Electrical Circuit Breaker

Abstract

To suppress 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 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 and a second connection end part, 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 housing main body has: an upper surface at the igniter side; a lower surface at a moving destination side of the projectile; and a slit part that is a recess provided on at least one of the upper and lower surfaces.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] An electric circuit may be provided with a circuit breaker that operates to emergency shut off continuity in the electric circuit when an abnormality occurs in a device that constitutes the electric circuit or in the system in which the electric circuit is installed. One proposed electric circuit breaker uses energy imparted from an ignition or the like to move a projectile at high speed, forcibly and physically disconnecting a conductor piece that forms part of the electric circuit. In recent years, the importance of electric circuit breakers applied to electric vehicles equipped with high-voltage power sources has been increasing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-212455 [Patent Document 2] Patent No. 4985871 Summary of the Invention [Problem to be solved by the invention]

[0004] Electrical circuit breakers sometimes combine a plastic housing with a metal holder to reduce weight and size. In this case, the projectile fired during operation of the electrical circuit breaker cuts the conductor piece and then strikes a part of the plastic housing, stopping it. However, if the plastic housing cracks during operation, gas evaporated by arc discharge during cutting may leak. Therefore, it is desirable to suppress gas leakage.

[0005] The technology of the present disclosure has been made in consideration of the above-described circumstances, and has an object to provide an electric circuit breaker that suppresses the occurrence of gas leakage after disconnection. [Means for solving the problem]

[0006] In order to solve the above problems, the electrical circuit breaker of the present disclosure comprises: a housing as an outer shell member containing an accommodation space extending in one direction; an igniter provided in the housing; a projectile disposed within the housing, launched from one end of the accommodation space by energy received from the igniter, and moving along an extension direction of the accommodation space; a conductor piece held in the housing and forming a part of an electric circuit, the conductor piece having a cut-off portion between one first connection end and the other second connection end that is cut off by the movement of the projectile, the cut-off portion being disposed across the accommodating space; Equipped with a holding region of the accommodating space defined by an inner wall of the housing that holds the conductor piece; the housing includes a housing body that contains the holding area, The housing main body has an upper surface on the igniter side, a lower surface on the destination side of the projectile, and a slit portion which is a recess provided in at least one of the upper surface and the lower surface. It shall be an electrical circuit breaker. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an electric circuit breaker that suppresses the occurrence of gas leakage after activation. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating the internal structure of an electrical circuit interruption device 1 according to an embodiment. [Figure 2] FIG. 2 is an example of a top view of the housing main body 100. As shown in FIG. [Figure 3] FIG. 3 is a top view of the conductor piece 50. FIG. [Figure 4] FIG. 4 is a front view of projectile 40. [Figure 5] FIG. 5 is a bottom view of the projectile 40. [Figure 6] FIG. 6 is a perspective view of the projectile 40. [Figure 7] FIG. 7 is a diagram illustrating the operation of the circuit breaker 1 according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment Hereinafter, an electrical circuit interruption device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that each configuration and combination thereof in the embodiment is merely an example, and addition, omission, substitution, and other modifications of the configuration are possible as appropriate within the scope of the gist of the present disclosure. The present disclosure is not limited by the embodiment, but is limited only by the claims.

[0010] <Configuration> FIG. 1 is a diagram illustrating the internal structure of an electrical circuit interrupting device (hereinafter simply referred to as "interrupting device") 1 according to an embodiment. The interrupting 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 contained in an automobile, a home 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 (the direction in which a housing space 13 described later extends) shown in FIG. 1 is referred to as a longitudinal cross section of the interrupting 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 interrupting device 1. FIG. 1 shows the state of the interrupting device 1 before it is activated.

[0011] 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 an accommodation space 13 extending from a first end 11 at the upper end to a second end 12 at the lower end. The accommodation 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 accommodation 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-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 embodiments. For example, the orientation of the circuit breaker 1 when installed is not limited to the directions shown in the figures.

[0012] [housing] The housing 10 includes a housing main body 100, a top holder 110, and a bottom container 120. The top holder 110 and the bottom container 120 are joined to the housing main body 100, thereby forming an integrated housing 10.

[0013] The housing body 100 has, for example, a generally rectangular columnar outer shape. However, the shape of the housing body 100 is not particularly limited. The housing body 100 is formed with a hollow portion 145 that penetrates in the vertical direction, and this hollow portion 145 forms part of the accommodation space 13. The housing body 100 has an upper surface 101 to which a flange portion 111 of the top holder 110 is fixed, and a lower surface 102 to which a flange portion 121 of the bottom container 120 is fixed. 2. In this embodiment, a cylindrical upper cylindrical wall 103 is erected on the outer periphery of the upper surface 101 of the housing main 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 may have other shapes. Furthermore, a cylindrical lower cylindrical wall 104 is erected on the outer periphery of the lower surface 102 of the housing main 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 may have other shapes. The housing main body 100 is molded from, for example, nylon, polycarbonate, polyamide, ABS resin, or the like, which is a type of polyamide synthetic resin.

[0014] FIG. 2 is an example of a top view of the housing main body 100. The housing main body 100 has a substantially rectangular outer shape in a plan view, with a hollow portion 145 provided in the center. This hollow portion 145 forms part of the accommodation space 13 when the housing main body 100 is combined with other components that form the housing 10. On the left and right sides of the hollow portion 145, conductor piece holding holes 105A and 105B are provided, which penetrate the housing main body 100 and through which the conductor piece 50 passes. By passing the conductor piece 50 through the conductor piece holding holes 105A and 105B, the conductor piece 50 is positioned so as to cross the hollow portion 145 (accommodation space 13). The housing main body 100 has bolt-through holes 133 provided at its four corners, penetrating in the vertical direction. A rectangular cylindrical upper cylindrical wall 103 extends upward from the outer edge of the top surface of the housing main body 100. The bolt through-hole 133 is an example of a fastening through-hole.

[0015] The housing main body 100 is also provided with slits 131 that penetrate in the vertical direction. That is, the slits 131 are provided as holes that penetrate between the upper surface 101 and the lower surface 102. Forming the slits 131 as holes that penetrate improves formability. The slits 131 are provided in positions that do not intersect with the conductor piece holding holes 105A and 105B. The slits 131 and the conductor piece holding holes 105A and 105B are provided in different positions within the housing main body 100. The slits 131 are provided in two locations around the cavity 145 but at positions that do not contact the cavity 145. The slits 131 are provided, for example, along the circumference of a circle centered at the center of the cavity 145 when viewed from above. That is, the shape of the slits 131 is, for example, an arc shape. The circumferential length of the slit portion 131 is longer than the radial length of a circle centered at the center position of the hollow portion 145. This makes it easier for a crack to reach the slit portion 131 if it occurs in the hollow portion 145 due to an impact or the like. In addition, the two slit portions 131 are provided, for example, in positions that are line-symmetrical with respect to the conductor piece 50 extending in the extension direction (X direction in FIG. 2) in a direction (Z direction in FIG. 2) perpendicular to the extension direction of the conductor piece 50 when viewed from above.

[0016] Furthermore, the slit portion 131 is not provided between the bolt-through hole 133 and the hollow portion 145. The distance from the hollow portion 145 to the slit portion 131 is shorter than the distance from the hollow portion 145 to the bolt-through hole 133. Here, the distance refers to the shortest distance. As a result, when comparing the portion between the hollow portion 145 and the bolt-through hole 133 with the portion between the hollow portion 145 and the slit portion 131, the strength of the former is higher than that of the latter. High strength makes cracks less likely to occur. Therefore, when subjected to an impact caused by piston operation, cracks are more likely to occur in the portion between the hollow portion 145 and the slit portion 131 than in the portion between the hollow portion 145 and the bolt-through hole 133. In other words, cracks directed from the hollow portion 145 toward the bolt-through hole 133 are less likely to occur. In other words, cracks are guided between the hollow portion 145 and the slit portion 131. This makes it possible to suppress gas leakage when subjected to an impact caused by piston operation. Cracks from cavity 145 to slit 131 do not affect the interruption performance, gas leakage, or insulation resistance of electrical circuit interruption device 1. Furthermore, by not providing slit 131 in the portion between cavity 145 and bolt-through hole 133, a decrease in strength of the portion between cavity 145 and bolt-through hole 133 can be suppressed.

[0017] Furthermore, the slit portion 131 does not have to be a hole penetrating between the upper surface 101 and the lower surface 102. Alternatively, the slit portion 131 may be a recess provided in at least one of the upper surface 101 and the lower surface 102, the recess being partially filled with a resin or the like. The shape of the slit portion 131 is not limited to that described herein. The slit portion 131 does not have to be provided along the circumference of a circle centered at the center of the hollow portion 145 when viewed from above. The shape of the slit portion 131 may be rectangular, elliptical, or the like when viewed from above. In this case, the length of the slit portion 131 in a direction perpendicular to the radial direction of the circle centered at the center of the hollow portion 145 is longer than the length in the radial direction of the circle. Here, the number of slit portions 131 is two, but the number is not limited to two and may be one or more.

[0018] [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 is hollow inside. 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 one size larger than that of the small-diameter cylinder portion 112.

[0019] 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 is provided with bolt-through holes (not shown) that pass through fastening bolts and that extend vertically.

[0020] The cavity formed inside small-diameter cylinder portion 112 of top holder 110 functions as an accommodating space that accommodates a portion of igniter 20, as shown in FIG. 1 . Furthermore, the cavity formed inside large-diameter cylinder portion 113 of top holder 110 communicates with the cavity of housing main body 100 located below, and forms a portion of accommodating space 13. Top holder 110 configured as described above can be formed from an appropriate metal member such as stainless steel or aluminum that has excellent strength and durability. However, the material from which top holder 110 is formed is not particularly limited. Furthermore, the above-described embodiment of the shape of top holder 110 is also an example, and other shapes may be adopted.

[0021] [Bottom container] Next, the bottom container 120 will be described. The bottom container 120 has a hollow, generally bottomed cylindrical shape, and is configured to include 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. A bolt-through hole (not shown) for passing a fastening bolt therethrough is provided in the flange 121 in the vertical direction.

[0022] The above-mentioned embodiment regarding the shape of the bottom container 120 is an example, and other shapes may be adopted. Furthermore, the hollow portion formed inside the bottom container 120 communicates with the housing main body 100 located above, and forms part of the storage space 13. The bottom container 120 configured as described above can be formed, for example, from an appropriate metal member such as stainless steel or aluminum, which has excellent strength and durability. However, there are no particular limitations on the material forming the bottom container 120. Furthermore, the bottom container 120 may have a multi-layer structure. For example, For example, the exterior portion of the bottom container 120 facing the outside may be made of an appropriate metal member such as stainless steel or aluminum, which has excellent strength and durability, and the interior portion facing the storage space 13 may be made of an insulating member such as synthetic resin. Of course, the entire bottom container 120 may be made of an insulating member.

[0023] As described above, the housing 10 in this embodiment is formed by vertically assembling the housing main body 100, top holder 110, and bottom container 120 together. During this assembly process, the conductor piece 50 is disposed within the housing main body 100. For example, the conductor piece 50 is passed through the conductor piece holding holes 105A and 105B of the housing main body 100, and the conductor piece is disposed across the cavity 145. In this state, the flange portion 111 of the top holder 110 is inserted into the inside of the upper cylindrical wall 103 of the housing main body 100, thereby positioning the top holder 110 above the housing main body 100. At the same time, the flange portion 121 of the bottom container 120 is inserted into the inside of the lower cylindrical wall 104 of the housing main body 100, thereby positioning the bottom container 120 below the housing main body 100. Then, bolts are passed through the bolt holes of the top holder 110, the housing main body 100, and the bottom container 120 to fasten the various parts together. Note that this fastening is not limited to bolts, and other fastening means such as rivets may also be used. Fastening means such as bolts and rivets are examples of fastening parts.

[0024] Furthermore, each part may be joined with a sealant applied between the top holder 110 and the housing main body 100, between the housing main body 100 and the conductor piece 50, and between the housing main body 100 and the bottom container 120. This increases the airtightness of the cylindrical storage space 13 formed inside the housing 10. Furthermore, the airtightness of the storage space 13 may be increased by interposing packing or gaskets between each part instead of or in addition to the sealant. The storage space 13 accommodates the igniter 20, the projectile 40, the cut-out portion 53 of the conductor piece 50, the coolant material 60, etc., which will be described in detail below.

[0025] [Igniter] Next, the igniter 20 will be described. The igniter 20 is an electric igniter that includes 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.

[0026] Igniter main body 22 includes a generally cylindrical main body portion 221 housed inside small-diameter cylinder portion 112 of top holder 110, and a connector portion 222 located on top of main body portion 221. Igniter main body 22 is fixed to small-diameter cylinder portion 112, for example, by press-fitting main body portion 221 into the inner circumferential surface of small-diameter cylinder portion 112. Furthermore, at an axially intermediate portion of main body portion 221, a constricted portion, the outer circumferential surface of which is recessed compared to other portions, is formed in an annular shape along the circumferential direction of main body portion 221, and an O-ring 223 is fitted into this constricted portion. 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 small-diameter cylinder portion 112 and main body portion 221.

[0027] 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.

[0028] As shown in FIG. 1, the ignition portion 21 of the igniter 20 is disposed so as to face the accommodation space 13 of the housing 10 (more specifically, the hollow portion formed inside the large-diameter cylinder portion 113). Ignition unit 21 is configured, for example, in a form in which an ignition charge is accommodated in an igniter cup. For example, the ignition charge is accommodated in the igniter cup of ignition unit 21 in a state in contact with a bridge wire (resistor) that is strung so as to connect the base ends of a pair of conductive pins. As the ignition charge, for example, ZPP (zirconium-potassium perchlorate), ZWPP (zirconium-tungsten-potassium perchlorate), THPP (titanium hydride-potassium perchlorate), lead tricinate, etc. may be used.

[0029] When the igniter 20 is operated, an operating current for igniting the ignition charge 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 ignition charge in the igniter cup to ignite and burn, generating combustion gas. As the ignition charge in the igniter cup of the ignition unit 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 accommodating 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 placed in the accommodating space 13. As a result, the projectile 40 is launched downward along the accommodating space 13 from the initial position shown in FIG. 1 .

[0030] [Conductor strip] Next, the conductor piece 50 will be described. Fig. 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 also forms a part of a predetermined electric circuit when the circuit breaker 1 is attached to the electric circuit, and is a bus bar ( ) The conductor piece 50 is held by the housing main body 100 and is arranged so as to cross a hollow portion 145 inside the housing main body. In this embodiment, the area (hollow portion 145) defined by the inner wall of the housing main body 100 holding the conductor piece 50 in this manner is used as the holding area.

[0031] The conductor piece 50 can be made of a metal such as copper (Cu). However, the conductor piece 50 may be made of a metal other than copper, or may be made 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).

[0032] In one embodiment shown in FIG. 3 , the conductor piece 50 is formed as a long, narrow flat piece overall, and includes a first connecting end 51 and a second connecting end 52 at both ends, and a cut-off portion 53 located in the middle thereof. 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 electric circuit. Note that the connection holes 51A and 52A of the conductor piece 50 are not shown in FIG. 1 . Furthermore, 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 and cut off from the first connecting end 51 and the second connecting end 52 when an abnormality such as an excessive current occurs in the electric circuit to which the circuit breaker 1 is applied. Slits 54 are formed at both ends of the cut-off portion 53 of the conductor piece 50 to facilitate the cut-off of the cut-off portion 53.

[0033] The conductor piece 50 is cut at a position overlapping the inner surface (inner wall surface) of the inner wall defining the cavity 145 of the housing body 100, ie, at a position overlapping the outer circumferential surface of the rod portion 42, and the cut portion 53 is cut off.

[0034] Here, the conductor piece 50 can take various forms, and its shape is not particularly limited. In the example shown in Fig. 2, the surfaces of the first connecting end 51, the second connecting end 52, and the cut-out portion 53 form the same plane, but this is not limiting. For example, the conductor piece 50 may be connected such that the cut-out portion 53 is perpendicular to the first connecting end 51 and the second connecting end 52 or inclined. The planar shape of the cut-out portion 53 of the conductor piece 50 is not particularly limited. Of course, the shapes of the first connecting end 51 and the second connecting end 52 of the conductor piece 50 are also not particularly limited. Furthermore, the notch 54 in the conductor piece 50 can be omitted as appropriate.

[0035] [Coolant material] Next, the coolant material 60 disposed in the accommodation space 13 of the housing 10 will be described. Here, as shown in FIG. 1 , before activation of the circuit breaker 1 (igniter 20), the excised portion 53 of the conductor piece 50 held in the pair of conductor piece holding holes 105A, 105B in the housing main body 100 is horizontally disposed across the accommodation space 13 of the housing 10. Hereinafter, within the accommodation space 13 of the housing 10, the region (space) on the side where the projectile 40 is disposed across the excised 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, as described above, a gap is formed on the side of the excised portion 53 disposed across the accommodation space 13, and therefore the projectile initial placement region R1 and the arc-extinguishing region R2 are not completely isolated by the excised portion 53 but are connected to each other. Of course, depending on the shape and size of the portion to be excised 53, the projectile initial placement region R1 and the arc extinguishing region R2 may be completely separated by the portion to be excised 53.

[0036] The arc-extinguishing region R2 of the accommodation space 13 is a region (space) for receiving the excised portion 53 excised by the rod portion 42 of the projectile 40 that is fired 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 is a coolant that absorbs and cools the arc and the thermal energy of the excised portion 53 that are generated when the projectile 40 excises the excised portion 53 of the conductor piece 50, thereby suppressing the generation of an arc when the current is interrupted or extinguishing (extinguishing) the generated arc.

[0037] The arc-extinguishing region R2 in the circuit breaker 1 is a space for receiving the cut-out portion 53 cut off 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 generated when the projectile 40 cuts off the cut-out portion 53. In order to effectively extinguish the arc generated when the cut-out portion 53 is cut off 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. Examples of 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] The coolant material 60 is formed, for example, in a roughly disk shape and is placed at the bottom of the bottom container 120 .

[0040] [Projectile] Next, the projectile 40 will be described. Fig. 4 is a front view of the projectile 40, Fig. 5 is a bottom view of the projectile 40, and Fig. 6 is a perspective view of the projectile 40. In Fig. 6, the bottom of the projectile 40 is shown facing upward in order to show the bottom of the projectile 40. The projectile 40 is formed of an insulating material such as synthetic resin, and comprises a piston portion 41 and a piston portion 41. The piston portion 41 includes a rod portion 42 connected to the top holder 110. 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 depending on the shape of the housing 10, etc. Furthermore, the piston portion 41 has an outer diameter that is larger than the diameter of the cavity 145 in the housing main body 100, and is configured to not enter the cavity 145 but to abut against the surrounding members that form the cavity 145. That is, the piston portion 41 is configured so that the cross-sectional area perpendicular to the movement direction (axial direction) at the tip end side connected to the rod portion 42 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 depending on the shape of the housing 10, etc.

[0041] Further, 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. Further, in the axial middle portion of the piston portion 41, a constricted portion is formed in an annular shape along the circumferential direction of the piston portion 41, where the outer circumferential surface is recessed compared to other portions, 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 improve the airtightness between the inner circumferential surface of the large-diameter cylinder portion 113 and the piston portion 41.

[0042] 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 accommodating 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 accommodating space 13 and is inserted into the hollow portion 145 of the housing main body 100. The lower end surface of the rod portion 42 is formed as a cutting surface 420 for cutting the cut portion 53 from the conductor piece 50 when the circuit breaker 1 is activated. Note that, although the rod portion 42 in this embodiment has a generally cylindrical shape, its shape is not particularly limited and can 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 cut surface 420 of the rod portion 42 of the projectile 40 is located above the hollow portion (holding area) 145 of the housing main body 100.

[0043] 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 accommodation space 13. Specifically, as shown in FIG. 1, the piston portion 41 of the projectile 40 is accommodated 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 has a generally cylindrical shape, 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 .

[0044] <Operation> Next, the operation when the circuit breaker 1 is activated to break the electric circuit will be described. 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 piston part 41 of the projectile 40 in the circuit breaker 1 is positioned on the first end 11 side (upper end side) in the accommodation space 13, and the cut surface 420 formed at the lower end of the rod part 42 is in contact with the upper surface of the cut portion 53 of the conductor piece 50. It is set to the initial position.

[0045] 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 (such as a vehicle, power generation equipment, or power storage equipment) 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, temperature sensor, acceleration sensor, or 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 exceeding a predetermined threshold set for protecting 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 a device separate from the circuit breaker 1, for example. Furthermore, the above-mentioned abnormality detection sensor and control unit are not essential components of the circuit breaker 1.

[0046] 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 accommodation space 13.

[0047] Here, the ignition portion 21 of the igniter 20 is received in the recessed portion 411 of 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 of 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 in the accommodation space 13 along the extension direction (axial direction) of the accommodation space 13.

[0048] FIG. 7 is a diagram illustrating the operation of the circuit breaker 1 according to the embodiment. The upper part of FIG. 7 shows the circuit breaker 1 during operation, and the lower part of FIG. 7 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 gas of the ignition charge and is forcefully pushed downward. As a result, the cutting 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-out portion 53 of the conductor piece 50. As a result, the cut-out portion 53 is cut off from the conductor piece 50. Note that 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 accommodating 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 equal to the inner diameter of the large-diameter cylinder portion 113 of the top holder 110.

[0049] 7, the projectile 40 moves downward along the extension direction (axial direction) of the accommodating space 13 by a predetermined stroke until the lower end surface of the piston portion 41 abuts (collides) with the upper surface 101 of the housing body 100. In this state, The portion 53 to be cut off from the conductor piece 50 by the rod portion 42 is received in the arc-extinguishing region R2 where the coolant material 60 is disposed. As a result, the first connection end 51 and the second connection end 52 located at both ends of the conductor piece 50 are electrically disconnected, forcibly interrupting the predetermined electrical circuit to which the circuit breaker 1 is applied. When the portion 53 to be cut off from the conductor piece 50 by the rod portion 42, an arc is likely to occur between the portion 53 to be cut off and the first connection end 51 and the second connection end 52. However, even if an arc occurs, the coolant material 60 absorbs the thermal energy of the arc and the portion 53 to be cut off, cooling them and quickly extinguishing the arc and suppressing its effects. Furthermore, when the projectile 40 moves by activation of the igniter 20 to cut the cut portion 53, the piston portion 41, as it moves within the large diameter cylinder portion 113, pushes the gas on the projectile initial placement region R1 side, along with particles of the conductor piece 50 evaporated by the arc heat, toward the arc extinction region R2 side, thereby guiding the arc toward the arc extinction region R2 side, where it is extinguished by the coolant material 60, etc.

[0050] <Actions and Effects of the Embodiment> The interrupter 1 in the embodiment has a housing main body 100 having a slit portion 131. Because the housing main body 100 has the slit portion 131, even if a crack occurs from the hollow portion 145 toward the outside when the housing main body 100 receives an impact due to piston operation, the crack stops at the slit portion 131, and the crack can be prevented from reaching the outside of the housing main body 100. Since the crack does not reach the outside of the housing main body 100, it is possible to prevent the internal gas from leaking to the outside.

[0051] Although the embodiments of the electrical circuit interruption device according to the present disclosure have been described above, each aspect disclosed herein can be combined with any other feature disclosed herein. [Explanation of symbols]

[0052] 1: Circuit breaker 10: Housing 13: Containment space 20:Igniter 40: Projectile 42: Rod part 50: Conductor piece 53: Part to be excised 60: Coolant material 100: Housing body 110: Top holder 120: Bottom container 131: Slit section 145: Cavity (holding area)

Claims

1. a housing as an outer shell member containing an accommodation space extending in one direction; an igniter provided in the housing; a projectile disposed within the housing, launched from one end of the accommodation space by energy received from the igniter, and moving along an extension direction of the accommodation space; a conductor piece held in the housing and forming a part of an electric circuit, the conductor piece having a cut-off portion between one first connection end and the other second connection end that is cut off by the movement of the projectile, the cut-off portion being disposed across the accommodating space; Equipped with a holding region of the accommodating space defined by an inner wall of the housing that holds the conductor piece; the housing includes a housing body that contains the holding area, The housing main body has an upper surface on the igniter side, a lower surface on the destination side of the projectile, and a slit portion which is a recess provided in at least one of the upper surface and the lower surface, the housing body has a conductor piece holding hole that is a hole through which the conductor piece passes, The slit portion does not intersect with the conductor piece holding hole. Electrical circuit interrupter.

2. A housing containing an accommodation space extending in one direction as an outer shell member; an igniter provided in the housing; a projectile disposed within the housing, launched from one end of the accommodation space by energy received from the igniter, and moving along an extension direction of the accommodation space; a conductor piece held in the housing and forming a part of an electric circuit, the conductor piece having a cut-off portion between one first connection end and the other second connection end that is cut off by the movement of the projectile, the cut-off portion being disposed across the accommodating space; Equipped with a holding region of the accommodating space defined by an inner wall of the housing that holds the conductor piece; the housing includes a housing body that contains the holding area, The housing main body has an upper surface on the igniter side, a lower surface on the destination side of the projectile, and a slit portion which is a recess provided in at least one of the upper surface and the lower surface, the housing main body has a fastening through-hole that penetrates between the upper surface and the lower surface and through which a fastening component is passed, a distance between the slit portion and the holding area is shorter than a distance between the fastening through hole and the holding area; The slit portion is disposed in a portion other than a portion between the fastening through hole and the holding region. Electrical circuit interrupter.

3. The slit portion is a through hole that penetrates between the upper surface and the lower surface.

3. An electrical circuit interruption device according to claim 1 or 2.

4. The slit portion has a circumferential length longer than a radial length of a circle centered at the center position of the holding area. An electrical circuit interruption device according to any one of claims 1 to 3.

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