Patent Application
20110073567
(1) Field of the Invention
The present invention relates to an electrode for a switch and a vacuum switch, and a method of manufacturing the electrode for the switch or the vacuum switch.
(2) Description of Related Art
Since the vacuum switch employs a vacuum insulation having a high insulation performance, and does not use a gas such as SF6 or the like having a high global warming coefficient, it is a switch which can achieve both downsizing and reduction of an environmental load.
The vacuum switch carries out an electric current break or the like in an inner portion of a vacuum vessel, however, a method of manufacturing the vacuum vessel in a high vacuum exists as a method of manufacturing the vacuum vessel. In this case, in a brazing in a manufacturing step of the vacuum vessel, it is necessary to properly use a brazing filler metal in correspondence to a material between members constructing the vacuum vessel. Accordingly, it is necessary to separate the brazing into at least two steps.
A first step is a step of connecting metals to each other such as a connection between an electrode and a conducting bar, and a second step is a step of including the members adhered in accordance with the first step in an inner portion, connecting an insulation tube and a metal end plate, and constructing a vacuum sealed vacuum vessel. The first step is structured such as to connect the metals to each other, however, the second step has to connect the insulation material and the metal. Accordingly, it is necessary to use different brazing filler materials, respectively.
Therefore, there is a possibility that the brazing filler material used in the first step is again molten in the second step, and if the brazing filler material is molten in the second step, the brazing filler material used for connecting the electrode and the conducting rod in the first step is deformed, so that there is a possibility that an air gap is generated between the electrode and the conductor rod, and a displacement is generated between the electrode and the conducting rod.
In order to prevent the displacement between the electrode and the conducting rod as mentioned above from being generated, for example, there is a structure described in patent document 1 (JP-A-5-298971). The patent document 1 has a description of an electrode which has an electrode rod provided with protruding portions 6a and 7a in an end portion, and an insertion hole having the same shape as the end portion of the electrode rod, and in which grooves 4a and 5b are formed in an inner portion, and describes an assembling method of the electrode rod and the electrode for finishing an assembly by setting a brazing filler material to a joint position between the electrode rod and the electrode, inserting the electrode rod to an electrode rod insertion port of the electrode, and rotating at about 90 degree in such a manner as to guide the protruding portions 6a and 7a of the end portion of the electrode rod to a groove in an inner portion of the electrode and locking, as an assembling method of the electrode rod and the electrode (paragraph [0008] to [0009] of the specification of the patent document 1.) Further, there is described that an object of the invention is to provide a vacuum valve which can prevent the electrode from coming off and being inclined and prevent a positional displacement between the electrode rod and the electrode in a final assembling step, and has a high reliability without lowering a performance serving as the vacuum valve, in the case that a brazing temperature in a partial assembling step is the same as a brazing temperature at which a vacuum sealing is carried out in a final assembling step (paragraph [0005] of the specification of the patent document 1).
In this case, in the case that an air gap is generated between the electrode and the conducting rod, the air gap portion is occupied with an insulation medium such as a vacuum or the like. Since this portion exhibits a high insulating property, this portion comes to a high resistance portion at a time of conducting an electric current, and a conducting property of the electric current is lowered. Further, since a coefficient of thermal conductivity is lower in the air gap portion (for example, filled with a vapor or a gas in the case of an air brake insulation switch, filled with a gas in the case of a gas insulation switch, and filled with a vacuum in the case of a vacuum insulation switch, respectively) in comparison with the electrode corresponding to the metal material, and a heat conduction is prevented in the air gap portion, the electrode coming to a high temperature at a time when the electric current is broken is hard to be radiated heat, and a possibility that the electrode member is molten becomes higher. There is a risk that they cause a reduction of a reliability.
In the patent document 1 mentioned above, the protruding portion of the end portion of the electrode rod is rotated and locked in such a manner as to be guided to the groove in the inner portion of the electrode, however, on the assumption that the assembling method mentioned above is achieved, it is necessary that a clearance gap is provided to some extent between the protruding portion of the end portion of the electrode rod and the groove in the inner portion of the electrode. In the case that no clearance gap is provided, the protruding portion of the end portion of the electrode rod can not be rotated with respect to the groove in the inner portion of the electrode. Further, the clearance gap corresponds to the air gap portion mentioned above eventually. Accordingly, in the case of intending to fix the electrode rod and the electrode on the basis of a rotation, it is unavoidable that an air gap portion exists to some extent or is enlarged.
Accordingly, an object of the present invention is to provide an electrode or a switch which can improve a reliability of the switch, or a method of manufacturing the electrode for the switch or a vacuum switch.
In order to achieve the object mentioned above, in accordance with the present invention, there is provided an electrode for a switch including a conductor rod, a contact point electrode inserted to the conductor rod, and a coupling plate fixing both the elements to an outer side in a diametrical direction of the conductor rod and the contact point electrode.
In the electrode for the switch in accordance with the present invention, it is preferable that the conductor rod is provided with a groove in a diametrical direction in an outer peripheral portion, the contact point electrode is provided with a groove in a diametrical direction in an outer peripheral portion, and the coupling plate is fitted to the groove in the diametrical direction which the conductor rod has its outer peripheral portion, and the groove in the diametrical direction which the contact point electrode has its outer peripheral portion, and fixes the conductor rod and the contact point electrode.
Further, in the electrode for the switch in accordance with the present invention, it is preferable that the coupling plate is provided with a groove in a diametrical direction in an outer peripheral portion, the contact point electrode is provided with a groove positioned in the same circumference as the groove which the coupling plate is provided in the diametrical direction in its outer peripheral portion, at a position except the outer peripheral portion to which the coupling plate is fitted, in the outer peripheral portion, and the coupling plate is provided with a fixing member fitted to the groove in the diametrical direction which the coupling plate is provided in its outer peripheral portion, and the groove which the contact point electrode is provided in its outer peripheral portion, the groove being positioned in the same circumference as the groove which the coupling plate is provided in the diametrical direction in its outer peripheral portion.
Further, in the electrode for the switch in accordance with the present invention, it is preferable that the coupling plate is provided with a flexibility.
Further, in the electrode for the switch in accordance with the present invention, it is preferable that the coupling plate and/or the fixing member is constructed by a plurality of members.
Further, in the electrode for the switch in accordance with the present invention, it is preferable that the contact point electrode is provided with a spiral groove at a position except a portion lapping over the conductor rod, in an axial direction of the conductor rod.
Further, in accordance with the present invention, there is provided a vacuum switch including the electrode for the switch in accordance with the present invention, and an insulation tube and an end plate constructing a vacuum vessel in which an inner portion comes to vacuum, wherein the insulation tube and the end plate are brazed therebetween, and the electrode for the switch is stored in the inner portion of the vacuum vessel.
In accordance with the present invention, there is provided a vacuum switch including a conductor rod having a groove in a diametrical direction in a part in an axial direction, a contact point electrode provided with an insertion hole to which the conductor rod is inserted, structured such that the conductor rod is inserted to the insertion hole, and having a groove in a diametrical direction in an outer peripheral portion, a coupling plate fitted to the groove in the diametrical direction which the conductor rod has, and the groove in the diametrical direction of the outer peripheral portion which the contact point electrode has, and fixing the conductor rod and the contact point electrode, and a vacuum vessel constructed by an insulation tube and a metallic end plate, connoting the conductor rod and the contact point electrode, and coming to vacuum in its inner portion, wherein a first brazing filler material is provided in a contact surface between the conductor rod and the contact point electrode, and a second brazing filler material is provided between the insulation tube and the metallic end plate.
Further, in accordance with the present invention, there is provided a vacuum switch including a conductor rod having a groove in a diametrical direction in a part in an axial direction, a contact point electrode provided with an insertion hole of the conductor rod, structured such that the conductor rod is inserted to the insertion hole, provided with concave portions at two positions or more in an outer peripheral portion, and structured such that a portion except the concave portions in the outer peripheral portion has a groove in a diametrical direction, a coupling plate fitted to the groove which the conductor rod has, and the concave portions which the contact point electrode has, and provided with a groove constructing the same circumference as the groove which the contact point electrode has in the portion except the concave portions in the outer peripheral portion, in the portion fitted to the concave portions which the contact point electrode has, a ring pin fitted to the groove which the contact point electrode has in its outer peripheral portion and the groove which the coupling plate is provided, and fixing the contact point electrode and the coupling plate, and a vacuum vessel constructed by an insulation tube and a metallic end plate, connoting the conductor rod and the contact point electrode, and coming to vacuum in its inner portion, wherein a first brazing filler material is provided in a contact surface between the conductor rod and the contact point electrode, and a second brazing filler material is provided between the insulation tube and the metallic end plate.
In the vacuum switch in accordance with the present invention, it is preferable that the coupling plate is provided with a flexibility.
Further, in the vacuum switch in accordance with the present invention, it is preferable that the coupling plate is separated into two or more sections.
Further, in the vacuum switch in accordance with the present invention, it is preferable that the contact point electrode is provided with spiral grooves at two positions or more in a portion except a portion lapping over the conductor rod, in an axial direction of the conductor rod.
Further, in accordance with the present invention, there is provided a vacuum switch including the vacuum switch in accordance with the present invention, a cable feeding an electric power to a load side, a bus bar feeding an electric power to the vacuum switch, and an operation device opening and closing the vacuum switch.
Further, in order to achieve the object mentioned above, in accordance with the present invention, there is provided a method of manufacturing an electrode for a switch, including a step of inserting a conductor rod to an electrode having an insertion hole, and thereafter fitting a coupling plate to an outer side in a diametrical direction of the conductor rod and the contact point electrode.
In the method of manufacturing the electrode for the switch in accordance with the present invention, it is preferable that a groove in a diametrical direction is formed in an outer peripheral portion in the coupling plate, and a groove positioned in the same circumferential shape as the groove which the coupling plate is provided in the diametrical direction in its outer peripheral portion, is formed at a position except the outer peripheral portion to which the coupling plate is fitted, in the outer peripheral portion, in the contact point electrode, and the method has a step of fitting the coupling plate to an outer side in the diametrical direction of the conductor rod and the contact point electrode, and thereafter fitting a fixing member to the groove formed in the coupling plate and the groove formed in the contact point electrode, thereby fixing the coupling plate, the conductor rod and the contact point electrode.
In accordance with the present invention, there is provided a method of manufacturing a vacuum switch including a step of brazing an insulation tube and an end plate under a vacuum or a hydrogen gas, while connoting the electrode for the switch, after the step mentioned above.
In the method of manufacturing the vacuum switch in accordance with the present invention, it is preferable that the brazing step is constructed by only one brazing step under the vacuum or the hydrogen gas.
In accordance with the present invention, it is possible to provide the electrode or the switch which can improve a reliability of the switch, or the method of manufacturing the electrode for the switch or the vacuum switch.
Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
A description will be given below of an embodiment which is preferable for carrying out the present invention.
A description will be given of a first embodiment in accordance with the present invention. As shown in
As shown in
A description will be given of a method of manufacturing a vacuum switch using the electrode mentioned above with reference to
Next, a sealing of the vacuum vessel is completed by brazing the insulation tube 74 and the metal end plate 75 while connoting the conductor rod 1 and the contact point electrode 2 which have been fixed as mentioned above, under a high vacuum or a hydrogen gas. In accordance with this brazing step, the first brazing filler material provided in the contact surface between the conductor rod 1 and the contact point electrode 2 is molten, and is simultaneously brazed. In this case, it is necessary to set a second brazing filler material between the insulation tube 74 and the metal end plate 75, before the present brazing step.
In the present embodiment, since the conductor rod 1 and the contact point electrode 2 are fixed by using the coupling plates 3 and 4, and a rotating motion is not used for fixing, it is possible to fix both the elements without generating any air gap in the center portion of the electrode and the conductor in which an electric current is conducted. In this case, the present embodiment is described as the embodiment about the vacuum switch gear including the electrode and the vacuum switch, as a matter of convenience, however, the invention itself can be realized as the electrode or the vacuum switch independently.
Further, as a very advantageous point in the present embodiment, there can be listed up the matter that the brazing step can be constructed only one step for brazing the insulation tube 74 and the metal end plate 75. This means that it is possible to omit the partially assembling step which has been conventionally carried out, by carrying out the fixing between the conductor rod 1 and the contact point electrode 2 by using the coupling plates 3 and 4. Accordingly, it is possible to achieve a wide improvement of a working efficiency.
Further, since the brazing of the conductor rod 1 and the contact point electrode 2 can be carried out at the same time of the brazing step of the insulation tube 74 and the metal end plate 75, it is possible to prevent the positional displacement between the conductor rod 1 and the contact point electrode 2 which are brazed in the first step from being generated in the second step. The positional displacement of the electrode causes a contact failure between the electrodes. In the case that the contact failure is generated, a non-contact portion between the electrodes comes to a high resistance portion due to a vacuum insulation, whereby an equipment performance of the switch is significantly deteriorated. Further, even if the conduction is generated, it is a contact by an arc so as to cause a melting of the electrode portion, and there is a risk that a reduction of a service life of the equipment is caused. The present embodiment is very useful in a point that the positional displacement of the electrode can be prevented.
Further, in the case that the air gap is generated, a high resistance portion caused by the vacuum insulation is formed within the air gap. Accordingly, the performance as the equipment of the switch is significantly deteriorated. Further, the contact point electrode 2 comes to a high temperature because of generation of an arc at a time of opening and closing, and is demanded to be heat radiated as soon as possible in the light of preventing the electrode from being molten. However, since the air gap is generated within the electrode, and the vacuum portion having a significantly small coefficient of thermal conductivity in comparison with the metal is generated, a heat dissipation performance is lowered, and there is a possibility that the electrode is molten. In the case that the electrode is molten, the electrode surface becomes non-flat, thereby causing the arc at a time of opening and closing on and after the next time. In the conventional case, in the case that the electric current of 25 kA is applied within the switch for about three second, the temperature of the electrode portion reaches 300 K, however, in accordance with the present embodiment, since the air gap is not generated in the conduction portion within the electrode, it is possible to hold down a temperature rise to 240 K, and it is possible to reduce a thermal loss at about 20%. Further, it is possible to prevent the electrode surface from being molten, and it is possible to reduce the generation of the art at a time of opening and closing.
Since the coupling plates 3 and 4 in the present embodiment are constructed by the member having the flexibility, for example, SUS or the like, a flexibility at a time of being fitted to the conductor rod 1 and the contact point electrode 2 is increased, and it becomes easy to fit at a time of coming into contact with the conductor rod 1 and the contact point electrode 2.
Further, in the present embodiment, the coupling plates 3 and 4 are divided into two sections, however, may be formed as one unit, or may be divided into three or more sections. At this time, if they are arranged uniformly in the diametrical direction, an incline or the like is not generated, and a stability for fixing is improved. Arranging uniformly in the diametrical direction indicates a case that a plurality of coupling plates are used and are arranged approximately symmetrically in a peripheral direction.
Next, a description will be given of a second embodiment in accordance with the present invention with reference to
A description will be given of a different point from the first embodiment in a method of manufacturing the vacuum switch using the electrode mentioned above, with reference to
The present embodiment can achieve the same effect as that of the first embodiment.
Further, in the present embodiment, the description is given of the structure using the ring pin 5 as the fixing member fixing the coupling plates 3 and 4 and the contact point electrode 2, however, it goes without saying that the fixing member is not limited to the ring pin, and can be replaced by a fixing member which can fix by fitting to a groove which is provided on the same circumference in the outer periphery of the coupling plate and the contact point electrode.
Further, the description is given of the ring pin 5 in the case that only one ring pin is provided, in the present embodiment, however, a structure in which it is separated into a plurality of pins is not excluded.
Further, in the present embodiment, the contact point electrode 2 is provide with the concave portions at two positions, however, may be provided at three positions or more. Further, there can be thought that two or more ring pins are used for fixing. In the case mentioned above, it goes without saying that it is necessary to increase the number of the grooves provided in the contact point electrode and the coupling plate in correspondence thereto.
Further, in order to improve the breaking performance of the electrode with respect to the contact point electrode 2 in both of the first and second embodiments mentioned above, there can be formed as a spiral electrode in which a hole 2d having a diameter equal to or less than an inner diameter of the contact point electrode is formed in the center portion close to the contact point shown in
Further, not particularly referring in the first and second embodiments, however, the coupling plates 3 and 4 may be structured such as to fix to whichever position in the axial direction of the conductor rods.
Further, referring to the vacuum switch in each of the embodiments mentioned above, however, the vacuum switch includes a vacuum grounding switch aiming at grounding. In other words, it goes without saying that the first and second embodiments can be applied to the vacuum grounding switch.
It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-225880 | Sep 2009 | JP | national |
| 2010-115888 | May 2010 | JP | national |
