A grommet includes: an enlarged-diameter cylindrical portion that has a fitted groove that is around a larger-diameter-side peripheral portion and is configured to be fitted to a through hole of a panel, and an elastically deformable portion that extends from the larger-diameter-side peripheral portion to a smaller-diameter-side peripheral portion and is elastically deformable; and a smaller-diameter cylindrical portion that is configured to be connected with the smaller-diameter-side peripheral portion of the enlarged-diameter cylindrical portion, and in which a wire harness is inserted. A reinforcement rib protrudes from an interior surface of the elastically deformable portion of the enlarged-diameter cylindrical portion. The reinforcement rib is T-shaped. The reinforcement rib has depressions for deformation. The depressions for deformation face in the opposite directions. An intersection of the reinforcement rib that is T-shaped is between the depressions for deformation.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on, and claims priority from Japanese Patent Application No. 2019-195790, filed on Oct. 29, 2019, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present application relates to a grommet.

BACKGROUND

A main body of a grommet disclosed in JP H11-252748 A includes a peripheral wall, an insertion cylinder, and an elastic wall. The peripheral wall is cylindrical. An annular groove extends around the peripheral wall. The annular groove is fitted to a through hole of a panel. The insertion cylinder has a small diameter. A wire harness is inserted in the insertion cylinder. The elastic wall is between the peripheral wall and the insertion cylinder. The elastic wall is integral with the peripheral wall and the insertion cylinder. Further, a reinforcement rib protrudes from an interior surface of the main body of the grommet. That is to say, the reinforcement rib protrudes from an interior surface of the peripheral wall and an interior surface of the elastic wall. The reinforcement rib has a shape like a cross.

SUMMARY

However, when the grommet disclosed in JP H11-252748 A is attached to a vehicle, that is to say when the elastic wall of the main body of the grommet is inserted into a through hole of a panel and the peripheral wall is fitted to the through hole, it is difficult to deform the elastic wall of the main body of the grommet since the interior surface of the main body of the grommet has the reinforcement rib that has a shape like a cross. Therefore, the insertion force is large.

The present application is made to solve the above problem. It is an object of the present application to provide the following grommet. The grommet allows a reinforcement rib to be easily deformed when the grommet is inserted into and attached to a through hole of a panel. Consequently, the insertion force is decreased. Further, after the grommet is attached, the reinforcement rib decreases a deformation of an elastically deformable portion, and thus increases a holding force.

A grommet according to an aspect of the present application includes: an enlarged-diameter cylindrical portion that has a larger-diameter-side peripheral portion, a fitted groove configured to be fitted to a through hole of a panel, and an elastically deformable portion that extends from the larger-diameter-side peripheral portion to a smaller-diameter-side peripheral portion and is elastically deformable; and a smaller-diameter cylindrical portion that is configured to be connected with the smaller-diameter-side peripheral portion of the enlarged-diameter cylindrical portion, and in which a wire harness is inserted. A reinforcement rib protrudes from an interior surface of the elastically deformable portion of the enlarged-diameter cylindrical portion. The reinforcement rib is T-shaped. The reinforcement rib has depressions for deformation. The depressions for deformation face in opposite directions. An intersection of the reinforcement rib that is T-shaped is between the depressions for deformation.

The reinforcement rib may have a lateral rib and a lengthways rib, and thus is T-shaped, and the lateral rib may have the depressions for deformation, the depressions for deformation may be near the intersection, and the depressions for deformation face in opposite directions.

The reinforcement rib may have a lateral rib and a lengthways rib, and thus is T-shaped, and the lateral rib may have the depressions for deformation, the depressions for deformation may be apart from the intersection, and the depressions for deformation face in opposite directions.

The elastically deformable portion of the enlarged-diameter cylindrical portion may have a shape like an elliptical cone, and the elastically deformable portion that has a shape like an elliptical cone may have an interior surface, two of the reinforcement rib that is T-shaped may be on both sides, respectively, on the interior surface, and the two reinforcement ribs may be opposite each other along a longer axis of the interior surface of the elastically deformable portion.

The above configurations each provide the following grommet. The grommet allows a reinforcement rib(s) to be easily deformed when the grommet is inserted into and attached to a through hole of a panel. Consequently, the insertion force is decreased. Further, after the grommet is attached, the reinforcement rib(s) decrease(s) a deformation of an elastically deformable portion, and thus increase(s) a holding force.

DETAILED DESCRIPTION

Hereinafter, a grommet according to a first embodiment of the present application will be described in detail with reference to the drawings.

As illustrated inFIGS. 1 to 3, a grommet10is made of, for example, synthetic rubber or an elastomer that is elastic, and the grommet10includes an enlarged-diameter cylindrical portion11and a cylindrical bellows portion (smaller-diameter cylindrical portion)17. The grommet10is used for a side door, and is attached to an elliptical through hole H of a door panel (panel) P of a vehicle. That is, the grommet10includes the enlarged-diameter cylindrical portion11and the cylindrical bellows portion17. The enlarged-diameter cylindrical portion11has a larger-diameter-side peripheral portion12, a fitted groove12afitted to the through hole H, and an elastically deformable portion14. The elastically deformable portion14extends from the larger-diameter-side peripheral portion12to a smaller-diameter-side peripheral portion13. The elastically deformable portion14is elastically deformable. The cylindrical bellows portion17is connected with the smaller-diameter-side peripheral portion13. A wire harness W is inserted in the cylindrical bellows portion17.

As illustrated inFIGS. 1 to 3, the larger-diameter-side peripheral portion12of the enlarged-diameter cylindrical portion11has a large thickness, and is elliptically annular. The smaller-diameter-side peripheral portion13of the enlarged-diameter cylindrical portion11has a thin thickness, has a short length, and is cylindrical. The elastically deformable portion14of the enlarged-diameter cylindrical portion11has a thickness that is smaller than the thickness of the larger-diameter-side peripheral portion12, and has a shape like an elliptical cone. The elastically deformable portion14that has a shape like an elliptical cone has an interior surface14a. The interior surface14ais opposite a surface of the enlarged-diameter cylindrical portion11on which the cylindrical bellows portion17is connected with the smaller-diameter-side peripheral portion13. Reinforcement ribs15integrally protrude from the interior surface14a.The reinforcement ribs15are T-shaped. The reinforcement ribs15are on upper and lower sides, respectively, on the interior surface14a. The smaller-diameter-side peripheral portion13is between the upper and lower sides. The reinforcement ribs15are opposite each other along a longer axis of the enlarged-diameter cylindrical portion11. Each of the two reinforcement ribs15on the upper and lower sides, respectively, has a lateral rib15aand a lengthways rib15b, and thus is T-shaped. The lateral rib15aextends in parallel to a lateral direction of the elastically deformable portion14(along a shorter axis of the enlarged-diameter cylindrical portion11). The lengthways rib15bextends from a center of the lateral rib15aperpendicularly (along a longer axis of the enlarged-diameter cylindrical portion11). The lateral rib15ahas depressions16for deformation. The depressions16for deformation are near an intersection15cof the lateral rib15aand the lengthways rib15b. The depressions16for deformation are made lower upward or downward along the longer axis of the enlarged-diameter cylindrical portion11. The depressions16for deformation face in the opposite directions. The intersection15cis between the depressions16for deformation along the shorter axis of the enlarged-diameter cylindrical portion11.

As illustrated inFIGS. 1 and 3, the cylindrical bellows portion17that is the smaller-diameter cylindrical portion protects the wire harness W inserted in the cylindrical bellows portion17. When the grommet10is attached to the through hole H of the door panel P, the cylindrical bellows portion17is pulled in a vehicle attachment direction (fitting direction) K while the cylindrical bellows portion17is rotated to insert the grommet10. Consequently, the fitted groove12athat is part of the enlarged-diameter cylindrical portion11and is elliptically annular is fitted to and engaged with an edge of the through hole H.

As described above, when the grommet10according to the first embodiment is inserted into and attached to the through hole H of the door panel P, the cylindrical bellows portion17is pulled in the vehicle attachment direction K while the cylindrical bellows portion17is rotated, as illustrated inFIG. 1. Consequently, the fitted groove12aof the enlarged-diameter cylindrical portion11is fitted to the through hole H. During the insertion, the depressions16for deformation between which the intersection15cof the lateral rib15aof each of the reinforcement ribs15exists become bending points, as illustrated inFIG. 4B. Consequently, the enlarged-diameter cylindrical portion11is more easily deformed diagonally. The insertion force is smaller. The grommet10is more efficiently attached.

Further, after the grommet10is attached to the door panel P, the lateral ribs15aof the reinforcement ribs15that are T-shaped are linear, as illustrated inFIG. 4C. Therefore, a holding force that holds the grommet10in the door panel P is not influenced.

As described above, when the grommet10is inserted into the through hole H of the door panel P, the grommet10is inserted while the grommet10is rotated. Therefore, the reinforcement ribs15are more easily deformed. The insertion force is decreased. When the grommet10that has been attached is held, the reinforcement ribs15decrease a deformation of the grommet10, and thus increase a holding force. The reason is that the lateral rib15aand the lengthways rib15bof each of the reinforcement ribs15are connected with each other at the intersection15c, and thus the reinforcement ribs15are T-shaped.

FIG. 5is a back view that illustrates one example of a grommet according to a second embodiment of the present application.FIG. 6Ais a schematic view of the grommet that has not been inserted.FIG. 6Bis a schematic view of the grommet that is being inserted.

A difference between a grommet10A according to the second embodiment and the grommet10according to the first embodiment is positions of depressions16for deformation. The depressions16for deformation are at intermediate positions of each of lateral ribs15a. The intermediate positions are apart from an intersection15cof each of the lateral ribs15aalong a shorter axis of an enlarged-diameter cylindrical portion11. The depressions16for deformation face in the opposite directions. The other configuration of the second embodiment is similar to the configuration of the first embodiment. Therefore, the same components are designated by the same reference numerals and will not be described in detail.

In the grommet10A according to the second embodiment, reinforcement ribs15protrude from an interior surface14aof an elastically deformable portion14. The reinforcement ribs15are T-shaped. Each of the reinforcement ribs15has a lateral rib15a. The lateral rib15ahas depressions16for deformation at intermediate positions of the lateral rib15a. The intermediate positions are apart from an intersection15cof the lateral rib15aalong the shorter axis of the enlarged-diameter cylindrical portion11. The depressions16for deformation face in the opposite directions. Therefore, the grommet10A according to the second embodiment has action and effect that are similar to the action and effect of the grommet10according to the first embodiment.

That is to say, when the grommet10A is inserted into a through hole H of a door panel P, the depressions16for deformation become bending points, as illustrated inFIG. 6B. The depressions16for deformation are at intermediate positions of the lateral rib15aof each of the reinforcement ribs15. The depressions16for deformation face in the opposite directions. Therefore, the reinforcement ribs15are easily deformed when the grommet10A is inserted while the grommet10A is rotated. Consequently, the insertion force is decreased. When the grommet10A that has been attached is held, the reinforcement ribs15decrease a deformation of the grommet10A, and thus increase a holding force. The reason is that the lateral rib15aand the lengthways rib15bof each of the reinforcement ribs15are connected with each other at the intersection15c, and thus the reinforcement ribs15are T-shaped.

The present embodiments have been described above. However, the present application is not limited to the present embodiments. The present embodiments are variously modified within a scope of a gist of the present application.

That is to say, the grommet is used in a side door in each of the embodiments. However, the grommet may be used in other vehicle parts, such as a back door.

Further, the smaller-diameter cylindrical portion includes the cylindrical bellows portion that includes elastic folds in each of the embodiments. However, the smaller-diameter cylindrical portion may include an elastic cylinder.

Next, a comparative example will be described. A main body of a grommet according to a comparative example includes a peripheral wall, an insertion cylinder, and an elastic wall. The peripheral wall is cylindrical. An annular groove extends around the peripheral wall. The annular groove is fitted to a through hole of a panel. The insertion cylinder has a small diameter. A wire harness is inserted in the insertion cylinder. The elastic wall is between the peripheral wall and the insertion cylinder. The elastic wall is integral with the peripheral wall and the insertion cylinder. Further, a reinforcement rib protrudes from an interior surface of the main body of the grommet. That is to say, the reinforcement rib protrudes from an interior surface of the peripheral wall and an interior surface of the elastic wall. The reinforcement rib has a shape like a cross.

However, when the grommet according to the comparative example is attached to a vehicle, that is to say when the elastic wall of the main body of the grommet is inserted into a through hole of a panel and the peripheral wall is fitted to the through hole, it is difficult to deform the elastic wall of the main body of the grommet since the interior surface of the main body of the grommet has the reinforcement rib that has a shape like a cross. Therefore, the insertion force is large.