JP2004319975A - Change-over switch for vacuum valve type on-load tap changer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simplified structure of stopper mechanism for preventing a driving axis from rotating during completing energy storing of an energizing spring of a change-over switch used in a vacuum valve type on-load tap changer. <P>SOLUTION: A stopper mechanism 30 for preventing a driving axis 4 from rotating during energy storing of an energizing spring 6, consists of a sub-cum 31 fixed to a driving cum 16 which has a stopper on the cum surface for driving a vacuum valve Mbw; a sub-cum follower 32 abutting to the cum surface of the sub-cum 31; and a sub-cum follower energizing spring 33 for energizing the sub-cum follower to the cum surface side of the sub-cum, and prevents the driving axis 4 from rotating during completing the energy storing of an energizing spring 6 by engaging the stopper on the cum surface of the sub-cum 31 with the sub-cum follower 32. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  As a vacuum valve type tap switching device at load, as shown in Patent Document 1, a tap switching is performed by using a switching switch including three vacuum valves and one current limiting resistor. Also, as shown in Patent Literature 2, various types such as a type in which tap switching is performed using a switching switch including two vacuum valves and a changeover switch and one current-limiting resistor. Are known.

  FIG. 5 shows, by way of example, an electrical configuration of a load tap switching device that performs tap switching using a switching switch including two vacuum valves and a switching switch and one current limiting resistor. In the figure, Wm is the 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 on the tap winding Wt. The odd tap selector T2 is an even tap selector for selecting even taps t2, t4, t6,... Provided on 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 at the time of tap switching. One end of this vacuum valve Ma is connected to the neutral point N of the transformer, and the other end is a 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 flowing at the time of tap switching, 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, and the other end is connected to an odd tap selector T1 through a current limiting resistor r.

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

  In the on-load tap switching device shown in FIG. 5, when an odd tap is selected, the changeover 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 changeover switch SW is switched to the even tap selector T2, so that the vacuum valve Ma is closed and the vacuum valve Mb is opened.

  When the taps are switched from the odd taps to the even taps, 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 arc, the vacuum valve Ma is closed and the vacuum valve Mb is further opened to complete the tap change. When the changeover switch SW is switched to the tap selector T2 to close the vacuum valve Ma, a short-circuit current flows between the taps t1 and t2, but this short-circuit current is limited by the current-limiting resistor r. You.

  When the tap is switched from the even tap to the odd tap, for example, with the changeover switch SW being switched to the tap selector T2 side, the vacuum valves Ma and Mb are respectively closed and opened, and the tap t2 is selected, Is switched from t2 to t3, the tap t3 is first 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. With Ma open, load current is transferred to current limiting resistor r. Next, after the changeover switch SW is switched to the tap selector T1 side without arc, the vacuum valve Ma is closed to terminate the tap change.

  In the above-described on-load tap changer, the switches (the vacuum valves Ma, Mb and the changeover switch SW in the above example) that constitute the changeover switch in connection with the operation of the tap selector at the time of the tap change are specified. Is provided.

  Usually, a driving mechanism of a switching switch used in this type of tap switching device includes an energy storage spring, an energy storage mechanism for storing the energy storage spring using a motor as a driving source, and an energy storage spring supported by a fixed frame. A drive shaft that is rotationally driven within a certain angular range by the urging force, a stopper mechanism that restrains the drive shaft at a rotation start position and prevents its rotation until the energy storage of the energy storage spring is completed, and A drive cam attached to the shaft and rotated 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 a cam surface of the drive cam, and a drive cam. A displacement transmission mechanism for transmitting the displacements of the plurality of cam followers to the movable shafts of the corresponding vacuum valves. The rotation of the drive shaft caused when the stopper mechanism releases the drive shaft. The cam surface of the drive cam is formed such 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 and closing operation at the time of tap switching in the predetermined sequence. .

  As described above, in the operating 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 accumulation of the energy storage spring is completed. Then, it is necessary to provide a stopper mechanism for preventing the rotation.

The stopper mechanism provided in the operation mechanism of the conventional switching switch for the on-load tap switching device is, for example, as shown in Patent Document 3, provided at the corner of a rotating plate attached to a drive shaft. 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 with the corners of the rotating plate.
JP-A-57-194509 JP-A-5-82365 JP-A-5-166543

  As described above, in the conventional on-load tap switching device, the stopper mechanism for preventing the rotation of the drive shaft until the energy storage of the energy storage spring is completed is provided by the rotating plate attached to the drive shaft. 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 urges both latch levers to engage the corners of the rotating plate. However, in such a configuration, many parts are required to configure the stopper mechanism, and the structure of the operation mechanism of the switching switch becomes complicated, so that the switching switch becomes large. However, there is a problem that the cost increases.

  SUMMARY OF THE INVENTION An object of the present invention is to simplify the structure of a stopper mechanism that prevents rotation of a drive shaft until the energy storage of an energy storage spring that drives a vacuum valve is completed, thereby reducing costs. It is an object of the present invention to provide a switching switch for a tap switching device at load which is made possible.

  The present invention relates to a vacuum valve for a switching device configured to be operated by a drive shaft driven by an energy storage spring, a drive cam attached to the drive shaft, and a cam mechanism including a cam follower cooperating with the drive cam. And a stopper mechanism for restricting the drive shaft to a rotation start position and preventing its rotation until the energy storage of the energy storage spring is completed. And

  In many cases, this type of switching switch includes a vacuum valve that opens and closes a load current flowing through a tap selector at the time of tap switching and a vacuum that opens and closes a current limiting resistor that limits a short-circuit current between taps flowing at the time of tap switching. A plurality of switching valves including a valve, a vacuum valve for forming a switching switch, a storage spring, a storage mechanism for storing the storage spring, and supported by a fixed frame to be rotationally driven by the biasing force of the storage spring. A drive shaft, a stopper mechanism for restraining the drive shaft at a rotation start position and preventing its rotation until the energy storage of the energy storage spring is completed, and a drive shaft attached to the drive shaft. A plurality of cam followers for driving a plurality of vacuum valves provided for each of the plurality of vacuum valves and abutting against the cam surface of the drive cam, and driven by the drive cam. And a displacement transmission mechanism for transmitting the displacement of the plurality of cam followers to the corresponding movable shafts of the vacuum valve, respectively, and the plurality of cam followers are fixed in accordance with the rotation of the drive shaft that occurs 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 perform the opening / closing operation at the time of tap switching by being displaced in the sequence (1).

  In the present invention, 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 an auxiliary cam follower for pressing the auxiliary cam follower toward the cam surface 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 when the drive shaft is at the rotation start position and prevents the rotation of the drive shaft. The urging force of the spring for urging the auxiliary cam follower and the shape of the stopper are set and selected so that the auxiliary cam follower retains the engagement state with the stopper on the cam surface of the auxiliary cam to prevent the rotation of the drive shaft. .

  As described above, the stopper portion is provided on the cam surface of the auxiliary cam fixed to the driving cam, and the auxiliary shaft is engaged with the auxiliary cam follower to restrain the drive shaft and until the energy storage of the energy storage spring is completed. During this period, if the rotation of the drive shaft is prevented, the stopper mechanism can be constituted only by adding the auxiliary cam, the auxiliary cam follower, and the spring for biasing the auxiliary cam follower. The configuration of the unit can be simplified.

  Further, when the stopper mechanism is constituted by the auxiliary cam and the auxiliary cam follower as described above, the displacement amount of the auxiliary cam follower and the member supporting the auxiliary cam follower is small, so that it is necessary to arrange the auxiliary cam follower and the supporting member. Only a small space is required, and the stopper mechanism can be made compact. Therefore, with the above configuration, the stopper mechanism can be provided by utilizing the empty space existing in the portion where the cam mechanism for operating the vacuum valve of the switching switch is provided, and the operating mechanism of the switching switch can be provided. Can be reduced in size.

  The normal load tap switching device includes an odd tap selector for selecting an odd tap of the tap winding and an even tap selector for selecting the even tap, and is supported by the fixed frame and is operated by the urging force of the energy storage spring. Odd taps to even taps while rotating a drive shaft provided to be reciprocally rotated in a certain angular range between the first position and the second position from the first position to the second position. , And a tap switching operation of switching from even-numbered taps to odd-numbered taps while rotating from the second position to the first position is performed. In this case, the stopper mechanism moves the drive shaft to the first position and the second position while the drive shaft is at the first position and at the second position until the storage of the storage spring is completed. , Respectively, to prevent the rotation.

  Also in the case where the present invention is applied to such a load tap switching device, the stopper mechanism is provided on the auxiliary cam fixed to the drive cam and the fixed frame side and is brought into contact with the cam surface of the auxiliary cam. An auxiliary cam follower and an auxiliary cam follower biasing spring for biasing the auxiliary cam follower so as to press the auxiliary cam follower against the cam surface of the auxiliary cam are provided.

  In this case, the cam surface of the auxiliary cam has a first stopper portion and a drive shaft which engage with the auxiliary cam follower when the drive shaft is at the first position to prevent the auxiliary cam from rotating toward the second position. A second stopper portion that engages with the auxiliary cam follower when the second cam is at the second position and prevents the auxiliary cam from rotating toward the first position.

  When the drive shaft is in the first position and in the second position, the auxiliary cam follower is connected to the first stopper portion and the second stopper portion on the cam surface of the auxiliary cam until the energy storage of the energy storage 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 as to keep the engagement with the respective stopper portions and prevent the rotation of the drive shaft.

  The stopper portion may be composed of a projection, or may be composed of a concave portion into which the auxiliary cam follower fits.

  In a preferred aspect of the present invention, each displacement transmission mechanism for transmitting the displacement of each vacuum valve driving cam follower to the corresponding vacuum valve is formed by a rotating shaft whose middle corner extends in a direction perpendicular to the axis of the drive shaft. An L-shaped lever for driving a vacuum valve, which is rotatably supported by a fixed frame and has one end connected to a cam follower for driving a vacuum valve and the other end connected to a movable shaft of a corresponding vacuum valve via a pin. I do.

  Further, in this case, the stopper mechanism is provided with a rotatable L-shaped lever for a stopper mechanism supported by the fixed frame via a rotation shaft whose intermediate corner portion extends in a direction perpendicular to the axis of the drive shaft, An auxiliary cam follower is attached to a 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 of the stopper mechanism L-shaped lever and the fixed frame.

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

  As described above, when a stopper mechanism L-shaped lever having the same shape and dimensions as the vacuum valve driving L-shaped lever is used, the same parts as the vacuum valve driving L-shaped lever are used. Therefore, the number of types of parts can be reduced and cost can be reduced.

  As described above, according to the present invention, an auxiliary cam fixed to a drive cam having a stopper on a cam surface to drive a vacuum valve, an auxiliary cam follower abutting on a cam surface of the auxiliary cam, and the auxiliary cam follower And an auxiliary cam follower biasing spring that biases the drive shaft toward the cam surface side of the auxiliary cam, constitutes a stopper mechanism for preventing rotation of the drive shaft when storing the storage spring, and Until the accumulating of the driving accumulating spring is completed, the rotation of the drive shaft is prevented by the engagement of the stopper portion on the cam surface of the auxiliary cam with the auxiliary cam follower, so that the cam mechanism for driving the vacuum valve The empty space can be effectively used to form the stopper mechanism, and the configuration 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 by taking an example where the present invention is applied to a switching switch of a load 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 line II-II of 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 shows the auxiliary cam and the 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 fixed frame provided so as to close the lower end of the insulating cylinder 1 and is fixed to the insulating cylinder 1, and 3 denotes an upper part of the lower fixing frame 2. The lower fixed frame 2 and the upper fixed frame 3 are fixed to the inner surface of the insulating tube 1, and the lower fixed frame 2 and the upper fixed frame 3 are provided with their respective plate faces oriented in the horizontal direction.

  Reference numeral 4 denotes a drive shaft rotatably supported by the fixed frames 2 and 3 via bearings (not shown) with the central axis directed vertically. The drive shaft 4 is made of a metal material, and is driven to reciprocate in a fixed angle 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 a rotation start position of the drive shaft when switching the tap from the odd tap to the even tap, and the second position is a rotation start position of the drive shaft when switching the tap from the even tap to the odd tap. Position.

  The illustrated driving device 5 includes a power storage spring 6 and a power storage mechanism 7 that stores the power of the power storage spring 6. The energy storage spring 6 is formed of a tension spring, and one end thereof is connected to a spring receiving member 9 </ b> A attached to the tip of a lever 8 fixed to the lower end of the drive shaft 4, and the other end is connected to the fixed frame 2. The rear end of the support post 10 fixed to the lower surface is connected to a spring receiving member 9B attached to the tip of a lever 11 rotatably supported.

  The energy storage mechanism 7 includes a rotating member 13 rotatably supported by a support fitting 12 fixed to the insulating cylinder 1 and driven to rotate by a motor (not shown), a lever 14 for transmitting rotation of the rotating member 13 to the lever 11, and When the drive shaft 4 is restrained at the first position or the second position (rotation start position) by a stopper mechanism described later and is prevented from rotating, the rotation member 13 is moved. When the stopper mechanism releases the drive shaft 4, the energy accumulated in the energy storage spring 6 is released at once, and the drive shaft 4 is released. 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 formed of a plate-like member having a plate surface orthogonal to the drive shaft 4, and is fixed to the drive shaft 4 in a state where the drive shaft 4 is fitted into a hole provided in the shaft core. ing. On the outer periphery of the driving cam 16, a cam surface 16a composed of three convex portions 16u to 16w arranged at 120 ° intervals and a cylindrical surface provided so as to connect these convex portions 16u, 16v, 16w to each other. Is formed.

  Around the drive shaft 4, U-phase to W-phase first vacuum valves Mau, Mav and Maw are arranged at intervals of 120 °, and are also arranged at intervals of 120 ° beside these first vacuum valves. The second vacuum valves Mbu, Mbv and Mbw of the U-phase to W-phase are arranged.

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

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

  At one end of each of the vacuum valve driving L-shaped levers 20au, 20bu, 20av, 20bv, 20aw and 20bw, a vacuum valve driving cam follower 23 (see FIG. 2) composed of a roller for rolling the cam surface of the driving cam is attached. 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 vacuum valve driving L-shaped levers 20au, 20bu, 20av, 20bv, 20aw and 20bw are pinned to a movable shaft (shaft connected to a movable contact) 24 (see FIG. 2) derived from the upper end of the corresponding vacuum valve. 25.

  In this example, a vacuum valve having an intermediate portion rotatably supported by the fixed frame 3, one end coupled to the cam follower 23, and the other end coupled to the movable shaft 24 of the corresponding 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. The displacement transmitting mechanism is configured.

  A wipe spring 26 is disposed 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 apply a contact pressure between the movable contact and the fixed contact of each vacuum valve. The cam follower 23 for driving the vacuum valve is pressed against the cam surface 16a of the driving cam 16 by the urging force of the wipe spring.

  In the illustrated example, when the convex portions 16u to 16w of the cam surface of the drive cam 16 are separated 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 to Maw, Mbw are in the closed state.

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

  A stopper mechanism 30 is provided to restrain the drive shaft 4 at the rotation start position (the first position or the second position) and prevent the rotation of the drive shaft until the storage of the storage spring 6 is completed. Have been.

  The stopper mechanism 30 includes an auxiliary cam 31 fixed to the driving 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 an auxiliary cam follower 32 An auxiliary cam follower biasing spring 33 for biasing the auxiliary cam follower 32 so as to press it toward the surface is provided.

  In the illustrated example, an L-shaped lever 34 for a stopper mechanism having the same shape and the same size as the L-shaped lever provided for the vacuum valve is provided, and an intermediate corner portion of the lever 34 is aligned with 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 direction. An auxiliary cam follower 32 consisting of a roller that rolls on the cam surface 31a of the auxiliary cam 31 is attached to the tip of the stopper mechanism L-shaped lever 34, and a pin 37 is attached to the rear end of the stopper mechanism L-shaped lever 34 via a pin 37. The auxiliary cam follower biasing spring 33 is provided between the fixed frame 3 and the spring receiving member 38 attached by mounting.

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

  When the drive shaft 4 is at the first position, the cam surface 31a of the auxiliary cam 31 engages with the auxiliary cam follower 32 as shown in FIG. When the drive shaft 4 is at the second position, the first stopper portion 31a1 that prevents rotation in the clockwise direction in FIG. 1 is engaged with the auxiliary cam follower 32 as shown in FIG. 3B. A second stopper portion 31a2 for preventing the drive shaft 4 from rotating toward the first position (counterclockwise in FIG. 1).

  In this example, the stopper portions 31a1 and 31a2 are formed as mountain-shaped projections, and the drive shaft 4 is moved until the auxiliary cam follower 32 gets over these stopper portions by the force applied from the energy storage spring through the drive shaft and the drive cam. It is restrained to prevent its rotation.

  When the drive shaft 4 is in the first position and in the second position, the auxiliary cam follower 32 is connected to the first cam surface 31 a of the auxiliary cam 31 until the energy storage of the energy storage spring 6 is completed. The biasing force of the auxiliary cam follower biasing spring 33 and the shapes of the stopper portions 31a1 and 31a2 are maintained so as to prevent the rotation of the drive shaft while maintaining the engagement with the stopper portion 31a1 and the second stopper portion 31a2. Height and inclination angle of the rising portion) 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 movable contact 41 selectively contacts with the rotation of the drive shaft. (FIG. 2 shows only one fixed contact 42). The fixed contact 42 is fixed to the insulating cylinder 1 with a space in the rotation direction of the drive shaft 4. In this example, the movable contact 41 and the fixed contacts 42, 42 constitute the changeover switch SW shown in FIG. 5, and one of the pair of fixed contacts 42, 42 is connected to the odd-numbered tap selector, and the other. Is connected to the even tap selector. The movable contact 41 is connected to a terminal (movable shaft) on the movable contact side of the first vacuum switch of the corresponding phase via a wiring (not shown).

  Although the changeover switch SW is provided for each of the three phases, FIG. 2 shows only one-phase changeover switch SW.

  Although not shown, a three-phase current limiting resistor is arranged in a 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-numbered tap selector. Is done. The illustration of the odd tap selector and the even tap selector is omitted.

  As described above, in the switching switch for the on-load tap switching switching device of 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 clockwise. The rotation angle position of the drive shaft 4 in the blocked state (the state of FIG. 3A) is defined as the first position of the drive shaft, and the first stopper portion 31a2 of the auxiliary cam 31 comes into contact with the auxiliary cam follower 32 to assist the auxiliary. The rotation angle position of the drive shaft 4 when the cam 31 is prevented from rotating counterclockwise (the state shown in FIG. 3B) is defined as the second position of the drive shaft.

  When the three-phase changeover switch SW is switched to the odd-numbered tap selector T1 and the vacuum valves Mau, Mbu, Mav, Mbv, Maw, and Mbw are closed and the odd-numbered tap is selected, the drive shaft 4 is turned off. The first position is slightly excessively far from 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 (FIG. 3A). Position) is slightly excessive in the counterclockwise direction.

  When the tap is switched to the even-numbered tap from this state, the energy storing mechanism 7 stores the energy in the energy storing spring 6. At this time, the first stopper portion 31a1 on the cam surface of the auxiliary cam 31 comes into contact with the auxiliary cam follower 32 as shown in FIG. 3A, whereby the drive shaft 4 is switched to the first position (from an odd tap to an even tap). (A rotation start position at the time of performing the rotation) to prevent the rotation, thereby accumulating the energy of the energy accumulating spring 6. 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, and Since the engagement between the stopper portion 31a2 and the auxiliary cam follower 32 is released, the auxiliary cam 31 starts rotating together with the drive cam 16 and the drive shaft 4, and the energy stored in the energy storage spring 6 is released at a stretch. Thereby, the drive shaft 4 rotates at a stroke clockwise 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 moves the three-phase switch SW to the tap selector T2. After switching without arc, the first vacuum valves Mau to Maw are closed, and the vacuum valves Mbu to Mbw are further opened to complete the tap switching. The tap change is completed, and the auxiliary cam follower 32 has moved beyond the second stopper portion 31a2 of the auxiliary cam 31 (the position where the stopper portion 31a2 comes into contact with the auxiliary cam follower 32 in FIG. 3B slightly excessively clockwise). When this happens, the drive shaft 4 stops.

  When the tap is switched to the odd-numbered tap from this state, the energy-storing mechanism 7 causes the energy-storing spring 6 to charge again. At this time, the second stopper portion 31a2 of the cam surface of the auxiliary cam 31 comes into contact with the auxiliary cam follower 32 as shown in FIG. 3 (B), thereby restraining the drive shaft 4 at the second position and preventing its rotation. , The energy of the energy accumulating 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, and 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. During the 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 to transfer the load current to the current limiting resistor r. After the changeover switch SW is switched to the tap selector T1 side without arc, the first vacuum valves Mau to Maw are closed to terminate the tap change. The state where the tap change is completed and the auxiliary cam follower 32 has exceeded the first stopper portion 31a1 of the auxiliary cam 31 (the state where the stopper portion 31a1 contacts the auxiliary cam follower 32 slightly in the counterclockwise direction in FIG. 3A). , The drive shaft 4 stops.

  As described above, in the present invention, the stoppers 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. Thus, the rotation of the drive shaft is prevented until the energy storage of the energy storage spring 6 is completed. Therefore, the stopper mechanism is simply added by adding the auxiliary cam, the auxiliary cam follower, and the spring for urging the auxiliary cam follower. Thus, the configuration of the operation mechanism of the switching switch can be simplified.

  In the case where the stopper mechanism is constituted by the auxiliary cam 31 and the auxiliary cam follower 32 as in the present invention, the auxiliary cam follower and the member supporting the auxiliary cam follower have a small displacement amount. Therefore, the auxiliary cam follower and the supporting member are arranged. Therefore, only a small space is required, 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 an empty space existing in a portion where the vacuum valve of the switching switch and the cam mechanism for operating the vacuum valve are arranged. The size of the operation mechanism of the switching switch can be reduced.

  Further, as in the above-described embodiment, when a lever having the same shape and the same size as the lever for supporting the cam follower 23 of the cam mechanism for driving the vacuum valve is used as the lever for supporting the auxiliary cam follower, the switching switch is constituted. Since the number of types of parts can be reduced, cost can be reduced.

  In the above embodiment, the stopper provided on the cam surface of the auxiliary cam is formed as a protrusion. However, as shown in FIG. 4, the first and second stoppers 31a1 formed of concave portions or grooves are formed on the cam surface 31a of the auxiliary cam 31. 'And 31a2'.

In this case, the auxiliary cam follower 32 is kept engaged with the stoppers 31a1 'and 31a2' on the cam surface of the auxiliary cam until the energy storage of the energy storage spring 6 is completed, thereby preventing the rotation of the drive shaft. Thus, the urging force of the auxiliary cam follower urging spring 33 and the shapes (depths of recesses or grooves) of the stopper portions 31a1 'and 31a2' 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 driving cam 16 and the auxiliary cam 31 is bolted to the driving cam 16 as in the above embodiment, the auxiliary cam 31 is fixed to the lower surface of the driving cam 16. You may make it.

  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 vacuum The present invention can also be applied to a switching switch used in another type of vacuum valve-type on-load tap switching device, such as a on-load tap switching device that performs tap switching using a valve.

FIG. 1 is a cross-sectional view illustrating a configuration of an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II of FIG. 1. (A) and (B) are explanatory views showing the positional relationship between the auxiliary cam and the auxiliary cam follower when the drive shaft is at the first position and the second position, respectively. FIG. 9 is an explanatory view showing a modified example of the auxiliary cam used in the present invention. FIG. 2 is a circuit diagram showing an example of a circuit configuration of a vacuum valve type tap switching device under load.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Insulating cylinder 2 Lower fixed frame 3 Upper fixed frame 4 Drive shaft 5 Drive device 6 Energy storage spring 7 Energy storage mechanism 16 Drive cam 20au-20aw, 20bu-20bw L-shaped lever for vacuum valve drive 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-Maw First vacuum valve Mbu-Mbw Second vacuum valve

Claims (7)

A drive shaft driven by a storage spring, a drive cam mounted on the drive shaft, and a vacuum valve for a switching device configured to be operated by a cam mechanism having a cam follower cooperating with the drive cam; Until the accumulation of the urging spring is completed, a switching mechanism for a vacuum valve type tap switching device at load provided with a stopper mechanism for restraining the drive shaft at a rotation start position and preventing the rotation thereof,
The stopper mechanism includes an auxiliary cam fixed to the driving cam, an auxiliary cam follower abutted on a cam surface of the auxiliary cam, and the auxiliary cam follower pressing the auxiliary cam follower toward the cam surface 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 that engages with the auxiliary cam follower when the drive shaft is at the rotation start position to prevent rotation of the drive shaft,
Until the energy storage of the energy storage spring is completed, the auxiliary cam follower retains a state in which the auxiliary cam follower is engaged with a stopper on the cam surface of the auxiliary cam and prevents rotation of the drive shaft. The biasing force of the biasing spring and the shape of the stopper portion are set and selected, respectively;
A switching switch for a vacuum valve type tap switching device at load characterized by the following. A plurality of vacuum valves including a vacuum valve for opening and closing a load current flowing through a tap selector at the time of tap switching, and a vacuum valve for turning on and off a current limiting resistor for limiting a short-circuit current between taps flowing at the time of tap switching; A spring, a storage mechanism for storing the storage spring, a drive shaft supported by a fixed frame and rotatably driven by the biasing force of the storage spring, and storage of the storage spring. Until the operation is completed, a stopper mechanism that restrains the drive shaft at a rotation start position to prevent the rotation, a drive cam attached to the drive shaft and rotated together with the drive shaft, and the plurality of vacuum valves. And a plurality of cam followers for driving a vacuum valve provided in contact with the cam surface of the driving cam, and the plurality of cams generated by the driving cam. A displacement transmission mechanism for transmitting a displacement of a follower to a movable shaft of a corresponding vacuum valve, wherein the plurality of cam followers are moved to a predetermined position by rotation of the drive shaft that occurs when the stopper mechanism releases the drive shaft. In a switching switch for a vacuum-valve-type load tap-switching device, a cam surface of the drive cam is formed so that the plurality of vacuum valves are opened and closed at the time of tap switching by being displaced in a sequence.
The stopper mechanism includes an auxiliary cam fixed to the driving cam, an auxiliary cam follower provided on the fixed frame side and in contact with a cam surface of the auxiliary cam, and a cam surface of the auxiliary cam follower. An auxiliary cam follower biasing spring that biases the auxiliary cam follower so as to press toward the side,
The cam surface of the auxiliary cam has a stopper that engages with the auxiliary cam follower when the drive shaft is at the rotation start position to prevent rotation of the drive shaft,
Until the energy storage of the energy storage spring is completed, the auxiliary cam follower retains a state in which the auxiliary cam follower is engaged with a stopper on the cam surface of the auxiliary cam and prevents rotation of the drive shaft. The biasing force of the biasing spring and the shape of the stopper portion are set and selected, respectively;
A switching switch for a vacuum valve type tap switching device at load characterized by the following. A plurality of vacuum valves including a vacuum valve for opening and closing a load current flowing through a tap selector at the time of tap switching, and a vacuum valve for turning on and off a current limiting resistor for limiting a short-circuit current between taps flowing at the time of tap switching; A spring, an energy-storing mechanism for accumulating the energy-storing spring, and reciprocatingly rotating in a fixed angle range between a first position and a second position by an urging force of the energy-storing spring supported by a fixed frame. A drive shaft provided so as to be driven, and the drive shaft being driven until the energy storage of the energy storage spring is completed when the drive shaft is at the first position and at the second position. A stopper mechanism that restricts the rotation at the first position and the second position and prevents the rotation, a drive cam attached to the drive shaft and rotated with the drive shaft, and a plurality of vacuum valves. hand And a plurality of cam followers for driving the vacuum valve, which are brought into contact with the cam surface of the driving cam, and a displacement for transmitting the displacement of the plurality of cam followers caused by the driving cam to the movable shaft of the corresponding vacuum valve. A transmission mechanism, wherein the plurality of cam followers are moved in accordance with 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. In the sequence described above, causing the plurality of vacuum valves to perform an opening / closing operation at the time of tap switching from an odd-numbered tap to an even-numbered tap, and the drive generated when the stopper mechanism releases the drive shaft at the second position. The plurality of cam followers are displaced in a predetermined sequence along with the rotation of the shaft from the second position to the first position, and an even number tap is applied to the plurality of vacuum valves. 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 driving cam, an auxiliary cam follower provided on the fixed frame side and in contact with a cam surface of the auxiliary cam, and a cam surface of the auxiliary cam follower. An auxiliary cam follower biasing spring that biases the auxiliary cam follower so as to press toward the side,
A cam surface of the auxiliary cam includes a first stopper portion that engages with the auxiliary cam follower when the drive shaft is at the first position and prevents rotation of the auxiliary cam toward a second position. A second stopper portion that engages with the auxiliary cam follower when the drive shaft is at the second position and prevents rotation of the auxiliary cam toward the first position;
When the drive shaft is at the first position and at the second position, the auxiliary cam follower is the first stopper on the cam surface of the auxiliary cam until the storage of the storage spring is completed. The urging force of the auxiliary cam follower urging spring and the shape of the stopper portion are set and selected respectively so as to hold the engaged state with the second stopper portion and to prevent the rotation of the drive shaft. That
Switching switch for a vacuum valve type tap switching device at load, characterized by the following. Each of the displacement transmitting mechanisms for transmitting the displacement of each of the vacuum valve driving cam followers to a corresponding vacuum valve includes a rotating shaft having an intermediate corner portion extending in a direction perpendicular to the axis of the driving shaft to the fixed frame. The stopper is movably supported and has one end coupled to the vacuum valve driving cam follower and the other end connected to a movable shaft of a corresponding vacuum valve via a pin via a pin; The mechanism has a rotatable stopper mechanism L-shaped lever supported by the fixed frame via a rotation 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 an L-shaped lever for a stopper mechanism,
The switching for the vacuum valve type tap switching device at load according to claim 2 or 3, wherein the auxiliary cam follower biasing spring is provided between a rear end portion of the L-shaped lever for the stopper mechanism and the fixed frame. Switch.   5. The changeover switch for a vacuum valve type 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 changeover switch for a vacuum valve-type load tap changer according to claim 1, wherein the stopper comprises a projection.   6. The switching switch for a vacuum valve type tap switching device at load according to any one of claims 1 to 5, wherein the stopper comprises a concave portion into which the auxiliary cam follower is fitted.

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