JPS6329770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum shield and breaker, and particularly to a vacuum shield and breaker that facilitates the opening of electrodes that are prone to welding.

Normally, in a vacuum switch, a fixed electrode and a movable electrode are placed against each other to close the circuit, and when a load current or a large current flows through this butted electrode, In order to counter the magnetic repulsion between the two electrodes, it is necessary to apply an appropriate contact pressure between the two electrodes, and the means for applying this contact pressure are usually
A wipe mechanism is used.

In this way, even though the above-mentioned wipe mechanism is provided to apply contact pressure between the two electrodes, the substantial contact surface between the two electrodes that are closed in the abutting state is
Due to the machining and finishing accuracy of the contact surface, the roughness of the surface, or the presence of fine objects, contact does not occur over the entire contact surface, and partial contact is formed, so the actual total contact area is small. Therefore, since a current flows therethrough, the electrode temperature rises, and eventually welding occurs between the two electrodes, albeit only partially. This welding occurs more easily in high vacuum environments such as in vacuum chambers and disconnectors than in atmospheric pressure or higher pressure gases because it is not possible to apply grease or the like to the contact surfaces. This causes welding.

When welding occurs between the two electrodes, the operating force required to open the shear breaker is larger than necessary, as extra force is required to break the welding. However, in order to generate this large force, an unnecessarily large operating mechanism for opening and closing the electrode must be provided.

Such a conventional vacuum shield and disconnector will be explained with reference to the attached drawing, FIG. 1, which shows its closed state, and FIG. 2, which shows the middle of the opening and closing operations. This vacuum breaker valve 1 includes an insulating outer cylinder 2, an upper end plate 3 made of metal, a lower end plate 4 also made of metal, a fixed electrode 5, a movable electrode 6, and a lower end. It is slidably provided through the plate 4 and has one end connected to the movable electrode 6,
A movable electrode rod 7 moves the movable electrode 6, and a movable electrode rod 7 is connected to the lower end plate 4 to maintain airtightness between the movable electrode rod 7 and the lower end plate 4 and to enable vertical sliding of the movable electrode rod 7. It consists of a rod and a bellows 8 attached at both ends to the rod.

Reference numeral 10 denotes a wiping device that is connected to the other end of the movable electrode rod 7 and operates the movable electrode 6 via the movable electrode rod 7. A piston 12 connected to the end and housed within the cylinder 11, an annular stopper 13 attached to the end of the cylinder on the vacuum shield valve 1 side to limit the rise of the piston 12, forming the bottom of the cylinder 11. bottom plate 14, piston 12
and a spring 15 that is located between the bottom plate 14 and the bottom plate 14 and pushes the piston 12 upward; and an operating rod that is attached to the bottom plate 14 and is actuated by a not-illustrated operating mechanism to move the wiping device 10 up and down. It consists of 16.

The conventional device is constructed as described above, and its operation will be explained next.

First, in order to change the polarity from the open state to the closed state, the operating rod 16 is pushed up by the operation of an operating mechanism (not shown). This pushing up causes the wiping device 10, in particular, the bottom plate 14, the spring 15, and the piston 1
2. The movable electrode rod 7 and the movable electrode 6 rise, and the movable electrode 6 comes into contact with the fixed electrode 5, resulting in the state shown in FIG. However, in this state, there is no contact pressure between the fixed and movable electrodes 5 and 6, and they are simply in contact with each other, but the operating rod 16 continues to rise due to the continued operation of the operating mechanism, and its rise The spring 15 is compressed by the amount shown in FIG. 1, and therefore corresponds to the total amount of strain of the amount of strain W in the spring 15 and the initial set amount (the amount of strain in the spring 15 in the state shown in FIG. 2). A spring load is applied to the movable electrode rod 7, that is, the movable electrode 6, and this spring load becomes the contact pressure between the fixed and movable electrodes 5 and 6, that is, the wipe pressure.

Next, when opening the pole from the closed state shown in FIG. 1, first, when an opening signal is input to the operation mechanism (not shown), the operating rod 16 and the wipe device 10 suddenly descends due to the previously stored opening force of the operating mechanism and the wiping pressure, and the stopper 13 attached to the cylinder of the wiping device 10 collides with the piston 12, resulting in the state shown in FIG. However, due to the opening force of the operating mechanism that continues thereafter, the piston 12, the movable electrode rod 7 and the movable electrode 6 connected thereto are pulled down, and the poles are opened. However, as shown in FIG. 3, the opening force in this case is in the vertical direction, that is,
It acts perpendicularly to the contact surfaces of the fixed and movable electrodes 5,6. At this time, if welding occurs on the contact surface, a tensile force is applied to the entire welded part, and an extremely large tensile force is applied to the welded part to separate the welded part, that is, to pull the welded part to break. As mentioned above, the conventional device has the disadvantage that the operating mechanism for generating this opening force must also be large in size.

An object of the present invention is to eliminate such drawbacks of conventional devices and to provide a vacuum shield and disconnector that can be opened with a small force even if welding occurs.

In order to achieve this object, the present invention is arranged between a piston and a stopper of a wiping device, and the piston and the stopper are provided so as to be movable with respect to each other. The present invention is characterized in that it is provided with biasing means for applying an opening force from the stopper only to the stopper.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings showing one embodiment thereof.

In FIG. 4, reference numeral 21 denotes a biasing means, for example a washer, which is rotatably provided between the piston 12 and the stopper 13 and is penetrated by the movable electrode rod 7, and one end surface thereof is a washer. As shown in FIG. 5, it forms a plane 21a perpendicular to its central axis and is in contact with either the piston 12 or the stopper 13, for example, the stopper 13, and the other end surface is provided close to the outer periphery thereof. This protrusion 21a is provided so as to contact the other object, for example, the piston 12, and a portion 21c other than the protrusion 21b on the other end surface forms a protrusion 21b that is a part of the piston 12. It is formed so that it does not come into contact with 12.

Note that, except for the above-mentioned washer 21, the configuration is the same as that of the conventional device. Therefore, the wipe device 20 of the present invention includes a cylinder 11, a piston 12, a stopper 13, a bottom plate 14, a spring 15, an operating rod 16, and It is composed of a washer 21.

Since the present invention is configured in this manner, when closing the pole, the washer floats, that is, the upper surface 21a does not contact the stopper 13, and therefore operates in the same manner as the conventional device, but when closing the pole, especially The operation after both end surfaces of the washer 21 come into contact with the piston 12 and the stopper 13 is as shown in FIG.

That is, the opening force P ₁ applied by an operating mechanism (not shown) is transmitted to the washer 21 via the bottom plate 14, the cylinder 11, and the stopper 13, and the force P ₂ transmitted to the washer 21 is transmitted to the washer 21. Collision acts on the piston 12 only at the protrusion of the washer 21, which is the contact point 31 between the washer 21 and the piston 12, that is, the part to which the opening force is transmitted. Therefore,
Force P ₂ acts as shown by arrow 33 with point 32 on the opposite side as a fulcrum, and therefore bends piston 12 as shown by the dotted line, but the force P 2 acts on movable electrode 6 via movable electrode rod 7 is bent in the direction of arrow 35, using a point 34 where the fixed and movable electrodes contact each other on the opposite side of the part to which the opening force of the washer is transmitted as a fulcrum, to bring it into the state shown by the dotted line.

The result is that the welded portion between the fixed and movable electrodes 5 and 6 is partially sequentially pulled or bent from one side, and furthermore, due to the lever principle, only a vertical force is applied. It is possible to open the pole with an extremely small force compared to the conventional device in which the pole is opened by holding the pole, and as a result, the operation mechanism can be made smaller and the weight can be reduced, and the entire cubicle is lighter. This has the effect of reducing manufacturing costs.

Further, the washer 21 according to the present invention has the movable electrode rod 7
Since the protrusion 21b and the piston 12 are fitted in a rotatable manner, the contact position between the protrusion 21b and the piston 12 always changes depending on the rotation of the washer 21. Since the impact is applied to the washer 21 and the piston 12, compared to a case where the relative position of the washer 21 and the piston 12 is fixed and the mutual contact position is always constant, it also has the effect of less wear and deformation and a longer life. There is.

In the above embodiment, one end surface of the washer 21 is inclined to form a protrusion 21b at the top thereof, and the protrusion 21b is opposed to the piston 12 so as to collide with the piston 12. However, the present invention is not limited to this, and as shown in FIG. The pin 41 may be provided protruding from a portion near the outer periphery of the end surface.
Further, as shown in FIG. 8, the washer 21 itself may be a ball 51 sandwiched between the piston 12 and the stopper 13, and in either case, the same effect as in the above embodiment can be achieved. is possible,
In addition, both the washer 21 and the pin-embedded washer 41 as shown in the embodiment, the protruding portion 21b and the pin 4
One end may be in contact with the piston 12 or may be in contact with the stopper 13, and the same effect can be obtained in either case.

[Brief explanation of the drawing]

Figures 1 and 2 are longitudinal cross-sectional views showing the closed state (Figure 1) and the intermediate state of opening and closing operations (Figure 2) of a conventional vacuum shield disconnector, and Figure 3 is a conventional vacuum disconnector. FIG. 4 is a longitudinal sectional view of an embodiment of the present invention, FIG. 5 is a perspective view showing an example of a washer used therein, and FIG. The figure is an explanatory diagram of how force is applied when opening the vacuum shield breaker of the present invention, Figure 7 is a perspective view showing another example of the washer, and Figure 8 is a perspective view showing another example of the washer.
The figure is a partial vertical sectional view showing another embodiment of the present invention. 5... Fixed electrode; 6... Movable electrode; 11... Cylinder; 12... Piston; 13... Stopper; 14
... Bottom plate; 15 ... Spring; 20 ... Wipe device;
21, 40... Biasing means (washer); 21b... A portion (protrusion) to which opening force is applied from the stopper; 41... Pin; 51... Biasing means (ball).

Claims (1)

[Scope of Claims] 1. A piston integrally connected to a movable electrode, a spring acting on the piston to press the movable electrode against the fixed electrode, a cylinder housing the piston and spring, and a movable electrode side of the cylinder. In a vacuum shield disconnector having a wipe device comprising a stopper of the piston provided at the end and a bottom plate provided on the side opposite to the stopper installation side of the cylinder and supporting a spring, The piston and the stopper are disposed between the piston and the stopper, and the piston and the stopper are movable relative to each other, and when the two electrodes are opened, the opening force from the stopper is applied only to a portion near the outer periphery of the piston. A vacuum cutter characterized in that it is equipped with a biasing means that gives. 2. Claim 1, wherein the biasing means is a washer provided between the piston and the stopper, and the part that applies the opening force from the stopper is a protrusion provided near the outer periphery of the washer. Vacuum cutter as described. 3. The biasing means is a washer provided between the piston and the stopper, and the part that applies the opening force from the stopper is the tip of a pin protruding near the outer periphery of the washer. A vacuum disconnector as described in Scope 1. 4. Claim 1, wherein the biasing means is a ball placed between the piston and the stopper, and a portion that applies the opening force from the stopper is a contact portion between the ball, the piston, and the stopper. Vacuum cutter as described.