CN107420226B - Bypass piezoelectric type internal guide gas injection valve with floating valve seat - Google Patents

Abstract

The invention aims to provide a bypass piezoelectric type internal guide gas injection valve with a floating valve seat, which realizes the reverse leakage function caused by unbalanced internal and external pressure of the gas injection valve through a floating valve seat structure, and ensures the working reliability of the gas injection valve; the air inlet and the flow guiding process are realized through the bypass structure and the flow guiding cavity structure; the control of the valve core and the control of the gas path are realized through the control of the piezoelectric actuator, so that the gas injection function of the gas valve is realized; the inner guide structure is matched with the pressure balance hole and the pressure balance groove, so that the perpendicularity of the valve core is ensured, the stable work and the reliable work of air flow are realized, and the 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.

Description

Bypass piezoelectric type internal guide gas injection valve with floating valve seat

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. The natural gas engine has good application prospect as ship power, in particular as the propulsion power of inland river ships. As a fuel supply device of a natural gas engine, the performance of a gas injection valve directly determines the economy and emission performance of the natural gas engine. At present, the natural gas engine always has the condition of insufficient gas supply under the full working condition state, so that the phenomenon of unstable rotating speed of the engine under the full working condition operation is caused, and the phenomenon is more serious on a high-power engine, so that the normal use of the engine and the performance of the engine are seriously influenced. Under the condition of severe engine working conditions, the injection valve is easy to generate reverse leakage. At the same time, in order to achieve more flexible jet control. Therefore, it is necessary to design an injection valve having a reverse leakage preventing function and a variable lift. Meanwhile, a high-flow gas injection valve with high response speed, high control precision and good reliability needs to be developed, so that the circulation capacity of the high-flow gas injection valve can meet the normal working requirement of a natural gas engine in a high-load state.

Disclosure of Invention

The invention aims to provide the bypass piezoelectric type internal guide gas injection valve with the floating valve seat, which has the advantages of high response speed, high control precision, high reliability, stable gas pressure, high-efficiency sealing, high flow and reverse leakage prevention.

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

the invention relates to a bypass piezoelectric type internal guide gas injection valve with a floating valve seat, which is characterized in that: comprises a valve body, a floating valve seat, a piezoelectric crystal, a control valve rod, a hydraulic amplifier, a baffle plate and a valve core assembly, wherein an opening structure is arranged above the valve body, a fixed block is fixed on the opening structure, a straight groove is arranged in the middle of the fixed block, the piezoelectric crystal is arranged in the straight groove, the baffle plate is arranged in the middle of the valve body, the hydraulic amplifier is arranged above the baffle plate, the valve core assembly is arranged below the baffle plate, through holes are respectively arranged on the baffle plate, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the baffle plate, the end part of the upper end of the sleeve is provided with a coarse outlet, the inner side of the end part of the upper end of the sleeve is provided with a fine outlet, the large piston is arranged in the coarse outlet, a 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, a small piston supporting spring is arranged between the flange of the small piston and the sleeve, hydraulic oil is filled in the sleeve below the large piston and the small piston, the valve core assembly comprises an armature, a spring seat, a bottom plate, 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 a main 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, a pressure balance hole is arranged in the guide pin, a pressure balance groove is arranged on the bottom plate, the valve core is of a hollow structure, and the pressure balance hole, the pressure balance groove is communicated with the hollow part of the valve core, the valve core is provided with a sealing ring belt, and the sealing ring belt forms a ring cavity; the floating valve seat comprises a guide base and a valve seat, wherein the guide base is fixed in the valve body, the valve seat is positioned below the valve core, a T-shaped structure is arranged on the inner ring of the guide base, the outer ring of the valve seat is arranged in the guide base through the T-shaped structure matched with the outer ring of the valve seat, two ends of a valve seat reset spring are respectively fixed on the valve seat and the valve core, an air outlet ring belt is arranged on the valve seat, the air outlet ring belt is positioned below the annular cavity, and an air outlet is arranged below the air outlet ring belt.

The invention may further include:

1. the double air leakage preventing structure is arranged between the valve seat and the guide base, the deformable sealing ring is arranged above the joint of the valve seat and the guide base, the pressing gasket is additionally arranged above the inner edge of the deformable sealing ring, the two layers of sealing rubber rings are arranged at the joint of the T-shaped structure of the valve seat and the guide base, and the elastic gasket is arranged at the joint of the T-shaped structure of the valve seat and the guide base.

2. The valve body is provided with an air inlet which is positioned at the part of the valve body extending outwards, a diversion cavity is formed below the air inlet, and the air inlet is communicated with the diversion cavity;

the gas flows into the valve body vertically through the air inlet, flows into the valve body fully along the flow guide cavity, is excited by current to extend after the piezoelectric crystal is electrified, so that the control valve rod moves downwards, the large piston moves downwards along with the pressure rise of hydraulic oil, the small piston moves upwards, the guide pin moves upwards after receiving the upward acting force of the small piston, the valve core assembly moves upwards along with the whole valve core assembly, the valve core is driven to move upwards and separate from the surface of the valve seat until the upper surface of the spring seat contacts with the lower surface of the partition plate, the gas circuit is opened, the gas valve is opened, and the gas flows in a mixed air inlet mode of the axial main gas tank and the circumferential gas filling hole, and vertically flows out of the gas outlet through the annular cavity; the piezoelectric crystal is shortened after power failure, the large piston moves upwards under the action of the large piston supporting spring, the hydraulic oil pressure is reduced, the guide pin moves downwards under the action of the main and auxiliary restoring springs, the small piston and the valve core assembly integrally move downwards along with the guide pin until the hydraulic oil pressure returns to an initial state, the large piston and the small piston return to the initial position, the valve core assembly returns to the initial position, the gas circuit is closed, and the gas valve is closed.

The invention has the advantages that: the invention adopts a structure with the floating valve seat, can effectively prevent the reverse leakage of the gas injection valve, has the function of shock absorption, and ensures the working reliability and safety of the gas injection valve; the air inlet and diversion process is realized through the bypass structure and the diversion cavity 31 structure; the control of the valve core and the control of the gas path are realized through the control of the piezoelectric actuator, so that the gas injection function of the gas valve is realized; the inner guide structure is matched with the pressure balance hole and the pressure balance groove, so that the perpendicularity of the valve core is ensured, 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 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 top view of the valve core structure;

FIG. 5 is a three-dimensional block diagram of a valve core structure;

FIG. 6 is an enlarged view of a floating valve seat structure;

FIG. 7 is a floating valve seat force diagram.

Detailed Description

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

referring to fig. 1-7, fig. 1 is a schematic diagram of the overall structure of the bypass type internal guide gas injection valve with a floating valve seat 17 according to the present invention, and the bypass type internal guide gas injection valve mainly comprises a piezoelectric actuator 3, a main return spring 14, an auxiliary return spring 9, a valve core assembly 15, a valve body 1 and the floating valve seat 17. The piezoelectric actuator 3 is fixed on the valve body 1 through a fixing bolt, and a valve core assembly 15 and a floating valve seat 17 are sequentially arranged below the piezoelectric actuator 3 from top to bottom.

As shown in fig. 2, the valve core assembly 15 of the bypass type piezoelectric internal guide gas injection valve with the floating valve seat mainly comprises a guide pin 18, an armature 19, a spring seat 20, a fastening bolt 27, a gasket 25, a bottom plate 21 and a valve core 22, wherein the armature 19 is connected with the bottom plate 21 and the valve core 22 through the fastening bolt 27, a layer of gasket 25 is arranged between the armature 19 and the bottom plate 21, the spring seat 20 is arranged above the bottom plate 21, the side surface of the inside of the spring seat is contacted with the side surface of the armature 19, two ends of a main return spring 14 are respectively positioned in annular grooves of a baffle 13 and the spring seat 20, a straight groove with a certain depth is formed in the center of the baffle 13, a pressure balance hole 24 is formed in the center of the guide pin 18, a certain number of pressure balance grooves 26 are formed in the bottom plate 21, the armature 19 is prevented from being subjected to axial force, the internal and external gas circuit pressure at the armature 19 is more easily balanced, the response speed of the armature 19 is improved, and an auxiliary return spring 9 is arranged above the guide pin 18. The pressure balance hole 24 at the center of the guide pin 18 is matched with the pressure balance groove 26 on the bottom plate 21, so that the inner space of the valve core assembly 15 is communicated with the outer space, the inner and outer gas paths reach balance, the inner and outer gas paths of the valve core assembly 15 have no pressure difference, the valve core 22 is prevented from being subjected to additional axial force during movement, and the valve core 22 consists of a valve core main body, ribs 29 and a sealing ring belt 23. The valve element assembly 15 is integrally disposed below the piezoelectric actuator 3.

The piezoelectric actuator 3 consists of a piezoelectric crystal 2, a control valve rod 4, a hydraulic amplifier and an auxiliary reset spring, wherein the hydraulic amplifier consists of a large piston 5, a large piston supporting spring 6, a small piston 10, a small piston supporting spring 11 and a sleeve 8, the hydraulic amplifier is arranged above a partition plate 13 on the valve body, the sleeve 8 is filled with fuel oil with certain pressure, and sealing rings 7 are arranged on the matching surfaces among the large piston 5, the small piston 10 and the sleeve 8; a control valve rod 4 is arranged below the piezoelectric crystal 2, the lower surface of the control valve rod 4 is contacted with the upper surface of a large piston 5 in the hydraulic amplifier, four large pistons and four small pistons in the hydraulic amplifier are symmetrically arranged, the piezoelectric crystal 2, the control valve rod 4 and the large piston 5 are tightly attached together under the action of a large piston supporting spring 6, a small piston 10 in the hydraulic amplifier is tightly attached to the lower surface of a guide pin by utilizing a small piston supporting spring 11, and an auxiliary reset spring 9 is arranged on the surface of the guide pin.

As shown in fig. 3, first, the fuel gas flows vertically into the valve body 7 through the gas inlet 30, and flows along the gas inlet 25 to fill the interior of the valve body 1. In the working process of the fuel gas injection valve, when the piezoelectric crystal 2 is not electrified, under the pretightening force of the main reset spring 14 and the auxiliary reset spring 9, the valve core assembly 15 keeps motionless at the initial position, the lower surface of the sealing ring belt 23 of the valve core 22 in the valve core assembly 15 is tightly attached to the upper surface of the air outlet ring belt 16 of the valve seat 39, at the moment, the air outlet ring belt 16 is not communicated with the inner space of the valve body 1, 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 that the control valve rod 4 moves downwards, the large piston 5 on the hydraulic amplifier moves downwards along with the control valve rod, the liquid pressure in the sleeve 8 in the hydraulic amplifier is increased, the small piston on the hydraulic amplifier moves upwards under the action of the liquid pressure, the guide pin moves upwards steadily after receiving the upward acting force of the four small pistons 10, the guide pin is used as a part of the valve core assembly 15, the valve core assembly 15 moves upwards along with the whole body, the valve core 22 is driven to move upwards to be separated from the surface of the valve seat 39 until the upper surface of the spring seat 20 contacts with the lower surface of the electromagnet 1, the axial movement and the circumferential positioning of the armature 19 are controlled by the cooperation between the guide pin 18 and the partition 13 in the whole movement process, at this time, the gas path is opened, the gas valve is opened, the gas flows in rapidly by the mixed gas inlet mode of the axial main gas groove 35 and the circumferential gas supplementing hole 33, passes through the multi-channel annular cavity 32, and finally flows vertically out of the gas outlet 34; the piezoelectric crystal 2 is powered off, the piezoelectric crystal 2 starts to shorten, the large piston 5 starts to move upwards under the action of the large piston supporting spring 6, the liquid pressure in the sleeve 8 in the hydraulic amplifier is reduced, the guide pin starts to move downwards under the action of the main and auxiliary return springs, the small piston 10 and the valve core assembly 15 integrally move downwards along with the guide pin until the pressure in the hydraulic amplifier returns to an initial state, the large piston returns to the initial position, the valve core assembly 15 correspondingly returns to the initial position at the moment, the gas path is closed, and the gas valve is closed.

As shown in fig. 6, the present invention employs a floating valve seat 17 structure in order to prevent reverse leakage of fuel gas and to improve reliability and safety of the fuel gas injection valve. The floating valve seat 17 can lock the gas valve when the external pressure and the internal pressure of the gas valve are high, so that the reverse leakage of the gas is effectively prevented. The floating valve seat 17 is composed of 7 parts: guide base 37, valve seat 39, valve seat return spring 43, sealing rubber ring 38, pressing washer 36, deformable sealing ring 41, elastic washer 42. The guide base 37 is of an integral structure with the valve body 1, and the valve seat 39 is mounted on the guide base 37. The inner ring of the guide base 37 is provided with a T-shaped structure which is matched with the T-shaped structure of the outer ring of the valve seat 39. The two ends of the valve seat return spring 43 are respectively fixed on the valve seat 39 and the valve core 15, and a certain pretightening force is maintained.

In order to prevent air leakage between the valve seat 39 and the guide base 37, a dual air leakage prevention structure is additionally arranged between the valve seat 39 and the guide base 37, a deformable sealing ring 41 is arranged above the joint of the valve seat 39 and the guide base 37, a compression washer 36 is additionally arranged above the inner edge and the outer edge of the deformable sealing ring 41, the compression washer 36 is fixed on the valve seat 39 through a screw 40, the stress of the compression washer 36 is ensured to be uniform, and the sealing performance is enhanced. The deformable sealing ring 41 is made of deformable soft plastic, so that the movement of the valve seat 39 is not affected. The second sealing is that two layers of sealing rubber rings 38 are additionally arranged at the T-shaped connection part of the valve seat 39 and the guide base 37, so that the sealing performance is further enhanced. A layer of elastic washer 42 is additionally arranged at the T-shaped connection part between the valve seat 39 and the guide base 37, so that vibration impact force during contact is reduced, and the shock absorption effect is achieved. The reliability of the gas valve is effectively increased.

The valve seat 39 is acted upon by the valve seat return spring 43 elastic force F4, the gas valve external gas pressures F1 and F2, the gas valve internal gas pressure F3, and the valve element 15 pressing force. The valve core 15 is acted by the elastic force of a return spring. When the gas pressure below the gas valve is greater than the gas pressure inside the gas valve, the gas pressure outside the gas valve F1 and F2 respectively act on the lower part of the valve seat 39 and the position of the gas outlet ring belt 16, the contact area below the valve seat 39 is far greater than that of the gas outlet ring belt 16, so that F1 is far greater than F2, and before the external gas pressure expands to cause the upward movement of the valve core 15, the external gas pressures F1 and F2 overcome the spring pretightening force of the return spring 7, and the valve seat 39 moves upward together with the valve core 15. The valve seat 39 moves upward until the spring seat 15 contacts the diaphragm 13. At this time, even if the piezoelectric crystal 2 is energized, the valve element 15 cannot move upward, and the gas valve cannot be opened. The gas valve is locked.

When the gas pressure inside and outside the gas valve is restored to normal, the valve seat 39 moves downward to return to the original position by the valve seat return spring 43. If the piezoelectric crystal 2 is electrified at this time, the valve core 15 still keeps still, and the gas valve is normally opened. When the gas valve is to be closed, the piezoelectric crystal 2 is powered off, the valve core 15 moves downwards under the action of the return spring, and the gas valve is closed. If the piezo-electric crystal 2 is not energized at this time, the valve seat 39 moves back down with the valve core 15 under the assistance of the return spring, and the gas valve remains closed. When the gas valve is to be opened, the piezoelectric crystal 2 is electrified, the valve core 15 moves upwards, and the gas valve is normally opened.

According to the working process, the bypass type externally-guided gas injection valve with the floating valve seat adopts the structure with the floating valve seat 17, so that the gas injection valve can be effectively prevented from reverse leakage under the condition of abnormal internal and external air pressure of the injection valve, has a damping function, and ensures the working reliability and safety of the gas injection valve; the air inlet and the flow guiding process are realized through the bypass structure and the air inlet 25 structure; the control of the valve core 22 is realized through the control of the actuator, and the control of the air path is realized to realize the air injection function; the perpendicularity of the valve core 22 is ensured by the inner guide structure; the pressure balance hole 24 is formed in the center of the guide pin 18, a certain number of pressure balance grooves 26 are formed in the bottom plate 21, so that the armature 19 is prevented from being subjected to axial force, the internal and external air path pressure at the armature 19 is more easily balanced, and the response speed of the armature 19 is improved; the structure that a plurality of circumferential air supplementing holes 33 are formed in the rib of the valve core 22, a plurality of annular cavities 32 are formed in the lower surface of the valve core 22 and the upper surface of the valve seat 39, so that the effective flow area is increased, the quality of the valve core 22 and the valve seat 39 is reduced, and the reliability is improved; the flow cone angle 28 with a certain angle is arranged at the circumferential air filling hole 33 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 35 and air inlet of the circumferential air-filling holes 33, 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 multi-seal ring belt 23 and the air outlet ring belt 16 are adopted between the valve core 22 and the valve seat 39, so that the surface seal, 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 technical scheme of the invention is as follows: the piezoelectric internal guide gas injection valve with floating valve seat consists of mainly piezoelectric actuator, main reset spring, auxiliary reset spring, valve core assembly, valve body and floating valve seat. The piezoelectric actuator consists of a piezoelectric crystal, a control valve rod, a hydraulic amplifier and an auxiliary reset spring, wherein the hydraulic amplifier consists of a large piston, a large piston supporting spring, a small piston supporting spring and a sleeve, the hydraulic amplifier is arranged above a partition plate on a valve body, fuel oil with certain pressure is fully distributed in the sleeve, and sealing rings 7 are arranged on the matching surfaces among the large piston, the small piston and the sleeve; the lower surface of the control valve rod is contacted with the upper surface of a large piston in the hydraulic amplifier, the four large pistons and the four small pistons in the hydraulic amplifier are symmetrically arranged, the piezoelectric crystal, the control valve rod and the large piston are tightly attached together under the action of a large piston supporting spring, the small piston in the hydraulic amplifier is tightly attached to the lower surface of a guide pin by utilizing a small piston supporting spring, and an auxiliary reset spring is arranged on the surface of the guide pin. The piezoelectric actuator is fixed on the valve body through a fixing bolt, and a valve core assembly and a floating valve seat are sequentially arranged below the piezoelectric actuator from top to bottom; the valve core assembly consists of a guide pin, an armature, a spring seat, a gasket, a bottom plate, a fastening bolt and a valve core, wherein 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 spring seat is arranged above the bottom plate, the side surface of the inside of the spring seat is contacted with the side surface of the armature, two ends of a main reset spring are respectively positioned in annular grooves of the partition plate and the spring seat, a pressure balance hole is formed in the center of the guide pin, a certain number of pressure balance grooves are formed in the bottom plate, the guide pin is fixed at the center of the armature through threads, the valve core consists of a valve core main body, ribs and a sealing ring belt, the valve core assembly is integrally arranged below an electromagnet, a circumferential air supplementing hole is formed in the rib of the valve core, a diversion cone angle is formed in the air supplementing hole, a sealing ring belt and an air outlet ring belt are adopted between the valve core and a floating valve seat, and the valve core is sealed in a stable pressure and balanced manner, and has a wider ring belt area. The floating valve seat consists of a guide base, a valve seat reset spring, a sealing rubber ring, a pressing gasket, a deformable sealing ring and an elastic gasket. The guide base is integrated with the valve body, and the valve seat is mounted on the guide base. The guide base inner ring is provided with a T-shaped structure which is matched with the T-shaped structure of the valve seat outer ring. The two ends of the valve seat reset spring are respectively fixed on the valve seat and the valve core, and a certain pretightening force is maintained. A dual air leakage prevention structure is additionally arranged between a valve seat and a guide base, a deformable sealing ring is arranged above the joint of the valve seat and the guide base, and a compression washer is additionally arranged above the inner edge and the outer edge of the deformable sealing ring and is fixed on the valve seat through screws. The deformable sealing ring is made of deformable soft plastic, so that the movement of the valve seat is not influenced. The second double seal is that two layers of sealing rubber rings are additionally arranged at the T-shaped connection part of the valve seat and the guide base.

Claims (3)

1. A bypass piezoelectric type internal guiding gas injection valve with a floating valve seat is characterized in that: comprises a valve body, a floating valve seat, a piezoelectric crystal, a control valve rod, a hydraulic amplifier, a baffle plate and a valve core assembly, wherein an opening structure is arranged above the valve body, a fixed block is fixed on the opening structure, a straight groove is arranged in the middle of the fixed block, the piezoelectric crystal is arranged in the straight groove, the baffle plate is arranged in the middle of the valve body, the hydraulic amplifier is arranged above the baffle plate, the valve core assembly is arranged below the baffle plate, through holes are respectively arranged on the baffle plate, the hydraulic amplifier comprises a large piston, a small piston and a sleeve, the sleeve is arranged on the baffle plate, the end part of the upper end of the sleeve is provided with a coarse outlet, the inner side of the end part of the upper end of the sleeve is provided with a fine outlet, the large piston is arranged in the coarse outlet, a 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, a small piston supporting spring is arranged between the flange of the small piston and the sleeve, hydraulic oil is filled in the sleeve below the large piston and the small piston, the valve core assembly comprises an armature, a spring seat, a bottom plate, 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 a main 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, a pressure balance hole is arranged in the guide pin, a pressure balance groove is arranged on the bottom plate, the valve core is of a hollow structure, and the pressure balance hole, the pressure balance groove is communicated with the hollow part of the valve core, the valve core is provided with a sealing ring belt, and the sealing ring belt forms a ring cavity; the floating valve seat comprises a guide base and a valve seat, wherein the guide base is fixed in the valve body, the valve seat is positioned below the valve core, a T-shaped structure is arranged on the inner ring of the guide base, the outer ring of the valve seat is arranged in the guide base through the T-shaped structure matched with the outer ring of the valve seat, two ends of a valve seat reset spring are respectively fixed on the valve seat and the valve core, an air outlet ring belt is arranged on the valve seat, the air outlet ring belt is positioned below the annular cavity, and an air outlet is arranged below the air outlet ring belt.

2. The bypass piezoelectric internally piloted gas injection valve with a floating valve seat of claim 1, wherein: the double air leakage preventing structure is arranged between the valve seat and the guide base, the deformable sealing ring is arranged above the joint of the valve seat and the guide base, the pressing gasket is additionally arranged above the inner edge of the deformable sealing ring, the two layers of sealing rubber rings are arranged at the joint of the T-shaped structure of the valve seat and the guide base, and the elastic gasket is arranged at the joint of the T-shaped structure of the valve seat and the guide base.

3. A bypass piezoelectric pilot gas injection valve with a floating valve seat according to claim 1 or 2, characterized in that: the valve body is provided with an air inlet which is positioned at the part of the valve body extending outwards, a diversion cavity is formed below the air inlet, and the air inlet is communicated with the diversion cavity;

the gas flows into the valve body vertically through the air inlet, flows into the valve body fully along the flow guide cavity, is excited by current to extend after the piezoelectric crystal is electrified, so that the control valve rod moves downwards, the large piston moves downwards along with the pressure rise of hydraulic oil, the small piston moves upwards, the guide pin moves upwards after receiving the upward acting force of the small piston, the valve core assembly moves upwards along with the whole valve core assembly, the valve core is driven to move upwards and separate from the surface of the valve seat until the upper surface of the spring seat contacts with the lower surface of the partition plate, the gas circuit is opened, the gas valve is opened, and the gas flows in a mixed air inlet mode of the axial main gas tank and the circumferential gas filling hole, and vertically flows out of the gas outlet through the annular cavity; the piezoelectric crystal is shortened after power failure, the large piston moves upwards under the action of the large piston supporting spring, the hydraulic oil pressure is reduced, the guide pin moves downwards under the action of the main and auxiliary restoring springs, the small piston and the valve core assembly integrally move downwards along with the guide pin until the hydraulic oil pressure returns to an initial state, the large piston and the small piston return to the initial position, the valve core assembly returns to the initial position, the gas circuit is closed, and the gas valve is closed.

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