JP2000057977A - Shielding member for vacuum switching tube, and method of fixing getter to shielding member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously fix in a vacuum switching chamber at a low cost by arranging a getter ring formed by closing a strip material outside of a shield, and forming the shield at least one fixed position for strong fixation by a mechanical means or welding. SOLUTION: A contact 21 and a fixed contact 31 are surrounded by a cylindrical shield 8 at a side thereof, the shield 8 is soldered to a cover 6 in an area of the fixed contact, a free end thereof reaches an area of an insulator 7, the shield 8 houses the radiation heat and the condensed metal vapor from the switching area, the housed metal vapor is led out, and the arc-like metal vapor is shielded by the cover 6 and an insulator 7. The shield 8 is made of copper capable of excellently conducting the heat out. In order to mix the gas to be generated by the arc-like metal vapor at the time of switching, a getter formed into the shape of the getter ring 9 is arranged near the free end of the shield 8 outside of the shield 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielding member having a getter material for a vacuum switching tube having a vacuum switching chamber, wherein the vacuum switching tube includes a relatively movable conductor having a contact member. Wherein the shielding member is configured in the form of a cylindrical metal shield having getter material disposed on the shield, wherein the shielding member surrounds the contact member at a distance. . Furthermore, the present invention
A method for securing getter material to a cylindrical shield for a vacuum switching tube in which a shield surrounds a contact member of the vacuum switching tube at a distance.

[0002] The shielding of a vacuum switching device, performed by means of a metallic shield arranged in a vacuum switching chamber, deposits conductive material which evaporates from the switching contacts during the switching process and deposits at disadvantageous points, especially insulators. It is to avoid things. Generally, high-grade steel is used as a shielding material for the shield. Another basic condition for ensuring the reliable functioning of the vacuum switching device is that a correspondingly high vacuum, i.
0 is that of providing ^-7 bar (bar) or less pressure than that. This pressure must not fall below during the entire service life of the vacuum switching chamber. The internal pressure of the vacuum switching chamber is
In a normal case, it shows dynamic characteristics instead of invariable characteristics. Even small leaks and outgassing of materials in the vacuum switching chamber will increase the pressure. It is known to arrange a getter element in a vacuum switching tube, which causes a pressure drop due to the combination of gases, in order to reduce the gas generated by material leakage and outgassing.

The construction and arrangement of the getter material in the vacuum switching chamber of a vacuum switching device is described, for example, in German Patent No. 3
No. 829,888. In this case, the metallic shield surrounding the switching contacts is composed entirely of getter material, which is vaporized by the heat generated during discharge and switching, so that sufficient getter capacitance is provided in the vacuum switching chamber. Provided. Titanium is advantageous as a getter material. According to the proposal disclosed in DE-A 1 910 833, the getter material is also arranged in a shield exposed to arc heat. According to the proposal disclosed in DE-A-1 118 690, a cut-out is provided in the shield of the vacuum switching chamber, in which a getter is fixed, in which case the getter is Do not protrude from the outer peripheral surface of the shield. This type of mounting is a intensive assembly and impairs the shielding effect.

In a known getter arrangement in a vacuum switching chamber, since the getter is mounted by spot welding,
This is only possible if the support or shield is made of high-grade steel, copper-nickel alloy, iron-nickel alloy, Monel and iron-nickel-cobalt alloy with sufficiently low thermal conductivity, instead of copper. The fixation of the getter by soldering has the danger that the getter will be toxic by the metal vapor from the solder during the high-temperature soldering process, which significantly impairs the function of the getter. Therefore, getter fixing by soldering is not performed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to fix a getter continuously in a vacuum switching chamber of a vacuum switching tube, and in this fixing, the assembly cost is not expensive and there are no other disadvantages. Is to do so. Another object of the invention is to provide a fixation for the getter, which is not limited to a shield made of high-grade steel or a corresponding alloy, as in spot welding.

[0006]

According to the present invention which solves this problem, a gettering formed by closing a band is disposed outside the shield, and the shield is formed at at least one fixing point. And is firmly fixed mechanically or by welding.

[0007]

According to the invention, on the one hand, there is provided a purely mechanical fixation of the getter to the shield, which can be performed without heating or without additional binders such as solder. Is done. On the other hand, according to the invention, in order to fix the getter material, while avoiding local high heating,
Welding such as spot welding, electron beam welding, ultrasonic welding, resistance welding, and especially laser welding can also be used. Furthermore, by fixing the getter in the form of a closed gettering according to the invention, it is also possible to use a shield or cylindrical shield made of a material having a high thermal conductivity, namely copper or a copper alloy. The fixation of the getter is advantageously obtained by mechanically deforming the shield after installation and by placing the gettering in the correct position on the shield. In this way, according to the invention, a getter, preferably in the form of a strip, can be firmly connected to the shield, which is also made of copper or only of copper.

Advantageous components of a shield constructed according to the invention with a getter for a vacuum switching tube are:
Claims 2 to 11 describe.

As a getter material, in addition to titanium, other metal alloys such as ZrAl, ZrTi, ZrAl
Ti, ZrVFeTi or MoTi is used. Advantageously, the getter element has the shape of an annular strip,
In this case, the gettering of the strip is formed at the end of the strip by riveting or welding (such as spot welding), or the gettering itself is also integral, for example as a cylindrical section of a cylindrical pipe. It can be manufactured so that it can be incorporated as a general part.

As an advantageous shielding material, in addition to copper having a high thermal conductivity, a low-content copper alloy or a high-content copper chromium, copper cobalt, copper iron, molybdenum copper, tungsten copper, tungsten silver, tungsten silver, tungsten carbide Copper or a combination of these materials is provided. These materials likewise have good thermal conductivity and help to extract heat well from the vacuum switching chamber.

According to the proposal of the invention, the gettering is arranged on the outer cylindrical shield. The shield is
It has a shape that matches the vacuum switching chamber. In connection with the gettering arrangement, it has been proposed to arrange the gettering on the shield such that the shield also does not protrude significantly beyond the outer surface of the shield. According to an advantageous feature of the invention, the cylindrical shield has a step-shaped step for accommodating the gettering, towards the end region in which the gettering is to be fitted, wherein the step-shaped step is provided. The portion has a width corresponding to the thickness of the gettering, in which case the outer diameter of the end region of the shield is not greater than the inner diameter of the gettering.

In a method for fixing a getter material and a method for forming a shielding portion, a gettering in the form of a closed band is manufactured from the getter material, and a cylindrical shield having good thermal conductivity is manufactured. Is manufactured from copper or an alloy containing copper, an end region is provided in the shield, and the outer diameter of the end region is configured to a size such that the gettering can be fitted over the end region, It has been proposed to fit the gettering over the end region of the shield and to secure the gettering to the shield mechanically or by welding.

[0013] Laser welding is preferred.

Further advantageous embodiments of the method according to the invention are described in claims 12 to 18.

In order to easily fix the shield by deforming the shield, the length of the end region extending from the step is configured to be larger than the width of the gettering, so that the end region is fitted. Protruding beyond gettering. Thereby, this edge region is locally deformed outward in order to form a claw-shaped or clamp-shaped deformed part for axially fixing the gettering.
It is also possible for the edge region to be bent outwardly in a ring shape and in this way the gettering is firmly fixed to its bearing. The gettering and the shield can also be connected by a fold connection which is positively connected.

According to another proposal of the invention, the cylindrical shield has a step-like tapered step towards the end area where the gettering is to be fitted, wherein the tapered step is provided. With slits extending from the end on the side of the end face, the end region of the shield between these slits being bent outwardly, forming a flange projecting at a distance from the shield. .

In manufacturing the shielding portion, for example, a cylindrical shield having a stepped tapered step portion for accommodating the gettering is formed, and the tapered step portion is provided with an end portion on the end face side. After the slit is formed from the gettering and the gettering is fixed to the outside of the shield, the end region of the shield of the gettering that exists between the slits is bent outward so as to overhang at a distance from the gettering. It has been proposed.

According to the present invention, a getter material having a large band-shaped gettering shape can be firmly fixed to the shield. This provides a large getter surface.
By fixing the gettering to the outside of the shield, the gettering can be protected from the direct effects of the arc (metal deposition arc) and ensure a sustained high functioning of the getter.

In this case, according to the proposal of the present invention, the welding operation such as spot welding, laser welding, ultrasonic welding, electron beam welding, or resistance welding is performed simultaneously with the joining operation of joining the strip-shaped materials to form gettering. It is also possible to fix the gettering to the shield.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the embodiments shown in the drawings.

FIG. 7 is a schematic cross-sectional view of a vacuum switching device having a main function according to an embodiment of the present invention, in which a vacuum switching tube according to the present invention is provided. Inserted. In this case, an electromagnet type switching device having a magnet driving device provided with a magnet core is targeted. The magnet drive is not shown in detail, and includes a mover, a fixed contact, a movable contact in direct linear connection with the stroke rod, a working connection with the stroke rod and the mover. A switching view gel for switching the driving movement to the switching movement of the movable contact. The stroke rod is rigidly connected at one end to a contact support that supports a movable contact, the contact support sliding on the output side in a tube support and relative to the longitudinal axis of the stroke rod. Supported as possible. The mover 110 is shown in FIG.
According to the above, the switching bugel (Schaltwippe; switching arc-shaped current collector) 120 which is fixed to the mover receiving portion 111,
It is fixed to the view gel receiving support 121 formed at one end of the switching view gel 120 by the pin 113 via the buffer bearing 122. Switching view gel 1
Reference numeral 20 is switchably supported by a rail support casing 140 or a drive casing (not shown) of the vacuum switching device 200. Rail support casing 140
A vacuum switching tube 1 is arranged in the upper region of the vacuum pump. The vacuum switching tube 1 has a fixed contact support 30 that supports a fixed contact 31 at one end.
Are fixed to the connection lug 160 a by screws 170 and are fixed in the rail support casing 140. The vacuum tube 1 has a movable contact 21 (movement direction is indicated by an arrow P).
2, indicated by P2 '), together with a movable contact support 20 with a metal folding bellows 4 sealed to the vacuum switching tube 1. On the output side, the vacuum switching tube 1 has a tube bearing 147,
A contact carrier 20 is slidably mounted therein in the direction of the switching movement. The stroke rod 150 fixed at the end of the contact support 20, which is in direct linear connection with the movable contact support 20 and thus with the movable contact 21, is also provided by a pipe support 147 in its fixed area. Guided. At its other end, the stroke rod 150 is guided axially in a shaft guide bearing 160, wherein the shaft guide bearing 160 is arranged in the region of the side wall of the rail support casing 140. , Screw 153
Has been fixed by. This screw 153 extends perpendicularly to the longitudinal axis X of the stroke rod and the vacuum switching tube 1. A litz wire 141 communicating with the connection rail 161 is further fixed to the stroke rod.
The litz wire 141 is directly connected to the end of the movable contact support 20, and is fixed to the stroke rod 150 by a hexagon nut on the other side. The switching bugel 120 has its fork ends 123a, b engaging between two bearings 147 and 160 on both sides of the stroke rod 150 for transmitting the switching movement P1 of the switching bugel. During the movement of the switching bugel by initiating the corresponding armature movement (see arrow P3), the switching bugel 120 is swung from its initial position shown in FIG. To
The stroke rod 150 is
Entrained together with the part connected to 0,
A switching movement (see arrow P2) for closing the contacts 21, 31 of the vacuum tube 1 takes place. Conversely, in order to open, the stroke rod moves in the direction of arrow P2 'to open the contacts 21, 31.

The vacuum switching tube 1 shown in FIG. 1 has a movable conductor 2 and a stationary conductor 3.
Have one contact support 20, 30, respectively, with contact members 21 or 31 attached to the end portions facing each other. The vacuum switching chamber is formed by metal cover parts 5, 6 and has an insulator 7 arranged between these cover parts 5, 6.
The movable conductor 2 is sealed to the casing or cover 5 by a guide 41 and a folding bellows 4. The outer parts forming the vacuum switching chamber are connected to one another via soldering points 10, 12, 14, 15 and the folding bellows 4 has a movable conductor 2 at the other end.
Are fixed via soldering points 16. The contact members 21 and 31 are likewise connected to the respective contact supports 20 or 30 via connection surfaces 11 and 13 configured as soldering points. Thus, a closed vacuum switching chamber 100 is formed. Contact member 21,
31 is laterally surrounded by a cylindrical shield 8, which is soldered on the one hand to the cover 6 in the area of fixed contacts and whose free end extends into the area of the insulator 7. Radiant heat from the switching area as well as concentrated metal vapors are accommodated in this manner,
As a result, the arc-shaped metal vapor is shielded by the cover 6 and the insulator 7. The shield 8 is made of copper, which allows for particularly good heat dissipation. In order to mix the gas generated by the arc-shaped metal vapor during switching,
A getter in the form of a gettering 9 is arranged outside the shield 8 and near the free end of the shield. Since the gettering 9 is mounted outside the shield 8 (see FIG. 1), it is likewise protected against the direct effects of metal vapor.

FIG. 2 shows the gettering, which consists of a correspondingly wide band,
It is manufactured by joining the strip ends 91 by spot welding, laser welding or, for example, electron beam welding or riveting. The inner diameter of the strip is indicated by lg, the thickness of the strip is indicated by d, and the width of the strip is indicated by b.

FIG. 3 shows the shield 8 in a perspective view. The shield 8 has a base shield part 81 by which the shield 8 surrounds the area of the switching contact. Further, the shield 8 has a cylindrical outer peripheral surface 83 following the base shield 81 with a stepped step 82 interposed therebetween, and the outer peripheral surface 83 also has a stepped step 84 interposed therebetween. Then, the taper continues to the end region 85. Stepped step 8
4 has a width a substantially corresponding to the thickness d of the gettering, as shown in FIG. 4, so that the gettering 9 rests on this step 84 and It forms substantially the same plane as the outer peripheral surface 83. The height or remaining length of the tapered cylindrical end region 85 is slightly larger than the width b of the gettering 9.

FIG. 5 shows a gettering 9 resting on a step 84 of the shield, with the upper free end of the shield 8 having a narrow edge of dimension Le-b. Area protrudes beyond gettering 9,
Mechanical deformation in this area, for example, by means of four collars or clamps 86a, 86b, 86c, 86
The d is shaped outward by caulking and the clamps secure the gettering 9 to the counter bearing of the step 84 in a position fitted over the shield 8. Thus, by mechanically assembling the gettering 9 to the shield 8 according to the invention, a flexible material that does not have particularly good weldability but has a high thermal conductivity for the shield 8, for example Copper can be used. Gettering 9 fitted over shield 8
In addition to simple shaping by crushing the shield edge, it is also possible by partially or completely folding the seal edge or the like.

FIG. 6 is a cross-sectional view showing a state in which the shield 8 having the gettering 9 is disposed in the vacuum switching tube shown in FIG.

To produce a shield with gettering on the outside, which additionally protects the gettering against metal vapors by means of an overhung shield region, the construction of the shield with shield is shown in FIG. Proposed. The cylindrical shield 8 has a tapered end region 85, also via one step or two steps. On these end regions 85, the gettering 9 is later fitted until it rests on the step. The tapered end region 85 is provided with three or more slits 8a, 8b, 8c extending in the longitudinal or axial direction of the shield 8. Since a larger height remains between the fitted gettering 9 and the end face on the end face side of the shield region 85, sufficient bending and overhang here (see FIGS. 9 and 10). Obtained by outward bending (as shown).

FIG. 9 shows a state where the tapered shield region 85 is bent outward in a U-shape after the gettering 9 is fitted on the shield 8. As a result, a flange 88 is formed.
Has its end 88a covered with the gettering 9 at an outer distance from the gettering 9. For this purpose, the tapered region 85 needs to be configured so large that a correspondingly wide bendable edge region is obtained from the step for mounting the gettering. Edge bending or bending is reduced by the configuration of the slit.
The gettering is, in an advantageous manner, completely sealed off by the flange configured in this way. In this manner, during the vacuum soldering phase and by a vacuum arc,
The getter can be well protected against being covered with the concentrated metal vapor. Furthermore, the bent edge and the flange 88 have a lower end 88a (if this end 88a is bent slightly outward), and at the same time, the structure of the vacuum switching tube shown in FIG. Is used as a means for centering In other words, the outer insulator 7, for example, a ceramic, is supported and is used as a means for centering the structure of the vacuum switching tube by centering the ceramic 7 in relation to the shield.

The composition and arrangement of the getter material according to the invention allows a large getter surface to be firmly fixed to the shield and protects the getter from metal vapors of the solder during the manufacturing process of the soldering of the vacuum switching tube. can do.

The placement of the getter material on the outer surface of the shield ensures that the getter material is protected from the direct effects of the arcuate metal vapor and maintains a sustained high function of the getter. Moreover, according to the present invention, a copper shield having high thermal conductivity can be used in combination with a getter. By securing the getter in the form of a strip in the form of a preformed ring mechanically or by welding, it is possible to firmly couple the getter material with the copper shield. The gettering may have any dimensions. Another advantageous fixing of the gettering takes place by means of laser welding in the shield part, in which case the shield is made of a material having good thermal conductivity, for example copper, a copper alloy.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a vacuum switching tube.

FIG. 2 is a perspective view of gettering.

FIG. 3 is a perspective view of a cylindrical shield.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a schematic perspective view of a shield having the gettering shown in FIGS. 2 and 3;

FIG. 6 is a partial tree sectional view of a vacuum switching tube provided with a shield and gettering shown in FIG. 5;

7 is a partial sectional view of a vacuum switching device having a vacuum switching tube provided with a shield and gettering shown in FIG. 5;

FIG. 8 is a perspective view of a cylindrical shield having a getter ring and a slit before molding.

9 is a longitudinal sectional view of the shield having the fixed gettering shown in FIG. 8;

FIG. 10 is a cross-sectional view of a shield according to another embodiment having the fixed gettering shown in FIG. 8;

[Explanation of symbols]

1 vacuum switching tube, 2,3 conductor, 4 metal folding bellows, 5,6 cover, 7 insulator, 8 shield, 9 gettering, 10,12,14,1
5, 16 soldering points, 20 contact supports, 2
1 contact point, 30, 31 fixed contact point, 81 base shield part, 82 stepped part, 83 outer peripheral surface, 84
Step, 85 end area (shield area), 86a,
b, c clamp, 88 flange, 91 end of strip, 100 vacuum switching chamber, 110 mover receiving part,
113 pin, 120 switching bugel, 121
Bugel receiving bearing, 122 cushion bearing, 123
a, b fork end, 140 rail support casing, 141 litz wire, 147 pipe bearing, 15
0 stroke rod, 153 screw, 160 shaft guide support, 160a connection lug, 161 connection rail, 170 screw

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jerry Liperts Netherlands Teher Venlo Thi Beliuslan 4 (72) Inventor Alfred Rietz Germany Frechen Yacht Her Wicheln Strasse 30

Claims (18)

[Claims] 1. A shielding member having getter material for a vacuum switching tube with a vacuum switching chamber, said vacuum switching tube having a relatively movable conductor with a contact member,
The shield, wherein the shield is configured in the form of a cylindrical metal shield having a getter material disposed on the shield, wherein the shield surrounds the contact member at an interval. The formed gettering (9) is arranged outside the shield (8) and is fixed to the at least one fixing point firmly mechanically by molding the shield or by welding. And
Shield for vacuum switching tubes. 2. The shield according to claim 1, wherein the gettering and the shield are connected by a foldable connection that is positively connected. 3. A strip of getter material, which is closed to form a getter ring, is riveted to the end of the strip, or is spot welded, laser welded, electron beam welded, resistance welded or ultrasonic welded. The shield of claim 1, wherein the shield is welded. 4. The shield according to claim 1, wherein the gettering is provided with an integrated cylindrical tube section made of getter material. 5. A shielding material comprising copper or a low-content copper alloy or a high-content copper chrome, copper cobalt, copper iron, molybdenum copper, tungsten copper, tungsten carbide silver,
5. The shield according to claim 1, wherein the shield is provided with copper tungsten carbide or a combination of these materials. 6. A gettering (9) in the direction of the end to which the cylindrical shield is fitted.
Has a stepped step portion (84) for accommodating the
The step (84) has a width (a) corresponding to the thickness (d) of the gettering (9), and the outer diameter (Ae) of the end region (85) of the shield is equal to the gettering (9). 6. The shield according to claim 1, which is not larger than the inner diameter (lg) of 9). 7. An end region (8) extending from a step (84).
5) The length (Le) is the width (b) of the gettering (9).
7. The shield of claim 6, wherein the shield is configured to be larger than this, so that the end region protrudes beyond the overlaid gettering. 8. The method according to claim 1, wherein the getter material is titanium, zircon aluminum, zircon titanium, zircon aluminum titanium, zircon vanadium iron titanium and / or molybdenum titanium. The shield according to any one of the preceding claims. 9. The edge of the end region of the shield, which protrudes beyond the gettering fitted over the shield, has a clamped outwardly directed shaped portion (86a, 86a, 86. The shield according to claim 1, wherein the shield is configurable to 86b, 86c, 86d). 10. An edge of an end region of the shield projecting beyond the gettering overlaid on the shield,
9. A ridge or flange that is bent outwardly to secure the gettering.
The shield according to any one of the above. 11. The cylindrical shield has a step-like tapered step toward an end region where the gettering is fitted, and the tapered step (85) has an end surface side. With a slit (87) extending from the end,
The end regions (8a, 8b, 8c) of the shield present between these slits are bent outwardly, forming a flange (88) projecting at a distance from the shield (8). Any one of items 1 to 8
The shield described in the section. 12. A method for fixing a getter material to a shield in the form of a cylindrical shield, said shield closing the contact member of a vacuum switching tube at a distance, wherein the shield is closed from the getter material. Manufacture gettering in the shape of a strip, manufacture a cylindrical shield with good thermal conductivity from copper or an alloy containing copper, provide an end region in the shield, Configuring the diameter to be such that the gettering can fit over the end region, fitting the gettering over the end region of the shield, and securing the gettering to the shield mechanically or by welding. Characterized by the method for fixing the getter to the shield. 13. The shield edge protrudes beyond the gettering and the gettering is secured to the shield until the gettering is secured to the shield by partially or completely bending the shield edge outward. 13. The method of claim 12, wherein the method fits over an end region. 14. The shield edge protrudes beyond the gettering, and the shield edge is crimped outward in some places to form a clamp to shield the gettering until it is secured to the shield. 13. The method of claim 12, wherein said end region is fitted over said end region. 15. The shield according to claim 12, wherein a step is provided in an end region of the shield where the gettering is fitted, and the step is used as a stopper for the gettering to be fitted. A method according to any one of the preceding claims. 16. The method according to claim 12, wherein the gettering is made from a strip-like getter material, the strip ends for forming the gettering being joined by rivets or welding. 17. A welding operation such as spot welding, laser welding, ultrasonic welding, electron beam welding, resistance welding, etc., at the same time as the joining operation of joining the band-shaped materials to form gettering
17. The method of claim 16, wherein the gettering is secured to the shield. 18. A cylindrical shield having a stepped taper for accommodating gettering is formed,
A slit (87) is formed in the tapered step (85) from the end on the side of the end face, and after the gettering (9) is fixed to the outside of the shield (8), there is a gap between the slits.
14. The method according to claim 12 or 13, wherein the end region of the shield of the gettering (8) is bent outward so as to overhang at a distance from the gettering (8).