JP4577061B2 - Electrical junction box - Google Patents

Description

The present invention relates to an electrical junction box.

As an electrical connection box having a lock structure in which a lock piece provided on one member rides on a lock projection provided on the other member while bending and deforming, and then elastically recovers and engages with this lock projection, The thing of patent document 1 is known. This electrical junction box is configured to cover a main body portion equipped with electrical parts with an upper cover and a lower cover, and each of the upper cover and the lower cover corresponds to a plurality of lock pieces, and one main body portion corresponds to this lock piece. A lock protrusion is provided for each position. As the cover is attached, the lock piece elastically deforms while riding on the lock protrusion, and then returns to be locked to the lock protrusion.
JP 2003-153414 A

  By the way, both the cover and the main body are made of synthetic resin. For this reason, due to dimensional errors at the time of molding, there may be variations in the finished product, such as a slight gap between the cover and the main body. Then, when the cover is assembled to the main body, the position of the cover is likely to be shifted, and the cover may be assembled with the position shifted as it is.

This invention is completed based on the above situations, Comprising: It aims at providing the electrical-connection box which can be assembled | attached without shifting a cover with respect to a main-body part.

As a means for achieving the above object, the invention of claim 1 is provided with a case part for accommodating the power distribution board and a cover part covering the opening part of the case part, and a lock provided on the case part. When the projection is provided on the cover, bent and deformed in the middle of the assembly of the case and the cover, and rides on the lock projection, the case and the cover are in a regular assembled state. An electrical connection box comprising a lock piece that elastically restores and engages with the lock protrusion, wherein the side wall of the cover portion is the above when the case portion and the cover portion are in a properly assembled state. The side wall of the case portion is covered from the outside, and the lock protrusion protrudes outward from the outer side surface of the side wall of the case portion, and the lock piece is formed on the cover portion. It is a cut piece formed between a pair of slits cut from the front edge in the assembling direction with the case portion, and the case portion corresponds to the slit by entering the slit. The guide rib for aligning the case portion and the cover portion is characterized in that it is provided to protrude outward from the outer surface of the side wall of the case portion .

  The invention according to claim 2 is characterized in that, in the guide rib according to claim 1, the leading end of the guide rib in the entering direction with respect to the slit is a tapered portion whose width becomes narrower toward the leading end.

<Invention of claim 1>
According to the invention of claim 1, the lock piece is a cut piece formed between a pair of slits cut from the front edge of the other engagement member in the assembly direction with the one engagement member. In one engagement member, a guide rib for aligning the pair of engagement members by entering the slit is provided at a position corresponding to the slit. According to such a configuration, since the positioning at the time of assembly is achieved by the cut portion and the guide rib that enters the cut portion, the pair of engaging members (the case portion and the cover portion) can be assembled without being displaced. it can. In particular, since the positioning structure is made using a slit for forming a cutable piece (lock piece) that can be flexibly deformed, positioning can be achieved without complicating the entire structure.

<Invention of Claim 2>
According to the second aspect of the present invention, the leading end of the guide rib in the entry direction with respect to the slit is a tapered portion whose width becomes narrower toward the leading end. According to such a configuration, even if the position of the guide rib with respect to the slit is slightly shifted in the initial assembly, the guide rib is drawn into the slit by sliding the opening edge of the slit to the tapered portion at the tip, While entering smoothly, the position of the guide rib relative to the slit is corrected. Thereby, the assembly of both engaging members is performed smoothly.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 shows an external perspective view of the electrical junction box 1 of the present embodiment, and FIG. 2 shows an exploded perspective view of the electrical junction box 1 of the present embodiment.
In the following, each component will be described with the upper side in FIG. 2 as the upper surface, the lower side as the lower surface, the lower left side as the front, the upper right side as the rear, the lower right side as the right side, and the upper left side as the left side.

  The electrical junction box 1 of the present embodiment includes a power distribution board 10, a case 20 (corresponding to the case part of the present invention) that accommodates the power distribution board 10, and a cover 30 that covers the opening of the case 20 (the cover of the present invention). Corresponding to the part).

  The distribution board 10 is obtained by attaching a bus bar substrate 12 that forms a predetermined conductive path serving as a power circuit to a lower surface of a circuit board 11 in which conductive paths (not shown) are formed in a predetermined pattern on both front and back surfaces. is there. The circuit board 11 has an outer shape in which a corner on the left front end side in a rectangle is dropped. Further, the bus bar substrate 12 has an outer shape substantially aligned with the circuit board 11, and a plurality of bus bars 12A project from the rear edge. An electronic component 13 such as a relay is mounted on the power distribution board 10.

  A PCB connector 14 is assembled on the front end side of the power distribution board 10. The PCB connector 14 is provided with a housing 15 made of synthetic resin that is horizontally long and opened to the front.

  The case 20 that houses the power distribution board 10 includes a frame body 21 that has a shape surrounding the power distribution board 10, and a heat radiating plate 22 that is attached to the lower side of the frame body 21. The power distribution board 10 on which the PCB connector 14 is mounted is assembled to the frame body 21 from above.

  The frame body 21 is made of an insulating material such as synthetic resin, and includes a lower frame portion 23 having a shape that allows the power distribution board 10 to be fitted almost tightly inside. A flange 24 projects outwardly along the outer peripheral surface of the lower frame portion 23 in the center in the vertical direction. Further, in the lower frame portion 23, side walls 25 are raised from the upper surfaces of the left and right lower frame portions 23 </ b> L and 23 </ b> R along both left and right edges of the power distribution board 10 along the inner edge thereof. The side wall 25 is approximately half the wall thickness of the lower frame portion 23, and the surface outside the side wall 25 on the upper surface of the lower frame portion 23 is a step surface 23 </ b> A that is substantially perpendicular to the side wall 25. ing. Further, lock projections 50 are provided on the outer surfaces of the left and right side walls 25, and the lock projections 50 constitute a lock structure together with a lock piece 40 of a cover 30 described later. This lock structure will be described in detail later.

  The heat radiating plate 22 attached to the lower side of the frame body 21 is formed in a shape substantially the same as the outer shape of the frame body 21 by a metal plate such as aluminum having high thermal conductivity. The heat radiating plate 22 is assembled to the frame body 21 so as to close the opening on the lower surface side, and is attached to the lower surface of the bus bar substrate 12 with an insulating adhesive. In addition, from the rear edge of the heat sink 22, it is formed with the attitude | position which the attachment piece 26 escaped diagonally downward.

  A cover 30 is assembled on the upper side of the case 20 so as to cover the opening on the upper side of the case 20. FIG. 3 shows a perspective view of the cover 30 as viewed from below. The cover 30 is made of a synthetic resin, and has a plate-like lid plate portion 31 that has substantially the same shape as the power distribution substrate 10 as a whole and covers the upper surface side of the power distribution substrate 10, and left and right edges of the lid plate portion 31. And a side wall portion 32 that hangs down, and is formed in a shallow dish shape that opens to the lower surface side as a whole. The left and right side wall portions 32 cover the side wall 25 of the frame body 21 from the outside, and when the cover 30 is properly assembled to the frame body 21, the lower end surface of the side wall portion 32 is the step surface 23A of the lower frame portion 23. (See also FIG. 1). The left and right side wall portions 32 are provided with lock pieces 40 constituting a lock structure together with the lock protrusions 50 of the frame body 21 described above. On the lower surface of the cover 30, ribs 33 for preventing “sinking” and “sledge” during resin molding are arranged in a lattice shape as a whole. In the cover plate portion 31 of the cover 30, a high-level portion 34 that covers the rear surface side of the PCB connector 14 is formed on the front end side, and a part of a fuse box 35 described later is fitted on the rear end side of the cover 30. A fitting recess 36 for escaping is provided. Further, mounting recesses 37 for screwing screws (not shown) are provided at both left and right end portions on the rear end side of the cover 30, and the cover 30 is screwed to the frame body 21 from the upper surface side in the mounting recesses 37. The frame 21 is fixed.

  The fuse box 35 disposed along the rear edge of the circuit board 11 is made of synthetic resin and covers the rear sides of the case 20 and the cover 30 over the entire length, and its upper portion is directed upward from the cover 30. It is formed in a projecting horizontally long shape. A bus bar 12A is inserted into the fuse box 35 from the front.

  A connector 38 is assembled from the front to a portion of the fuse box 35 that protrudes above the cover 30. The connector 38 has a horizontally long shape extending along the longitudinal direction of the fuse box 35.

  Now, the lock structure described above will be described in detail. This lock structure includes a lock protrusion 50 provided on the frame body 21 of the case 20 and a lock piece 40 provided on the cover 30. FIG. 4 shows a partially enlarged cross-sectional view showing a state in which the lock piece 40 and the lock protrusion 50 are engaged with each other. This lock structure is elastically restored when the lock piece 40 is bent and deformed in the middle of the assembly of the case 20 and the cover 30 and rides on the lock protrusion 50, and the case 20 and the cover 30 are in a regular assembled state. Thus, the lock projection 50 is engaged.

  First, the lock piece 40 provided in the cover 30 will be described. The left and right side wall portions 32 of the cover 30 have one lock piece 40 at each of the left and right positions corresponding to the lower part of the high position part 34 and one left and right position at the rear side of the lock piece 40 provided below the high order part 34. Are arranged in four places (see also FIG. 3). The lock piece 40 is a cut piece formed between a pair of slits 41 cut from the lower end of the side wall portion 32 and can be elastically deformed outward.

  Each of the slits 41 is elongated from the lower edge of the side wall 32 of the cover 30 (the front edge in the direction of assembly with the frame body 21) upward, and the height of the cut is the side wall. 32 is approximately half the vertical height of the portion excluding the portion corresponding to the lower portion of the high-order portion 34. The lower end of the slit 41 is an open end 41A into which a later-described guide rib 55 can enter, and a pair of surfaces raised upward from the open end 41A is a guide surface 42 parallel to each other. . The upper end edge of the slit 41 has a substantially semicircular arc shape that is recessed upward as viewed from the outside.

  On the inner side surface of the lock piece 40, a groove-shaped recess 43 is formed which is recessed in the outer direction and opened in the vertical direction. As a result, the intermediate portion in the front-rear direction of the lock piece 40 is a thin wall portion 44 having a wall thickness less than half that of other regions of the side wall portion 32, and is more rigid than other portions of the side wall portion 32. Is low. A through hole 45 is formed in a portion of the cover plate portion 31 of the cover 30 corresponding to the upper end of the recessed portion 43. The through-hole 45 is opened so as to penetrate in the thickness direction of the lid plate portion 31, and three sides excluding the side on the thin wall portion 44 side at the periphery of the through-hole 45 are surrounded by the rib 33 </ b> A. Further, a claw portion 46 that protrudes inward along the lower edge is formed at the lower end portion of the recessed portion 43. The claw portion 46 is slightly narrower than the width in the direction along the lower edge of the recessed portion 43. The lower surface of the claw portion 46 is a rising slope 47 that rises inward, and the upper surface of the claw portion 46 is a locking surface 48 that is substantially perpendicular to the inner surface of the recessed portion 43.

  Next, the lock protrusion 50 provided on the frame body 21 of the case 20 will be described. The lock protrusions 50 are provided on the left and right side walls 25 of the frame body 21 at positions corresponding to the lock pieces 40 of the cover 30, and are arranged at four places, two on each of the left and right side walls 25. Each lock projection 50 is arranged at the center in the vertical direction on the outer side surface of the side wall 25, and is formed to project outward from the outer side surface. The upper surface of the lock protrusion 50 is a guide slope 51 that descends outward, while the lower surface of the lock protrusion 50 is substantially perpendicular to the outer surface of the side wall 25 and faces the step surface 23A of the lower frame portion 23. A stop surface 52 is provided. The vertical spacing between the detent surface 52 and the stepped surface 23A of the lower frame portion 23 is substantially the same as the vertical height of the claw portion 46 of the lock piece 40 formed on the side wall portion 32 of the cover 30. The detent surface 52 that is the lower surface of the lock protrusion 50 and the locking surface 48 that is the upper surface of the claw 46 are in contact with each other. The outer surface of the lock projection 50 is a top surface 53 that is substantially parallel to the outer surface of the side wall 25 of the frame body 21, and the top surface 53 is located slightly inward from the outer surface of the lower frame portion 23. ing. The front and rear end surfaces 54 of the lock protrusion 50 are inclined so as to approach each other toward the outer side, and the lock protrusion 50 has a width from the connecting portion with the outer surface of the side wall 25 toward the top surface 53. It is designed to be narrow (see also FIG. 5).

  A pair of guide ribs 55 are provided at the front and rear positions of the lock protrusion 50. The pair of guide ribs 55 are arranged at positions corresponding to the pair of slits 41 formed in the cover 30, and each has a long and narrow shape that can be fitted into the slit 41. Each guide rib 55 is formed so as to rise upward from the step surface 23 </ b> A of the lower frame portion 23 along the outer surface of the side wall 25, and its upper end is above the lock protrusion 50 provided between the guide ribs 55. It is located slightly below the edge. The outer surface of the guide rib 55 is substantially flush with the outer surface of the lower frame portion 23. When the cover 30 is assembled to the frame body 21 and the guide rib 55 enters the slit 41, the outer surface of the guide rib 55 is positioned inside the outer surface of the side wall portion 32 of the cover 30. . The guide rib 55 has a portion from the lower end (connection position with the step surface 23A of the lower frame portion 23) to the center position in the vertical direction (substantially the same height as the detent surface 52 of the lock protrusion 50). The parallel portion 56 has a width substantially equal to the width of the slit 41 formed in the cover 30, and the upper portion (the tip portion in the entry direction with respect to the slit 41) is the width in the front-rear direction toward the tip. Is a tapered portion 57 in which is substantially halved.

  Next, the operation and effect of the present embodiment configured as described above will be described. 5A is a partially enlarged view of the state before the cover 30 is assembled to the case 20 from the outside, and FIG. 5B is a diagram illustrating the state where the cover 30 is assembled to the case 20 from the outside. A partial enlarged view is shown.

  To assemble the cover 30 on the upper side of the case 20, first, the slit 41 of the cover 30 and the guide rib 55 of the case 20 are aligned while the side wall 25 of the case 20 is fitted inside the side wall portion 32 of the cover 30. Thus, the cover 30 is aligned with the case 20. When the cover 30 is pushed downward, the leading end of the guide rib 55 enters the slit 41 from the open end 41 </ b> A of the slit 41. Here, the front end portion of the guide rib 55 is a tapered portion 57 whose width in the front-rear direction is almost halved toward the front end. The front-rear width in the front-end direction is larger than the opening width of the open end 41 </ b> A that is the entrance of the slit 41. Since the size is almost half, the opening width of the open end 41 </ b> A has a margin with respect to the tip width of the guide rib 55, and the guide rib 55 easily enters the slit 41. Further, even if the position of the guide rib 55 is slightly shifted with respect to the slit 41 in the initial stage of assembly and the leading end of the guide rib 55 enters from the corner of the open end 41A of the slit 41, the tapered portion is formed at the corner of the open end 41A. The guide ribs 55 are rubbed against each other, and the guide ribs 55 are guided into the slits 41 while their positions are corrected. In this way, the guide rib 55 smoothly enters the slit 41, and even if the position is slightly shifted, the guide rib 55 is corrected to the correct position as it enters. The cover 30 can be assembled smoothly.

  When the cover 30 is further pushed downward, the rising slope 47 of the claw portion 46 formed on the lock piece 40 of the cover 30 is guided by the guide slope 51 of the lock projection 50 of the frame body 21, and the claw portion 46 is locked to the lock projection 50. The lock piece 40 bends outward as it rides on. When the lower end of the lock piece 40 reaches substantially the same position as the detent surface 52 of the lock protrusion 50, the open end 41 </ b> A of the slit 41 passes through the tapered portion 57 of the guide rib 55 and reaches the parallel portion 56. The cover 30 is pushed further downward without being displaced with respect to the case 20 while the front and rear surfaces of the parallel portion 56 are in sliding contact with the guide surface 42 of the slit 41. At this time, since the appearance of the guide rib 55 entering the slit 41 can be visually observed from the outside, confirmation of the entry is easy.

  When the cover 30 is further pushed in and the lock piece 40 gets over the lock protrusion 50, the entire guide rib 55 is completely accommodated in the slit 41 as shown in FIG. The lower end of the side wall portion 32 comes into contact with the stepped surface 23A of the lower frame portion 23 to be in a regular assembled state. At this time, the lock piece 40 returns to its original posture by its own elastic force, and the detent surface 52 of the lock protrusion 50 is engaged with the engagement surface 48 of the lock piece 40 as shown in FIG. In this way, the cover 30 is assembled with respect to the frame body 21 without being displaced, and the cover 30 is held in a retaining state with the opening of the frame body 21 closed. Thus, since the positioning of the cover 30 and the case 20 is achieved by the guide rib 55 and the slit 41, for example, even if the dimensions of the cover 30 and the case 20 vary due to dimensional errors during molding, The cover 30 is assembled to the case 20 without being displaced. Moreover, since the guide rib 55 is positioned by entering the slit 41 provided to form the lock piece 40, the guide rib 55 may be newly formed as the positioning structure. The overall structure is not complicated. Moreover, since the guide rib 55 does not protrude outward from the cover 30 after the cover 30 is assembled, it does not interfere with other members such as a wire harness.

  Thereafter, the cover 30 is screwed to the frame body 21 by attaching a screw to the mounting recess 37 at the rear end. Here, since the cover 30 is assembled to the frame body 21 without being displaced, the screw holes are not misaligned, and a defect such as a screw being inserted obliquely does not occur.

  As described above, according to the present embodiment, the lock piece 40 is a cut piece formed between the pair of slits 41 cut from the lower end edge of the side wall portion 32 of the cover 30, and the frame of the case 20. Guiding ribs 55 are provided at positions corresponding to the slits 41 in the body 21 so as to align the cover 30 and the case 20 by entering the slits 41. Thereby, since positioning at the time of assembly is achieved by the slit 41 and the guide rib 55 entering the slit 41, the case 20 and the cover 30 can be assembled without being displaced. In particular, since the positioning structure is made using the slit 41 for forming the lock piece 40 that can be flexibly deformed, positioning can be achieved without complicating the entire structure.

  In addition, the leading end portion of the guide rib 55 in the approach direction with respect to the slit 41 is a tapered portion 57 whose width decreases toward the leading end. Thereby, even if the position of the guide rib 55 with respect to the slit 41 is slightly shifted in the initial stage of assembly, the guide rib 55 is drawn into the slit 41 by the sliding end 41A of the slit 41 being brought into sliding contact with the tapered portion 57 at the tip. In rare cases, the guide rib 55 enters smoothly and the position of the guide rib 55 relative to the slit 41 is corrected. Therefore, the cover 30 and the case 20 are assembled smoothly. In particular, in this embodiment, since the guide rib 55 is formed on the outer surface of the frame body 21, the guide rib 55 is easily visible, and the slit 41 is easily fitted into the guide rib 55 when the cover 30 is assembled.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

( 1 ) In this embodiment, the detent surface 52 of the locking projection 50 and the locking surface 48 of the claw portion 46 provided on the locking piece 40 are brought into contact with each other, but the structure is locked. For example, the structure may be such that a locking hole provided in the lock piece is locked to the lock protrusion.

External perspective view of electrical junction box in this embodiment The exploded perspective view of the electrical junction box in this embodiment A perspective view of the cover as viewed from below Partial enlarged sectional view showing a state in which the lock piece and the lock protrusion are locked to each other (A) Partial enlarged view of the state before the cover is assembled to the case from the outside (B) Partial enlarged view of the state where the cover is assembled to the case from the outside

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric junction box 10 ... Distribution board 20 ... Case (Case part, engaging member)
30 ... Cover (cover part, engaging member)
40 ... Lock piece 41 ... Slit 50 ... Lock projection 55 ... Guide rib 57 ... Tapered portion

Claims (2)

While having a case part that accommodates the power distribution board and a cover part that covers the opening part of the case part,
  A locking protrusion provided on the case portion;
  It is provided in the cover part, flexes and deforms in the middle of assembling the case part and the cover part, rides on the lock protrusion, and elastically recovers when the case part and the cover part are in a regular assembled state. And an electrical junction box provided with a locking piece to be engaged with the locking projection,
  The side wall of the cover part is adapted to cover the side wall of the case part from the outside when the case part and the cover part are properly assembled.
  The lock protrusion is provided to protrude outward from the outer surface of the side wall of the case portion,
  The lock piece is a cut piece formed between a pair of slits cut from the front edge of the cover portion in the assembly direction with the case portion,
  In the case portion, a guide rib that aligns the case portion and the cover portion by entering the slit protrudes outward from the outer surface of the side wall of the case portion at a position corresponding to the slit. An electrical junction box characterized by being provided. 2. The electrical junction box according to claim 1, wherein a tip end portion of the guide rib in an approach direction with respect to the slit is a tapered portion whose width becomes narrower toward the tip end.

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