The present invention relates to a switch having an openable and closable contact inside a tank.
A known switch, which is installed in a substation or a switching station and has a contact movable between an open position and a closed position, includes a torsion bar as disclosed in Patent Literature 1. For such a switch, energy accumulated due to torsion applied to the torsion bar is used to open and close the contact.
Patent Literature 1: Japanese Patent No. 6239193
In some case, the contact of the switch should be opened and closed in a maintenance operation such as replacement of a fixed contact and a movable contact that define the contact. Generally, a torsion bar applies a biasing force to a movable contact. For this reason, it is not easy to move the movable contact against the biasing force. To address such a problem, it has been necessary to provide the switch with a large-scale operation mechanism.
The present invention has been made in view of the above, and an object of the present invention is to obtain a switch that allows a movable contact to be easily moved against a biasing force from a torsion bar.
To solve the above problem and achieve the object, a switch according to the present invention comprises: a tank; a fixed contact provided inside the tank; a movable contact provided inside the tank and capable of reciprocating between a position where the movable contact is in contact with the fixed contact and a position away from the fixed contact; an opening/closing shaft rotatably provided outside the tank, rotation of the opening/closing shaft moving the movable contact; a jack base fixed to an outer side of the tank; a torsion bar to store a force to rotate the opening/closing shaft so as to move the movable contact in a direction away from the fixed contact; and an opening/closing lever detachably attached to the opening/closing shaft, wherein the jack base has a first penetrating portion formed therethrough and facing the opening/closing lever, the opening/closing lever has a second penetrating portion formed therethrough and facing the jack base, and the switch further comprises: a bolt inserted through the first penetrating portion and the second penetrating portion; and a nut attached to a portion of the bolt, the portion of the bolt extending out of the first penetrating portion and the second penetrating portion.
A switch according to the present invention has the effect that the movable contact can be easily moved against the biasing force from the torsion bar.
Hereinafter, a switch according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment.
The tank 2 includes a tubular main body 21 and a lid 22 that covers an end of the main body 21. The inside of the tank 2 is a closed space. The tank 2 may be filled with an insulating gas, or may be filled with the same air as the outside air. Furthermore, the tank 2 may be evacuated.
A mounting seat 23 is provided on the lid 22. A housing of an operation device or a jack base is fixed to the mounting seat 23, as will be described later. The lid 22 and the mounting seat 23 are formed integrally with each other. A fixed contact 3 and a movable contact 4 are provided inside the tank 2. The fixed contact 3 is fixed to the inside of the tank 2 via an insulator (not illustrated).
The movable contact 4 is capable of reciprocating between a position where the movable contact 4 is in contact with the fixed contact 3 and a position away from the fixed contact 3. The movable contact 4 and the fixed contact 3, which form a circuit contact, can move into contact with and away from each other. The switch 1 is a three-phase separation type switch in which the circuit contact defined by the movable contact 4 and the fixed contact 3 are provided in each of the tanks 2a to 2c. The movable contact 4 moves in a direction perpendicular to the X-axis. The direction of the movement of the movable contact 4 is defined as a Y-axis direction. Furthermore, a direction perpendicular to the X-axis and the Y-axis is defined as a Z-axis direction.
The movable contact 4 is connected to a contact rod 5 extending through the lid 22 to the outside of the tank 2. The contact rod 5 passes through the lid 22 via the center of the tank 2. An opening/closing shaft 6 is provided outside the tank 2 in such a way as to rotate about a rotation axis parallel to the X-axis. The opening/closing shaft 6 is a rod-shaped member extending in a direction parallel to the X-axis.
The shaft first lever 7 and the contact rod 5 are connected to each other by a link mechanism 16. Since the shaft first lever 7 and the contact rod 5 are connected to each other by the link mechanism 16, the movable contact 4 moves in a direction in which the movable contact 4 comes into contact with the fixed contact 3 or in a direction away from the fixed contact 3, in accordance with the direction of rotation of the opening/closing shaft 6. Specifically, when the opening/closing shaft 6 rotates clockwise under the condition illustrated in
The shaft first lever 7 and the shaft second lever 8 are provided in correspondence to each of the movable contacts 4 provided in the tanks 2a to 2c. Therefore, the movable contacts 4 provided in the tanks 2a to 2c can be operated together by rotation of the opening/closing shaft 6. That is, rotating the opening/closing shaft 6 can open and close the circuit contacts provided in the tanks 2a to 2c.
The switch 1 includes a breaking torsion bar 9 which is a breaking spring. The breaking torsion bar 9 is a bar-shaped spring extending parallel to the X-axis. The breaking torsion bar 9 is twisted about a rotation axis parallel to the X-axis, thereby storing a force to return from the twisted position.
A breaking shaft 10 is connected to the breaking torsion bar 9. Rotating the breaking shaft 10 in
A breaking lever 11 is connected to the breaking shaft 10. The breaking lever 11 rotates together with the breaking shaft 10. The breaking shaft 10 and the breaking lever 11 are connected to each other by a breaking rod 12. Since the breaking shaft 10 and the breaking lever 11 are connected to each other by the breaking rod 12, the shaft second lever 8 can be rotated in accordance with the direction of rotation of the breaking shaft 10.
That is, rotation of the breaking shaft 10 can move the movable contact 4 connected to the breaking shaft 10, via the shaft second lever 8, the opening/closing shaft 6, the shaft first lever 7, and the contact rod 5. As described above, a force to rotate the breaking shaft 10 clockwise is applied to the breaking shaft 10, and thus a force is applied to the movable contact 4 in the direction away from the fixed contact 3.
The switch 1 includes a closing torsion bar 13 which is a closing spring. As with the breaking torsion bar 9, the closing torsion bar 13 is twisted about a rotation axis parallel to the X-axis, thereby storing a force therein. The switch 1 includes a linkage mechanism that links the operation of the breaking torsion bar 9, the operation of the closing torsion bar 13, and the operation of the movable contact 4 with one another. Note that illustration of the linkage mechanism is omitted. Release of the force stored in the closing torsion bar 13 causes the movable contact 4 to move in such a direction as to come into contact with the fixed contact 3. The contact of the movable contact 4 with the fixed contact 3 closes the circuit contact. When the force stored in the closing torsion bar 13 is released, the linkage mechanism uses the released force to thereby twist the breaking torsion bar 9, so that a force is stored in the breaking torsion bar 9. Thereafter, the force stored in the breaking torsion bar 9 is released to thereby move the movable contact 4 in the direction away from the fixed contact 3. The movement of the movable contact 4 away from the fixed contact 3 opens the circuit contact.
In the present embodiment, the force stored in the breaking torsion bar 9 is not completely released with the circuit contact open. That is, with the circuit contact open as illustrated in
The switch 1 includes a housing 14 that accommodates therein the breaking shaft 10, the breaking lever 11, the breaking rod 12, and the linkage mechanism (not illustrated). The breaking shaft 10, the breaking lever 11, the breaking rod 12, the linkage mechanism (not illustrated), and the housing 14 define an operation device 15 that moves the movable contact 4. The housing 14 is fixed through bolts (not illustrated) to the mounting seat 23 provided on the lid 22 of the first tank 2a and the mounting seat 23 provided on the lid 22 of the second tank 2b.
In some case, maintenance such as replacement of the movable contact 4 and the fixed contact 3 is performed in the switch 1. In some case, the movable contact 4 should be moved when maintenance is performed. Such a case is, for example, where it is necessary to check an operation of the movable contact by moving the movable contact 4 to open and close the circuit contact. Since the force is stored in the breaking torsion bar 9 even after the circuit contact is opened as described above, it may be difficult to manually move the movable contact 4 against such a force. To address this problem, the present embodiment provides the switch 1 with an operation unit that allows the movable contact 4 to be manually moved with ease.
Next, the operation unit will be described. The operation unit includes a jack base 31, an opening/closing lever 32, an opening/closing bolt 33, a jack adapter 34, a lever adapter 35, a thrust bearing 36, and an opening/closing nut 37.
The jack base 31 is fixed through a bolt (not illustrated) to the mounting seat 23 provided on the lid 22 of the third tank 2c. As illustrated in
It is possible to attach the opening/closing lever 32 to the end of the opening/closing shaft 6 by inserting the protrusion 6a formed at the end of the opening/closing shaft 6 into the through hole 32e of the opening/closing lever 32. It is possible to rotate the opening/closing shaft 6 by rotating the opening/closing lever 32 with the protrusion 6a fitting in the through hole 32e.
The penetrating portion 31c formed through the jack base 31 faces the opening/closing lever 32 attached to the end of the opening/closing shaft 6. Furthermore, the penetrating portion 32c formed through the opening/closing lever 32 faces the jack base 31 with the opening/closing lever 32 attached to the end of the opening/closing shaft 6.
As illustrated in
The jack adapter 34 has a cylindrical shape. An abutment surface 34a is formed on the outer peripheral surface of the jack adapter 34 such that the abutment surface 34a abuts on the jack-side recesses 31d of the jack base 31 along the shapes of the jack-side recesses 31d. The abutment surface 34a is an arc surface as with the jack-side recesses 31d. The abutment between the abutment surface 34a and the jack-side recesses 31d, which is an abutment between the arc surfaces, allows the jack adapter 34 to change its posture such that the jack adapter 34 rotates about the central axis of the arc surface.
A step is formed on the inner peripheral surface of the jack adapter 34. Thus, a through hole 34b formed through the jack adapter 34 has a diameter smaller on a side of the jack base 31 than on a side opposite to the jack base 31.
As illustrated in
The lever adapter 35 has a cylindrical shape. A abutment surface 35a is formed on the outer peripheral surface of the lever adapter 35 such that the abutment surface 35a abuts on the lever-side recesses 32d of the opening/closing lever 32 along the shapes of the lever-side recesses 32d. The abutment surface 35a is an arc surface as with the lever-side recesses 32d. The abutment between the abutment surface 35a and the lever-side recesses 32d, which is an abutment between the arc surfaces, allows the lever adapter 35 to change its posture such that the lever adapter 35 rotates about the central axis of the arc surface. A through hole 35b is formed through the lever adapter 35.
The thrust bearing 36 has an annular shape. As illustrated in
The opening/closing bolt 33 has the head 33a and a shaft 33b. With the head 33a of the opening/closing bolt 33 located on a side of the opening/closing lever 32, the shaft 33b of the opening/closing bolt 33 is inserted through the penetrating portion 32c of the opening/closing lever 32 and the penetrating portion 31c of the jack base 31. As illustrated in
The opening/closing nut 37 is attached to the shaft 33b of the opening/closing bolt 33.
Tightening the opening/closing nut 37 on the shaft 33b of the opening/closing bolt 33 by using a tool such as the ratchet 38 rotates the opening/closing lever 32 such that the lever-side recesses 32d of the opening/closing lever 32 approach the jack base 31. At this time, a compressive force is applied to the flange 37a of the opening/closing nut 37 and the jack adapter 34, but the opening/closing nut 37 can be smoothly rotated as the thrust bearing 36 is sandwiched therebetween.
Use of a tool such as the ratchet 38 to tighten the opening/closing nut 37 provides a larger force to bring the movable contact 4 into contact with the fixed contact 3 than in moving the movable contact 4 without using a tool or the like. Thus, it is possible to easily move the movable contact 4 against the force applied to the movable contact 4 from the breaking torsion bar 9. Furthermore, a simple structure, which attaches the jack base 31 and the opening/closing lever 32 to the mounting seat 23 and the opening/closing shaft 6, can achieve space saving and cost reduction without requiring a large-scale operation mechanism.
Meanwhile, when the opening/closing nut 37 is loosened, the distance between the head 33a of the opening/closing bolt 33 and the opening/closing nut 37 increases, where, due to a force stored in the breaking torsion bar 9, a force to rotate the opening/closing shaft 6 counterclockwise in
When the maintenance is completed, the opening/closing lever 32 and the jack base 31 can be removed to restore the switch 1 to the normal operating state. If the opening/closing lever 32 remains attached to the opening/closing shaft 6, the moment of inertia of the opening/closing shaft 6 increases, and the rotation speed of the opening/closing shaft 6 decreases during normal operation. This may reduce the moving speed of the movable contact 4. The switch 1 requires the high-speed closing and high-speed breaking of the circuit contacts. In the first embodiment, the opening/closing lever 32 can be removed from the opening/closing shaft 6 except during maintenance. It is therefore possible to prevent the moving speed of the movable contact 4 from decreasing due to an increase in the moment of inertia.
Furthermore, in the first embodiment, the mounting seat 23 provided on the lid 22 of the tank 2 is used for fixing the housing 14 of the operation unit and the jack base 31, as illustrated in
Furthermore, as illustrated in
As illustrated in
Note that although the first embodiment has been described providing an example in which the opening/closing lever 32 is attached to the end of the opening/closing shaft 6, the present invention is not limited thereto. For example, referring back to
The configuration described in the above embodiment exemplifies the subject matter of the present invention, and can be combined with another known technique, and omissions and changes can also be made to a part of the configuration without departing from the gist of the present invention.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2018/018191 | 5/10/2018 | WO | 00 |