JP2003109448A - Grommet - Google Patents

Abstract

(57) [Problem] To provide a grommet having improved waterproofness and dustproofness while securing sufficient assembling property. SOLUTION: A grommet 1 which is inserted into an opening 11 formed at an end 10B of a fixing member 10A from the opening side of the opening 11 and is attached is formed in a shape corresponding to the opening shape of the opening 11. A concave portion 5 formed on a side surface of the substrate portion 2 with a predetermined gap distance from a peripheral edge of the opening portion 11, and an inner surface of the concave portion 5 facing a peripheral edge of the opening portion 11. Over the regions 5A, 5B, 5C to be formed, projecting ridges 6A,
6B and 6C.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on an opening formed at an end of a fixing member, and allows the passage through the opening while protecting the wiring. The present invention relates to a grommet for preventing moisture and dust from entering from a part. 2. Description of the Related Art In recent years, vehicles such as passenger cars have not only improved their environmental protection, improved fuel efficiency, and improved running performance, but also improved their performance.
Various electronic technologies are used in order to improve the comfort and convenience as a vehicle, and various electronic components are mounted in order to realize this control. for that reason,
The electronic components mounted on the vehicle are not limited to the vicinity of the driver's seat in the passenger compartment, but also extend to the rear seats and doors. Along with this, wiring routes for interconnecting electronic components also tend to be complicated, and wirings such as harnesses are stretched over details in the vehicle body. In the above-described wiring path, depending on the arrangement of the electronic components, there is a case where it is necessary to penetrate a frame from inside the vehicle and wire it to another frame. In such a case, wiring such as a harness is exposed between the frames, and the exposed wiring may be broken due to sharp burrs left uncorrected in the through holes of the frame. was there. In addition, since the frame has a through hole, moisture and dust can easily penetrate through the through hole, and the equipment and parts protected by the frame are directly affected by the poor environment outside the frame. I will. Therefore, when a wiring is made to pass through by providing a through hole in a frame or the like, a grommet is generally used, and the grommet can protect the wiring while ensuring waterproof and dustproof properties. ing. That is, most of the grommets are made of an elastically deformable material such as rubber or synthetic resin, and are mostly formed in a circular hollow donut shape according to the shape of the through hole. A large number of grommets having a rectangular shape, an L-shaped cross section, or a bellows-like portion are also used depending on the installation location. The grommet is mounted in the through hole of the frame, and the wiring passes through the through hole through the grommet, thereby protecting the wiring such as the harness between the frames and maintaining the waterproof and dustproof properties of the frame. Like that. As one type of the above-mentioned grommets, as shown in FIG. 4, a grommet 21 used for connecting wiring to a storage box 10 which is a housing for storing electronic components.
It has been known. The grommet 21 is configured to be slid from the end 10B side into the opening 11 formed by cutting out the upper end 10B of the storage box 10 having an upper opening, and to connect the wiring to the opening 11. An insertion portion 23 is provided to seal the periphery of the wiring while passing through. Further, since the grommet 21 is fixed by a cover member (not shown) which is a lid of the storage box 10 after the grommet 21 is attached, it is unnecessary to use a special fixing bracket or operation for fixing the grommet 21. In other words, the grommet 21 has a curved front end in the insertion direction according to the shape of the opening 11, and a base end continuous with the front end is formed from the end 10B after assembly. , And has a rectangular shape that projects slightly in a predetermined manner. The storage box 1 is provided on the side of the grommet 21.
A recess 25 is provided which fits around the periphery of the opening 11 of the "0". Therefore, after mounting the grommet 21,
When the cover member is attached to the housing, the base end side of the grommet 21 is closed by the cover member, and the grommet 21 is prevented from sliding sideways in the direction opposite to the insertion direction and detaching from the opening 11. At the same time, the base end of the grommet 21 is pressed in the insertion direction by the cover member.
Side, the gap between the two disappears and the grommet 2
Waterproofing and dustproofing between the opening 1 and the opening 11 can be obtained. [0010] However, in the grommet 21 having the above structure, there is a problem that the waterproof portion is not stably secured at a specific portion, and the waterproof and dustproof properties are unstable. Was. That is, as shown in FIG. 4, the recess 25 of the grommet 21 and the peripheral edge of the opening 11 are in flat contact with each other, so that the entire surface of the contacted surface is uniform. It is not always possible to obtain a proper contact pressure. Therefore, a gap is formed at the contact portion of the concave portion 25 where the contact pressure is insufficient, and moisture and dust easily enter. Further, it is difficult to assemble the grommet 21 into the opening 11, and there is a disadvantage that the assembling workability is not good. That is, the three inner surfaces of the recess 25 are:
Since it is in contact with the periphery of the opening 11 and has a large contact area,
The resistance to sliding the grommet 21 in the insertion direction is large, and a large assembling force is required. In addition, depending on the opening shape of the opening 11, as the length of the grommet 21 in the insertion direction becomes longer or the grommet 21 becomes larger, the required assembling force increases, and the assembling work becomes more difficult. In particular, when the grommet 21 is slid and assembled, the recess 25 and the opening 1
Of the contact surfaces with one, the surfaces parallel to the insertion direction are displaced while contacting each other, and a large frictional force is generated, so that a tendency to increase the required assembling force is promoted. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a grommet capable of improving waterproofness and dustproofness while securing sufficient assembling property. Means for Solving the Problems and Action Therefor To achieve the above object, the invention according to claim 1 is characterized in that an opening formed at an end of a fixing member is provided on an opening side of the opening. In a grommet to be inserted and mounted from, a substrate portion formed in a shape corresponding to the opening shape of the opening portion, on a side surface of the substrate portion, providing a predetermined gap distance with the periphery of the opening portion,
A recess formed so as to face, and a ridge formed so as to protrude toward the periphery of the opening over a region where the inner surface of the recess faces the periphery of the opening. It is a grommet. Therefore, according to the present invention, the concave portion of the grommet is brought into contact with the opening through the ridge,
The contact area per unit area of the contact surface is increased due to a significant reduction in the area of contact between the recess and the opening, making it difficult for spots with insufficient contact pressure to occur. it can. Further, when the grommet is assembled to the opening, the grommet is in line contact with the opening through the ridge, and the area where the fitting portion of the grommet contacts the periphery of the opening is greatly increased. Is reduced. Therefore, the resistance when the grommet is slid and fitted into the opening is reduced, and the force required for assembling the grommet can be reduced. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a specific example of the grommet of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a front view thereof. In the example shown here, an example in which the grommet 1 is applied to a storage box 10 which is a housing for storing electronic components (not shown) will be described. The storage box 10 is formed in a box shape with an open upper side, and is configured such that the upper side opening is closed by a cover member (not shown) serving as a lid member. The grommet 1 is mounted in an opening 11 formed by cutting out an opening end 10B of a side wall 10A forming the storage box 10, and electronic components housed in the storage box 10 and external electronic components are provided. Protects a harness (not shown) in which wiring for electrically connecting the
0 waterproof and dustproof. The opening 11 has a downward semicircular shape,
The semicircular base is formed in a shape in which a rectangle having the same long side is joined, and the long non-joined side of the rectangle is formed to coincide with the opening end 10B in a straight line. That is, the grommet 1 is
Grommet main body 2 fixed by being attached to opening 11
And an insertion portion 3 for holding the wiring. The grommet 1 is formed using an elastically deformable and insulating material such as synthetic resin or rubber. The insertion portion 3 is formed in a pipe shape having a predetermined diameter, and is provided at a substantially center of the grommet main body 2 so as to protrude at a predetermined length in a direction orthogonal to the grommet main body 2. The through-hole 3a of the pipe portion penetrates the grommet main body 2 and reaches behind the grommet body. The through-hole 3a accommodates and holds the middle portion of the harness and the water-blocking agent in the through-hole 3a. Like that. Therefore, while the harness in which the wires are bundled is stably held by the insertion portion 3, while the harness is passed through the insertion portion 3,
This prevents moisture, dust, and the like from passing through the through hole 3a of the insertion portion 3. The grommet body 2 has an outer shape
A tip portion formed in a predetermined large shape similar to the opening shape of the opening portion 11 and formed into a semicircular shape curved in accordance with the shape on the lower side of the opening portion 11 and a rectangular shape continuous with the tip portion And a base end. The length of the base end in the vertical direction is slightly longer than the length of the straight portion of the opening 11.
After the grommet 1 is attached to the opening 11, the upper end of the base end of the grommet body 2 is closed by the opening end 10 </ b> A of the storage box 10.
Slightly project from the end face. Therefore, when the cover member is attached to the storage box 10 after the grommet 1 is assembled, the cover member presses the base end side of the grommet in the insertion direction, so that the pressing force is supplied to the distal end portion of the grommet body 2. I have. Note that the cover member (not shown) is
By closing the upper opening of 0, the upper end of the base end of the grommet main body 2 which has become a part of the upper opening is also closed, and waterproof and dustproof properties of the upper end of the base end are ensured. Further, on the side surface of the grommet main body 2, a fitting portion 4 that fits around the periphery of the opening 11 is provided. The width of the fitting portion 4 is formed sufficiently larger than the thickness of the side wall 10A of the storage box 10. At the substantially center of the fitting portion 4 in the width direction, a rectangular concave portion 5 having a predetermined width and depth is provided over the longitudinal direction of the side surface of the grommet body 2. That is, the recess 5 is provided with the side walls 5A,
For example, between the peripheral region of the opening 11 facing the opening 5B and the peripheral surface of the opening 11 facing the bottom surface 5C, for example,
A slight gap distance of 1 mm or less is provided. At a predetermined position in the recess 5, three protrusions 6A, 6B, 6C having a protrusion amount slightly larger than the gap distance are integrally provided. These ridges 6A, 6B, 6C are provided on the side walls 5A, 5
B and a portion protruding from the bottom surface 5C are formed in a semicircular shape. Therefore, even if the mounting posture of the grommet 1 is slightly inclined, the projections 6A, 6
Since the contact starts from the arc portions of B and 6C, the impact received by each of the ridges 6A, 6B and 6C is reduced, and
6B, 6C can be deformed flexibly, and the ridges 6A,
6B and 6C can be prevented from being damaged. Further, the ridges 6A and 6B are
Along the periphery of each side wall 5A, 5B,
A, 5B and the upper end surface of the base end of the grommet main body 2 are formed up to the point where they are joined, and provided at positions facing each other. The ridge 6C is provided on the bottom surface 5C of the concave portion 5,
Along the peripheral surface of the bottom 5C of the recess 5 at the center in the width direction, a portion is formed up to a point where the peripheral surface of the bottom 5C and the upper end surface of the base end of the grommet body 2 are joined. According to the above-described specific example, the grommet is brought into contact with the opening 11 through the ridges formed on the side wall surface and the bottom surface of the recess 5, and the area where the grommet recess 5 contacts the periphery of the opening 11 is greatly increased. Due to the reduction, the contact pressure per unit area of the contact surface is increased, and it is difficult to generate a portion where the contact pressure is insufficient. In addition, the dust resistance can be improved. Further, when the grommet 1 is assembled to the opening 11, a wide fitting portion 4 for maintaining the shape of the grommet 1 and a ridge which is elastically deformed and closely adheres to the periphery of the opening 11. With this configuration, the parts in charge of waterproofing and dustproofing are in line contact with the ridges 6A, 6B, and 6C, and the pressing force is supplied stably from the fitting portion 4. The dustproofness can be stably ensured, and the performance of the grommet 1 can be improved. Further, when the grommet 1 is assembled, the grommet 1 is in line contact with the opening 11 through the ridges 6A, 6B, 6C, and the fitting portion 4 of the grommet 1 is in contact with the opening 11. Since the area in contact with the peripheral edge is greatly reduced, the force that resists sliding the grommet 1 into the opening 11 is reduced, and the force required for assembling the grommet can be reduced, thereby improving the ease of assembly. it can. In addition, the reduction in the force required for assembling means that no extra load is applied to the grommet 1 itself during the assembling operation, and the shape of each part of the grommet 1 is maintained, and It is possible to exhibit the performance of. Further, when the grommet 1 is assembled into the opening 11, if the mounting posture of the grommet 1 is slightly inclined, the projections 6A, 6A provided on the side walls 5A, 5B and the bottom surface 5C of the concave portion 5 must be provided. The periphery of the grommet 1 comes into contact with the opening 11 via 6B and 6C, and the line contact is maintained, so that the posture can be easily corrected, and also in this respect, the assembling property can be improved. Even when the opening 11 is formed in a slightly different shape, the ridges can be elastically deformed and absorbed by the amount of the deformed portion, so that the shape error and dimensional accuracy of the opening 11 can be reduced. On the other hand, the range in which the recess 5 of the grommet 1 can be tolerated is enlarged, and the process of forming and correcting the opening 11 can be simplified, and the cost can be reduced. Further, by merely changing the protrusion amounts of the ridges 6A, 6B and 6C, the contact pressure caused by the ridges abutting and deforming on the periphery of the opening 11 can be increased or decreased. The setting of the contact pressure can be easily changed according to the surrounding environment in which the grommet is installed, and the degree of freedom in designing the grommet can be sufficiently ensured. Here, the relationship between the above specific example and the present invention will be briefly described. The grommet 1 corresponds to the grommet of the present invention, the grommet main body 2 corresponds to the substrate portion of the present invention, and the concave portion 5 corresponds to this. The side wall 10A corresponds to the recess of the invention.
Corresponds to the fixing member of the present invention, the end 10B corresponds to the end of the present invention, and the opening 11 corresponds to the opening of the present invention. In the above embodiment, each of the surfaces 5A, 5B and 5 facing the peripheral edge of the opening 11 of the grommet.
Although the ridges 6A, 6B, and 6C each having a semicircular cross-sectional shape are independently provided in C, the shape and the number are not limited to the above. For example, the ridges 6A, 6B, 6C are
One or more may be provided, or the cross-sectional shape may be formed in a square shape or a wedge shape, and these may be appropriately combined.
Also, ridges 6 provided on each surface 5A, 5B, 5C of the recess 5 are provided.
Although the protrusion amounts of A, 6B, and 6C are set to be the same, they may be different. Further, the ridges 6A, 6B, 6C are formed integrally in the recess 5 of the grommet body 2, but the invention is not limited to this.
You may comprise by another member. For example, ridges 6A, 6
A groove may be provided at the installation location of B, 6C, and a predetermined deformable linear member may be fitted into this groove. Furthermore, although the grommet 1 having the insertion portion 3 for passing the wiring alone has been described, a plurality of insertion portions 3 may be provided. The front shape of the grommet main body 2 is a shape in which one side of a rectangle is joined to a semicircular linear portion, but the shape is not limited to this. What is necessary is just a shape according to an opening shape. For example, the front shape of the grommet main body 2 may be provided with an elliptical curved portion or a shape corresponding to an opening shape having no linear portion. Furthermore, an example has been described in which the grommet 1 is assembled to the opening 11 formed downward from the opening end 10B of the storage box 10 opened upward, but the opening 11 may be oriented in any direction. Good. Although the grommet 1 is configured to close the entire opening 11, the grommet 1 may be partially closed. For example, a configuration may be adopted in which only a curved portion on the distal end side of the opening 11 is closed, and a portion where the remaining opening 11 is not closed is closed by another member. As described above, according to the present invention, the configuration in which the recess of the grommet is in contact with the opening through the ridge greatly reduces the area where the recess contacts the opening. As a result, the contact pressure per unit area of the contact surface is increased, and it is difficult to generate a portion where the contact pressure is insufficient, and a gap is prevented from being formed between the two. Can be achieved. When the grommet is attached to the opening, the grommet is in line contact with the opening through the ridge, and the area where the recess of the grommet contacts the periphery of the opening is greatly reduced. Therefore, the resistance when the grommet is slid and fitted into the opening is reduced, the force required for assembling the grommet can be reduced, and the assemblability of the grommet can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a specific example of a grommet according to the present invention. FIG. 2 is a plan view showing a state in which the grommet of this example is assembled to an opening. FIG. 3 is a front view showing a state where the grommet according to the present specific example is assembled to an opening. FIG. 4 is a perspective view showing a grommet of a conventional example. FIG. 5 is a plan view showing a grommet of a conventional example. [Explanation of reference numerals] 1. Grommet, 2. Grommet body, 5. Depression,
5A, 5B: side wall, 5C: bottom surface, 6A, 6B, 6C
... ridge, 10A ... side wall of the storage box, 10B ... end of the side wall, 11 ... opening.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Kazuo Enomoto             1-5-1, Kiba, Koto-ku, Tokyo Stock Exchange             Inside Fujikura F-term (reference) 3H023 AA02 AB01 AC06                 4E352 AA09 BB02 BB15 CC04 CC33                       CC34 CC56 DD06 DR03 DR13                       DR14 DR46 GG04 GG11                 5G333 AA07 AA09 AB16 AB22 AB28                       CB19 DA03 EA02                 5G363 AA01 CA01 CB08

Claims (1)

Claims: 1. An opening formed at an end of a fixing member,
In the grommet inserted and mounted from the opening side of the opening, a substrate formed in a shape corresponding to the opening shape of the opening, and a predetermined gap between a peripheral edge of the opening and a side surface of the substrate Providing a distance, a recess formed so as to face, and a region in which the inner surface of the recess faces the periphery of the opening,
A grommet comprising: a ridge formed so as to protrude toward a peripheral edge of the opening.