JP6220911B2 - Vacuum interrupter - Google Patents

Description

  The present invention relates to a vacuum interrupter. In particular, the present invention relates to the structure of an insulating cylinder constituting a vacuum interrupter.

  In a conventional vacuum interrupter, a metal fixed side end plate and a movable side end plate are attached to each end face of an insulating cylinder made of cylindrical alumina ceramic or the like by brazing (for example, FIG. 5 of Patent Document 1). reference).

  The fixed side end plate and the movable side end plate have a deep dish shape, and a hole through which the electrode rod passes is formed at the center. When the fixed side end plate and the movable side end plate are in the shape of a deep dish, even if the flange part of each end plate thermally expands due to the high temperature environment during brazing, stress concentrates on the insulating cylinder at the brazing point. It is suppressed. The fixed side end plate (and the movable side end plate) and the insulating cylinder are joined mainly using a silver-based brazing material. The fixed side end plate is provided with a fixed side electrode rod, and the movable side end plate is provided with a movable side electrode rod via a bellows.

  The fixed side end plate (or movable side end plate) is brazed to the end surface of the insulating cylinder (that is, the sealing portion between the insulating cylinder and the fixed side end plate (or movable side end plate)). A metallized layer is formed. The metallized layer is extremely thin, and when an abnormally high voltage is applied to the vacuum interrupter, the electric field becomes higher than other parts, and there is a possibility that creeping flashes may occur outside the insulating cylinder starting from this part. That is, the withstand voltage may be reduced at the joint between the insulating cylinder and the fixed side end plate (or the movable side end plate).

  Therefore, in Patent Document 2, a step portion is provided at the end of the insulating cylinder to reduce the electric field at this portion. Furthermore, in patent document 1, while providing a projection part in the edge part of an insulating cylinder and forming a U-shaped groove part in the outer peripheral side of the end surface of an insulating cylinder, the edge part of the metallized layer outer peripheral part side is not exposed to the circumference | surroundings. The electric field in the electric field concentration portion at the outer corner of the insulating cylinder of the metallization layer is relaxed. In addition, by forming a U-shaped groove on the inner peripheral side of the end face of the insulating cylinder, the electric field at the electric field concentration portion at the inner corner of the insulating cylinder of the metallization layer is reduced.

JP 2010-282923 A Japanese Utility Model Publication No. 64-9335

  However, if the U-shaped groove is formed on the end surface of the insulating cylinder, the shape of the insulating cylinder becomes complicated, and it may be difficult to manufacture the insulating cylinder.

  Further, when connecting the insulating cylinder and the fixed side end plate (and the movable side end plate), the insulating cylinder and each end plate are brazed in a high temperature environment such as a vacuum furnace. Therefore, since the flange portion of the end plate is thermally expanded by the temperature at the time of brazing, it is necessary to consider a place where the U-shaped groove portion is formed. That is, the thickness of the insulating cylinder is increased not only for the width of the U-shaped groove but also for the thermal expansion of the flange, so that the thickness of the insulating cylinder may be increased.

  In view of the above circumstances, an object of the present invention is to provide a vacuum interrupter that can relax an electric field at an edge portion of a metallized layer, has high withstand voltage performance, and is easy to manufacture.

  One aspect of the vacuum interrupter of the present invention that achieves the above object is a vacuum container having a cylindrical insulating cylinder and an end plate that is airtightly joined to each end of the insulating cylinder, and the vacuum container includes A vacuum interrupter comprising a pair of electrodes provided so as to be separable from each other, and a protrusion projecting along an outer periphery of the insulating tube at an end of the insulating tube; And a joining portion to which the end plate is joined is formed, and the joining portion is inclined so that the insulating tube is tapered.

  Another aspect of the vacuum interrupter of the present invention that achieves the above object is characterized in that in the vacuum interrupter, the wall surface on the inner peripheral side of the protrusion is pleated.

  According to another aspect of the vacuum interrupter of the present invention that achieves the above object, in the vacuum interrupter, the joint portion of the end plate joined to the end portion of the insulating tube is inclined to the joint portion of the insulating tube. It is characterized by tilting to the combined angle.

  According to the above invention, it is possible to provide a vacuum interrupter that can relax the electric field at the edge portion of the metallized layer, has high withstand voltage performance, and is easy to manufacture.

It is sectional drawing which shows the outline of the vacuum interrupter which concerns on embodiment of this invention. It is an expanded sectional view of an insulating cylinder end part. It is an expanded sectional view showing other examples of an insulating cylinder end. (A) It is explanatory drawing explaining the case where the fixed side end plate is not suitable for a center position, (b) It is explanatory drawing explaining the process of positioning a fixed side end plate to a center position.

  A vacuum interrupter according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 to 4 are diagrams schematically showing a vacuum interrupter according to an embodiment of the present invention, and the illustrated dimensions do not necessarily coincide with the actual dimensions.

  As shown in FIG. 1, a vacuum interrupter 1 according to an embodiment of the present invention is configured by providing a fixed electrode 3 and a movable electrode 4 in a vacuum vessel 2 so as to be able to contact and separate. The vacuum vessel 2 includes an insulating cylinder 5 and a metal fixed side end plate 6 and a movable side end plate 7 provided at each opening of the insulating cylinder 5.

  The insulating cylinder 5 is made of, for example, alumina ceramics and is formed in a cylindrical shape. At the end portion of the insulating cylinder 5 on the side where the fixed side end plate 6 is provided, a joint portion 5a to which the fixed side end plate 6 is brazed, and a protruding portion 5b provided protruding from the outer peripheral side end portion of the insulating tube 5 And are formed. An intermediate shield 8 is provided inside the insulating cylinder 5 so as to cover the fixed electrode 3 and the movable electrode 4.

  The joint part 5a is an end face of the insulating cylinder 5 and a part to which the end part of the fixed side end plate 6 is brazed. As shown in FIG. 2, a metallized layer 9 for brazing the fixed-side end plate 6 is formed at the joint 5a. Further, the joint portion 5a is inclined such that an angle formed by the joint surface of the joint portion 5a and the inner peripheral wall surface of the insulating cylinder 5 is an acute angle. That is, the joint 5a (that is, the end inner peripheral portion side of the insulating tube 5) is inclined so that the insulating tube 5 is tapered.

  The protrusion 5 b is provided so as to protrude along the outer periphery of the insulating cylinder 5. The base end portion on the joint portion 5a side of the protrusion 5b is formed with a gentle curvature. By making the base end portion of the protrusion 5b have a gentle curvature, the electric field at the end portion of the metallized layer 9 formed at the base end portion can be relaxed. Moreover, manufacture (for example, manufacture by a ceramic manufacturing method in which alumina powder is press-molded and fired) is facilitated by making the base end portion a gentle curved surface. Also, as shown in FIG. 3, the creepage distance is obtained by processing the wall surface 5c on the inner peripheral side of the insulating cylinder 5 of the protruding portion 5b into a pleat shape (for example, the axial cross section of the insulating cylinder 5 is wavy). And can prevent external creeping flashes due to fouling. The shape of the wall surface 5c is not particularly limited as long as the creepage distance is increased. For example, the wall surface 5c is formed in a continuous concave / convex shape, a convex / convex continuous shape, a concave / convex continuous shape, or a ΔΔ shape.

  Further, a chamfered portion 5 d is formed at a corner portion on the inner peripheral side of the insulating cylinder 5. The chamfered portion 5d is not formed with the metallized layer 9, and the electric field in the electric field concentration portion at the inner peripheral side end portion of the insulating cylinder 5 is relaxed.

  As shown in FIG. 1, the fixed-side end plate 6 is formed in a deep dish shape, and this deep dish-shaped flange end portion is brazed to the metallized layer 9 provided in the opening on one end side of the insulating cylinder 5. Are joined together. If the end of the fixed side end plate 6 is formed to have an angle that matches the inclination angle of the joint portion 5a, the fixed side end plate 6 can be brazed to the insulating cylinder 5 stably. A fixed lead 3a is fixedly supported at the center of the fixed side end plate 6 in an airtight manner. The fixed electrode 3 is attached to the tip of the fixed lead 3a located in the vacuum vessel 2.

  The movable side end plate 7 is formed in a deep dish shape, and the end of the deep dish-shaped flange is joined to the metallized layer 9 provided in the opening on the other end side of the insulating cylinder 5 by a brazing material. A hole 7a through which the movable lead 4a is inserted is formed in the center of the movable side end plate 7, and the movable lead 4a is provided through the hole 7a. A movable electrode 4 is provided at the tip of the movable lead 4a located in the vacuum vessel 2. The movable lead 4a is moved in the axial direction by an external operating device (not shown). By moving the movable lead 4a in the axial direction, the fixed electrode 3 and the movable electrode 4 are brought into contact with and separated from each other. Blocking is performed. A thin stainless steel bellows 10 is provided between the movable side end plate 7 and the movable lead 4a so that the movable lead 4a can move in the axial direction while keeping the vacuum chamber 2 in a vacuum. It has become.

  In the vacuum interrupter 1 as described above, as shown in FIG. 4A, when the fixed side end plate 6 is displaced from the center position of the insulating cylinder 5, the fixed lead 3 a becomes oblique, and the vacuum interrupter 1 is opened and closed. There is a risk of malfunction. Therefore, when the fixed-side end plate 6 is brazed to the insulating cylinder 5, as shown in FIG. 4B, a jig 11 or the like is provided between the protruding portion 5b of the insulating cylinder 5 and the fixed-side end plate 6. , And the fixed side end plate 6 is aligned with the center position of the insulating cylinder 5. Then, the brazing material is melted in a high temperature environment such as a vacuum furnace, and the insulating cylinder 5 and the fixed side end plate 6 are brazed. At this time, since the joint portion 5a is inclined, unnecessary melted brazing material is excluded between the joint portion 5a and the projection portion 5b.

  According to the vacuum interrupter 1 according to the embodiment of the present invention as described above, the protruding portion 5b is provided on the outer peripheral portion of the end portion of the insulating cylinder 5, and the joint portion 5a to which the fixed side end plate 6 is joined is inclined. Thus, the withstand voltage performance in the metallized layer 9 can be improved.

  That is, by providing the protruding portion 5b at the end of the insulating cylinder 5 and making the base end of the protruding portion 5b have a gentle curvature, the electric field can be relaxed at the electric field concentration portion at the outer peripheral side corner of the metallized layer 9. Become. Moreover, since the edge part of the insulation cylinder 5 is protected by the barrier effect of the protrusion part 5b, an external creeping flash can be reduced. And the creeping distance between the inner peripheral side corner of the metallized layer 9 and the intermediate shield 8 can be increased by inclining the joint 5a. Furthermore, by providing the chamfered portion 5 d at the inner peripheral side end portion of the insulating cylinder 5, the voltage resistance of the inner peripheral side corner portion of the metallized layer 9 can be further improved.

  Further, since the processing of the insulating cylinder 5 is to provide the projection 5b at the end of the insulating cylinder 5 and to form the joint 5a so as to be inclined, the processing of the insulating cylinder 5 is easy, inexpensive and easy. The vacuum interrupter 1 can be manufactured.

  Moreover, brazing is stably performed by forming the end of the fixed side end plate 6 (and the movable side end plate 7) at an angle that matches the inclination angle of the joint 5a of the insulating cylinder 5. be able to.

  When the joint is not inclined as in the conventional vacuum interrupter, there is a problem that unnecessary brazing material is not discharged. If unnecessary brazing material is present inside the insulating cylinder 5, the withstand voltage performance inside the vacuum interrupter may be reduced. On the other hand, the vacuum interrupter 1 according to the embodiment of the present invention easily eliminates unnecessary molten brazing material between the proximal end portion of the protrusion 5b and the joint 5a by inclining the joint 5a. can do. As a result, it is possible to suppress a decrease in the withstand voltage performance inside the insulating cylinder 5 due to the brazing material leaking out to the inner peripheral side of the insulating cylinder 5.

  Further, by forming the wall surface 5c on the inner peripheral side of the insulating cylinder 5 of the protruding portion 5b in a pleat shape, it is possible to obtain a more creeping distance and to suppress external creeping flash.

  In the description of the embodiments of the present invention, the preferred embodiments of the present invention have been shown and described. However, the present invention is not limited to the embodiments, and the design can be changed as appropriate without departing from the characteristics of the invention. is there.

  For example, the protrusion 5 b and the inclined joint 5 a can be provided on one or both of the insulating cylinders 5. That is, by forming the protrusion 5b and the inclined joint 5a at least at one end of the insulating cylinder 5, it is possible to obtain part of the effect of the vacuum interrupter 1 of the present invention. However, it is preferable to provide the protrusion 5b and the inclined joint 5a at the end where the fixed end plate 6 to which a high voltage is applied is provided.

DESCRIPTION OF SYMBOLS 1 ... Vacuum interrupter 2 ... Vacuum container 3 ... Fixed electrode 3a ... Fixed lead 4 ... Movable electrode 4a ... Movable lead 5 ... Insulating cylinder 5a ... Joint part, 5b ... Projection part, 5c ... Wall surface, 5d ... Chamfering part 6 ... Fixed side End plate (end plate)
7 ... Movable end plate (end plate)
8 ... Intermediate shield 9 ... Metallized layer 10 ... Bellows 11 ... Jig

Claims (3)

A vacuum interrupter comprising: a cylindrical insulating tube and a vacuum vessel having an end plate hermetically joined to each end of the insulating tube; and a pair of electrodes provided in the vacuum vessel so as to be separable from each other. ,
At the end of the insulating tube, there are a protruding portion that protrudes in the axial direction of the insulating tube along the outer periphery of the insulating tube, and a bonding portion that is on the inner peripheral side of the protruding portion and to which the end plate is bonded , Is formed,
The vacuum interrupter, wherein the joint portion is inclined so that an end portion inside the insulating tube protrudes in an axial direction of the insulating tube . The vacuum interrupter according to claim 1, wherein a wall surface on an inner peripheral side of the protrusion is pleated. The vacuum according to claim 1 or 2, wherein a joint portion of the end plate joined to an end portion of the insulating cylinder is inclined at an angle corresponding to an inclination of the joint portion of the insulating cylinder. Interruptor.

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