Grommet and grommet-equipped wire

Provided is a grommet with high durability against bending and a grommet-equipped wire. A wire can be inserted in a grommet. The grommet includes a first fixing portion to be fixed to a door panel, a second fixing portion to be fixed to a vehicle panel, and a connecting portion that is elastically deformable and that connects the first fixing portion and the second fixing portion to each other. In this grommet, in a closed state in which the door panel is closed relative to the vehicle panel, an intermediate portion of the connecting portion hangs down to a level that is lower than levels of opposite end portions of the connecting portion. Accordingly, when the door is opened, the vehicle panel and the door panel are separated from each other, and the intermediate portion of the connecting portion is thereby lifted.

TECHNICAL FIELD

The present invention relates to a grommet and a grommet-equipped wire that are used for vehicle doors.

BACKGROUND ART

In the case where a wire harness is disposed extending via a through hole provided in a vehicle panel of an automobile and a through hole provided in a door panel of that automobile, a grommet is generally provided around the wire harness in order to protect the wire harness.

JP 2012-10494A discloses a grommet that has a bellows portion with ridge portions and valley portions that are formed successively in an axial direction of the grommet. In a state in which a door panel is closed relative to a vehicle panel, the door panel and the vehicle panel are near to each other, and thus, the bellows portion is contracted. In a state in which the door panel is open relative to the vehicle panel, the door panel and the vehicle panel are separated from each other, and thus, the bellows portion is expanded. In this manner, the grommet is bendably expandable and contractible in accordance with the opening and closing motion of the door panel.

JP 2012-10494A is an example of related art.

When the door panel is repeatedly opened and closed, the number of times the grommet expands and contracts increases accordingly. The configuration in which the bendable expansion and contraction of the grommet in accordance with the opening and closing motion of the door panel is achieved mainly due to expansion and contraction of the bellows portion is likely to cause localized concentration of bending stress.

Moreover, with respect to commercial vehicles, such as delivery vehicles and taxis, door panels are more frequently opened and closed compared with those of passenger automobiles, and therefore, there is demand for a grommet with high durability against bending.

The present invention was made in view of the above-described problems, and it is an object thereof to provide a grommet with high durability against bending and a grommet-equipped wire.

SUMMARY OF THE INVENTION

To address the above-described problems, a grommet according to a first aspect is a grommet in which a wire can be inserted, the grommet including a first fixing portion to be fixed to a door panel, a second fixing portion to be fixed to a vehicle panel, and a connecting portion that is elastically deformable and that connects the first fixing portion and the second fixing portion to each other, wherein, in a closed state in which the door panel is closed relative to the vehicle panel, an intermediate portion of the connecting portion hangs down to a level that is lower than levels of opposite end portions of the connecting portion.

A grommet according to a second aspect is the grommet according to the first aspect, wherein, in an open state in which the door panel is open relative to the vehicle panel, the intermediate portion of the connecting portion hangs down to a level that is lower than the levels of the opposite end portions of the connecting portion, and a hanging-down amount of the intermediate portion in the open state is smaller than a hanging-down amount of the intermediate portion in the closed state.

A grommet according to a third aspect is the grommet according to the first or second aspect, wherein the connecting portion has, as constituent elements in which the wire can be inserted, a first tubular portion that is located at the end portion of the connecting portion on the first fixing portion side, a second tubular portion that is located at the end portion of the connecting portion on the second fixing portion side, and a bellows portion that has a bellows-like shape and that is connected to the first tubular portion and the second tubular portion, and a portion of the first tubular portion on the bellows portion side and a portion of the second tubular portion on the bellows portion both extend downward.

A grommet according to a fourth aspect is the grommet according to any one of the first to third aspects, wherein the intermediate portion is a portion that deforms in accordance with switching between an open state in which the door panel is open relative to the vehicle panel and the closed state, the opposite end portions are portions that each have the same shape in both the open state and the closed state, and a length of the intermediate portion is larger than a distance between the opposite end portions in the open state.

A grommet-equipped wire according to a fifth aspect includes the grommet according to any one of the first to fourth aspects, and a wire that is inserted in the grommet.

According to the first to fourth aspects, in the closed state in which a door is closed relative to the vehicle panel, the intermediate portion of the connecting portion hangs down to a level that is lower than the levels of the opposite end portions of the connecting portion. Accordingly, when the door is opened, the vehicle panel and the door panel are separated from each other, and the intermediate portion of the connecting portion is thereby lifted. In this manner, during opening and closing of the door, the grommet is bent mainly as a result of the hanging shape of the connecting portion changing. According to these aspects, compared with a configuration in which a grommet is bent mainly due to expansion and contraction of the connecting portion, the durability of the grommet against bending is improved.

According to the second aspect, in the open state in which the door panel is open relative to the vehicle panel, the intermediate portion of the connecting portion hangs down to a level that is lower than the levels of the opposite end portions of the connecting portion. Moreover, the hanging-down amount of the intermediate portion in the open state is smaller than the hanging-down amount of the intermediate portion in the closed state. In this manner, according to the aspect in which the intermediate portion hangs down in both the open state and the closed state, the grommet is bent mainly as a result of the hanging shape changing, and thus the durability of the grommet against bending is improved.

According to the third aspect, both the portion of the first tubular portion on the bellows portion side and the portion of the second tubular portion on the bellows portion side extend downward. Thus, a state in which the bellows portion, which is connected to the first tubular portion and the second tubular portion, hangs down due to the effect of gravity is maintained, so that the bellows portion is unlikely to interfere with a nearby member, and the bellows portion can be disposed in a space-saving manner.

According to the fourth aspect, the length of the intermediate portion is larger than the distance between the opposite end portions in the open state. In this manner, a sufficient length is ensured for the intermediate portion, which deforms in accordance with opening and closing of the door panel, and thus, stress that is exerted on the grommet during opening and closing of the door panel is distributed, and the durability of the grommet against bending is improved.

According to the fifth aspect, the wire is protected using the grommet with high durability against bending, and thus, even after the door panel is repeatedly opened and closed, a state in which the wire is protected can be effectively maintained.

EMBODIMENTS OF THE INVENTION

Hereinafter, a grommet1according to an embodiment will be described.

FIG. 1is a side view showing a grommet1before being attached to an automobile.FIG. 2is a schematic plan view showing the grommet1in a closed state in which the grommet1is attached to the automobile and a door panel5is closed.FIG. 3is a schematic plan view showing the grommet1in an open state in which the grommet1is attached to the automobile and the door panel5is open.

The grommet1is a tubular member that is composed of an elastic material, such as rubber or an elastomer, and in which a wire8can be inserted. Note that, inFIG. 1, an axis7of an internal space of the grommet1is shown with a long dashed double-short dashed line. Here, the axis7corresponds to a line that connects the centers of transverse sections of the internal space of the tubular grommet1.

A grommet-equipped wire9is obtained by a worker inserting the wire8into the internal space of the grommet1along the axis7. The grommet-equipped wire9is used when the wire8is arranged extending via a through hole provided in a vehicle panel6of the automobile and a through hole provided in the door panel5of the automobile.

The vehicle panel6is a portion that is immovable relative to the main body of the automobile, whereas the door panel5is movable in a direction toward the vehicle panel6or a direction away from the vehicle panel6. Specifically, the door panel5is movable following an arc around a hinge100, which is shown in a simplified manner inFIGS. 2 and 3, in the direction toward the vehicle panel6or the direction away from the vehicle panel6. InFIGS. 2 and 3, the directions in which the door panel5is movable are indicated by the arcuate, double-headed arrows.

Here, a state in which the door panel5is nearest to the vehicle panel6and the door of the automobile is closed is referred to as the closed state, and a state in which the door panel5is partially separated from the vehicle panel6and the door of the automobile is open is referred to as the open state. When the door panel5is opened or closed relative to the vehicle panel6, the grommet1follows the opening/closing motion and bendably deforms. Moreover, due to the opening/closing motion of the door panel5, the wire8is also pressed against by an inner wall of the grommet1, and the wiring path of the wire8changes.

In the grommet-equipped wire9, the grommet1has the function of protecting the wire8inserted therein from shock and moisture. Here, a case where the wire8inserted in the grommet1is a wire harness in which a plurality of wires are bundled together is described; however, the wire8may be composed of a single wire.

FIG. 4is a perspective view showing the grommet1attached to the automobile in the closed state in which the door panel5is closed.FIG. 5is a perspective view showing the grommet1attached to the automobile in the open state in which the door panel5is open. Note that, from the standpoint of showing the configuration of the grommet1, the door panel5and the vehicle panel6are omitted fromFIGS. 4 and 5.

Hereinafter, a detailed configuration of the grommet1will be described with reference toFIGS. 1 to 5. Note that, inFIGS. 2 and 3, the front side of the paper plane means the upper side in the vertical direction, and the back side of the paper plane means the lower side in the vertical direction. InFIGS. 4 and 5, the upper side of the paper plane means the upper side in the vertical direction, and the lower side of the paper plane means the lower side in the vertical direction.

The grommet1has a first fixing portion10, a second fixing portion20, and a connecting portion30in a state in which internal spaces of the respective portions are in communication with one another along the axis7.

The first fixing portion10has an annular groove11in an outer surface thereof, and is to be fixed to the door panel5. The outer diameter of the groove11and the inner diameter of a through hole5hof the door panel5are the same. Moreover, an inclined surface12is provided in the outer surface of the first fixing portion10, the outer diameter of the inclined surface12gradually increasing from the second fixing portion20side toward a side that is opposite to the second fixing portion20.

Accordingly, when a worker pushes the first fixing portion10into the through hole5hof the door panel5that is located on the second fixing portion20side, an edge portion of the through hole5hof the door panel5is guided over the inclined surface12. While the edge portion of the through hole5hof the door panel5is being guided, the inclined surface12is pressed against by that edge portion in a diameter-reducing direction, and the first fixing portion10elastically deforms in the diameter-reducing direction. Then, upon the inclined surface12passing the edge portion of the through hole5hof the door panel5, the first fixing portion10returns to its original shape under a restoring force, and thus, the edge portion of the through hole5hof the door panel5is fitted into the groove11of the first fixing portion10. As a result, the grommet1is fixed to the door panel5.

The second fixing portion20has an annular groove21in an outer surface thereof, and is to be fixed to the vehicle panel6. The outer diameter of the groove21and the inner diameter of a through hole6hof the vehicle panel6are the same. Moreover, an inclined surface22is provided in the outer surface of the second fixing portion20, the outer diameter of the inclined surface22gradually increasing from a side that is opposite to the first fixing portion10toward the first fixing portion10side.

Accordingly, when the worker pushes the second fixing portion20into the through hole6hof the vehicle panel6that is located on the opposite side to the first fixing portion10, an edge portion of the through hole6hof the vehicle panel6is guided over the inclined surface22. While the edge portion of the through hole6hof the vehicle panel6is being guided, the inclined surface22is pressed against by that edge portion in the diameter-reducing direction, and the second fixing portion20elastically deforms in the diameter-reducing direction. Then, upon the inclined surface22passing the edge portion of the through hole6hof the vehicle panel6, the second fixing portion20returns to its original shape under a restoring force, and thus, the edge portion of the through hole6hof the vehicle panel6is fitted into the groove21of the second fixing portion20. As a result, the grommet1is fixed to the vehicle panel6.

Moreover, an end portion15that partially covers an outer peripheral surface of the wire8is provided at a position in the grommet1that is nearer to an end of the grommet1than the first fixing portion10is. An end portion25that partially covers the outer peripheral surface of the wire8is provided at a position in the grommet1that is nearer to the other end of the grommet1than the second fixing portion20is. Accordingly, when, in a state in which the wire8is inserted in the grommet1, pieces of tape or the like are wound around outer peripheral portions of the end portion15and the end portion25, respectively, the grommet1is fixed to the wire8at the two portions.

The connecting portion30is elastically deformable and connects the first fixing portion10and the second fixing portion20to each other. Moreover, the connecting portion30has, as constituent elements in which the wire8can be inserted, a first tubular portion31that is located at an end portion of the connecting portion30on the first fixing portion10side, a second tubular portion32that is located at the other end portion of the connecting portion30on the second fixing portion20side, and a bellows portion33that has a bellows-like shape and that is connected to the first tubular portion31and the second tubular portion32.

The first tubular portion31is a tubular portion that bends the wiring path of the wire8inserted therein. One end31aof the first tubular portion31is connected to the first fixing portion10, and the other end31bof the first tubular portion31is connected to one end of the bellows portion33. Moreover, the first tubular portion31does not have protrusions and depressions such as those of the bellows portion33and is configured to have a larger wall thickness than the bellows portion33. Therefore, the first tubular portion31has the same shape in both the open state and the closed state. Accordingly, a portion of the wire8inserted in the grommet1, the portion passing through the first tubular portion31, is arranged along the same path in both the open state and the closed state.

The second tubular portion32is a tubular portion that bends the wiring path of the wire8inserted therein. One end32aof the second tubular portion32is connected to the second fixing portion20, and the other end32bof the second tubular portion32is connected to the other end of the bellows portion33. Moreover, the second tubular portion32does not have protrusions and depressions such as those of the bellows portion33and is configured to have a larger wall thickness than the bellows portion33. Therefore, the second tubular portion32has the same shape in both the open state and the closed state. Accordingly, a portion of the wire8inserted in the grommet1, the portion passing through the second tubular portion32, is arranged along the same path in both the open state and the closed state.

The bellows portion33is a corrugated portion having annular ridge portions33aand annular valley portions33bthat are alternatingly successively formed in the direction of the axis7of the grommet1, and is configured to be bendable in accordance with the opening and closing motion of the door panel5. Accordingly, the bellows portion33is expandable and contractible in the direction of the axis7and also flexible in such a manner as to be bendable in a direction at an angle to the axis7, and deforms in accordance with switching between the open state and the closed state. Thus, the path along which a portion of the wire8inserted in the grommet1, the portion passing through the bellows portion33, is arranged is different between the open state and the closed state.

In this manner, the first tubular portion31and the second tubular portion32correspond to opposite end portions of the connecting portion30, and the bellows portion33corresponds to an intermediate portion of the connecting portion30. Note that it is not essential that the first tubular portion31and the second tubular portion32be provided as in the present embodiment, and either one of them may be omitted, or both of them may be omitted. If the first tubular portion31or the second tubular portion32is omitted, the corresponding end portion of the bellows portion33is directly connected to the first fixing portion10or the second fixing portion20. In this case, a portion where that end portion of the bellows portion33is directly connected to the first fixing portion10or the second fixing portion20corresponds to the end portion of the connecting portion30, and the bellows portion33corresponds to the intermediate portion of the connecting portion30.

As shown inFIG. 4, in the closed state, the bellows portion33(i.e., the intermediate portion of the connecting portion30) hangs down to a level that is lower than the levels of the first tubular portion31and the second tubular portion32(i.e., the opposite end portions of the connecting portion30). Then, as shown inFIG. 5, while the door panel5is being opened, the vehicle panel6and the door panel5are separated from each other, and the bellows portion33, which is the intermediate portion of the connecting portion30, is thereby lifted.

Here, paths of the axis7of the grommet1in the closed state and the open state will be described with reference toFIG. 6.FIG. 6is a conceptual diagram illustrating paths of the axis7of the grommet1in the closed state and the open state. Note that, inFIG. 6, the axis7in the closed state is shown with a solid line, and the axis7in the open state is shown with a long dashed double-short dashed line. Also, for the purpose of indicating specific positions on the axis7in the closed state, points P11to P14are shown as imaginary points. Similarly, for the purpose of indicating specific positions on the axis7in the open state, points P21to P24are shown as imaginary points.

InFIG. 6, the point P11indicates the position corresponding to the end32aof the second tubular portion32, on the axis7in the closed state. The point P12indicates the position of the end32bof the second tubular portion32, on the axis7in the closed state. The point P13indicates the position corresponding to the end31bof the first tubular portion31, on the axis7in the closed state. The point P14indicates the position corresponding to the end31aof the first tubular portion31, on the axis7in the closed state. Accordingly, as indicated by the points P12and P13, the grommet1in the closed state has a U-shape in which the bellows portion33hangs down to a level that is lower than the levels of the first tubular portion31and the second tubular portion32.

Moreover, inFIG. 6, the point P21indicates the position corresponding to the end32aof the second tubular portion32, on the axis7in the open state. The point P22indicates the position corresponding to the end32bof the second tubular portion32, on the axis7in the open state. The point P23indicates the position corresponding to the end31bof the first tubular portion31, on the axis7in the open state. The point P24indicates the position corresponding to the end31aof the first tubular portion31, on the axis7in the open state. Accordingly, as indicated by the points P22and P23, the grommet1in the open state has a U-shape in which the bellows portion33hangs down to a level that is lower than the levels of the first tubular portion31and the second tubular portion32.

As described above, a configuration is adopted in which the vehicle panel6is immovable, and the door panel5is movable. Moreover, each of the first tubular portion31and the second tubular portion32has the same shape in both the open state and the closed state. Accordingly, the positions of the point P11and the point P21coincide with each other, and the positions of the point P12and the point P22also coincide with each other. Moreover, the path of the axis7in a section between the point P13and the point P14and the path of the axis7in a section between the point P23and the point P24have the same shape. On the other hand, the path of the axis7in a section between the point P22and the point P23(i.e., path of the bellows portion33in the open state) is lifted up and elongated in the left-right direction, compared with the path of the axis7in a section between the point P12and the point P13(i.e., path of the bellows portion33in the closed state).

In the present embodiment, in the closed state, the bellows portion33hangs down to a level that is lower than the levels of the first tubular portion31and the second tubular portion32. Accordingly, during switching from the closed state to the open state, the vehicle panel6and the door panel5are separated from each other, and the bellows portion33is thereby lifted. Conversely, during switching from the open state to the closed state, the vehicle panel6and the door panel5are brought near to each other, and the bellows portion33is thereby caused to hang down to a lower level.

In this manner, the stress exerted on the grommet1during opening and closing of the door mainly acts to change the hanging shape of the bellows portion33, and is unlikely to act to expand and contract the bellows portion33. Accordingly, localized concentration of bending stress in the annular ridge portions33aand the annular valley portions33bof the bellows portion33due to an increase in the number of times the grommet1expands and contracts is suppressed, and the durability of the grommet1against bending is improved. Note that it does not matter if the bellows portion33slightly expands and contracts due to the effect of the stress exerted on the grommet1when the door is opened and closed.

Moreover, in the present embodiment, the first tubular portion31and the second tubular portion32are at the same level in the closed state and the open state, and therefore, device design is easy in terms of attachment of the grommet-equipped wire9to the automobile. Note that it is not essential that these tubular portions be at the same level, and the tubular portions may be at different levels. Moreover, it is preferable that the first tubular portion31and the second tubular portion32are at approximately the same level, and, for example, a configuration may also be adopted in which the first tubular portion31is at a level that is several tens of millimeters higher than the second tubular portion32.

Moreover, in the present embodiment, the length of the bellows portion33(i.e., length of the intermediate portion of the connecting portion30) is larger than the distance between the first tubular portion31and the second tubular portion32(i.e., distance between the opposite end portions of the connecting portion30) in the open state. Here, the length of the intermediate portion of the connecting portion30refers to the length between the points P12and P13or the points P22and P23along the axis7. Also, the distance between the opposite end portions of the connecting portion30refers to the distance between lower end portions (i.e., portions that support the bellows portion33) of the first tubular portion31and the second tubular portion32along the axis7. In this manner, a sufficient length is ensured for the bellows portion33, which deforms in accordance with opening and closing of the door panel5, and therefore, the stress exerted on the grommet1during opening and closing of the door panel5is distributed.

The stress mainly acts to change the hanging shape of the bellows portion33, and is unlikely to act to expand and contract the bellows portion33. Accordingly, in the grommet1, the distance along the axis7of the section between the points P12and P13and the distance along the axis7of the section between the points P22and P23are the same. In this manner, the grommet1is bent mainly as a result of the hanging shape changing, and the durability of the grommet1against bending is improved. Note that it is not essential that the above-described distances be the same, and, for example, the distance along the axis7of the section between the points P12and P13may be slightly larger than the distance along the axis7of the section between the points P22and P23.

Moreover, the length of the bellows portion33(i.e., length between the points P12and P13or the points P22and P23along the axis7) may be the same as the distance between the first tubular portion31and the second tubular portion32in the open state (i.e., linear distance between the point P22and the point P23). In this case, the bellows portion33does not hang down in the open state, but rather is linearly stretched between the point P22and the point P23in the open state.

Moreover, in the present embodiment, the bellows portion33hangs down in both the open state and the closed state, and the hanging-down amount of the bellows portion33in the open state is smaller than the hanging-down amount of the bellows portion33in the closed state. In this manner, according to an aspect in which the bellows portion33hangs down in both the open state and the closed state, the grommet1is bent mainly as a result of the hanging shape changing, and thus, the durability of the grommet1against bending is improved.

Moreover, in the present embodiment, at any point in time during the opening and closing motion of the door panel5, a portion of the first tubular portion31on the bellows portion33side and a portion of the second tubular portion32on the bellows portion33side both extend downward. Thus, a state in which the bellows portion33connected to the first tubular portion31and the second tubular portion32hangs down due to the effect of gravity is maintained, so that the bellows portion33is unlikely to interfere with a nearby member, and the bellows portion33can be disposed in a space-saving manner. Note that it is not essential that both the portion of the first tubular portion31on the bellows portion33side and the portion of the second tubular portion32on the bellows portion33side extend downward, and at least one of these portions may extend horizontally or upward.

In the grommet-equipped wire9, since the wire8is protected using the grommet1that has high durability against bending as described above, the state in which the wire8is protected can be effectively maintained even after the door panel5is repeatedly opened and closed. The grommet-equipped wire9is applicable to door portions of passenger automobiles, but is especially suitable for commercial vehicles, such as delivery vehicles and taxis, (e.g., automobiles whose doors are frequently opened and closed and for which high durability against bending is required). Moreover, since front doors are generally more frequently opened and closed than rear doors, the grommet-equipped wire9is especially suitable for front door portions.

Next, first to fourth comparative examples, which are comparative examples of the grommet1according to the present embodiment, will be described with reference toFIGS. 7 to 10. In the comparative examples below, constituent elements that are the same as various portions of the present embodiment will be denoted by the same reference numerals, and a redundant description will not be given. Moreover, axes7A to7D of grommets according to the first to fourth comparative examples correspond to the axis of the internal space of the bellows portion.

FIG. 7is a conceptual diagram illustrating paths of the axis7A of a linear grommet according to the first comparative example. Note that, inFIG. 7, the axis7A in the closed state is shown with a solid line, and the axis7A in the open state is shown with a long dashed double-short dashed line. Moreover, for the purpose of indicating specific positions on the axis7A in the closed state, points P31and P32are shown as imaginary points. Similarly, for the purpose of indicating specific positions on the axis7A in the open state, points P41and P42are shown as imaginary points.

InFIG. 7, the point P31indicates the position corresponding to an end portion of the axis7A on the second fixing portion20side in the closed state. The point P32indicates the position corresponding to the other end portion of the axis7A on the first fixing portion10side in the closed state. The point P41indicates the position corresponding to the end portion of the axis7A on the second fixing portion20side in the open state. The point P42indicates the position corresponding to the end portion of the axis7A on the first fixing portion10side in the open state. Since the vehicle panel6is an immovable portion as described above, the points P31and P41on the second fixing portion20side, which is fixed to the vehicle panel6, are at the same position.

As indicated by the points P31and P32, in the first comparative example, the bellows portion is linearly stretched in the closed state. Moreover, as indicated by the points P41and P42, in the first comparative example, the bellows portion is linearly stretched in the open state to be longer than that in the closed state. In the first comparative example, the stress exerted on the grommet in accordance with the opening and closing motion of the door panel5mainly acts in a direction in which the stress makes the bellows portion expand and contract. In the first comparative example, the bellows portion expands and contracts in accordance with the opening and closing motion of the door panel, and thus, bending stress is likely to concentrate locally on the ridge portions and the valley portions of the bellows portion.

FIG. 8is a conceptual diagram illustrating paths of the axis7B of an S-shaped grommet according to the second comparative example. Note that, inFIG. 8, the axis7B in the closed state is shown with a solid line, the axis7B in an intermediate state between the closed state and the open state is shown with a long dashed short dashed line, and the axis7B in the open state is shown with a long dashed double-short dashed line. Moreover, for the purpose of indicating specific positions on the axis7B in the closed state, points P51and P52are shown as imaginary points. For the purpose of indicating specific positions on the axis7B in the intermediate state, points P61and P62are shown as imaginary points. For the purpose of indicating specific positions on the axis7B in the open state, points P71and P72are shown as imaginary points.

InFIG. 8, the point P51indicates the position corresponding to an end portion of the axis7B on the second fixing portion20side in the closed state. The point P52indicates the position corresponding to the other end portion of the axis7B on the first fixing portion10side in the closed state. The point P61indicates the position corresponding to the end portion of the axis7B on the second fixing portion20side in the intermediate state. The point P62indicates the position corresponding to the end portion of the axis7B on the first fixing portion10side in the intermediate state. The point P71indicates the position corresponding to the end portion of the axis7B on the second fixing portion20side in the open state. The point P72indicates the position corresponding to the end portion of the axis7B on the first fixing portion10side in the open state. Since the vehicle panel6is an immovable portion as described above, the points P51, P61, and P71on the second fixing portion20side, which is fixed to the vehicle panel6, are at the same position.

As indicated by the points P51and P52, in the second comparative example, the bellows portion is bent into an S-shape in the closed state. Moreover, as indicated by the points P61and P62, in the second comparative example, the bellows portion is linearly stretched in the intermediate state. Moreover, as indicated by the points P71and P72, in the second comparative example, the bellows portion is linearly stretched in the open state to be longer than that in the intermediate state. In the second comparative example, the stress exerted on the grommet in accordance with the opening and closing motion of the door panel5mainly acts to change the hanging shape of the bellows portion during transition between the closed state and the intermediate state, and mainly acts in a direction in which the stress makes the bellows portion expand and contract during transition between the intermediate state and the open state. In the second comparative example, since the bellows portion expands and contracts during transition between the intermediate state and the open state, bending stress is likely to locally concentrate on the ridge portions and the valley portions of the bellows portion.

FIG. 9is a conceptual diagram illustrating paths of the axis7C of an S-shaped grommet according to the third comparative example. Note that, inFIG. 9, the axis7C in the closed state is shown with a solid line, and the axis7C in the open state is shown with a long dashed double-short dashed line. Moreover, for the purpose of indicating specific positions on the axis7C in the closed state, points P81and P82are shown as imaginary points. For the purpose of indicating specific positions on the axis7C in the open state, points P91and P92are shown as imaginary points.

InFIG. 9, the point P81indicates the position corresponding to an end portion of the axis7C on the second fixing portion20side in the closed state. The point P82indicates the position corresponding to the other end portion of the axis7C on the first fixing portion10side in the closed state. The point P91indicates the position corresponding to the end portion of the axis7C on the second fixing portion20side in the open state. The point P92indicates the position corresponding to the end portion of the axis7C on the first fixing portion10side in the open state. Since the vehicle panel6is an immovable portion as described above, the points P81and P91on the second fixing portion20side, which is fixed to the vehicle panel6, are at the same position.

As indicated by the points P81and P82, in the third comparative example, the bellows portion is bent into an S-shape in the closed state. Moreover, as indicated by the points P91and P92, in the third comparative example, the bellows portion is linearly stretched in the open state.

Note that, in the third comparative example, the grommet is configured such that the length of the bellows portion in the closed state is the same as the distance between the points P91and P92in the open state. For this reason, the stress exerted on the grommet in accordance with the opening and closing motion of the door panel5mainly acts to change the hanging shape of the bellows portion, and thus, the durability of the grommet is improved. However, the grommet according to the third comparative example is configured such that there is a large difference in level between the opposite ends of the bellows portion, in order to ensure a sufficient length for the S-shaped bellows portion. Accordingly, compared with the grommet1of the present embodiment, device design is difficult in terms of attachment of the grommet-equipped wire to an automobile.

FIG. 10is a conceptual diagram illustrating paths of the axis7D of an S-shaped grommet according to the fourth comparative example. Note that, inFIG. 10, the axis7D in the closed state is shown with a solid line, and the axis7D in the open state is shown with a long dashed double-short dashed line. Moreover, for the purpose of indicating specific positions on the axis7D in the closed state, points P101and P102are shown as imaginary points. For the purpose of indicating specific positions on the axis7D in the open state, points P111and P112are shown as imaginary points.

InFIG. 10, the point P101indicates the position corresponding to an end portion of the axis7D on the second fixing portion20side in the closed state. The point P102indicates the position corresponding to the other end portion of the axis7D on the first fixing portion10side in the closed state. The point P111indicates the position corresponding to the end portion of the axis7D on the second fixing portion20side in the open state. The point P112indicates the position corresponding to the end portion of the axis7D on the first fixing portion10side in the open state. Since the vehicle panel6is an immovable portion as described above, the points P101and P111on the second fixing portion20side, which is fixed to the vehicle panel6, are at the same position.

As indicated by the points P101and P102, in the fourth comparative example, the bellows portion is bent into an S-shape in the closed state. Moreover, as indicated by the points P111and P112, in the fourth comparative example, the bellows portion is linearly stretched in the open state.

Note that, in the fourth comparative example, the grommet is configured such that the length of the bellows portion in the closed state is the same as the distance between the points P111and P112in the open state. Therefore, the stress exerted on the grommet in accordance with the opening and closing motion of the door panel5mainly acts to change the hanging shape of the bellows portion, and thus, the durability of the grommet is improved. However, the grommet according to the fourth comparative example is configured such that bent portions101and102of the bellows portion in the closed state largely protrude leftward and rightward, in order to ensure a sufficient length for the S-shaped bellows portion. Accordingly, in the grommet according to the fourth comparative example, it is difficult to control the behavior of the bellows portion that deforms during opening and closing of the door. Therefore, in the grommet1of the present embodiment, in which the state in which the bellows portion33hangs down due to the effect of gravity is maintained, compared with the grommet of the fourth comparative example, the bellows portion33is less likely to interfere with a nearby member, and the bellows portion33can be disposed in a space-saving manner.

Although the present invention has been described in detail above, the foregoing description is to be considered in all respects as illustrative, and the present invention is not limited to the foregoing description. It should be understood that innumerable variations that are not described herein can be envisaged without departing from the scope of the present invention.

LIST OF REFERENCE NUMERALS