Electrical junction box

Abstract

An electrical junction box (11) comprises electrical circuit components (23, 33), and is provided with: a first circuit unit (21) that includes a plate-shaped first base member (22) and a standard electrical circuit component (23) which is disposed on the first base member (22) and which constitutes a part of an electrical circuit component; and a second circuit unit (31) that includes a plate-shaped second base member (32) and a supplemental electrical circuit component (33) which is disposed on the second base member (32) and which constitutes a part of an electrical circuit component. The second circuit unit (31) is layered onto the first circuit unit (21).

Description

Electrical junction box

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

[0002] Conventionally, an electrical junction box has been provided in, for example, a battery pack of a vehicle (see, for example, Patent Document 1). The battery pack includes a battery pack case, an electrical junction box, and a plurality of battery cells.

[0003] The electrical junction box is housed in a battery pack case together with multiple battery cells. The electrical junction box includes, for example, a case and electrical circuit components arranged on a base member that forms the bottom of the case. Some of the electrical circuit components are connected to the multiple battery cells. The electrical circuit components include, for example, multiple relays, fuses, bus bars, etc. Some of the electrical circuit components monitor the current value, temperature, etc. of the battery cells to achieve optimal input and output. Furthermore, the number of electrical circuit components in the electrical junction box may increase or decrease depending on the grade and optional equipment of the vehicle in which the electrical junction box is installed.

[0004] JP 2013-16467 A

[0005] In recent years, the number of battery cells in a battery pack has tended to increase. Due to size and / or volume constraints of the battery pack case, there is a need to reduce the size of the electrical junction box housed in the battery pack case together with the battery cells. For example, there is a need to reduce the space required for arranging the electrical junction box in the battery pack case when viewed from above, and there is a need to reduce the footprint of the electrical junction box. There is also a need for the electrical junction box to be highly versatile.

[0006] An object of the present disclosure is to provide an electrical junction box that is highly versatile and can be made compact.

[0007] The electrical connection box of the present disclosure is an electrical connection box equipped with electrical circuit components, and includes a first circuit unit having a plate-shaped first base member and basic electrical circuit components that are arranged on the first base member and form part of the electrical circuit components, and a second circuit unit having a plate-shaped second base member and additional electrical circuit components that are arranged on the second base member and form part of the electrical circuit components, and the second circuit unit is stacked on the first circuit unit.

[0008] The electrical junction box of the present disclosure can be made smaller while still providing high versatility.

[0009] Fig. 1 is a perspective view of an electrical junction box according to one embodiment. Fig. 2 is an exploded perspective view of the electrical junction box according to one embodiment. Fig. 3 is a plan view of a first circuit unit and a heat dissipation metal plate according to one embodiment. Fig. 4 is an enlarged perspective view of a portion of the heat dissipation metal plate according to one embodiment. Fig. 5 is a cross-sectional view taken along line 5-5 in Fig. 3.

[0010] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. The electrical junction box of the present disclosure includes: [1] an electrical junction box including electrical circuit components, the electrical junction box including: a first circuit unit having a plate-shaped first base member and basic electrical circuit components that are arranged on the first base member and that constitute part of the electrical circuit components; and a second circuit unit having a plate-shaped second base member and additional electrical circuit components that are arranged on the second base member and that constitute part of the electrical circuit components, the second circuit unit being stacked on the first circuit unit.

[0011] This configuration, in which the second circuit unit is stacked on the first circuit unit, is advantageous in reducing the footprint of the electrical junction box compared to, for example, an electrical junction box in which all electrical circuit components are arranged on a single plane. Therefore, the space required for the electrical junction box in the battery pack case when viewed from above can be reduced. Furthermore, additional electrical circuit components may be required when adapting the electrical junction box to a higher-grade vehicle or a vehicle with optional equipment. However, if additional electrical circuit components are not required, the electrical junction box can be used as an electrical junction box having only basic electrical circuit components by simply not providing the second circuit unit or omitting the second circuit unit from the electrical junction box. In other words, the first circuit unit can be used as a common component for the electrical junction box regardless of whether additional electrical circuit components are required when adapting the electrical junction box to a higher-grade vehicle or a vehicle with optional equipment. This increases the versatility of the electrical junction box.

[0012] [2] In the above [1], a heat dissipation metal plate may be attached below the first base member. With this configuration, stacking the second circuit unit on the first circuit unit tends to trap heat in the basic electric circuit components, but the heat dissipation metal plate attached below the first base member improves heat dissipation.

[0013] [3] In the above [2], the heat dissipation metal plate may have a female thread, and at least one of the first base member, the second base member, and the electrical circuit component may be fixed to the heat dissipation metal plate by a bolt screwed into the female thread.

[0014] According to this configuration, at least one of the first base member, the second base member, and the electric circuit component is fixed to the heat dissipation metal plate by a bolt that is threaded into the female thread of the heat dissipation metal plate, eliminating the need for nuts. This reduces the number of parts and assembly steps compared to when separate nuts are provided.

[0015] [4] In the above [3], the heat dissipating metal plate may have a column portion protruding upward, and the female thread may be formed on the column portion. According to this configuration, the heat dissipating metal plate has a column portion protruding upward, and the female thread is formed on the column portion, so that at least one of the first base member, the second base member, and the electric circuit component can be fastened well while shortening the bolt. In other words, if the heat dissipating metal plate does not have a column portion, it would be necessary to lengthen the bolt to fasten at least one of the first base member, the second base member, and the electric circuit component, and there is a risk that good fastening will not be achieved, but this can be avoided.

[0016] [5] In any one of [2] to [4] above, the heat dissipating metal plate may be a single heat dissipating metal plate formed to cover or face the entire area of ​​the underside of the first base member.

[0017] With this configuration, a single heat dissipating metal plate covers or faces the entire underside of the first base member, thereby achieving high heat dissipation performance and reducing the number of parts compared to when multiple heat dissipating metal plates are used.

[0018] [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. In each drawing, for the sake of convenience, some of the components may be exaggerated or simplified. Furthermore, the dimensional ratios of each part may differ between drawings. In this specification, "parallel," "orthogonal," and "circular" do not only refer to strictly parallel, orthogonal, or circular, but also include roughly parallel, orthogonal, or circular within the scope of the present embodiment's effects. The present invention is not limited to these examples, but is defined by the claims, and all modifications within the meaning and scope of the claims are intended to be included.

[0019] 1 and 2 , the electrical junction box 11 includes a first circuit unit 21, a second circuit unit 31, and a heat dissipation metal plate 41. The second circuit unit 31 is stacked on the first circuit unit 21. The heat dissipation metal plate 41 is attached below the first circuit unit 21.

[0020] The electrical junction box 11 of this embodiment is provided in a battery pack mounted on a vehicle such as an electric automobile, etc. That is, the electrical junction box 11 is housed in a battery pack case together with a plurality of battery cells.

[0021] The drawing also shows a first axis X, a second axis Y perpendicular to the first axis X, and a third axis Z perpendicular to the first axis X and the second axis Y. The drawing also shows a longitudinal direction X1, which is one direction along the first axis X, and a lateral direction Y1, which is one direction along the second axis Y. The drawing also shows an upward direction Z1 along the third axis Z, and a downward direction Z2, which is the opposite direction to the upward direction Z1.

[0022] (Configuration of first circuit unit 21) As shown in Figures 2 and 3, the first circuit unit 21 has a plate-shaped first base member 22 and basic electric circuit components 23 that are arranged on the first base member 22 and that form part of the electric circuit components.

[0023] The first base member 22 is made of a resin material. When viewed from above, the first base member 22 is formed in a rectangular shape. The first base member 22 has projections and recesses that allow the basic electric circuit components 23 to be positioned and arranged thereon. The first base member 22 forms the bottom surface of the case in the electrical junction box 11. The first base member 22 also has side wall portions 22a that protrude upward from its edge. The side wall portions 22a, together with the side walls of the upper case (not shown), form the side surfaces of the case in the electrical junction box 11.

[0024] The basic electric circuit components 23 are electric circuit components that are always required regardless of the grade or optional equipment of the vehicle in which the electric junction box 11 is installed. The basic electric circuit components 23 include, for example, a relay 24, a fuse 25, a bus bar 26, etc.

[0025] (Configuration of second circuit unit 31) As shown in Figures 1 and 2, the second circuit unit 31 has a plate-shaped second base member 32 and additional electric circuit components 33 that are arranged on the second base member 32 and that form part of the electric circuit components.

[0026] The second base member 32 is made of a resin material. The second base member 32 is formed in a rectangular shape when viewed from above. When viewed from above, the second base member 32 is formed in a rectangular shape that fits within the range of the rectangular shape of the first base member 22 and is slightly shorter than the first base member 22. The second base member 32 has irregularities that allow the additional electric circuit components 33 to be positioned and arranged thereon.

[0027] The additional electric circuit components 33 are electric circuit components that are added to and / or connected to the basic electric circuit components 23 depending on the grade and optional equipment of the vehicle in which the electric junction box 11 is installed. The additional electric circuit components 33 include, for example, a control unit 34 including a microcomputer and bus bars 35. Note that the number and arrangement of the basic electric circuit components 23 and the additional electric circuit components 33 in each drawing are not necessarily strictly those shown, but are shown as an example.

[0028] The second circuit unit 31 is stacked on the first circuit unit 21 and fixed to the first circuit unit 21. In the second circuit unit 31, additional electric circuit components 33 are connected to the basic electric circuit components 23.

[0029] (Configuration of Heat Dissipating Metal Plate 41) The heat dissipating metal plate 41 is made of a metal material with high heat dissipation properties, such as aluminum, etc. The heat dissipating metal plate 41 is formed, for example, by pressing an aluminum plate.

[0030] 3, the heat dissipating metal plate 41 is formed as a single heat dissipating metal plate that covers or faces the entire underside of the first base member 22. In other words, the heat dissipating metal plate 41 is formed in a shape that includes the entire area of ​​the first base member 22 when viewed from above. The heat dissipating metal plate 41 is also formed in a rectangular shape that is slightly larger than the first base member 22 in both directions along the first axis X and in both directions along the second axis Y.

[0031] 4 and 5 , the heat dissipating metal plate 41 has a female screw 42. More specifically, the heat dissipating metal plate 41 has a column portion 43 that protrudes upward. In this embodiment, the column portion 43 is provided at a position corresponding to the relay 24 of the basic electric circuit component 23. More specifically, a pair of column portions 43 is provided for each relay 24. The female screw 42 is formed on the column portion 43. The female screw 42 is formed so as to penetrate the heat dissipating metal plate 41 from the top of the column portion 43.

[0032] At least one of the first base member 22, the second base member 32, the basic electric circuit components 23, and the additional electric circuit components 33 is fixed to the heat dissipating metal plate 41 by bolts 44 that are threaded into the female threads 42. In this embodiment, the relay 24 and the first base member 22 are fixed to the heat dissipating metal plate 41 by bolts 44 that are threaded into the female threads 42. More specifically, the relay 24 has case fixing legs 24a, and is fastened and fixed to the heat dissipating metal plate 41 by bolts 44 that pass through the case fixing legs 24a and are threaded into the female threads 42. The first base member 22 is fixed to the heat dissipating metal plate 41 by being sandwiched between the case fixing legs 24a and the heat dissipating metal plate 41.

[0033] Next, we will explain the operation of the electrical junction box 11 configured as described above. The electrical junction box 11 electrically connects the electrical circuit components, including the basic electrical circuit components 23 and the additional electrical circuit components 33, to the battery cells housed in the battery pack case together with the electrical junction box 11. The electrical circuit components then monitor the current values, temperatures, etc. of the battery cells to achieve optimal input and output.

[0034] In addition, the additional electrical circuit components 33 are required when adapting the electrical connection box 11 to a higher grade vehicle or a vehicle with optional equipment added, but if the additional electrical circuit components 33 are not required, the electrical connection box 11 will be housed in the battery pack case in a manner that does not include the second circuit unit 31.

[0035] The advantages of the above embodiment are described below. (1) Because the second circuit unit 31 is stacked on the first circuit unit 21, the footprint of the electrical junction box can be reduced compared to, for example, an electrical junction box in which all electrical circuit components are arranged on a single plane. This reduces the space required for arranging the electrical junction box 11 in the battery pack case when viewed from above. Furthermore, the additional electrical circuit components 33 are required when adapting the electrical junction box to a higher-grade vehicle or a vehicle with optional equipment. However, if the additional electrical circuit components 33 are not required, the electrical junction box 11 can be used as an electrical junction box having only the basic electrical circuit components 23 by simply not providing the second circuit unit 31 or omitting the second circuit unit from the electrical junction box. In other words, the first circuit unit 21 can be used as a common component for the electrical junction box 11, regardless of whether the additional electrical circuit components 33 required when adapting the electrical junction box to a higher-grade vehicle or a vehicle with optional equipment are required. This increases the versatility of the electrical junction box 11.

[0036] (2) When the second circuit unit 31 is stacked on the first circuit unit 21, heat generated in the basic electrical circuit components 23 tends to become trapped. However, since the second circuit unit 31 is provided with a heat dissipation metal plate 41 attached under the first base member 22, heat dissipation is improved.

[0037] (3) The relay 24 and the first base member 22 are fixed to the heat dissipation metal plate 41 by the bolts 44 that are threaded into the female threads 42 of the heat dissipation metal plate 41, eliminating the need for nuts. This reduces the number of parts and assembly steps compared to when separate nuts are provided.

[0038] (4) The heat dissipating metal plate 41 has the pillars 43 that protrude upward, and the female threads 42 are formed on the pillars 43, so that the relay 24 and the first base member 22 can be fastened together satisfactorily while shortening the bolts 44. In other words, if the heat dissipating metal plate 41 does not have the pillars 43, it would be necessary to lengthen the bolts 44 in order to fasten the relay 24 and the first base member 22, and there is a risk that the bolts 44 will not be fastened together satisfactorily. This can be avoided.

[0039] (5) The heat dissipation metal plate 41 is a single heat dissipation metal plate formed to cover or face the entire underside of the first base member 22, thereby achieving high heat dissipation. Furthermore, the number of parts can be reduced compared to when multiple heat dissipation metal plates 41 are provided.

[0040] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be implemented in combination with each other to the extent that no technical contradiction occurs. In the above embodiment, the electrical junction box 11 includes the heat dissipation metal plate 41 attached below the first base member 22, but this is not limited to this, and the electrical junction box 11 may be configured not to include the heat dissipation metal plate 41 below the first base member 22. Furthermore, although not specifically mentioned in the above embodiment, the electrical junction box 11 may include a heat dissipation metal plate attached above the first base member 22, or may include a heat dissipation metal plate attached above or below the second base member 32.

[0041] In the above embodiment, the heat dissipating metal plate 41 has the female threads 42, but this is not limiting and the heat dissipating metal plate 41 may have a configuration without the female threads 42. In this case, for example, a nut may be used. That is, a nut onto which the bolt 44 is threaded may be disposed below the first base member 22. Furthermore, the heat dissipating metal plate 41 may be configured to fasten at least one of the first base member 22, the second base member 32, the basic electric circuit components 23, and the additional electric circuit components 33 by the bolt 44 threaded into the female threads 42.

[0042] In the above embodiment, the heat dissipating metal plate 41 has the pillar portion 43 that protrudes upward and on which the female screw 42 is formed, but this is not limited thereto, and the heat dissipating metal plate 41 may have a configuration that does not have the pillar portion 43. In other words, the female screw 42 may be formed in a portion of the heat dissipating metal plate 41 where the pillar portion 43 is not formed.

[0043] In the above embodiment, the heat dissipating metal plate 41 is formed as a single heat dissipating metal plate that covers or faces the entire lower surface of the first base member 22, but this is not limited thereto, and the heat dissipating metal plate 41 may be, for example, smaller than the first base member 22. Furthermore, the electrical junction box 11 may be configured to include multiple heat dissipating metal plates.

[0044] In the above embodiment, the basic electric circuit components 23 include, for example, the relay 24, the fuse 25, the bus bar 26, etc. However, the basic electric circuit components 23 are not limited to these and may include other electric circuit components.

[0045] In the above embodiment, the additional electric circuit components 33 include, for example, the control unit 34 including a microcomputer, the bus bar 35, etc. However, the additional electric circuit components 33 are not limited to these and may include other electric circuit components.

[0046] In the above embodiment, the electrical connection box 11 is provided in a battery pack mounted on a vehicle such as an electric vehicle, but this is not limited to this and the electrical connection box 11 may be provided in other devices.

[0047] The illustrated non-limiting embodiment of the electrical junction box 11 may be referred to as a stacking type electrical junction box that can be changed between a minimum stacking form including a heat dissipation metal plate 41 and a first circuit unit 21, and an extended stacking form in which a second circuit unit 31 is retrofitted to the minimum stacking form.

[0048] 1 and 2, the plate-like first base member 22 of a non-limiting embodiment is an example of a first synthetic resin chassis or tray having an upper surface or first mounting surface configured to mount a plurality of basic electrical circuit components 23. The first base member 22 includes an outermost edge that can define the footprint of the first base member 22.

[0049] 1 and 2 , the heat dissipation metal plate 41 of a non-limiting embodiment may have an upper surface adjacent to or facing the lower surface of the first base member 22, and may be coupled to the lower surface of the first base member 22 directly or indirectly via an air gap to enable heat exchange. In one example, the heat dissipation metal plate 41 and the first base member 22 may be in direct contact at least at the column portions 43 of the heat dissipation metal plate 41. The heat dissipation metal plate 41 and the first base member 22 may be separated by an air gap at predetermined locations on the upper surface of the heat dissipation metal plate 41 other than the column portions 43. The heat dissipation metal plate 41 includes an outermost edge that can define the footprint of the heat dissipation metal plate 41. In one example, the entire or almost the entire outermost edge of the heat dissipation metal plate 41 may be aligned with the entire outermost edge of the first base member 22 so that the footprint of the heat dissipation metal plate 41 is substantially the same as the footprint of the first base member 22. 5 , in a non-limiting embodiment, an operator can fasten the first base member 22 to the heat dissipation metal plate 41 by screwing bolts 44 into the posts 43 of the heat dissipation metal plate 41 from the upper side of the first base member 22. In one example, the heat dissipation metal plate 41 may define the lowermost layer or bottom surface of the electrical junction box 11.

[0050] 1 and 2, the plate-like second base member 32 of a non-limiting embodiment is an example of a second synthetic resin chassis or tray having a second mounting surface, which may be the upper surface of the second base member 32, configured to mount a plurality of additional electrical circuit components 33. The second base member 32 includes an outermost edge, which may define a footprint of the second base member 32. The footprint of the second base member 32 may be smaller than, but substantially the same as, the footprint of the first base member 22.

[0051] REFERENCE SIGNS LIST 11 Electrical junction box 21 First circuit unit 22 First base member 22a Side wall portion 23 Basic electric circuit component (constituting part of the electric circuit component) 24 Relay 24a Case fixing leg portion 25 Fuse 26 Bus bar 31 Second circuit unit 32 Second base member 33 Additional electric circuit component (constituting part of the electric circuit component) 34 Control unit 35 Bus bar 41 Heat dissipation metal plate 42 Female thread 43 Pillar portion 44 Bolt X First axis X1 Longitudinal direction Y Second axis Y1 Shortitudinal direction Z Third axis Z1 Upward direction Z2 Downward direction

Claims

1. An electrical junction box equipped with electric circuit components, comprising: a first circuit unit having a plate-shaped first base member and basic electric circuit components arranged on the first base member and constituting part of the electric circuit components; and a second circuit unit having a plate-shaped second base member and additional electric circuit components arranged on the second base member and constituting part of the electric circuit components, wherein the second circuit unit is stacked on the first circuit unit.

2. The electrical junction box according to claim 1, further comprising a heat dissipating metal plate attached under said first base member.

3. The electrical connection box according to claim 2, wherein the heat dissipating metal plate has a female thread, and at least one of the first base member, the second base member, and the electrical circuit component is fixed to the heat dissipating metal plate by a bolt screwed into the female thread.

4. The electrical junction box according to claim 3, wherein the heat dissipating metal plate has a column portion protruding upward, and the female screw is formed on the column portion.

5. The electrical junction box according to claim 2, wherein the heat dissipating metal plate is a single heat dissipating metal plate formed so as to cover or face the entire area of ​​the lower surface of the first base member.

Images