EP1345246A2 - Trip device for a ground fault circuit breaker and method of production - Google Patents

Abstract

An activator comprises a fixed primary element, a movable secondary element, and a permanent magnet and spool. The secondary element is pulled into a primary position against spring pressure by magnetic attraction, and is in contact with the primary element. When a fault current occurs, the spool creates an opposing magnetic flux, pushing the element into a secondary position. An activator for a fault current protection switch, comprises a fixed primary element, a movable secondary element, and a permanent magnet and spool. The secondary element is pulled into a primary position against spring pressure by magnetic attraction, and is in contact with the primary element. When a fault current occurs, the spool creates an opposing magnetic flux so the spring pressure exceeds the magnetic force, pushing the element into a secondary position. The contacts have a passifying layer which is resistant to water, oil, grease and silicone. The layer consists of PTFE.

Description

The invention relates to a tripping device for a residual current circuit breaker, and a method for their production, according to the preamble of claims 1, 14 and 15.

Especially for residual current protective devices that are independent of the mains voltage it is known as an actuator or trigger a magnetic circuit-based trigger with permanent magnets to use. In the mostly bistable actuators, the first rest position generated by a permanent magnet, a magnetic flux and the resultant holding force on a movably mounted component, such as. a movably mounted plunger or anchor, which thereby against the force of a spring in a first switching position against a stationary one Component is held. If a fault current occurs, a Coil generates a magnetic flux that corresponds to the magnetic flux of the permanent magnet counteracts, which reduces the magnetic holding force and the movable plunger or anchor by the force of the spring from the fixed one The component is detached and moved into a second release position in which the plunger or anchor then unlocks a key switch.

Embodiments that are used very frequently have an open magnetic circuit a movable element in the form of a hinged anchor. You have a magnetic one Yoke, mostly U-shaped, with a coil around one leg is wound, and on which there is a permanent magnet. The two ends of the Yokes are covered by an anchor which is rotatably mounted about an axis. in the The anchor rests against the force of a spring against the free ends attracted to the yoke; in the event of a fault current, the fault current in the coil generates a magnetic flux that corresponds to the magnetic flux in the permanent magnet is opposed and compensated so far that the magnetic holding force the yoke on the hinged anchor is reduced so far that the hinged anchor pulled by the force of the spring from the ends of the yoke and into the release position is moved, in which a switch lock is then unlocked by the folding anchor becomes. Such magnetic releases with a hinged armature system are for example in DE 25 29 221 and EP 0 228 345.

Another possible embodiment for a magnetic release is known from EP 1 063 666 known. Here the yoke is in the form of a pot, in which the permanent magnet system and - concentrically on the inner wall of the Fitting the pot - the coil is in place. The permanent magnet system is with the Connected to the bottom of the pot and contains pole shoes that comprise a plunger that opposes it the force of a spring from the permanent magnet against the bottom of the pot is pulled. In the event of a fault current, the fault current in the coil turns a magnetic one Generates flux that counteracts the permanent magnetic flux and this compensated so far that the plunger is pulled off the bottom of the pot by the force of the spring and is moved into the release position, in which then by the plunger Key switch is unlocked. Grasp the pole shoes and the lid of the pot the plunger in the manner of a plain bearing, whereby the plunger in its direction of movement to be led.

In all known magnetic triggers for residual current circuit breakers it can happen that the movable components are hinged anchors or plungers the contact points with the fixed components U-shaped yoke or cup-shaped Glue the yoke together, which means that the force of the spring is not in the event of a fault current is sufficient to move the movable component from the rest position into the release position move, the residual current circuit breaker fails and the protective function does not is guaranteed. Possible causes for the contact points sticking are Formation of adhesive layers between the contact surfaces on the fixed and movable component due to corrosion at the metallic contact points due to the deposition of water or due to the accumulation of dirt particles, such as. Dust or metallic abrasion, or due to the accumulation of an oil, Fat or lubricant layer, especially silicone layer, or due to the accumulation a layer of liquid and thus increasing the surface tension in the Contact gap.

In all of the embodiments known today, in the rest position on the Contact point between the fixed and the movable component Air gap over which the magnetic flux of the permanent magnet is guided and its Extension for the safe functioning of the trigger a critical size is. It results from the surface roughness of the fixed and movable components at the contact surface and is on the order of a few µm, typically it is 2 -3 µm. In order not to reduce the magnetic adhesive force too much, The expansion of the air gap may take additional constructive measures only by at most a fraction of their original extent, i.e. typically less than 1 µm.

To avoid the contact points sticking together, the contact points are used today fixed and movable components with corrosion protection layers made of metal or precious metal. Preferred materials for this are according to the prior art Technique nickel, gold or silver. However, since these layers are non-magnetic and thus the same effect for the magnetic circuit as increasing the expansion of the Air gap, they may be applied in a thickness of 1 - 2 µm become. In this small extent there are nickel, gold or silver layers However, there are no dense layers, so that the protection against corrosion is only incomplete given is. These also prevent them from being produced according to the prior art Do not layer the accumulation of oil or lubricants or particles such as Dust and they are insufficiently water-repellent. Thus, the residual current circuit breakers with magnetic triggers according to the prior art The contact points of the residual current release are liable to stick, which increases the reliability of the tripping is reduced in the event of a fault current.

The invention is therefore based on the object of a magnetic release device to further develop and manufacture for a residual current circuit breaker, that the contact points are significantly less prone to sticking and thus the tripping reliability of the residual current circuit breaker is significantly increased.

The task is set with regard to the triggering device by the characterizing Features of claim 1 solved. Further advantageous configurations and Improvements of the invention are given in dependent claims 2-13.

The essence of the invention is that to increase the triggering reliability Butt or sliding contact points on the fixed or on the movable component with a dense passivation layer resistant to water, oils, greases and silicones, are coated, the thickness of which is a fraction of the extent of the working air gap and is typically on the order of 10 to 500 nm.

In an embodiment according to the invention, the passivation layer is present made of hydrophobic material. Hydrophobic material is water-repellent. The advantage when using hydrophobic material is that water drops cannot get stuck on the surface or in the air gap and therefore also there is no adhesive force caused by increased surface tension can. Because water due to the hydrophobic surface properties of the passivation layer cannot adhere to the surface but runs off immediately also removes dirt particles adhering to the surface.

In an advantageous embodiment, the passivation layer consists of corrosion-resistant Material.

In a further advantageous embodiment, the passivation layer consists of reduced adhesive material, so that when detaching the movable from the fixed Component no high adhesive force has to be overcome.

In a further advantageous embodiment, the passivation layer consists of oil and dirt repellent material.

In a particularly advantageous embodiment of the invention, the surface of the Passivation layer nanostructured and designed like a lotus leaf surface. It is known from the lotus leaf surface that microstructures in the micrometer and nanometer range almost completely eliminates the adhesiveness on the surfaces. That means even pasty, otherwise strongly adhering substances such as oils, fats and silicones, cannot adhere permanently to this surface.

In a further advantageous embodiment, it is specified that the passivation layer consists of a nanocomposite material. Such nanocomposites are composite materials by a chemical or physical bond of at least consist of two different materials, at least one of the materials in the form of particles that are no larger than a few nanometers. Nanocomposites can either be purely inorganic materials, e.g. on Composite of silicon carbide nanoparticles in a matrix of silicon nitride, or a Composite of inorganic nanoparticles in a matrix of polymer materials, such as. Silicate nanoparticles in a polyamide matrix. In the latter case speaks one also of nanomers. Due to the special type of composition and the Material properties are achieved using nanometer-sized particles, which are far superior to conventional and pure materials, especially what the tightness, corrosion resistance, strength and other chemical and physical resistance.

In a further embodiment of the invention it is stated that the passivation layer is made of Teflon.

Another embodiment of the invention is that the passivation layer consists of metal-ceramic material. A material example from this class are the so-called 123 ceramics, such as Ti ₃ SiC ₂ , which is characterized by excellent temperature stability, low adhesiveness and high chemical resistance.

In a further embodiment, the passivation layer can also be made of metal nitride or Metal carbide exist.

Another advantageous embodiment of the invention is that the passivation layer consists of silicon nitride.

Another embodiment of the invention is that the passivation layer consists of amorphous carbon or diamond-like carbon.

It is also stated that the passivation layer is defect-free, in particular pinhole-free is trained.

With regard to a method for producing a triggering device for a Residual current circuit breaker of the type according to the invention is the task solved by the characterizing features of claim 14.

With regard to the method of manufacture, the essence of the invention is that to increase the reliability of tripping the butt or sliding contact points on the fixed or to the movable component with a tight, against water, oils, Grease and silicone resistant passivation layer, the thickness of which is a fraction the expansion of the working air gap by separation after a sol-gel Process.

The production of thin, nanostructured layers using a sol-gel process is known, but has so far only been used to coat large planar or three-dimensionally curved surfaces such as glass panes, shower enclosures, car body parts, Eyeglass lenses, separating membranes in pressure transmitters, turbocharger housings, applied and suggested. It has now surprisingly turned out that this coating technique with great success also for application from passivation layers in limited local areas to small, three-dimensional molded components can be applied and they in particular on the contact points of magnetic release devices are sealed against water, Oils, greases and silicones resist passivation layers, the thickness of which is one Is a fraction of the extent of the working air gap, forms with which the invention Task can be solved.

Very thin, dense can be particularly advantageously used with the sol-gel technique Create layers from nanomers. Material examples for the inorganic nanoparticles are silicates or titanates, from which initially an emulsion with the polymer Matrix material is formed. Applying the emulsion to the desired one Partial surface of the component can be immersed, spin-coated or Spraying happen, taking those parts of the component that are not coated should be masked beforehand so that no material is deposited there. As a result, the use of the nanomeric layer material is restricted to functionally important points of the component, which is a very economical handling allowed with the possibly very expensive special materials. After applying the Emulsion, the coating is polymerized, which is either UV-induced, thermally or plasma-assisted. When polymerizing forms the special, lotus leaf-like, nanostructured surface structure also emerges.

In an alternative method for producing a triggering device of the invention The type of task for a residual current circuit breaker becomes solved by the characterizing features of claim 15. More beneficial Refinements and improvements to the method are the dependent claims 16 - 19.

The essence of the invention lies in the alternative production method according to claim 15 in that to increase the tripping reliability the shock or Sliding contact points on the fixed or on the movable component a dense passivation layer resistant to water, oils, greases and silicones, the thickness of which is a fraction of the extent of the working air gap, be provided by separation from the gas phase.

The deposition of thin, dense passivation layers of the invention Type from the gas phase is known, but has so far only been used for planar surfaces, can have geometric dimensions in the micrometer to meter range, or for the coating of three-dimensional bodies, e.g. Housings, Sensors, complete actuators, or used. It has now become more surprising showed that the separation from the gas phase with very good success for the production of passivation layers on non-planar, spatially three-dimensional shaped areas can be applied to components and them especially dense on the contact points of magnetic tripping devices, passivation layers resistant to water, oils, greases and silicones, their Thickness is a fraction of the extent of the working air gap, forms with which the object of the invention can be achieved.

In an advantageous embodiment, the passivation layer consists of amorphous or diamond-like carbon by making the carbon plasma-assisted from the Gas phase is deposited.

In a further advantageous embodiment of the invention, the passivation layer consists of a metal-ceramic material, in that the metal-ceramic is sputtered or vapor-deposited entirely or at least in a chemical component. One example from this class of materials is the so-called 123 ceramics, such as Ti ₃ SiC ₂ , which is characterized by excellent temperature stability, low adhesiveness and high chemical resistance.

Furthermore, it is stated that the passivation layer consists of a metal nitride or Metal carbide consists of the metal nitride or the metal carbide entirely or at least sputtered or evaporated in a chemical component.

Another coating option is that the passivation layer consists of Teflon by Teflon plasma-assisted polymerizes from the gas phase is deposited.

Using the drawing, in which an embodiment of the invention is shown, the invention and further advantageous refinements and improvements and further advantages of the invention are explained and described in more detail. All explained Features are not only in the specified combination, but can also be used in other combinations or alone, without the frame to leave the invention.

The only Fig. 1 shows a magnetic residual current release with a hinged armature, whose contact points are coated.

Figure 1 shows a magnetic residual current release 1 with a yoke 20, which in U-shape is formed. Around one leg 22 of the yoke 20 is a coil 50 wrapped. The two end pieces 23 of the yoke 20 are covered by an anchor 40, the end piece of the leg, which carries the coil 50, only in part is covered. At the contact points between anchor 40 and yoke 20, the Working air gaps 22, the expansion of which is due to the surface roughness of the anchor and yoke is given at the contact points and on the order of some µm, is typically 2-3 µm. In the area of contact points between anchors 40 and yoke 20 is the anchor 40 with a dense, against water, oils, greases and Silicon resistant passivation layer 70 coated, which is so thin that it does not significantly increase the working air gap, i.e. it only extends a fraction of the air gap expansion and is significantly smaller than 1 µm. Here is in 1 shows that the coating 70 is not exclusively a planar layer is applied, but the end piece of the anchor 40 in its three-dimensional Form densely covered, that is, also around the edge, around a corrosive To prevent attack on the contact point from the front of the anchor, this, however, only in the area of the contact point between anchor 40 and yoke 20. The The remaining area of anchor 40 is layer-free, which means the required amount of coating material is reduced to the bare minimum and a very economical one Use of the possibly very expensive material is guaranteed. The anchor 40 is rotatably or hinged about an axis 41. On the other leg 24 of the yoke 20 is a permanent magnet system 30 consisting of the Permanent magnet 31 and a pole piece 32. The one pole of the permanent magnet 31 is connected to the free leg 24 of the yoke 20, the other pole with the pole piece 32. The pole piece 32 is also with the free leg 24 of the yoke 20 connected so that the magnetic flux of the permanent magnet 31 to is largely short-circuited via the pole shoe 32 and only a small part over the armature 40, the yoke 20 and over the air gaps 22. So that is magnetic attraction with which the armature 40 is pulled against the yoke 20 will not be very large. At the rear end of the armature 40, a spring 60 engages the second end firmly connected to the pole shoe 32 of the permanent magnet system Yoke 20 is connected. At rest, the magnetic attraction of the Permanent magnet system 30 on the armature 40 just large enough that the armature against the restoring force of the spring 60 is attracted to the free ends of the yoke 20 remains. In the event of a fault current, the fault current in the coil 50 becomes a magnetic one Flux generated, the magnetic flux in the yoke 20 and armature 40 formed Counteracts magnetic circuit and compensates it so far that the magnetic Holding force of the yoke 20 on the hinged anchor 40 is reduced so far that the Folding anchor 40 is pulled off the ends 23 of the yoke 20 by the force of the spring 60 becomes. It is moved into a release position - not shown here - in which then through the hinged anchor 40 a - also not shown here - key switch is unlocked. The advantage of the dense against water Oils, greases and silicones are resistant passivation layers 70. Without these Passivation layers would occasionally stick the hinged anchor 40 with the end pieces 23 of the yoke 20. Then the force of the spring 60 would not sufficient to pull the hinged anchor 40 off the yoke 20 in the event of release, with which the residual current circuit breaker would fail and the protective function would not more would be guaranteed. However, it would become known in the art Passivation layer applied, the thickness of which according to the prior art in the Order of magnitude or even greater than the expansion of the air gap, so the total magnetic resistance of the magnetic circuit would be multiplied, the flooding resulting from the fault current would only have a fraction their field-compensating effect and triggering would no longer be guaranteed. By using the dense, against water, oils, fats and silicones according to the invention durable passivation layer 70 that is so thin that it closes the working air gap not significantly increased, the disadvantages of the prior art are avoided and thus significantly increases the tripping reliability of the residual current release.

Claims (20)

Trigger for a residual current circuit breaker, with at least a first fixed component, with at least a second movable component, with a permanent magnet arrangement and with a coil, wherein the second movable component by the attraction force generated by the permanent magnet arrangement against the spring force of a spring connected to the movable component in is attracted to a first rest position and is brought into mechanical abutment or sliding contact with the first fixed component at at least one contact point, so that a working air gap of very small extent is established at the at least one contact point, the coil being one of the magnetic magnets opposite the permanent magnet arrangement when a fault current occurs Flux is generated so that the spring force overcomes the pulling force of the permanent magnet arrangement and the movable component is moved into a second release position, in which we unlock a switch lock d, characterized in that to increase the triggering reliability the butt and / or sliding contact points on the fixed and / or on the movable component with a dense passivation layer resistant to water, oils, greases and silicones, the thickness of which is a fraction of the extent of the working air gap is coated. Trigger for a residual current circuit breaker according to claim 1, characterized in that the passivation layer consists of water-repellent material. Trigger for a residual current circuit breaker according to claim 1, characterized in that the passivation layer consists of corrosion-resistant material. Tripping device for a residual current circuit breaker according to one of the preceding claims, characterized in that the passivation layer consists of reduced-adhesive material. Trigger for a residual current circuit breaker according to one of the preceding claims, characterized in that the passivation layer consists of oil and dirt-repellent material. Trigger for a residual current circuit breaker according to one of the preceding claims, characterized in that the surface of the passivation layer is nanostructured and is designed in the manner of a lotus leaf surface. Trigger for a residual current circuit breaker according to one of the preceding claims, characterized in that the passivation layer consists of a nanocomposite material. Trigger for a residual current circuit breaker according to claim 4, characterized in that the passivation layer consists of Teflon. Trigger for a residual current circuit breaker according to claim 4, characterized in that the passivation layer consists of metal-ceramic material. Trigger for a residual current circuit breaker according to claim 4, characterized in that the passivation layer consists of metal nitride or metal carbide. Trigger for a residual current circuit breaker according to claim 4, characterized in that the passivation layer consists of silicon nitride. Trigger for a residual current circuit breaker according to claim 4, characterized in that the passivation layer consists of amorphous carbon or diamond-like carbon. Trigger for a residual current circuit breaker according to one of the preceding claims, characterized in that the passivation layer is defect-free, in particular pinhole-free. Method for producing a trigger for a residual current circuit breaker according to one of Claims 1 to 13, characterized in that, in order to increase the reliability of the trigger, the abutment and / or sliding contact points on the fixed and / or on the movable component with a tight seal against water, oils, Greases and silicones resistant passivation layer, the thickness of which is a fraction of the expansion of the working air gap, are provided by deposition using a sol-gel process. A method for producing a trigger for a residual current circuit breaker according to one of claims 1 to 13, characterized in that to increase the reliability of the tripping, the shock or sliding contact points on the fixed or on the movable component are resistant to water, oils, greases and silicones Passivation layer, the thickness of which is a fraction of the extent of the working air gap, can be provided by deposition from the gas phase. A method according to claim 15, characterized in that the passivation layer consists of amorphous or diamond-like carbon in that the carbon is deposited in a plasma-assisted manner from the gas phase. A method according to claim 15, characterized in that the passivation layer consists of a metal-ceramic material in that the metal-ceramic is sputtered or vapor-deposited entirely or at least in a chemical component. A method according to claim 15, characterized in that the passivation layer consists of a metal nitride or metal carbide in that the metal nitride or the metal carbide is sputtered or vapor-deposited entirely or at least in a chemical component. A method according to claim 15, characterized in that the passivation layer consists of Teflon in that Teflon is deposited in a polymer-assisted manner from the gas phase in a polymer-supported manner. Residual current circuit breaker, characterized in that it has a magnetic release according to one of the preceding claims.

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