CN100575696C - The ignition system that is used for explosive motor - Google Patents

Abstract

This equipment relates to vehicle structure, i.e. the spark ignition system of explosive motor.The present invention can improve the reliability of engine performance, particularly under the situation of low temperature and high humility.Spark coil in this ignition system is designed to make that the wave impedance ρ by inductance in the secondary windings and the formed vibrator circuit of effective capacitance is in the following scope under considering the situation of leakage current: (1.4U _Br)/I _Max＜ρ＜(4.5U _Br)/I _Max, U wherein _BrBe the minimum value that is used for guaranteeing the voltage of the discharging gap that punctures, I _MaxBe to be used to make spark can not be converted to the maximum allowed current of the sparkover of low voltage Arc Discharge.The value of wave impedance ρ in this scope and the parameter of sparkover (breakdown voltage and discharge current) adapt, and this has reduced the energy loss of not expecting in the ignition system, and has improved spark power.

Description

The ignition system that is used for explosive motor

Technical field

The present invention relates to vehicle structure, be specifically related to be used for the electronic ignitin system of explosive motor (ICE).The present invention can be used for spark ignition system, thereby motor is more stably being operated under the condition of low temperature and/or high humility and under the situation of low quality of fuel-air mixture.

Background technique

Known a kind of equipment that increases the amount of plasma of the spark in the spark plug (calendar year 2001 disclosed Russ P 2171909, Int.class 7F02P3/04, F02P3/08).This equipment comprises the series LC circuit in parallel with the spark gap that is close to spark plug, with the influence of the rheostan of the secondary circuit of arc control plug.By spark is increased by 8 to 10 times period of combustion, this equipment has increased by 3 to 4 times with the spark amount, and has strengthened ionization and thermal effect.This known equipment has solved the problem that spark current increases, but additional element has been introduced this scheme.The major defect of this ignition system is the higher wave impedance (ρ～1M Ω) of the vibrator circuit that forms of the secondary windings by spark coil, and it is easily by leakage impedance (leakageimpedance) the institute bypass in the circuit.

The relaxation oscillation system (Russ P of announcing in 1996 2054575, Int.Class 7F02P3/04) that can pass through the electronic ignition of ICE obtains the controlled continuous discharge endurance of needed time.Two additional diodes have been introduced this ICE ignition system, and the primary circuit of the spark coil of this ICE ignition system comprises high voltage thyristor-capacitor unit, low voltage supercharger unit and thyristor switch.First diode is in parallel with the circuit of being made up of thyristor and capacitor, and connects thyristor anode and supercharger unit.The output of the mid point of second diode and thyristor-capacitor circuit and the elementary winding of spark coil links to each other.Ignition system produces the Zhang Zhen that speeds and swings, thereby can support needed time to the continuous discharge electric current, and forms wide initial flame front end.This ignition system has been guaranteed the active combustion of fuel mixture, and has improved fuel consumption efficiency.The shortcoming of this system is the introducing of add ons.The use of the existing spark coil of standard can not solve the shortcoming of higher wave impedance ρ of the vibrator circuit of secondary windings.Because the spark plug discharging gap is by the bypass of leakage impedance institute, this has reduced the operation of motor under adverse condition and the reliability of startup.

According to disclosed Russ P RU 2107184 in 1998, Int.class 7F02P3/04 under-adverse condition (particularly time) in the winter time, used the spark ignition system of ICE to help ato unit as can be known.This ignition system comprises: the transformer, voltage multiplier, voltage stabilizer and the circuit breaker that are included in the series connection in the elementary winding of spark coil.Introduced bigger additional spark gap in the secondary windings circuit of the spark coil before the spark plug discharging gap.This structure has reduced the leakage current effect of not expecting, the spark that makes almost whole energy all spend in the spark plug produces.Yet this structure is not eliminated the capacitor discharge stage (capacitancephase of a discharge), and wherein the major component of the current energy in the discharging gap spends in the destruction sparking-plug electrode.Another shortcoming is that this scheme has increased complexity, has introduced the add ons that is used for voltage stabilizing in a large number, and has corroded the material in the additional spark gap extraly.

At the ignition system of standard (for example, referring to the author is S.V.Akimov and Yu.P.Chizhov " Electrical equipment of automobiles ", a manual for higher school, the 188-191 page or leaf, " Za Rulem ", the common element of the ignition system maximum quantity that includes 2001) and proposed is elected to be immediate homologue (prototype) with this system.Oscillating circuit (tank) and active resistance (active resistance) in the circuit of spark coil, spark gap and this primary and secondary winding that this prototype ignition system comprises power supply, switch, be made up of primary and secondary winding and magnetic conductor.The shortcoming of this standard ignition system is its insecure performance.In flue dust on the spark plug insulator and humidity and the ignition distributor and dirt on the high voltage wire and the condensation product total failure that caused engine wobble or ignition system.Particularly this thing happens through regular meeting during the use motor vehicle under the low temperature in the winter time.

Analyze and show that in typical ignition system, when generation high voltage and discharge current on spark plug flowed therein, quite a few energy that is stored in the spark coil was depleted.Main loss is because the leakage current in the high voltage circuit.In addition, serious induction loss has taken place in magnetic conductor and the capacitor discharge at coil in the stage.

Summary of the invention

Problem solved by the invention is, owing to eliminate " expense " loss by making to be complementary with sparkover parameter (being breakdown voltage and discharge current), thereby increased the reliability of the spark generation of spark power and ignition system by numerical value as the wave impedance ρ of the inductance of the part of ignition system and the formed circuit of electric capacity.

Reach this technique effect by the following fact: as prototype, the ignition schemes that is proposed comprises the spark gap in spark coil of being made up of primary and secondary winding and magnetic conductor and the secondary windings circuit that is included in spark coil.

The novelty of the ignition system of being developed is that spark coil is designed to considering under the situation of leakage current, and the wave impedance ρ by inductance in the secondary windings and the formed vibrator circuit of effective capacitance is in the following scope:

$\frac{1.4\&CenterDot;U_{\mathrm{br}}}{I_{\max }}<\mathrm{\&rho;}<\frac{4.5\&CenterDot;U_{\mathrm{br}}}{I_{\max }}$

Wherein, U _BrBe the minimum value that is used for guaranteeing the voltage of the discharging gap that punctures, I _MaxIt is the maximum allowed current of sparkover.By the condition of high-voltage spark burning to the transformation of low voltage plasma arc discharge mode, limit the maximum value of discharge current, for low voltage plasma arc discharge mode, the main energy of this arc is not to spend in heating fuel-air mixture, but spends in the destruction sparking-plug electrode.

Under a kind of particular case, in order to eliminate the loss of capacitor discharge in the stage, can make the winding of the spark coil of stray flux with increase, for example make with the form of wafer.

Under another particular case, because the loss that foucault current causes can use the material with low specific loss to come the magnetic conductor of manufacturing place fire coil, for example rated frequency is the transformer iron core of 400Hz in order to reduce.

During high voltage produced, uncontrolled energy loss was relevant with leakage current.Calculating shows, the representative value of wave impedance ρ with ignition system of standard coil amounts to and is approximately 1M Ω.When in this system owing to revealing impedance and equal wave impedance and leakage current occurs, the voltage in the spark gap approximately reduces twice, this has caused the remarkable reduction of the fault or the spark energy of ignition system.

During the spark burning, the lot of energy loss is the transmission of heat owing to fuel-air mixture, and therefore under the situation of sparklet power, even through longer ignition duration, fuel-air mixture also may not be lighted a fire.

Can carry out following explanation to the effect of the statement that provided.

Can write out separating with the form of the voltage in the circuit by the wave equation of the represented parallel oscillatory circuit of the secondary windings circuit of ignition system:

$U=U_{\mathrm{amp}}\&CenterDot;e^{-\frac{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="C2006800240110010H1.png"\; state="\{\{state\}\}">t</figure-callout>}}{2\&CenterDot;R_{\mathrm{leak}}\&CenterDot;C}}\&CenterDot;e^{(\&PlusMinus;i\&CenterDot;\mathrm{\&omega;}\&CenterDot;t)},---\left(1\right)$

U wherein _AmpBe the vibration amplitude of voltage, ω and t are respectively frequency and time, L, C and R _LeakIt is circuit parameter with common name.

When the switch in the primary circuit of spark coil disconnected, voltage was constantly $t_{\max }=\frac{\mathrm{\&pi;}}{3\&CenterDot;\mathrm{\&omega;}}$ The time at R _Leak=ρ reaches maximum value.The necessary condition of igniting in the spark plug is U at this moment _Max〉=U _Br, wherein

$U_{\max }=I_{\max }\&CenterDot;\mathrm{\&rho;}\&CenterDot;e^{-\frac{{\mathrm{\&rho;}}^2\&CenterDot;t_{\max }}{2\&CenterDot;R_{\mathrm{leak}}\&CenterDot;L}}.---\left(2\right)$

According to equation (2), for the leakage impedance that keeps the discharging gap breakdown condition, we find:

$R_{\mathrm{leak}}\&GreaterEqual;\frac{{\mathrm{\&rho;}}^2\&CenterDot;t_{\max }}{2\&CenterDot;L\&CenterDot;\ln \frac{I_{\max }\&CenterDot;\mathrm{\&rho;}}{U_{\mathrm{br}}}}.---\left(3\right)$

According to equation (3), we find, for the wave impedance of the minimum value of leakage impedance are:

$\mathrm{\&rho;}=\mathrm{1,83}\&CenterDot;\frac{U_{\mathrm{br}}}{I_{\max }}---\left(4\right)$

Supposing has increased by 1.5 times at the acceptable terms that the fault-free of ignition system is served about minimum value, and then we find, but the scope of the permitted value of wave impedance ρ is:

$\frac{1.4\&CenterDot;U_{\mathrm{br}}}{I_{\max }}<\mathrm{\&rho;}<\frac{4.5\&CenterDot;U_{\mathrm{br}}}{I_{\max }}---\left(5\right)$

Consider U _BrAnd I _MaxRepresentative value add up to respectively～10-15kV and～0.3A, we obtain the scope with the corresponding numerical value ρ of condition (5):

50kΩ＜ρ＜180kΩ.(5a)

Obtain making that according to same equation (3) ignition system avoids the leakage impedance of fault, the minimum value of leakage impedance equals wave impedance as can be seen, also is R _Leak=ρ.

Description of drawings

Fig. 1 shows the equivalence of the ignition system that is proposed.

Embodiment

This ignition system comprises: be included in power supply 1, active resistance 2, capacitor 3 and commutator 4 in the elementary winding circuit 5 of spark coil.This spark coil also comprises magnetic conductor and the secondary windings 7 that is designed as magnetic core 6, the discharging gap 11 of electric capacity 9, leakage impedance 10 and spark plug that the circuit of this secondary windings 7 comprises the self-induction 8 of secondary windings 7, calculate according to primary circuit.

Power supply 1 is a battery, and resistance 2 is active resistances of primary circuit.Spark coil is designed to conversion conefficient К ≈ 15-30.Therefore, obtained the system of wave impedance ρ ≈ 100k Ω, it is corresponding with rating value (4).Maximum voltage in the elementary winding 5 of spark coil reaches 1000-1500V, and this has increased the requirement to the selection of the device substrate that is used for commutator 4 (element base).

Can use the have low specific loss material (for example the nominal operation frequency is the transformer iron core of 400Hz) of (specific loss) to come the magnetic core 6 of manufacturing place fire coil.

Secondary windings 7 can also be designed to wafer.In this case, (link to each other with elementary winding without the magnetic flux) self-induction 8 of secondary windings 7 has limited spark current and has eliminated the loss of capacitor discharge in the stage.

Based on the requirement that the energy that produces the required specified quantitative of spark in this system is accumulated, select the existing identical coil parameter of (off-the-shelf) spark coil with industrial design.Under the situation of specific embodiment, the inductance of the elementary winding 5 of spark coil adds up to L ≈ 4mH, coil current I ≈ 6-8A, and the electric capacity that is used to protect electronic switch (commutator 4) to bear superpotential capacitor 3 is C ≈ 0.1 μ F.

The following operation of the ignition system that is proposed shown in Fig. 1.When the commutator 4 in the elementary winding 5 of cut-in point fire coil, produce from power supply 1 through the elementary winding 5 of this coil and the electric current of commutator 4.When this electric current reaches maximum permissible value, accumulated the energy that enough is used for producing sparkover in the coil at spark plug.When from the signal cut commutator 4 of crank position indicator (not shown), the electric current of elementary winding 5 charges to capacitor 3, generates high voltage in secondary windings 7.When reaching in this circuit when enough being used to break the voltage of (break) spark gap 11, puncture, and cause electric current through the secondary windings 7 of this coil.This electric current is made up of the electric current of spark coil self and the discharge current of capacitor 3, by following formula it is calculated as electric capacity 9 at the secondary circuit of spark coil:

C ₂＝C ₁/K ²

Wherein, K is the ratio of the number of turn and the number of turn of the elementary winding 5 of this spark coil of the secondary windings 7 of this coil.

The spark coil of turn ratio that uses modern device substrate to make electronic switch (commutator 4) and have a change of elementary winding 5 and secondary windings 7 has produced following ignition system: it has and the corresponding lower wave impedance ρ of condition (5)～100k Ω, more insensitive for leakage current, and if the sparkover electric current be increased to I _Max≈ 0.3A then has the spark energy that significantly improves.

Ignition system with characteristic required for protection is used for constant energy consumption (constant maximum current of spark coil).Because the numerical value of leakage impedance 10 is almost always greater than the wave impedance ρ of secondary windings circuit, and can therefore do not compared with known homologue by bypass, the system that is obtained is more insensitive for leakage current, this makes it possible to eliminate " expense " loss, thereby solves the problem that is proposed.

Details according to ignition system operation of the present invention is, increased stray flux (magnetic stray flux) owing to comparing with homologue, thereby limited the sparkover electric current, for example, this realizes to eliminate the loss of capacitor discharge in the stage by the secondary windings 7 with the form manufacturing place fire coil of wafer.

Details according to ignition system operation of the present invention is during generation is high-tension, to make the core 6 of coil because use has the transformer iron core of low specific loss, so obviously reduced energy loss (magnetic conductor heating).

The high stability that the spark in the spark plug produces has been determined in test to the ignition system made according to the example of the specific embodiment on the 6th page, though therefore after about 100,000 kilometers spark plugs still keep available.The existence of the smoke deposition on the spark plug insulator, gasoline, antifreezing solution can not influence the stable operation of motor.

The increase of the discharging energy that the ignition system that passes through to be developed is guaranteed causes the burning more fully of fuel mixture, has reduced exhaust toxicity thus.

Industrial applicability

The ignition system of the ICE that develops is based on modern device substrate (assembly) and makes. The number of turn of the secondary windings of ignition coil adds up to～and 2000, because the common number of turn is in 16000 Range to 40000, so this should reduce its cost in producing continuously.

Now, for different vehicle manufacturing tests the ignition system of the ICE that develops Three samples. This test chart understands the high ignition effectiveness of fuel-air mixture.

The ignition system of the ICE that develops prepares to be used for large-scale production.

Claims (3)

1. ignition system of internal combustion engine, comprise: have spark coil, the magnetic conductor of elementary winding and secondary windings and be included in discharging gap in the secondary windings circuit of described spark coil, it is characterized in that described spark coil is designed to make that the wave impedance ρ by inductance in the described secondary windings and the formed vibrator circuit of effective capacitance is in the following scope under considering the situation of leakage current:

$\frac{{1.4\&CenterDot;U}_{\mathrm{br}}}{I_{\max }}<\mathrm{\&rho;}<\frac{4.5\&CenterDot;U_{\mathrm{br}}}{I_{\max }},$ Wherein

U _BrBe the minimum value that is used for guaranteeing the voltage of the discharging gap that punctures, and

I _MaxBe to be used to make spark can not be converted to the maximum allowed current of the sparkover of low voltage Arc Discharge.

2. ignition system of internal combustion engine according to claim 1 is characterized in that the winding of described spark coil is designed to have the stray flux of increase.

3. ignition system of internal combustion engine according to claim 1 and 2 is characterized in that the magnetic conductor of described spark coil is made by the material with low specific loss.

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