JPH0155527B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switching switch for a load tap changer, and in particular to a load tap switch equipped with a mechanical locking protection device suitable for protecting a rotary type resistor switching switch from early switching operation congestion. Regarding a switching switch for a switching device.

Conventionally, this type of switching switch is broadly classified into a reactor type and a resistance type. Since the resistive switching switch has a compact structure, there has recently been a strong demand for switching to this type of switch. This resistance type switching switch is classified into a type using a four-bar linkage mechanism and a rotary type, but the rotary type is preferable because it has a small interrupting duty and is advantageous in terms of life.

The configuration of a conventional rotary resistance switching switch is as follows:
A shaft that rotates reversibly is provided at the center, a movable contact is disposed on this shaft, and a blocking portion is provided in which a fixed contact is disposed within an insulating cylinder facing the movable contact. FIG. 1 shows the basic structure of a quick-cut drive device that is directly connected to the central axis of the reversibly rotating interrupting section of the rotary switching switch. Reference numeral 1 designates a quick-cut drive shaft that is directly connected to the center shaft of the cut-off section that rotates reversibly and is driven in the direction of the arrow. This quick cutting drive shaft 1 includes an electric drive shaft 2, a crank connector 3, a main lever 4 whose one end (point O) is rotatably attached,
A mechanism consisting of a drive spring 5, a quick cut lever 6, etc. performs a quick cutting operation.

When the electric drive shaft 2 is rotated, the main lever 4 is pulled clockwise in FIG. The installed drive spring 5 is energized. When the line connecting both ends of the drive spring 5 crosses the quick cutting drive shaft 1 (crosses the dead center),
The quick cut lever 6 starts rotating counterclockwise, rapidly rotates through a predetermined rotation angle, drives the movable contact of the above-mentioned cutoff part connected to the quick cut drive shaft 1, and completes the current switching operation. It's getting old. In the next operation, as in the previous operation, the drive spring 5 is biased by the rotation of the main lever 4, and the quick-cut drive shaft 1 is rapidly driven counterclockwise via the quick-cut lever 6.

As mentioned above, in the conventional quick cutting drive device, the quick cutting operation is driven by the stored force of the drive spring 5.
Once the quick cutting operation is started, the quick cutting lever 6 is rotated regardless of the operation of the electric drive shaft 2 to perform the quick cutting operation. However, when switching the shutoff section tap, the early cut drive section or the operating section of the shutoff section that is driven for quick cut,
If a problem such as stiffness or broken drive spring occurs, the switch will be unable to perform normal current switching operations. In this way, when the next tap switching operation starts from a state in which the switching switch's early switching operation is jammed, it is driven by the electric drive shaft 2 provided in the same oil tank as the transformer body.
The load current is cut off in the tap selector of the cut-off section, which normally switches taps in a no-current state (no-arc state).This causes a short circuit between the taps due to continued arcing, which progresses and transforms. There is a possibility of a serious accident occurring that could spread to the main body of the device.

Therefore, as a protection device against early cutting traffic jams, conventionally, the
Publications, etc. have been proposed. In these conventional examples, a cam having one notch groove is provided in a part of the electric drive shaft, a pair of locking levers with protrusions are provided to clamp the cam, and the locking lever portion and the quick-cutting lever are connected. The intermediate part of the switch is connected by a rotatable connecting lever, and in the unlikely event that the quick-cutting operation of the switching switch becomes jammed when switching taps, that is, if the quick-cutting lever does not operate at all, or if it stops mid-operation, The connecting lever that interlocks with the quick-cut lever does not operate, and the protrusion of the locking lever and the notch of the cam provided on the electric drive shaft connect, mechanically locking the next tap switching operation. The lock protection device is configured to do so.

In such a case, the mechanical locking device should be installed in an electric drive shaft section that is separate from the quick-cut drive section (see Figure 1).
This not only makes the electric drive shaft larger and more complex, but also increases the height dimension of the electric drive shaft. Therefore, the dimension in the height direction of the connected early cutting drive mechanism inevitably increases, resulting in a drawback that the device becomes larger. In addition, since the electric drive shaft and the quick-cut drive mechanism are generally constructed separately, when lifting the quick-cut drive during normal inspection, the connecting lever that connects the quick-cut lever and the locking lever should be removed. Because it is necessary to remove
This will complicate the inspection work and may reduce the credibility of the on-site inspection work.

The object of the present invention is to overcome the above-mentioned drawbacks and to provide a changeover switch for a tap changer on load, which is small in size, simple in structure, and highly reliable, and is equipped with a mechanical locking protection device for protecting against traffic jams with early switching action. Our goal is to provide the following.

The present invention provides two main levers, one end of which is rotatably fixed to a fixed shaft, and an intermediate part of which is connected to an electric drive shaft via a crank connector.
A cam is formed with notched grooves at certain points, the middle part is rotatably supported by the fixed shaft, one end is connected to the other end of the main lever by a drive spring, and the other end is connected to the quick cutting drive shaft. A quick-cutting lever equipped with a driving force transmission means is provided with a projection for locking and unlatching, one end is rotatably supported by a pin planted in the base, and a pair of locking levers is provided with a projection on the other end. , the cam formed on the main lever is arranged so as to clamp the cam, and when the fast cutting operation is jammed, the engagement between the locking protrusion and the locking lever is disengaged, and the notch groove formed on the cam of the main lever is disengaged. The above object is achieved by engaging the locking lever protrusion to prevent the switching operation.

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 2 and 3 are a plan view and a side view showing a quick cut drive device which is a main part of an embodiment of the on-load tap changeover switch according to the present invention. Main lever 7
is rotatably supported at one end by a fixed shaft 9 fixed to the base 8. A cam 11 having cutout grooves 10A and 10B is formed in the rotational center of the main lever 7, and the main lever 7 has an intermediate portion rotatably connected to one end of a crank connector 12. The other end of the crank connector 12 is rotatably connected to a drive lever 14 fixed to an electric drive shaft 13. The electric drive shaft 13 is directly connected to the electric operation device 15. When the electric drive shaft 13 rotates, the drive lever 1
4 and crank connector 12, the main lever 7 is driven.

The quick cut lever 16 has an intermediate portion rotatably supported by the fixed shaft 9, and one end of the quick cut lever 16 and
A drive spring 17 is installed between one end of the main lever 7 and is always biased in the direction of contraction. Also, the rotation center of this quick cut lever 16 and the drive spring 1
At the intermediate portion between the end portion 7 and the end portion 7, there are protrusions 18A and 18B for hanging and unlatching protruding on both sides.
Furthermore, a roller 1 is attached to the other end of the quick cut lever 16.
9 is attached, and this roller 19 is loosely fitted into a notched groove 21 of a driving force transmitting lever 20. Stopper pins 22 are arranged on both sides of the lever 20 to restrict its rotation range. Further, the driving force transmission lever 20 is fixed to one end of a quick cutting drive shaft 23 that is rotatably supported by the base 8, and the other end of this quick cutting drive shaft 23 is configured to transmit rotational force to the blocking part 24. It's getting old. Note that the roller 19 and the notch groove 21 of the lever 20 are engaged with each other with an appropriate amount of play.

The locking levers 25A, 25B are rotatably supported by pins 26A, 26B fixed to the base 8 at one end. These locking levers 25A,
Locking protrusions 27A and 27B are provided at the other end of 25B, and these protrusions are arranged to face the cam 11 provided at the center of rotation of the main lever 7. In addition, locking levers 25A, 25
In the middle of B is a spring 2 that is always biased in the direction of contraction.
A pair of locking levers 25A and 25B clamp the cam 11 by means of the spring 28. These locking levers 25A, 2
In the middle part of 5B, there are hanging pins 29A, 29B.
is provided, and either one of these pins 29A, 29B, that is, the notch groove 10A or 1 of the cam 11
0B and the locking pin on the opposite side of the locking protrusion 27A or 27B are engaged with the locking and unlatching protrusion 18A or 18B provided on a part of the quick-cutting lever 16 in the normal state. The notch grooves 10A, 10B for locking and the protrusions 27A, 27B for locking are configured so as not to engage with each other.

Next, the operation of this embodiment will be explained. The main lever 7 is a drive lever 1 directly connected to an electric drive shaft 13.
4 rotates counterclockwise, and the drive spring 1
Save up 7. When the drive spring 17 passes the dead center, the early cut lever 16 starts rotating clockwise. However, due to the predetermined play in the cutout groove 21 of the driving force transmission lever 20, this rotational force does not operate immediately, and the roller 19 of the quick cut lever 16
engages with the notched groove 21 for the first time in a state where the rotational speed and driving force are increased to some extent, causing the quick-cut drive shaft 23 to rapidly rotate clockwise. This quick cutting action allows
The locking protrusion 18B of the quick-cutting lever 16 engages with the locking pin 29B and operates to push and expand the locking lever 25B outward, and the locking protrusion 18B and the notch groove 10B provided on the cam 11 engage with the locking pin 29B. 27B so as not to engage with each other.

In the unlikely event that a malfunction occurs such as the fast-cut drive unit or the operating part of the cut-off part that is driven to fast-cut becomes stiff or the drive spring breaks, the tap switching operation will start from the state shown in Figure 2. Even when the main lever 7 is driven counterclockwise and the drive spring 17 has passed the dead center, the quick-cut lever 16 does not start operating and remains in its original state, but there is a traffic jam in the middle of the operation. do. In this case, the unlatching pin 29B and the unlatching protrusion 18B of the quick cut lever 16 do not engage, so the notch groove 10B provided in a part of the main lever 7 that is electrically driven and rotated counterclockwise. Then, the locking protrusion 27B of the locking lever 25B falls into engagement. When the next tap switching operation is started from this state, the main lever 7 starts rotating clockwise. However, as described above, due to the engagement between the locking notch 10B and the locking protrusion 27B, the switching operation is prevented, and the electric drive shaft 13 is locked via the crank connector 12 and the drive lever 14. Even if the above-mentioned problem occurs, the interrupter 2
Load current interruption at tap selector No. 4 can be prevented.

According to this embodiment, at the center of rotation of the main lever 7,
A cam 11 having notched grooves 10A and 10B is provided,
A pair of locking levers 25A, 25B having one end rotatably supported by pins 26A, 26B and having locking protrusions 27A, 27B at the other end are arranged so as to clamp the cam 11, and further , the pin 2 of the locking levers 25A and 25B is attached to the quick-cut lever 16.
9A, 29B and engaging protrusion 18A,
18B, the locking projection 27B is engaged with the cutout groove 10B provided in the cam 11 to prevent the switching operation, thereby mechanically protecting the blocking portion 24 when the early switching operation is congested. It is effective to do so. Further, the mechanical lock protection device of this embodiment includes a cam 11 having notch grooves 10A and 10B,
A pair of locking levers 25A, 25B having locking protrusions 27A, 27B, these locking levers 25
A and 25B are configured by a spring 28 for clamping the cam and 11, and locking and unlatching protrusions 18A and 18B provided on the quick cut lever 16,
It is provided on the side of the complete quick cutting drive device, and the cam 1
1 to a part of the main lever 7, a protrusion 18A for hooking and unhooking,
18B is provided in a part of the quick-cutting lever 16, compared to a conventional quick-cutting drive unit that does not have a lock protection device, there is no element that increases the size, so it is small and has a structure. This has the effect of providing a mechanical locking protection device for protecting against traffic jams that is simple and highly reliable. Therefore, it is easy to inspect the protection device on-site, and as mentioned above, the dimensions are almost the same as conventional devices, so there is no compatibility with existing products that do not have a lock protection device. It can be easily replaced with the early cut drive unit with lock protection device of this embodiment without damage.

As described above, according to the present invention, there is provided a switching switch for an on-load tap changer, which is small in size, has a simple structure, and is equipped with a mechanical locking protection device for early switching operation and protection against traffic congestion. be able to.

[Brief explanation of drawings]

Figure 1 is a perspective view showing an example of the structure of a conventional quick-cut drive device for a switch for a tap changer on load;
The figure is a plan view showing the structure of a quick-cut drive unit, which is a main part of an embodiment of the on-load tap changer switching switch of the present invention, and FIG. 3 is a partially sectional side view of FIG. 2. . 7... Main lever, 8... Base, 9... Fixed shaft, 10A, 10B, 21... Notch groove, 11...
Cam, 12...Crank connector, 13...Electric drive shaft, 16...Quick cut lever, 17...Drive spring, 18A, 18B...Protrusion for hanging, 19...
Roller, 20... Lever for driving force transmission, 23...
Early cutting drive shaft, 25A, 25B...Lock lever,
26A, 26B...pin, 27A, 27B...locking protrusion, 28...spring.

Claims (1)

[Claims] 1 A quick-cut drive shaft of a switching switch, a driving force transmission lever fixed to the drive shaft and provided with a notched groove, and a roller that engages with the notched groove and separated from the quick-cut drive shaft by a predetermined distance. a quick cut lever that is movably supported on a fixed shaft and rotates at a predetermined angle; a main lever that is movably supported on the fixed shaft and interlocked with an electric drive shaft; and one end of each of the quick cut lever and the main lever is supported at all times. A switching switch for a tap changer under load, comprising a drive spring that is biased in a retraction direction, and equipped with a quick-cut drive device that stores energy in the drive spring by rotation of the main lever to rapidly drive a quick-cut drive shaft, A cam with a notched groove is provided at the center of rotation of the main lever, and a pair of locking levers, one end of which is movably supported by a pin planted in the base and the other end of which has a protrusion, are arranged so as to clamp the cam. A changeover switch for a tap switch under load, characterized in that a part of the quick-cutting lever is provided with a protrusion for locking and unlatching so as to engage with a part of the locking lever during normal quick-cutting operation. .