JP2016207358A - Grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grommet that can increase sound-reducing effect by a sound insulation wall, and can exert high sound insulation performance without impairing moldability and releasability of a grommet body.SOLUTION: Inside a grommet body 10 which is formed of rubber or the like, an annular corrugated sound insulation wall 30 which partitions an internal space of the grommet body into two tightly closed air chambers S1, S2 is provided by connecting an outer peripheral end 31 to an inner periphery of large-diameter cylindrical part 11, and tightly attaching an inner peripheral end 32 to an outer periphery of an electric wire W. The grommet body 10 is separated into two divided grommet bodies 10A, 10B, and the bodies can be engaged with each other by engaging parts 21, 22.SELECTED DRAWING: Figure 1

Description

  For example, when wiring harnesses (electric wires) are routed through a vehicle body panel (such as a dash panel or a rear panel) that partitions the interior of a vehicle from the exterior of the vehicle, the protection of the panel penetration of the wire harness is provided. Therefore, the present invention relates to a grommet that is used by being fitted into a through-hole of a panel in order to ensure quietness and airtightness in a vehicle interior.

  This type of grommet is attached to a through-hole provided in a vehicle body panel that partitions the interior of a vehicle from the exterior of the vehicle to ensure airtightness and quietness in the interior of the vehicle. Recently, quietness in the passenger compartment has been strongly demanded, and grommets with improved sound insulation performance have been developed.

FIG. 4 shows a configuration example of a grommet in which a sound insulation wall is integrally provided in order to improve sound insulation performance (see, for example, Patent Document 1).
The grommet 101 includes a large-diameter cylindrical portion 111 having a panel engagement groove 112 that engages with an inner peripheral edge of the through hole Pa of the vehicle body panel P, and a first small-diameter cylindrical portion through which an electric wire (wire harness) W is inserted. 113 and the second small-diameter cylindrical portion 114, the thick wall 115 that couples the first small-diameter cylindrical portion 113 and the large-diameter cylindrical portion 111, the outer peripheral edge is coupled to the large-diameter cylindrical portion 111, and the inner peripheral edge is the second small-diameter cylindrical portion. 114, a thin tubular shielding wall 116 (funnel-shaped) coupled to 114, and an annular sound insulation wall 117 projecting on the inner periphery of the coupling shielding wall 116 near the large-diameter cylindrical portion 111. Have. The first small-diameter cylindrical portion 113 and the second small-diameter cylindrical portion 114 are formed so as to be tightly fitted to the outer periphery of the electric wire W finally.

  When this grommet 101 is attached to the through hole Pa of the panel P, the first small diameter cylindrical portion 113 and the electric wire W are wound and fixed with a tape, and the second small diameter cylindrical portion 114 and the electric wire W are also fixed with a tape. Thereby, two sealed spaces (air chambers) 118 and 119 partitioned by the sound insulation wall 117 are secured inside the grommet 101. Therefore, the presence of the sound insulating wall 117 and the sealed spaces 118 and 119 enhances the sound insulating property against the transmitted sound that attempts to pass through the grommet 101.

  By the way, since the sound insulation wall 117 in the conventional grommet 101 shown in FIG. 4 has only a flexible surface constituted by a flat flexible wall, the direction of the reflected sound reflected by the sound insulation wall 117 is substantially constant. The sound reduction effect due to the cancellation of sound cannot be expected so much.

  Therefore, it is conceivable to increase the thickness of the sound insulating wall 117 to inhibit the sound permeability through the sound insulating wall. However, when the thickness of the sound insulation wall 117 is increased, there is a problem that the releasability at the time of molding is deteriorated.

FIG. 5 is a schematic explanatory view for explaining a method of releasing the grommet 101 from the internal mold 140 after the grommet 101 of FIG. 4 is molded.
When releasing the molded grommet 101 from the internal mold 140, air N is blown from, for example, the second small-diameter cylindrical portion 114, which is an opening on one end side of the grommet 101, and the grommet 101 is removed by the force of air. The diameter is forcibly expanded as indicated by an arrow B1. Then, with the diameter expanded, the grommet 101 is released from the internal mold 140 by pulling the grommet 101 to one side in the axial direction indicated by the arrow B2.

  However, as shown in the example of FIG. 4, if the thickness of the sound insulating wall 117 integrally provided inside the grommet 101 is increased, the flexibility of the sound insulating wall 117 is reduced, and thus it is difficult to release the sound insulating wall 117. For example, the longer the length H1 of the sound insulation wall 117, the more difficult the mold release becomes, so the length of the sound insulation wall 117 is limited. However, if the length H1 of the sound insulation wall 117 is limited, the sound insulation performance may be affected.

JP 2005-324613 A Japanese Patent Laid-Open No. 11-122756

  As described above, in the conventional grommet 101 shown in FIG. 4, since the sound insulating wall 117 is only composed of a flexible wall having a flexible surface, the sound reducing effect by canceling out the sounds is not achieved. I couldn't expect much. In addition, if the wall thickness of the sound insulation wall 117 is increased to compensate for this, the mold releasability at the time of molding deteriorates, and if the length of the sound insulation wall is limited for the improvement, the sound insulation performance may be adversely affected. there were.

  The present invention has been made in view of the above-described circumstances, and the purpose thereof is to facilitate the molding and release of the grommet body, and to enhance the sound reduction effect by the sound insulation wall. The object is to provide a grommet capable of exhibiting high sound insulation performance.

In order to achieve the above-described object, the grommet according to the present invention is characterized by the following (1) to (7).
(1) A large-diameter cylindrical portion having a panel engaging portion that engages with the inner peripheral edge of the through hole of the panel on the outer periphery;
A first small-diameter cylindrical portion that is arranged to be spaced apart from the large-diameter cylindrical portion in the axial direction and closely fits to the outer periphery of the electric wire passed through the through hole;
A first connecting shielding wall that connects the large-diameter cylindrical portion and the first small-diameter cylindrical portion and defines a space between the large-diameter cylindrical portion and the first small-diameter cylindrical portion;
A sound insulation wall formed on the inner periphery of the first connection shielding wall in the vicinity of the large-diameter cylindrical portion, and a first member having
An engaging portion that engages with the large-diameter cylindrical portion of the first member;
A second small-diameter cylindrical portion that is arranged away from the engaging portion in the axial direction and closely fits to the outer periphery of the electric wire passed through the through hole;
A second member having a second connection shielding wall that connects the engagement portion and the second small-diameter cylindrical portion and defines a space between the engagement portion and the second small-diameter cylindrical portion;
In the grommet with
A grommet in which the engaging portion of the second member is engaged with the large-diameter cylindrical portion of the first member to integrate the first member and the second member.
(2) The grommet according to (1), wherein the sound insulation wall has a corrugated shape.
(3) The grommet according to (1) or (2), wherein an inner peripheral end of the sound insulation wall is in close contact with an outer periphery of the electric wire.
(4) The grommet according to (3), wherein an inner peripheral end of the sound insulation wall is formed in a convex curve shape toward the electric wire.
(5) The above-mentioned (1) to (1), wherein an S-shaped curved portion whose cross-sectional shape is curved in an S shape is provided on at least one of the first connection shielding wall and the second connection shielding wall. The grommet according to any one of (4).
(6) The sound insulation wall is disposed by fitting on an inner periphery of the first connection shielding wall,
With the sound insulation wall fitted to the first connection shielding wall, the engagement portion of the second member is engaged with the large-diameter cylindrical portion of the first member, and the first member and the second member The grommet according to any one of the above (1) to (5), wherein the grommet is integrated.
(7) The grommet according to any one of (1) to (6), wherein the panel engaging portion is disposed at a position away from the engaging portion in the axial direction.

According to the grommet configured as described above (1), the grommet is divided into the first member and the second member and integrated by being engaged with each other, so that the grommet has a sound insulation wall inside. Even in this case, it is possible to facilitate the formation and release of the grommet, and to increase the degree of design freedom for the shape of the sound insulating wall.
According to the grommet having the configuration (2), since the incident sound hitting the sound insulating wall having the waveform shape is reflected while being diffused, the cancellation of sound waves becomes active and the sound insulating property is improved.
According to the grommet having the configuration (3), the inner peripheral end of the sound insulation wall is in close contact with the electric wire without a gap, so that the effect of preventing sound leakage is enhanced.
According to the grommet having the configuration (4), since the inner peripheral end of the sound insulation wall is securely brought into close contact with the electric wire, the effect of preventing sound leakage is enhanced.
According to the grommet having the configuration (5), the vibration in the air chamber is absorbed by the S-shaped curved portion, so that a sound absorbing effect is obtained.
According to the grommet having the configuration (6), since the sound insulating wall can be manufactured as a separate body, the degree of freedom with respect to the shape and material of the sound insulating wall can be further increased.
According to the grommet having the configuration (7), the panel engaging portion of the grommet body is provided at a position away from the engaging portion of both split grommets main body in the axial direction, so that the fitting property to the panel is lowered. Can be prevented.

  According to the present invention, since the degree of freedom in designing the sound insulation wall is increased, the shape of the sound insulation wall can be optimized and the sound reduction effect by the sound insulation wall can be enhanced. Therefore, high sound insulation performance can be exhibited without impairing moldability and releasability.

  The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through a mode for carrying out the invention described below (hereinafter referred to as “embodiment”) with reference to the accompanying drawings. .

FIG. 1 is an exploded side sectional view of a grommet according to an embodiment of the present invention. FIG. 2 is a side sectional view showing a use state when the grommets are combined. FIG. 3 is an exploded perspective view of the grommet. FIG. 4 is a cross-sectional view showing a structural example of a conventional grommet with improved sound insulation. FIG. 5 is a schematic explanatory diagram for explaining a mold release method after forming the grommet of FIG. 4.

  Specific embodiments relating to the present invention will be described below with reference to the drawings.

  FIG. 1 is an exploded side sectional view of the grommet according to the present embodiment, FIG. 2 is a side sectional view showing a use state when the grommet is united, and FIG. 3 is an exploded perspective view of the grommet.

  As shown in FIGS. 1 and 2, the grommet 1 includes an electric wire (wire harness) W that passes through a through hole Pa provided in a vehicle body panel P that partitions the vehicle compartment side and the outdoor side of the automobile, and a through hole Pa of the panel P. The grommet main body 10 is integrally formed of an elastic material such as rubber or elastomer. An annular corrugated sound insulation wall 30 is formed integrally with the grommet body 10 inside the grommet body 10.

  The grommet body 10 includes a thick large-diameter cylindrical portion 11 having an annular panel engaging portion 12 that engages with the inner peripheral edge of the through hole Pa of the panel P on the outer periphery, and both sides of the large-diameter cylindrical portion 11 in the axial direction. Two small-diameter cylindrical portions 13 and 14 that are closely fitted to the outer periphery of the electric wire W that is passed through the through hole Pa, and the outer peripheral edge is coupled to the large-diameter cylindrical portion 11 and the inner peripheral edge is the small-diameter cylindrical portion. 13 and 14, and two tapered tubular thin shielding shielding walls 15 and 16 that shield the annular spaces between the large-diameter cylindrical portion 11 and the small-diameter cylindrical portions 13 and 14, respectively. ing.

  The corrugated sound insulating wall 30 is formed by forming a circular wall plate into a concentric corrugated shape, and the outer peripheral end 31 is on the inner periphery of the large-diameter cylindrical portion 11 or the inner periphery of the connection shielding wall 15 in the vicinity of the large-diameter cylindrical portion 11. The inner peripheral end 32 is coupled so as to be in close contact with the outer periphery of the electric wire W. The inner peripheral end 32 is in close contact with the outer periphery of the electric wire W passed through the small diameter cylindrical portions 13 and 14, so that the internal space of the grommet body 10 can be partitioned into two sealed air chambers S1 and S2. It has become. The waveform includes a bellows shape.

  The inner peripheral end 32 of the corrugated sound insulating wall 30 is formed in a convex curve shape toward the electric wire W, and is in close contact with the outer periphery of the electric wire W without a gap. In addition, S-shaped curved portions 15A and 16A whose cross-sectional shapes are curved in an S shape are provided on the connection shielding walls 15 and 16 around the small diameter cylindrical portions 13 and 14, respectively.

  Moreover, the grommet main body 10 is divided into two in the axial direction at the position of the large-diameter cylindrical portion 11 so as to respectively include a part of the large-diameter cylindrical portion 11. One split grommet main body (first member) 10A (the right side in FIG. 1) includes a large-diameter cylindrical half body 11A having a panel engaging portion 12 on the outer periphery, one connecting shielding wall 15 and one small-diameter cylinder. A portion 13 and a corrugated sound insulation wall 30 are included. The other (left side in FIG. 1) split grommet main body (second member) 10B includes a large-diameter cylindrical portion half body 11B, the other connecting shielding wall 16, and the other small-diameter cylindrical portion 14. Yes.

  Further, the mating portions of the two divided grommets main bodies 10A and 10B are engaged with each other when the two grommets main bodies 10A and 10B are combined, thereby engaging the two divided grommets main bodies 10A and 10B integrally (engaging recesses 21 and claws). An engaging projection 22) is provided. The panel engaging part 12 is separated from the position of this engaging part (engaging concave part 21, engaging convex part 22 with claw).

  When this grommet 1 is used, first, as shown in FIG. 2, both divided grommets main bodies 10 </ b> A and 10 </ b> B are combined to engage the engaging concave portion 21 and the engaging convex portion 22, thereby combining the two. In this state, the electric wire W is passed through the small diameter cylindrical portions 13 and 14. Further, the electric wire W is passed through the annular corrugated sound insulation wall 30. If it does so, the inner peripheral end 32 of the waveform sound insulation wall 30 will closely_contact | adhere to the outer periphery of the electric wire W, and the inside of the grommet main body 10 will be divided into two air chambers S1 and S2.

  Next, the small diameter cylindrical portions 13 and 14 at both ends of the grommet main body 10 and the electric wire W are fixed with a tape or a band, and then the grommet main body 10 is inserted into the through-hole Pa of the panel P. The panel engaging portion 12 on the outer periphery of the cylindrical portion 11 is engaged with the inner peripheral edge of the through hole Pa of the panel P. This completes the installation.

  In the grommet 1 having the above configuration, the incident sound hitting the corrugated sound insulation wall 30 is reflected while being diffused, so that the cancellation of sound waves becomes active and the sound insulation is improved.

  Moreover, since the inner peripheral end 32 of the waveform sound-insulating wall 30 is in a curved shape, it closely adheres to the electric wire W without a gap, so the sound leakage prevention effect is enhanced.

  In addition, since the S-shaped curved portions 15A and 16A are provided on the connecting shielding walls 15 and 16 around the small-diameter cylindrical portions 13 and 14, the air vibrations in the air chambers S1 and S2 are oscillated. 16A can be absorbed, and the sound insulation can be improved by the sound absorption effect.

  Further, when the corrugated sound insulating wall 30 is formed integrally with the grommet main body 10, compared to the case where the corrugated sound insulating wall 30 is manufactured separately and retrofitted inside the grommet main body 10, installation work is not required.

  Moreover, since the grommet body 10 is divided into two parts and integrated by engaging with each other, even if the corrugated sound insulation wall 30 is integrated with the divided grommet bodies 10A, 10B, the divided grommet bodies 10A, 10B It is possible to facilitate molding and mold release. Moreover, since the panel engaging part 12 of the grommet main body 10 is provided in the position away from the engaging parts 21 and 22 of both divided grommet main bodies 10A and 10B in the axial direction, the fitting property to the panel P is lowered. There is no fear.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimensions, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  For example, although the case where the waveform sound insulation wall 30 is provided in the divided grommet main body 10A on the side having the panel engaging portion 12 has been described in the above embodiment, it may be provided in the divided grommet main body 10B on the opposite side. In addition, both the divided grommet bodies 10A and 10B may be provided respectively. When two corrugated sound insulation walls 30 are arranged in this way, the internal space of the grommet body 10 can be partitioned into three air chambers, and a further sound insulation effect can be obtained.

  In the above embodiment, if the two air chambers S1 and S2 partitioned by the corrugated sound insulation wall 30 are filled with a sound absorbing material, the sound insulation performance can be further improved.

  Further, the corrugated sound insulation wall 30 may not be provided integrally with the grommet body 10. That is, the corrugated sound insulation wall 30 may be manufactured separately from the grommet body 10 and fixed later by fitting. In such a configuration, the material and shape of the corrugated sound insulation wall 30 can be freely set separately from the grommet body 10.

  For example, as the material of the corrugated sound insulation wall 30, a highly sound-insulating metal plate (for example, an iron plate or a lead plate), a metal or a laminated plate other than metal, a resin plate, a hard rubber plate, or the like can be employed. In addition, when fixing the waveform sound insulation wall 30 by retrofitting, if the electric wire W is inserted in the waveform sound insulation wall 30 in advance and it fits into the grommet main body 10, an assembly will become easy.

  Moreover, although the said embodiment demonstrated the case where the waveform sound insulation wall 30 whose cross-sectional shape is a waveform as shown in FIG. 1 was used as a sound insulation wall, the sound insulation wall may have another shape. For example, the sound insulation wall may have a jagged cross-sectional shape. Alternatively, the cross-sectional shape gradually increases from the outer peripheral end 31, swells most near the center, and gradually decreases toward the inner peripheral end 32, that is, between the outer peripheral end 31 and the inner peripheral end 32 in the annular wall plate. It may have a shape where the thickness of the position is the thickest and gradually decreases toward both ends. In this case, the thickness may be changed continuously or linearly.

Here, the features of the above-described grommets according to the present invention are summarized and listed in the following [1] to [7], respectively.
[1] A large-diameter cylindrical portion (11) having a panel engagement portion (12) engaged with the inner peripheral edge of the through hole (Pa) of the panel (P) on the outer periphery;
A first small-diameter cylindrical portion (small-diameter cylindrical portion 13) that is arranged to be spaced apart from the large-diameter cylindrical portion in the axial direction and is tightly fitted to the outer periphery of the electric wire (W) that is passed through the through hole;
A first connecting shielding wall (connecting shielding wall 15) that connects the large diameter cylindrical portion and the first small diameter cylindrical portion and defines a space between the large diameter cylindrical portion and the first small diameter cylindrical portion;
A first member (grommet body 10A) having a corrugated sound insulation wall (30) formed on the inner periphery of the first connection shielding wall in the vicinity of the large-diameter cylindrical portion;
An engaging portion (22) that engages with the large-diameter cylindrical portion of the first member;
A second small-diameter cylindrical portion (small-diameter cylindrical portion 14) that is disposed apart from the engaging portion in the axial direction and closely fits to the outer periphery of the electric wire passed through the through hole;
A second connecting shielding wall (connecting shielding wall 16) that connects the engaging portion and the second small diameter cylindrical portion and defines a space between the engaging portion and the second small diameter cylindrical portion; Two members (grommet body 10B);
In the grommet (1) with
A grommet in which the engaging portion of the second member is engaged with the large-diameter cylindrical portion of the first member to integrate the first member and the second member.
[2] The grommet according to the above [1], wherein the sound insulation wall has a corrugated shape.
[3] The grommet according to [1] or [2], wherein an inner peripheral end (32) of the sound insulation wall is in close contact with an outer periphery of the electric wire.
[4] The grommet according to [3], wherein an inner peripheral end of the sound insulation wall is formed in a convex curve shape toward the electric wire.
[5] An S-shaped curved portion (15A, 16A) having a S-shaped cross section is provided on at least one of the first connection shielding wall and the second connection shielding wall. The grommet according to any one of [1] to [4] above.
[6] The sound insulation wall is disposed by fitting on an inner periphery of the first connection shielding wall,
With the sound insulation wall fitted to the first connection shielding wall, the engagement portion of the second member is engaged with the large-diameter cylindrical portion of the first member, and the first member and the second member The grommet according to any one of the above [1] to [5], wherein the grommet is integrated.
[7] The grommet according to any one of [1] to [6], wherein the panel engagement portion is disposed at a position away from the engagement portion in the axial direction.

DESCRIPTION OF SYMBOLS 1 Grommet 10 Grommet main body 11 Large diameter cylinder part 12 Panel engagement part 13, 14 Small diameter cylinder part 15, 16 Connection shielding wall 15A, 16A S-shaped curved part 21 Engagement recessed part (engagement part)
22 Engaging convex part (engaging part)
30 Waveform sound insulation wall 31 Outer peripheral edge 32 Inner peripheral edge P Panel Pa Through hole W Electric wire (wire harness)
S1, S2 Air chamber

Claims (7)

A large-diameter cylindrical portion provided on the outer periphery with a panel engaging portion that engages with the inner peripheral edge of the through hole of the panel;
A first small-diameter cylindrical portion that is arranged to be spaced apart from the large-diameter cylindrical portion in the axial direction and closely fits to the outer periphery of the electric wire passed through the through hole;
A first connecting shielding wall that connects the large-diameter cylindrical portion and the first small-diameter cylindrical portion and defines a space between the large-diameter cylindrical portion and the first small-diameter cylindrical portion;
A sound insulation wall formed on the inner periphery of the first connection shielding wall in the vicinity of the large-diameter cylindrical portion, and a first member having
An engaging portion that engages with the large-diameter cylindrical portion of the first member;
A second small-diameter cylindrical portion that is arranged away from the engaging portion in the axial direction and closely fits to the outer periphery of the electric wire passed through the through hole;
A second member having a second connection shielding wall that connects the engagement portion and the second small-diameter cylindrical portion and defines a space between the engagement portion and the second small-diameter cylindrical portion;
In the grommet with
A grommet in which the engaging portion of the second member is engaged with the large-diameter cylindrical portion of the first member to integrate the first member and the second member.   The grommet according to claim 1, wherein the sound insulation wall has a corrugated shape.   The grommet according to claim 1, wherein an inner peripheral end of the sound insulation wall is in close contact with an outer periphery of the electric wire.   The grommet according to claim 3, wherein an inner peripheral end of the sound insulation wall is formed in a convex curve shape toward the electric wire.   5. The S-shaped curved portion whose cross-sectional shape is curved in an S shape is provided on at least one of the first connection shielding wall and the second connection shielding wall. The grommet according to item 1. The sound insulation wall is arranged by fitting on the inner periphery of the first connection shielding wall,
With the sound insulation wall fitted to the first connection shielding wall, the engagement portion of the second member is engaged with the large-diameter cylindrical portion of the first member, and the first member and the second member The grommet according to claim 1, wherein the grommet is integrated.   The grommet according to any one of claims 1 to 6, wherein the panel engaging portion is disposed at a position away from the engaging portion in the axial direction.

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