JP2002050267A - Vacuum valve switching mechanism for tap changer when loaded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the a vacuum valve switching mechanism which is reliable in operation by shortening the distance between the contact point of a switching boss and a driving boss and the central line in the axial direction of the movable contact point, and by removing the slants of the switching boss and the movable contact point to prevent a vacuum valve from reduction in opening speed. SOLUTION: The projection 102 is provided on the side of the surface being in contact with the driving boss arm 100 in the switching boss arm 101, and when the vacuum bulb 31 opens, the driving boss arm 100 comes in contact with the projection 102. Therefore, the distance L between the contact point of the driving boss 20 and the switching boss 24 and the central line in the axial direction of the movable contact point 41 becomes short, the movable contact point 41 is prevented from inclining, and thereby the reduction in opening speed does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve opening / closing mechanism for performing tap switching by a load tap changer, and more particularly to a vacuum valve of a load tap changer in which a member for opening and closing a vacuum valve is improved. It relates to an opening and closing mechanism.

[0002]

2. Description of the Related Art Generally, a transformer is provided with an on-load tap changer for voltage adjustment. The on-load tap changer employs a vacuum valve opening and closing mechanism for opening and closing a vacuum valve having an electrode to switch a tap of a transformer tap winding. Here, the conventional vacuum valve opening / closing mechanism of the on-load tap changer will be specifically described with reference to FIGS. This technology is disclosed in, for example, Japanese Patent Application No. 10-8 / 1998.
No. 7077, FIG.
7 is a vertical sectional view of the vacuum valve opening / closing mechanism, and FIG.
8 is a sectional view taken along the line EE of FIG. 7, and FIG. 9 is a sectional view taken along the line FF of FIG.

In FIG. 6, reference numeral 1 shown by a dotted line denotes an energy storage device which is a driving source of the vacuum valve opening / closing mechanism 30.
The energy storage device 1 rotatably supports an output shaft 1a that reciprocates in a predetermined range using a spring as an energy source. The 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 the vacuum valves 31a, 31b corresponding to the U, V, and W phases. More specifically, a movable contact 41 and a fixed contact 42 are opposed to each other inside the vacuum valves 31a and 31b.
By opening and closing a and 31b, the movable contact 41 performs a contact / separation operation with respect to the fixed contact.

[0004] The vacuum valve opening / closing mechanism 30 is provided with a rotatable cam 4 attached to the drive shaft 2. Cam 4
The cam groove 4a, 4b which is displaced in the vertical direction at an appropriate position in the circumferential direction is formed in the outer peripheral portion of the. A drive boss 20 is arranged near 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 mounted on the drive boss 20. The drive boss 20 has two drive boss arms 100 facing each other.

As shown in FIG. 8, a through hole 20a is formed in the drive boss 20 so as to penetrate the drive boss 20 in a vertical direction, and a guide rod 29 fixed between the plates 3 and 5 is inserted through the through hole 20a. A straight guide 28 is provided on the guide rod 29, and the drive boss 20 is supported so as to move up and down along the guide rod 29.

An opening / closing boss 24 is disposed adjacent to the driving boss 20, and the opening / closing boss 24 has the driving boss arm 100.
The opening / closing boss arm 101 is formed so as to be sandwiched from above and below. Both the drive boss arm 100 and the open / close boss arm 101 extend in the horizontal direction, and are configured to contact each other with a predetermined clearance.

As shown in FIG. 9, a screw hole 24a is formed in the bottom of the opening / closing boss 24. Opening boss 2
The movable contacts 41 of the vacuum valves 31a and 31b are arranged below the four bottom surfaces. 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 an inner peripheral portion thereof. The screw hole 24 a of the opening / closing boss 24 is screwed into the male screw 43, and the bolt 27 is screwed into the female screw 44. Thus, the opening / closing boss 24 is fixed to the movable contact 41 of the vacuum valves 31a, 31b.

Further, a concave portion 24b is provided in the opening / closing boss 24, and a wipe spring 25 is disposed in the concave portion 24b. The drive boss 20 is attached to one end of the wipe spring 25, and the bottom surface of the opening / closing 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. Has become. Guide holes 32 are formed at both left and right ends of the open / close boss arm 101, and guide pins 26 inserted into the guide holes 32 are fixed to left and right end portions of the drive boss arm 100.

Further, as shown in FIG.
A flexible conductor 22 is attached to the
2 is connected to a terminal N at the tip. Further, a changeover switch movable mechanism 50 is connected to the drive shaft 2 via an idling mechanism 40. Changeover switch movable mechanism 50
Are provided with a current collecting contact 70 and a switching contact 60 of a changeover switch. The fixed contact 42 of the vacuum valves 31 a and 31 b is connected to the current collecting contact 70, and the terminal S is connected to the switching contact 60. That is, the contact 6
The fixed contacts 42 of the vacuum valves 31a, 31b are connected to the terminal S via the terminals 0, 70, and the vacuum valves 31a, 3b.
When the movable contact 41 and the fixed contact 42 in 1b are in the closed state, a current supply path from the terminal S to the terminal N is formed. Reference numeral 7 denotes a plate.

In the vacuum valve opening / closing mechanism having the above 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 rotates 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 groove 4a, 4b, and the drive boss 20 on which the cam follower 21 is mounted
Ascend along 9 Then, the driving boss arm 100 comes into contact with the opening / closing boss arm 101, and the opening / closing boss 24 also moves up. At this time, since the guide pin 26 is inserted through the guide hole 32, the opening / closing boss 24 and the drive boss 20 rise while being guided in the same direction. Therefore, the movable electrodes 41 of the vacuum valves 31a and 31b fixed to the opening / closing boss 24 rise, and the movable contact 41 separates from the fixed contact 42 and reaches an opening.

[0011]

However, the above-mentioned conventional vacuum valve opening / closing mechanism has the following problems to be solved. This will be described with reference to FIG. FIG. 10 is a sectional view taken along line XX of FIG. Vacuum valve 31
When the poles a and 31b are opened, the drive boss 20 guided by the cam grooves 4a and 4b performs a rising motion.
00 may rise at a slight angle to the horizontal due to processing and assembly tolerances.

In such a case, as shown in FIG. 10, a distance L from the contact point between the opening / closing boss arm 101 and the driving boss arm 100 to the axial center line of the movable contact 41 of the vacuum valve.
Will increase. The movable contact 41 is the drive boss 20
The movable contact 41 is inclined with respect to the axial center line by the moment F1 and the moment generated from the distance L. That is, the greater the distance L, the greater the inclination of the movable contact 41. Therefore, the movable contact 4
The force F2 received from the bearing unit 200 by the contact 1 increases, and the opening speed of the movable contact 41 may decrease.

The present invention has been proposed to solve the above problems, and has a very simple structure to reduce the distance between the contact point of the open / close boss and the drive boss and the axial center line of the movable contact. It is an object of the present invention to provide a vacuum valve opening / closing mechanism in which the opening / closing boss and the movable contact are inclined to prevent the opening speed of the vacuum valve from lowering, thereby ensuring excellent operation reliability.

[0014]

In order to achieve the above object, the present invention comprises a rotatable cam, a vertically movable drive boss and an open / close boss, and a vacuum valve having a movable contact and a fixed contact. The driving boss is moved up and down by the rotation of the cam, and the opening and closing boss is moved up and down accordingly, and the movable contact and the fixed contact of the vacuum valve are opened and closed. The vacuum valve opening / closing mechanism has the following features.

According to the first aspect of the present invention, the drive boss and the opening / closing boss are formed with a contact surface that contacts each other with a predetermined clearance, one of which has a guide hole, and the other has a guide hole. A guide pin inserted into the hole is disposed, and at least one of the contact surfaces is provided with a protruding portion protruding toward the contact surface.

In the first aspect of the present invention, when the vacuum valve is opened and closed, the protruding portions provided on the contact surfaces of the opening / closing boss and the driving boss come into contact with the opposite contact surfaces.
For this reason, the distance between the contact point of the opening / closing boss and the drive boss and the axial center line of the movable contact becomes shorter than before. Therefore, the moment generated on the contact surface of the opening / closing boss becomes small, and the opening / closing boss and the movable contact are hardly 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. As a result, the movable contact can smoothly perform the opening operation, and excellent operation reliability can be obtained.

According to a second aspect of the present invention, in the vacuum valve opening and closing mechanism of the on-load tap changer according to the first aspect, the guide pin is provided with an annular spacer that can contact the contact surface. And

The third aspect of the present invention is the first or second aspect.
In the vacuum valve opening / closing mechanism of the on-load tap changer described in (1), a wire steel is attached to the guide pin.

According to a fourth aspect of the present invention, in the vacuum valve opening / closing mechanism of the on-load tap changer according to the first, second or third aspect, the projecting portion is formed of a threaded spacer.

In the above-mentioned inventions, the contact surfaces of the open / close boss and the drive boss come into contact with each other via the annular spacer, the linear steel, or the threaded spacer. Therefore, the contact point of the opening / closing boss and the driving boss approaches the center line of the movable contact in the axial direction, and the moment generated on the contact surface of the opening / closing boss is reduced, as in the first aspect of the invention. Can be avoided. Moreover, in the inventions according to the second to fourth aspects, since the protruding portion is formed of a separate member, the protruding amount can be easily changed. Therefore, the opening distance of the vacuum valve can be appropriately adjusted, and more excellent operation reliability can be obtained.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vacuum valve opening / closing mechanism of a load tap changer according to the present invention will be specifically described below with reference to the drawings. The same members as those in the conventional example shown in FIGS. 6 to 10 are denoted by the same reference numerals, and description thereof will be omitted.

(1) First Embodiment [Configuration] FIG. 1 is a perspective view showing a first embodiment to which the invention of claim 1 is applied. The first embodiment is characterized in that a projection 102 is provided on a side of a contact surface of the open / close boss arm 101 with the drive boss arm 100.

[Operation and Effect] The operation and effect of the first embodiment having the above-described configuration are as follows. When the drive boss 20 rises when the vacuum valves 31a and 31b 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 between the drive boss 20 and the opening / closing boss 24 to the center line of the movable contact 41 in the axial direction becomes shorter than before. Therefore, the moment generated in the opening / closing boss arm 101 is reduced, and the movable contact 41 is hardly inclined when performing the ascent operation. As a result, the force F2 received from the bearing portion 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.

(2) Second Embodiment [Configuration] FIG. 2 is a perspective view showing a second embodiment to which the invention of claim 2 is applied. The feature of the second embodiment resides in that an annular spacer 103 is provided between the open / close boss arm 101 and the drive boss arm 100 of the two guide pins 26 for guiding the drive boss 20.

[Effects] In the second embodiment having the above-described structure, when the drive boss 20 rises when the vacuum valves 31a and 31b are opened, the drive boss arm 100 opens and closes the open / close boss arm 101 and the drive boss. The annular spacer 103 between the arms 100 contacts the annular spacer 103, and the annular spacer 103
00 and is brought into contact with the arm 101 of the opening / closing boss, and the opening / closing boss 24 is pulled up.

That is, in the second embodiment, the contact between the opening / closing boss arm 101 and the driving boss arm 100 is via the annular spacer 103, so that the contact surface between the bosses 20 and 24 is limited to the annular spacer 103. And the distance L between the axial center line of the movable contact 41 and the contact point between the bosses 20 and 24 becomes shorter than before. Therefore, similarly to the first embodiment, the moment generated in the open / close boss arm 101 can be reduced, and the inclination of the movable contact 41 can be eliminated. Accordingly, a decrease in the opening speed of the movable contact 41 can be prevented, and the movable contact 41 can ensure excellent operation reliability.

According to the second embodiment, the protrusion amount of the protrusion can be changed only by changing the size of the annular spacer 103. Therefore, the height of the rising stroke of the opening / closing boss 24, that is, the vacuum valves 31a, 31
The opening distance of b can be appropriately adjusted, and more excellent operation reliability can be obtained.

(3) Third Embodiment [Configuration] FIG. 3 is a perspective view showing a third embodiment of the present invention. The third embodiment has a structure in which a linear steel 104 is wound around a guide pin 26 between the opening / closing boss arm 101 and the driving boss arm 100 instead of the annular spacer 103 in the second embodiment. ing.

[Effects] In the third embodiment having the above structure, the opening / closing boss arm 101 and the driving boss arm 1
00 contact with the drive boss 2
The contact surface between the 0 boss and the open / close 24 boss is limited to the linear steel 104. Therefore, similarly to the first and second embodiments, the axial center line of the movable contact 41 and the boss 20,
24, the distance L between the contact point and the movable contact 41 is reduced.
Of the movable contact 41 can be prevented from lowering.

Further, in the third embodiment, since the member for shortening the distance L between the center line in the axial direction of the movable contact 41 and the contact point between the bosses 20 and 24 is the linear steel 104, a vacuum is applied. Even after the valve opening / closing mechanism is assembled, it can be arbitrarily arranged around the guide pin 26. Therefore, the mounting is extremely easy, and the operating reliability of the movable contact 41 can be reliably improved by appropriately adjusting the opening distance of the vacuum valve.

(4) Fourth Embodiment [Configuration] FIG. 4 is a perspective view showing a fourth embodiment to which the invention of claim 4 is applied, and FIG. 5 is a main part of the fourth embodiment. It is sectional drawing. The fourth embodiment is characterized in that a threaded spacer 105 having a U-shaped groove cut in the middle so as to be later inserted into the guide pin 26 is fixed to the drive boss arm 100 with a screw. I have.

[Operation and Effect] In the fourth embodiment described above, the threaded spacer 105 shortens the distance L between the axial center line of the movable contact 41 and the contact point between the bosses 20 and 24. Therefore, similarly to the above embodiment, a decrease in the opening speed of the movable contact 41 can be prevented. In addition, in the fourth embodiment, the height at which the opening / closing boss 24 rises, 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 assembling the opening / closing mechanism of the vacuum valve, the opening distance of the assembled vacuum valves 31a and 31b can be easily set.

[0033]

As described above, according to the opening / closing mechanism of the vacuum valve of the on-load tap changer of the present invention, at least one of the contact surfaces between the driving boss and the opening / closing boss is directed toward the surface that comes into contact. The extremely simple structure of providing a protruding part that protrudes from the opening and closing boss and the movable contact makes it possible to prevent the opening speed of the vacuum valve from lowering, thereby ensuring excellent operation reliability. Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a perspective view of a second embodiment of the present invention.

FIG. 3 is a perspective view of a third embodiment of the present invention.

FIG. 4 is a perspective view of a fourth embodiment of the present invention.

FIG. 5 is a sectional view of FIG. 4;

FIG. 6 is a cross-sectional view of a conventional vacuum valve opening / closing mechanism of an on-load tap changer.

FIG. 7 is a sectional view taken along the line AA of FIG. 6;

FIG. 8 is a sectional view taken along the line EE in FIG. 7;

9 is a sectional view taken along the line FF in FIG. 7;

10 is a structural diagram showing a force applied to a movable contact of a vacuum valve opening / closing mechanism of a conventional load tap changer (XX in FIG. 7);
Sectional view).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Energy storage device 2 ... Drive shaft 3, 5, 7 ... Plate 4 ... Cam 4a, 4b ... Cam groove 20 ... Drive boss 21 ... Cam follower 22 ... Flexible conductive wire 24 ... Opening / closing boss 25 ... Wiping spring 26 ... Guide pin 27 ... Bolt 28 Linear guide 29 Guide rod 30 Vacuum valve opening and closing mechanism 31a, 31b Vacuum valve 32 Guide hole 40 Idling mechanism 41 Movable contact of vacuum valve 42 Fixed contact of vacuum valve 100 Driving boss arm 101 Opening / closing boss arm 102 ... Protrusion 103 ... Annular spacer 104 ... Linear steel 105 ... Threaded spacer 200 ... Bearing N, S ... Terminal F1 ... Force that movable contact 41 receives from drive boss 20 F2 ... Moving contact 41 is bearing Power received from 200

Claims (4)

[Claims] 1. A rotatable cam, a vertically movable drive boss and an open / close boss, and a vacuum valve having a movable contact and a fixed contact are provided, and the rotation of the cam causes the drive boss to move up and down. Along with this, the open / close boss moves up and down, and the movable contact of the vacuum valve opens and closes with respect to the fixed contact. A contact surface is formed to contact each other with a predetermined clearance, a guide hole is arranged on one side, and a guide pin inserted into the guide hole is arranged on the other side, and at least one of the contact surfaces has the other side. A vacuum valve opening / closing mechanism for a tap changer under load, wherein a projection is provided that protrudes toward a contact surface of the tap. 2. The vacuum valve opening / closing mechanism for a load tap changer according to claim 1, wherein an annular spacer capable of contacting the contact surface is provided on the guide pin. 3. The vacuum valve opening / closing mechanism of a tap changer under load according to claim 1, wherein a wire steel is attached to the guide pin. 4. The vacuum valve opening / closing mechanism for a load tap changer according to claim 1, wherein the projecting portion is formed of a threaded spacer.