JPH058721Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a grounding circuit for an electric vehicle having a motor equalizing line, which can prevent abnormal wear of the grounding device brush and electrolytic corrosion of bogie peripheral equipment. It is related to.

[Conventional technology]

FIG. 2 is a circuit diagram showing an example of a conventional vehicle grounding circuit. In FIG. 2, the current supplied from the overhead wire 1 by the pantograph 2 and passed through the control device 3 flows from the grounding switch 4 to the vehicle body 5. car body 5
The current that has passed through the grounding wires 6a, 6b and grounding devices 7a, 7b flows to the wheel sets 10a, 10b, and returns to the substation (not shown) through the rail 11. The electric motors 8a, 8b are equipped with grounding devices 7a, 7b.
Equalizing lines 9a and 9b connected to are provided. These pressure equalizing lines 9a, 9b are connected to electric motors 8a, 8b.
It has the role of grounding the motors 8a and 8b to prevent current from flowing to other equipment and causing burnout when abnormal voltage occurs.

[Problem that the invention attempts to solve]

In such a grounding circuit, when a return current from another vehicle (not shown) flows along the rail 11 in the direction of the arrow, a portion of the return current flows through the rail 11 due to the influence of electrical resistance.
1 → wheel axle 10a → grounding device 7a → pressure equalizing wire 9a → electric motor 8a → bogie frame (not shown) that fixes motors 8a and 8b → electric motor 8b → pressure equalizing wire 9b → earthing device 7b → wheel axle 10b → rail It is known that the flow is divided through 11 routes.

Therefore, an overcurrent exceeding the current that originally flows through the grounding wire 6b flows through the grounding device 7b, causing abnormal wear of the grounding device brush (not shown). It also caused electrolytic corrosion of the bearings and gears of the truck, drive device (not shown).

The present invention eliminates the above-mentioned problems and aims to provide a grounding circuit for a vehicle that can prevent abnormal wear of the grounding device brush and electrolytic corrosion of the peripheral equipment of the bogie.

[Means for solving problems]

A backflow prevention element is connected to the voltage equalizing line between the motor and the grounding device so that current flows only from the motor to the grounding device, and a part of the return current is prevented from being shunted to the voltage equalizing line. That is, the backflow prevention element 12
a, 12b and grounding devices 7a, 7b, the grounding circuit includes backflow prevention elements 12a,
12b has one end connected to the electric motors 8a, 8b and the other end to the grounding devices 7a, 7b, and the grounding devices 7a, 7b abut against the wheel axles 10a, 10b with brushes or the like.

[Effect]

Even if the return current from another vehicle flows through the rail, the backflow prevention element connected to the voltage equalization line operates and prevents a portion of the return current from being shunted to the voltage equalization line. It can prevent wear and electrolytic corrosion of trolley peripheral equipment.

〔Example〕

FIG. 1 is a circuit diagram showing an embodiment of a grounding circuit for a vehicle according to the present invention, in which the same reference numerals as in FIG. 2 indicate the same parts. As shown in FIG. 1, backflow is prevented so that current flows from the motors 8a, 8b to the grounding devices 7a, 7b in the voltage equalizing wires 9a, 9b between the motors 8a, 8b and the grounding devices 7a, 7b, respectively. The elements 12a and 12b are connected. Note that the flow of current supplied from the overhead wire 1 to the pantograph 2 is exactly the same as in FIG. 1.

In this circuit, even if the return current from another vehicle flows to the rail 11 in the direction of the arrow, the backflow prevention element 12a
acts to prevent part of the return current from being shunted to the pressure equalizing lines 9a and 9b. Therefore, the earthing device 7b
This prevents excessive current from flowing through the grounding device, preventing abnormal wear of the grounding device brush (not shown), and preventing electrolytic corrosion of the bearings and gears of the truck (not shown) and drive device (not shown). can. Furthermore, the original function of the pressure equalizing lines 9a and 9b is not lost.

Further, when the direction of the return current is opposite to the direction of the arrow, the backflow prevention element 12b works and the pressure equalizing lines 9b, 9
The return current is no longer shunted to a, and the same effect is obtained.

[Effect of idea]

As described above, the present invention prevents the return current from being shunted to the pressure equalizing line, and prevents abnormal wear of the grounding device brush and electrolytic corrosion of the peripheral equipment of the bogie, and has a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of a vehicle grounding circuit according to the present invention, and FIG. 2 is a circuit diagram showing an example of a conventional vehicle grounding circuit. DESCRIPTION OF SYMBOLS 1... Overhead line, 2... Pantograph, 3... Control device, 4... Ground switch, 5... Vehicle body, 6a,
6b...Grounding wire, 7a, 7b...Grounding device, 8
a, 8b... electric motor, 9a, 9b... electric motor 8
Equalizing lines a, 8b, 10a, 10b... wheel set, 1
1...Rail, 12a, 12b...Backflow prevention element.

Claims (1)

[Claims for Utility Model Registration] Backflow prevention elements 12a, 12b and grounding device 7
The backflow prevention elements 12a, 12b are connected at one end to the electric motors 8a, 8b and at the other end to the grounding devices 7a, 7b. , 7b is a grounding circuit for electric vehicles that comes into contact with the wheel axles 10a, 10b with brushes or the like.