JP2003009361A - Watertight structure based on grommet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ingress of water into an electrical junction box or a panel by a grommet without fail, even if the force of water is strong. SOLUTION: A watertight structure is designed with an elastic grommet 4 for leading out a wiring harness fit to a junction box body 2 and 3 or a panel. The grommet is provided with a water shut-off film 7, and the fit portion between the grommet and the junction box body or the panel is covered with the water shut-off film. The water shut-off film 7 is formed on the grommet 4 with the film being substantially an annular shape. The water shut off film 7 may be extended in the radial direction, and the extended portion may be anchored to the junction box bodies 2 and 3. The junction box body 2 and 3 or the panel is provided with water shut-off plates 9 and 11 for preventing ingress of water into the inside of the water shut off film 7. Instead of the water shut-off film 7, the junction box bodies 2 and 3 or the panel may be provided with a water shut-off plates 9 and 11, for prevent water from splashing directly on the portion thereof engaged with the grommet 4. Stepped portions may be formed, in place of the water shut-off plates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is equipped with a waterproof grommet in order to draw out a wire harness from a panel of an electric connection box or an automobile to prevent water from entering the electric connection box or the panel. It relates to a waterproof structure using grommets.

[0002]

2. Description of the Related Art FIG. 7 shows a waterproof structure in an electrical junction box as one form of a conventional waterproof structure using grommets. The electrical junction box is a case 71 and a cover 72 which are synthetic resin junction box bodies, a connection unit (not shown) including a fuse, a relay and the like housed in the case 71, and an elastic grommet 73 for waterproofing. And has a substantially U-shaped cutout portion 74 for leading out the wire harness and a guide portion 75 protruding outward from the peripheral edge of the cutout portion 74 on one side wall of the case 71. The grommet 73 is slidably attached to the grommet 73, and the wire harness (a plurality of electric wires) 76 following the connection unit (not shown) is inserted into the grommet 73 and led out to the outside.

The grommet 73 includes a bellows portion 77, a small-diameter cylindrical portion 78 following one of the bellows portion 77, a flange portion 79 following the other of the bellows portion 77, and a synthetic resin fitted in the flange portion 79. And a reinforcing member (not shown),
The flange portion 79 is slidably fitted to the guide portion 75 of the case 71, the cover 72 is further covered on the upper portion of the case 71, and the upper surface of the flange portion 79 is brought into close contact with the lower surface of the cover 72. From case 71
Ingress of water is prevented.

A rectangular ring-shaped packing (not shown) is provided on the inner peripheral edge of the cover 72, and the case 7 is attached to the packing.
When the upper edge of 1 is in close contact, the case 71 and the cover 72
Water is prevented from entering through the joints. Grommet 73
The tip of the cylindrical portion 78 is wound with a vinyl tape (not shown) while the wire harness 76 is inserted, and the water is stopped.

[0005]

However, in the above-mentioned conventional waterproof structure using grommets, when the electric junction box is exposed to the outside and mounted, for example, for a truck, it jumps up while the vehicle is traveling. When rainwater or high-pressure water during car wash hits directly the flange 79 of the grommet 73, there is a problem that high water pressure causes water to enter between the flange 79 and the case 1 and the cover 72. It was Also, the flange portion 7 of the grommet 73
Similarly, when water is vigorously applied from the side, above, or below with respect to 9, or when water circulates from the top wall of the cover 72 and hits the flange portion 79, water may similarly intrude. was there. If water enters the case 71,
There was a concern that the connection unit inside the case would be adversely affected.

The above-mentioned problems are also caused when a grommet is inserted and fitted into a hole of a panel (not shown) of an automobile or the like instead of the electric junction box, and the grommet is caused by high-pressure water or wraparound of water. There was a concern that water would get into the panel.

In view of the above points, the present invention is such that water is vigorously applied to the grommet from the front, water is vigorously applied to the grommet from the side, above, or below, or water flows around the grommet from above. It is an object of the present invention to provide a waterproof structure using grommets that can reliably prevent water from entering the inside of the junction box body or the panel even in cases such as cases.

[0008]

In order to achieve the above object, a waterproof structure using a grommet according to claim 1 of the present invention is a grommet in which an elastic grommet for guiding a wire harness is attached to a connection box body or a panel. In the waterproof structure, a water blocking film is provided on the grommet, and the water blocking film covers a fitting portion between the grommet and the connection box body or panel. With the above configuration, the elastic and flexible water blocking film is directly exposed to water from the front and adheres to the fitting portion between the grommet and the connection box body or the panel to be in close contact,
Prevents direct water from hitting the fitting part, or weakens the force of water on the fitting part. This improves the waterproof sealing property of the grommet.

A waterproof structure with a grommet according to a second aspect of the present invention is the waterproof structure with a grommet according to the first aspect, characterized in that the water blocking film is formed in a substantially annular shape on the grommet. With the above configuration, the substantially annular water blocking film covers the fitting portion in the entire circumferential direction or at least in the four directions at right, left, up, down, and right angles. In the electrical junction box, the cover as the junction box body is located in the upper direction, and the case as the junction box body is located in the left and right and in the downward direction, and the water-stop film on the upper side is the fitting part between the case and the cover (grommet is also fitted). The left and right and bottom waterproofing membranes cover the fitting portion between the case and the grommet.

The waterproof structure by the grommet according to claim 3 of the present invention is the waterproof structure by the grommet according to claim 1 or 2, wherein the water blocking film is extended in the radial direction, and the extended portion is provided in the junction box body. It is characterized by being locked. With the above configuration, fluttering and curling of the water blocking film are prevented, and not only water from the front surface but also water from the side surface, the upper surface, and the lower surface are stopped by hitting the extension part of the water blocking film, and Ingress of water is prevented.

A waterproof structure with a grommet according to claim 4 of the present invention is the waterproof structure with a grommet according to any one of claims 1 to 3, wherein
A water blocking plate for preventing water from entering the inside of the water blocking film is provided. With the above configuration, for example, the water is blocked from directing water in a direction orthogonal to the thickness of the water blocking film such as laterally or upward of the water blocking film by the water blocking plate, or the water force is weakened, and water to the inside of the water blocking film is blocked. Invasion is prevented, or the force of water invading inside the water blocking membrane is weakened.

A waterproof structure with a grommet according to claim 5 of the present invention is the waterproof structure with a grommet according to any one of claims 1 to 4, wherein a step portion is provided on the connection box body or the panel, and the inside of the step portion is provided. The grommet and the water blocking film are located in the, and the step portion functions as a water blocking plate. With the above configuration, the fitting portion of the grommet and the tip portion of the water blocking film are housed and protected inside the step portion, and water from the outside hits the water blocking film along the panel surface outside the step portion to stop the water. Direct exposure of water to the tip of the membrane is prevented.

A grommet waterproof structure according to a sixth aspect of the present invention is a grommet waterproof structure in which an elastic grommet for leading out a wire harness is attached to a connection box body or panel. A water blocking plate or a step portion that prevents water from being directly exposed to the fitting part of the junction box body or panel is provided. With the above configuration, water from sides other than the front side of the grommet, or from above or below is directly radiated to the water stop plate to be stopped, or the water force is weakened to the fitting part between the grommet and the connection box body or panel. Direct water is prevented from being hit from above, below, left and right, or the force of water applied to the fitting portion is weakened. In addition, the mating part of the grommet is stored and protected inside the step part, and water in directions other than the front of the grommet hits the grommet along the panel surface outside the step part, and the water directly hits the mating part of the grommet. Is prevented, or the force of water applied to the fitting portion is weakened.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 and 2 show a waterproof structure in an electric junction box as a first embodiment of a waterproof structure using a grommet according to the present invention.

The waterproof structure using the grommet is a thin elastic member having a substantially collar-like shape on the flange portion 6 of the elastic grommet 4 made of synthetic rubber or the like fitted to the guide portion 5 of the synthetic resin case 2 of the electric junction box 1. The water blocking film 7, 7 ′ or 7 ″ is integrally provided, and the water blocking film 7, 7 ′ or 7 ″ is used to fit the flange portion 6 to the guide portion 5 of the case 2 and the flange portion 6 and the synthetic resin. The first feature is that the fitting portion with the upper cover 3 made of the product is covered from the outside to prevent direct water from hitting each fitting portion.

Further, rib-shaped water stop plates 9 are provided on the front side wall portion 8 of the case 2 on both sides and below the guide portion 5 of the case 2.
By providing 9 ′, it is possible to prevent water from directly irradiating the fitting portion between the flange portion 6 and the guide portion 5 or the water blocking film 7, 7 ′ or 7 ″ from the side, and to cover the guide portion 5 near the side. By providing a rib-shaped water stop plate 11 on the ceiling wall 10 of 3, water is circulated from the cover 3 to the fitting portion between the flange portion 6 and the guide portion 5 and the inside of the water stop film 7, 7'or 7 ". The second feature is that it prevents the intrusion.

These water stop films 7, 7 ', 7 "and water stop plates 9,
9'and 11 may be used alone or may be used in combination as shown in FIG. Especially when used in combination,
It is extremely effective against splashing of water from the side or the top of the water blocking film 7, 7 ', 7 ".

As shown in FIG. 1, the grommet 4 has a bellows portion 12.
And a tubular portion 13 that continues in front of the bellows portion 12, and the bellows portion 13
And the flange portion 6 that continues through the bulging portion 14 to the rear of the bulging portion 14, and the water blocking films 7 and 7 ′ face outward from the front surface of the flange portion 6 on both sides and upper and lower sides of the bulging portion 14, that is, the entire circumference. That is, it is preferable that the flange portion 6 is formed so as to project in a substantially collar-like shape (substantially annular shape) in the width direction and the height direction. The water blocking films 7 and 7 ′ are projected outwardly beyond the peripheral edge of the flange portion 6 so as to cover the peripheral edge of the flange portion 6. The water blocking film 7 may be formed in a substantially elliptical shape (generally annular shape) uniformly over the entire circumference like a chain line 7 ″, and in this case, the upward water blocking film 7 ′ is unnecessary.

In this embodiment, the water blocking film 7, 7'or 7 "is formed on the surface of the flange portion 6, but instead of the surface of the flange portion 6, the water blocking film 7, 7'or 7'or It is also possible to integrally form the 7 ". The bulging portion 14 is the bellows portion 12.
It is a portion for forming the bellows portion 12 forward from the guide portion 5 of the case 2, which is formed with substantially the same plate thickness, and can be regarded as a part of the bellows portion 12. The water blocking film 7, 7'or 7 "can be formed simultaneously with the rubber molding of the grommet 4 using a molding die. The water blocking film 7, 7'or 7" is formed separately from the grommet 4. It is also possible to assemble it by adhering it to the grommet 4.

As shown in FIG. 1, the water blocking film 7, 7'or 7 "is preferably curved in a substantially arcuate cross section toward the front wall 8 of the case 2, whereby the water blocking film 7, 7'or 7 ' The tips 7a and 7a 'of the 7 "closely adhere to the wall surface 8 of the case 2 to exhibit high water blocking performance.

The flange portion 6 has a wire harness insertion hole (not shown) continuing to the inner space of the bellows portion 12. The outer periphery of the flange portion 6 is composed of a substantially U-shaped portion 15 and an upper straight portion 16 in the horizontal direction. Lips (substituting the reference numerals 15 and 16) are formed in an annular projection on the outer periphery of these portions.

The front wall 8 of the case 2 has a substantially U-shaped cutout 1
7 is provided, and the guide portion 5 for sliding engagement with the flange portion 6 is formed on the peripheral edge of the cutout portion 17 so as to project. A guide groove 1 having a substantially U-shape and a substantially L-shaped cross section and a peripheral wall (front wall) 8 of the case 2 having a U-shaped cross section.
9 is formed. By inserting the flange portion 6 of the grommet 4 into the guide groove 19 from above, the guide groove 19
Fifteen lips of the flange portion 6 adhere to the inner surface of the. This structure is similar to the conventional one.

In the present specification, the grommet 4 side is defined as the front and the cover 3 side is defined as the top for convenience of description, but this does not always coincide with the direction when the vehicle is mounted.
The front wall 8 and the ceiling wall 10 can also be simply expressed as walls.
In addition, a waterproof membrane 7, 7 ', 7 "or a waterproof plate 9 of the present invention is formed on a grommet (proposed in another application) in which the flange portion 6 and the guide portion 5 are formed in two stages to improve waterproofness. ，
It is also effective to add the configurations 9'and 11.

On both sides of the guide portion 5, the water blocking plates 9 and 9'having a substantially U shape are projected from the front wall 8 of the case 2.
The water stop plates 9 and 9 on both sides extend straight in the vertical direction (vertical direction), and the water stop plate 9 ′ on the lower side is curved and continues to the water stop plates 9 and 9 on both sides. The lower water stop plate 9 ′ may slightly project to the lower side of the front wall 8, and in this case, a drain hole is formed between the water stop plate 9 ′ and the front wall 8. The water blocking plates 9 and 9 ′ are preferably arranged near the guide portion 5 and at a position where they do not interfere with the water blocking film 7, that is, near the tip 7 a of the water blocking film 7. The forward projecting height of the water blocking plates 9 and 9'is higher than the projecting height of the guide part 5, and the vertical length of the water blocking plate 9 is as close as possible to the length of the guide part 5, respectively. It is preferable from the viewpoint of water stoppage.

Since it is not necessary to dispose the water stop plate 9 on the side not exposed to water depending on the mounting state on the vehicle, only one of the pair of water stop plates 9 and 9 is formed. In some cases, the lower water blocking plate 9'may be omitted. It is also possible to form the lower water blocking plate (9 ') horizontally following the water blocking plates 9 on both sides or independently. Further, the case 2 has a double peripheral wall 20 and an inner peripheral wall (not shown) is formed higher than the outer peripheral wall 20 (which is an existing technique).
It is also possible to apply the above water stop plates 9 and 9 ′.

An edge portion 21 is formed so as to project from the upper portion of the peripheral wall 8 of the case 2, and an engaging claw 22 as an engaging means for the cover 3 is provided on the front wall 8 integrally with the edge portion 21. The cover 3 is made of synthetic resin and constitutes the junction box body together with the case 2. Lock metal fitting support portions 24, which are locking means, are provided on both sides of the front wall 23 of the cover 3 (the lock metal fittings are not shown).

A step portion 26 is formed between the pair of lock fitting support portions 24, 24 to which the upper portion 25 of the flange portion 6 of the grommet 4 is fitted. The upper portion 25 of the flange portion 6 is inserted inside the step portion 26, and the upper portion 2
The lip 16 of No. 5 comes into close contact with the inner surface of the upper wall of the stepped portion 26. For example, a rectangular annular packing (not shown) is provided inside along the peripheral wall 27 of the cover 3, and the upper end of the peripheral wall 20 of the case 2 is in close contact with the packing.

The cover 3 is provided near the step 26 of the cover 3.
The water stop plate 11 is erected on the ceiling wall 10 of the above. The water stop plate 11 is formed over the entire width of the top wall 10 and is arranged in parallel with the front wall 23. The length of the water blocking plate 11 is set to be wider than the entire width of the water blocking film 7 of the grommet 4, that is, the distance from one end of the water blocking film 7 to the other end thereof. Water is prevented from wrapping around.

The shape of the water blocking plate 11 can be arbitrarily changed such as a curved shape. The height of the water stop plate 11 is such that water from the rear hits the water stop plate and is bounced back, or at least the water force is weakened, so that the flange portion 6 of the grommet 4 and the guide portion 5 (water stop film 7, 7 ′ of the case 2). , 7 "is not used), or the height is set so that the water blocking film 7, 7 ', 7" of the grommet 4 is not vigorously applied.

As shown in FIG. 2, the grommet 4 is fitted to the case 2, and the cover 3 is fitted to the case 2. In this state, the waterproof membrane 7, 7 ′ or 7 ″ of the grommet 4 covers the guide part 5 of the case 2 and the step part 26 of the cover 3 from the front side (front side), and the inside of the guide part 5 and the step part 26. To prevent the water from directly hitting the flange portion 6 of the water, that is, when the water is vigorously applied to the electric junction box 1 from the front (the direction of the arrow X), the water hits the water stop film 7, 7'or 7 "and stops. The water film 7, 7 ′ or 7 ″ bends and comes into close contact with the front wall 8 of the case 2 and the surface of the stepped portion 26 of the cover 3, and the water to the fitting portion of the guide portion 5 and the stepped portion 26, i.e., the grommet 4. In this way, water is prevented from entering the close contact part between the flange part 6 and the guide part 5 and the close contact part between the flange part 6 and the step part 26, and the inside of the connection box body (in the case 2). The ingress of water into the is reliably prevented.

In addition, the electric junction box 1 is provided laterally (direction of arrow Y).
When it is splashed with water, the water is directly reflected on the water blocking plates 9 on both the left and right sides or on either side, or at least the guide portion 5 of the case 2 or the flange portion 6 of the grommet 4 (water blocking film 7, (When 7 ′, 7 ″ is not used) and direct water to the water blocking film 7, 7 ′ or 7 ″ is prevented, and similarly water is prevented from entering the case 2. Water stop film 7,
When 7 ′ or 7 ″ is used, water is repelled by the water stop plate 9 or the water force is weakened, so that the space between the tip (free end) 7a of the water stop film 7 and the front wall 8 of the case 2 is reduced. Therefore, the water is prevented from invading the inside of the water blocking film 7 vigorously, and the waterproof property is improved.When water is splashed from below, the water blocking plate 9'also has the same effect.

In addition, the electric junction box 1 is located above (in the direction of arrow Z).
When water is splashed from the cover or water splashes from behind (in the direction of the arrow X ') onto the cover 3, the water is bounced off by the water stop plate 11 of the cover 3, or at least the water force is weakened and the guide portion 5 and flange 6 (water stop film 7,
Water is prevented from being vigorously applied to the inner side of the water blocking film 7, 7 ', 7 "(in the case where there is no 7', 7") and the waterproof property is improved.

FIG. 3 shows a second embodiment of a waterproof structure using grommets according to the present invention. It should be noted that the same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the waterproof structure of the electric junction box 31, the water blocking film 33 of the elastic grommet 32 of the first embodiment is extended in the radial direction, and the radial tip end of the water blocking film 33 is formed by the junction box body. It is characterized by being locked to a case 34 and a cover 35. The water stop plates 9 and 9'of the above-mentioned embodiment,
11 is not used.

The water blocking film 33 extends in four directions, up and down and left and right, and is locked to the case 34 and the cover 35 in a pulled state. The left and right extension parts 36, 36 are the case 3
4 extends to both side walls 37, and a locking hole 39 at the tip of the extension portion is engaged with a locking claw 38 provided on the front end side of both side walls 37. The locking claw 38 is formed in a substantially L-shaped cross section, and has a rearward facing claw portion (reference numeral 38 is substituted). Locking claw 38
The shape of can be changed appropriately.

The extension 40 on the upper side of the water blocking film 33 is the cover 3
5 extends shortly to the step portion 26, and the engaging hole 41 on the distal end side of the extension portion 40 is engaged with the engaging projection 41 or the engaging claw provided on the upper surface of the step portion 26. The extension 43 on the lower side of the water blocking film 33 extends shortly to the lower portion of the front wall 8 below the guide portion 5 of the case 34, and the locking claw 44 provided on the front wall 8 is provided on the tip side of the extension 43. The locking hole 45 is engaged. It is also possible to lock the lower extension 43 on a locking claw (not shown) on the bottom wall of the case 34.

A substantially annular water-stop film main portion (water-stop film central portion) 46 is located at the center of the four extension parts 36, 36, 40, 43. Similar to the above-described embodiment, the water-stop film main portion 46 completely hides the fitting portion of the guide portion 5 of the case 34 and the step portion 40 of the cover 35, that is, the flange portion 6 (see FIG. 1) of the grommet 32. Is preferred.

Left and right and lower locking holes 39, 4 of the water blocking film 33
After engaging (hooking) 5 with the locking claws 38, 44 of the case 34, the cover 35 is closed and the locking hole 42 on the upper side of the water blocking film 33 is fitted to the locking projection 41 of the cover 35. Engage. When opening the cover 35, the locking protrusion 41 of the cover 35
The cover 35 can be easily opened by removing the locking hole 42 on the upper side of the water blocking film 33. This is the reason why the locking projection 41 is used instead of the locking claw.

The extension portions 36, 3 on both sides of the water stop film 33 are provided.
6 is made short, and as in the stepped portion 40 of the cover 35, for example, a locking claw (not shown) provided on the outer peripheral surface of the guide portion 5 of the case 34 is provided with a short extension (not shown). It is also possible to engage the blind holes. In this case, it is possible to provide the water blocking plates 9 and 9 similar to those in the above-mentioned embodiment in terms of space. In addition, the waterproof membrane 32 and the connection box bodies 34, 35
The locking means may be appropriately provided. For example, a locking projection (not shown) is provided on the extension portions 36, 40, 43 of the water blocking film, and the locking projection is fitted to the connection box body. Stop recess (not shown)
It is also possible to provide.

According to the second embodiment described above, the water blocking film 33.
Since the water is locked to the case 34 and the cover 35, the water blocking film 33 is prevented from fluttering or curling, and the water blocking property is improved especially when water is applied to the water blocking film 33 from the side, above or below. . That is, for example, even when water directly hits the water blocking film 33 from the side, the water blocking film 33 does not curl, and it is located between the radial tip end 47 of the water blocking film 33 and the front wall 8 of the case 34. Since no gap is formed, water does not enter the inside of the water blocking film 33, and these allow the fitting portion of the guide portion 5 of the case 34 and the step portion 40 of the cover 35 to be fitted with the flange portion 6 of the grommet 32. It is possible to reliably prevent the water from being directly exposed.

Therefore, the water blocking plates 9 and 9'as in the first embodiment are unnecessary. The same applies to the relationship between the upper extension 40 of the water blocking film 33 and the water blocking plate 11 of the cover 3 and the lower extension 43.

In each of the above-mentioned embodiments, the structure in which the flange portion 6 of the grommet 4 is slidably fitted to the guide portion 5 of the case 2 is adopted. However, the waterproof membranes 7 and 7'in the present invention are used. The 7 "and 33 and the water blocking plates 9 and 11 are not necessarily limited to the above structure, and can be applied to, for example, a structure (not shown) in which a grommet is fitted in the hole of the connection box body. Will be explained in detail.

4 to 6 show another embodiment of the grommet in the embodiment of FIG. 4 is a rear view of the arrow A in FIG. 5, FIG. 5 is a side view, and FIG. 6 is a sectional view of the arrow B in FIG.

As shown in FIG. 4, the extension portions 50 to 53 of the water blocking film 49 of the grommet 48 project from the outer periphery of the flange portion 54 in the four directions of up, down, left and right in a rectangular shape. Extensions 50-53
A slit-shaped locking hole 55 in the horizontal or vertical direction is provided in the middle portion in the protruding direction of the. Left and right extensions 5 of this embodiment
Reference numerals 2 and 53 project relatively shortly and correspond to locking claws (not shown) provided on the front wall of the connection box body (see FIG. 3). Each locking hole 55 is formed to have a length that is slightly shorter than the width of each extension 50 to 53. Extensions 50-53
Crosses a ring-shaped waterproof membrane main portion (waterproof membrane central portion) 56 that covers the central portion of the flange portion 54 and its vicinity in a cross shape. The width of the lower half portion of the flange portion 54 is slightly narrower than that of the upper half portion because the guide portion of the case (reference numeral 5 in FIG. 1).
This is for facilitating the insertion of the flange portion 54 into the (see).

As shown in FIGS. 5 and 6, the water blocking film 49 extends outward from the inclined outer peripheral wall (substituting reference numeral 58) of the bulging portion 58 on the base side of the bellows portion 57 slightly forward of the flange portion 54. It projects in a flat plate shape in parallel with the flange portion 54. Since the extension parts 50 to 53 are locked to the connection box body,
9 need not be curved as in the embodiment of FIG.
The plate thickness of the water blocking film 49 is approximately the same as the plate thickness of the bulging portion 58. When molding the grommet 48 with a rubber material, by providing a wide and shallow recess for forming a waterproof film between the front mold and the rear mold (not shown), Water stop film 49
Can be easily formed. A projecting strip 59 is formed on the tip edge of each of the extension parts 50 to 53, so that an operator can easily pull and extend the extension parts 50 to 53 with fingers, and the strength of the extension parts 50 to 53 is increased. , Tearing, etc. are prevented.

Flange portion 54 of grommet 48 of this embodiment
Is formed in at least two stages, and when the flange portion 54 is fitted to the guide portion (not shown) of the connection box body,
The waterproof sealing property of the fitting portion between the flange portion 54 and the guide portion is improved. This will be proposed in detail in another application. In the present embodiment, the waterproof membrane 49 and the two-stage flange 5
Due to the synergistic effect with 4, the waterproof sealing property against high-pressure water is remarkably enhanced.

FIGS. 7 (a) and 7 (b) show a third embodiment of a waterproof structure using a grommet according to the present invention, in which a waterproof grommet is slidably fitted into a hole of a panel of an electric junction box or a vehicle. The figure shows a structure in which they are inserted and fitted together.

In FIG. 7, reference numeral 60 is a synthetic resin connection box body or a metal panel, and reference numeral 61 is an elastic grommet. The circumferential groove formed in the large diameter portion 65 of the grommet 61 is the wall portion 69 of the connection box body 60 or the hole portion 63 of the panel.
The large-diameter portion 65 is connected to the small-diameter portion (cylindrical portion) 64 via the tapered portion, and the water blocking film 62 is integrally formed between the small-diameter portion and the tapered portion. .

The water blocking film 62 is slightly curved and covers the tapered portion in a substantially umbrella shape and the large diameter portion 65, and the tip of the water blocking film 62 is a gap in the wall portion 69 of the junction box body 60 or the surface of the panel. There is no close contact. The water blocking film 62 is elastically pressed against the junction box body 60 or the panel. A wire harness insertion hole is formed in the grommet 61. Grommet 6 with a wire harness (not shown) inserted through grommet 61
1 is fitted and fixed to the junction box body 60 or the panel. The position of forming the water blocking film 62 may be a tapered portion.

The front surface of the grommet 61, that is, the small diameter portion 64.
When the water is vigorously applied from the side, the water blocking film 62 is crushed, and the tapered portion of the grommet 61, the large diameter portion 65, and the wall portion 6
9, so that the fitting portion between the hole 63 and the large diameter portion 65 is completely covered to prevent direct water from hitting the fitting portion.

When the grommet 61 is directly exposed to water from the vertical and horizontal directions, the water blocking film 62 is attached to the junction box body 60 or the panel by a locking means (not shown) as in the embodiment of FIG. This can be dealt with by stopping or by providing a water stop plate (not shown) on the junction box body 60 or the panel as in the embodiment of FIG.

FIG. 8 shows, as a fourth embodiment of the waterproof structure using grommets according to the present invention, a structure in which a waterproof grommet 61 is inserted and fitted into a hole of a panel 66 of an electric junction box or a vehicle. This shows a structure in which a step 67 is provided on the junction box body or panel 66 at a position outside the water blocking film 62 of the grommet 61, and the step 67 acts as a water blocking plate.

The structure of the grommet 61 is similar to that of the embodiment of FIG. 7, and the tip of the water blocking film 62 is in close contact with the wall 68 of the junction box body or the panel 66, and is close to the outside of the tip of the water blocking film 62. As a result, the step portion 67 is located, and the tip end side portion of the water blocking film 62 enters the inside of the step portion 67 and is protected.

When water is applied to the grommet 61 from the front, the water blocking film 62 is crushed and the wall portion 6 is broken as in FIG.
Although it comes into close contact with 8 or the like, when water is applied from above or below or from the left or right, the water hits the intermediate portion in the longitudinal direction of the water blocking film 62 along the outer surface of the junction box body or panel 66, and the tip of the water blocking film 62. No water is directly exposed to it. This prevents water from entering the inside of the waterproof membrane, and even if it does, the water pressure is weakened to a pressure at which the large diameter portion of the grommet 61 can reliably seal. In addition, the structure of FIG. 8 has a water stop plate (not shown).
The water-stopping property is further improved by adding. The step 67 is also effective for grommets that do not have the water blocking film 62.

[0055]

As described above, according to the first aspect of the present invention, the water-blocking film is attached to the fitting portion between the grommet and the connection box body or the panel, particularly when the water-proof film is directly exposed to water from the front side. The close contact prevents the direct water from hitting the fitting part and weakens the water pressure (water pressure), so the waterproof sealability by the grommet is improved, and the strong water force ensures the intrusion of water into the junction box body or panel. To be prevented. As a result, the connection unit in the connection box body and the devices in the panel are reliably protected from water damage, and waterproofness can be secured even if the shape of the mating part of the grommet is simplified, reducing the cost of parts. Etc. are planned.

According to the second aspect of the present invention, since the grommet fitting portion in at least the top, bottom, left, right, or the entire circumferential direction is covered by the substantially annular water blocking film, for example, when the water blocking film is arranged only in the left and right direction. Compared with the above, the water blocking property is remarkably improved, and the effect of the invention according to claim 1 is exhibited more reliably.

According to the third aspect of the invention, the water blocking film is locked to prevent the water blocking film from fluttering or curling.
Not only the water from the front of the grommet, but also the water from the side surface, the upper surface and the lower surface hits the extension part of the waterproof membrane and is stopped,
Water is prevented from entering the inside of the waterproof membrane, so that the waterproof sealing performance by the grommet is surely exhibited. In addition, since the water blocking function, that is, the function of receiving water and weakening the water force is secured without using a water blocking plate, which will be described later, the cost is reduced as compared with the case where the water blocking plate is used, and the electrical junction box, etc. The structure is downsized.

According to the fourth aspect of the present invention, the water is directly radiated to the water blocking plate, so that the water is not directly radiated from the lateral direction, the upper side, or the lower side of the water blocking film in the direction orthogonal to the thickness of the water blocking film. It is stopped by the water plate, or the water force (water pressure) is weakened by the water stop plate,
Water is prevented from entering the inside of the waterproof membrane, or the momentum of water entering the inside of the waterproof membrane is weakened.Therefore, not only from the front of the grommet but also from the side, above, below, etc. Improves and ensures waterproof sealing with grommets.

According to the fifth aspect of the present invention, the fitting portion of the grommet and the tip portion of the water blocking film are housed and protected inside the step portion, and water from the outside is applied to the panel surface or the like outside the step portion. Along the water stop film, the water is prevented from directly hitting the tip portion of the water stop film, so that the water is prevented from entering the inside of the water stop film and the waterproof property by the grommet is secured.

According to the sixth aspect of the present invention, water from the sides other than the front surface of the grommet, or from above or below is directly radiated to the water stop plate to be stopped, or the water force is weakened. Alternatively, it is possible to prevent the water from directly hitting the fitting portion with the panel from the vertical and horizontal directions, or to reduce the water pressure applied to the fitting portion, so that the waterproof sealing property by the grommet is surely exhibited. This is particularly effective when the electric junction box or panel is arranged at a position where water is applied from a direction other than the front of the grommet.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a waterproof structure using a grommet according to the present invention.

FIG. 2 is a perspective view showing an assembled state in which a grommet is also attached to the case and the cover is closed.

FIG. 3 is a perspective view showing a second embodiment of a waterproof structure using grommets according to the present invention.

FIG. 4 is a rear view (view A in FIG. 5) showing an embodiment of the grommet.

FIG. 5 is a side view showing the grommet.

FIG. 6 is a sectional view taken along line B-B of FIG. 4, which also shows the grommet.

7A and 7B show a third embodiment of a waterproof structure using a grommet according to the present invention, (a) is a front view and (b) is a sectional view taken along line CC of (a).

FIG. 8 is a cross-sectional view showing a fourth embodiment of a waterproof structure using grommets according to the present invention.

FIG. 9 is an exploded perspective view showing one form of a waterproof structure using a conventional grommet.

[Explanation of symbols]

1,31 Electric junction box 2,34 Case (junction box body) 3,35 Cover (junction box body) 4,32,48,61 Grommet 7,7 ', 7 ", 33,49,62 Water stop membrane 9, 9 ', 11 Water stop plates 36, 40, 43, 50-53 Extension parts 39, 42, 45, 50 Locking holes (locking means) 41, 38, 44 Locking claws (locking means) 60, 66 Connection Box body or panel 67 Stepped portion

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 5/02 H05K 7/00 M 5/06 H02G 3/28 F 7/00 F16L 5/02 A F term (Reference) 4E352 AA09 BB02 BB05 BB10 BB15 CC32 CC33 CC40 DD05 DD06 DD15 DR14 DR25 DR34 DR37 DR40 DR43 FF06 GG04 4E360 AB12 AB33 AB34 BB20 EA03 ED03 ED17 ED27 GA29 GB93 GB94 5G357 DA02 DB03 DC12 DD01 DD01 DD05 DD10 DD01 DD02 DD10 DD05 DD01 DD05 DD10 DD05 DD02 DD05 DD10 DD05 AC11 AE01 5G363 AA01 BA02 CB08 DC02

Claims (6)

[Claims] 1. In a waterproof structure using a grommet in which an elastic grommet for leading out a wire harness is attached to a junction box body or panel, a water blocking film is provided on the grommet, and the grommet and the junction box body are formed by the water blocking film. Alternatively, a waterproof structure with a grommet, which is characterized by covering a fitting portion with a panel. 2. The waterproof structure according to claim 1, wherein the water blocking film is formed in a substantially annular shape on the grommet. 3. The waterproof structure with a grommet according to claim 1, wherein the waterproof membrane is extended in the radial direction, and the extended portion is locked to the connection box body. 4. The grommet according to claim 1, wherein the junction box body or panel is provided with a water blocking plate that prevents water from entering the inside of the water blocking film. Waterproof structure. 5. The connection box body or panel is provided with a step portion, the grommet and the water blocking film are located inside the step portion, and the step portion functions as a water blocking plate. A waterproof structure using the grommet according to claim 1. 6. In a waterproof structure of a grommet in which an elastic grommet for leading out a wire harness is attached to a connection box body or panel, water is directly exposed to a fitting portion between the grommet and the connection box body or panel. A waterproof structure using a grommet, which is provided with a water blocking plate or a step portion for preventing the connection box body or panel.