JP2001319708A - Electric connection box for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform an electric connection of a power supply with each load with a small size and a plain structure compared with a traditional electric connection box, and enhance the versatility. SOLUTION: Plural semiconductor switching elements 14 are used in exchange with a relay block which has been coexisted between a bus bar circuit in the traditional electric connection box, and these semiconductor switching elements 14 accumulated to construct an independent power distribution part PD separated from the bus bar circuit part JB. Then each output terminal 12 of this power distribution part PD is connected to a proper bus bar 32 of the bus bar circuit part JB, and these power distribution part PD and bus bar circuit part JB is assembled in a common case 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric connection box of a vehicle for electrically connecting a plurality of on-vehicle loads to a power source such as a battery mounted on the vehicle.

[0002]

2. Description of the Related Art Conventionally, an electric connection box provided in a vehicle is provided with a bus bar substrate in which metal bus bars and insulating plates are alternately laminated, and the electric vehicle is mounted on a vehicle through a bus bar circuit formed by the bus bar substrate. It is generally known to connect a power supply (for example, a battery) to a number of on-vehicle loads (electric components). Further, a mechanical relay block is incorporated in the bus bar board, so that energization between the in-vehicle power supply and each load can be appropriately switched on / off during the bus bar board.

FIG. 7 shows an example of a structure for assembling the mechanical relay to an electric junction box. In the figure, a bus bar substrate 102 is provided inside an insulating case 101.
Are stored, and a plurality of tab terminals 103 are formed by bending the ends of the bus bars constituting the bus bar substrate 102 upward, and the relay terminals 105 are mounted on each of the tab terminals 103. ing. on the other hand,
The insulating case 101 is integrally formed with a connector housing portion 104 for a relay projecting outward from an outer surface thereof.
3 and a plurality of terminal receiving chambers 104a into which the relay terminals 105 are inserted from the back side (the lower side in the figure). Then, the relay block 10 is placed in these terminal accommodation chambers 104a.
6 is inserted, the respective terminals of the relay block 106 are connected to the respective tab terminals 103 via the respective relay terminals 105, and the relay block 106 is mounted on the outer surface of the insulating case 101. It has become.

[0004]

In the conventional electric junction box, a relay block 10 is provided on the bus bar substrate 102.
6, the relay block 106
Is of a mechanical type and has a large current specification which is directly connected to a vehicle-mounted battery, so that its structure is necessarily large.

On the other hand, on the busbar substrate 102 side,
A space for interposing the relay block 106 is required at the appropriate position, and the area of the bus bar substrate 102 is increased accordingly, and the structure is complicated. In addition, in order to connect the relay block 106 to the bus bar board 102, a plurality of (three in the illustrated example) tab terminals 103 are connected from the board.
Need to be erected at positions close to each other, it is necessary to design a layout with a margin so that the bus bars do not interfere with each other, and in some cases, it is necessary to increase the number of stacked bus bars.

For the above reasons, it is difficult to reduce the size and simplify the structure of the conventional electric junction box.
The drastic measures are an important issue.

Further, in the conventional structure, when the current used, that is, the relay capacity is changed according to the grade of the vehicle, the size of the relay block 106 changes according to the change. The interval between the plurality of tab terminals 103 for connection and the formation position must be changed. That is, in the conventional structure, since the relay block 106 is mixed in the circuit constituted by the bus bar substrate 102, when the relay block 106 having a different size is used in accordance with a change in specification, the relay block 106 is used. The design of the entire bus bar substrate 102 must be changed in accordance with 106, and there is a disadvantage that versatility is low.

The present invention has been made in view of the above circumstances, and provides an electric connection box which can perform electric connection between a power supply and each load with a small and simple structure and is excellent in versatility. Aim.

[0009]

According to the present invention, there is provided an electric connection box for a vehicle for connecting a plurality of on-vehicle loads to a power supply mounted on the vehicle. A power distribution unit having an input terminal connected to the power supply unit and a plurality of output terminals, and a semiconductor switching element interposed between each output terminal and the input terminal; a metal bus bar for circuit configuration; A bus bar circuit unit that connects each output terminal of the power distribution unit to a plurality of in-vehicle loads, and a part of a bus bar in the bus bar circuit unit and each output terminal of the power distribution unit. Are connected to each other, and the power distribution unit and the bus bar circuit unit are incorporated in a common case.

[0010] According to this configuration, each semiconductor switching element of the power distribution unit connected to the bus bar circuit unit functions as a relay block in a conventional electric connection box.
Not only the relay block can be omitted, but also the terminal structure for attaching the relay block to the bus bar substrate can be omitted from the bus bar circuit portion, and the configuration of the bus bar circuit portion is greatly simplified. Moreover, the power distribution unit has a small semiconductor switching element interposed between the input terminal and each output terminal, and has a smaller and lighter configuration than a mechanical relay block. Therefore, the electric connection box according to the present invention can make electrical connection between the power supply and each load with a smaller and simpler structure than the conventional electric connection box.

Further, in this electric junction box, since the power distribution unit and the bus bar circuit unit are independent of each other, the following advantages are obtained as compared with the conventional configuration in which relay blocks are mixed in the bus bar circuit. is there.

For example, when a semiconductor switching element has to be replaced in accordance with a change in a used current or the like, if there is no change in the circuit on the bus bar circuit portion side, it is possible to use a common bus bar circuit portion. That is, depending on the content of the specification change, it is possible to cope with the change only by replacing the power distribution unit without changing the design of the bus bar circuit unit side, and the versatility is high.

Each semiconductor switching element used in the power distribution unit generally has a relatively high calorific value.
There are many cases where heat radiation and cooling are required. Here, in a conventional structure in which the relay block 106 is mixed in the bus bar circuit, even if the relay block 106 is simply replaced with a semiconductor switching element, the heat generated by each semiconductor switching element dispersedly arranged in the bus bar circuit is generated. It is very difficult to effectively dissipate the outside of the case, which has greatly hindered the introduction of the semiconductor switching element.However, in the structure according to the present invention, the plurality of semiconductor switching elements to be connected to the bus bar circuit section are Since the switching devices are centrally arranged in the power distribution unit independent of the bus bar circuit unit, the cooling process of each semiconductor switching element can be collectively performed in the power distribution unit.

Specifically, the power distribution unit is provided with a heat radiating member which is connected to each semiconductor switching element so as to be able to conduct heat, and the power distribution unit is attached to the case such that the heat radiating member is exposed on the outer surface of the case. In this configuration, heat dissipation and cooling of each semiconductor switching element can be efficiently performed collectively on the power distribution unit side.

For example, a drain connection plate on which the semiconductor switching elements are mounted in a state where the semiconductor switching elements are electrically connected to the input terminals of the power distribution unit and the input-side energizing terminals of the semiconductor switching elements are electrically connected. It is also possible to adopt a configuration in which the heat dissipating member is connected to the drain connection plate so as to transfer heat. With such a configuration, the input-side energizing terminals of each semiconductor switching element can be electrically connected to the common input terminal collectively by using the drain connection plate, and the heat radiation member exposed on the outer surface of the case can be thermally connected. Can be connected collectively. Therefore, with a simple structure, simplification of the circuit configuration and efficient cooling can be realized.

Here, the drain connection plate only needs to be electrically connected to the input terminal, and the two may be formed of separate members and mechanically and electrically connected by, for example, welding. By forming the input terminal and the drain connection plate from the same single metal plate, the number of parts can be further reduced, and the structure of the electric connection box of the vehicle can be further simplified and thinned.

In the present invention, the specific connection structure between each output terminal of the power distribution unit and the bus bar circuit unit can be variously set. For example, when the bus bar circuit portion is configured by alternately stacking a plurality of layers of the bus bar and the insulating plate, the lowermost bus bar is exposed downward, so that the By connecting the output terminals of the power distribution unit, the power distribution unit and the bus bar circuit unit can be linked with a simple structure.

Each output terminal of the power distribution unit and a part of the bus bar may be connected by, for example, wire bonding. However, if they are connected in a state where they are directly overlapped, a more reliable connection can be obtained. Connection is possible. In addition, simple means such as welding can be used, so that the mechanical strength of the connection portion can be sufficiently ensured.

The output terminals of the power distribution unit are arranged in one direction so as to protrude in the same direction, and a plurality of output terminals are arranged on a peripheral portion of the bus bar circuit unit in a direction parallel to the arrangement direction of the output terminals. If the power distribution unit connection bus bars are arranged, and the power distribution unit and the bus bar circuit unit are arranged at positions adjacent to each other in a state where these bus bars are connected to the respective output terminals, each output of the power distribution unit is provided. By connecting the terminal and each bus bar of the bus bar circuit section with the shortest path, the power distribution section and the bus bar circuit section can be compactly housed in the case.

Furthermore, if the semiconductor switching elements are arranged in a direction parallel to the arrangement direction of the output terminals in the power distribution unit, the output-side energizing terminals of each semiconductor switching element are directly connected to each output terminal. In addition, the power distribution unit itself can be downsized.

Furthermore, not only the output terminals, but also the output terminals and the input terminals of the power distribution unit are arranged in one direction so as to protrude in the same direction, while the output terminals and the input terminals are arranged on the periphery of the bus bar circuit unit. A plurality of power distribution unit connection bus bars are arranged in a direction parallel to the arrangement direction of the input terminals, and the input terminals are connected via the bus bar circuit unit by connecting these bus bars to the output terminals and the input terminals. If it is configured to be connected to the power supply, it is possible to collectively perform input and output of the power distribution unit and the external circuit through the bus bar circuit unit, and, together with the rationalization of the circuit, miniaturization of the power distribution unit itself. Further progress.

In this electric junction box, a circuit for controlling the energization of each of the semiconductor switching elements is required. The location of this circuit can be variously set, and may be provided in the power distribution section. It is also possible to provide them in other places. For example, when a control circuit board connected to an external vehicle-mounted electronic unit through the bus bar circuit section is incorporated in the case, the control circuit board is electrically connected to a conduction control terminal of each semiconductor switching element of the power distribution section. By incorporating an energization control circuit that is connected and performs energization control of the semiconductor switching element, the energization control of the semiconductor switching element can be performed with a simple structure without specially adding a circuit board for energization control. it can.

Further, the power supply control circuit of the control circuit board is electrically connected to the power supply control terminal of each semiconductor switching element provided in the power distribution unit via the bus bar circuit unit. By using such a bus bar circuit section, the connection structure between the power supply control circuit and the power distribution section can be simplified.

Specifically, the power distribution unit is provided with control terminals connected to the energization control terminals of the semiconductor switching elements, and the control terminals and the output terminals are alternately arranged and project in the same direction. While the busbars are arranged in one direction, a plurality of power distribution unit connection busbars are arranged in a direction parallel to the arrangement direction of the output terminals and the control terminals on the peripheral edge of the busbar circuit unit. If the power distribution unit and the bus bar circuit unit are arranged at positions adjacent to each other in a state where the output terminals and the control terminals are connected, the size of the entire electric connection box can be reduced by the adjacent arrangement. However, the connection between the conduction control terminal and the output-side conduction terminal of the semiconductor switching element and the bus bar circuit portion can be accurately performed.

Further, by arranging the control circuit board substantially in parallel with the arrangement direction of the power distribution section and the bus bar circuit section, further downsizing is promoted.

In this case, the control circuit board is disposed so that at least a part of the control circuit board overlaps the power distribution section (that is, the control circuit board is disposed near the power distribution section), and the control circuit board is disposed in the case. If the board storage section for storing the control circuit board and the connector section for connecting the bus bar circuit section to an external circuit are formed side by side, the arrangement of the storage space for the control circuit board and the connector section is possible. The installation space can be rationally arranged, and further downsizing can be achieved.

The semiconductor switching elements are arranged in a direction parallel to the arrangement direction of the output terminals and the control terminals, and the output-side energizing terminals and the energizing control terminals of the semiconductor switching elements are respectively connected to the output terminals and the control terminals. With the configuration directly connected to the terminal, the size of the power distribution unit itself can be reduced.

In the present invention, the specific layout of the terminals in the power distribution unit is not particularly limited. However, if these terminals are formed of a metal plate and arranged on substantially the same plane,
The thickness of the power distribution unit can be made extremely small, which can contribute to making the entire electrical junction box compact and thin.

The phrase "arranged on the same plane" does not necessarily mean that all terminals are arranged on the same plane, that is, all terminals are not limited to a flat plate. It is intended that terminals or output terminals partially include a shape deviating from the “same plane”.
For example, a part of input terminals or output terminals basically arranged on the same plane may be bent to form a connection tab, or the terminal may have a shape in which end portions protrude over a plurality of rows. .

Further, it is possible to integrate the terminals with a resin mold. By forming the power distribution unit case with the resin mold, the arrangement of the terminals can be securely fixed with a structure having a small number of parts. Can be.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings.

First, a circuit configuration of an electric junction box of a vehicle according to this embodiment will be described with reference to FIG.

The circuit relating to the electric connection box is composed of a power distribution unit PD connected to a vehicle-mounted power supply (battery in the figure), a bus bar circuit unit JB composed of a bus bar substrate, and a control circuit substrate 18. .

The power distribution unit PD includes an input terminal 10 connected to the battery and a plurality of (three in the illustrated example) output terminals 1.
2 and the same number of control terminals 17.
A semiconductor switching element (the power MOSFET 14 in the illustrated example, hereinafter simply referred to as “FET”) is interposed between the input terminal 10 and the input terminal 10. Specifically, the input-side conducting terminal (drain) of each FET 14 is connected to the common input terminal 10, the output-side conducting terminal (source) of each FET 14 is connected to the corresponding output terminal 12,
The conduction control terminal (gate) of each FET 14 is connected to the corresponding control terminal 17.

The number of the output terminals 12 may be appropriately set according to the location and type of the power distribution target in the vehicle. In the example shown in the figure, the distribution targets are classified into three groups: IG load (wiper, window washer, heater, etc.), Acc load (cigar lighter, audio, accessory), and + B load (tail lamp, panel lamp, etc.). The FET 14 and the output terminal 12 are provided for each group.

The bus bar circuit portion JB is composed of a bus bar substrate in which a plurality of bus bar layers made of a metal plate and insulating layers made of an insulating plate are alternately laminated, and the input portion of the power distribution portion PD is provided at the periphery of the board. Bus bar for input terminal connection (bus bar for connection to power distribution unit) 30 connected to terminal 10
An output terminal connection bus bar (power distribution unit connection bus bar) 32 connected to the output terminal 12 and a control terminal connection bus bar 37 connected to the control terminal 17 are provided. Further, an external connection tab 34 and a control circuit board connection tab 36 protruding outward are provided at appropriate places of the bus bar.
The external connection tab 34 is connected to a circuit outside the electric connection box, and the control circuit board connection tab 36 is connected to the control circuit board 18.

Further, a fuse section 16 composed of a fuse block is incorporated in the middle portion of the bus bar circuit section JB.

The circuit connection performed by the bus bar circuit section JB is as follows.

The input terminal 10 of the power distribution unit PD and another on-vehicle load directly connected to a battery are connected to the on-vehicle battery (see the upper part of FIG. 1).

Each output terminal 12 of the power distribution unit PD is connected to a corresponding in-vehicle load via the fuse unit 16.

Each control terminal 17 of the power distribution unit PD, an external circuit that inputs an operation signal to the control circuit board 18, and an external circuit that outputs a control signal from the control circuit board 18 are connected to the control circuit board 18. I do.

The control circuit incorporated in the control circuit board 18 also operates via the bus bar circuit section JB on the basis of an operation signal input via the bus bar circuit section JB.
Alternatively, directly send a control signal to an onboard electronic control unit (for example, a door control unit or a lamp control unit),
The control is performed.

Further, in addition to the control circuit, a control circuit for controlling on / off switching of the FETs 14 is incorporated in the control circuit board 18. This control circuit
Based on an operation signal input through the bus bar circuit section JB, each FE is also transmitted through the bus bar circuit section JB.
A control signal is input to the gate terminal (conduction control terminal) of T14 to control the on / off switching of the conduction between the drain and the source.

Next, a specific structure of an electric junction box of a vehicle for realizing the circuit of FIG. 1 will be described with reference to FIGS.

As shown in FIGS. 2 and 3, the power distribution section P
D and the bus bar circuit portion JB are arranged side by side in the horizontal direction, and are incorporated in a common case 40.

The specific structure of the power distribution unit PD is shown in FIGS. In this power distribution unit PD, the conductors constituting the power distribution circuit are all composed of metal plates, and these metal plates are arranged on the same plane orthogonal to the thickness direction and are integrated by resin molding. .

As shown, the input terminal 10, the plurality of (three in the example) output terminals 12, and the control terminals 17 are formed in a strip shape, and all project in the same direction (the bus bar circuit portion JB described later). Are arranged in a horizontal row. Specifically, the output terminals 12 and the control terminals 17 are alternately arranged, and the input terminals 10 are arranged outside thereof.

On the back side (left side in FIG. 4) of these terminals 10, 12, 17 is arranged a drain connecting plate (conductor plate) 20 extending in the terminal arrangement direction.
0 and the input terminal 10 are formed of the same one metal plate. That is, the drain connection plate 20 and the input terminal 10 are integrally connected. And this drain connection plate 2
Multiple on the 0 in parallel with the arrangement direction of each terminal (three in the figure)
FETs 14 are mounted side by side.

Of the terminals of each FET 14, a drain terminal 14d, which is an input side conduction terminal, is formed so as to be exposed on the back surface of the chip body, and a source terminal 14s which is an output side conduction terminal and a gate terminal 14g which is a conduction control terminal. Project from the side surface of the chip body in the same direction. The drain connection plate 20 is arranged in an arrangement and a pitch corresponding to the arrangement and the pitch of the output terminals 12 and the control terminals 17.
The FETs 14 are arranged in a row, and the FETs 14 are mounted on the drain connection plate 20 by welding or the like (for example, by soldering) while the drain terminals 14 d of the FETs 14 are in direct contact with the drain connection plate 20. Source terminal 14s and gate terminal 1 of each FET 14
4g are electrically connected to the rear ends of the output terminal 12 and the control terminal 17 by means such as soldering.

The control circuit may include a booster circuit for increasing the gate voltage of each FET 14.
Further, this booster circuit is formed separately from the control circuit board 18 so that the control circuit board 18 and the gate terminal 1 of each FET 14 are connected.
4g (for example, disposed on the drain connection plate 20).

In the production of the power distribution unit PD, an original plate in which the terminals 10, 12, 17 and the drain connection plate 20 are connected to each other at a small connecting portion from a single metal plate is punched, and then the punching is performed. It is performed by a method in which a metal plate is resin-molded and then the joint portion is cut. The resin mold constitutes the case 22 of the power distribution unit PD.

This case 22, as shown in FIG.
A shape that opens the drain connection part 20 up and down,
Each of the FETs 14 is disposed in the upper space. Also,
Each of the terminals 10, 12, 17 penetrates the side wall of the case 22 and protrudes horizontally outside the case 22.

In the lower space of the case 22, a heat radiating member 24 is mounted so as to cover it.

The heat radiating member 24 is integrally formed of a material having high thermal conductivity (or high specific heat) such as an aluminum alloy or a copper alloy. A large number of linear fins 25 parallel to each other are formed on the surface exposed to the side.

On the upper surface of the heat radiating member 24, the FET
A base 26 extending in a direction parallel to the arrangement direction of the 14 is formed in a shape protruding upward. And this pedestal 2
The upper surface of the drain connection plate 20 is connected to the upper surface of the drain connection plate 6 via an insulating sheet 28 made of silicone or the like so that heat can be transferred.

In the present invention, the arrangement of the terminals can be freely set regardless of the specific structure of the power distribution unit PD.
For example, the terminals 10, 12, and 17 do not necessarily have to be arranged on the same plane, and may be arranged over a plurality of upper and lower stages. However, by arranging the terminals on substantially the same plane as described above, the power distribution unit PD can be made thinner, and by integrating these with a resin mold, the power distribution unit has a simple structure and is easy to handle. The unit PD can be constructed.

The bus bar circuit portion JB is composed of a bus bar substrate in which a plurality of layers of a bus bar BB, which is a circuit configuration conductor made of a metal plate, and an insulating plate IB disposed thereon are alternately stacked. Accordingly, the lowermost busbar is exposed at the lowermost surface of the busbar substrate.

The input terminal connection bus bar 30, which is a power distribution connection bus bar, is provided at one end of the substrate (the end near the power distribution unit PC) on the lowermost surface of the substrate.
The output terminal connection bus bar 32 and the control terminal connection bus bar 37 are arranged in the same arrangement as the arrangement of the input terminal 10, the output terminal 12, and the control terminal 17 on the power distribution unit PD side. Input terminals 1 to 37
The bus bar and the terminal are fixed by welding in a state where the output terminal 0, the output terminal 12, and the control terminal 17 are overlapped from below. Thereby, the power distribution unit PD and the bus bar board are arranged at positions adjacent to each other side by side in the direction orthogonal to the board thickness direction, and their ends are interconnected.

The end of each bus bar is appropriately bent upward or downward so that the external connection tabs 3 are formed.
4 and a control circuit board connection tab 36 are formed,
The control circuit board connection tab 36 is connected to the control circuit board 18.

The control circuit board 18 is disposed above the power distribution unit PD and the bus bar circuit unit JB so as to straddle the power distribution unit PD and the bus bar circuit unit JB in a state substantially parallel to the arrangement direction of the power distribution unit PD and the bus bar circuit unit JB. . That is, the control circuit board 18
The control circuit board 18 is disposed at a position where a part of the control circuit board 18 overlaps the power distribution unit PD and the remaining part overlaps an end of the bus bar circuit unit JB near the power distribution unit.

A through hole 19 for circuit connection is provided at an appropriate position on the control circuit board 18. On the other hand, the circuit board connection tabs 36 of the bus bar circuit portion JB are concentratedly arranged in a region near the power distribution portion PC (that is, a region overlapping with the control circuit board 18), and are all bent upward. . The relay terminals 38 are connected to these circuit board connection tabs 36, and the relay terminals 38 are soldered so as to penetrate the through holes 19, thereby connecting the circuit of the control circuit board 18 with the circuit. Circuit connection with the bus bar circuit unit JB is performed.

The case 40 of the electric connection box has a size that accommodates the power distribution unit PD and the bus bar circuit unit JB collectively, and the fins 25 of the heat radiating member 24 in the power distribution unit PD are provided below the case lower surface. It is exposed. On the upper surface of the power distribution unit PD side, a board storage unit 44 for housing the control circuit board 18 is further provided in a protruding manner.

A connector housing section 42 communicating between the inside and outside of the case is formed on the upper surface of the case 40 and on a portion aligned with the substrate housing section 44 and on the lower surface of the case 40. The external connection connectors OC are configured by projecting the external connection tabs 34 of the bus bar circuit portion JB. That is, the external connection tab 34 constitutes a connector terminal of the external connection connector OC, and the connector housing part 42 constitutes a housing of the external connection connector OC. The bus bar circuit portion JB is connected to an external circuit by connecting a connector provided in the wire harness of the first embodiment.

Further, in addition to the external connection connector OC, a fuse mounting portion 43 for appropriately mounting a fuse box constituting the fuse portion 16 is formed, and a bus bar protrudes from the fuse mounting portion 43. By mounting the fuse box on the housing part 43, the fuse part 16 is appropriately incorporated in the bus bar circuit part JB.

Next, the operation of the electric junction box will be described.

The electric power output from the unillustrated vehicle-mounted battery is supplied to an external connection tab 3 of an appropriate external connection connector JB.
4 through the input terminal connection bus bar 30 and the input terminal 10 to each FE.
It is distributed to the drain terminal 14d of T14. FET14
Is on, the power input to the drain terminal 14d is applied to the output terminal 12 and the output terminal connection bus bar 32.
Is supplied into the bus bar circuit section JB through the bus bar circuit section JB, and is distributed from the bus bar circuit section JB to the vehicle-mounted load through the external connection tab 34.

On the other hand, an operation signal (for example, a switch signal) sent from an external circuit is input to the control circuit of the control circuit board 18 through the bus bar circuit section JB. The control circuit inputs a control signal to the gate terminal 14g of each FET 14 through the bus bar circuit section JB in response to the operation signal,
The on / off switching of the current supply between the drain and the source in the FET 14 is controlled. When the FET 14 is turned off, the power supply to the bus bar circuit connected to the source terminal 14s of the FET 14 is cut off.

In the electric junction box of the vehicle described above, the mechanical relay switch conventionally incorporated in the bus bar circuit is replaced with the FET 14 and these FETs
Since the power distribution units PD are arranged independently and collectively as the power distribution unit PD, the structure of the bus bar circuit unit JB is greatly simplified and downsized, and the cooling process of the FET 14 is also easy, and the common heat radiation By connecting the member 24 thermally and exposing it to the outside of the case 40, highly efficient cooling can be performed. In addition, FETs are
Even when it is necessary to replace the power supply unit 14, the busbar circuit unit JB can be dealt with only by replacing the power distribution unit PD without changing the design, which is excellent in versatility.

Note that the embodiment of the present invention is not limited to the above, and the following form can be taken as an example.

The semiconductor switching elements used in the power distribution unit PD are not limited to the power MOSFETs described above, and various semiconductor elements having a switching function, such as other transistors (for example, IGBTs and normal bipolar transistors) and various thyristors including GTO. Can be applied according to the specifications. Further, such a semiconductor switching element is not limited to a package element, and may be, for example, one in which a semiconductor chip is directly mounted. Regardless of the connection form between the semiconductor switching element and each terminal,
For example, wire bonding may be used in place.

Further, in the present invention, the number and arrangement of the semiconductor switching elements and the output terminals can be appropriately set, and may be freely determined according to the arrangement and number of the electric components in the vehicle.

In the above embodiment, the drain connection plate 20 and the input terminal 10 in the power distribution unit PD are formed from the same single metal plate. However, these are connected as separate members by means such as welding. You may make it. Also,
It is also possible to connect the input-side energizing terminals of each semiconductor switching element individually to the input terminals without using the drain connection plate 20. However, due to the structure of the above embodiment,
The electrical connection between each semiconductor switching element and the input terminal and the cooling of each semiconductor switching element can be efficiently performed using the same drain connection plate 20, and the power distribution unit P
The effect that D can be drastically reduced can be obtained.

In the present invention, each output terminal may be projected upward from the power distribution unit PD, for example, and connected to the bus bar of the bus bar circuit unit JB from below. However, as in the above embodiment, each output terminal 12
Are arranged in one direction so as to protrude in the same direction, and a plurality of output terminal connection bus bars are arranged in a peripheral portion of the bus bar circuit portion JB in a direction parallel to the arrangement direction of the respective output terminals. If the power distribution unit and the bus bar circuit unit are arranged at positions adjacent to each other in a state where each output terminal is connected to the power supply unit, the power distribution unit PD and the bus bar circuit unit JB are brought into close proximity on the substantially same plane. The electric connection box can be arranged in a state where the electric connection box is in a closed state, so that the entire electric junction box can be significantly reduced in size.

In the present invention, each terminal 10,
The connection means between the busbars 12 and 17 and the busbars 30, 32 and 37 for connecting the power distribution units of the busbar circuit unit JB can be appropriately set. For example, the power distribution unit PD and the busbar circuit unit J can be set.
B can be rigidly fixed in the case 40 and the connection can be made by a flexible structure such as wire bonding. However, the terminal-
If the bus bars are directly overlapped and connected by welding, high connection reliability can be ensured with a simple structure having a small number of parts, and the mechanical strength of the connection portion can be maintained high.

According to the present invention, for example, the input terminal 10 of the power distribution unit PD can be projected in a direction different from that of the output terminal 12 so that an external circuit can be directly connected to the input terminal 10. However, as described above, if the input terminal 10 is also protruded in the same direction as the output terminal 12 so that the input terminal is connected to the power supply via the bus bar circuit unit, the input / output between the power distribution unit and the external circuit is performed. Can be performed collectively through the common bus bar circuit section JB,
Along with the rationalization of the circuit, the size of the power distribution unit itself can be further reduced. Also, the connection between the power distribution unit PD and the power supply,
There is also an advantage that both the connection between the on-vehicle load and the power supply without passing through the power distribution unit PD can be collectively performed using the common bus bar circuit unit JB.

In the present invention, a control circuit for controlling the energization of each semiconductor switching element in the power distribution unit PD can be incorporated in the power distribution unit PD separately from the control circuit board 18. Further, even when a circuit for controlling on / off of the semiconductor switching element is incorporated in the control circuit board 18, the control circuit and each semiconductor switching element in the power distribution unit PD can be directly connected without passing through the bus bar circuit unit JB. .

In the above-described embodiment, the bus bar substrate is formed by stacking a plurality of layers of the bus bar BB and the insulating plate IB. However, the bus bar circuit portion JB according to the present invention is composed of a single It may be composed of a bus bar and an insulating plate.

[0078]

As described above, the present invention provides a conventional electric junction box with a semiconductor switching element instead of a relay block mixed in a bus bar circuit, and integrates these semiconductor switching elements. Therefore, a power distribution unit independent of the bus bar circuit unit is constructed, and each output terminal of this power distribution unit is connected to an appropriate bus bar of the bus bar circuit unit. There is an effect that an electric connection between a power supply and each load can be made with a simple structure, and an electric connection box with high versatility can be provided.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an electric junction box of a vehicle according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional front view of the electric junction box.

FIG. 3 is a partial cross-sectional bottom view of the electric junction box.

FIG. 4 is a plan view of a power distribution unit incorporated in the electric junction box.

FIG. 5 is a perspective view of the power distribution unit.

FIG. 6 is a sectional view taken along line AA of FIG. 4;

FIG. 7 is a perspective view showing a mounting structure of a relay block in a conventional electric junction box.

[Explanation of symbols]

PD power distribution section JB bus bar circuit section BB bus bar IB insulating plate 10 input terminal 12 output terminal 14 FET (semiconductor switching element) 14d drain terminal (input side connection terminal) 14s source terminal (output side conduction terminal) 14g gate terminal (conduction control terminal) ) 18 control circuit board 20 drain connection plate (conductor plate) 24 heat dissipation member 25 fin 30 input terminal connection busbar (power distribution unit connection busbar) 32 output terminal connection busbar (power distribution unit connection busbar) 34 external connection tab 36 Circuit board connection tab 37 Control terminal connection bus bar (power distribution unit connection bus bar) 40 Case

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takahiro Onizuka 1-7-10 Kikuzumi, Minami-ku, Nagoya, Aichi Prefecture Inside Harness Research Institute, Inc. (72) Isao Isshiki 1, Kikuzumi, Minami-ku, Nagoya, Aichi Prefecture No. 7-10 Harness Research Institute, Ltd. F-term (reference) 5E077 BB13 BB18 BB31 CC22 DD01 DD03 JJ30 5G361 BA04 BB03

Claims (19)

[Claims] 1. An electric connection box for a vehicle for connecting a plurality of on-vehicle loads to a power supply mounted on a vehicle, the electric connection box having an input terminal connected to the power supply and a plurality of output terminals, and A power distribution unit in which a semiconductor switching element is interposed between each output terminal and the input terminal, a metal bus bar for circuit configuration and an insulating plate laminated thereon, and each output terminal of the power distribution unit A bus bar circuit section connected to a plurality of vehicle-mounted loads, and in a state in which the power distribution section and the bus bar circuit section are common in a state where a part of the bus bar in the bus bar circuit section and each output terminal of the power distribution section are connected. An electrical junction box for a vehicle, wherein the electrical junction box is incorporated. 2. The electric connection box for a vehicle according to claim 1, wherein the bus bar circuit portion is configured by alternately stacking a plurality of layers of the bus bar and the insulating plate, and the bus bar circuit portion is formed on a part of a lowermost bus bar. An electric connection box for a vehicle, wherein an output terminal of a power distribution unit is connected. 3. The electric connection box for a vehicle according to claim 1, wherein each output terminal of the power distribution unit and a part of the bus bar are connected in a state of being directly superimposed. Electrical junction box. 4. The electric junction box for a vehicle according to claim 3, wherein each output terminal of the power distribution unit and a part of the bus bar are connected by welding. 5. The electric junction box for a vehicle according to claim 1, wherein the power distribution unit is provided with a heat radiating member connected to each semiconductor switching element so as to be able to conduct heat, and the heat radiating member is provided. An electric connection box for a vehicle, wherein a power distribution unit is incorporated in the case such that the case is exposed to an outer surface of the case. 6. The electric junction box for a vehicle according to claim 5, wherein the electric distribution unit is electrically connected to an input terminal thereof.
A drain connection plate on which the semiconductor switching elements are mounted in a state where the input-side energizing terminals of the semiconductor switching elements are electrically connected is provided, and the heat dissipation member is connected to the drain connection plate so that heat can be transferred. An electric junction box for a vehicle, comprising: 7. The electric junction box for a vehicle according to claim 6, wherein the drain connection plate and the input terminal are formed from the same one metal plate. 8. The electric connection box for a vehicle according to claim 1, wherein the output terminals of the power distribution unit are arranged in one direction so as to protrude in the same direction, and the bus bar circuit unit. A plurality of power distribution unit connection busbars are arranged in a direction parallel to the arrangement direction of the output terminals at the periphery of the power supply unit, and in a state where these busbars and the output terminals are connected,
An electric connection box for a vehicle, wherein the power distribution unit and the bus bar circuit unit are arranged at positions adjacent to each other. 9. The electric junction box for a vehicle according to claim 8, wherein each semiconductor switching element is arranged in a direction parallel to an arrangement direction of each output terminal in the power distribution unit, and an output-side energizing terminal of each semiconductor switching element is provided. An electric connection box for a vehicle, which is directly connected to each output terminal. 10. The electric connection box for a vehicle according to claim 8, wherein the output terminals and the input terminals of the power distribution unit are arranged in one direction so as to protrude in the same direction. A plurality of power distribution unit connection busbars are arranged in a peripheral portion in a direction parallel to the arrangement direction of the output terminals and the input terminals, and these busbars are connected to the output terminals and the input terminals, so that the input terminals thereof are connected. An electric connection box for a vehicle, wherein a terminal is configured to be connected to the power supply via a bus bar circuit section. 11. The electric connection box for a vehicle according to claim 1, further comprising a control circuit board connected to an external vehicle-mounted electronic unit through said bus bar circuit section in said case. An electrical connection for a vehicle, wherein an electrical control circuit that is electrically connected to an electrical control terminal of each semiconductor switching element of the power distribution unit and controls electrical conduction of the semiconductor switching element is incorporated in the control circuit board. box. 12. An electric connection box for a vehicle according to claim 11, wherein an energization control circuit of said control circuit board and an energization control terminal of each semiconductor switching element provided in said power distribution section pass through said bus bar circuit section. An electric connection box for a vehicle, wherein the electric connection box is electrically connected to the vehicle. 13. The electric junction box for a vehicle according to claim 12, wherein the power distribution unit is provided with control terminals connected to the energization control terminals of the semiconductor switching elements, and the control terminals and the output terminals. The terminals are alternately arranged and arranged in one direction so as to protrude in the same direction, and a plurality of power distribution units are connected to the peripheral portion of the bus bar circuit unit in a direction parallel to the arrangement direction of the output terminals and the control terminals. A power distribution unit and a bus bar circuit unit are arranged at positions adjacent to each other in a state in which bus bars are arranged and these bus bars are connected to the output terminals and the control terminals. Connection box. 14. The electric connection box for a vehicle according to claim 11, wherein the control circuit board is arranged in a state substantially parallel to a direction in which the power distribution unit and the bus bar circuit unit are arranged. An electric junction box for a vehicle. 15. The electric connection box for a vehicle according to claim 14, wherein the control circuit board is provided so that at least a part of the control circuit board overlaps the power distribution unit, and the control circuit is provided in the case. An electric connection box for a vehicle, wherein a board housing section for housing a circuit board and a connector section for connecting the bus bar circuit section to an external circuit are formed side by side. 16. The electric junction box of a vehicle according to claim 11, wherein each of the semiconductor switching elements is arranged in a direction parallel to an arrangement direction of the output terminals and the control terminals. An electric connection box for a vehicle, wherein an output-side energization terminal and an energization control terminal of the element are directly connected to each output terminal and control terminal, respectively. 17. The electric junction box for a vehicle according to claim 11, wherein each of the output terminals of the power distribution unit includes:
While the input terminals and the control terminals are arranged in one direction in a state of protruding in the same direction, the output terminals, the input terminals, and the control terminals are arranged in a peripheral portion of the bus bar circuit portion in parallel with the arrangement direction. A plurality of power distribution unit connection bus bars are arranged in the direction, and these bus bars and the respective output terminals, input terminals,
And a control terminal, whereby the input terminal is connected to the power supply via a bus bar circuit section. 18. The electric junction box for a vehicle according to claim 1, wherein each terminal of said power distribution unit is formed of a metal plate and is disposed on substantially the same plane. Vehicle electrical junction box. 19. The electric connection box for a vehicle according to claim 18, wherein said terminals are integrated by a resin mold in a state of being arranged on substantially the same plane, and a power distribution unit case is constituted by said resin mold. The electric connection box for a vehicle, wherein the terminals protrude from the case toward the bus bar circuit portion.