KR20230032659A - Variable Stiffness Structure with Sandwich Structure - Google Patents

Abstract

A variable rigidity structure having a sandwich structure according to an embodiment of the present invention includes a hose, an enclosure, a core, and a sheet. The hose is a passage through which air moves. The enclosure is connected with a hose. The core is housed inside the enclosure. The sheets are accommodated inside the enclosure and are respectively disposed above and below the core. The overall structure of the core and the sheets disposed above and below the core, respectively, exhibits the sandwich structure. When the air inside the enclosure escapes to the outside through the hose, the inside of the enclosure is vacuum-compressed.

Description

Variable stiffness structure with sandwich structure {Variable Stiffness Structure with Sandwich Structure}

The present invention relates to a variable rigidity structure, and relates to a variable rigidity structure having a sandwich structure capable of maintaining a light and flexible function while having a higher variable rigidity.

In general, the performance of a variable rigidity structure using a vacuum compression method varies depending on the type of medium included in the chamber. The most widely known method is a particle jamming method including a medium in the form of small particles inside the chamber.

The particle jamming method is very flexible because the particles can move freely in the uncompressed state. However, in a compressed state, the supporting force is strong when an external force is applied in a compression direction, but the supporting force is weak when an external force is applied in a tensile direction, resulting in low bending stiffness. Therefore, it needs to be manufactured in a large size for greater bearing capacity.

In order to overcome the disadvantages of the particle jamming method, a layer jamming method in which several sheets are embedded has been developed.

The layer jamming decoration has a higher bending rigidity due to its strong bearing capacity when an external force is applied in both the compression direction and the tension direction, and can be manufactured in a small size. However, in the layer jamming method, flexibility in various directions is somewhat limited because movement in a direction parallel to the plane of the sheet is restricted due to the nature of the sheet structure.

Therefore, there is a need for a variable rigidity structure using a vacuum compression method that is light and has high bending stiffness in a compressed state and is capable of flexible movement in various directions in an uncompressed state.

Y. Li, Y. Chen, Y. Yang, Y. Wei, Passive particle jamming and its stiffening of soft robotic grippers. IEEE Trans. Robot. 33, 446-455 (2017).

Accordingly, an object to be solved by the present invention for solving the above problems is to provide a variable rigidity structure having a sandwich structure that is light and has high bending stiffness and is capable of flexible movement in various directions.

However, the problem to be solved by the present invention is not limited to the above objects, and may be expanded in various ways without departing from the spirit and scope of the present invention.

In order to solve the problem to be solved by the present invention, a variable rigidity structure having a sandwich structure according to an embodiment of the present invention includes a hose, an enclosure, a core, and a sheet. A hose is a passage through which air moves. The enclosure is connected with a hose. The core is housed inside the enclosure. The sheets are accommodated inside the enclosure and are respectively disposed above and below the core. The overall structure of the core and the sheets disposed above and below the core, respectively, exhibits a sandwich structure. When the air inside the enclosure escapes to the outside through the hose, the inside of the enclosure is vacuum-compressed.

According to one embodiment, the core and the sheets respectively disposed above and below the core are placed without being physically coupled to each other. In the vacuum pressed state, the core and sheet are pressed together.

According to one embodiment, the sheet includes an upper sheet disposed above the core and a lower sheet disposed below the core. The top sheet includes a first top sheet exposed to the outside and a second top sheet disposed below the first top sheet. The lower sheet includes a first lower sheet exposed to the outside and a second lower sheet disposed on the first lower sheet.

According to one embodiment, the upper first sheet and the lower first sheet are formed of a plastic material. In the vacuum compression state, the upper first sheet applies pressure to the upper second sheet, and the lower first sheet applies pressure to the lower second sheet.

According to one embodiment, the upper second sheet and the lower second sheet are formed of a rubber material. In the state of vacuum compression, the upper second sheet and the lower second sheet are compressed to the core and elastically deformed.

According to one embodiment, the core includes a plurality of cells surrounded by partition walls, and the partition walls have a predetermined height.

According to one embodiment, the cells are arranged vertically, and sheets are respectively arranged above and below the cells.

According to one embodiment, the shape of the cell includes a rectangular shape when looking down at the core from above. Rectangular cells are staggered.

According to one embodiment, a layer having a predetermined thickness is formed on a middle portion of one side of the core and the other side opposite to the one side.

According to one embodiment, the middle portion of the core has a pattern in which rectangular cells are alternately arranged, and both sides of the core connected to the middle portion of the core have a pattern in which cells of tessellating triangles are connected.

According to one embodiment, the shape of the cell has a circular shape when looking down the core from above. The circular cells are spaced apart from each other by a predetermined distance. In addition, a layer having a predetermined thickness connecting the cells to each other is formed between the outer and inner circumferential surfaces of the cells.

According to one embodiment, the shape of the cell has a hexagonal shape when looking down at the core from above. Hexagonal cells are connected to each other and arranged.

According to one embodiment, the shape of the cell has an auxiliary shape when looking down at the core from above.

According to one embodiment, the core has a pyramidal truss structure.

According to one embodiment, the sheet has a shape formed of one layer, combined with two layers only in the middle region, or woven with fabric. Then, a sheet made of rubber is laminated on one surface of the sheet.

A variable rigidity structure having a sandwich structure according to an embodiment of the present invention has high variable rigidity and is lightweight.

In addition, flexible movement is possible.

Also, it has high bending stiffness.

In addition, the configuration is simple and can be obtained easily.

Also, it is suitable for wearable devices.

In addition, it can be applied to a wearable design that can assist various parts of the body.

However, the effects of the present invention are not limited to the above effects, and may be expanded in various ways without departing from the spirit and scope of the present invention.

1 is a view showing a variable rigidity structure having a sandwich structure according to an embodiment of the present invention.
FIG. 2 is a view showing a case where the variable-stiffness structure having the sandwich structure of FIG. 1 is vacuum-compressed and a case where it is not vacuum-compressed.
FIG. 3 shows a displacement-load curve of the actually fabricated variable rigidity structure having the sandwich structure of FIG. 1 .
4 shows several designs of an anisotropic core and sheet of a variable stiffness structure having a sandwich structure according to an embodiment of the present invention.
5 shows a first application example to which a variable rigidity structure having a sandwich structure according to an embodiment of the present invention is applied.
6 is a view showing the shapes of the core and the sheet applied to FIG. 5 by way of example.
7 shows a second application example to which a variable rigidity structure having a sandwich structure according to an embodiment of the present invention is applied.
8 is a view showing the structure of the active protector of FIG. 7 by way of example.
FIG. 9 shows a case in which an object falls or an impact is applied to the active guard of FIG. 7 step by step.
FIG. 10 illustrates a load applied to the active protector of FIG. 7 when an impact force is applied to the protector in an unjammed and vacuum-jammed state.
FIG. 11 is a photograph showing the structure of the selectively hardening glove of FIG. 7 as an example.
FIG. 12 shows the load applied to the glove when an impact force is applied to the glove in an unjammed and vacuum-jammed state of the selectively rigid glove of FIG. 7 .

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Among the components of the present invention, specific descriptions of those that can be clearly understood and easily reproduced by those skilled in the art according to the prior art will be omitted in order not to obscure the gist of the present invention.

Hereinafter, a variable rigidity structure having a sandwich structure according to an embodiment of the present invention will be described.

1 is a view showing a variable rigid structure having a sandwich structure according to an embodiment of the present invention, and FIG. 2 is a view showing a case where the variable rigid structure having a sandwich structure of FIG. 1 is vacuum-compressed and not vacuum-compressed. .

1 and 2, a variable rigidity structure having a sandwich structure according to an embodiment of the present invention includes a hose 10, an enclosure 20, a core 30, a sheet ( Sheet) (40).

The hose 10 is a passage through which air moves.

One side of the hose 10 is connected to external equipment (not shown), and the other side of the hose 10 is connected to the enclosure 20 . Here, external equipment refers to general equipment that can supply or remove air.

By the operation of the external equipment, air flows into the enclosure 20 connected to the hose 10 through the hose 10 or flows out of the enclosure 20 .

Hose 10 may be a commonly used vacuum hose.

The hose 10 may be formed of a material having airtightness and flexibility, which is a bending property.

The enclosure 20 is connected to the hose 10 and accommodates the core 30 and the sheet 40 .

The enclosure 20 may be formed of a commonly used vinyl material.

The enclosure 20 has water resistance and airtightness, and the inside of the enclosure 20 has a receiving space for accommodating the core 30 and the sheet 40 .

When air flows into or out of the accommodation space of the enclosure 20 through the hose 10, the shape of the enclosure 20 may change accordingly. That is, the volume of the accommodation space of the enclosure 20 may change as air flows in or out.

The connection between the enclosure 20 and the hose 10 is fastened so as not to leak air. The fastening method of the connection portion is not limited to a specific fastening method as long as air is not leaked, and various fastening methods may be applied.

When the air in the accommodation space of the enclosure 20 escapes to the outside through the hose 10, the interior (reception space) of the enclosure 20 is in a vacuum compressed state. And, if the air in the accommodation space of the enclosure 20 does not escape to the outside through the hose 10, the inside (reception space) of the enclosure 20 is not vacuum compressed.

The core 30 is accommodated inside the enclosure 20 (accommodating space) and is disposed between the sheets 40. Sheets 40 are disposed above and below the core 30 . The overall structure of the core 30 and the sheets 40 respectively disposed above and below the core 30 represent (form) a sandwich structure.

The core 30 is formed of a cell pattern porous structure.

The porous structure of the cell pattern is a structure including a plurality of cells surrounded by barrier ribs, and the cells include through holes. Specifically, the core 30 includes a plurality of cells surrounded by barrier ribs, and the barrier rib has a predetermined height.

Referring to FIG. 1 , the shape of the cell (or through hole) of the core 30 includes a rectangular shape when the core 30 is viewed from top to bottom. In addition, the rectangular cells (or through holes) may be staggered.

To describe the core 30, if the direction of the core 30 is defined based on a rectangular cell, the direction of the long side (partition) in the rectangular cell is the y-axis direction, and the direction of the short side is The x-axis direction and the direction of the height of the rectangular cell may be referred to as the z-axis direction.

Therefore, when looking down at the core 30 from the top, the core 30 has a rectangular shape, and the length of the core 30 in the x-axis direction is longer than the length in the y-axis direction. And the height of the core 30 is the same as the height of the rectangular cell.

The core 30 is made of a plastic material, and may be specifically made of a polycarbonate material.

The cells (or through holes) surrounded by the barrier ribs of the core 30 are arranged in the z-axis direction (vertical). And, the sheet 40 is disposed above and below the cells (or through holes), respectively.

The core 30 separates the sheets 40 disposed above and below the core 30 at predetermined intervals or by the height of the core 30 .

The partition wall of the core 30 has a predetermined rigidity, and when an external force is applied to the core 30, the core 30 has bending (bending) and torsion characteristics (see FIG. 2).

Referring back to FIG. 1 , due to the geometric structure of rectangular cells having a long length in the y-axis direction, the structure of the core 30 may have anisotropic characteristics suitable for a variable rigidity structure having a sandwich structure. Here, anisotropy means that a material has different properties depending on the direction.

Specifically, a low Young's modulus in the x-axis direction significantly lowers the bending rigidity of the core 30 structure, allowing the core 30 to exhibit a well-bent (flexible) behavior in a non-vacuum compression state. Young's modulus refers to the modulus of elasticity that indicates the degree of elongation and deformation of an object.

In addition, the high Young's modulus in the z-axis direction allows the structure of the core 30 to limit deformation in the z-axis direction so that the distance between the sheets 40 disposed above and below the core 30 can be maintained.

In addition, the high shear modulus in the x-z plane minimizes the shear deformation and consequently increases the bending stiffness of the overall structure.

According to an embodiment of the present invention, the shape of the cell (or through hole) of the core 30 may have various shapes as shown in FIG. 4 . A description of FIG. 4 will be described in detail below.

The seats 40 are accommodated in the interior (accommodating space) of the enclosure 20 and are disposed above and below the core 30, respectively.

The sheet 40 includes an upper sheet 41 disposed above the core 30 and a lower sheet 42 disposed below the core 30 .

The upper sheet 41 and the lower sheet 42 may have a predetermined thickness and have a plate shape.

The top sheet 41 includes an upper first sheet 41a exposed to the outside and a second upper sheet 41b disposed under the upper first sheet 41a. The lower sheet 42 includes a lower first sheet 42a exposed to the outside and a lower second sheet 42b disposed on the lower first sheet 42a.

The upper second sheet 41b and the lower second sheet 42b are disposed to contact the core 30 . That is, the upper second sheet 41b is disposed above the core 30 and the lower second sheet 42b is disposed below the core 30 .

The core 30 and the sheets 40 respectively disposed above and below the core 30 are placed without being physically coupled to each other. That is, the upper sheet 41, the core 30 disposed under the upper sheet 41, and the lower sheet 42 disposed under the core 30 are placed without being physically coupled to each other.

More specifically, the upper first sheet 41a and the upper second sheet 41b are in an overlapped state, and the upper first sheet 41a and the upper second sheet 41b are placed without being physically bonded. In addition, the lower first sheet 42a and the lower second sheet 42b are overlapped, and the lower first sheet 42a and the lower second sheet 42b are placed without physical coupling.

The upper first sheet 41a and the lower first sheet 42a have a predetermined thickness and may be formed of a plastic material. Specifically, the upper first sheet 41a and the lower first sheet 42a may be formed of a polycarbonate material.

When the inside (receiving space) of the enclosure 20 is in a vacuum compression state, the core 30 and the sheet 40 are compressed to each other.

When the inside (receiving space) of the enclosure 20 is in a vacuum compression state, the upper first sheet 41a may apply pressure to the upper second sheet 41b disposed below the upper first sheet 41a, The lower first sheet 42a may apply pressure to the lower second sheet 42b disposed on the lower first sheet 42a.

The upper second sheet 41b and the lower second sheet 42b have a predetermined thickness and are made of a rubber material.

When the inside (receiving space) of the enclosure 20 is in a vacuum compression state, the upper second sheet 41b and the lower second sheet 42b may be elastically deformed by being compressed by the core 30 .

When the inside (receiving space) of the enclosure 20 is in a vacuum compression state, the upper second sheet 41b and the lower second sheet 42b are compressed to the core 30, as shown at the bottom of FIG. , The partition wall of the core 30 strongly compresses the upper second sheet 41b and the lower second sheet 42b so that the upper second sheet 41b and the lower second sheet 42b can be elastically deformed. In this case, portions of the upper second sheet 41b and the lower second sheet 42b that do not contact the partition walls of the core 30 may protrude into the cells (or through holes) of the core 30 due to elastic deformation.

The top sheet 41 and the bottom sheet 42 are spaced apart by a core 30 . The top sheet 41 and the bottom sheet 42 spaced apart by the core 30 increase the moment of inertia of the variable stiffness structure due to the low effective density and the height of the core 30, resulting in bending stiffness/strength. stiffness/strength) greatly increases.

FIG. 3 shows a displacement-load curve of the actually fabricated variable rigidity structure having the sandwich structure of FIG. 1 . This was done through experiments by dividing the variable rigidity structure into a case where it was vacuum-compressed (jammed) and a case where it was not vacuum-compressed (unjammed).

Referring to FIG. 3 , the variable rigidity structure according to the embodiment of the present invention shows that the load per displacement gradually increases in a vacuum-compressed state (jammed).

According to an embodiment of the present invention, the shape of the cell (or through hole) of the core 30 and the structure of the core 30 may be formed in various ways as shown in FIG. 4 .

4 shows several designs of an anisotropic core and sheet of a variable stiffness structure having a sandwich structure according to an embodiment of the present invention.

The variable rigidity structure having a sandwich structure according to an embodiment of the present invention is suitable for a wearable device and can be manufactured to suit the design or use of the wearable device, and accordingly, the shape or material of the core 30 can be formed in various ways. can

According to an embodiment of the present invention, each joint of the human body to which the wearable device can be mounted has one or several degrees of freedom according to the musculoskeletal structure, and surface deformation and overall shape change around the joint vary depending on the type of joint. For example, the spine, which is mainly responsible for the movement of the torso, provides a high degree of freedom of movement because it is composed of many joints connected in series.

A sandwich structure proposed to be part of a garment must ensure a sufficient number of degrees of freedom with low stiffness for local deformation of the target body part, so as to allow agile and dynamic movements of the wearer. This property is as important as the strengthening performance (stiffening performance) of the garment in the jammed state.

The variable rigidity structure having a sandwich structure according to an embodiment of the present invention has not only the number of degrees of freedom through the design of the sandwich structure (the structure of the core 30 and the sheet 40 having anisotropic properties), but also the mechanical properties of each degree of freedom. can be set in advance.

According to an embodiment of the present invention, the shape of the cell (or through hole) of the core 30 and the structure of the core 30 may be formed in various ways as shown in FIG. 4 .

Referring to FIGS. 1, 2, and 4, the rectangular cell pattern arranged in a zigzag pattern (A in FIG. 4) has four degrees of freedom (bending along the y-axis and z-axis, twisting along the x-axis) twisting) and x-axis extension/compression). The geometry of the cell permits the above operations but restricts all other operations.

In the structure of the core 30 shown in B of FIG. 4, the middle portion of the core 30 has a pattern in which rectangular cells are alternately arranged, and the core 30 connected to the middle portion of the core 30, respectively. Both sides represent a pattern in which cells of tessellating triangles are connected.

When the zigzag-arranged rectangular cell pattern is combined with the solid tessellating triangle cell pattern in all directions (FIG. 4B), the structure of the core 30 is partially partial only in the middle region where the rectangular cell pattern is located. become flexible with This indicates that, in accordance with the practice of the present invention, it is possible to design a single core 30 structure with different mechanical properties for different regions of the garment.

In the structure of the core 30 shown in C of FIG. 4, a layer having a predetermined thickness is formed in the middle of one side of the core 30 and the other side opposite to the one side (x-z plane of the core 30). The same structure as the core 30 shown in A of FIG. 4 is shown except that a thin layer is formed in the middle portion of the Here, the added intermediate layer allows the structure to have a single degree of freedom bending motion about the y-axis, while limiting bending about the z-axis, twisting about the x-axis, and expansion/compression about the x-axis. The difference in degrees of freedom of these structures is determined by anisotropic properties, which have different stiffnesses in each direction.

The structure of the core 30 shown in D of FIG. 4 is as follows. When the core 30 is viewed from top to bottom, the cells have a circular shape, and the circular cells are spaced apart from each other at predetermined intervals. In addition, a layer having a predetermined thickness connecting the cells to each other is formed at an intermediate portion of the outer and inner circumferential surfaces of the cells.

A structure having a circular cell pattern in which a thin layer is formed in the middle of the x-z plane of the core 30 (Fig. 4D) always forms a single curvature when bent around a single axis in any direction. On the other hand, structures with hexagonal (Fig. 4E) and auxetic cell patterns (Fig. 4F) form surfaces with double curvature even when bent only about a single axis. The Gaussian curvature of the hexagonal cell structure is negative, which means that the structure becomes a hyperbolic paraboloid shape when bent. The auxetic cell structure with rounded corners has a positive Gaussian curvature and forms a dome-shaped surface when deformed.

The shape of the cell of the core 30 shown in E of FIG. 4 has a hexagonal shape when the core 30 is viewed from top to bottom. The hexagonal cells are connected to each other and arranged. The shape of the cell of the core 30 shown in F of FIG. 4 has an auxiliary shape when the core 30 is viewed from top to bottom.

The structure of the two cores 30 shown in E and F of FIG. 4 may form a three-dimensional (3D) shape with double-curvature bending. However, since the deformation of a cell affects the deformation of an adjacent cell, each cell cannot completely transform freely.

The pattern of the core 30 may be more complexly formed in multiple layers, such as a pyramidal truss structure (G in FIG. 4). Nodes of each structural unit are individually (independently) flexible and can be freely deformed when unjammed, but in a lightweight pyramidal structure when vacuum squeezed. jammed) can effectively withstand compression and shear forces.

An advantage of the core 30 design shown in Fig. 4G is that each cell is more complex to form than other core 30 designs, but can be modified for better performance. For example, the contact area between the core 30 and the sheet 40 may be increased by enlarging upper and lower plates of each cell. This can form another anisotropic behavior of the core 30 structure.

Since the variable rigidity structure having a sandwich structure according to an embodiment of the present invention is a combination of the core 30 and the sheet 40, the overall mechanical behavior can be formed differently by changing the design of the sheet 40.

The sheet 40 shown in H of FIG. 4 is formed of one layer, and the sheet 40 shown in I of FIG. 4 is combined into two layers only in the middle region. And, the sheet 40 shown in J of FIG. 4 has a shape woven with fabric. A sheet made of rubber is laminated on one surface of the sheet 40 .

The sheet 40 (H in FIG. 4) formed of one layer has a low moment of inertia of thickness and low rigidity when bent around the y-axis, while the moment of inertia of width is large and has high stiffness when bent around the z-axis. high. Accordingly, the variable rigidity structure having a combination of the design of the seat 40 and the design of the core 30 as shown in A and B of FIGS.

The sheet 40 (I in FIG. 4 ) in which two layers are combined only in the middle region can overcome the above-described limited degrees of freedom. The seat 40 design shown in FIG. 4I allows for additional motion (movement), such as bending about the z-axis and expansion/compression in the x-axis. The double layer sheet shown in FIG. 4I can be used with the core 30 shown in FIGS. 4A and B to allow full degrees of freedom of the core. However, since the seat 40 design shown in FIGS. 4H and I provides only a single curved deformation, the seat 40 design may be a double curved deformation ( FIGS. 4E and F ) or a freeform deformation ( FIG. 4G ), the movement of the core 30 design with double curved deformation (E and F in FIG. 4) or free-form deformation (G in FIG. 4) can be limited. This problem can be solved by using the seat 40 design shown in FIG. 4J (a seat design having a shape woven into fabric). The seat 40 design shown in FIG. 4J (a seat design having a woven shape) allows small movement between the woven strips and can be applied to various surface deformations.

When designing a new functional clothing, the designer may select various combinations of the core 30 and the sheet 40 suggested in FIG. 4 to program target characteristics and degrees of freedom. For example, a variable rigidity structure including a sheet having a shape woven of fabric (J in FIG. 4) and a core having a pyramidal truss structure (G in FIG. can be applied to the area.

FIG. 5 shows a first application example to which a variable rigidity structure having a sandwich structure according to an embodiment of the present invention is applied, and FIG. 6 is a view showing the shapes of a core and a sheet applied to FIG. 5 exemplarily. In FIG. 6 , the upper drawing shows the core 30 and the lower drawing shows the sheet 40 .

Referring to FIGS. 1, 2, 5, and 6, a first application example to which the variable rigidity structure having a sandwich structure according to an embodiment of the present invention is applied is to offset the weight of the wearer's upper extremities. It is an arm support that can be selectively stiffened in a desired position.

The arm support includes a hose 10 and an enclosure 20, and inside the enclosure 20 (accommodating space), a core 30 and a seat 40 respectively disposed above and below the core 30 are provided. are provided The arm support can be fixed to the body to distribute the load.

The core 30 applied to the arm support is a core design shown in A in FIG. 4, and the seat 40 is a seat design shown in I in FIG.

The core 30 has another pattern in the middle. The direction of the staggered (arranged zigzag) rectangular cells formed on both sides of the core 30 is vertical, while the direction of the staggered (arranged zigzag) rectangular cells formed on the middle surface is the direction of the cells formed on both sides orthogonal to

The cell formed in the middle of the core 30 is the shoulder of the wearer's multiple degrees of freedom, including abduction-adduction and horizontal abduction-adduction, when unjammed. It allows motion, but becomes rigid enough to support the weight of the arm when jammed. At this time, both sides of the core 30 may be comfortably deformed to fit the upper arm and the torso. When vacuum compressed, the arm support can effectively transmit rigidity to the wearer's body using a large contact area. Thus, the arm support assists the wearer in carrying out motions that require lifting the arm and maintaining that position until the work is completed.

7 shows a second application example to which a variable rigidity structure having a sandwich structure according to an embodiment of the present invention is applied.

Referring to FIG. 7 , a second application example to which the variable rigidity structure having a sandwich structure according to an embodiment of the present invention is applied is an active protector and a selectively hardening glove.

8 is a view showing the structure of the active protector of FIG. 7 by way of example, FIG. 9 shows the case where an object falls or an impact is applied to the active protector of FIG. 7 step by step, and FIG. Shows the load that appears on the protector when an impact force is applied to the protector when the active protector of is not vacuum-pressed (unjammed) and in a vacuum-jammed state (jammed).

7 to 10, an active protector to which a variable stiffness structure having a sandwich structure according to an embodiment of the present invention is applied includes a hose 10 (see FIG. 1) and an enclosure 120, Inside the enclosure 120 (accommodating space), a rubber-laminated pyramidal core 130 and a sheet having a shape woven from fabric are disposed above and below the core 130, respectively. (woven face sheet) (141, 142) is provided. A conductive fabric 150 is attached to one surface of the enclosure 120 .

The active guard may detect a collision in advance and switch the mode from a 'soft' mode to a 'rigid' mode. Thus, active guards can be used to protect the wearer from unexpected impacts by hard objects.

The overall structure of the active protector is flexible. Therefore, the active guard can be easily deformed regardless of the movement or shape of the wearer's body part, and can adhere to the wearer's body part. In addition, even if the active protector is actively hardened by vacuum jamming, a large contact area between the protector and the wearer's body can be maintained. This facilitates dispersing the localized impact of an unexpected impact over a wider area of the wearer's body.

The rubber-laminated pyramidal core 130 of the active protector has a structure in which rubber is laminated on the core design shown in FIG. ) (141, 142) is the seat design shown in J in FIG. The sheets 141 and 142 allow large deformation in all directions.

A conductive fabric 150 is attached to one surface of the enclosure 120 of the active protector. The conductive fiber 150 may detect the proximity of an object by means of capacitive proximity sensing. As soon as the conductive fiber 150 gives a signal, the active protector can be quickly vacuumed before colliding with an object.

In the first phase (phase 1) of FIG. 9, the object is in a vacuum OFF state before colliding with the active guard, and at this time, the active guard is flexible outside the activation zone.

In the second phase (phase 2) of FIG. 9, the conductive fiber 150 detects the approach of an object and vacuum compression is in progress (vacuum ON), and at this time, the active guard is hard inside the activation zone. indicates that it is

The third phase (phase 3) of FIG. 9 is a state in which an object collides with the active protector and vacuum compression is completed (vacuum ON), and at this time, the active protector is hardened.

10 shows a strong load in a local area of the protector when an impact force is applied to the protector in a state where the active protector is not vacuum-pressed (jammed), and when an impact force is applied to the protector in a vacuum-jammed state (jammed), a wide It shows that the load appears weak in the region. This means that the impact force applied to the protector in the vacuum compressed state is distributed along the hardened surface of the protector. Therefore, when a high impact force is applied to a local area of the protector due to a collision with an object, the active protector can protect the wearer.

11 is a photograph showing the structure of the selectively hardening glove of FIG. 7 exemplarily, and FIG. 12 is the selectively hardening glove of FIG. 7 in an unjammed and vacuum-compressed state. In the jammed state, it represents the load that appears on the glove when an impact force is applied to the glove.

Referring to FIGS. 11 and 12 , a selectively hardening glove is an embodiment in which a variable rigidity structure having a sandwich structure according to an embodiment of the present invention is mounted (coupled) to a conventional glove. Here, the variable rigidity structure having a sandwich structure according to an embodiment of the present invention may be formed in the shape of a conventional glove. That is, the enclosure 20 (see FIG. 1), which is a component of a variable rigidity structure having a sandwich structure, and the core 30 (see FIG. 1) and the sheet ( 40) (see FIG. 1) may be formed in the shape of a conventional glove.

The selectively rigid glove includes a hose 10 (see FIG. 1) and an enclosure 20, and the inside of the enclosure 20 (receiving space) includes a core of various shapes shown in FIG. Sheets of various shapes each disposed below are provided.

Selectively rigid gloves can be used to increase the maximum impact pressure applied to an object by the wearer in a vacuum jammed state, and thus are useful for functional gloves that destroy objects without tools in an emergency.

Optionally, rigid gloves cover the back of the hand to protect the proximal phalanges of the fingers, excluding the thumb.

The selectively rigid glove is free of movement of the hand due to the anisotropic flexible core 30 structure in a non-vacuum unjammed state, and can be vacuum-jammed and hardened if necessary.

Referring to FIG. 12, the high stiffness of the selectively rigid glove disperses the reaction force applied to the wearer's hand over a wide area, thereby reducing the magnitude of the maximum impact pressure transmitted to the skin and bones of the hand, as well as reducing the force in a localized area. (pressure concentration effect).

The upper surface of the pressure-sensing pad was compressed by the glove according to an embodiment of the present invention until the compression force reached 50 N in both the vacuum jammed and unjammed states. The peak pressure in the non-vacuum compression state was 134.2 kPa (SD: 17.1 kPa), the contact area was 13.85 cm ² (SD: 1.17 cm ² ), and the peak pressure in the vacuum compression state was 184.0 kPa (SD: 31.2 kPa), The contact area was 11.25 cm ² (SD: 0.73 cm ² ). In the vacuum compressed state, the maximum pressure increased by 37%, but the contact area decreased by 19%. This indicates that the selectively rigid glove can increase the maximum impact pressure applied to an object while protecting the hand.

The above-described variable rigidity structure having a sandwich structure according to an exemplary embodiment of the present invention has high variable rigidity and is lightweight and capable of flexible movement.

In addition, the variable rigidity structure having a sandwich structure according to an embodiment of the present invention has high bending stiffness, is simple in construction, and can be easily obtained.

In addition, the variable rigidity structure having a sandwich structure according to an embodiment of the present invention is suitable for a wearable device and can be applied to a wearable design capable of assisting various parts of the body.

The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified with respect to other embodiments by those skilled in the art in the field to which the embodiments belong. Therefore, contents related to these combinations and variations should be construed as being included in the scope of the present invention.

In addition, although the embodiment has been described above, this is only an example and does not limit the present invention, and those skilled in the art to the present invention pertain to the above to the extent that does not deviate from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications not exemplified are possible. That is, each component specifically shown in the embodiment can be implemented by modifying it. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

10: Hose
20: Enclosure
30: Core
40: Sheet

Claims (15)

A hose that is a passage through which air moves;
an enclosure connected to the hose;
a core accommodated inside the enclosure; and
A sheet accommodated inside the enclosure and disposed above and below the core, respectively,
The overall structure of the core and the sheets respectively disposed above and below the core represents a sandwich structure,
Variable rigidity structure having a sandwich structure, wherein the inside of the enclosure is in a vacuum compressed state when the air inside the enclosure escapes to the outside through the hose.
According to claim 1,
The core and the sheets disposed above and below the core are placed without being physically coupled to each other,
Variable rigidity structure having a sandwich structure, wherein the core and the sheet are compressed to each other in the vacuum compressed state.
According to claim 1,
The sheet includes an upper sheet disposed above the core and a lower sheet disposed below the core,
The upper sheet includes a first upper sheet exposed to the outside and a second upper sheet disposed below the first upper sheet, wherein the lower sheet includes a first lower sheet exposed to the outside and the first lower sheet A variable rigidity structure having a sandwich structure, including a lower second sheet disposed thereon.
According to claim 3,
The upper first sheet and the lower first sheet are formed of a plastic material,
In the vacuum compression state, the upper first sheet applies pressure to the upper second sheet, and the lower first sheet applies pressure to the lower second sheet.
According to claim 3,
The upper second sheet and the lower second sheet are formed of a rubber material,
In the vacuum-compressed state, the upper second sheet and the lower second sheet are elastically deformed by being compressed by the core, the variable rigidity structure having a sandwich structure.
According to claim 1,
The variable rigidity structure having a sandwich structure, wherein the core includes a plurality of cells surrounded by barrier ribs, and the barrier rib has a predetermined height.
According to claim 6,
The variable rigidity structure having a sandwich structure, wherein the cells are arranged vertically, and sheets are disposed above and below the cells, respectively.
According to claim 6,
The variable rigidity structure having a sandwich structure, wherein the shape of the cells includes a rectangular shape when looking down at the core from top to bottom, and the rectangular cells are alternately disposed.
According to claim 8,
A variable rigidity structure having a sandwich structure, wherein a layer having a predetermined thickness is formed on a middle portion of one side of the core and the other side opposite to the one side.
According to claim 6,
The middle part of the core has a pattern in which rectangular cells are alternately arranged,
Variable rigidity structure having a sandwich structure, wherein both sides of the core connected to the middle portion of the core have a pattern in which cells of tessellating triangles are connected.
According to claim 6,
The shape of the cell, when looking down at the core from top to bottom, has a circular shape, and the circular cells are spaced apart from each other by a predetermined interval,
A variable rigidity structure having a sandwich structure, wherein a layer having a predetermined thickness connecting the cells to each other is formed between the outer and inner circumferential surfaces of the cells.
According to claim 6,
The variable rigidity structure having a sandwich structure, wherein the shape of the cells has a hexagonal shape when looking down at the core from top to bottom, and the hexagonal cells are connected to each other and disposed.
According to claim 6,
The variable rigidity structure having a sandwich structure, wherein the shape of the cell has an auxetic shape when looking down at the core from top to bottom.
According to claim 1,
The variable rigidity structure having a sandwich structure, wherein the core has a pyramidal truss structure.
According to claim 1,
The sheet is formed of one layer, or combined with two layers only in the middle region, or has a shape woven into a fabric,
A variable rigidity structure having a sandwich structure in which a rubber sheet is laminated on one side of the sheet.

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