WO2014088277A1

WO2014088277A1 - Elastic structure having variable piston made from soft sealing film

Info

Publication number: WO2014088277A1
Application number: PCT/KR2013/011070
Authority: WO
Inventors: 이재성
Original assignee: Lee Jae-Sung
Priority date: 2012-12-06
Filing date: 2013-12-02
Publication date: 2014-06-12
Also published as: KR101226285B1

Abstract

The present invention relates to an elastic structure using a phenomenon in which a soft sealing film moves reciprocally inside a container while having a variable form, like a piston inside a cylinder, as the soft sealing film comes into close contact with or separates from a pressure container. The present invention basically comprises: the pressure container which functions as a cylinder, and a variable piston having a form in which the soft sealing film is adhered near an opening, wherein the pressure in a first pressure space (A) defined by the sealing film and the pressure container is set to be different from an n^th pressure space (N) on the outside, so that the sealing film separates from being in close contact with an inner surface of the pressure container when pulled to move the variable piston (20). As a result, the pressure container, which can have a variety of shapes and sizes compared to a conventional cylinder having a cylindrical shape, can be used as the cylinder, and the distance and speed of form change can be simultaneously increased during a process of compressing and stretching the soft sealing film through repeated contact and separation, thereby exhibiting a wide range and a high speed of movement that cannot be enabled by a conventional piston.

Description

Elastic structure with variable piston with soft sealing membrane

The present invention is a technology that together with the pneumatic spring or pneumatic damper using the cylinder and the piston and its application field, the soft sealing membrane is in close contact with or peeled from the inner surface of the pressure vessel by the pressure difference inside and outside the pressure vessel in a variable form like a piston in the cylinder An elastic structure using the phenomenon of reciprocating inside the container.

Apparatus for converting the pressure of the fluid into mechanical forces and movements are conventional combinations of cylinders and pistons (eg actuators). There is also a diaphragm drive device as an elastic membrane type piston used for mechanical motion.

Pneumatic dampers using weak fluid pressure may be used for shock absorbers, etc. of bicycles. Hydraulic actuators using strong fluid pressure can also be used for joint driving of excavators and robots. If a high airtight level is not required or only a relatively short driving width is required, a diaphragm driving device using a bellows using a rubber tube or a short deformation of an elastic membrane may be used. The diaphragm drive device is particularly useful when a pressure-driven fluid such as a vacuum booster of an automobile brake or a flush valve of a toilet may dissipate to the outside of the drive system after performing its role.

On the other hand, an elastic body that is the object of the present invention, and typically a reciprocating elastic body such as a coil spring, can be made by appropriately applying a pneumatic damper or a diaphragm driving device among the above three devices. For example, if the piston of the pneumatic damper is composed of a hermetic seal, or if the bellows of the diaphragm is composed of a hermetic seal, an elastic body capable of elastic resistance against external force and having an appropriate elastic stroke is realized.

However, in the above-mentioned background, a structure in which a variable piston made of a flexible membrane, such as the present invention, adheres or peels directly in a pressure vessel and performs a role of a piston rod, is difficult to find.

The prior art document introduced below is not directly related to the unique and unique configuration of the present invention, but only relates to the pneumatic piston and the hermetic diaphragm of the elastic body type introduced to aid the understanding of the present invention.

(Patent Document 1) Korea Registered Patent 10-0527732 Pneumatic Suspension Device

(Patent Document 2) Korean Registered Patent 10-0844596 Diaphragm Compressor

(Patent Document 3) Actuator structure of Korea Patent Registration 10-1177269 Engine Turbocharger

Hydraulic pneumatic structures, which follow the conventional sliding methods of conventional springs or cylinders and pistons, including the prior art literature, have a disadvantage in that the elastic force or the range of elastic movement that occur in comparison with the total weight and volume of the structure are generally small. have.

For example, referring to a conventional vehicle air suspension shock absorber as shown in Document (1), most of the elastic bearing force is burdened by a heavy metal coil spring, and the pneumatic piston only generates a remarkably small elastic resistance to its volume and weight. At this time, the coil spring made of metal also has sufficient elastic force, but its elastic motion range is extremely small.

This is not an exception in the literature (2), where the elastic membrane acting as the piston of the compressor is considered to be the overall size of the equipment, considering the volume and weight of all the accessories surrounding it and the usual elastic membrane deformation limits. It has a small compression capacity that is significantly less than.

Similarly, the actuator of document (3) also produces only a reciprocating stroke (elastic drive range) of extremely small magnitude relative to the supply pressure required for driving, similarly to document (1).

As such, regardless of the object of the elastic body, which is the center of elasticity, not only the solid deformation but also the fluid deformation, conventional elastic bodies have to be accompanied by excessively large volume and heavy weight in order to satisfy a desired amount of work or a desired elastic displacement. There was no.

The present invention is to implement an innovative elastic structure and an elastic drive device using the same, which overcomes the limitations of the prior art as above, specifically, having a light weight and a wide range of elastic movement, and combining the two at the same time, a high speed elastic movement speed. To implement innovative elastic mechanism to implement.

The elastic structure 30 of the present invention for achieving the above technical goal is the pressure vessel 10 that serves as a cylinder first and the flexible piston membrane of the flexible sealing membrane type bonded to it as the core configuration.

The main difference between the present invention and the conventional diaphragm is that the diaphragm has to withstand all pressures by the elastic membrane itself, while the inelastic sealing membrane of the present invention has a force that expands laterally outside the direction of movement of the piston. It is supported.

Therefore, it can be used as a variable piston 20 by rolling a thin, wide and elongated hermetic membrane incomparable with the diaphragm, which can be combined with various types of pressure vessels 10 to withstand a high pressure difference which cannot be compared with the diaphragm, and also Long strokes are incomparable. This is the key feature that the present invention is different from all conventional elastic membrane type driving bodies.

The pressure vessel 10, which is one of the main components of the present invention, is, for example, when the inside is in a vacuum state, because it is easily bent and wrinkled due to slight deformation due to partial force due to atmospheric pressure. It is more durable to make thicker materials with a smaller specific gravity rather than to make them thicker (high Young's modulus), and it is more durable in the molding method and strength. Importantly, materials with very high Young's modulus, such as beryllium, may be adopted. Exceptionally, when intentional plastic deformation of a disposable product (such as a lifesaving mat) or a pressure vessel is required, the pressure vessel 10 of the present invention can be made thinner and lighter with synthetic resin. Breakage of the pressure vessel or complete permanent deformation will make it difficult to recover the elasticity of the sealing membrane, but in the process it can produce a wider range of elastic movements only once, and it is very necessary when intentionally suppressing the repulsive action of the elastic body. This is useful.

On the other hand, a component that is considered more important than the pressure vessel is a flexible sealing membrane that constitutes virtually all of the variable piston 20. Sealing membranes are thin and flexible, so it is basically required to be well crimped or straightened and also to ensure almost complete airtightness. In other words, the strength and airtightness should be sufficiently maintained even if the operation process of closely adhering to the inner wall of the pressure vessel and peeling it is repeated.

Although there is no theoretically perfect inelastic material, the material of the sealing film in the present invention needs to be designed with sufficient strength so that the elastic displacement in the tensile direction of the elastic structure 30 is substantially close to zero within a given load range according to the use of the product. There is. In other words, the true elastic displacement in the present invention refers to the change in volume caused by expansion and compression of the pressure fluid (even if it is a vacuum or a fluid having a pressure close to vacuum), that is, the fluid pressure difference of the pressure fluids. The movement of the encapsulation membrane seems to occur as an elastic displacement, but does not mean that the encapsulation membrane is stretched by itself.

Therefore, the sealing membrane is formed by arranging a plurality of first synthetic fibers 21 in the tensile direction so as to have a width and strength that are not substantially elastically deformed in the tensile direction, that is, the piston movement direction.

Here, the type of the first synthetic fiber 21 may be a high-strength fiber called a reinforcing polymer fiber or a super fiber that is in the spotlight recently. Typical high-strength fibers include aramid fibers used for tire cords and body armor, and carbon fibers having a weight of only 10% but 10 times stronger than steel may be used.

In addition, low specific gravity and excellent wear resistance, polymer polyethylene fiber used as a rope or fishing line, polyarylate fiber called Vectran, or PBO fiber called Zylon can be sufficiently applied according to the use and grade of elastic structure. These high-strength fibers are relatively small, for example, in the pressure vessel in the elastic structure according to the present invention, the pressure cross-sectional area in the pressure vessel is 100 cm2 to 1000 cm2, and the pressure difference between the inner and the outer is only a few strands to several ten strands when applied to a typical embodiment using simple vacuum pressure. In fact, it is possible to secure sufficient strength so that the elastic deformation amount is close to zero. Therefore, even thinner, high-strength fibers can be evenly spread to form a closed membrane that can be made thin and have a very strong sealing membrane in the tensile direction while folding well in the circumferential direction of the pressure vessel.

For example, suppose that the Vectran fiber is evenly stretched to one thickness to make an elastic structure with a pressure area of 100 cm2, and the actual maximum pressure and elastic deformation are calculated.

Vectran has a specific gravity of 1.4 g / cm 3 and one den of 5 denier, so the diameter of one of the balls is 0.0224 mm. The maximum tension of the vectran is 25 gf / denier, so the maximum tension of each roll is 125 gf. The inner diameter of a cylinder with a cross-section of 100cm2 is 11.28cm and the circumference is 35.45cm, so it takes 15,826ol when arranged in one layer.

The maximum tension of the sealed membrane, consisting of 15,826 Vectran fibers, reaches 1.98 ton, so the maximum pressure that can be applied in the cylinder is 3.88 MPa, which is equivalent to 38.3 atmospheres.

The elastic strain at this time is 3.8% (3.8% longer than the original fiber length), so if 0.1 MPa is applied, the elastic strain is 0.098%, which is almost zero.

For the Vectran fiber, the amount of creep is not measured when it is continuously pulled for more than one year within 50% of the maximum tension, and when used at 2.6% of the maximum tension as described above, it may sag even after decades of use. creep) does not occur.

Meanwhile, the sealing membrane additionally needs to be configured such that the second synthetic fibers 22 are arranged perpendicularly or obliquely to the direction in which the first synthetic fibers 21 are arranged. In this case, the second synthetic fibers 22 are required in the direction in which the second synthetic fibers are arranged. It is necessary to set so as to be elastically deformable. In this case, unlike the first synthetic fiber 21, the second synthetic fiber 22 is preferably a fiber having easy airtightness and flexibility rather than strength. If the sealing membrane is designed with a fiber material which does not elastically deform in the direction in which the second synthetic fibers are arranged or in the circumferential direction of the pressure vessel, the circumferential length of the sealing membrane needs to be set to the longest circumferential length in the circumferential direction of the pressure vessel.

The binding of the first synthetic fiber and the second synthetic fiber, which determines the airtightness and abrasion resistance of the sealing membrane, is suitable for general composite resins for bonding composite materials and has excellent ductility at most temperature ranges such as polymer resins for binding tire cords. It should maintain low friction properties, cracks should not occur in numerous repeated use, and it should be excellent in heat resistance and corrosion resistance because it can be exposed to various usage environments.

According to the present invention, pressure vessels having various shapes and a wide range of sizes having extremely superior degrees of freedom compared to conventional cylindrical cylinders can be used as a cylinder. Therefore, it greatly improves the freedom of design and the performance of the design in all applied technical fields regardless of vehicle, ship, aircraft, etc.

In addition, in the present invention, the closed membrane variable piston serving as the driving body is initially in close contact with the inner surface (mainly the inner circumferential surface or the inner surface) of the pressure vessel and moves while being peeled and deformed, thereby participating in the piston movement to the portion that is substantially folded and unfolded. Therefore, in most environments, it has a wide range of motion that is at least 1.5 times larger than the range of conventional piston movements. Due to the light, thin, and flexible sealing membrane, the ultra-high speed of movement that can not be followed by the conventional piston is achieved with strong tensile force. There is.

In addition, the present invention has the advantage that the piston rod is not necessarily arranged on the central axis line of the container because the sealing membrane that is freely deformed performs the same role as the piston rod. This can be laminated with a plurality of sealing membranes in one pressure vessel has an effect that is very useful to implement a multi-joint movement, such as the finger joints of the humanoid robot.

1 is a perspective view and a cross-sectional view showing a basic embodiment of the present invention

2 is a perspective view of a preferred embodiment of the present invention;

Figure 3 is a cross-sectional view showing an elastic mechanism of the embodiment of the present invention

4 is an embodiment using the present invention as a vehicle coil spring

5 is an embodiment using the present invention in the form of a flat elastic membrane

10: pressure vessel 11: opening

12: pressure increase space 13: protrusion space

14: valve 15: pressure gauge

20: variable piston 21: first synthetic fiber

22: second synthetic fiber 23: pressure outflow pipe

30: elastic structure

A: first pressure space (B = 2, C = 3, D = 4, ..)

N: nth pressure space

With reference to the embodiment of the present invention included in the drawings in order to technically support the above-described solution of the present invention will be described in detail.

However, the components represented by the specific terminology in the following embodiments and their coupling structures do not limit the technical spirit inherent in the present invention.

Figure 1 is an embodiment shown in the most simple and basic cylindrical form to determine the principle of operation and elastic capacity of the present invention elastic structure.

Looking at the embodiment of the elastic structure 30 shown in Figure 1a one end has an opening 11 and a variable piston 20 made of a soft sealing membrane in the pressure vessel 10 acting as a cylinder is the opening 11 It can be seen that the elastic structure 30 in the form of a typical cylindrical cylinder is joined to a position close to the.

Referring to the cross section shown in FIG. 1B, the operating structure of the FIG. 1 embodiment is well understood. The variable piston 20 is formed such that at least a portion of the sealing membrane is in close contact with the inner surface of the pressure vessel 10, and the sealing membrane is at least partially at the inner surface of the pressure vessel when the sealing membrane is pulled with the outer direction of the pressure vessel as the tensile direction. It is characterized by moving the variable piston 20 as a result of being peeled off in close contact with the.

* At this time, the part of the peeled sealing film acts like a piston rod, and the part where the sealed film is peeled off (the length of the cylinder) and the peeled sealing film are based on the simple cylindrical pressure vessel of FIG. Together with the rod-like extension (extended piston length), an elastic displacement of about twice the size of a conventional piston is obtained.

On the other hand, the sealing film is formed in a width and strength that is not elastically deformed in the tensile direction, a plurality of first synthetic fibers 21 are arranged in the tensile direction and the direction in which the first synthetic fibers 21 are arranged The second synthetic fibers 22 are arranged vertically or obliquely.

As described above, the first synthetic fiber 21 is set at a very high strength so that the sealing film does not stretch itself when pulled out, and is perpendicular to the direction in which the first synthetic fiber 21 is arranged, that is, the pressure. The second synthetic fiber 22 arranged in the circumferential direction of the container is made of a flexible material in order to be smoothly re-adhered to the inner surface of the pressure vessel at the time of return in consideration of the relatively small force is applied.

For reference, the second synthetic fiber needs to be made of a flexible material, but it does not necessarily need to be elastically deformable, and it does not matter even if it is made of a material that is not elastically deformable. The important thing is to be fast, perfect and re-adherent to the inner surface of the pressure vessel without being folded when re-adhesion after peeling. If it is made of inelastic material, if the circumference or diameter of the inner surface of the pressure vessel is changed, it is designed according to the largest perimeter or diameter It needs to be designed to fit the circumference or diameter of each corresponding point. If the pressure vessel has a large variation in cross-sectional area or circumference over the longitudinal direction, the sealing membrane uniformly formed in accordance with the largest circumference length will have many folded portions when in close contact. Therefore, it may be configured to be elastically deformable in the second synthetic fiber arrangement direction only in the portion where such a design is required.

This part can be sufficiently solved by the super fibers mentioned in the above-mentioned problem solving means, and the synthetic resin binding the fiber array can also be sufficiently solved by the special polymer resin.

For reference, the embodiment of FIG. 1 is the same as the elastic membrane spring of the vacuum method without any pressure fluid outflow. At this time, the first pressure space (A) is set to a pressure different from that of the n-th pressure space (N) which is its external space, that is, the vacuum (A) and the atmospheric pressure (N), respectively.

The vacuum is easily generated by simply pulling the variable piston 20 as long as the sealing structure of the first pressure space A is well made. A typical piston cross-sectional area, for example, the installation cross-sectional area of a coil spring and a cylindrical damper for a passenger car is 500 cm 2 or less and is manufactured to bear a weight in the range of 500 kg to 1000 kg. If the cross-sectional area 500 cm 2 of the cylindrical pressure vessel 10 is set in the elastic structure 30 of FIG. 1, even when only a simple vacuum is used, an elastic force of 250 kg is generated, which exceeds half of the atmospheric pressure 500 kg acting on the cross-sectional area. This is a case where the average atmospheric pressure is converted to approximately 1 kgf per 1 cm 2.) Therefore, the weight of the two pressure vessels 10 may be reduced when the weight of the variable piston 20 is closed. If it can be made smaller than the weight of the vehicle coil spring, even in the extremely simple embodiment as shown in FIG. 1 can exhibit a strong elastic force, such as a vehicle coil spring. In addition, the lightweight sealing membrane also has the advantage of greatly reducing the inertial mass of the elastic moving part.

2 is an expanded embodiment of the present invention further combined with additional configurations for more practical applications. Most of the main features of the present invention are inherent.

Referring to the perspective view shown in Fig. 2a, the pressure vessel 10 has a protruding space 13 at the top of the container in an elongated rectangular cross section with rounded corners, and a pressure increasing space in which the cross-sectional area gradually increases in the middle ( 12) have more.

In the vicinity of the opening 11, another pressure increasing space 12 is formed in which the pressure action area temporarily increases. In addition, the inner surface of the pressure vessel 10 is formed smoothly without angled corners, and the other end of the pressure vessel 11 opposite to the opening 11 has a valve 14 for adjusting pressure and a protruding space for adjusting an initial pressure state. (13) may be further formed.

Meanwhile, the pressure vessel 10 may further include a pressure outlet tube 23 through which the pressure fluid flows in and out of the space formed by the sealing membrane and the pressure vessel.

The protruding space 13 can be usefully used to create an initial vacuum state by, for example, depressurizing the pressure inlet and outlet pipe 23. The pressure indicator 15 provided in the protruding space makes it easy to see how closely the inner sealing membrane is in close contact. Once the initial setting of the pressure flow in and out through the valve 14 is completed, the valve 14 can be locked and used as an independent elastic structure. As the volume of the protruding space increases, the elastic structure can be easily coped with as the volume of the sealing membrane increases due to repeated use. Increases the service life of.

Referring to the cross-sectional view of Figure 2b the specific shape and technical role of each site is better understood.

Although not illustrated in the drawings, two or more sealing films may be stacked and disposed as necessary. That is, in the drawing, the closed space formed by the variable piston 20 and the pressure vessel 10 is represented by the first pressure space A and the outside space of the pressure vessel is represented by the nth pressure space N, When the pressure space is extended to the first pressure space (A), the second pressure space (B), the third pressure space (C) and the like, the outermost space may be defined as the n th pressure space (N).

If the developed embodiment is conceptually defined, the pressure vessel 10 means that the pressure action area of the pressure received from the first pressure space or the nth pressure space is changed according to the displacement direction of the variable piston 20. The projection area projecting the pressure action area in the displacement direction may be circular (or isotropic regular polygonal) shape as in FIG. 1 or elliptical (or elongated polygonal) shape as in FIG. 3.

The pressure increasing space 12 formed near the opening temporarily increases the elastic force near the distal end of the elastic movement displacement in order to prevent the junction of the sealing membrane from being broken by the shocking high load. This sudden pressure increase space 12 can be applied not only to prevent breakage of the joint but also to change the elastic modulus with various cross-sectional changes over the beginning and end of the pressure vessel. That is, in the conventional coil spring, a very simple change in elastic force is obtained, but the present invention obtains a change in elastic force according to the working area of the pressure fluid, and thus intentionally pressurizes the pressure increase space 12 in the initial pressure vessel 10 design. If designed to change the area can be obtained a variety of elastic force in accordance with the displacement of the variable piston (20).

FIG. 3 shows stepwise half of an elastic process in which the tensile force is applied to the variable piston in the embodiment shown in FIG. 2. Of course, when the tensile force is released, the soft sealing membrane which has been peeled off will again stick to the inner surface of the pressure vessel and the variable piston will return to the pressure vessel.

Referring to Figure 3 it can be seen that the pressure vessel 10 can be freely set the pressure action area in the form of a combination of a rectangle and an ellipse, and the pressure increase space 12 also increases the pressure action area monotonically (elastic resistance) There is a monotonically increasing section and a safety section that prevents bursting of the sealing membrane, breakage of the pressure vessel, or breakage of the coupling site by increasing the pressure operating area relatively suddenly.

On the other hand, when the length of the part in close contact with the container is L1, the distance that the variable piston moves can be seen that at least three times greater than L1 considering the peeling part of the sealing membrane. Theoretically, three times is generated in an extremely long and thin uniform cylindrical pressure vessel, and in the case of FIGS. 2 and 3, the cross section of the pressure vessel is increasing, so the moving distance of the variable piston will be slightly more than three times.

FIG. 4 is an example of using the configuration of the present invention according to the basic design method of FIG. 2 as an alternative to a coil spring for a vehicle, and FIG. 5 is an example used for a flat elastic membrane, for example, a lifesaving mat.

Referring to FIG. 4 in terms of the vacuum working area and the elastic working distance under atmospheric pressure, it can be seen that sufficient elastic force and elastic stroke are obtained in a compact installation space. The disadvantage that the proper shielding design with the road surface should be introduced to prevent the unexpected damage of the sealing membrane is that the shape and size of the pressure vessel and the space for the placement can be freed, as well as the total inertia of the elastic motion part due to the light inertial mass of the sealing membrane. This is offset by the advantages of mass reduction.

5 shows that it is possible to expand and arrange the elastic structure of the present invention in various forms. The frame and the elastic structure 30 can be stored separately when not in use, and can be fully equipped with the initial elastic force by immediately taking out the air to the pressure outflow pipe 23 by assembling urgently in use.

As inferred from the cross-sectional view of FIG. 5B, the embodiment of the plate-type elastic membrane is light, capable of high-speed movement, and can be sufficiently buffered by an elastic stroke sufficiently secured even by a highly secured object by a sealing membrane that can be significantly increased structurally. Able to know.

Meanwhile, as shown in FIG. 5B, the pressure vessel 10 of the present invention has a feature close to a rigid body in the allowable pressure range set according to the intended use, and may be elastic or plastic deformation when a pressure outside the allowable pressure range is applied. That is, in the one-time use where weight reduction and low price are important, not only the pressure vessel 10 but also the variable piston 20 made of a closed membrane do not necessarily need to be repeatedly elastically returned to the airtight state. This is also very useful to meet the requirement that bounce should not occur in life-saving mats, etc., and it is a function that can never be realized by an elastic body using a solid elastic deformation.

Meanwhile, in FIG. 5, the pressure vessel 10 is configured such that plastic deformation does not occur and is disposed in a circular shape, and then, when each sealing membrane is connected to the edge of a wide circular mat, a trampoline is widely used for exercise and leisure purposes. Can be. The trampoline thus made has a much lighter weight and superior elasticity than the conventional one in which a plurality of coil springs are arranged around.

While the embodiments of the present invention have been described in detail with reference to the drawings, the technical spirit of the present invention is not limited to the above embodiments.

In other words, one of ordinary skill in the art to which the present invention pertains may utilize a technical idea implied by the present invention to implement a simple change or simple extension case, which is not included in the specification and drawings as necessary. It is also clearly included in the scope of the technical idea of the present invention expressed by the following claims.

The present invention can be applied to various elastic bodies by modifying the shape and size of the pressure vessel.

Typically, it can replace the coil spring of automobile, and it can be used as a hanger of electronic equipment or surgical instruments that are suspended from the ceiling, and can be used as a lightest trampoline or a lifesaving mat that can be folded and carried.

In addition, the high-speed motion performance of the present invention can be very useful as the firing power of all kinds of low noise projectiles, including bows and catapults.

Finally, although not claimed as a right in the present invention, when the actuator is applied by applying the elastic structure of the present invention, it is very suitable as a flat object, for example, a flap driving or airfoil conversion device of a light aircraft, and has a narrow design space and a relatively large size. It can be used as a joint drive for human body implantable artificial muscles or humanoid robots that require force and require highly complex multi-stage movements. In addition, when the intake valve and the discharge valve is installed in the pressure vessel (cylinder) of the actuator while driving the closed membrane by external power can be used as a vacuum pump.

Claims

A pressure vessel 10 having an opening 11 at one end and serving as a cylinder; and

And a variable piston 20 made of at least one soft sealing film and bonded to a position close to the opening 11.

The first pressure space A, which is a closed space formed by the variable piston 20 and the pressure vessel 10, is set to a different pressure from the nth pressure space N, which is an external space thereof.

The variable piston 20 is formed such that at least a part of the sealing membrane is in close contact with the inner surface of the pressure vessel 10,

In addition, the sealing membrane is an elastic structure, characterized in that when moving the variable piston (20) while at least part is peeled in close contact with the inner surface of the pressure vessel when pulled in the direction of the outer direction of the pressure vessel ( 30).
The method of claim 1,

The sealing film is an elastic structure 30, characterized in that formed in a width and strength that is not elastically deformed in the tensile direction.
The method of claim 2,

The sealing membrane is an elastic structure (30) is composed of a plurality of first synthetic fibers 21 are arranged in the tensile direction.
The method of claim 3,

The sealing membrane is an elastic structure (30) characterized in that the elastic or inelastic second synthetic fibers 22 are arranged perpendicularly or obliquely to the direction in which the first synthetic fibers (21) are arranged.
The method of claim 4, wherein

The pressure vessel (10) is an elastic structure (30) formed to change the pressure action area of the pressure received from the first pressure space or the n-th pressure space in accordance with the displacement direction of the variable piston (20).
The method of claim 5,

And a projection area projecting the pressure action area in the displacement direction is formed in a circular or ellipse or regular polygon or elongated polygon.
The method of claim 6,

The pressure vessel (10) is an elastic structure (30) further comprises a pressure outflow pipe (23) for the flow in and out of the pressure fluid in the space formed by the sealing membrane and the pressure vessel.
The method of claim 7, wherein

The elastic structure (30) is further formed in the vicinity of the opening 11, the pressure increasing space 12 which temporarily increases the pressure action area.
The method of claim 8,

The inner surface of the pressure vessel 10 is formed smoothly without angled edges, and the other end of the pressure vessel 11 opposite to the opening 11 protrudes for the valve 14 and the pressure state indicator 15 for pressure control. An elastic structure 30 in which a space 13 is further formed.
The method of claim 9,

The pressure vessel 10 has a specific close to the rigid body in the allowable pressure range set according to the intended use and elastic or plastic deformation when the pressure outside the allowable pressure range is applied to the elastic structure 30.