JP5030225B2 - Electrical junction box - Google Patents

Description

  The present invention relates to an electrical connection box that is mounted on a vehicle or the like and is used to connect wiring of an electronic device, and more particularly, to an electrical connection box of a type that temporarily fixes a bolt for fixing an external terminal to the electrical connection box. .

  Conventionally, in order to assemble an electric junction box, a bus bar is inserted into an insulating block from above, and then a bolt for fastening the bus bar and an external terminal is inserted from above and screwed with a nut accommodated in advance. Thus, the bolt is temporarily fixed at a position where there is a gap in which an external terminal can be inserted between the bolt head and the bus bar later (see Patent Document 1). For this reason, a nut that is screwed with a bolt is held in the electric connection box in a non-rotatable manner. When shipping the electrical junction box, the bolts are screwed into the nuts in the junction box and temporarily fixed. At the installation site of the junction box, external terminals are connected to the bus bar and tightened to the end with bolts. The work is made more efficient by fastening.

Japanese Patent Laying-Open No. 2006-4733 (FIG. 3)

  In many cases, this type of electrical junction box is formed with a cavity for mounting an electrical component such as a fusible link on the upper surface of the electrical junction box. A slit for inserting the bus bar from above is formed in the cavity.

  However, when the slit is formed in the cavity, there are problems that the strength of the cavity is low, the molding accuracy of the cavity is low, and the shape of the electrical junction box is complicated.

  Further, in order to temporarily fix the bolt to the insulating block, it is necessary to insert the nut into the insulating block from above and load it in the back in advance, which makes the loading operation difficult.

  Accordingly, an object of the present invention is to eliminate the above-mentioned problems, and it is possible to omit a slit for inserting a bus bar in a cavity for mounting an electrical component, and an electrical connection that facilitates assembly of the bus bar and does not increase manufacturing costs. To provide a box.

The above object of the present invention is achieved by the following configurations.
(1) An insulating block having an electrical component cavity into which an electrical component is inserted and having a bus bar insertion portion communicating with the electrical component cavity, and an electrical component terminal portion electrically connected to the electrical component And a bus bar that is inserted into the insulating block from the bus bar insertion portion so that the electric component terminal portion protrudes into the electric component cavity, and a bolt that is inserted into a bolt insertion hole formed in the bus bar. In the electrical connection box comprising: a nut screwed to the bolt to fasten the bus bar and the external terminal to the insulating block in an electrically connected state; and a nut holder that holds the nut in a non-rotatable state.
The bus bar insertion portion is provided to open downward in the insulating block, and the insulating block is provided with a nut holder accommodating portion that opens downward, and the nut holder is configured separately from the insulating block, and the insulating block An electrical junction box, which is inserted and attached to the nut holder accommodating portion from below the block.

  (2) The electric connection box according to (1), wherein the nut holder is provided with a bolt insertion hole having a reduced diameter portion.

  (3) The electrical junction box according to (2), wherein the reduced diameter portion is a protrusion provided in a distributed manner in the circumferential direction.

  According to the configuration of (1), since the bus bar is inserted from below the insulating block, no slit for inserting the bus bar is required in the cavity above the insulating block. A nut holder holding the nut is similarly inserted from below the insulating block. Since the nut is loaded and held in the nut holder outside the insulating block, the nut loading operation can be performed in a wide area and the operation is easy.

  According to the configuration of (2), since the nut holder has the reduced diameter portion, the bolt passing through the nut advances while cutting the reduced diameter portion. Therefore, the bolt is in a state of being bitten into the reduced diameter portion, and the bolt is temporarily fixed together with the threaded engagement with the nut, and the bolt is not temporarily fixed. If the two shaft centers are matched and screwed accurately in advance, the state is maintained, so that the bolts are prevented from being tightened obliquely. Furthermore, for example, it is not necessary to use a special and expensive nut in which resin is integrated to prevent loosening on the screwed surface of the nut bolt, and a general-purpose product can be used, which increases costs. There is no.

  According to the configuration (3), since the reduced diameter portion is formed of a protrusion, the temporary fixing of the bolt can be stabilized with a simple configuration.

  According to the present invention, since the bus bar insertion portion is provided to open downward in the insulating block, the bus bar insertion slit can be omitted from the electrical component cavity above the insulating block, and the strength and molding accuracy of the electrical component cavity are increased. The mold is not complicated. Further, since the nut holder configured separately from the insulating block is inserted and mounted from below the insulating block, the bolt can be screwed onto the nut from above and temporarily fixed, and the work is easy.

  Furthermore, since the nut is fixed to the nut holder, there is no need to use a special structure to fix the bolt and nut to the insulating block, and the bolt is temporarily fixed to the insulating block using a conventional general-purpose nut and bolt. And cost does not increase.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. 1 is a perspective view of an electrical junction box according to an embodiment of the present invention, FIG. 2 is a plan view of the vicinity of a terminal connection portion of the electrical junction box of FIG. 1, FIG. 3 is a cross-sectional view taken along line AA in FIG. 2 is a cross-sectional view taken along line EE in FIG. 2, and FIG. 5 is a plan view of the bolt insertion hole.

  As shown in FIG. 1, an electrical junction box 10 has an insulating block 14 made of an insulating resin having a plurality of electrical component cavities 12 on the upper surface, and an electrical component mounted in the insulating block 14 and in the electrical component cavity 12a. Two conductive metal bus bars 18 from which the terminal portions 16 project, and conductive metal bolts 24 for electrically connecting the external terminals 22 (see FIG. 2) to the terminal connection portions 20 of the bus bars 18; A conductive metal nut 25 for fixing the bolt 24 to the insulating block 14 and an insulating resin nut holder 26 for fixing the nut 25 to the insulating block 14 are provided. The insulating block 14 is fixed to a vehicle body or the like by inserting a mounting bolt (not shown) into the mounting hole 28. In the illustrated example, various electrical components such as the fusible link 30 are mounted in the electrical component cavity 12. Of the electrical component cavities 12, in particular, the fusible link 30 is inserted and the terminals of the fusible link 30 are electrically connected to the electrical component terminal portions 16 of the bus bar 18. This is the cavity 12a.

  The insulating block 14 is provided with a bus bar insertion portion 19 (see FIGS. 3 and 4) at the bottom. The bus bar insertion portion 19 includes a slit (not shown) and a gap that are open downward. The slit width corresponds to the thickness of the bus bar 18, and the size of the gap corresponds to the size of the terminal connection portion 20 of the bus bar 18. Then, by inserting the bus bar 18 into the bus bar insertion portion 19 from below the insulating block 14, the bus bar 18 is mounted in the insulating block 14, and the electric component terminal portions 16 formed on the upper portion of the bus bar 18 are respectively connected to the electric components. It penetrates the bottom of the cavity 12a for use, protrudes into the cavity 12a for electrical parts, and is electrically connected to the electrical parts (that is, the fusible link 30) respectively mounted in the cavity 12a for electrical parts. . Note that bolt insertion holes 40 are respectively formed in the terminal connection portions 20.

  The nut holder 26 is formed with a U-shaped nut holding portion 36 in a plan view that holds the base 44 of the nut 25. The nut 25 is a square nut having a square base 44 in plan view. The nut 25 is held non-rotatable by the pedestal 44 being held by the nut holding portion 36. Further, the nut holding portion 36 is formed with a flange portion 37 at the upper ends of two opposite sides of the three sides constituting the U-shape so that the held nut 25 does not come out upward. In the nut holding portion 36, one end in the longitudinal direction of the flange portion 37 is a laterally open portion 38, and the nut 25 can be detached from the open portion 38 in the lateral direction. A bolt insertion hole 42 is formed in the nut holding portion 36.

  The electrical connection box 10 of the present embodiment is attached with the external terminals 22 shown in FIGS. 2 to 4 at the installation site to a vehicle or the like, but the bolts 24 are assembled in advance to the electrical connection box 10 in advance. In this case, the state in which the bolt 24 is screwed into the nut 25 halfway is maintained. The external terminal 22 used here is substantially U-shaped in a plan view, and a substantially U-shaped portion is attached from the side of the bolt 24 to the lower side of the bolt head of the bolt 24.

  2 to 4 show a main part of the electrical junction box 10 in a state where the external terminal 22 is just attached and before the external terminal 22 is completely fixed.

  As shown in FIGS. 3 and 4, the bus bar 18 is first inserted and attached to the insulating block 14 from below. Each terminal connection portion 20 of each bus bar 18 is loaded into the insulating block 14 via the bus bar insertion portion 19, and the upper terminal connection portion 20 is exposed upward to be able to contact the external terminal 22.

  A nut holder accommodating portion 32 opened downward is formed below the bus bar insertion portion 19 of the insulating block 14. Then, after the bus bar 18 is inserted into the insulating block 14 from below and attached, the nut holder 26 holding the nut 25 in the nut holding portion 36 in advance is inserted into the nut holder accommodating portion 32 from below and attached. The

  As shown in FIGS. 1 and 4, the nut holder 26 includes a pair of locking pieces 46 having flexibility. The pair of locking pieces 46 are cantilevered on the outer surface of the nut holder 26, and are provided so that the free ends extend downward. On the other hand, a pair of locking projections 48 for locking the locking pieces 46 are provided on the inner surface of the nut holder accommodating portion 32.

  In addition, the nut holder 26 is provided with two guide protrusions 52 extending in the loading / unloading direction that serve as a guide when the nut holder accommodating portion 32 is loaded (see FIG. 1). The inner wall is provided with a guide groove (not shown) extending in the loading / unloading direction for sliding engagement of the guide protrusion 52.

  When the guide protrusion 52 is slidably engaged with the guide groove and the nut holder 26 is inserted into the nut holder accommodating portion 32 from the lower side to the upper side, the inclined surface portion 46 a of the engaging piece 46 is inclined to the inclined surface portion of the engaging protrusion 48. Guided by 48a, the locking piece 46 is bent and deformed. Then, after the locking piece 46 gets over the locking projection 48, the tip end portion of the locking piece 46 is locked to the locking projection 48, so that the nut holder 26 is prevented from coming down downward. FIG. 4 shows a state in which the locking piece 46 gets over the locking projection 48.

  Moreover, the opening shape of the upper part of the nut holder accommodating part 32 is formed smaller than the nut holder 26, and the nut holder 26 does not slip out upward. Further, the upper end portion of the guide groove for guiding the guide protrusion 52 is a closed surface, and the nut holder 26 is prevented from coming out upward even when the guide protrusion 52 abuts on this surface.

  With such a configuration, the nut 25 held by the nut holder 26 is held so as to contact the lower surface of the terminal connection portion 20 of the lower bus bar.

  A bolt 24 is screwed onto the nut 25 held by the nut holder 26 from above. Here, as shown in FIGS. 2 to 4, an external terminal 22 can be placed on the terminal connection part 20 of the bus bar 18 so that the external terminal 22 can be placed between the lower surface 24 a of the bolt head and the terminal connection part 20. It is necessary to stop the screwing of the bolt 24 in a state where the gap S having a thickness larger than the thickness of the terminal 22 is formed and to temporarily fix the position. Since the external terminal 22 is mounted at the installation site of the electrical junction box 10, the bolt 24 is a nut so that a gap S is formed between the terminal connection portion 20 and the bolt 24 until the electrical junction box 10 is transported to the installation site. By being screwed to 25, the insulating block 14 is temporarily fixed.

  As shown in the plan view of the bolt insertion hole 42 of the nut holder 26 in FIG. 5, a protrusion 50 as a reduced diameter portion that slightly reduces the hole diameter is provided at the upper end of the bolt insertion hole 42 for temporarily fixing the bolt 24. Are distributed in the circumferential direction. In the present embodiment, projections 50 are formed at four locations in the circumferential direction with a central angle of 90 degrees. The bolt insertion hole 42 is reduced in diameter so that the hole diameter is slightly smaller than the diameter of the bolt 24 by forming the protrusion 50. The number of protrusions 50 may be one or more, and the protrusions 50 may have any shape, and the shape is not limited. Further, the protrusion 50 may be provided not only at the upper end of the bolt insertion hole 42 but also over the entire bolt insertion region of the bolt insertion hole 42.

  When the bolt 24 is tightened, the bolt 24 is screwed into the nut 25 and passes through the nut 25, and then proceeds further downward while shaving the protrusion 50 provided in the bolt insertion hole 42 with a screw thread. Therefore, as shown in FIG. 3, the bolt 24 is in a state of being bitten into the protrusion 50, temporarily fixed to the nut holder 26, and the bolt 24 is not loosened while the electric connection box 10 is being transported. In addition, when the bolt 24 is screwed into the nut 25, if the two shaft centers are aligned and screwed so that there is no oblique tightening, the state is maintained, so that the bolt 24 is prevented from being obliquely tightened. Is done.

  The electrical connection box 10 is transported to an installation site to a vehicle or the like with the bolts 24 temporarily fixed, and electrical components are mounted and the external terminals 22 are connected at the installation site. At the installation site, the external terminal 22 is loaded from the left side in FIG. 3 into the gap S between the lower surface 24a of the bolt head and the terminal connection portion 20 of the bus bar 18, and the bolt 24 that has been temporarily fixed is completely loaded. By completing the fastening by tightening, the terminal connecting portion 20 of the bus bar 18 and the external terminal 22 are fastened and electrically connected. Since the external terminal 22 is electrically connected to an external device (not shown) via a connected electric wire (not shown), various electrical components including the fusible link 30 are electrically connected to the external device (not shown). Will be conducted.

  According to the above embodiment, since the bus bar 18 is inserted from below the insulating block 14, there is no need to form a bus bar insertion slit in the electrical component cavity 12 a formed in the upper portion, and the electrical component cavity The strength of 12a is not weakened and the molding accuracy is not lowered. Further, since the nut 25 for fixing the external terminal is held in advance by the nut holder 26 and loaded from the lower side of the insulating block 14, the nut 25 can be loaded in a wide place outside the electric junction box. Work is easy. In addition, a general-purpose nut is used to insulate the external terminal connection bolt 24 without using a special structure nut (for example, a special and expensive nut in which a resin for preventing loosening of the bolt and the nut is integrated). 14 can be temporarily fixed, so that the manufacturing cost does not increase.

  In addition, this invention is not limited to the said embodiment, All modifications are possible based on the technical idea of this invention. For example, the above embodiment uses a square nut with a pedestal for bolt fastening, but instead uses a hex nut without a pedestal, and the nut holder holds the hex nut in a non-rotatable manner. Also good.

It is a perspective view of the electrical junction box which is an embodiment of the present invention. It is a principal part top view of the electrical junction box of FIG. It is AA sectional drawing of FIG. It is EE sectional drawing of FIG. It is a top view of a bolt insertion hole.

Explanation of symbols

10 Electrical junction box 12 Electrical component cavity 12a Electrical component cavity (for fusible link 30)
14 Insulating block 16 Electrical component terminal 18 Bus bar 19 Bus bar insertion part 20 Terminal connection part 22 External terminal 24 Bolt 24a Bolt head bottom face 25 Nut 26 Nut holder 30 Fusible link 32 Nut holder accommodating part 36 Nut holding part 38 Opening part 40, 42 Bolt insertion hole 44 Base 46 Locking piece 46a Slope 48 Locking projection 48a Slope 50 Projection 52 Projection S Space

Claims (3)

An insulating block having an electrical component cavity into which the electrical component is inserted and having a bus bar insertion portion communicating with the electrical component cavity; and an electrical component terminal portion electrically connected to the electrical component; A bus bar that is inserted into the insulating block from the bus bar insertion portion and protrudes into the electrical component cavity, a bolt inserted into a bolt insertion hole formed in the bus bar, and the bolt In an electrical connection box comprising a nut that is screwed to the bus bar and an external terminal to be fastened to the insulating block in an electrically connected state, and a nut holder that holds the nut in a non-rotatable state,
The bus bar insertion portion is provided to open downward in the insulating block, and the insulating block is provided with a nut holder accommodating portion that opens downward, and the nut holder is configured separately from the insulating block, and the insulating block An electrical junction box, which is inserted and attached to the nut holder accommodating portion from below the block.   The electrical connection box according to claim 1, wherein the nut holder is provided with a bolt insertion hole having a reduced diameter portion.   The electrical connection box according to claim 2, wherein the reduced diameter portion is a protrusion provided in a distributed manner in the circumferential direction.

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