Safety device and assembly with safety device

Abstract

The invention relates to a safety device (10) for disconnecting a surge protection device (12). The safety device (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 in an ignition section (30) by an ignition gap (32). The safety device (10) has an adjustment mechanism (40) configured to increase the ignition gap (32) between the electrodes (26, 28) in order to increase the dielectric strength of the safety device (10) by increasing the voltage difference required to establish an arc between the electrodes (26, 28) in the ignition section (30). The adjustment mechanism (40) is coupled to a tripping mechanism (64) configured to automatically trip the adjustment mechanism (40) after an arc occurs.Furthermore, the invention relates to an assembly (8) comprising the safety device (10) and a surge protection device (12).

Description

[0001] The invention relates to a safety device for disconnecting 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] From DE 622 462 A a high-voltage apparatus is known which comprises two electrodes between which an electric arc can be generated, wherein one of the electrodes is moved to pull apart the already generated electric arc until it breaks.

[0007] DE 10 2018 116 354 A1 shows a surge protection arrangement with a horn spark gap and a deion chamber.

[0008] Therefore, the object of the present invention is to provide a safety device for disconnecting a surge protection device, which ensures the safe replacement of a surge protection device connected in series with the safety device that is defective or overloaded.

[0009] The object of the invention is achieved by a safety device for disconnecting a downstream overvoltage protection device. The safety device comprises a housing in which a horn spark gap is arranged, having two electrodes spaced apart from each other in an ignition section by an ignition gap. Furthermore, the safety device has an adjustment mechanism configured to increase the ignition gap between the electrodes in order to increase the dielectric strength of the safety device by increasing the voltage difference required to establish an arc between the electrodes in the ignition section. The adjustment mechanism is coupled to a tripping mechanism configured to automatically trip the adjustment mechanism after the occurrence of an arc.

[0010] The invention is based on the core idea of ​​increasing the voltage difference required to establish an arc in the ignition section by increasing the distance between the two electrodes of the spark gap. 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 at a higher voltage, e.g., 6 kV. In other words, the dielectric strength of the fuse can be increased to 6 kV by enlarging the ignition gap between the electrodes. Ultimately, the free air gap that the arc must cross between the electrodes for a breakdown or ignition can be adjusted via the ignition gap. Put simply, increasing the dielectric strength raises the threshold for the fuse's tripping voltage.This means that even small overvoltages in the electrical network are insufficient to trigger an arc, thus shielding the downstream surge protection device from such voltages or rendering it de-energized. Consequently, safety is increased when replacing a surge protection device connected in series with the fuse.

[0011] The gap between the electrodes, i.e., the 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. Alternatively, after an arc occurs in the spark gap, the tripping mechanism can automatically trigger the adjustment mechanism, eliminating the need for manual operation.

[0012] The term "voltage withstand capability" therefore refers to the voltage required for an arc to occur between the two electrodes in the ignition section.

[0013] The term "ignition gap" refers to the narrowest point between the two electrodes, i.e., the area within the ignition section where the distance between the two electrodes is minimal. In the initial state of the fuse, the ignition gap is typically between 1.8 and 2.0 mm. The adjustment mechanism allows the ignition gap to be increased by at least 2.0 mm, and in particular by at least 2.5 mm. The increased ignition gap can be 4.5 mm.

[0014] 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 the ignition gap between the electrodes to be increased particularly easily and reliably. Furthermore, a mechanically functioning adjustment mechanism is also more reliable than an electrically operated one, as it cannot be affected or damaged by currents and / or overvoltages.

[0015] Another aspect of the invention provides that the actuating element has a starting position and an actuated position in which it remains after actuation, thus permanently increasing the dielectric strength in the actuated position. The actuated position allows the increased dielectric strength to be easily and permanently ensured after the occurrence of an arc. In particular, the actuating element can be locked in the actuated position to ensure that it does not accidentally return to its starting position, which would negate the increased dielectric strength.

[0016] 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 ignition gap. For example, the electrode can be displaced, bent, folded over, or otherwise physically influenced by the actuating element, in particular, it can be reversibly deformed, at least partially.

[0017] 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 that reliably releases the functional element when an arc occurs, i.e., in the event of a triggering event, 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 either case, the adjustment mechanism is actuated to increase the ignition gap. Since the aforementioned components are purely mechanical, the proposed embodiment is also particularly reliable.

[0018] 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.

[0019] 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 ignition gap.

[0020] 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.

[0021] In principle, it can therefore be designed so that the electrode, on which the actuating element mechanically acts, is either partially deformed and / or at least pivoted in order to enlarge the ignition gap. In this respect, the electrode can be mounted on a pivoting bearing to allow this pivoting movement.

[0022] 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.

[0023] A trigger element typically serves to facilitate the ignition 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 ignition gap between the electrodes by creating a shortened gap between the trigger element and the electrode to which it is not electrically connected. In the event of a trip, a breakdown occurs first across this shortened gap between the trigger element and the electrode to which it is not electrically connected. The resulting arc can then "jump" from this shortened gap into the actual ignition gap between the electrodes. This allows the arc to form even at low voltages.

[0024] 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 ignition gap between the trigger element and an electrode. 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 no longer influences the ignition of the arc.

[0025] 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 designed to be slidable or pushable.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.

[0026] 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).

[0027] 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. However, even after an arc flash, the adjustment mechanism of the fuse can be manually actuated, thereby also increasing the arc 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.

[0028] The safety device and the surge protection device can, in principle, be designed as separate devices connected in series, with each device having its own housing.

[0029] In principle, the invention provides that the ignition gap is enlarged to increase the dielectric strength of the fuse device in the event of a (further) occurring 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.

[0030] 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: - Fig. 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, - Fig. 2 in a cross-sectional view a safety device according to the invention in a first embodiment in an untriggered state; - Fig. 3 in a rear view the safety device according to the invention Fig. 2 in an untriggered state, - Fig. 4 in a cross-sectional view the locking device according to the invention Fig. 2 in a triggered state; - Fig. 5 in a cross-sectional view a safety device according to the invention in a second embodiment in an untriggered state; - Fig. 6 in a cross-sectional view the locking device according to the invention Fig. 5 in a triggered state; - Fig. 7 in a cross-sectional view a safety device according to an embodiment in an untriggered state; - Fig. 8 in a cross-sectional view the safety device Fig. 7 in a triggered state; - Fig. 9 an illustration of the safety device Fig. 7; - Fig. 10 in a cross-sectional view a safety device according to a further embodiment in an untriggered state; - Fig. 11 in a cross-sectional view the safety device Fig. 10 in a triggered state; - Fig. 12 in a cross-sectional view a detail from Fig. 10; - Fig. 13 in an isometric representation the detail from Fig. 12; - Fig. 14 in a cross-sectional view a detail from Fig. 11; - Fig. 15 in an isometric representation the detail from Fig. 14.

[0031] In Fig. Figure 1 shows a component assembly 8, which is used, for example, at an electrical energy supply point in a building. In the illustrated embodiment, the component assembly 8 is provided between a phase, L, and a protective conductor potential, PE.

[0032] Assembly 9 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.

[0033] 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.

[0034] As from Fig. As already evident from Figure 1, 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.

[0035] The basic structure of the safety device 10 is explained below.

[0036] The Fig. Figures 1 to 3 show a safety device 10 according to a first embodiment, which is configured to disconnect the surge protection device 12.

[0037] As in Fig. As shown in Figure 1, 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.

[0038] 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.

[0039] 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. Fig. The electrode on the right side is designated as long horn electrode 26 and the electrode on the left side as hook horn electrode 28.

[0040] 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 an ignition gap 32 that defines a distance d1 between the electrodes 26, 28.

[0041] 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.

[0042] An arc ignited 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 the arc enters the quenching chamber 36, which includes several quenching elements 38.

[0043] As in the Fig. As shown in Figures 2 to 4, the safety device 10 further comprises an adjusting mechanism 40 which is configured to increase the ignition gap 32 between the electrodes 26, 28 in order to increase the dielectric strength of the safety device 10.

[0044] To increase the ignition 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 Fig. 2 and Fig. 3 can be seen.

[0045] 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 Fig. Figure 2 shows. 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.

[0046] 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.

[0047] As in Fig. As shown in Figure 3, 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.

[0048] 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 Fig. 2 and Fig. 3 is shown.

[0049] Furthermore, the actuating element 42 is locked in the starting position, as shown in the Fig. 2 and Fig. Figure 3 shows 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 to hold the actuating element 42 in its initial position.

[0050] The locking element 60 is part of a release mechanism 64, by means of which the adjustment mechanism 40 can be automatically triggered.

[0051] The trigger mechanism 64 is described in more detail below.

[0052] As in the Fig. As shown in Figure 2, 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 Fig. 4 is visible because spring 66 is not shown there.

[0053] 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 Fig. 4 is shown.

[0054] 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.

[0055] 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 Fig. 4 is shown.

[0056] The melting element 72, for example, is a melting wire or melting rod that is thermally conductive and connected to the quenching chamber 36.

[0057] 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. Fig. 2 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 Fig. 4 is shown.

[0058] Since the locking element 60 is pre-tensioned via a spring element 78, as shown Fig. As becomes clear in Figure 3, 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 3. Fig. 4 shown.

[0059] The actuating element 42 then adjusts the electrode 26 via its engagement section 46, so that the ignition gap 32 becomes larger, namely has a distance d2 which is larger than the distance d1 which is in the initial position according to Fig. 2 was available. For example, the ignition gap 32 is increased from a distance d1 of 1.94 mm to a distance d2 of 4.4 mm.

[0060] This increases the voltage resistance of the fuse device 10 accordingly, in particular to a voltage of 6 kV.

[0061] 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 and facing 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 Fig. 2 and Fig. Figure 4 illustrates this. In this respect, it is ensured that not only is the ignition 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.

[0062] In the Fig. 5 and Fig. Figure 6 shows a second embodiment of a safety device 10.

[0063] 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.

[0064] 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.

[0065] Specifically, the lever 84 is rotatably mounted in the first housing part 18, as shown in the Fig. 5 and Fig. 6 is shown.

[0066] As in Fig. As shown in Figure 5, 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.

[0067] Therefore, by triggering the release mechanism 64, the rotatable lever 84 can be actuated, which then interacts with the electrode 26.

[0068] 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.

[0069] The opening 94 can be designed as an elongated hole in which the electrode arm 90 can movably engage.

[0070] 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 Fig. 5 and Fig. 6 becomes clear.

[0071] 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.

[0072] 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.

[0073] The functioning of the safety device 10 according to the second embodiment corresponds with regard to the release mechanism 64 to that of the first embodiment, so reference is made to the explanations concerning the first embodiment, which apply analogously: When the release mechanism 64 is 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 to exert a torque on the rotatable lever 84, which then rotates. Simultaneously, the functional element 68 lifts the contact spring 96 and breaks the contact between the contact spring 96 and the trigger circuit 82.

[0074] 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 Fig. 5 and Fig. Figure 6 illustrates this. 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.

[0075] As a result, the ignition gap 32 between the two electrodes 26, 28 is increased and the distance d2 in the triggered state of the safety device 10 is greater than the distance d1 in the untriggered state.

[0076] In the Fig. Figures 7 to 9 show an exemplary embodiment of the safety device 10, which is not included in the scope of protection. The following discussion focuses solely on the differences between this embodiment and the first and second embodiments. For the remaining components, please refer to the preceding description, which applies analogously to the third embodiment.

[0077] In contrast to the first two embodiments, this design does not have an automatically triggering release mechanism 64, but instead only a manually operated adjustment mechanism 40.

[0078] 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.

[0079] The pull slide 102 is rod-shaped and is connected at its end facing the ignition gap 32 to a trigger element 104, which is arranged at least partially between the electrodes 26, 28.

[0080] 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.

[0081] The trigger element 104 can be a graphite insert that extends into the ignition section 30 in order to shorten the effective air gap, i.e. the ignition gap 32.

[0082] 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.

[0083] According to this design, none of the electrodes 26, 28 are moved or adjusted, but only the ignition gap 32 is changed by moving the trigger element 104 provided in the ignition section 30.

[0084] 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 Fig. 9 is shown.

[0085] 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.

[0086] The following explains the operation of this design 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 32 with distance d1 to the enlarged ignition gap 32 with distance d2 between the electrodes 26 and 28. After retracting the slider 102, the locking element 110 can be used to lock and secure the slider 102 in the actuated position.

[0087] A further embodiment of the safety device 10 is described with reference to the Fig. 10 to 15 explained in more detail, focusing solely on the differences from the first two embodiments and the configuration according to the Fig. Sections 7 to 9 are addressed. Regarding the remaining components, reference is made to the preceding description, which applies analogously to further development.

[0088] In contrast to the first two embodiments, the further embodiment does not have an automatically triggering release mechanism 64, but instead only a manually operated adjustment mechanism 40, as is already the case in the embodiment according to the Fig. 7 to 9 was the case.

[0089] 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 32 with the other electrode 26, 28 in the ignition section 30, as can be seen in particular from the Fig. 12 to 15 becomes clear.

[0090] 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.

[0091] 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.

[0092] 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 Fig. 13 becomes clear.

[0093] 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 32, as shown from Fig. 13 emerges. The recess 120 can in particular be laser-milled.

[0094] More precisely, the recess 120 forms the ignition gap 32 with the distance d1 between the flexible conductor 112 and the hook horn electrode 28, wherein the ignition gap 32 is smaller than the ignition gap 32 with the distance d2 between the electrodes 26, 28 if the trigger element 104 were not positioned between the electrodes 26, 28.

[0095] 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.

[0096] The actuating element 42, designed as a push-button slide 114, is made in particular of an insulating material, for example of a plastic.

[0097] The following explains the functionality of the further embodiment in detail: The actuating element 42, designed as a push-button slider 114, can be manually actuated by a user. To do this, 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 adjusted. Specifically, the spark gap 118 of the flexible conductor 112 is bent.

[0098] The actuating element 42 is inserted between the trigger element 104, in particular the flexible conductor 112, and the electrode 28, thereby increasing the ignition gap 32 from distance d1 to distance d2. This is primarily due to the fact that the trigger element 104 is completely removed from the end face of the actuating element 42, as shown in the Fig. 14 and Fig. 15 is shown.

[0099] The achieved ignition gap 32 with the distance d2 ensures the desired voltage withstand of 6 kV.

[0100] In principle, numerous embodiments are shown with which the dielectric strength can be increased by changing the geometry in the area of ​​the ignition section 30, in particular by enlarging the ignition gap 32. 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.

[0101] The adjustment mechanism 40, which increases the ignition gap 32, can be operated manually or automatically via a triggering mechanism 64.

[0102] In any case, due to the increased voltage resistance of the fuse device 10, it is ensured that the downstream surge protection device 12 is de-energized and can therefore be replaced if necessary.

Claims

[1] Safety device (10) for an overvoltage protection device (12), wherein the safety device (10) has a housing (16) in which a horn spark gap (24) is arranged, which has two electrodes (26, 28) which are separated from each other in an ignition section (30) by a gap (32), wherein the safety device (10) has an adjusting mechanism (40) which is configured to increase the gap (32) between the electrodes (26, 28) and / or an ignition gap (39) in order to increase a dielectric strength of the safety device (10) by increasing the voltage difference required to build up an arc between the electrodes (26, 28) in the ignition section (30), wherein the adjustment mechanism (40) is coupled to a triggering mechanism (64) which is configured to automatically trigger the adjustment mechanism (40) as a result of at least one triggering event. [2] Safety device (10) according to claim 1,characterized by , that the adjustment mechanism (40) includes 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 , 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 , 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, that the release mechanism (64) comprises a spring (66) by which a functional element (68) is biased in an initial position, and a melting element (72) which locks the functional element (68) in the initial 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 any one of claims 2 to 5, characterized by , 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, that the 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), in particular wherein the electrode (26, 28) interacting 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 partially. [8] Safety device (10) according to claim 2 or 3, characterized by , that a trigger element (104) connected to the actuating element (42) is at least partially arranged between the electrodes (26, 28), in particular wherein the trigger element (104) is electrically connected to one of the electrodes (26, 28). [9] Safety device (10) according to claim 8, characterized by, 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 enlarge the ignition gap (39), in particular wherein the flexible conductor (112) has a recess (120) forming the ignition gap (39). [10] Safety device (10) according to any one of the preceding claims, characterized by, that at least one triggering event is the occurrence of an arc in the horn spark gap (24), the entry of the arc into a quenching chamber (36) and / or an event as a result of which the safety device (10) receives an external triggering signal, in particular a defect of an overvoltage protection device (12) connected in series with the safety device (10), as a result of which the external triggering signal is emitted. [11] 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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