JP6446525B1 - Wiring grommet - Google Patents

Abstract

An object of the present invention is to provide a wiring grommet having good workability during assembly and having a high dustproof effect. A wiring grommet 1 for inserting and locking an electric wire 3 having a receiving portion 6 and a lid portion 7 which are divided by a plane parallel to the insertion direction of the electric wire 3, which are overlapped. In some cases, it is provided with a clamping part, a dustproof recess 19 and a partitioning ridge 17 that are closely attached to the electric wire 3. Moreover, it has the fitting rib 9 and the primary shielding rib 10 in the outer periphery, and fits the fitting rib 9 to the fitting recess 12 of the chassis 2 and the outer surface of the chassis outside the fitting recess 12 with the primary shielding rib 10. Abut. [Selection] Figure 1

Description

  The present invention relates to a wiring grommet.

  In a structure in which various devices and wiring boards that control these devices are connected by electric wires, if the wiring substrate is housed in the case, the electric wires drawn from the case may be damaged at the corners of the outlets. Since dust, water, oil mist, or the like enters from the gap between the electric wire and the case, a wiring grommet is attached to the electric wire outlet of the case.

  The “waterproof structure of the electrical junction box” in Patent Document 1 is a structure in which a notch is provided in the case of the electrical junction box composed of a case and a cover, and an elastic grommet (wiring grommet) is attached to the notch and sandwiched by the cover. The notch has a groove-shaped guide portion, the grommet has a flange portion that fits into the guide portion, and a guide portion that fits the upper flange portion of the grommet is also provided on the cover side. The main point is to improve the waterproof function by configuring the part and flange part in the inner and outer directions.

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Patent document 2 “Mounting structure of waterproof grommet and electrical junction box equipped with the same” has an elastic waterproof grommet (wiring grommet) fitted into the opening of the lower cover (case), and the upper cover is joined thereto. The mounting structure is such that the grommet is mounted, and an extension rib that cuts into the lower cover side is provided in the upper cover. When the upper cover is joined, the elastic waterproof grommet is pressed with the extension rib and deformed to the upper cover side. The main point is to improve the waterproof performance on the upper cover side by crimping.
These are intended for waterproofing but serve as a reference for the sealing performance of the wiring grommet.

On the other hand, there is a type of wiring grommet that separates and penetrates a plurality of electric wires as described in Patent Document 3 and Patent Document 4.
However, the work of passing the wires one by one through the plurality of wire insertion holes formed in the grommet is inefficient and the amount of protrusion of the inserted wires varies, so when fixing the tip of the wire to the wiring board There is a problem that adjustment work such as cutting the electric wires is necessary. In this regard, the “branch connector” in the cited document 5 is not a wiring grommet, but a pair of split housings that can be opened and closed, and a cable and a relay contact are arranged in one split housing with the split housing open. Then, by closing the other divided housing, the relay contact is accommodated inside and the cable can be inserted into the connector.

Japanese Patent No. 3914399 Japanese Patent No. 4490784 Japanese Patent No. 5835057 Japanese Patent No. 5521777 JP 2017-117703 A

  Since the grommets described in Patent Documents 1 and 2 have elasticity, they easily adhere to the opening of the case, etc., and easily improve the waterproof performance and dust proof performance. It is conceivable that water and dust move little by little because the contact with the part disappears. For this reason, a hard resin grommet with little elasticity may be used in such a location.

However, hard grommet with little elasticity is not well adapted to the opening, and is not well adapted to the electric wire and its insertion point, and it is difficult to prevent dust and mist from entering with the structure described in the patent literature.
Accordingly, the present invention provides a grommet for wiring that has a high dustproof effect and good workability at the time of assembly, and particularly has a high dustproof effect in the case of a grommet using a hard material such as resin having low elasticity. Let it be an issue.

In wiring grommets (hereinafter simply referred to as grommets) for inserting and locking electric wires, the outer periphery of the grommets is fitted with a fitting rib along the surface perpendicular to the direction of electric wire insertion and the primary shielding parallel to the gap. Provide ribs.
The fitting rib and the primary shielding rib are provided so as to protrude outward from the grommet.
The fitting rib is fitted into the fitting groove of the chassis to which the grommet is attached, and the primary shielding rib is brought into contact with the outer surface of the chassis that is on the outer side in the electric wire insertion direction than the fitting groove.

The grommet is configured as follows.
It divides | segments into a receiving part and a cover part along the surface parallel to the insertion direction of an electric wire.
And when a receiving part and a cover part are superposed | polymerized integrally, it shall have a clamping part, a dustproof dent, and a partition protrusion on the inside.
The clamping part is composed of a receiving side clamping part provided inside the receiving part and a lid side clamping part provided inside the lid part.

The receiving side holding part has a plurality of electric wire receiving grooves arranged at intervals in a direction intersecting the electric wire insertion direction, and the lid side holding part is arranged at an interval in the direction intersecting with the electric wire insertion direction. It shall have a plurality of electric wire pushing grooves.
The wire receiving groove and the wire pushing groove are opposed to each other when the receiving portion and the lid portion are integrated together to hold the electric wire therebetween.

A dustproof recess is formed across the wire push groove at the intermediate portion of the lid-side clamping portion in the wire insertion direction, and the partition ridge is formed along the wire insertion direction between the wire receiving grooves, and the diameter of the wire. Are arranged at equal intervals.
The partition ridge is a comb-like ridge, and enters the dust-proof recess when the receiving portion and the lid portion are superposed together. Moreover, the partition ridges at both ends in the direction orthogonal to the insertion direction of the electric wires abut on the inner wall surfaces on both sides in the direction orthogonal to the electric wire insertion direction of the dust proof recess.

A support portion may be provided on the receiving portion so as to protrude forward in the insertion direction of the electric wire.
Moreover, the said support part may provide the mark which shows the protrusion position from the said clamping part in the grommet of the connector attached to the front-end | tip of an electric wire.

The grommet provided with the fitting rib and the primary shielding rib prevents double entry of dust. In particular, since the primary shielding rib prevents the dust from reaching the fitting recess directly, the dustproof effect is high.
Since the grommet is divided into the receiving part and the cover part, it is possible to incorporate a wire with a connector attached in advance, and to close the receiving member and the cover member so that the wire can be easily inserted into the grommet. Work efficiency.

  Since the dust-proof trap is formed by the clamping portion and the dust-proof recesses and partitioning ridges arranged perpendicular to the insertion direction of the electric wire, even if dust may enter the grommet from the place where the electric wire is inserted into the grommet The dust trap prevents the grommet from reaching the inside of the chassis containing the wiring board.

  This function is exhibited even when the grommet is molded from a hard synthetic resin with little elasticity. For example, the grommet is installed in the chassis of an electronic device (for example, installed in an automobile or heavy machinery) in an environment where vibrations mixed with impact are transmitted. High dustproof performance can be maintained even in a structure in which an electric wire to be connected to a wiring board stored in is incorporated using a grommet.

The top view which attached the grommet to the chassis of the apparatus (Example 1). The front view which showed the positional relationship of a wiring board, a contact, and a grommet. The perspective view which expand | deploys and shows a grommet. The perspective view seen from the upper part of a grommet. The perspective view seen from the downward direction of a grommet. The schematic diagram extracted in order to demonstrate a clamping part. The front view which showed the positional relationship of a wiring board, a contact, and a grommet (Example 2). The perspective view seen from the upper part of a grommet (Example 2).

A wiring grommet 1 according to the present embodiment (FIG. 1, hereinafter simply referred to as a grommet) is used in an electronic apparatus including a chassis 2.
[Example 1]
1 to 6 relate to the first embodiment.
The grommet 1 is attached to the chassis 2, and the electric wires 3 (five in the embodiment) are penetrated from the outside into the chassis 2 and connected to the wiring board 4 arranged inside the chassis 2 (FIG. 2). For the connection, a connector 5 attached to the front end of the electric wire 3 is used. In this embodiment, the upper surface of the grommet 1 and the chassis are flush with each other, and the inner surface of the chassis 2 is sealed with a single cover plate (not shown) that shields the upper surface.
For convenience of explanation, the connector 5 side in the insertion direction of the wire 3 penetrating the grommet 1 is “front”, the direction orthogonal to the insertion direction of the wire 3 is “left-right direction”, and the upper surface side of the wiring board 4 is upward. The lower surface side is the lower side.

As shown in FIG. 3, the grommet 1 includes a receiving portion 6 and a lid portion 7 that are divided vertically along a plane parallel to the insertion direction of the electric wire 3. In this embodiment, the material of the grommet 1 is nylon. Nylon is a hard synthetic resin that has a good balance of low-temperature toughness, heat resistance, and weather resistance, excellent heat aging resistance, and a tensile strength that is unlikely to decrease with increasing temperature.
The receiving portion 6 of the grommet 1 has a semi-cylindrical shape, and the lid portion 7 has a box shape, and these are connected by a bendable hinge portion 8.
When the receiving portion 6 and the lid portion 7 are superposed, as shown in FIGS. 4 and 5, an integrated grommet 1 having a box shape at the top and a semi-cylindrical shape at the bottom is obtained.

  A fitting rib 9 and a primary shielding rib 10 are provided on the outer periphery of the grommet 1 except for the upper surface along a surface orthogonal to the insertion direction of the electric wire 3. The fitting rib 9 and the primary shielding rib 10 are arranged in parallel with a space in the front-rear direction, and are formed to protrude outward from the basic outer surface of the grommet 1.

The fitting rib 9 is fitted to a fitting groove 12 formed on the inner surface of the grommet mounting opening 11 (FIG. 1) of the chassis 2, and the primary shielding rib 10 is rearward of the fitting groove 12. It abuts on the outer surface 13 of the chassis 2.
The opening 11 for attaching the grommet extends over the receiving portion 6 and the lid portion 7, and the shape of the inner surface matches the basic cross-sectional shape of the grommet 1.

  The interval between the fitting rib 9 and the primary shielding rib 10 is designed to be slightly smaller than the interval between the fitting recess 12 and the outer surface of the chassis 2, and the primary shielding rib 10 is in close contact with the outer surface. Further, in this embodiment, the fitting rib 9 is provided with a concave groove in the middle part in the front-rear direction and has a U-shaped cross section, thereby improving the adhesion to the fitting concave strip 12.

  According to this structure, dust that may enter from the outside of the chassis 2 to the inside through the periphery of the grommet 1 is prevented from entering by the long intrusion path formed by the fitting rib 9 and the fitting groove 12. Since the primary shielding rib prevents the dust from directly reaching the fitting groove before that, the dust itself reaching the fitting groove 12 is reduced and the dustproof effect is high.

The receiving part 6 and the lid part 7 will be described in detail (FIG. 3).
The receiving part 6 includes a receiving side clamping part 14 on the inner side, and the lid part 7 includes a lid side clamping part 15 on the inner side.
The receiving-side clamping unit 14 and the lid-side clamping unit 15 are portions that face and fix the electric wire 3 when the receiving unit 6 and the lid unit 7 are overlapped, and are joined to each other when they are overlapped. a, b. The joint surface is indicated by a chain line.

  The joint surfaces a and b may belong to the same surface, and may be surfaces having different heights as long as they are parallel. Further, the joint surfaces a and b are penetrated in the left-right direction in both the receiving portion 6 and the lid portion 7, and the outer flesh portion that divides the inside of the grommet 1 Are also formed on the same surface as the joint surfaces a and b. In short, when the lid portion 7 is overlapped with the receiving portion 6, the electric wire 3 is securely clamped, and at the same time, no gap is formed at the joint portion between the receiving portion 6 and the lid portion 7.

The receiving side clamping part 14 (FIG. 6) is arrange | positioned in the left-right direction inside the receiving part 6, forms five wire receiving grooves 16 at equal intervals on the joint surfaces a and b, and between the wire receiving grooves 16 and both sides. The partition protrusions 17 are formed so as to protrude upward on the joint surfaces a and b of the outer wall portion.
The electric wire receiving groove 16 has a diameter corresponding to the diameter of the electric wire 3 and penetrates in the front-rear direction. The partition ridges 17 are comb-like shapes that are long in the front-rear direction and thin in the left-right direction, and the distance between the partition ridges 17 is approximately equal to the diameter of the electric wire 3 at the base. The base in the front-rear direction of the partition projection 17 is smaller than the front-rear dimension of the joint surfaces a and b, and is substantially equal to the front-rear dimension (the width of the dust-proof recess 19) of a dust-proof recess 19 described later. For this reason, the joint surfaces a and b remain on both the front and rear sides of the base.
That is, the receiving side clamping portion 14 has the wire receiving grooves 16 at equal intervals, and the joining surfaces a and b appear on both front and rear sides with the partitioning ridges 17 aligned in the left-right direction between them as the center in the front-rear direction. It is a form.

The lid-side clamping unit 15 (FIG. 6) is disposed in the left-right direction inside the lid unit 7.
Five wire pushing grooves 18 are formed at equal intervals on the joint surfaces a and b of the lid-side clamping portion 15, and the dustproof recess 19 is formed at the center in the front-rear direction of the joint surfaces a and b. The dust-proof recesses 19 are formed on the left and right sides, and are arranged to block all of the wire pushing grooves 18 and have walls 20 at both ends in the left-right direction. The wall 20 is a part of the outline of the grommet 1.
That is, the lid-side clamping portion 15 has a configuration in which the wire pressing grooves 18 are equally spaced and the joint surfaces a and b appear on both front and rear sides with the dust-proof recess 19 at the center in the front-rear direction.

In FIG. 3, the receiving portion 6 includes a hook 23 and engages with the hook receiving 24 of the lid portion 7.
Further, the partition ridges 17a located at the left and right end portions of the partition ridge 17 in the receiving portion 6 are arranged such that when the lid portion 7 is superposed, the outer surface thereof is the left and right end portions of the dustproof recess 19 on the lid portion 7 side. It is arranged at a position in contact with the inner surface of the wall 20.
A positioning projection 25 is formed to protrude outward from the surface of the partitioning ridge 17a at the rear part of the partitioning ridge 17a located at the left and right ends, while the positioning recess 26 is located at a corresponding position of the outer shell of the lid part 7. When the lid portion 7 is superposed on the receiving portion 6, the front and rear positions of the receiving portion 6 and the lid portion 7 are determined by these, and the lid with respect to the receiving portion 6 is formed by the partition protrusions 17 a located at the left and right ends. The left and right positions of the part 7 are determined.

With the above structure, when the receiving part and the cover part are integrally superposed, the grommet 1 has a holding part, a dustproof recess 19 and a partitioning ridge 17 by the receiving side holding part 14 and the cover side holding part 15 inside. It will be a thing.
The grommet 1 is used as follows to connect the electric wire 3 to the wiring board 4 stored in the chassis 2 via the connector 5.
A connector 5 is attached in advance to the front end of the electric wire 3.

The grommet 1 is in a developed state (FIG. 3), and the electric wire 3 is arranged in the receiving portion 6 with the connector 5 being in front (FIG. 6). Each of the five electric wires 3 is arranged in the electric wire receiving groove 16 between the partitioning ridges 17. Each electric wire 3 is attached to each electric wire receiving groove 16 in a state of being sandwiched between the partition ridges 17.
Next, the lid portion 7 is superposed on the receiving portion 6. The receiving portion 6 and the lid portion 7 are in a state where the positioning projection 25 and the positioning recess 26 are fitted, and the hook 23 is engaged with the hook receiving 24 to be accurately and reliably closed.

Then, inside the grommet 1, the receiving side holding part 14 of the receiving part 6 and the lid side holding part 15 of the lid part 7 are superposed, and the receiving surface side joining surfaces a and b and the lid side joining surface a, b opposes and adheres, and the electric wire 3 in the electric wire receiving groove 16 is sandwiched by the electric wire pushing groove 18 on the lid side. In addition, the partition projection 17 of the receiving portion 6 enters the dustproof recess 19 of the lid portion 7. The partition ridges 17 a located at the left and right ends are in close contact with the inner surface of the wall 20 at the left and right ends of the dust-proof recess 19. Each partitioning ridge 17 enters between the electric wires 3 at 19 positions of the dust proof recesses, and keeps the electric wires 3 separated.
Next, the connector 5 is arranged on the lower surface side of the wiring board 4, and the connector pin 27 is inserted into a connection hole provided in the printed wiring on the wiring board 4 and fixed by soldering (FIG. 2).

In this way, the grommet 1 with the electric wire 3 inserted and the wiring board 4 and the connector 5 temporarily attached is mounted on the chassis 2.
After the wiring board 4 is stored in the chassis 2, the fitting rib 9 is fitted into the fitting recess 12 provided on the inner surface of the grommet mounting opening 11 of the chassis 2 as described above. The primary shielding rib 10 is applied to the outer surface 13 of the outer surface 13. This loading operation can be easily performed because the position of each part is predetermined.

  According to the above specific structure, the dust to enter the inside of the grommet 1 through the place where the electric wire 3 is inserted into the grommet 1 is received inside the grommet 1 and the receiving side holding part 14 and the lid side holding part 15. Intrusion is prevented by the clamping part that presses and clamps the electric wire 3. Even so, the dust that is about to enter the dust reaches the dust-proof depression 19 and is prevented from entering further. That is, the sandwiching portion including the receiving-side sandwiching portion 14 and the lid-side sandwiching portion 15, the dust-proof recess 19, and the partition protrusion 17 serve as a dust-proof trap for dust moving forward in the grommet 1.

By this dustproof trap, a path reaching the inside of the chassis 2 via the inside of the grommet 1, that is, an internal intrusion path is blocked, and dust is prevented from entering the inside of the chassis 2.
Further, the dust intrusion from the grommet mounting opening 11 of the grommet 1 and the chassis 2, that is, the external entry path of the dust is also blocked by a dust trap by the fitting ribs 9 and the primary shielding ribs 10, It is prevented from entering inside.
The left and right end portions of the dust-proof recess 19 are blocked from the outside by the partition ridges 17 at the left and right ends of the receiving portion 6 being in close contact with the inner surfaces of the right and left end walls 20 of the dust-proof recess 19.

[Example 2]
7 and 8 relate to the second embodiment.
The main part of the second embodiment is the same as that of the first embodiment, and the detailed description is not repeated because the same reference numerals are used.
In the second embodiment, the receiving portion 6 is integrally provided with a support portion 21 having a rectangular shape protruding forward from below. A mark 22 for attaching the connector 5 is formed on the support portion 21 (FIG. 7). The mark 22 indicates a protruding position from the clamping portion in the wiring grommet 1 of the connector 5 attached to the tip of the electric wire 3.
The positional relationship between the connector 5 and the wiring grommet 1 can be appropriately determined by the support portion 21 with the mark 22 provided on the wiring grommet 1. 4 can be easily aligned with the connection hole for attaching the connector in 4 and the contact pin 27 of the connector 5. As a result, the soldering operation between the circuit on the wiring board 4 and the contact pin 27 of the connector 5 can be performed efficiently.

The embodiment has been described above.
The form of the receiving part 6 and the cover part 7 is not limited to a semi-cylindrical shape or a box shape. Both the receiving part 6 and the lid part 7 may be semi-cylindrical. It is important that the receiving portion 6 and the lid portion 7 can be disassembled and developed, and that the inside is sealed when the wires 3 are inserted and superposed.
“Receiving portion” and “lid portion” are terms used for explanation, and are actually relative depending on how the wiring grommet 1 is used.
The form of the partition protrusion 17 is not limited to that of the embodiment. However, the longer one in the front-rear direction is preferable because it can come into contact with the electric wire 3 with a longer dimension along the electric wire 3.

  The procedure for attaching the grommet 1 to the chassis 2 is not limited to the above description. For example, the procedure may be such that the grommet 1 is first attached in the unfolded state to the grommet attachment opening 11 of the chassis 2 and then the electric wire 3 to which the connector 5 and the wiring board 4 are attached is loaded and the lid portion 7 is closed.

DESCRIPTION OF SYMBOLS 1 Grommet for wiring 2 Chassis 3 Electric wire 4 Wiring board 5 Connector 6 Receiving part 7 Cover part 8 Hinge part 9 Fitting rib 10 Primary shielding rib

DESCRIPTION OF SYMBOLS 11 Grommet attachment opening 12 Fitting recess 13 Chassis outer surface 14 Receiving side clamping part 15 Cover side clamping part 16 Wire receiving groove 17 Partition protrusion 18 Electric wire pushing groove 19 Dust-proof recess 20 Wall

21 Supporting part 22 Marking 23 Hook 24 Hook support 25 Positioning projection 26 Positioning recess 27 Connector pin

a Bonding surface b Bonding surface

Claims (4)

A wiring grommet that inserts and locks an electric wire,
The outer ribs are provided with primary ribs projecting outwardly in parallel with the mating ribs along the surface perpendicular to the direction of insertion of the electric wires and in parallel with the ribs,
The fitting rib is to be fitted to the fitting recess of the chassis to which the wiring grommet is attached,
The wiring grommet, wherein the primary shielding rib is brought into contact with the outer surface of the chassis which is on the outer side in the electric wire insertion direction than the fitting recess.
The wiring grommet according to claim 1,
It is divided into a receiving part and a lid part along a plane parallel to the insertion direction of the electric wire,
When the receiving portion and the lid portion are integrally superposed, the holding portion, the dustproof depression and the partitioning ridge are included inside,
The clamping part consists of a receiving side clamping part provided inside the receiving part and a lid side clamping part provided inside the lid part,
The receiving side clamping part has a plurality of electric wire receiving grooves arranged at intervals in a direction intersecting with the insertion direction of the electric wire,
The lid-side clamping portion has a plurality of wire pushing grooves arranged at intervals in a direction intersecting the wire insertion direction, and the wire receiving groove and the wire pushing groove are obtained by superposing the receiving portion and the lid portion integrally. Each of them faces each other and holds the electric wire.
The dust-proof recess is formed across all the wire pushing grooves in the intermediate portion of the lid-side clamping portion in the wire insertion direction,
The partition ridges are comb-like ridges that are disposed between the wire receiving grooves in the direction of insertion of the wires, with an interval equal to the diameter of the wires, and that enter the dust-proof recesses,
When the receiving part and the cover part are integrally polymerized, the partition protrusions at both ends in the direction orthogonal to the insertion direction of the electric wire abut on the inner wall surfaces on both sides in the direction orthogonal to the electric wire insertion direction of the dustproof recess. Grommet for wiring. The support part is protruded forward in the insertion direction of the electric wire to the receiving part,
The wiring grommet according to claim 2, wherein a mark indicating a protruding position of the connector attached to the tip of the electric wire from the clamping portion of the wiring grommet is provided on the support portion. The wiring grommet according to any one of claims 1 to 3, wherein the wiring grommet is made of a hard resin.