Patent Application
20100089874
The present application claims priority from Japanese patent application serial No. 2008-264746 filed on Oct. 14, 2008, the content of which is hereby incorporated by reference into this application
1. Field of the Invention
The present invention relates to a switchgear and more specifically relates to a switchgear that enhances a manipulability and safety for a manual disconnecting switch or a manual grounding switch of which open and close operation is performed by inserting a handle.
2. Description of the Related Art
Generally, an interlock device is provided each between a disconnecting switch and an grounding switch or between a circuit breaker connected on the same circuit thereof for ensuring safety, and the interlock device is required to be simple, easy to manipulate and highly reliable as much as possible.
A conventional interlock device with a manual manipulation mechanism, as disclosed, for example, in JP-A-62-262608, is provided with a solenoid for locking a shutter for open and closing a handle insertion hole and is constituted to excite the solenoid under a condition that safety is ensured to release the lock of the shutter. Further, in such interlock device, the solenoid is locked in a non-excited state in case of the control power source failure based on safety priority concept.
However, in the conventional art as above, in a site where an electric power can be used for the first time after a concerned switchgear receives an electric power, the interlock may forcedly be released, therefore, it was necessary to provide a separate countermeasure therefore. Further, because of the electrical interlock, other than the solenoid reliability for wirings, switches and the like connected to the solenoid is required in addition.
An object of the present invention is to provide a switchgear with a mechanical interlock that resolves the above problems, is simple and enhances reliability.
In order to achieve the above object, a switchgear of the present invention is characterized by being provided with a selection mechanism at a front face of the switchgear for manipulating a circuit breaker or a manual disconnecting switch, and is characterized in that the selection mechanism is mechanically coupled with a shutter provided for a manipulation handle insertion hole for the manual disconnecting switch and when disconnection is selected by the selection mechanism, the shutter is permitted to be opened.
Further, in order to achieve the above object, a switchgear of the present invention is characterized by being provided with a selection mechanism at a front face of the switchgear for manipulating a circuit breaker, a manual disconnecting switch or an grounding switch, and is characterized in that the selection mechanism is mechanically coupled with shutters provided for manipulation handle insertion holes for the manual disconnecting switch and the manual grounding switch and when disconnection or grounding is selected by the selection mechanism, the corresponding shutter is permitted to be opened.
Further, in the present invention as indicated above, the following measures are applied. Only when circuit break is selected by the selection mechanism, a circuit closing command for the circuit breaker is accepted. More specifically, a switch is provided that is turned ON when circuit break is selected by the selection mechanism, and the circuit closing command is provided to the circuit breaker via the switch. Further, the switchgear is constituted in such a manner that when the circuit breaker is in a circuit closed state, the selection mechanism and a link mechanism for the circuit breaker interfere to prevent the selection mechanism from being manipulated.
The switchgear is constituted in such a manner that when the shutter provided for the manipulation handle insertion hole for the manual disconnecting switch or the manual grounding switch is opened, the selection mechanism and the shutter interfere to prevent the selection mechanism from being manipulated. Further, the switchgear is constituted in such a manner that when the manual grounding switch is in a closed state, the selection mechanism and a link mechanism for the manual grounding switch interfere to prevent the selection mechanism from being manipulated.
Further, the switchgear of the present invention is constituted in such a manner that under a state where circuit break is selected by the selection mechanism, unless the manual disconnecting switch is opened, the selection mechanism is not permitted to select grounding. The switchgear of the present invention is constituted in such a manner that under a state where grounding is selected by the selection mechanism, unless the manual disconnecting switch is closed, the selection mechanism is not permitted to select circuit break.
According to the present invention, a switchgear with a mechanical interlock can be provided that is simple and enhances safety and reliability.
Herein below, an embodiment of the present invention will be explained with reference to
Further, a selection mechanism 7 for selecting manipulation for circuit break, disconnection and grounding, push button switches 8 and 9 for closing and opening of a circuit breaker, a manipulation handle insertion hole 20 used for disconnecting and a manipulation handle insertion hole 30 used for grounding are provided.
In the present embodiment, according to positions of a manipulation pin 12 for the selection mechanism 7, a machine and apparatus to be manipulated can be selected.
Namely, the positions orderly from right to left represent circuit break (CB), disconnection (DS) and grounding (ES), and the state illustrated in
More specifically, the followings are performed. Only when the manipulation pin 12 selects circuit break, the circuit closing operation of the circuit breaker is permitted. Further, in the case when the circuit breaker is in a circuit closed state, the manipulation pin 12 is mechanically locked and selection of other manipulations is prohibited. When the manipulation pin 12 selects disconnection, a shutter 21 used for disconnecting manipulation provided at the manipulation handle insertion hole 20 used for disconnecting is rendered openable.
Further, unless the shutter 21 used for disconnecting manipulation is closed, the manipulation pin 12 cannot be displaced. When the manipulation pin 12 selects grounding, a shutter 31 used for grounding manipulation provided at the manipulation handle insertion hole 30 used for grounding is rendered openable. Likely in the above, unless the shutter 31 used for grounding manipulation is closed, the manipulation pin 12 cannot be displaced.
Further, when the grounding switch is closed and the switchgear 1 is rendered in an grounded state, since the manipulation pin 12 is mechanically locked, the circuit breaker or the disconnecting switch is rendered inmanipulatable.
Further, under a state where the selection mechanism 7 selects circuit break, unless the state is rendered to disconnection, the movement of the manipulation pin 12 to the grounding side is prevented. Likely, when the selection mechanism 7 selects grounding, unless the state is rendered from disconnection to OFF state, the selection mechanism 7 cannot select circuit break.
According to the switchgear 1 of the present invention as has been explained hitherto, since the manipulation object is clarified by the selection mechanism 7, such is useful for preventing erroneous manipulation. Further, with the manipulation pin 12 of the selection mechanism 7, since a variety of interlocks required for the switchgear can be realized, safety and reliability of the switchgear are enhanced.
Now, a second embodiment of the present invention will be explained with reference to
The three phase components of the circuit opening and closing portion 50 are arranged in parallel in the depth direction of the drawing. The vacuum bulb 51 used for circuit braking and disconnecting is constituted by a U shaped vacuum vessel 49 and inside thereof two pairs of contacts are accommodated.
Movable conductors 54 and 55 are fixed together to a connection conductor 56 and are electrically insulated from the outside with a ceramic made insulating rod 57. A stationary conductor 58 at the right side of
On the other hand, a stationary conductor 61 at the back face side of the switchgear 1 is connected to a cable 63 via a feeder 62 at a load side. Namely, in this switchgear 1, an electric power is fed to the load through a route of the bus line 60-the feeder 59 at the bus line side-the stationary conductor 58-the movable conductor 54-the connection conductor 56-the movable conductor 55-the stationary conductor 61-the feeder 62 at the load side-the cable 63.
The movable conductors 54 and 55 and the connection conductor 56 operate as a unitary body. Herein below, the movable conductors 54 and 55 and the connection conductor 56 are inclusively called as a movable portion 70. A manipulation rod 63 connected to the insulation rod 57 is fixed to the vacuum vessel 49 via a bellows 67 so as to permit the movable portion 70 operable while being maintained in vacuum tight.
The movable portion 70 of the vacuum bulb 51 used for circuit breaking and disconnecting stops at three positions, namely, at an ON position Y1 for feeding an electric power to a load, an OFF position Y2 for interrupting a current and a disconnecting position Y3 for ensuring an insulation performance for protecting workers from lightning surges.
A stationary conductor 64 of the vacuum bulb 52 used for grounding is fixed to the feeder 62 at the load side. In an instance such as during inspection that requires an grounding work, a movable conductor 65 that is grounded to E is contacted to the stationary conductor 64. Further, Numeral 66 is a capacitor and is used for a voltage detection to judge whether the load is applied of any voltage or of no voltage.
Now, a manipulation mechanism of the present switchgear 1 will be explained with reference to
The manipulation mechanism is constituted by an electromagnet 80 for driving the movable portion 70 of the vacuum bulb 51 used for circuit breaking and disconnecting between ON position Y1-OFF position Y2, the manual manipulation mechanism 100 used for disconnecting for driving between OFF position Y2-disconnecting position Y3 and the manual manipulation mechanism 120 used for grounding for manipulating the vacuum bulb 52 used for grounding.
The movable portion 70 of the vacuum bulb 51 used for circuit breaking and disconnecting is coupled to a lever 82 fixed to a first main shaft 81. Further, to the first main shaft 81 a lever 83 is fixed that is connected to the electromagnet 80 via a coupling metal part 84. Namely, with respect to the vacuum bulb 51 used for circuit breaking and disconnecting, when the first main shaft 81 is rotated in clockwise direction, the closing operation is performed and when rotated in anti clockwise direction the opening operation is performed.
Further, the intermediate steel plate 86 and the permanent magnet 89 are formed in annular shapes so as to permit a T shaped movable core 91 to pass through inside thereof. When the coil 89 is excited, the movable core 91 is attracted to the center core 88. At this moment, the movable core 91 is driven downward in the drawing and the vacuum bulb 51 used for circuit breaking and disconnecting is closed and the movable portion 70 stops at ON position Y1.
Further, in the closed state, since an interruption spring 95 and a contact pressing spring 96 providing a contacting force to the contacts are placed in an energized state, it is necessary to provide some measure for enduring the reaction force.
The magnetic fluxes of the permanent magnet 90 circulate through a route of the permanent magnet 90-the T shaped movable core 91-the central core 88-the bottom steel plate 85 the steel tube 87-the intermediate steel plate 86-the permanent magnet 90, and an attraction forces is generated between the permanent magnet 90-the movable core 91 and between the movable core 91-the central core 88. In this closed state, this attraction force endures the above reaction force and the energized state of the interruption spring 95 and the contact pressing spring 96 is maintained.
For the opening operation, the coil 89 is excited in the opposite direction as that of the closing operation, namely, is excited in the opposite direction to the fluxes of the permanent magnet 90. Through the excitation in the opposite direction, the magnetic force induced by the permanent magnet 90 is reduced, and the movable portion 70 is driven toward the opening direction by the force due to the interruption spring 95 and the contact pressing spring 96.
Herein, the roller 101 is fixed to a blade 103 rotating around a shaft 102 via a pin 104. Through abutting of the pin 112 with the roller 101, although the blade 103 tends to rotate in clockwise direction, since the rotation is prevented through an interference of the roller 101 with a first stopper pin 105, the opening state is maintained.
Further, one end of a coiled spring 106 that is disposed in a manner to wind around the shaft 102 is fixed to the blade 103 and the other end thereof is fixed to a frame 107. This is for keeping the roller 101 to stop at the position as shown in
In the disconnection operation, a manipulation handle 108 used for disconnecting is inserted through the manipulation handle insertion hole 20 for disconnecting, is coupled to a pin 109 of the blade 103 and rotates the blade 103 in anti clockwise direction. After rotating the same slightly, and when a dead point where the pin 112, the pin 104 and the shaft 102 align on a straight line is exceeded, the first main shaft 81 and the blade 103 are rotated in anti clockwise direction by the force of the interruption spring 95.
Further, since the manipulation handle 108 used for disconnecting is operated in such a manner to jump up the pin 109 using the front face panel 2 as a fulcrum, there is no fear to suffer by the impacting force during the disconnection operation.
This operation will be explained with reference to
This manipulation is performed slowly while energizing the interruption spring 95. When the state as shown in
Now, an operation of the vacuum bulb 52 for grounding will be explained with reference to
A manipulation handle 121 for grounding is inserted through the insertion hole 30 to a handle receiving metal fitting 122. When the manipulation handle 121 for grounding is manipulated downward as in
At this moment, a pin 124 provided at the handle receiving fitting 122 interferes with a member 125 that rotates around the shaft 123, thereby, the member 125 also begins to rotate in clockwise direction. One end of a toggle spring 126 is connected to the member 125 and the other end thereof is connected to a blade 128 that rotates around a shaft 127.
Therefore, with the above operation, the toggle spring 126 is gradually compressed, and finally when a dead point where the shaft 123, a pin 129 that couples the member 125 and the toggle spring 126, a pin 130 that couples the toggle spring 126 and a blade 128 and the shaft 127 align on one straight line is exceeded, the second main shaft 132 is driven in the rotating direction by the energized force in the toggle spring 126. As a result, the movable conductor 65 of the vacuum bulb 52 for grounding is moved upward, namely closed (
In the opening operation, as shown in
When the dead point where the shaft 123, the pin 129 that couples the member 125 and the toggle spring 126, the pin 130 that couples the toggle spring 126 and the blade 128 and the shaft 127 align on one straight line is exceeded, the opening operation is performed, namely, the state as shown in
Further, during the opening operation since almost no energy is stored in the toggle spring 126, the operation is performed only depending on the interruption spring 137 and the contact pressing spring 138.
Herein below, an interlock device that is the gist of the present invention will be explained.
The selection mechanism 7 is constituted primarily by a panel 150 and a rod 151. To the panel 150 a rectangular member 152 is attached and the rod 151 passes through the bottom and top of the member 152.
Further, a return spring 154 is caught and held between the member 152 and the rod 151. At the side face of the rod 151 the manipulation pin 12 is fixed, and the manipulation pin 12 passes through an elliptical hole 153 provided at the panel 150. The panel 150 is only movable in the width direction of the switchgear 1 along rails 155 (
Further, to the rod 151, a first interlock pin 157 that interferes with the electromagnet 80 and the coupling metal part 84 of the first main shaft 81 and a second interlock pin 158 that interferes with the manual manipulation mechanism 120 for grounding and the coupling metal part 135 of the second main shaft 132 are fixed.
Further, at the upper tip end of the rod 151, a reversed C shape metal part 156 that couples with members for locking the shutters provided for the manipulation handle insertion hole 20 for disconnecting and the manipulation handle insertion hole 30 for grounding.
The front face panel 2 is provided with strips shaped (E shaped) groove 160, and the manipulation pin 12 passing through the groove 160 is constituted to be movable along the groove 160. Since the rod 151 is always forced downward by the return spring 154, the manipulation pin 12 stably positions respectively at circuit break position CB, disconnection position DS or grounding position ES.
Herein, it is implied that at the CB position the electromagnet 80, at the DS position the manual manipulation mechanism 100 for disconnecting and at the ES position the manual manipulation mechanism 120 for grounding are respectively manipulatable.
From the above, the following three kinds of interlocks are realized; “Only when circuit break is selected by the selection mechanism, the circuit breaker can be closed”, “During manual manipulation for disconnecting or grounding an electrical control for the manipulation mechanism is disabled” and “In a state where the circuit breaker is closed, a manipulation for disconnecting or grounding is rendered impossible.”
However, due to the interference between a tip end bent portion 162 of the first interlock pin 157 and the coupling metal part 84, a movement of the manipulation pin 12 to the ES position is prevented. Namely, an interlock “After disconnecting manipulation, an grounding manipulation is enabled” is realized.
When the manipulation pin 12 moves to the DS position, a first shutter lock metal part 163 for locking the shutter 21 for manipulating disconnection provided at the manipulation handle insertion hole 20 for disconnecting couples with the inverted C shape metal part 156 at the upper part of the rod 151 (
Further, under the state where the shutter 21 for manipulating disconnection is opened, even when the manipulation pin 12 is forced to move upward, such movement is prevented through the interference between the shutter 21 for manipulating disconnection and the first shutter clock metal part 163. Namely, an interlock “Only when disconnection is selected by the selection mechanism, the disconnecting operation can be performed” can be realized.
When the manipulation pin 12 is moved toward the ES position, the inverted C shape metal part 156 at the upper part of the rod 151 is released from the coupling with the first shutter lock metal part 163 for locking the shutter 21 for manipulating disconnection and is coupled with a second shutter lock metal part 171 for locking the shutter 31 for manipulating grounding as shown in
Under this condition, the second shutter lock metal part 171 is moved downward and when the manipulation pin 12 is moved downward to the ES position, the coupling between the shutter 31 for manipulating grounding and the second shutter lock metal part 171 is released and the shutter 31 for manipulating grounding becomes openable (
Further,
Further, as shown in
As has been explained hitherto, with the switchgear 1 of the present invention, since a manipulation object is clarified by the selection mechanism 7, erroneous manipulations by workers can be prevented. Further, with the manipulation pin 12 of the selection mechanism 7, a variety of interlocks required for the switchgear can be mechanically realized, and safety and reliability are enhanced.
According to the present invention, with the manipulation pin at the front face panel, since a variety of interlocks can be mechanically realized, a switchgear of inexpensive and enhanced reliability can be provided.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-264746 | Oct 2008 | JP | national |
