Macro-energy long-life semiconductor discharge plug discharge end structure
Technical field
The utility model belongs to Aeronautics and Astronautics engine ignition field, is specially a kind of macro-energy long-life semiconductor discharge plug discharge end structure.
Background technique
Existing aero-engine ignition sparking plug mainly contains: air gap igniter (utilizing air clearance between high-voltage breakdown electrode and the pyrophoric sparking plug of product that discharges), semiconductor discharge plug (utilize the semiconductor element of discharge end to produce initial current, form electron avalanche, cause electric energy to discharge, produce the sparking plug of electrical spark), surface discharge plug (utilizing the sparking plug of ceramics insulator surface gap between high-voltage breakdown centre electrode and lateral electrode).Domestic ripe ordnance engine ignition electric nozzle is also extensive with semiconductor discharge plug.Reason is that the advantage of semiconductor discharge plug is discharge voltage substantially not by the impact of the gentle pressure of gas medium, and igniting reliability is high.And the shortcoming of semiconductor discharge plug is that working life is shorter, the motor equipped our troops the at present supporting semiconductor discharge plug life-span is scarcely more than 1000h.
The working condition requirement of modern opportunity of combat is very harsh, especially to just having higher requirement in working life of sparking plug and reliability, especially require to bring up to more than 2000h to macro-energy (ignition system energy storage is greater than 10J) the ignition system supporting semiconductor discharge plug life-span.With the discharge end structural design of current ignition electric nozzle or most structure with reference to former matured product (flush type, depressed, outboard), and the semiconductor discharge plug of macro-energy long-life adopts depressed structure mostly, shown by shop test and outfield test run result, current product structure can only ensure life of product and reliability at short notice, there is larger failure risk more than long-time use after 1000h, cause a hidden trouble to flight safety.And modern opportunity of combat profile, weight demands are strict, in the situations such as engine interior bad environments (as higher temperature, air pressure), multiple undesirable element is had to suppress the raising of life of product.Therefore seek new semiconductor discharge plug discharge end structure, to mate the life of product index day by day increased, the usage requirement meeting new work engine becomes the problem of urgent research.
Semiconductor discharge plug working principle: semiconductor discharge plug accepts the high-voltage pulse electric energy that ignition mechanism exports, semiconductor discharge plug discharge end is transferred to by firing cable, puncture the semiconductor between centre electrode and lateral electrode, produce electrical spark, the fuel-air mixed gas in ignition engine firing chamber.
The engine combustion room temperature that the sparking plug of macro-energy long-life requirement is generally supporting is also higher, internal environment is complicated severe, find by inquiry, this type of sparking plug discharge end domestic mostly adopts depressed structure (referring to that semiconductor working surface is depressed between centre electrode and lateral electrode) at present.Depressed structure is generally divided into depression dew pole formula and depression hidden pole type.First we analyze the pluses and minuses of two kinds of structures:
A) cave in hidden pole type
What much have oxygenating sleeve pipe (namely has a housing wrapping up sparking plug discharge end in sparking plug outside, oxygen is introduced by the gap between housing and sparking plug, oil gas under auxiliary high altitude conditions ignites), and (being less than φ 6mm) that oxygenating cannula exit aperture is less, the discharge end structure of general employing depression hidden pole type is (see Fig. 2 a).Over head and ears lateral electrode is inner for the centre electrode of this structure, cone match with coated semiconductor, because oxygenating sleeve pipe aperture is less, adopt cone match can increase the excircle dimension of centre electrode as far as possible, the hidden pole type structure that caves in addition has resonant cavity, flame is concentrated lengthen, igniting reliability is high.
But it is still less that the shortcoming of this structure is electrode size, band conical surface electrocorrosion-resisting is poor, and its discharge end outside diameter of product that general oxygenating overlaps aperture less is also less, such cone match will cause semiconductor device head thinner, part strength is poor, in Long-Time Service process, have cracked risk.And the tolerance of size of semiconductor device is general comparatively large, the easy like this conical surface of semiconductor device and centre electrode that causes is fitted closely, can have influence on product performance like this.
B) depression dew pole formula
When conditions permit (discharge end cylindrical comparatively large (being greater than φ 15mm) and without oxygenating cover or oxygenating sleeve pipe aperture larger (being greater than φ 6mm)), depression dew pole formula (see Fig. 2 b) can be adopted, it is larger that this structure centre electrode cylindrical can design, thickness is even, improve the corrosion resistance of electrode, also increase the area of semiconductor working clearance simultaneously, can life of product be improved equally.
But this structure resonance free chamber, flame length is shorter, and igniting reliability is low compared to depression hidden pole type, and this structural semiconductor part is closer to flame high-temperature area, and the operating temperature near coated semiconductor can be made so higher, and application risk is larger.
Summary of the invention
The utility model object is to provide a kind of discharge end structure of macro-energy long-life semiconductor discharge plug, to meet new work engine test progress and flight safety, improve the life and reliability of the supporting semiconductor discharge plug of motor, for China's aeroengine and auxiliary power unit provide high performance semiconductor discharge plug early, carry out the improvement of semiconductor discharge plug discharge end structure.
The new semiconductor discharge plug discharge end structure that the utility model proposes should improve the electrocorrosion-resisting of coated semiconductor and electrode, has the advantage of depression hidden pole type and dew pole formula simultaneously, and improves its shortcoming.Therefore the utility model increases resonant cavity on the basis of depression dew pole formula structure, so both can increase the size of electrode, increase semiconductor work area, be equal to increase consumptive material, improve the corrosion resistance of electrode and coated semiconductor, again there is resonant cavity, can concentrate and lengthen flame, improve igniting reliability.
The technical solution of the utility model is:
Described a kind of macro-energy long-life semiconductor discharge plug discharge end structure, is made up of centre electrode, semiconductor device, lateral electrode, it is characterized in that: lateral electrode internal orifice dimension is φ 6mm ~ φ 7.5mm, hole depth 3mm ~ 6mm; Centre electrode outside diameter is φ 4.5mm ~ φ 6mm, thickness 1.5mm ~ 2.5mm.
Beneficial effect
In order to verify the validity of the long-life semiconductor discharge plug discharge end structure that this patent proposes, 1 semiconductor discharge plug testpieces is machined by above-mentioned discharge end structure, composition ignition system supporting with the ignition mechanism of energy storage 12J, carry out simulating life test in factory, according to the 40s that starts to work at every turn, rest 2min, 3 the rest 10min of working are the job specification of 1 circulation, cumulative activation starts the circulation more than 2000 (starting for 6000 times), this also to have no precedent and reaches its half level in semiconductor discharge plug in the past, life of product obtains and increases substantially, and also record has been carried out to the part important performance characteristic of semiconductor discharge plug in process of the test, test data is shown in Fig. 4.As can be seen from Figure 4, sparking plug testpieces insulation resistance vary stable, minimum discharge voltage is after after a while stable, slow rising, after 6000 energising work, be only elevated to 1200V, follow-up also have the very large rising space, demonstrates this semiconductor discharge plug in long-life using process like this, performance is still stable good, what this discharge end structure was effective improve semiconductor discharge plug working life.
Accompanying drawing explanation
Fig. 1: semiconductor discharge plug work system block diagram.
Fig. 2: semiconductor discharge plug commonly uses discharge end structure; Fig. 2 (a) caves in hidden pole type, Fig. 2 (b) depression dew pole formula.
Fig. 3: the utility model structural representation.
Fig. 4: testpieces life test testing property record.
Embodiment
Below in conjunction with specific embodiment, the utility model is described:
Macro-energy long-life semiconductor discharge plug discharge end structure in the present embodiment will improve the electrocorrosion-resisting of coated semiconductor and electrode, has the advantage of depression hidden pole type and dew pole formula simultaneously, and improves its shortcoming.Therefore be increase resonant cavity on the basis of depression dew pole formula structure, so both can increase the size of electrode, increase semiconductor work area, be equal to increase consumptive material, improve the corrosion resistance of electrode and coated semiconductor, again there is resonant cavity, can concentrate and lengthen flame, improving igniting reliability.
After determining the improvement direction of structure, the optimal size of this structure of primary study, therefore multiple testpieces be machined to this structure, verify the optimized scope of each size, by a series of shop test, finally draw sparking plug discharge end optimal size scope (see Fig. 3): lateral electrode endoporus should between φ 6mm ~ φ 7.5mm, hole depth 3mm ~ 6mm; Centre electrode cylindrical should between φ 4.5mm ~ φ 6mm, thickness 1.5mm ~ 2.5mm; Ensure that discharging gap is between 0.75mm ~ 1.5mm.
1 semiconductor discharge plug testpieces is machined by above-mentioned discharge end structure, composition ignition system supporting with the ignition mechanism of energy storage 12J, carry out simulating life test in factory, according to the 40s that starts to work at every turn, rest 2min, 3 the rest 10min of working are the job specification of 1 circulation, cumulative activation starts the circulation more than 2000 (starting for 6000 times), this also to have no precedent and reaches its half level in semiconductor discharge plug in the past, life of product obtains and increases substantially, and also record has been carried out to the part important performance characteristic of semiconductor discharge plug in process of the test, test data is shown in Fig. 4.As can be seen from Figure 4, sparking plug testpieces insulation resistance vary stable, minimum discharge voltage is after after a while stable, slow rising, after 6000 energising work, be only elevated to 1200V, follow-up also have the very large rising space, demonstrates this semiconductor discharge plug in long-life using process like this, performance is still stable good, what this discharge end structure was effective improve semiconductor discharge plug working life.