1.
are integrally molded. And the cylindrical leg portion 2a
As is clear from Figures 2 and 3, there are flange parts 2 at three locations on the outer periphery of the
c, 2d, and 2e are integrally molded, and a primary coil 6 is wound around the outer periphery of the cylindrical leg portion 2a between the flange portions 2c, 2d, and 2e. The main primary coil 6a is wound around the main primary coil 6a, and the auxiliary coil 1 is wound between the flange parts 2d and 2e.
The upper and middle flanges 2c and 2d have protrusions 2g and 2g for winding the end of the auxiliary primary coil 6b, respectively.
2h is integrally molded. Furthermore, a protrusion 2f for folding back the auxiliary primary coil 6b in the middle of winding and winding it in the opposite direction is integrally formed on the flange 2e located below. That is, the two flange parts 2d, 2e
When the first winding of the auxiliary primary coil 6b is wound in between, the first winding is wound clockwise, and then the first winding is wound in the counterclockwise direction. By winding the same winding that has been prepared, the necessary resistance of the auxiliary primary coil 6b can be secured, and a coil with no inductance can be obtained.

In the circuit shown in Figure 4, if the auxiliary primary coil 6b is only wound in one direction, a closed loop will be formed at the point indicated by the chain double-dashed line at the time of starting, so the performance will drop by 5 to 10 KV only at the time of starting. Put it away. As shown in Fig. 5, this principle is based on the magnetic flux F emitted from the main primary coil 6a.
However, since a closed loop is formed in the auxiliary primary coil 6b, a back electromotive force is generated, and this magnetic flux is absorbed by -Δ. Then, the magnetic flux interlinking with the secondary coil 5 decreases accordingly, resulting in a decrease in performance.
As a countermeasure, as shown in Fig. 6, even if a closed loop occurs in the auxiliary primary coil 6b, half of the windings are wound in opposite directions.
The coil portions 6b ₁ , 6 wound in mutually opposite directions
At _b2 , the -Δ and +Δ components cancel each other out, and the magnetic flux F emitted from the main primary coil 6a is directly linked to the secondary coil 5, so that performance does not deteriorate.

In addition, from the viewpoint of the configuration, the main primary coil 6a and the auxiliary 1
There is no problem even if the vertical relationship with the next coil 6b is reversed.

Furthermore, it goes without saying that the connection relationship between the winding end and the winding start of each coil 5, 6a, 6b may be reversed.

The cylindrical leg portion 2a of the coil cap 2 is provided with flange portions 2c, 2d, and 2e on the upper and lower outer periphery and intermediate flanges 2c, 2d, and 2e, so that the primary coil 6 can be directly wound around the coil cap 2, and the primary coil 6 can be Lord 1
It is structured so that it can be separated into the secondary coil 6a and the auxiliary primary coil 6b, in which half of the total number of turns is wound in opposite directions, and the primary terminal on the upper side of the coil cap 2 is also the same as the conventional one 8b, 8c. By providing the battery terminal 8a in addition to the terminal, the auxiliary primary coil 6b is short-circuited at the time of ignition start of the internal combustion engine, thereby achieving the same effect as short-circuiting the external resistor of the prior art. A large current flows through the starting coil (main primary coil 6a), and high performance can be obtained during ignition starting without energy absorption. At the same time, it is possible to eliminate the primary spool for winding the primary coil 6, and since the high voltage part is completely wrapped in the cap cylindrical foot 2a, a highly insulating coil can be obtained. Since the coil 6 is directly wound around the fixed cap, an ignition coil with excellent vibration resistance can be obtained.

According to the present invention, the battery terminal 8a, which is the primary terminal on the top of the coil cap 2 and connects the line coming from the power supply, is made of, for example, an M4 x 0.7 screw, in order to prevent erroneous connection with other lines. Use a round terminal for φ4 for the power line connected to the
This can be prevented by using M5 x 0.8 screws for other terminals and terminals.

Further, the cylindrical leg portion 2a of the coil cap 2 is extended, and the secondary coil 5 assembled around the central core is housed inside the cylindrical leg portion 2a, and above the outer periphery of the cylindrical leg portion 2a,
A flange part is provided at the bottom and the middle part, and the primary coil 6 can be wound between them, and the primary coil 6 also has a main primary coil 6a and an auxiliary primary coil 6.
Coil cap 2
In addition to the upper primary terminal, the battery terminal 8a
By providing the In addition to having the effect of achieving high performance, the primary spool around which the primary coil 6 is wound can also be eliminated, and an ignition coil with excellent vibration and insulation properties can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of an embodiment of an ignition coil for an internal combustion engine according to the present invention, FIGS. 2A and B are a partial sectional front view and a plan view of the coil cap portion of FIG. 1, and FIG. FIG. 4 is an electric circuit diagram of an ignition circuit using the coil shown in FIG. It is a circuit diagram. 1...Case, 2...Coil cap, 2a...
...Cylindrical foot part of the coil cap, 2b...Small cylinder part of the coil cap, 2c, 2d, 2e...Flange part, 2f, 2g, 2h...Protrusion part, 3...Secondary bobbin, 4...Center Core, 5... Secondary coil, 6...
...Primary coil, 6a...Main primary coil, 6b...
Auxiliary primary coil, 7...Secondary terminal, 8a...Second
8b, 8c...primary terminals forming the first and third terminals.

Claims (1)

[Claims] 1 central core and 2 arranged around the outer periphery of the central core
A secondary coil, an iron case that houses these, a coil cap made of an insulator that has a cylindrical leg that envelops the secondary coil and closes the open end of the case, and A main primary coil and an auxiliary primary coil are wound vertically and separately on the outer periphery of the cylindrical foot by means of each flange provided in the intermediate portion, and the coil cap is connected to a first terminal connected to one end of the main primary coil provided on the coil cap; a second terminal provided on the coil cap connected to one end of the auxiliary primary coil; a third terminal connecting the other end of the secondary coil and the other end of the auxiliary primary coil, and half of the total number of turns of the auxiliary primary coil are wound in opposite directions, and An ignition coil for an internal combustion engine in which the auxiliary primary coil is short-circuited when starting ignition of the internal combustion engine.