RU2285307C2 - Ignition coil for internal-combustion engine (alternatives) - Google Patents

Abstract

FIELD: electrical equipment for internal-combustion engines including their ignition systems.

SUBSTANCE: proposed ignition coil has case with former that carries magnetic circuit, secondary and primary windings and is disposed in center of case. Secondary winding has high-voltage terminal and primary winding, two low-voltage leads. Coil may be additionally provided with second primary winding. In addition, second primary winding may be provided with third low-voltage lead and secondary winding may have additional high-voltage terminal. Adequate choice of turn number and magnet wire sectional area has made it possible to attain desired effect.

EFFECT: reduced dependence of spark energy on engine mode of operation.

4 cl, 4 dwg

Description

The invention relates to electrical equipment of internal combustion engines, in particular to devices of the ignition system.

Closest to the invention, which is claimed, is the design of the ignition coil B-117 A, including a cylindrical body, in the middle of which there is a frame with a magnetic circuit, secondary and primary windings. Between windings insulation is placed. The windings have one high-voltage terminal and two low-voltage terminals, respectively, for the secondary and primary windings. In addition, the coil has a core, a cover and a spring of the central terminal. The primary winding has 308 turns, the secondary - 21035 turns (see. Car VAZ-2105, Multicolor album, M., 1984, p.65).

The design of this coil is selected as a prototype.

The prototype coincides with the invention, which is claimed, by the presence of common features:

- housing;

- frame;

- magnetic circuit;

- primary winding;

- secondary winding;

- high voltage terminal;

- low voltage leads of the primary and secondary windings.

However, the known coil has a significant drawback, which consists in the fact that the energy of the spark strongly depends on the mode of operation of the engine with a small or heavy load. The energy of a spark is composed of two parts, “capacitive” and “inductive”.

E _spark = E _c + E _u

Capacitive Phase Energy

where c is the capacity of the spark plug

U is the breakdown voltage.

The energy of the inductive phase E _u does not depend on the engine operating mode, but is determined only by the electrical parameters of the ignition system (switch, high-voltage wires and ignition coil).

The energy of the capacitive phase depends on the square of the breakdown voltage, which is directly proportional to the pressure in the cylinder. Pressure, in turn, depends on the mode of operation of the engine: small or large load. The pressure in the cylinder and, accordingly, the breakdown voltage change almost 2 times, therefore, E _c changes almost 4 times.

Therefore, the excessive dependence of E _c on the engine operating mode determines the strong dependence of the spark energy on the magnitude of the engine load, which makes the task of determining and maintaining the optimum ignition timing in the control systems of internal combustion engines very difficult.

The basis of the invention is the task in the ignition coil for internal combustion engines by providing an additional primary winding with a low voltage output, securing the secondary winding with an additional high voltage terminal, and also, due to a certain number of turns of the primary and secondary windings and selecting a specific wire section, to reduce the dependence of the spark energy from the engine operating mode.

The problem was solved by a group of inventions that are connected by a single inventive idea. In the first embodiment of the group of inventions, the problem is solved in the ignition coil for internal combustion engines, which is a transformer comprising a housing, in the middle of which there is a frame with a magnetic circuit, secondary and primary windings having a high-voltage terminal and two low-voltage leads, respectively, to the secondary and primary windings , the fact that the secondary winding contains 150-3000 turns of wire, which has a cross section of 0.11 ÷ 0.55 mm ² , and the primary winding has 7 ÷ 40 turns of wire, which has a cross section of 0.85 ÷ 2, 5 mm ² .

In the second embodiment of the group of inventions, the problem is solved in the ignition coil for an internal combustion engine, which is a transformer containing a housing, in the middle of which there is a frame with a magnetic circuit, secondary and primary windings having a high-voltage terminal and two low-voltage leads, respectively, to the secondary and primary windings in that the secondary winding comprises 150-3000 turns of wire having a section of 0.11 ÷ 0.55 mm ^2, and the primary winding has 7 ÷ 40 turns of wire having a section of 0.85 ÷ 2.5 mm ^2, When this secondary winding further comprises a high voltage terminal.

In the third embodiment of the group of inventions, the task is solved in the ignition coil for an internal combustion engine, which is a transformer containing a housing, in the middle of which there is a frame with a magnetic circuit, secondary and primary windings having a high-voltage terminal and two low-voltage leads, respectively, to the secondary and primary windings in that the secondary winding comprises 150-2000 turns of wire having a section of 0.85 ÷ 2.5 mm ^2, wherein the coil further comprises a second primary coil which 7 ÷ comprises 40 turns of wire having a section of 0.85 ÷ 2.5 mm ^2, in addition the second primary winding is provided by a third low-voltage terminal.

In the fourth embodiment of the group of inventions, the task is solved in the ignition coil for an internal combustion engine, which is a transformer containing a housing, in the middle of which there is a frame with a magnetic circuit, secondary and primary windings having a high-voltage terminal and two low-voltage leads, respectively, to the secondary and primary windings in that the secondary winding comprises 150 ÷ 2000 turns of wire having a section of 0.11 ÷ 0.55 mm ^2, and comprises a primary winding 7 ÷ 40 wires having a section of 0.85 ÷ 2.5 turns m ^2, moreover, the second primary winding is provided with a third low-voltage terminal and the secondary winding further comprises a high voltage terminal.

New in the first embodiment of the group of inventions is the number of turns of the wire of the secondary and primary windings, as well as the cross-section of the wire of the secondary and primary windings.

New in the second embodiment of the group of inventions is the presence of an additional high-voltage terminal at the secondary winding.

New in the third embodiment of the group of inventions is that the secondary winding contains fewer turns of wire, in addition, the coil further comprises a second primary winding, which is provided by the third low voltage output.

New in the fourth embodiment of the group of inventions is that the secondary winding is provided with an additional high-voltage terminal.

Due to the selected parameters of the ignition coil (a small number of turns of the secondary winding, a large diameter of the wire), the output resistance of the secondary winding is approximately 500 times less than in the coil of the prototype, and practically does not affect the current value of the "inductive" phase. Inductive phase current and duration are determined by the difference between the stored energy of the primary winding

energy of the "capacitive" phase

If you use wires without resistance and spark plugs without a built-in resistor, the current of the "inductive" phase is practically determined only by the ohmic resistance of the spark. Therefore, with a decrease in the energy of the "capacitive" phase in the minimum engine load mode, the energy of the "inductive" phase accordingly increases. The current of the "inductive" phase of the proposed ignition coil in low load mode is 20 times higher than the current of the ignition coil of the prototype. Therefore, the energy of the spark is practically independent of the engine operating mode. This greatly simplifies the task of determining and maintaining the optimum ignition timing of the internal combustion engine.

The proposed coil is shown in the drawing.

Figure 1 - sectional view of the coil, the first option;

figure 2 is a view of the coil in section, the second option;

figure 3 is a view of the coil in section, the third option;

4 is a sectional view of a coil, a fourth embodiment.

The ignition coil for an internal combustion engine according to embodiment 1 (FIG. 1) comprises a housing 1, in the middle of which a sectioned frame 2 is placed, on which a secondary winding 3 is wound so that the end of the winding of one section is connected to the beginning of the winding of the next section. The secondary winding 3 contains 400 turns of wire having a cross section of 0.25 mm ² . On top of the secondary winding 3, a primary winding 4 is wound, containing 12 turns of wire, which has a cross section of 1.2 mm ² . Between the secondary winding 3 and the primary winding 4 an insulating layer 5 is placed. The partitioned frame 2 is surrounded by a magnetic core 6 in which the gap 7 is made. The secondary winding 3 has a high-voltage terminal 8. The primary winding 4 has a first low-voltage terminal 9 and a second low-voltage terminal 10, which is connected with the beginning of the secondary winding 3. The primary winding 4 also has an insulating layer 11.

The ignition coil according to option 2 (figure 2) differs from the coil according to option 1 in that it has an additional high-voltage terminal 12, which is connected to the beginning of the secondary winding 3.

The ignition coil according to option 3 (figure 3) differs from the coil according to option 1 in that it has a second primary winding 13 and a third low-voltage terminal 14. The second primary winding 13 contains 20 turns of wire, which has a cross section of 1.1 mm ² , it is wound on top of the primary winding 4 on the insulating layer 15. The beginning of the second primary winding 13 is connected to the first low voltage terminal 9, and its end is connected to the third low voltage terminal 14. The direction of winding of the second primary winding 13 is opposite to the direction of winding of the first primary winding 4.

The ignition coil according to option 4 (figure 4) differs from the coil according to option 3 in that it has an additional high-voltage terminal 12, which is connected to the beginning of the secondary winding 3.

The ignition coil for an internal combustion engine according to option 1 operates as follows. An electric current is supplied to the first low-voltage terminal 9 and the second low-voltage terminal 10, which, passing through the primary winding 4, forms a magnetic field, the flow of which is closed through the magnetic circuit 6. The gap 7 in the magnetic circuit 6 reduces the residual magnetization by unipolar current pulses that flow in the primary winding 4. At the moment the current is turned off in the primary winding 4, the self-induction ε _emf appears, which forms a high voltage (~ 25 kV) in the secondary winding 3, breaking through the high-voltage terminal 8 of the secondary winding 3 air gap of the spark plug (not shown in the drawing).

The operation of the ignition coil for an internal combustion engine according to option 2 differs from the operation of the coil according to option 1 in that, due to the fact that another spark plug (not shown in Fig. 2) is additionally connected to it (to the high-voltage terminal 12), a spark is simultaneously generated in two spark plugs.

The operation of the ignition coil for an internal combustion engine according to option 3 differs from the operation of the coil according to option 1 in that, after a breakdown, a current is supplied to the second primary winding 13 through low-voltage leads 9 and 14, which supports the current of the secondary winding 3 and, accordingly, the current "inductive" spark phase. The magnitude of the current of the secondary winding 3 reaches 5 A, and its duration is determined by the duration of the current of the second primary winding 15.

The operation of the ignition coil for an internal combustion engine according to option 4 differs from the operation of the coil according to option 3 in that due to the connection of another spark plug (not shown in FIG. 4) using a high-voltage terminal 12, a spark is generated simultaneously in two candles.

The current of the "inductive" phase is determined by the formula:

For the coil described in the prototype Imax≈100 mA,

τ = 0.3 ms.

For coils of option 1 and option 2:

where U _VOIF - voltage of the secondary winding of the "inductive" phase,

r _v.o - resistance of the secondary winding,

r _V.P - resistance of a high-voltage wire,

r and _p - the resistance of the spark gap.

For ignition coils according to option 3 and option 4

U _v.o.f. ≈250 V,

to that

The above calculations indicate that the current of the inductive phase in the ignition coils, which are claimed, far exceeds this indicator for the known ignition coil.

Claims (4)

1. The ignition coil for an internal combustion engine, comprising a housing, in the middle of which is a frame with a magnetic circuit, secondary and primary windings having a high-voltage terminal and two low-voltage leads, respectively, to the secondary and primary windings, characterized in that the secondary winding contains 150 ÷ 3000 turns wire, which has a cross section of 0.11 ÷ 0.55 mm ² , and the primary winding has 7 ÷ 40 turns of wire, which has a cross section of 0.85 ÷ 2.5 mm ² . 2. An ignition coil for an internal combustion engine, comprising a housing in the middle of which is a frame with a magnetic circuit, secondary and primary windings having a high-voltage terminal and two low-voltage leads respectively to the secondary and primary windings, characterized in that the secondary winding contains 150 ÷ 3000 turns a wire having a cross section of 0.11 ÷ 0.55 mm ² , and the primary winding has 7 ÷ 40 turns of a wire having a cross section of 0.85 ÷ 2.5 mm ² , while the secondary winding further comprises a high voltage terminal. 3. The ignition coil for an internal combustion engine, comprising a housing in the middle of which is a frame with a magnetic circuit, secondary and primary windings having a high voltage terminal and two low voltage terminals respectively to the secondary and primary windings, characterized in that the secondary winding contains 150 ÷ 2000 turns a wire having a cross section of 0.85 ÷ 2.5 mm ² , while the coil further comprises a second primary winding, which contains 7 ÷ 40 turns of a wire having a cross section of 0.85 ÷ 2.5 mm ² , in addition, the second primary winding o secured by a third low voltage output. 4. The ignition coil for an internal combustion engine, comprising a housing in the middle of which is a frame with a magnetic circuit, secondary and primary windings having a high-voltage terminal and two low-voltage leads respectively to the secondary and primary windings, characterized in that the secondary winding contains 150 ÷ 2000 turns a wire having a cross section of 0.11 ÷ 0.5 mm ² , and the primary winding contains 7 ÷ 40 turns of a wire having a cross section of 0.85 ÷ 2.5 mm ² , in addition, the second primary winding is provided with a third low-voltage output, and the secondary the coil contains an additional high-voltage terminal.

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