Electrical junction box

Abstract

Disclosed herein is an electrical junction box capable of stably suppressing the exposure of a terminal part.　This electrical junction box 10 comprises: a case 14; a terminal part 18 which is exposed from an opening 16 of the case 14 and to which an external conductive member 12 is connected; a protective cover 20 which is rotatably held by the case 14 and covers the opening 16; an engagement projection 22 provided to the protective cover 20; and an engagement wall part 24 provided to the case 14. The protective cover 20 is arranged at an open position O where the opening 16 is exposed while being separated from the opening part 16 in an initial state. The protective cover 20 is allowed to rotate to a closed position C which overlaps the opening 16 and covers the opening 16 from the open position O by the elastic deformation of the engagement projection 22 to get over the engagement wall part 24. The contact with the engagement wall part 24 by the engagement projection 22, which has gotten over the engagement wall part 24 and elastically returned, limits a rotation region R of the protective cover 20 toward the open position O side to a range in which rotation toward the closed position C by the self-weight of the protective cover 20 occurs.

Description

Electrical junction box

[0001] The present disclosure relates to an electrical junction box.

[0002] Patent Document 1 discloses an electrical junction box to be mounted on a vehicle, which includes terminals exposed at an opening in the case to which external conductive members are connected, and a protective cover covering the terminals. During vehicle maintenance, the terminals exposed outside the case of the electrical junction box may become live. Therefore, providing a protective cover to cover the terminals ensures safety during work. Furthermore, in the electrical junction box of Patent Document 1, the protective cover is held to the case via a hinge made of thin resin, and the elastic restoring force of the hinge biases the lid in a direction that covers the terminals. This prevents the terminals from being exposed too much.

[0003] Japanese Patent Application Laid-Open No. 2023-71368

[0004] However, in the electrical connection box disclosed in Patent Document 1, the hinge that connects the protective cover to the case is made of thin resin, so it is possible that the hinge will become brittle and break in a low-temperature environment, making it impossible for the protective cover to cover the terminal portion.

[0005] Therefore, an electrical junction box is disclosed that can stably prevent the terminal portions from being exposed.

[0006] The electrical connection box of the present disclosure comprises a case, terminal portions exposed from an opening of the case and to which an external conductive member is connected, a protective cover rotatably held by the case and covering the opening, an engaging protrusion provided on one of the case and the protective cover, and an engaging wall portion provided on the other of the case and the protective cover, wherein the protective cover is initially positioned in an open position where it is separated from the opening and exposes the opening, and the protective cover can rotate from the open position to a closed position where it is placed over the opening and covers the opening by the engaging protrusion elastically deforming and climbing over the engaging wall portion, and the engaging protrusion, having climbed over the engaging wall portion and elastically returned to its original position, abuts against the engaging wall portion, limiting the rotation range of the protective cover toward the open position to a range where the protective cover rotates to the closed position under its own weight.

[0007] According to the electrical junction box of the present disclosure, exposure of the terminal portion can be stably suppressed.

[0008] FIG. 1 is a perspective view showing an electrical junction box according to the first embodiment with a protective cover in a closed position. FIG. 2 is a plan view of the electrical junction box shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a perspective view of the electrical junction box shown in FIG. 1, showing a state in which the protective cover is in an open position in an initial state. FIG. 5 is a perspective view of the electrical junction box shown in FIG. 4 from another direction. FIG. 6 is a plan view of the electrical junction box shown in FIG. 4. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 8 is a perspective view showing a state in which an external conductive member is connected to a terminal portion of the electrical junction box shown in FIG. 4. FIG. 9 is a perspective view of the electrical junction box shown in FIG. 8 with the protective cover in the middle of pivoting from the open position to the closed position, showing a state in which the engaging protrusion is elastically deformed by the engaging wall portion. FIG. 10 is a front view of the electrical junction box shown in FIG. 9. FIG. 11 is a perspective view showing a state in which the protective cover in the closed position of the electrical junction box shown in FIG. 1 has been pivoted toward the open position. Fig. 12 is a longitudinal cross-sectional view of the electrical junction box shown in Fig. 11 and corresponds to Fig. 3. Fig. 13 is a perspective view showing a state in which a protective cover is in an open position in the electrical junction box according to embodiment 2. Fig. 14 is a perspective view showing a state in which a protective cover is in a closed position in the electrical junction box shown in Fig. 13. Fig. 15 is a longitudinal cross-sectional view showing a main part of the XV-XV cross section in Fig. 14.

[0009]

[0013] <Description of Embodiments of the Present Disclosure> First, embodiments of the present disclosure will be described. The electrical junction box of the present disclosure includes: (1) a case, terminals exposed through an opening of the case to be connected to external conductive members, a protective cover rotatably held by the case and covering the opening, an engaging protrusion provided on one of the case and the protective cover, and an engaging wall provided on the other of the case and the protective cover, wherein the protective cover is initially positioned at an open position where it is separated from the opening to expose the opening, and the protective cover is allowed to rotate from the open position to a closed position where it overlaps the opening to cover the opening by the engaging protrusion elastically deforming and climbing over the engaging wall, and the engaging protrusion, having climbed over the engaging wall and elastically returned to its original position, abuts against the engaging wall, thereby limiting the rotation range of the protective cover toward the open position to a range where the protective cover rotates to the closed position under its own weight.

[0010] According to the electrical junction box of this aspect, the protective cover covering the opening of the case where the terminals are exposed is initially positioned in an open position exposing the opening. This allows for easy connection of an external conductive member, such as a wire harness, to the terminals during assembly into a vehicle, with a large working space. After the connection of the external conductive member to the terminals is completed, the protective cover is rotated toward a closed position that covers the opening. The engaging protrusions on one of the case and the protective cover elastically deform to overcome the engaging wall on the other, thereby covering the opening. When the protective cover is subsequently opened during vehicle maintenance or other such operations, the engaging protrusions, having overcome the engaging wall and elastically returned to their original position, abut against the engaging wall, limiting the range of rotation of the protective cover toward the open position to the range in which the protective cover would rotate to the closed position under its own weight. This ensures that the protective cover, once rotated toward the open position for maintenance or other operations, will always rotate toward the closed position under its own weight after the operation, reliably preventing the protective cover from being left unclosed. The electrical connection box according to the present invention has a structure in which the terminals are not exposed to the outside world, and the terminals are not exposed to the outside world due to the external force of the electrical connection box.

[0011] (2) In the above (1), it is preferable that the rotation shaft of the protective cover is held by a bearing portion provided in the case, and a gap is provided between the rotation shaft and the bearing portion. Since the rotation shaft of the protective cover is held by the bearing portion on the case side across a gap, friction between the rotation shaft and the bearing portion when the protective cover is rotated is suppressed. As a result, when the worker releases the protective cover after work, the protective cover automatically moves to the closed position, making it possible to more reliably prevent the protective cover from being left unclosed.

[0012] (3) In the above (1) or (2), it is preferable that the protective cover abuts against the upper surface of the peripheral wall of the opening when the protective cover is in the closed position. In the closed position, the protective cover abuts against the upper surface of the peripheral wall of the opening where the terminals are exposed, which more effectively prevents the exposure of the terminals, which may become live parts during maintenance work. This more effectively prevents or reduces the risk of electric shock to workers, thereby improving work safety.

[0013] (4) In any one of (1) to (3) above, it is preferable that the maximum central angle X around the rotation axis in the rotation region of the protective cover after the engaging protrusion has overcome the engaging wall portion and elastically returned to its original position is set in a range of 75°≦X<90° around the rotation axis of the protective cover, assuming that the closed position of the protective cover is 0°. If the maximum central angle X around the rotation axis in the rotation region is smaller than 75°, workability during maintenance will deteriorate, and if it is 90° or more, it will be difficult to reliably guide the protective cover to rotate to the closed position under its own weight.

[0014] (5) In any one of (1) to (4) above, it is preferable that a first locking mechanism be provided to detachably hold the protective cover in the closed position. The first locking mechanism can reliably hold the protective cover in the closed position, preventing unintentional exposure of the terminals and enabling the protective cover to be released during maintenance.

[0015] (6) In any one of (1) to (5) above, it is preferable to have a second locking mechanism that detachably holds the protective cover in the open position. This is because the second locking mechanism can stably hold the protective cover in the open position in the initial state, exposing the opening, thereby improving the ease of assembly when mounting the electrical junction box on a vehicle.

[0016] <Details of the Embodiments of the Present Disclosure> Specific examples of the electrical junction box of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0017] First Embodiment An electrical junction box 10 according to a first embodiment of the present disclosure will be described below with reference to FIGS. 1 to 12 . The electrical junction box 10 is mounted inside a battery pack in, for example, an electric vehicle or a hybrid vehicle, and is connected to an external conductive member. In the first embodiment, a bus bar 12, which is an example of a conductive member, is connected to the electrical junction box 10. Note that the electrical junction box 10 can be positioned in any orientation within the vehicle. However, in the following description, the upper side will be referred to as the upper side in FIG. 3 , the lower side as the lower side in FIG. 3 , the left side as the lower side in FIG. 2 , the right side as the upper side in FIG. 2 , the front side as the right side in FIG. 2 , and the rear side as the left side in FIG. 2 . Note that, in some cases, when multiple identical components are used, only some of the components will be designated by reference numerals, and the reference numerals will be omitted for the other components.

[0018] <Electrical Junction Box 10> The electrical junction box 10 includes a case 14 and terminal portions 18 that are exposed through an upper opening 16 of the case 14 and to which external conductive members (bus bars 12) are connected. The electrical junction box 10 also includes a protective cover 20 that is rotatably held by the case 14 and covers the opening (upper opening 16), an engaging protrusion 22 provided on one of the case 14 and the protective cover 20, and an engaging wall portion 24 provided on the other of the case 14 and the protective cover 20. In the first embodiment, the engaging protrusion 22 is provided on the protective cover 20, and the engaging wall portion 24 is provided on the case 14. In the first embodiment, the bus bar 12 is inserted into the terminal portions 18 from the side (right side) to be connected. A bolt insertion hole 25 is formed in the bus bar 12 at a portion that overlaps the terminal portion 18.

[0019] <Case 14> The case 14 that constitutes the electrical junction box 10 can be formed, for example, by assembling an upper case 26 and a lower case (not shown) in the vertical direction, but in the first embodiment, the characteristic parts are provided in the upper case 26, and the shape of the lower case is not limited, so a description of the lower case will be omitted. Furthermore, the shape of the upper case 26 shown in the drawings is merely an example and is not limited, and is intended to illustrate the characteristic parts of the present disclosure.

[0020] In the first embodiment, the upper case 26 shown in the drawings has a generally box-like shape that opens downward (having a lower opening 27) and is made of an insulating synthetic resin. The upper case 26 includes an upper bottom wall 28 that is generally rectangular in plan view and an upper peripheral wall 30 that protrudes downward from the outer periphery of the upper bottom wall 28. Specifically, the upper peripheral wall 30 includes a front wall 32a located at the front, a rear wall 32b located at the rear, and left and right wall portions 32c and 32d located on both the left and right sides. The upper bottom wall 28 has a larger longitudinal dimension than a transverse dimension.

[0021] Here, a storage space 36 is formed in the front portion of the internal space of the upper case 26 to accommodate the terminal portion 18 and a nut 34 to which a bolt 71 (described later) is fastened. This storage space 36 is generally rectangular in plan view and extends vertically through the upper case 26. That is, the storage space 36 is defined by an area surrounded by the front wall portion 32a and the front portions of the left wall portion 32c and the right wall portion 32d. A nut accommodating portion 38 is disposed in the storage space 36, and the nut 34 is assembled to this nut accommodating portion 38, thereby accommodating the nut 34 within the storage space 36. The nut accommodating portion 38 may be formed separately from the upper case 26, inserted into the storage space 36 from below through the lower opening 27, and fixedly attached to at least one of the front wall portion 32a, rear wall portion 32b, left wall portion 32c, and right wall portion 32d that constitute the storage space 36, for example, by a locking mechanism (not shown).

[0022] The upper bottom wall 28 has a front portion formed with the aforementioned upper opening 16 penetrating through it in the thickness direction (vertical direction), and the storage space 36 opens upward through the upper opening 16. The upper opening 16, like the storage space 36, has a generally rectangular shape in plan view. Furthermore, the vertical dimension of the front portion of the right wall 32d constituting the storage space 36 is smaller than that of other portions (e.g., the rear portion), and a right opening 40 opening to the right is formed at the top end of the storage space 36. As will be described later, the terminal 18 is positioned above the nut 34 in the storage space 36, and the terminal 18 is exposed upward through the upper opening 16 and laterally (to the right) through the right opening 40.

[0023] As a result, the peripheral wall 42 that defines the upper opening 16 at the upper end of the storage space 36 is composed of three walls excluding the right. In short, the peripheral wall 42 includes an upper portion of the front wall 32a, an upper portion of the front portion of the left wall 32c, and an intermediate wall 44 located behind the upper opening 16 (i.e., the middle portion of the upper case 26 in the front-to-rear direction). This intermediate wall 44 is formed over the entire length in the left-to-right direction at the top end of the case 14 (upper case 26), with the right end of the intermediate wall 44 connected to the right wall 32d, and the right end of this intermediate wall 44 defining the right opening 40. The upper surfaces 46 of the peripheral wall 42 configured in this manner are located at approximately the same vertical position and on the same plane that extends horizontally (orthogonal to the vertical direction).

[0024] The upper surface 46 of the peripheral wall 42 is located lower than the upper surface of the upper bottom wall portion 28 in a portion of the upper case 26 where the storage space 36 is not provided (for example, the rear portion). This prevents the vertical dimension of the front portion of the electrical junction box 10 from becoming too large when the protective cover 20 rotates from the open position O to the closed position C and abuts against the upper surface 46 of the peripheral wall 42, as will be described later.

[0025] A first locking portion 48 that constitutes a first locking mechanism 83 (described later) is provided on the front portion of the upper surface 46 of the peripheral wall 42 (i.e., the upper surface of the front wall portion 32a). In the first embodiment, the first locking portion 48 is provided in the left-right central portion of the upper surface of the front wall portion 32a and protrudes upward. A locking claw 50 that protrudes rearward is provided on the protruding tip (upper end) of the first locking portion 48.

[0026] A pair of bearings 52 are integrally formed on both the left and right sides of the upper bottom wall 28 of the upper case 26, at a portion rearward of the intermediate wall 44, to hold a pivot shaft 100 (described later) of the protective cover 20. Each bearing 52 is generally plate-shaped and has a predetermined thickness (left-right dimension), protruding upward from the upper bottom wall 28. A circular insertion hole 54 is formed at the upper end of each bearing 52, penetrating the thickness direction. In particular, a notch 56 is formed on the inner surface (inner surface in the left-right direction) of each bearing 52, opening upward and communicating with each insertion hole 54. This notch 56 facilitates insertion of each pivot shaft 100 into each insertion hole 54. An inclined surface is provided on the inner peripheral surface of the upper end of each bearing 52, where the notch 56 is formed, and this inclined surface forms a guide surface 58 that guides the insertion of each pivot shaft 100.

[0027] <Engagement Wall 24> Furthermore, the aforementioned engagement wall 24 is provided in the left-right central portion of the upper bottom wall 28 between the opposing bearing portions 52 in the left-right direction. As shown in Figures 3 and 10, the engagement wall 24 is a generally plate-shaped portion that protrudes upward with a predetermined protrusion dimension. The engagement wall 24 has a generally hexagonal shape when viewed from the front as shown in Figure 10, and its rear end surface is an inclined surface 59 that gradually slopes upward toward the tip. Furthermore, both left and right end surfaces of the engagement wall 24 are flat surfaces 60, 60 that extend vertically, and the upper ends of each flat surface 60 are connected to inclined surfaces 62, 62 that gradually slope inward in the left-right direction as they extend upward. When the protective cover 20 shown in Figures 4 to 6 is in the open position O, the inclined surfaces 108 of each engaging protrusion 22, which will be described later, are located above each inclined surface 62, and each inclined surface 62 of the engaging wall portion 24 and the inclined surface 108 of each engaging protrusion 22 face each other at an angle and with a slight gap between them.

[0028] Second locking portions 64 that constitute a second locking mechanism 97 (described later) are provided on both left and right sides of the upper bottom wall portion 28, behind the bearing portions 52. Each of these second locking portions 64 protrudes upward, and a locking claw 66 that protrudes inward in the left and right direction is provided at the protruding tip end (upper end) of each second locking portion 64.

[0029] <Terminal Portion 18> Bus bars 68 constituting the terminal portion 18 are housed inside the electrical junction box 10 (upper case 26). In the first embodiment, two bus bars 68 (a first bus bar 68a and a second bus bar 68b) are provided. Each of these bus bars 68a, 68b extends in the front-to-rear direction within the upper case 26 as a whole and is formed, for example, by bending a conductive metal sheet into a predetermined shape. The front ends of these bus bars 68a, 68b are overlapped with each other in the vertical direction and positioned within the storage space 36 of the upper case 26. Behind the storage space 36, the bus bar 68 positioned above the first bus bar 68a is the first bus bar 68a, and the bus bar 68 overlapped below the first bus bar 68a is the second bus bar 68b. As shown in Figure 7, the rear portions of these bus bars 68a, 68b are arranged spaced apart from each other in the left-right direction in the right part of the internal space of the upper case 26, and these bus bars 68a, 68b are exposed from the rear wall portion 32b of the upper case 26 while being spaced apart from each other in the left-right direction.

[0030] Here, the front ends of the bus bars 68a, 68b are overlapped with each other to form the terminal portion 18 that is placed within the accommodation space 36. Bolt insertion holes 70, 70 are formed in the front ends of the bus bars 68a, 68b, respectively, and the bus bars 68a, 68b are overlapped such that the bolt insertion holes 70 are in communication with each other in the up-down direction. Furthermore, the terminal portion 18 is overlapped on the upper surface of the nut 34 so that the bolt insertion holes 70 of the bus bars 68a, 68b are aligned with the inner holes of the nut 34 that are accommodated within the accommodation space 36.

[0031] When the terminal portion 18 and the bus bar 12 are electrically connected, one end of the bus bar 12 is placed over the terminal portion 18 through the upper opening 16 or the right opening 40, and the bolt insertion holes 25, 70, 70 are aligned with the inner holes of the nuts 34. The terminal portion 18 and the bus bar 12 are electrically connected by inserting a bolt 71 into each of the bolt insertion holes 25, 70, 70 and fastening it to the nut 34. For example, power input through the bus bar 12 can be output in two mutually different directions from the rear end of the electrical junction box 10 via the bus bars 68a, 68b.

[0032] <Protective Cover 20> When the protective cover 20 is in the closed position C in which the protective cover 20 is superimposed on the upper opening 16 to cover the upper opening 16 as shown in FIGS. 1 to 3 , the protective cover 20 has a generally box-like shape that opens downward as a whole and includes a cover bottom 72 and a cover peripheral wall 74 that protrudes downward from the outer periphery of the cover bottom 72. The cover bottom 72 is generally rectangular in plan view and is formed to be approximately the same size as the peripheral wall 42 in the front portion of the upper case 26. As a result, when the protective cover 20 is in the closed position C as shown in FIGS. 1 to 3 , the upper opening 16 provided in the front of the upper case 26 is covered from above by the protective cover 20. In the first embodiment, the upper surfaces 46 of the peripheral wall 42 that constitute the upper opening 16 are located on the same plane, and therefore, when the protective cover 20 is in the closed position C, the protective cover 20 abuts against approximately the entire upper surface 46 of the peripheral wall 42.

[0033] Furthermore, when the protective cover 20 is in the closed position C, an accommodation recess 76 for accommodating the head of the bolt 71 is formed in the left-right central portion of the cover bottom 72. The accommodation recess 76 has a downwardly opening recessed shape. Furthermore, a first locked portion 78 constituting a first locking mechanism 83 (described later) is provided in the left-right central portion of the protective cover 20, forward of the accommodation recess 76. In the first embodiment, the first locked portion 78 protrudes upward from the cover bottom 72 and then bends downward, protruding below the cover bottom 72 through a through hole 80 provided in the front end portion of the cover bottom 72. As a result, the first locked portion 78 is elastically deformable in the front-rear direction within the through hole 80, and a locked claw 82 protruding forward is provided at the lower end of the first locked portion 78. As a result, when the protective cover 20 is in the closed position C, the engaging claw 82 of the first engaged portion 78 engages with the engaging claw 50 of the first engaging portion 48, thereby maintaining the protective cover 20 in the closed position C. As a result, in the first embodiment, the first locking mechanism 83 that detachably holds the protective cover 20 in the closed position C is made up of the first engaging portion 48 and the first engaged portion 78, particularly the engaging claw 50 and the engaged claw 82.

[0034] Furthermore, first locked portions 84 that constitute a first locking mechanism 132 in the second embodiment, which will be described later, are formed on the outer peripheral surfaces of both the left and right sides of the cover peripheral wall portion 74 of the protective cover 20. Each of these first locked portions 84 protrudes outward in the left-right direction from the outer peripheral surfaces of both the left and right sides of the cover peripheral wall portion 74. Note that each of these first locked portions 84 does not perform any special function in the first embodiment. Recesses 86 that open to both the left and right sides are formed in the middle portion of the outer peripheral surfaces of both the left and right sides of the cover peripheral wall portion 74 in the front-rear direction, and each of the first locked portions 84 protrudes from the bottom surface of each recess 86. This keeps the outward protrusion of each first locked portion 84 small, and in the first and second embodiments, each of the first locked portions 84 does not protrude outward in the left-right direction beyond the outer peripheral surfaces of both the left and right sides of the cover peripheral wall portion 74.

[0035] An operating portion 88 that can be operated by an operator with his / her fingers is formed in the center in the left-right direction of the front end surface of the protective cover 20. Meanwhile, operating portions 90, 90 that can be operated by an operator with his / her fingers in a second embodiment, which will be described later, are formed in the front end portions of the outer peripheral surfaces on both the left and right sides of the cover peripheral wall portion 74 of the protective cover 20. These operating portions 90 do not perform any special function in the first embodiment.

[0036] When the protective cover 20 is in the closed position C as shown in FIGS. 1 to 3 , the rear end of the cover bottom 72 is provided with a thick portion 92 that is thicker in the vertical direction and continues rearward from the accommodation recess 76. The thick portion 92 has a larger left-right dimension than the accommodation recess 76, and both left and right ends of the thick portion 92 are located on both left and right sides of the cover bottom 72. Second engaging portions 94 that protrude downward and are elastically deformable in the left-right direction are formed on both left and right ends of the thick portion 92. A locking claw 96 that protrudes outward in the left-right direction is provided at a vertically intermediate portion of each second engaging portion 94. As a result, when the protective cover 20 is in the open position O as shown in FIGS. 4 to 7 , the locking claw 96 of the second engaging portion 94 engages with the locking claw 66 of the second engaging portion 64, thereby maintaining the protective cover 20 in the open position O. As a result, in embodiment 1, the second locking mechanism 97 that holds the protective cover 20 in the open position O in a freely attachable and detachable manner is composed of the second engaging portion 64 and the second engaged portion 94, particularly the engaging claw 66 and the engaged claw 96.

[0037] Furthermore, when the protective cover 20 is in the closed position C, elastic arms 98, 98 protrude rearward from both lateral ends of the thick portion 92, and pivot shafts 100, 100 protrude outward in the lateral direction from the protruding tip (rear end) of each elastic arm 98. Each elastic arm 98 is elastically deformable in the lateral direction, and when the protective cover 20 is assembled to the upper case 26, for example, each elastic arm 98 elastically deforms inward in the lateral direction, allowing each pivot shaft 100 to be inserted into the insertion hole 54 of each bearing 52. The protective cover 20 is assembled to the upper case 26 in the orientation shown in FIGS. 4 to 7. In the state shown in FIGS. 4 to 7, an inclined surface 102 is provided on the lower portion of the outer circumferential surface of each pivot shaft 100, and the abutment of each inclined surface 102 and each bearing 52 facilitates elastic deformation of each elastic arm 98 inward in the lateral direction.

[0038] The outer diameter of each pivot shaft 100 is slightly smaller than the inner diameter of each insertion hole 54. When the pivot shaft 100 is inserted into the insertion hole 54, a slight gap 103 (see FIG. 3 ) is formed between the pivot shaft 100 and the insertion hole 54. This prevents the pivot shaft 100 from getting caught on the inner circumferential surface of the insertion hole 54 during rotation of the protective cover 20, allowing for smooth rotation. In particular, the formation of such gap 103 makes the rotational force of the protective cover 20 to rotate toward the closed position C due to its own weight greater than the resistance to the rotational force. As a result, during maintenance or other servicing, as described below, after an operator releases the protective cover 20 from its grip, the resistance that prevents the protective cover 20 from freely falling toward the closed position C due to its own weight can be significantly reduced. Therefore, the released protective cover 20 can be quickly rotated toward the closed position C.

[0039] <Engagement Protrusions 22> Furthermore, when the protective cover 20 is in the closed position C, a pair of engagement protrusions 22, 22 are spaced apart in the left-right direction and protrude rearward inward of each elastic arm portion 98 in the thick portion 92. Each engagement protrusion 22 is configured to include an elastic support portion 104 that protrudes rearward from the thick portion 92, and an inward protrusion 106 that protrudes inward in the left-right direction from the protruding tip end (rear end) of each elastic support portion 104. Each elastic support portion 104 is capable of elastic deformation in the left-right direction.

[0040] Each inward protrusion 106 has a predetermined shape and protrusion dimensions and protrudes inward in the left-right direction from each elastic support portion 104. That is, when the protective cover 20 is in the open position O as shown in FIGS. 4 to 7 , the lower end surface of each inward protrusion 106 is provided with an inclined surface 108 that gradually slopes upward inward in the left-right direction. As described above, when the protective cover 20 is in the open position O, each inclined surface 108 faces the inclined surface 62 of the engagement wall portion 24 at a slight angle. Furthermore, the protruding tip surface (the end surface on the inner side in the left-right direction) of each inward protrusion 106 is a vertical surface 110 that extends vertically and continues from the inclined surface 108. Furthermore, the upper end surface of each inward protrusion 106 is a flat surface 112 that extends in the front-rear direction and continues from the vertical surface 110. In the initial state shown in Figures 4 to 7, each inner protrusion 106 is located above the engaging wall portion 24 provided on the upper case 26, and is located at a position approximately equal to the engaging wall portion 24 in the front-to-rear direction, or slightly forward of the engaging wall portion 24.

[0041] <Assembly of Electrical Junction Box 10> A specific example of a method for assembling the electrical junction box 10 will now be described. However, the method for assembling the electrical junction box 10 is not limited to the embodiment described below.

[0042] First, the first and second bus bars 68a, 68b are inserted into the upper case 26 through the lower opening 27 of the upper case 26. Next, the nut accommodating portion 38 with the nut 34 attached thereto is inserted from below into the accommodation space 36 in the upper case 26 and fixed in place by a locking mechanism (not shown). This aligns the bolt insertion holes 70, 70 in each bus bar 68a, 68b with the inner holes of the nuts 34, and the nut 34 is pressed against the second bus bar 68b from below, so that the first and second bus bars 68a, 68b are sandwiched between the upper bottom wall portion 28 of the upper case 26 and the nuts 34 in the vertical direction.

[0043] The protective cover 20 is then assembled to the upper case 26 from above. Specifically, the rotating shafts 100 are brought close to the bearings 52 of the upper case 26 from above, with the inclined surfaces 102 of the rotating shafts 100 of the protective cover 20 facing downward (the orientation shown in FIGS. 4 to 7 ). This brings the guide surfaces 58 on the inner surfaces of the bearings 52 into contact with the inclined surfaces 102 of the rotating shafts 100, causing the bearings 52 and / or the elastic arm portions 98 to elastically deform. This allows the protective cover 20 to be pushed further downward, and when the rotating shafts 100 enter the insertion holes 54, the bearings 52 and / or the elastic arm portions 98 elastically return to their original shape. Additionally, the latching claws 96 of the second latching portions 94 provided on the protective cover 20 are latched with the latching claws 66 of the second latching portions 64 provided on the upper case 26. This maintains the protective cover 20 in the open position O, completing the electrical junction box 10 in the initial state shown in Figures 4 to 7.

[0044] <Method of Using the Electrical Junction Box 10> In the initial state of the electrical junction box 10 manufactured as described above, the protective cover 20 is disposed in the open position O away from the upper opening 16, and the upper opening 16 and the terminal portions 18 are exposed to the outside. With the terminal portions 18 thus exposed to the outside, for example, a bus bar 12 having an end bent horizontally is placed over the terminal portions 18 through the upper opening 16 or the right opening 40, and the bolt insertion holes 70 are aligned with the bolt insertion holes 25 in the bus bar 12. Thereafter, bolts 71 are inserted into the bolt insertion holes 70, 25 and fastened to nuts 34, thereby connecting the terminal portions 18 and the bus bar 12 as shown in FIG. 8 .

[0045] In this manner, when the terminals 18 and the bus bars 12 are connected, the connection portions become live parts, so it is preferable to cover the live parts with the protective cover 20 to prevent electric shock to the operator. Therefore, from the state in which the protective cover 20 is in the open position O shown in Figure 8, the protective cover 20 is rotated around each rotation shaft 100 toward the closed position C. The states of the protective cover 20 during its rotation are shown in Figures 9 and 10.

[0046] In the electrical junction box 10 of the first embodiment, rotation of the protective cover 20 around the rotation shafts 100 first causes the inclined surfaces 108 on the inward protrusions 106 of the engaging protrusions 22 to abut against the inclined surfaces 62 on the engaging wall portions 24. Further rotation of the protective cover 20 with the inclined surfaces 108, 62 abutting against each other causes the elastic support portions 104 on the engaging protrusions 22 to elastically deform outward in the opposing direction (outward in the left-right direction) along the inclination of the inclined surfaces 108, 62. Rotation of the protective cover 20 while the inclined surfaces 108, 62 are in contact with each other causes the elastic support portions 104 to further elastically deform outward in the left-right direction. As a result, as shown in FIG. 10 , the vertical surfaces 110 on the inward protrusions 106 abut against the flat surfaces 60 on the engaging wall portions 24.

[0047] By further rotating the protective cover 20 while keeping each vertical surface 110 in contact with each flat surface 60, the inner protrusions 106 of each engaging protrusion 22 climb over the engaging wall portions 24. This causes each elastic support portion 104 to elastically restore and return each engaging protrusion 22 to its initial shape. In this state, as shown in FIG. 3 , each inner protrusion 106 is located rearward of the engaging wall portions 24. Then, the protective cover 20 is further rotated toward the closed position C, and the upper surface 46 of the peripheral wall 42 at the upper opening 16 overlaps with the protective cover 20. This positions the protective cover 20 in the closed position C. In other words, rotation from the open position O to the closed position C is permitted by each engaging protrusion 22 climbing over the engaging wall portions 24. 1 to 3, the protective cover 20 is held in the closed position C by engaging the engaging claws 82 of the first engaged portions 78 with the engaging claws 50 of the first engaging portions 48 at the front end side of the upper case 26. In this state, the live parts are covered by the protective cover 20, preventing an operator from accidentally coming into contact with them and receiving an electric shock.

[0048] During maintenance or other servicing, as shown in FIGS. 11 and 12 , the first locking portion 48 and the first locked portion 78 are disengaged, the protective cover 20 is displaced toward the open position O, the bolt 71 is released, and parts can be replaced or the like. That is, the protective cover 20, which is in the closed position C, is rotated toward the open position O about the rotation shafts 100, but this rotation toward the open position O is limited by the abutment of the engaging protrusions 22 with the engaging wall portion 24. Specifically, as shown in FIG. 12 , the flat surfaces 112 of the inward protrusions 106 of the engaging protrusions 22 abut against the left and right ends of the rear end surface (inclined surface 59) of the engaging wall portion 24, thereby limiting further rotation of the protective cover 20 toward the open position O. Here, the rotation region R of the protective cover 20 toward the open position O is limited to a range in which the protective cover 20 rotates toward the closed position C due to its own weight.

[0049] 11 and 12 show a state in which the protective cover 20 has been rotated to the open position O to the maximum, and the maximum central angle X (see FIG. 12 ) around each rotation axis 100 in the rotation region R of the protective cover 20 is preferably set in the range of 75°≦X<90° around each rotation axis 100, where 0° is the closed position C of the protective cover 20. As described above, the rotational displacement of the protective cover 20 towards the open position O is limited by the abutment between the flat surfaces 112 of each inward protrusion 106 and the inclined surfaces 59 of the engagement wall portion 24. Therefore, the magnitude of the maximum central angle X around each rotation axis 100 in the rotation region R of the protective cover 20 can be set, for example, by the inclination angle of the inclined surfaces 59.

[0050] In this manner, when each engaging protrusion 22 has climbed over the engaging wall portion 24, the angle does not exceed 90° even when the protective cover 20 is fully opened, and the protective cover 20 can automatically pivot to the closed position C due to its own weight. In particular, a small gap 103 is formed between each rotating shaft 100 and the insertion hole 54 through which each rotating shaft 100 is inserted, and although the protective cover 20 needs to be maintained in the open state during servicing, the protective cover 20 can be automatically pivoted to the closed position C by releasing the open state. After the protective cover 20 reaches the closed position C, the first locked portion 78 is locked to the first locking portion 48, thereby maintaining the protective cover 20 in the closed position C.

[0051] According to the electrical junction box 10 of the first embodiment having the above-described structure, the protective cover 20 is initially held in the open position O exposing the upper opening 16 and the terminal portions 18, facilitating the operation of overlapping and connecting the bus bar 12, which is an external conductive member, with the terminal portions 18. Furthermore, when the protective cover 20 is pivoted from the open position O to the closed position C, the engaging protrusions 22 must elastically deform to overcome the engaging wall portions 24, thereby preventing the protective cover 20 from unintentionally moving from the open position O to the closed position C. Furthermore, when the terminal portions 18 and the bus bar 12 are connected, these connection portions become live parts, but when the protective cover 20 is pivoted to the closed position C, the live parts are covered by the protective cover 20, reducing the risk of electric shock to the operator. Furthermore, once each engaging protrusion 22 overcomes the engaging wall portion 24, the protective cover 20 is then automatically and quickly displaced to the closed position C due to its own weight, which more reliably prevents the connection portion between the terminal portion 18, which has become an active part, and the bus bar 12 from being exposed to the outside and also reduces the burden on the worker.

[0052] Furthermore, when the protective cover 20 is in the closed position C, it is displaced toward the open position O during servicing such as maintenance. However, the rotation region R of the protective cover 20 toward the open position O is limited to a range in which the protective cover 20 rotates to the closed position C under its own weight due to the abutment of the engaging protrusions 22 with the engaging wall portions 24. As a result, even when the protective cover 20 is opened during servicing, the protective cover 20 is automatically displaced to the closed position C by releasing the external force that keeps the protective cover 20 open after the work, which prevents the protective cover 20 from being left closed. Furthermore, once the protective cover 20 is rotated from the initial state (open position O) and the engaging protrusions 22 overcome the engaging wall portions 24, the abutment of the engaging protrusions 22 with the engaging wall portions 24 limits the rotational displacement toward the open position O, making it difficult to restore the protective cover 20 to the initial state (open position O). Therefore, by checking whether the protective cover 20 is in the closed position C or the open position O, it is possible to easily determine whether the terminal portion 18 and the bus bar 12 are connected.

[0053] In particular, the structure for preventing the protective cover 20 from being left closed as described above does not use a hinge as in conventional structures, so there is no problem of the hinge being damaged when exposed to a low-temperature environment, for example, and the live parts can be covered with the protective cover 20 quickly and more reliably.

[0054] In the first embodiment, each rotation shaft 100 of the protective cover 20 is held by a corresponding bearing 52 provided in the upper case 26, and a gap 103 is provided between each rotation shaft 100 and each bearing 52. This makes the rotational force of the protective cover 20 rotating to the closed position C due to its own weight greater than the resistance force against the rotational force. As a result, the protective cover 20 can be automatically and quickly rotated to the closed position C when each engagement protrusion 22 has climbed over the engagement wall 24. Note that this configuration can be achieved, for example, by setting the outer diameter of each rotation shaft 100 slightly smaller than the inner diameter of the insertion hole 54 in each bearing 52, thereby providing a gap 103 between each rotation shaft 100 and each insertion hole 54.

[0055] When the protective cover 20 is in the closed position C, the protective cover 20 abuts against an upper surface 46 of the peripheral wall 42 of the upper opening 16. In particular, in the first embodiment, the upper surface 46 is located on the same plane over substantially the entirety, and substantially the entirety of the protective cover 20 abuts against the upper surface 46. This more reliably prevents unintentional contact with live parts (connection portions between the terminal parts 18 and the bus bars 12) through the upper opening 16.

[0056] For example, when the protective cover 20 is opened during maintenance or other servicing, the rotation angle of the protective cover 20 is set so that the maximum central angle X around the central axis of each rotation shaft 100 is in the range of 75°≦X<90°. Setting the protective cover 20 to open at an angle of 75° or more allows for stable servicing work. Furthermore, setting the protective cover 20 to open at an angle smaller than 90° allows the protective cover 20 to automatically move to the closed position C by releasing the external force in the opening direction of the protective cover 20 after the work is completed.

[0057] The electrical junction box 10 has a first locking mechanism 83 that detachably holds the protective cover 20 in the closed position C. This prevents the protective cover 20 in the closed position C from being unintentionally displaced toward the open position O.

[0058] The electrical junction box 10 has a second locking mechanism 97 that detachably holds the protective cover 20 in the open position O. This prevents the protective cover 20 in the open position O from being unintentionally displaced toward the closed position C.

[0059] Second Embodiment Next, an electrical junction box 120 according to a second embodiment of the present disclosure will be described with reference to FIGS. 13 to 15 . The basic structure of the electrical junction box 120 according to the second embodiment is similar to that of the electrical junction box 10 according to the first embodiment. However, whereas in the first embodiment, the bus bar 12, which is a conductive member, is inserted from the side (right side) of the terminal portion 18 and overlaps the terminal portion 18, in the second embodiment, the bus bar 12, which is a conductive member, is inserted from the front of the terminal portion 18 and overlaps the terminal portion 18. In the following description, components and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted. Also, in FIGS. 13 to 15 , only characteristic portions of the second embodiment are illustrated, and the entire electrical junction box 120 is not illustrated.

[0060] In the second embodiment, the upper case 122 also has an upper opening 16 as an opening for exposing the terminal portions 18. In the second embodiment, the bus bar 12 is inserted from the front, and therefore a front opening 126 is formed in the peripheral wall 124 of the upper opening 16. Therefore, in the second embodiment, the peripheral wall 124 of the upper opening 16 is configured to include an upper portion of the left wall portion 32 c, an upper portion of the right wall portion 32 d, and an intermediate wall portion 44 located behind the upper opening 16.

[0061] In the second embodiment, the left wall portion 32c and the right wall portion 32d each have an upwardly protruding first locking portion 128 formed at their upper ends, and a locking claw 130 protruding inward in the left-right direction is provided at the protruding tip (upper end) of each first locking portion 128. As described above, the protective cover 20 has outwardly protruding first locked portions 84 provided on the outer peripheral surface on both the left and right sides of the cover peripheral wall portion 74. Therefore, as shown in FIGS. 14 and 15 , when the protective cover 20 is in the closed position C, the first locked portions 84 are locked by the locking claws 130 of the first locking portions 128, thereby maintaining the protective cover 20 in the closed position C. Therefore, in the second embodiment, the first locking mechanism 132 that detachably holds the protective cover 20 in the closed position C is configured to include each first locking portion 128 and each first locked portion 84.

[0062] As described above, the electrical junction box 120 of the second embodiment is obtained by simply changing the insertion direction of the external conductive member (the bus bar 12) compared to the electrical junction box 10 of the first embodiment, and therefore can achieve the same effects as the first embodiment. In particular, the protective cover 20 described in the first and second embodiments has first latching portions 78, 84 formed on the front and side (both left and right sides) so that the bus bar 12 can be inserted from both the side (right or left) and the front. This allows the same shape of protective cover 20 to be used whether the bus bar 12 is inserted from the side or the front, eliminating the need to manufacture separate protective covers for when the bus bar 12 is inserted from the side and when it is inserted from the front, thereby facilitating parts management and reducing costs.

[0063] <Modifications> Although the first and second embodiments have been described above as specific examples of the present disclosure, the present disclosure is not limited to these specific descriptions. Modifications, improvements, etc., within the scope of achieving the object of the present disclosure, are included in the present disclosure. For example, the following modifications of the embodiments are also included in the technical scope of the present disclosure.

[0064] (1) In the above embodiment, the protective cover 20 is a common structure, and the bus bar 12, which is a conductive member, can be placed over the terminal portion 18 from either the side (right) or the front. However, this is not limited to this configuration. That is, the conductive member (e.g., a bus bar) may be placed over the terminal portion from either the side (right or left) or the front. Specifically, when the conductive member is placed over the terminal portion from the side, the first locking mechanism provided on the side (the first latched portions 84 and the first latching portions 128 on both the left and right sides) may not be provided. When the conductive member is placed over the terminal portion from the front, the first locking mechanism provided on the front (the front first latched portions 78 and the first latching portion 48) may not be provided. Note that the conductive member placed over the terminal portion is not limited to a bus bar and may be a wire harness with terminals connected to its ends. Furthermore, the first locking mechanism that detachably holds the protective cover in the closed position and the second locking mechanism that detachably holds the protective cover in the open position are not essential to the electrical junction box according to the present disclosure.

[0065] (2) The shapes of the engaging protrusions 22 and the engaging wall portions 24 in the above embodiment are merely exemplary, and the shapes of the engaging protrusions and the engaging wall portions are not limited as long as the engaging protrusions elastically deform to overcome the engaging wall portions when the protective cover is pivotally displaced from the open position to the closed position, and the protective cover that has reached the closed position does not open beyond a predetermined angle due to the abutment between the engaging protrusions and the engaging wall portions during servicing, for example. Also, in the above embodiment, the engaging protrusions 22 are provided on the protective cover 20, and the engaging wall portions 24 are provided on the case 14 (upper case 26, 122), but the engaging protrusions may be provided on the case, and the engaging wall portions may be provided on the protective cover.

[0066] (3) In the first embodiment, the bus bar 68 constituting the terminal portion 18 is composed of two bus bars, a first bus bar 68a and a second bus bar 68b. However, the bus bar constituting the terminal portion may be a single bus bar, as in the second embodiment.

[0067] (4) The case of the electrical junction box according to the present disclosure may have a plurality of connection portions between the conductive members and the terminal portions, and a protective cover may be provided at each connection portion. In this case, each conductive member may overlap each terminal portion from the side (right or left), or each conductive member may overlap each terminal portion from the front, or there may be portions overlapping from both the side and the front.

[0068] (5) In the above embodiment, the nuts 34 are housed in the case 14 (upper case 26, 122), and the terminal portions 18 and the bus bars 12 are fixed to each other by the bolts 71 inserted from above. However, the case may house stud bolts that protrude upward, and the terminal portions and the conductive members may be fixed to each other by nuts that are fastened from above.

[0069] REFERENCE SIGNS LIST 10 Electrical junction box (first embodiment) 12 Bus bar (conductive member) 14 Case 16 Upper opening (opening) 18 Terminal portion 20 Protective cover 22 Engagement protrusion 24 Engagement wall portion 25 Bolt insertion hole 26 Upper case 27 Lower opening 28 Upper bottom wall portion 30 Upper peripheral wall portion 32a Front wall portion 32b Rear wall portion 32c Left wall portion 32d Right wall portion 34 Nut 36 Storage space 38 Nut storage portion 40 Right opening 42 Peripheral wall 44 Middle wall portion 46 Upper surface 48 First locking portion 50 Locking claw 52 Bearing portion 54 Insertion hole 56 Notch 58 Guide surface 59 Inclined surface 60 Flat surface 62 Inclined surface 64 Second locking portion 66 Locking claw 68 Bus bar 68a First bus bar 68b Second bus bar 70 Bolt insertion hole 71 Bolt 72 Cover bottom 74 Cover peripheral wall 76 Housing recess 78 First locked portion 80 Through hole 82 Locked claw 83 First locking mechanism 84 First locked portion 86 Recess 88, 90 Operation portion 92 Thick portion 94 Second locked portion 96 Locked claw 97 Second locking mechanism 98 Elastic arm portion 100 Rotating shaft 102 Inclined surface 103 Gap 104 Elastic support portion 106 Inward protrusion 108 Inclined surface 110 Vertical surface 112 Flat surface 120 Electrical junction box (embodiment 2) 122 Upper case 124 Peripheral wall 126 Front opening 128 First locking portion 130 Locking claw 132 First locking mechanism C Closed position O Open position R Rotation range X Maximum central angle

Claims

1. An electrical junction box comprising: a case; terminal portions exposed from an opening of the case and for connection with external conductive members; a protective cover rotatably held by the case and covering the opening; an engaging protrusion provided on one of the case and the protective cover; and an engaging wall portion provided on the other of the case and the protective cover, wherein the protective cover is initially positioned in an open position away from the opening to expose the opening, and the protective cover is allowed to rotate from the open position to a closed position where it is superimposed on the opening to cover the opening by the engaging protrusion elastically deforming and climbing over the engaging wall portion, and the engaging protrusion, having climbed over the engaging wall portion and elastically returned to its original position, abuts against the engaging wall portion, limiting the rotation range of the protective cover towards the open position to a range where the protective cover rotates to the closed position under its own weight.

2. The electrical junction box according to claim 1, wherein the rotation shaft of the protective cover is held by a bearing portion provided in the case, and a gap is provided between the rotation shaft and the bearing portion.

3. The electrical connection box according to claim 1 or 2, wherein the protective cover abuts against an upper surface of a peripheral wall of the opening when the protective cover is placed in the closed position.

4. An electrical junction box as claimed in claim 1 or claim 2, wherein a maximum central angle X around a rotation axis in the rotation region of the protective cover after the engaging protrusion has overcome the engaging wall portion and elastically returned to its original position is set in a range of 75°≦X<90° around the rotation axis of the protective cover, when the closed position of the protective cover is defined as 0°.

5. The electrical junction box according to claim 1 or 2, further comprising a first locking mechanism for removably holding said protective cover in said closed position.

6. The electrical junction box according to claim 1 or 2, further comprising a second locking mechanism for removably holding the protective cover in the open position.

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