Grommets and fastening assemblies

Abstract

Providing grommets and fastening assemblies. [Solution] The grommet comprises a body, a head, and at least one elastic arm. Each of the at least one elastic arm extends from the inner surface of either a first or second wall portion and is at least partially flexible toward and away from the axis. The disclosure provides flexible elastic arms for forming a portion of the contact surface of the grommet for contacting a fastener. When the fastener is inserted into the receiving passage of the grommet, the outward flex of the elastic arm reduces the screw-in torque required to insert the fastener. Furthermore, after the fastener is assembled in place within the receiving passage of the grommet, the receiving passage jointly formed by the elastic arm and the inner surface of the grommet can provide sufficient holding torque to the fastener.

Description

Technical Field

[0001] [Related Application] The present disclosure claims priority to Chinese Patent Application No. 202510240288.8, filed on February 28, 2025, entitled "GROMMET, FASTENING ASSEMBLY AND FASTENING SYSTEM", the entire content of which is incorporated herein by reference.

[0002] The present disclosure relates to the field of fastener technology, and more particularly, to a grommet for use with a screw and a fastening assembly including such a grommet.

Background Art

[0003] In vehicle parts, it is common to use a grommet together with a fastener (e.g., a self-tapping screw) to connect two parts, for example, to attach an interior trim piece to an automobile door panel. During assembly, the grommet is first fitted into the mounting hole of the first part, then the fastener is inserted through the hole of the second part and inserted into the receiving passage of the grommet while positioned within the mounting hole of the first part. When the fastener is inserted into the receiving passage of the grommet, the fastener pushes the wall of the grommet outward, and the wall of the grommet is pressed against the wall of the mounting hole of the first part, thereby fixing the first part and the second part together. Generally, it is desirable to use a relatively low insertion torque (or initial torque) when screwing the fastener into the grommet. After the fastener is received in the receiving passage, it is typically desirable that the grommet provides sufficient retention force to maintain a secure connection between the first part and the second part.

Summary of the Invention

[0004] To address at least some of the technical problems described above, a grommet is provided according to a first aspect of the present disclosure, comprising a body, a head, and at least one elastic arm. The body has first and second wall portions and third and fourth wall portions facing each other. The body further defines a receiving passage extending along an axis and configured to receive a fastener. The head is provided around the body at one end of the body. Each of the at least one elastic arm extends from the inner surface of either the first or second wall portion and is at least partially flexible toward and away from the axis. The receiving passage is jointly defined by the at least one elastic arm and the inner surfaces of the first and second wall portions, at least in its upper portion adjacent to the head. The at least one elastic arm is also spaced apart from an adjacent third or fourth wall portion to allow the elastic arm to flex away from the axis.

[0005] In some embodiments, at least one elastic arm includes a first elastic arm set and a second elastic arm set connected to a first wall portion and a second wall portion, respectively. Each of the first and second elastic arm sets includes a first elastic arm and a second elastic arm provided on opposite sides of the axis. The first and second elastic arm sets are spaced apart from each other.

[0006] In some embodiments, a first elastic arm set and a second elastic arm set are connected to the upper portions of a first wall section and a second wall section, respectively. The grommet further comprises a first connecting wall and a second connecting wall, provided on opposite sides of the axis and interconnecting the lower portions of the first wall section and the second wall section. The bottom ends of the first elastic arm of the first elastic arm set and the second elastic arm of the second elastic arm set are connected to the first connecting wall, and the bottom ends of the second elastic arm of the first elastic arm set and the first elastic arm of the second elastic arm set are connected to the second connecting wall.

[0007] In some embodiments, each of the elastic arms extends from one of the first wall portion and the second wall portion toward the other of the first wall portion and is separated from there.

[0008] In some embodiments, at least one elastic arm includes a pair of elastic arms, each pair of elastic arms connected to a first wall portion and a second wall portion, respectively, and provided on opposite sides of the axis.

[0009] In some embodiments, the elastic arm further comprises an inner projection provided at its distal end.

[0010] In some embodiments, the main body has a generally square cross-section, and at least one elastic arm extends generally parallel to the third and fourth wall portions.

[0011] In some embodiments, the third and fourth wall portions are provided with outward projections on their outer surfaces, and the third and fourth wall portions are elastic so as to allow the grommet to be removably connected to the component via the outward projections.

[0012] In some embodiments, the outer projection comprises an upper segment, an intermediate segment, and a lower segment. The upper segment extends obliquely away from the axis in the direction from the top to the bottom, the intermediate segment extends generally parallel to the axis, and the lower segment extends obliquely toward the axis in the direction from the top to the bottom.

[0013] In some embodiments, the grommet further comprises a sealing portion that surrounds the head and is connected to the head.

[0014] A second aspect of the present disclosure provides a fastening assembly for connecting a first component to a second component, comprising a fastener and a grommet as described in the first aspect. The grommet is configured to be inserted into a first mounting hole of the first component. The fastener is configured to be inserted into a receiving passage of the grommet through a second mounting hole of the second component, while positioned within the first mounting hole, in order to fasten the second component to the first component.

[0015] In some embodiments, the fastener is a self-tapping screw, and at least one elastic arm provides a contact surface for contacting the self-tapping screw together with the inner surfaces of the first and second wall portions. The grommet is configured such that at least one elastic arm is separated from an adjacent third or fourth wall portion when the self-tapping screw has not yet been received into the receiving passage, and after the self-tapping screw has been received into the receiving passage, at least one elastic arm flexes so as to abut against the adjacent third or fourth wall portion.

[0016] This disclosure provides a flexible elastic arm for forming a portion of the contact surface of a grommet for contacting a fastener. When the fastener is inserted into the receiving passage of the grommet, the outward deflection of the elastic arm can reduce the screw-in torque (or initial torque) required to insert the fastener. Furthermore, after the fastener is assembled in place within the receiving passage of the grommet, the receiving passage jointly formed by the elastic arm and the inner surface of the grommet can provide sufficient holding torque (or release torque) to the fastener. Thus, even if the overall size of the grommet is relatively small, the grommet is not easily damaged, thereby ensuring that the fastener assembly securely connects the first and second parts. [Brief explanation of the drawing]

[0017] [Figure 1A] This is a perspective view of a grommet according to one embodiment of the present disclosure, viewed from one viewpoint. [Figure 1B] It is a perspective view of the grommet of FIG. 1A seen from another perspective. [Figure 1C] It is a front view of the grommet of FIG. 1A. [Figure 1D] It is a left side view of the grommet of FIG. 1A. [Figure 2A] It is a cross-sectional view of the grommet of FIG. 1D taken along line A-A. [Figure 2B] It is a cross-sectional view of the grommet of FIG. 2A taken along line B-B. [Figure 2C] It is a cross-sectional view of the grommet of FIG. 2A taken along line C-C. [Figure 3A] It is a view showing the assembling process of the grommet of FIG. 1A onto a first component. [Figure 3B] It is a view showing the assembling process of the grommet of FIG. 1A onto the first component. [Figure 3C-a] It is a view showing the assembling process of the grommet of FIG. 1A onto the first component. [Figure 3C-b] It is a view showing the assembling process of the grommet of FIG. 1A onto the first component. [Figure 4A] It is a view showing the structure of a fastening assembly provided with the grommet of FIG. 1A. [Figure 4B] It is a view showing the structure of a fastening assembly provided with the grommet of FIG. 1A. [Figure 4C] It is a view showing the structure of a fastening assembly provided with the grommet of FIG. 1A. [Figure 5A] It is a perspective view of a grommet according to another embodiment of the present disclosure. [Figure 5B] It is a cross-sectional view of the grommet of FIG. 5A. [Figure 5C] It is another cross-sectional view of the grommet of FIG. 5A. [Figure 6A] It is a perspective view of a grommet according to still another embodiment of the present disclosure. [Figure 6B] It is a cross-sectional view of the grommet of FIG. 6A showing an elastic arm in an undeflected state. [Figure 6C] It is a cross-sectional view of the grommet of FIG. 6A showing an elastic arm in a deflected state. [Figure 7A] This is a perspective view of a grommet according to yet another embodiment of the present disclosure. [Figure 7B] Figure 7A is a cross-sectional view of the grommet. [Figure 7C] This is another cross-sectional view of the grommet in Figure 7A. [Modes for carrying out the invention]

[0018] Hereinafter, various specific embodiments of the present disclosure will be described with reference to the drawings that constitute part of the application. In the present disclosure, terms indicating direction, such as “front,” “rear,” “top,” “bottom,” “left,” “right,” “inside,” and “outside,” are used to describe structural parts and elements in various examples of the present disclosure. These terms are used in the present application solely for the purpose of facilitating illustration and should be understood to be determined based on exemplary orientations as shown in the accompanying drawings. Since the arrangements in the embodiments disclosed in the present disclosure can be in various directions, these terms indicating direction are merely illustrative and should not be considered limiting.

[0019] Figures 1A to 1D show the structure of a grommet 100 according to one embodiment of the present disclosure. Figure 1A is a perspective view of the grommet 100 from one viewpoint, and Figure 1B is a perspective view of the grommet 100 from another viewpoint. Figure 1C is a front view of the grommet 100, and Figure 1D is a left side view of the grommet 100.

[0020] As shown in Figures 1A to 1D, the grommet 100 comprises a body 102 and a head 106. The body 102 defines a receiving passage 110 extending along axis i. The receiving passage 110 is configured to receive fasteners 433 such as self-tapping screws (see Figures 4A to 4C). The head 106 is provided around the body 102 at its axial end. The body 102 comprises a first wall portion 1041 and a second wall portion 1042 facing each other, and a third wall portion 1031 and a fourth wall portion 1032 facing each other. In the illustrated embodiment, the first wall portion 1041 and the second wall portion 1042 are symmetrical about axis i and have substantially the same shape. The third wall portion 1031 and the fourth wall portion 1032 are symmetrical about axis i and have substantially the same structure. The first wall portion 1041, the second wall portion 1042, the third wall portion 1031, and the fourth wall portion 1032 are interconnected, and the body 102 has a generally square cross-section. The body 102 having a square cross-section can match the shape of the square first mounting hole 332 (see Figure 3A) of the first component 331. In other embodiments, the first mounting hole 332 may be configured in a different shape, and the body 102 of the grommet 100 may be configured in a different shape accordingly.

[0021] The third wall portion 1031 and the fourth wall portion 1032 of the main body 102 are generally vertical walls, and each is provided with an outer projection 105 on its outer surface. Those skilled in the art will understand that in the illustrated embodiment the outer projections 105 are provided in pairs, but in other embodiments the outer projections 105 may be provided as one or three or more.

[0022] The third wall portion 1031 and the fourth wall portion 1032 are configured to be elastic. For example, the wall thickness of the third wall portion 1031 and the fourth wall portion 1032 is set to be relatively small. Thus, the third wall portion 1031 and the fourth wall portion 1032 can elastically deform from their initial state toward the receiving passage 110, pressing the outer projection 105 and moving toward the receiving passage 110. When the pair of outer projections 105 move inward toward the receiving passage 110, the distance between the pair of outer projections 105 can be shortened, allowing the grommet 100 to pass through the first mounting hole 332. Furthermore, the third wall portion 1031 and the fourth wall portion 1032 can return from their elastically deformed state to their initial state, pressing the outer projection 105 and moving outward (i.e., away from the receiving passage 110). As the pair of outer projections 105 move outward, the outer projections 105 can engage with the first mounting hole 332. Elastic deformation of the third wall portion 1031 and the fourth wall portion 1032 allows the grommet 100 to be removably connected to the first part 331 via the outer projections 105. Those skilled in the art can determine the magnitude of the force required for the elastic deformation of the third wall portion 1031 and the fourth wall portion 1032 by setting the dimensions of the elastically deformable portions of the third wall portion 1031 and the fourth wall portion 1032 and their wall thicknesses, and understand that the magnitude of this force reflects the magnitude of the insertion force required to insert the grommet 100 into the first mounting hole 332 of the first part 331.

[0023] The outer projection 105 comprises an upper segment 111, an intermediate segment 112, and a lower segment 113, arranged in order from the top to the bottom in the axial direction. The upper segment 111 is connected above the intermediate segment 112, and the lower segment 113 is connected below the intermediate segment 112. In the illustrated embodiment, the upper segment 111 extends diagonally away from the axis i in the direction from the top to the bottom, i.e., it extends diagonally outward. The lower segment 113 extends diagonally toward the axis i in the direction from the top to the bottom, i.e., it extends diagonally inward. The intermediate segment 112 extends approximately parallel to the direction of the axis i. In this embodiment, the upper segment 111, the intermediate segment 112, and the lower segment 113 have a linearly extending shape. However, those skilled in the art will understand that in other embodiments, the upper segment 111, the intermediate segment 112, and the lower segment 113 may also have other shapes, such as arc-shaped segments or sawtooth segments.

[0024] Each of the first wall section 1041 and the second wall section 1042 comprises a vertical wall 114 and an inclined wall 107. The vertical wall 114 is connected to the head 106. The inclined wall 107 has its upper end connected to the vertical wall 114 and its lower end connected to the bottom of the body 102 of the grommet 100. In the illustrated embodiment, the vertical wall 114 extends in a direction parallel to the axis and has dimensions that substantially coincide with the first mounting hole 332 in order to abut the edge of the first mounting hole 332. The width of the inclined wall 107 is substantially the same as the width of the vertical wall 114, but gradually extends obliquely toward the axis i from the top to the bottom. In this embodiment, the connection portion between the inclined wall 107 and the vertical wall 114 is generally located within the height range of the intermediate segment 112 of the outward projection 105.

[0025] The grommet 100 further comprises a sealing portion 101. The sealing portion 101 is connected around the head 106 of the grommet 100 at the periphery of the head 106. In some embodiments, the sealing portion 101 is integrally formed with the head 106 by means such as overmolding. When the head 106 of the grommet 100 is positioned between the first part 331 and the second part 434 (see Figures 4A to 4C), the sealing portion 101 seals against the first part 331 and the second part 434 to prevent dust or water from entering the space between the first part 331 and the second part 434. Those skilled in the art will understand that the sealing portion 101 may be connected to the head 106 of the grommet 100 in any desired way. In some embodiments, the grommet 100 may also not have a sealing portion.

[0026] The grommet 100 further comprises at least one elastic arm 145. Each elastic arm 145 extends from the inner surface of one of the first wall portion 1041 and the second wall portion 1042. The receiving passage 110 is jointly defined by the elastic arm 145 and the inner surfaces of the first wall portion 1041 and the second wall portion 1042, at least in its upper portion near the head 106. Each elastic arm 145 is at least partially flexible toward and away from the axis i. A more specific structure of the elastic arm 145 will be described in detail with reference to Figures 2A to 2C.

[0027] The elastic arm 145 is spaced apart from the adjacent third wall portion 1031 or fourth wall portion 1032 so as to form a space 108 between the elastic arm 145 and the third wall portion 1031 or fourth wall portion 1032. The space 108 is used to allow the third wall portion 1031 and the fourth wall portion 1032 to deform elastically inward, and to allow the elastic arm to deform elastically outward.

[0028] Figures 2A to 2C show the internal structure of the grommet 100. Figure 2A is a cross-sectional view of the grommet 100 along line AA in Figure 1D. Figure 2B is a cross-sectional view of the grommet 100 along line BB in Figure 2A. Figure 2C is a cross-sectional view of the grommet 100 along line CC in Figure 2A. As shown in Figures 2A to 2C, the receiving passage 110 is a passage with a generally circular cross-section for receiving the cylindrical shank portion 442 of the fastener 433 (see Figure 4B).

[0029] As shown in Figure 2A, at least one elastic arm includes a first elastic arm set (first set of elastic arms) 245 and a second elastic arm set (second set of elastic arms) 246. The first elastic arm set 245 is connected to a first wall portion 1041 and extends toward a second wall portion 1042. The second elastic arm set 246 is connected to a second wall portion 1042 and extends toward the first wall portion 1041. The first elastic arm set 245 includes a first elastic arm 2451 and a second elastic arm 2452 provided on opposite sides (both sides) of axis i. The second elastic arm set 246 includes a first elastic arm 2461 and a second elastic arm 2462 provided on opposite sides of axis i. The first elastic arm 2451 of the first elastic arm set 245 and the first elastic arm 2461 of the second elastic arm set 246 are provided symmetrically with respect to axis i, adjacent to and separated from the third wall portion 1031 and the fourth wall portion 1032, respectively. The second elastic arm 2452 of the first elastic arm set 245 and the second elastic arm 2462 of the second elastic arm set 246 are provided symmetrically with respect to axis i, adjacent to and separated from the fourth wall portion 1032 and the third wall portion 1031, respectively. Furthermore, the first elastic arm 2451 of the first elastic arm set 245 and the second elastic arm 2462 of the second elastic arm set 246, which are adjacent to the third wall portion 1031, are separated from each other by a slot 2481. The second elastic arm 2452 of the first elastic arm set 245 and the first elastic arm 2461 of the second elastic arm set 246, adjacent to the fourth wall portion 1032, are separated from each other by a slot 2482. Thus, each elastic arm is elastic, forming a cantilever shape and capable of bending toward and away from the axis i.

[0030] In the illustrated embodiment, the second elastic arm 2452 of the first elastic arm set 245 and the second elastic arm 2462 of the second elastic arm set 246 extend substantially parallel to the third wall portion 1031 and the fourth wall portion 1032. The inner surfaces of the first wall portion 1041 and the second wall portion 1042 are substantially arc-shaped and lie on the same periphery. Thus, in the cross-section shown in Figure 2A, the inner surfaces of the first wall portion 1041 and the second wall portion 1042 define a circle with a diameter D2, where D2 is slightly smaller than the outer diameter of the shank portion 442. The inner surface of each elastic arm is substantially planar. The furthest distance D1 between two elastic arms of each elastic arm set is smaller than the diameter D2 of the circle defined by the inner surfaces of the first wall portion 1041 and the second wall portion 1042. Therefore, when the shank portion 442 of the fastener 433 is inserted into the receiving passage 110, the first wall portion 1041 and the second wall portion 1042 can be pushed outward by the shank portion 442 and abut against the corresponding hole wall of the first part 331, and each elastic arm can be pushed by the shank portion 442 and bend away from the axis i. In some embodiments, the elastic arm can be bent to abut against an adjacent third wall portion 1031 or a fourth wall portion 1032.

[0031] Furthermore, as shown in Figures 2B and 2C, the grommet 100 further comprises a first connecting wall 2471 and a second connecting wall 2472. The first connecting wall 2471 and the second connecting wall 2472 are located on opposite sides of axis i and connect the lower portions of the first wall portion 1041 and the second wall portion 1042 to each other. The receiving passage 110 is jointly defined in its lower portion away from the head 106 by the first connecting wall 2471 and the second connecting wall 2472 and the inner surfaces of the first wall portion 1041 and the second wall portion 1042. The bottom ends of the first elastic arm 2451 and the second elastic arm 2462 are connected to the first connecting wall 2471, and the bottom ends of the second elastic arm 2452 and the first elastic arm 2461 are connected to the second connecting wall 2472. In other words, the first connecting wall 2471 and the second connecting wall 2472, their respective elastic arms, and the inner surfaces of the first wall portion 1041 and the second wall portion 1042 jointly define the receiving passage 110. After the fastener 433 is inserted into the receiving passage 110, the first connecting wall 2471, the second connecting wall 2472, their respective elastic arms, and the inner surfaces of the first wall portion 1041 and the second wall portion 1042 can all provide contact surfaces with the shank portion 442.

[0032] In some embodiments, the elastic arm is formed integrally with the corresponding connecting wall. The first elastic arm 2451 of the first elastic arm set 245, the second elastic arm 2462 of the second elastic arm set 246, and the first connecting wall 2471 are formed integrally. The second elastic arm 2452 of the first elastic arm set 245, the first elastic arm 2461 of the second elastic arm set 246, and the second connecting wall 2472 are formed integrally.

[0033] In some embodiments, the first elastic arms 2451 / 2461 and the second elastic arms 2452 / 2462 have different lengths in the cross-section of the grommet 100. Those skilled in the art will understand that by changing the length of the elastic arms, the force required for the elastic deformation of the elastic arms and the contact area between the grommet and the fastener can be changed.

[0034] Figures 3A to 3C-b show the assembly process of the grommet 100 to the first part 331. Figure 3A shows the grommet 100 aligned with the first mounting hole 332 of the first part 331. Figure 3B shows the grommet 100 in the process of being inserted into the first mounting hole 332 of the first part 331. Figures 3C-a and 3C-b show the grommet 100 after it has been properly inserted into the first mounting hole 332 of the first part 331. Figure 3C-a shows a cross-sectional view of the grommet 100 and the first part 331 along a line similar to line AA in Figure 2A. Figure 3C-b shows a cross-sectional view of the grommet 100 and the first part 331 along a line similar to line BB in Figure 2A.

[0035] As shown in Figure 3A, the first component 331 is generally plate-shaped and has a first mounting hole 332 that penetrates it. In the illustrated embodiment, the first mounting hole 332 is a square hole, and its dimensions are approximately the same as the dimensions of the square columnar body formed by the vertical walls 114 of the first and second wall portions 1041 and 1042 of the grommet 100 and the third and fourth wall portions 1031 and 1032. The operator can align the bottom of the grommet 100 with the first mounting hole 332 of the first component 331 and insert it into the first mounting hole 332 from top to bottom. Because the inclined wall 107 inclines inward from top to bottom, the grommet 100 can be easily inserted into the first mounting hole 332 until it reaches the position shown in Figure 3B.

[0036] As shown in Figure 3B, when the grommet 100 is inserted into the first mounting hole 332, the lower segment 113 of the outer projection 105 abuts against the edge of the first mounting hole 332. If the operator continues to apply a downward insertion force to the grommet 100, the edge of the first mounting hole 332 is pressed against the outer projection 105, causing the third wall portion 1031 and the fourth wall portion 1032 to elastically deform and move toward the space 108. The elastic deformation of the third wall portion 1031 and the fourth wall portion 1032 presses the outer projection 105 inward, thereby allowing the grommet 100 to continue moving downward to the positions shown in Figures 3C-a and 3C-b.

[0037] As shown in Figures 3C-a and 3C-b, the grommet 100 is fitted into the first mounting hole 332 of the first component 331. The head 106 and sealing portion 101 of the grommet 100 are in close contact with the upper surface of the first component 331. The outer projection 105 of the grommet 100 is located below the first component 331. The first mounting hole 332 is no longer pressed against the outer projection 105, allowing the third wall portion 1031 and the fourth wall portion 1032 to return outward from the space 108, pressing against the outer projection 105 and moving it outward. Furthermore, the upper segment 111 of the outer projection 105 abuts against the edge of the first mounting hole 332. The head 106 and sealing portion 101 of the grommet 100, together with the outward projection 105, hold the grommet 100 within the first mounting hole 332 of the first component 331. In this state, the third wall portion 1031 and the fourth wall portion 1032 of the grommet 100 are in close contact with the hole wall of the first mounting hole 332 (see Figure 3c-b), and the vertical walls 114 of the first wall portion 1041 and the second wall portion 1042 of the grommet 100 are also in close contact with the hole wall of the first mounting hole 332 (see Figure 3c-a).

[0038] Figures 4A to 4C show the structure of the fastening assembly 430 equipped with a grommet 100. Figure 4A shows a perspective view of the fastening assembly 430. Figure 4B shows a cross-sectional view of the fastening assembly 430 along a cutting line similar to line CC in Figure 2A. Figure 4C shows a cross-sectional view of the fastening assembly 430.

[0039] As shown in Figures 4A to 4C, the fastening assembly 430 comprises a grommet 100 and a fastener 433, configured to connect a first component 331 to a second component 434. The second component 434 has a second mounting hole 435. In this embodiment, the fastener 433 is a self-tapping screw. The self-tapping screw comprises a head 441 and a shank portion 442. The shank portion 442 passes through the second mounting hole 435 and is inserted into and held within the receiving passage 110 of the grommet 100, connecting the second component 434 above the head 106 and sealing portion 101 of the grommet 100. Thus, the fastener 433 connects the first component 331 and the second component 434 together by engaging with the grommet 100. In this embodiment, the second mounting hole 435 is a circular hole, and the shank portion 442 is generally cylindrical.

[0040] Specifically, since the diameter D2 of the circle defined by the inner surfaces of the first wall portion 1041 and the second wall portion 1042 defining the receiving passage 110, and the furthest distance D1 between the two elastic arms of each elastic arm set defining the receiving passage 110 are both smaller than the outer diameter of the shank portion 442, the shank portion 442 interferes with the inner surfaces of the first wall portion 1041 and the second wall portion 1042 after being inserted into the receiving passage 110. The first wall portion 1041 and the second wall portion 1042 can be pushed outward by the shank portion 442 and come into contact with the hole wall of the first part 331. Furthermore, the second elastic arms 2452 and 2462 can be pushed by the shank portion 442 and bend away from axis i. In this embodiment, the second elastic arm 2452 and the second elastic arm 2462 bend so as to contact the fourth wall portion 1032 and the third wall portion 1031, respectively.

[0041] After the shank portion 442 is inserted into the receiving passage 110, the head 441 is pressed against the upper surface of the second part 434, pushing the second part 434 down against the sealing portion 101 and head 106 of the grommet 100. The sealing portion 101 seals against the upper surface of the first part 331 and the lower surface of the second part 434. Thus, the first part 331 and the second part 434 are sealed together via the grommet 100 and fastener 433.

[0042] Figures 5A to 5C show the structure of a grommet 500 according to another embodiment of the present disclosure. Figure 5A shows a perspective view of the grommet 500. Figure 5B shows a cross-sectional view of the grommet 500. Figure 5C shows a longitudinal section of the grommet 500 along a cutting line similar to line BB in Figure 2B. As shown in Figures 5A to 5C, the structure of the grommet 500 is substantially the same as the structure of the grommet 100 and similarly comprises a body 102 and a head 106. The body 102 defines a receiving passage 510 therein, which is configured to receive a fastener 433. The body 102 comprises opposing first wall portions 1041 and second wall portions 1042 and opposing third wall portions 1031 and fourth wall portions 1032. The third wall portion 1031 and the fourth wall portion 1032 are provided with outer protrusions 105, which are pressed and moved by the elastic deformation of the third wall portion 1031 and the fourth wall portion 1032.

[0043] The elastic arm structure of grommet 500 differs from that of grommet 100. Specifically, grommet 500 comprises a pair of elastic arms 545. The pair of elastic arms 545 includes a first elastic arm 5451 and a second elastic arm 5452, which are provided on opposite sides of axis i. The first elastic arm 5451 is connected to the first wall portion 1041, extends toward the second wall portion 1042, and is separated from the second wall portion 1042. The second elastic arm 5452 is connected to the second wall portion 1042, extends toward the first wall portion 1041, and is separated from the first wall portion 1041. The first elastic arm 5451 is adjacent to the fourth wall portion 1032 and is separated from the fourth wall portion 1032, forming a space 108 between them. The second elastic arm 5452 is adjacent to the third wall portion 1031 and spaced away from it, forming a space 108 between them. Each elastic arm 545 is elastic, allowing it to flex from axis i into the space 108. Unlike the grommet 100, the grommet 500 no longer has a connecting wall, and each elastic arm 545 extends from the top to the bottom of the body 102. The receiving passage 510 is jointly defined by the pair of elastic arms 545 and the inner surfaces of the first wall portion 1041 and the second wall portion 1042.

[0044] Figures 6A to 6C show the structure of a grommet 600 according to yet another embodiment of the present disclosure. Figure 6A shows a perspective view of the grommet 600. Figure 6B shows a cross-sectional view of the grommet 600 with the elastic arm not biased. Figure 6C shows a cross-sectional view of the grommet 600 with the elastic arm biased. As shown in Figures 6A to 6C, the structure of the grommet 600 is substantially the same as that of the grommet 100 and grommet 500, and similarly comprises a body 102 and a head 106. The body 102 defines a receiving passage 610 therein, which is configured to receive a fastener 433. The body 102 comprises opposing first wall portions 1041 and second wall portions 1042 and opposing third wall portions 1031 and fourth wall portions 1032. The third wall portion 1031 and the fourth wall portion 1032 are provided with outer protrusions 105, which are pressed and moved by the elastic deformation of the third wall portion 1031 and the fourth wall portion 1032.

[0045] The elastic arm structure of grommet 600 differs from the elastic arm structure of grommet 500's elastic arm 545. Specifically, grommet 600 also includes a pair of elastic arms 645. The pair of elastic arms 645 includes a first elastic arm 6451 and a second elastic arm 6452, which are provided on opposite sides of axis i. The first elastic arm 6451 is connected to the first wall portion 1041, extends toward the second wall portion 1042, and is separated from the second wall portion 1042. The second elastic arm 6452 is connected to the second wall portion 1042, extends toward the first wall portion 1041, and is separated from the first wall portion 1041. The first elastic arm 6451 is adjacent to the fourth wall portion 1032, is separated from the fourth wall portion 1032, and forms a space 108 between them. The second elastic arm 6452 is adjacent to the third wall portion 1031 and spaced away from it, forming a space 108 between them. Each elastic arm 645 is elastic and allows to flex from axis i into the space 108. Unlike the elastic arm 545, the elastic arm 645 further comprises an inner projection 655 provided at its distal end. The inner projection 655 is formed to project toward the receiving passage 610. By providing the inner projection 655, the distance between the pair of elastic arms 645 is further reduced, thereby increasing the amount of interference when the fastener 433 is inserted into the receiving passage 610.

[0046] In the state shown in Figure 6B, the fastener 433 has not yet been inserted into the receiving passage 610, and the elastic arm 645 is in its initial state. The inner projection 655 protrudes inward from the distal end of the elastic arm 645.

[0047] In the state shown in Figure 6C, the fastener 433 is inserted into the receiving passage 610, pushing the elastic arm 645 and bending it away from axis i, entering the space 108. In this embodiment, the elastic arm 645 bends so as to contact the adjacent third wall portion 1031 or fourth wall portion 1032. Those skilled in the art will understand that in some embodiments, the elastic arm may not contact the third wall portion 1031 and the fourth wall portion 1032 even when bent.

[0048] Figures 7A to 7C show the structure of a grommet 700 according to yet another embodiment of the present disclosure. Figure 7A shows a perspective view of the grommet 700. Figure 7B shows a cross-sectional view of the grommet 700. Figure 7C shows a longitudinal section of the grommet 700 along a cutting line similar to line BB in Figure 2B. As shown in Figures 7A to 7C, the structure of the grommet 700 is substantially the same as the structure of the grommet 100, and similarly comprises a body 102 and a head 106. The body 102 defines a receiving passage 710 therein, which is configured to receive a fastener 433. The body 102 comprises opposing first wall portions 1041 and second wall portions 1042 and opposing third wall portions 1031 and fourth wall portions 1032. The third wall portion 1031 and the fourth wall portion 1032 are provided with outer protrusions 105, which are pressed and moved by the elastic deformation of the third wall portion 1031 and the fourth wall portion 1032.

[0049] The elastic arm structure of grommet 700 differs from that of grommet 100. Specifically, grommet 700 comprises a first elastic arm set 745 connected to a first wall portion 1041 and a second elastic arm set 746 connected to a second wall portion 1042. The first elastic arm set 745 and the second elastic arm set 746 each include a pair of elastic arms provided on opposite sides of the axis i. Furthermore, since the first elastic arm set 745 and the second elastic arm set 746 extend from one side of the first wall portion 1041 and the second wall portion 1042 toward the other and are spaced apart, each elastic arm is elastic and allows deflection from the axis i into the space 108. Unlike grommet 100, grommet 700 does not have a connecting wall, and each elastic arm extends from the top to the bottom of the body 102. The receiving passage 710 is jointly defined by the first elastic arm set 745, the second elastic arm set 746, and the inner surfaces of the first wall portion 1041 and the second wall portion 1042.

[0050] In the embodiments of this disclosure, the grommet is made from a plastic material. The first and second components may be plate-shaped members. When the grommet is used in a vehicle environment, the first and second components may be parts such as vehicle panels or vehicle doors.

[0051] Through long-term research, the applicant has found that in the prior art, the receiving passage is typically formed by the grommet wall, which provides a contact surface for contacting the fastener (screw). In order for a fastening assembly to fasten a first part to a second part, the grommet needs to provide the fastener with a relatively large holding torque (or release torque). For this reason, the size of the receiving passage formed by the grommet wall in the prior art needs to be designed to be relatively small, thereby providing the required holding torque by increasing the interference between the grommet wall and the fastener. However, such a design makes the grommet wall susceptible to damage, especially when the overall dimensions of the grommet are relatively small, and in that case, the grommet becomes even more susceptible to damage.

[0052] This disclosure provides a flexible elastic arm for forming a portion of the contact surface of a grommet for contacting a fastener. When the fastener is inserted into the receiving passage of the grommet, the outward deflection of the elastic arm can reduce the screw-in torque (or initial torque) required to insert the fastener. Furthermore, after the fastener is assembled in place within the receiving passage of the grommet, the receiving passage jointly formed by the elastic arm and the inner surface of the grommet can provide sufficient holding torque (or release torque) to the fastener. Thus, even if the overall size of the grommet is relatively small, the grommet is not easily damaged, thereby ensuring that the fastener assembly securely connects the first and second parts.

[0053] Furthermore, the grommet of the present invention is configured to include elastically deformable third and fourth wall portions, and the outer projection is provided on the third and fourth wall portions. This configuration not only reduces the insertion force required to insert the grommet into the first mounting hole of the first part, but also prevents the grommet from falling out of the first part. In addition, this configuration allows the operator to determine whether the grommet is properly installed in the first part by the clicking sound produced by the outer projection when the third and fourth wall portions return to their original position after the grommet has been elastically restored.

[0054] While this disclosure has been described in conjunction with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements, and / or substantial equivalents, whether known, currently foreseeable, or foreseeable, may become apparent to those skilled in the art. The technical effects and problems in this application are illustrative and not limiting. It should be noted that the embodiments described herein may have other technical effects and may solve other technical problems. Accordingly, the examples of embodiments of this disclosure shown above are intended to be illustrative and not limiting. Various modifications may be made without departing from the spirit or scope of the invention. Accordingly, this disclosure is intended to encompass all known or previously developed alternatives, modifications, variations, improvements, and / or substantial equivalents. [Explanation of Symbols]

[0055] 100 grommets 101 Sealing part 102 Main Unit 1041 First wall section 1042 Second wall section 1031 Third Wall Section 1032 Fourth Wall Section 105 Outer protrusion 106 heads 107 Slanted wall 108 Space 110 Receptive pathway 111 Upper segment 112 Intermediate Segments 113 Lower segment 114 Vertical Wall 145 Elastic Arm 245 Elastic Arm 2451 First elastic arm 2452 Second elastic arm 246 Elastic Arm 2461 First elastic arm 2462 Second elastic arm 2471 First connecting wall 2472 Second connecting wall 2481 slots 2482 slots 331 First part 332 First mounting hole 430 Fastening assembly 433 Fasteners 434 Second part 435 Second mounting hole 441 head 442 Shank 500 grommets 510 Receptive pathway 545 Elastic Arm 5451 First elastic arm 5452 Second elastic arm 600 Grommets 610 Receptive pathway 645 Elastic Arm 6451 First elastic arm 6452 Second elastic arm 655 Inner protrusion 700 Grommets 710 Receptive pathway 745 Elastic Arm 746 Elastic Arm

Claims

1. It is a grommet, A body (102) having a first wall portion (1041) and a second wall portion (1042) facing each other, and a third wall portion (1031) and a fourth wall portion (1032) facing each other, further having a receiving passage (110) extending along an axis (i), the receiving passage (110) being configured to receive a fastener (433), and the body (102), A head (106) is provided around the main body (102) at one end of the main body (102), At least one elastic arm (245, 246), each of which extends from the inner surface of one of the first wall portion (1041) and the second wall portion (1042), and is at least partially flexible toward and away from the axis (i), Equipped with, The receiving passage (110) is jointly defined at least in its upper portion adjacent to the head (106) by the at least one elastic arm (245, 246) and the inner surfaces of the first wall portion (1041) and the second wall portion (1042), The at least one elastic arm (245, 246) is spaced apart from the adjacent of the third wall portion (1031) or the fourth wall portion (1032) so as to allow the at least one elastic arm (245, 246) to bend away from the axis (i). Grommet.

2. The at least one elastic arm (245, 246) includes a first elastic arm set (245) and a second elastic arm set (246) connected to the first wall portion (1041) and the second wall portion (1042), respectively, and each of the first elastic arm set (245) and the second elastic arm set (246) includes a first elastic arm and a second elastic arm provided on opposite sides of the axis (i). The first elastic arm set (245) and the second elastic arm set (246) are separated from each other. The grommet according to claim 1.

3. The first elastic arm set (245) and the second elastic arm set (246) are connected to the upper portions of the first wall portion (1041) and the second wall portion (1042), respectively. The grommet (100) comprises a first connecting wall (2471) and a second connecting wall (2472) provided on opposite sides of the axis (i), further comprising the first connecting wall (2471) and the second connecting wall (2472) connecting the lower portions of the first wall portion (1041) and the second wall portion (1042), The first elastic arm (2451) of the first elastic arm set (245) and the second elastic arm (2462) of the second elastic arm set (246) are connected to the first connecting wall (2471) at their bottom ends, and the second elastic arm (2452) of the first elastic arm set (245) and the first elastic arm (2461) of the second elastic arm set (246) are connected to the second connecting wall (2472) at their bottom ends. The grommet according to claim 2.

4. The grommet according to claim 1, wherein each of the elastic arms extends from one of the first wall portion (1041) and the second wall portion (1042) toward the other of the first wall portion (1041) and the second wall portion (1042), and is separated from the other.

5. The grommet according to claim 4, wherein the at least one elastic arm includes a pair of elastic arms (545), the pair of elastic arms being connected to the first wall portion (1041) and the second wall portion (1042), respectively, and being provided on opposite sides of the axis.

6. The grommet according to claim 5, wherein the elastic arm further comprises an inner projection (655) provided at its distal end.

7. The main body (102) has a roughly square cross-section, The at least one elastic arm extends substantially parallel to the third wall portion and the fourth wall portion. The grommet according to claim 1.

8. The grommet according to claim 1, wherein the third wall portion (1031) and the fourth wall portion (1032) are provided with outward projections (105) on their outer surfaces, and the third wall portion (1031) and the fourth wall portion (1032) are elastic so as to allow the grommet (100) to be removably connected to a component via the outward projections (105).

9. The outer projection (105) comprises an upper segment (111), an intermediate segment (112), and a lower segment (113). The upper segment (111) extends diagonally away from the axis (i) in the direction from the top to the bottom, the intermediate segment (112) extends generally parallel to the axis (i), and the lower segment (113) extends diagonally toward the axis (i) in the direction from the top to the bottom. The grommet according to claim 8.

10. The grommet according to claim 1, wherein the grommet (100) further comprises a sealing portion (101) that surrounds the head (106) and is connected to the head (106).

11. A fastening assembly for connecting a first component to a second component, Fastener (433) and A grommet (100) according to any one of claims 1 to 10, configured to be inserted into a first mounting hole (332) of the first component (331), Equipped with, The fastener (443) is configured to be inserted through the second mounting hole (435) of the second part (434) into the receiving passage (110) of the grommet (100), which is positioned within the first mounting hole (332), in order to fasten the second part (434) to the first part (331). Fastening assembly.

12. The fastener (443) is a self-tapping screw, and the at least one elastic arm, together with the inner surface of the first wall portion (1041) and the inner surface of the second wall portion (1042), provides a contact surface that contacts the self-tapping screw. The grommet (100) is configured such that when the self-tapping screw has not yet been received in the receiving passage (110), at least one elastic arm is separated from the adjacent third wall portion (1031) or the fourth wall portion (1032), and after the self-tapping screw has been received in the receiving passage (110), at least one elastic arm bends and contacts the adjacent third wall portion (1031) or the fourth wall portion (1032). The fastening assembly according to claim 11.

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