CN100351512C - Electric control oil atomizer - Google Patents

Abstract

The present invention discloses an electric control oil atomizer which comprises a high speed electric control valve, an oil atomizer body, an oil nozzle, etc., wherein the high speed electric control valve is arranged on the upper part of the oil atomizer body; the oil nozzle is fixed on the lower end of the oil atomizer body; the lower end of the needle valve of the oil nozzle is an inverse circular cone, and the circular cone is corresponding to the inverse conic cavity of the oil nozzle to jointly form a variable nozzle. When oil is atomized, the nozzle can vary following the instructions and requirements, and fuel oil is not limited by the diversion closure of an atomizing hole; the true control of oil atomizing rate can be achieved, and the electric control oil atomizer can be widely used in various electric control common rail fuel oil systems of internal combustion engines.

Description

Electric-controlled fuel injector

Affiliated technical field

The present invention relates to internal-combustion engine fuel feeding technology, particularly relate to the electric-controlled fuel injector of internal-combustion engine.

Background technique

Because the Abgasgesetz in short supply and more and more harsher of world energy sources, make the development of internal-combustion engine more and more faster, electronic control injection technology particularly, now with fastest developing speed is the electric-controlled co-rail oil-fired system, typical case's representative has: the UNIJET of company of German Bosch, CRS electric-controlled co-rail system, the ECD-U2 of Japan electric coating company, ECD-U2 (P) electric-controlled co-rail system, the LDCR electricity liquid oil sprayer that other also has the LUCASVARITY company of the DETPHI company of the U.S. and Britain to produce, the piezoelectric crystal electric-controlled co-rail system of moral FEV company and SIEMENS is also practical, in the electric-controlled co-rail oil-fired system, the oil sprayer decisive role, because it is that high pressure fuel is atomized into easy ablaze mist of oil by volume on time, and make mist of oil and firing chamber size, shape matches, being distributed to the firing chamber fully mixes with air everywhere, oil sprayer is except influencing the atomization quality of fuel oil, outside the spray characteristics such as penetration degree and distribution, also to injection pressure, beginning of injection, injection characteristics such as oil spout perdurabgility and fuel injection rate have significant impact, oil sprayer is to the performance decisive role of motor thus, oil nozzle is the final outlet of fuel oil in oil sprayer, is most important element in the oil sprayer.The oil sprayer (mouth) that uses in the present various electronic controlled fuel system is the swing-in oil sprayer, and the disadvantage of swing-in oil sprayer is: can not the regulating and control of nozzle opening liquid communication area.

Because nozzle opening is the final outlet of fuel oil, thus nozzle opening can not regulate and control to have limited injection characteristics and spray characteristics, make oil sprayer under the various operating modes of motor, can't reach desirable oil spout effect, from formula $m=\frac{\mathrm{pihj}.L}{d.t}$ In as can be seen, when unit time t and single fuel injection quantity L one timing, oil atomizing quality m equals the ratio m of injection pressure pinj and nozzle opening cross-section area d, this ratio m is directly proportional with pinj, be inversely proportional to d, if in pinj one d setting value big (high load working condition) regularly, at little load condition particularly during idling operation, because the little m of L is just little, cause that engine idle shakiness or idling are too high, it is the high major reason of engine idle discharging, also make the engine idle excessive oil consumption, the d setting value hour (during a medium and small load) make motor fuel delivery deficiency in the unit time when high load working condition is worked, can only prolong oil injection duration, satisfy the fuel injection quantity demand of motor high load working condition, so just equal to have prolonged the time of diffusive combustion, making engine thermal efficiency worsen power descends, oil consumption increases, and makes soot particle increase in the exhaust, after pinj raises, shortened with the oil mass injection duration, but when loading greatly at a high speed, oil bundle penetration range increases, and mist of oil hits the increase of wall amount, it is bad to atomize, and raising pinj exists a series of technical barriers again in the existing technology.

Another shortcoming of swing-in oil sprayer is: the throttle effect between needle-valve sealing cone and the seat surface, make the real injection pressure of fuel pressure in the pressure chamber lower and spray orifice is certain, cause motor medium and small load particularly during idling throttle effect more obvious, m is less for the fuel-oil atmozation quality, atomization badness.

The 3rd shortcoming of swing-in oil sprayer is: the existence of pressure chamber's volume.Although adopted so-called VCO type oil nozzle, but still there be (comprising each spray orifice total measurement (volume)) in pressure chamber's volume, reducing pressure chamber's volume is one of effective way that reduces HC, CO, experiment shows that the discharging of HC can reduce about 50% when replacing the oil nozzle of 0.6-1.0mm with the volume 0.2-0.3mm of pressure chamber oil nozzle.

Be exactly in addition in the prior art oil sprayer in the electric-controlled co-rail oil-fired system all with the ECD-U2 electric-controlled co-rail oil-fired system of Japan electric coating company in electric-controlled fuel injector x1, x2 is close, so all be pressure+time control, be that injection pressure one regularly decides fuel injection quantity by the length of solenoid valve current"on"time, decide the elevation rate of needle-valve by the Flow characteristics of oil-feed metering-orifice and fuel-displaced metering-orifice, at injection pressure one regularly, the response characteristic of the rising or falling speed decision oil sprayer of needle-valve, also determine simultaneously the graphics shape of fuel injection rate, when the rising or falling speed of needle-valve is high, the fuel injection rate figure is also steep more, otherwise, what the figure of fuel injection rate also just became when the needle-valve rising or falling speed was slow is more slow, the needle-valve elevation rate equals the variation in pressure in the control room, is determined by the ratio between fuel-displaced metering-orifice and oil-feed metering-orifice and the control piston diameter.Certain when the control piston diameter, fuel-displaced metering-orifice is during less than the oil-feed metering-orifice, and the needle-valve rate of climb is slow relatively, and rate of descent is fast relatively, and fuel-displaced metering-orifice descends more slow relatively greater than oil-feed metering-orifice hour hands valve rises fast.

Equaling oil-feed metering-orifice hour hands valve lifting figure at fuel-displaced metering-orifice is the sinusoidal waveform that both sides equate, be that the fuel injection rate figure also is sinusoidal waveform, the anxious shape in slow back before wanting the fuel injection rate figure is, fuel-displaced metering-orifice just must be less than the oil-feed metering-orifice, and the oil-feed metering-orifice is wanted enough could guarantee that oil-break is clear-cut greatly with respect to the control piston diameter, but fuel-displaced metering-orifice also wants enough big with respect to the control piston diameter, too small meeting makes the response characteristic that the needle-valve rate of climb is crossed influences oil sprayer slowly, the pressure maximum that the size of oil pump capacity bore dia be can bear by solenoid valve again limits, the oil pump capacity bore dia is crossed conference makes the negative section pressure of solenoid valve big, and electromagnetic coil generates heat even burn out.

The above is the electric control fuel oil jet system of representative with Denso Corporation ECD-U2, its technological difficulties are exactly the oil pump capacity bore dia, parameter problem identificatioin between oil inlet quantity bore dia and the control piston diameter three, also this problem (turnover oil mass bore dia reaches as far as possible ± 1% fluid flow is poor) just, having limited ECD-U2 is the response characteristic of the electric control fuel oil jet system of representative, it is the oil pump capacity bore dia, the design flexibility of oil inlet quantity bore dia and control piston diameter is narrower, with but determine also just to have determined the inclination of injection shape, at injection pressure one regularly, fuel injection quantity can only be controlled by the width (dutycycle) of command pulse.

Total the above existing electric-controlled fuel injector does not also reach fuel injection rate control truly, makes electric-controlled fuel injector can not well adapt to the oil spout needs of high-speed high-power internal-combustion engine of the needs, particularly load variations big (being that fuel delivery changes greatly) of motor.

Summary of the invention

The purpose of this invention is to provide a kind of nozzle opening liquid communication cross-section area variable (variable-throat) pressure-less chamber, no seat surface throttle effect, can realize fuel injection rate control truly, have pre-spray and multi-injection function, can satisfy the big internal-combustion engine fuel feeding needs of load variations, the electric-controlled fuel injector of low oil consumption low emission standard.

The present invention is by providing the electric-controlled fuel injector with following structure to realize, electric-controlled fuel injector of the present invention is by oil injector body, the high-speed electric control valve, formations such as oil nozzle, common rail high pressure fuel distribution pipe interface is arranged on the described oil injector body, the oil return tubing interface, install with the lug in strap bolt hole or install and fix and use outside thread, in high-pressure oil duct is arranged, the oil return oil duct, the oil-feed metering-orifice, the instruction piston sleeve, locating stud, the valve support chamber of electrically-controlled valve etc., described high-speed electric control valve can be the high-speed electromagnetic valve that is contained in the valve casing, valve casing is pressed in valve seat in the oil injector body in the valve seat block chamber, there is the oil extraction metering-orifice valve seat center, the oil extraction metering-orifice is communicated with oil return oil duct in the oil injector body by annular oil groove on the valve seat periphery and the oil duct in the valve seat, below the valve seat and instruction be pressure chamber between the piston, and communicate with the oil extraction metering-orifice, instruction piston center has fuel-displaced metering-orifice and pressure chamber to communicate, high-speed electric control valve core upper end is thin cylinder type, upwards pass valve seat with street iron combination from center, valve seat lower end, return spring is arranged above, the spool lower end is a bipyramid face cone, just in time place between pressure chamber oil extraction metering-orifice and the fuel-displaced metering-orifice, and certain up and down distance arranged, the oil drain quantity bore dia is less than conical surface diameter on the bipyramid face cone of spool lower end, the oil pump capacity bore dia is less than conical surface diameter under the bipyramid face cone of core lower end, when high-speed electric control valve no electric circuit (not having the oil spout instruction), spool is descending under the effect of return spring, it is suitable for reading that the conical surface just in time is pressed in the fuel-displaced metering-orifice in instruction piston upper end under the bipyramid face body of spool lower end, close fuel-displaced metering-orifice, below the instruction piston is the control room, fuel-displaced metering-orifice lower end communicates with the control room, oil injector body inner high voltage oil duct communicates with the control room by the oil-feed metering-orifice, the instruction piston return spring is arranged in the control room, instruction piston hypomere is a guide portion, oil nozzle is fixed on the oil injector body lower end with connection set, its needle-valve upper end exceeds the oil nozzle upper end and puts in the oil injector body, the needle-valve return spring is enclosed within the needle-valve upper end, its lower end withstands on the oil nozzle, the upper end withstands on the pressure of needle-valve upper end and adjusts below the piece, it is that a porose bloom in center is enclosed within needle-valve upper end and fixing that pressure is adjusted piece, pressure has pressure buffer device above adjusting piece, its damping device upper end withstands on instruction piston guide subordinate end, the needle-valve lower end be drift angle upper bottom surface under back taper type cone (hereinafter to be referred as: back taper type cone), center, oil nozzle lower end have one with needle-valve lower end back taper type cone corresponding be drift angle upper bottom surface under the inverted cone conical cavity (hereinafter to be referred as: the inverted cone conical cavity), cone angle end in the inverted cone conical cavity has annular groove, and follow high-pressure oil duct to communicate, inverted cone conical cavity inner conical surface constitutes variable-throat with back taper type cone male cone (strobilus masculinus), high-speed electric control valve core and valve seat are that fine gtinding is joined mating plate, the instruction piston is that fine gtinding is joined mating plate with oil injector body, oil nozzle and needle-valve are that fine gtinding is joined mating plate, the high-speed electric control valve base, the oil extraction metering-orifice, spool, spool lower end bipyramid face cone, the instruction piston, fuel-displaced metering-orifice, all on same center line, it is 0.0025 millimeter that all fine gtindings are joined its gap of mating plate for oil nozzle and needle-valve.

The pressure buffer device that described pressure is adjusted on the piece can be the pressure buffer spring, and its upper end withstands on instruction piston guide subordinate end, and the lower end withstands on pressure and adjusts on the piece.

The pressure buffer device that described pressure is adjusted on the piece can be a cushion pad, can be the cushion pad that metallic material or nonmetallic material are made, and its upper end withstands on instruction piston guide subordinate end, and its lower end withstands on pressure and adjusts on the piece.

Described oil nozzle can be fixed on the oil injector body lower end with the attaching nut.

Described oil nozzle can be fastened on the oil injector body lower end with oil injector body with self screw thread.

Coning angle can equal needle-valve lower end back taper type cone coning angle in the inverted cone conical cavity of described oil nozzle lower end, and when the change spout was closed condition, two conical surfaces were just in time tightly taken the photograph and closed.

Described oil nozzle lower end inverted cone conical cavity coning angle can be less than needle-valve lower end back taper type cone coning angle, when variable-throat is closed condition, back taper type cone male cone (strobilus masculinus) outer rim and oil nozzle lower end inverted cone conical cavity inner conical surface outer rim are taken the photograph and are lumped together, and angle ∠ a is arranged between two conical surfaces.

Cone angle can be greater than needle-valve lower end back taper type cone coning angle in the inverted cone conical cavity of described oil nozzle lower end, when variable-throat is closed condition, inverted cone conical cavity inner conical surface inner edge and back taper type cone male cone (strobilus masculinus) are taken the photograph and are closed, and an angle ∠ b is arranged between two conical surfaces.

On the back taper type cone conical surface of described needle-valve lower end He on the inverted cone conical cavity inner conical surface of oil nozzle lower end the shallow skewed slot of arc can be arranged, its length must be less than the length of the place conical surface.

Owing to adopted said structure, injector valve can carry out opening and closing in strict accordance with control command, because injector valve is that the back taper type is outward opening, it is exactly the process of oil nozzle oil spout that injector valve is opened descending process, in whole injection process, the total cross-section area of nozzle opening is that the length along with the fuel injection needle stroke distances changes, realized the adjustable of nozzle opening, guaranteed that oil sprayer can spray the requirement of different oil masses when identical fuel pressure different load different rotating speeds in identical oil spout duration, accomplish really to control fuel injection rate, allow fuel injection rate change according to the height of oil spout instruction (electrical pulse), and no longer be to instruct the width (time) of (electrical pulse) to change according to oil spout, at fuel pressure one regularly, can in identical oil spout duration, obtain different fuel injection quantitys, can be in same oil spout duration, obtain higher oil atomizing quality under the situation of same fuel injection quantity, can satisfy heavy duty at little load slow-speed of revolution operating mode requirements of one's work, can satisfy simultaneously the high rotating speed high load working condition of high power engine requirements of one's work again, that is to say, because the changeable of spray orifice, can make motor particularly the Large-power High-Speed internal-combustion engine when the work of little load speed, obtain higher fuel-oil atmozation quality, promote burning, reduce the discharging of internal-combustion engine harmful substance when the little load slow-speed of revolution is worked, can make motor when the high rotating speed of big load, identical fuel injection quantity oil spout duration shortens, promptly shortened the duration of diffusive combustion, improved the mean effective pressure of internal-combustion engine, promptly improved fuel of internal combustion engine efficient, the internal-combustion engine oil consumption rate is reduced, also reduced simultaneously internal-combustion engine when high load working condition work since injection time prolong because of a bad unburned carbon hydrogen that brings of later stage diffusive combustion, noxious emission such as carbon monoxide and particulate, because back taper type outward opening oil sprayer has shortened motor oil spout duration with oil mass when the high rotating speed of big load, make the speed of response of oil sprayer higher, can be divided into multi-injection to every circulation injection process, cutting duration between shortening main injection and pre-spray, is to reduce noise, the important means of nitrogen oxide and particle emission.

The variable-throat of the outward opening oil sprayer of back taper type promptly is the final outlet of fuel oil, fuel pressure in the annular groove is final injection pressure, eliminated the throttle effect of the swing-in oil injector seat conical surface, injection pressure when therefore having improved low oil mass oil spout, so the atomization quality when having improved low oil mass oil spout does not have to produce the high problem of unburned carbon hydrogen discharging with regard to having had because of the pressure chamber outside the pressure chamber yet.

Bipyramid face spool can make oil sprayer rely on the difference in flow of oil-feed metering-orifice and fuel-displaced metering-orifice to make the control piston action no longer fully, and then make the action of control piston faster, fuel injection needle is closed rapidly, oil-break is clear-cut, shorten the diffusive combustion in later stage, the relative broad of back taper angle design freedom of the outward opening oil-fuel injector needle-valve of back taper type, can better be complementary with the engine piston size, form comparatively desirable combustion-chamber shape, make burning more complete, further reduce exhaust emission, the leading role of arc-shaped shallow slot on the back taper type cone conical surface of fuel injection needle lower end, the mist of oil that can make ejection is shape in the shape of a spiral, mate with the pressurized air eddy current again, make fuel oil be diffused in the pressurized air better faster, oil gas mixes more even, the helical mist of oil has prolonged the moving line of mist of oil in the firing chamber, the wall amount of hitting of mist of oil is reduced, increase with the Air mixing chance, adding suitable air swirl, can to allow oil gas mix better, and allow combustion flame be vortex motion to prevent the flame breath of quenching, reduce the burning dead angle, make oil inflame more thorough, more complete, reduce oil consumption and reduce discharging.

Description of drawings

Below in conjunction with accompanying drawing and several specific embodiment electric-controlled fuel injector of the present invention is further described:

Fig. 1: be electric-controlled fuel injector first embodiment's sectional drawing of the present invention (during high-speed electric control valve no electric circuit).

Fig. 2: be electric-controlled fuel injector second embodiment's sectional drawing of the present invention (during high-speed electric control valve no electric circuit).

Fig. 3: be electric-controlled fuel injector the 3rd embodiment's sectional drawing of the present invention (during high-speed electric control valve no electric circuit).

Fig. 4,5,6: the basic functional principle figure that is electric-controlled fuel injector of the present invention.

Fig. 7: be electric-controlled fuel injector A shown in Figure 1 place (variable-throat) enlarged view.

Fig. 8: be the sectional drawing of electric-controlled fuel injector variable-throat shown in Figure 7 when little load hangs down the fuel injection quantity oil spout.

Fig. 9: the sectional drawing that is electric-controlled fuel injector variable-throat shown in Figure 7 when the high fuel injection quantity oil spout of big load.

Figure 10: be electric-controlled fuel injector variable-throat fuel oil shown in Figure 8 section plan in shape when spraying in the shape of a spiral under the leading role of arc-shaped shallow slot.

Figure 11: the side sectional view that is electric-controlled fuel injector shown in Figure 1.

Figure 12: the enlarged view that is electric-controlled fuel injector B of the present invention place shown in Figure 2 (variable-throat).

Figure 13: the enlarged view that is electric-controlled fuel injector C of the present invention place shown in Figure 3 (variable-throat).

Embodiment

Fig. 1, Fig. 7, Figure 11 shows electric-controlled fuel injector first embodiment of the present invention jointly, the plastic jacket 4 that band wire harness guiding socket is arranged on high speed electromagnetic 1 shell 5, high-speed electromagnetic valve 1 shell is contained in oil injector body 2 tops with screw thread, valve seat 6 is pressed in 2 li valve support chamber of oil injector body, the oil extraction metering-orifice 7 of center, valve seat 6 lower end, communicate with 2 li oil return oil ducts 45 of oil injector body by annular oil groove 57 on valve seat 6 internal oil channels and valve seat 6 peripheries, below the valve seat 6 and the pressure chamber 15 between the instruction piston 14 communicate with oil extraction metering-orifice 7, the fuel-displaced metering-orifice 18 in instruction center, piston 14 upper end communicates with pressure chamber 15, spool 9 upper ends upwards pass valve seat 6 with 11 combinations of street iron from center, valve seat 6 lower end, there is spool return spring 34 its upper end, spool 9 lower end bipyramid face cones just in time place between pressure chamber 15 oil extraction metering-orifices 7 and the fuel-displaced metering-orifice 18, the last cone angle bottom surface diameter of bipyramid face cone is greater than the oil drain quantity bore dia, following cone angle bottom surface diameter is greater than the oil pump capacity bore dia, and high-speed electric control valve 1, street iron 11, spool 9 and spool 9 lower end bipyramid face cones, valve seat 6, oil extraction metering-orifice 7, fuel-displaced metering-orifice 18, instruction piston 14 is all on same center line, valve seat 6, spool 9 is precise finish idol parts, its gap 12 is 0.0025 millimeter, when solenoid valve no electric circuit (not having the oil spout instruction), it is suitable for reading that spool 9 conical surface 20 under the following enforcement of the effect of return spring 34 spool 9 lower end bipyramid face cones is pressed in fuel-displaced metering-orifice 18, close fuel-displaced metering-orifice 18, there are instruction piston 14 return springs 38 17 the insides, control room below the instruction piston 14, control room 17 communicates with fuel-displaced metering-orifice 18, and communicate by oil-feed metering- orifice 19 and 2 li high-pressure oil ducts 13 of oil injector body, instruction piston 14 is precise finish idol parts with oil injector body 2, its gap should be in 0.0025 millimeter, oil nozzle 3 usefulness set screw nuts 21 are fixed on oil injector body 2 lower ends, the annular groove 39 of its high-pressure oil duct 22 by oil nozzle 3 upper-end surfaces communicates with the high-pressure oil duct 13 of 2 li of oil injector bodies, stretch below the guide portion 16 of 2 li instructions of oil injector body piston 14 3 li needle-valve 23 upper ends of oil nozzle, and respective clearance arranged, needle-valve 23 return springs 24 are enclosed within needle-valve 23 upper ends, return spring 24 lower ends withstand on oil nozzle 3 upper ends, return spring 24 upper ends withstand on pressure and adjust below the piece 25, it is the lower end that pressure buffer spring 37 its upper ends withstand on instruction piston 14 guide portions 16 that pressure is adjusted above the piece 25, needle-valve 23 lower end back taper type cones (drift angle upper bottom surface under back taper type cone) 32 with oil nozzle 3 lower end inverted cone conical cavity (drift angle upper bottom surface under back taper type conical cavity) corresponding, back taper type cone 32 male cone (strobilus masculinus)s 27 and inverted cone conical cavity inner conical surface 28 constitutes variable-throats 61, and back taper type cone 32 cone angles 40 coning angles are greater than cone angle 41 coning angles in the inverted cone conical cavity, and variable-throat 61 is in off position the time, angle ∠ a29 is arranged between male cone (strobilus masculinus) 27 and the inner conical surface 28, male cone (strobilus masculinus) 27 outer rims and inner conical surface 28 outer rims are closely taken the photograph and are closed, and in angle ∠ a29, the shallow skewed slot 31 of equidirectional arc are arranged on male cone (strobilus masculinus) 27 and the inner conical surface 28, this skewed slot 31 prolongs downwards from upper limb 30 beginnings of male cone (strobilus masculinus) 27 and inner conical surface 28, its length is less than the width of the place conical surface, and just taking the photograph the outer rim place of closing at male cone (strobilus masculinus) 27 and inner conical surface 28 does not have the shallow skewed slot 31 of lonely shape, guarantees that male cone (strobilus masculinus) 27 outer rims and inner conical surface 28 outer rims are taking the photograph fashionable sealing, male cone (strobilus masculinus) 27 exterior rim are corresponding with inner conical surface 28 exterior rim when variable-throat 61 is closed, oil nozzle 3 lower end inverted cone conical cavity cone angle 41 ends have annular groove 35 to communicate with high-pressure oil duct 22, and the width of inverted cone conical cavity inner conical surface 28 is less than the width of back taper type cone 32 male cone (strobilus masculinus)s 27, and oil nozzle 3 and back taper chamber thereof and needle-valve 23 and inverted cone 32 thereof are all on same center line, and be even part through precise finish, its gap 33 should be in 0.0025 millimeter, has special antifriction material 42 to be used for reducing the frictional resistance of oil nozzle 3 inwalls and needle-valve 23 on the attrition surface of oil nozzle 3 inwalls and needle-valve 23, reduces wear, electric-controlled fuel injector of the present invention can be fixed on the cylinder head by the lug 59 in strap bolt hole 60 or with outside thread, high pressure fuel distribution pipe interface 12 is connected with common rail high pressure fuel distribution pipe, and when high-speed electromagnetic valve 1 no electric circuit (not having the oil spout instruction), instruction piston 14 is under the effect of return spring 38, remain on top dead center, spool 9 is descending under the effect of return spring 34 closes fuel-displaced metering-orifice 18, and needle-valve 23 is the up variable-throat 61 of closing under the effect of return spring 24, and high pressure fuel enters oil injector body through high pressure fuel distribution pipe interface 12 and is divided into two-way for 2 li, one the tunnel enters in the control room 17 through oil-feed metering-orifice 19, produce a hydraulic pressure that makes progress below instruction piston 14, when high-speed electromagnetic valve 1 no electric circuit (not having the oil spout instruction), high pressure fuel can not overflow from fuel-displaced metering-orifice 18, another road is in high- pressure oil duct 13 and 22 enters the annular oil groove 35 and angle ∠ a29 of oil nozzle 3 lower ends, produce a downward hydraulic pressure on back taper type cone 32 male cone (strobilus masculinus)s 27, this pressure must can not overflow high pressure fuel less than the tension of needle-valve 23 return springs 24 from variable-throat 61 after variable-throat 61 is closed.

Fig. 2 and Figure 12 show second embodiment of electric-controlled fuel injector of the present invention: the pressure buffer device on the needle-valve 23 upper ends pressure adjustment piece 25 is a pressure buffer cushion block 36 in the present embodiment, this cushion block 36 can be that backing metal also can be non-backing metal, cushion block 36 upper ends withstand on guide portion 16 lower ends of instruction piston 14, oil nozzle 3 upper-end surfaces are matrixs, oil nozzle 3 and oil injector body 2 usefulness self are threaded and are fixed together, install and fix on the oil nozzle 3 with outside thread 58, cone angle 41 ' coning angle is identical with needle-valve 23 lower end back taper type cone 32 cone angles 40 ' coning angles in the oil nozzle 3 lower end inverted cone conical cavity, variable-throat 61 in off position the time inverted cone conical cavity inner conical surface 28 and back taper type cone 32 male cone (strobilus masculinus)s 27 closely take the photograph and lump together, remove above-mentioned difference, other structure is all identical with first embodiment.

Fig. 3 and Figure 13 show the 3rd embodiment of electric-controlled fuel injector of the present invention: in the present embodiment on the needle-valve 23 end pressure adjust that pressure buffer devices are plastic cushions 36 above the piece 25, its upper end withstands on instruction piston 14 guide portions 16 lower ends, needle-valve 23 lower end back taper type cone 32 cone angles 40 " coning angle is less than cone angle 41 in the oil nozzle 3 lower end inverted cone conical cavity " coning angle, can spend spray 61 when closing, inverted cone conical cavity inner conical surface 28 inner edges are closely taken the photograph with back taper type cone 32 male cone (strobilus masculinus)s 27 and are closed, angle ∠ b43 is arranged between two conical surfaces, in angle ∠ b43, on inverted cone conical cavity inner conical surface 28 and back taper type cone 32 male cone (strobilus masculinus)s 27 the shallow skewed slot 31 of arc is arranged, remove last difference, other is all identical with first embodiment.

From above three embodiments as can be seen, some features of electric-controlled fuel injector of the present invention can be exchanged, oil nozzle 3 also can be the same with second embodiment in first embodiment, be connected and fixed with oil injector body 2 with self screw thread, and oil nozzle 3 also can be fixed in oil injector body 2 lower ends with set screw nut 21 among second embodiment, coning angle as needle-valve 23 lower end back taper type cone 32 cone angles 40 also can be less than or equal to oil nozzle 3 lower end inverted cone conical cavity cone angle 41 coning angles, and the same second and the 3rd implements middle variable-throat 61 also can be the same with first enforcement.Pressure buffer device also can exchange with the pressure buffer device among the two or three embodiment among first embodiment in addition.Can use the lug in strap bolt hole among first embodiment instead as outside thread on the oil nozzle 3 among second embodiment, same first embodiment also can use the outside thread among second embodiment instead.The shallow skewed slot of arc on the conical cavity inner conical surface 28 or cone 32 conical surfaces 27 can be both left-handed or be both dextrorotation in addition.

Fig. 8, Fig. 9 show Fig. 7 variable-throat different oil spout requirements (instruction) down during oil spout the aperture of spout change, shown in Fig. 8 is low fuel delivery spout aperture when requiring, shown in Fig. 9 is high fuel injection quantity spout aperture when requiring.

Figure 10 shows the oil bundle under the leading role of the shallow skewed slot 31 of arc on back taper type cone 32 male cone (strobilus masculinus)s 27 and the inverted cone conical cavity inner conical surface 28, the situation during ejection helical mist of oil.

Fig. 4, Fig. 5, Fig. 6 show the basic functional principle of electric-controlled fuel injector of the present invention jointly.

Electric-controlled fuel injector of the present invention shown in Figure 4 is not when high-speed electric control valve no electric circuit (having the oil spout instruction), spool 9 is the fuel-displaced metering-orifice 18 in descending out code piston 14 centers under the effect of return spring 34, instruction piston 14 is under the effect of return spring 38 and high pressure fuel pressure, remain on top dead center, needle-valve 23 is closed variable-throat 61 (not oil spout) under the tension of return spring 24.

When Fig. 5 is high-speed electric control valve 1 energising (the oil spout instruction is arranged), spool 9 is picked up, fuel-displaced metering-orifice 18 open with the time close oil extraction metering-orifice 7, high pressure fuel overflows from fuel-displaced metering-orifice 18, control room 17 pressure descend, high pressure fuel produces pressure and promotes instruction piston 14 descending compressing needle-valves 23 in pressure chamber 15 simultaneously, opens variable-throat 61, and high pressure fuel sprays (oil spout) from variable-throat 61.

During high-speed electric control valve 1 outage shown in Figure 6 (stopping the oil spout instruction), spool 9 descending oil extraction metering-orifice 7 of opening under the pressure effect of return spring 34 is closed fuel-displaced metering-orifice 18 simultaneously, pressure disappears in the pressure chamber 15, instruction piston 14 is got back to top dead center immediately under the pressure of high pressure fuel and return spring 38, needle-valve 23 is closed variable-throat 61 (stopping oil spout) rapidly under the tension effect of return spring 24.

Note

Back taper type cone be meant drift angle upper bottom surface under cone.

The inverted cone conical cavity be meant drift angle upper bottom surface under conical cavity.

Claims (9)

1: a kind of electric-controlled fuel injector is mainly by the high-speed electric control valve, oil injector body, oil nozzle constitutes, the high-speed electric control valve is installed in oil injector body top, the plastic jacket that band wire harness guiding socket is arranged on the valve casing, oil nozzle is fixed on the oil injector body lower end, oil return oil duct interface is arranged on the oil injector body and be total to rail high pressure fuel distribution pipe interface, lug with holes or outside thread, in oil return oil duct and high-pressure oil duct are arranged, it is characterized in that: the epimere of high-speed electric control valve (1) spool (9) is thin cylindrical body, the lower end is a bipyramid face cone, valve seat (6) is pressed in oil injector body (2) lining by valve casing (5), there is oil extraction metering-orifice (7) valve seat (6) center, lower end, on valve seat (6) periphery fluted (57), by valve seat (6) internal oil channel oil extraction metering-orifice (7) and oil return oil duct (45) are communicated with, below the valve seat (6) and to instruct between the piston (14) be that pressure chamber (15) and oil extraction metering-orifice (7) communicate, instruction piston (14) center has the same pressure chamber of fuel-displaced metering-orifice (18) (15) to communicate, the upper end of spool (9) upwards passes valve seat (6) with street iron (11) combination from valve seat (6) center, lower end, spool (9) lower end bipyramid face cone just in time places pressure chamber, between oil extraction metering-orifice (7) and the fuel-displaced metering-orifice (18), and corresponding up and down distance arranged, return spring (34) is arranged on street iron (11), spool (9) and valve seat (6) are fine gtinding idol parts, instruction piston (14) and oil injector body (2) are fine gtinding idol parts, spool (9), valve seat (6), oil extraction metering-orifice (7), instruction piston (14), spool (9) lower end bipyramid face cone and fuel-displaced metering-orifice (18) are all on same center line, oil extraction metering-orifice (7) diameter is less than the conical surface (10) diameter on the bipyramid face cone of spool (9) lower end, fuel-displaced metering-orifice (18) diameter is less than the conical surface (20) diameter under the bipyramid face cone, there is the return spring (38) of instruction piston (14) the inside, control room (17) below the instruction piston (14), same control room, fuel-displaced metering-orifice (18) lower end (17) communicates, oil-feed metering-orifice (19) is communicated with high-pressure oil duct (13) and control room (17), oil nozzle (3) the inside needle-valve (23) epimere is thin cylindrical body, upwards be inserted in the oil injector body (20), and be with return spring (24), return spring (24) lower end withstands on the upper end of oil nozzle (3), return spring (24) upper end withstand on pressure adjust piece (25) below, pressure adjustment piece (25) is enclosed within needle-valve (23) and goes up and fix, on adjusting piece (25), pressure have pressure buffer device to withstand on guide portion (16) lower end of instruction piston (14), oil nozzle (3) lower end have a drift angle upper bottom surface under the inverted cone conical cavity, needle-valve (23) lower end have one and inverted cone conical cavity corresponding be drift angle upper bottom surface under back taper type cone (32), inverted cone conical cavity inner conical surface (28) cone angle end has annular groove (35) to be communicated with oil nozzle (3) inner high voltage oil duct (22), oil nozzle (3) inner high voltage oil duct (22) communicates with the high-pressure oil duct (13) of oil injector body (2) lining, inverted cone conical cavity inner conical surface (28) and back taper type cone (32) male cone (strobilus masculinus) (27) constitute variable-throat (61) jointly, instruction piston (14), oil nozzle (3), needle-valve (23), back taper chamber and needle-valve (23) lower end back taper type cone (32) is on same center line, and needle-valve (23) and oil nozzle (3) are that fine gtinding is joined mating plate.

2: according to the described electric-controlled fuel injector of claim 1, it is characterized in that: the pressure buffer device that pressure is adjusted on the piece (25) is pressure buffer spring (37), its upper end withstands on instruction piston (14) guide portion (16) lower end, and its lower end withstands on pressure and adjusts on the piece (25).

3: according to the described electric-controlled fuel injector of claim 1, it is characterized in that: the pressure buffer device that pressure is adjusted on the piece (25) is pressure buffer cushion block (36), its upper end withstands on instruction piston (14) guide portion (16) lower end, and cushion block (36) lower end withstands on pressure and adjusts on the piece (25).

4: according to the described electric-controlled fuel injector of claim 1, it is characterized in that: oil nozzle (3) is to be fixed on oil injector body (2) lower end with set screw nut (21).

5: according to the described electronic control injection of claim 1, it is characterized in that: oil nozzle (3) is to be connected and fixed with self direct same oil injector body of screw thread (2).

6: according to each described electric-controlled fuel injector of claim 1 to 5, it is characterized in that: on needle-valve (23) lower end reverse mould cone (32) male cone (strobilus masculinus) (27) and oil sprayer (3) the lower end inverted cone conical cavity inner conical surface (28) the shallow skewed slot of arc (31) is arranged, its length is less than the width of the place conical surface.

7: according to the described electric-controlled fuel injector of claim 6, it is characterized in that: its coning angle of oil nozzle (3) lower end inverted cone conical cavity cone angle (41 ') equals the coning angle of needle-valve (23) lower end back taper type cone (32) cone angle (40 '), variable-throat (61) is in off position the time, and inner conical surface (28) is just in time tightly taken the photograph with male cone (strobilus masculinus) (27) and lumped together.

8: according to the described electric-controlled fuel injector of claim 6, it is characterized in that: needle-valve (23) lower end back taper type cone (32) cone angle (40 ") coning angle is greater than oil nozzle (3) lower end inverted cone conical cavity cone angle (41 ") coning angle, variable-throat (61) is in off position the time, back taper type cone (32) conical surface (27) outer rim and inverted cone conical cavity inner conical surface (28) outer rim are closely taken the photograph and are closed, and an angle ∠ a (29) is arranged between two conical surfaces.

9: according to 6 described electric-controlled fuel injectors in the claim, it is characterized in that: needle-valve (23) lower end back taper type cone (32) cone angle (40) coning angle is less than cone angle (41) coning angle in the inverted cone conical cavity of oil nozzle (3) lower end, variable-throat (61) is in off position the time, back taper type cone (32) male cone (strobilus masculinus) (27) and inverted cone conical cavity inner conical surface (28) inner edge are closely taken the photograph and are closed, and angle ∠ b (43) is arranged between two conical surfaces.

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