Fuse device for high-voltage applications

Abstract

The invention relates to fuse devices for high-voltage applications, comprising a housing (10); an actuation chamber (12) and an extinguishing chamber (14), which are formed in the housing (10); a busbar (16) which extends through the housing (10) and between the actuation chamber (12) and the extinguishing chamber (14); a separating element (34) which can be displaced out of the actuation chamber (12) and against the busbar (16) by means of an actuator (32) and by means of which a busbar section (42) can be displaced into the extinguishing chamber (14) in order to sever the busbar (16) at a first predetermined breaking point (74); and a guide element (48) which protrudes into the extinguishing chamber (14) and has two opposing lateral walls (52, 54) which extend up to a support surface (102) that delimits the extinguishing chamber (14) in the movement direction of the separating element (34) and which extend, when viewed in the movement direction of the separating element (34), opposite longitudinal side surfaces (55) of the busbar section (42) to be detached. The aim of the invention is to extinguish an arc in a faster manner by squeezing the arc in a gap-free manner in the triggered state. This is achieved in that the two lateral walls (52, 54) are equipped with webs (111) which extend in the movement direction of the separating element (34) and over the length of the lateral walls (52, 54) at least up to the support surface (102) that delimits the extinguishing chamber (14) in the movement direction of the separating element (34) and against which the separating element (34) rests upon moving into the extinguishing chamber (14).

Description

[0001] DESCRIPTION

[0002] Safety device for high-voltage applications

[0003] The invention relates to a fuse device for high-voltage applications, comprising a housing, an actuation chamber and an arcing chamber formed in the housing, a busbar extending through the housing and between the actuation chamber and the arcing chamber, a separating body displaceable from the actuation chamber against the busbar by means of an actuator, through which separating body a busbar section for severing the busbar at a first predetermined breaking point can be displaced into the arcing chamber, and a guide element which projects into the arcing chamber and has at least two opposite side walls which extend to a support surface delimiting the arcing chamber in the direction of movement of the separating body.

[0004] Such safety devices are usually designed with a pyrotechnic igniter as an actuator and are used, particularly in vehicles with high-voltage applications such as hybrid vehicles or fully electric vehicles, to disconnect the power line between the battery and the consumers, in particular the vehicle's drive, in the event of an accident in a few thousandths of a second in order to avoid short circuits.

[0005] However, due to the high voltages involved, arcing occurs between the free ends of the busbar when the busbars are separated. This causes a current to continue flowing for several seconds and can lead to extremely high short-circuit currents, which can cause electric shock to vehicle occupants or emergency personnel, which can be life-threatening. Since these arcs cannot be completely avoided, precautions must be taken to extinguish them as quickly as possible. Furthermore, the isolating element must be guided as well as possible within the housing to ensure safe separation.

[0006] For example, WO 2021 / 240104 A1 discloses a pyrotechnic safety device in whose housing a guide section is formed into which the separating piston is moved after the igniter is triggered, said guide section having a circumferential wall along which the separating piston is moved.

[0007] Furthermore, US Pat. No. 11,081,303 B2 describes a pyrotechnic safety device in which a rubber ring is arranged on the floor of the arcing chamber, through which the kinetic energy of the separating element is converted into deformation energy. After triggering, the severed busbar section lies between the separating element and the rubber ring, allowing the resulting arc to spread to both sides of the piston in the housing. Reliable, rapid arc extinguishing is not achieved in this way, which is why various blow-out channels are provided in the housing.

[0008] The task therefore arises to create a safety device for high-voltage applications by which, when the safety device is triggered, the arc is stretched on the one hand to accelerate extinguishing and on the other hand is mechanically separated reliably to ensure that the arc is completely extinguished as quickly as possible in order to avoid possible short-circuit currents that could lead to an electric shock.

[0009] This object is achieved by a safety device for high-voltage applications having the features of main claim 1. The safety device for high-voltage applications according to the invention has a housing in which an actuation chamber and an extinguishing chamber are formed. The housing can in particular be designed in several parts and, for example, have at least a second housing part which surrounds the extinguishing chamber, and a first housing part which surrounds the actuation chamber. An actuation chamber is understood to be a space in which an actuator is at least partially arranged. This can in particular be a pyrotechnic igniter, the triggering of which creates pressure which accelerates a separating body out of the actuation chamber. An extinguishing chamber is understood to be a space into which a busbar section is displaced, whereby the busbar is separated into at least two parts.The high voltages present create an arc, also known as plasma, between the separated busbar sections in the arcing chamber, which leads to burns. In order to keep these arcs as short as possible, this arc must be extinguished as quickly as possible. The fuse device also has a busbar that extends through the housing and between the actuation chamber and the arcing chamber. Furthermore, when the fuse device is not triggered, a separating body is arranged in the actuation chamber that can be moved against the busbar by means of the actuator. When the actuator is triggered, this separating body separates a busbar section at a predetermined breaking point to sever the busbar and moves it into the arcing chamber. In this way, it is itself at least partially moved from the actuation chamber into the arcing chamber.

[0010] In addition, the safety device has a guide element that projects into the arcing chamber and has at least two opposite side walls that extend to a support surface that delimits the arcing chamber in the direction of movement of the isolating body. These side walls therefore have an extension component that points from the busbar section to be severed into the arcing chamber and an extension component that runs parallel to the longitudinal side surfaces of the busbar section to be severed. However, this does not mean that the walls are straight. Instead, the walls can, for example, also form two opposite parts of a hollow cylinder. What is crucial is that, when projected onto the busbar from the actuation chamber, these side walls are arranged next to the busbar section to be severed and at least surround the isolating body.In other words, the side walls, viewed in the direction of movement of the separating body, extend opposite the long side surfaces of the busbar section to be separated and the side surfaces of the separating body. The separating body is guided during its movement by this guide section and along the side walls, so that tipping is impossible. The guide section can extend in particular from the actuation chamber, at least from the area of ​​the actuation chamber facing the busbar, surrounding it at least on its long side surfaces, up to the end of the arcing chamber, so that the separating body is guided in the guide section over its entire movement section. The guide section can also extend only from the side of the busbar section facing the arcing chamber. The two side walls can also be designed as connected wall surfaces.It is important that these partition walls are not parallel to the first predetermined breaking point, but rather are the side walls that guide the separating body along the main extension direction of the busbar. Thus, in a plan view of the busbar from the actuation chamber, the side walls are opposite the free side surfaces of the busbar. However, "opposite" does not mean that they have to be arranged parallel to them. The side walls can also have a partial circular shape or be angled to the long side surfaces. This depends on the shape of the separating body in order to serve as its guide.According to the invention, webs are formed on the two side walls that extend in the direction of movement of the separating body. These webs extend over the length of the side walls at least as far as the support surface that delimits the arcing chamber in the direction of movement of the separating body and against which the separating body rests as it moves into the arcing chamber. These webs thus extend from the busbar to the support surface, so that they reliably seal any gap that may be present between the side walls of the guide section and the separating body, resulting in completely gapless guidance of the separating body. These webs thus completely and tightly separate a space directed towards the first predetermined breaking point from a space into which the busbar section to be severed is rotated, as soon as the separating body rests against the support surface.This pinches the arc, as there is no longer any continuous space between the two free ends of the severed busbar section and the stationary busbar section. This prevents further flashover between these two ends, which leads to an extension of the arc during the movement of the separator and to rapid extinguishing of the arc when the separator is brought into contact.

[0011] Preferably, the webs are at least partially sheared off by the separating body after passing through the movement range of the separating body. This shearing off occurs during the movement if the webs are made of a material that is as hard as or less hard than the separating body. This gap-free state is thus ensured over the entire movement range and therefore also during the entire movement of the separating body, whereby the movement range is understood to be the area through which the separating body moves within the arcing chamber. Alternatively or additionally, the separating body is at least partially cut through the webs after passing through the movement range of the separating body. A pure cut into the separating body occurs during the movement through the webs if these are made of a harder material.If the webs and the separating element have a similar hardness, the separating element partially cuts into the separating element and partially shears off the webs. In all cases, gapless guidance and a completely sealed separation of the spaces in which the severed ends of the fixed busbar section and the severed busbar section are arranged are ensured.

[0012] In a particularly preferred embodiment, the support surface for the separating body after passing through the movement range is formed by a damping element, which is arranged on a base of the housing in the arcing chamber and against which the separating body rests after passing through the movement range of the separating body. The damping element is deformed when the separating body hits the stop in order to absorb the kinetic energy of the separating body and convert it into deformation energy. This deformation also creates a strong contact force and thus a high degree of tightness between the separating body and the damping element over an extended period of time, which reliably prevents arcing through the gaps that form between the damping element and the separating body.Accordingly, reliable complete separation and extinguishing of the arc is achieved and at the same time the housing is protected from excessive impact forces, so that it can be made thinner, thus saving material and space.

[0013] After passing through the movement range of the separating body, the separating body, the webs and the damping element completely separate a space in which the severed busbar section is located from a space in which a free end of the fixed busbar section forming the first predetermined breaking point is located. This prevents electrical flashover between the two free ends of the busbar. In this state, the severed busbar section is located on the side of the separating piston and the damping element opposite the first predetermined breaking point. As a result, the arc created between the predetermined breaking point on the fixed busbar section and the predetermined breaking point on the severed busbar section initially extends axially between the damping element and the separating body until the separating body strikes the damping element.During this phase, the busbar section to be severed is rotated toward the side of the separator facing away from the area of ​​the fixed busbar section adjacent to the first predetermined breaking point. As soon as the separator hits the damping element, the arc is pinched off, as there is no longer any continuous space between the two free ends of the severed busbar section and the fixed busbar section.

[0014] Preferably, the damping element is fixed to the floor at least by the two side walls of the guide section. This prevents the damping element from slipping on the floor without the need for additional components, preventing gaps from forming between the separating body and the damping element due to a suboptimal position of the damping element relative to the separating body or the guide section.

[0015] In another embodiment, the damping element is made of an elastic plastic, which allows for high deformation and thus allows a large amount of kinetic energy to be converted into deformation energy. This reliably reduces the mechanical load on the confining housing. Furthermore, manufacturing inaccuracies can be tolerated, as the possible deformation ensures that the separating body rests flatly on the damping element, at least temporarily, reliably preventing the formation of gaps when the arc is pinched off.

[0016] Furthermore, it is advantageous if the damping element has deformation structures with which the damping element rests on the floor of the arcing chamber. These structures allow the kinetic energy to be converted into deformation energy to a particularly high degree, thus achieving a more gradual deceleration of the separating body. By resting the deformation structures on the floor, the support surface of the damping element can be easily configured to correspond to the opposite separating surface of the separating body, despite the inclusion of these structures.

[0017] In a particularly preferred embodiment of the invention, the separating body has a first separating edge which, in the non-triggered state, has the smallest distance from the busbar section to be severed, viewed in the direction of movement of the separating body. A section of this separating edge which has the smallest distance from the first predetermined breaking point in the main extension direction of the busbar is shaped complementarily to a surface region of the damping element which is arranged opposite the section of the separating edge in the direction of movement of the separating body. This ensures that the separating body impinges flatly on the damping element with its separating edge, thus closing the gap between the separating body and the damping element across its entire width and thus also across the width of the arc and the busbar at the same time.This creates a tight contact area across the entire available width for the arc to expand, and the arc is reliably cut off.

[0018] In a further advantageous embodiment, a sealing lip is formed on the support surface of the damping element adjacent to the complementarily shaped surface area. This sealing lip, viewed in the direction of movement of the separating body, is at the shortest distance from the separating body before the safety device is triggered. This sealing lip reinforces the sealing effect in a known manner upon impact of the separating surface. The linear contact at the moment of separation of the light beam creates a high separating force.

[0019] The sealing lip preferably extends across the entire width of the arcing chamber up to the webs of the side walls of the guide section that border the arcing chamber, ensuring reliable separation across the entire available arc width. The web of the damping element and the webs on the side walls thus create a three-sided circumferential seal.

[0020] In an advantageous embodiment, the space defined by the separating body, in which the predetermined breaking point of the fixed busbar section is located, is fluidically connected to a metal mesh. Due to the other separation of this space by the damping element, the separating body, and the side walls, gas escape is only possible through this metal mesh. Accordingly, the arc must enter the metal mesh, which is thereby vaporized and absorbs part of the energy. The arc is thus extinguished more quickly.

[0021] It is particularly preferred if the guide section has a third side wall that connects the two opposite side walls and extends parallel to the first predetermined breaking point into the arcing chamber. The side surface of the separating body facing the first predetermined breaking point is located opposite the third side wall after passing through the movement range. This creates a three-sided guide for the separating body, which also prevents tilting in the longitudinal direction.

[0022] It is particularly advantageous if the metal mesh is arranged on the side of the third side wall opposite the separating body. This metal mesh is fluidly connected via an opening in the third side wall to the space in which the free end of the fixed busbar section, forming the first predetermined breaking point, is located. The arc must therefore penetrate the metal mesh, as otherwise there is no volume available for expansion. Nevertheless, the three-sided guidance is maintained, and the third side wall can also determine the position of the metal mesh.

[0023] The housing is preferably constructed in three parts, with a first housing part radially surrounding the actuation chamber, a second housing part radially surrounding the arcing chamber and forming a base of the arcing chamber on which the damping element is arranged, and a third housing part surrounding the busbar, with a flange section arranged between the first housing part and the second housing part, from which flange section the guide section with the side walls extends. By fastening the housing parts to one another, the damping element is also fastened to the base of the second housing part in one step and a double-walled boundary of the arcing chamber is created by the second and third housing parts. In addition, no further component needs to be formed as a guide section, since this simultaneously serves to fasten the busbar and align the separating body.Furthermore, it is advantageous if the distance between a separating surface of the separating body and the busbar increases from the first separating edge toward the opposite second end in the non-tripped state. This ensures that upon tripping, the busbar section to be separated initially rotates into the arcing chamber, enabling quenching by squeezing the arc on one side of the busbar section to be separated.

[0024] In a further embodiment, the busbar has a second predetermined breaking point, around which the busbar section to be separated can be rotated after the busbar has been severed at the first predetermined breaking point, wherein a pocket is formed in the space between the damping element and a side wall of the second housing part delimiting the arcing chamber, in which pocket the busbar section to be separated is arranged adjacent to the separating body after the separation. This pocket thus forms the fourth side of the arcing chamber. Upon triggering, the busbar section to be separated

[0025] The busbar section is rotated into the pocket, where it is held in an upright position. A further separation occurs at the second predetermined breaking point, so that the busbar section is separated on both sides and thus loosely held in the pocket. The pocket is separated from the space in which the first predetermined breaking point of the stationary busbar section is located by the webs and the separating piston.

[0026] This creates a safety device for high-voltage applications in which the arc created when the busbar section is separated is extinguished very quickly due to the large arc expansion and the subsequent squeezing of the arc by completely separating the severed busbar section from the stationary busbar section adjacent to the predetermined breaking point. This prevents prolonged short circuits and electric shocks, and the resulting personal injuries. Nevertheless, this safety device can be built relatively small with thin walls, as the kinetic energy of the separator is absorbed by the damping element. The webs on the bordering side walls and the damping element thus serve as a seal for a gap between the separator and the side walls and the base of the housing.

[0027] An embodiment of a safety device according to the invention for high-voltage applications is illustrated in the figures and is described below using a safety device designed as a pyrotechnic interrupter device. The terms "axial" and "radial" are used below depending on the movement of the separating body of the safety device, so that an axial direction corresponds to the direction of movement of the separating body, while a radial direction forms a component perpendicular to the direction of movement.

[0028] Figure 1 shows a side view of a safety device according to the invention in a sectional view before actuation.

[0029] Figure 2 shows the side view of the safety device according to the invention from Figure 1 in a sectional view after actuation.

[0030] Figure 3 shows a side view of the safety device according to the invention according to Figure 1 in a view rotated by 90° in a sectional view before actuation.

[0031] Figure 4 shows a top view in section through an extinguishing chamber of the safety device. The safety device according to the invention, shown in the figures, is designed as a pyrotechnic interrupter device and consists of a housing 10, inside which an actuation chamber 12 and an extinguishing chamber 14 are formed. These chambers are separated from one another by a busbar 16 that extends through the housing 10 and via which, for example, a vehicle battery is connected to a consumer, such as a drive motor.

[0032] The housing 10 is double-walled, wherein an inner wall 18 at least partially radially delimits the extinguishing chamber 14 and the actuation chamber 12 and an outer wall 20 is arranged radially spaced from the inner wall 18 and delimits the safety device to the outside.

[0033] The housing 10 is constructed in three parts, with a third housing part 26 being clamped between a first housing part 22, in which the actuation chamber 12 is formed centrally, and a second housing part 24, in which the extinguishing chamber 14 is formed, with sealing rings 28 interposed.

[0034] The actuation chamber 12 in the first housing part 22 is radially surrounded by an inner wall 30 of the first housing part 22. An actuator 32, designed as a pyrotechnic igniter, is arranged inside this actuation chamber 12 in the area remote from the extinguishing chamber 14. Furthermore, in the non-triggered state, a separating body 34, which has a piston-like shape, is displaceably arranged inside the actuation chamber 12. This separating body 34 is guided radially at least in sections through the inner wall 30 of the first housing part 22 and axially delimits the actuation chamber 12 in the direction of the actuator 32. Furthermore, the first housing part 22 has an outer wall 36, which is connected to the inner wall 30 via ribs (not shown). A pressure relief volume 38 is formed between the inner wall 30 and the outer wall 36 by the free spaces between the ribs.

[0035] The third housing part 26 has a flange section 40, with which the third housing part 26 is clamped between the first housing part 22 and the second housing part 24. This flange section 40 surrounds the busbar 16 on all sides, with the exception of a busbar section 42 to be separated, which axially directly borders the actuation chamber 12 and the arcing chamber 14 before triggering. This busbar section 42 is delimited only on its radial sides by the third housing part 26, while the two sides of the busbar section 42 facing the actuation chamber 12 and the arcing chamber 14 are exposed to the actuation chamber 12 and the arcing chamber 14. Furthermore, two or more flow openings 43 are formed in the flange section 40, which are arranged in an axial extension of the pressure reduction volume 38 of the first housing part 22.A guide section 44 extends axially from the flange section 40, which guide section engages in a receptacle 46 on the inner wall 30 of the first housing part 22 in the region of the first housing part 22 facing the third housing part 26 and radially delimits the actuation chamber 12 in this region and thus guides the separating body 34.

[0036] In addition, the third housing part 26 has a guide element 48 that extends into the second housing part 24 and has three side walls 50, 52, 54 that delimit the arcing chamber 14 on three sides, wherein the third side wall 50 extends approximately parallel to the first predetermined breaking point and thus perpendicular to the main extension direction of the busbar 16, and the two opposite side walls 52, 54 are arranged opposite longitudinal side surfaces 55 of the busbar section to be severed. This guide element 48 is open on a fourth side 57. On this side, a side wall 56 of the arcing chamber 14 is formed by an inner wall 58 of the second housing part 24. On this inner wall 58, lamellar stop ribs 60 that project into the arcing chamber 14 are formed.

[0037] The three side walls 50, 52, 54 of this guide element 48, which extend to a bottom 62 of the second housing part 24, are precisely received within wall sections 64 of the second housing part 24, which extend from the bottom 62 toward the first housing part 22. The side walls 50, 52, 54, the wall sections 64, and the side wall 56 of the second housing part 24 are arranged radially spaced from surrounding outer walls 66 of the second housing part 24, which radially outwardly delimit the securing device.

[0038] A damping element 68 is arranged on the base 62, which delimits the arcing chamber 14 axially relative to the base 62 of the second housing part 24, axially below the separating body 34. Immediately laterally adjacent to the damping element 68, on the side of the arcing chamber 14 opposite the stop ribs 60, there is also arranged on the base 62 a metal mesh 70, which extends axially between the side wall 50 and the outer wall 66 surrounding the arcing chamber 14. The metal mesh 70 extends axially to just before the flange section 40 of the third housing part 26. An opening 72 is formed in the side wall 50 of the guide element 48 of the third housing part 26, via which opening a fluidic connection is established from the interior of the arcing chamber 14 to the metal mesh 70.This opening 72 is formed directly adjacent to the flange portion 40, specifically on the side wall 50, which is arranged in axial extension of a first predetermined breaking point 74 of the busbar 16.

[0039] In addition to the first predetermined breaking point 74, the busbar 16 also has a second predetermined breaking point 76 spaced apart therefrom. In the present exemplary embodiment, the two predetermined breaking points 74, 76 are formed by arranging the busbar section 42 to be severed between the two predetermined breaking points 74, 76, offset in an axial direction corresponding to the direction of movement X of the separating body 34, relative to the busbar sections 78 adjacent to the predetermined breaking points 74, 76, which are surrounded by the third housing part 26 and thus fixed. As a result, the busbar section 42 to be severed is only 10-60% connected to the adjacent busbar sections 78 in cross-section.

[0040] Viewed in a main extension direction Y of the busbar 16, the first predetermined breaking point 74 is located directly opposite a first separating edge 80 of the separating body 34 formed at a first end, at which end the separating body 34 has the shortest distance from the busbar section 42 to be separated. A separating surface 82 of the separating body 34 extends in cross-section in the main extension direction Y of the busbar 16, initially over a short section 83 of the separating edge 80 with a shortest distance parallel to the busbar section 42 and then has a distance from the busbar section 42 that steadily increases in the direction of the second predetermined breaking point 76 and is thus formed obliquely, so that the second end 84 remote from the separating edge 80 has the greatest distance from the busbar section 42.While the first predetermined breaking point 74, as already mentioned, is arranged directly below the separating edge 80 of the separating body 34 in the non-triggered state of the separating body 34, the second end 84, viewed in the main extension direction of the busbar 16, has a distance from the second predetermined breaking point 76 that is greater than the axial extent of the busbar section 42 to be severed. In this area between the second end 84 of the separating body 34 and the second predetermined breaking point 76, viewed in the main extension direction of the busbar 16, there is a stop 86 in the quenching chamber 14 that is formed on the flange section 40 of the third housing part 26. After the actuator 32 has been triggered and the busbar section 42 has been severed at the first predetermined breaking point 74, the separating body 34 is subsequently driven further into the quenching chamber 14.In this case, the busbar section 42 is rotated around the second predetermined breaking point 76 into the arcing chamber 14 until the underside of the busbar section 42 strikes the stop 86. The continued movement of the separating body 34 creates a shear stress in the area of ​​the second predetermined breaking point 76, which ultimately leads to a break at the second predetermined breaking point 76. Since at this point in time the separating body 34 has already penetrated relatively far into the arcing chamber 14 and the movement of the busbar section 42 to be severed occurs purely in a rotational manner around the second predetermined breaking point 76, this movement continues after the separation. This means that the busbar section 42 is rotated against the stop ribs 60, which absorb its kinetic energy.The busbar section 42 is rotated into a pocket 88, which is laterally delimited on the one hand by the inner wall 58 of the second housing part 24 and on the other hand by a side surface 90 of the separating body 34 directed towards the second predetermined breaking point 76. For this purpose, the distance between the adjacent busbar sections 78 and the base 62 in the region of the pocket 88 must be selected such that it is greater than the longitudinal extent of the severed busbar section 42, in order to ensure that there is no longer any contact between the adjacent busbar sections 78 fastened in the housing 10 and the severed busbar section 42. In addition, the distance of the stop ribs 60 from the separating body 34 in the triggered state must be selected to be greater than the extent of the busbar section 42 before triggering, viewed in the direction of movement of the separating body 34.

[0041] In the area of ​​the bottom 62, the pocket 88 is also delimited by a limiting web 92 which extends in the direction of the first housing part 22 into the arcing chamber 14 and, on the one hand, delimits the severed busbar section 42 in its upright end position and, on the other hand, serves as a limit for the damping element 68.

[0042] This damping element 68 is made, in particular, of an elastic plastic and has a damper body 96, from which deformation structures 98 extend to the bottom 62 of the second housing part 24. These deformation structures 98 are designed in the form of ribs 100, with the ends of which the damping element 68 rests on the bottom 62.

[0043] The damping element 68 has a bearing surface 102 on the damper body 96, which is directed towards the separating body 34. A surface area adjacent to the side wall 50 in which the opening 72 is formed

[0044] 104 of the support surface 102 of the damper body 96, which is arranged axially opposite to a section 105 of the separating edge 80, which in the non-triggered state is arranged closest to the first predetermined breaking point 74, is complementary to this section

[0045] 105 of the separating edge 80. In the present exemplary embodiment, this surface region 104 has an inner curvature 106 directed toward the separating body 34, while the separating body 34 has a correspondingly inwardly directed recess 108 in this region. Viewed in the direction of extension of the busbar 16, this surface region 104 is adjoined by a sealing lip 110, which extends from the side wall 52 to the side wall 54 of the guide element 48 on the support surface 102 of the damping element 68.

[0046] According to the invention, a web 111 is formed on each of the side walls 52, 54, which web is directed towards the separating body 34, i.e., into the interior of the extinguishing chamber 14. The webs 111 extend in the direction of movement of the separating body 34 and thus in the direction of extension of the side walls 52, 54 in the direction of and up to the support surface 102 and thus along the entire area of ​​the separating body 34 through which it is to travel. The height of these webs 111, i.e., their extension into the extinguishing chamber 34, is selected such that the separating body 34 always bears at least against these webs 111 during its movement.In the present exemplary embodiment, the webs 111 are arranged opposite one another, and their distance from one another is selected such that it is somewhat smaller than the width of the separating body 34 in this area viewed in the same direction, so that the separating body 34 shears off the webs 111 in the upper area during its movement through the guide element 48 and is guided along the guide element 48 without a gap.

[0047] The side walls 52, 54 extend from the ends of the side wall 50 to define three-sided boundaries of the arcing chamber 14, approximately at right angles to the side wall 50, so that the sealing lip 110 runs perpendicular to the main direction of extension of the busbar 16 and approximately parallel to the separating edge 80 of the separating body 34, while the webs 111 are arranged directly behind the sealing lip 110, viewed from the separating edge 80 along the separating surface. In a radially outer region 112, the damping element 68 has a shoulder 114 on three sides, the surface 116 of which facing the busbar 16 is correspondingly at a smaller distance from the busbar 16 than the remaining support surface 102 of the damping element 68, and with which the damping element 68 projects below the side walls 50, 52, 54.During assembly, the side walls 50, 52, 54 are pressed onto the surface 116 of the shoulder 114, thereby clamping the damping element 68 in position on the base 62 of the second housing part 24. Displacement toward the fourth side 57 is prevented during assembly by the limiting web 92. By pressing the radially outer region 112 of the damping element 68 together, a seal is also created between the damping element 68 and the third housing part 26 and thus the three side walls 50, 52, 54 of the extinguishing chamber 14. If an emergency occurs, for example, due to a vehicle accident, the pyrotechnic actuator 32 is triggered. The separating body 34 is pressed against the busbar 16 by the explosion and separates the busbar section 42 at the first predetermined breaking point 76 from the remaining busbar 16. An arc is created in the area of ​​the first predetermined breaking point 76 between the free busbar ends due to the high voltage.This arc can, on the one hand, expand through the opening 72 to the metal mesh 70, which is melted by the thermal energy and thus cools the arc. However, the busbar section 78 adjacent to the first predetermined breaking point 74 and the detached end of the busbar section 42 rotated into the arcing chamber 14 are initially connected by the arc, which continues to expand as the busbar section 42 continues to rotate. As the separating body 34 continues to move through its range of motion, a gap through which the arc passes becomes increasingly smaller between the separating body 34 and the damping element 68 until the separating body 34 finally impacts the support surface 102. This impact initially converts the kinetic energy into deformation energy of the ribs 100.In addition, the gap between the separating body 34 and the damping element 68 is completely sealed, as the separating body 34 initially impacts the sealing lip 110 at high speed, suddenly creating a high contact force on a very small surface, which causes the arc to be pinched or separated in this area. Arcing through a gap between the separating body 34 and the guide element 48 is also prevented during the entire movement of the separating body 34 and in its end position, as the webs ensure complete gap-free operation between the side walls 52, 54 and the separating body 34.As a result of the following movement, the contact surface between the damping element 68 becomes significantly larger, since the separating body 34 is brought into contact with its separating edge 80 on the complementarily shaped surface area 104 extending from the side wall 52 to the side wall 54, so that a wide sealing surface is created which prevents a renewed flashover of the arc.This means that by means of the damping element 68 and the separating body 34 as well as the webs 111 of the side walls 52, 54 and the separating body 34, a space 117 in which the free end of the region of the fixed busbar section 78 adjacent to the first predetermined breaking point 74 is arranged and which is delimited by the first side wall 50 and the side walls 52, 54 up to the webs 111 is completely and tightly separated from a space 118 which is formed on the fourth side 57 of the arcing chamber 14 and into which the busbar section 42 is first rotated and later torn off and in which the pocket 88 for receiving the busbar section 42 is formed.

[0048] In addition, when the busbar 16 is severed at the second predetermined breaking point 76, another arc can occur, increasing the total length of the existing arcs to such an extent that the resistance increases to such an extent that the separation voltage exceeds the source voltage. These measures lead to complete and rapid extinguishing and cooling of the arc in a short time.

[0049] In addition to extinguishing and cooling the arc, the pressure generated by the igniter explosion and by the melting of the metal mesh 70 and the resulting arc must also be reduced. To guide this gas flow into the pressure reduction volume 38 available between the inner wall section 30 and the outer wall section 36 of the actuation chamber 12, channels 120 are formed in the base 62 of the second housing part 24. These channels extend from the area below the metal mesh 70 on both sides of the second housing part 24 along the base 62, initially in a groove shape, down to below the damping element 68. From here, the channels 120 extend on both sides to the opposite outer walls 66 of the second housing part 24.From here, the channels 120 extend upwards as groove-shaped depressions on the inner wall surface of the outer walls 66 until they merge into the flow openings 43 of the third housing part 26, which in turn are fluidically connected to the pressure reduction volume 38, so that the pressure can be reliably reduced via the available volumes.

[0050] This creates a safety device that can be used in a small installation space to quickly and reliably extinguish the arc, preventing prolonged short circuits and resulting injuries, and reliably preventing emissions. Nevertheless, high separation performance can be achieved thanks to the good damping and rapid extinguishing. This also allows the wall thicknesses to be kept relatively thin, as rapid pressure reduction, rapid and reliable arc extinguishing, and effective absorption of the separating element's kinetic energy occur. In particular, all gaps between the first severed end of the sheared busbar section and the fixed end of the busbar section adjacent to the first predetermined breaking point are reliably sealed.

[0051] It should be clear that the scope of protection is not limited to the described embodiment, but various modifications are possible. In particular, different housing divisions or shapes of the components used can be provided. If necessary, a busbar with differently designed predetermined breaking points can also be used or the damping stop can be provided by a modified component, whereby a reliable separation of the space formed on the side of the separating body opposite the free end of the fixed busbar section adjacent to the first predetermined breaking point must be ensured from this first predetermined breaking point and this space must be sealed off from the free end of the fixed busbar section. For this purpose, the webs can also be slightly offset within the support surface of the separating body compared to the embodiment.The guide element can also be designed as a hollow cylinder when using a cylindrical piston.

[0052] Here, too, the webs can create a suitable seal between the guide element and the separator. Depending on the selected hardness of the guide element and the separator, the webs can also cut into the separator during the movement of the separator, instead of shearing off the webs.

Claims

P A T E N T A N S P R Ü C H E 1. Fuse device for high-voltage applications with a housing (10), an actuation chamber (12) and an arcing chamber (14) formed in the housing (10), a busbar (16) extending through the housing (10) and between the actuation chamber (12) and the arcing chamber (14), a separating body (34) displaceable from the actuation chamber (12) against the busbar (16) by means of an actuator (32), through which a busbar section (42) for severing the busbar (16) at a first predetermined breaking point (74) is displaceable into the arcing chamber (14), and a guide element (48) projecting into the arcing chamber (14) and having two opposite side walls (52, 54) extending to a support surface (102) delimiting the arcing chamber (14) in the direction of movement of the separating body (34), characterized in that side walls (52, 54) are formed with webs (111) extending in the direction of movement of the separating body (34),which extend over the length of the side walls (52, 54) at least as far as the support surface (102) delimiting the extinguishing chamber (14) in the direction of movement of the separating body (34) and against which the separating body (34) rests during its movement into the extinguishing chamber (14).

2. Safety device for high-voltage applications according to claim 1, characterized in that the webs (111) are at least partially sheared off by the separating body (34) after passing through the movement range of the separating body (34).

3. Safety device for high-voltage applications according to claim 1 or 2, characterized in that the separating body (34) is at least partially cut through the webs (111) after passing through the movement range of the separating body (34).

4. Fuse device for high-voltage applications according to one of the preceding claims, characterized in that the support surface (102) for the separating body (34) after passing through the movement range is formed by a damping element (68) which is arranged on a base (62) of the housing (10) in the arcing chamber (14) and against which the separating body (34) rests after passing through the movement range of the separating body (34).

5. Safety device for high-voltage applications according to claim 4, characterized in that after passing through the movement range of the separating body (34), the separating body (34), the webs and the damping element (68) completely delimit a space (118) in which the severed busbar section (42) is arranged from a space (117) in which a free end of the fixed busbar section (78) forming the first predetermined breaking point (74) is arranged.

6. Safety device for high-voltage applications according to claim 4 or 5, characterized in that the damping element (68) is fixed to the base (62) at least by the two side walls (52, 54) of the guide element (48).

7. Safety device for high-voltage applications according to one of claims 4 to 6, characterized in that the damping element (68) is made of an elastic plastic.

8. Safety device for high-voltage applications according to one of the preceding claims, characterized in that the damping element (68) has deformation structures (98) with which the damping element (68) rests on the floor (62) of the arcing chamber (14).

9. Fuse device for high-voltage applications according to one of the preceding claims, characterized in that the separating body (34) has a first separating edge (80) which, in the non-triggered state, has a smallest distance from the busbar section (42) to be severed, viewed in the direction of movement of the separating body (34), wherein a section (105) of this separating edge (80), which has the smallest distance from the first predetermined breaking point (74) in the main extension direction of the busbar (16), is shaped complementarily to a surface region (104) of the damping element (68), which is arranged opposite the section (105) of the separating edge (80) in the direction of movement of the separating body (34).

10. Safety device for high-voltage applications according to claim 9, characterized in that a sealing lip (110) is formed on the support surface (102) of the damping element (68) adjacent to the complementarily shaped surface area (104), which has the smallest distance from the separating body (34) before the safety device is triggered.

11. Fuse device for high-voltage applications according to claim 10, characterized in that the sealing lip (110) extends over the entire width of the arcing chamber (14) up to the webs (111) of the side walls (52, 54) of the guide element (48) delimiting the arcing chamber (14).

12. Safety device for high-voltage applications according to one of claims 5 to 11, characterized in that the space (117) delimited by the separating body (34), in which the free end of the fixed busbar section (78) forming the first predetermined breaking point (74) is arranged, is fluidically connected to a metal mesh (70).

13. Fuse device for high-voltage applications according to one of the preceding claims, characterized in that the guide element (48) has a third side wall (50) which connects the two opposite side walls (52, 54) to one another and extends parallel to the first predetermined breaking point (74) into the arcing chamber (14) and to which the separating body (34) lies opposite with its side surface (90) facing the first predetermined breaking point (74) after passing through the movement range.

14. Safety device for high-voltage applications according to claim 13, characterized in that the metal mesh (70) is arranged on the side of the third side wall (50) opposite the separating body (34), which metal mesh is fluidically connected via an opening (72) in the third side wall (70) to the space (117) in which the free end of the fixed busbar section (78) forming the first predetermined breaking point (74) is arranged.

15. Fuse device for high-voltage applications according to one of claims 4 to 14, characterized in that the housing (10) is constructed in three parts, wherein a first housing part (22) radially surrounds the actuation chamber (12), a second housing part (24) radially surrounds the arcing chamber (14) and forms a bottom (62) of the arcing chamber (14) on which the damping element (68) is arranged, and a third housing part (26) surrounds the busbar (16), is arranged with a flange section (40) between the first housing part (22) and the second housing part (24), and from which the guide element (48) with the side walls (52, 54) extends.

16. Fuse device for high-voltage applications according to one of claims 9 to 15, characterized in that the distance of a separating surface (82) of the separating body (34) to the busbar (16) in the non-triggered state increases from the first separating edge (80) in the direction of an opposite second end (84).

17. Safety device for high-voltage applications according to one of the preceding claims, characterized in that the busbar (16) has a second predetermined breaking point (76) about which the busbar section (42) to be severed can be rotated after the busbar (16) has been severed at the first predetermined breaking point (74), wherein a pocket (88) is formed in the space (118) between the damping element (68) and a side wall (56) of the second housing part (24) delimiting the arcing chamber (14), in which pocket the busbar section (42) to be severed is arranged adjacent to the separating body (34) after the separation.

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