JPH1163313A - Grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the restoring force of a grommet and the fitting force of an annular groove and a panel hole. SOLUTION: In a grommet with a harness insert-through cylinder 4 connected to one end 2a of a body 2 with an annular groove 3 and a through hole, through a peripheral wall 5, a bellows part 5a is provided at the periphery of the peripheral wall 5, and the recessed direction of a recessed part 7 of the bellows part 5a and the protruding direction of a protruding part 8 are arranged parallel with an insert direction so as to improve the bending ability of the peripheral wall 5. At least one reinforcing rib 6 is arranged in the recessed part 7 or the protruding part 8 so as to reinforce the restoring force of the peripheral wall 5. The position of the reinforcing rib 6 is radial or symmetric with respect to the insert-through cylinder 4. The bellows part 5a is provided two rounds or more. An inner cylinder is provided in the insert direction between the through-cylinder 4 and the bellows part 5a at the internal wall surface of the peripheral wall 5. A keep piece is protrusively provided toward the insert- through cylinder 4 from the other end side of the body 2 at the internal wall surface of the through hole, and the free end part energizes the inner cylinder so as to suppress the bending of the peripheral wall 5 by the keep piece. The bellows part 5a, the inner cylinder and the keep piece form a noise cut-off space, and air is closed into the space to prevent engine sound from penetrating into a cabin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the flexibility, waterproofness, soundproofing, and resilience of a grommet.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional grommet. Grommets as shown in the figure have been proposed to protect the wire harness routed from the engine room in the vehicle to the room and to prevent the transmission of noise from the engine room to the room.

In FIG. 7, a grommet 40 has a cylindrical grommet main body 41 and a wire harness insertion tube 43 connected to one side of the grommet main body 41 through a peripheral wall 47. An annular groove 44 is formed on the outer periphery of the grommet main body 41. To form. In order to improve the resilience of the insertion tube 43, a bellows portion 43a is formed on the peripheral wall 47 side of the insertion tube 43. Note that 45
Reference numeral denotes a panel wall of a vehicle or the like, and reference numeral 46 denotes panel holes formed in the panel wall.

When forming the grommet 40, the bellows 4
Since the direction of expansion and contraction of 3a is parallel to the direction of insertion of the wire harness, it is necessary to divide the molding die 50 into three as shown in FIG. That is, in order to form a penetrating portion of the grommet main body 41, as shown in the figure, the core molding die 53 is formed in a different direction from the female molding die 51 and the male molding die 52.
Need to move. Then, there is a problem that the number of grommets 40 that can be formed at one time is small. Reference numeral 54 denotes a division surface between the female molding die 51 and the male molding die 52.

In order to reduce the number of molding dies 50 to be used and increase the number of grommets 40 that can be molded at one time, a grommet 40 'as shown in FIG. 9 has been proposed. The grommet 40 ′ has an insertion tube 43 connected to one side of the grommet main body 41 via a peripheral wall 47, and forms an annular groove 44 on the outer periphery of the grommet main body 41. In order to improve the resilience of the insertion tube 43,
A bellows portion 47a that expands and contracts in a direction orthogonal to the wire harness insertion direction is formed on the peripheral wall 47.

However, when the grommet 40 ', through which the wire harness 42 is inserted, is pulled in a direction as shown in FIG. 10, the bellows portion 47a is extended in a direction different from the direction in which the grommet 47 can expand and contract. The surrounding wall 47
However, there was a drawback that it was in an extended state. When the peripheral wall 47 was in a stretched state, the grommet 40 'could not be securely arranged at the design location, and even if it was arranged, the appearance of the grommet 40' was poor.

As shown in FIG. 11, a bellows portion 47b of the peripheral wall 47 is formed at a position θ = 45 ° from the center axis of the insertion tube 43 (see Japanese Utility Model Laid-Open No. 61-172277) 40 ″. In this case, the molding of the grommet 40 ″ is simplified, but the resilience of the peripheral wall 47 is weak.

Conventionally, a grommet 60 as shown in FIG. 12 has also been proposed (Japanese Patent Laid-Open No. Hei 4-249817). In the grommet 60, a projection 63 is provided around the annular groove 62 of the grommet main body 61 to partition and form the first circumferential groove 64 and the second circumferential groove 65. Since it has the first peripheral groove 64 and the second peripheral groove 65, it can correspond to the shape of the panel hole 46 formed in the panel wall 45.

However, when the insertion tube 65 of the grommet 60 is bent after the wire harness (not shown) is inserted, the peripheral wall 66 is pulled, so that the panel hole 46 and the first circumferential groove 64 or the second circumferential groove 64 are bent. There is a problem that a gap (not shown) is formed between the groove and the groove 65, and the waterproof property is reduced.

[0010]

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to reliably improve the restoring force of the peripheral wall of the grommet body and the fitting force between the annular groove of the grommet body and the panel hole of the panel wall. The purpose is to provide a grommet.

[0011]

In order to achieve the above-mentioned object, the present invention provides a wire harness which is provided on one end of a grommet main body having an annular groove fitted into a panel hole and a through hole therein through a peripheral wall. In a grommet formed by connecting an insertion tube for insertion, a bellows portion is provided around the peripheral wall, and a concave direction of a concave portion of the bellows portion and a projecting direction of a convex portion are arranged in parallel with a wire harness insertion direction, The flexibility of the peripheral wall is improved (claim 1). At least one reinforcing rib is arranged in the concave portion or the convex portion to enhance the restoring force of the peripheral wall (claim 2).
The position of the reinforcing rib is radial and symmetric about the insertion tube (claim 3). The bellows part is provided at least two times around the circumference (claim 4). An inner tube is provided in the wire harness insertion direction between the insertion tube and the bellows portion on the inner wall surface of the peripheral wall, and a pressing piece is provided on the inner wall surface of the through hole from the other end of the grommet body in the insertion tube direction. In addition to the protrusion, the free end of the pressing piece is urged against the outer surface of the inner cylinder, and the pressing piece suppresses the bending of the peripheral wall. The bellows, inner cylinder,
A noise blocking space is defined by the holding piece and the holding piece, and the transmission of engine sound into the vehicle is prevented by confining air in the noise blocking space (claim 6).

According to the first aspect, the peripheral wall formed between one end of the grommet main body and the insertion tube surrounds the bellows portion, and the concave direction of the concave portion of the bellows portion and the projecting direction of the convex portion are the wire harness. Since it is parallel to the insertion direction, the peripheral wall is easily bent in the uneven direction of the bellows portion. Thus, when the insertion tube is bent, the peripheral wall is bent accordingly. According to claim 2, since at least one reinforcing rib is located in the concave portion or the convex portion of the bellows portion, the portion where the reinforcing rib is arranged is:
It becomes thicker than the part where the reinforcing rib is not arranged. Thereby, the restoring force of the portion where the reinforcing ribs are arranged is enhanced.

According to the third and fourth aspects, since the reinforcing ribs are radial and symmetric about the insertion tube, the reinforcing ribs are arranged on one surface of the peripheral wall in a straight line from the insertion tube. Thereby, the thickened portions where the reinforcing ribs are arranged are arranged in a row on one surface of the peripheral wall. According to the fifth aspect, the inner cylinder extends in the wire harness insertion direction from the position between the insertion cylinder and the bellows portion on the inner surface of the peripheral wall. The pressing piece protrudes from the other end of the grommet body in the direction of the insertion cylinder on the inner wall surface of the through hole of the grommet body. At the same time, the free end of the holding piece urges the outer surface of the inner cylinder. Thus, even when the peripheral wall is bent, the free end of the holding piece contacts the outer surface of the inner cylinder.

According to the sixth aspect, since the noise blocking space is defined by the bellows portion, the inner cylinder, and the holding piece, air is confined in the noise blocking space. This allows
When the engine sound enters the noise blocking space, the engine sound is confined in the air and does not pass through the surrounding wall.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of a grommet according to the present invention. It should be noted that the same components as those in the related art are given the same names, and detailed descriptions thereof are omitted. In FIG. 1, the grommet 1 has an insertion tube 4 for inserting a wire harness through a peripheral wall 5 on one side 2 a of a cylindrical grommet body 2, and an annular groove 3 is provided on the outer periphery of the grommet body 2. Then, a bellows portion 5a is formed on the peripheral wall 5, and a reinforcing rib 6 is arranged in a concave portion 7 of the bellows portion 5a.
The annular groove 3 is fitted into a panel hole 46 formed in a panel wall 45 of a vehicle or the like.

The bellows portion 5a is formed from the insertion tube 4 side of the peripheral wall 5 to the grommet main body 2 side. ). Recess 7
Is in parallel with the P direction, so that the peripheral wall 5 is more easily bent than before. Thereby, the work of fitting the grommet 1 into the panel hole 31 is performed smoothly. In addition, the concave portion 7 and the convex portion 8 are
It is also possible to provide two or more rounds.

As shown in FIGS. 1 and 2, two reinforcing ribs 6 are arranged in the concave portion 7, and
Radial and symmetric from a. The reinforcing ribs 6 in the concave portion 7 are formed from the bottom of the concave portion 7 to the same height as the apex of the convex portion 8. Although two reinforcing ribs 6 and 6 are arranged in the present embodiment, the number of reinforcing ribs 6 does not need to be limited to two, and at least one reinforcing rib 6 may be arranged. Further, the reinforcing ribs 6 can be provided in the convex portions 8 instead of the concave portions 7. In short, the surrounding wall 5
The reinforcing ribs 6 may be formed on one side of the above.

In this embodiment, the concave portion 7 or the convex portion 8 of the bellows portion 5a is provided around the peripheral wall 5 one by one, but as shown in FIG. Even in the case where two rounds are formed, the reinforcing ribs 6 can be provided in the same manner. Therefore, the same applies to the case of three or more turns. The case where the reinforcing rib 6 is arranged in the concave portion 7 of the bellows portion 5a will be described. Note that the same applies to the case where the reinforcing ribs 6 are provided in the projections 8.

When the reinforcing ribs 6 are arranged in the concave portions 7, the thick portion 10 and the thin portion 11 coexist in the bellows portion 5a as shown in FIG. The restoring force is strong, and the thin portion 11 is more flexible than the thick portion 10. Thereby, for example, as shown in FIG. 4, when the grommet 1 into which the wire harness 12 is inserted is bent, the grommet 1 is easily bent at the thin portion 11 of the peripheral wall 5, but is thickened in order to return the peripheral wall 5 to the original state. A restoring force is generated in the meat portion 10.
That is, the resilience of the peripheral wall 5 is improved as compared with the related art.

Further, the reinforcing rib 6 is connected to the center axis 4a of the insertion tube 4.
Are arranged radially and symmetrically with respect to each other, so that when the peripheral wall 5 is bent, the restoring force generated by the thick portion 10
Acts almost evenly around. Thereby, the appearance of the bent grommet 1 is improved as compared with the related art.

FIGS. 5 and 6 show a second embodiment of the grommet according to the present invention. The same components as those in the first embodiment are given the same names, and detailed descriptions are omitted. In FIG. 5, the grommet 20 has a grommet main body 22 having a side 22a connected to an insertion tube 24 for inserting a wire harness through a peripheral wall 25, and an annular groove 23 provided around the outer periphery of the grommet main body 22. 25, a bellows portion 25a is formed, and an inner cylinder 26 is provided around an inner wall surface 25b of the peripheral wall 25,
A pressing piece 30 that urges the inner cylinder 26 from the inner wall surface 29a of the through hole 29 of the grommet body 22 is provided in a protruding manner.

The inner cylinder 26 extends parallel to the wire harness insertion direction (P direction) from the insertion cylinder 24 side of the bellows portion 25 a on the inner wall surface 25 b of the peripheral wall 25, and extends from the other end 2 of the grommet main body 22.
Reaches 2b. The holding piece 30 is formed on the inner wall surface 29 a of the through hole 29 of the grommet body 22 at the other end 2 of the grommet body 22.
It protrudes from the 2b side. Inner wall surface 29a of through hole 29
The pressing piece 30 protruding from the inner cylinder 26 is urged so as to abut the free end 30a against the outer surface 26a of the inner cylinder 26 in a state inclined toward the insertion cylinder 24. The reinforcing ribs 6 are provided on the peripheral wall 25.
(See FIG. 1).

A noise blocking space 31 is defined inside the grommet main body 22 by the inner cylinder 26, the holding piece 30, and the bellows portion 25a of the peripheral wall 25. Noise shielding space 3
Since the air is confined in 1, the engine room sound is confined in the air in the noise cutoff space 31, and the vibration of the engine sound is not transmitted into the vehicle. Thereby, soundproofness is maintained.

After the grommet 20 into which the wire harness 32 has been inserted is fitted into the panel hole 46, for example, as shown in FIG. 6, when the peripheral wall 25 is bent to the left, as shown in FIG. Of the bellows 25a 'extends, and the bellows 25a on the left side contracts. Since the right pressing piece 30 'shifts to the upright state and the left pressing piece 30 shifts slightly to the sideways state, the free end 3 of the holding piece 30 (30') is moved.
0a (30a ') always contacts the outer surface 26a of the inner cylinder 26.

As a result, the right and left pressing pieces 30, 30 'are intended to return the bent peripheral wall 25 to the original state.
Presses the outer surface 26a of the inner cylinder 26. Therefore, the fitting force between the annular groove 23 of the grommet main body 22 and the panel hole 46 does not decrease. That is, even if the insertion tube 24 and the wire harness 32 are bent, the waterproofness between the grommet 20 and the panel wall 45 does not decrease.

[0026]

As described above, according to the first aspect, the bellows portion is formed on the peripheral wall between one end of the grommet main body and the insertion tube, and the concave direction of the concave portion of the bellows portion and the projection of the convex portion are formed. Since the direction is parallel to the insertion direction of the wire harness,
The peripheral wall is easily bent in the uneven direction of the bellows. Thus, when the insertion tube is bent, the peripheral wall is bent accordingly. Therefore, the work of fitting the grommet into the panel hole becomes smoother than in the past.

According to the second aspect, the portion in which at least one reinforcing rib is disposed in the concave portion or the convex portion of the bellows portion,
Since the wall is thicker than the portion where the reinforcing rib is not disposed, the restoring force of the portion where the reinforcing rib is disposed becomes stronger than the portion where the reinforcing rib is not disposed. Thereby, the portion where the reinforcing rib is not arranged can maintain the easiness of bending of the peripheral wall, and the portion where the reinforcing rib is arranged can enhance the restoring force. Therefore, it is easy to fit the grommet into the panel hole, and the fitting force between the annular groove and the panel hole does not decrease after the fitting.

According to the third and fourth aspects, the reinforcing ribs arranged radially and symmetrically with respect to the insertion tube are arranged on one surface of the peripheral wall in a straight line from the insertion tube. Are arranged in a row on one surface of the peripheral wall. Thereby, when the grommet is bent,
The restoring force exerted on the peripheral wall by the thickened portion acts substantially evenly on the peripheral wall, and the peripheral wall does not stretch out. Therefore, the appearance of the grommet at the time of bending becomes better than before, and the problem of the installation place where the grommet is arranged is solved.

According to the fifth aspect of the present invention, the grommet main body is formed on the inner wall surface of the through hole so as to urge the outer surface of the inner cylinder provided in the wire harness direction between the insertion tube and the bellows portion on the inner surface of the peripheral wall. Since the pressing piece protrudes from the other end side in the direction of the insertion cylinder, for example, even when the peripheral wall is bent, the pressing piece is displaced and the free end always contacts the outer surface of the inner cylinder. Thereby, the free end of the pressing piece suppresses the bending of the peripheral wall in an attempt to return the bent peripheral wall to the original state. Therefore,
After the grommet is fitted into the panel hole, the fitting force between the annular groove of the grommet body and the panel hole does not decrease, and the waterproofness between the annular groove and the panel hole is reliably maintained.

According to the sixth aspect, since the noise cutoff space defined by the bellows portion, the inner cylinder, and the holding piece in the grommet traps air therein, when the engine sound enters the noise cutoff space, The engine sound is confined in the air and cannot pass through the surrounding wall. As a result, the transmission of the engine sound through the grommet and into the vehicle is prevented. That is, the inside of the vehicle is soundproofed.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of a grommet according to the present invention.

FIG. 2 is a front view of FIG. 1 from which a wire harness is omitted.

FIG. 3 is a sectional view showing another example of the bellows portion of the grommet according to the present invention.

FIG. 4 is a sectional view showing a case where the grommet is fixed in an inclined state in FIG.

FIG. 5 is a sectional view showing a second embodiment of the grommet according to the present invention.

FIG. 6 is a cross-sectional view showing a state where the grommet is bent in FIG.

FIG. 7 is a side view showing a conventional example, showing a grommet having a parallel type expansion and contraction portion.

FIG. 8 is a view showing a molding die for molding a grommet.

FIG. 9 is a side view showing another conventional example, showing a grommet having a vertical expansion / contraction portion.

FIG. 10 is a side view showing a state where the harness of FIG. 7 is pulled.

FIG. 11 is a cross-sectional view showing another conventional example, showing a grommet having an inclined elastic portion.

FIG. 12 is a sectional view showing still another conventional example.

[Explanation of symbols]

 1, 20 Grommet 2, Grommet main body 5, 25 Peripheral wall 5a, 25a Bellows part 6 Reinforcement rib 7 Concave part 8 Convex part 26 Inner cylinder 30 Holding piece 31 Noise shielding space 46 Panel hole

Claims (6)

[Claims] 1. A grommet comprising a grommet main body having an annular groove fitted into a panel hole and a through hole therein and an insertion cylinder for inserting a wire harness through a peripheral wall. A grommet, wherein a bellows portion is provided around the bellows, and a concave direction of the concave portion of the bellows portion and a projecting direction of the convex portion are arranged in parallel with a wire harness insertion direction to improve the flexibility of the peripheral wall. 2. The grommet according to claim 1, wherein at least one reinforcing rib is disposed in the concave portion or the convex portion to enhance a restoring force of the peripheral wall. 3. The position of the reinforcing rib is radial and symmetric about the insertion tube.
Grommet described. 4. The grommet according to claim 1, wherein the bellows portion is provided at least two times. 5. An inner tube is provided on the inner wall surface of the peripheral wall between the insertion tube and the bellows portion in the wire harness insertion direction, and the insertion tube is provided on the inner wall surface of the through hole from the other end of the grommet body. 2. A grommet according to claim 1, wherein a pressing piece protrudes in the direction, and a free end of the pressing piece is urged against the outer surface of the inner cylinder so that the pressing piece suppresses bending of the peripheral wall. . 6. A noise cut-off space is defined by the bellows portion, the inner cylinder, and the holding piece, and transmission of engine sound into a vehicle is prevented by confining air in the noise cut-off space. The grommet according to claim 5.