Electrical circuit breaker

Abstract

To provide an electrical circuit interrupter capable of quickly extinguishing an arc generated during actuation.SOLUTION: An electrical circuit interrupter includes: an igniter provided in a housing; a projectile that is formed in the housing and disposed in a containing space extending in one direction, the projectile being fired along the containing space by energy imparted from the igniter; a conductor strip that is provided in the housing and that forms a part of an electrical circuit, the conductor strip having, in the part, a cut-off portion that is disposed to run across the containing space and is to be cut off by the projectile: and an arc-extinguishing area which is provided in the containing space and in which a coolant material is disposed. The projectile includes a first projectile fired by energy imparted from the igniter and reaching a stop position, and a second projectile separated from the first projectile, cutting off the cut-off portion from the conductor strip, and pushing the cut-off portion having been cut off into the coolant material disposed in the arc-extinguishing area.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric circuit breaker.

Background Art

[0002] In an electric circuit, there may be provided a circuit breaker that operates when an abnormality occurs in a device constituting the electric circuit or when an abnormality occurs in a system on which the electric circuit is mounted, and urgently cuts off conduction in the electric circuit. As one aspect, an electric circuit breaker has been proposed that moves a projectile at high speed by energy applied from an igniter or the like and forcibly and physically cuts a conductor piece forming a part of the electric circuit (see, for example, Patent Documents 1, 2, etc.). In recent years, the importance of an electric circuit breaker applied to an electric vehicle equipped with a high-voltage power supply has been increasing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an electric circuit breaker, it is a fact that an arc is likely to occur when a conductor piece forming a part of the electric circuit is cut. If an arc occurs, the electric circuit cannot be quickly cut off, so in an electric circuit breaker, it is required to quickly extinguish the generated arc. To quickly extinguish the arc, it is required to move the cut conductor piece to a position away from the cutting position.

[0005] The technology of the present disclosure has been made in view of the above circumstances, and its object is to provide an electric circuit breaker capable of quickly extinguishing an arc during operation. [Means for solving the problem]

[0006] To solve the above problems, the following measures will be taken. That is, the first embodiment is an electrical circuit interruption device comprising: an igniter provided in a housing; a projectile disposed in a housing space formed within the housing and extending in one direction, the projectile being launched along the housing space by energy received from the igniter; a conductive piece provided in the housing and forming part of an electrical circuit, the conductive piece having a portion to be cut off that is positioned to cross the housing space and to be cut off by the projectile; and an arc extinguishing region provided in the housing space and where coolant material is disposed, wherein the projectile includes a first projectile launched by energy received from the igniter and reaching a stopping position, and a second projectile separated from the first projectile, which cuts off the portion to be cut off from the conductive piece and pushes the cut portion into the coolant material disposed in the arc extinguishing region.

[0007] A second embodiment further comprises an electrical circuit breaker, the second projectile being attached to the first projectile before the ignition is activated and launched together with the first projectile by the energy received from the ignition.

[0008] A third embodiment further comprises an electrical circuit breaker attached to the first projectile so as to be coaxial with the first projectile before the ignition is activated.

[0009] A fourth embodiment further comprises an electrical circuit breaker in which the first projectile has a mounting recess for attaching the second projectile, and the second projectile is positioned facing the portion to be cut off before the ignition is activated and has a cutting surface for cutting off the portion to be cut off.

[0010] A fifth embodiment further comprises an electrical circuit breaker in which the first projectile has a connecting passage for guiding energy received from the igniter to the pressure-receiving portion of the second projectile, which is mounted in the mounting recess. [Effects of the Invention]

[0011] According to this disclosure, it is possible to provide an electrical circuit interrupter capable of rapidly extinguishing arcs generated during operation. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a diagram illustrating the internal structure of a circuit breaker. [Figure 2] Figure 2 is a top view of the conductor piece. [Figure 3] Figure 3 is an exploded view of the projectile 30. [Figure 4] Figure 4 illustrates the operation of the circuit breaker. [Figure 5] Figure 5 illustrates the internal structure of a circuit breaker when no connecting passage exists. [Figure 6] Figure 6 is an exploded view of the projectile 30 when there is no connecting passage. [Figure 7] Figure 7 illustrates the operation of the circuit breaker when no connecting passage exists. [Modes for carrying out the invention]

[0013] An electrical circuit breaker according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the configurations and combinations thereof in the embodiments are examples only, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of the present disclosure. This disclosure is not limited by the embodiments, but is limited only by the claims.

[0014] <Structure> FIG. 1 is a diagram for explaining the internal structure of an electric circuit breaker (hereinafter simply referred to as "breaker") 1 according to an embodiment. The breaker 1 is a device for preventing major damage by interrupting an electric circuit when an abnormality occurs in an electric circuit included in, for example, an automobile or a household electrical appliance, or a system including a battery (for example, a lithium ion battery) of the electric circuit. In this specification, a cross section along the height direction (the direction in which the accommodation space 13 described later extends) shown in FIG. 1 is referred to as a longitudinal cross section of the breaker 1, and a cross section in a direction orthogonal to the longitudinal cross section is referred to as a transverse cross section of the breaker 1. FIG. 1 shows the state of the breaker 1 before operation. FIG. 5 is a diagram for explaining the internal structure of the breaker when there is no communication path, and is the same as FIG. 1 except for the presence or absence of the communication path.

[0015] The breaker 1 includes a housing 10 as an outer shell member, an igniter 20, a projectile 30, a conductor piece 50, a coolant material 60, and the like. The housing 10 has an accommodation space 13 extending in the direction from the first end portion 11 on the upper end side to the second end portion 12 on the lower end side. This accommodation space 13 is a linearly formed space in which the projectile 30 can move, and extends along the vertical direction of the breaker 1. However, in this specification, the vertical direction of the breaker 1 only indicates the relative positional relationship of each element in the breaker 1 for the convenience of explaining the embodiment.

[0016] As shown in FIG. 1, the projectile 30 is accommodated in the accommodation space 13 formed inside the housing 10. Although details will be described later, the projectile 30 includes a first projectile 40 and a second projectile 70 attached to the first projectile 40 in the initial state before the breaker 1 is operated. in the initial state before operation.

[0017] [Housing] The housing 10 includes a housing main body 100, a top holder 110, and a bottom container 120. The top holder 110 and the bottom container 120 are coupled to the housing main body 100, thereby forming an integral housing 10.

[0018] The housing body 100 has, for example, an outer shape of a generally prismatic shape. However, the shape of the housing body 100 is not particularly limited. Further, a cavity is formed in the housing body 100 so as to penetrate in the vertical direction, and this cavity forms a part of the accommodation space 13. Furthermore, the housing body 100 has an upper surface 101 to which the flange portion 111 of the top holder 110 is fixed, and a lower surface 102 to which the flange portion 121 of the bottom container 120 is fixed. In the present embodiment, on the outer peripheral side of the upper surface 101 of the housing body 100, a cylindrical upper cylindrical wall 103 is erected upward from the upper surface 101. In the present embodiment, the upper cylindrical wall 103 has, for example, a square cylindrical shape, but may have other shapes. Also, on the outer peripheral side of the lower surface 102 of the housing body 100, a cylindrical lower cylindrical wall 104 is vertically provided downward from the lower surface 102. In the present embodiment, the lower cylindrical wall 104 has, for example, a square cylindrical shape, but may have other shapes. The housing body 100 configured as described above can be formed of an insulating member such as synthetic resin or the like. For example, the housing body 100 may be formed of nylon, which is a kind of polyamide synthetic resin.

[0019] [Top Holder] Next, the top holder 110 will be described. The top holder 110 is, for example, a cylindrical member having a stepped cylindrical shape, and the inside is hollow. The top holder 110 includes a small-diameter cylindrical portion 112 located on the upper side (the first end portion 11 side), a large-diameter cylindrical portion 113 located on the lower side, a connecting portion 114 connecting these, a flange portion 111 extending outward from the lower end of the large-diameter cylindrical portion 113, and the like. For example, the small-diameter cylindrical portion 112 and the large-diameter cylindrical portion 113 have a cylindrical shape arranged coaxially, and the large-diameter cylindrical portion 113 has a diameter slightly larger than that of the small-diameter cylindrical portion 112. Also, the connecting portion 114 connects the small-diameter cylindrical portion 112 and the large-diameter cylindrical portion 113 by extending in the radial direction thereof.

[0020] Furthermore, the contour of the flange portion 111 of the top holder 110 has a roughly rectangular shape that fits inside the upper cylindrical wall 103 of the housing body 100. The flange portion 111 may be integrally fastened to the upper surface 101 of the housing body 100 using screws or the like, or fixed with rivets or the like, while positioned inside the upper cylindrical wall 103. Alternatively, the top holder 110 may be joined to the housing body 100 with sealant applied between the upper surface 101 of the housing body 100 and the lower surface of the flange portion 111 of the top holder 110. This can improve the airtightness of the housing space 13 formed inside the housing 10. Alternatively, the airtightness of the housing space 13 may be improved by interposing an O-ring between the upper surface 101 of the housing body 100 and the flange portion 111 of the top holder 110, either instead of sealant or in combination with sealant.

[0021] The cavity formed inside the small-diameter cylinder portion 112 of the top holder 110 functions as a housing space for a part of the igniter 20, as shown in Figure 1. Furthermore, the cavity formed inside the large-diameter cylinder portion 113 of the top holder 110 communicates with the cavity in the housing body 100 located below, forming a part of the housing space 13. The top holder 110, configured in this manner, can be formed from a suitable metal component such as stainless steel or aluminum, which have excellent strength and durability. However, the material used to form the top holder 110 is not particularly limited. Furthermore, the above-described embodiment of the top holder 110 is merely an example, and other shapes may be adopted.

[0022] [Bottom container] Next, the bottom container 120 will be described. The bottom container 120 has a generally bottomed cylindrical shape with a hollow interior and is composed of a side wall portion 122, a bottom wall portion 123 connected to the lower end of the side wall portion 122, a flange portion 121 connected to the upper end of the side wall portion 122, etc. The side wall portion 122 has, for example, a cylindrical shape, and the flange portion 121 extends outward from the upper end of the side wall portion 122. The contour of the flange portion 121 in the bottom container 120 has a generally rectangular shape that fits inside the lower cylindrical wall 104 of the housing body 100. The flange portion 121 may, for example, be integrally fastened to the lower surface 102 of the housing body 100 using screws or the like while positioned inside the lower cylindrical wall 104, or it may be fixed by rivets or the like. Here, the bottom container 120 may be bonded to the housing body 100 with sealant applied between the lower surface 102 of the housing body 100 and the upper surface of the flange portion 121 of the bottom container 120. This can improve the airtightness of the containment space 13 formed inside the housing 10. Alternatively, instead of sealant, or in combination with sealant, an O-ring may be interposed between the lower surface 102 of the housing body 100 and the flange portion 121 of the bottom container 120 to improve the airtightness of the containment space 13.

[0023] The above description of the shape of the bottom container 120 is merely an example, and other shapes may be adopted. Furthermore, the cavity formed inside the bottom container 120 communicates with the housing body 100 located above it, forming part of the storage space 13. The bottom container 120, configured as described above, can be made from suitable metal materials such as stainless steel or aluminum, which have excellent strength and durability. However, the material used to form the bottom container 120 is not particularly limited. The bottom container 120 may also have a multi-layer structure. For example, the exterior of the bottom container 120 facing the outside may be made from suitable metal materials such as stainless steel or aluminum, which have excellent strength and durability, while the interior facing the storage space 13 may be made from an insulating material such as synthetic resin. Of course, the entire bottom container 120 may also be made from an insulating material.

[0024] As described above, the housing 10 in the embodiment is composed of a housing body 100, a top holder 110, and a bottom container 120 which are assembled together, and a housing space 13 is formed inside it, extending from the first end 11 to the second end 12. The igniter 20, projectile 40, the cut-off portion 53 of the conductive piece 50, the coolant material 60, etc., which will be described in detail below, are housed in this housing space 13.

[0025] [Igniter] Next, the igniter 20 will be described. The igniter 20 is an electric igniter comprising an ignition unit 21 containing an ignition charge and an igniter body 22 having a pair of conductive pins (not shown) connected to the ignition unit 21. The igniter body 22 is surrounded by, for example, an insulating resin. The tips of the pair of conductive pins in the igniter body 22 are exposed to the outside and are connected to the power supply when the shut-off device 1 is used.

[0026] The igniter body 22 comprises a roughly cylindrical main body 221 housed inside the small-diameter cylinder portion 112 of the top holder 110, and a connector portion 222 located on the upper part of the main body portion 221. The igniter body 22 is fixed to the small-diameter cylinder portion 112, for example, by press-fitting the main body portion 221 into the inner circumferential surface of the small-diameter cylinder portion 112. Also, the shaft of the main body portion 221 In the middle of the directional section, a constricted portion is formed in an annular shape along the circumferential direction of the main body 221, with its outer surface being recessed compared to other areas, and an O-ring 223 is fitted into this constricted portion. The O-ring 223 is made of, for example, rubber (e.g., silicone rubber) or synthetic resin, and functions to improve airtightness between the inner circumferential surface of the small-diameter cylinder section 112 and the main body 221.

[0027] The connector portion 222 in the igniter 20 is positioned to protrude to the outside through an opening 112A formed at the upper end of the small-diameter cylinder portion 112. The connector portion 222 has, for example, a cylindrical shape that covers the sides of the conductive pins and is configured to connect to the power supply side connector.

[0028] As shown in Figure 1, the ignition unit 21 of the igniter 20 is positioned to face the housing space 13 of the housing 10 (more specifically, the cavity formed inside the large-diameter cylinder section 113). The ignition unit 21 is configured, for example, to house the igniter in an igniter cup. For example, the igniter is housed in the igniter cup of the igniter unit 21 in contact with a bridge wire (resistor) that is strung together to connect the base ends of a pair of conductive pins. Examples of igniters that can be used include ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), THPP (titanium hydride potassium perchlorate), and lead tricinate.

[0029] When the igniter 20 is activated, an operating current for igniting the igniter is supplied from the power source to the conductive pin. As a result, the bridge wire in the ignition unit 21 heats up, causing the igniter in the igniter cup to ignite and burn, generating combustion gas. Then, as the igniter burns in the igniter cup of the igniter unit 21, the pressure inside the igniter cup increases, causing the split surface 21A of the igniter cup to split, and the combustion gas is released from the igniter cup into the containment space 13. More specifically, the combustion gas from the igniter cup is released into the recess 411 of the piston portion 41 of the projectile 40, which will be described later, located in the containment space 13.

[0030] [Conducting piece] Next, the conductor piece 50 will be described. Figure 2 is a top view of the conductor piece 50 according to the embodiment. The conductor piece 50 is a conductive metal body that constitutes a part of the components of the circuit breaker 1 and forms a part of the electrical circuit when the circuit breaker 1 is attached to a predetermined electrical circuit, and is sometimes called a bus bar. The conductor piece 50 is made of a metal such as copper (Cu), for example. Thus, it can be formed. However, the conductive piece 50 may be made of a metal other than copper, or it may be made of an alloy of copper and another metal. Examples of metals other than copper that can be included in the conductive piece 50 include manganese (Mn), nickel (Ni), platinum (Pt), etc.

[0031] In one embodiment shown in Figure 2, the conductor piece 50 is formed as an elongated flat plate piece overall, and includes first connection ends 51 and second connection ends 52 at both ends, and a cut-off portion 53 located in the middle portion. Connection holes 51A and 52A are provided at the first connection ends 51 and the second connection ends 52 of the conductor piece 50, respectively. These connection holes 51A and 52A are used to connect to other conductors (e.g., lead wires) in an electrical circuit. Note that in Figure 1, the connection holes 51A and 52A of the conductor piece 50 are not shown. The cut-off portion 53 of the conductor piece 50 is the part that is forcibly and physically cut by the projectile 30 (second projectile 70), which will be described in detail later, and cut off from the first connection ends 51 and the second connection ends 52 when an abnormality such as an overcurrent occurs in the electrical circuit to which the circuit breaker 1 is applied. At both ends of the portion to be cut 53 of the conductive piece 50, notches (slits) 54 are formed to facilitate the cutting and removal of the portion to be cut 53.

[0032] Here, the conductor piece 50 can take on various forms, and its shape is not particularly limited. In the example shown in Figure 2, the surfaces of the first connecting end 51, the second connecting end 52, and the cut-off portion 53 are While the same surface is formed, this is not the only limitation. For example, the conductor piece 50 may be connected to the first connecting end 51 and the second connecting end 52 with the cut-off portion 53 in a perpendicular or inclined position. Furthermore, the planar shape of the cut-off portion 53 on the conductor piece 50 is not particularly limited. Of course, the shapes of the first connecting end 51 and the second connecting end 52 on the conductor piece 50 are also not particularly limited. In addition, the cut 54 on the conductor piece 50 can be omitted as appropriate.

[0033] In this embodiment, the housing body 100 has a pair of conductor piece holding holes 105A and 105B. The pair of conductor piece holding holes 105A and 105B extend in a cross-sectional direction perpendicular to the vertical direction (axial direction) of the housing body 100. More specifically, the pair of conductor piece holding holes 105A and 105B extend in a straight line across the cavity (housing space 13) of the housing body 100. The conductor piece 50 configured as described above is held in the housing body 100 with the conductor piece inserted through the pair of conductor piece holding holes 105A and 105B formed in the housing body 100. In the example shown in Figure 1, the first connecting end 51 of the conductor piece 50 is held with the conductor piece holding hole 105A inserted, and the second connecting end 52 is held with the conductor piece holding hole 105B inserted. Furthermore, in this state, the portion to be cut 53 of the conductor piece 50 is positioned in the cavity (housing space 13) of the housing body 100. As described above, the conductor piece 50 mounted on the housing body 100 is held in a position perpendicular to the extending direction (axial direction) of the housing space 13, with the portion to be cut 53 crossing the housing space 13. Note that the reference numeral L1 in Figure 2 indicates the outer circumference position of the second projectile 70 located above the conductor piece 50 when mounted on the housing body 100 of the blocking device 1. In this embodiment, the conductor piece 50 is installed such that the outer circumference position L1 of the second projectile 70 generally coincides with the positions of the cuts 54 located at both ends of the portion to be cut 53. In this embodiment, for example, since the cross-sectional area of ​​the housing space 13 is larger than the cross-sectional area of ​​the portion to be cut 53, a gap is formed on the side of the portion to be cut 53.

[0034] [Coolant material] Next, the coolant material 60 placed in the housing space 13 of the housing 10 will be described. As shown in Figure 1, before the shutdown device 1 (igniter 20) is activated, the portion to be cut off 53 of the conductor piece 50, which is held in the pair of conductor piece holding holes 105A and 105B in the housing body 100, is horizontally positioned across the housing space 13 of the housing 10. Hereinafter, the area (space) in the housing space 13 of the housing 10 on the side of the portion to be cut off 53 of the conductor piece 50 where the projectile 30 is placed will be called the "initial projectile placement area R1," and the area (space) located on the opposite side of the projectile 30 will be called the "arc extinguishing area R2." In this embodiment, the cross-sectional area of ​​the housing space 13 is larger than the cross-sectional area of ​​the portion to be cut off 53, and a gap is formed on the side of the portion to be cut off 53. Therefore, the initial projectile placement area R1 and the arc extinguishing area R2 in the housing space 13 are not completely isolated by the portion to be cut off 53, but rather the two are in communication with each other through the gap. Of course, depending on the shape and size of the portion to be cut 53, the initial projectile placement area R1 and the arc extinguishing area R2 may be completely isolated by the portion to be cut 53.

[0035] The arc-extinguishing region R2 of the containment space 13 is a region (space) for receiving the cut-off portion 53 that is cut off by the projectile 30 fired when the shut-off device 1 (igniter 20) is activated. Coolant material 60 is placed in this arc-extinguishing region R2 as an arc-extinguishing material. The coolant material 60 is a coolant that removes the thermal energy of the arc and the cut-off portion 53 generated when the projectile 30 cuts off the cut-off portion 53 of the conductor piece 50, thereby suppressing arc generation when the current is interrupted, or extinguishing (eliminating) the generated arc.

[0036] The arc extinguishing region R2 in the circuit breaker 1 is a space for receiving the cut-off portion 53 removed from the first connecting end 51 and the second connecting end 52 of the conductor piece 50, and at the same time, it has significance as a space for effectively extinguishing the arc generated when the cut-off portion 53 is removed. Furthermore, in order to effectively extinguish the arc generated when the portion to be cut 53 is cut from the conductor piece 50, a coolant material 60 is placed in the arc extinguishing region R2 as an arc extinguishing material. In one embodiment, the coolant material 60 is solid. The coolant material 60 is placed, for example, on the sides and bottom of the bottom container 120. The inner circumferential surface of the coolant material 60 placed on the sides of the bottom container 120 has an inner diameter that generally corresponds to the inner diameter of the inner circumferential surface of the housing body 100. The inner diameter of the inner circumferential surface of the coolant material 60 placed on the sides of the bottom container 120 is, for example, equal to the inner diameter of the inner circumferential surface of the housing body 100. The coolant material 60 may be formed, for example, by shaping woven metal fibers into a desired shape. The metal fibers forming the coolant material 60 include at least one of steel wool and copper wool. However, the above embodiments of the coolant material 60 are examples and are not limited thereto. For example, the coolant material 60 may be a compressed form of powder or the like. Also, the coolant material 60 may be a gel rather than a solid. The coolant material 60 may be placed not only on the sides and bottom of the bottom container 120, but also in other locations within the housing 10, such as the sides (inside) of the housing body 100, the sides (inside) of the top holder 110, and the sides (outside) of the first projectile 40. By placing the coolant material 60 in multiple locations, the arc can be extinguished more effectively.

[0037] [Projectile] Next, the projectile 30 will be described. The projectile 30 is composed of a first projectile 40 and a second projectile 70. Figure 3 is an exploded view of the projectile 30, showing the first projectile 40 and the second projectile 70 separated. The first projectile 40 and the second projectile 70 are formed of an insulating material such as synthetic resin. Also, as shown in Figure 3, the outer diameter of the second projectile 70 is approximately equal to the outer diameter of the rod portion 42 of the first projectile 40. Figure 6 is an exploded view of the projectile 30 when there is no connecting passage, and is the same as Figure 3 except for the presence or absence of the connecting passage.

[0038] The first projectile 40 will now be described. The first projectile 40 is composed of a piston portion 41 and a rod portion 42 connected to the piston portion 41. The piston portion 41 has a generally cylindrical shape and an outer diameter that roughly corresponds to the inner diameter of the large-diameter cylinder portion 113 in the top holder 110. For example, the diameter of the piston portion 41 may be slightly smaller than the inner diameter of the large-diameter cylinder portion 113. The shape of the piston portion 41 can be appropriately changed according to the shape of the large-diameter cylinder portion 113, etc.

[0039] The rod portion 42 of the first projectile 40 is, for example, a rod-shaped member having a smaller outer diameter than the piston portion 41, and is integrally connected to the lower end of the piston portion 41. Here, the rod portion 42 in this embodiment has a generally cylindrical shape, but its shape is not particularly limited. The diameter of the rod portion 42 is, for example, slightly smaller than the inner diameter of the inner surface of the housing body 100, so that when the shutoff device 1 is operated, the outer surface of the rod portion 42 is guided along the inner surface of the housing body 100.

[0040] Furthermore, a recessed portion 44, which is a cylindrical recess, is formed on the upper surface of the piston portion 41 of the first projectile 40, and this recessed portion 44 is configured to accept the ignition portion 21. The bottom surface of the recessed portion 44 is formed as a first pressure receiving portion 44A that receives energy received from the ignitioner 20 when the ignitioner 20 is in operation. In addition, a constricted portion, which is recessed on the outer circumferential direction of the piston portion 41, is formed in the axial middle portion of the piston portion 41, and an O-ring 43 is fitted into this constricted portion. The O-ring 43 is made of rubber (e.g., silicone rubber) or synthetic resin, and functions to improve airtightness between the inner circumferential surface of the large-diameter cylinder portion 113 and the piston portion 41.

[0041] The lower end of the first projectile 40 is provided with a mounting recess 45 for accommodating and attaching a portion of the second projectile 70. This mounting recess 45 is formed to open onto the lower end surface 421 of the rod portion 42 of the first projectile 40. In the examples shown in Figures 1 and 3, the mounting recess 45 has a cylindrical shape. The recess 44 and the mounting recess 45 of the first projectile 40 are arranged coaxially so as to pass through the central axis of the first projectile 40. Furthermore, as shown in Figures 1 and 3, the first projectile 40 is provided with a connecting passage 46 that connects (connects) the recess 44 and the mounting recess 45. The connecting passage 46 of the first projectile 40 is formed so as to pass through the central axis of the first projectile 40, and the connecting passage 46 is also arranged coaxially with respect to both the recess 44 and the mounting recess 45. Also, as shown in Figures 5 and 6, the connecting passage 46 may not be present. In other words, the recessed portion 44 and the mounting recess 45 do not need to be in communication with each other.

[0042] Next, the second projectile 70 will be described. The second projectile 70 is composed of an upper part 71 having a shape and size that can be accommodated in the mounting recess 45 of the first projectile 40, and a lower part 72 connected to the upper part 71. The upper part 71 of the second projectile 70 has a generally cylindrical shape and an outer diameter that roughly corresponds to the inner diameter of the rod portion 42 (the diameter of the mounting recess 45). For example, the diameter of the upper part 71 may be slightly smaller than the inner diameter of the rod portion 42. The shape of the upper part 71 can be appropriately changed depending on the shape of the mounting recess 45, etc. The upper part 71 is the part that is accommodated in the mounting recess 45. The lower part 72 of the second projectile 70 has a generally cylindrical shape and an outer diameter that roughly corresponds to the outer diameter of the rod portion 42. The outer diameter (diameter) of the lower part 72 is, for example, equal to the outer diameter of the rod portion 42. The diameter of the lower part 72 is, for example, slightly smaller than the inner diameter of the inner circumferential surface of the housing body 100. That is, the diameter of the lower part 72 is slightly smaller than the inner diameter of the inner surface of the coolant material 60 arranged on the side of the bottom container 120. When the shut-off device 1 is activated, the outer surface of the lower part 72 is guided along the inner surface of the housing body 100 and the inner surface of the coolant material 60 arranged on the side of the bottom container 120. The lower part 72 is integrally connected to the lower end side of the upper part 71. The roughly cylindrical axis of the upper part 71 and the roughly cylindrical axis of the lower part 72 are coaxial. The outer diameter of the upper part 71 is smaller than the outer diameter of the lower part 72. The roughly cylindrical axis of the rod portion 42 of the first projectile 40 and the axis of the upper part 71 (or lower part 72) of the second projectile 70 are coaxially arranged. Here, the lower part 72 in this embodiment has a roughly cylindrical shape, but its shape is not particularly limited.

[0043] The lower end surface 421 of the rod portion 42 of the first projectile is positioned facing the upper end surface of the lower part 72 of the second projectile when the second projectile 70 is positioned in the initial position shown in Figure 1. The lower end surface of the lower part 72 of the second projectile 70 is positioned facing the portion to be cut 53 when the second projectile 70 is positioned in the initial position shown in Figure 1. The lower end surface of the lower part 72 is formed as a cutting surface for cutting the portion to be cut 53 from the conductor piece 50 when the shutoff device 1 is activated.

[0044] The upper end surface of the second projectile 70 is formed as a second pressure receiving section 73 that receives energy from the igniter 20 when the shut-off device 1 (igniter 20) is activated. The lower end surface of the second projectile 70 is formed as a pressing section 74 that pushes the cut-off portion 53, which is cut off by the second projectile 70 when the shut-off device 1 (igniter 20) is activated, into the arc extinguishing region R2. That is, the lower end surface of the lower part 72 is both a cutting surface for cutting off the cut-off portion 53 and a pressing section 74 for pushing the cut-off portion 53 into the arc extinguishing region R2. When the second projectile 70 is attached to the first projectile 40, the upper part 71 of the second projectile 70 is inserted into the mounting recess 45 of the first projectile 40 from the side of the second pressure receiving section 73 (upper surface). As a result, as shown in Figure 1, the second projectile 70 is mounted on the first projectile 40 such that the second pressure-receiving portion 73 of the second projectile 70 faces the communication passage 46 and recess 44 of the first projectile 40, while the pressing portion 74 is positioned on the open end 45A side of the mounting recess 45. In this embodiment, the second projectile 70 is positioned coaxially with the first projectile 40 when mounted in the mounting recess 45. However, the second projectile 70 may be eccentric with respect to the first projectile 40 when mounted on the first projectile 40.

[0045] Furthermore, in this embodiment, the axial depth of the mounting recess 45 in the first projectile 40 is greater than the axial length of the second projectile 70. Alternatively, the axial depth of the mounting recess 45 in the first projectile 40 may be equal in dimension to the axial length of the upper part 71 of the second projectile 70. By inserting the upper part 71 of the second projectile 70 into the mounting recess 45 of the first projectile 40, the second projectile 70 can reach the coolant material 60 at the bottom wall 123 of the bottom container 120 in a straight and stable manner during operation.

[0046] As described above, the projectile 30 is positioned in the initial projectile placement area R1 of the housing space 13 in the initial pre-operation state shown in Figure 1, with the upper part 71 of the second projectile 70 mounted in the mounting recess 45 of the first projectile 40. In the example shown in Figure 1, the piston portion 41 of the first projectile 40 is positioned on the first end 11 side (upper end side) of the housing space 13. The lower part 72 of the second projectile 70 is positioned with its lower end surface resting on the conductive piece 50. Here, the reference numeral L1 shown in Figure 2 indicates the outer circumference position of the lower part 72 of the second projectile 70, which is located above the conductive piece 50 when mounted on the housing body 100 of the shut-off device 1. In the initial pre-operation state of the shut-off device 1, the outer circumference position L1 of the lower part 72 of the second projectile 70 roughly coincides with the positions of the notches 54 located at both ends of the cut-off portion 53. Furthermore, before the ignition device 20 is activated, the second projectile 70 is attached to the first projectile 40 such that its central axis C1 passes near the center of the section to be cut 53.

[0047] <Operation> Next, we will explain the operation of the circuit breaker 1 when it is activated to interrupt the electrical circuit. Figure 4 is a diagram illustrating the operation of the circuit breaker 1 according to this embodiment. The upper part of Figure 4 shows the state of the circuit breaker 1 during operation, and the lower part of Figure 4 shows the state of the circuit breaker 1 after operation is complete. Below, we will explain the operation of the circuit breaker 1 when it is activated with reference to Figures 3 and 4.

[0048] The circuit breaker 1 according to this embodiment further includes an abnormality detection sensor (not shown) for detecting abnormal currents in an electrical circuit, and a control unit (not shown) for controlling the operation of the igniter 20. The abnormality detection sensor may also be able to detect voltage and temperature of the conductor piece 50 in addition to the current flowing through the conductor piece 50. The control unit of the circuit breaker 1 is a computer that can perform predetermined functions by executing a predetermined control program, for example. The predetermined functions of the control unit can also be realized by corresponding hardware. When an excessive current flows through the conductor piece 50 that forms part of the electrical circuit to which the circuit breaker 1 is applied, the abnormal current is detected by the abnormality detection sensor. Abnormal information regarding the detected abnormal current is passed from the abnormality detection sensor to the control unit. For example, based on the current value detected by the abnormality detection sensor, the control unit receives power from an external power supply (not shown) connected to the conductive pins of the igniter 20 and operates the igniter 20. Here, the abnormal current may be a current value that exceeds a predetermined threshold set for the protection of a predetermined electrical circuit. Furthermore, the anomaly detection sensor and control unit described above do not necessarily have to be included as components of the tripping device 1; for example, they may be included in a separate device. Also, the anomaly detection sensor and control unit are not essential components of the tripping device 1.

[0049] For example, when an abnormal current in an electrical circuit is detected by an abnormal current detection sensor, the control unit of the circuit breaker 1 activates the igniter 20. That is, an operating current is supplied to the conductive pins of the igniter 20 from an external power source (not shown), causing the igniter in the ignition unit 21 to ignite and burn, generating combustion gas. Then, due to the pressure rise inside the ignition unit 21, the crack surface 21A cracks open, and the combustion gas of the igniter is released from inside the ignition unit 21 into the containment space 13.

[0050] As described above, the projectile 30 in the shutoff device 1 includes a first projectile 40 and a second projectile 70, and is launched from its initial position by receiving energy from the igniter 20 when activated, more specifically the energy from the combustion gas generated by the combustion of the igniter in the ignition unit 21, and is configured to move along the containment space 13. The first projectile 40 and the second projectile 70 in the projectile 30 each have different functions (roles). Specifically, when the shutoff device 1 (igniter 20) is activated, the first projectile 40 is launched towards the second end 12 side of the containment space 13 by the energy it receives from the combustion gas of the igniter in the igniter 20, thereby functioning to push the second projectile 70 into the arc extinguishing area R2. On the other hand, when the shut-off device 1 (igniter 20) is activated, the second projectile 70 is propelled toward the second end 12 side through the containment space 13 by the energy it receives from the combustion gas of the igniter 20, thereby cutting off the portion to be cut 53 from the conductor piece 50 and pushing the cut portion 53 into the arc extinguishing region R2. The operation of the first projectile 40 and the second projectile 70 when the shut-off device 1 (igniter 20) is activated will be described in detail below.

[0051] As shown in Figure 1, the ignition unit 21 of the igniter 20 is received in the recess 411 of the piston unit 41 of the first projectile 40, and the splitting surface 21A of the ignition unit 21 is positioned opposite the first pressure receiving portion 44A of the recess 411 of the first projectile 40. As a result, the combustion gas from the ignition unit 21 is released toward the recess 411 of the first projectile 40, and the pressure (combustion energy) of the combustion gas is transmitted to the upper surface of the piston unit 41, including the pressure receiving surface 411A. This presses the upper surface of the piston unit 41, including the pressure receiving surface 411A, of the first projectile 40, and the first projectile 40 is forcefully biased downward (towards the second end 12). As a result, the lower end surface of the second projectile 70, positioned below the first projectile 40, is strongly pressed against each boundary (the area where the notch 54 is formed) between the first connecting end 51 and the second connecting end 52 of the conductor piece 50 and the portion to be cut 53. In this way, for example, the portion to be cut 53 of the conductor piece 50 can be cut off from the conductor piece 50 by shearing.

[0052] As shown in the upper part of Figure 4, the first projectile 40 moves downward (towards the second end 12) along the extending direction (axial direction) of the housing space 13 by a predetermined stroke until the lower end surface 411 of the piston portion 41 comes into contact with (collides with) the upper surface 101 of the housing body 100. This state in which the movement of the first projectile 40 further downward (towards the second end 12) is restricted by the lower end surface 411 of the piston portion 41 coming into contact with (collides with) the stopper portion 101A on the upper surface 101 of the housing body 100 is called the "movement restriction state". As shown in the upper part of Figure 4, in the shutoff device 1 according to this embodiment, the length of the rod portion 42, or the vertical dimensions of the arc extinguishing region R2, are set so that when the first projectile 40 is launched from its initial position and reaches the movement restriction state during operation, the lower end surface 421 of the rod portion 42 is positioned in a relatively upper region of the arc extinguishing region R2. When the system is activated, the position of the first projectile 40 when it is launched from its initial position and reaches the movement restriction state is the stopping position of the first projectile 40. When activated, the first projectile 40 reaches the stopping position and comes to a halt.

[0053] Furthermore, when the lower end surface 411 of the piston portion 41 of the first projectile 40 collides with the stopper portion 101A during the operation of the blocking device 1, a holding portion may be provided on at least one of the lower end surface 411 of the piston portion 41 and the stopper portion 101A to hold the lower end surface 411 of the piston portion 41 in contact with the stopper portion 101A. Such a holding portion is not particularly limited, but for example, it may be formed by a projection provided on the lower end surface 411 of the piston portion 41 or the stopper portion 101A. For example, when the lower end surface 411 of the piston portion 41 collides with the stopper portion 101A, the projection provided on the lower end surface 411 of the piston portion 41 pierces the stopper portion 101A, or a projection provided on the stopper portion 101A pierces the lower end surface 411 of the piston portion 41, thereby holding the lower end surface 411 of the piston portion 41 in contact with the stopper portion 101A. This is possible. Alternatively, instead of actively providing the above-mentioned protrusions, the holding portion may be formed by the engagement of a rounded inner corner portion 47 formed at the boundary between the lower end surface 411 of the piston portion 41 and the outer peripheral surface of the rod portion 42, as shown in Figure 1, and a right-angled outer corner portion 106 formed by the connection of the upper surface 101A (upper surface 101) and the inner peripheral surface of the housing body 100 at a right angle. In this case, when the lower end surface 411 of the piston portion 41 collides with the stopper portion 101A during the operation of the shut-off device 1, the right-angled outer corner portion 106 bites into (pierces) the rounded inner corner portion 47, causing them to engage with each other and holding the lower end surface 411 of the piston portion 41 in contact with the stopper portion 101A.

[0054] Next, the operation of the second projectile 70 when the shut-off device 1 (igniter 20) is activated will be described. As described above, in the initial state before the shut-off device 1 is activated, the upper part 71 of the second projectile 70 is mounted in the mounting recess 45 of the first projectile 40. As described above, the recess 44 and the mounting recess 45 of the first projectile 40 are in communication via a connecting passage 46, and the second pressure receiving part 73 of the second projectile 70, when mounted on the first projectile 40, is positioned opposite the lower end of the connecting passage 46. Therefore, when the shut-off device 1 (igniter 20) is activated, a portion of the combustion gas from the ignition part 21 released toward the recess 411 of the first projectile 40 is guided through the connecting passage 46 to the second pressure receiving part 73 of the second projectile 70, and as a result, the pressure (combustion energy) of the combustion gas is transmitted to the second pressure receiving part 73 of the second projectile 70. As a result, the second pressure-receiving portion 73 of the second projectile 70, which is mounted (housed) in the mounting recess 45 of the first projectile 40, is pressed, and the second projectile 70 is forcefully biased downward (towards the second end 12). Consequently, the second projectile 70, which is stored in the mounting recess 45 of the first projectile 40, is ejected downward from the open end 45A of the mounting recess 45 and launched. As a result, as shown in the upper part of Figure 4, the portion to be cut off 53 from the conductive piece 50 by the lower end surface of the second projectile 70 is pressed downward by the pressing portion 74 of the second projectile 70, thereby pushing the portion to be cut off 53 towards the bottom side of the arc extinguishing region R2 (i.e., towards the second end 12), as shown in the lower part of Figure 4.

[0055] As described above, the projectile 30 of the shut-off device 1 in this embodiment includes a first projectile 40 and a second projectile 70 that are launched in two stages by receiving energy from the combustion gas generated when the igniter 20 burns, which is produced when the igniter 21 is activated. That is, when the igniter 20 is activated, the first projectile 40 and the second projectile 70, which are launched by the energy received from the combustion gas of the igniter, are pushed down toward the second end 12 side of the housing space 13, so that the second projectile 70 cuts through the portion to be cut 53, and the portion to be cut 53 is cut off from the conductor piece 50. As a result, the first connection end 51 and the second connection end 52 located at both ends of the conductor piece 50 become electrically inoperable, and the predetermined electrical circuit to which the shut-off device 1 is applied can be forcibly shut off.

[0056] Then, similar to the first projectile 40, the second projectile 70 is launched from the first projectile 40 toward the second end 12 by the energy received from the combustion gas of the igniter generated when the igniter 20 is activated. As a result, the pressing portion 74 (lower end surface) of the second projectile 70 can quickly push the part to be cut 53 toward the bottom side (second end 12 side) of the arc extinguishing region R2. Consequently, the part to be cut 53 pushed toward the bottom side of the arc extinguishing region R2 by the second projectile 70 is rapidly cooled by the coolant material 60 placed in the arc extinguishing region R2, thereby quickly extinguishing the arc generated when the part to be cut 53 is cut from the first connecting end 51 and the second connecting end 52. Consequently, if an abnormality is detected in the electrical circuit to which the shut-off device 1 is applied, the electrical circuit can be quickly shut off. In other words, by effectively suppressing the prolonged extinguishing of the arc generated when the electrical circuit is shut off, the prolonged shutdown of the electrical circuit can be suppressed. Furthermore, the circuit breaker 1 effectively suppresses the generation of large sparks or flames, and loud impact noises, when the electrical circuit is interrupted. It also suppresses damage to the housing 10 of the circuit breaker 1 caused by these events.

[0057] As described above, the circuit breaker 1 includes a second projectile 70 that is launched from the first projectile 40 separately from the first projectile 40 when the igniter 20 is activated, in order to push the portion to be cut off 53, which has been cut off by the second projectile 70, towards the bottom side (second end 12 side) of the arc extinguishing region R2. By employing such a two-stage mechanism in the projectile 30, even if the axial length of the rod portion 42 of the first projectile 40 is designed to be short, the second projectile 70 can pull the portion to be cut off 53 away from the cutting surface 421 of the first projectile 40 and push the portion to be cut off 53 towards the bottom side (second end 12 side) of the arc extinguishing region R2. This quickly moves the portion to be cut off 53 away from the first connecting end 51 and the second connecting end 52 of the conductor piece 50, reducing arcing when the electrical circuit is interrupted and improving its insulation performance.

[0058] Figure 7 illustrates the operation of the shutoff device 1 when there is no connecting passage, and is the same as Figure 4 except for the presence or absence of the connecting passage. When there is no connecting passage 46, the second pressure receiving part 73 (upper end surface) of the second projectile 70 does not receive the energy received from the igniter 20 when the shutoff device 1 (igniter 20) is activated. However, when the shutoff device 1 (igniter 20) is activated, the energy received from the combustion gas of the igniter in the igniter 20 propels the containment space 13 toward the second end 12, pushing the second projectile 70 into the arc extinguishing region R2 together with the first projectile 40. When the lower end surface 411 of the piston part 41 of the first projectile 40 collides with the stopper part 101A, the first projectile 40 stops, but the second projectile 70 separates from the first projectile 40 and flies out forcefully downward (towards the second end 12). As a result, the portion to be cut 53 can be quickly pushed into the bottom side (second end 12 side) of the arc extinguishing region R2 by the pressing portion 74 (lower end surface) of the second projectile 70, just as in the case where the connecting passage 46 is present.

[0059] On the other hand, in conventional interruption devices that do not have a two-stage firing mechanism for projectiles, in order to increase the distance between the conductor piece and the part to be cut, a projectile movement stroke corresponding to the distance to be separated from the conductor piece is usually required, and therefore the axial length of the projectile must also be increased in accordance with the movement stroke. In contrast, the axial length of the rod portion 42 in the first projectile 40 according to this embodiment only needs to be long enough to push the second projectile 70 and cut off the part to be cut 53 when the igniter 20 is activated, and it is not necessary for the rod portion 42 to push the part to be cut 53 all the way to the bottom of the arc extinguishing region R2. For example, the axial length of the rod portion 42 in the first projectile 40 only needs to be set such that when the piston portion 41 reaches the movement restriction state when the igniter 20 is activated, the position of the lower end surface of the second projectile 70 is lower than the position of the lower surface (the surface facing the arc extinguishing region R2) of the part to be cut 53 in the initial state before activation. This allows the axial length of the rod portion 42 in the first projectile 40 to be shortened while simultaneously cutting off the portion to be cut off 53 during launch, and quickly separating the cut portion 53 from the first connecting end 51 and the second connecting end 52 after the cut. Shortening the axial length of the rod portion 42, and consequently the axial length of the first projectile 40, offers the following advantages.

[0060] In other words, in the initial state before the operation of the circuit breaker 1, as shown in Figure 1, the projectile 30 is positioned above the cut portion 53 of the conductor piece 50 in the initial projectile placement area R1, i.e., the housing space 13. Therefore, the longer the axial length of the first projectile 40, the larger the axial length of the initial projectile placement area R1 needs to be, and the larger the height dimension of the housing 10 needs to be. In contrast, with the circuit breaker 1 of this embodiment, the axial length of the first projectile 40 (rod portion 42) can be shortened, so the height dimension of the housing 10 can be reduced. Thus, with the circuit breaker 1 of this embodiment, while achieving a more compact overall housing 10, an improvement in insulation performance (arc reduction effect) during electrical circuit interruption can be obtained.

[0061] In addition, the timing at which the second projectile 70 is launched from the first projectile 40 when the igniter 20 is activated in the shutoff device 1 is not particularly limited. For example, by the lower end surface of the second projectile 70 The second projectile 70 may be launched from the first projectile 40 at the moment the portion to be cut 53 is removed, or, as shown in the upper part of Figure 4, the second projectile 70 may be launched from the first projectile 40 at a timing after the lower end surface 411 of the piston portion 41 has come into contact with (collided with) the stopper portion 101A of the housing body 100, thus reaching a movement-restricted state. Alternatively, the second projectile 70 may be launched from the first projectile 40 at a timing during the process (intermediate) of reaching the movement-restricted state after the second projectile 70 has removed the portion to be cut 53 when the igniter 20 is activated.

[0062] Furthermore, according to the shutoff device 1, as described above, the second projectile 70 is attached to the first projectile 40 before the igniter 20 is activated (initial pre-activation state), and is configured to be launched from the first projectile 40 by the energy received from the igniter 20. This allows the second projectile 70 to be positioned in a rational manner suitable for pushing the cut portion 53 after excision toward the bottom side (second end 12 side) of the arc extinguishing region R2.

[0063] Furthermore, in this embodiment, since the second projectile 70 is smaller than the first projectile 40, the impact when the cut-off portion 53, which is cut off when the shut-off device 1 is activated, collides with the bottom wall portion 123 of the bottom container 120 can be reduced. Therefore, even if the thickness of the bottom wall portion 123 of the bottom container 120 is reduced, deformation and damage to the bottom wall portion 123 can be suppressed. However, the form of the second projectile 70 is not particularly limited, as long as it can push the cut-off portion 53, which is cut off when the igniter 20 is activated, into the arc extinguishing region R2. For example, in the initial state before activation, the second projectile 70 may not be attached to the first projectile 40, but may be positioned at a distance from the first projectile 40. Also, the second projectile 70 does not necessarily have to be smaller than the first projectile 40; the second projectile 70 may be the same size as the first projectile 40, or it may be larger than the first projectile 40.

[0064] Furthermore, according to the blocking device 1, it is attached to the first projectile 40 so as to be coaxial with the first projectile 40. With this configuration, when the second projectile 70 is launched from the first projectile 40, the second projectile 70 can push the portion to be cut 53 into the bottom side (second end 12 side) of the arc extinguishing region R2 in a balanced manner. In addition, the diameter of the lower part 72 of the second projectile 70 is slightly smaller than the inner diameter of the inner surface of the coolant material 60 arranged on the side of the bottom container 120, which suppresses the rebound of the second projectile 70 at the bottom of the arc extinguishing region R2. Furthermore, by suppressing the rebound of the second projectile 70, the second projectile 70 can push and hold the cut portion to be cut 53 into the coolant material 60 at the bottom of the bottom container 120. Furthermore, because the diameter of the lower part 72 of the second projectile 70 is slightly smaller than the inner diameter of the inner surface of the coolant material 60 placed on the side of the bottom container 120, the second projectile 70 is less likely to move in directions other than vertical, making it easier to push the cut-off portion 53 into the coolant material 60 at the bottom of the bottom container 120.

[0065] Furthermore, the first projectile 40 in this embodiment has a lower end surface 421, a mounting recess 45 that opens in the cut surface 421 and is for mounting the second projectile 70, and a communication passage 46 for guiding the energy received from the igniter 20 to the second pressure receiving section 73 of the second projectile 70 mounted in the mounting recess 45. With this configuration, the combustion gas generated when the igniter 20 is activated can be suitably introduced to the second pressure receiving section 73 of the second projectile 70 mounted in the mounting recess 45 of the first projectile 40 via the communication passage 46. Then, the pressure (combustion energy) of the combustion gas introduced to the second pressure receiving section 73 allows the second projectile 70 to be smoothly launched from the first projectile 40.

[0066] While embodiments of the electrical circuit breaker according to this disclosure have been described above, each embodiment disclosed herein can be combined with any other features disclosed herein. [Explanation of Symbols]

[0067] 1: Circuit breaker 10: Housing 13: Containment Space 20:Igniter 30: Projectile 40: First projectile 50: Conductor piece 53: Part to be excised 60: Coolant material 70: Second projectile

Claims

1. The igniter is located in the housing, A projectile positioned in a housing space formed within the housing and extending in one direction, the projectile being launched along the housing space by energy received from the igniter, A conductive piece provided in the housing and forming part of an electrical circuit, having a portion of the conductive piece that is positioned to cross the housing space and is to be cut off by the projectile, An arc-extinguishing region is provided in the aforementioned containment space and where a coolant material is placed, Equipped with, The aforementioned projectile, The projectile includes a first projectile that is launched by energy received from the igniter and reaches a stopping position, and a second projectile that is separated from the first projectile, cuts off the portion to be cut from the conductive piece, and pushes the cut portion into the coolant material placed in the arc extinguishing region. Electrical circuit breaker.

2. The second projectile is attached to the first projectile before the ignition is activated, and is launched together with the first projectile by the energy received from the ignition. The electrical circuit breaker according to claim 1.

3. The second projectile is mounted on the first projectile so as to be coaxial with the first projectile before the ignition device is activated. The electrical circuit breaker according to claim 2.

4. The first projectile has a mounting recess for attaching the second projectile, The second projectile is positioned facing the portion to be cut before the ignition is activated and has a cutting surface for cutting the portion to be cut. The electrical circuit breaker according to claim 2 or 3.

5. The first projectile has a communication passage for guiding energy received from the igniter to the pressure-receiving portion of the second projectile, which is mounted in the mounting recess. The electrical circuit breaker according to claim 4.

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