CN107165747B - Piezoelectric type internal guide gas injection valve with bypass type axial air inlet - Google Patents

Abstract

The invention aims to provide a piezoelectric internal guide gas injection valve with bypass type axial air 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, and 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, so that the gas injection function of the gas valve is realized; the bypass air supply mode is adopted to guide the flow of the fuel gas in the valve body; the bottom end of the valve core is provided with a sealing ring belt so as to form an air inlet ring cavity, so that fuel gas is prevented from entering along the axial direction, the gas path balance is ensured, the valve seat quality is lightened, and the response speed is improved; the invention adopts the valve seat structure with the pressure stabilizing cavity, which can effectively inhibit the fluctuation of the gas pressure in the gas injection valve and ensure the stability of the gas injection pressure of the gas injection valve.

Description

Piezoelectric type internal guide gas injection valve with bypass type axial air inlet

Technical Field

The invention relates to a gas injection valve, in particular to a gas injection valve on a gas engine and a dual-fuel internal combustion engine.

Background

With the rapid development of society, the energy demand is increasing, the problem of environmental pollution is also increasing, natural gas is the most promising energy source for the development because of its abundant reserves, low price and good economy and emission, and the natural gas is used as the main fuel for the operation of the internal combustion engine in the internal combustion engine industry, and has remarkable effect for reducing the emission problem, so the internal combustion engine using natural gas as the main fuel has become a research hotspot in the internal combustion engine industry in recent years. The fuel gas injection valve is used as an important executive component in the gas supply system of the gas fuel internal combustion engine, and the performance of the fuel gas injection valve directly influences the characteristics of the internal combustion engine. At present, in the actual working process of the gas injection valve, 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 of the gas injection valve, meanwhile, the gas injection valve also needs to have a gas outlet cross section area as large as possible so as to ensure that the internal combustion engine obtains sufficient gas quantity, and in addition, the characteristics of the flowing state of the gas itself, the stability of the injected gas pressure, the control precision and the like can influence the performance of the internal combustion engine when the gas injection valve works.

Disclosure of Invention

The invention aims to provide a bypass type axial air inlet piezoelectric type internal guide gas injection valve with variable lift, high response speed and stable air injection pressure.

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

the invention relates to a bypass type piezoelectric internal guide gas injection valve with axial air inlet, which is characterized in that: comprises a valve body, a valve seat, a piezoelectric crystal, a hydraulic amplifier, a partition board and a valve core assembly, wherein a fixed block is fixed above the valve body, a straight slot is formed in the middle of the fixed block, the piezoelectric crystal is installed in the straight slot, the valve body is fixed on the valve seat, the valve body is internally provided with the partition board, the hydraulic amplifier is arranged above the partition board, the valve core assembly is arranged below the partition board, through holes are respectively arranged on the partition board, a valve space is formed between the valve body below the partition board and the valve seat, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the partition board, a thick outlet is formed at the end part of the upper end of the sleeve, a thin outlet is formed at the inner side of the end part of the upper end of the sleeve, 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 a 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 arranged on 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 is arranged on the valve core, the sealing ring belt forms an air inlet ring cavity, an air outlet ring belt is arranged on the valve seat, the air outlet ring belt is arranged below the air inlet ring cavity, and an air outlet is arranged below the air outlet ring belt.

The invention may further include:

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

2. The valve body is provided with a protruding part, the protruding part is provided with an air inlet, a flow guide cavity is arranged in the valve body below the air inlet, the air inlet and the flow guide cavity are communicated and form an external space, the external space is communicated with the internal space, and the valve core is provided with an axial air inlet;

the fuel gas vertically flows into the flow guiding cavity through the air inlet, a part of the fuel gas flows into the inner space and the central pressure stabilizing cavity of the valve seat, the rest of the fuel gas flows into the upper part of the valve core, a part of the fuel gas flows through the axial air inlet hole to fill the air inlet ring cavity on the valve core, and the other part of the fuel gas flows into the end pressure stabilizing cavity at the outer end of the valve seat;

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 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 stops, gas flows in from an axial air inlet hole on the valve core, passes through a gas inlet ring cavity, passes through a gap between the valve core and a valve seat, and finally flows out vertically after being guided by the gas 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 the piezoelectric crystal driving mode, effectively improves the response speed of the gas injection valve, and realizes the variable lift of the gas injection valve through different current driving modes of the piezoelectric crystal; the invention adopts a bypass air supply mode to guide the flow of the fuel gas in the valve body; the bottom end of the valve core is provided with a sealing ring belt so as to form an air inlet ring cavity, so that fuel gas is prevented from entering along the axial direction, the gas path balance is ensured, the valve seat quality is lightened, and the response speed is improved; the invention adopts the valve seat structure with the pressure stabilizing cavity, which can effectively inhibit the fluctuation of the gas pressure in the gas injection valve and ensure the stability of the gas injection pressure of the gas injection valve; according to the invention, the pressure balance hole is arranged at the guide pin, the pressure balance groove is arranged at the bottom plate, so that the inner and outer gas paths of the valve core assembly are balanced, no gas pressure difference between the upper and lower parts of the valve core assembly is ensured, the valve core assembly is prevented from receiving additional axial force, the response speed of the gas injection valve is further improved, and the control difficulty of the gas injection valve is reduced.

Drawings

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

FIG. 2 is an enlarged view of the valve core assembly structure of the present invention;

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

FIG. 4 is an enlarged view of the three-dimensional structure of the valve core;

fig. 5 is an enlarged view of a three-dimensional structure of a valve seat.

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 bypass type axial air intake piezoelectric internal guide gas injection valve according to the present invention, including a 1 fixed block, a 2 piezoelectric crystal, a 3 valve body, a 4 control valve rod, a 5 large piston, a 6 large piston support spring, a 7 seal ring, an 8 sleeve, a 9 seal ring, a 10 seal ring, a 12 positioning bolt, a 13 seal ring, a 14 guide pin return spring, a 15 small piston, a 16 small piston support spring, a 19 valve core assembly, and a 21 valve seat. The valve body 3 is a cuboid, a gas inlet 33 and a flow guide cavity 34 are arranged near one end of the center of the valve body 3, holes with a certain depth are arranged at the other end near the center of the valve body 3 along the axial direction, a partition 18 with a certain depth is arranged between the two holes, a through hole below the partition 18 is communicated with the flow guide cavity 34, the fixed block 1 is connected with the valve body 3 by utilizing a positioning bolt 12 to fix the fixed block 1 to the center position of the top end of the through hole above the partition 18, a straight slot with a certain depth is arranged at the center position of the fixed block 1 on the matching surface between the fixed block 1 and the valve body 3 through a sealing rubber ring 13, a through hole with a smaller diameter is arranged above the straight slot and used for arranging a connecting wire of the piezoelectric crystal 2 and a control unit outside the valve body 3, 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 action of the pretightening force of the guide pin return spring 14 and the large piston supporting 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 is tightly attached to the upper surface of the large piston 5, the upper end of the sleeve 8 is provided with two outlets which are a thick outlet and a thin outlet respectively, the lower end of the sleeve 8 is provided with 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 is ensured not to integrally enter the sleeve 8, the sleeve 8 is filled with hydraulic oil 17 with certain pressure, a small piston 15 is arranged above the thin outlet of the sleeve 8, the lower end of the small piston 15 is arranged in the small piston 15, the small piston supporting spring 16 is arranged between the flange of the small piston 15 and the sleeve 8 so as to ensure that the small piston 15 cannot integrally enter the sleeve, a sealing ring 7 is arranged between the side surfaces of the large piston 5 and the small piston 15 and the inner wall of the sleeve 8 so as to prevent leakage of hydraulic oil 17 in the sleeve 8, the large piston 5, the small piston 15, the large piston support spring 6 and the small piston support spring 16 form a hydraulic amplifier of the piezoelectric crystal 2 together with the sleeve 8, the hydraulic amplifier is integrally arranged above a partition 18 in the valve body 3, a valve core assembly 19 and a valve seat 21 are sequentially arranged below the central position of the control valve rod 4 from top to bottom, the upper surface of the small piston 15 is tightly attached to the upper end of the valve core assembly 19 under the pretightening force of the small piston support spring 16, a bolt hole 38 is formed in the valve seat 21, the valve seat 21 and the valve body 3 are fixedly connected together through bolts, the matching surfaces between the two are sealed through a sealing rubber ring 10, the valve seat 21 is provided with pressure stabilizing cavities 11 at the two ends close to a sealing ring belt 27 at the central position, the pressure stabilizing cavities 11 at the central position of the valve seat 21 are communicated with a gas space inside the valve core assembly 19, and the pressure stabilizing cavities 11 at the two ends of the valve seat 21 are communicated with a diversion cavity 33 inside the valve body 3;

as shown in fig. 2, a valve core assembly 19 of the bypass type axial air inlet piezoelectric internal guide gas injection valve consists of a guide pin 22, an armature 23, a spring seat 24, a bottom plate 25, a valve core 26, an armature return spring 29, a gasket 30 and a fastening bolt 32, wherein a plurality of sleeves 8 are arranged below the guide pin 22 for ensuring smooth movement of the guide pin 22, a corresponding plurality of small pistons 15 are symmetrically arranged below the guide pin 22, the number is even, the upper surface of the small pistons 15 is closely attached to the lower surface of the guide pin 22 in the valve core assembly 19 under the action of the small piston support spring 16, the center of the guide pin 22 is provided with a pressure balance hole 28, the guide pin 22 is arranged in a through hole in the center of a partition plate 18, the lower end of the guide pin 22 is fixed with the armature 23 through threaded connection, the armature 23 is connected with the bottom plate 25 and the valve core 26 through the fastening bolt 32, a layer of gasket 30 is arranged between the armature 23 and the bottom plate 25, four pressure balance grooves 31 are formed above the bottom plate 25, the spring seat 24 is arranged above the bottom plate 25, the inner side surfaces of the springs are contacted with the side surfaces of the armature 23, the side surfaces of the armature return spring 29 are respectively arranged below the annular grooves 24 and the valve core assembly is formed by the annular ring groove 24 below the valve core assembly 19, and the valve core assembly is formed by the valve core assembly 4 and the valve core assembly is sealed under the annular ring groove 24.

As shown in fig. 3, in a bypass type axial air-intake piezoelectric internal guide gas injection valve, firstly, gas vertically enters from an air inlet 33 on a valve body 3, is guided by a guide cavity 34, and then flows into a space around a valve core assembly 19 from the vertical direction to the horizontal direction, and due to the existence of a pressure balance groove 31 on a bottom plate 25, the inner space of the valve core assembly 19 is communicated with the inner space of the valve body 3, a part of the gas flows into the inner space of the valve core assembly 19, and then fills the inner space of the valve core assembly 19 and a pressure stabilizing cavity 11 in the center of a valve seat 21, and due to the existence of a pressure balance hole 28 on a guide pin 22, the gas flows into the space above the valve core assembly 19 and also fills the space above the valve core assembly 19; the rest of the fuel gas flows into the upper part of the valve core 26, one part of the fuel gas flows into the inlet annular cavity 36 with a certain depth around the multi-channel sealing ring belt 27 through the axial inlet holes 35 on the valve core 26, and the other part of the fuel gas fills the pressure stabilizing cavities 11 at the two ends of the valve seat 21 and the surrounding space of the valve core 26. When the piezoelectric crystal 2 is not electrified, the surface of the valve core 26 is attached to the surface of the valve seat 21, and an air inlet annular cavity 36 on the valve core 26 is not communicated with an annular cavity near the air outlet annular belt 20 on the valve seat 21; after the piezoelectric crystal 2 is electrified, the piezoelectric crystal 2 stretches, the valve core assembly 19 is driven to move upwards after being amplified by the hydraulic amplifier, the surface of the valve core 26 is separated from the surface of the valve seat 21, at the moment, the air inlet ring cavity 36 is communicated with the ring cavity near the air outlet ring belt 20, and the lifting and seating of the valve core 26 controls the on-off between the air inlet ring cavity 36 and the ring cavity near the air outlet ring belt 20.

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 return spring 14 and the armature return spring 29, the valve core assembly 19 is kept motionless at the initial position, the sealing ring belt 27 on the valve core 26 in the valve core assembly 19 is tightly matched with the upper surface of the valve seat 21, the air inlet ring cavity 36 on the valve core 26 is not communicated with the ring cavity near the air outlet ring belt 20 on the valve seat 21, and the whole space inside the valve body 3 of the fuel gas injection valve is filled with fuel gas. After the piezoelectric crystal 2 is electrified, the piezoelectric crystal 2 is excited by current to extend, so that the control valve rod 4 moves downwards, the large piston 5 moves downwards along with the control valve rod, the pressure of hydraulic oil 17 in the sleeve 8 rises, the small pistons 15 move upwards under the action of the pressure of the hydraulic oil 17, the guide pins 22 move upwards smoothly after receiving the upward acting force of the small pistons 15, the guide pins 22 serve as part of the valve core assembly 19, the valve core assembly 19 moves upwards along with the valve core assembly, at the moment, the gas injection valve is opened, the gas path is opened until the pressure of the hydraulic oil 17 in the sleeve 8 returns to the initial state, the large piston 5 and the small pistons 15 stop moving, the valve core assembly 19 stops moving along with the valve core assembly, the valve core assembly 19 is maintained at the position for a period of time, in the process, fuel gas flows in from the axial air inlet holes 35 on the valve core 26, an air inlet annular cavity 36 with a certain depth is formed around the multi-channel sealing annular band 27, the fuel gas flows out vertically after being guided through a gap between the valve core 26 and the valve seat 21 and finally through an air outlet 37, the multi-channel annular band is adopted between the valve core 26 and the valve seat 21, the surface is sealed, the pressure is stabilized and balanced, the impact can be reduced by the wider annular band area, the reliability is improved, and the pressure stabilizing cavities 11 arranged at the positions close to the two ends of the air inlet annular cavity 36 and the center of the valve seat 21 enable the surrounding fuel gas to be uniformly ventilated and the air pressure to be 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 5 starts to move upwards under the action of the large piston supporting spring 6, the pressure of the hydraulic oil 17 in the sleeve 8 decreases, the guide pin 22 starts to move downwards under the action of the guide pin return spring 14, the small piston 15 and the valve core assembly 19 move downwards together until the pressure of the hydraulic oil 17 in the sleeve 8 returns to an initial state, the large piston 5 and the small piston 15 return to the initial positions, the valve core assembly 19 correspondingly returns to the initial positions at the moment, the surface of the valve core 26 is attached to the surface of the valve seat 21, the valve returns to the initial positions again, the fuel gas injection valve is closed, and the gas path is closed.

The working process can be known as follows: in the working process, the piezoelectric crystal 2 is electrified and elongated, the guide pin 22 of the valve core assembly 19 is pushed to move after the displacement is amplified by the hydraulic amplifier, and the whole valve core assembly 19 moves away from the valve seat 21 under the internal guide action of the matching surface between the guide pin 22 and the partition 18, 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 through different current driving modes of the piezoelectric crystal 2; the invention adopts a bypass air supply mode to guide the flow of the fuel gas in the valve body 3; the bottom end of the valve core 26 is provided with a sealing ring belt 27 so as to form an air inlet ring cavity 36, so that fuel gas enters axially, on one hand, the interference of the fuel gas is avoided, the balance of the air path is ensured, on the other hand, the quality of the valve seat 21 is reduced, and the response speed is improved; the invention adopts the valve seat 21 structure with the pressure stabilizing cavity 11, which can effectively inhibit the fluctuation of the gas pressure in the gas injection valve and ensure the stability of the gas injection pressure of the gas injection valve; according to the invention, the pressure balance hole 28 is arranged at the guide pin 22, the pressure balance groove 31 is arranged at the bottom plate 25, so that the internal and external gas paths of the valve core assembly 19 are balanced, no gas pressure difference between the upper and lower parts of the valve core assembly 19 is ensured, the valve core assembly 19 is prevented from receiving extra axial force, the response speed of the gas injection valve is further improved, and the control difficulty of the gas injection valve is reduced.

The invention relates to a piezoelectric internal guide gas injection valve with bypass type axial air intake, which comprises a fixed block, a piezoelectric crystal, a valve body, a control valve rod, a large piston supporting spring, a sealing ring, a sleeve, a sealing rubber ring, a positioning bolt, a guide pin reset spring, a small piston supporting spring, a valve core assembly and a valve seat, wherein the valve body is a cuboid, one end close to the center of the valve body is provided with a gas inlet and a flow guide cavity, the other end close to the center of the valve body is provided with holes with a certain depth up and down along the axial direction, the two holes are provided with a partition plate with a certain depth at the middle, a hole space below the partition plate is communicated with the flow guide cavity, the fixed block is connected with the valve body by the positioning bolt, so that the valve body is fixed at the center position of the top end of the hole above the partition plate, and the sealing is kept on the matching surface between the fixed block and the valve body by the sealing rubber ring, the fixed block is provided with a straight slot with a certain depth at the center position, the piezoelectric crystal is arranged in the straight slot, a through hole with a smaller diameter is arranged above the straight slot 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 closely 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 pretightening force of a guide pin reset spring and a large piston supporting spring, the lower surface of the piezoelectric crystal is closely attached to the upper surface of the control valve rod, the lower surface of the control valve rod and the upper surface of the large piston, the upper end of a sleeve is provided with two outlets, namely 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 a flange of the large piston and the sleeve, the large piston is prevented from integrally entering the sleeve, the sleeve is filled with hydraulic oil with a certain pressure, the small piston is arranged above the thin outlet 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, 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 under the pretightening force of the small piston supporting spring, a bolt hole is formed in the valve seat, the valve seat is fixedly connected with the valve body through bolts, a matching surface between the two is sealed through a sealing rubber ring, the pressure stabilizing cavity is formed at the center position of the valve seat and two ends close to a sealing ring, the center position of the valve seat is communicated with a fuel gas space in the assembly, and the pressure stabilizing cavity at the center position of the valve seat is communicated with a guide cavity in the valve body; the valve core assembly comprises a guide pin, an armature return spring, a spring seat, a bottom plate, a valve core, a gasket and a fastening bolt, wherein a plurality of sleeves are arranged below the guide pin to ensure that the guide pin moves stably, a plurality of corresponding small pistons are symmetrically arranged below the guide pin, the number of the corresponding small pistons is even, under the action of the small piston support spring, the upper surface of each small piston 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 guide pin is arranged in a through hole in the center of a partition plate, the lower end of the guide pin is fixedly connected with the armature through threads, 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, 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, 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 and a seal, and the valve core assembly is integrally arranged below a control valve rod; after the gas is guided by the guide cavity, the flowing direction of the gas is changed from the vertical direction to the horizontal direction and flows into the space around the valve core assembly, and due to the existence of the pressure balancing groove on the bottom plate, the space inside the valve core assembly is communicated with the space inside the valve body, a part of the gas flows into the space inside the valve core assembly, and then fills the space inside the valve core assembly and the pressure stabilizing cavity in the center of the valve seat, and due to the existence of the pressure balancing hole on the guide pin, the gas flows into the space above the valve core assembly and also fills the space above the valve core assembly; the rest of the fuel gas flows into the upper part of the valve core, one part of the fuel gas flows in through the air inlet holes on the valve core, fills the air inlet annular cavity with a certain depth around the multi-channel sealing annular band, and the other part of the fuel gas fills the pressure stabilizing cavities at the two ends of the valve seat and the surrounding space of the valve core. When the piezoelectric crystal is not electrified, the surface of the valve core is attached to the surface of the valve seat, and an air inlet annular cavity on the valve core is not communicated with an annular cavity near an air outlet annular band on 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 surface of the valve core is separated from the surface of the valve seat, at the moment, the air inlet ring cavity is communicated with the ring cavity near the air outlet ring belt, and lifting and seating of the valve core control on-off between the air inlet ring cavity and the ring cavity near the air outlet ring belt.

Claims (3)

1. A piezoelectric internal guiding gas injection valve with bypass type axial air intake is characterized in that: comprises a valve body, a valve seat, a piezoelectric crystal, a hydraulic amplifier, a partition board and a valve core assembly, wherein a fixed block is fixed above the valve body, a straight slot is formed in the middle of the fixed block, the piezoelectric crystal is installed in the straight slot, the valve body is fixed on the valve seat, the valve body is internally provided with the partition board, the hydraulic amplifier is arranged above the partition board, the valve core assembly is arranged below the partition board, through holes are respectively arranged on the partition board, a valve space is formed between the valve body below the partition board and the valve seat, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the partition board, a thick outlet is formed at the end part of the upper end of the sleeve, a thin outlet is formed at the inner side of the end part of the upper end of the sleeve, 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 a 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 arranged on 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 is arranged on the valve core, the sealing ring belt forms an air inlet ring cavity, an air outlet ring belt is arranged on the valve seat, the air outlet ring belt is arranged below the air inlet ring cavity, and an air outlet is arranged below the air outlet ring belt.

2. The bypass axial inlet piezoelectric internal pilot gas injection valve of claim 1, wherein: the outer end of the valve seat is provided with an end pressure stabilizing cavity.

3. A bypass axial inlet piezoelectric pilot gas injection valve according to claim 1 or 2, characterized in that: the valve body is provided with a protruding part, the protruding part is provided with an air inlet, a flow guide cavity is arranged in the valve body below the air inlet, the air inlet and the flow guide cavity are communicated and form an external space, the external space is communicated with the internal space, and the valve core is provided with an axial air inlet;

the fuel gas vertically flows into the flow guiding cavity through the air inlet, a part of the fuel gas flows into the inner space and the central pressure stabilizing cavity of the valve seat, the rest of the fuel gas flows into the upper part of the valve core, a part of the fuel gas flows through the axial air inlet hole to fill the air inlet ring cavity on the valve core, and the other part of the fuel gas flows into the end pressure stabilizing cavity at the outer end of the valve seat;

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 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 stops, gas flows in from an axial air inlet hole on the valve core, passes through a gas inlet ring cavity, passes through a gap between the valve core and a valve seat, and finally flows out vertically after being guided by the gas 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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