1, a spark plug
is generated by a spark discharge phenomenon between the electrodes, by a gasoline engine and a fuel combustion gas mixture so as to timely generate power, but gasoline as a fuel is also difficult to spontaneous combustion even in high temperature environments, in order to make timely burning need to use “fire” to ignite. Here that is the role of spark ignition “spark plug” of. Overall engine performance is good or bad depends entirely flashed spark the spark plug to decide the good or bad. We tend to engine than as a “heart of the car,” but more than that can spark plug as the “engine of the heart.”
2. Materials
The basic operation of the modified car is started from the engine ignition system and the intake system. The spark plugs and ignition system high-voltage wiring is the first step changes.
ordinary spark plugs, spark plugs platinum, iridium spark plugs, the spark plug in fact, this is a different electrode materials and distinguish the particular title. General automobile factory spark plug after the electrode material which is a nickel-manganese alloy (i.e., normal spark plugs), they are generally traveling 10,000 km or one year should be checked or replaced. The platinum spark plug can be achieved within a free check and replace the 100,000 km, and have only recently appeared iridium spark plugs can also achieve this level. This gives the car a great convenience, but a word of warning here, in the repair of the engine if not specifically stated, the repair shop is not going to put on platinum spark plugs, as an ordinary spark plugs only tens of dollars, while the original platinum products are only hundreds of transactions (generally only Mercedes-Benz, BMW and part of a class of high-end cars Toyota car factory was equipped with platinum spark plugs), it is necessary to bear in mind that ordinary spark plug maintenance time, and always check for the wonderful (nothing more than color, spark plug gap, etc.
Platinum, iridium spark plug more expensive price, after all, it is rare! fact very little weight thereof, only a little bit small welding the two electrodes at the tip, but not look down on so little. Why use rare metal, as mentioned before is the first durable. cylindersIn operation, compressed gas mixture, combustion temperature and a high pressure, so that the spark plug electrode temperature as high as 900 ℃, spark ignition case also, the degree of high temperature on the electrodes can be imagined. Since the melting point of silver, gold is too low it can not be used as electrode materials families, and the nickel is nearly 1500 deg.] C melting point and is inexpensive, it is widely applied. Platinum is close to 2000 deg.] C was only melt away, which stability
Natural qualitative and ablative better than nickel. Iridium and emerging material is higher than the melting point of platinum have, therefore more suitable for high-performance engines for a long time, the use for high speeds. Also relatively stable chemical properties of nature are rare, so platinum, iridium at high speed under high temperature, high pressure, still able to provide timely, strong spark. To know that in this extreme case, ordinary spark plugs is likely to issue instability, sparks are not allowed, there may even “fire”, the work of the engine and therefore greatly reduced.
after modification understand why high-performance spark plugs, do not blindly follow the trend. Spark plugs need to change their own circumstances and car use habits contact with. In other platinum spark plugs definitely better, you pay for, whether their own assessment. Iridium spark plug while more expensive, often go to “drag racing” do? If not, a good platinum iridium spark plug is not worse than, no need to waste money.
The spark plug life of the spark plug failure is usually 15000km, long-lasting life of the spark plug 30000km. When the engine is operating, the temperature of the spark plug insulator skirt portion should be maintained at 500 ~ 600 ℃. If the temperature is too low, easy to coke insulator, may cause leakage arising misfire; if the temperature is too high, can lead to pre-ignition and detonation.
3, Troubleshooting
The spark plug in common faults using the following:
(1) melting of the electrode and the insulatingIt takes the shape of a white edge. It indicates that the combustion chamber temperature is too high. This may be too much coke combustion chamber, the valve clearance is too small and the like due to overheating of the exhaust valve failure or cooling device is operated, it may be a spark plug according to the specified tightening torque and the like.
(2) electrode and the insulator rounded junction scar. It showed that pre-ignition engine, ignition timing may be premature or low octane gasoline, high heat value of the spark plug and other reasons.
(3) to the top of the insulator fragmentation. Knocking combustion is the main reason insulator rupture. The premature ignition time, low-octane gasoline, the combustion chamber temperature is too high, it can cause engine knock combustion.
(4) has an insulator top gray and black stripes. This spark plug has leak Stripes, it should be replaced with new parts.
(II), deposits spark plug . Spark plug insulator between the electrode tip and sometimes sticky deposits, will cause serious engine does not work, such as cleaning of the spark plug may be temporarily remedied. In order to maintain good performance, it is necessary to identify the source of the problem.
(1) an oily deposit. There oily deposits on the spark plug, indicating that the lubricating oil into the combustion chamber. If only individual spark plugs, the valve stem seal may be damaged. If the spark plugs of each cylinder such deposits are sticky, indicating channeling oil cylinder, check the air cleaner and the ventilation system is blocked.
(2) The black deposit. The spark plug electrode and the inner black sediment indicated that mixture is too thick, the engine running speed can be increased, and a few minutes, can burn left on the electrode layer of black soot layer.
4, health check
(1) on the vehicle inspection method
A, the touch method: starting the engine, so that idling touch the plug insulating ceramic parts, such as the temperature rises very soon, indicating that the spark plug is normal, otherwise it is not normal.
b, the short-circuit method: starting the engine, idling operation itSwitch, then the spark plug with a screwdriver on the cylinder by a short circuit, and listen to the sound of the engine speed changes, changes in sound speed and clear, indicating that the spark plug normal, otherwise abnormal.
c, flashover method: Unscrew the spark plug on the cylinder block, with a high-voltage test fire, without spark or weak spark, the spark plug show leakage or inoperative.
(2) View colorimetric method
Remove the spark plug was observed, such as russet or rust, showed a spark plug normal; such as stains oil, showed that the spark plug gap disorder or excessive oil, high-voltage short or open; the black smoke was indicative of the spark plug or the wrong type of hot and cold air mixture concentrated, channeling oil; as sediments between the electrode tip, when the oily deposit, described independent cylinder channeling oil to the spark plug, when the black deposits, spark plug fouling and bypass instructions, when gray deposit, is covering the electrode lead additives in gasoline misfire; if severe erosion, such as scar from the top, black burst pattern, melting of the electrode, the spark plug showed damage.
5, the choice of
above to check the spark plug damaged indeed, should be been replaced, the end of life in addition should also be replaced. The structure should replace the spark plug of the engine performance characteristics, particularly the engine specification should be selected predetermined model. The use of the spark plug fouling seriously, one should choose a large heat value of the spark plug; hot when the engine has an ignition phenomena, the spark plug should be selected from the heat of a small value. Multi-cylinder engine to ensure that each cylinder spark plug type, recency unity. Recommended replacement group, avoid runs the risk. For imported cars, can be used instead of the absence of a spark plug made model fitting, alternative models of the required spin thread length, thread diameter and heat value must be consistent with the original model.
6, cleaning
spark plug gap inspection adjustment
(1) Gap Measurement
gauge or thickness gauge inspection specific amount, but the thickness gauge of the measured value is not accurate .
(2) lash adjuster
Application of a special tool to adjust the pulling-side electrode, or can not be pulled tap center electrode.
Note :
When the multi-polarity spark plug gap adjustment should be made on each side of the center electrode and the electrode gap as uniform as possible. Each cylinder spark plug gap should be substantially consistent. The spark plug gap and related conditions, such as the CA6102 type gasoline engine, the spark plug electrode gap winter predetermined 0.6-0.7mm, other seasons of 0.9-1.0mm.
7, Precautions for Handling
(2) behind the engine cooling detachable, unscrewing when the spark plug is to be removed, one by one clean blowing dirt around the spark plug with a thin hose, to prevent the dirt falls out of the spark plug screwed combustion indoor.
(3) around the screw, the spark plug electrodes and gaskets must be kept clean, dry and free of oil, otherwise it will lead to leakage, leakage, weakening the spark failure.
(4) when installed, the first screw hole aligned with the spark plug socket, gently screwed screwed to about 1/2 of the entire length of the screw, and then urging the lever fastening. Poor hand, should exit if checked whether positive screwing screw thread or absence entrained impurities, must not blindly urging fastening screw to avoid damage, affecting head, in particular an aluminum alloy cylinder head.
(5) should be tightened as required, too loose will result in leakage, loss of elasticity of the gasket is too tight, it will also cause leakage. Cone-type spark plugs because they are not packing, comply with the tightening torque of utmost importance.
8, using
In actual operation, in addition to the right to choose their own car spark plug, there are some measures that can effectively control a variety of the contamination, give full play to the spark plug. For example, avoid prolonged low-speed, low-load operation; reduce idling time, experts believe that more and more car idling the car damage cars; avoid ultra-high speed, overload, if not change, like buy a mobile phone, it is best not to drag racing ; fuel to maintain a certain purity, look for the brand of oil is critical; avoid hard acceleration, sudden speed reduction and other bad driving habits. The only way to effectively control the contamination variety of spark plugs, spark plug extend the life and improve the work efficiency of the engine.
9, life
spark plug life, often used as a consumable electrode to measure lifetime is defined spark plug as “until the electrodes can not jump normal spark So far, “the impact of large consumption visible on the spark plug electrode life. A consumable electrode by ablation (burning caused by the electrical ignition) and corrosion (chemical, thermal effect) caused, in turn related to the electrode with the electrode material and the operating temperature. Practical tests show, to a temperature above 580 ℃ electrode corrosion begins, the temperature rises and a corresponding increase in the corrosion, the vicinity of 890 ~ 1000 ℃ oxidation begins. If an invasion (burning) etching, the electrode becomes angular arc, the electrode gap becomes larger, so that flashover between the electrodes will increase the necessary discharge voltage. With the general increase in the electrode gap with the engine running or the car distance necessary discharge voltage are constantly rising, more voltage will be provided to limit the ignition coil, so ignition more difficult, and ultimately breakage occurs fire. Spark plug life will end here.
10, specifications
In an overseas M14 and M12 thread diameter mainly, M10 followed; M14 of the main only, M12 and M10 spark plug produced in special cases. Spark plug model representation of different countries, such as represented T8126J spark plug, where “T” denotes structure type, “8” indicates hexagonal thread size and on the side, “12” indicates the length is screwed “6” represents heat value, “J” represents a feature, structure type common standard type (represented by B), projection type (represented by T). There are three kinds of sizes Thread 1,4,8, 1 denotes M10 × 1, S = 16; 4 represents M14 × 1.25, S = 19; 8 represents M18 × 1.5, S = 22. Is screwed lengths 11, 12, three. Calorific value comprises nine digits 1 to 9; low calorific value wherein 1 to 3, 4 to 6 are heat value, the calorific value of 7-9. The higher heating value, the faster the heat, cold type spark plug; lower calorific value, the slower the cooling, thermal type spark plug.
11, the structure
by a center electrode, cylindrical core wire, a ceramic insulator, a conductive glass or the like.
12 kinds
according to the heating value of the high and low points, a cold type and thermal type; electrode material according to points, nickel alloy, silver alloy, platinum alloy and the like; if more professional look, the spark plug of the type generally are the following:
1, the quasi-type spark plug:
which is an insulator the skirt is slightly retracted into the housing end, outside the housing end side electrode, is the most widely used one.
2, spark plug projecting rim body:
insulator long skirt, projecting outside the housing end. It has an endothermic capacity, and good dirt capacity, and can be directly cooled by the intake air temperature is lowered, and thus is less likely to cause hotIgnition, so a wide range of thermal adaptation.
3-electrode type spark plug:
which electrode is very small, and there is a strong spark, good ignition ability, in the cold season, but also to ensure the engine quickly and reliably start, wide thermal range, to meet a variety of uses.
4, Block type spark plug:
and which is screwed into a threaded housing is made conical, and therefore the gasket can not maintain a good seal, thereby reducing the volume of the spark plug the design of the engine is more favorable.
5, polarity type spark plug:
side electrode is generally two or more, the advantage of reliable ignition, do not require frequent adjustment of the gap, it is easy electrode and ablative spark plug gap adjustment can not always some of the gasoline is often used.
6, surface flashover type spark plug: between the
That is creeping gap, which is a coldest-type spark plug, the center electrode and the end face of the housing the gap is concentric.
In addition, in order to suppress radio interference automotive ignition system, but also the production of the shielded resistor type and a spark plug. Resistive type spark plug is a spark plug with a built-in resistance 5-10kΩ, the spark plug is shielded with a metal housing shielding the entire spark plug is sealed. Shielded spark plug can not only prevent radio interference, it may also be used for waterproofing, explosion-proof case.
13, functions and effects
Where the gasoline engine has a spark plug, a one-cylinder, gasoline engine speed of each individual cylinder is also provided with two spark plugs. Although only a spark plug is a small part, but it is extremely important, without it the engine would not move. Those who frequently drive people will be very familiar with this stuff.
The role of the spark plug an ignition coil of the high voltage (10,000 volts or more) into the engine cylinder, sparks ignite the mixture between the electrodes of the spark plug gap. The spark plug of extremely poor working conditions, the spark plug to an ordinary four-cycle gasoline engine as an example, the temperature in the intake stroke onlyThere are 60 ℃, pressure of 90KPa; in ignition combustion, the temperature instantly rises to 3000 deg.] C, a pressure of 4000 kPa; this thermal shock alternating high frequency, can not generally cope material, but also to ensure the insulation performance, Thus as the requirements for the spark plugs and very harsh.
The spark plug is very small, a few pockets put away, but it is not simple configuration. It has two major components of the insulator and the metal housing: a metal housing is threaded for screwing into the cylinder; insulator is installed in the housing, through which the inside of a center electrode, an upper end of the center electrode with a wire nuts, the connection from the distribution board over high voltage power lines; welded at the end face of the housing has a ground electrode, there is a gap of 0.6-1.0 mm between the center electrode and the ground electrode, the high voltage through this gap will burst out into the spark ignition gas mixture .
is a key part of a spark plug insulator, does not work if the insulator, a high voltage will “short cuts” in lieu of the poles into the ground, resulting in no sparks. The spark plug insulator must have good mechanical properties and a high withstand voltage, high temperature shock resistance, chemical corrosion ability to use more ordinary spark plugs alumina-based ceramic is made. The size of the spark plug is uniform around the world, on any car can be common, but the gasoline engine types are different, so the spark plug will be divided into two basic types, hot and cold type type. Cold type heat type is relative, it reflects the thermal performance characteristics of the spark plug. Spark plugs have a proper temperature to work well, no coke to work properly. Practice has proved that the spark plug insulator is maintained at a temperature of 500-600 deg.] C, the droplets fall on the insulator can be burned off instantly without forming coke, this temperature will be higher than the pre-ignition temperatures lower than the coke. In different engine temperature will be different, designers using the length of the insulator skirt to resolve this conflict. Some short skirt small heating area, rapid cooling, so these low temperatures the skirt, called cold spark plug for high-speed high-power engine compression ratio; some large skirt elongated heating area, heat slowly, so the skirt portion higher temperature, called thermal type spark plug, suitable for low power low speed low compression ratio engines. What spark plugs with your own car, to use the provisions in accordance with the manufacturer’s model, not a spark plug are applicable.
The spark plug of this stuff looks simple, but not easy, itRequirements for materials and manufacturing processes is very high, due to the working environment is very bad, spark plug insulator breakdown, electrode coke failure often occurs, therefore it belongs to the “consumables”, there are a lot of drivers spark plug toolbox standing order replaced at any time. Of course, with the development of technology, the spark plug durability also increased, copper electrode materials used to replace conventional platinum alloy – nickel alloy, extending the life of spark plugs, spark plugs commonly used modern car mileage of about one hundred and fifty thousand kilometers .
select the factors to consider more spark plug, such as engine type, cooling mode, the number of strokes, fuel grade and use of conventional ambient temperature conditions and the like. Motorcycle general, the spark plug when the vehicle has been factory model is determined, in the case where the size of the installation matches, the user can heat the old and new values of the spark plug to be selected according to the ambient temperature, the road conditions, the machine. Under standard conditions, typically a spark plug such as domestic heating value of the model used is 5 (7.8 NGK in Japan), when the temperature below 5 ℃, then it should be used in a low heat value of the spark plug to ensure an operating temperature of the spark plug skirt. For the old engine, the spark plug of a selection of low calorific value, can resist contamination due to mechanical abrasion channeling oil on the spark plug.
14, damage
First, the fault should be checked. Cleaning throttle, after replacing the spark plugs and high-voltage lines, the fault does not improve, when the air conditioning failure phenomenon is more pronounced. When the oil pressure gauge connected test, the jitter idling, stalling, the hydraulic pressure is maintained at 260 kPa, indicating that the normal supply; Check the cylinders and the ignition off cylinder operation state using the method, high voltage is removed first cylinder, a spark plug with a good do flashover test, but does not stall while engine shake; 2,3,4 cylinder respectively remove high-voltage flashover test doing, it is difficult to start the engine, even occasionally activated will automatically turn off. Whereby the first cylinder is determined that the spark plug workFor the poor.
Next troubleshooting, after the first cylinder new spark plug replacement, failure to completely eliminate.
Finally, failure analysis, verification data of the ignition system that models: modular vehicle, distributorless type, dual spark-static high-voltage distribution ignition system, the body has a static high-voltage distribution ignition coil 2 each ignition coil secondary output of each 2, is connected to the spark plugs of each cylinder through high-voltage respectively, is formed dual ignition circuit. When the ignition coil normal ignition, the spark plug gap when the two normal work of a compression top dead center in the cylinder, compressing the combustible mixture, the impedance between the electrodes of the spark plug is formed small, easily breakdown flashover ignition charge the spark plug is concentrated to the spark acting cylinder; and the impedance of the cylinder relative to the other due to the dead center in the exhaust gas, the gas cylinder is formed larger, difficult to breakdown flashover, thus ensuring the normal work cylinder ignition . When a short circuit of a spark plug, the spark plug breakdown voltage is reduced, most of the energy lost by the failure of the spark plug, resulting in another cylinder not firing properly, resulting in two cylinders are working poor, it is difficult to start the engine; and when a spark plug when the short circuit occurs because of the high breakdown voltage of the spark plug, the spark ignition energy is a spark plug by the normal, therefore, still another normal ignition operation relative cylinder, three cylinder engine has to work properly, so the stability and dynamic very poor.
15, the calorific value of
representative of its heat value of the spark plug cooling speed. The larger the faster the heat radiation different values (or colder spark plug), requires the use of different engine spark plugs, it must be fitted. In general, a car driving speed, the compression ratio within the cylinder, required a high calorific value (heat dissipation) of the spark plug, the cart is generally slow speed, usually with a low calorific value (slow cooling) of the spark plug.
is too high calorific value, i.e., excessive heat, easy to make spark plug temperature is too low, the ignition head produce coke, causing electric leakage, fire to play no spark plug; and the heat value is too low, not enough heat, spark plug temperature is too high, can cause knocking, etc., easy to make the ceramic plug head burning, electrode dissolution.
Each number represents the heat value of the spark plug brand is not the same, can refer to the following table:
DENSO (Denso) – Japan Japan NGK– CHAMPION (Champion) – American the BOSCH (Bosch) – Germany
921 810
144 16.14 9
165 8 12.11
206 10.9 7.6
227 5 8.7
248 4 6.63.61
3 279 4.59
9.5 57 29
3110552
32 10.5 53 [123 ] 34 11
35 11.5
16, brand
If all of the spark plug brand list them out less likely, only four commonly used include common.
1, Bosch Bosch (BOSCH) Group is one of the world’s 500 leading multinational companies,? Mr. founded by Robert Bosch in 1886 in Stuttgart, Germany. After 120 years of development, the Bosch Group has become the world’s most professional automotive technology research and development institutions and the largest auto parts manufacturer. Group’s products include: automotive technology research and development, automotive equipment, auto parts, communications systems, radio and traffic systems, security systems, power tools, household appliances, kitchen utensils, packaging and automation, energy and science and technology.
Although little is known about the Bosch brand stands for an extremely wide range of quality products, but almost no one does not know Bosch. Bosch motorist service station, the Bosch spark plug, the wiper blade or the starter motor, batteries are very familiar, but perhaps do not know their vehicle with perhaps Bosch electrical and electronic systems, engine management system (the Motronic), such as anti-lock system brake system (ABS), electronic diesel control (EDC), published in 1994, and even include vehicle dynamic control system (VDC).
2, NGK was founded in 1936, special pottery industry of Japan, Ltd. (headquartered in Nagoya, Japan), respectively, in 2001 in Guangzhou, China, was established in 2002 in Shanghai Representative Office, through a variety of market divisionAfter the analysis of the results, expected China’s economy to a high level of sustainable growth, and predicted that China’s auto market will be centered on Shanghai and other coastal cities continue to expand, especially as China has entered the motorcycle and car manufacturers on the existing land supply strong demand for this requirement by strengthening the system in 2003 as the first production base in Shanghai, China set up special Tao Co., Ltd. (wholly-owned) was set up. At this point it is possible to provide the world’s highest level of technology and services in China, we firmly believe that the development of China’s automobile industry to make modest contribution.
3, Torch leading products for “Torch” brand of spark plugs, high-voltage lines, ignition coils, ignition system is the largest manufacturing company.
torch spark plug company as General Ford’s suppliers in 2004, with the international industry giants successfully signed converting a cooperation agreement; in 2005 successfully entered the Russian market; successfully complete with the world’s largest small gasoline engine company. With the United States GM technology, Delphi’s AC automated production lines, broad automation assembly line and other professional production lines, and in 2006 to spend again the full acquisition of US Delphi (delphi) spark plug manufacturing plant, introduced a complete set of production equipment, technology, patents; to secure the international advanced spark plug development, production, manufacturing technology, to ensure that the company complies with international engine of the matching requirements.
4, 1949 Denso, Denso Toyota Group separated from independence to the size of 15 million yen of capital and 1445 employees in Kariya, Aichi, Japan established the “Japan’s Denso.” Today, Denso has grown to number one in Japan, the world’s top automotive supplier group company, has 187 affiliates in more than 30 countries and regions, the number of Group employees amounted to 119,919 (2009 March 31 deadline). As in China Denso omnibus company – Denso (China) Investment Co., Ltd. was established in 2003. DENSO offers a variety of products and after-sales service, including automotive air-conditioning and heating systems, electronic automation and electronic control products, fuel management systems, radiators, spark plugs, instrument cluster, filters, industrial robotics, telecommunications and information processing equipment. Currently, Denso total of 21 kinds of products ranked first in the world.
5, other brands: Autolite (United States Auto Leto), Eyquem (France Yikang) and so on. domesticSpark plugs, more brands, in general, the market the more famous manufacturers of quality generally better performance, long service life, of course, price is definitely higher.
According to statistics, Beijing’s vehicle population of about 2.5 million, automobile spark plugs need to be replaced every year nearly 10 million, the average retail price of 20 yuan terms of ordinary spark plugs are factory, the annual consumption of nearly 200 million yuan.
17, the transducer when the vehicle ignition plug
of
Typically, the service life of the spark plug is 15,000 km, the spark plug life is not long-lasting more than 30,000 km. However, many owners of the spark plug is often such kind of problems, not up to their normal life. In fact, the spark plug operating temperature is very high. During normal engine operation, the temperature of the spark plug insulator of the skirt is generally maintained at between 500 to 600 degrees Celsius. Temperature is too high or too low impact on the spark plug is not good. In the spark plug temperature is too low, the spark plug insulator is easy to coke, and ultimately lead to leakage that might yield misfire. If the spark plug high operating temperature, and prone to early ignition engine knock.
The spark plug common fault occurs summarized into two: a severe erosion of the spark plug, the spark plug of the other sediments. Ablative spark plug when the owners discovered a scar on the top of the spark plug or damage, electrode melting occurs when the ablation phenomenon, have shown a spark plug has been destroyed, then you should replace the spark plug. Check the owner can change the spark plug and the color of the symptoms of ablation during the replacement procedure.
1 Symptom: melting of the electrode and the insulator as a white Diagnosis: This phenomenon shows that the combustion chamber temperature is too high. This may be too much coke combustion chamber, causing the valve gap is too small, the exhaust valve is further caused overheating or failure caused by the cooling device work. Failing can also cause the spark plug electrodes melt, the insulator appears white when the phenomenon and tightened.
2 Symptom: rounded electrode and the insulator junction scar Diagnosis: This indicates that pre-ignition engine, ignition timing may be premature or low octane gasoline, high heat value of the spark plug and the like caused by reasons.
Symptoms 3: broken insulator top Diagnosis: General, Knocking combustion is the main reason insulator rupture. The premature ignition time, low-octane gasoline, the combustion chamber temperature is too high, it can cause engine knock combustion.
Symptoms 4: an insulator to the top diagnostic gray black stripes: This indicates that the spark plug has been streaking leak, the owner needs to unconditionally replaced with new parts.
18, works
When the boosted voltage of the engine with the spark plug electrode gap (0.6 to 0.9 mm), the electric field strength between the electrodes increasing, reaches a critical value (about 10,000V), the gap between the electrodes and the discharge channels are formed i.e., “breakdown.” Under the strong electric field, electrons moving at high speed and a high ion channel formed in the discharge of hot gas emitters, i.e. the spark discharge phenomenon. The high temperature electrical spark, generally up to 2,000-3,000 ° C, the combustible gas mixture in the cylinder is sufficient to ignite.
In order to make regular spark plug in normal working condition, so that the operating temperature must be threaded skirt portion held between 450-850 ° C, this temperature range is called self-cleaning spark plug temperature. Such as below 450 ° C, the skirt portion can easily produce coke, and cause a short circuit; such as above 850 ° C, will produce hot ignition phenomenon, i.e. due to the hot gas mixture is ignited, the spark plug rather than by the discharge of course, occurs early fire phenomenon. For the working temperature of the spark plug maintained within the range of 450-850 ° C, it is necessary to maintain the thermal balance of the spark plug, i.e., the heat absorbed equals the heat dissipated. And the heat absorption surface area depends on the size of the skirt portion.
The heat generated when the size of the generator and the compression ratio, the concentration of the mixed gas, the heat dissipation efficiency, air flow and so on. Generally, for high speeds and large loads often, the compression ratio of the motorcycle generators, heat should be used preferably cold type spark plug (i.e., heat value larger number); and for the low speeds, the load is small motorcycle generators, should be used in any thermal transfer type spark plug (i.e., a smaller heat value numbers), the spark plug to ensure normal operating temperature.