JP3034444B2 - Grommet and method of assembling it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof grommet which is fitted to a panel of a vehicle or the like and through which electric wires are inserted, and a method of assembling the grommet.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional grommet 1 of this kind (see Japanese Utility Model Laid-Open No. 24425/1990).

As shown in FIG. 1, when a wire harness W is inserted into a panel 3 defining an internal space Si and an external space So, a grommet 1 is fitted into a hole 5 formed in the panel 3, and W is inserted through the grommet 1 and drawn from the internal space Si to the external space So. The internal space Si is a space that requires waterproofing, for example, the interior of an automobile, and the external space So is a space that does not require waterproofing, such as an engine room. In this case, the panel 3 corresponds to a dash panel.

The grommet 1 includes a cylindrical grommet body 9 having an inner portion serving as an electric wire insertion portion 7 and an elastic swelling portion 11 swelling on the outer periphery of the grommet body. A groove 13 to be fitted into the hole 5 of the panel 3 is formed at the tip. According to the grommet 1,
Water or the like can be prevented from entering the internal space Si from the external space So through the hole 5.

The wire harness W is composed of a plurality of electric wires Wa.
Are bundled with a tape T, and water or oil may leak from a gap between the electric wires Wa. In this conventional example, the grommet main body 9 has a pipe portion 15 communicating with the electric wire insertion portion 7. A liquid hardening filler R is injected and filled into the electric wire insertion portion 7 from the tube portion 15. Thereby, the gap between the electric wires Wa inserted into the electric wire insertion portion 7 without winding the tape T is filled with the filler R, and a water stopping effect can be obtained in the electric wire insertion portion 7.

FIG. 7 shows another conventional grommet 21 (see Japanese Utility Model Laid-Open No. 1-66713).

The grommet 21 is, like the grommet 1 in FIG. 6, formed into a cylindrical grommet body 9 having an inner side as the wire insertion portion 7 and a bulge formed on the outer periphery of the grommet body 9 and formed with a groove 13 at the tip. Elastic swelling portion 11 having
The wire harness W extends from the wire insertion portion 7 to the elastic swelling portion 11.
Inside 11a is inserted. Inside 1 of elastic bulging part 11
Liquid curing filler R is filled in 1a to fill gaps between electric wires Wa, and the same waterproofness as grommet 1 in FIG. 6 can be obtained.

[0008]

However, in the conventional grommets 1 and 21, the gap between the grommet main body 9 and the wire harness W is completely closed at the end 9a of the grommet main body 9 on the side of the external space So. As a result, water invades from the gap 15 between the
There is a possibility that water may stay in the wire insertion portion 7 between the a and the filler R. In particular, water that has entered the gaps between the electric wires Wa is difficult to escape, and the pool of water causes the tape T wound around the electric wires Wa and the external space So of the grommet main body 9.
There is a fear that the durability of the end 9a on the side is reduced.

Further, in the grommet 21 shown in FIG. 7, since the filler R is filled in the inside 11a of the elastic bulging portion 11,
When the elastic bulging portion 11 is formed large, a large amount of the filler R
However, there was a disadvantage that it was necessary.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a grommet that can improve durability by suppressing the amount of filler to a small amount.

[0011]

According to a first aspect of the present invention, there is provided a grommet body having an electric wire insertion portion, and a hole formed in a panel formed on the outer periphery of the grommet body so as to divide the inner space and the outer space. An elastic bulging portion fitted to the portion,
A cylindrical filler accommodating portion projecting from an end of the grommet body on the outer space side and injecting a filler into the inside from an opening whose diameter is larger than the electric wire insertion portion; and a filler accommodating portion. And a cutout section defined by a thin-walled easy-to-break portion on the opening side of the grommet, wherein the cutout section of the grommet body is formed on the opening side of the filler accommodating section before the injection of the filler. It is characterized by being turned upside down to be located outside.

According to a second aspect of the present invention, there is provided a grommet main body having an electric wire insertion portion, and fitted to a hole of a panel formed to bulge around the outer periphery of the grommet main body and partition an internal space and an external space. An elastic bulging portion, a cylindrical filler housing portion projecting from an end of the grommet main body on the outer space side, and in which the filler is injected into the inside from an opening whose diameter is larger than the electric wire insertion portion. A method of assembling a grommet, comprising: a grommet provided with a cutout section defined by a thin-walled easy-to-break portion on an opening side of the filler accommodating section; In the initial state in which the wire insertion portion is expanded and the electric wire is inserted in an inverted state in which the opening side of the filler accommodating portion is turned back so as to be located outside the filler accommodating portion, the filler accommodating portion is returned in an initial state. Injecting filler into the compartment It is an feature.

[0013]

According to the first or second aspect of the present invention, when assembling the grommet to the electric wire, the electric wire insertion portion is expanded outward and the electric wire is inserted in the inverted state in which the opening side of the filler accommodating portion is turned over. After the insertion of the electric wire, the filler accommodating portion is returned from the inverted state to the initial state, the filler is injected into the filler accommodating portion from the opening to be cured, and after the curing, the cutout portion is separated from the filler accommodating portion.

As a result, on the opening side of the filler accommodating portion, the space between the hardened filler and the electric wire is completely closed, so that the intrusion of water into the grommet is completely prevented, and Generation can be prevented, and if the filler is filled between the electric wires in the filler accommodating portion, the gap between the electric wires is filled with the filler, so that a water stopping effect can be obtained.

Further, since the filler accommodating portion is provided separately from the elastic swelling portion, the dimension of the filler accommodating portion is set to the minimum irrespective of the size and shape of the elastic swelling portion, and the amount of the filler is reduced. It can be reduced to a small amount.

Further, since the cut portion is defined by the easily breakable portion, the operator can easily separate the cut portion from the filler accommodating portion along the easily breakable portion. And
Since the cutout is cut off after the filler is cured, the filler can be prevented from overflowing from the opening even if the injection amount of the filler slightly increases. From the opening, it is possible to prevent water from accumulating between the opening and the filler.

Further, before assembling the grommet to the electric wire, the opening side of the filler accommodating portion is turned upside down,
Since the filler accommodating portion and the grommet main body have a double structure, the filler accommodating portion is not easily crushed from the lateral direction before the grommet is assembled, and the filler accommodating portion is not plastically deformed. For this reason, when the filler is injected, the filler container is reliably returned to the initial set shape, so that uneven filling due to deformation of the filler container is less likely to occur, and stable waterproofness can be secured.

Also, when the electric wire insertion portion is expanded and the electric wire is inserted, the easily breakable portion is located outside the grommet main body, and the jig or wire for expanding the diameter does not interfere with the easily breakable portion. Further, it is possible to prevent the easily breakable portion from being broken before the injection of the filler.

[0019]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show a grommet in an inverted state according to this embodiment. FIG. 1A is a side view showing a partial cross section, and FIG. 1B is a cross sectional view taken along line AA of FIG. 2 is a side sectional view showing a use state of the grommet of FIG. 1, FIG. 3 is a side sectional view showing an initial state of the grommet of FIG. 1, and FIG. 4A is BB of FIG.
FIG. 5B is a cross-sectional view, FIG. 5B is an enlarged view of a portion C in FIG. 5A, and FIG. 5 is a side cross-sectional view showing a state in which a filler is injected into the grommet of FIG. The same parts as those in the related art are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 2 and 3, in the grommet 31 of this embodiment, the end 9a of the grommet main body 9 on the side of the outer space So is filled with a hollow, liquid curable filler R inside. In this case, a filler accommodating section 33 is provided. The filler accommodating portion 33 is formed so as to bulge from the end 9a of the grommet main body 9 toward the inner side of the external space So, and has an opening 35 at its tip. The opening 35 communicates with the electric wire insertion portion 7, and the outer diameter of the opening 35 is larger than the outer diameter of the electric wire insertion portion 7. Also, the inner peripheral surface 33a of the filler accommodating portion 33
Is smaller in diameter than the inner peripheral surface 11 a of the elastic bulging portion 11.

On the inner peripheral surface 33a of the filler accommodating portion 33, upper and lower ridges 37 for preventing the cured filler R from peeling off.
(37a, 37b) are protruded from left and right in two steps in the figure. The opening 35 side of the filler accommodating portion 33 has
A cut-out portion 39 is provided. The cutout portion 39 is divided into a thin-walled easy-to-break portion 41 and is formed integrally with the filler accommodating portion 33. The lower side of the easily breakable portion 41 substantially coincides with the upper end of the upper ridge 37a located on the opening 35 side.

As shown in FIG. 4B, the thickness of the easily breakable portion 41 is formed to be less than half the thickness of the filler accommodating portion 33 and the cutout portion 39 by the cutout groove 43. Thereby, the operator can cut the easily breakable portion 41 by the force of the fingertip and easily cut off the cutout portion 39 from the filler accommodating portion 33 along the easily breakable portion 41.

A bellows portion 47 is formed in a part of the grommet body 9, and a wire harness inserted through the wire insertion portion 7 is provided on an inner peripheral surface of the grommet body 9 closer to the end 9 a than the bellows cover portion 47. A projection 17 is provided on the outer periphery of W (see FIG. 3).

Further, the filler accommodating section 3 before the injection of the filler R is provided.
3 from the initial state shown in FIG.
As shown in (a), the cutout portion 39 is located outside the grommet body 9 and the inner peripheral surface 33a is exposed outside.
The grommet body 9 is folded back at the end 9a and inverted.
In the inverted state, the outer peripheral surface of the filler accommodating portion 33 abuts on the bellows portion 47, and as shown in FIG. 1B, the filler accommodating portion 33 and the grommet main body 9 have a double structure.

Next, the operation will be described.

Before assembling the grommet 31 to the wire harness W, the grommet 31 is
The grommet 3 is in an inverted state in which the grommet 3 is turned over, and the filler accommodating portion 33 and the grommet body 9 have a double structure.
When packing, transporting, or the like, by itself, the filler accommodating portion 33 is not easily crushed even if it receives a load from the lateral direction. For this reason, the filler accommodating portion 33 is less likely to be plastically deformed into an oval shape (indicated by a two-dot chain line in FIG. 4A), and when returning from the inverted state to the initial state, the filler accommodating portion 33 is in the initial state. It returns to the set shape of.

When assembling the grommet 31 to the wire harness W, as shown in FIG. 1, the grommet 31 is passed through the wire insertion portion 7 while the grommet 31 is in an inverted state. The electric wire insertion portion 7 is expanded, and the wire harness W is moved from the opening 35 of the filler accommodating portion 33 to the electric wire insertion portion 7.
And the wire harness W is held at a predetermined position, and then the filler container 33 is returned from the inverted state to the initial state (see FIG. 3).

When the diameter of the wire insertion portion 7 is increased, since the grommet 31 has the easily breakable portion 41 located outside the grommet main body 9, the easily breakable portion 41 is connected to the diameter increasing jig 51 and the wire harness W. There is no interference. That is, as shown in FIG.
When the wire insertion portion 7 is expanded by the above, the thin-walled easy-to-break portion 41 may be damaged by interfering with the diameter increasing jig 51, the wire harness W, and the like.
The interference does not occur, and it is possible to prevent the easily breakable portion 41 from being damaged by the interference with the jig 51 or the like.

After the grommet 31 is returned to the initial state, when the wire harness W is not sufficiently pressed by the projection 17, the inflow of the filler R into the electric wire insertion portion 7 is reliably prevented. As shown in the figure, a tape Ta is wound around the outer periphery of the end portion 9a side of the grommet body 9,
The wire harness W is tightened from outside the grommet main body 9 by the tape Ta.

Next, the grommet 31 held on the outer periphery of the wire harness W is erected so that the opening 35 of the filler accommodating portion 33 is located above, and the liquid curable liquid is transferred from the opening 35 to the filler accommodating portion 33. The filler R is injected. The filling of the filler R is performed when the upper surface of the filler R reaches the upper end of the ridge 37a.
That is, it stops when it reaches the lower side of the easily breakable portion 41. At this time, even if the injection amount of the filler R slightly increases, the filler R can be prevented from overflowing from the opening 35 by the cutout portion 39.

When the injected filler R has hardened, the cut-out portion 39 is separated from the filler accommodating portion 33 and the elastic swelling portion 1 is cut off.
The first groove 13 is fitted into the hole 5 of the panel 3.

At this time, since the cutout portion 39 is divided into the thin-walled easy-to-break portion 41, the operator grips both sides of the easy-to-break portion 41 with a fingertip and tears it with the force of the fingertip. The cutout 39 can be easily cut off along the break 41.

As shown in FIG. 2, when the grommet 31 is used in a state where the grommet 31 is fitted into the hole 5 of the panel 3, the filler accommodating portion 3
On the opening 35 side of No. 3, the space between the cured filler R and the tape T wound around the outer periphery of the wire harness W is completely closed. Thereby, the intrusion of water into the grommet 31 is completely prevented, and the occurrence of water pools inside the grommet 31 can be prevented.
In addition, the durability of the tape T can be improved.

In use, the cutting portion 39 (see FIG. 2)
Since water flows down from the portion where the filler R is cut off, water can be prevented from collecting from the opening 35 to the upper surface of the filler R, and a simple structure in which a cutout portion 39 is provided and the filler R is separated at the same time as curing is provided. And the work can further improve the durability of the grommet 31 and the tape T.

Further, a filler accommodating portion 33 is provided separately from the elastic swelling portion 11, and the peripheral surface 33 a of the filler accommodating portion 33 is smaller in diameter than the inner peripheral surface 11 a of the elastic swelling portion 11. The size and shape of the filler accommodating portion 33 can be set to the minimum irrespective of the size and shape of the protrusion portion 11, and the necessary amount of the filler R can be suppressed to a small amount.

Further, since the cutout portions 39 are provided at two opposing portions of the filler accommodating portion 33, two opposing tongue portions 45 remain after the cutout portion 39 is cut off. By wrapping a tape (not shown) from the outside of 45, grommet 31 and wire harness W can be securely fixed.

If the tape T is not wound around the wire harness W in the filler accommodating portion 33, the filler R can be filled between the electric wires Wa. Since the gap between them is filled with the filler R, a water stopping effect between the electric wires Wa can be obtained.

Further, before the grommet 31 is assembled to the wire harness W, the filler accommodating portion 33 is in an inverted state in which the opening 35 side is turned over, and the filler accommodating portion 33 and the grommet main body 9 have a double structure. Therefore, before the grommet 31 is assembled, the filler accommodating portion 33 is hardly crushed from the lateral direction, and the filler accommodating portion 33 is not plastically deformed.
For this reason, at the time of the injection of the filler R, the filler container 33 can be returned to the initial set shape, and the filler container 3
The uneven filling due to the deformation of No. 3 hardly occurs, and stable waterproofness can be secured.

When the wire insertion portion 7 is expanded and the wire harness W is inserted, the jig 51 for expanding the diameter is attached to the easily breakable portion 41.
Since the wire harness W and the like do not interfere with each other, it is possible to prevent the easily breakable portion 41 from being damaged before the injection of the filler R.

In this embodiment, since the cutout portions 39 are provided at two opposing positions of the filler accommodating portion 33, the cutout portions 39 are provided.
The two tongue pieces opposing each other remain after the cut-off, and the grommet and the wire harness can be securely fixed by winding a tape (not shown) from the outside of the tongue pieces.

The present invention is not limited to this,
For example, it may be provided so as to cut off the entire periphery of the end of the filler accommodating portion 33 on the opening 35 side.

[0043]

As described above, according to the first or second aspect of the present invention, the space between the cured filler and the electric wire is completely closed at the opening side of the filler accommodating portion. As a result, the intrusion of water into the grommet can be completely prevented to prevent the formation of water pools, and the durability of the grommet and the tape can be improved.

Since the filler accommodating portion is provided separately from the elastic swelling portion, the amount of the filler can be suppressed to a small amount regardless of the size and shape of the elastic swelling portion.

Since at least a part of the opening side of the filler accommodating portion is a cut portion, the filler does not overflow from the opening even when the injection amount is slightly increased.
The cut-off part can be easily separated from the filler storage part by the easily breakable part, and by cutting off the cut-out part, the water flows down from the part where the cut-out part is separated during use,
Water can be prevented from accumulating between the opening and the filler. Therefore, the durability of the grommet and the tape can be further improved by a simple structure and operation.

Further, before assembling the grommet to the electric wire, the filler accommodating portion and the grommet main body are in an inverted state in which the filler accommodating portion and the grommet main body have a double structure. Because it does not deform plastically,
At the time of filling the filler, the filler accommodating portion is reliably returned to the initial set shape, and uneven filling due to the deformation of the filler accommodating portion is less likely to occur, so that stable waterproofness can be secured.

Further, when the electric wire insertion portion is expanded and the electric wire is inserted, the jig for diameter expansion or the electric wire does not interfere with the easily breakable portion, so that the easily breakable portion is damaged before the injection of the filler. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a grommet in an inverted state according to an embodiment of the present invention, in which (a) is a side view showing a partial cross-section, and (b) is a cross-sectional view taken along AA of (a).

FIG. 2 is a side sectional view showing a use state of the grommet of FIG. 1;

FIG. 3 is a side sectional view showing an initial state of the grommet of FIG. 1;

4A is a cross-sectional view taken along line BB of FIG. 3, and FIG.
FIG.

FIG. 5 is a side sectional view showing a state where a filler is being injected into the grommet of FIG. 1;

FIG. 6 is a sectional view showing a conventional example.

FIG. 7 is a sectional view of a main part showing another conventional example.

[Explanation of symbols]

 Reference Signs List 3 Panel 5 Hole 7 Wire insertion part 9 Grommet main body 9a End on outer space side 11 Elastic bulging part 31 Grommet 33 Filler accommodating part 35 Opening 39 Cutout part 41 Fragile part R Filler Si Internal space So External space T Tape W Wire harness Wa Electric wire

Claims (2)

(57) [Claims] A grommet body having an electric wire insertion portion;
An elastic bulging portion that is formed by bulging out on the outer periphery of the grommet main body and is fitted into a hole of a panel that divides the internal space and the external space; and a projecting portion provided at an end of the grommet main body on the external space side, A cylindrical filler accommodating portion into which a filler is injected from an opening that is larger in diameter than the electric wire insertion portion, and a thin-walled easily breakable portion formed on the opening side of the filler accommodating portion. A grommet provided with a cutout portion, wherein an opening side of the filler accommodating portion before the injection of the filler is turned upside down so that the cutout portion is located outside the grommet main body. And grommet. A grommet body having an electric wire insertion portion;
An elastic bulging portion that is formed by bulging out on the outer periphery of the grommet main body and is fitted into a hole of a panel that divides the internal space and the external space; and a projecting portion provided at an end of the grommet main body on the external space side, A cylindrical filler accommodating portion into which a filler is injected from an opening that is larger in diameter than the electric wire insertion portion, and a thin-walled easily breakable portion formed on the opening side of the filler accommodating portion. A grommet assembling method comprising: attaching a grommet provided with a cut-out portion to an electric wire, wherein the cut-off portion is turned upside down on an opening side of the filler accommodating portion such that the cut-out portion is located outside the grommet body. A method for assembling a grommet, comprising: after expanding the electric wire insertion portion and inserting an electric wire, injecting a filler into the filler accommodating portion in an initial state in which the filler accommodating portion is returned.