CN107165745B - Piezoelectric internal guide gas injection valve for straight-through mixed air intake - Google Patents

Abstract

The invention aims to provide a piezoelectric internal guide gas injection valve for straight-through mixed gas inlet, which utilizes piezoelectric crystals to electrify and elongate, and pushes a guide pin of a valve core assembly to move after amplifying displacement by a hydraulic amplifier, so that the valve core assembly moves away from a valve seat under the internal guide action of a matching surface between the guide pin and a baffle plate, and the function of gas injection of the gas valve is realized; 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 internal guide gas injection valve for straight-through mixed air intake

Technical Field

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

Background

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 internal 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 internal guide gas injection valve of straight-through mixed air inlet, which is characterized in that: comprises a valve body, a valve seat, a piezoelectric crystal, a control valve rod, a hydraulic amplifier, a partition plate 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 inside of the valve body, a straight groove is formed in the middle of the fixed block, the piezoelectric crystal is arranged in the straight groove, the partition plate is arranged in the middle of the valve body, the hydraulic amplifier is arranged above the partition plate, the valve core assembly is arranged below the partition plate, through holes and vent holes are respectively arranged on the partition plate, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the partition plate, the end part of the upper end of the sleeve is provided with a thick outlet, the inner side of the end part of the upper end of the sleeve is provided with a thin outlet, the large piston is arranged in the thick outlet, the small piston is arranged in the thin outlet, a large piston supporting spring is arranged between the flange of the large piston and the sleeve, a small piston supporting spring is arranged between the flange of the small piston and the sleeve, the sleeve below the large piston and the small piston is filled with hydraulic oil, the guide pin penetrates through the through hole of the partition plate, the control valve rod is arranged above the guide pin, the guide pin reset spring is arranged between the guide pin and the control valve rod, the upper surface of the control valve rod is attached to the piezoelectric crystal, the lower surface of the control valve rod is attached to the upper surface of the large piston, the upper surface of the small piston is attached to the guide pin, 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 arranged from top to bottom and are simultaneously connected together through fastening bolts, 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 armature reset spring are respectively arranged in the annular groove of the partition plate and the annular groove of the spring seat, the guide pin is fixed with the armature, the guide pin is internally provided with a pressure balance hole, the bottom plate is provided with a pressure balance groove, the valve core is of a hollow structure, a central pressure stabilizing cavity is formed in a valve seat below the valve core, a pressure balancing hole, a pressure balancing groove, a hollow part of the valve core and the central pressure stabilizing cavity are communicated and form an inner space, a sealing ring belt and ribs are arranged on the valve core, the sealing ring belt forms a ring cavity, an air outlet ring belt is arranged on the valve seat, the air outlet ring belt is arranged below the ring cavity, an air outlet is arranged below the air outlet ring belt, an axial main air groove is formed in the upper surface of the valve core, a circumferential air supplementing hole is formed in the ribs, and a flow guiding cone angle is formed 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 between 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, the external space is communicated with the internal space, and an axial air inlet hole is formed in the valve core;

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 pressure, the guide pin also moves upwards to drive the valve core assembly to move upwards, the gas injection valve is opened, the gas circuit is opened until the hydraulic oil pressure in the sleeve returns to an initial state, the large piston and the small piston do not move any more, the valve core assembly is stopped, and gas flows in a mixed air inlet mode of the axial main air groove and the circumferential air supplementing 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 guide pin moves downwards under the action of the guide pin restoring spring, the small piston and the valve core assembly move downwards along with the guide pin 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 valve core surface is attached to the valve seat surface, the gas injection valve is closed, and the gas path is closed.

The invention has the advantages that: the piezoelectric crystal is electrified and elongated, the guide pin of the valve core assembly is pushed to move after the displacement is amplified by the hydraulic amplifier, and the valve core assembly moves away from the valve seat under the internal guide action of the matching surface between the guide pin and the partition plate, 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:

referring to fig. 1-5, fig. 1 is a schematic diagram of an overall structure of a piezoelectric internal guiding gas injection valve for straight-through mixed gas intake, which comprises a valve body 1, a piezoelectric crystal 2, a fixed block 3, a control valve rod 4, a large piston 5, a large piston supporting spring 6, a sealing ring 7, a sleeve 8, a guide pin 9 return spring 10, a small piston 11, a small piston supporting spring 13, a partition plate 14, a valve core assembly 15, a sealing rubber ring and a valve seat 16. The fixed block 3 is connected with the valve body 1 by utilizing threads, so that the fixed block is fixed at the central position above the valve body 1, a straight groove with a certain depth is formed in the central position of the fixed block 3, the piezoelectric crystal 2 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 2 and a control unit outside the valve body 1, a control valve rod 4 is tightly arranged below the piezoelectric crystal 2, the lower surface of the control valve rod 4 is contacted with the upper surface of the large piston 5, under the pretightening force of a guide pin reset spring 9 and a large piston support spring 6, the lower surface of the piezoelectric crystal 2 is tightly attached to the upper surface of the control valve rod 4, the lower surface of the control valve rod 4 and the upper surface of the large piston 5, the upper end of the sleeve 8 is provided with two outlets which are respectively a thick outlet and a thin outlet, the lower end is a communicated closed cavity, the lower end of the large piston 5 is arranged in the thick outlet of the sleeve 8, the large piston supporting spring 6 is positioned between the flange of the large piston 5 and the sleeve 8, the large piston 5 cannot integrally enter the sleeve 8, the sleeve 8 is filled with hydraulic oil 12 with certain pressure, a small piston 10 is arranged above the thin outlet of the sleeve 8, the lower end of the small piston 10 is arranged therein, a small piston supporting spring 11 is arranged between the flange of the small piston 10 and the sleeve 8, the small piston 10 cannot integrally enter the sleeve 8, a sealing ring 7 is arranged between the side surfaces of the large piston 5 and the small piston 10 and the inner wall of the sleeve 8, so as to prevent leakage of hydraulic oil 12 in the sleeve 8, the large piston 5, the small piston 10, the large piston supporting spring 6, the small piston supporting spring 11 and the sleeve 8 together form a hydraulic amplifier of piezoelectric crystal, the hydraulic amplifier is integrally arranged above a baffle 13 in the valve body 1, the valve core assembly 14 and the valve seat 16 are sequentially arranged below the center position of the control valve rod 4 from top to bottom, the upper surface of the small piston 10 is tightly attached to the upper end of the valve core assembly 14 under the pretightening force of the small piston supporting spring 11, the valve seat 16 is fixedly connected with the valve body 1 through bolts, and the matching surface between the valve seat 16 and the valve body is sealed through the sealing rubber ring 15.

As shown in fig. 2, the valve core assembly 14 of the piezoelectric internal guide gas injection valve for straight-through mixed gas inlet consists of a guide pin 18, an armature 19, a spring seat 20, a bottom plate 21, a valve core 22, an armature return spring 26, a gasket 27 and a fastening bolt 29, in order to ensure that the guide pin 18 moves stably, a plurality of small pistons 10 are symmetrically arranged below the guide pin 18, the number is even number, under the action of a small piston support spring 11, the upper surface of the small piston 10 is tightly attached to the lower surface of the guide pin 18 in the valve core assembly 14, the center of the guide pin 18 is provided with a pressure balance hole 25, the pressure balance hole is arranged in a through hole in the center of a partition 13, the lower end of the guide pin 18 is fixed with the armature 19 through threaded connection, the armature 19 is connected with the bottom plate 21 and the valve core 22 through the fastening bolt 29, a layer of gasket 27 is arranged between the armature 19 and the bottom plate 21, four pressure balance grooves 28 are formed above the bottom plate 21, so that the inner space of the valve core assembly 14 is communicated with the outer space, the inner and outer air passage pressure is more easily balanced, the response speed of the valve core is improved, the upper surface of the small piston 10 is arranged above the bottom plate 21 and the valve seat 20 is tightly attached to the lower surface of the guide pin 18, the armature 19 is contacted with the surface of the valve core 20 at the lower surface of the valve seat 20, and the lower surface of the valve core 20 is respectively arranged below the valve seat 20 and the valve core body, and the valve core body is formed by the lower than the surface of the valve core body and the valve core body is in contact with the surface of the valve body and the bottom plate body and is respectively, and the valve body is formed by the surface of the valve body and is formed and the valve body and is respectively and the valve body and is formed.

As shown in fig. 3, firstly, the fuel gas vertically flows into the valve body 1 through the air inlet 31, flows along the air inlet cavity 32 until flowing through the air holes 33 at two ends of the partition 13 on the valve body 1, the inner space of the valve core assembly 14 is communicated with the inner space of the valve body 1 due to the existence of the pressure balance groove 28 on the bottom plate 21, a part of the fuel gas flows into the inner space of the valve core assembly 14, then fills the inner space of the valve core assembly 14 and the pressure stabilizing cavity 36 at the center of the valve seat 16, and the fuel gas flows into the space above the valve core assembly 14 due to the existence of the pressure balance hole 25 on the guide pin 18, and also fills the space above the valve core assembly 14, so that the internal and external air paths reach balance, no pressure difference is ensured inside and outside the valve core assembly 14, and the fuel gas is prevented from being subjected to additional axial force; the rest of the fuel gas flows into the full valve body 1 along the guide chamber 34, filling the pressure stabilizing chamber 36 at the periphery of the valve seat 16 and the surrounding space of the valve core 22. When the piezoelectric crystal 2 is not electrified, the surface of the valve core 22 is attached to the surface of the valve seat 16, and the annular cavity 37 between the valve core 22 and the valve seat 16 is not communicated; after the piezoelectric crystal 2 is electrified, the piezoelectric crystal 2 stretches, the valve core assembly 14 is driven to move upwards after being amplified by a hydraulic amplifier, the lower surface of the valve core 22 is separated from the upper surface of the valve seat 16, at the moment, a gas path is opened, fuel gas rapidly flows in a mixed gas inlet mode of an axial main gas groove 39 and a circumferential gas supplementing hole 35, flows out vertically through a plurality of annular cavities 37 between the valve core 22 and the valve seat 16 and finally flows out from a gas outlet 38, and the lifting and seating of the valve core 22 controls the on-off between the annular cavities 37.

When the piezoelectric crystal 2 is not electrified in the working process of the fuel gas injection valve, under the pretightening force of the guide pin reset spring 9 and the armature reset spring 26, the valve core assembly 14 is kept motionless at the initial position, the sealing ring belt 24 on the valve core 22 in the valve core assembly 14 is tightly matched with the air outlet ring belt 17 on the valve seat 16, the valve core 22 is not communicated with the ring cavity 37 between the valve seat 16, 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 so as to extend, the control valve rod 4 moves downwards, the large piston 5 moves downwards along with the control valve rod, the pressure of hydraulic oil 12 in the sleeve 8 rises, the small piston 10 moves upwards under the action of the pressure of the hydraulic oil 12, the guide pin 18 moves upwards steadily after receiving the upward acting force of the four small pistons 10, the guide pin 18 serves as a part of the valve core assembly 14, the valve core assembly 14 moves upwards along with the guide pin until the pressure of the hydraulic oil 12 in the sleeve 8 returns to an initial state, the large piston 5 and the small piston 10 stop moving, the valve core assembly 14 stops moving along with the valve core assembly 14, the valve core assembly 14 is maintained at the position for a period of time, during the process, fuel gas flows in a mixed air inlet mode of an axial main air groove 39 and a circumferential air supplementing hole 35 rapidly, and finally flows out vertically after being guided through a plurality of annular belts between the valve core 22 and the valve seat 16 by an air outlet 38, the surfaces of the annular belts are sealed, the pressure stabilizing balance is realized, the impact can be reduced, the impact can be improved, the central position and peripheral position of the valve seat 16 are opened with a cavity 36, so that the ambient air pressure is balanced in the 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 5 starts to move upwards under the action of the large piston supporting spring 6, the pressure of the hydraulic oil 12 in the sleeve 8 decreases, the guide pin 18 starts to move downwards under the action of the guide pin return spring 9, the small piston 10 and the valve core assembly 14 move downwards together until the pressure of the hydraulic oil 12 in the sleeve 8 returns to an initial state, the large piston 5 and the small piston 10 return to the initial positions, the valve core assembly 14 correspondingly returns to the initial positions at the moment, the lower surface of the valve core 22 is attached to the upper surface of the valve seat 16 and returns to the initial positions again, and the fuel gas injection valve is closed and the gas path is closed.

According to the piezoelectric internal guide gas injection valve for straight-through mixed gas inlet, in the working process, the piezoelectric crystal 2 is electrified and stretched, the guide pin 18 of the valve core assembly 14 is pushed to move after the displacement is amplified by the hydraulic amplifier, and the whole valve core assembly 14 moves away from the valve seat 16 under the internal guide action of the matching surface between the guide pin 18 and the partition plate 13, 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 is ensured; the perpendicularity of the valve core 22 is ensured by the inner guide structure; the pressure balance hole 25 is formed in the center of the guide pin 18, and a certain number of pressure balance grooves 28 are formed in the bottom plate 21, so that the internal and external air path pressures at the valve core assembly 14 are more easily balanced, the valve core assembly 14 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 23 of the valve core 22 is provided with a plurality of circumferential air supplementing holes 35, the lower surface of the valve core 22 and the upper surface of the valve seat 16 are provided with a plurality of annular cavities 37, so that the effective flow area is increased, the quality of the valve core 22 is reduced, and the reliability is improved; the flow guide cone angle 30 with a certain angle is arranged at the circumferential air filling hole 35 of the valve core 22, 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 39 and air inlet of the circumferential air-filling holes 35, 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 22 and the valve seat 16 adopt a structure of a plurality of sealing ring belts 24 and an air outlet ring belt 17, 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 36 are arranged at the center and the periphery of the valve seat 16, 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 internal guide gas injection valve consists of valve body, piezoelectric crystal, fixed block, control valve rod, large piston supporting spring, sealing ring, sleeve, guide pin restoring spring, small piston supporting 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, a control valve rod is tightly arranged below the piezoelectric crystal, the lower surface of the control valve rod is contacted with the upper surface of a large piston, under the action of the pretightening force of a guide pin reset spring and a large piston supporting spring, the lower surface of the piezoelectric crystal is tightly attached to the upper surface of the control valve rod, the lower surface of the control valve rod is tightly attached to the upper surface of the large piston, the upper ends of the sleeve are respectively provided with a thick outlet and a thin outlet, the lower end is a communicated closed cavity, the lower end of the large piston is arranged in the thick outlet of the sleeve, the large piston supporting spring is positioned between the large piston flange and the sleeve to ensure that the large piston cannot integrally enter the sleeve, the sleeve is filled with hydraulic oil with certain pressure, a small piston is arranged above a thin outlet of the sleeve, the lower end of the small piston is arranged in the small piston, the small piston supporting spring is arranged between the small piston flange and the sleeve 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 to prevent leakage of the 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, a valve core assembly and a valve seat are sequentially arranged below the center position of a control valve rod from top to bottom, the upper surface of the small piston is tightly attached to the upper end of the valve core assembly, the valve seat and the valve body are fixedly connected together through bolts, and the matching surface between the valve seat and the valve body is sealed through a sealing rubber ring; the valve core assembly comprises a guide pin, an armature return spring, a spring seat, a gasket, a bottom plate, fastening bolts and a valve core, wherein the guide pin moves stably, a plurality of small pistons are symmetrically arranged below the guide pin, the number of the small pistons is an even number, under the action of a small piston support spring, the upper surface of the small pistons is tightly attached to the lower surface of the guide pin in the valve core assembly, the center of the guide pin is provided with a pressure balance hole, the pressure balance hole is arranged in a through hole in the center of a partition plate, the lower end of the guide pin is fixed with the armature through threaded connection, the armature is connected with the bottom plate and the valve core through the fastening bolts, a layer of gasket is arranged between the armature and the bottom plate, four pressure balance grooves are formed above the bottom plate, the spring seat is arranged above the bottom plate, the side surface of the spring seat is contacted with the side surface of the armature, the two ends of the armature return spring are respectively positioned in annular grooves of the partition plate and the spring seat, the valve core below the bottom plate is composed of a valve core main body, a rib and a sealing ring, the valve core assembly is integrally arranged below a control valve rod, a flow compensation hole is formed in the rib, a flow guide cone angle is arranged at the position of the rib, the air hole is arranged between the air hole and the valve seat, the valve seat is connected with the valve seat, the valve seat is provided with the flow guide cone, the pressure balance cavity is connected with the valve seat, the pressure stabilizing cavity is communicated with the pressure stabilizing cavity, and the pressure stabilizing cavity is arranged at the peripheral, and the valve seat is communicated with the pressure stabilizing cavity. 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 internal guiding gas injection valve of straight-through mixed air intake is characterized in that: comprises a valve body, a valve seat, a piezoelectric crystal, a control valve rod, a hydraulic amplifier, a partition plate 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 inside of the valve body, a straight groove is formed in the middle of the fixed block, the piezoelectric crystal is arranged in the straight groove, the partition plate is arranged in the middle of the valve body, the hydraulic amplifier is arranged above the partition plate, the valve core assembly is arranged below the partition plate, through holes and vent holes are respectively arranged on the partition plate, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the partition plate, the end part of the upper end of the sleeve is provided with a thick outlet, the inner side of the end part of the upper end of the sleeve is provided with a thin outlet, the large piston is arranged in the thick outlet, the small piston is arranged in the thin outlet, a large piston supporting spring is arranged between the flange of the large piston and the sleeve, a small piston supporting spring is arranged between the flange of the small piston and the sleeve, the sleeve below the large piston and the small piston is filled with hydraulic oil, the guide pin penetrates through the through hole of the partition plate, the control valve rod is arranged above the guide pin, the guide pin reset spring is arranged between the guide pin and the control valve rod, the upper surface of the control valve rod is attached to the piezoelectric crystal, the lower surface of the control valve rod is attached to the upper surface of the large piston, the upper surface of the small piston is attached to the guide pin, 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 arranged from top to bottom and are simultaneously connected together through fastening bolts, 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 armature reset spring are respectively arranged in the annular groove of the partition plate and the annular groove of the spring seat, the guide pin is fixed with the armature, the guide pin is internally provided with a pressure balance hole, the bottom plate is provided with a pressure balance groove, the valve core is of a hollow structure, a central pressure stabilizing cavity is formed in a valve seat below the valve core, a pressure balancing hole, a pressure balancing groove, a hollow part of the valve core and the central pressure stabilizing cavity are communicated and form an inner space, a sealing ring belt and ribs are arranged on the valve core, the sealing ring belt forms a ring cavity, an air outlet ring belt is arranged on the valve seat, the air outlet ring belt is arranged below the ring cavity, an air outlet is arranged below the air outlet ring belt, an axial main air groove is formed in the upper surface of the valve core, a circumferential air supplementing hole is formed in the ribs, and a flow guiding cone angle is formed at the air supplementing hole.

2. The piezoelectric internal pilot 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 internal pilot gas injection valve for straight-through mixed intake according to claim 1 or 2, characterized in that: 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 between 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, the external space is communicated with the internal space, and an axial air inlet hole is formed in the valve core;

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 pressure, the guide pin also moves upwards to drive the valve core assembly to move upwards, the gas injection valve is opened, the gas circuit is opened until the hydraulic oil pressure in the sleeve returns to an initial state, the large piston and the small piston do not move any more, the valve core assembly is stopped, and gas flows in a mixed air inlet mode of the axial main air groove and the circumferential air supplementing 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 guide pin moves downwards under the action of the guide pin restoring spring, the small piston and the valve core assembly move downwards along with the guide pin 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 valve core surface is attached to the valve seat surface, the gas injection valve is closed, and the gas path is closed.

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