Electric circuit breaker device

Abstract

Provided is an electric circuit breaker device capable of more reliably preventing leakage of combustion gas emitted from an igniter. The electric circuit breaker device includes: a housing that encloses a discharge space extending in one direction; an igniter that is provided in the housing and operates to discharge combustion gas into the discharge space; and a conductor piece that is provided in the housing and forms a part of an electric circuit, wherein a cut part cut by the energy of the combustion gas discharged into the discharge space is provided in a portion of the conductor piece and extends across the discharge space. In the conductor piece, a plurality of small projections or a plurality of small recesses are arranged in at least a portion of a region of contact with the housing to prevent the combustion gas discharged into the discharge space from leaking to the outside of the housing from between the housing and the region of contact.

Description

Electrical Circuit Breaker

[0001] The present invention relates to an electrical circuit interruption device.

[0002] Conventionally, an electrical circuit interrupting device has been proposed which includes an igniter provided in a housing, a projectile arranged in a cylindrical space formed within the housing and configured to be movable within the cylindrical space by energy received from the igniter, a conductor piece provided in the housing and forming part of an electrical circuit, the conductor piece having a portion to be cut off by the projectile, the conductor piece being arranged so that the portion to be cut off crosses the cylindrical space, an arc-extinguishing area located on the opposite side of the projectile across the portion to be cut off before activation of the igniter, for receiving the portion to be cut off by the projectile, and a fibrous coolant material arranged in the arc-extinguishing area (for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-128894

[0004] In an electric circuit breaker, the igniter releases high-pressure combustion gas, generating energy to cut the conductor piece. At this time, there is a possibility that the combustion gas may leak from between the housing and the conductor piece.

[0005] The technique of the present disclosure aims to provide an electric circuit breaker that can more reliably prevent leakage of combustion gas emitted by an igniter.

[0006] The electrical circuit interruption device comprises a housing containing a discharge space extending in one direction, an igniter provided in the housing and activating to discharge combustion gas into the discharge space, and a conductor piece provided in the housing and forming part of an electrical circuit, the conductor piece having a cuttable portion on one part that is cut by the energy of the combustion gas discharged into the discharge space, the conductor piece being arranged so that the cuttable portion crosses the discharge space, and at least a part of the contact area of ​​the conductor piece with the housing is formed with a leakage prevention portion having a plurality of small protrusions or a plurality of small recesses arranged to prevent the combustion gas discharged into the discharge space from leaking outside the housing from between the housing and the contact area.

[0007] In addition, the leakage prevention portion may be formed so that when a gap is formed between the housing and the leakage prevention portion when the igniter is activated, the flow path of the combustion gas formed by the gap becomes labyrinth-shaped.

[0008] The leakage prevention portion may be formed on at least a surface of the conductor piece opposite to the igniter in the direction in which the combustion gas is released.

[0009] The leakage prevention portion may be formed on both sides of the conductor piece.

[0010] The entire leak prevention portion may be covered by the housing.

[0011] The leakage prevention portion may have a plurality of diamond-shaped small protrusions formed in a checkerboard pattern.

[0012] The leakage prevention portion may have a plurality of small annular recesses.

[0013] The leakage prevention portion may be embedded in the housing.

[0014] The housing and the conductor pieces may be integrally formed.

[0015] According to the present disclosure, it is possible to provide an electric circuit breaker that can more reliably prevent leakage of combustion gas emitted by an igniter.

[0016] Fig. 1 is a diagram illustrating the internal structure of an electric circuit interruption device (interruption device) according to an embodiment. Fig. 2 is a diagram illustrating a conductor piece according to an embodiment. Fig. 3 is a diagram illustrating the operation of the interruption device. Fig. 4 is a diagram illustrating a conductor piece according to a first modified example of the embodiment. Fig. 5 is a diagram illustrating a conductor piece according to a second modified example of the embodiment. Fig. 6 is a diagram illustrating a conductor piece according to a third modified example of the embodiment.

[0017] <Embodiments> An electrical circuit interruption device 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 each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate within the scope of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the claims.

[0018] <Configuration> FIG. 1 is a diagram illustrating the internal structure of an electrical circuit interruption device (hereinafter simply referred to as "interruption device") 1 according to an embodiment. The interruption device 1 is a device for preventing major damage by interrupting an electrical circuit in the event of an abnormality in, for example, an electrical circuit included in an automobile, a household appliance, a solar power generation system, or a system including a battery (e.g., a lithium-ion battery) of the electrical circuit. In this specification, a cross section taken along the height direction (one direction in which a discharge space 13 described later extends) shown in FIG. 1 is referred to as a longitudinal cross section of the interruption device 1, and a cross section taken in a direction perpendicular to the height direction is referred to as a transverse cross section of the interruption device 1. The height direction coincides with the direction in which an igniter 20 described later discharges combustion gas. FIG. 1 illustrates the interruption device 1 in a state prior to activation.

[0019] The circuit breaker 1 includes a housing 10, an igniter 20, a projectile 40, a conductor piece 50, a coolant material 60, and the like. The housing 10, as an outer shell member, contains a discharge space 13 extending from a first end 11 at the upper end to a second end 12 at the lower end. The discharge space 13 is a linear space that allows the projectile 40 to move and extends along the vertical direction of the circuit breaker 1. As shown in FIG. 1 , the projectile 40 is accommodated at the upper end of the discharge space 13 formed inside the housing 10 in the vertical direction (extension direction). In this specification, the vertical direction is also referred to as the Y-axis direction, the left-right direction is also referred to as the X-axis direction, and the depth direction is also referred to as the Z-axis direction. However, in this specification, the vertical direction and the X, Y, and Z directions of the circuit breaker 1 merely indicate the relative positional relationships of the elements in the circuit breaker 1 for the convenience of explaining the embodiment. For example, the orientation of the circuit breaker 1 when installed is not limited to the directions shown in the figures.

[0020] [Housing] The housing 10 includes a housing 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 body 100, thereby forming the integrated housing 10.

[0021] [Housing Main Body] The housing main body 100 has, for example, a generally rectangular prism-shaped outer shape. However, the shape of the housing main body 100 is not particularly limited. A hollow portion 145 is formed in the housing main body 100 so as to penetrate in the vertical direction, and this hollow portion 145 forms a part of the discharge space 13. The housing main body 100 further 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 this embodiment, a cylindrical upper cylindrical wall 103 extends upward from the outer periphery of the upper surface 101 of the housing main body 100. In this embodiment, the upper cylindrical wall 103 has, for example, a rectangular prism shape, but may have other shapes. A cylindrical lower cylindrical wall 104 extends downward from the outer periphery of the lower surface 102 of the housing main body 100. In this embodiment, the lower tube wall 104 has, for example, a rectangular tube shape, but may have other shapes. Furthermore, the housing main body 100 has a contact portion 105 formed between the upper surface 101 and the lower surface 102 in the vertical direction to hold the conductor piece 50. The contact portion 105 faces and contacts the leakage prevention portion 54, which is part of the conductor piece 50. The housing main body 100 configured as described above can be formed from an insulating material such as a synthetic resin. For example, the housing main body 100 may be formed from nylon, which is a type of polyamide synthetic resin.

[0022] Furthermore, the housing main body 100 holds the conductor piece 50 at a position that coincides with the leakage prevention portion 54 of the conductor piece 50 so that the entire leakage prevention portion 54 is covered by the contact portion 105. However, the manner in which the housing main body 100 holds the conductor piece 50 is not limited to this, and for example, the conductor piece 50 may be held so that a portion of the contact portion 105 and a portion of the leakage prevention portion 54 are in contact with each other.

[0023] The housing main body 100 may be molded integrally with the conductor piece 50. For example, by using insert molding or the like, the conductor piece 50 and the housing main body 100 may be molded so as to be in close contact with each other at a position that coincides with the leakage prevention portion 54 of the conductor piece 50 and to be integrated.

[0024] [Top Holder] Next, the top holder 110 will be described. The top holder 110 is, for example, a cylinder member having a stepped cylindrical shape and a hollow interior. The top holder 110 is configured to include a small-diameter cylinder portion 112 located on the upper side (first end 11 side), a large-diameter cylinder portion 113 located on the lower side, a connection portion 114 connecting these, and a flange portion 111 extending outward from the lower end of the large-diameter cylinder portion 113. For example, the small-diameter cylinder portion 112 and the large-diameter cylinder portion 113 are arranged coaxially, and the large-diameter cylinder portion 113 has a diameter slightly larger than that of the small-diameter cylinder portion 112.

[0025] The flange portion 111 of the top holder 110 has a generally rectangular outline that fits inside the upper cylindrical wall 103 of the housing main body 100. The flange portion 111 may be integrally fastened to the upper surface 101 of the housing main body 100 using screws or the like, or may be fixed with rivets or the like, while being disposed inside the upper cylindrical wall 103. The top holder 110 may be joined to the housing main body 100 with a sealant applied between the upper surface 101 of the housing main body 100 and the lower surface of the flange portion 111 of the top holder 110. This can improve the airtightness of the discharge space 13 formed in the housing 10. Alternatively, instead of or in addition to the sealant, an O-ring may be interposed between the upper surface 101 of the housing main body 100 and the flange portion 111 of the top holder 110 to improve the airtightness of the discharge space 13.

[0026] The space formed inside the small-diameter cylinder portion 112 of the top holder 110 functions as a space for accommodating a portion of the igniter 20, as shown in FIG. 1 . Furthermore, the space formed inside the large-diameter cylinder portion 113 of the top holder 110 communicates with the space of the housing body 100 located below, and forms a portion of the emission space 13. The top holder 110 configured as described above can be formed from an appropriate metal member such as stainless steel or aluminum, which has excellent strength and durability. However, the material for forming the top holder 110 is not particularly limited. Furthermore, the above-described embodiment of the shape of the top holder 110 is merely an example, and other shapes may be adopted.

[0027] [Bottom Container] Next, the bottom container 120 will be described. The bottom container 120 has a hollow, generally bottomed cylindrical shape and includes a side wall 122, a bottom wall 123 connected to the lower end of the side wall 122, and a flange 121 connected to the upper end of the side wall 122. The side wall 122 has, for example, a cylindrical shape, and the flange 121 extends outward from the upper end of the side wall 122. The flange 121 of the bottom container 120 has a generally rectangular outline that fits inside the lower cylindrical wall 104 of the housing main body 100. The flange 121 may be disposed inside the lower cylindrical wall 104 and fastened to the lower surface 102 of the housing main body 100 using screws or the like, or may be fixed by rivets or the like. Here, the bottom container 120 may be coupled to the housing body 100 with a 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 increase the airtightness of the discharge space 13 formed in the housing 10. Also, instead of or in addition to the 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 increase the airtightness of the discharge space 13.

[0028] The above-described shape of the bottom container 120 is merely an example, and other shapes may be adopted. The space formed inside the bottom container 120 is connected to the housing main body 100 located above and forms part of the discharge space 13. The bottom container 120 configured as described above may be formed from an appropriate metal member, such as stainless steel or aluminum, that has excellent strength and durability. However, the material from which the bottom container 120 is formed is not particularly limited. The bottom container 120 may also have a multi-layer structure. For example, the exterior portion of the bottom container 120 facing the outside may be formed from an appropriate metal member, such as stainless steel or aluminum, that has excellent strength and durability, and the interior portion facing the discharge space 13 may be formed from an insulating material, such as synthetic resin. Of course, the entire bottom container 120 may be formed from an insulating material.

[0029] As described above, the housing 10 in this embodiment is configured to include the housing main body 100, the top holder 110, and the bottom container 120, which are assembled together, and inside thereof is formed the discharge space 13, which extends from the first end 11 to the second end 12. This discharge space 13 accommodates the igniter 20, the projectile 40, the cut portion 53 of the conductor piece 50, the coolant material 60, etc., which will be described in detail below.

[0030] [Igniter] Next, the igniter 20 will be described. The igniter 20 is an electric igniter including 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, insulating resin. Furthermore, the tip sides of the pair of conductive pins in the igniter body 22 are exposed to the outside and are connected to a power source when the circuit breaker 1 is in use.

[0031] The igniter main body 22 includes a generally cylindrical main body portion 221 housed inside the small-diameter cylinder portion 112 of the top holder 110, and a connector portion 222 located on top of the main body portion 221. The igniter main 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. Furthermore, a constricted portion, whose outer circumferential surface is recessed compared to other portions, is formed in an annular shape along the circumferential direction of the main body portion 221 at an axially intermediate portion of the main body portion 221, 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 increase the airtightness between the inner circumferential surface of the small-diameter cylinder portion 112 and the main body portion 221.

[0032] Connector portion 222 of igniter 20 is disposed so as to protrude to the outside through opening 112A formed at the upper end of small-diameter cylinder portion 112. Connector portion 222 has, for example, a cylindrical shape that covers the side of the conductive pin, and is configured so as to be connectable to a connector on the power supply side.

[0033] As shown in FIG. 1 , the ignition unit 21 of the igniter 20 is disposed so as to face the discharge space 13 of the housing 10. The ignition unit 21 is configured, for example, as an ignition charge accommodated in an ignition cup. For example, the ignition charge is accommodated in the ignition cup of the ignition unit 21 while in contact with a bridge wire (resistor) that is connected to connect the base ends of a pair of conductive pins. Examples of the ignition charge that may be used include ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), THPP (titanium hydride potassium perchlorate), and lead tricinate.

[0034] When the igniter 20 is operated, an operating current for igniting the ignition charge is supplied from the power source to the conductive pin, causing the bridge wire in the ignition portion 21 to heat up, igniting and burning the ignition charge in the igniter cup and generating combustion gas. As the ignition charge in the igniter cup of the ignition portion 21 burns, the pressure in the igniter cup increases, causing the cleavage surface 21A of the igniter cup to cleave, and combustion gas is released from the igniter cup into the discharge space 13. More specifically, the combustion gas from the igniter cup is released into a recess 411 in a piston portion 41 (described later) of a projectile 40 disposed in the discharge space 13. This launches the projectile 40 downward along the discharge space 13 from the initial position shown in FIG. 1 .

[0035] [Coolant Material] Next, the coolant material 60 disposed in the discharge space 13 of the housing 10 will be described. Here, as shown in FIG. 1 , before activation of the interrupter 1 (igniter 20), the cut portion 53 of the conductor piece 50 is horizontally disposed across the discharge space 13 of the housing 10. Hereinafter, within the discharge space 13 of the housing 10, the region (space) where the projectile 40 is disposed across the cut portion 53 of the conductor piece 50 will be referred to as the "projectile initial placement region R1," and the region (space) located on the opposite side of the projectile 40 will be referred to as the "arc-extinguishing region R2." Note that, because a gap is formed on the side of the cut portion 53 disposed across the discharge space 13 in the depth direction (Z-axis direction), the projectile initial placement region R1 and the arc-extinguishing region R2 are not completely isolated by the cut portion 53 but are instead connected to each other. Of course, depending on the shape and size of the cut portion 53, the projectile initial placement region R1 and the arc-extinguishing region R2 may be completely isolated by the cut portion 53.

[0036] The arc-extinguishing region R2 of the discharge space 13 is a region (space) for receiving the cut portion 53 cut by the rod portion 42 of the projectile 40 launched when the circuit breaker 1 (igniter 20) is activated. A coolant material 60 is disposed in this arc-extinguishing region R2 as an arc-extinguishing material. The coolant material 60 has a generally cylindrical shape with a bottom and is disposed inside the bottom container 120 along the side wall portion 122 and the bottom wall portion 123. The coolant material 60 absorbs and cools the arc and the heat energy of the cut portion 53 that are generated when the projectile 40 cuts the cut portion 53 of the conductor piece 50, thereby suppressing arc generation during current interruption or extinguishing (extinguishing) any generated arc.

[0037] The arc-extinguishing region R2 in the circuit breaker 1 is a space for receiving the cut portion 53 that has been cut from the first connection end 51 and the second connection end 52 of the conductor piece 50 by the projectile 40, and also serves as a space for effectively extinguishing the arc that is generated when the projectile 40 cuts the cut portion 53. In order to effectively extinguish the arc that is generated when the cut portion 53 is cut from the conductor piece 50, a coolant material 60 is disposed in the arc-extinguishing region R2 as an arc-extinguishing material.

[0038] In one aspect of the embodiment, the coolant material 60 is solid. In another aspect of the embodiment, the coolant material 60 is formed from a shape-retaining material. The shape-retaining material here refers to a material that maintains a certain shape when no external force is applied and that can maintain its integrity (does not fall apart) even if it is deformed when an external force is applied. For example, a fibrous material formed into a desired shape can be used as the shape-retaining material. In this embodiment, the coolant material 60 is formed from metal fibers, which are shape-retaining materials. Here, examples of the metal fibers that form the coolant material 60 include at least one of steel wool and copper wool. However, the above-described aspects of the coolant material 60 are merely examples and are not intended to be limiting.

[0039] [Projectile] Next, the projectile 40 will be described. The projectile 40 is formed of an insulating material such as synthetic resin, and includes 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 piston portion 41 also has an outer diameter larger than the diameter of the cavity portion 145 in the housing main body 100, and is configured to not enter the cavity portion 145 but to abut against the surrounding members that form the cavity portion 145. That is, the piston portion 41 has a cross-sectional area perpendicular to the movement direction (axial direction) at the tip end connected to the rod portion 42 that is larger than the cross-sectional area at the rear end of the rod portion 42 and the cross-sectional area of ​​the cavity portion 145. The shape of the projectile 40 can be modified as appropriate depending on the shape of the housing 10, etc.

[0040] Furthermore, a recess 411 having, for example, a cylindrical shape is formed on the upper surface of the piston portion 41, and this recess 411 receives the ignition portion 21. The bottom surface of the recess 411 is formed as a pressure-receiving surface 411A that receives energy from the igniter 20 when the igniter 20 is activated. Furthermore, a constricted portion, whose outer peripheral surface is recessed compared to other portions, is formed in an annular shape along the circumferential direction of the piston portion 41 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, for example, rubber (e.g., silicone rubber) or synthetic resin, and functions to increase the airtightness between the inner peripheral surface of the large-diameter cylinder portion 113 and the piston portion 41.

[0041] The rod portion 42 of the projectile 40 is, for example, a rod-shaped member having an outer circumferential surface with a smaller diameter than the piston portion 41 and extending along the extension direction of the discharge space 13, and is integrally connected to the lower end side of the piston portion 41. When the igniter 20 is activated, the rod portion 42 moves along the extension direction of the discharge space 13 and is inserted into the cavity 145 of the housing main body 100. The lower end surface of the rod portion 42 is formed as a tip surface 420 for cutting the cut portion 53 from the conductor piece 50 when the circuit breaker 1 is activated. While the rod portion 42 in this embodiment has a generally cylindrical shape, its shape is not particularly limited and may be changed depending on the shape and size of the cut portion 53 to be cut from the conductor piece 50 when the circuit breaker 1 is activated. The rod portion 42 may have a columnar shape, such as a circular cylinder, an elliptical cylinder, or a rectangular cylinder. In addition, in the initial position of the projectile 40 shown in Figure 1, the tip side area including the tip surface 420 of the rod portion 42 of the projectile 40 is located above the cavity portion 145 (holding area) of the housing main body 100.

[0042] When the igniter 20 is activated, the upper surface of the piston portion 41, including the pressure-receiving surface 411A, receives energy from the igniter 20, causing the projectile 40 to be launched from the initial position shown in FIG. 1 and move at high speed toward the second end 12 (downward) along the discharge space 13. Specifically, as shown in FIG. 1 , the piston portion 41 of the projectile 40 is housed inside the large-diameter cylinder portion 113 of the top holder 110 and is capable of sliding axially along the inner wall surface of the large-diameter cylinder portion 113. After launch, the projectile 40 stops when the lower end surface of the piston portion 41 abuts (collides) against the upper surface 101 of the housing main body 100. That is, the rod portion 42 is fitted into the cavity 145 up to the rear end 421. In this embodiment, the piston portion 41 of the projectile 40 is generally cylindrical, but the shape is not particularly limited. The piston portion 41 may have an outer shape and size appropriate for the shape and size of the inner wall surface of the large-diameter cylinder portion 113 .

[0043] [Conductor Piece] Next, the conductor piece 50 will be described. As shown in FIG. 1 , the conductor piece 50 is held by a pair of contact portions 105A and 105B in the housing main body 100. The housing main body 100 holds the conductor piece 50 so that the contact portions 105A and 105B face and contact the leakage prevention portion 54 of the conductor piece 50. The conductor piece 50 is a conductive metal body that constitutes a part of the circuit breaker 1 and also forms part of a predetermined electric circuit when the circuit breaker 1 is attached to the electric circuit, and is sometimes called a bus bar. The conductor piece 50 and the housing main body 100 are integrally molded. The conductor piece 50 is held by the housing main body 100 and is disposed so as to cross a cavity 145 within the housing main body. In this embodiment, the region (cavity 145) defined by the inner wall of the housing main body 100 that holds the conductor piece 50 in this manner is the holding region.

[0044] The conductor piece 50 may be formed of a metal such as copper (Cu). However, the conductor piece 50 may be formed of a metal other than copper, or may be formed of an alloy of copper and another metal. Examples of metals other than copper contained in the conductor piece 50 include manganese (Mn), nickel (Ni), and platinum (Pt).

[0045] FIG. 2 illustrates a conductor piece 50 according to an embodiment. FIG. 2(A) is a plan view of the conductor piece 50, and FIG. 2(B) is a side view of the conductor piece 50. In one embodiment shown in FIG. 2, the conductor piece 50 is formed as an elongated flat piece overall, including a first connecting end 51 and a second connecting end 52 at both ends, a cut-off portion 53 located in the middle between them, and leakage prevention portions 54 formed between the first connecting end 51 and the cut-off portion 53 and between the second connecting end 52 and the cut-off portion 53. The cut-off portion 53 is generally circular, and the widths (lengths in the Z-axis direction) of the first connecting end 51 and the second connecting end 52 gradually decrease toward the cut-off portion 53. The first connecting end 51 and the second connecting end 52 of the conductor piece 50 are provided with connection holes 51A and 52A, respectively. These connection holes 51A and 52A are used to connect to other conductors (e.g., lead wires) in an electrical circuit.

[0046] The cut-off portion 53 of the conductor piece 50 is a portion that is forcibly and physically cut off by the rod portion 42 of the projectile 40 when an abnormality such as an excessive current occurs in the electric circuit to which the interrupting device 1 is applied. The cut-off portion 53 is physically cut off from the first connecting end 51 and the second connecting end 52, but the cut-off portion 53 does not have to be cut off from both the first connecting end 51 and the second connecting end 52. More specifically, the cut-off portion 53 need only be cut off from at least one of the first connecting end 51 and the second connecting end 52 to cut off the electric circuit to which the interrupting device 1 is applied; the cut-off portion 53 does not need to be completely removed from both the first connecting end 51 and the second connecting end 52. The conductor piece 50 is cut off at a position overlapping the inner surface (inner wall surface) of the inner wall 143 ( FIG. 1 ) that defines the cavity 145 of the housing main body 100, i.e., at a position overlapping the outer circumferential surface of the rod portion 42, and the cut-off portion 53 is cut off.

[0047] The leakage prevention portion 54 is a portion formed in at least a portion of the contact area of ​​the conductor piece 50 with the housing main body 100 (contact portion 105). The leakage prevention portion 54 is provided on the first connection end 51 side relative to the cut portion 53 and on the second connection end 52 side relative to the cut portion 53 in the left-right direction (X-axis direction). The leakage prevention portion 54 is also knurled to form a plurality of small diamond-shaped protrusions. As a result, when a gap is formed between the housing main body 100 (contact portion 105) and the leakage prevention portion 54 during activation of the igniter 20, the combustion gas flow path formed by the gap is formed in a so-called labyrinth shape. In this embodiment, the leakage prevention portion 54 is formed along the cut portion 53 on both the front side (the igniter 20 side of the conductor piece 50) and the back side (the opposite side of the igniter 20 of the conductor piece 50). The conductor piece 50 is integrally molded with the housing main body 100, and the leakage prevention portion 54 is embedded in the contact portion 105 of the housing main body 100. The leakage prevention portion 54 prevents the combustion gas generated by the igniter 20 from leaking from the discharge space 13 to the outside when the cut portion 53 is cut by the projectile 40. More specifically, when the combustion gas discharged from the igniter cup into the discharge space 13 enters between the contact portion 105 and the leakage prevention portion 54, the labyrinth structure creates a complex flow path for the combustion gas, preventing the combustion gas from leaking from the housing 10 to the outside. In this embodiment, the leakage prevention portion 54 having a plurality of small protrusions is embedded in the contact portion 105, increasing the contact area between the housing main body 100 and the conductor piece 50 and thereby strengthening the adhesion between the housing main body 100 and the conductor piece 50.

[0048] Here, the conductor piece 50 is not limited to the example shown in Figure 2. For example, the conductor piece 50 may have the cut portion 53 connected perpendicularly or at an angle to the first connecting end 51 and the second connecting end 52. Furthermore, the planar shape of the cut portion 53 in the conductor piece 50 is not particularly limited. Of course, the shapes of the first connecting end 51 and the second connecting end 52 in the conductor piece 50 are also not particularly limited.

[0049] The leakage prevention portion 54 is not limited to the example shown in this embodiment. For example, it may be a plurality of small recesses in the shape of a diamond, square, or parallelogram; a plurality of small protrusions or recesses in the shape of a rectangle; a plurality of small protrusions or recesses in the shape of a circle; a plurality of small protrusions or recesses in the shape of a ring; or a combination of these shapes. The leakage prevention portion 54 does not have to be formed on both the front and back sides of the plate-shaped conductor piece 50; it may be formed on either one of the surfaces. Preferably, it is formed at least on the back side of the conductor piece 50 in the direction of combustion gas release in the discharge space 13. The leakage prevention portion 54 may be formed so that at least a portion thereof contacts the contact portion 105. For example, the leakage prevention portion 54 may include the cut portion 53 and extend from the first connection end 51 to the second connection end 52, based on the cut portion 53.

[0050] <Operation> Next, a description will be given of the operation performed when the circuit breaker 1 is activated to interrupt an electric circuit. As described above, Fig. 1 shows the state before activation of the circuit breaker 1 (hereinafter also referred to as the "initial state before activation"). In this initial state before activation, the projectile 40 in the circuit breaker 1 is set to an initial position in which the piston portion 41 is positioned on the first end 11 side (upper end side) of the discharge space 13 and the tip surface 420 formed at the lower end of the rod portion 42 is positioned on the upper surface of the cut portion 53 of the conductor piece 50.

[0051] Furthermore, the circuit breaker 1 according to the embodiment further includes an abnormality detection sensor (not shown) that detects an abnormal state of a device (e.g., a vehicle, a power generation facility, or a power storage facility) connected to the electrical circuit to be interrupted, and a control unit (not shown) that controls the operation of the igniter 20. The abnormality detection sensor may be capable of detecting an abnormal state based on the voltage or temperature of the conductor piece 50 in addition to the current flowing through the conductor piece 50. The abnormality detection sensor may also be, for example, an impact sensor, a temperature sensor, an acceleration sensor, or a vibration sensor, and may detect an abnormal state such as an accident or fire based on impact, temperature, acceleration, or vibration in a device such as a vehicle. The control unit of the circuit breaker 1 is, for example, a computer that can perform a predetermined function by executing a predetermined control program. The predetermined function of the control unit can also be realized by corresponding hardware. When an excessive current flows through the conductor piece 50, which forms part of the electrical circuit to which the circuit breaker 1 is applied, the abnormal current is detected by the abnormality detection sensor. Abnormality information regarding the detected abnormal current is passed from the abnormality detection sensor to the control unit. For example, the control unit receives current from an external power source (not shown) connected to the conductive pin of the igniter 20 based on the current value detected by the abnormality detection sensor, and activates the igniter 20. Here, the abnormal current may be a current value that exceeds a predetermined threshold value set to protect a predetermined electric circuit. Note that the above-mentioned abnormality detection sensor and control unit do not need to be included as components of the circuit breaker 1, and may be included in, for example, a device separate from the circuit breaker 1. Furthermore, the above-mentioned abnormality detection sensor and control unit are not essential components of the circuit breaker 1.

[0052] For example, when an abnormal current in the electric circuit is detected by an abnormality detection sensor that detects abnormal current in the electric circuit, the control unit of the circuit breaker 1 activates the igniter 20. That is, as a result of an operating current being supplied from an external power source (not shown) to the conductive pin of the igniter 20, the ignition charge in the ignition portion 21 is ignited and burned, and combustion gas is generated. Then, due to a pressure increase in the ignition portion 21, the cleavage surface 21A cleaves, and the combustion gas of the ignition charge is released from the ignition portion 21 into the release space 13.

[0053] Here, the ignition portion 21 of the igniter 20 is received in the recessed portion 411 in the piston portion 41, and the cleavage surface 21A of the ignition portion 21 is disposed opposite the pressure-receiving surface 411A of the recessed portion 411 in the projectile 40. Therefore, the combustion gas from the ignition portion 21 is released into the recessed portion 411, and the pressure of the combustion gas (combustion energy) is transmitted to the upper surface of the piston portion 41, including the pressure-receiving surface 411A. As a result, the projectile 40 moves downward through the discharge space 13 along the extension direction (axial direction) of the discharge space 13.

[0054] FIG. 3 illustrates the operation of the circuit breaker 1 according to the embodiment. (A) in the upper part of FIG. 3 shows the circuit breaker 1 during operation, while (B) in the lower part of FIG. 3 shows the circuit breaker 1 after completion of operation. As described above, when the igniter 20 is activated, the projectile 40 is subjected to the pressure (combustion energy) of the combustion gases from the ignition charge, and is forced downward with great force. As a result, the leading end surface 420 formed on the lower end of the rod portion 42 shears and cuts the boundaries between the first connecting end 51 and the second connecting end 52 and the cut portion 53 of the conductor piece 50. At this time, as indicated by the dashed arrows, the projectile 40 and the lower portion of the housing main body 100 generate a bending moment in the conductor piece 50. Note that as the clearance between the projectile 40 and the housing main body 100 increases, the distortion of the conductor piece 50 increases. The shape and dimensions of the projectile 40 can be freely determined as long as it can move smoothly along the extension direction (axial direction) of the discharge space 13 when the igniter 20 is activated. For example, the outer diameter of the piston portion 41 in the projectile 40 may be set to a dimension equal to the inner diameter of the large diameter cylinder portion 113 in the top holder 110.

[0055] 3, the projectile 40 moves downward a predetermined stroke in the extension direction (axial direction) of the discharge space 13 until the lower end surface of the piston portion 41 abuts (collides) against the upper surface 101 of the housing body 100. In this state, the cut portion 53, which has been physically cut from at least one of the first connection end 51 and the second connection end 52 by the rod portion 42 of the projectile 40, is received in the arc-extinguishing region R2 in which the coolant material 60 is disposed. As a result, at least a portion of the first connection end 51 or the second connection end 52 located at both ends of the conductor piece 50 becomes electrically disconnected, and the predetermined electric circuit to which the circuit breaking device 1 is applied is forcibly interrupted.

[0056] In this embodiment, the cut portion 53 is cut from the conductor piece 50 when the cut portion 53 receives the energy of the combustion gas through the projectile 40, but the manner in which the cut portion 53 is cut is not limited to this, and for example, the cut portion 53 may be cut from the conductor piece 50 when the cut portion 53 directly receives the pressure of the combustion gas released from the igniter 20 into the release space 13.

[0057] <Actions and Effects> The shutoff device 1 in this embodiment includes an igniter 20 that contains a discharge space 13 extending in one direction and is provided in the housing main body 100 and that discharges combustion gas into the discharge space 13 when activated, and a conductor piece 50 that is provided in the housing main body 100 and forms part of an electric circuit, a part of which has a cuttable portion 53 that is cut by the energy of the combustion gas discharged into the discharge space 13, and the conductor piece 50 is arranged so that the cuttable portion 53 crosses the discharge space 13, and at least a part of the contact area of ​​the conductor piece 50 with the housing main body 100 (contact portion 105) is formed with a leakage prevention portion 54 that has a plurality of small protrusions or a plurality of small recesses arranged so as to prevent the combustion gas discharged into the discharge space 13 from leaking out of the housing 10 from between the housing main body 100 and the contact area. As a result, since multiple small protrusions (or small recesses) are formed in the leakage prevention portion 54, it is expected that the adhesion between the housing main body 100 and the conductor piece 50 will be improved, thereby preventing gas from leaking from the housing 10.

[0058] Furthermore, in the cutoff device 1 of this embodiment, when a gap is formed between the housing main body 100 (contact portion 105) and the leakage prevention portion 54 during operation of the igniter 20, the flow path of the combustion gas formed by the gap is formed in a labyrinth shape. As a result, when the combustion gas enters between the leakage prevention portion 54 and the contact portion 105, the flow path of the combustion gas becomes complex, preventing the combustion gas from leaking from the housing 10.

[0059] Furthermore, in the circuit breaker 1 of this embodiment, a leakage prevention portion 54 may be formed on at least one of the surfaces on both sides of the conductor piece 50 in the direction of combustion gas emission, the surface opposite the igniter 20 (the back side). When the circuit breaker 1 is in operation, the pressure of the combustion gas increases in a direction along the emission direction of the combustion gas emitted from the igniter 20. More specifically, the combustion gas emitted from the igniter 20 advances toward the lower surface 102 of the housing body 100, and the pressure of the combustion gas is applied below the emission space 13. At this time, the combustion gas tends to flow around to the back side of the conductor piece 50, so by forming the leakage prevention portion 54 on the back side of the conductor piece 50, leakage of the combustion gas is effectively prevented.

[0060] Furthermore, in the circuit breaker 1 of this embodiment, the leakage prevention portions 54 are formed on both sides of the conductor piece 50. This more reliably prevents combustion gas leakage not only when the combustion gas gets around to the back side of the conductor piece 50 as described above, but also immediately after the operation of the circuit breaker 1, when there is a possibility that combustion gas will leak from the housing 10 on the front side of the conductor piece 50 (the igniter 20 side of the conductor piece 50).

[0061] Furthermore, in the cutoff device 1 of this embodiment, the entire leakage prevention portion 54 is covered by the housing main body 100 (contact portion 105). As a result, when a gap is formed between the housing main body 100 (contact portion 105) and the leakage prevention portion 54 during activation of the igniter 20, the entire leakage prevention portion 54 becomes a labyrinth-shaped flow path for the combustion gas, and therefore, the effect of forming the flow path for the combustion gas in a complex shape can be more effectively exhibited.

[0062] Furthermore, in the circuit breaker 1 of this embodiment, the leakage prevention portion 54 has a plurality of small diamond-shaped protrusions formed in a crisscross pattern. In other words, the leakage prevention portion 54 is knurled in a crisscross pattern. This makes it possible to more effectively achieve the effects of improving the adhesion between the housing body 100 and the conductor pieces 50 and the effects of forming a complex shape for the combustion gas flow path.

[0063] Furthermore, in the circuit breaker 1 of this embodiment, the leakage prevention portion 54 is embedded in the housing body 100 (contact portion 105), which improves the adhesion between the housing body 100 and the conductor piece 50.

[0064] In the circuit breaking device 1 of this embodiment, the housing body 100 and the conductor pieces 50 may be integrally formed. This can further improve the adhesion between the housing body 100 and the conductor pieces 50.

[0065] <Modifications of the embodiment> Figures 4 to 6 are diagrams illustrating modifications 1 to 3 of the embodiment. Figure 4 is a diagram illustrating a conductor piece 50a according to modification 1 of the embodiment, Figure 5 is a diagram illustrating a conductor piece 50b according to modification 2 of the embodiment, and Figure 6 is a diagram illustrating a conductor piece 50c according to modification 3 of the embodiment. Below, the conductor pieces 50a to 50c according to the modifications of the embodiment will be described using Figures 4 to 6. Note that the description of the modifications will focus on differences from the conductor piece 50 described using Figures 1 to 3. Furthermore, among the elements constituting the conductor pieces 50a to 50c, elements common to the conductor piece 50 will be assigned the same reference numerals and will not be described in detail.

[0066] As in the conductor piece 50a according to Modification 1 of FIG. 4, a plurality of small round convex portions may be formed on the leakage prevention portion 54a provided on the front and back sides of the conductor piece 50a. Also, as in the conductor piece 50b according to Modification 2 of FIG. 5, a plurality of small round concave portions may be formed on the leakage prevention portion 54b provided on the front and back sides of the conductor piece 50b. Also, as in the conductor piece 50c according to Modification 3 of FIG. 6, a plurality of small annular concave portions may be formed on the leakage prevention portion 54c provided on the front and back sides of the conductor piece 50c. Modifications 1 to 3 can more effectively achieve the effects of improving the adhesion between the housing main body 100 and the conductor pieces 50a, 50b, and 50c and the effects of providing a complex combustion gas flow path.

[0067] Each feature disclosed herein may be combined with any other feature disclosed herein.

[0068] 1: Shut-off device 10: Housing 13: Discharge space 20: Igniter 40: Projectile 50: Conductor piece 51: First connecting end 52: Second connecting end 53: Cutting portion 54: Leak prevention portion 60: Coolant material

Claims

1. An electrical circuit interruption device comprising: a housing containing a discharge space extending in one direction; an igniter provided in said housing and operable to discharge combustion gas into said discharge space; and a conductor piece provided in said housing and forming part of an electrical circuit, the conductor piece having a cuttable portion on part of the conductor piece that is cut by the energy of the combustion gas discharged into said discharge space, the cuttable portion being arranged so as to cross said discharge space, wherein at least part of the contact area of said conductor piece with said housing is formed with a leakage prevention portion having a plurality of small protrusions or a plurality of small recesses arranged so as to prevent the combustion gas discharged into the discharge space from leaking out of the housing from between the housing and the contact area.

2. An electrical circuit interrupter as described in claim 1, wherein the leakage prevention portion is configured so that when a gap is formed between the housing and the leakage prevention portion when the igniter is activated, the flow path of the combustion gas formed by the gap becomes labyrinth-shaped.

3. An electrical circuit breaker as claimed in claim 1 or 2, wherein the leakage prevention portion is formed on at least one of the two surfaces of the conductor piece in the direction of release of the combustion gas, the surface opposite the igniter.

4. An electrical circuit breaker according to claim 1 or 2, wherein the leakage prevention portion is formed on both sides of the conductor piece.

5. An electric circuit breaker according to claim 1 or 2, wherein the entirety of the leakage prevention portion is covered by the housing.

6. An electrical circuit breaker according to claim 1 or 2, wherein the leakage prevention portion has a plurality of diamond-shaped small protrusions formed in a checkerboard pattern.

7. An electrical circuit breaker according to claim 1 or 2, wherein the leakage prevention portion has a plurality of annular small recesses.

8. The electrical circuit breaker according to claim 1 or 2, wherein the leakage prevention portion is embedded in the housing.

9. An electrical circuit interrupting device according to claim 1 or 2, wherein the housing and the conductor piece are integrally formed.

Images