JP2004064872A - Electric connection box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high water-proofing electric connection box which prevents water having splashed on an electric connection box from hitting on a lock and spattering. <P>SOLUTION: The lock 20 is provided opposite to the wall 17 of a lower cover 15, and a through groove 35 for drainage is made between the lock 20 and the wall 17. The groove 35 is demarcated by sidewalls 35a and 35b on both sides and a bottom wall 35c. One sidewall 35a ranges from the wall 17 of a lower cover 15, the other sidewall 35b ranges from the lock 20, and the bottom wall 35c ranges from the rig 28 around the cover 15. The lock 20 is a tongue-shaped locking piece which projects in the engaging direction from the opening end 16 of the lower cover 15, and the groove 35 constitutes space for flexure to the locking piece. The inner edge of the abutment end 63 of a box body 50 is laid in double wall state on the outer edge of the opening end 16 of the lower cover 15, and they are entered into the groove 35. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric junction box having a junction block on which a relay, a fuse, and the like are mounted, and including a box body and a lower cover.
[0002]
[Prior art]
The number of electric wires and the number of assembled parts for supplying power and transmitting and receiving signals between electronic peripheral devices mounted on a vehicle or the like is enormous. Vehicles equipped with these electronic peripheral devices include four-wheeled vehicles, two-wheeled vehicles, tractors, crane vehicles, and the like. Examples of the wiring means in these vehicles include a wire harness, a connector that collectively accommodates terminals connected to the ends of the wires constituting the wire harness, an electric connection box equipped with a plurality of connectors, and the like. Commonly used.
[0003]
Electrical junction boxes are mounted around the engine room and instrument panel of automobiles, and are assembled automotive parts that supply power to instruments, switches, lamps, and other electronic peripheral devices, and relay signals that exchange signals. is there. Further, the electric connection box does not merely branch the wiring, but also forms a relay circuit or a fuse circuit, or forms an ECU (Electronic Control Unit) circuit for controlling various devices.
[0004]
By the way, the electric connection box mounted in the engine room may be exposed to water during running on rainy weather, or may receive high-pressure washing water or steam during car washing. In view of this, electrical junction boxes that prevent entry of water, steam, or the like are widely provided.
[0005]
FIG. 6 shows an example of such an electric connection box. The electric connection box 70 includes a lower cover 75 having an opening at an upper part, an upper cover 73 having an opening at a lower part, and a box body 87 disposed between the lower cover 75 and the upper cover 73. A junction block to which a relay, a fuse, a connector, and the like (not shown) are attached is attached to the box body 87.
[0006]
The attachment of the box body 87 to the lower cover 75 is performed by engaging an insertion locking piece 78 provided on the lower cover 75 with an engaging portion (not shown) provided on the box body 87. FIGS. 6 and 7 show a plug-in locking piece 78 that serves as a locking portion of the electric junction box 70.
[0007]
As shown in FIG. 6, the insertion locking piece 78 is formed integrally with the side wall 76 of the lower cover 75. The insertion locking piece 78 includes a pair of root portions 79 and an insertion portion 80. The insertion portion 80 is a free end portion that follows the base portion 79, and the tip end protrudes above the open end 77 of the lower cover 75. The root side of the insertion portion 80 is formed on the same plane as the opening end 77, so that the rib 85 formed on the outer periphery of the side wall 76 is discontinuous.
[0008]
When the lower cover 75 is attached to the box main body 87, the insertion portion 80 of the insertion locking piece 78 enters a locking frame (not shown) of the box main body 87, and is inserted into the outer surface 82 of the insertion portion 79. The formed locking step 83 engages with a locking projection (not shown) in the locking frame. The contact end portion 89 of the box main body 87 is provided with a notched escape portion 90, and the root side of the insertion portion 80 is engaged with the escape portion 90, so that the box body 87 and the lower cover 75 Are fitted.
[0009]
[Problems to be solved by the invention]
However, the conventional electric junction box has the following problems to be solved.
[0010]
One is that high-pressure washing water, steam, and the like enter through a gap 81 between a rib 85 on the outer periphery of the lower cover 75 and a contact end 89 of the box body 87 as shown in a drainage path C shown in FIG. There is a fear that water or steam may enter the electrical junction box 70 from the boundary between the box main body 87 and the lower cover 75 and bounce back and forth.
[0011]
On the other hand, the electric connection box 70 including the box body 87 and the lower cover 75 is an injection-molded body made of synthetic resin. There is a concern that the sealing property between the lower cover 75 and the opening end 77 is impaired, and that water or the like enters through the gap.
[0012]
In order to bring the contact end 89 and the opening end 77 into close contact with each other so as not to form a uniform gap, it is necessary to increase the number of lock portions, which increases the manufacturing cost. It is conceivable to change the material to a sealing material having good water stopping properties, but this also increases the manufacturing cost.
[0013]
In view of the above, an object of the present invention is to provide a highly waterproof electric connection box in which water applied to the electric connection box is prevented from hitting the locking portion and bouncing off.
[0014]
[Means for Solving the Problems]
Means for Solving the Problems To achieve the above object, an invention according to claim 1 is directed to an electric connection box including a lower cover having a locking portion on a wall portion, and a box body having an engaging portion engaged with the locking portion. The locking portion is provided so as to face a wall portion of the lower cover, and a communication groove for drainage is formed between the locking portion and the wall portion.
[0015]
According to the above configuration, since the drainage groove is formed between the locking portion and the wall of the lower cover, water is applied to the electric connection box, and water that has entered through the gap bounces off the locking portion. Without being drained out of the electrical junction box through the drainage channel. Therefore, the water that has entered through the gap in the electrical junction box is prevented from entering the interior of the electrical junction box by splashing against the locking portion. Further, even if the water hits the locking portion and is splashed, the splashed water falls into the groove and is discharged, so that water is prevented from entering the inside of the electric connection box.
[0016]
According to the second aspect of the present invention, in the electrical junction box according to the first aspect, the groove is defined by both side walls and a bottom wall, and one of the side walls is continuous with a wall portion of the lower cover, The other side wall is connected to the locking portion, and the bottom wall is connected to a rib on the outer periphery of the lower cover.
[0017]
According to the above configuration, since the side walls on both sides forming the groove are connected to the wall portion and the locking portion of the lower cover, respectively, and the bottom wall is connected to the rib, the water applied to the electric connection box is The discharge enters the groove from one opening without being hindered, passes through the groove, and is smoothly discharged from the other opening.
[0018]
According to a third aspect of the present invention, in the electric contact box according to the first aspect, the locking portion is a tongue-shaped locking piece that protrudes in a fitting direction from an opening end of the lower cover. The groove serves as a bending space for the locking piece.
[0019]
According to the above configuration, since the drainage groove is a bending space of the locking piece, the fitting operation between the box body and the lower cover is easily performed, and by bending the locking piece inward, The disengagement operation is easily performed.
[0020]
According to a fourth aspect of the present invention, in the electrical junction box according to any one of the first to third aspects, the inner edge of the abutting end of the box main body is doubled at the outer edge of the opening end of the lower cover. It is characterized by overlapping and fitting in the wall state and entering the groove.
[0021]
According to the above configuration, since the lower cover and the box body overlap in a double-walled state, the overlapping portion is covered by the wall of the box body, and the water that has splashed on the electric connection box directly enters the electric connection box. Is prevented. Also, since the contact end of the box body enters the groove, there is no need to provide a cut-out relief at the contact end as in the electric connection box shown in the section of the prior art, and the lower cover and the box body are not required. The sealing performance with the seal is improved.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific examples of the embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an embodiment of an electric junction box according to the present invention.
[0023]
As shown in the figure, the electric connection box 10 is the same as the electric connection box 70 described in the section of the prior art, and has a lower cover 15 having an opening at an upper part, an upper cover 13 having an opening at a lower part, a lower cover 15 and an upper part. And a box body 50 disposed between the cover 13 and a junction block 62 to which a relay 70, a fuse (not shown), a connector (not shown), and the like are mounted. Have been. The lower cover 15, the upper cover 13, and the box body 50 are made of a synthetic resin material as components, and are molded with high precision by an injection molding method or the like.
[0024]
The box body 50 and the lower cover 15 overlap in a double wall state. That is, the inner edge of the contact end 63 of the box body 50 overlaps the outer edge of the open end 16 of the lower cover 15. With such fitting, the double wall functions as a waterproof wall without interposing a sealing material, and water can be prevented from entering the electric connection box 10.
[0025]
The box body 50 and the lower cover 15 are fitted by a locking means described later. The lower cover 15 is provided with an insertion locking piece (locking portion) 20 which forms one of the locking means. The box main body 50 is provided with a locking frame (engaging portion) 60 which forms the other of the locking means. Inside the locking frame 60, a locking projection 61 is provided inward, and the locking projection 61 is engaged with the locking step 26 (FIG. 2) formed on the insertion locking piece 20. Thus, the lower cover 15 is locked to the box body 50.
[0026]
The box body 50 and the upper cover 13 also overlap in a double wall state. That is, the inner edge of the open end 14 of the upper cover 13 overlaps the outer edge of the contact end 66 of the box body 50. The box body and the upper cover 13 are fitted by a locking means (not shown) to prevent water from entering the electric connection box 10.
[0027]
The junction block 62 is a component that forms a main part of the electric junction box 10 that performs functions such as signal transfer between electronic peripheral devices and power supply. In the junction block 62, a bus bar 62b (FIG. 2) is superposed on the insulating substrate 62a (FIG. 2) to form a signal branch circuit, or a relay 70 or a fuse is provided on the bus bar 62b. Are connected to form a relay circuit or a fuse circuit. What constitutes a relay circuit is sometimes called a so-called relay block, and what constitutes a fuse circuit is sometimes called a so-called fuse block. The functional components include, in addition to the relay 70 and the fuse, a fusible link (not shown), a circuit breaker (not shown), a connector (not shown), and the like.
[0028]
The lower cover 15 shown in FIG. 1 is formed in a box shape having an opening at an upper part. Inside, an electric wire connected to the junction block 62 is accommodated. The accommodated electric wire is drawn out from an electric wire outlet (not shown) formed in the outer wall (wall portion) 17 and is connected to peripheral equipment.
[0029]
The outer wall 17 is formed from a bottom wall 18 and a side wall 19 surrounding the bottom wall 18. First and second mounting brackets 40 and 42 for a vehicle body panel (not shown) are formed at two positions on the bottom wall 18, respectively. This is because the electric connection box 10 contains a bus bar formed by punching a conductive metal plate and is heavy, and therefore, there is a concern that the electric connection box 10 may become unstable if it is attached at one place. In addition, a drain hole may be formed in the bottom wall 18 in consideration of the case where water enters the lower cover 15 (not shown), just in case.
[0030]
The mounting brackets 40, 42 are composed of legs 40a, 42a that continue to the outer wall 17 of the lower cover 15, and substantially circular mounting portions 40b, 42b located at the distal ends of the legs 40a, 42a. A mounting hole 40c for bolt insertion (only the first mounting bracket is shown) is formed substantially at the center of the mounting portions 40b and 42b. The mounting hole 40c is formed as a so-called fool hole. The holes are formed in the fool holes so that even if the hole positions of the mounting brackets 40 and 42 and the hole positions of the vehicle body panel are shifted, the position shift can be absorbed.
[0031]
A plurality of locking claw pieces 30 protruding from the opening end 16 in the fitting direction are provided on the side wall 19 on the upper opening side of the lower cover 15. The locking claw piece 30 is formed on the other side wall 19 except the side wall 19 on which the insertion locking piece 20 is formed. The number of locking claw pieces 30 is arbitrary, but an appropriate number of locking claw pieces 30 are formed so that the box body 50 and the lower cover 15 do not come off. Such locking claw pieces 30 are integrally formed on the outer surface of the side wall 19.
[0032]
The locking claw piece 30 is bendable in the plate thickness direction, and a protrusion 30a is formed at a distal end portion of the locking claw piece 30 to be engaged with the locking hole 64 of the other party. On the outer surface of the locking claw piece 30, a ridge portion 30b is formed which extends straight in the direction in which the box body 50 and the lower cover 15 are fitted (vertical direction X). A guide 65 is formed in the locking hole 64 of the box body 50 to guide the ridge 30b while sliding. Accordingly, when the lower cover 15 and the box body 50 are fitted together, the projecting portion 30b of the locking claw piece 30 is guided by the guide portion 65 of the locking hole 64, and the opening end 16 of the lower cover 15 and the box body 50 are fitted together. The positioning of the abutting end 63 of 50 is performed accurately.
[0033]
An insertion locking piece 20 is formed on a side wall 19 on one side in the longitudinal direction of the lower cover 15. The insertion locking piece 20 is formed in a flat plate shape, and is arranged parallel to the side wall 19. A drain groove (groove) 35 is formed between the insertion locking piece 20 and the side wall 19. This is a difference between the electric connection box 10 of the present invention and the electric connection box 70 described in the section of the prior art.
[0034]
As shown in FIG. 2, the insertion locking piece 20 includes a pair of root portions 23 on the root side connected to the side wall 19, and a plate-shaped insertion portion 24 following the root portion 23. The insertion portion 24 is a free end protruding above the opening end 16 of the lower cover 15, and the height of the protrusion from the opening end 16 is equal to the protrusion height of the locking claw piece 30 (FIG. 1). They are formed substantially equally. The thickness of the insertion portion 24 is formed to be equal to the thickness of the side wall 19 of the lower cover 15. For this reason, deformation and breakage of the insertion locking piece 20 are prevented, and locking can be reliably performed even when the attachment and detachment of the box body 50 and the lower cover 15 are repeatedly performed.
[0035]
As shown in FIG. 3, the insertion portion 24 includes a distal end portion 25 and a locking step portion 26. The tip portion 25 has an inclined portion 25a (FIG. 4) and a curved portion 25b. For this reason, the insertion locking piece 20 has a tapered shape in the front-rear and left-right directions, and is smoothly guided to the locking frame 60 (FIG. 1) of the box body 50 without being caught.
[0036]
The locking step 26 is an edge of a recess 27 formed in the outer surface 21 of the insertion locking piece 20. The locking step 26 is located near the tip of the insertion section 24. On the inner surface of the locking frame 60 into which the insertion portion 24 enters, a locking projection 61 (FIG. 1) that engages with the locking step portion 26 is provided to project inward.
[0037]
As shown in FIG. 5, the insertion locking piece 20 is formed so as to face the side wall 19, and a drain groove 35 is formed between the insertion locking piece 20 and the side wall 19. The drain groove 35 is defined by a groove side wall (side wall) 35a, 35b on both sides and a groove bottom wall (bottom wall) 35c so as to form a U-shape in cross section, and the upper side and both right and left sides are opened. The groove side wall 35a on one side is formed so as to be continuous with the side wall 19 of the lower cover 15, and the groove side wall 35b on the other side is formed so as to be continuous with the inner surface 22 of the insertion locking piece 20, and the groove bottom wall 35c is formed. Is formed so as to be continuous with the rib 28 on the outer periphery of the lower cover 15. That is, the side wall 19 and the rib 28 of the lower cover 15 extend continuously in the left-right direction Y (FIG. 2) without being discontinuous due to the insertion locking piece 20.
[0038]
Here, for convenience of description of the present embodiment, the vertical direction X, the horizontal direction Y, and the front-back direction Z are determined. The vertical direction X is defined as the direction in which the box body 50 and the lower cover 15 are fitted, the horizontal direction Y is defined as the direction in which the drain groove 35 communicates, and the longitudinal direction Z is defined as the insertion locking piece 20. In the plate thickness direction or the bending direction of the insertion locking piece 20.
[0039]
Since a drain groove 35 is formed between the insertion locking piece 20 and the side wall 19, water or steam entering from the gap 45 between the box body 50 and the lower cover 15 passes through the drain groove 35 to the outside. Since it is discharged, it is prevented from hitting and hitting the inner surface 22 of the insertion locking piece 20, and water or the like is prevented from entering the electric connection box 10.
[0040]
As shown in FIG. 2, the box main body 50 includes a partition wall 58 that vertically partitions the internal space of the electrical junction box 10, and a side wall 59 that surrounds the partition wall 58. On one side wall 59 in the longitudinal direction (front-back direction Z), a third mounting bracket 67 for the vehicle body panel is formed. Therefore, even if the lock between the box body 50 and the lower cover 15 is released, the box body 50 is prevented from falling from the vehicle body panel.
[0041]
The box main body 50 is provided with a contact end 63 with the open end 16 of the lower cover 15 and a contact end 66 with the open end 14 of the upper cover 13. An L-shaped notch 63 a (FIG. 2) is formed in the contact end 63 so as to overlap the opening end 16 of the lower cover 15. The contact end 66 has an L-shaped notch 66 a overlapping the opening end 14 of the upper cover 13.
[0042]
A junction block 62 on which a relay 70 as a functional component is mounted is attached to the box body 50. The box body 50 and the junction block 62 can be attached by various methods. In the present embodiment, the junction block 62 is overlaid on the box body 50 and attached using a not-shown tightening screw. I have. The relay 70 is mounted above the junction block 62, and an electric wire (not shown) is drawn out below the junction block 62. In addition, a fuse, a connector, and the like (not shown) can be mounted on the junction block 62 in addition to the relay 70.
[0043]
As shown in FIG. 1, a plurality of frame-shaped locking holes 64 are formed in the side wall 59 of the box body 50 at positions corresponding to the locking claw pieces 30 of the lower cover 15. A guide portion 65 is formed inside the locking hole 64, and slides and guides the ridge portion 30 b of the locking claw piece 30 in the fitting direction to position the lower cover 15 and the box body 50. Can be done.
[0044]
A locking frame 60 for the plug-in locking piece 20 is formed on the other side wall 59 in the longitudinal direction (the front-back direction Z). Since the upper and lower portions of the locking frame 60 are open, the locking frame 60 is a penetrating frame. Inside the locking frame 60, a locking projection 61 for the locking step 26 of the insertion locking piece 20 is formed to protrude inward. The locking projection 61 has an inclined surface (not shown) positioned on the insertion side of the insertion locking piece 20 and a locking surface (not shown) formed perpendicularly to the inner surface of the locking frame 60 following the inclined surface. ).
[0045]
Hereinafter, the operation of the above configuration will be described.
First, functional components such as a relay 70 and a fuse are connected to a tab terminal (not shown) formed by punching an end or an intermediate portion of a bus bar 62b formed by punching a conductive substrate such as copper or a copper alloy. I do. Then, the junction block 62 to which the functional component is connected is attached to the box body 50. When an electric wire is connected to the junction block 62, the electric wire (not shown) is drawn out to an electric wire outlet (not shown) of the lower cover 15 so that the electric wire is not entangled in the lower cover 15.
[0046]
Next, the lower cover 15 is fitted to the box body 50. The positioning of the locking claw piece 30 of the lower cover 15 and the locking hole 64 of the box body 50, the insertion locking piece 20 of the lower cover 15 and the locking frame 60 of the box body 50 are performed, and the box body 50 and the lower cover 15 are aligned. Fit so that they abut each other. Then, the insertion locking piece 20 of the lower cover 15 rides on the locking projection 61 provided in the locking frame 60 of the box body 50, and the locking step 26 of the insertion locking piece 20 is locked. At the position beyond the position 61, the elastic step returns, and the locking step 26 is locked to the locking surface of the locking projection 61. The same applies to the locking claw pieces 30 and the locking holes 64. In this way, the box body 50 and the lower cover overlap in a double wall state.
[0047]
Subsequently, the upper cover 13 is put on the upper part of the box body 50. Since the notch 14a is formed at the opening end 14 of the upper cover 13, the notch 14a overlaps the notch 66a of the contact end 66 of the box body 50, and the box body 50 and the upper cover 13 Fit tightly.
[0048]
To fix the electric connection box 10 to the vehicle body panel, the mounting holes 40c of the first, second, and third mounting brackets 40, 42, and 67 of the electric connection box 10 (the mounting holes of the first mounting bracket 40). 40c) is aligned with the hole of the vehicle body panel, and a bolt (not shown) not shown is screwed into both holes.
[0049]
When such an electric connection box 10 is disposed in an engine room and is subjected to high-pressure washing water or steam at the time of car washing or the like, as shown in a drainage path D in FIG. There is a case where water or the like entering from the gap 45 at the boundary hits the inner surface 22 of the insertion locking piece 20 and rebounds. From the other opening. Therefore, it is prevented that water or the like that has hit the electric connection box 10 hits the root side of the insertion portion 24 and is splashed back, and the waterproofness of the electric connection box 10 is improved.
[0050]
To remove the lower cover 15 and the upper cover 13 from the box body 50 for maintenance of the relay 70 and the like, an operation reverse to the fitting operation may be performed. When removing the lower cover 15, the insertion locking piece 20 is tilted inward to release the locking between the locking step 26 of the insertion locking piece 20 and the locking projection 61 of the locking frame 60, Similarly, the locking between the locking claw pieces 30 and the locking holes 64 is released, and the lower cover 15 and the box main body 50 are detached by pulling them apart in a direction opposite to the fitting.
[0051]
【The invention's effect】
As described above, according to the first aspect of the present invention, water or steam entering from the gap of the electric junction box enters the groove from one opening of the groove, and is discharged from the other opening while being guided by the groove. You. Therefore, it is possible to prevent water or the like that has splashed on the electric connection box from hitting the engaging portion and rebounding, and to improve the waterproofness of the electric connection box.
[0052]
According to the second aspect of the present invention, water or the like that has splashed on the electric junction box is smoothly discharged from one opening toward the other without being prevented from being discharged by an obstacle or the like. Therefore, the effect of the invention described in claim 1 is further improved, and the waterproofness of the electric junction box is improved.
[0053]
According to the third aspect of the present invention, since the drainage groove serves as a bending space for the locking piece, the locking piece can be bent inward, and the fitting operation or the release of the fitting between the box body and the lower cover is performed. The operation can be easily performed. Accordingly, the workability of assembling the electric connection box is improved.
[0054]
According to the fourth aspect of the present invention, since the box body and the lower cover overlap in a double-walled state, both the openings of the box body and the lower cover are closed, and water or the like applied to the electric connection box is Infiltration into the electrical junction box is prevented. Therefore, the intrusion of water into the electric junction box is prevented twice, and the reliability of the electric connection is maintained.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of an electric junction box according to the present invention.
FIG. 2 is a perspective view showing an insertion locking piece formed on a lower cover shown in FIG. 1;
FIG. 3 is a front view of the insertion locking piece shown in FIG. 2;
FIG. 4 is a plan view of the insertion piece locking.
FIG. 5 is a sectional view of a plane of the insertion locking piece cut along the line AA.
FIG. 6 is a partial cross-sectional perspective view of an example of a conventional electric connection box, showing a plug-in locking piece thereof.
7 is a cross-sectional view of the insertion locking piece shown in FIG. 6 taken along line BB.
[Explanation of symbols]
Reference Signs List 10 Electrical connection box 13 Upper cover 15 Lower covers 14, 16 Open end 17 Outer wall (wall)
20 Insertion locking piece (locking part)
24 insertion part 25 tip part 26 locking step part 28 rib 35 drainage groove (groove)
35a, 35b Groove side wall (side wall)
35c Groove bottom wall (bottom wall)
45 gap 50 box body 60 locking frame (engaging portion)
61 Locking projection 62 Junction block 64 Locking hole

Claims (4)

An electrical junction box including a lower cover having a locking portion on a wall portion, and a box body having an engaging portion that engages with the locking portion.
The electric connection box, wherein the locking portion is provided to face a wall portion of the lower cover, and a communicating groove for drainage is formed between the locking portion and the wall portion. The groove is defined by side walls and a bottom wall on both sides, one of the side walls is connected to the wall of the lower cover, the other is connected to the locking portion, and the bottom wall is connected to a rib on the outer periphery of the lower cover. The electrical junction box according to claim 1, wherein The locking portion is a tongue-shaped locking piece protruding from the opening end of the lower cover in the fitting direction, and the groove serves as a bending space for the locking piece. The electrical junction box according to claim 1 or 2. The inner edge of the abutting end of the box body overlaps with the outer edge of the opening end of the lower cover in a double wall state, and fits into the groove to enter the groove. Electrical junction box described in one of the above.

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