JP7681502B2 - Contact wire voltage detector and grounding device - Google Patents

Description

The present invention relates to a voltage tester and grounding device that detects the voltage of a contact wire prior to electric line construction and grounds a non-voltage contact wire while encouraging appropriate measures without grounding a live contact wire.

Generally, a voltage-detecting earthing device is equipped with a detector having a resistor between the contact wire and the ground wire for detecting the contact wire's voltage to ground, and a grounding switch in parallel with the detector for opening and closing the grounding wire to ground the contact wire. When the detector detects the no-voltage state of the contact wire, the grounding switch can be operated and the contact wire can be grounded, so that construction work on the railway line can be safely carried out. On the other hand, when the detector detects the live line state, the grounding switch cannot be operated and the contact wire cannot be grounded, so countermeasures for construction work are taken.
Conventionally, as described in Patent Document 1, a voltage detection grounding device is mounted on a work vehicle that can run on rails using iron wheels, together with a working device whose height can be adjusted by an actuator. The voltage detection grounding device includes a conductive contact member that can contact the trolley wire, a grounding circuit that electrically connects the contact member and the iron wheel, a contact determination circuit that determines whether the contact member is in contact with the trolley wire, and an actuator operation restriction means that restricts the operation of the actuator unless the contact determination circuit determines that the contact member is in contact with the trolley wire. The contact determination circuit includes a sensor that detects the load when the contact member is in contact with the trolley wire and the protruding length of the cylinder of the push-up mechanism. In the voltage detection grounding device configured in this manner, if the contact determination circuit does not determine that the contact member is in contact with the trolley wire, the actuator operation restriction means restricts the operation of the actuator in the direction of moving the working device closer to the trolley wire. Therefore, a static elimination operation must be performed by bringing the contact member into contact with the trolley wire prior to the actual construction work, thereby preventing electric shock accidents of workers.

Patent No. 3966652

In the above-mentioned conventional voltage detection grounding device, a sensor for detecting the lift load and lift position is required in the contact determination circuit, which makes the structure of the device complicated and increases the manufacturing cost. Therefore, a means for easy detection with a simple structure is desired.
Therefore, an object of the present invention is to provide a voltage detecting grounding device that can reliably detect contact wire breakage without using expensive sensors and prevent electric shock accidents by prompting rapid response measures.

In order to solve the above problems, in this invention, a voltage detection and grounding device 1 is composed of a grounding contactor 10 that is electrically connected between the trolley wire T and the rail R and opens and closes the gap between them to ground the trolley wire T to the rail R, a voltage detector 11 that detects the voltage to ground of the trolley wire T, and a control panel 6 that controls the grounding contactor 10 so that the voltage detector 11 enables the grounding operation of the grounding contactor 10 for railway track construction when the trolley wire T is at or below a predetermined voltage, but disables the grounding operation of the grounding contactor 10 when the voltage is above the predetermined voltage. The device is equipped with a pair of contact plates 4 that are spaced apart in the extension direction of the trolley wire T and contact the trolley wire T from below to electrically connect the grounding contactor 10 and the voltage detector 11 to the trolley wire T, and a wire separation detection unit 9 that electrically opens and closes the gap between the contact plates 4 and the trolley wire T when they come into contact with each other or separate from each other.

The present invention can reliably detect contact wire breakage with a simple structure without using expensive sensors, etc., and can prevent electric shock accidents by promptly taking corrective measures.

1 is a perspective view of a voltage detecting grounding device according to the present invention; FIG. 2 is a front view of the voltage detection grounding device of FIG. 1 . FIG. 2 is a left side view of the voltage detection grounding device of FIG. 1 . FIG. 2 is a right side view of the voltage detection grounding device of FIG. 1 . FIG. 2 is a rear view of the voltage detection grounding device of FIG. 1 . FIG. 2 is a plan view of the voltage detecting grounding device of FIG. 1 . FIG. 2 is a schematic circuit diagram of the electroscopic grounding device of FIG. 1 . FIG. FIG. 9 is a side view of the push-up device of FIG. 8 . FIG. FIG. 1 is a schematic circuit diagram of a contact detection unit, in which (A) shows the separated state between the contact plate and the trolley wire, and (B) shows the contact state. FIG. FIG.

An embodiment of the present invention will be described with reference to the drawings.
1 to 6, the voltage detecting grounding device 1 includes a hand-pushed cart 2 that is provided with wheels 2b that roll on the rails R of the railway track at the bottom of a frame body 2a and can be moved along the railway track. Into this frame body 2a, a main body 3 of the voltage detecting grounding device 1, a push-up device 5 that supports a pair of contact plates 4 that are spaced apart from each other in the front-rear direction in the extension direction of the trolley wire T, a control panel 6, and a generator 7 are incorporated.

The main body 3 is fixed to the lower frame inside the frame body 2a, and as shown in FIG. 7, it is equipped with a voltage detection grounding section 8 equipped with a grounding contactor 10 and a voltage detector 11, a line loss detection section 9 equipped with a line loss detection contactor 12, and a clamp release detection section 13.

One contact of the ground contactor 10 is connected to one contact plate 4 through a high-voltage ground cable 14, and the other contact is connected to a rail clamp 16 through a low-voltage ground cable 15. The rail clamp 16 is attached to and electrically connected to the rail R, and when the ground contactor 10 is turned ON, the trolley wire T is grounded to the rail R. The high-voltage ground cable 14 moves in and out of a cable cover 17 provided on the side of the main body 3 in response to the extension and retraction of the telescopic arm 30 of the push-up device 5, preventing interference with other parts.

The voltage detector 11 is equipped with large and small resistors 11a and 11b connected in series to divide the voltage to detect the voltage, and a voltmeter 11c that detects the voltage to ground of the trolley wire T by measuring the small voltage of the small resistor 11a. The voltage detector 11 is connected in parallel with the ground contactor 10 between the high-voltage ground cable 14 and the low-voltage ground cable 15. When the voltage detector 11 detects a no-voltage state of the trolley wire T, it is controlled by the control panel 6 to turn on the ground contactor 10.

The line loss detection unit 9 includes a line loss detection contactor 12 having one contact connected to one of the contact plates 4 through a ground high-voltage cable 14 and the other contact connected to the other of the contact plates 4 through a line loss detection cable 18, and a resistance measuring device 19 in the control panel 6. The line loss detection contactor 12 detects the resistance value measured by the resistance measuring device 19 in the ON state to detect that either of the pair of contact plates 4, 4 is separated or in poor contact with the trolley wire T. The line loss detection cable 18 moves in and out of the cable cover 17 together with the ground high-voltage cable 14 in response to the extension and retraction of the extension arm 30 of the push-up device 5, preventing interference with other parts.

The clamp detachment detection unit 13 is connected to the rail clamp 16 through a low-voltage grounding cable 15 and to the earth holder 21 through a clamp detachment detection cable 20, and is equipped with a resistance meter 22 in the control panel 6 that detects the resistance between the rail clamp 16 and the earth holder 21.

As shown in Figures 8 and 9, the push-up device 5 that supports the contact plate 4 so that it can be raised and lowered includes a motor 24 fixed to a storage cover 23 fixed to the upper part of the frame body 2a of the cart 2, a drive pulley 26 to which rotation is transmitted by the motor 24 via a belt 25, a reducer 27 that is connected to the rotation axis of the drive pulley 26 to convert the rotation into an orthogonal direction, a ball screw unit 29 that is connected to the output shaft of the reducer 27 via a chain coupling 28, and a telescopic arm 30 that expands and contracts up and down as a movable nut 29b that screws into the ball screw 29a of the ball screw unit 29 moves in the screw axial direction. The telescopic arm 30 has a so-called magic hand link structure in which one of a pair of arm pieces 30a, 30b that cross at the lower end is connected to the movable nut 29b and expands and contracts by approaching and moving away from the other one fixed to the lower end frame 31a. A pair of intersecting arm pieces 30a, 30b at the upper end of the telescopic arm 30 is fixed to the upper end frame 31b, and the other is pivoted to the upper end frame 31b so that it can move toward and away from the other.

A pair of contact plates 4 arranged at intervals in the forward and backward directions of travel of the trolley 2 are fixed horizontally via insulators 34 on a mounting plate 33 supported for vertical movement by a linear bushing 32 fixed on the upper end frame 31b of the push-up device 5. The mounting plate 33 is equipped with a load cell 35 that is connected to the inside of the control panel 6 via a lead wire 36 and detects the pressing load of the contact plate 4. The contact plate 4 is supported by the push-up device 5 and pushed up, so that it is pressed against the trolley wire T from below with a predetermined pressure.

As shown in Figs. 13 and 14, the control panel 6 contains a wiring board 39 for the sequence circuit, a terminal board 40, a digital panel meter 41, and the like inside a housing 37 with inner and outer main body doors 38. The surface of the main body door 38 is provided with first and second lamp groups 42, 43 for displaying status in two upper and lower rows, and below that, a group of switches 44 covered by an operation door 45 that can be opened and closed.

In this voltage detection grounding device 1, it is moved on the rail R to a predetermined position, and a rail clamp 16 and an earth holder 21 are attached to the rail R. When the power switch in the switch group 44 is turned on and the push-up button switch is pressed, the push-up device 5 raises the contact plate 4. When the contact plate 4 contacts the trolley wire T and the load cell 35 detects a specified contact load, the push-up device 5 stops the contact plate 4. When the contact plate 4 contacts the trolley wire T, the voltage detector 11 of the voltage detection grounding unit 8 detects the voltage of the trolley wire T, and when no voltage is applied, when the button switch for grounding is pressed, the grounding contactor 10 is turned on, the trolley wire T and the rail R are conductive, and the trolley wire T is grounded. This ensures safety and allows construction work to begin. On the other hand, when a voltage is applied to the trolley wire T, the corresponding lamp lights up to call attention and prompt the user to take appropriate measures.
12(A) and 12(B), when the contactor 12 for detecting loss of contact is turned on, if the upward force of the contact plates 4, 4 against the trolley wire T is reduced and insufficient contact or separation occurs with the trolley wire T, the resistance meter 19 in the loss of contact detection unit 9 measures the resistance to detect this abnormality and turns on the corresponding lamp in the first lamp group 42. In response to this, when the corresponding switch for pushing up or pulling down in the switch group 44 is pressed, the upward force against the trolley wire T is adjusted and the contact plate 4 is restored to an appropriate contact state with the trolley wire T.
In addition, if the trolley wire T is in a grounded state and the rail clamp 16 comes off the rail R, causing insufficient attachment to the rail R or falling off, the resistance meter 22 in the clamp detachment detection unit 13 detects this abnormality by measuring the resistance, and lights up the corresponding lamp in the first lamp group 42 to issue a warning.
After the work is completed, the contactor 12 for detecting disconnection is turned OFF, and the corresponding button switch for removing the grounding device is pressed, which turns OFF the grounding contactor 10, and then when the corresponding button switch for pressing down the contact plate 4 is pressed, the contact plate 4 is lowered by the lifting device 5. Finally, the switch for the operating power supply is turned OFF, the operating door 45 is closed, the rail clamp 16 and the earth holder 21 are removed from the rail R, and the device is removed.

LIST OF SYMBOLS 1 Electrical detection grounding device 2 Cart 2a Frame body 2b Wheels 3 Main body 4 Contact plate 5 Push-up device 6 Control panel 7 Generator 8 Electrical detection grounding section 9 Line loss detection section 10 Ground contactor 11 Electrical detection device 11a Small resistor 11b Large resistor 11c Voltmeter 12 Line loss detection contactor 13 Clamp loss detection section 14 High voltage ground cable 15 Low voltage ground cable 16 Rail clamp 17 Cable cover 18 Line loss detection cable 19 Resistance meter 20 Clamp loss detection cable 21 Earth holder 22 Resistance meter 23 Housing cover 24 Motor 25 Belt 26 Drive pulley 27 Reducer 28 Chain coupling 29 Ball screw unit 29a Ball screw 29b Movable nut 30 Expandable arm 30a Arm piece 30b Arm piece 31a Lower end frame 31b Upper end frame 32 Linear bushing 33 Mounting plate 34 Insulator 35 Load cell 36 Lead wire 37 Housing 38 Main body door 39 Wiring board 40 Terminal board 41 Digital panel meter 42 First lamp group 43 Second lamp group 44 Switch group 45 Operation door R Rail T Trolley wire

Claims (1)

A voltage-detecting and grounding device comprising: a grounding contactor electrically connected between a contact wire and a rail of a railway track and opening and closing the contact wire to ground the contact wire to the rail; a voltage detector for detecting a voltage to ground of the contact wire; and a control device for controlling the contactor so as to enable a grounding operation of the grounding contactor for railway track construction when the voltage detector detects that no voltage is applied to the contact wire, and to disable the grounding operation of the grounding contactor when the voltage detector detects that a voltage is applied to the contact wire.
a pair of contact plates arranged at intervals in the extending direction of the contact wire and contacting the contact wire from below to electrically connect the grounding contactor and the voltage detector to the contact wire;
A contact wire grounding device comprising: a contact detection unit having a resistance measuring device that detects the electrical resistance between the contact plate and the contact wire due to contact and separation between the contact plate and the contact wire.

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