JP7790960B2 - Electrical junction boxes and wire harnesses - Google Patents

Description

The present invention relates to an electrical junction box and a wire harness.

Conventionally, a connector box is a type of electrical connection box installed in a vehicle, and is attached, for example, to a mounting panel separating the interior and exterior of the vehicle. A connector box is composed of, for example, a box body, a grommet, a grommet inner, and an upper cover. For example, Patent Document 1 describes a waterproof grommet mounting structure in which one cover has an opening, a waterproof grommet for inserting electrical wires is fitted into the opening, one cover is joined to the other cover to form a box body, and the other cover abuts the end of the waterproof grommet. In this way, connector boxes typically have a waterproof structure that prevents water from entering from the outside.

Japanese Patent Application Laid-Open No. 2006-129545

In connector boxes, waterproof structures are used at the mating parts between the box body and upper cover and the grommet, but if water enters the inside of the box body, it is drained through the through-holes in the grommet for inserting the electrical wires. However, due to the structure of conventional box bodies and upper covers, water that enters the inside of the box body may not move toward the through-holes in the grommet for inserting the electrical wires, but may instead move to the side of the box body opposite the grommet, leaving room for improvement in terms of waterproofing.

The present invention was made in consideration of the above-mentioned issues, and aims to provide an electrical junction box that can improve waterproofing.

In order to achieve the above object, the electrical junction box of the present invention includes a box-shaped main body portion that accommodates electrical components in a box-side internal space, an opening formed at one end of the main body portion in an assembly direction, the opening connecting the box-side internal space to the outside in the assembly direction, and a box-side cutout portion formed in an opening wall that forms the opening, the box-side internal space connecting the outside to the outside in an insertion direction that is perpendicular to the assembly direction and along a vertical direction , a cover that closes the opening and faces the box-side cutout portion in the assembly direction in an assembled state where the box is assembled to the box body in the assembly direction, thereby forming an insertion hole with the box body that penetrates along the insertion direction, and a cover that fits into the insertion hole and and a grommet that waterproofs the insertion hole and through which a wiring material connected to the electrical component housed inside the box body is inserted along the insertion direction, the grommet having at least a cylindrically formed grommet body through which the wiring material is inserted into the grommet side internal space, the grommet body having a cylindrical portion and a water-stopping portion that is formed in an annular shape and protrudes from one outer peripheral end of the cylindrical portion in the insertion direction in a direction perpendicular to the insertion direction, and that fits into the insertion hole to waterproof the insertion hole, the box body having a waterproof wall that protrudes from the inner wall surface of the opening wall toward the box side internal space and is formed along the box side cutout portion when viewed from the box side internal space side in the insertion direction.

In order to achieve the above object, a wire harness according to the present invention includes a conductive wiring material and an electrical junction box electrically connected to the wiring material, the wire harness including: a main body formed in a box shape and accommodating electrical components in a box-side internal space; an opening formed at one end in an assembly direction of the main body and communicating the box-side internal space with the outside in the assembly direction; and a box-side cutout formed in an opening wall constituting the opening and communicating the box-side internal space with the outside in an insertion direction perpendicular to the assembly direction and along a vertical direction ; and a box-side cutout formed in an assembly state in which the main body is assembled to the box body in the assembly direction, the box-side cutout closing the opening and opposing the box-side cutout in the assembly direction, thereby forming an insertion hole penetrating along the insertion direction with the box body. and a grommet that fits into the insertion hole to waterproof the insertion hole and through which a wiring material connected to the electrical component housed inside the box body is inserted along the insertion direction, the grommet having at least a cylindrically formed grommet body through which the wiring material is inserted into a grommet-side internal space, the grommet body having a cylindrical portion and a water-stopping portion that is formed in an annular shape and protrudes from one outer peripheral end of the cylindrical portion in the insertion direction in a direction perpendicular to the insertion direction, and fits into the insertion hole to waterproof the insertion hole, the box body having a waterproof wall that protrudes from an inner wall surface of the opening wall toward the box-side internal space and is formed along the box-side cutout portion when viewed from the box-side internal space side in the insertion direction.

The electrical junction box and wire harness according to the present invention have the advantage of being able to improve waterproofing.

FIG. 1 is a perspective view of an electrical junction box according to an embodiment. FIG. 2 is an exploded perspective view of the electrical junction box according to the embodiment. FIG. 3 is a partial perspective view of the electrical junction box according to the embodiment. FIG. 4 is an exploded perspective view of the grommet according to the embodiment. FIG. 5 is a partial perspective view of a main body of the electrical junction box according to the embodiment. FIG. 6 is a partial vertical cross-sectional view of the electrical junction box according to the embodiment.

Embodiments of an electrical junction box and a wire harness according to the present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the embodiments shown below. Furthermore, the components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially identical.

[Embodiment]
The electrical junction box 1 shown in Figures 1 and 2 is mounted on a vehicle such as an automobile and incorporated into a wire harness WH. The wiring material W in Figure 1 is indicated by a two-dot chain line, and is omitted in Figure 2. The wire harness WH is, for example, a collection of multiple wiring materials W used for power supply and signal communication to connect various devices mounted on a vehicle, and the multiple wiring materials W are connected to the devices using connectors or the like. The wire harness WH includes conductive wiring material W and an electrical junction box 1 attached to the wiring material W to protect the wiring material W. The wiring material W is, for example, composed of a flexible electric wire, a wire bundle, or the like. The electric wire has a conductor portion (core wire) made of multiple conductive metal wires, the outside of which is covered with an insulating coating. The wire bundle is a bundle of such electric wires. The wire harness WH may further include a protector, an exterior material, a fixing tool, and the like.

Here, the X direction shown in the figure is the assembly direction of the electrical junction box 1 in this embodiment. The Y direction is the width direction of the electrical junction box 1 in this embodiment, and is a direction perpendicular to the X direction. The Z direction is the insertion direction of the electrical junction box 1 in this embodiment, and is a direction perpendicular to the X and Y directions. The insertion direction is along the vertical direction. In particular, of the X directions, the X1 direction is the outdoor direction, and the X2 direction is the indoor direction. Furthermore, of the Z directions, the Z1 direction is the upward direction, and the Z2 direction is the downward direction. Unless otherwise specified, the directions used in the following explanation are those in the state in which the various parts of the electrical junction box 1 are assembled.

The electrical junction box 1 is a connector box that aggregates and connects, for example, multiple connectors provided at the ends of the wiring material W of a wire harness WH to connectors of various vehicle devices. The electrical junction box 1, once incorporated into the wire harness WH, is inserted and fixed into a panel through-hole 101 formed in a mounting panel 100 that separates the exterior space (e.g., engine compartment) and the interior space (e.g., cabin) of a vehicle (not shown). The mounting panel 100 is formed, for example, from a metal flat plate and forms the vehicle body. The mounting panel 100 has a panel surface 100a facing the exterior, a panel back surface 100b facing the interior, and a panel through-hole 101 and four bolt through-holes 102 that penetrate from the panel surface 100a to the panel back surface 100b. The electrical junction box 1 is fixed to the mounting panel 100 with a portion inserted into the panel through-hole 101. As shown in Figures 1 and 2, the electrical junction box 1 comprises a box body 10, a grommet 20, an exterior cover 30, and an interior cover 31.

The box body 10 accommodates an electrical component D and a portion of the wiring material W connected to the electrical component D. The electrical component D is, for example, an electronic component such as a connector, fuse, relay, branch, or electronic control unit that is incorporated into a wire harness WH and constitutes a connection processing component for the wiring material W, etc. The box body 10 has multiple compartments inside, and an electrical component D is arranged in each compartment. The box body 10 is formed from an insulating synthetic resin or the like. The box body 10 includes a main body 11, openings 12 and 17, a box-side cutout 13, an opening wall 15, and a waterproof wall 16.

The main body 11 is box-shaped and houses electrical components D in the box-side internal space 10a formed therein. The main body 11 is provided with holding portions for holding each of the electrical components D in the box-side internal space 10a. The main body 11 houses the electrical components D in the box-side internal space 10a with the electrical components D held by these holding portions.

Opening 12 is formed at one end (toward the outside) of main body 11 in the assembly direction, and connects box-side internal space 10a to the outside in the assembly direction. Opening 12 is formed by opening wall 15. Opening 12 is formed in a rectangular shape when viewed from the assembly direction. Opening 17 is formed at the other end (toward the inside) of main body 11 in the assembly direction, and connects box-side internal space 10a to the outside in the assembly direction.

As shown in Figures 2, 3, and 5, the box-side cutout 13 is formed in the opening wall 15 of the main body 11 that constitutes the opening 12, and connects the box-side internal space 10a to the outside in the insertion direction. The box-side cutout 13 is formed in a portion of the opening wall 15 that is located on one side (downward) in the insertion direction, and is fitted with a grommet 20. When viewed from the insertion direction, the box-side cutout 13 is recessed from the end face of the opening wall 15 on one side of the assembly direction (toward the outside of the room) toward the other side of the assembly direction (toward the inside of the room). The box-side cutout 13 has a cutout surface 13a and a recess 13b.

The cutout surface 13a constitutes the box-side cutout portion 13 of the opening wall 15. When the box-side cutout portion 13 is viewed from one side of the assembly direction (the outside direction), the cutout surface 13a is composed of a cutout surface 131 facing one side of the assembly direction (the outside direction) and a pair of cutout surfaces 132 facing each other in the width direction with the cutout surface 131 in between.

The recesses 13b are formed so as to recess from the cutout surface 13a into the opening wall 15. The recesses 13b are provided on each cutout surface 131, 132, and each recess 13b is formed continuously along the cutout surfaces 131, 132. The bottom surface of the recesses 13b has an uneven shape that matches the outer peripheral shape of the water stop portion 41 of the grommet 20. The water stop portion 41 of the grommet 20 is fitted into the recesses 13b when the exterior cover 30 is assembled to the box body 10 in the assembly direction. This assembled state includes a state in which the grommet inner 22, described below, is housed in the grommet-side internal space 20a.

In addition, when the outdoor cover 30 is assembled to the box body 10 in the assembly direction, the box-side cutout 13 and the outdoor cover 30 face each other in the assembly direction, forming an insertion hole 14 that penetrates along the insertion direction. The insertion hole 14 is waterproofed by fitting a portion of the grommet 20 into it. When viewed from the insertion direction, the insertion hole 14 is formed in a roughly oval shape whose width is longer than its length in the assembly direction.

As shown in Figures 3 and 5, the waterproof wall 16 protrudes from the inner wall surface 15a of the opening wall 15 toward the box-side internal space 10a and is formed along the box-side cutout 13 when viewed from the box-side internal space 10a in the insertion direction of the box-side cutout 13. When the exterior cover 30 is assembled to the box body 10 in the assembly direction, the waterproof wall 16 faces the protruding portion 50 of the grommet inner 22 housed in the grommet 20, described below, along the extension direction of the protruding portion 50. The upward length (height) of the waterproof wall 16 is the length (height) upward from one end face 41a of the water-stopping portion 41, described below, in the insertion direction, when the exterior cover 30 is assembled to the box body 10 in the assembly direction. The upward length of the waterproof wall 16 is formed longer (higher) than the upward length (height) from the end face 41a of the protruding portion 50. When the outdoor cover 30 is assembled to the box body 10 in the assembly direction, both widthwise ends of the waterproof wall 16 abut against the outdoor cover 30 in the assembly direction.

As shown in Figure 2, the grommet 20 fits into the insertion hole 14 to waterproof the insertion hole 14, and allows the wiring material W connected to the electrical component D housed inside the box body 10 to pass through along the insertion direction. The grommet 20 has a grommet body 21 and a grommet inner 22.

The grommet body 21 is formed at least cylindrically, and the wiring material W is inserted into the grommet-side internal space 20a. The grommet body 21 is formed from an insulating elastic resin material with low rigidity and high flexibility, such as rubber or thermoplastic elastomer (e.g., ethylene-propylene-diene rubber (EPDM)). As shown in Figure 4, the grommet body 21 has a cylindrical portion 40 and a water-stopping portion 41, which are integrally formed as an elastic body.

The tubular portion 40 extends from the watertight portion 41 toward the other side of the insertion direction (downward). The tubular portion 40 is formed integrally with the watertight portion 41 and is generally cylindrical with both ends in the insertion direction open. When viewed from the insertion direction, the tubular portion 40 has an opening that is generally oval in shape, with its width longer than its length in the assembly direction.

The water-stopping portion 41 is formed in an annular shape, protruding from one outer peripheral end (upper direction) of the tubular portion 40 in a direction perpendicular to the insertion direction, and fits into the insertion hole 14 to seal off the water in the insertion hole 14. When viewed from the insertion direction, the water-stopping portion 41 is formed in a roughly oval shape whose width is longer than its length in the assembly direction. When the exterior cover 30 is assembled to the box body 10 in the assembly direction, the water-stopping portion 41 has a portion on the end surface 41a of the grommet 20 that is surrounded by the waterproof wall 16 and the protrusion 50.

The grommet inner 22 is formed in a ring shape around the insertion direction and is housed in the grommet-side internal space 20a. The grommet inner 22 is made of a hard synthetic resin material with insulating properties and is harder than the water-stopping portion 41. It is attached to the inner surface of the water-stopping portion 41 with the wiring material W inserted inside. When viewed from the insertion direction, the grommet inner 22 is formed in a roughly oval shape whose width is longer than its length in the assembly direction. The grommet inner 22 has a protrusion 50 and a grommet-side cutout 51.

When the grommet inner 22 is housed in the grommet-side internal space 20a, i.e., in the assembled state described above, the protrusion 50 protrudes further in the insertion direction (upward) than the outer peripheral edge of the tubular portion 40 on one side in the insertion direction (upward). When the exterior cover 30 is assembled to the box body 10 in the assembly direction, a portion of the protrusion 50 is formed along the box-side cutout 13 when viewed from the box-side internal space 10a side (above) in the insertion direction.

As shown in Figures 3 and 4, the grommet-side cutout 51 is formed at one end (upper) of the protrusion 50 in the insertion direction, connecting the outside and the inside. The "outside" here refers to the grommet-side internal space 20a, which is connected to the outside, and the "inside" refers to the space within the box-side internal space 10a sandwiched between the waterproof wall 16 and the protrusion 50. The bottom surface of the grommet-side cutout 51 on the other side (lower) in the insertion direction is located at the same height in the insertion direction as the end face 41a of the grommet 20 when the exterior cover 30 is assembled to the box body 10 in the assembly direction. The grommet-side cutout 51 is formed in a portion of the protrusion 50 that faces the waterproof wall 16 in a direction perpendicular to the insertion direction when the exterior cover 30 is assembled to the box body 10 in the assembly direction. The grommet-side cutouts 51 are provided, for example, in two locations on the annular projection 50, on the side facing the interior of the vehicle in the assembly direction.

As shown in Figures 1 and 2, the outdoor cover 30 closes the opening 12 in the main body portion 11 of the box body 10 when the outdoor cover 30 is assembled to the box body 10 in the assembly direction. Furthermore, when the outdoor cover 30 is assembled to the box body 10 in the assembly direction, the outdoor cover 30 faces the box-side cutout portion 13 in the assembly direction, thereby forming an insertion hole 14 that penetrates along the insertion direction with the box body 10. The outdoor cover 30 is formed in a tray shape from insulating synthetic resin or the like. When the outdoor cover 30 is assembled to the box body 10 in the assembly direction, the outdoor cover 30 is located on one side of the box body 10 in the assembly direction (toward the outside) and is fastened to the box body 10 by a fastening mechanism.

As shown in FIG. 1, the indoor cover 31 closes the opening 17 of the main body portion 11 of the box body 10 when the indoor cover 31 is assembled to the box body 10 in the assembly direction. The indoor cover 31 is formed in a tray shape from an insulating synthetic resin or the like. When the indoor cover 31 is assembled to the box body 10 in the assembly direction, the indoor cover 31 is located on the other side of the assembly direction (toward the interior of the room) of the box body 10, and is detachably locked to the box body 10 by a locking mechanism.

Next, the assembly process for the electrical junction box 1 will be described with reference to Figures 1 and 2. The grommet 20 is assumed to be in an assembled state, with the grommet inner 22 already housed in the grommet-side internal space 20a and one or more wiring materials W connected to electrical components D inserted into the grommet-side internal space 20a.

The worker attaches the box body 10 to the mounting panel 100 from the panel back surface 101b side. The worker inserts the opening wall 15 of the box body 10 into the panel through-hole 101 of the mounting panel 100, inserts each stud bolt 18 into each bolt through-hole 102, and pushes the box body 10 in one direction of assembly (toward the outside of the room) until the locking portion on the box body 10 locks into the panel through-hole 101.

Next, the worker attaches the grommet 20 to the box body 10 attached to the mounting panel 100 from the panel surface 101a side. The worker fits the watertight portion 41 of the grommet 20 into the box-side cutout portion 13 of the box body 10. At this time, the worker assembles the electrical component D into the holder inside the box body 10. Next, the worker attaches the exterior cover 30 to the box body 10 from the panel surface 101a side and fastens each stud bolt 18 by screwing nuts onto them. The worker then attaches the interior cover 31 to the box body 10 from the panel back surface 101b side, completing the work.

As described above, the electrical junction box 1 according to this embodiment includes a box body 10, an exterior cover 30 attached to the box body 10, and a grommet 20. The grommet 20 has a grommet body 21 formed at least cylindrically and through which a wiring material W is inserted into the grommet-side internal space 20a. The grommet body 21 has a cylindrical portion 40 and a water-stopping portion 41 formed in an annular shape and protruding from one outer peripheral end of the cylindrical portion 40 in a direction perpendicular to the insertion direction, and fitting into the insertion hole 14 to seal the insertion hole 14. The box body 10 has a waterproof wall 16 that protrudes from the inner wall surface 15a of the opening wall 15 toward the box-side internal space 10a and is formed along the box-side cutout 13 when viewed from the box-side internal space 10a in the insertion direction.

With this configuration, when viewed from the insertion direction, the waterproof wall 16 blocks the flow path of water that has entered the box body 10 toward the opposite side of the grommet 20, i.e., toward the inside of the vehicle cabin, and water that has entered the interior can be actively drained to the outside through the grommet-side internal space 20a, improving the waterproofing and drainage properties of the electrical junction box 1. Furthermore, by not adding any additional parts to conventional electrical junction boxes and simplifying the part shapes, costs can be kept down.

In addition, in the electrical junction box 1 according to this embodiment, the box-side cutout portion 13 has a recess 13b formed so as to recess from the cutout surface 13a into the opening wall 15, and the water-stopping portion 41 on the grommet 20 side fits into the recess 13b when assembled. This prevents the grommet 20 from moving in the insertion direction relative to the box body 10 and the exterior cover 30 when assembled.

The electrical junction box 1 according to this embodiment also has a grommet inner 22 that accommodates the grommet 20 in the grommet-side internal space 20a. When the grommet inner 22 is accommodated in the grommet-side internal space 20a, the grommet inner 22 has a grommet-side cutout 51 formed at one end in the insertion direction of the protrusion 50, connecting the outside and inside. This allows water that has entered the space between the waterproof wall 16 and the protrusion 50 in the box-side internal space 10a to be guided into the grommet-side internal space 20a via the grommet-side cutout 51 without stagnating, improving the drainage performance of the electrical junction box 1.

The wire harness WH comprises a conductive wiring material W and an electrical junction box 1 electrically connected to the wiring material W, and achieves the same effects as the electrical junction box 1 described above.

In the above embodiment, the grommet-side cutouts 51 are provided in two locations on the annular protrusion 50, on the portion of the protrusion 50 that is located toward the interior of the vehicle in the assembly direction, but this is not limited to this. For example, the grommet-side cutouts 51 may be provided at any position on the annular protrusion 50, and the number of locations is not limited to two.

In addition, in the above embodiment, the electrical junction box 1 is described as a connector box, but it is not limited to this and may be, for example, a junction box, fuse box, relay box, etc.

REFERENCE SIGNS LIST 1 Electrical connection box 10 Box body 10a Box-side internal space 11 Body portion 12 Opening 13 Box-side cutout portion 14 Insertion hole 15 Opening wall 15a Inner wall surface 16 Waterproof wall 20 Grommet 20a Grommet-side internal space 21 Grommet body 22 Grommet inner 30 Outdoor cover 40 Cylindrical portion 41 Water-stopping portion D Electrical component W Wiring material WH Wire harness

Claims (4)

a box body having a main body formed in a box shape and accommodating electrical components in a box-side internal space; an opening formed at one end in an assembly direction of the main body, the opening communicating the box-side internal space with the outside in the assembly direction; and a box-side cutout formed in an opening wall constituting the opening, the box-side internal space communicating with the outside in an insertion direction perpendicular to the assembly direction and along a vertical direction ;
a cover that closes the opening when assembled to the box body in the assembly direction and faces the box-side cutout portion in the assembly direction to form, with the box body, an insertion hole that penetrates along the insertion direction;
a grommet that fits into the insertion hole to waterproof the insertion hole and through which a wiring material connected to the electrical component housed inside the box body is inserted along the insertion direction,
The grommet is
The grommet body has at least a cylindrical shape and has an internal space on the grommet side through which the wiring material is inserted,
The grommet body is
A cylindrical portion;
a water-stopping portion that is formed in an annular shape and protrudes from one outer peripheral end of the tubular portion in the insertion direction in a direction perpendicular to the insertion direction, and that fits into the insertion hole to stop water from entering the insertion hole,
The box body includes:
a waterproof wall protruding from an inner wall surface of the opening wall toward the box-side internal space and formed along the box-side cutout portion when viewed from the box-side internal space portion side in the insertion direction of the box-side cutout portion;
An electrical junction box characterized by: The box-side cutout portion is
A cutout surface of the opening wall that constitutes the box-side cutout portion;
a recess formed so as to be recessed from the cutout surface into the opening wall,
The recessed portion is
In the assembled state, the water stopping portion is fitted.
2. The electrical junction box according to claim 1. The grommet is
a grommet inner formed in an annular shape around the insertion direction and accommodated in the grommet-side internal space;
The grommet inner is
When the grommet inner is housed in the grommet-side internal space, the grommet inner has a protruding portion that protrudes further toward one side in the insertion direction than one outer peripheral end of the cylindrical portion in the insertion direction,
The protrusion is
a grommet-side notch formed at one end in the insertion direction and communicating the outside and the inside;
3. The electrical junction box according to claim 1 or 2. A conductive wiring material;
an electrical connection box electrically connected to the wiring material,
The electrical connection box comprises:
a box body having a main body formed in a box shape and accommodating electrical components in a box-side internal space; an opening formed at one end in an assembly direction of the main body, the opening communicating the box-side internal space with the outside in the assembly direction; and a box-side cutout formed in an opening wall constituting the opening, the box-side internal space communicating with the outside in an insertion direction perpendicular to the assembly direction and along a vertical direction ;
a cover that closes the opening when assembled to the box body in the assembly direction and faces the box-side cutout portion in the assembly direction to form, with the box body, an insertion hole that penetrates along the insertion direction;
a grommet that fits into the insertion hole to waterproof the insertion hole and through which a wiring material connected to the electrical component housed inside the box body is inserted along the insertion direction,
The grommet is
The grommet body has at least a cylindrical shape and has an internal space on the grommet side through which the wiring material is inserted,
The grommet body is
A cylindrical portion;
a water-stopping portion that is formed in an annular shape and protrudes from one outer peripheral end of the tubular portion in the insertion direction in a direction perpendicular to the insertion direction, and that fits into the insertion hole to stop water from entering the insertion hole,
The box body includes:
a waterproof wall protruding from an inner wall surface of the opening wall toward the box-side internal space and formed along the box-side cutout portion when viewed from the box-side internal space portion side in the insertion direction of the box-side cutout portion;
A wire harness characterized by: