DE2513540C3 - AC magnetic core with short-circuit ring - Google Patents

Description

3.

The invention relates to an alternating current magnet core for electrical switchgear with short-circuit ring, the long sides of which in grooves in the pole surface are inserted and its cross sections on the side surfaces running perpendicular to the pole face of the magnetic core and by means of rivet bolts arranged in coaxial openings with the magnetic core are riveted.

In a known fastening arrangement of the type mentioned above (US Pat. No. 1,491,386), the webs are of the short-circuit ring is provided with a hole through which the rivet that lamellates the magnetic core holds together, is passed through and by which the short-circuit ring is held on the leg of the magnetic core after riveting the rivet. Due to the plastic deformation of the short-circuit ring web when riveting, the long sides of the short-circuit rings lift in this known arrangement, even if only slightly, out of the grooves, so that home operation of the switching device a vibrating mass is given, which can lead to breakage of the short-circuit ring.

The invention is intended to provide a means of attaching short-circuit rings to AC magnetic cores are created whose functional behavior with regard to fatigue failure with the same

• 5 time cheaper the type of fastening is improved, which is the case with an alternating current magnet core Above type is done in a simple manner that the opening of each transverse side of the short-circuit ring as a substantially semicircular, for

»° pole face open recess is formed and that on it the rivet head of the Nielbolzcns so with Stress is applied that in the transverse side of the pole face to the rivet head directed tensile stresses to rule.

^a 5 Although transverse widths of Kurzscfclußringen hooked over the rivet are known (DE-Gbm 7220530 and DE-AS 1764 522), there is no bracing of the short-circuit ring with the AC magnet. It is also known.

3 »the long sides of a short-circuit ring before inserting to bend so that they are preloaded on the groove base after the short-circuit ring has been inserted (DE-Gbm 7 147 973). The holder of the long sides of the short-circuit rings can with the object the invention in the usual way by caulking or pressing (DE-OS 1489 806, made known Patent application S 28703VIIIb / 2Ic) can be achieved.

To carry out the process according to the invention

Stigung has a method for riveting the short-circuit ring to the magnetic core as advantageous highlighted, which is characterized by the combination of the following process steps:

a) the short-circuit ring is loosely inserted with its long sides into the grooves of the pole face;

b) the rivet bolt is pushed through the recesses in the transverse sides and the hole in the magnet core pushed;

c) the two ends of the rivet bolt are plastically deformed into a rivet head each in such a way that each The transverse side of the short-circuit ring experiences a length extension limited by a stop and is pressed against the side surface of the magnetic core at the same time.

Because stops are assigned to the transverse sides on the sides facing away from the rivet bolts, Overstretching of the short-circuit ring is avoided, but it is ensured that with laminated cores the packing density and thus the pressure to be applied by the rivet bolt on *> ° the individual sheets the desired Corresponds to the circumstances. Additional fasteners can be dispensed with if that The method set out above is supplemented to the effect that the longitudinal sides of the short-circuit ring by a Hold-down devices are pressed into the grooves of the pole face during the riveting process.

The attachment of the short-circuit rings is explained in more detail using the drawing. It shows

Fig. I the short-circuit ring inserted in U ic grooves with inserted rivet unexpectedly in side view,

2 shows the short / slip ring fastened in the alternating current magnet core after riveting has been carried out,

3 shows a side view of the arrangement according to FIGS

FIG. 4 shows a side view of the arrangement according to FIG. 2.

The U-shaped alternating current magnet core 1 has the two legs 2, on whose pole faces 3 slots 4 are introduced into which the longitudinal sides 5 of the short-circuit rings 6 are inserted. The Qucrsciten 7 of the im Exemplary embodiment asymmetrically designed short-circuit rings encompass the through an opening 8 in the leg 2 of the magnetic core inserted rivet bolts 9, in the embodiment according to FIG Game, through a substantially semicircular recess 16 of the transverse sides 7. The diameter des Nictholzcns is denoted here with 10. If the rivet bolt is now from the one in Fig. 1 or in the side view Fig. 3 brought the shape shown in Fig. 2 or Fig. 4 by riveting, so the diameter 10 increases to the diameter 11, with a full support of the longitudinal sides 5 takes place in the groove bottom of the grooves 4, and tensile stresses, indicated by arrows 12, arise in the Connecting parts of the longitudinal sides 5 with the transverse ropes 7. The tensile stress is increased during axial upsetting Rivet heads through plastic diameter enlargement achieved from diameter 10 to diameter 11. To the head formation of the To support rivet heads 13 and thus to ensure

s len that the lamellae 14 pressed together sufficiently and thus to increase the frictional force of the transverse sides between rivet and cover plate, the extension path of the transverse sides 7 is limited by stops 15, as can be seen from FIG

ίο is. As already mentioned, the stops 15 can be formed on the core itself, for example by the cover sheets, or in the hold-down device of the riveting tool to be available.

In the type of fastening according to the invention for the

The short-circuit ring lies snugly against the core on the transverse sides. This makes the lever arm the overhanging one Mass reduced to a minimum. It corresponds practically to half the sheet metal thickness of the short-circuit ring. Due to the high frictional engagement between the rivet head

jo and core and through the FormschniS is the possibility of movement of the short-circuit ring blocked when switching. The pretensioning of the transverse sides when riveting completely prevents oscillation amplitudes in the short-circuit ring perpendicular to the pole face or perpendicular to: rivet axis occur. This means that the punched edges of the short-circuit rings can remain untreated. The plastic deformation also increases the fatigue strength of the Short-circuit ring.

1 sheet of drawings

Claims (1)

Patent claims: 1. AC magnet core for electric Switching devices with short-circuit ring, the long sides of which are inserted into grooves in the pole face and the transverse sides of which rest in the side surfaces of the magnet core that run perpendicular to the pole surface and riveted to the magnetic core by rivet bolts that are disordered in coaxial openings are, characterized in that the opening of each transverse side (7) of the short-circuit ring (6) as essentially semicircular, to the pole face (3) open recess (16) is formed and that the rivet head (13) of the rivet bolt is formed on it (9) is applied with tension in such a way that in the transverse side (7) from the pole face (3) to the rivet head (13) directed tensile stresses prevail. 2. Verfakr <: n for riveting the short-circuit ring with the magnetic core according to claim 1, characterized by combining the following process steps: a) the short-circuit ring (6) with its long sides (5) is loosely in the grooves (4) of the pole face (3) inserted; the rivet bolt (9) is pushed through the recesses (16) of the transverse sides (7) and the bore (8} of the magnetic core (1); c) the two ends of the rivet bolt (9) are thus zi; one rivet head (13) each plastically deformed so that each transverse side (7) of the short-circuit ring (6) experiences a length extension limited by a stop (15) and is simultaneously pressed against the side surface (2) of the magnetic core (1).
Method according to Claim 2, characterized in that the longitudinal sides (5) of the short-circuit ring (6) are pressed into the grooves (4) of the pole face (3) by a hold-down device during the riveting process. 4. The method according to claim 2 or 3, characterized in that the elongation as the Transverse sides (7) when riveting limit stops (15) correspondingly dimensioned cover plates of the magnetic core (1) can be used. 5. Device for performing the method according to claim 2 or 3, characterized in that that the hold-down device with a length expansion of the transverse sides (7) when riveting limiting stop is provided. b)