JPH0252376B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum chamber disconnector, and more specifically, the present invention relates to a vacuum chamber disconnector, in which a cylindrical vacuum vessel is formed by closing both ends of a metal cylinder with an insulating disk made of an inorganic insulator, and this The present invention relates to a vacuum shield and disconnector in which a pair of electrodes are provided in a container so as to be able to come in contact with and separate from each other.

To manufacture this type of vacuum shield and disconnector, the joints are usually vacuum-tightly brazed in a vacuum furnace. In this vacuum-tight brazing, a brazing material is provided between the joining members, so that the brazing material evaporates during brazing. The evaporated brazing filler metal is adhered to the vacuum side plate surface of the insulating disk during slow cooling during brazing. When metal vapor is attached to an insulating disk, it becomes conductive. The dielectric strength of the above-mentioned vacuum shield disconnector is determined by the creepage distance of the insulating disk, but as mentioned above, if metal vapor is attached to the vacuum side plate surface of the insulating disk, the creepage distance becomes significantly shortened, and the dielectric strength increases. This results in a decrease in Therefore, it is necessary to prevent the metal vapor of the brazing material from adhering to the vacuum side plate surface of the insulating disk. However, since a ceramic member is used for the insulating disc,
It had the following drawbacks, and it was difficult to prevent metal vapor from adhering to it. In other words, the thermal radiation coefficient (or blackness) in radiation such as ceramic parts
Large members tend to heat up easily, but they also tend to cool down easily. Because they cool easily, ceramic parts tend to have brazing filler metal vapor adhering to them when they are cooled, a phenomenon very similar to dew condensation.

The present invention was made in view of the above circumstances, and
A groove is provided in one joint member of the joint part forming the vacuum container and each joint part in the container, a brazing material is placed in the groove, and the groove is covered with the other joint member. Therefore, it is an object of the present invention to provide a vacuum shield and disconnector that can prevent brazing filler metal vapor from adhering to areas that reduce dielectric strength.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a vacuum sheath disconnector according to the present invention, which has insulating discs 2, 2, which are made of an inorganic insulator at both ends of a metal cylinder 1 and will be described in detail later.
This is also airtightly joined with cylindrical auxiliary members 3, 3 whose details will be described later, to form a vacuum container 4,
A pair of fixed and movable electrode rods 5 are introduced from each insulating disk 2 into the vacuum container 4 so as to be able to approach and separate from each other.
6, a pair of fixed and movable electrodes 7 and 8 are provided so as to be able to come into contact with and separate from each other.

That is, the metal cylinder 1 constituting a part of the vacuum container 4 is made of austenitic stainless steel, which is a non-magnetic material and has high mechanical strength, and is formed into a cylindrical shape. In addition, metal cylinder 1
Alternatively, thicker copper may be used to increase mechanical strength, or inexpensive iron may be used as a vacuum shield or disconnector for small currents. Cylindrical auxiliary shields 10 and 1 are arranged opposite to each other near both ends inside the metal cylinder 1.
0 is fitted to each outer end via an integrally molded flange portion 10a, and the outer circumferential surface of each flange portion 10a is joined and fixed by brazing. Each auxiliary shield 10 is made of austenitic stainless steel, and together with the arc shield described later, fixed and movable electrodes 7 and 8
This is to prevent metal vapor generated by the contact and separation of the insulating disks 2 from adhering to the inner end surface of each insulating disk 2 or the bellows, which will be described later. In addition, each auxiliary shield 10 may be made of inexpensive iron if the vacuum shield or breaker is for a small current. The auxiliary member 3 is used to improve the reliability of the airtight joint between the metal cylinder 1 and the insulating disc 2, which have different coefficients of thermal expansion, and is made of a non-magnetic material and an inorganic insulating material such as ceramic. It is made of copper that can be plastically deformed during the slow cooling process after brazing due to the thermal stress generated by brazing with the disc 2. The auxiliary member 3 is made of a magnetic material and can be plastically deformed during the slow cooling process after brazing due to thermal stress generated by brazing with the insulating disk 2 made of an inorganic insulator such as ceramic. If a material made of iron is used, or if the metal cylinder 1 is made of copper or iron, which can be plastically deformed during the slow cooling process after brazing due to thermal stress caused by brazing, an inorganic insulating material such as ceramic may be used. An insulating disk 2 consisting of an Fe-Ni-Co alloy with a similar thermal expansion coefficient, Fe
A material made of -Ni alloy may also be used.

The insulating disks 2 are fitted into each of the auxiliary members 3 and are hermetically joined.
That is, each insulating disk 2 is made of an inorganic insulator such as alumina ceramic or crystallized glass, and is formed into a disk shape with a hole 11 provided in the center. Further, each insulating disk 2 has stepped portions 12 and 13 with a metallized layer of about 1 to 3 mm in diameter at the peripheral end of one surface thereof and the peripheral end of the hole 11. As a result, an annular protrusion 14 is formed on the insulating disc 2. As shown in FIGS. 2A and 2B, the auxiliary member 3 has a flange portion 3a at one end of a cylindrical shape, a protrusion 3b on the outer periphery of the other end, and a projection 3b at the center of the inner peripheral surface. A protrusion 3c is formed inward. The flange portion 3a has a concave groove 3 for attaching the brazing material.
A similar groove 3cc is also formed in the protrusion 3c. Further, a groove 3bb for mounting a brazing material is formed on the outer periphery of the auxiliary member 3 along the projection 3b.
Flange portion 3 of the auxiliary member 3 formed in this way
A is brought into contact with the insulating disk 2, the metal cylinder 1 is brought into contact with the protrusion 3b, and the flange portion 10a of the auxiliary shield 10 is brought into contact with the protrusion 3c, and each part is brazed by heating as described below. At this time, for example, when the brazing material melts in the groove 3aa, its volume expands and enters the gap between the flange portion 3a and the insulating disk 2, and the two are brazed together.

As shown in FIG.
5a is brazed to the bottom 15b of the member 15.
penetrates the fixed electrode rod 5, and its penetrating portion is brazed and held airtight. The fixed electrode rod 5 is provided with a retaining ring 9, such as a snap ring, which is fitted into the circumferential groove 5a and is in contact with the bottom 15b of the auxiliary member 15. This auxiliary member 15 is similar to the auxiliary member 3 interposed between the metal cylinder 1 and the insulating disc 2, and is composed of one insulating disc 2 and the fixed electrode rod 5 that is hermetically joined to the insulating disc 2. This is to prevent a decrease in the reliability of the airtight joint at the joint between the two due to thermal stress caused by the difference in coefficient of thermal expansion, which is caused by brazing with the insulating disk 2 made of alumina ceramic or the like. Made of copper that can be plastically deformed during the slow cooling process after brazing due to thermal stress. Note that, like the auxiliary member 3, this auxiliary member 15 is made of iron, Fe-Ni-Co alloy, or Fe-Ni-Co alloy.
A material made of Ni alloy may also be used. and,
A fixed electrode rod 6 made of copper or a copper alloy is introduced into the vacuum container 4 by passing through an auxiliary member 15. The fixed electrode rod 5 has an outer diameter approximately equal to the inner diameter of the auxiliary member 15. At the inner end of the fixed electrode rod 5, there is an arc shield 17 formed in a cup shape with a larger diameter than the auxiliary shield 10, with its open end facing one of the insulating disks 2, and at the center of its bottom. It is fitted through the provided hole 18. Then, the arc shield 17
As shown in FIG. Fixed nearby. Note that the brazing material 25 is provided in a groove 5c formed in the fixed electrode rod 5. The arc shield 17 cooperates with the auxiliary shield 10 on the side of the one insulating disk 2 described above to prevent metal vapor from adhering to the one insulating disk 2, and is made of austenitic stainless steel. The vicinity of the open end and the vicinity of the open end of the auxiliary shield 10 on one side of the insulating disk 2 are concentrically overlapped with the fixed electrode rod 5 as the center. Note that this arc shield 17 may be made of inexpensive iron if the vacuum shield or breaker is for a small current.

Further, the fixed electrode 7 formed in a substantially disk shape is fitted into the inner end of the fixed electrode rod 5, and a groove 7a for mounting a brazing material is formed in the electrode 7.
A contact 7b is fitted into the electrode 7 so as to cover the groove 7a.

The stepped portion 12 of the other insulating disk 2 has a cylindrical portion formed by extending the inner diameter side of one end of a bellows 20 made of austenitic stainless steel concentrically housed in the vacuum container 4 in the axial direction. 20a, and is hermetically joined to the auxiliary member 16 by brazing, as shown in FIG. 2E. This auxiliary member 16 has a notch 16a and a groove 16b for mounting a brazing material. The other end of the bellows 20 is joined to a protrusion 6a for attaching a brazing material, which is protruded from the movable electrode rod 6, as shown in FIG. 2F. In the vacuum container 4, there is a bellows 2.
The movable electrode rod 6 is inserted through the center of the electrode and is introduced with the movable electrode rod 6 protruding appropriately. Movable electrode rod 6
is made of copper or copper alloy.

At the inner end of the movable electrode rod 6, like the arc shield 17 of the fixed electrode rod 5, there is an arc shield 22 formed in a cup shape with a larger diameter than the auxiliary shield 10 on the other insulating disk 2 side. , with its open end facing the other insulating disk 2, and is fitted through a hole 23 provided at the center of the bottom. Then, the arc shield 22 includes the projection 6
movement in the direction of the other insulating disk 2 is restricted by a, and is fixed near the inner end of the movable electrode rod 6 by brazing. In addition, in the closed state shown in FIG. They are arranged so that they are superimposed on each other. Moreover, at the inner end of the movable electrode rod 6,
The movable electrode 8, which is formed approximately in the shape of a disk, is fitted through a recess 8a protruding from the center of the opposing back surface (lower surface in FIG. 1), and is fitted into the recess 8b in the recess groove 8b for mounting the solder metal. It is fixed by brazing with a material 25. A circular groove 8d centered at the center of the movable electrode 8 is formed on the facing surface of the movable electrode 8, and a ring-shaped contact 2 is provided in the groove 8d.
4 protrudes appropriately from the opposing surface and is fitted thereinto, and is fixed by brazing with the brazing material 25 in the brazing material mounting groove 8e.

In order to manufacture the vacuum shield and disconnector having the above configuration, the vacuum shield and disconnector is temporarily assembled by interposing a brazing material between each component (the groove for installing the brazing material), and then the vacuum Braze in a furnace. First, in order to temporarily assemble the vacuum shield and disconnector, the other insulating disk 2 is supported horizontally so that its stepped portion 13 with a metallized layer faces upward, and the cylindrical portion 20a of the bellows 20 is attached to the auxiliary member 16. 1 and 2.
As shown in FIGS. AF, a brazing material 25 is provided.
Similarly, the auxiliary member 3 and the brazing material 25 are arranged on the outer periphery of the other insulating disc 2. Further, the auxiliary shield 10 is brought into contact with the metal cylinder 1 with the brazing material 25 interposed therebetween. Then, the movable electrode rod 6 is inserted into the bellows 20, and a brazing material 25 is placed between the movable electrode rod 6 and the movable electrode 8.

In addition, at the upper end of the movable electrode rod 6, an arc shield 22 is interposed with a brazing material 25, and a movable electrode 8, which is fitted into the groove 8d with the contact 24 interposed with a brazing material 25, is soldered into the concave groove 8e. The material 25 is interposed and then fitted in advance.

As mentioned above, the movable electrode 8 is placed on the other insulating disk 2.
After temporarily assembling the movable side such as the metal cylinder 1 and the movable side such as the fixed electrode 7, etc., the fixed side such as the fixed electrode 7 is temporarily assembled on the upper end of the metal cylinder 1. That is, the fixed electrode 7 is fitted into the fixed electrode rod 5 with a brazing material interposed therebetween, and the fixed contact 7b disposed at the end of the electrode rod 5 is positioned at the center of the metal cylinder 1, thereby forming the movable electrode 8. on the contact 24 of. The arc shield 17 is fitted onto the fixed electrode rod 5, and the brazing material 25 is interposed in the groove 5c of the stepped portion 5b near the lower end of the arc shield 17 to lock it.
Next, the flange portion 10a of the auxiliary shield 10 is attached to the protrusion 3c at the center of the auxiliary member 3 using a brazing material 25.
(See FIGS. 2A and B).
A brazing material 25 is similarly interposed and placed on aa.
At this time, although not shown, there is a slight gap between the contact surface between the groove 3aa and the flange portion 3a for assembly and gas release. Then, insert one insulating disk 2 into its hole 1.
1 through which the fixed electrode rod 5 is inserted. Furthermore, the auxiliary member 15 is fitted onto the fixed electrode rod 5, and the brazing material 25 is placed on the end portion 15a and bottom portion 15b of this member 15, thereby completing the temporary assembly of the vacuum shield breaker.

The vacuum shield and disconnector temporarily assembled as described above were heated to 10 ^-4
It is placed in a vacuum furnace that can be freely evacuated to a pressure below Torr, and heated at 820°C to 860°C for 1 to 2 hours for soaking. Note that heating is for exhausting, degassing, and removing the oxide film on the brazed part, so if the temperature does not melt the brazing filler metal 25, a higher heatable temperature is better, and the degree of vacuum also needs to be higher.
Desirably 10 ^-4 Torr or less. Then, inside the vacuum furnace,
In order to activate the surface of the austenitic stainless steel, the temperature is raised to 940° C. or higher and lower than 980° C., and each component member is airtightly joined using a brazing filler metal 25 while being evacuated to a pressure of 10 ⁻⁴ Torr or lower. Then, the inside of the vacuum furnace is lowered to a predetermined temperature by slow cooling (furnace cooling), held at this temperature for a predetermined time, and then lowered to room temperature again by slow cooling, or after the inside of the vacuum furnace is cooled to room temperature by slow cooling. After it has cooled, remove the vacuum chamber and disconnector to obtain the desired result.

In addition, in the manufacturing method described above, the heating temperature is
The temperature between 940°C and 980°C was achieved by using Cu−35%Mn− as the brazing material.
This is because 10% Ni was used, and the solidus temperature was 880
℃, the liquidus temperature is 910℃. When this brazing filler metal is used for stainless steel, a good vacuum can be maintained for a long period of time. This is because it can be hermetically sealed at high temperatures and in high vacuum. Note that the brazing material 25 is the auxiliary member 3.
The protrusion 3b may be arranged on the atmosphere side. At this time, even if the brazing filler metal 25 provided on the atmosphere side evaporates and adheres to the insulating disk 2, the third
As shown in the figure, by coating the insulating disk 2 and the auxiliary member 3 with resin, a decrease in withstand voltage can be prevented.

In FIG. 3, the insulating disk 2 and the auxiliary member 3 are coated with resin to improve weather resistance.

Fig. 4 is a diagram showing the voltage withstand characteristics at vacuum creepage distance when the protrusion 14 is provided on the insulating disk 2, and the withstand voltage characteristics are good when the height t of the stepped portions 12 and 13 is about 1 mm to 3 mm. Show that.

FIG. 5 is an enlarged view of the insulating disk, and when the outer peripheral part 2a of the disk 2 is polished, even if a moment is applied to the auxiliary member 3 after the auxiliary member 3 and the insulating disk 2 are brazed, the insulating disk becomes Cracks no longer occur on the plate 2.

In addition, in the embodiment, if the vacuum shield switch is constructed of only non-magnetic material, it can also be used for high-frequency current switching.

As described above, according to the present invention, in order to prevent the vapor of the brazing material from scattering into the vacuum space, a groove is provided in one joint member of each joint part in the vacuum container,
By placing the brazing metal in the groove and covering the groove with the other bonding member, it is possible to prevent the vapor of the brazing metal from adhering to areas that would reduce dielectric strength, and maintain stable insulation performance. . Further, manufacturing is easy because temporary assembly can be performed simply by installing the brazing material into the groove of the auxiliary member or the groove formed in the electrode, etc.
Furthermore, when temporarily assembling, since the structure allows positioning between each member, no assembly jig is required. Furthermore, since the brazing material melts and penetrates into the joint, the brazing becomes strong and reliable.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing one embodiment of the present invention, Figs. 2A to 2F are enlarged sectional views of various parts where brazing filler metal is arranged, and Fig. 3 is a vacuum shield at both ends of the disconnector. FIG. 4 is a diagram showing the withstand voltage characteristics of the insulating disk, and FIG. 5 is an enlarged view of the insulating disk. 1... Metal cylinder, 2... Insulating disk, 3... Auxiliary member, 4... Vacuum container, 5, 6... Fixed, movable electrode bar, 7, 8... Fixed, movable electrode, 20... Bellows , 25...brazing material.

Claims (1)

[Claims] 1. A vacuum vessel is formed by airtightly joining insulating discs made of an inorganic insulator to both ends of a metal cylinder with a ring-shaped auxiliary member made of a metal material that can be plastically deformed by thermal stress. In the vacuum shield disconnector, a pair of electrodes are separately connected to a pair of electrode rods introduced from each insulating disc so as to be able to approach and separate from each other in the vacuum vessel so as to be able to come into contact with and separate from each other. A concave groove is provided in one joint member of the joint part forming the vacuum container and each joint part in the container,
A vacuum shield and disconnector characterized in that a brazing material is arranged in the groove, the groove is covered with the other joining member, and the brazing part is placed in a vacuum container.