Grommets

Abstract

To provide a grommet that offers excellent workability for inserting electrical wires into the cylindrical portion. [Solution] The grommet 1 comprises a cylindrical portion 20 that is elastically deformable in the radial direction and through which an electric wire W is inserted, and a main body portion 10 that extends from the cylindrical portion 20 and is fitted into a through hole Pa of the mounting target P. The cylindrical portion 20 has a first variable portion 21 which is configured such that a part of the cylindrical wall of the cylindrical portion 20 is grooved inward or outward in the radial direction and extends along the cylindrical axis of the cylindrical portion 20. The main body portion 10 has a second variable portion 14 which is configured such that a part of the main body portion 10 is grooved in the radial direction and extends continuously with the first variable portion 21. The first variable portion 21 has a thin-walled structure in which, in a cross section perpendicular to the cylindrical axis of the cylindrical portion 20, the thickness of the first variable portion 21 is smaller than the thickness of a different part of the first variable portion 21.

Description

Technical Field

[0001] The present invention relates to a grommet including a cylindrical portion that is elastically deformable in the radial direction and through which an electric wire is to be inserted, and a main body portion that extends from the cylindrical portion and is to be fitted into a through hole of an attachment target.

Background Art

[0002] Conventionally, for example, when routing a wire harness that constitutes an electric wire bundle so as to penetrate a vehicle body panel (for example, a dash panel or the like) that separates the inside and outside of a vehicle cabin, a grommet may be attached so as to close a gap between a through hole of the vehicle body panel and the electric wire bundle from the viewpoints of waterproofing, soundproofing, and the like (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When attaching a grommet of the above-described type to an electric wire bundle, usually, a dedicated device (so-called an expander) is used to elastically expand the diameter of the cylindrical portion, and the electric wire bundle is to be inserted into the expanded cylindrical portion. This is because it is difficult for an operator to manually expand the diameter of the cylindrical portion in consideration of the elastic modulus, shape, and the like of the cylindrical portion. However, the requirement for such a dedicated device may hinder the improvement of the workability of the operation of attaching the grommet to the electric wire bundle, and in some cases, the cylindrical portion may be damaged due to excessive diameter expansion. For these reasons, a grommet having excellent workability in the operation of inserting an electric wire into the cylindrical portion is desired.

[0005] One object of the present invention is to provide a grommet having excellent workability in the operation of inserting an electric wire into a cylindrical portion. [Means for solving the problem]

[0006] To achieve the aforementioned objectives, the grommet according to the present invention is characterized by the following:

[0007] A grommet comprising a cylindrical portion that is elastically deformable in the radial direction and through which an electric wire is inserted, and a main body portion that extends from the cylindrical portion and is fitted into a through hole in the object to be attached, The aforementioned cylindrical portion is The cylindrical portion has a first variable portion which is configured such that a part of the cylindrical wall of the cylindrical portion is recessed in a groove-like shape toward the radially inward or radially outward direction and extends along the cylindrical axis of the cylindrical portion, The main body is, The second variable portion extends continuously with the first variable portion and is configured such that a part of the main body portion is recessed in a groove shape. It must be a grommet. [Effects of the Invention]

[0008] According to the grommet of the present invention, the cylindrical portion of the grommet is provided with a first variable portion configured to be grooved inward or outward in a part thereof and to extend along the cylindrical axis of the cylindrical portion, and the main body of the grommet is provided with a second variable portion configured to extend continuously with the first variable portion and to be grooved in a part thereof. As a result, when the first variable portion is deformed so as to separate a pair of groove walls of the first variable portion that face each other in the circumferential direction of the cylindrical portion, the diameter of the cylindrical portion expands, and when the first variable portion is deformed so as to bring the pair of groove walls closer together, the diameter of the cylindrical portion contracts. The second variable portion deforms in conjunction with the deformation of the first variable portion, as its pair of groove walls move in conjunction with the deformation of the first variable portion. Due to the operation of the first and second variable portions in this way, the cylindrical portion can be easily expanded and contracted by the operator by hand without the use of a dedicated device (expanding machine). As a result, the work of attaching the grommet to a bundle of electric wires can be made easier, and the possibility of damage to the cylindrical portion due to excessive expansion can be reduced. Therefore, the grommet of the present invention offers excellent workability in the process of inserting electric wires into the cylindrical portion.

[0009] The present invention has been briefly described above. Further details of the present invention will be clarified by referring to the accompanying drawings and reading through the embodiments for carrying out the invention described below. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of a grommet according to an embodiment of the present invention. [Figure 2] Figure 2 is a front view of the grommet shown in Figure 1. [Figure 3] Figure 3 is a top view of the grommet shown in Figure 1. [Figure 4] Figure 4 is a top view corresponding to Figure 3, showing the state in which the cylindrical portion is enlarged by deforming the first variable portion so that the pair of groove walls constituting the groove-shaped first variable portion are separated from each other. [Figure 5] Figure 5 is a perspective view of the grommet according to the modified example. [Modes for carrying out the invention]

[0011] <Embodiment> Hereinafter, a grommet 1 according to an embodiment of the present invention will be described with reference to the drawings. Typically, as shown in Figures 1 and 2, when routing a bundle of wires W that constitutes a wire harness through a vehicle body panel P (for example, a dash panel, etc.) that separates the inside and outside of the passenger compartment of an automobile, the grommet 1 is attached to a through-hole Pa (see Figure 2) in the vehicle body panel P to seal the gap between the through-hole Pa in the vehicle body panel P and the bundle of wires W.

[0012] For the sake of explanation, the terms "front," "rear," "left," "right," "up," and "down" are defined below, as shown in Figure 1, etc. The "up" side corresponds to the inside of the passenger compartment relative to the vehicle body panel P, and the "down" side corresponds to the outside of the passenger compartment relative to the vehicle body panel P. In other words, the "up and down direction" can be rephrased as the "inside and outside direction." The "up and down direction," "left and right direction," and "front and rear direction" are orthogonal to each other. Note that the "up and down direction," "left and right direction," and "front and rear direction" are defined solely for the sake of explanation and do not necessarily have to correspond to the up and down, left and right, and front and rear directions of the vehicle when the grommet 1 is mounted on the vehicle.

[0013] The grommet 1 is a molded product made of an elastic material (for example, rubber), and as shown in Figures 1 and 2, it integrally comprises a main body portion 10 and a cylindrical portion 20. The configuration of each part constituting the grommet 1 will be described in order below.

[0014] First, let's describe the main body portion 10. The main body portion 10 is the part that will be fitted into the through hole Pa of the vehicle body panel P. As shown in Figures 1 and 2, the main body portion 10 consists of a cylindrical base portion 11 extending in the vertical direction, a tapered cylindrical first upper projection 12 that is continuous with the upper end of the base portion 11 and gradually decreases in diameter at a first inclination angle as it moves upward from the base portion 11, and a tapered cylindrical second upper projection 13 that is continuous with the upper end of the first upper projection 12 and gradually decreases in diameter at a second inclination angle greater than the first inclination angle as it moves upward from the first upper projection 12. An annular engagement groove 11a is formed on the outer peripheral side of the base portion 11, which will be fitted into the through hole Pa of the vehicle body panel P.

[0015] Next, the cylindrical portion 20 will be described. The cylindrical portion 20 is a substantially cylindrical part that extends upward from the upper end of the second upper projection 13 of the main body portion 10 and through which the wire bundle W is inserted. The cylindrical portion 20 is elastically deformable in the radial direction. The internal space of the cylindrical portion 20 is in communication with the internal space of the main body portion 10.

[0016] As shown in FIGS. 1 and 2, a first variable portion 21 is provided in the cylindrical portion 20. The first variable portion 21 is recessed in a groove shape toward the radially inner side (i.e., the inner space side of the cylindrical portion 20) at one location in the circumferential direction of the cylindrical wall constituting the cylindrical portion 20, and extends straight along the cylindrical axis direction (i.e., the vertical direction) over the entire region in the cylindrical axis direction from the tip (i.e., the upper end) to the base end (i.e., the lower end) of the cylindrical portion 20. As shown in FIG. 3, the wall thickness of a pair of groove walls 22 that face each other in the circumferential direction of the cylindrical portion 20 and constitute the first variable portion 21 is smaller than the wall thickness of the cylindrical wall constituting the cylindrical portion 20 at a location different from the first variable portion 21. In other words, the first variable portion 21 has a thin-walled structure in which the thickness of the first variable portion 21 is smaller than the thickness at a location different from the first variable portion 21 in a cross section orthogonal to the cylindrical axis of the cylindrical portion 20.

[0017] Corresponding to the provision of the first variable portion 21 in the cylindrical portion 20, a second variable portion 14 is also provided in the second upward protruding portion 13 of the main body portion 10 as shown in FIGS. 1 and 2. The second variable portion 14 is recessed in a groove shape toward the inner side (the inner space side of the main body portion 10) at the same circumferential location as the circumferential location where the first variable portion 21 is provided in the tapered cylindrical wall constituting the second upward protruding portion 13, and extends straight along the direction orthogonal to the circumferential direction over the entire region from the upper end to the lower end of the second upward protruding portion 13. The second variable portion 14 extends continuously from the lower end of the first variable portion 21. In other words, each of a pair of groove walls 15 (see FIGS. 2 and 3) that face each other in the circumferential direction of the second upward protruding portion 13 and constitute the second variable portion 14 is continuous with each of the pair of groove walls 22 constituting the first variable portion 21. The wall thickness of the pair of groove walls 15 is smaller than the wall thickness of the tapered cylindrical wall constituting the second upward protruding portion 13 at a location different from the second variable portion 14. In other words, the second variable portion 14 has a thin-walled structure in which the thickness of the second variable portion 14 is smaller than the thickness at a location different from the second variable portion 14 in a cross section orthogonal to the cylindrical axis of the second upward protruding portion 13.

[0018] As described above, the first variable portion 21 is provided in the cylindrical portion 20, and the second variable portion 14 continuous from the first variable portion 21 is provided in the second upward protruding portion 13 of the main body portion 10. When the first variable portion 21 is deformed so that the pair of groove walls 22 of the first variable portion 21 approach each other, the diameter of the cylindrical portion 20 is reduced. When the first variable portion 21 is deformed so that the pair of groove walls 22 are separated from each other (see FIG. 4), the diameter of the cylindrical portion 20 is increased. At that time, the second variable portion 14 is deformed so that the pair of groove walls 15 interlocks with the deformation of the first variable portion 21. Specifically, when the first variable portion 21 is deformed so that the pair of groove walls 22 approach each other, the second variable portion 14 is deformed so that the pair of groove walls 15 approach each other. When the first variable portion 21 is deformed so that the pair of groove walls 22 are separated from each other, the second variable portion 14 is deformed so that the pair of groove walls 15 are separated from each other. Here, since each of the first variable portion 21 and the second variable portion 14 has a thin-walled structure as described above, it becomes easier to deform the first variable portion 21 and the second variable portion 14.

[0019] In the grommet 1, due to the functions of the first variable portion 21 and the second variable portion 14 as described above, the operator can easily expand and contract the cylindrical portion 20 manually without using a dedicated device (so-called expander). As a result, the work of attaching the grommet 1 to the wire bundle W can be facilitated, and the possibility of damage to the cylindrical portion 20 due to excessive diameter expansion can be reduced.

[0020] Furthermore, as another effect, the versatility of the grommet 1 can be improved. Specifically, since the diameter expansion and contraction of the cylindrical portion 20 are easy, the single-shaped grommet 1 can be attached to both a thin wire bundle W and a thick wire bundle W. In other words, the range of the upper and lower limits of the thickness of the wire bundle W that can be properly inserted into the cylindrical portion 20 (that is, the cylindrical portion 20 can absorb the difference in the thickness of the wire bundle W) can be expanded compared to the conventional grommet. The configuration of each part constituting the grommet 1 has been described above.

[0021] A wire bundle W is inserted through the grommet 1 having the above configuration (see Figures 1 and 2). Depending on the specifications of the vehicle on which the wire bundle W is mounted, the thickness of the wire bundle W inserted through the grommet 1 may vary. When inserting the wire bundle W into the grommet 1, without using a special device (so-called expansion machine), the worker manually deforms the first variable part 21 so that the pair of groove walls 22 of the first variable part 21 are separated from each other, maintaining a state in which the cylindrical part 20 is expanded in diameter (see Figure 4). The wire bundle W is then inserted into the grommet 1 by inserting it into the internal space of the cylindrical part 20 from the open end (upper end) side of the cylindrical part 20 or the open end (lower end) side of the main body part 10.

[0022] After the wire bundle W is inserted into the grommet 1, the manually expanded state of the cylindrical portion 20 is released. As a result, the first variable portion 21 elastically recovers so that the pair of groove walls 22 move closer to each other, and the cylindrical portion 20 shrinks in diameter, causing the inner wall surface of the cylindrical portion 20 to adhere closely to the outer surface of the wire bundle W. This enables the sealing performance of the cylindrical portion 20. Next, the cylindrical portion 20 and the wire bundle W are secured by wrapping them together with tape (not shown). Specifically, the tape is wrapped around the cylindrical portion 20 and the wire bundle W so that the tip (upper end) of the cylindrical portion 20 and the wire bundle W located near the upper end of the cylindrical portion 20 are covered by the tape. By wrapping the tape in this way, the gap between the open end (upper end) of the cylindrical portion 20 and the wire bundle W is sealed by the tape. This further improves the sealing performance of the cylindrical portion 20.

[0023] After the tape wrapping is completed, as shown in Figures 1 and 2, the engagement groove 11a of the main body 10 is fitted into the through hole Pa of the vehicle body panel P, thereby attaching the grommet 1 through which the wire bundle W is inserted to the through hole Pa of the vehicle body panel P. As a result, the gap between the wire bundle W, which is routed to pass through the through hole Pa of the vehicle body panel P, and the through hole Pa is sealed by the grommet 1 (specifically the cylindrical part 20), thereby achieving the waterproof function (sealing performance) of the grommet 1.

[0024] <Effects and Actions> As described above, the cylindrical portion 20 of the grommet 1 is provided with a first variable portion 21 which is grooved in a part of the cylindrical portion 20 toward the radially inward or radially outward direction and extends along the cylindrical axis of the cylindrical portion 20, and the main body portion 10 of the grommet 1 is provided with a second variable portion 14 which extends continuously with the first variable portion 21 and is grooved in a groove. As a result, when the first variable portion 21 is deformed so that the pair of groove walls 22 of the first variable portion 21 that face each other in the circumferential direction of the cylindrical portion 20 are separated from each other, the diameter of the cylindrical portion 20 is expanded, and when the first variable portion 21 is deformed so that the pair of groove walls 22 are brought closer to each other, the diameter of the cylindrical portion 20 is reduced. The second variable portion 14 is deformed so that its pair of groove walls 15 are linked to the deformation of the first variable portion 21. The functions of the first variable section 21 and the second variable section 14 allow the cylindrical section 20 to be easily expanded and contracted by the operator's manual labor without the need for a dedicated device (expander). As a result, the work of attaching the grommet 1 to the wire bundle W is simplified, and the possibility of damage to the cylindrical section 20 due to excessive expansion is reduced. Therefore, the grommet 1 according to this embodiment offers excellent workability in the work of inserting wires into the cylindrical section 20.

[0025] Furthermore, according to the grommet 1 of this embodiment, the first variable portion 21 has a thin-walled structure in which the thickness of the first variable portion 21 is smaller than the thickness of other parts of the grommet. This makes it even easier to deform the first variable portion 21 when inserting the wire bundle W into the cylindrical portion 20.

[0026] <Other embodiments> It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the embodiments described above, and can be modified, improved, etc. as appropriate. Furthermore, the material, shape, dimensions, number, placement, etc. of each component in the embodiments described above are arbitrary and not limited as long as they can achieve the present invention.

[0027] In the above embodiment, the first variable portion 21 provided on the cylindrical portion 20 is grooved inward (towards the internal space of the cylindrical portion 20) and extends along the cylindrical axis direction of the cylindrical portion 20, and the second variable portion 14 provided on the main body portion 10 (the second upper projection 13) is grooved inward (towards the internal space of the main body portion 10) and extends continuously from the first variable portion 21 in a direction perpendicular to the circumferential direction. In contrast, as shown in the modified example in Figure 5, the first variable portion 21 provided on the cylindrical portion 20 is grooved inward (projects outward) towards the radially outward (towards the outside of the cylindrical portion 20) and extends along the cylindrical axis direction of the cylindrical portion 20, and the second variable portion 14 provided on the main body portion 10 (the second upper projection 13) is grooved inward (projects outward) towards the outside (towards the outside of the main body portion 10) and extends continuously from the first variable portion 21 in a direction perpendicular to the circumferential direction.

[0028] Herein, the features of the embodiment of the grommet 1 according to the present invention described above are briefly summarized below.

[0029] [1] A grommet (1) comprising a cylindrical portion (20) that is elastically deformable in the radial direction and through which an electric wire (W) is inserted, and a main body portion (10) that extends from the cylindrical portion (20) and is fitted into a through hole (Pa) of the object to be attached (P), The cylindrical portion (20) is The cylindrical portion (20) has a first variable portion (21) which is configured such that a part of the cylindrical wall of the cylindrical portion (20) is grooved inward or outward and extends along the cylindrical axis of the cylindrical portion (20), The main body (10) is The first variable portion (21) is continuously extended, and a second variable portion (14) is configured such that a part of the main body portion (10) is recessed in a groove shape. Grommet (1).

[0030] According to the grommet configuration described in [1] above, the cylindrical portion of the grommet is provided with a first variable portion configured such that a part of the cylindrical portion is grooved inward or outward and extends along the cylindrical axis of the cylindrical portion, and the main body of the grommet is provided with a second variable portion configured to extend continuously with the first variable portion and be grooved. As a result, when the first variable portion is deformed so as to separate a pair of groove walls of the first variable portion that face each other in the circumferential direction of the cylindrical portion, the diameter of the cylindrical portion expands, and when the first variable portion is deformed so as to bring the pair of groove walls closer together, the diameter of the cylindrical portion contracts. The second variable portion deforms in conjunction with the deformation of the first variable portion, as its pair of groove walls move in conjunction with the deformation of the first variable portion. Due to the operation of the first and second variable portions in this way, the cylindrical portion can be easily expanded or contracted by the operator's manual labor without the need for a dedicated device (expanding machine). As a result, the process of attaching the grommet to the wire bundle is made easier, and the possibility of damage to the cylindrical part due to excessive expansion is reduced. Therefore, this grommet configuration offers excellent workability when inserting wires into the cylindrical part.

[0031] [2] In the grommet (1) described in [1] above, The first variable part (21) is, In a cross-section perpendicular to the cylindrical axis of the cylindrical portion (20), the thickness of the first variable portion (21) is smaller than the thickness of a portion other than the first variable portion (21), thus having a thin-walled structure. Grommet (1).

[0032] According to the grommet configuration described in [2] above, the first variable part has a thin-walled structure in which the thickness of the first variable part is smaller than the thickness of a different part. This makes it even easier to deform the first variable part when inserting an electric wire through the cylindrical part. [Explanation of symbols]

[0033] 1 grommet 10 Main body 14. Second variable section 20 Cylindrical part 21 First variable section P Body panel (for installation) Pa through hole W Wire bundle (wire)

Claims

1. A grommet comprising a cylindrical portion that is elastically deformable in the radial direction and through which an electric wire is inserted, and a main body portion that extends from the cylindrical portion and is fitted into a through hole in the object to be attached, The aforementioned cylindrical portion is The cylindrical portion has a first variable portion which is configured such that a part of the cylindrical wall of the cylindrical portion is recessed in a groove-like shape toward the radially inward or radially outward direction and extends along the cylindrical axis of the cylindrical portion, The main body is, The second variable portion extends continuously with the first variable portion and is configured such that a part of the main body portion is recessed in a groove shape, Grommet.

2. In the grommet according to claim 1, The first variable part is, In a cross-section perpendicular to the cylindrical axis of the cylindrical portion, the thickness of the first variable portion is smaller than the thickness of a portion other than the first variable portion, thus having a thin-walled structure. Grommet.

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