JPS6320037Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vacuum switch equipped with a vacuum valve.

Conventional vacuum switches of this type include those shown in FIGS. 1 to 4. In the figure, 1 is 10 ^-4 ~
A vacuum valve maintains a vacuum of 10 ^-6 Torr.
The vacuum valves are vertically mounted on a mounting plate 4 by means of screws 3 so as to be adjacent to each other and mounted on a mounting base 2 made of plastic that provides grounding and insulation between each phase (see FIG. 1).

Reference numerals 5 and 6 denote a fixed contact and a movable contact of the vacuum valve 1, and a flexible conductor 8 is attached above the fixed electrode 7 of the fixed contact 5 by a fastening member screwed to the fixed electrode 7, and a flexible conductor 8 is connected to the power supply side terminal through this. A flexible conductor 11 is attached to the lower part of the movable electrode 10 of the movable contact 6 by a fastening member, and a load side terminal 12 is connected thereto. An operating rod 13 is screwed to the lower end of the movable electrode 10 to which the flexible conductor 11 is attached, and a spring receiver 14 inserted into the operating rod 13 is connected to the lower end of the operating rod 13. Pressure spring 15
Further, at the lower end of the operating rod 13 into which the spring receiver 14 is inserted, there is an adjustment nut 16 and a support nut 17 for adjusting the gap and contact wipe amount when the contacts 5 and 6 are opened. are screwed together (see Figure 3).

Further, 18 has a distal end inserted between the spring receiver 14 and the adjustment nut 16, and engages with the operating rod 13 to support the spring receiver 14, while the other end is fixed to the mounting plate 4. The operation arm 22 is screwed together with a movable iron core 21 to a shaft 20 rotatably supported by a bearing 19, and has a U-shaped tip made of an insulating material and moves the operation rod 13 in the axial direction. A fixed iron core 23, a yoke 24, which are arranged opposite to the movable iron core 21 and are attached to the mounting plate 4 so as to be adjacent to each other.
and an operating coil 25 wound around the fixed core 23
an electromagnet 26 that attracts the movable iron core 21 and rotates the operating arm 18 in the counterclockwise direction in the figure, thereby pushing up the movable electrode 10 and bringing the movable contact 6 and the fixed contact 5 into contact contact; Reference numeral 27 indicates a trip spring that applies a rotational force to the movable iron core 21 in the clockwise direction shown in the figure when the electromagnet 22 is deenergized, thereby pulling down the movable electrode 10 via the operating arm 18 to open the contact. 26 adjustment nuts (see Figure 1).

In the vacuum switch configured as described above, when a voltage is applied to the operating coil 25 of the electromagnet 22, the movable core 21 is attracted to the fixed core 23 against the tripping spring 26, and the fixed contact 5 and the movable contact 6 is closed by the differential pressure, that is, the pressure difference between atmospheric pressure and the pressure inside the vacuum valve 1, and the force of the pressure spring 15. At this time, the operating arm 18 rotates further by the contact wipe amount from the position where the fixed contact 5 and the movable contact 6 contact each other (see FIG. 4). Therefore, the adjusting nut 16 and the operating arm 18 are separated, and the force of the tripping spring 26 does not act on the movable contact 6, so that the fixed contact 5 and the movable contact 6 are closed by the pressure difference.

In this state, when the electromagnet 22 is demagnetized, the movable core 21 is separated from the fixed core 23 by the force of the tripping spring 26, and moves clockwise around the shaft 20 to the position shown by the dashed line in FIG. Rotate. Accordingly, the operating arm 18 fixed to the shaft 20 also rotates clockwise in the figure around the shaft 20,
This movement of the operating arm 18 is transmitted to the adjusting nut 16 and is connected to the movable contact 6 via the operating arm 18.
is pulled downward and the contact opens.

However, in conventional vacuum switches, the vacuum valve 1 is damaged due to shocks caused by repeated opening and closing of the contacts.
The bellows of the machine broke down, causing a vacuum leak. In other words, the bellows of the vacuum valve 1 is usually made of a thin spring stainless steel material and is formed into a bellows shape by welding or pressing. The lifespan of valve 1 is determined by the bellows as well as the contacts, and in particular, sudden destruction of the bellows is the most difficult maintenance issue, and a vacuum valve 1 with a vacuum leak will have no breaking performance and the arc will continue. . If the vacuum valve is used for a long period of time under such conditions, the vacuum valve may be damaged due to the heat of the arc, and the surrounding insulation may be burned out, leading to a fire or a short circuit between phases.

Therefore, the present invention was devised to eliminate the drawbacks of the conventional ones as described above, and provides a vacuum switch that can detect vacuum leaks at an early stage.

In order to achieve such an object, the present invention includes a detection means for detecting a vacuum leak by contacting an operating arm that rotates by the biasing force of the pressing spring when a vacuum leak occurs in the vacuum valve, It is characterized by early detection of vacuum leaks.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 5 to 7, in which the same parts as in FIGS. 1 to 4 are denoted by the same reference numerals. In the figure, reference numeral 28 denotes an operating arm in the present invention, one end 28a drives the operating rod 19, the other end 28b is driven by the operating plate 29 and rotates around a shaft 30, and the vacuum valve 1 to 1
They are provided in a number corresponding to each other and rotate independently around the shaft 30. The operation plate 29 is screwed onto a cross bar 31, which has one end connected to the movable iron core 21 and rotates about a shaft 32. Further, the operating arm 28 has a recess 28c, and a pressing spring 33 is engaged with the recess 28c. 34 is a trip spring for pulling down the movable contact 6 via the operating plate 29 and operating arm 28 to open the contact.

Reference numeral 35 designates a micro switch that contacts one end 28d of the operating arm 28 and outputs a detection signal when the operating arm 28 is rotated clockwise in the figure by the pressing spring 33. Vacuum leakage within the vacuum valve 1 is detected.

In the vacuum switch having the above configuration, when the electromagnet 22 is now excited, the movable core 21 is attracted against the tripping spring 34, and the fixed contact 5 and the movable contact 6 are closed due to the differential pressure. At this time, the pressing spring 33 has a biasing force in the opposite direction to the differential pressure and acts in a direction to reduce the differential pressure, and the value of the spring force is set to a value that does not interfere with the contact of the contacts. That is, differential pressure>force of pressing spring 33, and contact pressure=(differential pressure-pressing spring force).

However, if a vacuum leak occurs in the vacuum valve 1 while the circuit is closed, the differential pressure becomes zero, so the operating arm 28
The spring 33 rotates clockwise, and one end 28d of the spring 33 rotates to the position indicated by the dashed line in FIG. I will do it. And with this micro switch 35,
If there is a power cutter on the power supply side, it will open the circuit and issue an alarm. In addition, if the vacuum switch is equipped with vacuum valves 1 for each phase in a three-phase circuit, even if a vacuum leak occurs in one vacuum valve 1, the remaining vacuum valves will have the ability to shut off the electromagnet. 22 can be demagnetized by the micro switch 35 to open the circuit and issue an alarm.

Furthermore, as shown in FIG. 7, if a vacuum leak occurs in the open state, the operation arm 28 will
8d rotates to the position indicated by the dashed line and contacts the micro switch 35, so that the same operation as in the closed circuit state is possible.

As described above, according to the present invention, an operating arm that rotates in response to excitation control of an electromagnet, an operating arm that is connected to a movable contact that is arranged opposite to a fixed contact in a vacuum valve, and that engages one end of the operating arm. In a vacuum switch equipped with a rod and a pressing spring that engages with the other end of the operating arm and has a biasing force in the direction of opening the contact, the biasing force of the pressing spring is applied when a vacuum leak occurs in the vacuum valve. Equipped with a detection means that detects vacuum leaks by coming into contact with the operating arm that rotates, it is possible to detect vacuum leaks early and prevent damage to the vacuum valve due to arc heat, burnout of surrounding insulators, etc. It can be prevented.

[Brief explanation of the drawing]

Figure 1 is a partially sectional side view showing a conventional vacuum switch, Figure 2 is a front view of Figure 1, and Figures 3 and 4 are
5 to 7 show a vacuum switch according to an embodiment of the present invention, FIG. 5 is a front view, FIG. 6 is a left side sectional view of FIG. 5, and FIG. 5 is a partially enlarged view illustrating the operation in the contact open state in FIG. 5. FIG. DESCRIPTION OF SYMBOLS 1... Vacuum valve, 5... Fixed contact, 6... Movable contact, 13... Operating rod, 28... Operating arm, 22... Electromagnet, 33... Pressing spring, 35... Detecting means (micro switch). In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] An operating arm that rotates in response to excitation control of an electromagnet, an operating rod that is connected to a movable contact placed opposite to a fixed contact in the vacuum valve and that engages one end of the operating arm, and the other end of the operating arm. In a vacuum switch equipped with a pressing spring that is engaged and has a biasing force in the direction of opening the contact, when a vacuum leak occurs in the vacuum valve, the operating arm that is rotated by the biasing force of the pressing spring comes into contact with the vacuum switch. A vacuum switch characterized in that it is equipped with a detection means for detecting a vacuum leak.