JP2008232100A - Ignition mechanism and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition mechanism and its control method for improving the life of a spark plug and preventing generation of a bridge by removing sweat particles. <P>SOLUTION: The ignition mechanism has the spark plug 1 arranged on each cylinder, a discharge energy generation device 5 for generating primary voltage supplied to a spark coil 3, and a control device 6. The control device 6 performs control wherein low-level discharge energy Ew sufficient to generate a spark necessary for ignition between the spark plug and an electrode and high-level discharge energy Es sufficient to remove sweat particles generated on the electrode of the spark plug 1 are alternately and repeatedly outputted from the discharge energy generation device 5 to the spark coil 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ignition mechanism for a spark plug in a spark ignition engine, particularly a stationary gas engine.

  As shown in FIG. 4, a general ignition mechanism used in a spark ignition engine includes a discharge energy generation means (power source) 10 that generates discharge energy, a high voltage generation unit (ignition coil) 3, and a high voltage generation unit. 3, a high-pressure cord 2 that connects the secondary side of 3 and the spark plug 1, and the spark plug 1. Here, the high voltage generator (ignition coil) 3 has an effect of boosting the generated energy (primary side) of the discharge energy generating means 10 to obtain a secondary high voltage.

The discharge energy generating means 10 is roughly classified into a current interruption type and a capacitor type depending on how energy is stored. The discharge energy generating means 10 is classified into a battery type and a magneto type depending on the discharge energy source.
Here, in any type of energy generating means 10, the discharge energy is kept at a constant value and does not have a function of increasing or decreasing at a constant time interval.

In the conventional ignition mechanism, when the discharge energy is set to a high value, the number of electrons having momentum increases (current increases), so that the electrode wear rate is accelerated. And this wear of an electrode will widen the distance between electrodes, and will raise the request voltage with respect to discharge.
When the increase in the distance between the electrodes and the increase in the required voltage are extremely advanced, no discharge occurs between the electrodes, and external electrode energization occurs in another part having a lower withstand voltage (for example, the insulator part). If this happens, the air-fuel mixture in the engine will not ignite and will misfire.
Therefore, setting discharge energy to a high value has been avoided.

However, when the discharge energy is set to a low value, the energy for physically peeling off the sweat particles generated with the discharge is not supplied. For this reason, the growth of sweating particles cannot be suppressed.
When the sweat particles grow, a bridge is formed between the electrodes, causing a short circuit, so that the spark does not fly. As a result, it still misfires.

In a stationary gas engine, the operating environment of the spark plug is severer than that of, for example, a vehicle engine, and the occurrence of the above problem is more remarkable.
When a misfire occurs in a stationary gas engine, it is necessary to replace the spark plug, which increases the operating cost.
The problem of misfire when the discharge energy is high and low is difficult to improve as long as the discharge energy is supplied at a constant level.

On the other hand, a spark plug with improved durability has been proposed as another conventional technique (see Patent Document 1).
However, in this prior art (Patent Document 1), since the electrode body is made of a material mainly composed of iridium or platinum, the spark plug itself is expensive even if the wear resistance can be improved. , Leaving issues in its economics and increasing the overall cost.
JP 2005-1000074 A1

  The present invention has been proposed in view of the above-described problems, and can improve the life of a spark plug, prevent the growth of sweat particles, and does not require the use of expensive materials. And it aims at providing the control method.

  The ignition mechanism of the present invention boosts a low voltage primary voltage in order to supply a high voltage secondary voltage to a spark plug (1) provided in each cylinder of a stationary gas engine and the spark plug (1). An ignition coil (3), a discharge energy generator (5) for generating a primary voltage supplied to the ignition coil (3), and a controller (6) for controlling the discharge energy generator (5) The control device (6) has a sufficiently low level of discharge energy (Ew) sufficient to cause a spark required for ignition to occur between the electrodes of the spark plug (1), and perspiration generated at the electrode of the spark plug (1). It has a function of performing a control to alternately and repeatedly output the discharge energy (Es) at a high level sufficient to remove particles from the discharge energy generator (5) to the ignition coil (3). Trying Claim 1).

  In the present invention, the control device (6) designates the low level discharge energy (Ew) and its discharge period (Tw), and the high level discharge energy (Es) and its discharge period (Ts). A discharge energy specifying device (7) and a control signal for causing the discharge energy generating device (5) to output the discharge energy (Ew, Es) of the level and discharge period specified by the discharge energy specifying device (7). And a signal generator (6).

  The discharge period (Ts) of the high level discharge energy (Es) is preferably set shorter than the discharge period (Tw) of the low level discharge energy (Ew). ).

  The ignition mechanism control method of the present invention is the above-described ignition mechanism control method (of claim 2), wherein the discharge energy is at a level sufficiently low that a spark required for ignition is generated between the electrodes of the spark plug (1). (Ew) and a high level of discharge energy (Es) sufficient to remove sweat particles generated on the electrode of the spark plug (1) are designated by the discharge energy designation device (7), and the high level of discharge energy is designated. A control signal in which the discharge period (Ts) of (Es) is set shorter than the discharge period (Tw) of low level discharge energy (Ew) is output by the signal generator (8), and thus the discharge energy The generator (5) is controlled (claim 4).

According to the present invention having the above-described configuration, the discharge energy (Ew) at a level sufficiently low that a spark necessary for ignition is generated between the spark plug electrodes, and the sweat particles generated at the electrode of the spark plug (1). The high level of discharge energy (Es) sufficient to remove the energy is alternately and repeatedly output to the ignition coil (3), thereby reducing energy consumption during the discharge period of the low level discharge energy (Ew). It can be suppressed and answer the request for energy saving. At the same time, the amount of wear in the electrode is reduced, the rate of increase in the required voltage is reduced, and it is difficult for the external current to flow.
On the other hand, during the discharge period of a high level of discharge energy Es, the sweat particles are removed from the electrode (physically peeled off), so that the growth of sweat particles and the generation of bridges are prevented.

  Therefore, the discharge period of the low level and the high level of discharge energy is alternately introduced to suppress the generation of the bridge and the occurrence of off-electrode energization, thereby preventing the engine from being stopped due to misfire and the spark plug. Can extend the service life. In particular, for stationary gas engines where the operating environment of the spark plug is severe, the effect of preventing the engine from being stopped due to misfire and extending the life of the spark plug is great.

  Furthermore, by providing the control device (6) for controlling the discharge energy generating device (5) with the discharge energy designating device (7) and the signal generating device (8) (claim 2), the discharge energy as described above is provided. The output control can be carried out reliably and easily.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
The configuration of one embodiment of the present invention is shown in FIG. 1 in block diagram form.
In FIG. 1, the code | symbol 1 has shown the spark plug provided in each cylinder of a stationary gas engine. The spark plug 1 is supplied with a high secondary voltage from the ignition coil 3, and the additive coil 3 boosts the low primary voltage to the high secondary voltage.
The ignition coil 3 is supplied with the primary voltage generated by the discharge energy generator 5.

The discharge energy generation device 5 is configured in a known manner so that the level of discharge energy to be generated is variable. The level and discharge period of the discharge energy generated by the discharge energy generation device 5 are controlled by the control device 6. Be controlled.
The control device 6 includes a discharge energy specifying device 7 and a signal generating device 8.

Although the discharge energy designating device 7 is at a level lower than the conventional discharge energy E ₀ , the discharge energy designating device 7 has sufficient discharge energy Ew (low level discharge energy Ew) that a spark necessary for ignition is generated between the electrodes of the spark plug 1. specify. At the same time, the discharge energy designating device 7 also designates a discharge energy Es (high level discharge energy Es) sufficient to remove sweat particles generated on the electrode of the spark plug 1.
Here, the discharge energy Es has a higher level than the conventional discharge energy E _0.

Furthermore, the discharge energy designating device 7 designates the discharge period Tw of the low level discharge energy Ew and the discharge period Ts of the high level discharge energy Es.
That is, the discharge energy designation device 7 outputs the discharge energy level (low level) Ew, the discharge period Tw, the discharge energy level (high level) Es, and the discharge period Ts to the signal generator 8 as parameters.

  In the signal generator 8, when the discharge energy level Ew, level Es, discharge period Tw, and discharge period Ts are input from the discharge energy designating device 7, the discharge energy generator 5 determines the discharge energy. A control signal is output to the discharge energy generating device 5 so as to output in a pattern.

The output pattern of the discharge energy output from the discharge energy generator 5 is shown in FIG.
In FIG. 2, the vertical axis represents the discharge energy level, and the horizontal axis represents time. As shown in FIG. 2, in the output pattern from the discharge energy generating device 5, the low level discharge energy Ew lasts for a relatively long time, and the high level discharge energy Es is generated for a relatively short time, which is a constant interval. Is repeated.

Lower the output pattern from the discharge energy generating device 5, if the pattern as shown in Figure 2, continued low level of discharge energy Ew is a relatively long time, the level of discharge energy Ew than conventional discharge energy E ₀ Therefore, during the low level discharge energy Ew serving as a base, consumption of electric power energy can be suppressed to meet the demand for energy saving. As a result, electrode wear is reduced, the rate of increase in the required voltage is reduced, and the effect that it is difficult to cause external electrode conduction.

  On the other hand, if a high level of discharge energy Es is discharged, even if sweat particles are generated in the electrode, it is removed from the electrode by the high level of discharge energy Es. Therefore, the growth of sweat particles and the generation of bridges are prevented.

In the illustrated embodiment, a procedure for discharging like the output pattern shown in FIG. 2 will be described with reference to FIG.
First, the discharge energy designating device 7 designates a low level discharge energy Ew, a high level discharge energy Es, a low level discharge energy Ew discharge period Tw, and a high level discharge energy Es discharge period Ts. Are output to the signal generator 8 as parameters (step S1 in FIG. 3).

Based on the parameters Ew, Tw, Es, and Ts specified by the discharge energy specifying device 7, the signal generating device 8 outputs a control signal to the discharge energy generating device 5 so that the output pattern shown in FIG. Step S2).
Thus, the discharge energy is output from the discharge energy generating device 5 to the ignition coil 3 side so as to have the output pattern shown in FIG.

  The procedure of steps S1 and S2 in FIG. 3 is repeated each time a spark is generated in the spark plug 1, and is continued until the operation is completed (step S3 is No loop).

  It should be noted that the illustrated embodiments are merely examples, and are not intended to limit the technical scope of the present invention.

The block diagram which shows embodiment of this invention. The characteristic view which shows the output pattern of the discharge energy in embodiment. The flowchart which shows the procedure of the discharge in embodiment. The figure which shows the conventional ignition mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Spark plug 3 ... Ignition coil 5, 10 ... Discharge energy generation means 6 ... Control apparatus 7 ... Discharge energy designation | designated apparatus 8 ... Signal generator

Claims (4)

  A spark plug provided in each cylinder of the stationary gas engine, an ignition coil for boosting a low primary voltage to supply a high secondary voltage to the spark plug, and a primary voltage supplied to the ignition coil A discharge energy generating device that generates and a control device that controls the discharge energy generating device, the control device having a low level of discharge energy sufficient to cause a spark required for ignition to occur between the spark plug electrodes; The discharge energy generating device has a function of alternately and repeatedly outputting discharge energy at a high level sufficient to remove sweat particles generated on the electrode of the spark plug to the ignition coil. Ignition mechanism.   The control device includes a discharge energy designating device for designating the low level discharge energy and the discharge period, the high level discharge energy and the discharge period, and a level and a discharge period designated by the discharge energy designating device. The ignition mechanism according to claim 1, further comprising: a signal generation device that transmits a control signal that causes the discharge energy generation device to output the discharge energy of the discharge energy.   The ignition mechanism according to any one of claims 1 and 2, wherein a discharge period of the high level discharge energy is set shorter than a discharge period of the low level discharge energy.   3. The method of controlling an ignition mechanism according to claim 2, wherein the discharge energy is low enough to cause a spark required for ignition to occur between the electrodes of the spark plug, and sufficient to remove sweat particles generated on the electrode of the spark plug. A signal generator generates a control signal that designates a high level of discharge energy with a discharge energy designation device and sets the discharge period of the designated high level discharge energy shorter than the discharge period of the low level discharge energy. The control method of the ignition mechanism characterized by controlling the discharge energy generating device.

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