Electric connection box

The electric connection box includes a case main body; a lower cover to be attached at the case main body; a harness-through opening to be structured into a cylindrical shape with the case main body and the lower cover; a wiring harness to be passed through the harness-through opening; and a water-protect elastic sheet wound around the wiring harness to be arranged in the harness-through opening. The harness-through opening has a large diameter portion, which has an inner diameter larger than an outer diameter of the part of the wiring harness wound with the water-protect sheet, and a small diameter portion, which has an inner diameter smaller than the outer diameter of the part of the wiring harness wound with the water-protect sheet.

The priority application Number Japan Patent Application 2008-307231 upon which this patent application is based is hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to an electric connection box, arranged in an engine room of a car.

BACKGROUND OF THE INVENTION

Description of the Related Art

In a car, various electronic equipments are mounted. An electric connection box, which is structured integrally with electric components, such as fuses and relays, is arranged at a suitable location between a power supply and the electronic equipments in the car for supplying electric power to the various electronic equipments.

The electric connection box may be described by the name of a junction block, a fuse block and a relay box. In this specification, the junction block, the fuse block and relay box are described with an electric connection box as a generic name hereafter.FIG. 4is a sectional view of an electric connection box by prior art.

The electric connection box101shown inFIG. 4includes a case main body102, in which various electric components115,116are mounted, a lower cover103to be arranged at a bottom side of the case main body102, an upper cover to be arranged at an upper side of the case main body102, a harness-through opening105formed into a cylindrical shape with the case main body102and the lower cover103when the lower cover103is attached on the case main body102, a wiring harness108to be passed through the harness-through opening105, and an elastic water-protect sheet109wound around the wiring harness108and arranged inside the harness-through opening105.

The harness-through opening105is structured with a projection106projecting with a half-cylindrical shape from a lower edge of an outer wall121of the case main body102, and a projection107projecting with a half-cylindrical shape from an upper edge of an outer wall131of the lower cover103, the outer wall131corresponding to the outer wall121. When the lower cover103is attached on the case main body102, the projections106and107are overlapped to each other so as to form the harness-through opening105.

The wiring harness108is structured by bundling a plurality of electric wires for connecting various electric components115,116to be arranged at the case main body102and various electronic equipments mounted at the car. Outer diameter of the wiring harness108varies according to a type or grade of the car in which the number of electric wires is different from each. When the outer diameter of the wiring harness108is small, by winding the water-protect sheet109around the wiring harness108, a gap to be existed between the wiring harness108and the harness-through opening105is filled so as to prevent that a liquid like a water penetrates through the gap into the case main body102.

The electric connection box101is assembled by arranging a part of the wiring harness108wound with the water-protect sheet109between the projections106,107, and attaching the lower cover103on the case main body102so as to clamp the part wound with the water-protect sheet109between the projections106,107. Japan Patent Application Published No. 2007-259652 should be referred.

SUMMARY OF THE INVENTION

Objects to be Solved

In the electric connection box101by Prior Art, there is a problem as following:At the harness-through opening105, the part of the wiring harness wound with the water-protect sheet109is pressed and crushed by whole inner wall of the harness-through opening109, so that a very large force pressing the lower cover103is required when the lower cover103is attached to the case main body102.

According to the above problems, an object of the present invention is to provide an electric connection box, in which a cover can be attached to a case main body with a small force. How to attain the object of the present invention

In order to overcome the above problems and attain the object of the present invention, an electric connection box according to the present invention includes a case main body, a cover to be attached to the case main body, a harness-through opening to be structured into a cylindrical shape with the case main body and the cover when the cover is attached to the case main body, a wiring harness to be passed through the harness-through opening and an elastic sheet wound around the wiring harness to be arranged in the harness-through opening, and the harness-through opening has a large diameter portion, which has an inner diameter larger than an outer diameter of a part of the wiring harness wound with the sheet, and a small diameter portion, which has an inner diameter smaller than the outer diameter of the part of the wiring harness wound with the sheet.

In the electric connection box according to the present invention, the harness-through opening includes a cylindrical portion structuring the large diameter portion and a slant portion arranged at an inner surface of the cylindrical portion and slanting from an end of the cylindrical portion to the other end of the cylindrical portion to approach gradually toward a center of the cylindrical portion so as to structure the small diameter portion.

In the electric connection box according to the present invention, the harness-through opening includes a cylindrical portion structuring the large diameter portion and a rib projecting from an inner surface of the cylindrical portion toward a center of the cylindrical portion and extending along the cylindrical portion so as to structure the small diameter portion.

Effects of the Invention

According to the present invention, since the harness-through opening includes the large diameter portion, which has the inner diameter larger than the outer diameter of the part of the wiring harness wound with the sheet, and the small diameter portion, which has the inner diameter smaller than the outer diameter of the part of the wiring harness wound with the sheet, it can make only the small diameter portion bite the sheet so as to seal a gap between the wiring harness and the harness-through opening. Thus, the cover can be attached with a small force on the case main body of the electric connection box.

In the electric connection box according to the present invention, the harness-through opening includes the cylindrical portion structuring the large diameter portion and the slant portion arranged at the inner surface of the cylindrical portion and slanting from the end of the cylindrical portion to the other end of the cylindrical portion to approach gradually toward the center of the cylindrical portion so as to structure the small diameter portion. It can make the small diameter portion and the slant portion bite the sheet so as to seal a gap between the wiring harness and the harness-through opening. Thus, the cover can be attached with a small force on the case main body of the electric connection box.

In the electric connection box according to the present invention, the harness-through opening includes the cylindrical portion structuring the large diameter portion and the rib projecting from the inner surface of the cylindrical portion toward the center of the cylindrical portion and extending along the cylindrical portion so as to structure the small diameter portion. It can make the rib bite the sheet so as to seal the gap between the wiring harness and the harness-through opening. Thus, the cover can be attached with the small force on the case main body of the electric connection box.

The above and other objects and features of this invention will become more apparent from the following description taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

First Embodiment

An electric connection box of a first embodiment according to the present invention will be described with reference toFIGS. 1,2.FIG. 1is a perspective view of the electric connection box of the first embodiment.FIG. 2is a cross-sectional view taken along the line II-II inFIG. 1.

The electric connection box is mounted at an engine room of a car for supplying electric power to various electronic equipments mounted at the car. In this description, a junction block, a fuse block and a relay box are called the electric connection box as a generic name.

The electric connection box1A, as shown inFIGS. 1,2, includes a case main body2A, in which various electric components15,16are arranged; a lower cover3A to be attached at a bottom side of the case main body2A; an upper cover4to be attached at an upper side of the case main body2A; a harness-through opening5A to be structured into a cylindrical shape with the case main body2A and the lower cover3A when the lower cover3A is attached to the case main body2A; a wiring harness8to be passed through the harness-through opening5A and a water-protect sheet9as an elastic sheet wound around the wiring harness8to be arranged in the harness-through opening5A. The case main body2A, the lower cover3A and the upper cover4are made of synthetic resin by injection molding.

The wiring harness8is formed by bundling a plurality of electric wires connecting the various electric components15,16mounted at the case main body2A and the various electronic equipments mounted at the car. Outer diameter of the wiring harness8varies according to a type or grade of the car in which the number of electric wires is different from each.

The water-protect sheet9is made of urethane foam or urethane rubber, and wound around the wiring harness8and arranged tightly on an inner wall of the harness-through opening5A so as to seal a gap between the wiring harness8and the harness-through opening5A. Thereby, it can be prevented that a liquid like water penetrates through the gap into the case main body2A.

The harness-through opening5A is structured with a projection6A projecting with a half-cylindrical shape from a lower edge of an outer wall21of the case main body2A, and a projection7A projecting with a half-cylindrical shape from an upper edge of an outer wall31of the lower cover3A, the outer wall31corresponding to the outer wall21. When the lower cover3A is attached on the case main body2A, the projections6A and7A are overlapped to each other so as to form the harness-through opening5A. The harness-through opening5A communicates an outside of the case main body2A and an inside of the case main body2A.

The harness-through opening5A has a large diameter portion11(shown by surrounding with a chain double-dashed line inFIG. 2), which has an inner diameter C2larger than an outer diameter d1of the part of the wiring harness8wound with the water-protect sheet9, and a small diameter portion12(shown by surrounding with a dashed line inFIG. 2), which has an inner diameter C1smaller than the outer diameter d1of the part of the wiring harness8wound with the water-protect sheet9. The outer diameter of the part of the wiring harness8wound with the water-protect sheet9correspond to an outer diameter of the wiring harness8added with thickness of the water-protect sheet9.

The harness-through opening5A includes a cylindrical portion50structuring the large diameter portion11and a slant portion51arranged at an inner surface of the cylindrical portion50and slanting from an end of the cylindrical portion50to the other end of the cylindrical portion50to approach gradually toward a center of the cylindrical portion50so as to structure a small diameter portion12. Thus, the cylindrical portion50is formed with the projections6A,7A, and the slant portion51is arranged at the inner surface of the projection7A. The end of the cylindrical portion50corresponds to an end apart from the outer wall21, and the other end of the cylindrical portion50corresponds to the end nearer to the outer wall21.

The slant portion51of the harness-through opening5A structured above bites into the water-protect sheet9wound around the wiring harness8so as to press and deform the water-protect sheet9toward the center of the wiring harness8. Thereby, the water-protect sheet9water-tightly seals a gap between the wiring harness8and the inner surface of the harness-through opening5A, especially an inner surface of the small diameter portion12.

As mentioned above, according to the present invention, by the part of the harness-through opening5A biting the water-protect sheet9, the gap between the wiring harness8and the harness-through opening5A is sealed. Therefore, the small diameter portion12, that is the slant portion51, is dimensioned so as to bite the water-protect sheet9wound around the wiring harness8.

The electric connection box1A is assembled by arranging the part of the wiring harness8wound with the water-protect sheet9between the projections6A,7A, and attaching the lower cover3A on the case main body2A so as to clamp the part wound with the water-protect sheet9between the projections6A,7A. A lock receiver22arranged at the outer wall21of the case main body2A engages with a lock arm32arranged at the outer wall31of the lower cover3A, so that the lower cover3A is assembled to the case main body2A.

According to the present invention mentioned above, only by the small diameter portion12biting the water-protect sheet9, the gap between the wiring harness8and the harness-through opening5A can be sealed. Thereby, the lower cover3A can be attached to the case main body2A with a small force.

Second Embodiment

An electric connection box of a second embodiment according to the present invention will be described with reference toFIG. 3.FIG. 3is a cross-sectional view of the electric connection box of the second embodiment according to the present invention. With respect toFIG. 3, components same as the first embodiment mentioned above are put with the same marking and descriptions bout them will be omitted.

An electric connection box1B as shown inFIG. 3includes a case main body2B, in which the various electric components15,16are arranged; a lower cover3B to be attached at a bottom side of the case main body2B; an upper cover4to be attached at an upper side of the case main body2B; a harness-through opening5B to be structured into a cylindrical shape with the case main body2B and the lower cover3B when the lower cover3B is attached to the case main body2B; a wiring harness8to be passed through the harness-through opening5B and a water-protect sheet9as an elastic sheet wound around the wiring harness8to be arranged in the harness-through opening5B. The case main body2B, the lower cover3B and the upper cover4are made of synthetic resin by injection molding.

The harness-through opening5B is structured with a projection6B projecting with a half-cylindrical shape from a lower edge of the outer wall21of the case main body2B, and a projection7B projecting with a half-cylindrical shape from an upper edge of the outer wall31of the lower cover3B, the outer wall31corresponding to the outer wall21. When the lower cover3B is attached on the case main body2B, the projections6B and7B are overlapped to each other so as to form the harness-through opening5B. The harness-through opening5B communicates an outside of the case main body2B and an inside of the case main body2B.

The harness-through opening5B has a large diameter portion13(shown by surrounding with a chain double-dashed line inFIG. 3), which has an inner diameter C12larger than an outer diameter d11of the part of the wiring harness8wound with the water-protect sheet9, and a small diameter portion14(shown by surrounding with a dashed line inFIG. 3), which has an inner diameter C11smaller than the outer diameter d11of the part of the wiring harness8wound with the water-protect sheet9. The outer diameter of the part of the wiring harness8wound with the water-protect sheet9correspond to an outer diameter of the wiring harness8added with thickness of the water-protect sheet9.

The harness-through opening5B includes a cylindrical portion54structuring the large diameter portion13and three ribs53projecting from an inner surface of the cylindrical portion54toward a center of the cylindrical portion54and extending along the cylindrical portion54so as to structure the small diameter portion14. Three ribs53are arranged at intervals from each other. Thus, the cylindrical portion54is formed with the projections6B,7B, and the ribs53are arranged at the inner surfaces of the projections6B,7B. The large diameter portion13corresponds to a part other than the part in which the ribs53of the cylindrical portion54are arranged.

The three ribs53of the harness-through opening5B structured above bite into the water-protect sheet9wound around the wiring harness8so as to press and deform the water-protect sheet9toward the center of the wiring harness8. Thereby, the water-protect sheet9water-tightly seals a gap between the wiring harness8and the inner surface of the harness-through opening5B, especially an inner surface of the small diameter portion14.

As mentioned above, according to the present invention, by the part of the harness-through opening5B biting the water-protect sheet9, the gap between the wiring harness8and the harness-through opening5B is sealed. Therefore, the small diameter portion14, that is the rib53, is dimensioned so as to bite the water-protect sheet9wound around the wiring harness8.

The electric connection box1B is assembled by arranging the part of the wiring harness8wound with the water-protect sheet9between the projections6B,7B, and attaching the lower cover3B on the case main body2B so as to clamp the part wound with the water-protect sheet9between the projections6B,7B.

According to the present invention mentioned above, only by the small diameter portion14biting the water-protect sheet9, the gap between the wiring harness8and the harness-through opening5B can be sealed. Thereby, the lower cover3B can be attached to the case main body2B with a small force.

According to the first and second embodiments mentioned above, the harness-through opening5A,5B is structured, for example, by the lower cover3A,3B. For structuring the harness-through opening, the upper cover also can be applied according to he present invention.

While, in the embodiment, the present invention is described, it is not limited thereto. Various change and modifications can be made with the scope of the present invention.