JP2002034121A - Circuit component for 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: Low-voltage system bus-bars to which a voltage not higher than 14 V or not higher than 28 V is applied and 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. The low-voltage system bus-bars and the high-voltage system bus-bars are arranged on the same insulating board. The high-voltage system bus-bars are arranged together respectively at different sections. An insulating partition wall, consisting of an insulating plate, is made to protrude from the surface of the insulating board between the high-voltage system bus-bar section and the low-voltage system bus-bar section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a passenger car of an internal combustion engine generally has one battery with 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 connection 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 track.

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 intake / exhaust device for an engine requiring a high voltage such as 36 V, an electric power steering, etc. are rated 1
It cannot be operated with a 2V battery power supply, and is therefore operated mechanically 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-mentioned engine intake / exhaust device, it cannot be operated with a power supply from a battery due to a large required power, and if it is operated mechanically, fine intake / exhaust control cannot be performed, and fuel consumption becomes poor. It is not preferable from the viewpoint of environment. Therefore, it is preferable that the intake / exhaust device or the like which has been conventionally operated by a mechanical cam be electrically driven by a power source from a battery as much as possible.

[0005] In view of the above, in a car, a voltage of up to 14 V from a generally mounted battery is used,
By increasing the voltage so that a voltage higher than the voltage can be applied, the required current amount can be reduced, and accordingly, the wire diameter can be reduced and the wire bundle (wire harness) can be reduced, and the wire weight can be reduced. Can be planned. In addition, the above-mentioned intake / exhaust device and power steering, which have conventionally been operated mechanically or hydraulically, can be electrically controlled, thereby enabling fine control of the intake / exhaust system, improving fuel efficiency, and improving the environment. be able to.

[0006]

As described above, it is preferable to apply a high voltage of about 42 V to an electric power steering, an engine intake / exhaust / exhaust device, a fan, etc., which require a large amount of electric power. In general passenger cars, it is preferable to apply the power of 12 V (maximum voltage: 14 V) to the coils of relays and the like in general passenger cars.

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.

The present invention has been made in view of the above problems, and has as its object to prevent the occurrence of leakage current when a circuit to which a low voltage is applied and a circuit to which a high voltage is applied are provided. And

[0009]

In order to solve the above-mentioned problems, the present invention provides a low-voltage bus bar to which a maximum voltage of 14 V or 28 V is applied, and a voltage of 200 V or less which is higher than the applied voltage of the low-voltage bus bar. A high-voltage busbar to which a voltage is applied is provided, and the low-voltage busbar and the high-voltage busbar are arranged on one insulating plate in the same layer, and the high-voltage busbar and the low-voltage busbar are collectively provided. A partition for disposing is provided, and an insulating partition wall is protruded from an insulating plate between the high-voltage bus bar section and the low-voltage bus bar section, and the height h of the insulating partition wall is For the thickness t of the bus bar, t <h ≦ t × 20, and the width w of the insulating partition wall is 1.5 mm <w ≦ with respect to the maximum width s of the bus bar on the insulating plate. Height set in the range of s × 20 We provide circuits for use in voltage junction boxes.

As described above, when the high-voltage bus bar and the low-voltage bus bar are apt to be separated from each other, an insulating partition wall is provided between the high-voltage bus bar and the low-voltage bus bar. It is possible to prevent a leak current from being generated between the voltage bus bar. As described above, by adopting a configuration for preventing generation of a leak current, the low-voltage bus bar and the high-voltage bus bar can be arranged on one insulating plate constituting the same layer, and these different voltage buses can be arranged. Since it is not necessary to layer the bus bars to which the voltage is applied, it is possible to prevent the electric connection box from being enlarged.

The height h of the insulating partition wall is set so that t <h ≦ t × 20 with respect to the thickness t of the bus bar, and the width w is set with respect to the maximum width s of the bus bar on the insulating plate. 1.5
The reason for setting the range of mm <w ≦ s × 20 is that as a result of an experiment conducted by the inventor, no leak current occurred even at the minimum height and the minimum width in the above range. Further, the maximum height and the maximum width in the above range are due to the fact that the circuit body becomes unnecessarily large if it is made larger than this. From the experimental results, the height h of the insulating partition wall is t <h ≦ t × 10,
The width w is most preferably 1.5 mm <w ≦ s × 10.

The high-voltage bus bar and the low-voltage bus bar are divided into left and right sections on an insulating plate, or the center of the insulating plate is a high-voltage bus bar section and the periphery is a low-voltage bus bar section.

The low-voltage busbar and the high-voltage busbar are fixed to the board resin portion by inserting ribs protruding from the insulating plate into holes formed in these busbars and caulking. I have.

Preferably, the high voltage is 42V. The reason why the voltage is set to 42V is that if three batteries having a rated voltage of 12V (maximum voltage of 14V), which are widely used in general passenger cars, are connected in series and used, the voltage can be easily increased to 42V. 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 if the voltage is raised to more than 50 V beyond 42 V, it is dangerous if a person accidentally touches it. Further, as a result of the present inventor fitting the terminal connected to the electric wire terminal to the tab of the bus bar and applying a high voltage to the bus bar and performing a salt water immersion experiment, even if the voltage is increased to 42 V, the electric component to be energized is easily melted. No loss was caused. Specifically, the voltage was applied continuously at 42 V for 8 hours, and then 1
Even after stopping the application for 6 hours and repeating this 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.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. First, as schematically shown in FIG.
A passenger car to which the present invention is applied is an engine car using an engine E mounted in an engine room (X) for running and power generation. The low-voltage battery 1 and the high-voltage battery are provided in the engine room (X). 2 is installed. The low-voltage battery 1 is a single battery having a rated voltage of 12 V and a maximum voltage of 14 V, which are widely used. The high-voltage battery 2 includes three batteries 2a, 2b, and 2c each having a rated voltage of 12 V similar to the above-described battery.
Are connected in series to have a maximum voltage of 42V. It goes without saying that one battery with a maximum voltage of 42 V may be used.

The low-voltage battery 1 is connected to a low-voltage busbar 10 housed in an electric junction box 3 formed of a junction box mounted on the indoor side Y (in some cases, in an engine room) and connected to a low-voltage bus (maximum voltage). 14V). The high-voltage battery 2 is connected to a high-voltage bus bar 11 housed in the electric junction box 3 to apply a high voltage (a maximum voltage of 42 V).

The load side of the high-voltage bus bar is connected to actuators requiring a large amount of electric power, such as power steering and an engine intake / exhaust device, and these are operated electrically. On the other hand, the load side of the low-voltage bus bar is connected to devices requiring a small amount of power, such as a sensor and a lamp system, as in the conventional case.

As shown in FIG. 2, circuit bodies 5 are vertically stacked inside the electric junction box 3. As shown in FIG. 3, one of the stacked circuit bodies 5 divides an insulating plate 12 into left and right portions, and protrudes an insulating partition wall 12a therebetween. The low-voltage bus bar 10 is arranged in one section S1 with the insulating partition wall 12a interposed therebetween, while the high-voltage bus bar 11 is arranged in the other section S2.

The insulating partition wall 12a is integrally formed upright from the substrate 12b of the insulating plate 12 over the entire length in the front-rear direction at an intermediate position in the left-right direction of the insulating plate 12. The height h of the insulating partition wall 12a is equal to the height of the bus bars 10, 1
Assuming that the thickness of 1 is t, t <h ≦ t × 10 is set. In addition, the width w of the insulating partition wall 12a is
Assuming that the maximum width among 0 and 11 is s, 1.5 mm <w ≦
It is set to s × 10.

The substrate 12b of the insulating plate 12 is a thin flat plate as in the prior art, and has ribs 12c for fixing bus bars protruding from the surface thereof. These ribs 12c are fixed to the surface of the substrate 12b by inserting the ribs 12c into mounting holes 10b, 11b formed in advance in the strip-shaped horizontal portions 10a, 11a of the bus bars 10, 11 and then caulking the rib tips.

Further, the bus bars 10 and 11 are provided with tabs 10c and 11c projecting from the horizontal strip portions 10a and 11a in the same manner as in the prior art. These tabs 10c, 1
Reference numeral 1c denotes a connector provided on the outer surface of the case of the electric connection box 3 directly or via a relay terminal, which is fitted and connected to a terminal of an external circuit. That is, the terminal of the electric wire terminal connected to the low-voltage battery 1 is fitted and connected to the tab 10c on the power supply side of the low-voltage bus bar 10, and the tab 11c on the power supply side of the high-voltage bus bar 11 is connected. The terminal of the wire terminal connected to the high-voltage battery 2 is fitted and connected.

As described above, even if the low-voltage bus bars 10 and the high-voltage bus bars 11 having different voltages are arranged in one circuit body 5 constituting the same layer, these bus bars 10 and 11
And the busbars 10 and 11 to which different voltages are applied because the partition walls 12a are arranged so as to sandwich the insulating partition wall 12a.
Can be prevented from generating a leak current.

FIG. 4 shows a second embodiment, in which an insulating plate 12 '
A central portion of the partition S1 is a section S2 on which the high-voltage bus bar 11 is disposed, and a periphery thereof is a section S1 on which the low-voltage bus bar 10 is disposed, and an insulating partition wall 1 is provided between the sections S1 and S2.
2a 'is projected.

The above embodiment relates to a general passenger car equipped with a 12V rated battery. Even in a passenger car, a maximum voltage of 28V is applied to a bus bar, and a truck applies a maximum voltage of 28V to a bus bar. In this case, the bus bar to which a voltage of 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 referred to as the high-voltage bus bar. Has 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, the voltage is higher than 42 V and reaches 200 V. It goes without saying that a high voltage 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. When the high-voltage busbar and the high-voltage busbar are accommodated inside the electrical junction box, the busbars to which these different voltages are applied are separately arranged, and the insulating partition wall is erected between them. It is possible to prevent a leak current from being generated between the low-voltage bus bar and the high-voltage bus bar.

[Brief description of the drawings]

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

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

3A is a perspective view of a circuit body, and FIG. 3B is a cross-sectional view of a main part.

FIG. 4 is a diagram illustrating a circuit body according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low-voltage battery 2 High-voltage battery 3 Electric connection box 5 Circuit body 10 Low-voltage bus bar 10c tab 11 High-voltage bus bar 11c tab 12 Insulating plate 12a Insulating partition S1, S2 Section

Claims (4)

[Claims] 1. A low-voltage bus bar to which a maximum voltage of 14 V or 28 V is applied, and a high-voltage bus bar to which a voltage higher than the applied voltage of the low-voltage bus bar and not more than 200 V is applied. The high-voltage bus bar and the high-voltage bus bar are arranged on one insulating plate of the same layer, and the high-voltage bus bar and the low-voltage bus bar are separately arranged. An insulating partition wall protrudes from the insulating plate between the voltage bus bar sections, and the height h of the insulating partition wall is the thickness t of these bus bars.
And the width w of the insulating partition wall is 1.5 mm <w ≦ s × 20 with respect to the maximum width s of the bus bar on the insulating plate. Circuits used for high-voltage electrical junction boxes set in the range. 2. The height h of the insulating partition wall is t <h ≦ t.
The circuit body according to claim 1, wherein × 10 and width w are set to 1.5 mm <w ≦ s × 10. 3. The high-voltage bus bar and the low-voltage bus bar are divided on the left and right on the insulating plate, or the center of the insulating plate is a high-voltage bus bar and the periphery is a low-voltage bus bar. A circuit body for use in the high-voltage electrical junction box according to claim 1. 4. The high voltage bus bar has a maximum voltage of 42.
The circuit body for use in the high-voltage electrical junction box according to any one of claims 1 to 3, wherein V is applied.