JP4364681B2 - Switching switch for vacuum valve load tap changer - Google Patents

Description

  The present invention relates to a switching switch used in a vacuum valve type on-load tap switching device.

  As a vacuum valve type load tap switching device, as shown in Patent Document 1, tap switching is performed by using a switching switch composed of three vacuum valves and one current limiting resistor. In addition, as shown in Patent Document 2, there are various types of devices such as a tap switch using a switching switch composed of two vacuum valves and a changeover switch and a current limiting resistor. Are known.

  FIG. 5 shows, as an example, an electrical configuration of an on-load tap switching device that performs tap switching using a switching switch composed of two vacuum valves and a changeover switch and a current limiting resistor. , Wm is a main winding of the transformer, Wt is a tap winding connected in series with the main winding, and T1 is an odd tap t1, t3, t5,... Provided in the tap winding Wt. An odd tap selector T2 is an even tap selector that selects even taps t2, t4, t6,... Provided in the tap winding Wt.

  Ma is a first vacuum valve that opens and closes a load current flowing through the tap selectors T1 and T2 when the tap is switched. One end of the vacuum valve Ma is connected to a neutral point N of the transformer, and the other end is a changeover switch SW. Are selectively connected to the odd tap selector T1 and the even tap selector T2.

  r is a current limiting resistor for limiting a short-circuit current between taps when the tap is switched, Mb is a second vacuum valve for turning on and off the current limiting resistor r, and one end of the second vacuum valve Mb is a neutral point. N is connected to the other end, and the other end is connected to the odd tap selector T1 through the current limiting resistor r.

  In this tap switching device, there is provided a switching switch for switching load current from one of the adjacent taps selected by the tap selectors T1 and T2 to the other in the tap switching process by the vacuum valves Ma and Mb and the selector switch SW. It is configured.

  In the on-load tap switching device shown in FIG. 5, when the odd tap is selected, the selector switch SW is switched to the odd tap selector T1, and the vacuum valves Ma and Mb are closed as shown. . When the even tap is selected, the selector switch SW is switched to the even tap selector T2 side, the vacuum valve Ma is closed, and the vacuum valve Mb is opened.

  When the tap is switched from the odd-numbered tap to the even-numbered tap, for example, as shown in the figure, the switch SW is switched to the tap selector T1, the vacuum valves Ma and Mb are closed, and the tap t1 is selected. When switching the tap from t1 to t2, first the vacuum valve Ma is opened and the load current is transferred to the current limiting resistor r. In this state, after the changeover switch SW is switched to the tap selector T2 side without arcing, the vacuum valve Ma is closed, and the vacuum valve Mb is opened to complete the tap switching. When the changeover switch SW is switched to the tap selector T2 side and the vacuum valve Ma is closed, a short-circuit current between taps flows between the taps t1 and t2, but this short-circuit current is limited by the current limiting resistor r. The

  When switching from an even tap to an odd tap, for example, with the changeover switch SW switched to the tap selector T2 side, the tap t2 is selected with the vacuum valves Ma and Mb closed and open, respectively. When t2 is switched from t2 to t3, first the tap t3 is selected by the tap selector T1, then the vacuum valve Mb is closed, and the current limiting resistor r is connected to the tap t3 through the tap selector T1. Ma is opened and the load current is transferred to the current limiting resistor r. Next, the selector switch SW is switched to the tap selector T1 side without arcing, and then the vacuum valve Ma is closed to complete the tap switching.

  In the on-load tap changer as described above, the switches (the vacuum valves Ma and Mb and the changeover switch SW in the above example) that are associated with the operation of the tap selector at the time of tap changeover are predetermined. A drive mechanism unit that operates in this sequence is provided.

  Usually, the drive mechanism of the switching switch used in this type of tap switching device includes an accumulating spring, an accumulating mechanism that accumulates the accumulating spring using a motor as a driving source, and an accumulating spring supported by a fixed frame. A drive shaft that is driven to rotate within a certain angle range by the biasing force, a stopper mechanism that restricts the drive shaft to the rotation start position and prevents its rotation until the accumulation of the accumulation spring is completed, and a drive A drive cam attached to the shaft and rotated together with the drive shaft, a plurality of vacuum valve drive cam followers provided for each of the plurality of vacuum valves and brought into contact with the cam surface of the drive cam, and a drive cam A displacement transmission mechanism that transmits the generated displacements of the plurality of cam followers to the corresponding movable shafts of the vacuum valves, respectively, for the rotation of the drive shaft that occurs when the stopper mechanism releases the drive shaft. Thus, the cam surface of the drive cam is formed so that the plurality of cam followers are displaced in a predetermined sequence to cause the plurality of vacuum valves constituting the switching switch to perform the opening / closing operation at the time of tap switching in the predetermined sequence. .

  As described above, in the operation mechanism in which the drive shaft is rotated by the urging force of the energy storage spring to perform a series of operations of the switching switch, the drive shaft is restrained until the energy storage of the energy storage spring is completed. Therefore, it is necessary to provide a stopper mechanism for preventing the rotation.

The stopper mechanism provided in the operation mechanism part of the conventional switching switch for the tap switching device at the time of loading is provided at the corner of the rotating plate attached to the drive shaft, as shown in Patent Document 3, for example. The latch mechanism includes a pair of latch levers that engage to prevent rotation of the drive shaft, and a latch spring that biases both latch levers to engage the corners of the rotating plate.
JP 57-194509 A JP-A-5-82365 Japanese Patent Laid-Open No. 5166664

  As described above, in the conventional on-load tap switching device, the stopper plate that prevents the rotation of the drive shaft until the accumulation of the energy storage spring is completed is a rotating plate attached to the drive shaft. And a pair of latch levers that engage the corners of the rotating plate to prevent rotation of the drive shaft, and a latch spring that biases both latch levers to engage the corners of the rotating plate. However, in such a configuration, a large number of parts are required to configure the stopper mechanism, and the structure of the operation mechanism section of the switching switch becomes complicated. However, there is a problem that the cost becomes high.

  An object of the present invention is to simplify the structure of a stopper mechanism that prevents rotation of the drive shaft until the accumulation of the accumulation spring that drives the vacuum valve is completed, and to reduce the cost. It is an object of the present invention to provide a switching switch for an on-load tap switching device.

  The present invention relates to a vacuum valve for a switching switch operated by a cam mechanism having a drive shaft driven by an accumulator spring, a drive cam attached to the drive shaft, and a cam follower cooperating with the drive cam. And a switch for a vacuum valve load tap changer with a stopper mechanism that restrains the drive shaft at the rotation start position and prevents its rotation until the accumulation of the energy storage spring is completed. And

  In many cases, this type of switching switch is a vacuum that switches on and off the vacuum valve that opens and closes the load current that flows through the tap selector when switching taps and the current limiting resistor that limits the short-circuit current between taps when switching taps. A plurality of switching switches including vacuum valves, an accumulating spring, an accumulating mechanism for accumulating the accumulating spring, and supported by a fixed frame and driven to rotate by the energizing force of the accumulating spring. And a stopper mechanism that restrains the drive shaft at the rotation start position and prevents its rotation until the accumulation of the energy storage spring is completed, and a drive shaft attached to the drive shaft. And a plurality of vacuum valve driving cam followers provided for each of the plurality of vacuum valves and brought into contact with the cam surface of the driving cam, and the driving cam. A displacement transmission mechanism for transmitting the displacement of the plurality of cam followers to the corresponding movable shafts of the vacuum valves, and the plurality of cam followers are predetermined as the drive shaft rotates when the stopper mechanism releases the drive shaft. The cam surface of the drive cam is formed so as to cause the plurality of vacuum valves to open and close when the tap is switched by displacing in this sequence.

  In the present invention, the stopper mechanism assists the auxiliary cam fixed to the drive cam, the auxiliary cam follower abutted against the cam surface of the auxiliary cam, and the auxiliary cam follower against the cam surface side of the auxiliary cam. An auxiliary cam follower biasing spring that biases the cam follower.

  The cam surface of the auxiliary cam has a stopper portion that engages with the auxiliary cam follower to prevent the rotation of the drive shaft when the drive shaft is at the rotation start position, and until the accumulation of the accumulation spring is completed, The urging force of the auxiliary cam follower urging spring and the shape of the stopper portion are set and selected so that the auxiliary cam follower is kept engaged with the stopper portion of the cam surface of the auxiliary cam and prevents the drive shaft from rotating. .

  As described above, a stopper portion is provided on the cam surface of the auxiliary cam fixed to the drive cam, and the auxiliary cam follower is engaged with the stopper portion to restrain the drive shaft and complete the accumulation of the accumulation spring. If the rotation of the drive shaft is prevented during this time, the stopper mechanism can be configured only by adding the auxiliary cam, the auxiliary cam follower, and the spring for urging the auxiliary cam follower. The configuration of the part can be simplified.

  Further, when the stopper mechanism is constituted by the auxiliary cam and the auxiliary cam follower as described above, the amount of displacement of the auxiliary cam follower and the member supporting the auxiliary cam follower is small, so that it is secured for arranging the auxiliary cam follower and the supporting member. Only a small space is required, and the stopper mechanism can be made compact. Therefore, if comprised as mentioned above, a stopper mechanism can be provided using the empty space which exists in the part by which the cam mechanism which operates the vacuum valve of a switching switch is arrange | positioned, and the operation mechanism part of a switching switch Can be miniaturized.

  The normal load tap switching device includes an odd tap selector that selects an odd tap of the tap winding and an even tap selector that selects an even tap, and is supported by a fixed frame by an urging force of an accumulator spring. An odd-numbered tap and an even-numbered tap while rotating a drive shaft provided so as to be reciprocatingly driven in a certain angular range between the first position and the second position from the first position to the second position A tap switching operation for switching from the even-numbered tap to the odd-numbered tap is performed while rotating from the second position to the first position. In this case, the stopper mechanism moves the drive shaft to the first position and the second position until the accumulation of the accumulation spring is completed when the drive shaft is in the first position and the second position. And are configured to prevent rotation thereof.

  Even when the present invention is applied to such an on-load tap switching device, the stopper mechanism is provided on the side of the fixed frame on the side of the auxiliary cam fixed to the drive cam, and is brought into contact with the cam surface of the auxiliary cam. An auxiliary cam follower and an auxiliary cam follower biasing spring that biases the auxiliary cam follower so as to press the auxiliary cam follower toward the cam surface of the auxiliary cam are provided.

  In this case, the cam surface of the auxiliary cam includes a first stopper portion and a drive shaft that engage with the auxiliary cam follower and prevent the auxiliary cam from rotating toward the second position when the drive shaft is in the first position. Is provided with a second stopper portion that engages with the auxiliary cam follower to prevent rotation of the auxiliary cam to the first position side when is in the second position.

  Further, the auxiliary cam follower has the first stopper portion and the second stopper on the cam surface of the auxiliary cam until the accumulation of the accumulation spring is completed when the drive shaft is in the first position and the second position. The urging force of the auxiliary cam follower urging spring and the shape of the stopper portion are set and selected so as to prevent the rotation of the drive shaft while maintaining the engaged state with the respective stopper portions.

  The stopper portion may be formed of a protrusion, or may be formed of a concave portion into which the auxiliary cam follower is fitted.

  In a preferred aspect of the present invention, each displacement transmission mechanism that transmits the displacement of each vacuum valve driving cam follower to the corresponding vacuum valve is provided by a rotary shaft with an intermediate corner extending in a direction perpendicular to the axis of the drive shaft. Consists of an L-shaped lever for driving a vacuum valve, one end of which is rotatably supported by a fixed frame and coupled to a cam follower for driving a vacuum valve, and the other end is connected to a movable shaft of the corresponding vacuum valve via a pin. To do.

  Further, in this case, an L-shaped lever for a pivotable stopper mechanism supported by the fixed frame via a pivot shaft whose middle corner extends in a direction perpendicular to the axis of the drive shaft is provided in the stopper mechanism. An auxiliary cam follower is attached to the tip of the L-shaped lever for the stopper mechanism.

  In this case, the auxiliary cam follower biasing spring is provided between the rear end portion of the stopper mechanism L-shaped lever and the fixed frame.

  The L-shaped lever for stopper mechanism is preferably formed to have the same shape and dimensions as the L-shaped lever for driving a vacuum valve.

  As described above, if the L-shaped lever for the stopper mechanism has the same shape and dimensions as the L-shaped lever for driving the vacuum valve, the same parts as the L-shaped lever for driving the vacuum valve are used. Therefore, it is possible to reduce the cost by reducing the types of parts.

  As described above, according to the present invention, the auxiliary cam that has the stopper portion on the cam surface and is fixed to the drive cam that drives the vacuum valve, the auxiliary cam follower that contacts the cam surface of the auxiliary cam, and the auxiliary cam follower The auxiliary cam follower biasing spring that biases the cam toward the cam surface of the auxiliary cam constitutes a stopper mechanism for preventing the rotation of the drive shaft when accumulating the accumulator spring. The cam mechanism that drives the vacuum valve is configured to prevent the rotation of the drive shaft by engaging the stopper portion of the cam surface of the auxiliary cam and the auxiliary cam follower until the energy storage of the driving energy storage spring is completed. A stopper mechanism can be configured by effectively using the empty space, and the structure of the drive mechanism of the switching switch can be simplified to reduce the size and cost of the switching switch.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4 as an example when the present invention is applied to a switching switch of a tap switching device of the type shown in FIG.

  FIG. 1 is a cross-sectional view showing a mechanical configuration of a main part of a switching switch according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. FIG. 3B is an explanatory view showing the positional relationship between the auxiliary cam and the auxiliary cam follower when the shaft is at the first position, and FIG. 3B is an auxiliary cam and auxiliary when the drive shaft is at the second position in this embodiment. It is explanatory drawing which showed the positional relationship with a cam follower. FIG. 4 is a top view showing a modification of the auxiliary cam.

  1 and 2, reference numeral 1 denotes an insulating cylinder, 2 denotes a lower fixing frame which is provided so as to close the lower end of the insulating cylinder 1 and is fixed to the insulating cylinder 1, and 3 is arranged above the lower fixing frame 2. The upper fixed frame fixed to the inner surface of the insulating cylinder 1 is provided with the lower fixed frame 2 and the upper fixed frame 3 with their plate surfaces oriented in the horizontal direction.

  Reference numeral 4 denotes a drive shaft that is rotatably supported by the fixed frames 2 and 3 via bearings (not shown) with the central axis oriented in the vertical direction. The drive shaft 4 is made of a metal material, and is driven to reciprocate in a certain angular range between the first position and the second position by a drive device 5 disposed below the lower fixed frame 2.

  Here, the first position is the rotation start position of the drive shaft when the tap is switched from the odd tap to the even tap, and the second position is the rotation start of the drive shaft when the tap is switched from the even tap to the odd tap. Position.

  The illustrated drive device 5 includes an energy storage spring 6 and an energy storage mechanism 7 that stores the energy storage spring 6. The accumulator spring 6 is composed of a tension spring, one end of which is connected to a spring receiving member 9A attached to the tip of a lever 8 fixed to the lower end of the drive shaft 4 and the other end of the fixed frame 2 A support post 10 fixed to the lower surface is connected to a spring receiving member 9B attached to the tip of a lever 11 whose rear end is rotatably supported.

  The energy storage mechanism 7 includes a rotating member 13 that is rotatably supported by a support fitting 12 fixed to the insulating cylinder 1 and is driven to rotate by a motor (not shown), a lever 14 that transmits the rotation of the rotating member 13 to the lever 11, and 15 and the drive shaft 4 is restrained to the first position or the second position (rotation start position) by a stopper mechanism which will be described later, and the rotation member 13 is prevented from rotating. When the lever 11 is rotated and the accumulator spring 6 is pulled to accumulate energy, and the stopper mechanism releases the drive shaft 4, the energy accumulated in the accumulator spring 6 is released at a stroke to drive the drive shaft 4. Is rotated from the first position to the second position, or from the second position to the first position at once.

  A drive cam 16 is attached to the drive shaft 4. The drive cam 16 is made of a plate-like member whose plate surface is orthogonal to the drive shaft 4, and is fixed to the drive shaft 4 in a state where the drive shaft 4 is fitted in a hole provided in the shaft core portion. ing. On the outer periphery of the drive cam 16, a cam surface 16a comprising three convex portions 16u to 16w arranged at intervals of 120 ° and a cylindrical surface provided so as to connect the convex portions 16u, 16v, 16w to each other. Is formed.

  Around the drive shaft 4, U-phase or W-phase first vacuum valves Mau, Mav, and Maw are arranged at intervals of 120 °, and are arranged at intervals of 120 ° at the sides of the first vacuum valves. Further, U-phase or W-phase second vacuum valves Mbu, Mbv and Mbw are arranged.

  The vacuum valves Mau, Mbu, Mav, Mbv, Maw and Mbw are arranged with their respective central axes oriented in the vertical direction, and the terminals on the fixed contact side derived from the respective lower ends are fixed to the insulating cylinder 1. The terminal fittings 17au, 17bu, 17av, 17bv, 17aw and 17bw are fixed.

  Vacuum valve driving L-shaped levers 20au, 20bu, 20av, 20bv, 20aw and 20bw corresponding to the vacuum valves Mau, Mbu, Mav, Mbv, Maw and Mbw, respectively, are provided, and an intermediate corner of these L-shaped levers is provided. The support member 22 fixed to the fixed frame 3 is rotatably supported by a rotation shaft 21 extending in a direction perpendicular to the axis of the drive shaft 4.

  A vacuum valve drive cam follower 23 (see FIG. 2), which is a roller that rolls on the cam surface of the drive cam, is attached to one end of the vacuum valve drive L-shaped levers 20au, 20bu, 20av, 20bv, 20aw and 20bw. A cam follower 23 attached to one end of each of the levers 20au, 20bu, 20av, 20bv, 20aw and 20bw is in contact with the cam surface 16a of the drive cam 16. The other ends of the L-shaped levers 20au, 20bu, 20av, 20bv, 20aw and 20bw for driving the vacuum valve are pinned to movable shafts (shafts connected to the movable contacts) 24 (see FIG. 2) derived from the upper ends of the corresponding vacuum valves. 25 are connected.

  In this example, the intermediate portion is rotatably supported by the fixed frame 3, one end is coupled to the cam follower 23, and the other end is connected to the corresponding movable shaft 24 of the vacuum valve via a pin 25. The displacement of the cam follower 23 corresponding to each of the vacuum valves Mau, Mbu, Mav, Mbv, Maw and Mbw is transmitted to the movable shaft 25 of the corresponding vacuum valve by the driving L-shaped levers 20au, 20bu, 20av, 20bv, 20aw and 20bw. A displacement transmission mechanism is configured.

  A wipe spring 26 is provided between the upper end of the movable shaft 24 of the vacuum valves Mau, Mbu, Mav, Mbv, Maw and Mbw and the fixed frame 3 to provide contact pressure between the movable contact and the fixed contact of each vacuum valve. The urging force of the wipe spring presses the vacuum valve drive cam follower 23 toward the cam surface 16 a of the drive cam 16.

  In the illustrated example, when the convex portions 16u to 16w of the cam surface of the drive cam 16 are away from the cam followers 23 corresponding to the U-phase to W-phase vacuum valves Mau, Mbu to Maw, Mbw, respectively, the vacuum valves Mau, Mbu, Maw and Mbw are in the closed state.

  When the convex portions 16u to 16w of the cam surface of the drive cam 16 abut against the cam followers 23 corresponding to the U-phase to W-phase vacuum valves Mau, Mbu to Maw, Mbw, respectively, and the cam followers are displaced, the vacuum valves The movable shaft 24 of Mau, Mbu or Maw, Mbw is displaced upward against the biasing force of the wipe spring 26, and these vacuum valves are opened.

  A stopper mechanism 30 is provided to restrain rotation of the drive shaft by restraining the drive shaft 4 to the rotation start position (first position or second position) until the accumulation of the accumulation spring 6 is completed. It has been.

  The stopper mechanism 30 includes an auxiliary cam 31 fixed to the drive cam 16, an auxiliary cam follower 32 provided on the fixed frame side and brought into contact with the cam surface of the auxiliary cam 31, and the auxiliary cam follower 32 as a cam of the auxiliary cam 31. An auxiliary cam follower biasing spring 33 that biases the auxiliary cam follower 32 so as to be pressed to the surface side is provided.

  In the illustrated example, an L-shaped lever 34 for a stopper mechanism having the same shape and the same dimensions as the L-shaped lever provided for the vacuum valve is provided, and an intermediate corner of the lever 34 is connected to the axis of the drive shaft 4. It is supported by a support member 36 fixed to the upper fixed frame 3 via a rotation shaft 35 extending in a direction perpendicular to the upper fixed frame 3. An auxiliary cam follower 32 composed of a roller that rolls on the cam surface 31 a of the auxiliary cam 31 is attached to the tip of the stopper mechanism L-shaped lever 34, and a pin 37 is interposed at the rear end of the stopper mechanism L-shaped lever 34. An auxiliary cam follower urging spring 33 is provided between the spring receiving member 38 and the fixed frame 3 attached in this manner.

  The illustrated auxiliary cam 31 is formed of a plate-like member having a cam surface 31 a having a substantially cylindrical surface as a whole, and the cam surface 31 a faces the same side as the cam surface 16 a of the drive cam 16. Are arranged on the drive cam 16 and are fixed to the drive cam 16 by bolts 39.

  When the drive shaft 4 is in the first position, the cam surface 31a of the auxiliary cam 31 engages with the auxiliary cam follower 32 and moves to the second position side of the drive shaft 4 as shown in FIG. When the drive shaft 4 is in the second position and the auxiliary cam follower 32 is engaged with the first cam follower 32 as shown in FIG. 3B when the drive shaft 4 is in the second position. And a second stopper portion 31a2 that prevents the drive shaft 4 from rotating in the first position side (counterclockwise in FIG. 1).

  In this example, the stopper portions 31a1 and 31a2 are formed of chevron-shaped protrusions, and the drive shaft 4 is moved until the auxiliary cam follower 32 gets over these stopper portions by the force applied from the accumulator spring through the drive shaft and the drive cam. Restrained to prevent its rotation.

  In addition, the auxiliary cam follower 32 remains on the first cam surface 31a of the auxiliary cam 31 until the accumulation of the accumulation spring 6 is completed when the drive shaft 4 is in the first position and the second position. The urging force of the auxiliary cam follower urging spring 33 and the shapes of the stopper portions 31a1 and 31a2 so as to prevent the rotation of the drive shaft while maintaining the engaged state with the stopper portion 31a1 and the second stopper portion 31a2 (see FIGS. The height and the inclination angle of the rising part) are set and selected, respectively.

  In the present embodiment, the movable contact 41 is attached to the drive shaft 4 via the insulating member 40, and the pair of fixed contacts 42, 42 that the movable contact 41 selectively contacts with the rotation of the drive shaft. (FIG. 2 shows only one fixed contact 42) is fixed to the insulating cylinder 1 with a space in the rotational direction of the drive shaft 4. In this example, the changeover switch SW shown in FIG. 5 is configured by the movable contact 41 and the fixed contacts 42, 42, and one of the pair of fixed contacts 42, 42 is connected to the odd tap selector, and the other Are connected to an even tap selector. The movable contact 41 is connected to a terminal (movable shaft) on the movable contact side of the corresponding first phase vacuum switch via a wiring (not shown).

  The change-over switch SW is provided for each of the three phases, but FIG. 2 shows only the single-phase change-over switch SW.

  Although not shown, a three-phase current limiting resistor is disposed in the space above the upper fixed frame 3, and the current limiting resistor is connected between the second vacuum valve of each phase and the odd tap selector. Is done. The illustration of the odd tap selector and the even tap selector is omitted.

  As described above, in the on-load tap switching on / off device switching switch according to the present embodiment, the first stopper portion 31a1 of the auxiliary cam 31 contacts the auxiliary cam follower 32 to rotate the auxiliary cam 31 in the clockwise direction. The rotational angle position of the drive shaft 4 when in the blocked state (the state of FIG. 3A) is the first position of the drive shaft, and the first stopper portion 31a2 of the auxiliary cam 31 contacts the auxiliary cam follower 32 to assist. The rotational angle position of the drive shaft 4 when the cam 31 is prevented from rotating counterclockwise (state shown in FIG. 3B) is defined as the second position of the drive shaft.

  When the three-phase selector switch SW is switched to the odd tap selector T1 and the vacuum valves Mau, Mbu, Mav, Mbv, Maw and Mbw are closed and the odd taps are selected, the drive shaft 4 is The position is slightly over the first position (the position shown in FIG. 1). At this time, the first stopper portion 31a1 of the cam surface of the auxiliary cam 31 contacts the auxiliary cam follower 32 (shown in FIG. 3A). Position) is slightly overclockwise.

  When the tap is switched from this state to the even-numbered tap, the energy storage spring 6 is stored by the power storage mechanism 7. At this time, the first stopper portion 31a1 on the cam surface of the auxiliary cam 31 abuts on the auxiliary cam follower 32 as shown in FIG. 3A, thereby switching the drive shaft 4 from the first position (from odd tap to even tap). The rotation is prevented by restraining the rotation at the rotation start position at the time when the energy accumulation is performed, and the energy accumulation of the energy accumulation spring 6 is advanced. When the energy storage of the energy storage spring 6 is completed, the force transmitted from the energy storage spring 6 to the auxiliary cam 31 through the drive shaft 4 exceeds the pressing force applied from the spring 33 to the auxiliary cam follower 32. Since the stopper portion 31a2 and the auxiliary cam follower 32 are disengaged, the auxiliary cam 31 starts rotating together with the drive cam 16 and the drive shaft 4, and the energy accumulated in the energy storage spring 6 is released at once. As a result, the drive shaft 4 rotates in a clockwise direction in FIG. In the process of rotating the drive shaft 4, the drive cam 16 first opens the vacuum valves Mau to Maw to transfer the load current to the current limiting resistor r, and then sets the three-phase selector switch SW to the tap selector T2 side. After switching without arc, the first vacuum valves Mau to Maw are closed, and the vacuum valves Mbu to Mbw are opened to complete the tap switching. After the tap switching is finished, the auxiliary cam follower 32 exceeds the second stopper portion 31a2 of the auxiliary cam 31 (the state where the stopper portion 31a2 is in contact with the auxiliary cam follower 32 in FIG. 3B slightly overclockwise). At this point, the drive shaft 4 stops.

  When the tap is switched from this state to an odd-numbered tap, the accumulator spring 6 is again energized by the accumulator mechanism 7. At this time, the second stopper portion 31a2 on the cam surface of the auxiliary cam 31 abuts the auxiliary cam follower 32 as shown in FIG. 3B, thereby restraining the drive shaft 4 to the second position and preventing its rotation. The power storage of the power storage spring 6 is advanced. When the energy storage of the energy storage spring 6 is completed, the force transmitted from the energy storage spring 6 to the auxiliary cam 31 through the drive shaft 4 exceeds the pressing force applied from the spring 33 to the auxiliary cam follower 32. The engagement between the stopper portion 31a2 and the auxiliary cam follower 32 is released, and the auxiliary cam 31 starts rotating together with the drive cam 16. In the process of rotation of the drive shaft 4, the drive cam 16 first closes the vacuum valves Mbu to Mbw, then opens the vacuum valves Mau to Maw and transfers the load current to the current limiting resistor r, and then the three-phase. Is switched to the tap selector T1 side without arcing, and then the first vacuum valves Mau to Maw are closed to complete the tap switching. Tap switching is completed, and the auxiliary cam follower 32 exceeds the first stopper portion 31a1 of the auxiliary cam 31 (the state where the stopper portion 31a1 contacts the auxiliary cam follower 32 in FIG. 3A slightly overclockwise) Then, the drive shaft 4 stops.

  As described above, in the present invention, the stopper portions 31a1 and 31a2 are provided on the cam surface of the auxiliary cam 31 fixed to the drive cam 16, and the drive shaft 4 is restrained by engaging the auxiliary cam follower 32 with the stopper portion. Since the rotation of the drive shaft is prevented until the accumulating of the accumulating spring 6 is completed, the stopper mechanism is simply added by adding an auxiliary cam, an auxiliary cam follower, and a spring for urging the auxiliary cam follower. The configuration of the operation mechanism unit of the switching switch can be simplified.

  Further, when the stopper mechanism is configured by the auxiliary cam 31 and the auxiliary cam follower 32 as in the present invention, the amount of displacement of the auxiliary cam follower and the member that supports the auxiliary cam follower is small, so the auxiliary cam follower and its support member are arranged. Therefore, the space to be secured is small, and the stopper mechanism can be made compact. Therefore, when configured as described above, the stopper mechanism can be incorporated into the cam mechanism by utilizing the empty space existing in the portion where the vacuum valve of the switching switch and the cam mechanism for operating the vacuum valve are disposed. The operation mechanism part of the switching switch can be downsized.

  In addition, as in the above-described embodiment, when a lever that supports the auxiliary cam follower has the same shape and dimensions as the lever that supports the cam follower 23 of the cam mechanism that drives the vacuum valve, a switching switch is configured. Since the types of parts can be reduced, the cost can be reduced.

  In the above-described embodiment, the stopper portion provided on the cam surface of the auxiliary cam is a projection. However, as shown in FIG. 4, the first and second stopper portions 31a1 each having a recess or a groove on the cam surface 31a of the auxiliary cam 31. 'And 31a2' may be provided.

Also in this case, until the accumulation of the accumulation spring 6 is completed, the auxiliary cam follower 32 is kept engaged with the stopper portions 31a1 ′ and 31a2 ′ of the cam surface of the auxiliary cam to prevent the drive shaft from rotating. Thus, the biasing force of the auxiliary cam follower biasing spring 33 and the shapes of the stopper portions 31a1 ′ and 31a2 ′ (the depth of the recesses or grooves) are set.
In the above embodiment, the auxiliary cam 31 is formed separately from the drive cam 16 and the auxiliary cam 31 is bolted to the drive cam 16. However, the auxiliary cam 31 may be fixed to the drive cam. Therefore, the auxiliary cam 31 may be provided integrally with the drive cam 16.

  When the auxiliary cam 31 is formed separately from the drive cam 16 and the auxiliary cam 31 is bolted to the drive cam 16 as in the above embodiment, the auxiliary cam 31 is fixed to the lower surface of the drive cam 16. You may make it do.

  In the above embodiment, the present invention is applied to the switching switch used in the on-load tap switching device in which each phase has a circuit configuration as shown in FIG. 5, but one current limiting resistor and three vacuums per phase. The present invention can also be applied to a switching switch used for other types of vacuum valve type on-load tap switching devices such as a on-load tap switching device that performs tap switching using a valve.

It is a cross-sectional view which shows the structure of one Embodiment of this invention. It is the II-II sectional view taken on the line of FIG. (A) And (B) is explanatory drawing which showed the positional relationship of an auxiliary cam and an auxiliary cam follower when a drive shaft exists in a 1st position and a 2nd position, respectively. It is explanatory drawing which showed the modification of the auxiliary cam used by this invention. It is the circuit diagram which showed the circuit structural example of the tap switching apparatus at the time of a vacuum valve type load.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulating cylinder 2 Lower fixed frame 3 Upper fixed frame 4 Drive shaft 5 Drive device 6 Accumulated spring 7 Accumulated mechanism 16 Drive cam 20au-20aw, 20bu-20bw Vacuum valve drive L-shaped lever 23 Cam follower 30 Stopper mechanism 31 Auxiliary cam 32 Auxiliary cam follower 33 Auxiliary cam follower biasing spring 34 L-shaped lever for stopper mechanism Mau to Maw first vacuum valve Mbu to Mbw Second vacuum valve

Claims (7)

A drive shaft driven by an accumulator spring; a drive valve attached to the drive shaft; and a vacuum valve for a switching switch operated by a cam mechanism having a cam follower cooperating with the drive cam; In the switching switch for the tap switching device at the time of the vacuum valve type load, provided with a stopper mechanism that restrains the drive shaft at the rotation start position and prevents the rotation until the accumulation of the spring spring is completed,
The stopper mechanism includes an auxiliary cam fixed to the drive cam, an auxiliary cam follower abutted on the cam surface of the auxiliary cam, and the auxiliary cam follower so as to press the auxiliary cam follower toward the cam surface side of the auxiliary cam. An auxiliary cam follower biasing spring for biasing the cam follower,
The cam surface of the auxiliary cam has a stopper portion that engages with the auxiliary cam follower to prevent rotation of the drive shaft when the drive shaft is in the rotation start position,
The auxiliary cam follower is attached to the auxiliary cam follower so as to prevent the drive shaft from rotating while maintaining the auxiliary cam follower engaged with the stopper portion of the cam surface of the auxiliary cam until the energy storage of the energy storage spring is completed. The biasing force of the biasing spring and the shape of the stopper are respectively set and selected;
A switch for a vacuum valve type tap switching device with a load. A plurality of vacuum valves including a vacuum valve that opens and closes a load current flowing through the tap selector at the time of tap switching and a vacuum valve that switches on and off a current limiting resistor that limits a short-circuit current between taps when the tap is switched; A spring; a power storage mechanism that stores the power storage spring; a drive shaft that is supported by a fixed frame so as to be rotationally driven by the power of the power storage spring; and the power storage of the power storage spring A stopper mechanism for restraining the rotation of the drive shaft at the rotation start position and preventing the rotation, a drive cam attached to the drive shaft and rotated together with the drive shaft, and the plurality of vacuum valves A plurality of vacuum valve drive cam followers provided for each of the drive cams and brought into contact with the cam surface of the drive cam, and the plurality of cables generated by the drive cam. A displacement transmission mechanism that transmits the displacement of the follower to the corresponding movable shaft of the vacuum valve, and the plurality of cam followers are transmitted in a predetermined manner as the drive shaft rotates when the stopper mechanism releases the drive shaft. In a switching switch for a tap switching device at the time of a vacuum valve type load, in which the cam surface of the drive cam is formed so as to cause the plurality of vacuum valves to perform opening and closing operations at the time of tap switching by being displaced in a sequence,
The stopper mechanism includes an auxiliary cam fixed to the drive cam, an auxiliary cam follower provided on the fixed frame side and brought into contact with the cam surface of the auxiliary cam, and the auxiliary cam follower connected to the cam surface of the auxiliary cam. An auxiliary cam follower urging spring for urging the auxiliary cam follower to press the auxiliary cam follower,
The cam surface of the auxiliary cam has a stopper portion that engages with the auxiliary cam follower to prevent rotation of the drive shaft when the drive shaft is in the rotation start position,
The auxiliary cam follower is attached to the auxiliary cam follower so as to prevent the drive shaft from rotating while maintaining the state where the auxiliary cam follower is engaged with the stopper portion of the cam surface of the auxiliary cam until the accumulation of the energy storage spring is completed. The biasing force of the biasing spring and the shape of the stopper are respectively set and selected;
A switch for a vacuum valve type tap switching device with a load. A plurality of vacuum valves including a vacuum valve that opens and closes a load current flowing through the tap selector at the time of tap switching and a vacuum valve that switches on and off a current limiting resistor that limits a short-circuit current between taps when the tap is switched; A spring, a power storage mechanism that stores the power storage spring, and a fixed frame supported by a fixed frame, and reciprocatingly rotating in a certain angular range between the first position and the second position by the biasing force of the power storage spring A drive shaft provided so as to be driven, and when the drive shaft is in the first position and in the second position until the energy storage of the energy storage spring is completed. For each of the plurality of vacuum valves, a stopper mechanism that restrains the first position and the second position and prevents the rotation, a drive cam attached to the drive shaft and rotated together with the drive shaft, and The A plurality of vacuum valve drive cam followers that are brought into contact with the cam surface of the drive cam, and displacements that transmit displacements of the plurality of cam followers generated by the drive cam to the corresponding movable shafts of the vacuum valves, respectively. A plurality of cam followers in accordance with the rotation of the drive shaft from the first position to the second position, which occurs when the stopper mechanism releases the drive shaft at the first position. The drive that occurs when the stopper mechanism releases the drive shaft in the second position by causing the plurality of vacuum valves to open and close when the tap is switched from odd taps to even taps. As the shaft is rotated from the second position to the first position, the plurality of cam followers are displaced in a predetermined sequence, and the plurality of vacuum valves are evenly tapped. In Luo odd tap switching vacuum valve type load tap switching device for switching switch cam surface of the drive cam so as to perform the closing operation is formed in the tap,
The stopper mechanism includes an auxiliary cam fixed to the drive cam, an auxiliary cam follower provided on the fixed frame side and brought into contact with the cam surface of the auxiliary cam, and the auxiliary cam follower connected to the cam surface of the auxiliary cam. An auxiliary cam follower urging spring for urging the auxiliary cam follower to press the auxiliary cam follower,
The cam surface of the auxiliary cam includes a first stopper portion that engages with the auxiliary cam follower and prevents the auxiliary cam from rotating to the second position side when the drive shaft is in the first position; A second stopper portion that engages with the auxiliary cam follower to prevent rotation of the auxiliary cam toward the first position when the drive shaft is in the second position;
The auxiliary cam follower moves the first stopper on the cam surface of the auxiliary cam until the accumulation of the accumulation spring is completed when the drive shaft is in the first position and the second position. The urging force of the auxiliary cam follower urging spring and the shape of the stopper portion are respectively set and selected so as to prevent the rotation of the drive shaft while maintaining the engaged state with the first and second stopper portions. Being
A switch for a vacuum valve type tap switching device with a load. Each displacement transmission mechanism that transmits the displacement of each vacuum valve driving cam follower to the corresponding vacuum valve is rotated around the fixed frame by a rotating shaft with an intermediate corner extending in a direction perpendicular to the axis of the driving shaft. The stopper comprises an L-shaped lever for driving the vacuum valve, one end of which is coupled to the cam follower for driving the vacuum valve and the other end of which is connected to a movable shaft of the corresponding vacuum valve via a pin. The mechanism has an L-shaped lever for a pivotable stopper mechanism supported by the fixed frame via a pivot shaft whose middle corner extends in a direction perpendicular to the axis of the drive shaft, The auxiliary cam follower is attached to the tip of the L-shaped lever for the stopper mechanism,
4. The switch for a vacuum valve load tap switching device according to claim 2, wherein the auxiliary cam follower biasing spring is provided between a rear end portion of the L lever for the stopper mechanism and the fixed frame. Switch.   5. The switch for a vacuum valve load tap changer according to claim 4, wherein the L-shaped lever for the stopper mechanism is formed to have the same shape and the same size as the L-shaped lever for driving the vacuum valve.   6. The switching switch for a vacuum valve load tap switching device according to claim 1, wherein the stopper portion is formed of a protrusion.   6. The switch for a vacuum valve load tap switching device according to any one of claims 1 to 5, wherein the stopper portion comprises a recess into which the auxiliary cam follower is fitted.

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