CN109026476A - The variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic - Google Patents

The variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic Download PDF

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Publication number
CN109026476A
CN109026476A CN201810833837.2A CN201810833837A CN109026476A CN 109026476 A CN109026476 A CN 109026476A CN 201810833837 A CN201810833837 A CN 201810833837A CN 109026476 A CN109026476 A CN 109026476A
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CN
China
Prior art keywords
oil
control valve
valve
pressure
injector
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Withdrawn
Application number
CN201810833837.2A
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Chinese (zh)
Inventor
白云
付立洲
蒋顺豪
范立云
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Harbin Engineering University
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Harbin Engineering University
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Priority to CN201810833837.2A priority Critical patent/CN109026476A/en
Publication of CN109026476A publication Critical patent/CN109026476A/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
    • F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0014—Valves characterised by the valve actuating means
    • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
    • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

The purpose of the present invention is to provide the pressure accumulation type piezoelectric fuel injectors that fuel injection characteristic can be changed, including pressurization control valve portion, three-level piston component, Injection Control valve portion, needle-valve portion.The present invention uses pressurization control valve arrangement, controls the pressurization area of three-level piston, different pressure ratios can be effectively realized, so that fuel injection characteristic is more flexible；The action process of needle-valve is driven by piezoelectric pile, and needle-valve fast response time, control freedom degree is big, and fuel injection characteristic is flexibly controllable, effectively increases the dynamic property of diesel engine and the economy of fuel oil, and diesel engine is made to can satisfy stringenter emission regulation；In addition pressure accumulation chamber can slowing oil injection when caused pressure oscillation, be conducive to the accurate control to distributive value, it is remarkably improved especially for the control precision of small oil mass, the pressure stabilization function of pressure accumulation chamber reduces the size of common rail pipe, so that the service life of common rail pipe extends.

Description

The variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic
Technical field
The present invention relates to a kind of diesel engines, specifically diesel fuel system.
Background technique
Positive injector is convex by high-pressure fuel-feed pump due to injection characteristics such as injection timing, injection pressure and injection rates Wheel restricts, and it is not flexible that there is injection characteristics, low-response, the disadvantages of to distributive value control accuracy difference.With the day of emission regulation It is beneficial stringent, it is difficult further to improve the economy and emission performance of engine.
Electromagnetic control type fuel injector applied to Electronic Control for Fuel Injection System of Diesel Engine is responded compared to positive injector Faster, injection characteristics are flexibly controllable for speed, also more accurate to the control of distributive value.Although electromagnetic control type fuel injector is to diesel oil The emission performance of machine makes moderate progress, but there is also some shortcomings: fuel injector generallys use the form of single channel oil inlet, and needle-valve is taken a seat Response speed is slow, and the equilibrium relation due to passing in and out oilhole aperture, it is desirable to it is more difficult to further increase response characteristic；Two two The dynamic recirculating oil quantity of the form of port valve is larger, influences fuel utilization ratio；Axial gap between needle-valve and control plunger causes to spray There is static leakage fuel oil in oily device；Since the inductance of electromagnetic valve coil acts on, its response is made to have certain lag time, Cause to further increase fuel oil injecting times and be restricted, fuel-injected repeatability is to be improved；In big oil mass spray regime Under, uniformity and stability decline of each cylinder injection process etc..
Summary of the invention
The purpose of the present invention is to provide be able to achieve to control pressure ratio flexibly to reach the fuel injection characteristic of different jeting effects Variable pressure accumulation type piezoelectric fuel injector.
The object of the present invention is achieved like this:
The variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic of the present invention, it is characterized in that: include oil injector body, pressure accumulation cavity wall, Pressurization control valve portion, three-level piston component, Injection Control valve portion, needle-valve portion, pressure accumulation cavity wall are fixed in the injector body Side, pressurization control valve portion and three-level piston component are mounted in oil injector body from top to bottom, Injection Control valve portion and needle-valve Part is mounted below three-level piston component by its external tight cap of nozzle, and pressure accumulation chamber is opened up in pressure accumulation cavity wall, and pressure accumulation chamber connects Logical high-pressure oil passage；
The pressurization control valve portion includes piezoelectric pile, supercharger control valve valve rod, bacterium shape sleeve, hydraulic core, pressurization control Valve stem sleeve, piezoelectric pile sleeve, bacterium shape sleeve limit orifice plate, charged piston limit orifice plate, piezoelectric pile sleeve, bacterium shape sleeve limit Position orifice plate and charged piston limit orifice plate are arranged from top to bottom, and hydraulic core is mounted in hydraulic sleeve, piezoelectric pile, hydraulic sleeve, pressurization Control valve stem sleeve is arranged in from top to bottom in piezoelectric pile sleeve, and supercharger control valve valve is installed in supercharger control valve stem sleeve Bar, the upper end of supercharger control valve valve rod stretch in hydraulic sleeve and are formed between hydraulic core hydraulic fluid chamber, the limit of bacterium shape sleeve Supercharger control valve valve chamber is set in orifice plate, and bacterium shape sleeve is arranged in supercharger control valve valve chamber, the lower end of supercharger control valve valve rod It protrudes into bacterium shape sleeve, the exterior panel shape spring of hydraulic sleeve, the bottom end of plate-shaped springs is pressed in supercharger control valve stem sleeve Top, the upper end of plate-shaped springs are pressed in the upper end of hydraulic sleeve, and the middle part setting supercharger control valve valve rod of supercharger control valve valve rod is convex It rises, supercharger control valve valve rod spring, the conical surface lower end of bacterium shape sleeve is set between supercharger control valve valve rod protrusion and bacterium shape sleeve Setting is set with sleeve spring between charged piston limit orifice plate, and oil return circuit and level-one is arranged on supercharger control valve stem sleeve Pressure Increasing Oil-Line, bacterium shape sleeve limit setting pressurization throttle orifice on orifice plate, and charged piston, which limits, is arranged two-stage supercharging oil circuit on orifice plate, Level-one Pressure Increasing Oil-Line is connected to supercharger control valve valve chamber by the access among bacterium shape sleeve, and oil return circuit is connected to low pressure oil way, increases Pressure throttle orifice is respectively communicated with high-pressure oil passage and supercharger control valve valve chamber, two-stage supercharging oil communication supercharger control valve valve chamber；
The three-level piston component includes charged piston, piston return spring, and charged piston is three-level stepped cylinder structure, It is respectively from top to bottom the first-third cylinder, and diameter successively decreases, the first cylinder and the charged piston above it limit between orifice plate Form plunger shaft, plunger shaft limits the hole in orifice plate by charged piston and is connected to high-pressure oil passage, the first cylinder and the second cylinder and Level-one booster cavity is formed between oil injector body, and two-stage supercharging chamber is formed between the second cylinder and third cylinder and oil injector body, the Three-level booster cavity is formed between three cylinders and oil injector body below, and piston return spring, level-one are installed in three-level booster cavity Booster cavity is connected to level-one Pressure Increasing Oil-Line, and two-stage supercharging chamber is connected to two-stage supercharging oil circuit, and three-level booster cavity is connected to high by check valve Pressure oil road, three-level booster cavity lower part are provided with Pressure Increasing Oil-Line；
The Injection Control valve portion includes injector control valve piezoelectric pile, injector control valve hydraulic sleeve, injector control valve valve Rod sleeve, injector control valve valve rod, injector control valve limit orifice plate, umbrella shape piston, intermediate orifice plate, injector control valve piezoelectric pile, Injector control valve hydraulic sleeve and injector control valve stem sleeve are arranged in oil injector body from top to bottom, injector control valve hydraulic sleeve In the hydraulic core of injector control valve is set, injector control valve valve rod is mounted in injector control valve stem sleeve, injector control valve valve The upper end of bar stretch in injector control valve hydraulic sleeve and with hydraulic fluid chamber is formed between it, oil injector body and injector control valve limit Position orifice plate, intermediate orifice plate form injector control valve valve chamber, and umbrella shape piston is mounted in injector control valve valve chamber, injector control valve valve Bar lower end is pressed on umbrella shape piston, installs injector control valve return spring between the conical surface lower end of umbrella shape piston and intermediate orifice plate, The external of injector control valve hydraulic sleeve installs injector control valve plate-shaped springs, and the bottom end of injector control valve plate-shaped springs is pressed in oil spout Above control valve stem sleeve, the upper end of injector control valve plate-shaped springs is pressed in the upper end of injector control valve hydraulic sleeve, oil spout control The oil circuit being connected to high-pressure oil passage and oil inlet metering-orifice are offered on valve stem sleeve processed, are arranged on injector control valve limit orifice plate Low pressure oil leak hole, low pressure oil leak hole are respectively communicated with low pressure oil way and injector control valve valve chamber；
The needle-valve portion includes needle-valve limit orifice plate, needle-valve block, and needle-valve limit orifice plate and needle-valve block are arranged from top to bottom Below intermediate orifice plate, fluid power compensating piston epicoele in-line, non-return passage are set in intermediate orifice plate, installs and stops in non-return passage Valve is returned, fluid power compensating piston epicoele in-line is connected to high-pressure oil passage, and non-return passage is connected to oil inlet metering-orifice, is arranged in needle-valve limit hole Fluid power compensating piston, control chamber oil circuit are set, fluid power compensating piston reset spring, fluid power compensation are cased with outside fluid power compensating piston The upper end of piston reset spring is withstood on fluid power compensating piston, and the lower end of fluid power compensating piston reset spring withstands on needle below Valve limits on orifice plate, is formed on the fluid power compensating piston communicated with fluid power compensating piston epicoele in-line above fluid power compensating piston Chamber, fluid power compensating piston reset spring present position are fluid power compensating piston cavity of resorption, fluid power compensating piston lower end with below Needle-valve, which limits, forms fluid power compensating piston draining chamber, control chamber oil communication oil inlet metering-orifice between orifice plate；Needle is installed in needle-valve block Valve, needle-valve top are cased with needle-valve reset spring, and the upper end of needle-valve reset spring is withstood on needle-valve limit orifice plate, needle-valve reset spring Lower end withstand on needle-valve, needle-valve reset spring present position is control chamber, and control chamber is connected to control chamber oil circuit, is set in needle-valve block Oil holding slot in-line is set, forms oil holding slot between needle-valve and needle-valve block, spray orifice, oil holding slot in-line difference is arranged in needle-valve block bottom It is connected to oil holding slot and Pressure Increasing Oil-Line, fluid power compensating piston cavity of resorption is connected to below check-valves by fluid power compensating piston cavity of resorption in-line Non-return passage, fluid power compensating piston cavity of resorption by fluid power compensating piston vent line be connected to control chamber.
The present invention may also include:
1, when without working under boost mode, when injector control valve partial current, injector control valve piezoelectric pile oppresses oil spout Control valve hydraulic sleeve and the hydraulic core of injector control valve move downward jointly, make injector control valve hydraulic sleeve and injector control valve valve rod Oil pressure in the oil pocket of formation increases, and injector control valve valve rod is moved downward by pressure effect in oil pocket, and then oppresses umbrella shape The elastic force of piston overpowers injector control valve return spring moves downward, and the conical surface of injector control valve valve rod lower end is closed at this time, makes High-pressure oil passage is cut off, while the conical surface seal of umbrella shape upper piston area is opened, and control chamber is logical by the conical surface of umbrella shape upper piston area Road and injector control valve valve chamber are connected with low pressure oil leak hole, and the fuel oil in control chamber flow back into fuel tank by low pressure oil leak hole It is interior；The pressure of fluid power compensating piston cavity of resorption decreases in fluid power compensating piston simultaneously, and the pressure of fluid power compensating piston epicoele is big The resultant force that the elastic force of cavity pressure and fluid power compensating piston spring is formed under fluid power compensating piston, fluid power compensating piston is downward at this time Movement, closure of check ring, fluid power compensating piston make to control under cavity pressure by the fuel-displaced road direction control chamber repairing of fluid power compensating piston Reduction of speed degree slows down；When the resultant force that the elastic force of pressure and needle valve spring in control chamber is formed is less than the liquid that fuel oil is upward in oil holding slot When pressure, needle-valve is lifted up, spray orifice commencement of fuel injection；When the power-off of Injection Control valve portion, injector control valve valve rod is in oil spout It takes a seat under the elastic force effect of control valve valve rod return spring, opens high-pressure oil passage, non-return while by low pressure draining bore closure Valve is opened, and control chamber builds pressure by oil inlet metering-orifice and fluid power compensating piston cavity of resorption again, when the pressure and needle-valve bullet in control chamber When the resultant force that the elastic force of spring is formed is greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops oil spout.
2, when working under low pressure charging mode, supercharger control valve is powered, and piezoelectric pile is elongated under the action of inverse piezoelectric effect Locations of low pressure, oppresses hydraulic sleeve and hydraulic core moves downward jointly, in the oil pocket for forming hydraulic sleeve and supercharger control valve valve rod Oil pressure increase, supercharger control valve valve rod moved downward by the pressure in oil pocket, by the conical surface on supercharger control valve valve rod Bacterium shape sleeve closes the channel on supercharger control valve valve rod head while sealing is opened, at this time high-pressure oil passage and level-one pressurised oil Road is no longer connected to, while level-one Pressure Increasing Oil-Line is connected by the conical surface of supercharger control valve valve rod with oil return circuit.Level-one pressurization Intracavitary fuel oil flows through oil return circuit by level-one Pressure Increasing Oil-Line and returns in low-pressure reservoir, and the pressure in plunger shaft is greater than one at this time The sum of grade booster cavity, two-stage supercharging chamber and elastic force of pressure and piston return spring in three-level booster cavity, charged piston is downward It moves, the closed check valve at the oil inlet of three-level booster cavity；Injector control valve partial current, injector control valve piezoelectric pile is inverse It is extended under the action of piezoelectric effect, oppresses injector control valve hydraulic sleeve and the hydraulic core of injector control valve moves downward jointly, make to spray The oil pressure in oil pocket that oil control valve hydraulic sleeve and injector control valve valve rod are formed increases, and injector control valve valve rod is by oil pocket Pressure effect moves downward, and then the elastic force for oppressing umbrella shape piston overpowers injector control valve return spring moves downward.It sprays at this time The conical surface of oil control valve valve rod lower end is closed, is cut off high-pressure oil passage, while the conical surface seal of umbrella shape upper piston area is opened, control Chamber processed is connected by the conical surface channel and injector control valve valve chamber of umbrella shape upper piston area with low pressure oil leak hole, the combustion in control chamber Oil is flow back into fuel tank by low pressure oil leak hole；The pressure of fluid power compensating piston epicoele be greater than fluid power compensating piston under cavity pressure with The resultant force that the elastic force of fluid power compensating piston spring is formed, fluid power compensating piston moves downward at this time, closure of check ring, fluid power compensation Piston passes through the fuel-displaced road direction control chamber repairing of fluid power compensating piston；When its pressure and the resultant force of needle-valve reset spring are less than oil holding slot When interior fuel oil is to the hydraulic coupling of needle-valve, needle-valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, Injection Control Valve valve rod is taken a seat under the elastic force effect of injector control valve valve rod return spring, is opened while by low pressure draining bore closure high Pressure oil road, check-valves are opened, and control chamber builds pressure by oil inlet metering-orifice and fluid power compensating piston cavity of resorption again, when the pressure in control chamber When the resultant force that the elastic force of power and needle valve spring is formed is greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops Oil spout；When the power-off of pressurization control valve portion, supercharger control valve valve rod is under the spring-force driven dual of supercharger control valve valve rod spring It drops back into one's seat, the access in bacterium shape sleeve is opened while closing the supercharger control valve valve rod conical surface, high pressure fuel passes through one Grade Pressure Increasing Oil-Line reenters level-one booster cavity, and the pressure in plunger shaft is less than level-one booster cavity, two-stage supercharging chamber and three at this time The sum of pressure and the elastic force of piston return spring in grade booster cavity, charged piston is back up into initial position, and check valve is again It opens, fuel oil is entered in three-level booster cavity by check valve and enters back into oil holding slot.
3, when working under high pressure-charging mode, supercharger control valve is powered, and piezoelectric pile is elongated under the action of inverse piezoelectric effect High pressure-charging position, oppresses hydraulic sleeve and hydraulic core moves downward jointly, the oil pocket for forming hydraulic sleeve and supercharger control valve valve rod In oil pressure increase, supercharger control valve valve rod moved downward by the pressure in oil pocket, by the cone on supercharger control valve valve rod Bacterium shape sleeve closes the channel on supercharger control valve valve rod head while face sealing is opened；High-pressure oil passage and level-one are pressurized at this time Oil circuit is no longer connected to, while level-one Pressure Increasing Oil-Line is connected by the conical surface of supercharger control valve valve rod with oil return circuit, and level-one increases It presses intracavitary fuel oil to flow through oil return circuit by level-one Pressure Increasing Oil-Line to return in low-pressure reservoir；Supercharger control valve valve rod continues downward Movement drives bacterium shape sleeve to move downward, opens the conical surface seal of bacterium shape sleeve, and the intracavitary fuel oil of two-stage supercharging passes through bacterium shape The conical surface seal of sleeve is connected with oil return circuit；At this time the pressure in plunger shaft be greater than level-one booster cavity, two-stage supercharging chamber and The resultant force that the elastic force of pressure and charged piston return spring in three-level booster cavity is formed, charged piston move downward, and three-level increases Press the closed check valve at the oil inlet of chamber；Injector control valve partial current, injector control valve piezoelectric pile is in inverse piezoelectric effect The lower elongation of effect, oppresses injector control valve hydraulic sleeve and the hydraulic core of injector control valve moves downward jointly, make injector control valve liquid The oil pressure in oil pocket that pressing sleeve and injector control valve valve rod are formed increases, injector control valve valve rod by pressure in oil pocket act on to Lower movement, and then the elastic force for oppressing umbrella shape piston overpowers injector control valve return spring moves downward；Injector control valve valve at this time The conical surface of bar lower end is closed, is cut off high-pressure oil passage, while the conical surface seal of umbrella shape upper piston area is opened, and control chamber passes through umbrella The conical surface channel of shape upper piston area and injector control valve valve chamber are connected with low pressure oil leak hole, and the fuel oil in control chamber passes through low pressure Oil leak hole is flow back into fuel tank；The pressure of fluid power compensating piston epicoele is greater than cavity pressure and fluid power compensation under fluid power compensating piston and lives The resultant force that the elastic force of spring is formed is filled in, fluid power compensating piston moves downward at this time, closure of check ring, and fluid power compensating piston passes through liquid The fuel-displaced road direction control chamber repairing of force compensating piston；When the resultant force of control cavity pressure and needle-valve reset spring is less than fuel oil in oil holding slot When to the hydraulic coupling of needle-valve, needle-valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, injector control valve valve rod It takes a seat under the elastic force effect of injector control valve valve rod return spring, opens high pressure oil while by low pressure draining bore closure Road, check-valves are opened, and control chamber builds the newly-built pressure of ballast by oil inlet metering-orifice and fluid power compensating piston cavity of resorption again, when in control chamber Pressure and the resultant force that is formed of elastic force of needle valve spring when being greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, Stop oil spout；When the power-off of pressurization control valve portion, supercharger control valve valve rod is in supercharger control valve valve rod spring and bacterium shape sleeve It drives bacterium shape sleeve to take a seat together under the force action of spring, the upper conical surface of bacterium shape sleeve is closed, by supercharger control valve valve rod The access among bacterium shape sleeve is opened while the conical surface is closed, high pressure fuel passes through level-one Pressure Increasing Oil-Line and two-stage supercharging oil circuit weight Newly enter level-one booster cavity and two-stage supercharging chamber, the pressure in plunger shaft is less than level-one booster cavity, two-stage supercharging chamber and three at this time The sum of the elastic force of pressure and charged piston return spring in grade booster cavity, charged piston is back up into initial position；Three-level increases Intracavitary pressure reduction is pressed, check valve is again turned on, and fuel oil is entered in three-level booster cavity by check valve enters back into Sheng oil Slot.
4, at three rib type parts at supercharger control valve valve rod and bacterium shape sleeve cooperation, bacterium shape sleeve lining length is longer than trigone Type partial-length.
Present invention has an advantage that the pressure accumulation type piezoelectric fuel injector that 1, fuel injection characteristic of the invention can be changed uses three-level step The charged piston of circular table changes pressure ratio by way of changing pressure application surface product, makes the fuel pressure in oil holding slot It can be adjusted according to actual condition, effectively improve the flexibility of oil spout, diesel engine is enable to better meet sternly The emission regulation demands of lattice, the effective economy and dynamic property for improving diesel engine；2, the supercharger control valve energy that the present invention uses It is enough to realize multistage positioning, it realizes that the on-off of a plurality of Pressure Increasing Oil-Line is controllable, so as to adjust the high pressure oil active area of charged piston, protects Demonstrate,prove the flexible control of electric-controlled fuel injector pressure ratio；3, it is fixed come the difference for realizing supercharger control valve that present invention employs piezoelectric actuators Position, it is more accurate and flexible not only to make the positioning of supercharger control valve, while also accelerating the adjustment speed of charged piston pressure ratio, Improve the control precision of fuel injection characteristic more；4, pressure accumulation chamber can slowing oil injection when caused pressure oscillation, be conducive to Accurate control to distributive value is remarkably improved especially for the control precision of small oil mass.Common rail pipe is advantageously reduced simultaneously Requirement to material improves its service life.It is provided with AND DEWATERING FOR ORIFICE STRUCTURE in pressure accumulation chamber, flows to fuel injector high pressure oil to from pressure accumulation chamber The fuel oil of pipe plays the role of throttling and filtering, to reduce the pressure oscillation of fuel injector intermediate fuel oil, reduces circulating fuel injection quantity wave It is dynamic, further more accurately control high-pressure common-rail fuel system multi-injection process.Fluid power compensating piston can be returned in control chamber It can play the role of the repairing into control chamber in the process of oil, slow down control chamber oil pressure decrease speed, built in control chamber and press through journey In play the role of bleed off circuit, accelerate control chamber voltage built-up rate, so that rule anxious after first delaying is presented in fuel injection characteristic curve.
Detailed description of the invention
Fig. 1 is the structural diagram of the present invention；
Fig. 2 is pressure control valve partial structure diagram；
Fig. 3 is three-level pressurizing pack structural schematic diagram；
Fig. 4 is injector control valve partial structure diagram；
Fig. 5 is needle-valve portion structural schematic diagram；
Fig. 6 is fluid power compensating piston structural schematic diagram.
Specific embodiment
It illustrates with reference to the accompanying drawing and the present invention is described in more detail:
In conjunction with Fig. 1-6, the variable pressure accumulation type piezoelectric fuel injector of a kind of fuel injection characteristic of the present invention, by fastening cap 1, pressure accumulation cavity wall 2, pressurization control valve portion 3, three-level piston component 4, Injection Control valve portion 5, needle-valve portion 6, oil injector body 8,9 and of pressure accumulation chamber Orifice plate 10 is filtered to form.The pressurization control valve portion 3 is mainly by piezoelectric pile 12, gasket 13, plate-shaped springs 14, pressurization control Valve valve rod 16, bacterium shape sleeve limit orifice plate 22, bacterium shape sleeve spring 24, supercharger control valve valve rod spring 25, increases bacterium shape sleeve 18 Pressure control valve stem sleeve 26, hydraulic core 27 and hydraulic sleeve 28 form.16 head of supercharger control valve valve rod is provided with prismatic fuel oil Oil circuit, 18 sets of bacterium shape sleeve, on 16 head of supercharger control valve valve rod, are cut off and are opened the combustion in bacterium shape sleeve by relative motion Oily access, and be connected with level-one Pressure Increasing Oil-Line 17 and supercharger control valve valve chamber 21, level-one Pressure Increasing Oil-Line 17 passes through pressurization control The conical surface of valve valve rod 16 is connected with low pressure oil way, supercharger control valve valve chamber 21 and two-stage supercharging oil circuit 19 and pressurization throttle orifice 23 It communicates, bacterium shape sleeve 18 is located in supercharger control valve valve chamber 21.Three-level piston component 4 mainly includes charged piston 35, piston time Position spring 32 and check valve 34, charged piston 35 are three-level step frustum cone structure, and charged piston 35 and oil injector body 8 constitute one Grade booster cavity 29, two-stage supercharging chamber 30 and three-level booster cavity 31, level-one booster cavity 29 are connected with level-one Pressure Increasing Oil-Line 17, second level Booster cavity 30 is connected with two-stage supercharging oil circuit 19, and three-level booster cavity 31 is connected with oil holding slot 56, and by check valve 34 with High-pressure oil passage is connected.The Injection Control valve portion 5 is by injector control valve piezoelectric pile 37, Injection Control valve gasket 38, spray Oil control valve plate-shaped springs 39, injector control valve return spring 42, injector control valve limit orifice plate 46, umbrella shape piston 47, oil spout Control valve hydraulic sleeve 50 and the hydraulic core 49 of injector control valve collectively form.Needle-valve portion 6 includes check-valves 59, fluid power compensating piston 60, fluid power compensating piston spring 64, control chamber 51, oil holding slot 56, spray orifice 55, needle-valve 53 and needle valve spring 52.Fluid power compensation is lived Plug portion 58 is mounted on the top of needle-valve portion 6, and needle-valve limits and is equipped with fluid power compensating piston epicoele 66 in orifice plate 57, fluid power compensates Piston cavity of resorption 65 and fluid power compensating piston draining chamber 63,66 top of fluid power compensating piston epicoele are connected to high-pressure oil passage, and fluid power is mended It repays piston cavity of resorption 65 to be connected to fluid power compensating piston in-line 61 and fluid power compensating piston vent line 62 respectively, fluid power compensating piston Check-valves 59 is installed in in-line 61.
Fig. 1 is the overall structure diagram for the pressure accumulation type piezoelectric fuel injector that fuel injection characteristic of the present invention can be changed, mainly by fastening Cap 1, pressure accumulation cavity wall 2, pressurization control valve portion 3, three-level piston component 4, Injection Control valve portion 5, needle-valve portion 6, fuel injector Body 8 and filtering orifice plate 10 form.Pressurization control valve portion 3 is linked closely by screw thread and is fixed on oil injector body 8 by fastening cap 1, Injection Control valve portion 5 and needle-valve portion 6 are pressed together and linked closely by screw thread by the tight cap 7 of nozzle is fixed on oil injector body 8 On, fastening cap 1 is closed pressure accumulation chamber 9 by screw thread, while fuel inlet 11 is machined on fastening cap 1 for introducing high pressure oil To pressure accumulation chamber 9.
Fig. 2 is the pressurization control valve portion 3 for the pressure accumulation type piezoelectric fuel injector that fuel injection characteristic can be changed, pressurization control valve portion 3 It mainly include piezoelectric pile 12, gasket 13, plate-shaped springs 14, supercharger control valve valve rod 16, bacterium shape sleeve 18, the limit of bacterium shape sleeve Orifice plate 22, bacterium shape sleeve spring 24, supercharger control valve valve rod spring 25, supercharger control valve stem sleeve 26, hydraulic core 27 and liquid Pressing sleeve 28.Piezoelectric pile 12 is superimposed placement with gasket 13.Wherein hydraulic core 27 is nested among hydraulic sleeve 28, supercharger control valve valve rod 16 are also inserted into hydraulic sleeve 28, form a hydraulic fluid chamber.14 bottom end of plate-shaped springs is pressed in supercharger control valve stem sleeve 26 Hydraulic sleeve 28 is pressed on gasket 13 by top, 14 upper end of plate-shaped springs, so that hydraulic sleeve 28 and hydraulic core 27 are obtained with piezoelectric pile 12 act and act.Supercharger control valve valve rod 16 passes through supercharger control valve stem sleeve 26, the lower end cap of supercharger control valve valve rod 16 There is bacterium shape sleeve 18, bacterium shape sleeve 18 is located at the pressurization control that bacterium shape sleeve limit orifice plate 22 and charged piston limit orifice plate 20 surround In valve valve chamber 21 processed, bacterium shape sleeve 18 is lifted up under the action of bacterium shape 24 elastic force of sleeve spring, the conical surface of bacterium shape sleeve 18 Sealing surface is formed with bacterium shape sleeve limit orifice plate 22.Pressurization control is placed among bacterium shape sleeve 18 and supercharger control valve valve rod 16 Valve valve rod spring 25 processed, the elastic force of supercharger control valve valve rod spring 25 are less than bacterium shape sleeve spring 24, in the common of two springs Supercharger control valve valve rod 16 is lifted up under active force, the conical surface and supercharger control valve stem sleeve of supercharger control valve valve rod 16 26 form sealing surface.Three rib types are processed at supercharger control valve valve rod 16 and 18 cooperation of bacterium shape sleeve, in bacterium shape sleeve 18 Wall length is longer than trigone partial-length, and in the initial state, trigone part is not exclusively closed by bacterium shape sleeve 18, and fuel oil can lead to The gap at cooperation is crossed to be connected to up and down.When supercharger control valve valve rod 16 is moved downward with respect to bacterium shape sleeve 18, trigone part is complete Entirely closed by bacterium shape sleeve 18, the fuel flow path in bacterium shape sleeve 18 is closed.Increasing is machined in bacterium shape sleeve limit orifice plate 22 Throttle orifice 23 is pressed, pressurization throttle orifice 23 1 is connected to high-pressure oil passage, and other end is connected to supercharger control valve valve chamber 21, by high pressure Oil introduces supercharger control valve valve chamber 21.Two-stage supercharging oil circuit 19, two-stage supercharging oil are machined on charged piston limit orifice plate 20 Road 19 is connected with supercharger control valve valve chamber 21.Supercharger control valve valve between bacterium shape sleeve 18 and supercharger control valve valve rod 16 Level-one Pressure Increasing Oil-Line 17 is machined on rod sleeve 26, level-one Pressure Increasing Oil-Line 17 is by the access among bacterium shape sleeve 18 and is pressurized control Valve valve chamber 21 processed is connected.Oil return circuit is machined on the supercharger control valve stem sleeve 26 on 16 conical surface top of supercharger control valve valve rod 15, oil return circuit 15 is connected with low pressure oil way.
Charged piston 35, oil injector body 8, piston return spring 32 and check valve 34 together constitute what fuel injection characteristic can be changed The three-level piston component 4 of pressure accumulation type piezoelectric fuel injector, as shown in Figure 3.Charged piston 35 is a three-level stepped cylinder structure, with Charged piston limit orifice plate 20 collectively forms plunger shaft 36, and high pressure oil is passed through plunger shaft by the hole opened on piston limit orifice plate 20 36.Charged piston 35 and oil injector body 8 together constitute level-one booster cavity 29, two-stage supercharging chamber 30 and three-level booster cavity 31, Middle level-one booster cavity 29 and two-stage supercharging chamber 30 are connected with level-one Pressure Increasing Oil-Line 17 and two-stage supercharging oil circuit 19 respectively, pressurization control High pressure oil in valve valve chamber 21 processed respectively enters 29 He of level-one booster cavity by level-one Pressure Increasing Oil-Line 17 and two-stage supercharging oil circuit 19 Two-stage supercharging chamber 30.Three-level booster cavity 31 is connected by check valve 34 with high-pressure oil passage, is placed with work in three-level booster cavity 31 Return spring 32 is filled in, while 31 lower part of three-level booster cavity is also provided with Pressure Increasing Oil-Line 33, Pressure Increasing Oil-Line 33 will be in three-level booster cavity 31 Oil be introduced into oil holding slot 56.
Injector control valve piezoelectric pile 37, Injection Control valve gasket 38, injector control valve plate-shaped springs 39, injector control valve valve Bar return spring 42, injector control valve limit orifice plate 46, umbrella shape piston 47, injector control valve hydraulic sleeve 50 and injector control valve liquid Pressure core 49 together constitutes the Injection Control valve portion 5 of the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic, as shown in Figure 4.Spray Oil control valve piezoelectric pile 37 is superimposed placement with Injection Control valve gasket 38, and wherein the hydraulic core 49 of injector control valve is nested in oil spout control Among valve hydraulic sleeve 50 processed, injector control valve valve rod 48 is also inserted into injector control valve hydraulic sleeve 50, forms a hydraulic oil Chamber.39 bottom end of injector control valve plate-shaped springs is pressed in 40 top of injector control valve stem sleeve, injector control valve plate-shaped springs 39 Injector control valve hydraulic sleeve 50 is pressed on Injection Control valve gasket 38 by upper end, so that injector control valve hydraulic sleeve 50 and oil spout The hydraulic core 49 of control valve, which is obtained, to be acted and acts with injector control valve piezoelectric pile 37.Injector control valve valve rod 48 passes through injector control valve Sleeve.Injector control valve limit orifice plate 46 and intermediate orifice plate 44 together constitute injector control valve valve chamber 43, in injector control valve 48 lower end of injector control valve valve rod is pressed on umbrella shape piston 47 under the action of 42 spring force of return spring.Umbrella shape piston 47 is located at In injector control valve valve chamber 43, in the initial state, the upper conical surface and injector control valve stem sleeve 40 formation of umbrella shape piston 47 Sealing surface.When injector control valve valve rod 48 moves downward, the lower conical surface can be formed with injector control valve stem sleeve 40 and be sealed Face, while injector control valve valve rod 48 also will drive umbrella shape piston 47 and move downward, and open the sealing surface of umbrella shape piston 47.Spray It is machined with oil circuit in the injector control valve stem sleeve 40 of the lower conical surface upper end of oil control valve valve rod 48 to be connected with high-pressure oil passage, two Oil inlet metering-orifice 45 is machined in injector control valve stem sleeve 40 between a sealing cone to communicate with control chamber 51.In Injection Control It is also machined with low pressure oil leak hole 41 in valve limit orifice plate 46, one end is connected to injector control valve valve chamber 43, the other end and low pressure oil Case connection.
Fig. 5 show the structural schematic diagram of the needle-valve portion 6 of the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic, including needle Valve 53, needle valve spring 52, fluid power compensating piston part 58 and nozzle 54.Fluid power compensating piston part 58 is as shown in fig. 6, include liquid Force compensating piston 60 and fluid power compensating piston spring 64.Fluid power compensating piston part 58 is located in needle-valve limit orifice plate 57, with needle Valve limits orifice plate 57 and forms fluid power compensating piston cavity of resorption 65 and fluid power compensating piston draining chamber 63, while being formed with intermediate orifice plate 46 Fluid power compensating piston epicoele 66, needle valve spring 52 are located in fluid power compensating piston cavity of resorption 65.Fluid power compensating piston epicoele 66 and height Pressure oil road is connected, and fluid power compensating piston cavity of resorption 65 is gone out by fluid power compensating piston in-line 61 and fluid power compensating piston respectively Oil circuit 62 is connected with injector control valve valve chamber 43 and control chamber 51, is wherein provided with non-return in fluid power compensating piston in-line 61 Valve 59.Nozzle 54 is located in control chamber 51 with needle-valve limit orifice plate 57 composition control chamber 51 and oil holding slot 56, needle valve spring 52.Spray 54 lower end of mouth is provided with spray orifice 55, when the resultant force of the pressure initiation in 52 elastic force of needle valve spring and control chamber 51 is right greater than oil holding slot 56 When the pressure that needle-valve 53 applies, needle-valve 53, which is taken a seat, closes spray orifice 55；When needle-valve 53 lifts, spray orifice 55 and oil holding slot 56 connect It is logical, commencement of fuel injection.
Fuel oil enters pressure accumulation chamber 9 from fuel inlet 11, and filtering orifice plate 10, pressure accumulation chamber 9 are horizontally arranged in pressure accumulation chamber 9 Positioned at the top of fuel injector, it is connected respectively with fuel inlet 11 and lower section high-pressure oil passage, high-pressure oil passage is limited in bacterium shape sleeve A branch is drawn at the orifice plate 22 of position, is entered in supercharger control valve valve chamber 21 by being pressurized throttle orifice 23, is controlled using pressurization Valve valve chamber 21 processed is divided into two-way, enters level-one booster cavity 29 by level-one Pressure Increasing Oil-Line 17 all the way, another way passes through two-stage supercharging Oil circuit 19 enters two-stage supercharging chamber 30.Fuel oil continues to draw a branch at charged piston limit orifice plate 20 down, this Branch leads to plunger shaft 36.Fuel oil is divided into two-way in the continuation of oil injector body 8 down and wherein: continuing to pass through oil spout down all the way Control valve limits high-pressure oil passage and the lower conical surface of injector control valve valve rod 48 in orifice plate 46, then enters control by oil inlet metering-orifice 45 Chamber 51；Another way is entered in three-level booster cavity 31 by check valve 34, enters oil holding slot by Pressure Increasing Oil-Line 33 still further below In 56.The hydraulic coupling in plunger shaft 36 is less than the liquid in level-one booster cavity 29, two-stage supercharging chamber 30 and three-level booster cavity 31 at this time The resultant force that the elastic force of pressure and piston return spring 32 is formed, charged piston 35 are in extreme higher position, therefore three-level booster cavity Fuel oil in 31 is not pressurized.The resultant force that the pressure in oil holding slot 56 and needle valve spring 52 are formed simultaneously is greater than in control chamber 51 Pressure, needle-valve 53 is taken a seat at this time.According to the difference of injection process, fuel injector can be divided into three kinds of different operating modes: without pressurization Mode, low pressure charging mode and high pressure-charging mode.
When fuel injector works under no boost mode, 3 no power of pressurization control valve portion, since three-level piston is each at this time The pressure balance of a acting surface, check valve 34 is opened, therefore the fuel pressure in three-level booster cavity 31 does not increase, oil holding slot 56 Interior fuel pressure is equal to the pressure of 34 another side of check valve.When Injection Control valve portion 5 is powered, injector control valve piezoelectric pile 37 extend under the action of inverse piezoelectric effect, and Injection Control valve gasket 38 is driven to oppress injector control valve hydraulic sleeve 50 and oil spout control The hydraulic core 49 of valve processed moves downward jointly, in the oil pocket for forming injector control valve hydraulic sleeve 50 and injector control valve valve rod 48 Oil pressure increases, and injector control valve valve rod 48 is moved downward by pressure effect in oil pocket, and then is oppressed umbrella shape piston 47 and overcome spray The elastic force of oil control valve return spring 42 moves downward.The conical surface of 48 lower end of injector control valve valve rod is closed at this time, makes high pressure oil Road is cut off, while the conical surface seal on 47 top of umbrella shape piston is opened, and control chamber 51 is logical by the conical surface on 47 top of umbrella shape piston Road and injector control valve valve chamber 43 are connected with low pressure oil leak hole 41, and the fuel oil in control chamber 51 is flowed back to by low pressure oil leak hole 41 Into fuel tank.The pressure of fluid power compensating piston cavity of resorption 65 decreases in fluid power compensating piston 60 simultaneously, on fluid power compensating piston The pressure of chamber 66 is greater than the resultant force of the elastic force formation of 65 pressure of fluid power compensating piston cavity of resorption and fluid power compensating piston spring 64, at this time Fluid power compensating piston 60 moves downward, check-valves 59 close, fluid power compensating piston 60 by fluid power compensating piston vent line 62 to 51 repairing of control chamber slows down 51 pressure decrease speed of control chamber.When the elastic force of pressure and needle valve spring 52 in control chamber 51 When the resultant force of formation is less than the upward hydraulic coupling of fuel oil in oil holding slot 56, needle-valve 53 is lifted up, and spray orifice 55 is opened, and fuel injector is opened Beginning oil spout.When Injection Control valve portion 5 powers off, bullet of the injector control valve valve rod 48 in injector control valve valve rod return spring 42 It takes a seat under power effect, high-pressure oil passage is opened while closing low pressure oil leak hole 41, check-valves 59 is opened, and control chamber 51 passes through Oil inlet metering-orifice 45 and fluid power compensating piston cavity of resorption 65 build pressure again, when the elastic force shape of pressure and needle valve spring 52 in control chamber 51 At resultant force be greater than the upward hydraulic coupling of fuel oil in oil holding slot 56 when, needle-valve 53 drops back into one's seat, and fuel injector stops oil spout.
When fuel injector works under low pressure charging mode, supercharger control valve is powered, work of the piezoelectric pile 12 in inverse piezoelectric effect Locations of low pressure is elongated under, band mobile gasket 13 oppresses hydraulic sleeve 28 and hydraulic core 27 moves downward jointly, makes 28 He of hydraulic sleeve The oil pressure in oil pocket that supercharger control valve valve rod 16 is formed increases, and supercharger control valve valve rod 16 is transported downwards by the pressure in oil pocket Dynamic, bacterium shape sleeve 18 is by 16 head of supercharger control valve valve rod while opening the conical surface seal on supercharger control valve valve rod 16 Channel close.High-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line 17 at this time, while level-one Pressure Increasing Oil-Line 17 passes through pressurization control The conical surface of valve valve rod 16 processed is connected with oil return circuit 15.Fuel oil in level-one booster cavity 29 is flowed through by level-one Pressure Increasing Oil-Line 17 Oil return circuit 15 returns in low-pressure reservoir, at this time the pressure reduction in level-one booster cavity 29, and the pressure in plunger shaft 36 is greater than one The sum of grade booster cavity 29, two-stage supercharging chamber 30 and elastic force of pressure and piston return spring 32 in three-level booster cavity 31, pressurization Piston 35 moves downward, and the check valve 34 at the oil inlet of three-level booster cavity 31 is closed, the fuel pressure in three-level booster cavity 31 It is pressurized and increases, and then the fuel pressure in oil holding slot 56 is caused to increase.3 partial current of subsequent injector control valve, injector control valve Piezoelectric pile 37 extends under the action of inverse piezoelectric effect, and Injection Control valve gasket 38 is driven to oppress 50 He of injector control valve hydraulic sleeve The hydraulic core 49 of injector control valve moves downward jointly, the oil for forming injector control valve hydraulic sleeve 50 and injector control valve valve rod 48 Oil pressure in chamber increases, and injector control valve valve rod 48 is moved downward by pressure effect in oil pocket, and then oppresses umbrella shape piston 47 The elastic force of injector control valve return spring 42 is overcome to move downward.The conical surface of 48 lower end of injector control valve valve rod is closed at this time, makes High-pressure oil passage is cut off, while the conical surface seal on 47 top of umbrella shape piston is opened, and control chamber 51 passes through 47 top of umbrella shape piston Conical surface channel and injector control valve valve chamber 43 are connected with low pressure oil leak hole 41, and the fuel oil in control chamber 51 passes through low pressure oil leak hole 41 flow back into fuel tank.Pressure reduction in control chamber 51 at this time, while fluid power compensating piston cavity of resorption in fluid power compensating piston 60 65 pressure decreases, and the pressure of fluid power compensating piston epicoele 66 is greater than 65 pressure of fluid power compensating piston cavity of resorption and fluid power compensates The resultant force that the elastic force of piston spring 64 is formed, fluid power compensating piston 60 moves downward at this time, and check-valves 59 is closed, and fluid power compensation is lived Plug 60, to 51 repairing of control chamber, slows down 51 pressure decrease speed of control chamber by fluid power compensating piston vent line 62.When its pressure When the resultant force of power and needle-valve reset spring 51 is less than the hydraulic coupling of fuel oil in oil holding slot 56 to needle-valve 53, needle-valve 53 is lifted up, Spray orifice 55 is opened, fuel injector commencement of fuel injection.When Injection Control valve portion 5 powers off, injector control valve valve rod 48 is in Injection Control It takes a seat under the elastic force effect of valve valve rod return spring 42, opens high-pressure oil passage, non-return while closing low pressure oil leak hole 41 Valve 59 is opened, and control chamber 51 builds pressure by oil inlet metering-orifice 45 and fluid power compensating piston cavity of resorption 65 again, the pressure in control chamber 51 When the resultant force that the elastic force of power and needle valve spring 52 is formed is greater than the upward hydraulic coupling of fuel oil in oil holding slot 56, needle-valve 53 is fallen again Seat, fuel injector stop oil spout.When pressurization control valve portion 3 powers off, supercharger control valve valve rod 16 is in supercharger control valve valve rod bullet It drops back into one's seat under the spring-force driven dual of spring 25, is opened in bacterium shape sleeve 18 while closing 16 conical surface of supercharger control valve valve rod Access, high pressure fuel reenters level-one booster cavity 29 by level-one Pressure Increasing Oil-Line 17, and the pressure in plunger shaft 36 is small at this time In in level-one booster cavity 29, two-stage supercharging chamber 30 and three-level booster cavity 31 pressure and piston return spring 32 the sum of elastic force, Charged piston 35 is back up into initial position.Pressure reduction in three-level booster cavity 31, check valve 34 are again turned on, and fuel oil passes through Check valve 34, which enters in three-level booster cavity 31, enters back into oil holding slot 56.
When fuel injector works under high pressure-charging mode, supercharger control valve is powered, work of the piezoelectric pile 12 in inverse piezoelectric effect High pressure-charging position is elongated under, band mobile gasket compressing hydraulic sleeve 28 and hydraulic core 27 move downward jointly, make 28 He of hydraulic sleeve The oil pressure in oil pocket that supercharger control valve valve rod 16 is formed increases, and supercharger control valve valve rod 16 is transported downwards by the pressure in oil pocket Dynamic, bacterium shape sleeve 18 is by 16 head of supercharger control valve valve rod while opening the conical surface seal on supercharger control valve valve rod 16 Channel close.High-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line 17 at this time, while level-one Pressure Increasing Oil-Line 17 passes through pressurization control The conical surface of valve valve rod 16 processed is connected with oil return circuit 15, the fuel pressure decline in level-one booster cavity 29.Level-one booster cavity 29 Interior fuel oil flows through oil return circuit 15 by level-one Pressure Increasing Oil-Line 17 and returns in low-pressure reservoir.Subsequent supercharger control valve valve rod 16 after It is continuous to move downward, it drives bacterium shape sleeve 18 to move downward, opens the conical surface seal of bacterium shape sleeve 18, in two-stage supercharging chamber 30 Fuel oil is connected by the conical surface seal of bacterium shape sleeve 18 with oil return circuit 15, and 30 pressure of two-stage supercharging chamber also declines.This When plunger shaft 36 in pressure be greater than level-one booster cavity 29, two-stage supercharging chamber 30 and three-level booster cavity 31 in pressure and pressurization live The resultant force that the elastic force of return spring 32 is formed is filled in, charged piston 35 moves downward, unidirectional at the oil inlet of three-level booster cavity 31 Valve 34 is closed, and the fuel pressure in three-level booster cavity 31 increases, and then the fuel pressure in oil holding slot 56 is caused to increase.Then it sprays Oil control valve part 5 is powered, and injector control valve piezoelectric pile 37 extends under the action of inverse piezoelectric effect, drives Injection Control valve pad Piece 38 oppresses injector control valve hydraulic sleeve 50 and the hydraulic core 49 of injector control valve moves downward jointly, makes injector control valve hydraulic sleeve 50 and the oil pocket that is formed of injector control valve valve rod 48 in oil pressure increase, injector control valve valve rod 48 acted on by pressure in oil pocket It moves downward, and then oppresses umbrella shape piston 47 and the elastic force of injector control valve return spring 42 is overcome to move downward.Oil spout control at this time The conical surface of 48 lower end of valve valve rod processed is closed, is cut off high-pressure oil passage, while the conical surface seal on 47 top of umbrella shape piston is opened, control Chamber processed is connected by the conical surface channel and injector control valve valve chamber 43 on 47 top of umbrella shape piston with low pressure oil leak hole 41, control chamber Interior fuel oil is flow back into fuel tank by low pressure oil leak hole 41.Fluid power compensating piston cavity of resorption 65 in fluid power compensating piston 60 simultaneously Pressure decreases, and the pressure of fluid power compensating piston epicoele 66 is greater than 65 pressure of fluid power compensating piston cavity of resorption and fluid power compensating piston The resultant force that the elastic force of spring 64 is formed, fluid power compensating piston 60 moves downward at this time, and check-valves 59 is closed, fluid power compensating piston 60 By fluid power compensating piston vent line 62 to 51 repairing of control chamber, slow down 51 pressure decrease speed of control chamber.Control chamber at this time Pressure reduction in 51, when the resultant force of its pressure and needle-valve reset spring 51 is less than in oil holding slot 56 fuel oil to the hydraulic of needle-valve 53 When power, needle-valve 53 is lifted up, and spray orifice 55 is opened, fuel injector commencement of fuel injection.When Injection Control valve portion 5 powers off, oil spout control Valve valve rod 48 processed is taken a seat under the elastic force effect of injector control valve valve rod return spring 42, same closing low pressure oil leak hole 41 When open high-pressure oil passage, check-valves 59 is opened, and control chamber 51 is built again by oil inlet metering-orifice 45 and fluid power compensating piston cavity of resorption 65 The newly-built pressure of ballast, when the resultant force that the elastic force of pressure and needle valve spring 52 in control chamber 51 is formed be greater than in oil holding slot 56 fuel oil to On hydraulic coupling when, needle-valve 53 drops back into one's seat, fuel injector stop oil spout.When pressurization control valve portion 3 powers off, supercharger control valve Valve rod 16 drives bacterium shape sleeve 18 to rise and fall under the force action of supercharger control valve valve rod spring 25 and bacterium shape sleeve spring 24 Seat now closes the upper conical surface of bacterium shape sleeve 18, and bacterium shape is then opened while closing 16 conical surface of supercharger control valve valve rod Access among sleeve 18, high pressure fuel reenter level-one booster cavity by level-one Pressure Increasing Oil-Line 17 and two-stage supercharging oil circuit 19 29 and two-stage supercharging chamber 30, the pressure in plunger shaft 36 is less than level-one booster cavity 29, two-stage supercharging chamber 30 and three-level pressurization at this time The sum of the elastic force of pressure and charged piston return spring 32 in chamber 31, charged piston 35 is back up into initial position.Three-level increases Press the pressure reduction in chamber 31, check valve 34 is again turned on, fuel oil by check valve 34 enter in three-level booster cavity 31 again into Enter to oil holding slot 56.
The course of work for the pressure accumulation type piezoelectric fuel injector that can be changed by fuel injection characteristic is it is found that the present invention passes through during the work time Change the action response of supercharger control valve, it can be achieved that different pressure ratios enables fuel injector to reach different injection pressures Realize more flexible injection characteristics.Present invention employs the injector control valves of piezoelectric type simultaneously, on the basis of electromagnetic drive The response speed and control precision of fuel injector are further improved, enables the invention to realize more accurate multi-injection.Have Effect improves the dynamic property of diesel engine and the economy of fuel oil.Present invention employs piezoelectric actuators to realize supercharger control valve Difference positioning, it is more accurate and flexible not only to make the positioning of supercharger control valve, while also accelerating the tune of charged piston pressure ratio Speed is saved, improves the control precision of fuel injection characteristic more.Pressure accumulation chamber can effectively extenuate caused pressure wave when fuel oil injection It is dynamic, be conducive to the accurate control to distributive value, be remarkably improved especially for the control precision of small oil mass.Meanwhile working as oil spout When device is applied in common rail fuel combustion system, the pressure stabilization function of pressure accumulation chamber can be such that the size of common rail for diesel engine pipe reduces, this is advantageous In reducing requirement of the common rail pipe to material, its service life is improved.Meanwhile it being provided with AND DEWATERING FOR ORIFICE STRUCTURE in pressure accumulation chamber, on orifice plate It is drilled with the throttle orifice of different pore size, plays the role of throttling and filtering to the fuel oil for flowing to fuel injector high-pressure oil pipe from pressure accumulation chamber, To reduce the pressure oscillation of fuel injector intermediate fuel oil, circulating fuel injection quantity fluctuation is reduced, further more accurate control high-pressure common rail Fuel system multi-injection process.The repairing in control chamber pressure release of the fluid power compensating piston structure of use, plays two-way when building pressure The effect of oil inlet improves oil spout performance so that fuel injection characteristic realizes characteristic anxious after first delaying.

Claims (9)

1. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic, it is characterized in that: including oil injector body, pressure accumulation cavity wall, pressurization control Valve portion, three-level piston component, Injection Control valve portion, needle-valve portion, pressure accumulation cavity wall are fixed on above oil injector body, pressurization control Valve portion processed and three-level piston component are mounted in oil injector body from top to bottom, and Injection Control valve portion and needle-valve portion pass through it The external tight cap of nozzle is mounted below three-level piston component, and pressure accumulation chamber is opened up in pressure accumulation cavity wall, and pressure accumulation chamber is connected to high-pressure oil passage；
The pressurization control valve portion includes piezoelectric pile, supercharger control valve valve rod, bacterium shape sleeve, hydraulic core, supercharger control valve valve Rod sleeve, piezoelectric pile sleeve, bacterium shape sleeve limit orifice plate, charged piston limit orifice plate, piezoelectric pile sleeve, bacterium shape sleeve limit hole Plate and charged piston limit orifice plate are arranged from top to bottom, and hydraulic core is mounted in hydraulic sleeve, piezoelectric pile, hydraulic sleeve, pressurization control Valve stem sleeve is arranged in from top to bottom in piezoelectric pile sleeve, and supercharger control valve valve rod is installed in supercharger control valve stem sleeve, The upper end of supercharger control valve valve rod stretches in hydraulic sleeve and is formed between hydraulic core hydraulic fluid chamber, and bacterium shape sleeve limits orifice plate In be arranged supercharger control valve valve chamber, bacterium shape sleeve be arranged in supercharger control valve valve chamber, the lower end of supercharger control valve valve rod is protruded into In bacterium shape sleeve, the exterior panel shape spring of hydraulic sleeve, the bottom end of plate-shaped springs is pressed in above supercharger control valve stem sleeve, The upper end of plate-shaped springs is pressed in the upper end of hydraulic sleeve, and the middle part setting supercharger control valve valve rod protrusion of supercharger control valve valve rod increases Supercharger control valve valve rod spring, the conical surface lower end of bacterium shape sleeve and pressurization are set between pressure control valve valve rod protrusion and bacterium shape sleeve Setting is set with sleeve spring between piston limit orifice plate, and oil return circuit and level-one pressurised oil is arranged on supercharger control valve stem sleeve Road, bacterium shape sleeve limit setting pressurization throttle orifice on orifice plate, and charged piston, which limits, is arranged two-stage supercharging oil circuit on orifice plate, level-one increases Pressure oil road is connected to supercharger control valve valve chamber by the access among bacterium shape sleeve, and oil return circuit is connected to low pressure oil way, pressurization throttling Hole is respectively communicated with high-pressure oil passage and supercharger control valve valve chamber, two-stage supercharging oil communication supercharger control valve valve chamber；
The three-level piston component includes charged piston, piston return spring, and charged piston is three-level stepped cylinder structure, from upper And lower is respectively the first-third cylinder, and diameter successively decreases, the first cylinder and the charged piston above it are limited and are formed between orifice plate Plunger shaft, plunger shaft limit the hole in orifice plate by charged piston and are connected to high-pressure oil passage, the first cylinder and the second cylinder and oil spout Level-one booster cavity is formed between body, and two-stage supercharging chamber, third column are formed between the second cylinder and third cylinder and oil injector body Three-level booster cavity is formed between body and oil injector body below, and piston return spring, level-one pressurization are installed in three-level booster cavity Chamber is connected to level-one Pressure Increasing Oil-Line, and two-stage supercharging chamber is connected to two-stage supercharging oil circuit, and three-level booster cavity is connected to high pressure oil by check valve Road, three-level booster cavity lower part are provided with Pressure Increasing Oil-Line；
The Injection Control valve portion includes injector control valve piezoelectric pile, injector control valve hydraulic sleeve, injector control valve valve stem sleeve Cylinder, injector control valve valve rod, injector control valve limit orifice plate, umbrella shape piston, intermediate orifice plate, injector control valve piezoelectric pile, oil spout Control valve hydraulic sleeve and injector control valve stem sleeve are arranged in oil injector body from top to bottom, set in injector control valve hydraulic sleeve The hydraulic core of injector control valve is set, injector control valve valve rod is mounted in injector control valve stem sleeve, injector control valve valve rod Upper end stretch in injector control valve hydraulic sleeve and with hydraulic fluid chamber, oil injector body and injector control valve limit hole are formed between it Plate, intermediate orifice plate form injector control valve valve chamber, and umbrella shape piston is mounted in injector control valve valve chamber, under injector control valve valve rod Side pressure installs injector control valve return spring, oil spout between the conical surface lower end of umbrella shape piston and intermediate orifice plate on umbrella shape piston The external of control valve hydraulic sleeve installs injector control valve plate-shaped springs, and the bottom end of injector control valve plate-shaped springs is pressed in Injection Control Above valve stem sleeve, the upper end of injector control valve plate-shaped springs is pressed in the upper end of injector control valve hydraulic sleeve, injector control valve The oil circuit being connected to high-pressure oil passage and oil inlet metering-orifice are offered on stem sleeve, and low pressure is set on injector control valve limit orifice plate Oil leak hole, low pressure oil leak hole are respectively communicated with low pressure oil way and injector control valve valve chamber；
The needle-valve portion includes needle-valve limit orifice plate, needle-valve block, needle-valve limit orifice plate and during needle-valve block is arranged in from top to bottom Between below orifice plate, fluid power compensating piston epicoele in-line, non-return passage are set in intermediate orifice plate, non-return is installed in non-return passage Valve, fluid power compensating piston epicoele in-line are connected to high-pressure oil passage, and non-return passage is connected to oil inlet metering-orifice, sets in needle-valve limit hole Fluid power compensating piston, control chamber oil circuit are set, fluid power compensating piston reset spring is cased with outside fluid power compensating piston, fluid power compensation is lived The upper end of plug reset spring is withstood on fluid power compensating piston, and the lower end of fluid power compensating piston reset spring withstands on needle-valve below It limits on orifice plate, is formed on the fluid power compensating piston communicated with fluid power compensating piston epicoele in-line above fluid power compensating piston Chamber, fluid power compensating piston reset spring present position are fluid power compensating piston cavity of resorption, fluid power compensating piston lower end with below Needle-valve, which limits, forms fluid power compensating piston draining chamber, control chamber oil communication oil inlet metering-orifice between orifice plate；Needle is installed in needle-valve block Valve, needle-valve top are cased with needle-valve reset spring, and the upper end of needle-valve reset spring is withstood on needle-valve limit orifice plate, needle-valve reset spring Lower end withstand on needle-valve, needle-valve reset spring present position is control chamber, and control chamber is connected to control chamber oil circuit, is set in needle-valve block Oil holding slot in-line is set, forms oil holding slot between needle-valve and needle-valve block, spray orifice, oil holding slot in-line difference is arranged in needle-valve block bottom It is connected to oil holding slot and Pressure Increasing Oil-Line, fluid power compensating piston cavity of resorption is connected to below check-valves by fluid power compensating piston cavity of resorption in-line Non-return passage, fluid power compensating piston cavity of resorption by fluid power compensating piston vent line be connected to control chamber.
2. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1, it is characterized in that: without under boost mode When work, when injector control valve partial current, injector control valve piezoelectric pile oppresses injector control valve hydraulic sleeve and Injection Control The hydraulic core of valve moves downward jointly, the oil pressure liter in oil pocket for forming injector control valve hydraulic sleeve and injector control valve valve rod Height, injector control valve valve rod is moved downward by pressure effect in oil pocket, and then is oppressed umbrella shape piston overpowers injector control valve and returned The elastic force of position spring moves downward, and the conical surface of injector control valve valve rod lower end is closed at this time, is cut off high-pressure oil passage, while umbrella The conical surface seal of shape upper piston area is opened, control chamber by the conical surface channel of umbrella shape upper piston area and injector control valve valve chamber with it is low Pressure oil leak hole is connected, and the fuel oil in control chamber is flow back into fuel tank by low pressure oil leak hole；Liquid in fluid power compensating piston simultaneously The pressure of force compensating piston cavity of resorption decreases, the pressure of fluid power compensating piston epicoele be greater than under fluid power compensating piston cavity pressure with The resultant force that the elastic force of fluid power compensating piston spring is formed, fluid power compensating piston moves downward at this time, closure of check ring, fluid power compensation Piston slows down control cavity pressure decrease speed by the fuel-displaced road direction control chamber repairing of fluid power compensating piston；When in control chamber When the resultant force that the elastic force of pressure and needle valve spring is formed is less than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve is lifted up, spray Hole commencement of fuel injection；When the power-off of Injection Control valve portion, bullet of the injector control valve valve rod in injector control valve valve rod return spring It takes a seat under power effect, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, and control chamber passes through oil inlet quantity Hole and fluid power compensating piston cavity of resorption build pressure again, contain when the resultant force that the elastic force of pressure and needle valve spring in control chamber is formed is greater than In oil groove when the upward hydraulic coupling of fuel oil, needle-valve drops back into one's seat, and stops oil spout.
3. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1 or 2, it is characterized in that: low pressure charging mould When working under formula, supercharger control valve is powered, and piezoelectric pile is elongated to locations of low pressure under the action of inverse piezoelectric effect, oppresses hydraulic sleeve It is moved downward jointly with hydraulic core, the oil pressure in oil pocket for forming hydraulic sleeve and supercharger control valve valve rod increases, pressurization control Valve valve rod is moved downward by the pressure in oil pocket, bacterium shape set while opening the conical surface seal on supercharger control valve valve rod Cylinder closes the channel on supercharger control valve valve rod head, and high-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line at this time, while level-one Pressure Increasing Oil-Line is connected by the conical surface of supercharger control valve valve rod with oil return circuit.Fuel oil in level-one booster cavity is increased by level-one Pressure oil road flows through oil return circuit and returns in low-pressure reservoir, and the pressure in plunger shaft is greater than level-one booster cavity, two-stage supercharging chamber at this time With the sum of the elastic force of pressure and piston return spring in three-level booster cavity, charged piston is moved downward, three-level booster cavity into The closed check valve of oil port；Injector control valve partial current, injector control valve piezoelectric pile are stretched under the action of inverse piezoelectric effect It is long, it oppresses injector control valve hydraulic sleeve and the hydraulic core of injector control valve moves downward jointly, make injector control valve hydraulic sleeve and spray The oil pressure in oil pocket that oil control valve valve rod is formed increases, and injector control valve valve rod is moved downward by pressure effect in oil pocket, And then the elastic force for oppressing umbrella shape piston overpowers injector control valve return spring moves downward.Injector control valve valve rod lower end at this time The conical surface is closed, is cut off high-pressure oil passage, while the conical surface seal of umbrella shape upper piston area is opened, and control chamber passes through on umbrella shape piston The conical surface channel in portion and injector control valve valve chamber are connected with low pressure oil leak hole, and the fuel oil in control chamber passes through low pressure oil leak hole stream It returns in fuel tank；The pressure of fluid power compensating piston epicoele is greater than cavity pressure and fluid power compensating piston spring under fluid power compensating piston The resultant force that elastic force is formed, fluid power compensating piston moves downward at this time, closure of check ring, and fluid power compensating piston is compensated by fluid power and lived Fill in fuel-displaced road direction control chamber repairing；When the resultant force of its pressure and needle-valve reset spring is less than in oil holding slot fuel oil to the hydraulic of needle-valve When power, needle-valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, injector control valve valve rod is in injector control valve It takes a seat under the elastic force effect of valve rod return spring, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, Control chamber builds pressure by oil inlet metering-orifice and fluid power compensating piston cavity of resorption again, when the elastic force of pressure and needle valve spring in control chamber When the resultant force of formation is greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops oil spout；When pressurization control valve portion When disjunction electricity, supercharger control valve valve rod drops back into one's seat under the spring-force driven dual of supercharger control valve valve rod spring, will be pressurized control The access in bacterium shape sleeve is opened while the valve valve rod conical surface processed is closed, high pressure fuel reenters one by level-one Pressure Increasing Oil-Line Grade booster cavity, the pressure in plunger shaft is less than level-one booster cavity, two-stage supercharging chamber and pressure and work in three-level booster cavity at this time Fill in the sum of the elastic force of return spring, charged piston is again turned on back up into initial position, check valve, fuel oil by check valve into Enter and enters back into oil holding slot into three-level booster cavity.
4. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1 or 2, it is characterized in that: high pressure-charging mould When working under formula, supercharger control valve is powered, and piezoelectric pile is elongated to high pressure-charging position under the action of inverse piezoelectric effect, oppresses hydraulic Set and hydraulic core move downward jointly, and the oil pressure in oil pocket for forming hydraulic sleeve and supercharger control valve valve rod increases, pressurization control Valve valve rod processed is moved downward by the pressure in oil pocket, bacterium shape while opening the conical surface seal on supercharger control valve valve rod Sleeve closes the channel on supercharger control valve valve rod head；High-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line at this time, while one Grade Pressure Increasing Oil-Line is connected by the conical surface of supercharger control valve valve rod with oil return circuit, and the fuel oil in level-one booster cavity passes through level-one Pressure Increasing Oil-Line flows through oil return circuit and returns in low-pressure reservoir；Supercharger control valve valve rod continues to move downward, drive bacterium shape sleeve to Lower movement opens the conical surface seal of bacterium shape sleeve, and the intracavitary fuel oil of two-stage supercharging passes through the conical surface seal of bacterium shape sleeve and returns Oil circuit is connected；The pressure in plunger shaft is greater than the pressure in level-one booster cavity, two-stage supercharging chamber and three-level booster cavity at this time The resultant force formed with the elastic force of charged piston return spring, charged piston move downward, the list at the oil inlet of three-level booster cavity It is closed to valve；Injector control valve partial current, injector control valve piezoelectric pile extend under the action of inverse piezoelectric effect, oppress oil spout Control valve hydraulic sleeve and the hydraulic core of injector control valve move downward jointly, make injector control valve hydraulic sleeve and injector control valve valve rod Oil pressure in the oil pocket of formation increases, and injector control valve valve rod is moved downward by pressure effect in oil pocket, and then oppresses umbrella shape The elastic force of piston overpowers injector control valve return spring moves downward；The conical surface of injector control valve valve rod lower end is closed at this time, makes High-pressure oil passage is cut off, while the conical surface seal of umbrella shape upper piston area is opened, and control chamber is logical by the conical surface of umbrella shape upper piston area Road and injector control valve valve chamber are connected with low pressure oil leak hole, and the fuel oil in control chamber flow back into fuel tank by low pressure oil leak hole It is interior；The elastic force that the pressure of fluid power compensating piston epicoele is greater than cavity pressure and fluid power compensating piston spring under fluid power compensating piston is formed Resultant force, fluid power compensating piston moves downward at this time, closure of check ring, fluid power compensating piston pass through fluid power compensating piston vent line To control chamber repairing；When the resultant force of control cavity pressure and needle-valve reset spring is less than in oil holding slot fuel oil to the hydraulic coupling of needle-valve When, needle-valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, injector control valve valve rod is in injector control valve valve It takes a seat under the elastic force effect of bar return spring, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, control Chamber processed builds the newly-built pressure of ballast by oil inlet metering-orifice and fluid power compensating piston cavity of resorption again, when the pressure and needle valve spring in control chamber The resultant force that is formed of elastic force when being greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops oil spout；When pressurization is controlled When valve portion processed powers off, supercharger control valve valve rod band under the force action of supercharger control valve valve rod spring and bacterium shape sleeve spring Dynamic bacterium shape sleeve is taken a seat together, and the upper conical surface of bacterium shape sleeve is closed, and is opened while the supercharger control valve valve rod conical surface is closed Access among bacterium shape sleeve, high pressure fuel by level-one Pressure Increasing Oil-Line and two-stage supercharging oil circuit reenter level-one booster cavity and Two-stage supercharging chamber, at this time the pressure in plunger shaft be less than level-one booster cavity, two-stage supercharging chamber and three-level booster cavity in pressure with The sum of the elastic force of charged piston return spring, charged piston is back up into initial position；Pressure reduction in three-level booster cavity, it is single It is again turned on to valve, fuel oil is entered in three-level booster cavity by check valve and enters back into oil holding slot.
5. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 3, it is characterized in that: under high pressure-charging mode When work, supercharger control valve is powered, and piezoelectric pile is elongated to high pressure-charging position under the action of inverse piezoelectric effect, compressing hydraulic sleeve and Hydraulic core moves downward jointly, and the oil pressure in oil pocket for forming hydraulic sleeve and supercharger control valve valve rod increases, supercharger control valve Valve rod is moved downward by the pressure in oil pocket, bacterium shape sleeve while opening the conical surface seal on supercharger control valve valve rod The channel on supercharger control valve valve rod head is closed；High-pressure oil passage is no longer connected to level-one Pressure Increasing Oil-Line at this time, while level-one increases Pressure oil road is connected by the conical surface of supercharger control valve valve rod with oil return circuit, and the fuel oil in level-one booster cavity is pressurized by level-one Oil circuit flows through oil return circuit and returns in low-pressure reservoir；Supercharger control valve valve rod continues to move downward, and bacterium shape sleeve is driven to transport downwards It is dynamic, open the conical surface seal of bacterium shape sleeve, the intracavitary fuel oil of two-stage supercharging passes through the conical surface seal of bacterium shape sleeve and oil return oil Road is connected；The pressure in plunger shaft is greater than level-one booster cavity, two-stage supercharging chamber and pressure and increasing in three-level booster cavity at this time The resultant force for pressing the elastic force of piston return spring to be formed, charged piston move downward, the check valve at the oil inlet of three-level booster cavity It closes；Injector control valve partial current, injector control valve piezoelectric pile extend under the action of inverse piezoelectric effect, oppress Injection Control Valve hydraulic sleeve and the hydraulic core of injector control valve move downward jointly, form injector control valve hydraulic sleeve and injector control valve valve rod Oil pocket in oil pressure increase, injector control valve valve rod by oil pocket pressure effect move downward, and then oppress umbrella shape piston The elastic force of injector control valve return spring is overcome to move downward；The conical surface of injector control valve valve rod lower end is closed at this time, makes high pressure Oil circuit is cut off, while the conical surface seal of umbrella shape upper piston area is opened, control chamber by the conical surface channel of umbrella shape upper piston area and Injector control valve valve chamber is connected with low pressure oil leak hole, and the fuel oil in control chamber is flow back into fuel tank by low pressure oil leak hole；Liquid The pressure of force compensating piston upper chamber is greater than the conjunction that the elastic force of cavity pressure and fluid power compensating piston spring is formed under fluid power compensating piston Power, fluid power compensating piston moves downward at this time, closure of check ring, and fluid power compensating piston passes through the fuel-displaced road direction control of fluid power compensating piston Chamber repairing processed；When the resultant force for controlling cavity pressure and needle-valve reset spring is less than the hydraulic coupling of fuel oil in oil holding slot to needle-valve, needle Valve is lifted up, spray orifice oil spout；When the power-off of Injection Control valve portion, injector control valve valve rod is in injector control valve valve rod return It takes a seat under the elastic force effect of spring, high-pressure oil passage is opened while by low pressure draining bore closure, check-valves is opened, and control chamber is logical It crosses oil inlet metering-orifice and fluid power compensating piston cavity of resorption builds the newly-built pressure of ballast again, when the elastic force of pressure and needle valve spring in control chamber When the resultant force of formation is greater than the upward hydraulic coupling of fuel oil in oil holding slot, needle-valve drops back into one's seat, and stops oil spout；When pressurization control valve portion When disjunction electricity, supercharger control valve valve rod drives bacterium shape under the force action of supercharger control valve valve rod spring and bacterium shape sleeve spring Sleeve is taken a seat together, and the upper conical surface of bacterium shape sleeve is closed, and bacterium shape set is opened while the supercharger control valve valve rod conical surface is closed The intermediate access of cylinder, high pressure fuel reenters level-one booster cavity by level-one Pressure Increasing Oil-Line and two-stage supercharging oil circuit and second level increases Chamber is pressed, the pressure in plunger shaft is less than pressure and pressurization work in level-one booster cavity, two-stage supercharging chamber and three-level booster cavity at this time The sum of the elastic force of return spring is filled in, charged piston is back up into initial position；Pressure reduction in three-level booster cavity, check valve is again Secondary opening, fuel oil are entered in three-level booster cavity by check valve and enter back into oil holding slot.
6. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 1 or 2, it is characterized in that: pressurization control At three rib type parts at valve valve rod and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.
7. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 3, it is characterized in that: supercharger control valve valve At three rib type parts at bar and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.
8. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 4, it is characterized in that: supercharger control valve valve At three rib type parts at bar and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.
9. the variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic according to claim 5, it is characterized in that: supercharger control valve valve At three rib type parts at bar and the sleeve cooperation of bacterium shape, bacterium shape sleeve lining length is longer than three rib type partial-lengths.
CN201810833837.2A 2018-07-26 2018-07-26 The variable pressure accumulation type piezoelectric fuel injector of fuel injection characteristic Withdrawn CN109026476A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110748682A (en) * 2019-07-22 2020-02-04 宜宾三江机械有限责任公司 Safety valve with pilot structure

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5954030A (en) * 1994-12-01 1999-09-21 Oded E. Sturman Valve controller systems and methods and fuel injection systems utilizing the same
JP2006161568A (en) * 2004-12-02 2006-06-22 Nippon Soken Inc Control valve and fuel injection valve having the same
CN104018969A (en) * 2014-05-29 2014-09-03 哈尔滨工程大学 Piezoelectric control pressure accumulation and stabilization oil sprayer
CN104632485A (en) * 2014-12-29 2015-05-20 沪东重机有限公司 Common-rail fuel oil jet system controlled by double electromagnetic valves and applied to low-speed diesel engine for ship

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5954030A (en) * 1994-12-01 1999-09-21 Oded E. Sturman Valve controller systems and methods and fuel injection systems utilizing the same
JP2006161568A (en) * 2004-12-02 2006-06-22 Nippon Soken Inc Control valve and fuel injection valve having the same
CN104018969A (en) * 2014-05-29 2014-09-03 哈尔滨工程大学 Piezoelectric control pressure accumulation and stabilization oil sprayer
CN104632485A (en) * 2014-12-29 2015-05-20 沪东重机有限公司 Common-rail fuel oil jet system controlled by double electromagnetic valves and applied to low-speed diesel engine for ship

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110748682A (en) * 2019-07-22 2020-02-04 宜宾三江机械有限责任公司 Safety valve with pilot structure

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Application publication date: 20181218