Electrical circuit breaker

Abstract

To provide an electric circuit breaker device capable of suppressing occurrence of gas leakage after actuation.SOLUTION: An electric circuit breaker device comprises: a housing that includes an accommodation space extending in one direction therein as an outer shell member; an igniter provided on the housing; a projectile arranged in the housing and that moves in an extending direction of the accommodation space by being released from one end side of the accommodation space by an energy received from the igniter; and a conductor piece held by the housing to form a part of an electric circuit and that has a to-be-cut-off part that is cut off by the movement of the projectile between a first connection end part provided at one end and a second connection end part provided at the other end, the to-be-cut-off part being arranged so as to go across the accommodation space. Of the accommodation space, a region demarcated by an inner wall of the housing holding the conductor piece is defined as a holding region. The housing has a housing main body that includes the holding region therein. The main body has: an inside molding part arranged so as to face the holding region; and an outside molding part molded separately from the inside molding part and arranged at an outer peripheral side of the inside molding part.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 to urgently cut off conduction in the electric circuit when an abnormality occurs in the devices constituting the electric circuit or when an abnormality occurs in the system on which the electric circuit is mounted. 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 to forcibly and physically cut a conductor piece forming a part of the electric circuit (see, for example, Patent Document 1). In recent years, the importance of an electric circuit breaker applied to an electric vehicle equipped with a high-voltage power source has been increasing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] An electric circuit breaker may combine a resin housing and a metal holder for weight reduction and miniaturization. In this case, in the electric circuit breaker, the projectile launched during operation stops by hitting a part of the resin housing after cutting the conductor piece, but there is a possibility that the resin housing cracks during operation, causing the gas evaporated by the arc discharge during cutting to leak. Therefore, it is desirable to suppress the occurrence of gas leakage.

[0005] The technology disclosed herein has been developed in view of the circumstances described above, and its purpose is to provide an electrical circuit breaker that suppresses the occurrence of gas leakage after cutting. [Means for solving the problem]

[0006] To solve the above problems, the electrical circuit breaker of this disclosure is As an outer shell component, it includes a housing that contains a dwelling space extending in one direction, An igniter provided in the housing, A projectile is disposed within the housing, is launched from one end of the containment space by energy received from the igniter, and moves along the extending direction of the containment space; A conductive piece held in the housing and forming part of an electrical circuit, having a portion to be cut off by the movement of the projectile between one first connection end and the other second connection end, and the conductive piece is arranged such that the portion to be cut off crosses the housing space, Equipped with, Of the aforementioned containment space, the area defined by the inner wall of the housing that holds the conductor piece is defined as the holding area. The housing comprises a housing body that encloses the holding area, The housing body has an inner molded portion that is positioned facing the holding area, and an outer molded portion that is molded separately from the inner molded portion and positioned on the outer circumference side of the inner molded portion. It will be used as an electrical circuit breaker. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide an electrical circuit breaker that suppresses the occurrence of gas leakage after operation. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram illustrating the internal structure of an electrical circuit breaker 1 according to an embodiment. [Figure 2] Figure 2 is an example of a top view of the housing body 100. [Figure 3] Figure 3 is a top view of the conductor piece 50. [Figure 4] Figure 4 is a front view of the projectile 40. [Figure 5] Figure 5 is a bottom view of the projectile 40. [Figure 6] Figure 6 is a perspective view of the projectile 40. [Figure 7] Figure 7 is a diagram illustrating the operation of the circuit breaker 1 according to this embodiment. [Modes for carrying out the invention]

[0009] <First Embodiment> 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, 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.

[0010] <Structure> Figure 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 an electrical circuit included in, for example, an automobile, a household electrical appliance, a solar power generation system, or a system including the battery (e.g., a lithium-ion battery) of said electrical circuit. In this specification, the cross section along the height direction shown in Figure 1 (the direction in which the accommodation space 13, described later, extends) is referred to as the longitudinal cross section of the interruption device 1, and the cross section in the direction perpendicular to the height direction is referred to as the transverse cross section of the interruption device 1. Figure 1 shows the state of the interruption device 1 before operation.

[0011] The cutoff device 1 includes a housing 10, an igniter 20, a projectile 40, a conductor piece 50, a coolant material 60, etc. The housing 10, as an outer shell member, encloses a housing space 13 that extends 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 housing space 13 is a linearly formed space in which the projectile 40 can move and extends along the vertical direction of the cutoff device 1. As shown in FIG. 1, the projectile 40 is accommodated on the upper end side in the vertical direction (extending direction) of the housing space 13 formed inside the housing 10. In this specification, the vertical direction is also referred to as the Y-axis direction, the horizontal direction is referred to as the X-axis direction, and the depth direction is referred to as the Z direction. However, in this specification, the vertical direction and the XYZ directions of the cutoff device 1 merely indicate the relative positional relationship of each element in the cutoff device 1 for the convenience of explaining the embodiment. For example, the posture when installing the cutoff device 1 is not limited to the direction shown in the figure.

[0012] [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 an integral housing 10.

[0013] The housing body 100 has, for example, an approximately prismatic outer shape. However, the shape of the housing body 100 is not particularly limited. Further, the housing body 100 is formed such that a cavity 145 penetrates along the vertical direction, and this cavity 145 is the housing space 13 It forms part of the void 145. The housing body 100 has an inner molded portion 131 that contacts the cavity 145 and an outer molded portion 132 that contacts the outer circumference of the inner molded portion 131 and does not contact the cavity 145. The outer molded portion 132 is positioned on the outer circumference of the inner molded portion 131. The inner molded portion 131 and the outer molded portion 132 are integrated. The housing body 100 also 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. The upper surface 101 extends over the inner molded portion 131 and the outer molded portion 132. The lower surface 102 extends over the inner molded portion 131 and the outer molded portion 132. In this embodiment, a cylindrical upper wall 103 is erected on the outer circumference of the upper surface 101 of the housing body 100, extending upward from the upper surface 101. In this embodiment, the upper cylindrical wall 103 has, for example, a rectangular cylindrical shape, but it may have other shapes. Also, a cylindrical lower cylindrical wall 104 is vertically attached to the outer circumference of the lower surface 102 of the housing body 100, extending downward from the lower surface 102. In this embodiment, the lower cylindrical wall 104 has, for example, a rectangular cylindrical shape, but it may have other shapes. The upper cylindrical wall 103 and the lower cylindrical wall 104 are located in the outer molded portion 132.

[0014] The inner molded portion 131 and outer molded portion 132 of the housing body 100, as configured above, can be formed from an insulating material such as synthetic resin. The materials for the inner molded portion 131 and the outer molded portion 132 may be different or the same. The inner molded portion 131 and the outer molded portion 132 are molded separately (two-stage molding), regardless of whether they are made of different or the same material. By molding them separately, even if a crack occurs in the inner molded portion 131 due to impact or the like, the occurrence of a crack in the outer molded portion 132 is suppressed. In other words, a crack that occurs in the inner molded portion 131 can be contained within the inner molded portion 131. Two-stage molding is performed, for example, by molding the inner molded portion 131 with the material for the inner molded portion 131 in a first mold, then setting the inner molded portion 131 in a second mold, and molding the outer molded portion 132 with the material for the outer molded portion 132. Furthermore, the two-stage molding may involve molding the outer molded part 132 with a first material and then molding the inner molded part 131 with a second material using a single mold. The two-stage molding may also be performed by other methods. The first material and the second material may be the same or different. For example, the housing body 100 may be formed from nylon, which is a type of polyamide synthetic resin. The inner molded part 131 may be molded from, for example, polycarbonate. The outer molded part 132 may be molded from, for example, polycarbonate, polyamide, ABS resin, etc. It is preferable that the outer molded part 132 has a higher heat resistance temperature than the inner molded part 131. It is also preferable that the inner molded part 131 has higher impact resistance than the outer molded part 132. Impact resistance is durability against impacts received from the outside. Impact resistance is evaluated, for example, by the impact value based on a predetermined impact test. Alternatively, the inner molded portion 131 may be divided into an upper molded portion located above (towards the top holder 110 and the igniter 20) and a lower molded portion located below (towards the bottom container 120 and the destination of the projectile 40), and molded separately. By forming the upper and lower molded portions separately, for example, it is possible to suppress the propagation of cracks that occur in the upper part (upper molded portion) of the inner molded portion 131 to the lower part (lower molded portion) of the inner molded portion 131.Further, the outer molding portion 132 may be divided into an upper molding portion disposed above and a lower molding portion disposed below and molded separately. That is, the housing body 100 may be molded three or more times. By molding the housing body 100 multiple times, the generation of voids can be suppressed. The interface between the inner molding portion 131 and the outer molding portion 132 (resin interface) may be welded. Also, the interface between the inner molding portion 131 and the outer molding portion 132 (resin interface) may be sealed with a sheet-like gasket.

[0015] Figure 2 is an example of a top view of the housing body 100. The housing body 100 has a substantially rectangular outer shape in plan view, and a cavity portion 145 is provided at the center thereof. This cavity portion 145 forms part of the accommodation space 13 when the housing body 100 is combined with other members forming the housing 10. An inner molding portion 131 is provided around the cavity portion 145, and an outer molding portion 132 is provided around the inner molding portion 131. On the left and right sides of the cavity portion 145, conductor piece holding holes 105A and 105B, which are holes for passing the conductor piece 50 and penetrate the inner molding portion 131 and the outer molding portion 132, are provided. By passing the conductor piece 50 through the conductor piece holding holes 105A and 105B, the conductor piece 50 is disposed so as to cross the cavity portion 145 (accommodation space 13). Bolt through holes 133 penetrating in the vertical direction are provided at the four corners of the housing body 100. At the outer edge portion of the upper surface of the housing body 100, a rectangular tube-shaped upper tube wall 103 is erected upward from the upper surface.

[0016] [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 composed of 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 connecting portion 114 connecting them, 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 that is slightly larger than the small-diameter cylinder portion 112.

[0017] 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 is provided with bolt holes (not shown) that pass through in the vertical direction for fastening bolts.

[0018] The cavity formed inside the small-diameter cylinder portion 112 of the top holder 110 functions as a housing space for accommodating 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 part of the housing space 13. The top holder 110, configured as described above, can be made from a suitable metal material 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. Also, the above-described shape of the top holder 110 is merely an example, and other shapes may be adopted.

[0019] [Bottom container] Next, the bottom container 120 will be described. The bottom container 120 has a roughly 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 roughly rectangular shape that fits inside the lower cylindrical wall 104 of the housing body 100. The flange portion 121 is provided with bolt holes (not shown) that penetrate vertically for fastening bolts.

[0020] 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 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... This may be formed by an insulating material.

[0021] As described above, the housing 10 in this embodiment is constructed by integrally assembling a housing body 100, a top holder 110, and a bottom container 120 in the vertical direction. During this assembly process, a conductor piece 50 is placed through the inside of the housing body 100. For example, the conductor piece 50 is passed through the conductor piece holding holes 105A and 105B of the housing body 100, and the conductor piece is positioned so as to cross the cavity 145. In this state, the flange portion 111 of the top holder 110 is fitted inside the upper cylindrical wall 103 of the housing body 100 to position the top holder 110 on the housing body 100, and the flange portion 121 of the bottom container 120 is fitted inside the lower cylindrical wall 104 of the housing body 100 to position the bottom container 120 below the housing body 100. Then, bolts are passed through the bolt holes in the top holder 110, the housing body 100, and the bottom container 120 to fasten the parts together. Note that this fastening is not limited to bolts; other fastening means such as rivets may also be used.

[0022] Furthermore, the parts may be joined with sealant applied between the top holder 110 and the housing body 100, between the housing body 100 and the conductor piece 50, and between the housing body 100 and the bottom container 120. This increases the airtightness of the cylindrical containment space 13 formed inside the housing 10. Alternatively, the airtightness of the containment space 13 may be increased by interposing packing or gaskets between the parts instead of sealant, or in combination with sealant. The containment space 13 houses the igniter 20, projectile 40, the cut-off portion 53 of the conductor piece 50, and the coolant material 60, which will be described in detail below.

[0023] [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.

[0024] 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 221. The igniter body 22 is fixed to the small-diameter cylinder portion 112, for example, by press-fitting the main body 221 into the inner circumferential surface of the small-diameter cylinder portion 112. In addition, a constricted portion, which is recessed on the outer circumferential surface of the main body 221, is formed in an annular shape along the circumferential direction of the main body 221 in the axial middle portion, 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 portion 112 and the main body 221.

[0025] 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.

[0026] 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 portion 113). The ignition unit 21 is configured, for example, to house the igniter charge in an igniter cup. For example, the igniter charge 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. Yes. As an ignition agent, for example, ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), THPP (titanium hydride potassium perchlorate), lead tricinate, etc. may be used.

[0027] 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 part 41 of the projectile 40, which will be described later, located in the containment space 13. As a result, the projectile 40 is launched downward along the containment space 13 from its initial position in Figure 1.

[0028] [Conducting piece] Next, the conductor piece 50 will be described. Figure 3 is a top view of the conductor piece 50. 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 a bus bar. It is sometimes referred to as a conductor. The conductor piece 50 is held by the housing body 100 and is positioned to cross the cavity 145 inside the housing body. In this embodiment, the region (cavity 145) defined by the inner wall of the housing body 100 that holds the conductor piece 50 in this way is used as the holding region.

[0029] The conductive piece 50 can be formed from a metal such as copper (Cu). However, the conductive piece 50 may be formed from a metal other than copper, or from 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), and platinum (Pt).

[0030] In one embodiment shown in Figure 3, 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 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 rod portion 42 of the projectile 40 and cut off from the first connection ends 51 and second connection ends 52 when an abnormality such as an overcurrent occurs in the electrical circuit to which the circuit breaker 1 is applied. Notches (slits) 54 are formed at both ends of the cut-off portion 53 of the conductor piece 50 to facilitate cutting and removal of the cut-off portion 53.

[0031] The conductor piece 50 is cut at a position where it overlaps with the inner surface (inner wall surface) of the inner wall that defines the cavity 145 of the housing body 100, that is, at a position where it overlaps with the outer surface of the rod portion 42, and the portion to be cut off 53 is severed.

[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 form the same plane, but this is not limited to this. For example, the cut-off portion 53 of the conductor piece 50 may be connected to the first connecting end 51 and the second connecting end 52 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 notch 54 on the conductor piece 50 can be omitted as appropriate.

[0033] [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 40 is positioned will be called the "initial projectile placement area R1," and the area (space) located on the opposite side of the projectile 40 will be called the "arc extinguishing area R2." Note that, as described above, a gap is formed on the side of the portion to be cut off 53 which is positioned across the housing space 13, so the initial projectile placement area R1 and the arc extinguishing area R2 are not completely isolated by the portion to be cut off 53, but are in communication with each other. 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.

[0034] The arc extinguishing region R2 of the containment space 13 is a region (space) for receiving the cut portion 53 that is cut off by the rod portion 42 of the projectile 40 fired when the shutoff 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 absorbs the heat energy of the arc and the cut portion 53 generated when the projectile 40 cuts off the cut portion 53 of the conductor piece 50, thereby suppressing arc generation when the current is interrupted, or extinguishing (eliminating) the generated arc.

[0035] The arc extinguishing region R2 in the shutoff device 1 is a space for receiving the cut-off portion 53 that has been cut off from the first connecting end 51 and the second connecting end 52 of the conductor piece 50 by the projectile 40, and at the same time, it has significance as a space for effectively extinguishing the arc generated when the projectile 40 cuts off the cut-off portion 53. In order to effectively extinguish the arc generated when the cut-off portion 53 is cut off from the conductor piece 50, a coolant material 60 is placed in the arc extinguishing region R2 as an arc extinguishing material.

[0036] In one embodiment, the coolant material 60 is solid. In another embodiment, the coolant material 60 is formed from a shape-retaining material. A shape-retaining material, as used here, is a material that maintains a constant shape when no external force is applied, and can maintain its integrity (not fall apart) even if deformation occurs when an external force is applied. For example, a fibrous material formed into a desired shape can be exemplified as a shape-retaining material. In this embodiment, the coolant material 60 is formed from metal fibers that are shape-retaining materials. Here, the metal fibers forming the coolant material 60 may 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 to these.

[0037] The coolant material 60 is, for example, formed into a roughly disc shape and placed at the bottom of the bottom container 120.

[0038] [Projectile] Next, the projectile 40 will be described. Figure 4 is a front view of the projectile 40, Figure 5 is a bottom view of the projectile 40, and Figure 6 is a perspective view of the projectile 40. In Figure 6, the bottom surface of the projectile 40 is shown facing upwards in order to show the bottom surface of the projectile 40. 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 shape of the projectile 40 can be appropriately changed according to the shape of the housing 10, etc. Furthermore, the piston portion 41 has an outer diameter larger than the diameter of the cavity 145 in the housing body 100, and is configured not to enter the cavity 145, but to abut against the surrounding members that form the cavity 145. That is, the piston portion 41 has a cross-sectional area perpendicular to the direction of movement (axial direction) at the tip side connected to the rod portion 42 that is larger than the cross-sectional area at the rear end side of the rod portion 42 and the cross-sectional area of ​​the cavity 145. The shape of the projectile 40 can be appropriately changed according to the shape of the housing 10, etc.

[0039] Furthermore, a cylindrical recess 411 is formed on the upper surface of the piston portion 41, and the ignition unit 21 is received in this recess 411. The bottom surface of the recess 411 is formed as a pressure receiving surface 411A that receives energy from the ignition unit 20 when the ignition unit 20 is in operation. In addition, a constricted portion, which is recessed on the outer circumference of the piston portion 41, is formed in an annular shape along the circumferential direction of the piston portion 41 in the axial middle portion, 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.

[0040] The rod portion 42 of the projectile 40 is, for example, a rod-shaped member having a smaller outer diameter than the piston portion 41 and extending along the extending direction of the housing space 13, and is integrally connected to the lower end side of the piston portion 41. When the igniter 20 is operated, the rod portion 42 moves along the extending direction of the housing space 13 and is inserted into the cavity portion 145 of the housing body 100. The lower end surface of the rod portion 42 is formed as a cutting surface 420 for cutting off the portion to be cut off 53 from the conductor piece 50 when the shut-off device 1 is operated. In this embodiment, the rod portion 42 has a generally cylindrical shape, but its shape is not particularly limited and can be changed according to the shape and size of the portion to be cut off 53 from the conductor piece 50 when the shut-off device 1 is operated. The rod portion 42 may have a columnar shape such as a cylinder, elliptical column, or rectangular prism. In the initial position of the projectile 40 shown in Figure 1, the tip-side region of the rod portion 42 of the projectile 40, including the cut surface 420, is located above the cavity (holding area) 145 of the housing body 100.

[0041] As described above, the projectile 40 is launched from the initial position shown in Figure 1 when the igniter 20 is activated, as the upper surface of the piston portion 41, including the pressure receiving surface 411A, receives energy from the igniter 20 and moves at high speed along the housing space 13 toward the second end 12 side (downward). Specifically, as shown in Figure 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 slidable in the axial direction 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 comes into contact with (collides with) the upper surface 101 of the housing body 100. That is, the rod portion 42 is fitted into the cavity portion 145 up to its rear end 421. In this embodiment, the piston portion 41 of the projectile 40 is generally cylindrical in shape, but its shape is not particularly limited. The external shape of the piston portion 41 can be appropriately shaped and sized according to the shape and size of the inner wall surface of the large-diameter cylinder portion 113.

[0042] <Operation> Next, the operation of the circuit breaker 1 to interrupt the electrical circuit will be explained. As described above, Figure 1 shows the state of the circuit breaker 1 before operation (hereinafter also referred to as the "initial pre-operation state"). In this initial pre-operation state, the projectile 40 of the circuit breaker 1 is set in an initial position in which the piston portion 41 is positioned on the first end 11 side (upper end side) of the housing space 13, and the cut 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.

[0043] Furthermore, the circuit breaker 1 according to this embodiment is connected to a device (vehicle, power generation) to which the electrical circuit to be interrupted is connected. The circuit breaker 1 further includes an abnormality detection sensor (not shown) for detecting abnormal conditions in equipment (such as equipment and energy storage equipment), and a control unit (not shown) for controlling the operation of the igniter 20. The abnormality detection sensor may also detect abnormal conditions based on 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 abnormal conditions such as accidents or fires based on impact, temperature, acceleration, or vibration in equipment such as vehicles. The control unit of the circuit breaker 1 is, for example, a computer that can perform predetermined functions by executing a predetermined control program. 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, the control unit receives power from an external power supply (not shown) connected to the conductive pins of the igniter 20 based on the current value detected by the abnormality detection sensor 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 given electrical circuit. Note that the abnormal detection sensor and control unit described above do not necessarily have to be included as components of the circuit breaker 1; for example, they may be included in a separate device. Furthermore, the abnormal detection sensor and control unit are not essential components of the circuit breaker 1.

[0044] 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.

[0045] Here, the ignition unit 21 of the igniter 20 is received in the recess 411 of the piston unit 41, and the splitting surface 21A of the ignition unit 21 is positioned opposite the pressure-receiving surface 411A of the recess 411 in the projectile 40. As a result, the combustion gas from the ignition unit 21 is released into the recess 411, 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. Consequently, the projectile 40 moves downward in the containment space 13 along the extending direction (axial direction) of the containment space 13.

[0046] Figure 7 is a diagram illustrating the operation of the shut-off device 1 according to the embodiment. The upper part of Figure 7 shows the state of the shut-off device 1 during operation, and the lower part of Figure 7 shows the state of the shut-off device 1 after operation is complete. As described above, when the igniter 20 is activated, the projectile 40, which is subjected to the pressure (combustion energy) of the combustion gas of the igniter, is forcefully pushed downward, and as a result, the cutting surface 420 formed on the lower end side of the rod portion 42 cuts through the boundaries between the first connecting end 51 and the second connecting end 52 of the conductor piece 50 and the portion to be cut 53 by shearing. As a result, the portion to be cut 53 is cut off from the conductor piece 50. The shape and dimensions of the projectile 40 can be freely determined as long as it can move smoothly along the extending direction (axial direction) of the housing space 13 when the igniter 20 is activated. For example, the outer diameter of the piston portion 41 of the projectile 40 may be set to be equal to the inner diameter of the large diameter cylinder portion 113 of the top holder 110.

[0047] Then, as shown in the lower part of Figure 7, the projectile 40 moves downward along the extending direction (axial direction) of the housing space 13 by a predetermined stroke until the lower end surface of the piston portion 41 contacts (collides with) the upper surface 101 of the housing body 100. In this state, the cut portion 53 of the projectile 40, which has been cut off from the conductor piece 50 by the rod portion 42, is received within the arc extinguishing region R2 where the coolant material 60 is located. As a result, the first connecting end 51 and the second connecting end 52 located at both ends of the conductor piece 50 become electrically closed, and the shutoff device 1 is applied. The predetermined electrical circuit is forcibly shut off. When the portion to be cut off 53 is cut off from the conductor piece 50 by the rod portion 42, an arc is likely to occur between the portion to be cut off 53 being separated and the first connecting end 51 and the second connecting end 52. However, even if an arc occurs, the coolant material 60 quickly extinguishes the arc by absorbing the thermal energy of the arc and the portion to be cut off 53, thereby suppressing the effects of the arc. Furthermore, when the projectile 40 moves due to the operation of the igniter 20 and cuts off the portion to be cut off 53, the piston portion 41 moves within the large-diameter cylinder portion 113, pushing the gas on the projectile initial positioning area R1 side, along with the particles of the conductor piece 50 that have been vaporized by the arc heat, towards the arc extinguishing area R2 side, thereby guiding the arc towards the arc extinguishing area R2 side and allowing it to be extinguished by the coolant material 60, etc.

[0048] <Effects and Effects of the Embodiment> The shut-off device 1 in this embodiment has a housing body 100 having an inner molded portion 131 that is in contact with the cavity 145, and an outer molded portion 132 outside the inner molded portion 131. Because the housing body 100 has an inner molded portion 131 and an outer molded portion 132 that are molded separately, even if a crack occurs in the inner molded portion 131 when subjected to impact by piston operation, it is possible to suppress the occurrence of such a crack in the outer molded portion 132. By preventing a crack from occurring in the outer molded portion 132, it is possible to suppress the leakage of internal gas to the outside.

[0049] 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]

[0050] 1: Circuit breaker 10: Housing 13: Containment Space 20:Igniter 40: Projectile 42: Rod section 50: Conductor piece 53: Part to be excised 60: Coolant material 100: Housing body 110: Top holder 120: Bottom container 131:Inner molding part 132:Outer molding part 145: Cavity (holding area)

Claims

1. As an outer shell component, it includes a housing that contains a dwelling space extending in one direction, An igniter provided in the housing, A projectile is disposed within the housing, is launched from one end of the containment space by energy received from the igniter, and moves along the extending direction of the containment space; A conductive piece held in the housing and forming part of an electrical circuit, having a portion to be cut off by the movement of the projectile between one first connection end and the other second connection end, and the conductive piece is arranged such that the portion to be cut off crosses the housing space, Equipped with, Of the aforementioned containment space, the area defined by the inner wall of the housing that holds the conductor piece is defined as the holding area. The housing comprises a housing body that encloses the holding area, The housing body has an inner molded portion made of resin that is positioned facing the holding area, and an outer molded portion made of resin that is molded separately from the inner molded portion and positioned on the outer circumference side of the inner molded portion. The resin interface between the inner molded portion and the outer molded portion is sealed by a sheet-like gasket. The inner molded portion has an upper molded portion located on the igniter side, and a lower molded portion which is molded separately from the upper molded portion and located on the destination side of the projectile. Electrical circuit breaker.

2. The material of the inner molded portion and the material of the outer molded portion are the same. The electrical circuit breaker according to claim 1.

3. The material of the inner molded part and the material of the outer molded part are different materials. The electrical circuit breaker according to claim 1.

4. The material of the outer molded portion is a material with a higher heat resistance temperature than the material of the inner molded portion. The electrical circuit breaker according to claim 3.

5. The material of the inner molded portion is a material with higher impact resistance than the material of the outer molded portion. The electrical circuit breaker according to claim 3 or 4.

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