CN107165748B - Piezoelectric type external guiding gas injection valve for straight-through type mixed air inlet - Google Patents

Abstract

The invention aims to provide a piezoelectric type external guide gas injection valve for straight-through mixed gas inlet, which utilizes piezoelectric crystals to electrify and elongate, and small pistons which are symmetrically arranged push a circular ring disc to move upwards steadily after the piezoelectric crystals amplify displacement, and the circular ring disc drives a valve core assembly to move away from a valve seat under the external guide action of a guide block on the outer side through a valve rod so as to realize the gas injection function of the gas valve; the piezoelectric crystal driving mode is adopted, so that the response speed of the gas injection valve is effectively improved, and the lift of the gas injection valve is variable; the high flow is realized by the mixed air inlet mode of direct air inlet of the axial main air groove and air inlet of the circumferential air-filling holes, the air supply efficiency of the engine is effectively improved, meanwhile, the air flow interference can be avoided, and the stability of an air path is realized; the surface sealing and high reliability of the gas injection valve are realized through the multi-channel annular band structure between the valve core and the valve seat.

Description

Piezoelectric type external guiding gas injection valve for straight-through type mixed air inlet

Technical Field

The invention relates to a gas injection valve, in particular to a gas injection valve of a natural gas engine.

Background

In recent years, with the rapid increase of petroleum consumption in China, petroleum is seriously imported. Natural gas burns cleanly and has abundant reserves in China, making it the most likely fuel to replace diesel. In the internal combustion engine industry, the natural gas-based internal combustion engine has become a research hot spot in the industry in recent years, wherein the natural gas-based internal combustion engine can greatly reduce emission pollution under the premise of ensuring the dynamic performance. As a fuel supply device for a natural gas engine, the performance of a gas injection valve directly determines the characteristics of the natural gas engine. At present, in the actual working process of the gas injection valve, the flexibility of the gas injection control of the gas injection valve, the stability of the injected gas pressure, the control precision and other characteristics can all affect the performance of the internal combustion engine, and the response time of the gas injection valve is generally between a few milliseconds and tens of milliseconds according to the different rotation speeds of the internal combustion engine, namely the gas injection valve needs to have high response speed to meet the requirement of rapid switching, and meanwhile, the gas injection valve also needs to have the largest gas outlet cross section area as much as possible so as to ensure that the internal combustion engine obtains sufficient gas quantity. Therefore, the development of the high-flow gas injection valve with variable lift, stable gas pressure, high control precision, high response speed and high reliability is a trend of the development of the gas injection valve of the natural gas engine at present.

Disclosure of Invention

The invention aims to provide the piezoelectric type external guide gas injection valve with the through type mixed air inlet, which has the advantages of variable lift, high response speed, high control precision, high reliability, stable air injection pressure, high efficiency sealing and large flow.

The purpose of the invention is realized in the following way:

the invention relates to a piezoelectric type external guiding gas injection valve of straight-through mixed air inlet, which is characterized in that: comprises a valve body, a valve seat, a valve rod, a piezoelectric crystal, a hydraulic amplifier, a partition board and a valve core assembly, wherein the valve seat is fixed below the valve body and forms a valve space with the valve body, a fixed block is fixed above the interior of the valve body, a straight slot is formed in the middle of the fixed block, the piezoelectric crystal is arranged in the straight slot, the partition board is arranged in the middle of the valve body, the hydraulic amplifier is arranged above the partition board, the valve core assembly is arranged below the partition board, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the partition board, the center of the upper end of the sleeve is a coarse outlet, the end part of the upper end of the sleeve is a fine outlet, the large piston is arranged in the coarse outlet, the small piston is arranged in the fine outlet, a large piston supporting spring is arranged between a flange of the large piston and the sleeve, hydraulic oil is filled in the sleeve below the large piston and the small piston, the upper surface of the large piston is attached to the lower surface of the piezoelectric crystal, the annular disc is arranged outside the large piston, the upper surface of the small piston is attached to the lower surface of the annular disc, grooves are formed in the annular disc and the fixed block, two ends of the reset spring are respectively arranged in the grooves of the annular disc and the fixed block, the valve core assembly comprises an armature, a spring seat, a bottom plate and a valve core, the armature, the bottom plate and the valve core are simultaneously connected together through fastening bolts from top to bottom, the spring seat is positioned outside the armature and forms an annular groove with the armature, the lower surface of the partition plate is provided with the annular groove, two ends of the reset spring are respectively arranged in the annular groove of the partition plate and the annular groove of the spring seat, a pressure balance hole is formed in the center of the armature, a pressure balance groove is formed in the bottom plate, the valve core is of a hollow structure, a central pressure stabilizing cavity is formed in a valve seat below the valve core, and the pressure balance hole and the pressure balance groove, the hollow part of the valve core and the central pressure stabilizing cavity are communicated and form an internal space, the valve core is provided with a sealing ring belt and a rib, the sealing ring belt forms an annular cavity, the valve seat is provided with an air outlet ring belt and a guide block, the guide block is positioned around the valve core, the air outlet ring belt is positioned below the annular cavity, the air outlet ring belt is provided with an air outlet, the partition plate is provided with a through hole and an air vent respectively, the middle part of the valve rod passes through the through hole, the upper part of the valve rod is connected with the annular disk, the lower part of the valve rod is fixed with the armature through a clamp spring, the upper surface of the valve core is provided with an axial main air groove, the rib is provided with a circumferential air supplementing hole, and a flow guiding cone angle is arranged at the air supplementing hole.

The invention may further include:

1. the outer end of the valve seat is provided with an end pressure stabilizing cavity.

2. An air inlet is formed between the upper part of the fixed block and the valve body, an air inlet cavity is formed between the middle lower part of the fixed block and the hydraulic amplifier and the valve body, a flow guiding cavity is formed between the valve core assembly and the valve body, the air inlet cavity, the air vent and the flow guiding cavity are communicated and form an external space, and the external space is communicated with the internal space;

the fuel gas vertically flows into the valve body through the air inlet, vertically flows along the air inlet cavity until flowing through the vent hole, and part of the fuel gas flows into the inner space of the valve core assembly and the central pressure stabilizing cavity of the valve seat, and the rest of the fuel gas continuously flows along the flow guiding cavity to fill the end pressure stabilizing cavity at the outer end of the seat and the surrounding space of the valve core;

when the piezoelectric crystal is not electrified, a sealing ring belt on the valve core is tightly matched with the upper surface of the valve seat, and the gas fills the external space and the internal space inside the valve body of the gas injection valve; after the piezoelectric crystal is electrified, the piezoelectric crystal is excited by current to extend so as to push the large piston to move downwards, hydraulic oil in the sleeve is compressed, the small piston moves upwards under the action of hydraulic oil pressure, the valve rod also moves upwards, the valve core assembly is driven to move upwards under the fixing action of the clamp spring until the hydraulic oil pressure in the sleeve returns to an initial state, the small piston does not move any more, the valve core assembly is stopped, and fuel gas flows in a mixed air inlet mode of the axial main air groove and the circumferential air-filling holes, passes through the annular cavity and finally flows out vertically from the air outlet; after the piezoelectric crystal is powered off, the piezoelectric crystal is shortened, the large piston returns to the initial position under the action of the large piston supporting spring, the pressure of hydraulic oil in the sleeve is reduced, the annular disc and the small piston move downwards under the action of the reset spring, the valve rod and the valve core assembly move downwards along with the annular disc and the small piston until the pressure of the hydraulic oil in the sleeve returns to the initial state, the large piston and the small piston return to the initial position, the valve core assembly returns to the initial position, the surface of the valve core is attached to the surface of the valve seat, the gas injection valve is closed, and the gas path is closed.

The invention has the advantages that: according to the invention, the piezoelectric crystal is electrified and elongated, after displacement is amplified by the hydraulic amplifier, the symmetrically arranged small pistons push the annular disc to move upwards steadily, and the annular disc drives the valve core assembly to move away from the valve seat under the external guiding action of the outer guide block through the valve rod, so that the gas injection function of the gas valve is realized; the invention adopts a piezoelectric crystal driving mode, effectively improves the response speed of the gas injection valve, and realizes the variable lift of the gas injection valve; the invention adopts a straight-through air supply mode to ensure sufficient supply of fuel gas entering the valve body; the pressure balance hole, the pressure balance groove and the pressure stabilizing cavity are matched, so that fluctuation of the gas pressure in the gas injection valve can be effectively restrained, stable operation of gas flow is realized, reliable operation is realized, and high response speed is realized; the high flow is realized by the mixed air inlet mode of direct air inlet of the axial main air groove and air inlet of the circumferential air-filling holes, the air supply efficiency of the engine is effectively improved, meanwhile, the air flow interference can be avoided, and the stability of an air path is realized; the surface sealing and high reliability of the gas injection valve are realized through the multi-channel annular band structure between the valve core and the valve seat.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic view of a valve core assembly according to the present invention;

FIG. 3 is a schematic diagram of the gas path of the present invention;

FIG. 4 is a schematic view of a three-dimensional structure of a valve core;

fig. 5 is a top view of a valve seat structure.

Detailed Description

The invention is described in more detail below, by way of example, with reference to the accompanying drawings:

with reference to fig. 1-5, fig. 1 is a schematic diagram of an overall structure of a piezoelectric type external guide gas injection valve for straight-through mixed gas intake, which comprises a valve body 1, a piezoelectric crystal 2, a fixed block 3, a large piston 4, a large piston supporting spring 5, a sealing ring 6, a sleeve 7, a return spring 8, a ring disk 9, a valve rod 10, a small piston supporting spring 11, a small piston 12, a clamping spring 14, a partition plate 15, a valve core assembly 16, a sealing rubber ring 18 and a valve seat 19, wherein the fixed block 3 is connected with the valve body 1 by threaded connection so as to fix the fixed block on the central position above the valve body 1, a straight slot with a certain depth is formed in the central position of the fixed block 3, the piezoelectric crystal 2 is arranged in the straight slot, a through hole with a smaller diameter is formed above the straight slot and is used for arranging a connecting wire of the piezoelectric crystal 2 and an external control unit of the valve body 1, the lower surface of the piezoelectric crystal 2 is contacted with the upper surface of the large piston 4, under the pretightening force of the large piston supporting spring 5, the lower surface of the piezoelectric crystal 2 is tightly attached to the upper surface of the large piston 4, the upper end of the sleeve 7 is provided with a plurality of outlets, the central outlet is a thick outlet, the peripheral outlets are thin outlets, the lower end of the sleeve 7 is symmetrically arranged below the circular disk 9, the lower end of the sleeve 7 is provided with a communicated closed cavity, the lower end of the large piston 4 is arranged in the thick outlet at the center of the sleeve 7, the large piston supporting spring 5 is positioned between the flange of the large piston 4 and the sleeve 7, the large piston 4 cannot integrally enter the sleeve 7, the sleeve 7 is filled with hydraulic oil 13 with certain pressure, the thin outlets at the two ends of the sleeve 7 are provided with small pistons 12, the lower ends of the small pistons 12 are arranged in the sleeve, the small piston supporting springs 11 are arranged between the flange of the small pistons 12 and the sleeve 7, so that the small pistons 12 cannot integrally enter the sleeve 7, a sealing ring 6 is arranged between the side surfaces of a large piston 4 and a small piston 12 and the inner wall of a sleeve 7 to prevent leakage of hydraulic oil 13 in the sleeve 7, the large piston 4, the small piston 12, a large piston supporting spring 5 and a small piston supporting spring 11 form a piezoelectric crystal hydraulic amplifier together with the sleeve 7, the hydraulic amplifier is integrally arranged above a partition plate 15 in a valve body 1, under the pretightening force of the small piston supporting spring 11, the upper surface of the small piston 12 is tightly attached to the lower surface of a circular ring disk 9, two ends of a return spring 8 are respectively arranged in grooves on a fixed block 3 and the circular ring disk 9, two ends of the circular ring disk 9 are provided with round holes, threads are arranged in the holes to connect the circular ring disk 9 with a valve rod 10 together by means of the threads, the valve rod 10 is arranged in a through hole in a partition plate 15, the lower end of the valve rod is fixed together with the upper end of a valve core assembly 16 by means of a clamp spring 15, two ends of the partition plate 15 are also provided with vent holes 35 with larger diameters, the valve core assemblies 16 and 19 are sequentially arranged below the partition plate 15 from top to bottom, the valve seat 19 and the valve body 1 are fixedly connected together by a bolt face between the two valve seats and the valve body 1, and the sealing 18 is realized by sealing the sealing surface is realized by the bolt.

As shown in fig. 2, the valve core assembly 16 of the piezoelectric type external guide gas injection valve for straight-through mixed air intake consists of an armature 21, a spring seat 22, a bottom plate 23, a valve core 24, an armature return spring 28, a gasket 29 and a fastening bolt 31, wherein the armature 21 is connected with the bottom plate 23 and the valve core 24 through the fastening bolt 31, a layer of gasket 29 is arranged between the armature 21 and the bottom plate 23, a pressure balance hole 27 is formed in the armature 21, four pressure balance grooves 30 are formed above the bottom plate 23, the pressure balance hole 27 at the center of the armature 21 is matched with the pressure balance grooves on the bottom plate 23 to enable the inner space of the valve core assembly 16 to be communicated with the outer space, the internal and external gas channels are balanced, the internal and external gas of the valve core assembly 16 have no pressure difference, the external gas is prevented from being subjected to additional axial force during movement, the spring seat 22 is arranged above the bottom plate 23, the side surface of the interior of the valve core assembly is contacted with the side surface of the armature 21, two ends of the armature return spring 28 are respectively arranged on annular grooves of the partition 15 and the spring seat 22, the valve core 24 consists of a valve core main body, a rib 25 and a sealing ring 26, four guide blocks 17 are circumferentially fixed on the valve seat 19, the four guide blocks 17 are vertically arranged on the valve seat 19, the valve core 24 and the valve core assembly is vertically arranged below the partition 15 and the partition 15 is arranged below the partition plate 16;

as shown in fig. 3, firstly, the fuel gas vertically flows into the valve body 1 through the air inlet 33, flows along the air inlet cavity 34 and flows until flowing through the vent holes 35 at two ends of the partition plate 15 on the valve body 1, and due to the pressure balance holes 27 on the armature 21 and the pressure balance grooves 30 on the bottom plate 23, the inner space of the valve core assembly 16 is communicated with the inner space of the valve body 1, and a part of the fuel gas flows into the inner space of the valve core assembly 16, so that the inner space of the valve core assembly 16 and the pressure stabilizing cavity 38 at the center of the valve seat 19 are filled, the balance of the inner and outer air paths of the valve core assembly 16 is ensured, no pressure difference is caused, and the valve core assembly is prevented from being subjected to additional axial force; the rest of the fuel gas flows into the full valve body 1 along the diversion chamber 36, filling the pressure stabilizing chamber 38 at the periphery of the valve seat 19 and the surrounding space of the valve core 24. When the piezoelectric crystal 2 is not electrified, the lower surface of the valve core 24 is attached to the upper surface of the valve seat 19, and the annular cavity between the valve core 24 and the valve seat 19 is not communicated; after the piezoelectric crystal 2 is electrified, the piezoelectric crystal 2 stretches, the valve core assembly 16 is driven to move upwards after being amplified by a hydraulic amplifier, the lower surface of the valve core 24 is separated from the upper surface of the valve seat 19, at the moment, a gas path is opened, fuel gas rapidly flows in a mixed air inlet mode of an axial main air groove 41 and a circumferential air supplementing hole 37, flows out vertically through a plurality of annular cavities 39 between the valve core 24 and the valve seat 19 through an air outlet 40, and the lifting and seating of the valve core 24 control the on-off between the annular cavities 39.

When the piezoelectric crystal 2 is not electrified in the working process of the fuel gas injection valve, under the action of the armature return spring 28, the valve core assembly 16 is kept motionless at the initial position, the sealing ring belt 26 on the valve core 24 in the valve core assembly 16 is tightly matched with the air outlet ring belt 20 on the valve seat 19, the valve core 24 is not communicated with the annular cavity 39 between the valve seat 19, and the fuel gas fills the whole space inside the valve body 1 of the fuel gas injection valve. After the piezoelectric crystal 2 is electrified, the piezoelectric crystal 2 is excited by current to extend so as to push the large piston 4 to move downwards, the hydraulic oil 13 in the sleeve 7 is compressed and the pressure rises, the small pistons 12 on the thin outlet in the sleeve 7 move upwards under the pressure of the hydraulic oil 13, the small pistons 12 are symmetrically distributed below the circular ring disk 9 and smoothly push the circular ring disk 9 to move upwards, the valve rod 10 also moves upwards due to the connecting effect of the threads, finally, the valve core assembly 16 is driven to move upwards under the fixing effect of the clamp spring 15, the external guide is realized through the guide block 17 in the moving process of the valve core assembly 16 until the pressure of the hydraulic oil 13 in the sleeve 7 returns to the initial state, the small piston 12 does not move any more, the valve core assembly 16 stops along with the movement, the valve core assembly 16 maintains at the position for a period of time, in the process, fuel gas flows in rapidly by a mixed air inlet mode of an axial main air groove 41 and a circumferential air supplementing hole 37, and flows out vertically after being guided by a plurality of annular cavities 39 between the valve core 24 and the valve seat 19 and finally flows out vertically through an air outlet 40, a plurality of annular zones between the valve core 24 and the valve seat 19 are sealed, the pressure stabilizing is balanced, the impact can be reduced by a wider annular zone area, the reliability is improved, and the central position and the peripheral position of the valve seat 19 are provided with pressure stabilizing cavities 38, so that the ventilation of surrounding fuel gas is uniform and the air pressure is balanced in the flowing process; after the fuel gas is sprayed out a certain amount, the piezoelectric crystal 2 starts to be powered off, the piezoelectric crystal 2 shortens, the large piston 4 starts to return to the initial position under the action of the large piston supporting spring 5, the pressure of the hydraulic oil 13 in the sleeve 7 is reduced, the annular disc 9 and the small piston 12 start to move downwards under the action of the reset spring 8, the valve rod 10 and the valve core assembly 16 move downwards along with the pressure of the hydraulic oil 13 in the sleeve 7 until the pressure of the hydraulic oil 13 returns to the initial state, the large piston 4 and the small piston 12 return to the initial position, the valve core assembly 16 correspondingly returns to the initial position at the moment, the lower surface of the valve core 24 is attached to the upper surface of the valve seat 19 and returns to the initial position again, and the fuel gas injection valve is closed and the gas path is closed.

According to the piezoelectric type external guide gas injection valve for straight-through mixed gas inlet, in the working process, the piezoelectric crystal 2 is electrified and stretched, after the displacement is amplified by the hydraulic amplifier, the small pistons 12 which are symmetrically arranged push the annular disc 9 to move upwards steadily, and the annular disc 9 drives the valve core assembly 16 to move away from the valve seat 19 under the external guide action of the guide block 17 at the outer side through the valve rod 10, so that the gas injection function of the gas valve is realized; the invention adopts the mode of driving the piezoelectric crystal 2, effectively improves the response speed of the gas injection valve, and realizes the variable lift of the gas injection valve; the invention adopts a straight-through air supply mode, so that the sufficient supply of the fuel gas entering the valve body 1 is ensured; the perpendicularity of the valve core 24 is ensured by the outer guide structure; the pressure balance hole 27 is formed in the center of the armature 21, and a certain number of pressure balance grooves 30 are formed in the bottom plate 23, so that the internal and external air path pressures at the valve core assembly 16 are more easily balanced, the valve core assembly 16 is prevented from being subjected to axial force, the response speed of the valve core assembly is improved, and the control difficulty is reduced; the rib 25 of the valve core 24 is provided with a plurality of circumferential air supplementing holes 37, the lower surface of the valve core 24 and the upper surface of the valve seat 19 are provided with a plurality of annular cavities 39, so that the effective flow area is increased, the quality of the valve core 24 is reduced, and the reliability is improved; the flow guide cone angle 32 with a certain angle is arranged at the circumferential air supply hole 37 of the valve core 24, so that the flow loss is reduced, and the flow coefficient is increased; the invention adopts a mixed air inlet mode of directly air inlet of the axial main air groove 41 and air inlet of the circumferential air-filling holes 37, increases the air inlet flow coefficient, realizes large flow, effectively improves the air supply efficiency of the gas injection valve, can avoid air flow interference, and realizes balance and stability of the air path; the valve core 24 and the valve seat 19 adopt a structure of a plurality of sealing ring belts 26 and an air outlet ring belt 20, so that the surface sealing, the pressure stabilization and the balance of the fuel gas injection valve are realized, the impact can be reduced due to the wider ring belt area, and the reliability is improved; the pressure stabilizing cavities 38 are arranged at the center and the periphery of the valve seat 19, so that fluctuation of the gas pressure in the gas injection valve can be effectively restrained, stable and reliable operation of the gas flow is realized, and high response speed is realized.

The technical scheme of the invention is as follows: the piezoelectric outer guide gas injection valve consists of mainly valve body, piezoelectric crystal, fixing block, large piston supporting spring, sealing ring, sleeve, restoring spring, circular disc, valve rod, small piston supporting spring, small piston, clamping spring, partition board, valve core assembly, sealing rubber ring and valve seat. The fixed block is connected with the valve body by utilizing threaded connection, so that the fixed block is fixed at the central position above the valve body, a straight groove with a certain depth is formed in the central position of the fixed block, the piezoelectric crystal is arranged in the straight groove, a through hole with a smaller diameter is formed above the straight groove and is used for arranging a connecting wire of the piezoelectric crystal and a control unit outside the valve body, the lower surface of the piezoelectric crystal is contacted with the upper surface of a large piston, the lower surface of the piezoelectric crystal is tightly attached to the upper surface of the large piston under the pretightening force of a large piston supporting spring, the upper end of a sleeve is provided with a plurality of outlets, the central outlet is a thick outlet, the peripheral outlets are thin outlets and are symmetrically arranged below a circular disc, the lower end of the large piston is provided with a communicated closed cavity, the lower end of the large piston is arranged in the thick outlet at the center of the sleeve, the large piston supporting spring is positioned between a large piston flange and the sleeve, and the large piston is ensured not to integrally enter the sleeve, the sleeve is filled with hydraulic oil with certain pressure, a small piston is arranged above a thin outlet at two ends of the sleeve, the lower end of the small piston is arranged in the small piston, a small piston supporting spring is arranged between a small piston flange and the sleeve so as to ensure that the small piston cannot integrally enter the sleeve, sealing rings are arranged between the side surfaces of the large piston and the small piston and the inner wall of the sleeve so as to prevent leakage of hydraulic oil in the sleeve, the large piston, the small piston, the large piston supporting spring and the small piston supporting spring form a hydraulic amplifier of a piezoelectric crystal together with the sleeve, the hydraulic amplifier is integrally arranged above a baffle plate in a valve body, the upper surface of the small piston is tightly attached to the lower surface of the circular disc under the pretightening force of the small piston supporting spring, two ends of a reset spring are respectively arranged in grooves on a fixed block and the circular disc, two ends of the circular disc are provided with round holes, the valve rod is arranged in a through hole in the partition board, the lower end of the valve rod is fixed with the upper end of the valve core assembly by using a clamp spring, the two ends of the partition board are also provided with vent holes with larger diameters, the valve core assembly and a valve seat are sequentially arranged below the partition board from top to bottom, the valve seat and the valve body are fixedly connected together through bolts, the matching surface between the valve seat and the valve body is sealed through a sealing rubber ring, the valve core assembly consists of an armature, a spring seat, a bottom plate, a valve core, an armature return spring, a gasket and a fastening bolt, the armature is connected with the bottom plate and the valve core through the fastening bolt, a layer of gasket is arranged between the armature and the bottom plate, the armature is provided with a pressure balance hole, four pressure balance grooves are formed in the upper portion of the bottom plate, the pressure balance hole in the center of the armature is matched with the pressure balance groove in the bottom plate, so that the inner space of the valve core assembly is communicated with the outer space, the inner gas circuit and the outer gas circuit are balanced, the inner gas circuit and the outer gas circuit of the valve core assembly are free from pressure difference, the valve core assembly is prevented from receiving extra axial force during movement, a spring seat is arranged above the bottom plate, the inner side surface of the spring seat is contacted with the side surface of the armature, two ends of an armature return spring are respectively arranged on annular grooves of the partition plate and the spring seat, the valve core is composed of a valve core main body, ribs and a sealing annular belt, the valve core is circumferentially fixed on four guide blocks on a valve seat, the perpendicularity of the valve core assembly is guaranteed, the valve core movement lift is limited through the distance between the spring seat and the partition plate, and the valve core assembly is integrally arranged below the partition plate; the rib of the valve core is provided with a circumferential air-filling hole, a flow guide cone angle is arranged at the air-filling hole, a sealing ring belt and an air-out ring belt are adopted between the valve core and the valve seat, the valve core is sealed, stable pressure is balanced, the valve core has a wider ring belt area, the central position and the peripheral position of the valve seat are both provided with pressure stabilizing cavities, the pressure stabilizing cavity at the central position of the valve seat is communicated with a gas space inside the valve core assembly, and the pressure stabilizing cavity at the peripheral position of the valve seat is communicated with the flow guide cavity in the valve body. When the piezoelectric crystal is not electrified, the lower surface of the valve core is attached to the upper surface of the valve seat, and the valve core is not communicated with the annular cavity between the valve seat; after the piezoelectric crystal is electrified, the piezoelectric crystal stretches, the valve core assembly is driven to move upwards after being amplified by the hydraulic amplifier, the lower surface of the valve core is separated from the upper surface of the valve seat, at the moment, the valve core is communicated with an annular cavity between the valve seats, and the lifting and seating of the valve core control the on-off between the annular cavities.

Claims (3)

1. A piezoelectric type external guiding gas injection valve of straight-through type mixed air inlet is characterized in that: comprises a valve body, a valve seat, a valve rod, a piezoelectric crystal, a hydraulic amplifier, a partition board and a valve core assembly, wherein the valve seat is fixed below the valve body and forms a valve space with the valve body, a fixed block is fixed above the interior of the valve body, a straight slot is formed in the middle of the fixed block, the piezoelectric crystal is arranged in the straight slot, the partition board is arranged in the middle of the valve body, the hydraulic amplifier is arranged above the partition board, the valve core assembly is arranged below the partition board, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the partition board, the center of the upper end of the sleeve is a coarse outlet, the end part of the upper end of the sleeve is a fine outlet, the large piston is arranged in the coarse outlet, the small piston is arranged in the fine outlet, a large piston supporting spring is arranged between a flange of the large piston and the sleeve, hydraulic oil is filled in the sleeve below the large piston and the small piston, the upper surface of the large piston is attached to the lower surface of the piezoelectric crystal, the annular disc is arranged outside the large piston, the upper surface of the small piston is attached to the lower surface of the annular disc, grooves are formed in the annular disc and the fixed block, two ends of the reset spring are respectively arranged in the grooves of the annular disc and the fixed block, the valve core assembly comprises an armature, a spring seat, a bottom plate and a valve core, the armature, the bottom plate and the valve core are simultaneously connected together through fastening bolts from top to bottom, the spring seat is positioned outside the armature and forms an annular groove with the armature, the lower surface of the partition plate is provided with the annular groove, two ends of the reset spring are respectively arranged in the annular groove of the partition plate and the annular groove of the spring seat, a pressure balance hole is formed in the center of the armature, a pressure balance groove is formed in the bottom plate, the valve core is of a hollow structure, a central pressure stabilizing cavity is formed in a valve seat below the valve core, and the pressure balance hole and the pressure balance groove, the hollow part of the valve core and the central pressure stabilizing cavity are communicated and form an internal space, the valve core is provided with a sealing ring belt and a rib, the sealing ring belt forms an annular cavity, the valve seat is provided with an air outlet ring belt and a guide block, the guide block is positioned around the valve core, the air outlet ring belt is positioned below the annular cavity, the air outlet ring belt is provided with an air outlet, the partition plate is provided with a through hole and an air vent respectively, the middle part of the valve rod passes through the through hole, the upper part of the valve rod is connected with the annular disk, the lower part of the valve rod is fixed with the armature through a clamp spring, the upper surface of the valve core is provided with an axial main air groove, the rib is provided with a circumferential air supplementing hole, and a flow guiding cone angle is arranged at the air supplementing hole.

2. The piezoelectric externally piloted gas injection valve of a straight through mixed intake of claim 1, characterized by: the outer end of the valve seat is provided with an end pressure stabilizing cavity.

3. A piezo-electric externally directed gas injection valve for straight through mixed intake according to claim 1 or 2, characterized by: an air inlet is formed between the upper part of the fixed block and the valve body, an air inlet cavity is formed between the middle lower part of the fixed block and the hydraulic amplifier and the valve body, a flow guiding cavity is formed between the valve core assembly and the valve body, the air inlet cavity, the air vent and the flow guiding cavity are communicated and form an external space, and the external space is communicated with the internal space;

the fuel gas vertically flows into the valve body through the air inlet, vertically flows along the air inlet cavity until flowing through the vent hole, and part of the fuel gas flows into the inner space of the valve core assembly and the central pressure stabilizing cavity of the valve seat, and the rest of the fuel gas continuously flows along the flow guiding cavity to fill the end pressure stabilizing cavity at the outer end of the valve seat and the surrounding space of the valve core;

when the piezoelectric crystal is not electrified, a sealing ring belt on the valve core is tightly matched with the upper surface of the valve seat, and the gas fills the external space and the internal space inside the valve body of the gas injection valve; after the piezoelectric crystal is electrified, the piezoelectric crystal is excited by current to extend so as to push the large piston to move downwards, hydraulic oil in the sleeve is compressed, the small piston moves upwards under the action of hydraulic oil pressure, the valve rod also moves upwards, the valve core assembly is driven to move upwards under the fixing action of the clamp spring until the hydraulic oil pressure in the sleeve returns to an initial state, the small piston does not move any more, the valve core assembly is stopped, and fuel gas flows in a mixed air inlet mode of the axial main air groove and the circumferential air-filling holes, passes through the annular cavity and finally flows out vertically from the air outlet; after the piezoelectric crystal is powered off, the piezoelectric crystal is shortened, the large piston returns to the initial position under the action of the large piston supporting spring, the pressure of hydraulic oil in the sleeve is reduced, the annular disc and the small piston move downwards under the action of the reset spring, the valve rod and the valve core assembly move downwards along with the annular disc and the small piston until the pressure of the hydraulic oil in the sleeve returns to the initial state, the large piston and the small piston return to the initial position, the valve core assembly returns to the initial position, the surface of the valve core is attached to the surface of the valve seat, the gas injection valve is closed, and the gas path is closed.

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