JP6951201B2 - Switch unit and railroad vehicle using it - Google Patents

Description

The present invention relates to a switch unit and a railroad vehicle using the switch unit.

Railroad vehicles are equipped with switch units to protect the equipment used from load currents and accident currents. When the switch unit senses a load current or an accident current, the operating mechanism opens the electrodes and cuts off the current.

Some switch units employ a solid insulation method in which the switch is covered with a molded resin such as an epoxy resin cured product and then cured. Since the solid insulation method uses resin as the insulating medium, a tank for sealing the insulating medium required for gas insulation or oil insulation becomes unnecessary, and the switch unit can be made smaller. Further, the solid insulation method does not require measures against leakage of the insulating medium, and maintenance and inspection for leakage of the insulating medium can be omitted.

The switch unit is classified into a surface grounded structure in which the surface of the molded resin cured product covering the switch is coated with a conductor, and a surface non-grounded structure in which the surface of the molded resin cured product is not coated with the conductor. When the surface grounding structure is used, it is possible to prevent an electric shock of the operator during maintenance and inspection.

Patent Document 1 describes an operating mechanism in which a vacuum container composed of a metal container, an insulating container, and a sealing member, and a movable shaft supporting a movable electrode arranged to face the fixed electrode are connected via an insulating member. It has a structure in which a conductive member is provided on the surface of a mold insulator formed of an epoxy resin or the like, including an operation rod, and the conductive member is formed by spraying a metal such as aluminum or zinc or applying a conductive paint. A composite insulated switch gear is disclosed, wherein the operating rod and the conductive member have a grounded structure.

Japanese Unexamined Patent Publication No. 2005-197128

Since railroad cars run outdoors, the temperature changes significantly. Therefore, it is necessary to take measures against heat stress in the switch unit installed in the railway vehicle.

In the composite insulated switchgear described in Patent Document 1, there is a gap between the mold insulator and the operating mechanism, and the metal sealing member, operating rod, bellows and the like are exposed to the atmosphere. Further, not all the surfaces of the mold insulator formed of the cured resin product are subjected to the conductive treatment, and the operating rod and the conductive member on the surface of the mold insulator are separately grounded. Therefore, there is a triple point where the metal of the mold insulator and the conductive member and air come into contact with each other, and when heat stress is applied, this triple point becomes the starting point, and cracks may occur in the mold insulator, the conductive member and the like. In addition, since grounding is performed separately, circuit parts for that purpose are required, and there is room for improvement in terms of manufacturing cost.

An object of the present invention is to have a switch unit having a structure in which triple points do not occur and to suppress the occurrence of cracks even when thermal stress is applied.

The switch unit of the present invention includes a switch in which a fixed electrode and a movable electrode are arranged in contact with each other, an aerial insulation operation rod connected to the movable electrode, and an electromagnetic operator for driving the aerial insulation operation rod. The insulation case that covers the switch, the mechanism case that covers the electromagnetic controller, and the bushing that connects the cables are provided, and the surface of the insulation case and the surface of the mechanism case are electrically connected, and these surfaces are grounded. It is configured to be an electric potential.

According to the present invention, the switch unit has a structure in which triple points do not occur, and the occurrence of cracks can be suppressed even when thermal stress is applied.

It is a schematic block diagram which shows the example of the vehicle formation of the train which connected the railroad vehicle. It is a schematic block diagram which shows the feeder circuit in the train of FIG. It is a top view which shows the switch unit of an Example. It is a partial cross-sectional view which shows the state which the cable is connected to the switch unit of FIG. It is a top view which shows the state which the switch unit of FIG. 4 is installed on the roof of a railroad vehicle. It is a side view which shows the switch unit of FIG.

Hereinafter, examples suitable for carrying out the present invention will be described with reference to the drawings. It should be noted that the following is merely an example of implementation, and the content of the invention is not limited to the following specific aspects. Of course, the present invention can be transformed into various aspects including the aspects described in the present specification.

First, a vehicle formation example of a railway vehicle to which the switch unit according to the present invention is applied will be described.

FIG. 1 schematically shows an example of train formation.

In this figure, the train 100 is composed of eight trains of railway vehicles 100a, 100b, 100c, 100d, 100e, 100f, 100g, and 100h. Of these, high-voltage lead-through cables RC1, RC2, RC3, RC4, and RC5 are arranged on the roofs 72 of the railway vehicles 100b, 100c, 100d, 100e, and 100f, respectively. Pantographs PG1 and PG2 are connected to the high-voltage pull-through cables RC3 and RC5. The pantographs PG1 and PG2 receive electric power from electric wires (not shown). Further, the high-voltage pull-through cables RC1, RC2, RC3, RC4, and RC5 are connected between vehicles by straight joints SJ1, SJ2, SJ3, and SJ4, and are branched in the vehicle floor direction by T-branch joints TJ1 and TJ2.

Next, the feeder circuit of the railway vehicle will be described.

FIG. 2 shows an outline of the feeder circuit in the train of FIG.

As shown in this figure, in the train 100, the power receiving vacuum breaker VCB1 is placed under the floor (Bottom) of the railroad vehicle 100b (second car), the railroad car 100d (fourth car), and the railroad car 100f (sixth car), respectively. , VCB2, VCB3, and main transformers Tr1, Tr2, Tr3 are provided.

Further, the high-voltage lead-through cable RC1 of the railway vehicle 100b (second car) is directly connected to the primary side of the power receiving vacuum circuit breaker VCB1 provided under the floor. The secondary side of the power receiving vacuum circuit breaker VCB1 is connected to the primary winding of the main transformer Tr1. The secondary winding of the main transformer Tr1 supplies electric power to the motor, and the tertiary winding supplies electric power to auxiliary equipment such as an air conditioner and lighting. Similarly, the high-voltage lead-through cables RC3 and RC5 branched by the T-branch joints TJ1 and TJ2 of the railroad car 100d (fourth car) and the railroad car 100f (sixth car) are the power receiving vacuum breakers VCB2 provided under the floor, respectively. , Is connected to the primary side of the VCB3. The secondary sides of the power receiving vacuum circuit breakers VCB2 and VCB3 are connected to the primary windings of the main transformers Tr2 and Tr3, respectively. The secondary windings of the main transformers Tr2 and Tr3 supply electric power to their respective motors, and the tertiary windings supply electric power to their respective auxiliary devices.

The T-branch joint TJ1 and the straight joint SJ2 form an integrated switch unit 70a. The T-branch joint TJ2 and the straight joint SJ4 form an integrated switch unit 70b.

For example, when a ground fault fault occurs in the high-voltage lead-through cable RC2 of a railroad vehicle 100c (third car), the switch unit 70a is operated by an external command to automatically open the straight joint SJ2. , Ground fault fault The main transformer Tr1 affected by Fault and the motor connected to it are disconnected. At this time, the main transformers Tr2 and Tr3, which are not affected by the ground fault fault, remain connected. Therefore, the operation of the train 100 can be continued by using the motors connected to them.

In this figure, the case where a ground fault occurs at the position indicated by the symbol Fault is described as an example. Therefore, in order to prevent the spread of the failure, the switch unit 70a is operated to open the linear joint SJ2. .. Not limited to this example, another switch unit 70b may be operated to disconnect the linear joint SJ4 according to the location of the ground fault failure. With such a structure, the high-voltage cable including the defective portion and the sound high-voltage cable can be automatically separated without the operator climbing on the roof 72 of the railway vehicle.

Next, a detailed configuration of the switch unit will be described with reference to examples.

FIG. 3 is a plan view showing the switch unit of this embodiment.

In this figure, the switch unit 70 integrates a T-branch joint and a straight joint. The dashed line shows the internal structure.

The switch unit 70 includes a switch 1, a fixed-side bushing 10A, a movable-side bushing 10B, 10C, an aerial insulation operating rod 20, an insulating case 21, and an electromagnetic operator 30. ..

The bushings 10A, 10B, and 10C all have a shape protruding from the insulating case 21.

The switch 1 supports the fixed electrode 3, the movable electrode 5 that contacts or separates from the fixed electrode 3, the arc shield 6 that covers the fixed electrode 3 and the movable electrode 5, and the switch 1 that supports the arc shield 6. Includes a cylindrical ceramic insulating cylinder 7 and a bellows 2 that form a part of the outer container of the above. In other words, the switch 1 has a configuration in which the fixed electrode 3 and the movable electrode 5 are arranged so as to be in contact with each other.

The ceramic insulating cylinder 7 is composed of a ceramic insulating cylinder 7A and a ceramic insulating cylinder 7B. The arc shield 6 has a flange portion. This flange portion is sandwiched between the ceramic insulating cylinder 7A and the ceramic insulating cylinder 7B. As a result, the arc shield 6 is fixed. Both ends of the ceramic insulating cylinder 7 are covered with end plates. As a result, the inside of the ceramic insulating cylinder 7 is maintained in a vacuum state.

The fixed electrode 3 of the switch 1 is electrically connected to the bushing conductor 12A via a fixed conductor drawn out of the switch 1. Further, the movable electrode 5 is electrically connected to the bushing conductors 12B and 12C via a movable conductor drawn out of the switch 1. Then, the movable electrode 5 is controlled to be in contact with and separated from the fixed electrode 3 by the air insulation operating rod 20. The aerial insulation operation rod 20 is connected to the electromagnetic operator 30 and is driven. The electromagnetic actuator 30 is housed in the mechanism case 82. The mechanism case 82 is made of metal. When the mechanism case 82 is made of an insulating material such as resin, it is desirable to provide a metal layer on the surface of the mechanism case 82 as in the case of the metal layer 22 of the insulating case 21 described later.

Bushings 10A, 10B, and 10C are formed by combining the bushing conductors 12A, 12B, and 12C with the insulating material constituting the insulating case 21. With this configuration, the fixed side bushing 10A can be separated from the movable side bushings 10B and 10C. The bellows 2 is arranged between the movable conductor and the end plate on the movable side. With this structure, the movable conductor can be moved while maintaining the vacuum state of the switch 1.

The switch unit 70 is fixed to the base 81 via stays 83A, 83B, and 83C.

The insulating case 21 forms the outer shell of the switch unit 70, and is made of a cured epoxy resin or the like. The insulating case 21 has a structure in which a switch 1, a bushing conductor 12A on a fixed side, a bushing conductor 12B, 12C on a movable side, and the like are molded. The periphery of the aerial insulation operation rod 20 is covered with an insulation case 21 with a predetermined peripheral space. The space around the aerial insulation operation rod 20 is sealed by the insulation case 21 and the sealing means. Insulating gas such as dry air and SF ₆ gas is sealed in the surrounding space inside. As the sealing means, a straight seal or a bellows is applied.

The insulating case 21 and the mechanical case 82 are connected by flanges 85a and 85b, respectively.

A continuous metal layer 22 (indicated by a thick line in the figure) is formed on the surface of the insulating case 21. The metal layer 22 reaches a portion corresponding to the root of the bushings 10A, 10B, and 10C (a portion where the end of the cable head is in contact (a portion where the bushings 10A, 10B, and 10C are in contact with the cable)). As a result, the surface (metal layer 22) of the insulating case 21 is electrically connected to the grounded portion of the cable with the cable connected. In other words, when the cable is connected, it is desirable that the entire exposed surface of the insulating case 21 is covered with the metal layer 22.

Further, the metal layer 22 covers all or at least a part of the connection surface of the flange 85a with the mechanism case 82. As a result, the surface of the insulating case 21 covered with the metal layer 22 and the metal mechanical case 82 are all electrically connected. If this part is grounded, the exposed surface that becomes a high voltage disappears, so that the safety of the operator can be ensured.

The metal layer 22 is formed by spraying zinc. The metal used to form the metal layer 22 may be any as long as it has conductivity, and is not limited to zinc. The metal may be an aluminum alloy, a zinc / aluminum alloy, an aluminum / magnesium alloy, or the like.

The insulating case 21 is made of an epoxy resin composition. The insulating case 21 was manufactured by molding and curing the switch 1, the bushing conductor 12A on the fixed side, the bushing conductors 12B, 12C on the movable side, and the like. As the mold resin, an epoxy resin manufactured by Nagase ChemteX (model number: XNR4038) and a curing agent (model number: XNH4038) were used. The molding and curing procedure is as follows.

After arranging parts such as the switch 1 in the mold, the mixture was heated at 80 ° C. for 3 hours. The epoxy resin and the curing agent were each heated at 60 ° C. for 3 hours and then mixed, and the epoxy resin composition as a mixture was defoamed and kneaded at 60 ° C. for 30 minutes using a vacuum kneader.

The vacuum casting method was used for the mold of the switch 1 and the like.

The defoamed epoxy resin composition was poured into a mold in which parts such as a switch 1 were arranged and heated at 80 ° C. for 3 hours. The epoxy resin composition was cured in two steps of 80 ° C. for 8 hours and 150 ° C. for 12 hours. The molded switch 1 and the like were removed from the mold after primary curing at 80 ° C. for 8 hours, and secondary curing was performed for 12 hours in a constant temperature bath heated to 150 ° C. When the temperature was lowered from 150 ° C. to room temperature, the cured product was cooled from 150 ° C. to room temperature over 5 hours in order to prevent cracking of the cured product due to shrinkage.

The metal layer 22 was formed by spraying zinc on the surface of the insulating case 21 which is a cured epoxy resin.

FIG. 6 shows the side surface of the switch unit 70 of FIG.

As shown in FIG. 6, the switch 1, the fixed side bushing conductor 12A, the movable side bushing conductors 12B and 12C, the aerial insulation operation rod 20, and the like are installed substantially parallel to the base 81.

According to this embodiment, since the connection portion between the insulating case 21 and the mechanical case 82 is covered with the cured epoxy resin, the effect that triple points do not occur can be obtained. Then, even when heat stress is applied, the effect that cracks do not occur in the cured epoxy resin or the metal layer 22 of the insulating case 21 can be obtained.

FIG. 4 shows a state in which a cable is connected to the switch unit 70 of FIG. The cable connection is shown in cross section. In the following, mainly the parts different from FIG. 3 will be described.

As shown in FIG. 4, the switch unit 70 is installed so that the movable direction of the movable electrode 5 and the traveling direction of the railway vehicle substantially coincide with each other and are in contact with the roof of the railway vehicle. Cables 42A, 42B, and 42C are connected to the bushings 10A, 10B, and 10C, respectively. It is desirable that the portion where the bushings 10A, 10B and 10C are in contact with the cables 42A, 42B and 42C and the surface of the insulating case 21 are electrically connected.

The cable 42A is routed to the front of the railroad vehicle (to the left in FIGS. 1 and 2). The cable 42B is routed to the rear of the railroad vehicle (to the right in FIGS. 1 and 2). The cable 42C is connected to the main transformer via an underfloor power receiving vacuum circuit breaker. In other words, the switch unit 70 has a function as a straight joint for connecting the cable 42A and the cable 42B, and also has a function as a T-shaped joint for branching the cable 42C. It is desirable that the surfaces of the cables 42A, 42B, and 42C are grounded so as not to have a high voltage. When the surface of the cables 42A, 42B, 42C is not directly grounded, a grounding layer (for example, a metal mesh is wound around the conductor through an insulating layer) inside the surface layer of the cables 42A, 42B, 42C. ) Is provided. Further, it is desirable that the grounded portion of the cables 42A, 42B and 42C and the metal layer 22 are electrically connected.

The bushings 10A, 10B, and 10C connecting the T-type cable heads 40A, 40B, and 40C of each cable are arranged laterally with respect to the traveling direction and are arranged substantially in the same plane as the switch 1. As a result, a plurality of cables can be connected so as not to interfere with the insulating case 21 (switch 1) and the mechanism case 82 (electromagnetic actuator 30) arranged linearly in the front-rear direction. Therefore, the overall height and width of the switch unit 70 are reduced and progressed as compared with the conventional configuration in which the insulating case 21 (switch 1) and the mechanism case 82 (electromagnetic controller 30) are arranged in the vertical direction or the horizontal direction. The projected area when viewed from the direction can be reduced. As a result, even if the switch unit 70 is provided on the roof of the railway vehicle, the increase in air resistance due to the switch unit 70 can be suppressed.

The T-type cable heads 40A, 40B, 40C are provided with insulating plugs 41A, 41B, 41C on the side opposite to the connection end. As a result, the surfaces of the T-type cable heads 40A, 40B, and 40C are kept at the ground potential.

FIG. 5 is a top view showing a state in which the switch unit 70 of FIG. 4 is installed on the roof of a railway vehicle.

In FIG. 5, the switch unit 70 is housed in the outer case 80. The switch unit 70 is housed in the outer case 80 in a state of being fixed to the base 81. Further, the switch unit 70 is mounted on a railroad vehicle in a state of being housed in the outer case 80.

The outer case 80 has an inclined portion in the front (the traveling direction of the train), and has flat portions on the left and right sides of the switch unit 70. Further, the cables 42A, 42B and 42C are mechanically supported. As a result, the switch unit 70 can be covered, vibration and shake of the cables 42A, 42B, and 42C can be suppressed, and air resistance can be reduced. Further, it is possible to prevent an eccentric load from being applied to the bushings 10A, 10B and 10C.

As described above, since the switch unit 70 has a smaller overall height and width than the conventional structure, the outer case 80 covering the switch unit 70 can also have a smaller overall height and width, and the projected area when viewed from the traveling direction can be reduced. Can be made smaller. As a result, even when the switch unit 70 on the roof of the railway vehicle is covered with the outer case 80, the increase in air resistance due to this can be suppressed.

As described above, in this embodiment, in order to ensure the safety of the operator, the roof of the railway vehicle, the T-type cable heads 40A, 40B, 40C, and the surface of the switch unit 70 are all ground potentials. It has become. Therefore, it is not necessary to secure an insulation distance between the switch unit 70 or the outer case 80 and the roof of the railway vehicle, and both may be arranged close to each other. As a result, the height from the roof of the railroad vehicle to the highest part of the switch unit 70 or the outer case 80 can be suppressed.

More specifically, the switch unit 70 or the outer case 80 can be arranged in contact with the roof of the railway vehicle. As a result, even if the roof of the railroad vehicle is made higher than before, the position of the pantograph can be kept at the same height as before.

Further, the bushings 10A, 10B, and 10C are arranged in a direction substantially perpendicular to the movable direction of the movable electrode 5. This makes it possible to improve workability when connecting the T-type cable heads 40A, 40B, and 40C.

1: Switch, 2: Bellows, 3: Fixed electrode, 5: Movable electrode, 6: Arc shield, 7: Ceramic insulation tube, 10A, 10B, 10C: Bushing, 12A, 12B, 12C: Bushing conductor, 20: Qi Medium insulation operation rod, 21: Insulation case, 22: Metal layer, 30: Electromagnetic operator, 40A, 40B, 40C: T-type cable head, 41A, 41B, 41C: Insulation plug, 42A, 42B, 42C: Cable, 70 , 70a, 70b: Switch unit, 72: Roof, 80: Exterior case, 81: Base, 82: Mechanical case, 83A, 83B, 83C: Stay, 85a, 85b: Flange.

Claims (7)

A switch in which the fixed electrode and the movable electrode are arranged in contact with each other,
An aerial insulation operating rod connected to the movable electrode,
An electromagnetic manipulator that drives the aerial insulation operating rod,
An insulating case that covers the switch and
A mechanical case that covers the electromagnetic actuator and
With a bushing to connect the cable,
The insulating case and the mechanical case are connected by flanges of each.
The surface of the insulating case and the surface of the mechanism case are electrically connected, and these surfaces are configured to have a ground potential .
The surface of the insulating case is covered with a metal layer,
A switch unit in which at least a part of the surface of the insulating case in contact with the mechanical case is covered with the metal layer. Wherein in the state in which the cable is connected, the entire exposed surface of the insulating case is configured covered with the metal layer, the opening and closing unit of claim 1, wherein. The switch unit according to claim 1, wherein the insulating case is made of a cured epoxy resin. The switch unit according to claim 1 , wherein the metal layer reaches a portion corresponding to the root of the bushing. The metal layer is zinc, aluminum, and is formed by zinc-aluminum alloy or aluminum-magnesium alloy, switch unit according to claim 1, wherein. The switch unit according to claim 1, wherein the mechanism case is made of metal. A railway vehicle provided with the switch unit according to any one of claims 1 to 6.

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