EP3061113B1 - Overvoltage protection system comprising at least one surge arrester and a thermal switch in series with the surge arrester - Google Patents

Description

The invention relates to an overvoltage protection device, comprising at least one surge arrester and, connected in series with the surge arrester, thermally triggered switching device, said means forming a structural unit and the thermal release means is arranged in the region of the expected heating of the surge arrester at its overload, wherein the thermal release means is formed as not flowing from the operating or surge current stop member which releases a release of the switching device in thermal overload, further the stop member is thermally and mechanically coupled to a surface side of the surge arrester and blocks the path of movement of a mechanically biased Entriegelungsschiebers, according to the preamble of the claim 1.

From the DE 295 19 313 U1 is a surge arrester on Varistorbasis previously known, being provided for a direct transfer of the varistor caused in the event of damage unacceptable heat to a thermal trip device. For this purpose, a support wall is present in the plug-in part, wherein the varistor are attached to a side surface of the support wall and the thermal release and the associated switching means on the other side surface of the support wall. As a result, the thermal release is opposite to the varistor. In one embodiment, one or more terminal lugs of the varistor are inserted through the partition wall into the area in which the thermal tripping and the corresponding switching means are located.

The leadership of the operating current or the occurring overload currents via contact means of a male part, which in turn can be introduced into a base part. The current passes through the switching means to the varistor in such a way that the actual thermal release agent, in particular as a solder, is also flowed through.

The entire execution after DE 295 19 313 U1 can switch only very small currents safely. In the case of the occurrence of short-circuit currents or DC applications, an additional external switching device, eg in the form of a separate switching means or a fuse is required.

The EP 1 447 831 B1 or EP 2 065 914 A1 show identical combinations of surge plugs with additional switching devices that are either placed in a common base housing or surrounded by such a housing. The solutions there have a tripping or switch-off, which is not adaptable to the particular properties of each surge arrester used, such as varistors.

From the DE 10 2011 018 556 A1 is an overvoltage protection device, comprising at least one surge arrester and, with the surge arrester connected in series, thermally triggered switching device previously known. The local release means is formed as not flowing from the operating or surge current stop member, which releases a release of the switching device in case of thermal overload, which has an increased self-extinguishing capacity. With such a solution occurring network-related fault or short-circuit currents that do not lead to the triggering of external fuses are automatically switched off by the internal switching device, so that there is an extended, seamless self-protection area. The previously known stop part after DE 10 2011 018 556 A1 is thermally and mechanically coupled to the surge arrester and blocks the displacement of a likewise provided unlocking slide.

In the opening case of the switching device penetrates into the moving away from each other contact pieces, a separating element, which consists of an insulating, quenching gas-releasing material, e.g. POM can exist.

At the solution after DE 10 2011 018 556 A1 However, the required structural and thus production-side effort is disadvantageous. The local ones Contact pieces must interlock, wherein at least one of the contact pieces is movable.

From the foregoing, it is therefore an object of the invention to provide a further developed overvoltage protection device comprising at least one surge arrester and, connected to the surge arrester in series, thermally triggered switching device, which is the solution of a non-surge current flowing through the triggering resort, however, the constructive and production-side effort while increasing the reliability is to be minimized.

The object of the invention is achieved by an overvoltage protection device according to the feature combination according to claim 1, wherein the dependent claims comprise at least expedient refinements and developments.

It is therefore assumed that an overvoltage protection device comprising at least one surge arrester. The surge arrester is preferably designed as a varistor. Furthermore, one, with the surge arrester connected in series, thermally triggered switching device available. The aforementioned means form a structural unit and can be comprised by a common housing. The unit with housing represents a plug-in part, which can be introduced into a corresponding socket, for the purpose of mounting on or in the system to be protected. The male part is easily interchangeable in case of failure and can be replaced by an intact part.

The thermal release means of the switching device is arranged in the region of the expected heating of the surge arrester when overloaded. With regard to the arrangement of this triggering means there is virtually a free choice, since the triggering means just does not have to be introduced into the current path of the overvoltage protection device.

Specifically, the thermal release agent is designed as not flowing from the operating or surge current stop member which releases a release of the switching device in case of thermal overload or unlocks the switching device itself. Furthermore, the stop member is thermal and mechanically coupled to a surface side of the surge arrester, blocking the path of travel of a particular unlocking slide. The unlocking slide can be designed as a plastic injection or -Press- or -casting and is inexpensive to produce.

In addition, the Entriegefungsschieber is mechanically biased, which can be realized by means of a spring or the like force storage device.

According to the invention, in the unlocking slide, e.g. has an elongated surface portion, a contact plate inserted, which produces the desired electrical connection between the elements of the switching device.

With the release of the contact pad is subject to a sliding movement with the result of interrupting the series connection and moving the Entriegelungsschiebers in the originally occupied by the contact plate space, wherein at least this hineinbewegte portion of the Entriegelungsschiebers is formed isolated or consists of a quenching gas-emitting material.

The dimensions of the contact plate with respect to the opening or recess of the Entriegelungsschiebers are chosen so that a secure contact with respect to the corresponding elements of the switching device is guaranteed. The dimensions of the contact pad, e.g. in terms of cross-section and thickness are oriented to the desired current carrying capacity.

In one embodiment of the invention, it is possible to provide the contact plate with securing properties.

In a further development of the invention, an element of the switching device is designed as a pin or bolt, which is under mechanical bias in the direction of the further element of the switching device. This further element is a mating contact, which is electrically connected to the terminal side of the surge arrester, for example a varistor.

The pin or bolt in turn is connected to a terminal bracket. This connection bracket can simultaneously represent the outer plug connection of the plug-in part designed as a surge arrester.

Moreover, according to the invention, a rocker having elastic properties, e.g. also designed as a plastic injection molded part, provided which is mounted with a first rocker end at a fixed point. This fixed point can be realized by elements of the housing of the male part. A second rocker end engages a movable stop.

The elastic properties having rocker can also consist of a metallic material with correspondingly elastic properties. Also conceivable is an embodiment of the rocker as a composite element made of plastic and metal. The decisive factor is that for the application of the invention, the rocker is able to act as a force storage, without a removal or breaking away of parts of the rocker is the case.

The movable stop is part of a pivot arm, wherein the pivot arm has a shape which rests on the stop member. This shape can e.g. be a nose, which is an integral part of the swivel arm. The swivel arm can be realized as a plastic injection molded part.

The unlocking slide according to the invention has a locking arm, which is blocked in the non-triggered state by the pivot arm.

Furthermore, the pivot arm has a guide recess for a pivot pin, wherein the pivoting movement of the pivot arm about the axis of the axle bolt is executable. The axle may be an integral part of the housing and may be e.g. extend perpendicularly from a housing center surface to receive according to the pivot arm with there Führungsausnehmung.

The pivotal arm further includes a pin extension that can penetrate a recess in the bottom of the housing and interact with a fault signaling device.

The unlocking slider itself is movably mounted in a guide member, wherein the guide member has a space for receiving a spring for the purpose of the spring bias of the release slide.

The guide member is placed on the desired electrical properties and dimensioned and in this respect consists of appropriately suitable insulation materials that may differ from the material of other parts, in particular of the housing. Thus, only the parts of possibly more costly materials must be made, which are subject to a corresponding electrical load. Both the guide member and the unlocking slider may be made of an insulating, gas-emitting material, e.g. POM exist.

In addition, the release slide has a status display area. This includes e.g. to the top of the housing of the male part and there presents a display surface, e.g. Green or red, for condition "OK" or "defective" free.

As already mentioned, the surge arrester is expediently a varistor which has a surface side which has metallic, conductive properties. From this surface side, e.g. may be a flat piece of metal, extending a smaller area piece, forming the mating contact, preferably perpendicular to the corresponding surface plane.

In a preferred embodiment of the invention, the above-mentioned surface side fixing surfaces, which for example also extend perpendicularly from the surface plane and engage in complementary recesses of a corresponding housing part to fix the varistor.

At the opposite rear side of the aforementioned surface side, a further contact of the varistor is present, which communicates with a further connection bracket, which also merges into an external electrical connection of the plug-in part of the respective overvoltage protection device.

The invention will be explained below with reference to an embodiment and with the aid of figures.

Fig. 1 und 2

eine stark vereinfachte prinzipielle Ausbildung der erfindungsgemäßen Lösung im normalen Funktionszustand (Fig. 1) und im Abtrennfall (Fig. 2) und

Fig. 3 und 4

eine perspektivische Darstellung der wesentlichen funktionalen Elemente der erfindungsgemäßen Überspannungsschutzeinrichtung im Betriebszustand (Fig. 3) und im Abtrennfall (Fig. 4), wobei bei den Darstellungen nach Fig. 3 und 4 der besseren Übersichtlichkeit halber das Gehäuse bzw. Teile des Gehäuses, die letztendlich ein Steckteil bilden, in Fortfall gekommen ist.

Hereby show:

Fig. 1 and 2

a greatly simplified basic design of the solution according to the invention in the normal functional state ( Fig. 1 ) and in the separation case ( Fig. 2 ) and

3 and 4

a perspective view of the essential functional elements of the overvoltage protection device according to the invention in the operating state ( Fig. 3 ) and in the separation case ( Fig. 4 ), whereby in the representations after Fig. 3 and 4 for better clarity, the housing or parts of the housing, which ultimately form a plug-in, has come to an end.

Like from the Fig. 1 and 2 As can be seen, the overvoltage protection device according to the invention initially consists of a surge arrester 1, in particular a varistor 1, with a corresponding surface side 2.

On the surface side 2 of the varistor 1, a stop member 4K is fixed. This stop member 4K is e.g. fixed with a solder on the corresponding surface side 2. When the varistor 1 has a certain temperature exceeding the allowable operating temperature, the solder which connects the stopper part 4K to the surface side 2 melts. The stop member 4K then performs a movement in the arrow direction.

Within a guide part 3, an unlocking slider 6 is mounted displaceably movable, wherein the unlocking slide 6 is under bias of a spring 61. The spring bias causes the release slide 6 is caused, in the absence of a stop relative to the Fig. 1 to 4 to move to the right. This is with the corresponding arrow representation within the part 6 in the Fig. 1 and 2 symbolizes.

Furthermore, in the Fig. 1 and 2 the actual switching device comprising the parts 9, 10 and 11, can be seen.

A first element is designed as a pin or pin 11, which stands under mechanical bias, symbolized by the spring XX, in the direction of the other element 10. This further element 10 forms a mating contact, which is electrically connected to the connection side 2 or the corresponding surface side and a conductive part of the surge arrester 1 present there.
The part 9 can form the connecting bracket or a plug-in contact simultaneously with a lower end shown in the figures.
In normal operating condition according to Fig. 1 the current path is closed via the parts 9, 11, 111 and 10. The part 111 is preferably a contact plate which is embedded in a respective recess of the unlocking slide 6. This contact plate 111 thus provides the desired connection between the terminal bracket 9 and the mating contact 10, which communicates with the varistor, ago.
When the allowable operating temperature is exceeded, the stopper 4K releases and then comes to a position similar to that in FIG Fig. 2 shown. Thus, the unlocking slide 6 can move in the image direction to the right. The result is that the contact pad 111 is also shifted out of the current path to the right. Instead of the contact plate now enters an insulating section of the release slide in the space becoming vacant and ensures a very high self-extinguishing capacity. The corresponding portion of the Entriegelungsschiebers 6 may consist of a gas-emitting material, such as POM, which improves the extinguishing properties and counteracts the occurrence of arcing.
Characterized in that the thermal release means 4K according to its original position Fig. 2 has left, the pivot arm 4 can move to the right according to the drawn arrow. In this case, the biasing force by means of symbolically represented spring XX loses its effect. In the invention, as in the Fig. 3 and 4 is shown, a rocker XX is present, which has elastic properties. The rocker generates a corresponding bias voltage in the Fig. 1 and 2 still with the symbolized spring is symbolized. A first rocker end is mounted at a fixed point X1. A second rocker end engages the movable stop X2 of the swivel arm 4.

The movable stop X2 is thus part of the pivot arm 4, wherein the pivot arm 4 is still a formation X3 (see Fig. 3 and 4 ), which rests on the stop member or release means 4K.

The unlocking slide 6 also comprises a locking arm X4, which in the non-triggered state of the pivot arm 4 and an existing there end, seen in particular in the Fig. 3 , is blocked.

The pivot arm 4 has a guide recess 41 for a pivot pin, not shown in the figures, wherein the pivotal movement of the pivot arm 4 is executable about the axle.

The pivot arm 4 also has a pin extension 42, which penetrates a recess in the bottom of the housing, not shown, and can interact with a fault signaling device, also not shown.

From the Fig. 3 and 4 it can be seen that the unlocking slide 6 is movably mounted in the guide part 3, wherein the guide member 3 has a space for receiving the spring 61.

The Fig. 3 and 4 also show the state indicator surface 62 formed on the unlocking slide 6 or formed on it.

Another terminal bracket 92, the lower end of which forms one of the plug contacts of the plug-in part, which accommodates the overvoltage protection device, is connected to a further contact 93 of the surge arrester 1.

The surge arrester 1 has a plurality of fixing surfaces 94, e.g. formed as metallic bends, which engage in complementary recesses of a housing part, not shown, and hold the varistor there.

Claims (10)

1. A surge protection device, comprising at least one surge arrester (1) and one thermally trippable switching device (9; 10; 11) connected in series with the surge arrester (1), wherein the aforementioned means form a structural unit and the thermal tripping means (4K) is arranged in the region in which heating of the surge arrester (1) is to be expected on overloading thereof, wherein the thermal tripping means (4K) is formed as a stop part through which no operating or surge current flows and which releases unlatching of the switching device in the case of thermal overload, wherein the stop part (4K) is further coupled thermally and mechanically to a surface side (2) of the surge arrester (1) and blocks the movement path of a mechanically prestressed (61) unlatching slide (6), wherein a contact platelet (111) is inserted into the unlatching slide (6), said contact platelet producing an electrical connection between the elements (10; 11) of the switching device, wherein the contact platelet (111), with unlatching, is subjected to a shifting movement resulting in an interruption to the series circuit of the switching device and movement of the unlatching slide (6) into the space previously assumed by the contact platelet (111), wherein at least the section of the region of the unlatching slide which separates the elements of the switching device is formed in an insulating manner, wherein the element (11) of the switching device is formed as a pin or bolt (10), which is mechanically prestressed in the direction of the element (11), wherein the latter is a counter-contact which is electrically connected to the connection surface of the surge arrester (1), the pin or bolt (10) is connected to a connection bracket (9), characterized in that a rocker (XX) having elastic properties is provided, which is mounted with a first rocker end on a fixed point (X1) and acts with a second rocker end on a movable stop (X2).
2. A surge protection device according to claim 1, characterized in that the movable stop (X2) is part of a swivel arm (4), wherein the swivel arm (4) comprises a formed portion (X3) which rests on the stop part (4K).
3. A surge protection device according to claim 2, characterized in that the unlatching slide (6) comprises a blocking arm (X4), which in the non-tripped state is blocked by the swivel arm (4).
4. A surge protection device according to claim 3, characterized in that the swivel arm (4) comprises a guide recess (41) for an axle pin, wherein the pivoting movement can be carried out about the axle pin.
5. A surge protection device according to one of the claims 2 to 4, characterized in that the swivel arm (4) comprises a pin protrusion (42) which penetrates a recess in the base of the housing and interacts with a fault communications device.
6. A surge protection device according to one of the preceding claims, characterized in that the unlatching slide (6) is movably mounted in a guide part (3), wherein the guide part (3) comprises a space for accommodating a spring (61).
7. A surge protection device according to one of the claims 3 to 6, characterized in that the unlatching slide (6) comprises a state indicator surface (62).
8. A surge protection device according to one of the claims 1 to 7, characterized in that the surge arrester is a varistor which comprises a surface side (2) having metallic, conductive properties and from which a surface portion extends which forms the counter-contact (10).
9. A surge protection device according to one of the claims 1 to 8, characterized in that a further connection bracket (92) is connected to a contact (93) of the surge arrester (1).
10. A surge protection device according to one of the preceding claims, characterized in that fixing surfaces (94) are disposed on the surge arrester (1) which engage in complementary recesses of a housing part.

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