JP4201963B2 - Vacuum valve opening / closing mechanism of tap changer when loaded - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum valve opening / closing mechanism that performs tap switching with a load tap changer, and more particularly to a vacuum valve opening / closing mechanism of a load tap changer in which a member that opens and closes a vacuum valve is improved.
[0002]
[Prior art]
Generally, the transformer is provided with a load tap changer for voltage adjustment. The on-load tap changer employs a vacuum valve opening / closing mechanism that opens and closes a vacuum valve having electrodes to switch the tap of the transformer tap winding. Here, a conventional vacuum valve opening / closing mechanism of the on-load tap changer will be specifically described with reference to FIGS. This technique is, for example, as disclosed in Japanese Patent Application No. 10-87077. FIG. 6 is a longitudinal sectional view of a vacuum valve opening / closing mechanism, and FIG. 7 is a sectional view taken along line AA in FIG. 8 is a cross-sectional view taken along the line EE in FIG. 7, and FIG. 9 is a cross-sectional view taken along the line FF in FIG.
[0003]
In FIG. 6, reference numeral 1 indicated by a dotted line is an energy storage device that is a drive source of the vacuum valve opening / closing mechanism 30. An output shaft 1a that reciprocally rotates within a certain range using a spring as an energy source is rotatably supported by the energy storage device 1. A drive shaft 2 is connected to the output shaft 1a so that the rotational force from the output shaft 1a is transmitted. A plate 3 is attached to the drive shaft 2, and a vacuum valve opening / closing mechanism 30 is provided below the plate 3. As shown in FIG. 7, the vacuum valve opening / closing mechanism 30 opens and closes vacuum valves 31a and 31b corresponding to U, V, and W phases. More specifically, the movable contact 41 and the fixed contact 42 are disposed opposite to each other inside the vacuum valves 31a and 31b. When the vacuum valves 31a and 31b are opened and closed by the vacuum valve opening / closing mechanism 30, the movable contact 41 is fixed to the fixed contact 42. It is designed to perform contact and separation operations.
[0004]
The vacuum valve opening / closing mechanism 30 is provided with a rotatable cam 4 attached to the drive shaft 2. Cam grooves 4 a and 4 b are formed on the outer peripheral portion of the cam 4 by displacing appropriate portions in the circumferential direction in the vertical direction. A drive boss 20 is disposed in the vicinity of the outer periphery of the cam 4, and a cam follower 21 that engages with the cam grooves 4 a and 4 b is rotatably attached to the drive boss 20. The drive boss 20 has two drive boss arms 100 facing each other.
[0005]
As shown in FIG. 8, the drive boss 20 is formed with a through hole 20 a penetrating in the vertical direction, and a guide rod 29 fixed between the plates 3 and 5 is inserted therethrough. A straight guide 28 is installed on the guide rod 29, and the drive boss 20 is supported so as to move up and down along the guide rod 29.
[0006]
An open / close boss 24 is disposed adjacent to the drive boss 20, and an open / close boss arm 101 is formed on the open / close boss 24 so as to be sandwiched between the drive boss arm 100 from above and below. The drive boss arm 100 and the open / close boss arm 101 both extend in the horizontal direction and are configured to contact each other with a predetermined clearance.
[0007]
As shown in FIG. 9, a screw hole 24 a is formed in the bottom surface of the opening / closing boss 24. A movable contact 41 of vacuum valves 31a and 31b is disposed below the bottom surface of the open / close boss 24. A male screw 43 is disposed on the upper surface of the movable contact 41 so as to protrude upward, and a female screw 44 is disposed on the inner periphery thereof. The male screw 43 is screwed into the screw hole 24a of the opening / closing boss 24, and the bolt 27 is screwed into the female screw 44. In this way, the open / close boss 24 is fixed to the movable contact 41 of the vacuum valves 31a and 31b.
[0008]
Further, the opening / closing boss 24 is provided with a recess 24b, and a wipe spring 25 is disposed in the recess 24b. The drive boss 20 is attached to one end of the wipe spring 25, and the bottom surface of the open / close boss 24 is in contact with the other end so that a necessary contact force is applied to the movable contact 41 according to the vertical movement of the drive boss 20. It has become. In addition, guide holes 32 are formed in the left and right ends of the open / close boss arm 101, and guide pins 26 inserted through the guide holes 32 are fixed to the left and right ends of the drive boss arm 100.
[0009]
Further, as shown in FIG. 6, a flexible conducting wire 22 is attached to the open / close boss 24, and a distal end portion of the flexible conducting wire 22 is connected to a terminal N. Further, a changeover switch movable mechanism 50 is connected to the drive shaft 2 via an idle rotation mechanism 40. The changeover switch movable mechanism 50 is provided with a current collecting contact 70 and a changeover contact 60 of the changeover switch. A stationary contact 42 of vacuum valves 31 a and 31 b is connected to the current collecting contact 70, and a terminal S is connected to the switching contact 60. That is, when the fixed contact 42 of the vacuum valves 31a and 31b is connected to the terminal S via the contacts 60 and 70, and the movable contact 41 and the fixed contact 42 in the vacuum valves 31a and 31b are in a closed state, A current conduction path from the terminal S to the terminal N is formed. Reference numeral 7 denotes a plate.
[0010]
In the vacuum valve opening / closing mechanism having the above-described configuration, the opening operation of the movable contact 41 and the fixed contact 42 is performed as follows. That is, when the output shaft 1a of the energy storage device 1 is rotated in response to the opening command, the rotational force is transmitted to the drive shaft 2 and the cam 4 rotates. At this time, the cam follower 21 engaged with the cam groove 4a or 4b rises according to the displacement of the cam grooves 4a and 4b, and the drive boss 20 to which the cam follower 21 is attached rises along the guide rod 29. Then, the drive boss arm 100 contacts the open / close boss arm 101, and the open / close boss 24 is also raised. At this time, since the guide pin 26 is inserted into the guide hole 32, the open / close boss 24 and the drive boss 20 are raised while being guided in the same direction. Therefore, the movable electrode 41 of the vacuum valves 31a and 31b fixed to the open / close boss 24 is lifted, and the movable contact 41 is separated from the fixed contact 42 to be opened.
[0011]
[Problems to be solved by the invention]
However, the conventional vacuum valve opening / closing mechanism described above has the following problems to be solved. This point will be described with reference to FIG. 10 is a cross-sectional view taken along the line XX of FIG. When the vacuum valves 31a and 31b are opened, the drive boss 20 guided by the cam grooves 4a and 4b moves upward, but the drive boss arm 100 has a slight angle with respect to the horizontal plane due to processing and assembly tolerances. May rise.
[0012]
In such a case, as shown in FIG. 10, the distance L from the contact point of the open / close boss arm 101 and the drive boss arm 100 to the axial center line of the movable contact 41 of the vacuum valve increases. The moment generated from the force F 1 received by the movable contact 41 from the drive boss 20 and the distance L causes an inclination with respect to the axial center line of the movable contact 41. That is, the greater the distance L, the greater the inclination of the movable contact 41. Therefore, the force F2 that the movable contact 41 receives from the bearing portion 200 becomes strong, and the opening speed of the movable contact 41 may be reduced.
[0013]
The present invention has been proposed in order to solve the above-described problems, and the distance between the contact point of the open / close boss and the drive boss and the axial center line of the movable contact is shortened by an extremely simple configuration. An object of the present invention is to provide a vacuum valve opening / closing mechanism that eliminates the inclination of the boss and the movable contact to prevent the opening speed of the vacuum valve from being lowered, thereby ensuring excellent operational reliability.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is provided with a rotatable cam, a drive boss and an open / close boss capable of moving up and down, and a vacuum valve having a movable contact and a fixed contact. In the vacuum valve opening / closing mechanism of the on-load tap changer configured such that the drive boss moves up and down and the opening and closing boss moves up and down to open and close the movable contact and the fixed contact of the vacuum valve. It has the following features.
[0015]
That is, according to the present invention, the drive boss and the opening / closing boss are formed with contact surfaces that contact each other with a predetermined clearance, and a guide hole is inserted in one and the guide is inserted through the guide hole in the other. A pin is disposed, and at least one of the contact surfaces is provided with a protrusion that protrudes toward the other contact surface, and the protrusion includes a threaded spacer.
[0016]
In the present invention as described above, at the time of the vacuum valve opening and closing, the projecting portion provided on the contact surface of the opening and closing boss and the driving boss is in contact with the contact surface facing. For this reason, the distance between the contact point of the open / close boss and the drive boss and the axial center line of the movable contact is shorter than in the prior art. Therefore, the moment generated on the contact surface of the open / close boss is reduced, and the open / close boss and the movable contact are not easily inclined with respect to the axial center line of the movable contact. As a result, the force that the movable contact receives from the horizontal direction can be reduced, and a decrease in the opening speed can be prevented. Accordingly, the movable contact can smoothly perform the opening operation, and excellent operation reliability can be obtained.
[0020]
Further, the contact surfaces of the open / close boss and the drive boss come into contact with each other through the threaded spacer. For this reason , the contact point of the open / close boss and the drive boss will be close to the axial center line of the movable contact, and the moment generated on the contact surface of the open / close boss will be reduced to avoid a decrease in the opening speed of the movable contact. be able to. In addition , since the projecting portion is composed of another member, the projecting amount can be easily changed. Therefore, it is possible to appropriately adjust the opening distance of the vacuum valve, and it is possible to obtain more excellent operation reliability.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the vacuum valve opening / closing mechanism of the on-load tap changer according to the present invention will be specifically described below with reference to the drawings. In addition, about the same member as the prior art example shown in FIGS. 6-10, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0022]
(1) Embodiments [Configuration] as a premise of the present invention
Figure 1 is a perspective view showing an embodiment which is a premise of the present invention. The present embodiment is characterized in that a protrusion 102 is provided on the contact surface side of the open / close boss arm 101 with the drive boss arm 100.
[0023]
[Function and effect]
The operational effects of the present embodiment having the above-described configuration are as follows. When the drive boss 20 is lifted when the vacuum valves 31 a and 31 b are opened, the drive boss arm 100 comes into contact with the protrusion 102 provided on the open / close boss arm 101. For this reason, the distance L from the contact point of the drive boss 20 and the opening / closing boss 24 to the center line in the axial direction of the movable contact 41 is shorter than the conventional one. Therefore, the moment generated in the opening / closing boss arm 101 is small, and the movable contact 41 is difficult to tilt when performing the ascending operation. As a result, the force F2 received from the bearing part 200 of the movable contact 41 can be reduced, and the opening speed of the movable contact 41 does not decrease. That is, the movable contact 41 can perform a smooth opening operation, and the operation reliability is improved.
[0024]
(2) Reference example 1
[Constitution]
FIG. 2 is a perspective view showing Reference Example 1. FIG. The feature of this reference example 1 is that an annular spacer 103 is installed between the open / close boss arm 101 and the drive boss arm 100 of the two guide pins 26 that guide the drive boss 20.
[0025]
[Function and effect]
In the first reference example having the above-described configuration, when the drive boss 20 is raised when the vacuum valves 31 a and 31 b are opened, the drive boss arm 100 contacts the annular spacer 103 between the open / close boss arm 101 and the drive boss arm 100. Then, the annular spacer 103 is pushed by the driving boss arm 100 to come into contact with the arm 101 of the opening / closing boss, and pulls up the opening / closing boss 24.
[0026]
That is, in Reference Example 1 , since the contact between the open / close boss arm 101 and the drive boss arm 100 is via the annular spacer 103, the contact surface between the bosses 20, 24 is limited to the annular spacer 103, and the movable contact 41 The distance L between the center line in the axial direction and the contact point between the bosses 20 and 24 is shorter than in the prior art. Therefore, as in the embodiment which is the premise of the present invention, the moment generated in the open / close boss arm 101 can be reduced, and the inclination of the movable contact 41 can be eliminated. Thereby, the fall of the opening speed of the movable contact 41 can be prevented, and the movable contact 41 can ensure excellent operation reliability.
[0027]
Moreover, according to the reference example 1 , the protrusion amount of the protrusion can be changed only by changing the size of the annular spacer 103. Therefore, the height of the lift stroke of the open / close boss 24, that is, the opening distance of the vacuum valves 31a and 31b can be adjusted appropriately, and more excellent operational reliability can be obtained.
[0028]
(3) Reference Example 2
[Constitution]
FIG. 3 is a perspective view showing Reference Example 2 . The reference example 2 has a structure in which the linear steel 104 is wound around the guide pin 26 between the opening / closing boss arm 101 and the drive boss arm 100 instead of the annular spacer 103 in the reference example 1 .
[0029]
[Function and effect]
In Reference Example 2 having the above-described structure, the contact between the open / close boss arm 101 and the drive boss arm 100 is via the linear steel 104, so the contact surface between the drive boss 20 and the open / close 24 boss is the linear steel 104. Limited. For this reason, as in the embodiment and the reference example 1 as the premise of the present invention, the distance L between the axial center line of the movable contact 41 and the contact point between the bosses 20 and 24 is shortened, and the inclination of the movable contact 41 is reduced. This can prevent the decrease in the opening speed of the movable contact 41.
[0030]
Moreover, in the reference example 2 , the member for shortening the distance L between the axial center line of the movable contact 41 and the contact point between the bosses 20 and 24 is the linear steel 104, so that the vacuum valve opening / closing mechanism is assembled. Even after this, it can be arbitrarily arranged around the guide pin 26. Therefore, the attachment is extremely easy, and it is possible to reliably improve the operation reliability of the movable contact 41 by appropriately adjusting the opening distance of the vacuum valve.
[0031]
(4) Embodiment [Configuration]
FIG. 4 is a perspective view showing an embodiment of the present invention (hereinafter referred to as the present embodiment), and FIG. 5 is a cross-sectional view of the main part of the present embodiment . This embodiment is characterized in that a threaded spacer 105 having a U-shaped groove in the middle so that it can be inserted into the guide pin 26 later is fixed to the drive boss arm 100 with a screw.
[0032]
[Function and effect]
In above-described embodiment, since the threaded spacer 105 is to shorten the distance L between the contact point of the center line and the boss 20, 24 to each other in the axial direction of the movable contact 41, as a premise of the present invention described above similar to the embodiments and reference examples, it is possible to prevent deterioration of opening speed of the movable contact 41. In addition, in this embodiment , the rising height of the open / close boss 24, that is, the opening distance of the vacuum valves 31a and 31b, can be easily adjusted by the screwing depth of the threaded spacer 105. Moreover, since the threaded spacer 105 can be inserted after the vacuum valve opening / closing mechanism is assembled, the opening distance in the assembled vacuum valves 31a and 31b can be easily set.
[0033]
【The invention's effect】
As described above, according to the vacuum valve opening / closing mechanism of the on-load tap changer according to the present invention, at least one of the driving boss and the contact surface between the opening / closing bosses protrudes toward the contact surface. With an extremely simple configuration, it is possible to prevent the opening and closing bosses and the movable contact from being inclined, thereby preventing a decrease in the opening speed of the vacuum valve, thereby ensuring excellent operational reliability.
[Brief description of the drawings]
FIG. 1 is a perspective view of an embodiment as a premise of the present invention.
2 is a perspective view of Reference Example 1. FIG.
3 is a perspective view of Reference Example 2. FIG.
FIG. 4 is a perspective view of an embodiment of the present invention.
FIG. 5 is a cross-sectional view of FIG.
FIG. 6 is a cross-sectional view of a conventional vacuum valve opening / closing mechanism of a load tap changer.
7 is a cross-sectional view taken along the line AA in FIG. 6;
8 is a cross-sectional view taken along the line E-E in FIG. 7;
9 is a cross-sectional view taken along the line FF in FIG.
10 is a structural diagram (cross-sectional view taken along the line XX in FIG. 7) showing a force applied to a movable contact of a vacuum valve switching mechanism of a conventional load tap changer.

Claims (1)

A rotatable cam, a vertically movable drive boss and open / close boss, and a vacuum valve having a movable contact and a fixed contact are provided, and the drive boss moves up and down by the rotation of the cam, and the open / close is accordingly performed. In the vacuum valve opening and closing mechanism of the load tap changer configured such that the boss moves up and down and the movable contact of the vacuum valve opens and closes with respect to the fixed contact,
The drive boss and the opening / closing boss are formed with contact surfaces that contact each other with a predetermined clearance, a guide hole is disposed on one side, and a guide pin that is inserted through the guide hole is disposed on the other side.
At least one of the contact surface, the projecting portion is provided which protrudes toward the other of the contact surfaces,
The vacuum valve opening / closing mechanism of the on-load tap changer, wherein the protruding portion is constituted by a threaded spacer .

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