Grommet

Abstract

To reduce insertion force.SOLUTION: A waterstop member 60A has an annular body 61 which abuts an annular wall surface 20c on a peripheral part 503 side of an open hole 502 on a flange 20 of a base member 10X, an annular peripheral lip 62 which projects toward the peripheral part 503 so as to be released off from a hole axial of the open hole 502 as it approaches the peripheral part 503 coaxially from the body 61 and is flexurally deformed at an attachment completion position and is placed in close contact with an annular plane 503a of the peripheral part 503 over one circumference, and an annular inner circumferential lip 63 which projects toward the peripheral part 503 so as to approach to the hole axial of the open hole 502 as it approaches the peripheral part 503 more closely than the peripheral lip 62 on the body 61 from the inner peripheral part 61b side coaxially and is flexibly deformed at an attachment completion position and is placed in close contact with an annular plane 503a side of the peripheral part 503 over one circumference.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a grommet. [Background technology]

[0002] Conventionally, in a wire harness, a wiring material such as an electric wire is inserted through a through hole provided in an object to be inserted (for example, a body panel of a vehicle, etc.) to draw the wiring material from one space separated by the object to be inserted to another space. For this reason, a grommet is attached to the object to be inserted to protect the wiring material from the periphery of the through hole and to close the gap between the through hole and the wiring material in order to prevent liquid from entering the gap. For example, the grommet is composed of a base member made of a hard synthetic resin material and an annular water-stopping member made of a flexible synthetic resin material such as rubber, and is inserted into the through hole to bring the water-stopping member into close contact with the periphery of the through hole in the object to be inserted. For example, the following Patent Document 1 discloses a grommet configured in this way. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-251769 Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional grommet, a water-stopping member may be provided with an annular lip to improve water-stopping ability between the water-stopping member and the periphery of the through hole. The lip protrudes in the direction of insertion of the grommet into the through hole, and when the grommet is assembled to the periphery of the through hole, the lip abuts against the periphery and is deflected to make a tight contact. Therefore, in this type of grommet, the lip increases the insertion force into the through hole.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a grommet that allows for a reduction in the insertion force. [Means for solving the problem]

[0006] The present invention comprises a base member made of a synthetic resin material, through which a conductive wiring material is inserted inside to be passed through a through hole of an object to be inserted from one space to the other space, and an annular grommet body assembled to the base member and disposed in the one space at a position where attachment to the peripheral portion of the through hole of the object to be inserted is completed, the base member having an annular flange disposed in the one space at the attachment completion position and disposed coaxially opposite to an annular plane of the annular peripheral portion on the one space side with a gap therebetween, and a tubular body protruding coaxially from the flange towards the other space and inserted into the through hole at the attachment completion position, the other flange protruding beyond the outer circumferential surface of the tubular body in the other space at the attachment completion position, and the other flange being disposed coaxially opposite to the peripheral portion of the other space at the attachment completion position. the grommet body has a plurality of engaging portions in a circumferential direction of the cylindrical body that come into contact with the flange from the space side toward the flange, the grommet body being provided with an annular water-stopping member made of a synthetic resin material that is softer and elastically deformable than the base member, the water-stopping member comprising: an annular main body that comes into coaxial contact with an annular wall surface on the peripheral edge side of the flange, an annular outer peripheral lip that protrudes coaxially from the main body toward the peripheral edge so as to move away from the hole axis of the through hole as it approaches the peripheral edge, and which flexes and deforms at the installation completion position to come into close contact with the annular flat surface of the peripheral edge over the entire circumference, and an annular inner peripheral lip that protrudes coaxially from the main body toward the peripheral edge so as to move closer to the hole axis of the through hole as it approaches the peripheral edge, and which flexes and deforms at the installation completion position to come into close contact with the annular flat surface side of the peripheral edge over the entire circumference. The inner peripheral lip has a thin-walled portion at its tip end which is flexible and flexible at the installation completion position to bring the outer wall surface in the radial direction into close contact with the annular flat surface of the peripheral edge portion. It is characterized by: Effect of the Invention

[0007] In the grommet according to the present invention, when the cylindrical body is inserted into the through hole from one space and comes into contact with the annular flat surface of the peripheral edge, the outer peripheral lip and the inner peripheral lip begin to flex and deform without being caught by the peripheral edge. Therefore, the grommet according to the present invention can reduce the insertion force into the through hole. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a grommet of an embodiment after it has been attached to an object to be inserted therethrough. [Diagram 2] FIG. 2 is a plan view of the grommet of the embodiment after it has been attached to an object to be inserted, as viewed from the cylindrical body side. [Diagram 3] FIG. 3 is a plan view of the grommet of the embodiment after it has been attached to an object to be passed through, as viewed from the tubular body side. [Figure 4] FIG. 4 is a cross-sectional view taken along line XX in FIG. [Diagram 5] FIG. 5 is a perspective view of the grommet of the embodiment before it is attached to an object to be inserted, as viewed from a different angle. [Figure 6] FIG. 6 is a cross-sectional view taken along line XX in FIG. 2, and shows the state before being attached to the object to be passed through. [Figure 7] FIG. 7 is an exploded perspective view showing the grommet of the embodiment. [Figure 8] FIG. 8 is an exploded perspective view of the grommet of the embodiment as viewed from a different angle. [Figure 9] FIG. 9 is an exploded perspective view showing the grommet of the embodiment separated into two base members and a grommet body after assembly. [Figure 10] FIG. 10 is an exploded perspective view of the base member and the waterproof member. [Figure 11] FIG. 11 is an exploded perspective view of the grommet body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a grommet according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to this embodiment.

[0010] [Embodiment] One embodiment of a grommet according to the present invention will be described with reference to FIGS.

[0011] Reference numeral 1 in Fig. 1 to Fig. 9 indicates a grommet of this embodiment. This grommet 1 protects the conductive wiring material We passing from one space S1 to the other space S2 through a through hole 502 of an object to be inserted 501 from a peripheral portion 503 of the through hole 502 in the object to be inserted 501, and prevents liquid (water, etc.) from entering the gap between the annular peripheral portion 503 and the wiring material We (Figs. 1 to 6). Therefore, this grommet 1 is attached to the peripheral portion 503 of the through hole 502 of the object to be inserted 501 after the wiring material We is inserted therethrough.

[0012] Here, the wiring material We refers to, for example, an electric wire (an electric wire as a communication line, an electric wire as a power supply line, etc.). The insertion object 501 refers to a member for inserting the wiring material We, and in the case of a vehicle, refers to a wall such as a panel of the body. The wiring material We is routed between one space S1 and the other space S2 separated by the insertion object 501 by inserting it through a through hole 502 of the insertion object 501. For example, the wiring material We is responsible for communication between the devices in the one space S1 and the other space S2, and for supplying power to electrical equipment in the one space S1 from a power source in the other space S2.

[0013] A peripheral portion 503 of a through hole 502 of an object to be inserted 501 has an annular flat plate portion (hereinafter referred to as an "annular flat plate portion") 504 and an annular protrusion portion (hereinafter referred to as an "annular protrusion portion") 505 protruding from an end portion (inner peripheral edge portion 504a) of an inner peripheral edge of the annular flat plate portion 504 toward the other space S2 (FIGS. 1 to 6). The grommet 1 is attached to the annular flat plate portion 504 and the annular protrusion portion 505 at the peripheral portion 503. For example, the object to be inserted 501 is formed by press molding, at which time the annular flat plate portion 504 and the through hole 502 are formed. Then, in the object to be inserted 501, the annular protrusion portion 505 is formed by burring the peripheral edge of the through hole 502. Therefore, in the peripheral portion 503, a bent portion 506 is formed between the annular flat portion 504 and the annular protrusion portion 505 such that the outer side of the bend forms an arc-shaped surface 506a (FIGS. 4 and 6). Since the through hole 502 is formed in a circular shape, the annular flat portion 504 and the annular protrusion portion 505 are each formed in a circular ring shape.

[0014] The grommet 1 comprises a base member 10X through which the wiring material We is inserted on the inside (FIGS. 1 to 10). This base member 10X may consist of one member, or may consist of multiple members assembled together. The base member 10X shown here comprises two base members (a first base member, a second base member) that are assembled together. These two base members may be members with different shapes, or each may be the same member with the same shape. In the grommet 1 shown here, the two base members are the same member with the same shape (base members 10, 10) (FIGS. 1 to 10).

[0015] This base member 10X has at least an annular flange 20 and a cylindrical body 30 coaxially, and the wiring material We is inserted into these (FIGS. 1 to 9). The base member 10X shown here has a tubular body 40 coaxially with the flange 20 and cylindrical body 30, and the wiring material We is inserted into these (FIGS. 1 and 3 to 9). Here, the cylindrical body 30 protrudes from the flange 20 in one direction, and the tubular body 40 protrudes from the flange 20 in the other direction on the same axis.

[0016] In the base member 10X shown here, as described below, the base members 10, 10 are assembled together to form an annular flange 20, a cylindrical body 30, and a tubular body 40 on the same axis. For this reason, a holding mechanism (hereinafter referred to as a "base holding mechanism") 50 for holding the two base members 10, 10 in their assembled state is provided between the two base members 10, 10 (FIGS. 1, 3, 5, and 7 to 9).

[0017] Moreover, this grommet 1 includes an annular grommet body 60 that is assembled to a base member 10X (base members 10, 10 assembled to each other) (FIGS. 1, 3 to 9, and 11). This grommet body 60 is disposed in one space S1 at a position where mounting of the grommet 1 to the peripheral portion 503 is completed, so as to prevent infiltration of liquid (such as water) from one space S1 into the other space S2 via the through-hole 502 (FIG. 4). Note that in the following, when the term "mounting completion position" is simply used, this refers to the position where mounting of the grommet 1 to the peripheral portion 503 is completed.

[0018] The base member 10X (base members 10, 10) is molded using an insulating hard synthetic resin material (hereinafter, referred to as "hard resin"). Here, the base member 10X (base members 10, 10) is molded using a hard resin such as plastic, for example.

[0019] The two base members 10, 10 are assembled by matching their joint surfaces 10a (FIGS. 2, 3, 7, and 8). The two base members 10, 10 sandwich the wiring material We in the assembled state, and the wiring material We is inserted between them. Here, by assembling the two base members 10, 10, an annular flange 20, a cylindrical tubular body 30, and a circular tubular body 40 are formed. Note that a straight tubular body 40 is taken as an example here. However, the tubular body 40 may be bent after protruding from the flange 20.

[0020] The flange 20 is disposed in one space S1 at the installation completion position, and is disposed coaxially opposite the annular flat surface 503a on the one space S1 side of the peripheral edge portion 503 with a gap therebetween (FIG. 4). This annular flat surface 503a is provided on the annular flat plate portion 504. The annular flat surface 503a shown here is the annular flat surface on the one space S1 side of the annular flat plate portion 504 itself. This flange 20 is formed in a circular plate shape. For example, this flange 20 is formed in a shape similar to the circular annular flat surface 503a. The flange 20 shown here has its circular outer peripheral edge portion 20a disposed opposite the annular flat surface 503a, and the wiring material We is inserted inside the circular inner peripheral edge portion 20b (FIG. 4). The outer peripheral edge portion 20a is disposed coaxially opposite to the inner peripheral edge portion 504a of the annular flat plate portion 504 on the annular plane 503a with a gap in the axial direction of the through hole 502 in one space S1 (FIG. 4).

[0021] Each of the two base members 10, 10 has a split flange 11 that joins with each other's joint surfaces 10a to form a flange 20 (FIGS. 1 to 9). The split flange 11 shown here is obtained by splitting the flange 20 in half along the central axis, and is formed in a semicircular arc shape.

[0022] The tubular body 30 protrudes from the flange 20 coaxially toward the other space S2, and is inserted into the through hole 502 at the installation completion position (FIGS. 4 and 6). That is, in this tubular body 30, the tip end protruding from the flange 20 is disposed in the other space S2. This tubular body 30 is formed in a cylindrical shape. For example, this tubular body 30 is formed so that the cross section perpendicular to the hole axis of the through hole 502 is similar in shape to the cross section perpendicular to the hole axis of the annular protrusion 505. The tubular body 30 shown here protrudes from the inner peripheral edge 20b side of the flange 20 relative to the outer peripheral edge 20a, and the wiring material We is inserted inside (FIGS. 4 and 6).

[0023] Each of the two base members 10, 10 has a split tube 12 that joins the joint surfaces 10a to form a cylindrical body 30 (FIGS. 2 and 4 to 9). The split tube 12 shown here is obtained by splitting the cylindrical body 30 in half along the central axis, and is formed in a semicircular arc shape.

[0024] The tubular body 40 protrudes from the flange 20 coaxially in the opposite direction to the cylindrical body 30 (FIGS. 4 to 6). The tubular body 40 is formed in a circular tube shape. For example, the tubular body 40 is formed such that a cross section perpendicular to the axis of the through hole 502 is similar in shape to a cross section perpendicular to the axis of the hole in the annular protrusion 505. The tubular body 40 shown here protrudes from the inner peripheral edge 20b of the flange 20, and the wiring material We is inserted inside (FIGS. 4 and 6).

[0025] Each of the two base members 10, 10 has a split tube 13 that joins its joint surface 10a to form a tubular body 40 (FIGS. 1 and 3 to 9). The split tube 13 shown here is obtained by splitting the tubular body 40 in half along the central axis, and is formed in a semicircular arc shape.

[0026] As described above, the main parts of the two base members 10, 10 (split flange 11, split cylinder 12, split pipe 13) are made of high hardness and are not easily elastically deformed. For this reason, the two base members 10, 10 may form minute gaps between their respective joint surfaces 10a due to, for example, the surface roughness of the joint surfaces 10a. Therefore, the grommet 1 of this embodiment is provided with a waterproof member 71 on at least one of the joint surfaces 10a of the two base members 10, 10, which is made of a synthetic resin material (hereinafter referred to as "soft resin") that is softer and elastically deformable than the hard resin of the base members 10 and which eliminates the gap between the joint surfaces 10a (FIGS. 7, 8, and 10).

[0027] The waterproof member 71 is molded using a synthetic resin material such as elastomer. The waterproof member 71 is provided over the joint surfaces 10a of the split flange 11, the split cylinder 12, and the split pipe 13. The base member 10 shown here has a groove 10b formed in one of the two joint surfaces 10a between the split flange 11 and the split pipe 13, and the waterproof member 71 is fitted into the groove 10b (FIG. 10). The waterproof member 71 protrudes from the groove 10b. For example, the waterproof member 71 is molded integrally with the base member 10 by two-color molding with the base member 10 or by insert molding with the base member 10 housed in a mold. The waterproof member 71 may also be molded as a separate part from the base member 10 and attached to the groove 10b of the base member 10 with an adhesive or the like. In this base member 10X, the two base members 10, 10 are assembled together, so that the waterproof member 71 protruding from the groove portion 10b of one joint surface 10a of one base member 10 is brought into close contact with the other joint surface 10a of the other base member 10.

[0028] The base holding mechanism 50 is a holding mechanism for holding the two base members 10, 10 in a state in which their joint surfaces 10a are aligned. The base holding mechanism 50 is provided at a plurality of locations between the two base members 10, 10. For example, the base holding mechanism 50 shown here includes a piece 51 protruding from the joint surface 10a of one of the two base members 10, 10, and a claw-shaped first locking portion 52 protruding from a wall surface of the piece 51 (FIGS. 7 and 8). The base holding mechanism 50 shown here is provided with an insertion opening 53 on the joint surface 10a of the other of the two base members 10, 10, into which one of the piece portions 51 and the first locking portion 52 is inserted, a flexible portion 54 on the other of the two base members 10, 10, which is pushed and bent by the first locking portion 52 inserted through the insertion opening 53, and which releases the first locking portion 52 when the joint surfaces 10a of the two base members 10, 10 are brought together, thereby eliminating the bending, and a second locking portion 55 on the other of the two base members 10, 10, which is positioned opposite the first locking portion 52 when the joint surfaces 10a of the two base members 10, 10 are brought together, thereby holding the two base members 10, 10 in a state in which their respective joint surfaces 10a are aligned (Figures 7 and 8).

[0029] Each of the two base members 10, 10 shown here has a set of a piece portion 51 and a first locking portion 52 at one circumferential end of the split tube 12, and a set of an insertion opening 53, a flexible portion 54, and a second locking portion 55 at the other circumferential end of the split tube 12. With the joint surfaces 10a of the two base members 10, 10 facing each other, the first locking portion 52 at one end of one split tube 12 is locked to the second locking portion 55 at the other end of the other split tube 12, and the second locking portion 55 at the other end of one split tube 12 is locked to the first locking portion 52 at one end of the other split tube 12. In other words, the two base members 10, 10 have two base holding mechanisms 50 that connect the split tubes 12 and hold them in the connected state. Furthermore, each of the two base members 10, 10 has a set of a piece portion 51 and a first locking portion 52 at one circumferential end of the split pipe 13, and a set of an insertion opening 53, a flexible portion 54, and a second locking portion 55 at the other circumferential end of the split pipe 13. With the joint surfaces 10a of the two base members 10, 10 facing each other, the first locking portion 52 at one end of one split pipe 13 is locked to the second locking portion 55 at the other end of the other split pipe 13, and the second locking portion 55 at the other end of one split pipe 13 is locked to the first locking portion 52 at one end of the other split pipe 13. In other words, the two base members 10, 10 are provided with two base holding mechanisms 50 that connect the split pipes 13 and hold them in the connected state.

[0030] The grommet body 60 includes an annular water-stopping member 60A made of soft resin (i.e., an elastically deformable synthetic resin material softer than the hard resin of the base member 10X (base member 10)) and an annular support member 60B made of a synthetic resin material harder than the soft resin of the water-stopping member 60A and integrated with the water-stopping member 60A (FIGS. 1, 3 to 8, and 11). The water-stopping member 60A is molded using a synthetic resin material such as an elastically deformable elastomer that is softer than the hard resin of the base member 10X (base member 10) and the support member 60B. The support member 60B is made of the same hard resin as the base member 10X (base member 10) or a different hard resin having the same hardness as the hard resin of the base member 10X (base member 10), and is molded using a synthetic resin material such as plastic.

[0031] The water-stopping member 60A has an annular main body 61 that is brought into coaxial contact with the annular wall surface 20c on the peripheral edge portion 503 side of the flange 20 (FIGS. 1, 4, 6 to 8, and 11). The main body 61 is formed in an annular plate shape. The main body 61 shown here is brought into contact with the wall surface 20c at the peripheral edge portion 20a of the flange 20 with its outer peripheral edge portion 61a protruding from the outer peripheral edge portion 20a of the flange 20 (FIGS. 4 and 6).

[0032] Furthermore, this water-stopping member 60A has an annular outer peripheral lip 62 that protrudes coaxially from the main body 61 toward the peripheral portion 503 so as to be pulled away from the hole axis of the through hole 502 as it approaches the peripheral portion 503, and which flexes and deforms to fit closely to the annular flat surface 503a of the peripheral portion 503 over the entire circumference at the completion of installation, and an annular inner peripheral lip 63 that protrudes coaxially toward the peripheral portion 503 from the inner peripheral portion 61b side of the main body 61 toward the peripheral portion 503 so as to be closer to the hole axis of the through hole 502 as it approaches the peripheral portion 503 over the entire circumference, and which flexes and deforms to fit closely to the annular flat surface 503a of the peripheral portion 503 over the entire circumference at the completion of installation (Figures 1, 3 to 9 and 11).

[0033] The outer peripheral lip 62 has a radially inner wall surface 62a and two annular sub-lip portions 62b that protrude coaxially from this wall surface 62a (FIGS. 4 and 6). When the outer peripheral lip 62 is in the installation completion position, it is flexed and deformed from its base on the main body 61 side, and the two sub-lip portions 62b are brought into close contact with the annular flat surface 503a of the peripheral edge portion 503.

[0034] Furthermore, the inner lip 63 has a radially outer wall surface 63a in close contact with the annular flat surface 503a of the peripheral portion 503 at the installation completion position (FIG. 4). The inner lip 63 has a flexible thin portion 63b at its tip end (FIGS. 4 and 6). The inner lip 63 has a thin portion 63b that is thinner at the tip end than at its base on the main body 61 side, and the thin portion 63b is flexible at the installation completion position to bring the radially outer wall surface 63a of the thin portion 63b into close contact with the annular flat surface 503a of the peripheral portion 503. The inner lip 63 shown here may have the wall surface 63a of its thin-walled portion 63b in close contact with the arcuate surface 506a of the bent portion 506 of the peripheral portion 503 all around, or may have the wall surface 63a of its thin-walled portion 63b in close contact with the annular flat surface 503a of the peripheral portion 503 all around.

[0035] In this grommet body 60, the water-stopping member 60A is integrated with the support member 60B. For example, the water-stopping member 60A is produced by two-color molding with the support member 60B, or is insert molded into the support member 60B housed in a mold, so as to be integrally molded with the support member 60B. Also, the water-stopping member 60A may be molded as a part separate from the support member 60B, and attached to the support member 60B with an adhesive or the like.

[0036] The support member 60B has an annular portion (hereinafter referred to as a "first annular portion") 65a that is arranged coaxially opposite to a ring-shaped abutment surface 61c of the main body 61 of the water-stopping member 60A with a gap therebetween, the ring-shaped abutment surface 61c being in contact with the wall surface 20c of the flange 20 (FIGS. 1, 3, 4, 6 to 8, and 11). The first annular portion 65a is formed in a circular plate shape. The base member 10X (the base members 10, 10 assembled together) fits the outer peripheral edge portion 20a of the flange 20 into the annular gap between the abutment surface 61c of the main body 61 and the first annular portion 65a. As a result, the grommet main body 60 is assembled integrally with the outer peripheral edge portion 20a of the flange 20.

[0037] The support member 60B also has an annular portion (hereinafter referred to as the "second annular portion") 65b that protrudes coaxially from the outer peripheral edge of the first annular portion 65a toward the outer peripheral edge 61a of the main body 61 of the water-stopping member 60A and abuts against the outer peripheral edge 61a over the entire circumference (FIGS. 1, 3 to 8, and 11). The second annular portion 65b is formed in a cylindrical ring shape.

[0038] The water-stopping member 60A is integrated in a state of close contact with the outer peripheral edge of the first annular portion 65a and the inner wall surface of the second annular portion 65b, and the outer peripheral edge 61a of the main body 61 is integrated in a state of close contact with the abutting surface of the second annular portion 65b with the outer peripheral edge 61a. The water-stopping member 60A has an annular portion 64 that is integrated in a state of close contact with the outer peripheral edge of the first annular portion 65a and the inner wall surface of the second annular portion 65b (FIGS. 4, 6, and 11). The annular portion 64 is formed in a cylindrical shape and protrudes from the main body 61 coaxially in the opposite direction to the outer peripheral lip 62 and the inner peripheral lip 63. For example, in the water-stopping member 60A, the annular portion 64 is integrally molded in a state of close contact with the outer peripheral edge portion of the first annular portion 65a and the inner wall surface of the second annular portion 65b, and the main body 61 is integrally molded with the outer peripheral edge portion 61a in close contact with the abutment surface of the second annular portion 65b with the outer peripheral edge portion 61a.

[0039] Strictly speaking, the outer peripheral edge 20a of the flange 20 is fitted inside the annular portion 64 of the water-stopping member 60A in the annular gap between the abutment surface 61c of the main body 61 of the water-stopping member 60A and the first annular portion 65a of the support member 60B. For example, although not described in detail, an annular lip is formed on the inner peripheral surface of the annular portion 64, which is in close contact with the outer peripheral surface of the outer peripheral edge 20a of the flange 20 all around. This ensures that the grommet main body 60 is waterproof in the gap between the water-stopping member 60A and the support member 60B.

[0040] The grommet 1 configured in this manner includes a retention mechanism 80 that retains the assembled base member 10X (the assembled base members 10, 10) and the grommet body 60 on the peripheral portion 503 of the through hole 502 in the object 501 to be inserted (FIGS. 2 and 4 to 9). The retention mechanism 80 shown here utilizes a resilient force accompanying elastic deformation of the outer peripheral lip 62 and the inner peripheral lip 63 of the water-stopping member 60A, and holds the grommet 1 on the peripheral portion 503 by sandwiching the peripheral portion 503 between the outer peripheral lip 62, the inner peripheral lip 63 and an engagement portion 81 provided on the base member 10X (base member 10) described below.

[0041] The base member 10X has a locking portion 81 that protrudes from the outer circumferential surface 30a of the cylindrical body 30 in the other space S2 at the attachment completion position and that contacts the peripheral edge portion 503 from the other space S2 side in the other space S2 at the attachment completion position (FIGS. 4 to 9). The locking portion 81 locks a part of the peripheral edge portion 503 in the circumferential direction. Therefore, the base member 10X has a plurality of locking portions 81 in the circumferential direction of the cylindrical body 30.

[0042] The base member 10X also has a cantilevered locking piece 82 with a locking portion 81 at its free end in the other space S2 at the installation completion position (FIGS. 2 and 4 to 9). The locking piece 82 protrudes from the fixed end on the outer circumferential surface 30a side of the cylindrical body 30 to the one space S1 side in the other space S2 at the installation completion position, and the free end side protrudes from the outer circumferential surface 30a of the cylindrical body 30 (initial shape). The locking piece 82 is formed to have flexibility that allows it to bend and deform so as to change the amount of protrusion from the outer circumferential surface 30a on the free end side. The locking piece 82 moves back and forth through the notch portion 30b, which is a cutout portion of the cylindrical body 30, by its bending deformation (FIGS. 2 and 4 to 9). A plurality of combinations of locking portions 81, locking pieces 82, and notches 30b are provided at equal intervals in the circumferential direction of the cylindrical body 30. The cylindrical body 30 shown here has four combinations of locking portions 81, locking pieces 82, and notches 30b provided at equal intervals in the circumferential direction. Here, each of the split tubes 12 of the base member 10 has two combinations of locking portions 81, locking pieces 82, and notches 30b.

[0043] When the cylindrical body 30 is inserted into the through hole 502 from one space S1, the locking piece 82 is subjected to a force from the annular protrusion 505 of the peripheral portion 503, and is deflected and deformed from its initial shape toward the notch 30b side, passes through the position of the annular protrusion 505, and advances to the tip (hereinafter referred to as the "locking end") 505a (FIGS. 4 to 6) of the annular protrusion 505, and begins to return to its initial shape when the force from the annular protrusion 505 is removed. Therefore, the locking piece 82 is disposed at the tip of the locking end 505a of the annular protrusion 505 together with the locking portion 81. Meanwhile, the outer peripheral lip 62 and the inner peripheral lip 63 of the water-stopping member 60A are deflected and deformed by contacting the annular flat surface 503a side of the peripheral portion 503 when a series of movements of the locking portion 81 and the locking piece 82 are occurring. Therefore, when the force for inserting the grommet 1 into the through hole 502 (so-called insertion force) is removed, the grommet 1 moves back toward one of the spaces S1 due to the elastic force caused by the elastic deformation of the outer peripheral lip 62 and the inner peripheral lip 63. Accordingly, the locking portion 81 comes into contact with the locking end 505a of the annular protrusion 505 and is locked by this locking end 505a (FIG. 4). That is, the annular protrusion 505 locks the locking portion 81 at the tip (locking end 505a) of the end protruding from the annular flat plate portion 504. The annular locking end 505a locks the locking portion 81 at each location in the circumferential direction. Therefore, the peripheral portion 503 is sandwiched by the outer peripheral lip 62 and the inner peripheral lip 63 of the water-stopping member 60A and the locking portions 81 of the base member 10X (base members 10, 10).

[0044] Here, in the grommet 1 of this embodiment, as described above, the outer peripheral lip 62 protrudes toward the peripheral portion 503 so as to be pulled away from the hole axis of the through hole 502 as it approaches the peripheral portion 503, and the inner peripheral lip 63 protrudes toward the peripheral portion 503 so as to be closer to the hole axis of the through hole 502 as it approaches the peripheral portion 503. Therefore, when the outer peripheral lip 62 and the inner peripheral lip 63 abut against the annular flat surface 503a side of the peripheral portion 503 while the cylindrical body 30 is being inserted into the through hole 502 from one space S1, the outer peripheral lip 62 and the inner peripheral lip 63 begin to flex and deform without being caught by the peripheral portion 503. Therefore, the grommet 1 of this embodiment can reduce the insertion force into the through hole 502. [Explanation of symbols]

[0045] 1 Grommet 10X Base material 20 Flange 20a Outer periphery 20c Wall 30 Cylindrical body 30a Outer surface 60 Grommet body 60A Water-stopping material 60B Support member 61 Main unit 61b Inner periphery 61c Contact surface 62 Outer lip 63 Inner lip 63b Thin wall part 65a First annular part (annular part) 81 Locking part 501 Insertion object 502 Through hole 503 Periphery 503a Circular Plane 504 Annular plate section 504a Inner edge 505 Annular protrusion 505a Locking end S1 One side of the space S2 The other space We wiring material

Claims

1. A base member made of a synthetic resin material, through which a conductive wiring material is inserted on the inside to be passed from one space to another space through a through hole of an object to be inserted; an annular grommet body that is assembled to the base member and disposed in the one space at a position where attachment to a periphery of the through hole of the insertion object is completed; Equipped with the base member has an annular flange that is disposed in the one space at the installation completion position and that is disposed coaxially opposite to the annular plane of the annular peripheral portion on the one space side with a gap therebetween, and a cylindrical body that protrudes coaxially from the flange toward the other space and is inserted into the through hole at the installation completion position, and has a plurality of engaging portions in the circumferential direction of the cylindrical body that protrude beyond the outer circumferential surface of the cylindrical body in the other space at the installation completion position and contact the peripheral portion from the other space side in the other space at the installation completion position, The grommet body includes an annular water-stopping member made of an elastically deformable synthetic resin material that is softer than the base member, The water-stopping member has an annular main body that is brought into coaxial contact with an annular wall surface on the peripheral edge side of the flange, an annular outer peripheral lip that protrudes coaxially from the main body toward the peripheral edge so as to move away from the hole axis of the through hole as it approaches the peripheral edge, and is flexibly deformed at the installation completion position to be in close contact with the annular flat surface of the peripheral edge over the entire circumference, and an annular inner peripheral lip that protrudes coaxially toward the peripheral edge from an inner peripheral edge side of the main body so as to move closer to the hole axis of the through hole as it approaches the peripheral edge over the entire circumference, and is flexibly deformed at the installation completion position to be in close contact with the annular flat surface side of the peripheral edge over the entire circumference, The grommet is characterized in that the inner lip has a thin-walled portion at its tip side that is flexible and that flexes and deforms at the completion of installation position to bring the outer wall surface into close contact with the annular flat surface side of the peripheral edge portion in the radial direction.

2. The grommet according to claim 1 , wherein the thin portion has a radially outer wall surface that is in intimate contact with the annular flat surface of the peripheral edge portion over the entire circumference.

3. 2. The grommet as described in claim 1, characterized in that the peripheral portion has an annular flat portion on which the annular plane is provided, and an annular protrusion portion that protrudes from an end of an inner peripheral edge of the annular flat portion toward the other space and engages the engaging portion at its tip.

4. A bent portion is formed between the annular flat portion and the annular protrusion at the peripheral portion such that the outer side of the bend forms an arc-shaped surface, 4. The grommet according to claim 3, wherein the thin portion has a radially outer wall surface that is in intimate contact with the arcuate surface of the bent portion of the peripheral edge portion over the entire circumference.

5. The grommet body is made of a synthetic resin material harder than the water-stopping member and includes an annular support member integrated with the water-stopping member, the support member has an annular portion disposed coaxially opposite to and spaced apart from an annular abutment surface of the flange of the main body that abuts against the wall surface of the flange, 5. The grommet according to claim 1, wherein the base member has an outer peripheral edge portion of the flange fitted into the annular gap between the contact surface of the main body and the annular portion.

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