Safety device and assembly with safety device

Abstract

The invention relates to a fuse (10) for a surge protection device (12). The fuse (10) has a housing (16) in which a horn spark gap (24) is arranged, the spark gap having two electrodes (26, 28) separated from each other by a gap (32) in an ignition section (30). The fuse (10) has an adjustment mechanism (40) configured to increase the gap (32) between the electrodes (26, 28) and / or an ignition gap (39) in order to increase the dielectric strength of the fuse (10). The adjustment mechanism (40) is manually operable or coupled to a tripping mechanism (64) configured to automatically trip the adjustment mechanism (40) following at least one tripping event. The invention further relates to an assembly (8) comprising the fuse (10) and a surge protection device (12).

Description

[0001] The invention relates to a safety device for a surge protection device. The invention further relates to an assembly comprising such a safety device.

[0002] Surge protection devices are well-known and used in a wide variety of applications. One major area of ​​application for surge protection using such devices is at electrical power supply points in buildings or in branched power distribution systems.

[0003] Surge protection devices, also known as surge protection devices (SPDs), function by becoming low-impedance in the event of a transient or temporary overvoltage to dissipate the energy of the surge pulse. Overloads and operating conditions outside the specified ratings of the surge protection devices can lead to their failure. Typically, a failed surge protection device results in a permanently low-impedance condition, causing upstream protective devices (overcurrent protection - OCP) such as fuses or miniature circuit breakers (MCBs) to trip and disconnect the defective or overloaded device.

[0004] However, dimensioning these (pre-)fuses is complicated because two criteria must be met, which make correct dimensioning difficult. On the one hand, the (pre-)fuses must not be too small, so that impulse currents do not cause them to trip; on the other hand, the respective (pre-)fuses must not be too large, so that a defective surge protection device is not destroyed by high thermal stress. Generally, such (pre-)fuses are designed to trip at currents in the kiloampere range.

[0005] In the event of a defect or overload of the surge protection device, it must be replaced. This requires manual work on the surge protection device, ensuring adequate surge protection.

[0006] Therefore, the object of the present invention is to provide a safety device for a surge protection device that reliably protects the surge protection device connected in series with the safety device from voltage spikes, for example when the surge protection device is defective or overloaded, and furthermore ensures a safe replacement of the defective or overloaded surge protection device.

[0007] The problem is solved according to the invention by a fuse device for a downstream overvoltage protection device. The fuse device comprises a housing in which a horn spark gap is arranged, having two electrodes spaced apart from each other by a gap in an ignition section. Furthermore, the fuse device has an adjustment mechanism configured to increase the gap between the electrodes and / or an ignition gap in order to increase the dielectric strength of the fuse device. The adjustment mechanism is manually operable or coupled to a tripping mechanism configured to automatically trigger the adjustment mechanism as a result of at least one tripping event.

[0008] The invention is based on the core idea of ​​increasing the voltage difference required to establish an arc between the electrodes in the ignition section by increasing the distance between the two electrodes of the horn spark gap, i.e., the gap between the two electrodes of the horn spark gap, and / or by increasing the ignition gap through which the initial ignition of the arc occurs. As a result of this measure, the dielectric strength of the fuse is increased, making it more difficult for an arc to (re)occur between the electrodes, or causing it to occur only above a higher voltage, e.g., a voltage of 6 kV. The dielectric strength of the fuse is thus increased by increasing the voltage difference required to establish an arc between the electrodes in the ignition section.In other words, the dielectric strength of the fuse can be increased to 6 kV by increasing the gap between the electrodes and / or the ignition gap. Ultimately, the gap determines the free air gap that the arc must cross between the electrodes for a breakdown or flashover to occur. The ignition gap determines the free air gap that the arc must cross during the initial ignition to establish the arc.

[0009] Basically, the arc is initially ignited via the ignition gap.

[0010] The ignition gap can be located between the electrodes. Alternatively, the arc is initially ignited in a different area, particularly between one of the two electrodes and another component, so that the ignition gap is located in this area. Subsequently, the arc commutates to both electrodes, i.e., from the component to the other of the two electrodes. In this case, the commutation distance is set via the gap between the electrodes.

[0011] In both cases, the arc forms between the electrodes, either due to the initial ignition directly between the two electrodes or due to the commutation to both electrodes after a previous initial ignition.

[0012] In simple terms, increasing the dielectric strength raises the tripping voltage threshold of the fuse. This means that even small overvoltages in the electrical network are insufficient to form an arc between the electrodes or to ignite the fuse, thus shielding the downstream surge protection device from such voltages or ensuring it remains de-energized. Consequently, safety is increased when replacing a surge protection device connected in series with the fuse.

[0013] Furthermore, the surge protection device can be protected from further voltage spikes or impulses by the fuse until it is replaced, thus preventing further damage to the device. This ultimately increases the operational reliability of the surge protection device until it is replaced.

[0014] The distance between the electrodes, i.e., the gap or ignition gap, can be easily increased by manually adjusting the mechanism before replacing the surge protection device. This involves manually changing the geometry of the ignition section of the spark gap, for example, changing the position and / or shape of at least one of the electrodes.

[0015] Alternatively, following at least one tripping event, for example, after the occurrence of an arc in the horn spark gap, the tripping mechanism can automatically trigger the adjustment mechanism, thus eliminating the need for manual operation by a user. The tripping event can also be detected by an external device, which then sends an external tripping signal to the fuse, which is received and processed by the fuse. This external device could be the surge protection device connected in series with the fuse.

[0016] The term "voltage withstand capability" refers to the voltage required for an arc to occur between the two electrodes in the ignition section.

[0017] The term "gap" refers to a narrowing between the two electrodes, i.e., the area within the ignition section where the distance between the two electrodes is minimal. In its initial state, the gap of the fuse is typically between 1.8 and 2.0 mm. The adjustment mechanism allows the gap to be increased by at least 2.0 mm, and in particular by at least 2.5 mm. The increased gap can be 4.5 mm.

[0018] According to the invention, the dielectric strength of the fuse is increased by enlarging the gap between the electrodes and / or the ignition gap, i.e., before an arc is present. However, the arc that forms upon tripping is not extinguished by the movement of the electrodes, as was sometimes the case with older surge protection devices, e.g., DE 622 462, where an already formed arc is pulled apart by moving the electrodes in order to interrupt it. Modern surge protection devices interrupt or extinguish the arc, for example, by having the arc enter a deionization chamber.

[0019] Surge protection devices are generally installed in protected areas and must provide a corresponding level of protection. If, for example, the surge protection device is worn, the electrode gap or the ignition gap used for triggering can be increased to achieve a higher response voltage. This ensures that the surge protection device no longer triggers, or triggers later, at a higher voltage, thus preventing the risk of an uncontrolled reaction. This always occurs when there is no arc between the electrodes.

[0020] A first aspect of the invention provides that the adjustment mechanism includes an actuating element that is at least partially movably mounted in the housing. The mechanical actuating element allows for particularly simple and reliable enlargement of the gap between the electrodes and / or the ignition gap. Furthermore, a mechanically operated adjustment mechanism is also more reliable than an electrically operated one, as it cannot be affected or damaged by currents and / or overvoltages. The mechanically operated adjustment mechanism can be triggered automatically following at least one triggering event.

[0021] Another aspect of the invention provides that the actuating element has a starting position and an actuating position in which it remains after actuation, thus permanently increasing the dielectric strength in the actuating position. The actuating position allows the increased dielectric strength following the triggering event, for example, after the occurrence of an arc, to be easily and permanently ensured. In particular, the actuating element can be locked in the actuating position to ensure that it does not accidentally return to its starting position, which would negate the increased dielectric strength.

[0022] Furthermore, the actuating element can interact with at least one of the electrodes in a force-transmitting manner to change the position of the electrode, at least partially. In particular, the actuating element is connected to the electrode in a force-transmitting manner. The electrode can be the long horn electrode of the horn spark gap. In other words, the actuating element is configured to move at least one of the electrodes from one position to another, so that ultimately the electrodes are moved away from each other to increase the gap between them. For example, the electrode can be displaced, bent, folded, or otherwise physically influenced by the actuating element, in particular, it can be reversibly deformed, at least partially.

[0023] According to a further aspect of the invention, the release mechanism comprises a spring by which a functional element is biased in a starting position, and a melting element that locks the functional element in the starting position. The functional element can interact with the actuating element. In particular, it can be provided that the functional element releases the actuating element when the melting element has melted. This arrangement provides a purely mechanical release mechanism which, as a result of the triggering event, e.g., the occurrence of an electric arc, i.e., in the event of triggering, reliably releases the functional element so that it can be moved by the spring, thereby activating the actuating element.The functional element can either act mechanically on the actuating element, in particular directly, to move the actuating element into the actuating position, or release the actuating element, which is also spring-loaded, so that the actuating element is moved into the actuating position by the spring preload. In any case, the adjusting mechanism is actuated to increase the gap and / or the ignition gap. Since the aforementioned components are purely mechanical, the proposed embodiment is also particularly reliable.

[0024] In particular, the actuating element is designed as a rotatable lever that mechanically acts on one of the electrodes to change the electrode's position, at least partially. A rotatable lever can act on the electrode with particularly efficient force, so the release mechanism requires less force to move or rotate the lever, making the adjustment mechanism especially sensitive. Furthermore, this results in a compact design for the safety device. If the actuating element is designed as a rotatable lever, the electrode on which the lever mechanically acts can be pivotally mounted, for example, at an end facing away from the point of application of the rotatable lever.

[0025] Another aspect of the invention provides that the rotatable lever has a base rotatable about an axis of rotation, from which an actuating arm and an electrode arm extend, the actuating arm interacting with the functional element and the electrode arm interacting with the electrode. In particular, the electrode interacting with the lever has an engagement section with an opening into which the electrode arm engages to change the position of the electrode, at least partially. This embodiment represents a variant for transmitting the force flow from the functional element to the contact spring. The functional element can actuate the actuating arm to exert a torque on the rotatable lever, thereby setting the rotatable lever in rotation.The electrode arm of the rotatable lever then adjusts the electrode by moving the electrode arm in the engagement section to change the position of the electrode, thereby increasing the gap and / or the ignition gap.

[0026] Furthermore, the arms can be used to trigger additional functions within the safety device by interacting with other elements during rotation. For example, the actuating arm can also be configured to interact with a contact spring of a trigger device to move the contact spring away from an electrode. The contact spring may initially have been released from the electrode by the functional element.

[0027] In principle, it can therefore be designed that the electrode, on which the actuating element mechanically acts, is either partially deformed and / or at least pivoted in order to enlarge the gap and / or the ignition gap. In this respect, the electrode can be pivotally mounted to allow the pivoting movement.

[0028] Another aspect of the invention provides that a trigger element connected to the actuating element is arranged at least partially between the electrodes, in particular wherein the trigger element is electrically conductively connected to one of the electrodes.

[0029] A trigger element typically serves to facilitate the ignition or commutation of an arc between the electrodes by reducing the dielectric strength of the fuse. The trigger element acts as a kind of auxiliary electrode, effectively narrowing the gap between the electrodes by creating a shortened gap to the electrode with which it is not electrically connected. The ignition gap is thus adjusted accordingly via the trigger element. From the trigger element, the initially ignited arc then commutates to the previously uninvolved electrode. In the event of a trip, a breakdown therefore first occurs across the shortened gap between the trigger element and the electrode with which the trigger element is not electrically connected, i.e., the ignition gap.The resulting arc can then "jump" or commutate from the shortened gap, namely the ignition gap, into the gap between the electrodes. This allows the arc to form even at low voltages.

[0030] Conversely, according to this aspect of the invention, the dielectric strength of the fuse can be increased by moving a trigger element connected to the actuating element between the electrodes, thus increasing the gap between the trigger element and an electrode, i.e., the ignition gap. This increases the voltage required to form the arc, thereby increasing the dielectric strength of the fuse. This can be achieved simply by moving the trigger element out of the ignition section via the actuating element, so that the trigger element has no influence on the ignition of the arc.

[0031] According to a further aspect of the invention, the trigger element is designed as a flexible conductor that is electrically connected to one of the electrodes and forms the ignition gap with the other electrode in the ignition section. The actuating element is movably arranged between the electrodes so that the position of the flexible conductor between the electrodes can be changed to enlarge the ignition gap. In particular, the flexible conductor has an edge region that includes a recess forming the ignition gap. The conductor can be a conductive track. A shortened ignition gap is provided between the flexible conductor and the electrode to which the conductor is not electrically connected. This shortened ignition gap is enlarged by moving the actuating element. For example, the actuating element can be displaceable, and in particular, pressable.Furthermore, the actuating element can be designed to bend the flexible conductor, thereby increasing the shortened ignition gap between the edge of the conductor and the electrode to which it is not electrically connected.

[0032] The conductor may have a cutout to allow the arc to be centered with respect to the electrode(s). For this purpose, the cutout is located in the center, particularly with respect to the electrode(s).

[0033] The at least one tripping event can be the occurrence of an arc in the horn spark gap, the arc entering an arc chamber, and / or an event that causes the fuse to receive an external tripping signal. For example, a fault in the surge protection device connected in series with the fuse is detected, causing the external tripping signal to be sent. This signal is received and processed by the fuse to increase the gap between the electrodes and / or the ignition gap, thus increasing the dielectric strength of the fuse. The occurrence of the arc and / or its entry into the arc chamber can be detected optically and / or thermally. Similarly, the arc can cause a fuse element to melt, thereby triggering the tripping mechanism.

[0034] The invention further relates to an assembly comprising a fuse according to one of the preceding aspects and a surge protection device connected in series with the fuse. The automatically tripping mechanism increases the dielectric strength of the fuse without manual intervention, thus enabling safe work on the surge protection device, for example, to replace it. Alternatively, following a tripping event, for example, after the occurrence of an arc flash, the adjustment mechanism of the fuse can be manually actuated, which also increases the gap between the electrodes to achieve greater dielectric strength in the fuse. This, too, allows safe work on the surge protection device, for example, to replace it.

[0035] The fuse and the surge protection device can be designed as separate devices connected in series, each with its own housing. Alternatively, the assembly can be configured with a single housing containing both the fuse and the surge protection device.

[0036] In principle, the invention provides that the gap between the electrodes and / or the ignition gap is increased to improve the dielectric strength of the fuse device in the event of a (further) overvoltage event, i.e., preventively. Therefore, the invention does not aim to increase the distance between the electrodes of the horn spark gap while an arc is present in order to lengthen the arc so that it can be extinguished more effectively, e.g., to prevent (mains) follow-through currents.

[0037] Further features and advantages of the invention will become apparent from the following description and the accompanying drawings, to which reference is made. The drawings show: Figure 1 a schematic representation of an assembly according to the invention with a safety device according to the invention and a surge protection device connected in series with the safety device, Figure 2 in a cross-sectional view a safety device according to the invention in a first embodiment in an untriggered state; Figure 3 in a rear view the safety device according to the invention Figure 2 in an untriggered state, Figure 4 in a cross-sectional view the locking device according to the invention. Figure 2 in a triggered state; Figure 5 in a cross-sectional view a safety device according to the invention in a second embodiment in an untriggered state; Figure 6 in a cross-sectional view the locking device according to the invention. Figure 5 in a triggered state; Figure 7 in a cross-sectional view a safety device according to the invention in a third embodiment in an untriggered state; Figure 8 in a cross-sectional view the safety device made of Figure 7 in a triggered state; Figure 9 an illustration of the safety device according to the invention Figure 7 ; Figure 10 in a cross-sectional view a safety device according to the invention in a fourth embodiment in an untriggered state; Figure 11 in a cross-sectional view the safety device made of Figure 10 in a triggered state; Figure 12 a detail in a cross-sectional view Figure 10 ; Figure 13 in an isometric representation the detail from Figure 12 ; Figure 14 a detail in a cross-sectional view Figure 11 ; Figure 15 in an isometric representation the detail from Figure 14 .

[0038] In Figure 1 Figure 8 shows a component assembly which is used, for example, at an electrical energy supply point in a building. In the embodiment shown, the component assembly 8 is provided between a phase, L, and a protective conductor potential, PE.

[0039] The assembly 8 comprises a fuse 10 and a surge protection device 12 connected in series with the fuse 10, which is designed separately from the fuse 10. The surge protection device 12 is also referred to as a "surge protection device" (SPD). The surge protection device 12 is designed to become low-impedance in the event of a transient or temporary overvoltage in order to dissipate the energy of an overvoltage pulse. For this to be possible, the upstream fuse 10 must also become low-impedance simultaneously with the surge protection device 12 in the event of an overvoltage, so that the pulse or surge current can be passed on to the surge protection device 12.

[0040] Specifically, the surge protection device 12 is connected upstream of the fuse device 10, which acts as a pre-fuse for the surge protection device 12.

[0041] As from Figure 1As is already evident, the fuse 10 has a short-circuit current extinguishing and / or surge-switching component 14, which is designed as a spark gap. Due to the series connection of the fuse 10 and the surge protection device 12, the short-circuit current extinguishing and / or surge-switching component 14 generally switches simultaneously with the actual surge protection device 12 in the event of an overvoltage and dissipates the impulse / surge current. With an intact surge protection device 12, the short-circuit current extinguishing and / or surge-switching component 14 is not subjected to the functions of the surge protection device 12, such as follow current extinguishing, but merely forms a low-resistance path for the impulse current dissipation.However, if the surge protection device 12 degrades, the follow current extinguishing capability of the short-circuit current extinguishing and / or surge-switching component 14 comes into play in the event of an overvoltage.

[0042] In the embodiment shown, the fuse 10 and the surge protection device 12 are designed separately from each other. However, the assembly 8 can also have a housing in which both the fuse 10 and the surge protection device 12 are accommodated.

[0043] The basic structure of the safety device 10 is explained below.

[0044] The Figures 2 to 4 show a safety device 10 according to a first embodiment, which is configured to protect the surge protection device 12.

[0045] As in Figure 2As shown, the locking device 10 comprises a housing 16 formed from a first housing part 18 and at least one second housing part (not shown here), which are attached to one another, in particular screwed together, to form a receiving space 20 in which components of the locking device 10 are received. The second housing part can receive the first housing part 18, which is thus inserted into the second housing part. Alternatively, the second housing part can be designed as a cover, which is placed on the first housing part 18 to close the receiving space 20. Several second housing parts can then also be provided, which are arranged, for example, on opposite sides of the first housing part 18. In the assembled state of the locking device 10, the second housing part in any case closes off the first housing part 18 to the outside.

[0046] The first housing part 18 provides the short-circuit current extinguishing and / or overvoltage switching component 14, which is electrically connected to terminals 22 in the form of plug contacts, via which the fuse device 10 can be electrically integrated.

[0047] Specifically, the short-circuit current-quenching and / or overvoltage-switching component 14 is designed as a horn spark gap 24, which has two electrodes 26, 28 that are at least electrically conductively connected to the terminals 22, in particular integrally formed with the terminals 22. The cross-sectional view shown below is described below. Figure 2 The electrode arranged on the right side is designated as long horn electrode 26 and the electrode provided on the left side as hook horn electrode 28.

[0048] Both electrodes 26, 28 are spaced apart from each other and form an ignition section 30 between them, which represents a constriction between the electrodes 26, 28, which is a gap 32 that defines a distance d 1 between the electrodes 26, 28.

[0049] The two electrodes 26, 28 extend from the ignition section 30 along a spark gap section 34, in which the distance between the two electrodes 26, 28 increases with increasing distance from the ignition section 30, towards an quenching chamber 36. Within the spark gap section 34, at least one of the electrodes 26, 28 has a curved shape, so that the electrodes 26, 28 are not parallel to each other. In particular, the two electrodes 26, 28 form the shape of a horn in the spark gap section 34, which is why this type of spark gap is also referred to as a horn spark gap 24.

[0050] An electric arc present in the ignition section 30 travels along the spark gap section 34 towards the quenching chamber 36, whereby the arc is pulled apart due to the shape of the electrodes 26, 28 before entering the quenching chamber 36, which comprises several quenching elements 38. The quenching elements 38 can be designed as quenching plates.

[0051] The arc is initially ignited between electrode 28, the hook-horn electrode, and another component in an ignition gap 39. The arc then commutates from the component to electrode 26, the long-horn electrode. Gap 32 thus defines a commutation path to electrode 26, the long-horn electrode. This will be explained in more detail below.

[0052] As in the Figures 2 to 4As shown, the safety device 10 further comprises an adjustment mechanism 40 which is configured to increase the gap 32 between the electrodes 26, 28, in particular the commutation distance, in order to increase the dielectric strength of the safety device 10.

[0053] To increase the gap 32 between the electrodes 26, 28, the adjusting mechanism 40 includes an actuating element 42, which is mounted at least partially movably in the housing 16. In the embodiment shown, the actuating element 42 is designed as a translationally displaceable slide 44, which is arranged on the side of the first housing part 18 facing away from the horn spark gap 24, as shown in the Figures 2 to 4 can be seen.

[0054] The slide 44 has an engagement section 46, for example in the form of a pin, wherein the engagement section 46 interacts with the long-horn electrode 26, as shown in the Figures 2 and 4As shown. More precisely, the engagement section 46 extends through a recess 48 in the first housing part 18 from the rear of the first housing part 18 to the front of the first housing part 18, in order to engage in a retaining section 50 of the long horn electrode 26, which is formed by a hook-shaped deformation of the long horn electrode 26 in the area of ​​the ignition section 30.

[0055] Furthermore, the slide 44 has a stop contour 52 which can interact with a stop surface 54 in the first housing part 18 to limit movement of the slide 44.

[0056] As in Figure 3As shown, a preload element 56 acts on the slide 44, which is supported by a support body 58 attached to the first housing part 18. This support body can have an additional function besides its mechanical support function, for example, it can be designed as a varistor. Alternatively, the first housing part 18 can form a support surface for the preload element 56, for example, on a projection.

[0057] The actuating element 42 or the slide 44 is pre-tensioned in a starting position by the pre-tensioning element 56, which is in the Figures 2 and 3 shown.

[0058] Furthermore, the actuating element 42 is locked in the starting position, as shown in the Figures 2 and 3 This is shown, namely via a locking element 60, which is designed, for example, as a pin. The locking element 60 engages in an opening 62 of the actuating element 42 in order to hold the actuating element 42 in its initial position.

[0059] The locking element 60 is part of a release mechanism 64, by means of which the adjustment mechanism 40 can be automatically triggered.

[0060] The trigger mechanism 64 is described in more detail below.

[0061] As in the Figure 2 As shown, the release mechanism 64 has a spring 66 which biases a functional element 68 in a starting position. For this purpose, the spring 66 is supported, for example, on the first housing part 18 or on one of the electrodes 26, 28 and is mounted on a pin 70 of the functional element 68, which is located in particular in Figure 4 This is visible because spring 66 is not shown there.

[0062] The functional element 68 is mounted in a translationally displaceable manner, so that the functional element 68 can be moved by the spring 66 into a release position, which in Figure 4 shown.

[0063] The functional element 68 is arranged in the area of ​​the extinguishing chamber 36 and is secured in the initial position by a melting element 72, which interacts with a retaining element 74 of the functional element 68, e.g. a hook.

[0064] If an electric arc is extinguished by the quenching chamber 36, the melting element 72 melts, whereby the functional element 68 is no longer secured and the spring 66 moves the functional element 68 into the release position, which is in Figure 4 shown.

[0065] The melting element 72 is, for example, a fusible wire or rod that is in thermally or electrically conductive contact with the quenching chamber 36. For example, the melting element 72 is in electrically conductive contact with several of the quenching elements 38, so that when an electric arc enters the quenching chamber 36, a current is generated in the melting element 72, which heats the melting element 72 and causes it to be severed.

[0066] The functional element 68 has a retaining section 76, by which the locking element 60 is held in its position, as shown in the figure. Figure 2 This becomes clear. As soon as the functional element 68 has been moved into its release position, the locking element 60 is released from the retaining section 76, which in Figure 4 shown.

[0067] Since the locking element 60 is pre-tensioned via a spring element 78, as shown Figure 3As becomes clear, the release of the locking element 60 results in the locking element 60 being pulled out of the opening 62, thereby releasing the actuating element 42, which can also move into its release position due to the preload provided by the preloading element 56. This is shown in Figure 4 shown.

[0068] The actuating element 42 then adjusts the electrode 26 via its engagement section 46, so that the gap 32 becomes larger, namely has the distance d 2, which is larger than the distance d 1, which in the initial position according to Figure 2 was present. For example, the gap 32 is increased from a distance d 1 of 1.94 mm to a distance d 2 of 4.4 mm.

[0069] This increases the voltage resistance of the fuse device 10 accordingly, in particular to a voltage of 6 kV.

[0070] Furthermore, it should be mentioned that the functional element 68 has an interruption section 80 at its end pointing away from the retaining section 76, which faces the electrodes 26, 28, via which a trigger circuit 82 can be interrupted. For this purpose, a contact spring (not shown) can be lifted and moved away from an electrode of the trigger circuit 82 by means of the interruption section 80 when the functional element 68 is moved from the initial position to the trigger position, as a comparison of the Figures 2 and 4 This clarifies the situation. Therefore, it is ensured that not only is the gap 32 enlarged, but also that no triggering can occur via the trigger circuit 82, thereby increasing the dielectric strength of the fuse device 10 accordingly.

[0071] The trigger circuit 82 can be arranged on a printed circuit board (PCB) whose tip extends through an opening in electrode 28, namely the hook-horn electrode. The PCB is electrically connected to the other electrode 26, namely the long-horn electrode, and thus has the same potential as the other electrode 26, namely the long-horn electrode. The initial ignition of the arc therefore takes place between the tip of the PCB and electrode 28, i.e., the hook-horn electrode, through whose opening the tip of the PCB extends. The ignition gap 39 is thus defined by this. The ignition gap 39 remains constant because the variable gap 32 changes the commutation distance to electrode 26, i.e., the long-horn electrode.

[0072] In the Figures 5 and 6 A second embodiment of a safety device 10 is shown.

[0073] The following discussion focuses solely on the differences from the first embodiment. Regarding the remaining components, please refer to the preceding description, which applies analogously to the second embodiment.

[0074] According to the second embodiment, the actuating element 42 is designed as a rotatable lever 84 which mechanically acts on one of the electrodes 26, 28 in order to change the position of the electrodes 26, 28, at least partially. In this case, the position of the longhorn electrode 26 is changed.

[0075] Specifically, the lever 84 is rotatably mounted in the first housing part 18, as shown in the Figures 5 and 6 shown.

[0076] As in Figure 5As shown, the rotatable lever 84 has a base 86 that is rotatable about a rotational axis, from which an actuating arm 88 and an electrode arm 90 extend. The actuating arm 88 interacts with the functional element 68 of the release mechanism 64, and the electrode arm 90 interacts with the electrode 26.

[0077] Therefore, by triggering the release mechanism 64, the rotatable lever 84 can be actuated, which then interacts with the electrode 26.

[0078] In order to interact with the electrode 26, the electrode 26 has an engagement section 92 with an opening 94 in which the electrode arm 90 engages to change the position of the electrode 26, at least in certain areas.

[0079] The opening 94 can be designed as an elongated hole into which the electrode arm 90 can movably engage.

[0080] The actuating arm 88 is arranged in a starting position between the functional element 68 in its starting position and a contact spring 96, which in this embodiment, unlike in the first embodiment, is shown and establishes the contact from the trigger circuit 82 to the electrode 26, since the contact spring 96 is also attached to the engagement section 92, as shown in the Figures 5 and 6 becomes clear.

[0081] The contact spring 96 can have a ramp-shaped section facing the functional element 68, in which the functional element 68 can engage to lift the contact spring 96 and release it from the trigger circuit 82, in particular a contact of the trigger circuit 82.

[0082] The contact spring 96 also ensures that the circuit board on which the trigger circuit 82 is arranged has the same potential as the electrode 26, i.e. the long horn electrode, as has already been described previously in relation to the first embodiment.

[0083] Furthermore, the rotatable lever 84 can have a third arm 98 which, for example, mechanically interacts with an indicator element not shown in detail, to indicate whether the safety device 10 is triggered or not triggered.

[0084] The operation of the safety device 10 according to the second embodiment corresponds to that of the first embodiment with regard to the release mechanism 64, so reference is made to the explanations concerning the first embodiment, which apply analogously: When the release mechanism 64 has been triggered, i.e., when the melting element 72 has melted, the functional element 68 is also automatically released, which now interacts directly with the actuating element 42 in the form of the rotatable lever 84. Specifically, the functional element 68 is pressed against the actuating arm 88 by the spring force of the spring 66 in order to exert a torque on the rotatable lever 84, which then rotates. At the same time, the functional element 68 lifts the contact spring 96 and breaks the contact between the contact spring 96 and the trigger circuit 82.

[0085] Due to the rotational movement of the lever 84, the electrode arm 90 also rotates about the axis of rotation D, so that the position of the electrode 26 is changed, at least in part, by pivoting. For this purpose, the electrode 26 is pivotally mounted at one end and is also electrically connected to the associated terminal 22 via a flexible cable 100, as a comparison of the Figures 5 and 6 This is illustrated. The flexible conductor 100 can be a flat copper strand which is connected to the associated terminal 22 and the electrode 26 by means of ultrasonic welding.

[0086] As a result, the gap 32 between the two electrodes 26, 28 is enlarged, and the distance d2 in the tripped state of the safety device 10 is greater than the distance d1 in the untried state. As previously explained with regard to the first embodiment, the initial ignition occurs between electrode 28, i.e., the hook-horn electrode, and the tip of the circuit board, between which the ignition gap 39 is formed. The initially ignited arc then commutates from the tip of the circuit board via the variable gap 32 to electrode 26, i.e., the long-horn electrode. In this respect, the commutation distance is again set via the gap 32.

[0087] In the Figures 7 to 9A third embodiment of the locking device 10 is shown, with only the differences from the first and second embodiments being discussed. Regarding the remaining components, reference is made to the preceding description, which applies analogously to the third embodiment.

[0088] In contrast to the first two embodiments, the third embodiment does not have an automatically triggering release mechanism 64 in the illustrated version, but instead only a manually operated adjustment mechanism 40. However, an automatically triggering release mechanism 64 can also be provided, which interacts with the adjustment mechanism 40 described below.

[0089] The adjusting mechanism 40 in turn has the actuating element 42, which in this case is designed as a slide, in particular as a pull slide 102, which is movably received in the housing 16.

[0090] The pull slide 102 is rod-shaped and is connected at its end facing the ignition gap 39 to a trigger element 104, which is arranged at least partially between the electrodes 26, 28.

[0091] In particular, the trigger element 104 is connected to the trigger circuit 82, which initiates a triggering action. However, it can also be provided that the trigger element 104 is electrically connected to one of the electrodes 26, 28, for example the hook-horn electrode 28.

[0092] The trigger element 104 may be a graphite insert that extends into the ignition section 30 to shorten the effective air path.

[0093] Since the pull slide 102 is arranged to be translationally displaceable in the housing 16, the trigger element 104 is also movably arranged between the two electrodes 26, 28. In particular, the pull slide 102 is configured to completely remove the trigger element 104 from the ignition section 30.

[0094] According to the third embodiment shown, neither electrode 26, 28 is moved or adjusted; instead, only the ignition gap 39 is changed by moving the trigger element 104 provided in the ignition section 30. This makes the initial ignition of the arc more difficult when the trigger element 104 is removed from the ignition section 30.

[0095] To lock the pull slide 102 in the actuating position, a locking hole 106 is provided in the pull slide 102, which corresponds to an opening 108 in the housing 16, particularly in the second housing part. When the pull slide 102 is in the actuating position, it can be fixed to the housing 16 by means of a locking element 110, preferably a screw or a pin, as shown in Figure 9 shown.

[0096] The electrical contact of the electrode 26 with the associated terminal 22 can be effected via a varistor, which is arranged on the back of the first housing part 18 and is connected in series with the horn spark gap 24.

[0097] The following explains the operation of the third embodiment in more detail: If the safety device 10 has been triggered as a result of an arc flash, a user can manually pull the slider 102 to move the trigger element 104, i.e., the graphite insert, away from the electrode 28, thereby increasing the shortened ignition gap 39 with distance d1 to the enlarged ignition gap 39 with distance d2. After retracting the slider 102, the locking element 110 can be used to lock and secure the slider 102 in the actuated position.

[0098] Alternatively, the adjustment mechanism 40 of the third embodiment described above can also be coupled with an automatically triggering release mechanism 64, as mentioned previously. The automatically triggering release mechanism 64 can be configured as described in the previous embodiments.

[0099] The triggering mechanism 64 is in any case designed to trigger the adjustment mechanism 40 as a result of at least one triggering event, for example after the occurrence of an arc flash or an external triggering signal.

[0100] Ultimately, in the adjustment mechanism 40 according to the third embodiment, which is operated manually or interacts with the automatically triggering release mechanism 64, the trigger element 104 is moved to change, in particular to enlarge, the ignition gap 39. The trigger element 104 can therefore be moved manually or by means of the automatically triggering release mechanism 64.

[0101] A fourth embodiment of the locking device 10 is described with reference to the Figures 10 to 15This will be explained in more detail, focusing solely on the differences compared to the first three embodiments. Regarding the remaining components, please refer to the preceding description, which applies analogously to the fourth embodiment.

[0102] The fourth embodiment shown here, unlike the first two embodiments, does not have an automatically triggering release mechanism 64, but instead only a manually operated adjustment mechanism 40, as was also the case with the third embodiment. However, in principle, an automatically triggering release mechanism 64 can also be provided in the fourth embodiment, which interacts with the adjustment mechanism 40 described below.

[0103] The safety device 10 also includes the trigger element 104, which in this case is designed as a flexible conductor 112 that is electrically conductively connected to one of the electrodes 26, 28 and forms the ignition gap 39 with the other electrode 26, 28 in the ignition section 30, as can be seen in particular from the Figures 12 to 15 becomes clear.

[0104] The trigger element 104 interacts with the actuating element 42, which is movably arranged between the electrodes 26, 28. In this case, the actuating element 42 is a push-button slide 114.

[0105] The flexible conductor 112 can be designed as a printed circuit board having a contact section 116 that is directly adjacent to the longhorn electrode 26, so that the flexible conductor 112 is in electrically conductive contact with the longhorn electrode 26.

[0106] A spark gap 118 borders the contact section 116 and forms the free end of the flexible conductor 112, which in the initial position of the actuating element 42 is positioned between the two electrodes 26, 28 in the ignition section 30, as shown from Figure 13 becomes clear.

[0107] The flexible conductor 112 has an edge in the spark section 118 which faces the hook-horn electrode 28, the edge having a recess 120 forming the ignition gap 39, as shown from Figure 13 The recess 120 can be laser-milled in particular.

[0108] More precisely, the recess 120 forms the ignition gap 39 with a distance d 1 between the flexible conductor 112 and the hook-horn electrode 28. The ignition gap 39 is smaller than the gap 32 with a distance d 2 between the electrodes 26 and 28, which would now function as the ignition gap if the trigger element 104 were not positioned between the electrodes 26 and 28. In this respect, the ignition gap is enlarged because the initial ignition of the arc is no longer performed by the ignition gap 39 with a distance d 1 between the flexible conductor 112 and the hook-horn electrode 28, but rather by the gap 32 with a distance d 2 between the electrodes 26 and 28.

[0109] In addition to the recess 120, a projection is provided, which is arranged adjacent to the hook-horn electrode 28 and is equipped with an insulator 122, in particular a polyimide-based insulator. For example, a Kapton film can be used as the insulator 122. The insulator 122 prevents a breakdown or the formation of an arc between the projection and the electrode 28, so that the breakdown can only occur in the area of ​​the recess 120.

[0110] The actuating element 42, designed as a push-button slide 114, is made in particular of an insulating material, for example of a plastic.

[0111] The operation of the fourth embodiment is explained in detail below: The actuating element 42, designed as a push-button slider 114, can be manually actuated by a user, but automatic triggering by means of an automatic triggering mechanism 64 can also be provided. In manual actuation, the user pushes the actuating element 42 towards the housing 16 of the safety device 10, so that the end face of the actuating element 42, on which the trigger element 104 is provided, is moved. Specifically, the spark gap 118 of the flexible conductor 112 is bent. In automatic triggering, the actuating element 42 is moved accordingly by the automatic triggering mechanism 64, so that the end face of the actuating element 42, on which the trigger element 104 is provided, is moved, thereby bending the spark gap 118 of the flexible conductor 112.

[0112] The actuating element 42 is inserted between the triggering element 104, in particular the flexible conductor 112, and the electrode 28 (either manually or by the automatically triggering release mechanism 64), thereby increasing the firing gap 39 from distance d1 to distance d2, namely the gap 32 between the electrodes 26, 28. This is due in particular to the fact that the triggering element 104 is completely removed from the end face of the actuating element 42, as shown in the Figures 14 and 15 shown.

[0113] The achieved ignition gap 39, i.e. the gap 32 between the electrodes 26, 28 with the distance d 2 , ensures the desired voltage withstand of 6 kV.

[0114] The ignition gap 39 can be further increased by moving the push-button slide 114 even further towards the housing 16 and thus deeper into the running area of ​​the spark gap. This is because the electrodes 26, 28 move apart towards the quenching chamber 36, which further increases the distance between the electrodes 26, 28.

[0115] The automatically triggering release mechanism 64 of the fourth embodiment can correspond to that of the previous embodiments.

[0116] Alternatively, it may also be provided that an actuator is provided which is controlled to automatically trigger the adjustment mechanism 40.

[0117] As described above, the automatically triggering release mechanism 64 can be triggered by a thermal event caused by the arc and / or a current flow also caused by the arc. Alternatively, an optical sensor can be provided to detect the arc, particularly in the area of ​​the horn spark gap 24 and / or in the quenching chamber 36.

[0118] The at least one triggering event, which causes the triggering mechanism 64 to automatically trigger the adjusting mechanism 40, can be the occurrence of an arc in the horn spark gap 24, the entry of the arc into the quenching chamber 36, and / or an event that causes the safety device 10 to receive an external triggering signal. The occurrence of the arc or the entry of the arc into the quenching chamber 36 can be detected thermally, optically, electrically, and / or electromagnetically.

[0119] The event that triggers the external trip signal received by the fuse 10 may be a defect and / or an overload of the surge protection device 12 connected in series with the fuse 10, which then sends out the external trip signal. A defect is defined as a permanent fault that permanently impairs the operation of the surge protection device 12, whereas an overload is a temporary fault that temporarily impairs the operation of the surge protection device 12. However, the overload can ultimately lead to a defect.

[0120] In principle, numerous embodiments are shown and described with which the dielectric strength can be increased by changing the geometry in the area of ​​the ignition section 30, in particular by increasing the ignition gap 39 and / or the gap 32 between the electrodes 26, 28. This can be achieved either by moving one of the electrodes 26, 28 at least partially, or by moving a trigger element 104, which is arranged between the electrodes 26, 28 in the initial state.

[0121] The adjustment mechanism 40, by which the ignition gap 39 and / or the gap 32 between the electrodes 26, 28 is increased, can be operated manually or automatically via a triggering mechanism 64.

[0122] In any case, the increased voltage withstand capability of the fuse 10 ensures that the downstream surge protection device 12 is de-energized and can therefore be replaced if necessary. Furthermore, the increased voltage withstand capability ensures that no unwanted surge pulse is transmitted to the surge protection device 12, particularly if the device is overloaded or defective. This increases the operational reliability of the surge protection device 12 until it is replaced or repaired.

[0123] At the same time, the safety device 10 still fulfills its underlying safety function, namely that if an overvoltage impulse arrives, it is reliably diverted by the safety device 10 and, if necessary, a short circuit or a follow current is extinguished.

Claims

1. A safety device (10) for a surge protection device (12), wherein the safety device (10) has a housing (16) in which a horn spark gap (24) is arranged, the horn spark gap having two electrodes (26, 28) separated from each other in an ignition section (30) by a gap (32), wherein the safety device (10) has an adjustment mechanism (40) configured to increase the gap (32) between the electrodes (26, 28) and / or an ignition gap (39) in order to increase the dielectric strength of the safety device (10), wherein the adjustment mechanism (40) is manually operable or coupled to a tripping mechanism (64) configured to automatically trip the adjustment mechanism (40) as a result of at least one tripping event.

2. Safety device (10) according to claim 1, characterized by the fact that the adjustment mechanism (40) comprises an actuating element (42) which is mounted in the housing (16) so as to be at least partially movable.

3. Safety device (10) according to claim 2, characterized by the fact that the actuating element (42) has a starting position and an actuating position in which the actuating element (42) remains after its actuation, so that the tensile strength in the actuating position is permanently increased.

4. Safety device (10) according to claim 2 or 3, characterized by the fact that the actuating element (42) interacts with at least one of the electrodes (26, 28) in a force-transmitting manner in order to change the position of the electrode (26, 28) at least in certain areas, in particular is connected to the electrode (26, 28) in a force-transmitting manner.

5. Safety device (10) according to one of claims 2 to 4, characterized by the fact thatthe release mechanism (64) comprises a spring (66) by which a functional element (68) is biased in a starting position and a melting element (72) which locks the functional element (68) in the starting position, wherein the functional element (68) interacts with the actuating element (42) when the melting element (72) has melted.

6. Safety device (10) according to one of claims 2 to 5, characterized by the fact that the actuating element (42) is designed as a rotatable lever (84) which mechanically acts on one of the electrodes (26, 28) in order to change the position of the electrode (26, 28) at least in a range.

7. Safety device (10) according to claim 5 and claim 6, characterized by the fact thatthe rotatable lever (84) has a base (86) rotatable about an axis of rotation (D), from which an actuating arm (88) and an electrode arm (90) extend, wherein the actuating arm (88) interacts with the functional element (68) and the electrode arm (90) interacts with the electrode (26, 28).

8. Safety device (10) according to claim 7, characterized by the fact that the electrode (26, 28) which interacts with the lever (84) has an engagement section (92) with an opening (94) into which the electrode arm (90) engages in order to change the position of the electrode (26, 28) at least in certain areas.

9. Safety device (10) according to claim 2 or 3, characterized by the fact that a trigger element (104) connected to the actuating element (42) is arranged at least partially between the electrodes (26, 28).

10. Safety device (10) according to claim 9, characterized by the fact thatthe trigger element (104) is electrically connected to one of the electrodes (26, 28).

11. Safety device (10) according to claim 9 or 10, characterized by the fact that the trigger element (104) is designed as a flexible conductor (112) which is electrically connected to one of the electrodes (26, 28) and forms the ignition gap (39) with the other electrode (26, 28) in the ignition section (30), wherein the actuating element (42) is movably arranged between the electrodes (26, 28) so that the position of the flexible conductor (112) between the electrodes (26, 28) can be changed to increase the ignition gap (39).

12. Safety device (10) according to claim 11, characterized by the fact that the flexible conductor (112) has a recess (120) forming the ignition gap (39).

13. Safety device (10) according to one of the preceding claims, characterized by the fact thatthat at least one triggering event is the occurrence of an arc in the horn spark gap (24), the entry of the arc into an extinguishing chamber (36) and / or an event as a result of which the safety device (10) receives an external triggering signal.

14. Safety device (10) according to one of the preceding claims, characterized by the fact that that at least one triggering event is a defect in a surge protection device (12) connected in series with the safety device (10), due to which the external triggering signal is sent.

15. Assembly (8) comprising a safety device (10) according to one of the preceding claims and a surge protection device (12) connected in series with the safety device (10).

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