A force-transmitting capsule capable of achieving ultra-high hydraulic loading

Abstract

The present invention discloses a force-transmitting capsule capable of achieving ultra-high hydraulic loading, including a capsule body, and the capsule body is provided with an inturned skirt interface. The present invention can not only achieve self-tightening sealing of the capsule body, but also has a better sealing effect as the loading pressure increases; in particular, the present invention can meet the loading requirements of ultra-high hydraulic pressure up to dozens of megapascals or even hundreds of megapascals, cleverly solving the problem of flexible large-load loading, and significantly improving the loading pressure of the force-transmitting capsule by dozens of times or even hundreds of times; in addition, under the condition of achieving the same hydraulic loading, the present invention can easily miniaturize the volume of the force-transmitting capsule, which will be more conducive to the combination of the true triaxial test device and the CT scanning technology; moreover, the present invention also has many advantages such as simple structure, easy processing, good sealing performance, and convenient use.

Description

Technical Field

[0001] The present invention relates to a force transmission capsule, specifically, to a force transmission capsule capable of realizing ultra-high hydraulic loading, belonging to the technical field of rock mechanics test instruments. Background Art

[0002] A force transmission capsule is a sac-shaped object made of highly elastic rubber and is an instrument for flexible loading in a specific space and a specific direction. When used for hydraulic loading, one or more liquid inlet and outlet interfaces need to be provided on the capsule body. When a liquid with pressure enters the capsule body through the interfaces on the capsule body, the capsule body will deform under the action of hydraulic pressure. When used for hydraulic loading, a rigid constraint is usually applied outside the capsule body, and only allows the capsule body to expand in one direction or several directions. Since the capsule body cannot deform in the direction of the rigid constraint, the deformation only occurs at the position where the constraint is deliberately released. If the experimental object to be pressurized is placed at this position where the constraint is released, the liquid pressure in the capsule body will be applied to the experimental object through the deformation of the capsule wall.

[0003] Currently, the interface on the force transmission capsule body is a circular opening, and a bolt and nut compression sealing connection structure is basically adopted between the circular opening interface and the external joint of the pressurized liquid. For details, please refer to Figure 1 As shown, that is: a circular opening is provided on the capsule body 1. Utilizing the high elasticity of the capsule body material (generally rubber material), the orifice of the opening is first enlarged, and then the liquid injection pipe 4 pre-installed with the lower compression nut 2 and the lower gasket 3 is inserted into the capsule body 1, and then the upper gasket 5 is added and the upper compression nut 6 is tightened, so that the upper and lower gaskets compress the rubber wall at the capsule body interface, causing it to undergo pre-deformation, so as to achieve sealing when adding pressurized liquid. If a specimen 7 is clamped between such a pair of capsule bodies and is rigidly constrained and wrapped in other directions, when pressurized liquid is injected into the two capsules through the liquid injection pipe 4, due to the action of the rigid constraint, these two capsule bodies can only deform in the direction of being close to the specimen 7. Therefore, when the internal pressures of this pair of capsule bodies are the same, a pressure of σ can be applied to the specimen 7 (for details, please refer to Figure 2As shown). Since this sealing connection structure will generate great stress locally, and there is a clear boundary between the upper and lower gaskets and the capsule wall, which will cause shearing of the rubber wall at the capsule body interface, when the liquid pressure reaches several MPa or even below one MPa, shear rupture may occur locally, so that the pressure cannot be increased any further. In other words, with the existing capsule body interface and the sealing connection structure between the capsule body interface and the external joint with the pressurized liquid, when the pressure in the capsule increases, the rubber at the capsule entrance will be locally squeezed or sheared by the high-pressure metal gasket, so it is easy to cause local rupture, resulting in pressure leakage and loading failure, so that the liquid pressure in the capsule body cannot be greatly increased, and at most only a few MPa of pressure loading can be achieved, resulting in an application bottleneck.

[0004] In addition, in the field of rock mechanics, simulation tests on rocks under true triaxial stress states have become a technical problem that needs to be solved urgently in this field; in particular, since CT scanning technology can characterize the microstructure inside the rock and accurately obtain the pore structure, it is an effective method to reveal the seepage characteristics and mechanisms of porous media without causing damage to the internal structure of the rock. Therefore, the coordinated use of true triaxial test devices and CT scanning technology has also become the main research direction in this field. To achieve the combination of true triaxial test devices and CT scanning technology, it is first necessary to solve the problem of whether the force transmission capsule can achieve ultra-high hydraulic pressure (such as: 30 to 100 MPa or even higher pressure) loading. However, there has been no market launch of force transmission capsule products that can achieve ultra-high hydraulic pressure (up to tens of MPa, or even hundreds of MPa pressure) loading and reports on related technologies. Summary of the invention

[0005] In view of the above problems and needs existing in the prior art, the purpose of the present invention is to provide a force transmission capsule capable of achieving ultra-high hydraulic pressure (up to tens of MPa, or even hundreds of MPa) loading, so as to promote the combination of true triaxial testing equipment and CT scanning technology.

[0006] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0007] A force transmission capsule capable of realizing ultra-high hydraulic loading comprises a capsule body having an inverted skirt interface.

[0008] In one embodiment, a sealing plug is interference-connected in the inverted skirt interface, and a liquid injection tube connected to the capsule body cavity is passed through the sealing plug.

[0009] In one embodiment, the capsule body has an inverted skirt interface, and one or more liquid injection tubes are passed through a sealing plug in the inverted skirt interface.

[0010] In another embodiment, the capsule body is provided with a plurality of inwardly turned skirt interfaces, and a liquid injection tube is inserted through a sealing plug in each inwardly turned skirt interface.

[0011] In a preferred solution, the inwardly turned skirt interface is an embedded cylindrical through-hole.

[0012] In a preferred solution, the sealing plug is a metal cylinder.

[0013] In a further preferred solution, one or more outwardly convex annular bands are provided on the outer peripheral surface of the sealing plug.

[0014] In a preferred solution, the force transmission surface of the capsule body is a plane or a curved surface.

[0015] In a preferred solution, a buffer spacer is provided between the force transmission surface of the capsule body and the force-bearing surface of the specimen.

[0016] In a further preferred solution, the buffer spacer is made of a non-metallic material.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] Since the body of the force transmission capsule provided by the present invention has inwardly turned skirt interfaces, when a sealing plug is press-fitted in the inwardly turned skirt interfaces, and a liquid injection tube communicating with the inner cavity of the capsule is inserted through the sealing plug, a pressurized liquid can be injected into the capsule body through the liquid injection tube, and the pressure of the pressurized liquid will be applied to the inwardly turned skirt, causing the inwardly turned skirt to tightly press against the outer peripheral surface of the sealing plug, thereby realizing the self-tightening seal of the capsule body. Moreover, the greater the pressure p in the capsule body, the greater the pressure p of the inwardly turned skirt against the outer peripheral surface of the sealing plug, and thus the better the sealing effect;

[0019] In particular, the present invention creatively provides inwardly turned skirt interfaces on the capsule body, thus ingeniously avoiding the shear damage of the rubber wall at the interface of the capsule body by the pressurized liquid, making the pressure resistance performance of the force transmission capsule no longer limited by the interface, but only depending on the crushing strength of the rubber material constituting the capsule body. By simply selecting a rubber material with the required crushing strength to make the capsule body, the capsule body can meet the loading requirements of ultra-high hydraulic pressure of up to dozens of megapascals or even hundreds of megapascals, ingeniously solving the problem of large-load flexible loading, and significantly improving the loading pressure of the force transmission capsule relative to the prior art (which can only achieve a few megapascals at most) by dozens of times or even hundreds of times (up to dozens of megapascals or even hundreds of megapascals);

[0020] In addition, under the condition of achieving the same hydraulic loading, the present invention can relatively easily miniaturize the volume of the force transmission capsule compared with the prior art, which will be more conducive to the combination of the true triaxial test device and the CT scanning technology;

[0021] Moreover, the present invention also has many advantages such as simple structure, easy processing, good sealing performance, and convenient use, and has remarkable practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural view of the existing force transmission capsule described in the background art;

[0023] Figure 2 is a schematic structural view of the existing force transmission capsule in force transmission application described in the background art;

[0024] Figure 3 is a partial cross-sectional view of a force transmission capsule capable of achieving ultra-high hydraulic loading provided by an embodiment of the present invention;

[0025] Figure 4 is a schematic structural view of the force transmission capsule after installing the sealing plug provided by an embodiment of the present invention;

[0026] Figure 5 is a schematic view of the force received by the inturned skirt interface after injecting pressurized liquid described in an embodiment of the present invention;

[0027] Figure 6 is Figure 5 the view from direction A in

[0028] Figure 7 is a schematic structural view of the sealing plug described in an embodiment of the present invention;

[0029] Figure 8 is a schematic connection structure view between the inturned skirt interface and the sealing plug described in an embodiment of the present invention;

[0030] Figure 9 is a schematic structural view of the force transmission capsule provided by an embodiment of the present invention in force transmission application.

[0031] The reference numerals in the figures are indicated as follows: 1, capsule body; 11, force transmission surface; 2, lower compression nut; 3, lower gasket; 4, liquid injection pipe; 5, upper gasket; 6, upper compression nut; 7, specimen; 71, force receiving surface; 8, inturned skirt interface; 81, inturned skirt; 9, sealing plug; 91, outer convex ring; 10, buffer spacer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions of the present invention will be further described in detail below with reference to the drawings and embodiments.

[0033] Embodiment

[0034] Please refer to Figure 3As shown: A force - transmitting capsule capable of achieving ultra - high hydraulic loading provided in this embodiment includes a capsule body 1, and the capsule body 1 has an in - turned skirt interface 8, and the in - turned skirt interface 8 is preferably an embedded cylindrical through - hole.

[0035] Please refer to Figures 4 to 6 As shown, when the force - transmitting capsule is applied for force transmission, a sealing plug 9 needs to be interference - connected inside the in - turned skirt interface 8 (that is: the outer diameter of the sealing plug 9 is slightly larger than the inner diameter of the in - turned skirt interface 8, so that a pre - deformation can occur to the in - turned skirt 81, and it can wrap around the outer peripheral surface of the sealing plug 9 with a very small force). A liquid injection pipe 4 communicating with the inner cavity of the capsule body 1 is penetrated through the sealing plug 9. When the pressurized liquid enters the capsule body 1 through the liquid injection pipe 4, the pressure of the pressurized liquid will be applied to the in - turned skirt 81, causing the in - turned skirt 81 to press more tightly against the outer peripheral surface of the sealing plug 9, thereby realizing the self - tightening seal of the capsule body 1. Moreover, the greater the pressure p in the capsule body 1, the greater the pressure p of the in - turned skirt 81 against the outer peripheral surface of the sealing plug 9, and thus the better the sealing effect.

[0036] Please refer to Figure 7 and Figure 8 As shown, the sealing plug 9 is preferably a metal cylinder, and it is better that one or more outer convex rings 91 are provided on the outer peripheral surface of the sealing plug 9, because in this way, an uneven joint surface can be formed between the outer peripheral surface of the sealing plug 9 and the in - turned skirt 81, which is beneficial to realizing the ultra - high - pressure loading seal.

[0037] The force - transmitting surface 11 of the capsule body 1 can be a plane (please refer to Figure 3 、 Figure 4 and Figure 8 As shown), which is beneficial to the force transmission and loading of cubic specimens; but it can also be a curved surface to facilitate the force transmission and loading of cylindrical specimens.

[0038] Figure 9 It shows the structural schematic diagram of the force - transmitting capsule provided in the embodiment of the present invention when realizing the force transmission application in the horizontal direction. It can be seen from Figure 9 that when flexible loading in a certain direction (such as the horizontal direction) needs to be achieved for the specimen 7, the specimen 7 can be symmetrically clamped between two force - transmitting capsules provided in the embodiment of the present invention; because there may be local unevenness or cracks on the force - receiving surface of the specimen 7, therefore, it is preferred to set a buffer spacer 10 between the force - transmitting surface 11 of the capsule body 1 and the corresponding force - receiving surface 71 of the specimen 7 to avoid local damage of the force - transmitting capsule due to the local irregular shape or cracks of the specimen; the buffer spacer 10 is preferably made of a non - metal material to avoid affecting the penetration of X - rays and thus unable to be used in combination with CT scanning.

[0039] In addition, the present invention can either be configured such that an inwardly turned skirt interface 8 is provided on the capsule body 1, and one or two liquid injection tubes 4 are inserted through a sealing plug 9 within the inwardly turned skirt interface 8; or two inwardly turned skirt interfaces 8 can be provided on the capsule body 1, and one liquid injection tube 4 is inserted through the sealing plug 9 within each inwardly turned skirt interface 8. When two liquid injection tubes are provided on the capsule body 1, a one-in-one-out circulation of the liquid within the capsule body 1 can be achieved, thereby realizing the purpose of heating or cooling while loading the specimen.

[0040] In summary, it can be seen that by creatively providing the inwardly turned skirt interface 8 on the capsule body 1, the present invention ingeniously avoids the shear damage of the rubber wall at the capsule interface caused by the pressurized liquid, enabling the pressure resistance performance of the force-transmitting capsule to no longer be limited by the interface, but only depending on the crushing strength of the rubber material constituting the capsule body. By simply selecting a rubber material with the required crushing strength to manufacture the capsule body, the capsule body can meet the loading requirements of ultra-high hydraulic pressure up to dozens of megapascals or even hundreds of megapascals, ingeniously solving the problem of large-load flexible loading, and significantly increasing the loading pressure of the force-transmitting capsule by dozens of times or even hundreds of times (up to dozens of megapascals or even hundreds of megapascals) compared with the prior art (which can at most achieve a few megapascals). Additionally, in the case of achieving the same hydraulic loading, the present invention can relatively easily miniaturize the volume of the force-transmitting capsule compared with the prior art, which will be more conducive to the combination of the true triaxial test device and CT scanning technology. Moreover, the present invention also has many advantages such as simple structure, easy processing, good sealing performance, and convenient use, with remarkable practicality. Therefore, the present invention has made significant progress and achieved unexpected technical effects compared with the prior art.

[0041] Finally, it is necessary to point out here that: The above description is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A force transmission capsule capable of achieving ultra-high hydraulic loading, comprising a capsule body, characterized in that: The capsule body is provided with an inturned skirt interface, and a sealing plug is press-fitted in the inturned skirt interface. A liquid injection pipe communicating with the inner cavity of the capsule body is penetrated through the sealing plug. When the pressurized liquid enters the capsule body through the liquid injection pipe, the pressure of the pressurized liquid will act on the inturned skirt, causing the inturned skirt to be more tightly pressed against the outer peripheral surface of the sealing plug, so as to realize the self-tightening seal of the capsule body.

2. The force transmission capsule capable of achieving ultra-high hydraulic loading according to claim 1, characterized in that: The capsule body is provided with an inturned skirt interface, and one or more liquid injection pipes are penetrated through the sealing plug in the inturned skirt interface.

3. The force-transmitting capsule capable of achieving ultra-high hydraulic loading according to claim 1, wherein: The capsule body is provided with a plurality of inturned skirt interfaces, and one liquid injection pipe is penetrated through the sealing plug in each inturned skirt interface.

4. The force-transmitting capsule capable of achieving ultra-high hydraulic loading according to any one of claims 1 to 3, characterized in that: The inturned skirt interface is an embedded cylindrical through hole.

5. The force transmission capsule capable of achieving ultra-high hydraulic loading according to any one of claims 1 to 3, characterized in that: The sealing plug is a metal cylinder.

6. The force-transmitting capsule capable of achieving ultra-high hydraulic loading according to claim 5, wherein: One or more convex annular bands are arranged on the outer peripheral surface of the sealing plug.

7. The force-transmitting capsule capable of achieving ultra-high hydraulic loading according to claim 1, wherein: The force transmission surface of the capsule body is a plane or a curved surface.

8. The force transmission capsule capable of achieving ultra-high hydraulic loading according to claim 7, characterized in that: A buffer spacer is arranged between the force transmission surface of the capsule body and the force receiving surface of the specimen.

9. The force-transmitting capsule capable of achieving ultra-high hydraulic loading according to claim 8, characterized in that: The buffer spacer is made of a non-metallic material.

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