Grommet

Abstract

To prevent an increase in cost, enhance water cutoff property of a grommet while bearing high water pressure and utilizing the high water pressure, and facilitate assembling work of the grommet to an installation object of a vehicle.SOLUTION: A grommet 3 comprises a main body portion 4 and an insertion portion 5. The main body portion 4 comprises a flexible annular wall portion 6, a first seal portion 7, a second seal portion 8, a thin wall portion 9, and a fitting portion 10. The first seal portion 7 comprises: a bulging portion 7b bulging out to an outer circumference of the annular wall portion 6 in a circumferential direction, and being located on an opposite side to a protruding direction of the second seal portion 8, and, together with one portion of the annular wall portion 6, forming a portion thicker than the other portions; and an action surface 7c formed on an outer circumference of the bulging portion 7b, and when receiving an external pressure, generating a stress that deforms outward with respect to the second seal portion 8 and a stress that presses a contact surface 7a against a lower surface circumferential edge portion of a through hole H.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a grommet into which a wiring material is inserted and fits in one direction, which is the fitting direction, into a through hole formed in an attachment target.

Background Art

[0002] Generally, among various electronic devices provided in a vehicle interior, for example, there is a wire harness connected to a seat belt wearing detection sensor for a rear seat, which penetrates the vehicle floor surface and is routed outside the vehicle.

[0003] When routing a wire harness connected to such an electronic device in the vehicle interior outside the vehicle, conventionally, for example, a grommet as described in Patent Document 1 is fitted into a through hole formed in a vehicle floor panel and assembled, and the wire harness is inserted into the grommet to lead the wire harness from the vehicle interior to the outside of the vehicle, thereby routing the wire harness outside the vehicle.

[0004] At this time, since the grommet is assembled into the through hole of the vehicle floor surface, it is necessary to take water stop measures so that external water does not enter through the gap between the through hole and the grommet, and it is also necessary to make it possible to easily perform the operation of assembling the grommet into the through hole. Therefore, conventionally, the grommet is formed of a flexible material such as EPDM, and the flexibility of the grommet is used to make it adhere so that no gap occurs between the grommet and the through hole when assembled into the through hole. Further, the thickness of the fitting portion of the grommet into the through hole is made thinner to reduce the fitting force into the through hole and facilitate the attachment operation.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when cleaning the entire vehicle with a high-pressure washer, if the thickness of the grommet's fitting portion is reduced as described above, the thin fitting portion may not be able to withstand the high water pressure from high-pressure washing, and the high water pressure may create a gap between the grommet and the through-hole, potentially allowing water to enter the vehicle interior from the outside.

[0007] One possible solution to this problem is to add a resin inner to the grommet's fitting section. This would allow the inner to seal any gaps that form between the grommet and the through-hole due to deformation caused by high water pressure, preventing water from entering the vehicle's interior from the outside. However, this would require preparing a separate resin inner part, which would increase the cost of the component.

[0008] The present invention aims to prevent cost increases, improve the watertightness of grommets by utilizing high water pressure while withstanding it, and facilitate the assembly of grommets. [Means for solving the problem]

[0009] To achieve the above objectives, the grommet of the present invention comprises a main body portion that fits into a through hole formed in an object to be mounted in one direction which is the fitting direction to stop water flow, and a cylindrical insertion portion located radially inward of the main body portion through which a cable guide is inserted, wherein the main body portion comprises a flexible annular wall portion that extends circumferentially from the central axis of the insertion portion and is formed annularly around the insertion portion, and a first sealing portion formed on the outer circumference of the annular wall portion, the contact surface of which contacts the peripheral edge of the through hole opposite to the one direction which stops water flow from the through hole, and the The first seal portion comprises a second seal portion formed in an annular shape, projecting from the outer peripheral end of the contact surface of the first seal portion toward the mounting object, the first seal portion having a bulge formed circumferentially on the outer peripheral circumference of the annular wall portion, located on the opposite side of the projection direction of the second seal portion and forming a thicker portion together with a part of the annular wall portion, and an action surface formed on the outer peripheral circumference of the bulge portion that generates stress that deforms the second seal portion outward when subjected to external pressure, and stress that presses the contact surface of the first seal portion against the peripheral edge of the through hole, The main body is, Both ends consist of a thin-walled portion that is thinner than the annular wall portion and connected to the end of the insertion portion on the one-way side and the end of the annular wall portion opposite to the one-way side, and a fitting portion that is integrally formed on the one-way side of the annular wall portion to be the same as or greater than the thickness of the bulging portion in the central axis direction and is fitted into the through hole in the one-way direction. Furthermore The thin portion is provided with a connection portion between the insertion portion and the end on the one-way side, and the cross-section is bent in an inverted U-shape, and is located on the one-way side of the contact surface of the first seal portion. ru.

[0010] With this configuration, the working surface of the bulging portion of the first seal portion, which forms the thickened part, receives high water pressure from a high-pressure washer or the like. This generates stress that causes the second seal portion, which is formed in an annular shape protruding from the outer peripheral edge of the contact surface of the first seal portion toward the mounting object, to deform outward, and stress that presses the contact surface of the first seal portion against the peripheral edge of the through hole of the mounting object. As a result, the contact surface of the first seal portion can be brought into close contact with the peripheral edge of the through hole, and at the same time, the second seal portion can be deformed outward and brought into close contact with the peripheral edge of the through hole. Thus, a two-stage water-stopping system by the first and second seal portions is possible, reliably preventing water from entering the interior from the outside.

[0012] Also When the working surface of the first seal is subjected to high water pressure, such as from a high-pressure washer, the thin-walled portion easily deforms, and this deformation of the thin-walled portion causes the second seal to easily deform outward as well, thus providing a high water-stopping effect through close contact with the peripheral edge of the through-hole of the second seal. In addition, since the thickness of the fitting portion formed on one side of the annular wall portion, which is the fitting direction, is the same as or greater than the thickness of the bulging portion in the direction of the central axis, a high water-stopping effect can also be obtained due to the thick fitting portion.

[0013] Furthermore, the connection portion between the thin-walled section and the end on one side of the insertion section is bent into an inverted U-shape in cross-section and is located on one side of the contact surface of the first seal section. As a result, when assembling the grommet into the through hole, the fitting portion, which is flexible like the annular wall section, flexes in the direction of the central axis during fitting, making it easier to fit and thus making the assembly of the grommet into the through hole very easy. [Effects of the Invention]

[0014] According to the present invention, it is possible to prevent cost increases by not requiring separate parts such as resin inners as in the conventional method, and it is possible to improve the watertightness of the grommet by utilizing high water pressure while withstanding it, and the assembly work of the grommet can be easily performed. [Brief explanation of the drawing]

[0015] [Figure 1] It is an external perspective view of a vehicle to which the grommet according to the present invention is applied. [Figure 2] It is a perspective view seen obliquely from above of the grommet applied to the vehicle of FIG. 1. [Figure 3] It is a perspective view seen obliquely from below obliquely upward of the grommet of FIG. 2. [Figure 4] It is a cutaway front view of the grommet of FIG. 2. [Figure 5] It is a cutaway front view of the state where the grommet of FIG. 2 is assembled to the vehicle. [Figure 6] It is a cutaway front view of the grommet of FIG. 5 during high-pressure washing.

Mode for Carrying Out the Invention

[0016] The grommet according to the present invention will be described in detail with reference to FIGS. 1 to 6.

[0017] FIG. 1 shows a vehicle 1 to which the grommet in the present embodiment is assembled, which is a one-box type commercial vehicle having a structure with a substantially flat floor surface. For example, when wiring a wire harness connected to a seat belt wearing detection sensor of a rear seat outside the vehicle compartment, the grommet is used. In FIG. 1, 2 is a cleaning nozzle of a high-pressure washer.

[0018] And, the grommet 3 used for wiring the above-described wire harness outside the vehicle compartment is configured as shown in FIGS. 2 to 6, and is fitted in a circular through-hole H formed in a floor board B which is an attachment target of the vehicle 1 in one direction from the outside of the vehicle compartment toward the inside of the vehicle compartment (hereinafter referred to as "upward direction") in the fitting direction to stop water, and a cylindrical insertion portion 5 located inside the main body portion 4 and through which a wire harness W which is a wiring material is inserted. Here, the main body portion 4 and the insertion portion 5 are integrally formed by molding EPDM, and both the main body portion 4 and the insertion portion 5 have flexibility.

[0019] As shown in FIGS. 2 to 6, the main body portion 4 includes a flexible annular wall portion 6 that extends circumferentially from the central axis of the insertion portion 5 and is formed annularly around the insertion portion 5, a first seal portion 7 that is formed on the outer periphery of the annular wall portion 6 and abuts against the lower peripheral edge portion where the contact surface 7a is on the opposite side to the upward direction of the through hole H to block the through hole H, and a second seal portion 8 that protrudes annularly from the outer peripheral end of the contact surface 7a of the first seal portion 7 toward the floor plate B side.

[0020] As shown in FIGS. 2 to 6, the first seal portion 7 includes a bulging portion 7b that bulges circumferentially on the outer periphery of the annular wall portion 6 and is located on the lower side opposite to the upward direction which is the protruding direction of the second seal portion 8, and forms a thicker portion together with a part of the annular wall portion 6 than other parts, an inclined working surface 7c that is formed on the outer periphery of the bulging portion 7b and generates a stress that causes the second seal portion 8 to deform outward when receiving external pressure, and a stress that presses the contact surface 7a of the first seal portion 7 against the peripheral edge portion of the through hole H.

[0021] The working surface 7c is preferably inclined at an angle of 30° to 40° between the direction perpendicular to the working surface 7c and the horizontal direction in the longitudinal section, and the most preferable inclination angle is 34.5°. Also, the thick portion formed by the bulging portion 7b together with a part of the annular wall portion 6 means the portion in the direction perpendicular to the working surface 7c as indicated by the double-headed arrow in FIG. 4, and it is desirable to set this thick portion to a thickness that can withstand, for example, a high water pressure of 8N by a high-pressure washer or the like.

[0022] Furthermore, as shown in FIGS. 2 to 6, the main body portion 4 includes a thin-walled portion 9 whose both ends are connected to the upper end portion on the upper side of the insertion portion 5 and the lower end portion on the opposite side to the upward direction of the annular wall portion 6 and is thinner than the annular wall portion 6, and a fitting portion 10 that is integrally formed on the upper side from the annular wall portion 6 toward the vehicle interior with a thickness substantially the same as the thickness in the central axis direction of the bulging portion 7b and is fitted upward into the through hole H. A depression 11 is formed at the boundary between the fitting portion 10 and the bulging portion 7b, and the peripheral edge of the through hole H of the floor plate B fits into this depression 11 so that the grommet 3 is fitted into the through hole H. Here, the thickness of the fitting portion 10 may be not less than the thickness in the central axis direction of the bulging portion 7b.

[0023] Furthermore, the connecting portion 12 between the thin-walled portion 9 and the upper end of the insertion portion 5 is bent in an inverted U-shape in cross-section and is located on the upper side of the contact surface 7a of the first sealing portion 7, from outside the vehicle to inside the vehicle. In Figures 2 to 6, T is a projection provided on the annular wall portion 6 to allow the worker to know the orientation of the grommet 3 when assembling the grommet 3.

[0024] When assembling a grommet 3 with this configuration by fitting it into a through-hole H in the floor plate B, the grommet 3 is assembled by inserting the wire harness W through the insertion portion 5 of the grommet 3 and then fitting the fitting portion 10 upward from outside the vehicle compartment into the through-hole H, as shown in Figure 5. At this time, since the fitting portion 10 is integrally molded with the flexible annular wall portion 6, the fitting portion 10 is also flexible like the annular wall portion 6, and when the fitting portion 10 is pushed into the through-hole H, the fitting portion 10 easily deforms toward the central axis of the insertion portion 5 of the grommet, making it easy to fit the fitting portion 10 into the through-hole H.

[0025] Then, as the fitting portion 10 is pushed in further, as shown in Figure 5, the periphery of the through hole H fits into the recess 11 located at the boundary between the fitting portion 10 and the bulging portion 7b, thereby assembling the grommet 3 into the through hole H in a fitted state. At this time, the second sealing portion 8 abuts against the lower peripheral edge of the floor plate B, and the contact surface 7a of the first sealing portion 7 is held in a floating state without completely contacting the lower peripheral edge of the floor plate B.

[0026] Furthermore, when the grommet 3 is fitted into the through hole H and assembled, the wire harness W, which is the routing material inserted through the insertion part 5, is led out from inside the vehicle to outside the vehicle, and the wire harness W is routed in a predetermined routing state outside the vehicle.

[0027] Thus, when washing a vehicle using a high-pressure washer with the grommet 3 assembled, the nozzle 2 of the high-pressure washer is brought close to the grommet 3 and high-pressure water is sprayed onto the grommet 3, as shown in Figure 6. The grommet 3 receives high water pressure P1 (for example, 8N) in a direction perpendicular to the working surface 7c, as indicated by the thin solid arrow in Figure 5. This generates a stress P2 in a direction perpendicular to the working surface 7c, as indicated by the thick solid arrow in Figure 5. This stress P2 acts as a stress that deforms the second seal portion 8 outward as shown in Figure 6, and as a stress that presses the contact surface 7a of the first seal portion 7 against the lower peripheral edge of the through hole H in the floor plate B, as shown in Figure 6. As a result, the contact surface 7a of the first seal portion 7 can be brought into close contact with the lower peripheral edge of the through hole H, and at the same time, the second seal portion 8 can be deformed outward and brought into close contact with the lower peripheral edge of the through hole H. This results in water being stopped in two stages by the first seal portion 7 and the second seal portion 8.

[0028] On the other hand, when high-pressure cleaning is stopped, the high water pressure P1 acting on the grommet 3 is eliminated, and the stress P2 caused by the high water pressure is also eliminated. As a result, the second seal portion 8, which was deformed by the stress, returns to its pre-deformation state as shown in Figure 5, and the pressing force of the first seal portion against the contact surface 7a is also eliminated. As a result, the contact surface 7a becomes separated from the lower peripheral edge of the through hole H in the floor plate B and floats away from it, as shown in Figure 5.

[0029] Therefore, according to the above embodiment, the first seal portion 7 is formed by bulging outwards in the circumferential direction on the outer circumference of the annular wall portion 6, and is located on the opposite side of the protruding direction of the second seal portion 8, forming a thicker portion together with a part of the annular wall portion 6 than other parts, and is equipped with an inclined working surface 7c formed on the outer circumference of the bulging portion 7b that generates stress that causes it to deform outwards relative to the second seal portion 8 when subjected to external pressure, and stress that presses the contact surface 7a of the first seal portion 7 against the lower peripheral edge of the through hole H. As a result, when the working surface 7c is subjected to high water pressure from a high-pressure washer, the contact surface 7a of the first seal portion 7 can be brought into close contact with the lower peripheral edge of the through hole H of the floor plate B, and at the same time, the second seal portion 8 can be deformed outwards and brought into close contact with the lower peripheral edge of the through hole H. This enables two-stage water stopping by the first seal portion 7 and the second seal portion 8, reliably preventing water from entering the vehicle interior from the outside, and moreover, since it does not require a conventional resin inner, cost increases can be suppressed.

[0030] Furthermore, when the working surface 7c of the first seal portion 7 is subjected to high water pressure, the thin portion 9 deforms easily, and as a result the second seal portion 8 also deforms easily outward. This allows for a high water-stopping effect to be obtained by the second seal portion 8 adhering tightly to the lower peripheral edge of the through hole H in the floor plate B.

[0031] Furthermore, since the thickness of the fitting portion 10 formed on the upward side of the annular wall portion 6, which is the fitting direction, is formed to be approximately the same as (or greater than) the thickness of the bulging portion 7b in the direction of the central axis, a high water-stopping effect can be expected from the thick fitting portion 10.

[0032] Furthermore, the connecting portion 12 between the thin-walled portion 9 and the upper end of the insertion portion 5 is bent into an inverted U-shape in cross-section and is located above the contact surface 7a of the first sealing portion 7. Therefore, when assembling the grommet 3 into the through hole H, the fitting portion 10, which is flexible like the annular wall portion 6, bends in the direction of the central axis during fitting, making it easier to fit and allowing the grommet to be assembled into the through hole to be extremely easy.

[0033] It should be noted that the present invention is not limited to the embodiments described above, and various modifications other than those described above can be made without departing from the spirit of the invention.

[0034] For example, the above-described embodiment described the application of the present invention to a one-box type commercial vehicle with a nearly flat floor structure, but the vehicles to which the present invention can be applied are not limited to such commercial vehicles.

[0035] Furthermore, although the above-described embodiment shows an example in which a grommet 3 is assembled into a through hole H formed in the floor plate B of the vehicle, it goes without saying that the same effect can be obtained by applying the water-sealing structure of the present invention to grommets attached to mounting targets other than the floor plate B.

[0036] The present invention is widely applicable to grommets through which a cable guide is inserted and which are fitted in one direction, such as the fitting direction, into through holes formed in various mounting objects, not limited to vehicles. [Explanation of symbols]

[0037] 1 ... Vehicle 3… Grommets 4 ...Main body 5 ... Insertion part 6 ... Annular wall section 7 ...First seal section 7a…Abutment surface 7b...bulge 7c…Action surface 8 ...Second seal section 9 ...thin section 10 ... Fitting part 12…Connection part B... Floorboard (to be installed) H...Through hole W... Wire harness (cable / rope material)

Claims

[Claim 1] A grommet comprising a main body that fits into a through hole formed in the object to be installed in one direction, which is the fitting direction, to stop water flow, and a cylindrical insertion part located radially inward of the main body and through which a cable material is inserted, The main body is, A flexible annular wall portion extends circumferentially from the central axis of the insertion portion and is formed in an annular shape around the insertion portion, A first sealing portion is formed on the outer circumference of the annular wall portion, the contact surface of which contacts the peripheral edge of the through hole opposite to the one direction, thereby sealing the through hole. A second seal portion is formed in an annular shape, protruding from the outer peripheral end of the contact surface of the first seal portion toward the mounting object. Equipped with, The first sealing portion is, A bulge is formed on the outer circumference of the annular wall portion, bulging in the circumferential direction, and located on the opposite side of the protruding direction of the second seal portion, forming a thickened portion together with a part of the annular wall portion. The bulging portion is formed on its outer circumference and comprises an action surface that generates a stress that causes it to deform outward relative to the second seal portion when subjected to external pressure, and a stress that presses the contact surface of the first seal portion against the peripheral edge of the through hole, The main body is, Both ends are thin-walled portions that are thinner than the annular wall portion and are connected to the end of the insertion portion on the one-way side and the end of the annular wall portion on the opposite side of the one-way side. The annular wall portion further comprises a fitting portion integrally formed on one side of the annular wall portion to have a thickness equal to or greater than the thickness of the bulging portion in the central axis direction, and which is fitted into the through hole in the one direction. A grommet in which the connecting portion of the thin-walled portion to the end on the one-way side of the insertion portion is bent in an inverted U-shape in cross-section, and is located on the one-way side of the contact surface of the first seal portion.

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