Soft muscle mold

Abstract

The invention provides a soft muscle mold which comprises a mold body, the mold body is provided with a cylindrical forming cavity with a central axis, the mold body comprises a first side wall (1) and a second side wall (2) surrounding the outer side of the first side wall (1), the first side wall (1) comprises a plurality of first folding faces (11) arranged along the central axis, and the second side wall (2) comprises a plurality of second folding faces (12) arranged along the central axis. The second side wall (2) comprises a plurality of second folding faces (21) arranged in the extending direction of the central axis, the first folding faces (11) and the second folding faces (21) are correspondingly arranged to form a plurality of forming layers, and the forming layers are stacked in the extending direction of the central axis to form a forming cavity.

Description

Technical Field

[0001] The present disclosure relates to the field of robotics, and in particular to a soft muscle mold. Background Art

[0002] Fluid actuators are used in a range of high-end technology application fields, including but not limited to flexible robotic arms, soft robots, new energy vehicles, small UAV work platforms, as well as power equipment and automated work platforms. Soft muscles are a key component of fluid brakes, and can achieve force transmission and control with the help of pressure changes in fluids (such as gas or liquid). By regulating the internal pressure of soft muscles, the soft muscles can expand or contract like natural muscles, and then converted into the braking torque or displacement required by the brake. Soft muscles have the characteristics of light weight, flexibility, large deformation ability and fast response speed. They not only improve the reaction speed and efficiency of the braking system, but also greatly enhance its adaptability and reliability in complex environments. They are of great significance to promoting the development of high-tech industries such as soft robots, intelligent equipment and new energy vehicles.

[0003] However, in the design and production of soft muscles mainly made of elastic materials, the related molding process faces many technical difficulties.

[0004] Although traditional molding equipment is suitable for molding certain low-hardness elastomers, it encounters great challenges when processing rubber products with higher hardness that are not easily deformed, especially when removing the products from the mold. In addition, the blow molding process may cause problems with insufficient wall thickness uniformity when manufacturing thicker rubber products, which in turn affects the stability of the product and the feasibility of the production process for bellows with a small aspect ratio, resulting in reduced product durability. At the same time, although bellows manufactured using thin film processing technology can be molded, they often have problems such as insufficient mechanical strength, low fatigue life, poor wear resistance and aging resistance, long production cycles, and low consistency in physical properties between batches. When designing stacked structure fluid actuators, as the required material hardness increases and the designed wall thickness increases, it becomes extremely difficult to remove muscles after injection molding or molding, especially those made of highly hardened elastomer materials with complex internal structures.

[0005] It should be noted that the statements in this background technology section only provide background technology related to the present disclosure and do not necessarily constitute prior art. Summary of the Invention

[0006] The present disclosure provides a soft muscle mold to improve the production efficiency of soft muscles.

[0007] According to one aspect of the present disclosure, a soft muscle mold is provided, including a mold body, the mold body being provided with a cylindrical molding cavity having a central axis, the mold body comprising a first side wall and a second side wall surrounding the outside of the first side wall, the first side wall comprising a plurality of first folding surfaces arranged along the central axis, the second side wall comprising a plurality of second folding surfaces arranged along the extension direction of the central axis, the plurality of first folding surfaces and the plurality of second folding surfaces being arranged correspondingly to constitute a plurality of molding layers, and the plurality of molding layers being stacked along the extension direction of the central axis to form a molding cavity.

[0008] In some embodiments,

[0009] In the extension direction of the central axis, the shapes of the multiple first folding surfaces are the same, or the shapes of the multiple first folding surfaces are similar and the sizes vary proportionally; and / or

[0010] In the extension direction of the central axis, the shapes of the plurality of second folding surfaces are the same, or the shapes of the plurality of second folding surfaces are similar and the sizes vary proportionally.

[0011] In some embodiments, the first folding surface and the second folding surface have the same or similar shapes.

[0012] In some embodiments, in the extension direction of the central axis, the generatrix of the first folding surface and / or the second folding surface for constituting the at least one forming layer is a y-axis or spline curve.

[0013] In some embodiments,

[0014] In the extension direction of the central axis, the connection between two adjacent first folding surfaces forms a circumferentially closed first fold; and / or

[0015] In the extension direction of the central axis, the connection between two adjacent second folding surfaces forms a circumferentially closed second fold.

[0016] In some embodiments,

[0017] The first fold is an axisymmetric shape, a centrally symmetrical shape, or a rotationally symmetrical shape; and / or

[0018] The second fold is an axisymmetric shape, a centrally symmetrical shape, or a rotationally symmetrical shape.

[0019] In some embodiments, in the extension direction of the central axis,

[0020] In the three first folds set in succession,

[0021] The two first folds arranged at intervals have the same or similar shapes and are located at the same circumferential position relative to the central axis, and the two adjacent first folds have different concave-convex states on the first side wall;

[0022] and / or

[0023] In the three second folds set in succession,

[0024] The two second folds arranged at intervals have the same or similar shapes and the same circumferential positions relative to the central axis. The two second folds arranged adjacent to each other have different concave-convex states on the second side wall.

[0025] In some embodiments,

[0026] The first protruding fold is a curve including straight line segments and having a continuous G1; and / or

[0027] The concave second fold is a curve including straight line segments and having a continuous G1.

[0028] In some embodiments,

[0029] The first convex fold further includes at least one curved segment with constant curvature; and / or

[0030] The concave second fold further includes at least one curved line segment with a constant curvature.

[0031] In some embodiments,

[0032] The first convex fold is a G2 continuous curve; and / or

[0033] The concave second fold is a curve that is continuous with G2.

[0034] In some embodiments,

[0035] The convex first fold includes a first curved segment convex relative to the central axis and a second curved segment concave relative to the central axis, the first curved segment being tangentially connected to the second curved segment; and / or

[0036] The concave second fold includes a third curved segment convex relative to the central axis and a fourth curved segment concave relative to the central axis, and the third curved segment is tangently connected to the fourth curved segment.

[0037] In some embodiments, the first side wall also includes a forming groove arranged at the concave first fold, and the forming groove is concave toward the central axis in a direction perpendicular to the central axis to form a crease shape retaining portion at the convex fold of the inner wall of the soft body muscle, which extends along the shape of the convex fold of the inner wall of the soft body muscle.

[0038] In some embodiments, the soft muscle has an intrusion depth coefficient a and a folding surface area difference coefficient σk. In the extension direction of the central axis, the first fold and the second fold located at the same end of the forming layer are coplanar, and the plane on which they are located is defined as the fold surface.

[0039] There is a first intrusion angle θ1 between the crease surface between two adjacent forming layers and the first folding surfaces connected to both sides thereof. The first intrusion angle θ1 is defined based on the cross-section of the first folding surface 11剖切 by the S plane, and the magnitude of the first intrusion angle θ1 satisfies the following formula:

[0040] σk = a(1 - cosθ1) / (2cosθ1 - a),

[0041] where, when the preset working pressure difference range of the soft muscle is -0.08 to 0 Mpa, 0.4 < a < 0.6, 0.05 < σk < 0.7; when the preset working pressure difference range of the soft muscle is -0.08 to 0.2 Mpa, 0.25 < a < 0.55, 0.01 < σk < 0.1;

[0042] and / or

[0043] There is a second intrusion angle θ2 between the crease surface between two adjacent forming layers and the second folding surfaces connected to both sides thereof. The second intrusion angle θ2 is defined based on the cross-section of the second folding surface 21剖切 by the S plane, and the magnitude of the second intrusion angle θ2 satisfies the following formula:

[0044] σk = a(1 - cosθ2) / (2cosθ2 - a),

[0045] where, when the preset working pressure difference range of the soft muscle is -0.08 to 0 Mpa, 0.4 < a < 0.55, 0.05 < σk < 0.125; when the preset working pressure difference range of the soft muscle is -0.08 to 0.2 Mpa, 0.25 < a < 0.55, 0.01 < σk < 0.1.

[0046] In some embodiments,

[0047] The width l of the forming layer is equal to the width L of the folding surface of the soft muscle, and the distance t between the first folding surface and the second folding surface is equal to the initial thickness T of the soft muscle. The width l of the forming layer and the distance t between the first folding surface and the second folding surface are defined based on the cross-section of the first folding surface and the second folding surface剖切 by the S plane,

[0048] Then the following relational expression is satisfied between t and l:

[0049] t = m*l,

[0050] where, m is a preset proportionality coefficient, 0.07 < m < 0.3.

[0051] In some embodiments, the magnitude of t is between 0.5 and 7 mm.

[0052] Note: The symbol "剖切" is not a recognized English word. It seems to be a special term in Chinese. If there is a correct English equivalent for this word in the context of this patent text, it should be used instead. Here, I just keep it as it is for the purpose of translation according to the rules.In some embodiments, the distance between the first side wall and the second side wall at the connection point of two adjacent molding layers is greater than the distance between the first side wall and the second side wall at other positions.

[0053] In some embodiments, the mold body includes a top cover, a base, a mold shell and a mold core. The mold shell and the mold core are arranged between the top cover and the base. The mold shell is arranged on the outer periphery of the mold core. The inner side of the top cover, the inner side of the base, the outer side of the mold core and the inner side of the mold shell are combined to form a molding cavity, and the first side wall is formed on the outer side of the mold core, and the second side wall is formed on the inner side of the mold shell.

[0054] In some embodiments, the mold core is provided with a first mating portion for positioning with the top cover and / or the base, and the mold shell is provided with a second mating portion for positioning with the top cover and / or the base, so that the multiple first folding surfaces and the multiple second folding surfaces correspond one to one in the extension direction of the central axis, and the corresponding first folding surfaces and the second folding surfaces have a uniform circumferential distance and a uniform axial distance.

[0055] In some embodiments, the mold shell is a split structure, and / or the mold core is a split structure.

[0056] In some embodiments, the mold core includes at least five split parts, and the at least five split parts are detachably connected.

[0057] In some embodiments, one of the at least five split parts serves as a central block, and the remaining split parts are circumferentially distributed around the central block.

[0058] In some embodiments, the volume of the center block accounts for 28-45% of the volume of the mold core.

[0059] Based on the soft muscle mold provided by the embodiment of the present disclosure, the soft muscle can be formed by means of injection molding or molding. A first side wall and a second side wall surrounding the outside of the first side wall are provided to form a cylindrical molding cavity, which can be used for one-time molding of soft muscles with a cylindrical hollow driving cavity, reducing the processing steps, which can not only improve production efficiency, but also help to ensure the sealing of the driving cavity, thereby ensuring the reliability of the soft muscle when working. In addition, a plurality of corresponding first folding surfaces and second folding surfaces are provided on the first side wall and the second side wall, so that a molding layer is formed between the corresponding first folding surfaces and the second folding surfaces, and the plurality of molding layers constitute a molding cavity with a multi-layer stacking structure, so that it can be used for one-time molding of soft muscles with a multi-layer folding structure. Compared with the traditional layer-by-layer stacking or weaving technology, the process complexity can be significantly reduced, thereby improving the production efficiency of the soft muscle.

[0060] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0062] Figure 1 An exploded view of a soft muscle mold according to an embodiment of the present disclosure is shown;

[0063] Figure 2 A cross-sectional view showing a molding cavity of a soft muscle mold according to an embodiment of the present disclosure cut along an S plane;

[0064] Figure 3a 、 Figure 3b 、 Figure 3c and Figure 3d 1. A front view, an AA cross-sectional view, and BB and CC cross-sectional views along different crease surfaces of a circular cross-section soft muscle mold according to an embodiment of the present disclosure are respectively shown;

[0065] Figure 4a and Figure 4b Schematic diagrams showing two parts of a mold shell of a circular cross-section soft muscle mold according to an embodiment of the present disclosure;

[0066] Figure 5a 、 Figure 5b and Figure 5c 1. A front view, a left view and a top view of a mold core of a circular cross-section soft muscle mold according to an embodiment of the present disclosure are respectively shown;

[0067] Figure 6a 、 Figure 6b and Figure 6c 1. A first front view, an AA cross-sectional view, and a CC cross-sectional view along a crease surface of a fan-shaped annular cross-section soft muscle mold according to an embodiment of the present disclosure are respectively shown;

[0068] Figure 7a 、 Figure 7b and Figure 7c 1. A second front view, a BB cross-sectional view, and a DD cross-sectional view along a crease surface of a fan-shaped ring-shaped cross-section soft muscle mold according to an embodiment of the present disclosure are respectively shown;

[0069] Figure 8a and Figure 8b Schematic diagrams showing two parts of a mold shell of a soft muscle mold with a fan-shaped ring cross section according to an embodiment of the present disclosure;

[0070] Figure 9 A perspective view showing a mold core of a soft muscle mold with a fan-shaped annular cross-section according to an embodiment of the present disclosure;

[0071] Figure 10A longitudinal cross-sectional view through the center of a circle at a crease of a soft muscle mold according to an embodiment of the present disclosure is shown.

[0072] In the picture:

[0073] 1. First side wall; 11. First folding surface; 12. First crease; 13. Forming groove;

[0074] 2. Second side wall; 21. Second folding surface; 22. Second crease;

[0075] 100, mold core; 200, mold shell; 300, base; 400, top cover. DETAILED DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0077] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0078] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be subsequently positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device may also be positioned in other different ways, and the spatially relative descriptions used herein are interpreted accordingly.

[0079] Among the existing soft muscle manufacturing technologies, the known methods have some limitations. For example, 3D printing technology, although it can realize the manufacture of complex structures, the types of materials that can be used for printing are relatively limited, and the 3D printing process is time-consuming and costly, which is not conducive to mass production. Another example is electrospinning technology. The electrospinning process usually generates single fibers in sequence, and it is difficult to achieve completely consistent diameters of nanofibers, which may affect the mechanical properties and consistency of the final soft muscle. In addition, when manufacturing soft muscle structures with large areas or large amounts of fiber accumulation, long-term continuous production is required, and the efficiency is relatively low, which is not conducive to rapid and large-scale industrial production.

[0080] Therefore, the present disclosure provides a soft muscle mold to improve the production efficiency of soft muscles.

[0081] In some embodiments, the soft muscle mold provided by the present disclosure includes a mold body, the mold body is provided with a cylindrical molding cavity having a central axis, Figure 3a 、 Figure 3b 、 Figure 4a 、 Figure 4b 、 Figure 5a 、 Figure 5b As shown, the mold body includes a first side wall 1 and a second side wall 2 surrounding the outside of the first side wall 1, the first side wall 1 includes a plurality of first folding surfaces 11 arranged along the central axis, the second side wall 2 includes a plurality of second folding surfaces 21 arranged along the extension direction of the central axis, the plurality of first folding surfaces 11 and the plurality of second folding surfaces 21 are correspondingly arranged to form a plurality of molding layers, and the plurality of molding layers are stacked along the extension direction of the central axis to form a molding cavity.

[0082] Based on the soft muscle mold disclosed herein, the soft muscle can be formed by injection molding or molding.

[0083] The soft muscle mold disclosed herein comprises a first sidewall 1 and a second sidewall 2 surrounding the first sidewall 1 to form a cylindrical molding cavity, thereby enabling the molding of soft muscles having a cylindrical hollow driving cavity. During the molding process of the soft muscle, the first sidewall 1 forms the inner wall of the soft muscle, and the second sidewall 2 forms the outer wall of the soft muscle.

[0084] The cylindrical molding cavity can perform one-time molding of soft muscles with a hollow driving cavity, reducing the processing steps, which can not only improve production efficiency, but also help to ensure the sealing of the driving cavity, thereby ensuring the reliability of the soft muscles when working.

[0085] And, as Figure 2 As shown, the soft muscle mold provided by the present disclosure is provided with a plurality of corresponding first folding surfaces 11 and second folding surfaces 21 on the first side wall 1 and the second side wall 2, so that a molding layer can be formed between the corresponding first folding surfaces 11 and the second folding surfaces 21, and the plurality of molding layers constitute a molding cavity with a multi-layer stacking structure, thereby being able to be used to mold soft muscles with a multi-layer folding structure. In the molding process of the soft muscle, the first folding surface 11 is used to form the inner wall of the soft muscle stacking layer, and the second side wall 2 is used to form the outer wall of the soft muscle stacking layer.

[0086] The molding cavity with a stacking structure can realize the one-time molding of the multi-layer folding structure of soft muscles. Compared with the traditional layer-by-layer stacking or weaving technology, it can significantly reduce the process complexity and thus improve the production efficiency of soft muscles.

[0087] In the embodiment of the soft muscle mold disclosed herein, the shapes of the first folding surface 11 and the second folding surface 21 can be designed differently according to actual needs. For example, an adaptive design can be made based on the characteristics of the soft muscle to be manufactured, thereby ensuring that the manufactured soft muscle can achieve its predetermined deformation and stress distribution during the folding process.

[0088] For example, in the extension direction of the central axis, multiple first folding surfaces 11 may be provided with the same shape, or multiple first folding surfaces 11 may be provided with similar shapes and sizes varying proportionally; and / or

[0089] In the extension direction of the central axis, a plurality of second folding surfaces 21 may be provided with the same shape, or a plurality of second folding surfaces 21 may be provided with similar shapes and sizes varying proportionally.

[0090] Such a structure helps to form soft muscles with continuous or gradual strain distribution patterns with preset geometric parameters. In addition, it can also form soft muscles with irregular cross-sections and different wall thicknesses.

[0091] Specific reference Figure 2As shown, in some embodiments, multiple first folding surfaces 11 and multiple second folding surfaces 21 have the same shape, thereby forming multiple molding layers of the same shape between the first sidewall 1 and the second sidewall 2. In other words, along the extension direction of the central axis, the dimensions of the laminated structure of the molding cavity remain unchanged, thereby enabling molding of soft muscles with constant axial geometric dimensions.

[0092] If a soft muscle having a gradually contracting or expanding shape in the axial direction is to be formed, the multiple first folding surfaces 11 are set to have similar geometric shapes, and / or the multiple second folding surfaces 21 are set to be similar, and according to the degree of gradual contraction or expansion of the soft muscle, the multiple first folding surfaces 11 and / or the multiple second folding surfaces 21 are set to have appropriate size ratios and change trends.

[0093] Since the size change trends of the inner and outer walls of the soft muscle can be the same or different, the size change trends of the multiple first folding surfaces 11 and the multiple second folding surfaces 21 can also be set to be the same or different accordingly, according to the parameters of the soft muscle to be formed.

[0094] The first folding surface 11 and the second folding surface 21 can be annular surfaces, so that an annular molding layer is formed between the first folding surface 11 and the second folding surface 21. The specific shape and direction of the annular layer can be designed according to the actual application requirements of the soft muscle, such as a circle (such as Figure 4a 、 Figure 4b 、 Figure 5a 、 Figure 5b 、 Figure 5c As shown), fan ring (as shown Figure 6c 、 Figure 7c 、 Figure 8a 、 Figure 8b 、 Figure 9 as shown), or other suitable shapes, to produce soft muscles with different specifications and sizes that can adapt to different application scenarios.

[0095] In some embodiments, the shapes of the first folding surface 11 and the second folding surface 21 are the same or similar, which helps to arrange the first folding surface 11 and the second folding surface 21 in corresponding spatial positions, thereby enhancing the symmetry and consistency of the circumferential shape of the formed soft muscle, thereby ensuring that the soft muscle maintains sufficient stability during the deformation process.

[0096] The first folding surface 11 and the second folding surface 21 may be surfaces with preset shapes and curvatures, and their specific shapes and curvatures may be analyzed and designed based on the application scenarios of soft muscles.

[0097] For example, in some embodiments, in the extension direction of the central axis, the generatrix of the first folding surface 11 and / or the second folding surface 21 for constituting at least one forming layer is a y-axis or spline curve.

[0098] Such a setting ensures that the shape changes of the first folding surface 11 and the second folding surface 21 maintain a certain regularity in the circumferential direction, which is not only convenient for design and manufacturing, but also helps the formed soft muscle to obtain an orderly and uniform stress distribution during the working process. It has obvious positive significance for improving the energy conversion efficiency of the soft muscle, enhancing the environmental and working tolerance (wider temperature range, greater pressure difference, etc.), and extending the service life.

[0099] In addition, the design of the soft muscle mold disclosed herein also takes into account the connection characteristics between the folded surfaces.

[0100] In some embodiments, in the extension direction of the central axis, the connection between two adjacent first folding surfaces 11 forms a circumferentially closed first fold 12; and / or

[0101] In the extension direction of the central axis, the connection between two adjacent second folding surfaces 21 forms a circumferentially closed second fold line 22 .

[0102] In the application of soft muscles, soft muscles usually include a combination structure formed by multiple folding surfaces and multiple folds with different concave and convex states. The expansion and contraction of the soft muscles can be achieved through the expansion and contraction of the structure, thereby outputting power.

[0103] That is to say, the outer wall of the soft muscle includes convex folds or concave folds formed between multiple folding surfaces. In order to achieve the molding of soft muscles with this structure, a molding structure with similar folds is also provided in the embodiment of the soft muscle mold disclosed in the present invention.

[0104] In some embodiments, in the extension direction of the central axis, among the three continuously arranged first folds 12, the shapes of the two second folds 22 arranged at intervals are the same or similar, and their circumferential positions relative to the central axis are the same, and the two adjacent first folds 12 have different concave and convex states on the first side wall 1.

[0105] In other embodiments, among the three consecutive second folds 22, the shapes of the two second folds 22 arranged at intervals are the same or similar, and the circumferential positions relative to the center axis are the same, and the two adjacent second folds 22 have different concave and convex states on the second side wall 2.

[0106] Specific reference Figure 2, shows a longitudinal section of the soft muscle mold of the present disclosure along its central axis. It can be seen that the multiple first folds 12 on the first side wall 1 alternate between convex and concave, giving the longitudinal section of the first side wall 1 a wave-like structure. Similarly, the multiple second folds 22 on the second side wall 2 also alternate between convex and concave, giving the longitudinal section of the second side wall 2 a wave-like structure.

[0107] In the above embodiment, structures such as rounded corners and chamfers can be used at the connection between adjacent folded surfaces to provide a smooth transition between the first fold 12 and the second fold 22. Furthermore, while achieving a tight connection between adjacent folded surfaces, stress concentration at the folds can be minimized, thereby helping to extend the service life of the soft muscle.

[0108] Figure 10 A schematic diagram of a longitudinal section of the forming cavity cut by the S plane near the fold is shown, wherein the arc radius of the contour line of the forming cavity at the corresponding first fold 12 and second fold 22 close to the first side wall 1 is r1, and the arc radius of the contour line of the forming cavity at the fold close to the second side wall 2 is r2, and the distance between the first side wall 1 and the second side wall 2 here is w.

[0109] In the present disclosure, the above-mentioned "S plane" is defined as follows: when any section of the outer contour line (i.e., the second fold 22) or the inner contour line (i.e., the first fold 12) of the molding cavity on the crease surface is a curved segment, the plane perpendicular to the tangent line of any point on the curved segment and passing through the point is the S plane of the point; when any section of the outer contour line (i.e., the second fold 22) or the inner contour line (i.e., the first fold 12) of the molding cavity on the crease surface is a straight line segment, the plane perpendicular to the straight line segment and passing through the point is the S plane of the point; when the outer contour line (i.e., the second fold 22) or the inner contour line (i.e., the first fold 12) of the molding cavity on the crease surface is a circle, the S plane and the longitudinal section passing through the center axis are coplanar.

[0110] In the present disclosure, for a soft muscle mold with a circular cross-section (ie, its folds are also circular), the longitudinal section along the central axis may coincide with the longitudinal section passing through the center of the circle.

[0111] In some embodiments, the distance between the first side wall 1 and the second side wall 2 at the connection point of two adjacent molding layers is greater than the distance between the first side wall 1 and the second side wall 2 at other positions.

[0112] The soft muscle mold disclosed in the present invention is provided with a mold penetration depth u and a mold preset radius R. Figure 2 and Figure 10As shown in the embodiment, in order to make the strain of the formed soft muscle evenly distributed and not concentrated at the folds, the distance w between the first side wall 1 and the second side wall 2 at the first fold 12 and the second fold 22 can be set to be greater than the distance t between the first folding surface 21 and the second folding surface 21.

[0113] Therefore, when r1=i*t and r2=j*t, r1 and r2 can be advantageously configured to satisfy the following relationship:

[0114] r1 <t / (2*cosθ),

[0115] r2<3t / (2*cosθ),

[0116] 0<(1-j+i)(1 / sinθ-1),

[0117] Among them, i and j are preset proportional coefficients.

[0118] In the above embodiment, the first fold 12 can be designed to be axially symmetrical, centrosymmetrical, or rotationally symmetrical, and the second fold 22 can also be designed to be axially symmetrical, centrosymmetrical, or rotationally symmetrical. Thus, the inner and outer walls of the soft muscle formed using the present disclosure also have axially symmetrical, centrosymmetrical, or rotationally symmetrical folds, ensuring symmetry and balance in deformation and force applied when the soft muscle folds during operation.

[0119] In addition, in the soft muscle, the protruding folds on the outer wall of the soft muscle can be set to have a closed shape with G1 continuity or G2 continuity, which can reduce the degree to which stress and / or strain are concentrated locally in the circumferential direction.

[0120] In this disclosure, G1 continuity refers to tangency continuity, specifically, point-to-point continuity of a curve, with all connected line segments being tangent to each other. A curve is considered G1 continuous if it is continuous, smooth, and free of sharp corners. G2 continuity refers to curvature continuity, specifically, point-to-point continuity of a curve, with curvature analysis results showing continuous variation. If a curvature analysis of a curve shows a continuous curve with no breakpoints, it is considered G2 continuous.

[0121] Correspondingly, when the soft muscle is molded and manufactured using the soft muscle mold disclosed herein, a corresponding crease structure is provided on the soft muscle mold.

[0122] In some embodiments, in the extension direction of the central axis, two adjacent second folds 22 have different concave and convex states on the second side wall 2, wherein the concave second fold 22 is a curve including a straight line segment and G1 is continuous.

[0123] Correspondingly, the protruding first fold 12 corresponding to the second fold 22 can also be set to a similar shape. Figure 9 As shown in the protruding first fold 12 , two protruding curved segments on the first fold 12 can be connected by a straight line segment.

[0124] In the soft muscle mold disclosed herein, the concave second fold 22 corresponds to the convex fold on the outer wall of the soft muscle, so the design of the concave second fold 22 can be set based on the actual parameters of the convex fold on the outer wall of the soft muscle.

[0125] In some embodiments, the concave second fold 22 further includes at least one curved segment with a constant curvature. Specifically, the concave second fold 22 can be runway-shaped, fan-shaped (such as Figure 6c Correspondingly, the protruding first fold 12 corresponding to the second fold 22 can also be set to a similar shape (such as Figure 6c shown).

[0126] In addition, the convex second fold 22 and the concave first fold 12 can also be set to similar shapes, such as fan rings (such as Figure 7c shown).

[0127] In other embodiments, two adjacent second folds 22 have different concave and convex states in the extension direction of the central axis, wherein the concave second fold 22 is a continuous curve G2, such as a circle (such as Figure 3c as shown), oval, or any other suitable shape.

[0128] Correspondingly, the protruding first fold 12 corresponding to the second fold 22 can also be set to a similar shape (such as Figure 3c shown).

[0129] In addition, the convex second fold 22 and the concave first fold 12 can also be set to similar shapes, such as a circle (such as Figure 3d shown).

[0130] In some other embodiments, in the extension direction of the central axis, two adjacent second folds 22 have different concave and convex states on the second side wall 2, wherein the concave second fold 22 includes a third curved segment convex relative to the central axis and a fourth curved segment concave relative to the central axis, and the third curved segment is tangently connected to the fourth curved segment. Specifically, the concave second fold 22 can be a fan ring (such as Figure 6c Correspondingly, the protruding first fold 12 corresponding to the second fold 22 can also be set to a similar shape (such as Figure 6c shown).

[0131] Similarly, the convex second fold 22 and the concave first fold 12 can also be set to similar shapes (such as Figure 7c shown).

[0132] In the embodiment of the soft muscle mold disclosed herein, the first fold 12 located on the first side wall 1 can be designed with a structure and shape similar to the second fold 22 described above.

[0133] In the application of soft muscles, the soft muscles have an intrusion angle θ, an intrusion depth coefficient a, a folding surface width L, a folding surface area difference coefficient σk, and a wall thickness T. These parameters are numerically related to each other and have a set value combination. When the soft muscles are deformed, the flexible side walls only bend or stretch in a uniformly strained stacking structure, and the strain of the flexible side walls is evenly distributed on each folding surface rather than concentrated at the crease.

[0134] Accordingly, the corresponding parameters of the soft muscle mold disclosed in the present invention are set with reference to the relevant parameters of the soft muscle itself.

[0135] In the present disclosure, the soft muscle mold has corresponding parameters such as the mold penetration depth coefficient u, the width of the molding layer l, the distance t between the first folding surface 11 and the second folding surface 21, the mold penetration angle (including the first penetration angle θ1 and the second penetration angle θ2), etc. These parameters are defined based on the cross-section of the molding layer cut by the S plane.

[0136] In the present disclosure, the "S plane" is defined as follows: when any section of the outer contour line (i.e., the second fold 22) or the inner contour line (i.e., the first fold 12) of the molding cavity on the crease surface is a curved segment, the plane perpendicular to the tangent line of any point on the curved segment and passing through the point is the S plane of the point; when any section of the outer contour line (i.e., the second fold 22) or the inner contour line (i.e., the first fold 12) of the molding cavity on the crease surface is a straight line segment, the plane perpendicular to the straight line segment and passing through the point is the S plane of the point; when the outer contour line (i.e., the second fold 22) or the inner contour line (i.e., the first fold 12) of the molding cavity on the crease surface is a circle, the S plane and the longitudinal section passing through the center axis are coplanar.

[0137] In other embodiments of the present disclosure, in the extension direction of the central axis, the first fold 12 and the second fold 22 located at the same end of the forming layer are coplanar, and the plane where they are located is defined as the fold surface.

[0138] There is a first intrusion angle θ1 between the crease surface between two adjacent forming layers and the first folding surfaces 11 connected on both sides thereof. The magnitude of the first intrusion angle θ1 satisfies the following formula: σk=a(1-cosθ1) / 2(cosθ1-a),

[0139] Among them, when the preset working pressure difference range of the soft muscle is -0.08 to 0 Mpa, 0.4 < a < 0.6, 0.05 < σk < 0.7; when the preset working pressure difference range of the soft muscle is -0.08 to 0.2 Mpa, 0.25 < a < 0.55, 0.01 < σk < 0.1.

[0140] There is a second intrusion angle θ2 between the crease surface between two adjacent forming layers and the second folding surfaces 21 connected to both sides thereof. The magnitude of the second intrusion angle θ2 satisfies the following formula: σk = a(1 - cosθ2) / 2(cosθ2 - a),

[0141] Among them, when the preset working pressure difference range of the soft muscle is -0.08 to 0 Mpa, 0.4 < a < 0.55, 0.05 < σk < 0.125; when the preset working pressure difference range of the soft muscle is -0.08 to 0.2 Mpa, 0.25 < a < 0.55, 0.01 < σk < 0.1.

[0142] For specific reference Figure 2 As shown, the dotted line represents multiple crease surfaces in the soft muscle mold of the present disclosure. There can be two folding surfaces symmetric about the crease surface between two crease surfaces.

[0143] The dotted lines P1 to P3 respectively represent any three consecutive crease surfaces among multiple crease surfaces in the soft muscle mold of the present disclosure. The angle between the first folding surface 11 and the crease surface P2 is shown as the first intrusion angle θ1 in the figure, and the angles between the second folding surface 21 and the crease surfaces P1 and P3 are both shown as the second intrusion angle θ2 in the figure.

[0144] The soft muscle has an initial intrusion angle in the initial state. The first intrusion angle θ1 of the soft muscle mold of the present disclosure forms the initial intrusion angle of the inner wall of the soft muscle, and the second intrusion angle θ2 of the soft muscle mold of the present disclosure forms the initial intrusion angle of the outer wall of the soft muscle.

[0145] By making the magnitudes of the first intrusion angle θ1 and the second intrusion angle θ2 satisfy the above formula settings, a favorable initial intrusion angle range of the soft muscle can be obtained, thereby prompting the strain uniform stacking structure of the soft muscle to have a smaller strain and / or a more uniform strain distribution during the deformation process.

[0146] Refer to Figure 2As shown, in some embodiments, the first side wall 1 further includes a forming groove 13 provided at the recessed first crease 12. The forming groove 13 recesses towards the central axis in a direction perpendicular to the central axis, so as to form a crease shape holding portion extending along the shape of the protruding crease on the inner wall of the soft muscle at the protruding crease of the inner wall of the soft muscle. By forming the crease shape holding portion integrally formed with the soft muscle, the overall structure of the soft muscle can be supported, thereby increasing the structural stability of the soft muscle during operation.

[0147] In some embodiments, the magnitudes of the first intrusion angle θ1 and the second intrusion angle θ2 are not equal, so that a soft muscle with unequal initial intrusion angles of the inner and outer walls can be formed.

[0148] In some embodiments, θ1 > 18.4°, and / or θ2 > 18.4°.

[0149] In some embodiments, the width l of the forming layer is equal to the width L of the folding surface of the soft muscle, and the distance t between the first folding surface 11 and the second folding surface 21 is equal to the initial thickness T of the soft muscle.

[0150] Then, the following relationship is satisfied between t and l:

[0151] t = m * l,

[0152] where m is a preset proportionality coefficient, and 0.07 < m < 0.3.

[0153] In some embodiments, the magnitude of t is between 0.5 and 7 mm.

[0154] In some embodiments, in the extending direction of the central axis, the height of the forming layer is h1, and the distance between the first folding surface 11 and the second folding surface 21 is t. To make the formed soft muscle generate as uniform a strain distribution as possible during the folding deformation process,

[0155] h1, t, and θ1 satisfy the following relationship:

[0156] 0.05h1 / sinθ1 < t < 0.2h1 / sinθ1; and / or

[0157] h1, t, and θ2 satisfy the following relationship:

[0158] 0.05h1 / sinθ2 < t < 0.2h1 / sinθ2.

[0159] In addition, referring to Figure 2 As shown, the projection of the width l of the forming layer on a plane perpendicular to the central axis is defined as the intrusion depth u of the mold, and the intrusion depth u of the mold is set to be equal to the intrusion depth v of the soft muscle.

[0160] The penetration depth coefficient a of the soft muscle, the penetration depth v, and the equivalent radius R0 of the protruding crease satisfy the following proportional relationship: a=v / R0.

[0161] In the embodiment of the soft muscle mold disclosed herein, the mold has a mold penetration depth u (in Figure 2 As shown in the figure), the mold preset radius R (in Figure 2 As shown in FIG, the mold penetration depth u is set to be equal to the penetration depth v of the soft muscle, and the mold preset radius R is set to be equal to the equivalent radius R of the protruding fold of the soft muscle, then u and R satisfy a=u / R.

[0162] For Figure 3c The circular crease shown, R is the radius of the circular crease.

[0163] For an elliptical crease, R is the radius of a circle with the same perimeter as the elliptical cross section at the crease.

[0164] For a racetrack-shaped crease, R is the radius of the arc-shaped curve segments at both ends of the racetrack-shaped crease.

[0165] For Figure 6c In the fan-shaped fold shown, R is the radius of a circle having the same circumference as the fan-shaped cross section at the fold.

[0166] refer to Figure 1 As shown, in some embodiments, the mold body includes a top cover 400, a base 300, a mold shell 200 and a mold core 100, the mold shell 200 and the mold core 100 are arranged between the top cover 400 and the base 300, the mold shell 200 is arranged on the periphery of the mold core 100, the inner side of the top cover 400, the inner side of the base 300, the outer side of the mold core 100 and the inner side of the mold shell 200 are enclosed to form a molding cavity, and the first side wall 1 is formed on the outer side of the mold core 100, and the second side wall 2 is formed on the inner side of the mold shell 200.

[0167] In some embodiments, the mold shell 200 is a split structure, and / or the mold core 100 is a split structure.

[0168] This split design avoids the difficulty in demolding caused by the complex structure of the molded product in traditional one-piece molds. The separated parts can be extracted separately during the demolding process, reducing stress damage to the molded soft muscle and ensuring product quality and integrity.

[0169] When the mold is worn or needs to be updated according to the new soft muscle product, the mold with a split structure only needs to replace or repair the corresponding split part, without the need to replace the entire mold, which reduces maintenance costs and update cycles.

[0170] In addition, the detachable mold design allows the same set of molds to produce soft muscle products with various structures by combining different split parts, which enhances the versatility and economy of the mold and expands its applicability in different application scenarios.

[0171] In some embodiments, the mold core 100 and / or the mold shell 200 are made of at least one of 304 stainless steel, tin bronze, 35CrMo, and 20CrMn5. Alternatively, other materials with a yield strength greater than 900 MPa may be used to ensure the stability of the molding cavity.

[0172] In some embodiments, the mold core 100 includes at least five split parts, and the at least five split parts are detachably connected.

[0173] In some embodiments, one of the at least five split parts serves as a central block, and the remaining split parts are circumferentially distributed around the central block.

[0174] Different split parts can be designed according to different parts or layers of soft muscles to adapt to their complex three-dimensional geometric shapes and multi-layer structures.

[0175] In addition, the value of the soft muscle penetration depth coefficient a determines the size of the area of ​​the central block on a cross section perpendicular to the central axis. The soft muscle penetration depth v = a * R0, where R0 is the equivalent radius of the soft muscle protrusion fold.

[0176] Specific reference Figure 9 As shown, the portion of the mold core 100 whose distance from the outer periphery (i.e., the protruding first fold 12) is greater than the penetration depth v of the soft muscle can be split into a center block, so that the center block can be directly pulled out axially during the demolding process after the soft muscle is formed. The portion of the mold core 100 whose distance from the outer periphery (i.e., the protruding first fold 12) is within v (i.e., within the penetration depth range of the soft muscle) will be blocked by the folds and folded surfaces on the inner wall of the molded soft muscle during the demolding process after the soft muscle is formed, and cannot be pulled out axially. Therefore, it is necessary to split the mold into split parts around the center block, and these split parts move radially into the space left by the pulled out center block and then be pulled out axially.

[0177] Therefore, the size ratio of the central block is affected by the value of the penetration depth coefficient a of the soft muscle. Furthermore, the way the split parts around the central block are divided (size ratio and number) is also related to the value of the penetration depth coefficient a of the soft muscle.

[0178] In such Figure 5a 、 Figure 5b 、 Figure 5cIn the embodiment of the soft muscle mold shown, seven split parts are provided. The split parts 100b, 100c, and 100d are symmetrical structures provided in pairs and arranged on the periphery of the central block 100a.

[0179] In such Figure 9 In the embodiment of the soft muscle mold shown, nine split parts are provided, and the split parts 100b, 100d, and 100f are all symmetrical structures arranged in pairs, the split part 100e is arranged between the two split parts 100f, and the split part 100c is arranged between the two split parts 100d. The above eight split parts are arranged around the periphery of the central block 100a.

[0180] In some embodiments, the volume of the center block accounts for 28-45% of the volume of the mold core 100 , which helps to smoothly extract the center block during the mold removal process while maintaining the stability of the overall structure of the mold core 100 .

[0181] In some embodiments, the materials of the multiple split parts of the mold core 100 can be set to different. For example, the center block can be set to be made of aluminum alloy to reduce the overall weight of the mold core 100 and facilitate the operator to perform upper and lower mold operations.

[0182] In other embodiments, a chamfer with a radius greater than 0.5 mm is provided at the connection position between the central block and the surrounding split parts to prevent the operator from being scratched during the process of disassembling and assembling the mold.

[0183] In some embodiments, the multiple split parts of the mold core 100 are manufactured by machining, 3D metal printing, or mold replication.

[0184] In some embodiments, the molding surface of the mold (i.e., the first side wall 1 and the second side wall 2 mentioned above, i.e., the molding surface of the molding cavity) can be coated, for example, a fluorine-containing coating can be used, so as to reduce the adhesion between the molding surface and the surface of the polymer used to manufacture the soft muscle, thereby facilitating the removal of multiple split parts after the muscle is molded, and also facilitating the separation of the mold core 100 and the mold shell 200 from the molded soft muscle.

[0185] Furthermore, the coating can reduce damage (such as scratches) to the molded product during the demolding process, ensuring consistent dimensions and quality across the product. Soft muscles manufactured using the disclosed soft muscle molds have demonstrated a lifespan exceeding 3 million cycles through aging testing.

[0186] The mold core 100 of the spliced ​​structure disclosed herein can be used in a 100-ton press or injection molding machine, and the service life of the mold core 100 is not less than 5,000 times.

[0187] In some embodiments, the mold core 100 is provided with a first mating portion for positioning with the top cover 400 and / or the base 300, and the mold shell 200 is provided with a second mating portion for positioning with the top cover 400 and / or the base 300, so that the plurality of first folding surfaces 11 and the plurality of second folding surfaces 21 correspond to each other in the extending direction of the central axis, and a uniform circumferential distance and a uniform axial distance are provided between the corresponding first folding surface 11 and the second folding surface 21.

[0188] Through the above settings, the mold shell 200 and the mold core 100 can be relatively positioned, so that there is a corresponding relationship between the plurality of first folding surfaces 11 and the second folding surfaces 21, and a uniform circumferential and axial distance is provided between the folding surfaces. This design can ensure the uniformity and consistency of the formed soft muscle layer structure, thereby helping to improve the quality and performance stability of the final product.

[0189] In the application of the soft muscle, to further improve the lateral stability of the soft muscle, the following relationship is satisfied between the initial height H0 of the soft muscle and the equivalent radius R0 of the convex crease of the soft muscle: 0.6 < H0 / R0 < 3.

[0190] Therefore, in some embodiments of the soft muscle mold of the present disclosure, the height h2 of the forming cavity is set to be equal to the initial height H0 of the soft muscle, that is, the following is also satisfied between the height h2 of the forming cavity and the equivalent radius R0 of the convex crease of the soft muscle: 0.6 < h2 / R0 < 3.

[0191] Moreover, in order for the soft muscle to have good folding performance, considering the diversity of the working environment of the soft muscle, the number of layers F of the stacked structure of the soft muscle can be set to satisfy the following relationship: 8 < F < 12.

[0192] Correspondingly, in the soft muscle mold of the present disclosure, when determining the number of layers f of the forming layer, if the working space where the soft muscle is located satisfies the above value range of H0 / R0, the number of layers f of the forming layer can be directly determined to be 8 < f < 12. If the working space where the soft muscle is located does not satisfy the value range of H0 / R0, the working space can be regarded as a combination of multiple space units that satisfy the value range of H0 / R0, or a part of a single space unit, and then the number of layers F of the stacked structure of the soft muscle corresponding to each space unit is determined, and then the number of layers f of the forming layer of the soft muscle mold of the present disclosure is correspondingly determined.

[0193] The following describes several specific embodiments of manufacturing a soft muscle for a fluid brake using the soft muscle mold of the present disclosure:

[0194] In the following embodiments, the central block and the split part of the mold core 100 are both referred to as splicing blocks.

[0195] Example 1:

[0196] A polyurethane stacked structure soft muscle with a hardness of Shore A 95 and a peak-to-trough angle (intrusion angle) of 30 degrees was produced:

[0197] The temperature, time, pressure, clamping force and other parameters were set in the injection molding machine. BASF C70A C95 A polyurethane resin was dried at 80°C for 2 hours and then added to the hopper at the feed port. The injection molding machine was cleaned with this brand of TPU resin.

[0198] Assemble the center block of the mold core 100 and the surrounding split parts to form a complete mold core 100. There are two steps at the top and bottom of the mold core 100. Place the mold core 100 in the mold shell 200 and check whether the peaks and troughs of each splicing block are in the same plane. The designed angle of the peaks and troughs of the mold core 100 (intrusion angle) is 25 degrees. Close the infrared protection door of the injection molding machine, and close the top cover 400, base 300 and left and right mold shells 200.

[0199] Under the set injection molding parameters, TPU resin is injected into the mold. After holding the pressure for 60 seconds, the infrared safety door of the injection molding machine is opened, the mold shell 200 is opened, the mold core 100 after injection molding is removed, and after removing the center block, the surrounding split parts are removed. The soft muscle preparation is completed.

[0200] The wall thickness of the product is 3.0 mm for thin walls and 4.3 mm for thick walls. The angles of the crests and troughs are 25-26 degrees. After the mold cores 100 are spliced ​​together, the next set of molds is put into production.

[0201] After aging testing, the stacked structure fluid actuator with this soft muscle has been used 3.3 million times.

[0202] Example 2:

[0203] When the hardness of the polymer is Shore A 80-90, the mold needs to be designed in combination with the use conditions of the product. The thinnest and thickest wall thicknesses of the product are preferably 1.5-5mm, the gate diameter inside the mold is preferably 2-6mm, the intrusion angle is preferably 10-30°, the wave height is preferably 5-13mm, the holding time is preferably 60-75 seconds, and the injection temperature is preferably 15-30℃ above the melting point.

[0204] Within the above parameter range, the injection molded products can achieve a high compression ratio of more than 3.3 under pneumatic drive conditions. The thrust and pull output of the soft muscle during inflation and exhaust show linear changes, and the aging resistance is greater than 3.2 million times of use.

[0205] The following describes the production of a polyester (TPEE) stacked structure soft muscle with a hardness of Shore A 85 and a wall thickness greater than 5mm at all locations:

[0206] The temperature, time, pressure, clamping force and other parameters are set in the injection molding machine. A modified polyester (TPEE) resin with the brand SK G172D and 5% carbon black is dried at 75°C for 3 hours and then added to the hopper at the feed port. The injection molding machine is cleaned with the TPEE resin of the brand. The central block of the spliced ​​mold core 100 and the surrounding split parts are assembled into a complete mold core 100.

[0207] There are three calibration steps at the bottom of the mold core 100. The mold core is placed in the mold shell 200. The central block of the mold core 100 is made of PEEK material, accounting for 35% of the volume of the mold core 100, and the split parts around it are made of 35Crmo material.

[0208] Check whether the peaks and troughs of each splicing block are in the same plane. The gap wall thickness between the mold core 100 and the mold shell 200 is 5.0-5.5mm. Close the infrared protection door of the injection molding machine, close the four mold bases on the top, bottom, left and right, and inject TPEE resin into the mold under the set injection molding parameters. After holding the pressure for 40 seconds, open the infrared safety door of the injection molding machine, open the mold shell 200, remove the mold core 100 after injection, and disassemble the mold core 100 into 5 splicing blocks. The stacked structure soft muscle preparation is completed.

[0209] The thin-walled part has a thickness of 5.2mm, while the thick-walled part has a thickness of 5.5mm. After the mold cores 100 are assembled, the next set of production begins. After aging testing, the stacked fluid actuators with the soft muscle have been used 3.32 million times.

[0210] Example 3:

[0211] When the hardness of the polymer is Shore A 70-80, the mold needs to be designed in combination with the working conditions of the product. The thinnest and thickest wall thicknesses of the product are preferably 1.5-6mm, the gate diameter inside the mold is preferably 2-5mm, the intrusion angle is preferably 10-25°, the wave height is preferably 7-12mm, the holding time is preferably 60-90 seconds, and the injection temperature is preferably 10-30°C above the melting point. Within the above parameter range, the injection molded product can achieve a high compression ratio of more than 3.5 under pneumatic drive conditions, the thrust and pull output of the soft muscle inflation and exhaust output show linear changes, and the aging resistance is greater than 4 million times of use.

[0212] The following describes a method for fabricating a soft muscle made of fluororubber (FKM) and silicone rubber (SR) with a hardness of Shore A 77 and an aspect ratio of 7:1.

[0213] The injection molding machine is set to set parameters such as temperature, time, pressure, and clamping force. A modified FKM elastomer, prepared from 70 phr of DAI-EL G-558 fluororubber (FKM), 20 phr of LS4-9038 fluorosilicone, 9 phr of carbon black, and 1 phr of TAIC crosslinker, is added to the machine. The center piece of the spliced ​​core 100 and the surrounding split parts are assembled to form a complete core 100. The top of the core 100 has two calibrated steps, and the core 100 is placed in the mold shell 200.

[0214] The splicing blocks of the mold core 100 are all made of 20Crmn5 material. The crests and troughs of each splicing block are tested to see if they are in the same plane. The inner diameter of the mold core 100 is 35 mm, and the aspect ratio is designed to be 7:1.

[0215] Close the infrared protection door of the injection molding machine, close the upper and lower mold shells 200, and inject the FKM modified elastomer into the mold under the set injection molding parameters. The temperature of the mold core 100 is 135°C. After holding the pressure for 190 seconds, open the infrared safety door of the injection molding machine, open the mold shell 200, remove the mold core 100 after injection, and disassemble the mold core 100 into 4 splicing blocks. The soft muscle preparation is completed. The wall thickness of the soft muscle product is 1.7 mm at the thin wall position and 2.1 mm at the thick wall position.

[0216] After the mold core 100 is assembled, the next mold is produced. After aging testing, the stacked structure fluid actuator with the soft muscle has been used 4.2 million times.

[0217] Through the description of multiple embodiments of the soft muscle mold disclosed in the present invention, it can be seen that the soft muscle mold disclosed in the present invention can realize the one-time molding of soft muscles with complex structures, can quickly manufacture soft muscles with complex structures, significantly improve the production efficiency of soft muscles, and is particularly suitable for batch production. Among them, the soft muscle mold disclosed in the present invention can flexibly design the molding cavity structure, and can also adjust different design parameters according to the actual needs of the soft muscles, thereby ensuring the precise molding of the inner and outer walls and multi-layer stacking structure of the soft muscles, and ensuring product quality and consistency. Based on the properties of the soft muscles, the mold is designed accordingly, and the various design parameters of the mold are closely related to the working parameters of the soft muscles. For example, the folding surface is designed with a preset shape and curvature, and the shape and continuity of the crease are accurately set. This can ensure that the stress distribution of the molded soft muscles during the working process is orderly and uniform, which is conducive to improving energy conversion efficiency, enhancing environmental adaptability and work tolerance, and extending service life. In addition, the mold adopts a detachable split structure design, which is convenient for assembly, maintenance and replacement of the mold, and also helps to adapt to the production needs of soft muscle products with different structures, enhancing the versatility and economy of the mold.

[0218] To sum up, the soft muscle mold disclosed in the present invention has the advantages of high production efficiency, precise molding, strong structural adaptability, good parameter matching, high mold design flexibility and strong versatility. It can significantly improve the manufacturing efficiency and product quality of soft muscles and broaden its applicability in various application scenarios.

[0219] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and not to limit it. Although the present disclosure has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present disclosure can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solutions of the present disclosure, which should all be included in the scope of the technical solutions requested for protection in the present disclosure.

Claims

1. A soft muscle mold, characterized in that: The invention comprises a mold body, wherein the mold body is provided with a cylindrical molding cavity having a central axis, the mold body comprises a first side wall (1) and a second side wall (2) surrounding the outside of the first side wall (1), the first side wall (1) comprises a plurality of first folding surfaces (11) arranged along the central axis, the second side wall (2) comprises a plurality of second folding surfaces (21) arranged along the extension direction of the central axis, the plurality of first folding surfaces (11) and the plurality of second folding surfaces (21) are correspondingly arranged to form a plurality of molding layers, and the plurality of molding layers are stacked along the extension direction of the central axis to form the molding cavity.

2. The soft muscle mold according to claim 1, characterized in that: In the extension direction of the central axis, the shapes of the plurality of first folding surfaces (11) are the same, or the shapes of the plurality of first folding surfaces (11) are similar and their sizes vary proportionally; and / or In the extension direction of the central axis, the shapes of the plurality of second folding surfaces (21) are the same, or the shapes of the plurality of second folding surfaces (21) are similar and their sizes vary proportionally.

3. The soft muscle mold according to claim 1, characterized in that: The shapes of the first folding surface (11) and the second folding surface (21) are the same or similar.

4. The soft muscle mold according to claim 1, characterized in that: In the extension direction of the central axis, the generatrix for forming the first folding surface (11) and / or the second folding surface (21) of at least one of the molding layers is a or spline curve.

5. The soft muscle mold according to claim 1, characterized in that: In the extension direction of the central axis, a circumferentially closed first fold (12) is formed at the connection between two adjacent first folding surfaces (11); and / or In the extension direction of the central axis, a circumferentially closed second fold (22) is formed at the connection between two adjacent second folding surfaces (21).

6. The soft muscle mold according to claim 5, characterized in that: The first fold (12) is axially symmetrical, centrally symmetrical or rotationally symmetrical; and / or The second fold (22) is in an axisymmetric shape, a centrally symmetrical shape, or a rotationally symmetrical shape.

7. The soft muscle mold according to claim 5, characterized in that: In the extension direction of the central axis, In the three first folds (12) arranged in succession, The two first folds (12) arranged at intervals have the same or similar shapes and the same circumferential positions relative to the central axis, and the two adjacent first folds (12) have different concave-convex states on the first side wall (1); and / or In the three consecutively arranged second folds (22), The two second folds (22) arranged at intervals have the same or similar shapes and the same circumferential positions relative to the central axis, and the two adjacent second folds (22) have different concave-convex states on the second side wall (2).

8. The soft muscle mold according to claim 7, characterized in that: The first protruding fold (12) is a curve including straight line segments and having a continuous G1; and / or The second concave fold (22) is a curve including straight line segments and having a continuous G1.

9. The soft muscle mold according to claim 8, characterized in that: The protruding first crease (12) further includes at least one curve segment with a constant curvature; and / or The recessed second crease (22) further includes at least one curve segment with a constant curvature.

10. The soft muscle mold according to claim 7, wherein The protruding first crease (12) is a G2 continuous curve; and / or The recessed second crease (22) is a G2 continuous curve.

11. The soft muscle mold according to claim 7, wherein The protruding first crease (12) includes a first curve segment convex with respect to the central axis and a second curve segment concave with respect to the central axis, and the first curve segment is tangentially connected to the second curve segment; and / or The recessed second crease (22) includes a third curve segment convex with respect to the central axis and a fourth curve segment concave with respect to the central axis, and the third curve segment is tangentially connected to the fourth curve segment.

12. The soft muscle mold according to claim 7, characterized in that: The first side wall (1) further includes a forming groove (13) provided at the recessed first crease (12), and the forming groove (13) recesses towards the central axis in a direction perpendicular to the central axis, so as to form a crease shape holding portion extending along the shape of the protruding crease on the inner wall of the soft muscle.

13. The soft muscle mold according to any one of claims 5 to 12, characterized in that: The soft muscle has an intrusion depth coefficient a and a folding surface area difference coefficient σk. In the extending direction of the central axis, the first crease (12) and the second crease (22) at the same end of the forming layer are coplanar, and the plane where they are located is defined as the crease plane. There is a first intrusion angle θ1 between the crease plane between two adjacent forming layers and the first folding surfaces (11) connected to its two sides. The first intrusion angle θ1 is defined based on the cross-section of the forming layer剖切 by the S plane, and the magnitude of the first intrusion angle θ1 satisfies the following formula: σk = a(1 - cosθ1) / (2cosθ1 - a), where, when the preset working pressure difference range of the soft muscle is -0.08~0 Mpa, 0.4 < a < 0.6, 0.05 < σk < 0.7; when the preset working pressure difference range of the soft muscle is -0.08~0.2 Mpa, 0.25 < a < 0.55, 0.01 < σk < 0.

1. and / or There is a second intrusion angle θ2 between the crease plane between two adjacent forming layers and the second folding surfaces (21) connected to its two sides. The second intrusion angle θ2 is defined based on the cross-section of the forming layer剖切 by the S plane, and the magnitude of the second intrusion angle θ2 satisfies the following formula: σk = a(1 - cosθ2) / (2cosθ2 - a), where, when the preset working pressure difference range of the soft muscle is -0.08~0 Mpa, 0.4 < a < 0.55, 0.05 < σk < 0.125; when the preset working pressure difference range of the soft muscle is -0.08~0.2 Mpa, 0.25 < a < 0.55, 0.01 < σk < 0.

1.

14. The soft muscle mold according to any one of claims 1~12, wherein The width l of the shaping layer is equal to the width L of the folding surface of the soft muscle, the distance t between the first folding surface (11) and the second folding surface (21) is equal to the initial thickness T of the soft muscle, and the width l of the shaping layer and the distance t between the first folding surface (11) and the second folding surface (21) are defined based on a cross section of the shaping layer cut by the S plane. Then the following relationship is satisfied between t and l: t=m*l, Among them, m is the preset proportional coefficient, 0.07 <m<0.3。 15. The soft muscle mold according to claim 14, characterized in that: The size of t is between 0.5 and 7 mm.

16. The soft muscle mold according to any one of claims 1 to 12, characterized in that: The distance between the first side wall (1) and the second side wall (2) at the connection point of two adjacent molding layers is greater than the distance between the first side wall (1) and the second side wall (2) at other positions.

17. The soft muscle mold according to claim 1, wherein the mold body comprises a top cover (400), a base (300), a mold shell (200) and a mold core (100), the mold shell (200) and the mold core (100) are arranged between the top cover (400) and the base (300), the mold shell (200) is arranged on the outer periphery of the mold core (100), the inner side of the top cover (400), the inner side of the base (300), the outer side of the mold core (100) and the inner side of the mold shell (200) enclose the molding cavity, and the first side wall (1) is formed on the outer side of the mold core (100), and the second side wall (2) is formed on the inner side of the mold shell (200).

18. The soft muscle mold according to claim 17, characterized in that: The mold core (100) is provided with a first matching portion for positioning with the top cover (400) and / or the base (300), and the mold shell (200) is provided with a second matching portion for positioning with the top cover (400) and / or the base (300), so that the plurality of first folding surfaces (11) and the plurality of second folding surfaces (21) correspond one to one in the extension direction of the central axis, and the corresponding first folding surfaces (11) and the second folding surfaces (21) have a uniform circumferential distance and a uniform axial distance.

19. The soft muscle mold according to claim 17, characterized in that: The mold shell (200) is a split structure, and / or the mold core (100) is a split structure.

20. The soft muscle mold according to claim 19, characterized in that: The mold core (100) comprises at least five split parts, and the at least five split parts are detachably connected.

21. The soft muscle mold according to claim 20, characterized in that: One of the at least five split parts serves as a central block, and the remaining split parts are circumferentially distributed around the central block.

22. The soft muscle mold according to claim 21, characterized in that: The volume of the central block accounts for 28-45% of the volume of the mold core (100).

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