CN112431800A

CN112431800A - Gas-liquid isolation sealing method for piston type energy accumulator

Info

Publication number: CN112431800A
Application number: CN202011439006.0A
Authority: CN
Inventors: 金成毅; 郑红; 匡克焕; 汪驰; 其他发明人请求不公开姓名
Original assignee: SICHUAN LINGFENG AVIATION HYDRAULIC MACHINERY CO Ltd
Current assignee: SICHUAN LINGFENG AVIATION HYDRAULIC MACHINERY CO Ltd
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-03-02

Abstract

The invention discloses a gas-liquid isolation sealing method for a piston type energy accumulator, and aims to solve the problems that extreme dynamic sealing performance of a sealing ring of the piston type energy accumulator is difficult to guarantee and a sealing piece is inclined and damaged under the action of high pressure. The invention is realized by the following technical scheme: according to a cylindrical piston, a compression nut and a sealing element which are assembled in a cylinder barrel and perform bidirectional movement, and end covers at two ends of the cylinder barrel, the piston type energy accumulator end cover and the cylinder barrel are connected by threads, three to four annular rectangular ring grooves are arranged on the excircle of the piston, wherein a guide ring is assembled between a first rectangular ring groove and a fourth rectangular ring groove, an O-shaped sealing ring is assembled on a second annular groove, a sealing ring pressed on the O-shaped sealing ring is assembled on the O-shaped sealing ring, a triangular sealing ring is assembled on a third rectangular ring groove, and triangular protective rings are arranged on two sides of the triangular sealing ring. The invention avoids trapped pressure between the combined seal formed by the O-shaped ring and the sealing ring and the triangular seal.

Description

Gas-liquid isolation sealing method for piston type energy accumulator

Technical Field

The invention relates to a hydraulic sealing system, in particular to a sealing method for gas-liquid isolation in a piston type energy accumulator in the hydraulic and pneumatic fields.

Background

An accumulator is an energy storage device that stores hydraulic pressure in a pressure-resistant container and releases it when needed. The accumulator is an important accessory in a hydraulic system and plays an important role in ensuring the normal operation of the system, improving the dynamic performance of the system, maintaining the working stability, prolonging the working life, reducing noise and the like. The piston accumulator is a high-pressure piston accumulator, relates to the technical field of hydraulic auxiliary elements, and can be applied to hydraulic systems of die casting machines, metallurgy and other industries as an auxiliary power source to reduce power consumption and save energy. The piston accumulator is a common hydraulic accessory in a hydraulic system, is an energy conversion device and is mainly used for storing energy, absorbing pulsating pressure, eliminating pulsation, reducing noise, recovering energy and the like in the hydraulic system. The piston type energy accumulator separates gas and liquid by a piston, and a seal is arranged between the piston and the inner wall of the cylindrical energy accumulator, so that oil is not easy to oxidize. The piston type energy accumulator has long service life, light weight, easy installation, simple structure and convenient maintenance, but has the defects of large mass block inertia, poor response sensitivity and difficult sealing; it is not suitable for low pressure to absorb pulsation. The piston accumulator stores hydraulic oil by utilizing the compressibility of gas, can be quickly released when needed, and improves the effective power of the hydraulic pump under the condition of less power. The piston type energy accumulator cylinder piston separates gas and liquid, and a seal is arranged between the piston and the inner wall of the energy accumulator cylinder barrel. Because the inertia of the piston is large, the sealing friction resistance exists, and the like, when the end face of the piston is just close to the end face of the lower end cover, the starting pressure is larger, particularly, the small-size energy accumulator is more obvious, the starting pressure and the sealing performance of the piston type energy accumulator are poor in action sensitivity in the using process, and the nitrogen end cannot keep the pressure. The technical problem of prolonging the service life and improving the sealing performance is solved. The sealing form of the piston to ensure the reliability of the sealing is the key to ensure the safe and reliable operation of the piston accumulator. The consequences of a seal failure can sometimes be quite severe.

The piston type energy accumulator mainly structurally comprises a cylinder barrel, a piston, a lower end cover, an upper end cover and a compression nut sealing piece, wherein the lower end cover is in threaded connection with the cylinder barrel, the upper end cover is compressed by the compression nut, the compression nut is in threaded connection, a hydraulic oil cavity and a nitrogen gas cavity are formed in a separated mode through the piston, and internal and external sealing is guaranteed by the sealing piece. When the hydraulic system works, the hydraulic pump injects high-pressure oil into the hydraulic oil cavity, the piston moves upwards and compresses nitrogen in the nitrogen cavity, when the set pressure, also called the highest working pressure, is reached, the hydraulic pump stops and is closed by the hydraulic valve for pressure maintaining, and at the moment, a certain amount of high-pressure oil is stored in the energy accumulator. In addition, when the end face of the piston is just in contact with the end face of the lower end cover, hydraulic oil cannot directly enter a cylinder barrel of the energy accumulator, the minimum starting pressure of the energy accumulator is increased greatly, and the larger starting pressure of the energy accumulator is caused by the fact that the oil inlet hole of the small-size energy accumulator is small in diameter and internal leakage. In the prior art, a piston sealing structure of a piston type energy accumulator generally adopts a 0-shaped sealing ring and a Yx-shaped sealing ring which are respectively provided with a Yx sealing ring at two ends and provided with double check rings in the middle, and although the dynamic and static sealing performance is better, the reciprocating motion speed is suitable to be 0.5m/s because of the limitation of the sealing element structure and the sealing element material. The piston (material LD10) directly contacts with the cylinder barrel, a Yx sealing ring near the nitrogen cavity end is always in a dry friction or semi-dry friction state, the friction resistance can be increased, the action sensitivity of the piston type energy accumulator is poor, in this case, the high-speed motion of the piston can generate high temperature, so that the sealing element has aging phenomenon, blackening, hardening and embrittling phenomena, the sealing element of the sealing element loses the sealing effect, the internal leakage naturally occurs, the sealing performance of the sealing element is influenced, the service life of the sealing element is shortened, and in addition, the size precision and the surface roughness of the inner surface processing of the cylinder barrel are improved; the size precision and the surface roughness of the piston sealing groove are processed; protection of the seals during installation and cleanliness of the hydraulic oil used, all of which affect internal leakage.

High-speed piston type energy accumulator of high-speed energy accumulator structure's piston velocity of motion is fast, leads to the piston to violently collide the end cover, and this is more common in high-power hydraulic system. The high-speed accumulator controls the pre-charging pressure of the accumulator through a high-pressure air source and a pressure reducing valve, a main valve is in a closed state in an initial state, the accumulator is firstly filled with liquid through an oil source, after the liquid filling is finished, the position of a valve core of a servo valve is switched, the main valve is opened, and the accumulator stores oil and enters a hydraulic cylinder through the main valve to realize the high-speed movement of a piston. The energy accumulator piston is divided into rotary sealing and reciprocating sealing according to the requirements of the energy accumulator piston on gas-liquid sealing, the buffering requirement and the existence of relative motion between piston sealing surfaces. When the sliding speed is low, the friction force of the piston rod during retraction is larger than that during extension, and a small amount of leakage oil can be brought back to the pressure cavity due to the shearing flow effect of the piston rod during retraction. The reciprocating sealing is the change of the sealing clearance generated by the deformation of the contact type sealing element and the cylinder sleeve. The required elasticity and wear resistance of the seal are difficult to achieve simultaneously in one part. The piston energy accumulator in the hydraulic sealing system can be mainly divided into three types of energy accumulators, namely gas, spring and heavy hammer. The most common of these three is the accumulator in a gas configuration. Among the gas-filled accumulators, piston accumulators and bladder accumulators are most widely used. The piston accumulator of the hydraulic sealing element system (the piston accumulator structure of the hydraulic sealing element system shown in figure 2) uses a piston in a cylinder barrel to isolate gas and oil, the piston can float in the cylinder barrel, the gas is filled into an accumulator air cavity through an inflation valve, and an accumulator oil cavity is connected with the system and is filled with pressure oil. The piston accumulator of such hydraulic seal systems may be affected by the inertia of the piston and the friction of the seal with the cylinder, and thus not react as sensitive. The cylinder barrel processing and piston sealing member requirements are high. The piston type energy accumulator mainly comprises a cylinder barrel, a piston in the cylinder barrel, three main body parts of end covers at two ends of the cylinder barrel, other sealing parts, a compression nut and other accessories. The closed end surface of the piston bears the pressure of the working fluid and forms a combustion chamber or compression volume with the cylinder cover and the cylinder wall. Piston rings or rubber seals are installed on the piston to prevent fluid leakage. The piston can be made of cast iron, forged steel, cast steel or aluminum alloy and the like. A baffle ring, a dirt baffle ring, a sealing ring, a shaft sleeve and a check ring are sequentially arranged in an inner cavity of the cover body of the oil cylinder; an O-shaped ring is arranged outside the outer end of the cylinder cover body of the oil cylinder; one side of the oil cylinder cover body is provided with an oil way connector; the oil cylinder cover is characterized in that a buffering sealing ring is arranged between the sealing ring and the shaft sleeve, a buffering cavity communicated with an oil duct connector is arranged on the outer side of the retaining ring, a throttle valve connecting hole communicated with the buffering cavity is arranged on the other side of the oil cylinder cover body, and a buffering oil way is arranged at the inner end of the throttle valve connecting hole. In the working process, the piston of the piston type energy accumulator is in a frequent movement process, the internal pressure at the piston is required to rapidly reach a system pressure value during oil storage, the internal sealing pressure of the piston is not too high during oil discharge, and the high pressure at the gas side acts on the sealing element to cause the inclination of the sealing element and destroy the sealing function. The accumulator piston seal arrangement shown in fig. 2 is in the form of a conventional seal arrangement which is sealed by two O-ring seals. Because the O-shaped sealing ring is made of rubber, the friction coefficient is high, heat generated by friction is large, the phenomenon of mechanical seal loss of elasticity is caused, the mechanical seal loss of elasticity is easy to wear, coke is possibly generated, the solid particles can scratch the sealing end face, the sealing can be failed, meanwhile, the O-shaped sealing ring is easy to twist off, and the service life of the piston type energy accumulator is also influenced.

When the accumulator is used as a large-flow oil output source, nitrogen with a certain pressure is pre-charged before working, the flow hydraulic pump outputs high-pressure oil to enter an oil cavity of the accumulator and push the piston to compress gas to store energy, and when the accumulator works, the gas expands and pushes the piston to move rapidly. And outputting large-flow oil. In the using process, a small amount of products have poor action sensitivity, the nitrogen end can not keep pressure, the upper end cover is disassembled to find that the nitrogen end has a small amount of hydraulic oil, and the products have two problems of 1) large starting pressure; 2) internal leakage occurs. After the breakdown inspection of the fault product, the following conditions are found, namely 1) the inner surface of the cylinder barrel is found to have a pull mark; 2) a tool mark caused by vibration during processing is found on the surface of a groove for mounting a sealing element on the piston; 3) when the end face of the piston is just close to the end face of the lower end cover, the starting pressure is larger, particularly, the small-size energy accumulator is more obvious, and the large-size energy accumulator is better; when the piston leaves the end face of the lower end cover, the starting pressure becomes normal; 4) the seal member becomes black, hard, brittle, etc. The reason for the large starting pressure is as follows: and under the condition that the nitrogen cavity is communicated with the atmosphere, hydraulic oil is introduced into the hydraulic oil cavity, the pressure of an overflow valve of the pressure test system is gradually increased from zero, and the pressure reflected by a pressure gauge when the piston is started is called as the lowest starting pressure. The piston sealing structure of the original piston type energy accumulator adopts a piston sealing structure that two ends are respectively provided with a Yx sealing ring and the middle is provided with an O-shaped ring with double check rings. The Yx sealing ring and the O-shaped ring have good dynamic and static sealing performance, but the suitable reciprocating speed is less than or equal to 0.5m/s because of the limitation of the sealing element structure and the sealing element material. The piston (material LD10) directly contacts with the cylinder barrel, a Yx sealing ring close to the nitrogen cavity end is always in a dry friction or semi-dry friction state, the friction resistance can be increased, the action sensitivity of the piston type energy accumulator is poor, in this case, the high-speed movement of the piston can generate high temperature, so that the sealing element is aged, the sealing performance of the sealing element is influenced, the service life of the sealing element is shortened, the phenomena of blackening, hardening and embrittlement of the sealing element are verified, the sealing element loses the sealing effect, and the internal leakage can naturally occur.

In the aircraft hydraulic control system, the compressibility of the sealing gas at the end of the air cavity of the energy accumulator is utilized to work, the functions of oil absorption and oil discharge are realized through the compression and expansion of the volume of the inflation cavity and the flexible expansion of the pressure, and the requirement on the sealing performance of the piston is higher. When the accumulator piston moves rapidly, the temperature of hydraulic oil rises rapidly, the extreme working temperature reaches 150 ℃ or even higher, and meanwhile, the accumulator sometimes has the working condition of working at the extreme low temperature of minus 55 ℃, so that the upper seal of the accumulator piston needs to be ensured to work normally in a large temperature range, and the increase of the dynamic tightness of two O-shaped seal rings on the currently adopted accumulator piston at the extreme low temperature working frequency is difficult to ensure, so that the dynamic tightness of the accumulator at the extreme low temperature and the extreme high temperature is ensured to be more important.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a sealing method of a piston type energy accumulator, which has the advantages of small friction force, more stable movement, superior dynamic sealing property and good wear resistance, so as to solve the problems of torsion of the sealing element, large piston starting friction force, poor dynamic sealing property and wear resistance in the piston sealing structure in the conventional piston type energy accumulator, and simultaneously avoid the problem of trapped pressure between the combined seal formed by an O-shaped ring and the sealing ring and a triangular seal.

The technical scheme adopted by the invention for solving the technical problem is as follows: a gas-liquid isolation sealing method for a piston type energy accumulator is characterized by comprising the following technical steps: according to a cylindrical piston, a compression nut and a sealing element which are assembled in a cylinder barrel and perform two-way motion, and end covers at two ends of the cylinder barrel, a piston type energy accumulator end cover and the cylinder barrel 1 which are connected by threads are adopted, three to four annular rectangular ring grooves are arranged on the excircle of the piston 2, wherein a guide ring 3 is assembled between a first rectangular ring groove and a fourth rectangular ring groove, an O-shaped sealing ring 6 is assembled on a second annular groove, a sealing ring 7 which is pressed on the O-shaped sealing ring 6 is assembled on the O-shaped sealing ring 6, a triangular sealing ring 4 is assembled on a third rectangular ring groove, and triangular protective rings 5 are arranged on two sides of the triangular sealing ring 4.

Compared with the prior art, the invention has the following gain effects:

the piston has small starting friction force, good dynamic sealing effect, torsion resistance of the sealing element and good wear resistance of the sealing ring. The invention adopts a triangular sealing structure between the front sealing defense line and the rear sealing defense line of the bidirectional moving piston, and the adopted triangular sealing ring has high contact stress with the cylinder barrel, small frictional resistance and good dynamic sealing performance. The triangular protection rings are arranged on two sides of the triangular sealing ring assembled through the second annular groove, so that the triangular sealing ring can be prevented from being twisted and extruded, and the problems that sealing elements of two O-shaped sealing rings of a piston in a conventional piston type energy accumulator are twisted and extruded, and the dynamic sealing performance of the two O-shaped sealing rings on the piston of the energy accumulator in the prior art is difficult to guarantee due to extreme working temperature are solved.

The movement is smoother. The guide rings 3 are arranged in the first ring groove and the fourth ring groove which are assembled in the directions of the front end and the rear end of the bidirectional movement piston bus to serve as a first gas sealing defense line between the gas cavity end and the liquid cavity end, the guide rings on the two sides of the piston are utilized to enable the piston to start and move more stably, the phenomenon that the piston moves unstably due to the fact that a gap between the piston and the cylinder barrel is too large is avoided, the friction force of the piston during starting is reduced, and the stability of the piston movement is improved.

The reliability is increased. The invention adopts the third ring groove to install the O-shaped sealing ring 6, and the O-shaped sealing ring 6 is assembled with the sealing ring 7 pressed on the O-shaped sealing ring 6. The seal ring and the O-shaped ring which are sealed in a one-way mode form a combined seal to serve as liquid cavity end sealing oil, the energy accumulator is in direct contact with a cylinder body through the seal ring 7 during working, the abrasion resistance and the reliability of a sealing piece are improved, friction force is reduced, the O-shaped seal ring 6 is concentrated on a dynamic sealing surface, the liquid film erasing performance is good, the friction coefficient is small, the requirement of piston sealing in the gas-liquid energy accumulator is well met, the problem that the sealing piece is inclined and the sealing function is damaged due to the fact that high pressure on the side of the liquid cavity acts on the sealing piece is solved.

The invention adopts double-layer sealing of the guide ring, the triangular sealing ring and the sealing ring 7 pressed on the one-way sealing O-shaped sealing ring 6 in sequence, has good air tightness and no leakage, effectively ensures the sealing performance of the piston and the cylinder barrel, and solves the problem of large starting pressure when the end face of the piston just contacts with the end face of the lower end cover. The air pressure of the four-sealing wire-proof oil groove forms an oil seal capable of preventing nitrogen in a nitrogen cavity from leaking to a hydraulic system, the triangular sealing ring is provided with triangular protection ring structures on two sides, the piston can be subjected to the damping action of the buffering action before reaching the lower end cover, the piston can be prevented from being impacted, in addition, the guide rings are arranged in the first annular groove and the fourth annular groove which are assembled in the front end direction and the rear end direction of the piston, the piston can be prevented from being directly contacted with the cylinder barrel, the bearing capacity is high, the friction force is small, the wear resistance is good, and the service life is long. If lubricating oil is filled in the oil grooves of the two sealing rings, not only friction resistance is small, static sealing performance is good, but also the lubricating oil can be prevented from creeping, the nitrogen in the nitrogen cavity can be isolated from the hydraulic oil cavity, the inner surface of the nitrogen cavity can be lubricated, the gas-end sealing ring is prevented from being in a dry friction or semi-dry friction state, and the action sensitivity of the piston type energy accumulator is improved. Because the special structure of the one-way sealing ring has the function of 'pumping back', a high-pressure area is prevented from being formed between the sealing elements, and the problem of pressure trapping between the triangular sealing ring and the combined sealing element can be effectively solved. Compared with the prior art, the starting pressure is further reduced by providing three to four annular rectangular groove sealing structures, the action sensitivity of the piston type energy accumulator is improved, the service life of the sealing ring is prolonged, and the requirement on the instantaneous rapid movement speed of the piston in the energy accumulator can be met. Test results prove that the piston sealing structure and the whole structure are reasonable in design, the action sensitivity of the piston type energy accumulator can be improved, and the designed piston type energy accumulator can well meet the actual use requirements.

Drawings

FIG. 1 is a schematic view, partially in section, of a gas-liquid isolation seal of a piston accumulator according to the present invention.

Fig. 2 is a schematic view of a conventional piston sealing structure.

In the figure: 1 cylinder, 2 pistons, 3 guide rings, 4 triangular sealing rings, 5 triangular protective rings, 6O-shaped sealing rings and 7 sealing rings.

The invention is further illustrated by the following figures and examples.

Detailed Description

See fig. 1. According to the invention, according to a cylindrical piston, a gland nut and a sealing element which are assembled in a cylinder barrel and perform bidirectional movement, and end covers at two ends of the cylinder barrel, a piston type energy accumulator end cover and the cylinder barrel 1 which are connected by threads are adopted, three to four annular rectangular ring grooves are arranged on the excircle of the piston 2, wherein, a guide ring 3 is assembled between the first rectangular ring groove and the fourth rectangular ring groove, an O-shaped sealing ring 6 is assembled on the second ring groove, a sealing ring 7 which is pressed on the O-shaped sealing ring 6 is assembled on the O-shaped sealing ring 6, a triangular sealing ring 4 is assembled on the third rectangular ring groove, and triangular protective rings 5 are arranged at two sides of the triangular sealing ring 4.

In a preferred embodiment described below, a piston accumulator gas-liquid isolation sealing method includes: the assembly carries out cylinder piston, gland nut and the sealing member of two-way motion in the cylinder to and the end cover at cylinder both ends, piston accumulator end cover and cylinder adopt threaded connection, wherein: be provided with three to four annular rectangle annular on piston 2's the excircle, first rectangle annular is equipped with guide ring 3 with fourth rectangle annular, and second annular assembles O type sealing washer 6 to be equipped with the sealing ring 7 of pressure on O type sealing washer 6, third rectangle annular is equipped with triangle-shaped sealing washer 4, the both sides of triangle-shaped sealing washer 4 are equipped with triangle-shaped guard circle 5.

Further, the guide rings 3 are installed on the first ring groove and the fourth ring groove, and the support guide rings are used for preventing the phenomenon that the piston moves unstably due to overlarge clearance between the piston and the cylinder.

Further, O type sealing washer 6 is installed to the second annular to be equipped with one-way sealed sealing ring 7 on O type sealing ring, wherein O type circle is as the force application component of sealing ring, provide sufficient sealing force, sealing ring 7 is the step trapezium structure, trapezoidal seal edge has precipitous contact stress gradient at the high pressure side, the trapezoidal seal edge of low pressure side has mild contact pressure gradient, guarantee that the oil film attached to on the cylinder barrel returns the liquid chamber at the piston to the liquid chamber removal in-process, prevent that the piston from taking out the interior surface trace oil reservoir of liquid intracavity barrel to reveal in the motion process, can also avoid trapping pressure problem between the combination seal that O type circle and sealing ring formed and the triangle-shaped seal simultaneously.

Furthermore, a triangular sealing ring 4 is arranged on the third ring groove, triangular protecting rings 5 are arranged on the two side waists of the triangular sealing ring 4, the triangular sealing ring 4 is used for sealing the gas in the gas cavity, and the triangular protecting rings 5 are arranged on the two sides of the triangular sealing ring to prevent the triangular sealing ring from turning over and extruding. When the triangular sealing ring is designed, a proper rubber material is selected according to the high-low temperature environment used by the energy accumulator, the triangular sealing ring is designed according to the compression rate of 12% -18%, the sealing belt of the triangular sealing ring and the cylinder barrel is narrow after installation, but the contact stress between the triangular sealing ring and the cylinder barrel is high, and the dynamic sealing performance is better.

The working principle of the piston type energy accumulator is as follows: the piston separates the cylinder body into a gas distribution cavity and a liquid cavity, and inert gas with certain pressure is filled into the gas cavity in advance when the piston is used. When the accumulator is charged, the oil hydraulic pressure acts on the end face of the piston to push the piston to compress gas, so that the volume of the oil cavity is increased, and the volume of the air cavity is reduced, thereby storing oil and improving the pressure of the air cavity. The upper part of the piston is compressed gas, the lower part of the piston is pressure oil, the pressure oil enters from an oil inlet at the lower part of the piston to push the piston, and the gas in the upper cavity of the piston is compressed to store energy; when the pressure of the system is lower than the pressure in the accumulator, the gas pushes the piston to release pressure oil, when the pressure accumulator releases the pressure, the gas pressure acts on the end face of the piston, the gas expands to push the piston to move, and therefore the pressure of the gas cavity is reduced while the oil is discharged.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A gas-liquid isolation sealing method for a piston type energy accumulator is characterized by comprising the following technical steps: according to the cylinder piston, gland nut and the sealing member that assemble and carry out two-way motion in the cylinder to and the end cover at cylinder both ends, adopt threaded connection's piston energy storage ware end cover and cylinder (1), set up three to four annular rectangle annular on the excircle of piston (2), wherein, first rectangle annular and fourth rectangle annular assemble guide ring (3), second annular assembly O type sealing washer (6), and assemble sealing ring (7) of pressing on O type sealing washer (6), third rectangle annular assembly triangle-shaped sealing washer (4), and triangle-shaped guard circle (5) are established to the both sides of triangle-shaped sealing washer (4).

2. The piston accumulator gas-liquid isolation sealing method of claim 1, wherein: the guide rings (3) are arranged on the first ring groove and the fourth ring groove, and the support guide rings are used for preventing the phenomenon that the piston moves unstably due to overlarge clearance between the piston and the cylinder.

3. The piston accumulator gas-liquid isolation sealing method of claim 1, wherein: sealing ring (7) are step trapezium structure, trapezoidal seal edge has precipitous contact stress gradient at the high pressure side, the trapezoidal seal edge of low pressure side has mild contact pressure gradient, guarantee that the oil film attached to on the cylinder barrel moves the in-process to the sap cavity at the piston, prevent that the piston from taking out revealing of the interior surface trace oil reservoir of liquid intracavity barrel in the motion process, O type sealing washer (6) and the seal structure of one-way sealing ring (7) constitution can avoid and the triangle-shaped sealing washer between the trapped pressure.

4. The piston accumulator gas-liquid isolation sealing method of claim 1, wherein: the triangular sealing ring (4) is used for sealing the gas in the gas cavity, and the triangular protecting rings (5) arranged on the two sides of the triangular sealing ring prevent the triangular sealing ring from turning over and extruding.

5. The piston accumulator gas-liquid isolation sealing method of claim 1, wherein: the triangular sealing ring (5) is made of rubber materials according to the high-temperature and low-temperature environment used by the energy accumulator, and is designed according to the compression rate of 12% -18%.