JP2002027639A - High-voltage electrical junction box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a leakage current between bus-bars to which different voltages are applied in an electrical junction box. SOLUTION: A 1st case 4 containing low-voltage system bus-bars, to which a voltage which is not higher than 14 V or not higher than 28 V is applied, and a 2nd case 5 containing high-voltage system bus-bars, to which a voltage higher than the voltage applied to the low-voltage system bus-bars and not higher than 200 V is applied, are provided. A base case 20 is divided into housings 20b and 20c by a partition wall 20d and the 1st case 4 is housed in the one side housing 20b, and the 2nd case 5 is housed in the other side housing 20c. The top part of the housing 20b of the base case 20 for housing the 1st case 4 is opened, and an upper cover 22 is attached detachably to it. The top part of the housing 20c of the base case 20 for housing the 2nd case 5 is closed by an upper wall 20f, formed integrally and continuously on the upper end of the partition wall 20d. One lower cover 21 is attached to the lower part of the base case 20, to cover the whole lower part of the base case 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage electrical junction box mounted on an automobile.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine type passenger car is equipped with one battery having a rated voltage of 12 V and a maximum voltage of 14 V, and a voltage of a maximum of 14 V is supplied from the battery to a circuit such as a bus bar in an electric junction box. The power is distributed by the internal circuit of the electric connection box, and the electric components mounted on the vehicle are controlled and the signals are transmitted and received through the electric wires connected to the internal circuit. In some cases, a rated voltage of 24 V and a maximum voltage of 28 V are applied to the truck.

In recent years, the number of electrical components mounted on automobiles has increased rapidly, and the amount of current supplied to one electrical component tends to increase. For example, the power required to drive a fan has conventionally been 130 watts. However, in recent years it has been 260 watts. Further, an engine intake / exhaust device requiring a high voltage such as 36 V, a power steering, and the like cannot be operated with a battery power supply with a rated voltage of 12 V, and therefore are mechanically operated by the driving force of the engine.

[0004] As described above, the diameter of the electric wire is increased as the required current amount of the single electric component is increased, and the number of electric wires is increased due to the rapid increase of the electric component. . As a result, the weight of electric wires routed to the vehicle increases. Also, as in the case of the above-described engine intake / exhaust device, the required power is large, so that it cannot be operated with a power supply from a battery, and when operated with an engine, the engine load increases and fuel efficiency deteriorates. Not preferred. Therefore, it is preferable that the intake / exhaust device or the like that is conventionally operated by the engine is also electrically driven by the power from the battery as much as possible.

[0005] From the above point, the rated voltage of 12V
In place of the current situation where one battery is mounted and the maximum voltage is 14 V, if the voltage is increased so that a high voltage of 14 V or more can be applied, the required current amount can be reduced, and accordingly the wire diameter becomes thinner. The diameter of the wire bundle (wire harness) can be reduced, and the weight of the wire can be reduced. In addition, the air intake / exhaust device, power steering, and the like, which are conventionally operated by the engine, can be electrically controlled, and accordingly, the engine load can be reduced, fuel consumption can be improved, and the environment can be improved.

[0006]

As described above, power steering, engine intake and exhaust systems,
It is preferable that a fan or the like applies a high voltage of about 42 V, while a signal system of an electrical component or a coil of a relay or the like is preferably applied at a conventional rated power of 12 V (a maximum voltage of 14 V).

Accordingly, a circuit in which a low voltage of a maximum voltage of 14 V is applied to a circuit of an electric junction box for distributing power,
When a circuit to which a high voltage of about V is applied is provided, a leakage current due to a potential difference is likely to occur. Further, there is a problem that a leak current easily occurs even between circuits to which a high voltage such as 42 V is applied. However, if the low-voltage circuit and the high-voltage circuit are housed in completely separate electrical junction boxes, there is a problem that connection of these circuits is not easy and the number of connection parts increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. In the case where a circuit to which a low voltage is applied and a circuit to which a high voltage is applied are provided, it is possible to prevent the occurrence of a leak current, It is an object of the present invention to facilitate the connection of

[0009]

In order to solve the above-mentioned problems, the present invention provides a first case containing a low-voltage bus bar to which a maximum voltage of 14 V or 28 V is applied; Larger than the applied voltage of 20
A second case accommodating a high-voltage busbar to which a voltage of 0 V or less is applied, wherein the first case is accommodated in the one-side accommodation chamber partitioned by a partition provided in the base case, while the other side is accommodated. The second case is accommodated in the accommodation room, and the upper cover is removably covered with the upper part of the accommodation room of the first case of the base case as an opening, while the upper part of the accommodation room of the second case is formed by the peripheral wall of the base case and the upper case. An electric connection box for high voltage, which is closed by an upper wall provided integrally and continuously at the upper end of the partition wall, and one lower cover is attached to a lower portion of the base case to cover the entire lower portion of the base case. providing.

As described above, first, a high-voltage bus bar and a low-voltage bus bar, which are likely to cause leakage current when placed adjacent to each other, are housed in separate cases, and a partition is provided between these cases in a base case. , The occurrence of a leak current between the low voltage bus bar and the high voltage bus bar can be prevented. Further, a second case in which the high-voltage bus bar is arranged and a first case in which the low-voltage bus bar is arranged.
Because the case is housed inside one lower cover,
The connection between the high-voltage busbar and the low-voltage busbar can be made inside one electric junction box.

[0011] In addition, since the base case is continuous with the upper wall on the housing side of the high-voltage bus bar and has a closed structure,
During maintenance, safety can be ensured without the user accidentally touching the high-voltage bus bar. On the other hand, since the upper cover of the low-voltage bus bar is removable, maintenance work can be performed.

The low-voltage busbar and the high-voltage busbar are fixed on the insulating plate by inserting ribs protruding from the insulating plate into holes formed in these busbars and caulking. . The insulating plates to which the bus bars are fixed are stacked and arranged inside the first case and the second case.

The high voltage is preferably 42V. The reason why the voltage is set to 42 V is that if three commonly used batteries having a rated voltage of 12 V (maximum voltage of 14 V) are connected in series and used, the voltage can be easily increased to 42 V. It goes without saying that one battery with a maximum voltage of 42 V may be provided. The reason why the maximum voltage is set to 42 V is that when the voltage is increased to more than 50 V beyond 42 V,
Because it is dangerous if touched by mistake. Also,
The present inventor engaged a terminal connected to an electric wire terminal to a tab of a bus bar and applied a high voltage to the bus bar to perform a salt water immersion experiment. Due to not having occurred. Specifically, 4
Application was continued at 2 V for 8 hours and then stopped for 16 hours. Even when this was repeated twice, no ignition or melting phenomenon occurred, and melting occurred at the third time. Therefore, it has been confirmed from a normal use condition of an automobile that there is no problem even when a high voltage of 42 V is applied.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, as schematically shown in FIG.
The vehicle to which the present invention is applied is an engine vehicle that uses an engine E mounted in an engine room X for running and power generation, and has a low-voltage battery 1 and a high-voltage battery 2 mounted in the engine room X. are doing. The low-voltage battery 1 has a commonly used rated voltage of 12
V, consisting of one battery with a maximum voltage of 14V. The high-voltage battery 2 has a maximum voltage of 42 V by connecting three batteries 2a, 2b and 2c having a rated voltage of 12V similar to the above-mentioned battery in series. In addition, the maximum voltage 4
It goes without saying that one 2V battery may be used.

The low-voltage battery 1 is connected to a low-voltage bus bar 10 in a first case 4 housed in an electric junction box 3 consisting of a junction box mounted on the indoor side Y (in some cases in the engine room). And a low voltage (maximum voltage 12 V) is applied. The high-voltage battery 2 is connected to a high-voltage bus bar 11 in the second case 5 housed in the electric junction box 3 to apply a high voltage (a maximum voltage of 42 V).

As shown in FIG. 2, the electric connection box 3 includes a base case 20 for accommodating the first case 4 and the second case 5, a lower cover 21 and an upper cover 22.

The base case 20 includes an outer peripheral wall 20a,
A partition wall 20d protruding from the opposing inner surface of the outer peripheral wall 20a to partition the inside into two accommodation chambers 20b and 20c;
A case support frame 20e protruding from the inner surface at the lower end of Oa and the lower end of the partition 20d, the outer peripheral wall 20a surrounding the one storage chamber 20c and the upper end of the partition 20d, and the upper part of the storage chamber 20c is closed. An upper wall 20f is provided. The upper portion of the other storage chamber 20b is detachably covered with the upper cover 22 and is locked and coupled thereto.

The lower cover 21 is attached to the base case 2
0, and its outer peripheral wall 21a is
Is connected to the outer peripheral wall 20a by a lock connection.

In the first case 4, the low-voltage bus bars 10 and the insulating plates 12 are alternately stacked. The high voltage bus bars 11 and the insulating plates 13 are alternately stacked inside the second case 5. The first and second cases 4 and 5 have relays 1 respectively.
4. Attach the fuses 15 and the busbars 10,
11 is connected directly or via a relay terminal.

As shown in FIG. 4, the low-voltage bus bar 10 in the first case 4 and the high-voltage bus bar 11 in the second case 5 are connected to the tabs 10a, 11a provided on the bus bars 10, 11, respectively. Terminals T1, connected to both ends of electric wire w
T2 is fitted and connected.

The wire group W1 connected to the low-voltage bus bar 10 in the first case 4 and the wire group W2 connected to the high-voltage bus bar 11 in the second case 5 are each a wire outlet provided in the lower cover 20. It is drawn out through 20g and 20h.

The electric wire on the power supply side connected to the low-voltage bus bar 10 is connected to the low-voltage battery 1, and the electric wire on the load side is a device such as a sensor or a lamp system which requires a small amount of electric power, as in the prior art. Kind of connected. on the other hand,
The electric wire on the power supply side connected to the high-voltage bus bar 11 is connected to the battery 2 for high voltage, and the electric wire on the load side is connected to an actuator such as a power steering and an engine intake / exhaust device which requires a large amount of electric power. Is operated electrically.

As described above, the low-voltage bus bar 10 and the high-voltage bus bar 11 having different voltages are housed in separate cases, respectively, and are blocked by the partition wall 20d protruding from the common base case 20. It is possible to prevent a leak current from being generated between the bus bars 10 and 11 to which different voltages are applied.

The above embodiment relates to a general passenger car equipped with a 12V rated battery, but also applies to a case where a maximum voltage of 28V is applied to a bus bar in a passenger car, and a case where a maximum voltage of 28V is applied to a bus bar in a truck. The bus bar to which a voltage of up to 28 V is applied is referred to as the low-voltage bus bar, and the bus bar to which a voltage of 42 V is applied is distinguished as the high-voltage bus bar. Have been placed.

In the above embodiment, the maximum voltage of 42 V is applied to the high-voltage bus bar 11. However, if the weight of the battery is reduced and the safety is sufficiently ensured, 4
It goes without saying that a high voltage larger than 2 V and up to 200 V may be applied.

[0026]

As is apparent from the above description, according to the present invention, in order to reduce the amount of current, to reduce the thickness of the electric wire and to prevent the wiring harness from being enlarged, the voltage is increased and the low-voltage busbar is reduced. And the high-voltage busbar are housed inside the electrical junction box, the case for housing the busbars to which these different voltages are applied is separated, and
Because these cases are housed in the common lower cover and base case, and are blocked by the partition provided in the base case,
Leakage current can be prevented from occurring between the low-voltage bus bar and the high-voltage bus bar and between the high-voltage bus bars.

Further, since the high voltage bus bar is housed in a closed structure by the base case on the housing side, it is possible to surely prevent the user from touching the bus bar and to improve the integrity. On the other hand, maintenance work can be performed on the storage side of the low-voltage bus bar because the upper cover can be removed.

Furthermore, since one is accommodated in the base case and the lower cover, the connection between the high-voltage bus bar and the low-voltage bus bar can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a state where a circuit body is housed in the electric junction box shown in FIG.

FIG. 3 is an enlarged sectional view of a main part of FIG. 2;

FIG. 4 is a drawing showing circuit connection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low voltage battery 2 High voltage battery 3 Electric connection box 4 1st case 5 2nd case 10 Low voltage system bus bar 11 High voltage system bus bar 12 Insulating board 20 Base case 20a Outer peripheral wall 20d Partition wall 20f Upper wall 21 Lower cover 22 Upper cover

Claims (2)

[Claims] A first case accommodating a low-voltage bus bar to which a maximum voltage of 14 V or 28 V is applied;
A second case accommodating a high-voltage bus bar to which a voltage of 0 V or less is applied, wherein the first case is accommodated in the one-side accommodation chamber partitioned by a partition provided in the base case, and the other side is accommodated. The second case is accommodated in the accommodation room, and the upper cover of the first case of the base case is removably covered with the opening of the upper part of the accommodation room of the first case. An electric connection box for high voltage, which is closed by an upper wall provided integrally and continuously with an upper end of a partition wall, and one lower cover is attached to a lower portion of the base case to cover the entire lower portion of the base case. 2. The high-voltage electrical junction box according to claim 1, wherein the high voltage is 42V.