Fastening parts, manufacturing method thereof, and mold device

Abstract

To avoid or suppress shortened lifespan of a mold directly affecting a manufacturing cost of a fastening component.SOLUTION: A fastening component 1 comprises a two-dimensional array 20 of engaging elements 2 in which a plurality of engaging elements 2 are arranged corresponding to a plurality of lattice points of a plane lattice, a plurality of first ribs 31, a plurality of second ribs 32, and a plurality of openings 4 formed in a fastening area 15 including the two-dimensional array 20. The first ribs 31 connect engaging elements 2 adjacent in the first direction, to each other. The second ribs 32 connect engaging elements 2 adjacent in a second direction different from the first direction, to each other. The plurality of first ribs 31 and / or the plurality of second ribs 32 are provided such that two or more openings 4 having opening areas corresponding to two or more unit lattices of the plane lattice are included in the plurality of openings 4.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a fastening part, a manufacturing method thereof, and a mold device. [Background technology]

[0002] Patent Document 1 discloses a fastening part in which a number of engaging elements are provided on a base in which a number of windows are formed (see FIG. 1 of the document).

[0003] Patent Document 2 discloses a hook-and-loop fastener made entirely from a thermoplastic elastomer. Multiple first strands and multiple second strands intersect to form multiple holes. The hook-and-loop fastener is manufactured by stretching, as shown in Figure 4 of the document.

[0004] Other hook-and-loop fastener structures are also known (see, for example, Patent Documents 3 and 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 7,246,416 [Patent Document 2] International Publication No. 2019 / 107444 [Patent Document 3] Utility Model Registration No. 2586918 [Patent Document 4] Japanese Patent Application Publication No. 3-205001 Summary of the Invention [Problem to be solved by the invention]

[0006] When protrusions are provided on a mold to form openings in fastening parts, the risk of mold protrusion damage increases in proportion to the number of mold protrusions. The mold life directly affects the manufacturing cost of fastening parts, so it is desirable to avoid or suppress a shortening of the mold life. [Means for solving the problem]

[0007] The present inventors have newly discovered that there is room for extending the life of the molds used to manufacture fastening parts by modifying their structure.

[0008] A fastening part according to a first embodiment of the present disclosure includes a two-dimensional array of engaging elements in which a plurality of engaging elements are arranged corresponding to a plurality of lattice points of a planar lattice, a plurality of first ribs each connecting adjacent engaging elements in a first direction in the two-dimensional array, a plurality of second ribs each connecting adjacent engaging elements in a second direction different from the first direction in the two-dimensional array, and a plurality of openings formed in a fastening region in which the two-dimensional array is provided. The plurality of first ribs and / or the plurality of second ribs are provided so that the plurality of openings includes two or more openings having opening areas corresponding to two or more unit cells of the planar lattice.

[0009] In some embodiments, (i) the plurality of openings are formed in a mesh pattern in the fastening region in accordance with at least the plurality of first ribs and the plurality of second ribs, and / or (ii) each of the two or more openings is wide in one of the first and second directions and narrow in the other of the first and second directions, and / or (iii) each of the two or more openings has an opening area corresponding to two or three unit cells of a planar lattice.

[0010] In one or any combination of the above embodiments, the unit cell of the planar lattice and / or the aperture shape of the apertures may be a square, a rectangle, a parallelogram, or a rhombus.

[0011] In one or any combination of the above-described embodiments, the fastening part may further include a frame-shaped base surrounding the fastening region, and a plurality of third ribs, each of which connects an engaging element located at the outermost position in the two-dimensional array to the frame-shaped base. An embodiment in which the first rib and / or the second rib are thicker than the frame-shaped base and the third rib is thinner than the first rib and / or the second rib is also envisioned.

[0012] In one or any combination of the above embodiments, each of the plurality of engaging elements may include at least an engaging head and a stem portion, and the stem portion may have a T-shaped cross section in a plane parallel to the planar lattice. A configuration is also envisioned in which the stem portion includes a first stem wall connected to the engaging head by a first width from one end of the engaging head to the other end in one of the first and second directions, and a second stem wall connected to the engaging head by a second width from the one end of the engaging head to the first stem wall in the other of the first and second directions.

[0013] In one or any combination of the above embodiments, the number of first ribs may be 2 / 3 or less, or 1 / 2 or less, of the total number of first ribs that can be allocated for connecting the engaging elements in the fastening region. Embodiments in which the number of second ribs is equal to the total number of second ribs that can be allocated for connecting the engaging elements in the fastening region are also envisioned.

[0014] A mold apparatus according to another aspect of the present disclosure is a mold apparatus for manufacturing any of the fastening parts described above, comprising a first mold and a second mold, wherein the first mold comprises a plurality of recesses for molding the engaging heads of the engaging elements included in at least a two-dimensional array, and the second mold has a plurality of block portions provided corresponding to the plurality of openings, the plurality of block portions including two or more block portions having opening areas corresponding to two or more unit cells of a planar lattice. In some embodiments, the plurality of block portions include a plurality of types of block portions that differ in width and length perpendicular to the width when the main surface of the second mold is viewed from the front. The present disclosure also relates to a manufacturing method for manufacturing a fastening part using the above-described mold apparatus. [Effects of the Invention]

[0015] According to one aspect of the present disclosure, a fastening part that can promote a longer life of a mold can be provided. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic top perspective view of a fastening part according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic bottom perspective view of the fastening part. [Figure 3] FIG. 2 is a schematic top view of the fastening part. [Figure 4] FIG. 2 is a schematic bottom view of the fastening part. [Figure 5] 1 is an enlarged perspective view of a two-dimensional array of engaging elements, and also shows a schematic view of the manner in which engaging heads and stems of the engaging elements are joined together. [Figure 6] 4 is a schematic end view of the fastening part, showing the end faces along imaginary straight lines C1, C3, and C5 extending in the row direction of FIG. 3. [Figure 7] 4 is a schematic end view of the fastening part, showing the end surface along imaginary straight lines C2 and C4 extending in the row direction of FIG. 3. FIG. [Figure 8] 4 is a schematic end view of the fastening part, showing the end faces along imaginary straight lines R1, R2, R3, and R4 extending in the column direction of FIG. 3. [Figure 9] 1 is a schematic perspective view of a fastening device made up of a pair of fastening parts of the same structure and material. [Figure 10] FIG. 2 is a front view of the fastening device showing how the fastening parts are engaged with each other. [Figure 11] 3 is a cross-sectional view of the fastening device showing how fastening parts are engaged with each other. FIG. [Figure 12] FIG. 2 is a front view of a first mold for manufacturing a fastening part. [Figure 13] FIG. 10 is a front view of a second mold for manufacturing a fastening part. [Figure 14]FIG. 10 is a schematic top perspective view of a fastening part according to another embodiment of the present disclosure. [Figure 15] FIG. 15 is a schematic bottom perspective view of the fastening part of FIG. 14. [Figure 16] FIG. 15 is a schematic top view of the fastening part of FIG. 14. [Figure 17] FIG. 15 is a schematic bottom view of the fastening part of FIG. 14. [Figure 18] FIG. 1 is a schematic diagram showing a manufacturing example using a die wheel. DETAILED DESCRIPTION OF THE INVENTION

[0017] Non-limiting embodiments and features of the present invention will be described below with reference to the drawings. Those skilled in the art will be able to combine the various embodiments and / or features without the need for excessive explanation, and will also be able to understand the synergistic effects of such combinations. Duplicate descriptions between embodiments will generally be omitted. The reference drawings are primarily intended to describe the invention, and are simplified for ease of illustration. Each feature is not only applicable to the fastening part disclosed in this specification, but is understood as a universal feature that is also applicable to various other fastening parts not disclosed in this specification.

[0018] A fastening part 1 will be described with reference to FIGS. 1 to 8. FIG. 1 is a schematic top perspective view of a fastening part 1 according to one embodiment of the present disclosure. FIG. 2 is a schematic bottom perspective view of the fastening part 1. FIG. 3 is a schematic top view of the fastening part 1. FIG. 4 is a schematic bottom view of the fastening part 1. FIG. 5 is an enlarged perspective view of a two-dimensional array 20 of engaging elements 2. FIG. 6 is a schematic end view of the fastening part 1, showing the end surface along imaginary lines C1, C3, and C5 extending in the row direction of FIG. 3. FIG. 7 is a schematic end view of the fastening part 1, showing the end surface along imaginary lines C2 and C4 extending in the row direction of FIG. 3. FIG. 8 is a schematic end view of the fastening part 1, showing the end surface along imaginary lines R1, R2, R3, and R4 extending in the column direction of FIG. 3.

[0019] The fastening part 1 is designed to be able to engage and disengage with another fastening part of the same structure, i.e., it can be a hook-to-hook type fastening part. The fastening part 1 is formed from a soft and elastic material (e.g., thermoplastic elastomer (TPE)) and has both shape retention (shape stability) and flexibility. Specifically, the fastening part 1 bends and deflects in response to the application of an external force, but can return to its original shape by stopping the force. Therefore, the fastening parts 1 can be repeatedly engaged and disengaged with each other over a long period of time. Typically, the fastening part 1 has larger engaging elements than the male members of ordinary hook-and-loop fasteners, and their density is, for example, 2 to 28 elements / cm. 2 However, this is not necessarily the case. Of course, the various features of the present disclosure do not necessarily require such a type of fastening part. Specific examples of thermoplastic elastomers that can be used for the fastening part 1 include, but are not limited to, thermoplastic polyurethane (TPU) and thermoplastic styrene (TPS).

[0020] The fastening part 1 has a two-dimensional array 20 of hook-shaped engaging elements 2, a plurality of first ribs 31, a plurality of second ribs 32, a plurality of third ribs 33, a group of openings 4A, and a frame-shaped base 5. In the two-dimensional array 20 of the engaging elements 2, a plurality of engaging elements 2 are arranged corresponding to a plurality of lattice points of a planar lattice. Typically, the planar lattice may be a square lattice, a rectangular lattice, a parallelepiped lattice, or a rhombic lattice. Note that the unit lattice (smallest unit lattice) of a square lattice is a square. The unit lattice (smallest unit lattice) of a rectangular lattice is a rectangle. The unit lattice (smallest unit lattice) of a parallelepiped lattice is a parallelogram. The unit lattice (smallest unit lattice) of a rhombic lattice is a rhombic shape. In either type of unit lattice, the lattice points are arranged along a first direction and a second direction different from the first direction, resulting in the formation of the two-dimensional array 20. The first direction and the second direction intersect at an arbitrary angle. In square and rectangular lattices, the first and second directions are perpendicular to each other. In parallelepiped and rhombic lattices, the first and second directions are not perpendicular to each other, but intersect at a predetermined angle. It is also possible to omit the placement of engaging elements 2 at some lattice points without providing engaging elements 2 at all lattice points of a planar lattice.

[0021] For a clearer or more detailed explanation, please refer to FIGS. 3 and 4. The square lattice shown in FIGS. 3 and 4 is defined by virtual lines C1 to C5 parallel to a first direction (here, the row direction) and virtual lines R1 to R4 parallel to a second direction (here, the column direction). The number of virtual lines parallel to the first direction can be in the range of 3 to 15. The same applies to the number of virtual lines parallel to the second direction. The virtual lines C1 to C5 are arranged at equal intervals. The same is true for the virtual lines R1 to R4. In the case of a square lattice, the pitch interval P1 between the virtual lines R1 to R4 and the pitch interval P2 between the virtual lines C1 to C4 are equal, but if a different type of planar lattice is used, the two may be different. The pitch interval P1 is equal to the lattice point interval in the first direction. The pitch interval P2 is equal to the lattice point interval in the second direction. Typically, the lattice point intervals in the first and second directions are in the range of 1.9 mm to 6.5 mm.

[0022] The following description focuses on the virtual straight lines C1 to C5. The intersections of the virtual straight line C1 and the virtual straight lines R1 to R4 are lattice points, and the engaging elements 2 are arranged at regular intervals on the virtual straight line C1 to form a one-dimensional array of the engaging elements 2 along the first direction. The same description applies to the other virtual straight lines C2 to C5. In this way, the two-dimensional array 20 described above is formed from a collection of the one-dimensional arrays of the engaging elements 2 on the virtual straight lines C1 to C5. The following description focuses on the virtual straight lines R1 to R4. The intersections of the virtual straight line R1 and the virtual straight lines C1 to C5 are lattice points, and the engaging elements 2 are arranged at regular intervals on the virtual straight line R1 to form a one-dimensional array of the engaging elements 2 along the second direction. The same description applies to the other virtual straight lines R2 to R4. In this way, the two-dimensional array 20 described above is formed from a collection of the one-dimensional arrays of the engaging elements 2 on the virtual straight lines R1 to R4.

[0023] Each engaging element 2 is hook-shaped rather than loop-shaped and typically includes at least an engaging head 6 and a stem 7. The engaging head 6 has a curved top surface 61 and a flat engaging surface 62 opposite the top surface 61. The top surface 61 faces upward (opposite the side where the first rib 31, the second rib 32, and the frame-shaped base 5 are located), and the engaging surface 62 faces downward (the side where the first rib 31, the second rib 32, and the frame-shaped base 5 are located). The engaging head 6 may have a spherical crown shape or a hemispherical shape obtained by cutting a sphere with a plane for simpler molding or other purposes. The engaging head 6 has a circular outline when viewed from the front as shown in FIG. 3, but can also have other shapes such as an ellipse, a cross, or a star. The maximum width (or maximum diameter) of the engaging head 6 in the first and second directions is within a range of 70% to 95% of the lattice point spacing in the first and second directions, e.g., within a range of 1 mm to 5 mm. The locking surface 62 may be a plane parallel to the plane on which the frame-shaped base 5 is disposed.

[0024] The stem portion 7 may be connected to multiple ribs. The stem portion 7 may also have a T-shaped cross section in a plane parallel to the planar grid (see FIG. 5). This may result from a total of three ribs (here, the first to third ribs 31, 32, and 33 are not distinguished from one another and are simply referred to as "ribs" as a general concept) being connected to one engaging element 2. In other words, each engaging element 2 may be connected to other surrounding engaging elements and / or the frame-shaped base 5 via a total of three ribs. This allows the fastening part 1 to achieve a good balance between flexibility and mechanical strength. In the illustrated example, this characteristic applies to all engaging elements 2, but it is also possible to connect two or four ribs to some engaging elements 2.

[0025] Advantageously, the stem portion 7 includes a first stem wall 71 connected to the engaging head 6 by a first width W1 from one end of the engaging head 6 to the other end in one of the first and second directions (in the second direction in FIG. 5 ), and a second stem wall 72 connected to the engaging head 6 by a second width W2 from one end of the engaging head 6 to the first stem wall 71 in the other of the first and second directions (in the first direction in FIG. 5 ). Directly connecting the engaging head 6 and the stem portion 7 without any gaps in this manner simplifies the structure of the mold used to manufacture the fastening part 1 (for example, a two-way punch mold can be used) and / or promotes its long life. Furthermore, because the engaging elements 2 are connected by linear ribs such as the first rib 31 and the second rib 32, the required flexibility of the fastening part 1 as a whole can be ensured.

[0026] When fastening parts 1 engage with each other in the vertical direction, the top surfaces 61 of the engaging heads 6 of the upper and lower fastening parts 1 come into contact with each other, and the curved top surfaces 61 of these engaging heads 6 properly align the fastening parts 1 (i.e., the top surfaces 61 function as guide surfaces for aligning the fastening parts 1). When the upper and lower fastening parts 1 engage with each other, the locking surfaces 62 of the respective engaging elements 2 come into (partial) contact with each other. By increasing or decreasing the contact area between the locking surfaces 62, the engaging force of the fastening parts 1 per unit area and the force required to engage them can be adjusted.

[0027] The first rib 31 connects adjacent engaging elements 2 (e.g., their stem portions 7) to each other in a first direction in the two-dimensional array 20. The second rib 32 connects adjacent engaging elements 2 (e.g., their stem portions 7) to each other in a second direction different from the first direction in the two-dimensional array 20. The third rib 33 connects the engaging elements 2 (e.g., their stem portions 7) located at the outermost positions (in other words, the outermost periphery) in the two-dimensional array 20 to the frame-shaped base 5. Note that in a configuration in which the frame-shaped base 5 is omitted, the third rib 33 is omitted, or is provided for a purpose other than connection to the frame-shaped base 5.

[0028] The first rib 31, the second rib 32, and the third rib 33 are all linear ribs and are provided on the same plane (i.e., one rib is not stacked on another rib). Each first rib 31 has a predetermined width in the second direction. This predetermined width may be a constant distance (spacing) between adjacent engaging elements 2 connected by the first rib 31 in the first direction. Similarly, each second rib 32 has a predetermined width in the first direction. This predetermined width may be a constant distance (spacing) between adjacent engaging elements 2 connected by the second rib 32 in the second direction. The third rib 33 extends along either the first or second direction and may have a constant predetermined width, similar to the first rib 31 and the second rib 32. In this configuration, the mold for forming the locking surface 62 of the engaging head 6 can be block-shaped, which facilitates simplification of the mold structure.

[0029] The opening group 4A includes a plurality of openings 4 formed in the fastening region 15 (see FIG. 3 ) in which the two-dimensional array 20 is provided. The plurality of openings 4 are formed in the fastening region 15, and the engaging elements 2 are connected in the fastening region 15 by ribs (particularly, the first rib 31 and the second rib 32). Each opening 4 is a through-hole that penetrates a portion of the fastening part 1 that is in the same layer as the ribs (particularly, the first rib 31 and the second rib 32) or on the same plane as them, and communicates with a space above and below the plane on which the ribs (particularly, the first rib 31 and the second rib 32) are present. Note that, when a frame-shaped base 5 is provided, each opening 4 penetrates a portion of the fastening part 1 that is in the same layer as the frame-shaped base 5 or on the same plane as it.

[0030] The multiple openings 4 are typically formed in a mesh pattern in the fastening region 15 corresponding to at least the multiple first ribs 31 and the multiple second ribs 32. For example, the multiple openings 4 are formed corresponding to multiple (e.g., all) unit cells of a planar lattice in which the engaging elements 2 are arranged at each lattice point. The number of openings 4 may be 70% or more, 80% or more, or 90% of the total number of unit cells of the planar lattice. This reduces the weight of the fastening part 1 and ensures its high flexibility. Each opening 4 included in the opening group 4A may be formed to have an opening shape such as a square, rectangle, parallelogram, or rhombus depending on the type of planar lattice. Each opening 4 may be formed to have the same or different opening area (mesh size). Note that the opening area of ​​the openings 4 refers to the opening area of ​​the openings 4 in the same layer (same plane) as the ribs (particularly the first ribs 31 and the second ribs 32) and / or the frame-shaped base 5, regardless of whether they are partially covered by the engaging heads 6 of the engaging elements 2. The minimum number of openings 4 that can be said to be formed in a mesh pattern may be 50%, 60%, or 70% of the total number of unit cells of the planar lattice.

[0031] The openings 4 may be defined by different portions depending on their positions in the fastening region 15. For example, one opening 4 surrounded by imaginary straight lines R1, R2, C2, and C4 is defined by the first rib 31 connecting the engaging elements 2 on the imaginary straight lines C2 and C4, and by the second rib 32 connecting the engaging elements 2 on the imaginary straight lines R1 and R2. In contrast, one opening 4 surrounded by imaginary straight lines R1, R2, and C2 and the frame-shaped base 5 is defined by the first rib 31 connecting the engaging elements 2 on the imaginary straight lines C2, the second rib 32 connecting the engaging elements 2 on the imaginary straight lines R1 and R2, and the third rib 33 connecting the engaging elements 2 on the imaginary straight lines R1 and R2 to the frame-shaped base 5. An opening 4 located at a corner of the rectangular fastening region 15 is defined by the third rib 33 extending in the first direction and the third rib 33 extending in the second direction connecting the engaging elements 2 to the frame-shaped base 5. In this way, there are some openings 4 in which the first and second ribs 31, 32 are not involved in defining the opening 4, but they are in the minority. The opening shape of the opening 4 can be further changed by changing the shape of the frame-like base 5 and the length of the third rib 33.

[0032] Forming the openings 4 in a mesh pattern does not necessarily require that the openings 4 correspond to all unit cells of the planar lattice. For example, it is possible to seal one or more openings 4 with a thin-walled portion. The thin-walled portion prevents the mold protrusions from colliding with each other during mold mating, thereby promoting a longer life for the mold protrusions. The thin-walled portion may have the same thickness as the frame-shaped base 5.

[0033] In the fastening region 15, a mesh structure is constructed from the two-dimensional array 20, the first rib 31, and the second rib 32 (and optionally, the third rib 33). By providing a frame-shaped base 5 so as to surround the fastening region 15 (and the mesh structure), it is possible to reinforce the mechanical strength of the fastening part 1 while ensuring high flexibility. When the frame-shaped base 5 is provided, the fastening part 1 can be easily attached to the article by sewing, adhering, or welding the frame-shaped base 5 to the article. The frame-shaped base 5 includes a pair of frame portions 51 extending in a first direction and a pair of frame portions 52 extending in a second direction. The frame portions 51 are arranged at a fixed interval in the second direction. The frame portions 52 are arranged at a fixed interval in the first direction. Note that a configuration in which the frame portions extend in a direction different from the first and second directions is also envisioned.

[0034] 6 to 8. The first rib 31 and / or the second rib 32 can be thicker than the frame-shaped base 5. This allows for a good balance between the mechanical strength, flexibility, and ease of sewing of the fastening part 1. The third rib 33 is thinner than the first rib 31 and / or the second rib 32, and is formed to have, for example, the same thickness as the frame-shaped base 5.

[0035] Between two adjacent engaging elements 2 in the first direction, a groove 8 is formed, extending from the open end between the engaging heads 6 of those engaging elements 2 to the bottom end defined by the first rib 31. Similarly, between two adjacent engaging elements 2 in the second direction, a groove 8 is formed, extending from the open end between the engaging heads 6 of those engaging elements 2 to the bottom end defined by the second rib 32. The thinning of the first and second ribs 31, 32 due to such groove 8 makes it easier for the engaging elements 2 to deform, promoting smooth engagement of the fastening parts 1 with each other.

[0036] As can be seen from the referenced drawings, in this embodiment, multiple first ribs 31 and / or multiple second ribs 32 are provided so that the opening group 4A (i.e., multiple openings) includes two or more openings 4 having opening areas corresponding to two or more unit cells of the planar lattice. This increases the flexibility of the fastening part 1 and reduces the total number of block parts of the mold used to manufacture the fastening part 1. Increasing the opening area of ​​two or more openings also reduces material costs. When an engaging element 2 without a gap between the engaging head 6 and the stem portion 7 is used, adopting the above-mentioned configuration promotes displacement and deformation of the engaging element 2.

[0037] 3 and 4, a plurality of first ribs 31 are provided so that the two or more openings 4 described above are included in the opening group 4A, but a plurality of second ribs 32 are not provided in this manner. The key point is to omit (i.e., thin out) two or more first ribs from the total number of first ribs that can be allocated for connecting adjacent lattice points in a first direction with respect to the planar lattice (specifically, connecting the engaging elements 2), and additionally or alternatively, to omit (i.e., thin out) two or more second ribs from the total number of second ribs that can be allocated for connecting adjacent lattice points in a second direction with respect to the planar lattice (specifically, connecting the engaging elements 2). Note that one rib used for connecting between lattice points (connecting the engaging elements 2) is typically a single molded part.

[0038] The opening surrounded by the imaginary lines R1, R2, C2, and C4 (referred to as the first opening) has an opening area corresponding to two unit cells of the planar lattice. This is also true for the opening surrounded by the imaginary lines R2, R3, C1, and C3 (referred to as the second opening), the opening surrounded by the imaginary lines R2, R3, C3, and C5 (referred to as the third opening), and the opening surrounded by the imaginary lines R3, R4, C2, and C4 (referred to as the fourth opening). The first through fourth openings are all wide in the second direction and narrow in the first direction. Of course, the first through fourth openings can also be formed so that they are wide in the first direction and narrow in the second direction. It is practical for the first through fourth openings to have opening areas corresponding to two or three unit cells of the planar lattice. In other words, if the first through fourth openings have opening areas corresponding to four or more unit cells, the mechanical strength of the fastening part 1 may be reduced beyond the allowable range.

[0039] Referring to FIG. 4, the total number of first ribs 31 that can be allocated in the fastening region 15 is 15. In this regard, the number of first ribs 31 that are actually arranged in the fastening region 15 is 7. In other words, the number of first ribs 31 is 2 / 3 or less, or 1 / 2 or less, of the total number of first ribs 31 that can be allocated for connecting the engaging elements 2 in the fastening region 15. By reducing (i.e., thinning out) the number of first ribs 31 in this way, it is possible to easily form openings 4 having an opening area corresponding to two or more unit cells. Note that the number of first ribs 31 used for connecting adjacent engaging elements 2 is one.

[0040] Explaining further with reference to Figure 4, the number of second ribs 32 that can be allocated in the fastening region 15 is 16. In this regard, the number of second ribs 32 that are actually arranged in the fastening region 15 is 16. In other words, the number of second ribs 32 is equal to the total number of second ribs 32 that can be allocated for connecting the engaging elements 2 in the fastening region 15. This makes it possible to ensure the desired mechanical strength of the fastening part 1 even if the first ribs 31 are thinned out as described above. Note that the number of second ribs 32 used for connecting adjacent engaging elements 2 is one.

[0041] Fig. 9 is a schematic perspective view of a fastening device composed of a pair of fastening parts 1, 1' having the same structure and material. Fig. 10 is a front view of the fastening device showing how the fastening parts 1, 1' engage with each other. Fig. 11 is a cross-sectional view of the fastening device showing how the fastening parts 1, 1' engage with each other. Of the fastening parts 1, 1' shown in Figs. 9 to 11, fastening part 1 will be referred to as the lower part, and fastening part 1' will be referred to as the upper part.

[0042] Referring to FIG. 11 , when the upper part 1' is gently pressed downward to engage with the lower part 1, the engaging elements 2 of the upper and lower parts 1, 1' come into contact at the top surfaces 61 of their engaging heads 6, thereby properly aligning the two parts. When the upper part 1' is pressed against the lower part 1, the engaging elements 2 of the lower part 1 pass over the engaging heads 6 of the engaging elements 2 of the upper part 1' and enter the opening 4 of the upper part 1', causing the engaging elements 2 of the upper and lower parts 1, 1' to come into contact at their locking surfaces 62. In this manner, the upper and lower parts 1, 1' are engaged. The engagement between the upper and lower parts 1, 1' can be released by grasping the outer periphery of the upper part 1' and pulling it away from the lower part 1. Note that in the state shown in FIG. 10 , the engaging heads of the engaging elements 2 of the lower part 1 can be seen through the opening 4 of the upper part 1'.

[0043] The fastening part 1 can be manufactured by injection molding using a mold assembly constructed from a first mold 100 shown in FIG. 12 and a second mold 200 shown in FIG. 13. For example, the second mold 200 is a fixed mold, and the first mold 100 is a movable mold that is moved up and down relative to the second mold 200. The first mold 100 shown in FIG. 12 has a main surface 101 formed to correspond to the fastening region 15, a protrusion 103 for thinning the third rib 33, a plurality of recesses 106 for molding the engaging head 6 of each engaging element 2 in the two-dimensional array 20, and a protrusion 108 for forming the above-mentioned groove 8 in the first rib 31 and the second rib 32. The recess 106 is recessed from the main surface 101. The protrusions 103 and 108 protrude from the main surface 101. A step is formed on the outer periphery of the main surface 101 to ensure the thickness of the first and second ribs 31 and 32.

[0044] The second mold 200 shown in FIG. 13 has a plurality of block portions 204 provided corresponding to the plurality of openings 4. Grooves 201, 202, and 203 are formed between the block portions 204, which form ribs (first rib 31, second rib 32, and third rib 33) and / or stem walls (first stem wall 71 and second stem wall 72). When viewed from the front of the main surface of the second mold 200 as shown in FIG. 13, the block portion 204 includes two or more block portions (see 204B) each having an area corresponding to two or more unit cells of the planar lattice described for the fastening part 1. This increases the strength of the block portions and promotes a longer life for the second mold 200.

[0045] When the first mold 100 and the second mold 200 are mated, the block portion 204 abuts against the main surface 101 of the first mold 100, thereby defining a molding cavity for molding the fastening part 1. Advantageously, the multiple block portions 204 include multiple types of block portions 204 that differ in width and length perpendicular to the width when the main surface of the second mold 200 is viewed from the front. This can satisfy constraints regarding the shape of the fastening part 1 in addition to the flexibility and mechanical strength of the fastening part 1. Each block portion 204 can have a main block surface (e.g., rectangular when viewed from the front) that contacts the main surface 101 of the first mold 100 and multiple (e.g., four) side wall surfaces that extend from the outer periphery of the main block surface in the depth direction of the groove. When the opening shape of the opening 4 changes, the shape of the block portion 204 also changes accordingly. The side wall surfaces of the block portion 204 can be non-vertical surfaces with a draft angle or vertical surfaces without a draft angle.

[0046] Another embodiment will be described with reference to FIGS. 14 to 17 , and the various features and any combinations thereof described above are applicable. FIG. 14 is a schematic top perspective view of a fastening part according to another embodiment of the present disclosure. FIG. 15 is a schematic bottom perspective view of the fastening part of FIG. 14 . FIG. 16 is a schematic top view of the fastening part of FIG. 14 . FIG. 17 is a schematic bottom view of the fastening part of FIG. 14 . As shown in FIGS. 14 to 17 , the square lattice is set at an oblique angle with respect to the frame-shaped base 5, resulting in the first rib 31, the second rib 32, and the third rib 33 extending in an oblique direction (compared to FIGS. 3 and 4 ). Even in this embodiment, the same effect as described above can be achieved by thinning out the first rib 31 and / or the second rib 32.

[0047] Fastening part 1 can also be manufactured by methods other than injection molding, as schematically shown in FIG. 18. In FIG. 18, a first mold 100 is provided as a first die wheel, and a second mold is provided as a second die wheel. The mold structure shown in FIG. 12 is continuously formed on the circumferential surface of the first die wheel. The mold structure shown in FIG. 13 is continuously formed on the circumferential surface of the second die wheel. The first and second die wheels are positioned adjacent to each other with a predetermined minimum gap between them and are continuously controlled to rotate. Fastening part 1 is continuously molded by supplying molten material from discharge section 300 between the first and second die wheels.

[0048] In light of the above disclosure, those skilled in the art can make various modifications to each feature and each embodiment. The reference numerals included in the claims are for reference purposes only and should not be used to limit the interpretation of the claims. [Explanation of symbols]

[0049] 1: Fastening parts 1': Fastening parts 2: Engagement element 4:Aperture 5: Frame base 6: Engagement head 7: Stem part 15: Fastening area 20: Two-dimensional array 31: First rib 32: Second rib 33: Third rib 71: First stem wall 72: Second stem wall 100: First mold 101: Main surface 106: Recess 200: Second mold 204: Block section

Claims

1. a two-dimensional array (20) of engaging elements (2) in which a plurality of engaging elements (2) are arranged corresponding to a plurality of lattice points of a planar lattice; a plurality of first ribs (31), each of which connects adjacent engaging elements (2) in the two-dimensional array (20) in a first direction; a plurality of second ribs (32), each of which connects adjacent engaging elements (2) in a second direction different from the first direction in the two-dimensional array (20); A fastening part (1) having a plurality of openings (4) formed in a fastening region (15) in which the two-dimensional array (20) is provided, A fastening part in which the plurality of first ribs (31) and / or the plurality of second ribs (32) are provided so that the plurality of openings (4) include two or more openings (4) having opening areas corresponding to two or more unit cells of the planar lattice.

2. 2. The fastening part according to claim 1, wherein the plurality of openings (4) are formed in a mesh pattern in the fastening region (15) according to at least the plurality of first ribs (31) and the plurality of second ribs (32).

3. 3. The fastening part according to claim 2, wherein each of the two or more openings (4) is wide in one of the first and second directions and narrow in the other of the first and second directions.

4. The fastening part according to claim 3, wherein each of the two or more openings (4) has an opening area corresponding to two or three unit cells of the planar lattice.

5. The fastening part according to claim 1 , wherein the unit cell of the planar lattice and / or the opening shape of the opening (4) is a square, a rectangle, a parallelogram, or a rhombus.

6. a frame-like base (5) surrounding the fastening area (15); 2. The fastening part according to claim 1, further comprising a plurality of third ribs (33), each of which connects an engaging element (2) located outermost in the two-dimensional array (20) to the frame-shaped base (5).

7. 7. The fastening part according to claim 6, wherein the first rib (31) and / or the second rib (32) are thicker than the frame-shaped base (5), and the third rib (33) is thinner than the first rib (31) and / or the second rib (32).

8. Each of the plurality of engaging elements (2) includes at least an engaging head (6) and a stem portion (7), 8. A fastening part according to any one of claims 1 to 7, wherein the stem portion (7) has a T-shaped cross section in a plane parallel to the planar grid.

9. The stem portion (7) is a first stem wall (71) connected to the engaging head (6) with a first width from one end to the other end of the engaging head (6) in one of the first and second directions; 9. The fastening part according to claim 8, further comprising a second stem wall (72) connected to the engaging head (6) at a second width from one end of the engaging head (6) to the first stem wall (71) in the other direction of the first and second directions.

10. A fastening part according to any one of claims 1 to 7, wherein the number of the first ribs (31) is 2 / 3 or less, or 1 / 2 or less, of the total number of the first ribs (31) that can be allocated for connecting the engaging elements (2) in the fastening region (15).

11. 11. The fastening part according to claim 10, wherein the number of the second ribs (32) is equal to the total number of the second ribs (32) that can be allocated for connecting the engaging elements (2) in the fastening region (15).

12. A mold device for manufacturing a fastening part (1) according to claim 1, A first mold (100); a second mold (200), The first mold (100) includes a plurality of recesses (106) for molding the engaging heads (6) of the engaging elements (2) included in at least the two-dimensional array (20), The second mold (200) has a plurality of block portions (204) provided corresponding to the plurality of openings (4), The plurality of block portions (204) include two or more block portions (204) having opening areas corresponding to two or more unit lattices of the planar lattice.

13. The mold apparatus according to claim 12, wherein the plurality of block portions (204) include a plurality of types of block portions (204) that differ in width and length perpendicular to the width when the main surface of the second mold (200) is viewed from the front.

14. A manufacturing method for manufacturing a fastening part using the mold apparatus according to claim 12.

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