Grommet

Abstract

A hard resin base member (10X) has an annular flange (20), and an elastically deformable soft resin grommet main body (60) has: an annular body (61); an annular lip section (61) that is in close contact with the outer peripheral edge (20a) side of the first annular wall surface (20c) of the flange at the assembly completion position; a first annular portion (64) disposed coaxially facing the outer peripheral edge portion (61a) of the annular body and the outer peripheral edge portion side of the flange with a gap therebetween; and a second annular part (65) that connects the outer peripheral edge of the annular body and the outer peripheral edge of the first annular part, and the first annular part is hooked to the outer peripheral edge of the flange from a second annular wall surface (20d) side on the back side of the first annular wall surface at the assembly completion position.

Description

Technical Field

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

[0002] Conventionally, in a wire harness, wiring materials such as electric wires are inserted through through-holes provided in an insertion object (for example, a panel of a vehicle body), so that the wiring materials are introduced from one space separated by the insertion object to the other space. Therefore, in order to protect the wiring materials from being damaged by the peripheral edge of the through-hole and prevent liquid from entering the gap between the through-hole and the wiring materials, a grommet for blocking the gap is installed in the insertion object. For example, the grommet is composed of a base member and a ring-shaped grommet body. The base member is made of a hard synthetic resin material, and the wiring materials pass through the inside between one space and the other space. The ring-shaped grommet body is made of a flexible synthetic resin material such as rubber. The grommet is inserted into the through-hole, and the grommet body is brought into close contact with the peripheral edge of the through-hole in the insertion object. In this grommet, the base member and the grommet body are integrally formed by an integral molding method such as two-color molding. Such a grommet is disclosed, for example, in Patent Document 1 below.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 8-251769 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] However, in the conventional grommet, when pulling out the mold for integrally molding the base member and the grommet body, it is necessary to suppress the deterioration of the quality of the flexible grommet body by reducing the load applied to the grommet body from the mold. However, in this grommet, since the wiring materials pass through the inside between one space and the other space, the volume of the base member is larger than that of the grommet body, and the shape of the base member is likely to become complicated. Therefore, depending on the shapes of the base member and the grommet body, an overload from the mold to the grommet body cannot be avoided. Therefore, in this case, the base member and the grommet body are separately prepared as different components, and by assembling them, the load from the mold during molding of the grommet body can be reduced. However, in this grommet, it is necessary to keep them in the assembled position between the base member and the grommet body.

[0008] Therefore, an object of the present invention is to provide a grommet capable of holding the base member and the grommet body in the assembled position.

[0009] Technical Means for Solving the Problem

[0010] The grommet of the present invention is characterized by comprising: a cylindrical base member made of a hard synthetic resin material and having a conductive wiring material inserted therethrough for passing an insertion object from one space to the other space; and an annular grommet body coaxially assembled to the base member and disposed in the one space at the installation completion position of the peripheral portion of the through hole with respect to the insertion object. The base member has: an annular flange disposed in the one space at the installation completion position and having an outer peripheral portion disposed coaxially with and spaced apart from the annular peripheral portion; and a cylindrical body protruding coaxially from the flange toward the other space and inserted into the through hole at the installation completion position. The grommet body is made of a synthetic resin material softer than the base member and capable of elastic deformation, and is an annular water stop member that is coaxially in close contact with the outer peripheral portion of the flange at the assembly completion position and is coaxially in close contact with the peripheral portion at the installation completion position. The grommet body has: an annular body disposed coaxially with and spaced apart from the outer peripheral portion side of the first annular wall surface of the flange at the assembly completion position and disposed coaxially with and spaced apart from the peripheral portion at the installation completion position; an annular lip protruding coaxially from the annular body, elastically deformed at the assembly completion position, and in close contact with the outer peripheral portion side of the first annular wall surface of the flange over the entire circumference; a first annular portion disposed coaxially with and spaced apart from the outer peripheral portion of the annular body on the outer peripheral portion side of the flange; and a second annular portion protruding coaxially from the outer peripheral portion of the annular body toward the flange and connecting the outer peripheral portion of the annular body and the outer peripheral portion of the first annular portion. The first annular portion is hooked around the outer peripheral portion of the flange over the entire circumference from the second annular wall surface side on the back side of the first annular wall surface at the assembly completion position.

[0011] Advantages of the Invention

[0012] In the grommet according to the present invention, in a state where the first lip is in close contact with the outer peripheral portion side of the first annular wall surface of the flange, the first annular portion is hooked around the outer peripheral portion of the flange from the second annular wall surface side, and the outer peripheral portion of the flange is clamped by the first annular portion and the first lip. Therefore, in this grommet, at the assembly completion position, the grommet body is held on the outer peripheral portion of the flange, so that the base member and the grommet body can be held in their mutual assembly completion positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view showing the grommet of the embodiment.

[0014] Figure 2 It is a perspective view of the grommet of the embodiment before being installed on the insertion object, observed from another angle.

[0015] Figure 3 It is a plan view of the grommet of the embodiment, observed from the side of the cylindrical body.

[0016] Figure 4 It is a plan view of the grommet of the embodiment, observed from the side of the tubular body.

[0017] Figure 5 It is a view showing Figure 4 the X-X cross-section together with the insertion object before installation.

[0018] Figure 6 It is an exploded perspective view showing the grommet of the embodiment.

[0019] Figure 7 It is an exploded perspective view of the grommet of the embodiment, observed from another angle.

[0020] Figure 8 It is an exploded perspective view showing the grommet of the embodiment separated into two assembled base parts and the grommet body.

[0021] Figure 9 It is an exploded perspective view of the base part and the waterproof part of the embodiment.

[0022] Figure 10 It is a partial cross-sectional view showing a part of the molding die of the grommet body of the embodiment.

[0023] Explanation of reference numerals

[0024] 1 Grommet

[0025] 10X Base part

[0026] 14 Annular groove part

[0027] 20 Flange

[0028] 20a Outer peripheral edge part

[0029] 20c First annular wall surface

[0030] 20d Second annular wall surface

[0031] 30 Cylindrical body

[0032] 60 Grommet body

[0033] 61 Annular body

[0034] 61a Outer peripheral edge part

[0035] 62 First lip part (lip)

[0036] 64 First annular part

[0037] 65 Second annular part

[0038] 501 Object to be inserted

[0039] 502 Through-hole

[0040] 503 Peripheral part

[0041] S1 One space

[0042] S2 The other space

[0043] We Wiring material Detailed implementation mode

[0044] Hereinafter, an embodiment of the grommet of the present invention will be described in detail based on the drawings. In addition, the present invention is not limited to this embodiment.

[0045] [Embodiment]

[0046] Based on Figures 1 to 10 One embodiment of the grommet of the present invention will be described.

[0047] Figures 1 to 8 The reference numeral 1 in the attached drawing represents the grommet of this embodiment. This grommet 1 protects the conductive wiring material We that is erected from one space S1 through the through-hole 502 of the object to be inserted 501 to the other space S2 from the influence of the peripheral part 503 of the through-hole 502 of the object to be inserted 501, and prevents liquid (such as water) from entering the gap between the annular peripheral part 503 and the wiring material We ( Figure 2 and Figure 5 ). Therefore, this grommet 1 is installed on the peripheral part 503 of the through-hole 502 of the object to be inserted 501 on the basis of inserting the wiring material We.

[0048] 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.). In addition, the object to be inserted 501 is a component for inserting the wiring material We. For example, in the case of a vehicle, it represents a wall body such as a panel of the vehicle body. The wiring material We is laid between the one space S1 and the other space S2 separated by the object to be inserted 501 by being inserted into the through-hole 502 of the object to be inserted 501. For example, the wiring material We is responsible for communication between devices in the one space S1 and the other space S2 respectively, or for supplying power from the power supply in the other space S2 to the electrical equipment in the one space S1, etc.

[0049] The peripheral portion 503 of the through-hole 502 of the object 501 to be inserted has an annular flat portion (hereinafter referred to as "annular flat portion") 504 and an annular protrusion (hereinafter referred to as "annular protrusion") 505 that protrudes from the end of the inner peripheral edge of the annular flat portion 504 (inner peripheral edge portion 504a) toward the other space S2 ( Figure 2 and Figure 5 ). The grommet 1 is mounted on the peripheral portion 503 to the annular flat portion 504 and the annular protrusion 505. For example, the object 501 to be inserted is formed by stamping, and at this time, the annular flat portion 504 and the through-hole 502 are formed. Moreover, in the object 501 to be inserted, the annular protrusion 505 is formed by flanging the peripheral edge of the through-hole 502. Here, since the through-hole 502 is formed in a circular shape, the annular flat portion 504 and the annular protrusion 505 are respectively formed in a circular ring shape.

[0050] The grommet 1 includes a cylindrical base member 10X through which the wiring material We is inserted inside ( Figures 1 to 9 ). The base member 10X may be composed of one member or may be assembled from a plurality of members. The base member 10X shown here includes two base members (first base member, second base member) that are assembled with each other. These two base members may be members with different shapes or may be identical members with the same shape. In the grommet 1 shown here, these two base members use identical members with the same shape (base members 10, 10) ( Figures 1 to 9 ).

[0051] The base member 10X has at least an annular flange 20 and a cylindrical body 30 coaxially, and the wiring material We is inserted inside them ( Figure 1 and Figure 2 ). The base member 10X shown here further has a tubular body 40 coaxially with the flange 20 and the cylindrical body 30, and the wiring material We is inserted inside them ( Figure 1 and Figure 2 ). Here, on this coaxial axis, the cylindrical body 30 protrudes from the flange 20 toward one side, and the tubular body 40 protrudes from the flange 20 toward the other side.

[0052] In the base member 10X shown here, as will be described later, the annular flange 20, the cylindrical body 30, and the tubular body 40 are formed coaxially by the base members 10, 10 that are assembled with each other. Therefore, a holding mechanism (hereinafter referred to as "base holding mechanism") 50 is provided between the two base members 10, 10 to keep them in an assembled state with each other ( Figures 1 to 3 and Figures 6 to 8 ).

[0053] In addition, the grommet 1 includes an annular grommet body 60, and the grommet body 60 is coaxially assembled to the base member 10X (the base members 10, 10 that are assembled to each other)( Figures 1 to 8 ). In order to prevent liquid (such as water) from infiltrating from one space S1 to the other space S2 through the through hole 502, the grommet body 60 is disposed in one space S1 at the installation completion position of the grommet 1 with respect to the peripheral portion 503( Figure 2 and Figure 5 ). In addition, hereinafter, when only referred to as the "installation completion position", it represents the installation completion position of the grommet 1 with respect to the peripheral portion 503.

[0054] The base member 10X (the base members 10, 10) is molded using an insulating hard synthetic resin material (hereinafter referred to as "hard resin"). Here, for example, a hard resin such as plastic is used to mold the base member 10X (the base members 10, 10).

[0055] The two base members 10, 10 are assembled by bringing their joint surfaces 10a together( Figure 3 , Figure 4 , Figure 6 and Figure 7 ). The two base members 10, 10 sandwich the wiring material We in their assembled state and are in a state where the wiring material We is inserted therethrough. 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. In addition, here, a straight tubular body 40 is taken as an example. However, the tubular body 40 may be bent after protruding from the flange 20.

[0056] The flange 20 is disposed in one space S1 at the installation completion position, and the outer peripheral edge portion 20a is disposed coaxially and spaced apart from the peripheral portion 503( Figure 5 ). Then, the wiring material We is inserted inside the inner peripheral edge portion 20b of the flange 20( Figure 5 ). The flange 20 has a circumferential wall surface (hereinafter referred to as the "first circumferential wall surface") 20c on the side of the peripheral portion 503 and a circumferential wall surface (hereinafter referred to as the "second circumferential wall surface") 20d on the back side of the circumferential wall surface 20c( Figures 5 to 8)。Specifically, the flange 20 is arranged coaxially and at a gap with respect to the annular plane 503a on the side of the space S1 of one side of the outer peripheral edge portion 20a of the first annular wall surface 20c and the peripheral edge portion 503. The annular plane 503a is provided on the annular flat plate portion 504. The annular plane 503a shown here is the annular plane itself on the side of the space S1 in the annular flat plate portion 504. The flange 20 is formed in a plate shape of a ring where the first annular wall surface 20c and the second annular wall surface 20d are circular planes. For example, the flange 20 is formed in a shape similar to the annular plane 503a which is circular. The flange 20 shown here is arranged such that the circular outer peripheral edge portion 20a side in the first annular wall surface 20c faces the inner peripheral edge portion 504a side of the annular flat plate portion 504 in the annular plane 503a, and the wiring material We is inserted through a position inside the circular inner peripheral edge portion 20b.

[0057] The two base components 10, 10 each have a split flange 11 that forms the flange 20 by bringing their joint surfaces 10a together Figures 1 to 8 )。The split flange 11 shown here is formed by splitting the flange 20 along the central axis into two halves, and is formed in a semi-circular arc shape.

[0058] The cylindrical body 30 projects coaxially from the flange 20 toward the other space S2, and is inserted through the through-hole 502 at the installation completion position Figure 2 and Figure 5 )。That is, in the cylindrical body 30, the end of its end projecting from the flange 20 is arranged in the other space S2. The cylindrical body 30 is formed in a cylindrical shape. For example, the cross-section of the cylindrical body 30 orthogonal to the hole axis of the through-hole 502 is formed in a shape similar to the cross-section of the annular protrusion 505 orthogonal to the hole axis. The cylindrical body 30 shown here projects from the inner peripheral edge portion 20b side of the first annular wall surface 20c of the flange 20 compared to the outer peripheral edge portion 20a, and the wiring material We is inserted through its interior Figure 5 )。

[0059] The two base components 10, 10 each have a split cylinder 12 that forms the cylindrical body 30 by bringing their joint surfaces 10a together Figure 2 and Figures 4 to 8 )。The split cylinder 12 shown here is formed by splitting the cylindrical body 30 along the central axis into two halves, and is formed in a semi-circular arc shape.

[0060] The tubular body 40 projects coaxially from the flange 20 in the direction opposite to the cylindrical body 30 Figure 5)。The tubular body 40 is formed into a circular tube shape. For example, a cross-section of the tubular body 40 orthogonal to the hole axis of the through hole 502 is formed into a shape similar to a cross-section of the annular protrusion 505 orthogonal to the hole axis. The tubular body 40 shown here protrudes from the inner peripheral edge portion 20b of the flange 20, and a wiring material We is inserted therethrough( Figure 5 )。

[0061] The two base members 10, 10 each have a split tube 13 that forms a tubular body 40 by bringing their joint surfaces 10a together( Figures 1 to 3 and Figures 5 to 8 )。The split tube 13 shown here is a split tube that divides the tubular body 40 in half along the central axis and is formed into a semi-circular arc shape.

[0062] As described above, the main body portions (split flanges 11, split cylinders 12, split tubes 13) of the two base members 10, 10 are hard members that are difficult to elastically deform. Therefore, it is possible that minute gaps are formed between the joint surfaces 10a of the two base members 10, 10, such as those associated with the surface roughness of the joint surfaces 10a. Therefore, the grommet 1 of the present embodiment has a waterproof member 71 on at least one of the joint surfaces 10a of the two base members 10, 10. The waterproof member 71 is made of a synthetic resin material (hereinafter referred to as "soft resin") that is softer than the hard resin of the base member 10 and can elastically deform, and the waterproof member 71 eliminates the gaps between the respective joint surfaces 10a( Figure 6 , Figure 7 and Figure 9 )。

[0063] The waterproof member 71 is formed using a synthetic resin material such as an elastomer, for example. Moreover, the waterproof member 71 is provided, for example, over the joint surfaces 10a of the split flange 11, the split cylinder 12, and the split tube 13. In the base member 10 shown here, a groove portion 10b is formed in one of the joint surfaces 10a of the two portions from the split flange 11 to the split tube 13, and the waterproof member 71 is inserted into the groove portion 10b( Figure 9 )。The waterproof member 71 protrudes from the groove portion 10b. For example, the waterproof member 71 is integrally formed with the base member 10 by two-color molding with the base member 10 or by insert molding with respect to the base member 10 housed in a mold. In addition, the waterproof member 71 may be formed as a member different from the base member 10 and adhered to the groove portion 10b of the base member 10 using an adhesive or the like. In the base member 10X, by assembling the two base members 10, 10, 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.

[0064] The base body holding mechanism 50 is a holding mechanism for holding two base body components 10, 10 in a state where their respective joint surfaces 10a are held together. The base body holding mechanism 50 is provided at a plurality of positions between the two base body components 10, 10. For example, the base body holding mechanism 50 shown here includes a piece portion 51 protruding from the joint surface 10a of one of the two base body components 10, 10 and a claw-shaped first locking portion 52 protruding from the wall surface of the piece portion 51( Figure 6 and Figure 7 ). Moreover, the base body holding mechanism 50 shown here includes: an insertion port 53 provided in the joint surface 10a of the other of the two base body components 10, 10 for inserting the piece portion 51 and the first locking portion 52 of one of them; a flexible portion 54 provided in the other of the two base body components 10, 10, which is pushed by the first locking portion 52 inserted from the insertion port 53 and flexes, and the first locking portion 52 separates and the flexure is eliminated when the joint surfaces 10a are brought together; and a second locking portion 55 provided in the other of the two base body components 10, 10, which is disposed opposite to the first locking portion 52 when the joint surfaces 10a are brought together, and holds the two base body components 10, 10 in a state where their respective joint surfaces 10a are together( Figure 6 and Figure 7 ).

[0065] Each of the two base body components 10, 10 shown here has a set of piece portion 51 and first locking portion 52 at one end in the circumferential direction of the split cylinder 12, and has a set of insertion port 53, flexible portion 54 and second locking portion 55 at the other end in the circumferential direction of the split cylinder 12. In the two base body components 10, 10, in a state where their respective joint surfaces 10a are brought together, the first locking portion 52 at one end of one split cylinder 12 is locked with the second locking portion 55 at the other end of the other split cylinder 12, and the second locking portion 55 at the other end of one split cylinder 12 is locked with the first locking portion 52 at one end of the other split cylinder 12. That is, in the two base body components 10, 10, the base body holding mechanism 50 for connecting and holding the respective split cylinders 12 in a connected state is provided at two places. Moreover, each of the two base body components 10, 10 has a set of piece portion 51 and first locking portion 52 at one end in the circumferential direction of the split tube 13, and has a set of insertion port 53, flexible portion 54 and second locking portion 55 at the other end in the circumferential direction of the split tube 13. In the two base body components 10, 10, in a state where their respective joint surfaces 10a are brought together, the first locking portion 52 at one end of one split tube 13 is locked with the second locking portion 55 at the other end of the other split tube 13, and the second locking portion 55 at the other end of one split tube 13 is locked with the first locking portion 52 at one end of the other split tube 13. That is, in the two base body components 10, 10, the base body holding mechanism 50 for connecting and holding the respective split tubes 13 in a connected state is provided at two places.

[0066] The grommet main body 60 is an annular water stop member made of a soft resin (i.e., a synthetic resin material that is softer than the hard resin of the base member 10X (base member 10) and can elastically deform). The grommet main body 60 is formed, for example, using a synthetic resin material such as an elastomer that is softer than the hard resin of the base member 10X (base member 10) and can elastically deform.

[0067] The grommet main body 60 has an annular body 61 which is disposed coaxially and at a gap with respect to the outer peripheral edge portion 20a of the flange 20 at the assembly completion position with respect to the base members 10X (the mutually assembled base members 10, 10), and is disposed coaxially and at a gap with respect to the peripheral edge portion 503 at the installation completion position ( Figure 1 , Figure 2 and Figures 5 to 8 ). The grommet main body 60 is formed in an annular shape. Therefore, the annular body 61 is formed in a circular plate shape. Further, hereinafter, when only the "assembly completion position" is mentioned, it means the assembly completion position of the base members 10X (the mutually assembled base members 10, 10) and the grommet main body 60.

[0068] The grommet main body 60 is in close contact coaxially with the outer peripheral edge portion 20a of the flange 20 at the assembly completion position. For example, in the grommet main body 60, the annular body 61 is disposed coaxially and at a gap with respect to the outer peripheral edge portion 20a side of the first annular wall surface 20c of the flange 20 at the assembly completion position ( Figure 5 ). Therefore, the grommet main body 60 has an annular lip (hereinafter referred to as the "first lip") 62 which projects coaxially from the annular body 61 and elastically deforms at the assembly completion position to closely contact the outer peripheral edge portion 20a of the flange 20 over the entire circumference ( Figure 5 , Figure 6 and Figure 8 ). The first lip 62 elastically deforms at the assembly completion position to closely contact the outer peripheral edge portion 20a side of the first annular wall surface 20c of the flange 20 over the entire circumference.

[0069] In addition, the grommet main body 60 is in close contact coaxially with the peripheral edge portion 503 at the installation completion position. For example, in the grommet main body 60, the annular body 61 is disposed coaxially and at a gap with respect to the annular plane 503a of the peripheral edge portion 503 at the installation completion position ( Figure 5 ). Therefore, the grommet main body 60 has an annular lip (hereinafter referred to as the "second lip") 63 which projects coaxially from the annular body 61 and elastically deforms at the installation completion position to closely contact the peripheral edge portion 503 over the entire circumference ( Figure 1 , Figure 2 and Figures 4 to 8The second lip portion 63 is elastically deformed at the installation completion position and is in close contact with the annular plane 503a of the peripheral edge portion 503 all around.

[0070] The grommet body 60 has an outer lip 63A and an inner lip 63B as the second lip 63. The outer lip 63A is provided on the outer circumferential edge 61a side of the annular body 61 and is coaxial with the annular body 61. The inner lip 63B is provided on the inner circumferential edge 61b side of the annular body 61 and is coaxial with the annular body 61. Figure 2 , Figure 4 , Figure 5 and Figure 7 ).

[0071] The grommet body 60 includes: a first annular portion 64, which is coaxially disposed with a gap between the outer peripheral edge 61a of the annular body 61 and the outer peripheral edge 20a of the flange 20; and a second annular portion 65, which protrudes coaxially from the outer peripheral edge 61a of the annular body 61 toward the flange 20, and connects the outer peripheral edge 61a of the annular body 61 to the outer peripheral edge of the first annular portion 64 ( Figure 1 , Figure 5 , Figure 6 and Figure 8 The first annular portion 64 and the second annular portion 65 serve as one end of a holding mechanism for holding the base member 10X (the base members 10, 10 assembled to each other) and the grommet body 60 in the mutually assembled position, and interact with the first lip portion 62 and the outer peripheral edge portion 20a of the flange 20 to function ( Figure 1 , Figure 3 , Figure 5 , Figure 6 and Figure 8 ).

[0072] The holding mechanism holds the base member 10X (the base members 10, 10 assembled to each other) and the grommet body 60 in the assembled position ( Figure 5 ). Therefore, the first annular portion 64 is hooked on the outer peripheral edge portion 20a of the flange 20 from the second annular wall surface 20d side all around the assembly completion position. In the assembly completion position, the first lip portion 62 is elastically deformed and closely adheres to the outer peripheral edge portion 20a side of the first annular wall surface 20c of the flange 20 all around. Therefore, the first annular portion 64 sandwiches the outer peripheral edge portion 20a of the flange 20 between the first lip portion 62 in the assembly completion position.

[0073] Specifically, the outer peripheral edge portion 20a of the flange 20 has a concentric annular groove portion 14 ( Figures 5 to 8)。The outer peripheral edge portion 20a shown here has a concentric annular groove portion 14 similar to an annular corner portion where its outer peripheral surface side and the second annular wall surface 20d side are cut. The first annular portion 64 is inserted into the annular groove portion 14 at the assembly completion position, and is hooked around the outer peripheral edge portion 20a of the flange 20 over the entire circumference from the second annular wall surface 20d side in the annular groove portion 14.

[0074] In the grommet 1, when assembling the base member 10X (the base members 10, 10 assembled with each other) and the grommet body 60, the first annular portion 64 is inserted into the annular groove portion 14 while flexing the first annular portion 64, and the first annular portion 64 and the second annular portion 65 are covered on the outer peripheral edge portion 20a of the flange 20. Thus, in this grommet 1, the outer peripheral edge portion 20a of the flange 20 is clamped by the first annular portion 64 and the first lip portion 62 at the assembly completion position, so that the grommet body 60 is held on the outer peripheral edge portion 20a. Therefore, this grommet 1 can hold the base member 10X (the base members 10, 10 assembled with each other) and the grommet body 60 at the assembly completion position.

[0075] In this grommet body 60, the annular body 61, the first lip portion 62, the first annular portion 64, and the second annular portion 65 are formed by the first die 601, and the second lip portion 63 (the outer peripheral lip portion 63A and the inner peripheral lip portion 63B) is formed by the second die 602 ( Figure 10 )。After the grommet body 60 is molded, the first die 601 is withdrawn in the withdrawal direction M1 on one side in the axial direction toward the annular body 61. In addition, after the grommet body 60 is molded, the second die 602 is withdrawn in the withdrawal direction M2 on the other side in the axial direction toward the annular body 61.

[0076] The first lip portion 62 is formed into a circular ring shape with an outer wall surface whose cross section bulges from the annular body 61 toward the withdrawal direction M1 of the first die 601 and is circular arc-shaped in a direction orthogonal to the circumferential direction. Moreover, the second annular portion 65 projects from the annular body 61 toward the withdrawal direction M1 of the first die 601. Therefore, in this grommet body 60, the load applied to the annular body 61, the first lip portion 62, and the second annular portion 65 from the first die 601 when the first die 601 is withdrawn in the withdrawal direction M1 can be reduced.

[0077] On the other hand, the first annular portion 64 projects from the second annular portion 65 over a full circumference toward the axial side of the second annular portion 65 and is disposed coaxially with a gap from the outer peripheral edge portion 61a of the annular body 61, forming an annular space between the annular body 61 and the second annular portion 65. This annular space becomes an undercut portion when the first mold 601 is pulled out in the pulling-out direction M1. Therefore, the first annular portion 64 projects from the second annular portion 65 with the minimum protrusion amount within the range capable of holding the hook on the outer peripheral edge portion 20a of the flange 20, making the depth of this annular space (undercut portion) (depth in the direction orthogonal to the axis) as shallow as possible.

[0078] In this grommet body 60, by disposing the circular first annular portion 64 coaxially with a gap from the outer peripheral edge portion 61a of the circular annular body 61, the inner diameter of the first annular portion 64 is made larger than the inner diameter of the annular body 61. And in this grommet body 60, the outer diameter of the annular body 61 is made the same as the outer diameter of the flange 20. By hooking the first annular portion 64 on the outer peripheral surface side of the outer peripheral edge portion 20a of the flange 20, the position of the inner peripheral surface of the first annular portion 64 can be made closer to the outer peripheral surface side of the outer peripheral edge portion 61a of the annular body 61 in the radial direction. That is, in this grommet body 60, the inner diameter of the first annular portion 64 is made much larger than the inner diameter of the annular body 61. Therefore, in this grommet body 60, the depth of the annular space (undercut portion) can be made as shallow as possible. Thus, in this grommet body 60, when the first mold 601 is pulled out in the pulling-out direction M1, the load applied from the first mold 601 to the annular body 61, the first lip portion 62, the first annular portion 64, and the second annular portion 65 can be reduced.

[0079] The outer peripheral lip portion 63A projects in such a manner that it is farther from the axis (hole axis of the through hole 502) of the annular body 61 as it is farther from the annular body 61 in the pulling-out direction M2 of the second mold 602. And the inner wall surface 63a in the radial direction of this outer peripheral lip portion 63A has two circular sub-lip portions 63b projecting coaxially from this wall surface 63a in the pulling-out direction M2 of the second mold 602 ( Figure 10 ). The outer peripheral lip portion 63A is flexurally deformed from the root on the annular body 61 side at the installation completion position, causing the two sub-lip portions 63b to closely adhere to the annular plane 503a of the peripheral edge portion 503. In addition, the outer wall surface 63c in the radial direction of this outer peripheral lip portion 63A is formed by at least two third molds 603 that are pulled out in the pulling-out direction M3 toward the outside in the radial direction thereof. Thereby, in this grommet body 60, the load applied from the third mold 603 when the third mold 603 is pulled out in the pulling-out direction M3 can be reduced.

[0080] In addition, the inner peripheral lip portion 63B has: an inner peripheral surface 63d that is inclined so as to be farther away from the axis (the hole axis of the through hole 502) of the annular body 61 as it is farther away from the annular body 61 in the pulling-out direction M2 of the second mold 602; and an outer peripheral surface 63e that is parallel to the pulling-out direction M2 of the second mold 602( Figure 10 ).

[0081] In the grommet main body 60, due to the shape of the second lip portion 63 (the outer peripheral lip portion 63A and the inner peripheral lip portion 63B), the load applied from the second mold 602 when the second mold 602 is pulled out in the pulling-out direction M2 can be reduced.

[0082] The grommet 1 configured in this way includes a holding mechanism 80 that holds the mutually assembled base members 10X (the mutually assembled base members 10 and 10) and the grommet main body 60 at the peripheral portion 503 of the through hole 502 of the insertion object 501( Figure 2 and Figures 4 to 8 ). The holding mechanism 80 shown here utilizes the elastic deformation force of the second lip portion 63 (the outer peripheral lip portion 63A and the inner peripheral lip portion 63B) of the grommet main body 60, and clamps the peripheral portion 503 with the second lip portion 63 (the outer peripheral lip portion 63A and the inner peripheral lip portion 63B) and the following locking portion 81 provided on the base member 10X (the base member 10), thereby holding the grommet 1 at the peripheral portion 503.

[0083] The base member 10X has a locking portion 81 that protrudes from the outer peripheral surface 30a of the cylindrical body 30 in the other space S2 at the installation completion position and contacts the peripheral portion 503 from the other space S2 side in the other space S2 at the installation completion position( Figure 2 and Figures 5 to 8 ). The locking portion 81 locks a circumferential part of the peripheral portion 503. Therefore, the base member 10X has a plurality of such locking portions 81 in the circumferential direction of the cylindrical body 30.

[0084] In addition, the base member 10X has a cantilevered locking piece portion 82 at each locking portion 81, and the locking portion 81 is provided at the free end in the other space S2 at the installation completion position( Figure 2 and Figures 4 to 8)。The locking piece portion 82 has its end projecting from the fixed end on the outer peripheral surface 30a side of the cylindrical body 30 toward the one space S1 as a free end in the other space S2 at the installation completion position, and causes the free end side to project from the outer peripheral surface 30a of the cylindrical body 30 (initial shape). Further, the locking piece portion 82 is formed to have flexibility capable of flexural deformation that changes the amount of projection from the outer peripheral surface 30a on the free end side. The locking piece portion 82 reciprocates in the cutout portion 30b formed by cutting a part of the cylindrical body 30 through its flexural deformation ( Figure 2 and Figures 4 to 8 ). A plurality of sets of combinations of the locking portion 81, the locking piece portion 82, and the cutout portion 30b are provided at equal intervals in the circumferential direction with respect to the cylindrical body 30. On the cylindrical body 30 shown here, four sets of combinations of the locking portion 81, the locking piece portion 82, and the cutout portion 30b are provided at equal intervals in the circumferential direction. Here, two sets of combinations of the locking portion 81, the locking piece portion 82, and the cutout portion 30b are provided on each of the divided cylinders 12 of each base member 10.

[0085] When the cylindrical body 30 is inserted into the through-hole 502 from the one space S1, the locking piece portion 82 is forced by the annular protrusion portion 505 of the peripheral edge portion 503 to flexurally deform from the initial shape toward the cutout portion 30b, and advances to the end (hereinafter referred to as "locking end portion") 505a of the annular protrusion portion 505 after leaving the position of the annular protrusion portion 505 ( Figure 2 and Figure 5 ). The end of the locking piece portion 82 starts to return to the initial shape due to the disappearance of the force received from the annular protrusion portion 505. Therefore, the locking piece portion 82 is arranged together with the locking portion 81 at the end of the locking end portion 505a of the annular protrusion portion 505. On the other hand, the second lip portion 63 (outer peripheral lip portion 63A, inner peripheral lip portion 63B) of the grommet body 60 abuts against the annular flat surface 503a side of the peripheral edge portion 503 and flexurally deforms when a series of operations occur in the locking portion 81 and the locking piece portion 82. Therefore, when the force (so-called insertion force) for inserting into the through-hole 502 is released, the grommet 1 moves back toward the one space S1 by the elastic force accompanying the elastic deformation of the second lip portion 63 (outer peripheral lip portion 63A, inner peripheral lip portion 63B). Along with this, the locking portion 81 comes into contact with the locking end portion 505a of the annular protrusion portion 505 and is locked by the locking end portion 505a ( Figure 5 ). That is, the annular protrusion portion 505 locks the locking portion 81 using the end of the end projecting from the annular flat plate portion 504 (locking end portion 505a). In each part in the circumferential direction of the annular locking end portion 505a, the locking portion 81 is locked. Therefore, the peripheral edge portion 503 is clamped by the second lip portion 63 (outer peripheral lip portion 63A, inner peripheral lip portion 63B) of the grommet body 60 and the locking portions 81 of the base members 10X (base members 10, 10) respectively.

[0086] In the grommet 1 of the present embodiment shown above, in a state where the first lip portion 62 is in close contact with the outer peripheral edge portion 20a side of the first annular wall surface 20c of the flange 20, the first annular portion 64 is hooked on the outer peripheral edge portion 20a of the flange 20 from the second annular wall surface 20d side, and the outer peripheral edge portion 20a of the flange 20 is clamped by the first annular portion 64 and the first lip portion 62. Therefore, in this grommet 1, at the assembly completion position, the grommet main body 60 is held on the outer peripheral edge portion 20a of the flange 20, so that the base member 10X (the base members 10, 10 assembled with each other) and the grommet main body 60 can be held in the mutual assembly completion position. And, in the grommet main body 60 of the present embodiment, the inner diameter of the first annular portion 64 can be made significantly larger than the inner diameter of the annular body 61, and the depth of the annular space (undercut portion) between the annular body 61, the first annular portion 64, and the second annular portion 65 can be made as shallow as possible. Therefore, in this grommet main body 60, the first mold 601 can be pulled out in the pulling-out direction M1 without applying an excessive load to the annular body 61, the first lip portion 62, the first annular portion 64, and the second annular portion 65, and the second mold 602 can be pulled out in the pulling-out direction M2 without applying an excessive load to the second lip portion 63 (outer peripheral lip portion 63A, inner peripheral lip portion 63B) ( Figure 10 ). Therefore, the grommet 1 of the present embodiment can have a grommet main body 60 with reduced quality degradation.

Claims

1. A grommet, characterized in that: have: a cylindrical base member made of a hard synthetic resin material and having a conductive wiring material inserted therein so as to pass through a through hole of an object to be inserted from one space toward the other space; and an annular grommet body, the grommet body being coaxially assembled to the base member and arranged in the one space at a mounting completion position relative to the peripheral edge of the through hole of the insertion object, The base member has an annular flange, the flange being arranged in the one space at the mounting completion position, and having an outer peripheral edge portion arranged to face the annular peripheral edge portion coaxially with a gap therebetween; and a cylindrical body, the cylindrical body coaxially protruding from the flange toward the other space and inserted into the through hole at the installation completion position, The grommet body is made of a synthetic resin material that is softer than the base member and can be elastically deformed, and is an annular water-stopping member that is coaxially in close contact with the outer peripheral edge portion of the flange at the assembly completion position with the base member and coaxially in close contact with the peripheral edge portion at the installation completion position. The grommet body comprises: an annular body that is coaxially arranged opposite to the outer peripheral edge portion side of the first annular wall surface of the flange at the assembly completion position with a gap therebetween, and coaxially arranged opposite to the peripheral edge portion at the installation completion position with a gap therebetween; an annular lip portion, the lip portion coaxially protruding from the annular body, elastically deforming in the assembled position, and in close contact with the outer peripheral edge side of the first annular wall surface of the flange all around; a first annular portion, the first annular portion and the outer peripheral edge portion of the annular body are arranged coaxially opposite to each other with a gap therebetween on the outer peripheral edge side of the flange; a second annular portion, the second annular portion coaxially protruding from the outer peripheral edge portion of the annular body toward the flange, connecting the outer peripheral edge portion of the annular body and the outer peripheral edge portion of the first annular portion, The first annular portion is hooked on the outer peripheral edge portion of the flange from the second annular wall surface side on the rear side of the first annular wall surface all around in the assembly completion position.

2. The grommet according to claim 1, characterized in that The outer peripheral edge portion of the flange has a concentric annular groove portion that is recessed relative to the outer peripheral surface on the second annular wall surface side. The first annular portion is inserted into the annular groove portion at the assembly completion position, and is hooked on the outer peripheral edge portion of the flange from the second annular wall surface side in the annular groove portion over a circumference.

3. The grommet according to claim 1, characterized in that The outer peripheral edge portion of the flange has a concentric annular groove portion similar to an annular corner portion cut on the outer peripheral surface side and the second annular wall surface side. The first annular portion is inserted into the annular groove portion at the assembly completion position, and is hooked on the outer peripheral edge portion of the flange from the second annular wall surface side in the annular groove portion over a circumference.

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