Waterproof structure and wire harness

Abstract

To provide a waterproof structure which enables improvement of cut-off performance, and to provide a wire harness.SOLUTION: A waterproof structure 1 includes: a corrugate tube 3 into which an electric wire 2 is inserted; and a grommet 4 having a first cylinder part 41 into which the corrugate tube is inserted and configured to hold the corrugate tube. The first cylinder part has: a first seal part 43 which protrudes to a center axis of the first cylinder part and closely contacts with an outer peripheral surface of the corrugate tube; a second seal part 44 which protrudes to the center axis and closely contacts with the outer peripheral surface of the corrugate tube; and a flexible part 45 which is disposed between the first seal part and the second seal part and may curve.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a waterproof structure and a wire harness. [Background technology]

[0002] Conventionally, there are grommets that are attached to corrugated tubes. Patent Document 1 discloses a grommet that includes a cylindrical corrugated end portion that can be connected to the outer periphery of the corrugated tube in a sealed state, and a plurality of sealing lips that are provided on the inner periphery of the corrugated end portion so as to fit closely to valley portions of the corrugated tube.

[0003] Patent Document 2 discloses a grommet having a grommet tubular portion, an inner tubular portion, an outer tubular portion, a binding member assembly portion, an outer tubular side clamping portion, and an inner tubular side clamping portion. The inner tubular portion is inserted into the corrugated tube from its end. The outer tubular portion is formed on a portion that covers the corrugated tube from its end to the outside. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-225339 A [Patent Document 2] Patent Publication No. 2021-13253 Summary of the Invention [Problem to be solved by the invention]

[0005] It is desirable to improve the watertightness in a waterproof structure and a wire harness having a corrugated tube and a grommet. For example, it is desirable to improve the watertightness when the corrugated tube is installed while being curved.

[0006] An object of the present invention is to provide a waterproof structure and a wire harness that can improve water stopping performance. [Means for solving the problem]

[0007] The waterproof structure of the present invention comprises a corrugated tube into which an electric wire is inserted, and a grommet having a first tubular portion into which the corrugated tube is inserted and which holds the corrugated tube, wherein the first tubular portion has a first seal portion that protrudes toward a central axis of the first tubular portion and is in close contact with an outer peripheral surface of the corrugated tube, a second seal portion that protrudes toward the central axis and is in close contact with the outer peripheral surface of the corrugated tube, and a flexible portion that is arranged between the first seal portion and the second seal portion and is bendable. Effect of the Invention

[0008] In the waterproof structure according to the present invention, the first tubular portion of the grommet has a first seal portion that protrudes toward the central axis of the first tubular portion and is in close contact with the outer circumferential surface of the corrugated tube, a second seal portion that protrudes toward the central axis and is in close contact with the outer circumferential surface of the corrugated tube, and a bendable flexible portion that is disposed between the first seal portion and the second seal portion. The waterproof structure according to the present invention has the effect of improving water stopping performance. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a waterproof structure and a wire harness according to an embodiment. [Diagram 2] FIG. 2 is a plan view of the waterproof structure and the wire harness according to the embodiment. [Diagram 3] FIG. 3 is an exploded perspective view of the waterproof structure according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the grommet according to the embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of the corrugated tube according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the waterproof structure according to the embodiment. [Figure 7]FIG. 7 is a cross-sectional view of the waterproof structure according to the embodiment. [Figure 8] FIG. 8 is a cross-sectional view of the waterproof structure according to the embodiment. [Figure 9] FIG. 9 is a cross-sectional view of a curved grommet and a corrugated tube. [Figure 10] FIG. 10 is a diagram showing a waterproof structure and a wire harness according to a first modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A waterproof structure and a wire harness according to an embodiment of the present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the embodiment. In addition, the components in the following embodiments include those that a person skilled in the art can easily imagine or that are substantially the same.

[0011] [Embodiment] An embodiment will be described with reference to Fig. 1 to Fig. 9. The embodiment relates to a waterproof structure and a wire harness. Fig. 1 is a perspective view of the waterproof structure and the wire harness according to the embodiment, Fig. 2 is a plan view of the waterproof structure and the wire harness according to the embodiment, Fig. 3 is an exploded perspective view of the waterproof structure according to the embodiment, Fig. 4 is a cross-sectional view of a grommet according to the embodiment, Fig. 5 is a cross-sectional view of a corrugated tube according to the embodiment, Fig. 6 is a cross-sectional view of the waterproof structure according to the embodiment, Fig. 7 is a cross-sectional view of the waterproof structure according to the embodiment, Fig. 8 is a cross-sectional view of the waterproof structure according to the embodiment, and Fig. 9 is a cross-sectional view of the curved and deformed grommet and corrugated tube.

[0012] As shown in Fig. 1, a wire harness 100 of this embodiment has a waterproof structure 1 and an electric wire 2. The wire harness 100 is mounted on a vehicle such as an automobile. The waterproof structure 1 has a corrugated tube 3, a grommet 4, an exterior member 5, and a band member 6. The waterproof structure 1 of this embodiment can appropriately suppress water from entering through a gap between the corrugated tube 3 and the grommet 4.

[0013] As shown in Fig. 2, the grommet 4 is fitted into the panel 200. The panel 200 is, for example, a metal plate that separates an interior space 210 of a vehicle from an exterior space 220. The panel 200 has a through hole 201 into which the grommet 4 can be inserted. The grommet 4 is inserted into the through hole 201 and comes into close contact with a wall surface 200a of the panel. In this specification, the axial direction of the grommet 4 is referred to as a "first direction X". The grommet 4 penetrates the panel 200 along the first direction X.

[0014] The corrugated tube 3 is a flexible exterior member and has a bellows shape. The corrugated tube 3 has a cylindrical shape and both axial ends are open. The corrugated tube 3 of this embodiment does not have a slit. Therefore, the cross-sectional shape of the corrugated tube 3 in a cross section perpendicular to the axial direction is an endless circle. The exterior member 5 of this embodiment is a member similar to the corrugated tube 3 and has flexibility. The grommet 4 is a waterproof member and is molded from an elastically deformable resin such as rubber. The grommet 4 has higher flexibility than the corrugated tube 3.

[0015] 3, the grommet 4 has a fitting portion 40, a first tubular portion 41, and a second tubular portion 42. The fitting portion 40 is a portion that fits into the panel 200. The first tubular portion 41 is a portion into which the corrugated tube 3 is inserted, and the second tubular portion 42 is a portion into which the exterior member 5 is inserted. The illustrated first tubular portion 41 and second tubular portion 42 each have a cylindrical shape.

[0016] As shown in FIG. 4, the fitting portion 40 has an annular groove portion 40a and an outer seal portion 40b. The groove portion 40a is provided on the outer peripheral surface of the grommet 4. The groove portion 40a is recessed along the radial direction of the grommet 4 toward the central axis C1 of the grommet 4. The panel 200 fits into the groove portion 40a. The outer seal portion 40b protrudes in a flange-like shape toward the radially outward direction from the groove portion 40a. The outer seal portion 40b faces the wall surface 200a of the panel 200 in the first direction X and is in close contact with the wall surface 200a.

[0017] The first cylindrical portion 41 is disposed on a first side X1 in the first direction X with respect to the fitting portion 40, and the second cylindrical portion 42 is disposed on a second side X2 in the first direction X with respect to the fitting portion 40. In other words, the fitting portion 40 is disposed between the first cylindrical portion 41 and the second cylindrical portion 42.

[0018] The first cylindrical portion 41 has a first seal portion 43, a second seal portion 44, a flexible portion 45, a first tapered portion 46, and a second tapered portion 47. The first seal portion 43 is disposed at an end portion of the first cylindrical portion 41 that is farther from the fitting portion 40. The second seal portion 44 is disposed between the first seal portion 43 and the fitting portion 40. The flexible portion 45 is disposed between the first seal portion 43 and the second seal portion 44. That is, the first seal portion 43 is disposed on a first side X1 with respect to the flexible portion 45, and the second seal portion 44 is disposed on a second side X2 with respect to the flexible portion 45. The first tapered portion 46 is disposed between the first seal portion 43 and the flexible portion 45, and the second tapered portion 47 is disposed between the second seal portion 44 and the flexible portion 45.

[0019] The first seal portion 43 and the second seal portion 44 are formed to closely contact the outer peripheral surface of the corrugated tube 3. The first seal portion 43 and the second seal portion 44 are cylindrical in shape. The first seal portion 43 has a seal surface 43a that closely contacts the outer peripheral surface of the corrugated tube 3. The second seal portion 44 has a seal surface 44a that closely contacts the outer peripheral surface of the corrugated tube 3. The first seal portion 43 and the second seal portion 44 protrude toward the central axis C1 of the first cylindrical portion 41.

[0020] More specifically, the seal surface 43a of the first seal portion 43 protrudes toward the central axis C1 relative to the inner circumferential surface 45a of the flexible portion 45. The seal surface 44a of the second seal portion 44 protrudes toward the central axis C1 relative to the inner circumferential surface 45a of the flexible portion 45. The value of the inner diameter D1 of the first seal portion 43 is equal to the value of the inner diameter D2 of the second seal portion 44, for example. The value of the inner diameter D3 of the flexible portion 45 is larger than the values ​​of the inner diameters D1, D2.

[0021] The sealing surface 43a has a length L1, and the sealing surface 44a has a length L2. The lengths L1 and L2 are lengths in the first direction X. In the grommet 4 of the present embodiment, the length L1 of the sealing surface 43a of the first seal portion 43 is greater than the length L2 of the sealing surface 44a of the second seal portion 44.

[0022] An annular groove 43b corresponding to the band member 6 is provided on the outer peripheral surface of the first seal portion 43. The groove 43b is disposed at an end of the first seal portion 43 on the first side X1. A thickness t3 from the bottom surface of the groove 43b to the seal surface 43a is greater than a thickness t5 of the flexible portion 45. An annular groove 44b corresponding to the band member 6 is provided on the outer peripheral surface of the second seal portion 44. A thickness t4 from the bottom surface of the groove 44b to the seal surface 44a is greater than a thickness t5 of the flexible portion 45.

[0023] The first tapered portion 46 connects the first seal portion 43 and the flexible portion 45 along the first direction X. The thickness t1 of the first tapered portion 46 decreases as it moves away from the first seal portion 43 along the first direction X. The inner diameter of the first tapered portion 46 increases as it moves from the first seal portion 43 toward the flexible portion 45. In other words, the inner circumferential surface of the first tapered portion 46 has a tapered shape in which the inner diameter decreases as it moves from the flexible portion 45 toward the first seal portion 43.

[0024] The second tapered portion 47 connects the flexible portion 45 and the second seal portion 44 along the first direction X. The thickness t2 of the second tapered portion 47 decreases as it moves away from the second seal portion 44 along the first direction X. The inner diameter of the second tapered portion 47 increases from the second seal portion 44 toward the flexible portion 45. In other words, the inner circumferential surface of the second tapered portion 47 has a tapered shape in which the inner diameter decreases from the flexible portion 45 toward the second seal portion 44.

[0025] The second cylindrical portion 42 has a cylindrical shape into which the exterior member 5 can be inserted. The second cylindrical portion 42 of the present embodiment has a bellows portion 42a having a bellows shape.

[0026] As shown in FIG. 5, the corrugated tube 3 has a plurality of peaks 31 and a plurality of valleys 32. The peaks 31 are portions that protrude radially outward. The valleys 32 are portions between the bottom of one peak 31 and the bottom of another peak 31. In the corrugated tube 3, the peaks 31 and the valleys 32 are alternately arranged in the first direction X. The cross-sectional shape of the peaks 31 in a cross section taken along the central axis C2 is a trapezoid. The peaks 31 have a top surface 31a. The top surface 31a is the outer peripheral surface of the corrugated tube 3. The corrugated tube 3 has an outer diameter D4. The outer diameter D4 is the diameter of the top surface 31a. The value of the outer diameter D4 is determined by the following formulas (1) and (2). That is, the outer diameter D4 of the corrugated tube 3 is equal to or larger than the inner diameter D1 of the first seal portion 43 and equal to or larger than the inner diameter D2 of the second seal portion 44. D4≧D1 (1) D4≧D2 (2)

[0027] The inner diameter D1 of the first seal portion 43 and the inner diameter D2 of the second seal portion 44 may be determined so that the seal surfaces 43a, 44a can be in close contact with the outer circumferential surface of the corrugated tube 3 even if permanent compression strain occurs in the first tubular portion 41. In this case, the values ​​of the inner diameters D1, D2 are each set to a value smaller than the outer diameter D4 of the corrugated tube 3.

[0028] The peaks 31 are disposed at equal intervals with a pitch P1. The pitch P1 is the distance in the first direction X from a reference position of one valley 32 to a reference position of an adjacent valley 32. The reference position is, for example, a boundary line between the valley 32 and the peak 31.

[0029] The corrugated tube 3 has a first length M1, a second length M2, and a third length M3. The lengths M1, M2, and M3 are all lengths in the first direction X when the corrugated tube 3 extends linearly. The first length M1 is the width of the top surface 31a in the first direction X. The second length M2 is a length determined by two adjacent top surfaces 31a. In other words, the second length M2 is the distance from the end of the first side X1 of one top surface 31a to the end of the second side X2 of the adjacent top surface 31a. The third length M3 is a length determined by three consecutive top surfaces 31a. In other words, the third length M3 is the distance from the end of the first side X1 of one top surface 31a to the end of the second side X2 of the top surface 31a adjacent to the first side X1.

[0030] The corrugated tube 3 is inserted into the first cylindrical portion 41, for example, from the side of the first seal portion 43. The corrugated tube 3 is inserted into the grommet 4 at least to a position where it penetrates the second seal portion 44.

[0031] FIG. 6 shows the corrugated tube 3 inserted into the first seal portion 43. The first seal portion 43 is formed so that the seal surface 43a can be in close contact with at least the entirety of two adjacent apex surfaces 31a. Specifically, the length L1 of the seal surface 43a of the first seal portion 43 is equal to or greater than the second length M2 shown in FIG. 5. In this case, the first seal portion 43 is appropriately positioned with respect to the corrugated tube 3 so that the seal surface 43a can be in close contact with the entirety of the two adjacent apex surfaces 31a. The length L1 of this embodiment is greater than the second length M2. The length L1 of the seal surface 43a may be equal to or greater than the third length M3 shown in FIG. 5. In this case, the seal surface 43a can be in close contact with at least the entirety of two apex surfaces 31a, and can also be in close contact with the entirety of three consecutive apex surfaces 31a.

[0032] 6, the corrugated tube 3 may be inserted into the first seal portion 43 while elastically deforming the first seal portion 43. In this case, the value of the inner diameter D1 of the first seal portion 43 is smaller than the value of the outer diameter D4 of the corrugated tube 3. This increases the degree of contact between the seal surface 43a and the outer peripheral surface of the corrugated tube 3.

[0033] 7 shows the corrugated tube 3 inserted into the second seal portion 44. The second seal portion 44 is formed so that the seal surface 44a can be in close contact with at least the entirety of two adjacent top surfaces 31a. Specifically, the length L2 of the seal surface 44a of the second seal portion 44 is equal to or greater than the second length M2 shown in FIG. The length L2 in this embodiment is greater than the second length M2.

[0034] 7, the corrugated tube 3 may be inserted into the second seal portion 44 while elastically deforming the second seal portion 44. In this case, the value of the inner diameter D2 of the second seal portion 44 is smaller than the value of the outer diameter D4 of the corrugated tube 3. This increases the degree of contact between the seal surface 44a and the outer peripheral surface of the corrugated tube 3.

[0035] FIG. 8 shows the band member 6 fastened to the first tubular portion 41. The first seal portion 43 and the second seal portion 44 are in close contact with the outer circumferential surface of the corrugated tube 3 to hold the corrugated tube 3. A band member 6A is fastened to the groove 43b of the first seal portion 43. The band member 6A tightens the first seal portion 43 against the corrugated tube 3, and presses the seal surface 43a against the outer circumferential surface of the corrugated tube 3. A band member 6B is fastened to the groove 44b of the second seal portion 44. The band member 6B tightens the second seal portion 44 against the corrugated tube 3, and presses the seal surface 44a against the outer circumferential surface of the corrugated tube 3.

[0036] The width of the band member 6 is preferably larger than the first length M1 of the corrugated tube 3. The width of the band member 6 may be larger than the pitch P1 of the corrugated tube 3. In this case, the band member 6 can press the sealing surfaces 43a, 44a against the two adjacent top surfaces 31a.

[0037] 8, a gap G1 is provided between an inner circumferential surface 45a of the flexible portion 45 and an outer circumferential surface of the corrugated tube 3. Therefore, when the corrugated tube 3 is curved and deformed, the flexible portion 45 can easily follow the deformation of the corrugated tube 3 and bend and deform.

[0038] 9 shows the curved and deformed corrugated tube 3 and grommet 4. The first seal portion 43 is in close contact with the outer peripheral surface of the corrugated tube 3. Therefore, the first seal portion 43 can effectively prevent water from entering the gap G1 from the outside of the grommet 4. The first seal portion 43 is fastened to the corrugated tube 3 by the band member 6A. Therefore, the first seal portion 43 is prevented from shifting relative to the corrugated tube 3 when the first tubular portion 41 follows the deformation of the corrugated tube 3, and deterioration of the sealing performance is prevented.

[0039] The second seal portion 44 is in close contact with the outer peripheral surface of the corrugated tube 3. Therefore, the second seal portion 44 can effectively prevent water from entering the side of the fitting portion 40. The second seal portion 44 is fastened to the corrugated tube 3 by the band member 6B. Therefore, the second seal portion 44 is prevented from shifting relative to the corrugated tube 3 when the first tubular portion 41 follows the deformation of the corrugated tube 3, and deterioration of the sealing performance is prevented.

[0040] In this manner, the waterproof structure 1 of this embodiment prevents water from entering the vehicle interior space 210 from the external space 220 by the two seal portions 43, 44. In addition, the elastically deformable flexible portion 45 is provided between the two seal portions 43, 44. Therefore, the waterproof structure 1 of this embodiment can achieve both the ability of the grommet 4 to follow the bending deformation of the corrugated tube 3 and the assurance of waterproof performance.

[0041] As described above, the waterproof structure 1 of this embodiment includes the corrugated tube 3 into which the electric wire 2 is inserted, and the grommet 4. The grommet 4 has the first tubular portion 41 into which the corrugated tube 3 is inserted, and holds the corrugated tube 3. The first tubular portion 41 includes the first seal portion 43, the second seal portion 44, and the bendable flexible portion 45. The first seal portion 43 and the second seal portion 44 protrude toward the central axis C1 of the first tubular portion 41, and are in close contact with the outer circumferential surface of the corrugated tube 3. The flexible portion 45 is disposed between the first seal portion 43 and the second seal portion 44. The waterproof structure 1 of this embodiment includes the seal portions 43, 44 on both sides of the flexible portion 45, thereby improving water stopping performance.

[0042] In the waterproof structure 1 of this embodiment, the peak portion 31 of the corrugated tube 3 has a top surface 31a. The length L1 of the first seal portion 43 and the length L2 of the second seal portion 44 in the direction of the central axis C1 are lengths capable of covering the two adjacent top surfaces 31a. The first seal portion 43 of this embodiment can cover the entire two adjacent top surfaces 31a, and the second seal portion 44 can cover the entire two adjacent top surfaces 31a. Therefore, the waterproof structure 1 of this embodiment can improve the water stopping performance.

[0043] The grommet 4 of this embodiment has a fitting portion 40 that fits into the through hole 201 of the panel 200. The fitting portion 40 is disposed on the opposite side of the second seal portion 44 from the first seal portion 43. The length L1 of the first seal portion 43 is greater than the length L2 of the second seal portion 44. In other words, the waterproof structure 1 of this embodiment can effectively stop water at the first seal portion 43 on the side farther from the fitting portion 40.

[0044] In the waterproof structure 1 of this embodiment, a first tapered portion 46 with a varying thickness is provided between the flexible portion 45 and the first seal portion 43. The thickness t1 of the first tapered portion 46 decreases with increasing distance from the first seal portion 43 along the direction of the central axis C1. In other words, the rigidity of the first tapered portion 46 increases from the flexible portion 45 toward the first seal portion 43. Therefore, the waterproof structure 1 of this embodiment can suppress a decrease in the sealing ability of the first seal portion 43 when the flexible portion 45 deforms in response to the deformation of the corrugated tube 3.

[0045] The wire harness 100 of the present embodiment includes the electric wires 2 and the above-described waterproof structure 1. Therefore, the wire harness 100 of the present embodiment can suppress the intrusion of water between the grommet 4 and the corrugated tube 3, and can improve the waterproofing property.

[0046] The exterior member 5 inserted into the second cylindrical portion 42 is not limited to a corrugated tube without a slit. The exterior member 5 may be, for example, a corrugated tube with a slit or a twisted tube.

[0047] The shape of the flexible portion 45 is not limited to the cylindrical shape shown in the example. The cross-sectional shape of the flexible portion 45 may be an ellipse or another shape. The inner diameter D3 of the flexible portion 45 does not have to be constant. In this case, the shape of the flexible portion 45 may be a shape in which the inner diameter D3 changes along the first direction X like a cone.

[0048] [First Modification of the Embodiment] A first modified example of the embodiment will be described with reference to Fig. 10. Fig. 10 is a diagram showing a waterproof structure and a wire harness according to the first modified example of the embodiment. Fig. 10 shows a cross section of a grommet 4. The first modified example of the embodiment differs from the above embodiment in that the first tubular portion 41 has a bellows portion 48, for example.

[0049] As shown in FIG. 10, the flexible portion 45 according to the first modified example of the embodiment has a bellows portion 48. The bellows portion 48 has a plurality of peaks 48a and a plurality of valleys 48b. An inner diameter D5 of the valleys 48b is larger than an outer diameter D4 of the corrugated tube 3. The first tubular portion 41 having the bellows portion 48 has high conformability to the deformation of the corrugated tube 3. The first tubular portion 41 can conform to the bending deformation of the corrugated tube 3 mainly by deforming the bellows portion 48. Therefore, the grommet 4 of the first modified example can appropriately suppress the displacement of the first seal portion 43 and the displacement of the second seal portion 44 relative to the corrugated tube 3.

[0050] As described above, the flexible portion 45 according to the first modified embodiment has a bellows-shaped bellows portion 48. The innermost diameter of the flexible portion 45 is larger than the outer diameter D4 of the corrugated tube 3. Therefore, the waterproof structure 1 according to the first modified embodiment can improve the ability of the flexible portion 45 to follow the deformation of the corrugated tube 3. The innermost diameter of the flexible portion 45 may be the inner diameter D5 of the valley portion 48b, or may be the inner diameter D6 of the portion adjacent to the bellows portion 48.

[0051] The contents disclosed in the above-mentioned embodiments and modifications can be implemented in appropriate combinations. [Explanation of symbols]

[0052] 1: Waterproof structure, 2: Electric wire, 3: Corrugated tube, 4: Grommet 5: Exterior material, 6, 6A, 6B: Band material 31: Mountain, 31a: Top, 32: Valley 40: fitting portion, 40a: groove portion, 40b: outer seal portion 41: first cylindrical portion, 42: second cylindrical portion, 42a: bellows portion 43: first seal portion, 43a: seal surface, 43b: groove 44: second seal portion; 44a: seal surface; 44b: groove 45: flexible portion; 46: first tapered portion; 47: second tapered portion 200: panel, 200a: wall surface, 210: interior space of vehicle, 220: exterior space D1: inner diameter of the first seal portion, D2: inner diameter of the second seal portion, D3: inner diameter of the flexible portion D4: Outer diameter of corrugated tube G1: Gap L1: Length of the seal surface of the first seal part, L2: Length of the seal surface of the second seal part M1: first length, M2: second length, M3: third length P1: Pitch t1: thickness of the first taper section, t2: thickness of the second taper section X: first direction, X1: first side, X2: second side

Claims

1. A corrugated tube into which the electric wire is inserted; a grommet having a first tubular portion into which the corrugated tube is inserted and which holds the corrugated tube; Equipped with the first tubular portion has a first seal portion that protrudes toward a central axis of the first tubular portion and is in close contact with an outer peripheral surface of the corrugated tube, a second seal portion that protrudes toward the central axis and is in close contact with the outer peripheral surface of the corrugated tube, and a bendable flexible portion that is disposed between the first seal portion and the second seal portion, The peak portion of the corrugated tube has a top surface, a length of the first seal portion and the second seal portion in the direction of the central axis that is sufficient to cover two adjacent top surfaces of the corrugated tube, the grommet has a fitting portion that fits into a through hole of a panel, and the fitting portion is disposed on an opposite side to a side of the first seal portion with respect to the second seal portion, The length of the first seal portion in the direction of the central axis is greater than the length of the second seal portion. A waterproof structure characterized by:

2. The flexible portion has a bellows shape, and the innermost diameter of the flexible portion is larger than the outer diameter of the corrugated tube. The waterproof structure according to claim 1.

3. a tapered portion having a varying thickness is provided between the flexible portion and the first seal portion, The thickness of the tapered portion decreases with increasing distance from the first seal portion along the direction of the central axis. The waterproof structure according to claim 1.

4. Electric wires and a corrugated tube into which the electric wire is inserted; a grommet having a first tubular portion into which the corrugated tube is inserted and which holds the corrugated tube; Equipped with The first cylindrical portion has a first seal portion that protrudes toward a central axis of the first cylindrical portion and is in close contact with an outer circumferential surface of the corrugated tube, a second seal portion that protrudes toward the central axis and is in close contact with an outer circumferential surface of the corrugated tube, and a bendable flexible portion that is disposed between the first seal portion and the second seal portion. A wire harness comprising:

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