Electrical circuit breaker

Abstract

This invention provides a technology that can suppress the deterioration of insulation performance in electrical circuit breakers. [Solution] The electrical circuit breaker comprises a housing containing a habitable space extending in one direction; an igniter that ignites gunpowder to generate combustion gases; a resin piston that is launched by the pressure of the combustion gases; a conductive piece arranged to cross the habitable space and cut by the piston when the igniter is activated; a resin housing portion having a holding portion for holding the conductive piece and a sliding surface on which the outer circumferential surface of the piston slides; and a concave housing portion provided on at least one of the resin housing portion and the piston so as to open to the habitable space and for accommodating soot-like conductive material generated when the igniter is activated.

Description

Technical Field

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

Background Art

[0002] An electric circuit may be provided with an interrupting device that urgently interrupts conduction in the electric circuit by operating when an abnormality occurs in equipment constituting the electric circuit or in a system equipped with the electric circuit. As one aspect thereof, there has been proposed an electric circuit interrupting device that fires a piston at high speed by the pressure of combustion gas generated by an igniter that ignites explosive powder during operation, to forcibly and physically cut a conductor piece forming a part of the electric circuit (see, for example, Patent Document 1 and the like). In this type of electric circuit interrupting device, normally, a holding portion for holding the conductor piece in the housing, a piston for cutting the conductor piece during operation, and the like are made of resin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0004] During operation of the electric circuit interrupting device, the resin portion of the housing and the piston are exposed to a high temperature environment due to the heat of combustion gas generated by combustion of the explosive powder, arc heat, and the like. Therefore, the resin portion of the housing or a part of the piston may be carbonized, or the conductor piece may be transpired, so that a soot-like conductive substance may be formed. If such a soot-like conductive substance adheres between the sliding surface on the housing side and the piston, there is a risk of causing a decrease in insulation performance (insulation deterioration).

[0005] The present invention aims to provide a technology that can suppress the deterioration of insulation performance in electrical circuit breakers. [Means for solving the problem]

[0006] (Aspect 1) A housing containing a containment space extending in one direction, The housing includes an igniter that ignites gunpowder to generate combustion gases, A resin piston is placed within the containment space and is launched by the pressure of the combustion gas from the first end to the second end of the containment space along the extending direction of the containment space, A conductive piece is arranged to cross the aforementioned containment space, forms part of the electrical circuit before the ignition is activated, and is cut by the piston when the ignition is activated. A resin housing portion constituting a part of the housing, having a holding portion for holding the conductive piece and a sliding surface that faces the housing space and on which the outer circumferential surface of the piston slides, A recessed housing portion is provided in at least one of the resin housing portion and the piston so as to open to the housing space, for housing the sooty conductive substance generated when the igniter is in operation, Equipped with, Electrical circuit breaker.

[0007] (Aspect 2) The electrical circuit breaker according to embodiment 1, wherein the housing portion is formed by a recess in which the outer circumferential surface of the piston or the sliding surface of the resin housing portion is concave.

[0008] (Aspect 3) The electrical circuit breaker according to embodiment 2, wherein the recess has a groove shape that extends along the circumferential direction of the outer surface of the piston or the sliding surface of the resin housing portion.

[0009] (Aspect 4) The electrical circuit breaker according to embodiment 2 or 3, wherein the housing portion is provided on the sliding surface of the resin housing portion at a position closer to the second end portion than the holding portion.

[0010] (Aspect 5) The housing portion is provided on the outer surface of the piston, An electrical circuit interrupter according to any one of embodiments 2 to 4, wherein, when the piston that was launched in conjunction with the operation of the ignition device is positioned at a predetermined piston stop position, the housing portion is positioned on the second end side of the holding portion.

[0011] (Aspect 6) The resin housing portion comprises a first cylindrical portion whose inner wall is formed as the sliding surface, and a second cylindrical portion which is connected to the first cylindrical portion toward the second end and has an inner circumferential surface with an inner diameter larger than that of the sliding surface. The aforementioned housing section is provided in the second cylindrical section. An electrical circuit breaker according to Embodiment 1.

[0012] (Aspect 7) The housing portion is formed by a recess in which the inner circumferential surface of the second cylindrical portion is concave, or by a notch provided in the second cylindrical portion. An electrical circuit breaker according to embodiment 6.

[0013] The means described for solving the problem can be combined as much as possible without departing from the problem or technical concept of this disclosure. [Effects of the Invention]

[0014] This disclosure provides a technology that can suppress the deterioration of insulation performance in electrical circuit breakers. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a diagram illustrating the internal structure of an electrical circuit breaker according to Embodiment 1. [Figure 2]Figure 2 is a cross-sectional view taken along line A-A shown in Figure 1. [Figure 3] Figure 3 is a cross-sectional view taken along line B-B shown in Figure 1. [Figure 4] Figure 4 is a top view of the upper resin housing part according to Embodiment 1. [Figure 5] Figure 5 is a top view of the lower resin housing part according to Embodiment 1. [Figure 6] Figure 6 is a vertical cross-sectional view of the lower resin housing part taken along line C-C shown in Figure 5. [Figure 7] Figure 7 is a side view of the piston according to Embodiment 1 [Figure 8] Figure 8 is a bottom view of the piston according to Embodiment 1. [Figure 9] Figure 9 is a perspective view of the piston according to Embodiment 1. [Figure 10] Figure 10 is a diagram for explaining the operating state of the interrupting device according to Embodiment 1. [Figure 11] Figure 11 is a diagram for explaining an interrupting device according to a modification of Embodiment 1. [Figure 12] Figure 12 is a diagram showing the state where the operation of the interrupting device according to the modification of Embodiment 1 is completed. [Figure 13] Figure 13 is a diagram for explaining an interrupting device according to Embodiment 2. [Figure 14] Figure 14 is a bottom view of the lower resin housing part in the interrupting device according to Embodiment 2. [Figure 15] Figure 15 is a view of the accommodating portion as viewed from the direction of arrow D in Figure 14. [Figure 16] Figure 16 is a diagram showing the state where the operation of the interrupting device according to Embodiment 2 is completed. [Mode for Carrying Out the Invention]

[0016] 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 scope of the claims. Furthermore, in this specification, descriptions of numerical ranges such as "X or more and Y or less" or "X~Y" mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified.

[0017] <Embodiment 1> The electrical circuit interruption device according to Embodiment 1 interrupts an electrical circuit by using the pressure of combustion gas generated by an igniter that ignites gunpowder to launch a piston, which forcibly and physically cuts a conductive piece that forms part of the electrical circuit. The electrical circuit interruption device can be used, for example, as an interruption device to interrupt an electrical circuit in an electrical circuit included in an automobile, household electrical appliance, solar power generation system, etc., or in the event of a malfunction in a system including the battery (e.g., lithium-ion battery) of said electrical circuit.

[0018] <Structure> Figure 1 is a diagram illustrating the internal structure of an electrical circuit breaker (hereinafter simply referred to as "breaker") 1 according to Embodiment 1. Figure 2 is a cross-sectional view along line AA shown in Figure 1. Figure 3 is a cross-sectional view along line BB shown in Figure 1. In this specification, the cross-section along the height direction (the direction in which the accommodation space 13, described later, extends) shown in Figure 1 is referred to as the longitudinal cross-section of the breaker 1, and the cross-section in a direction perpendicular to the height direction is referred to as the transverse cross-section of the breaker 1. Figure 1 shows the breaker 1 in its state before operation.

[0019] The shut-off device 1 comprises a housing 10, an igniter 20, a piston 40, a conductor piece 50, a coolant material 60, etc. The housing 10, as an outer shell member, contains a housing space 13 that extends from the first end 11 at the upper end to the second end 12 at the lower end. This housing space 13 is a linearly formed space that allows the piston 40 to move, and extends along the vertical direction of the shut-off device 1. As shown in Figure 1, the piston 40 is housed at the upper end of the housing space 13 formed inside the housing 10 in the vertical direction (extension direction). In this specification, the vertical direction of the shut-off device 1 is also referred to as the Y-axis direction, the left-right direction as the X-axis direction, and the depth direction as the Z-axis direction. However, in this specification, the vertical direction and XYZ directions of the shut-off device 1 merely indicate the relative positional relationship of each element in the shut-off device 1 for the convenience of describing the embodiments. For example, the orientation when installing the shut-off device 1 is not limited to the direction shown in the figure.

[0020] [housing] The housing 10 includes a resin housing portion 100, a top holder 110, and a bottom container 120. The top holder 110 and the bottom container 120 are attached to the resin housing portion 100, thereby forming an integrated housing 10.

[0021] The resin housing portion 100 is divided vertically at the position where the conductor piece 50 is arranged, and has an upper resin housing portion 130 located above the conductor piece 50 and a lower resin housing portion 140 located below the conductor piece 50. The resin housing portion 100 is not limited to a vertically divided structure; it may also be integrally formed from the upper end connecting to the top holder 110 to the lower end connecting to the bottom container 120. The upper resin housing portion 130 and the lower resin housing portion 140 can be formed from an insulating material such as synthetic resin. For example, the upper resin housing portion 130 and the lower resin housing portion 140 may be made of polycarbonate or nylon, which is a type of polyamide synthetic resin.

[0022] The resin housing portion 100, formed by integrally assembling the upper resin housing portion 130 and the lower resin housing portion 140, has, for example, a roughly rectangular prism-shaped outer form. However, the shape of the resin housing portion 100 is not particularly limited. Furthermore, the resin housing portion 100 is formed with a cavity running through it in the vertical direction, and this cavity forms part of the storage space 13. In addition, the resin housing portion 100 has an upper surface 101 to which the flange portion 111 of the top holder 110 is fixed, and a lower surface 102 to which the flange portion 121 of the bottom container 120 is fixed. In this embodiment, a cylindrical upper cylindrical wall 103 is erected on the outer circumference of the upper surface 101 of the resin housing portion 100, extending upward from the upper surface 101. The upper cylindrical wall 103 has, for example, a rectangular cylindrical shape, but may have other shapes. Furthermore, a cylindrical lower wall 104 is provided vertically on the outer circumference of the lower surface 102 of the resin housing portion 100, extending downward from the lower surface 102. In this embodiment, the lower wall 104 has, for example, a rectangular shape, but it may have other shapes.

[0023] Next, the upper resin housing portion 130 will be described. Figure 4 is a top view of the upper resin housing portion 130 according to Embodiment 1.

[0024] As shown in Figure 4, the upper resin housing portion 130 has a roughly rectangular shape in plan view, with a cavity 135 in its center. This cavity 135 forms part of the housing space 13 when the upper resin housing portion 130 is combined with other components that make up the housing 10.

[0025] The cylindrical inner wall defining the cavity 135 of the upper resin housing portion 130 is formed as a sliding surface 133 on which the outer circumferential surface 421 (see Figure 7, etc.) of the rod portion 42 of the piston 40, which will be described later, slides when the igniter 20 is in operation. A portion of the sliding surface 133 is provided with relief grooves 131A to 131D that are enlarged in the outer diameter direction of the upper resin housing portion 130. When relief grooves 131A to 131D are not specifically distinguished, they may simply be referred to as "relief groove 131".

[0026] The relief grooves 131 extend along the extension direction (vertical direction, Y-axis direction) of the housing space 13. The number, position, and range of the relief grooves 131 are not particularly limited, but in this example, four relief grooves 131A to 131D are provided on the sliding surface 133.

[0027] The relative positions of relief grooves 131A and 131B are symmetrical with respect to the YZ plane passing through the center C1 of the accommodating space 13 in the cross-section (XZ plane) of the shutoff device 1. Similarly, the relative positions of relief grooves 131C and 131D are symmetrical with respect to the YZ plane passing through the center C1. Furthermore, the relative positions of relief grooves 131A and 131C are symmetrical with respect to the XY plane passing through the center C1. The relative positions of relief grooves 131B and 131D are symmetrical with respect to the XY plane passing through the center C1.

[0028] In Figure 4, the symbol IC1 indicates that the sliding surface 133 of the upper resin housing portion 130 is perfectly circular. This is a virtual circle assuming that the relief grooves 131A to 131D are not formed. The virtual circle IC1 is, for example, a perfect circle centered at C1. The relief groove 131 is formed concave outward relative to the virtual circle IC1, that is, concave radially outward from the upper resin housing portion 130. The relief groove 131 functions as a relief space that allows expansion when at least one of the piston 40 (rod portion 42) and the upper resin housing portion 130 expands in volume relative to the other.

[0029] The inner diameter of the sliding surface 133 (the diameter of the virtual circle IC1) is, for example, the same as the diameter (contour) of the piston 40 (rod portion 42) before the operation of the shut-off device 1 (igniter 20). In one embodiment, the sliding surfaces 133A (see Figure 4) located between the relief grooves 131A and 131B, and between the relief grooves 131C and 131D, respectively, have a radial dimension (radius) from the center C1 that is slightly smaller than the radius of the rod portion 42 of the piston 40, and the sliding surface 133A is positioned to protrude slightly radially inward from the virtual circle IC1. In this embodiment, when the shut-off device 1 (igniter 20) is operated, the rod portion 42 of the piston 40 slides along the sliding surface 133 (133A) while being press-fitted.

[0030] In addition, as shown in Figure 4, the upper resin housing portion 130 has bolt holes 132 that penetrate vertically at all four corners. Furthermore, a rectangular tubular upper wall 103 is erected on the outer edge of the upper surface of the upper resin housing portion 130, extending upward from the upper surface (see Figure 1).

[0031] Next, the lower resin housing portion 140 will be described. Figure 5 is a top view of the lower resin housing portion 140 according to Embodiment 1. Figure 6 is a longitudinal cross-sectional view of the lower resin housing portion 140 along the CC line shown in Figure 5.

[0032] As shown in Figure 5, the lower resin housing portion 140 has a roughly rectangular shape in plan view, with a cylindrical cavity portion 145 in its center. The cavity portion 145 forms part of the housing space 13 when the lower resin housing portion 140 is combined with other members that make up the housing 10. The cylindrical inner wall defining the cavity portion 145 of the lower resin housing portion 140 is formed as a sliding surface 143 on which the outer circumferential surface 421 of the rod portion 42 of the piston 40 slides. Reference numeral 146 denotes a first cylindrical portion having a sliding surface 133.

[0033] As shown in Figure 5, the upper surface of the lower resin housing portion 140 is provided with a conductor piece holding portion 144, which is a recess for fitting the conductor piece 50. In a top view of the lower resin housing portion 140, the conductor piece holding portions 144 are arranged on both the left and right sides of the cavity portion 145, sandwiching the cavity portion 145. The conductor piece holding portion 144 has a shape in which the upper surface of the lower resin housing portion 140 is recessed downward along the contour of the conductor piece 50. By fitting the end of the conductor piece 50 into the conductor piece holding portion 144, the conductor piece 50 can be held so that it crosses the cavity portion 145 (housing space 13). The conductor piece holding portion 144 is an example of a holding portion according to this disclosure.

[0034] In a portion of the sliding surface 143 of the lower resin housing portion 140, relief grooves 141A to 141D, which are enlarged in the outer diameter direction in the lower resin housing portion 140, extend along the direction of extension (vertical direction) of the housing space 13, similar to the relief groove 131 of the upper resin housing portion 130. Hereinafter, when relief grooves 141A to 141D are not specifically distinguished, they may simply be referred to as "relief groove 141". The function of relief groove 141 is the same as that of relief groove 131 described above. Various dimensions of relief groove 141, such as width and depth, may be the same as those of relief groove 131 of the upper resin housing portion 130.

[0035] The relative positions of relief grooves 141A and 141B are symmetrical with respect to the YZ plane passing through the center C1, and the relative positions of relief grooves 141C and 141D are also symmetrical with respect to the YZ plane passing through the center C1. Furthermore, the relative positions of relief grooves 141A and 141C are symmetrical with respect to the XY plane passing through the center C1, and the relative positions of relief grooves 141B and 141D are also symmetrical with respect to the XY plane passing through the center C1.

[0036] When the upper resin housing section 130 and the lower resin housing section 140 are assembled together, the upper ends of each relief groove 141A to 141D in the lower resin housing section 140 are connected to the lower ends of each relief groove 131A to 131D in the upper resin housing section 130, so that the relief grooves 131 on the upper resin housing section 130 and the relief grooves 141 on the lower resin housing section 140 are aligned in a straight line along the height direction (Y direction).

[0037] The symbol IC2 shown in Figure 5 is a virtual circle assuming that the sliding surface 143 of the lower resin housing portion 140 is a perfect circle. That is, the virtual circle IC2 is a virtual outline of the sliding surface 143 assuming that the relief grooves 141A to 141D are not formed. The virtual circle IC2 is a perfect circle with the same diameter as the virtual circle IC1, centered at C1. The relief groove 141 is concave outward relative to the virtual circle IC2, that is, concave radially outward from the lower resin housing portion 140. The inner diameter of the sliding surface 143 (diameter of the virtual circle IC2) is, for example, the same as the diameter (outline) of the piston 40 (rod portion 42) before the operation of the shut-off device 1 (igniter 20). In one configuration, the sliding surfaces 143A (see Figure 5) located between relief grooves 141A and 141B, and between relief grooves 141C and 141D, respectively, have a radial dimension (radius) from the center C1 that is slightly smaller than the radius of the rod portion 42 of the piston 40, and the sliding surfaces 143A are positioned to protrude slightly radially inward from the virtual circle IC2. In this configuration, when the shut-off device 1 (igniter 20) is activated, the rod portion 42 of the piston 40 slides along the sliding surface 143 (143A) while being press-fitted.

[0038] Furthermore, as shown in Figure 5, the lower resin housing portion 140 has bolt holes 142 that penetrate vertically at all four corners. A rectangular cylindrical lower wall 104 is provided vertically from the outer edge of the lower surface of the lower resin housing portion 140, extending downward from the lower surface. In addition, an annular groove 148 for fitting an O-ring 147 (see Figure 1) is opened on the lower surface of the lower resin housing portion 140. The O-ring 147 is made of, for example, rubber (e.g., silicone rubber) or synthetic resin, and functions to improve airtightness between the lower resin housing portion 140 and the flange portion 121 of the bottom container 120 which is assembled integrally with it.

[0039] Furthermore, the lower resin housing portion 140 has a second cylindrical portion 149 that is connected to the lower surface of the first cylindrical portion 146 and extends downward (towards the second end portion 12) (see Figures 1, 6, etc.). The second cylindrical portion 149 of the lower resin housing portion 140 has a cylindrical shape. The second cylindrical portion 149 has an inner circumferential surface 149A with a larger diameter than the sliding surface 143. Therefore, a step 149B is formed between the sliding surface 143 of the first cylindrical portion 146 and the inner circumferential surface 149A of the second cylindrical portion 149 in the lower resin housing portion 140, along the cross-sectional direction (XZ plane direction) of the shut-off device 1.

[0040] As shown in Figures 1 and 6, the first cylindrical portion 146 of the lower resin housing portion 140 has a concave housing portion 70 that opens facing the housing space 13 (cavity portion 145). The housing portion 70 functions as a housing (capture) space for housing and capturing sooty conductive material (conductive material containing soot) generated when the shut-off device 1 (igniter 20) is activated.

[0041] In the examples shown in Figures 1 and 6, the housing portion 70 is formed as a recess where the sliding surfaces 143, 143A of the first cylindrical portion 146 in the lower resin housing portion 140 are concave, and the housing space It has a pocket shape that opens into 13 (cavity 145). As an example, the housing portion 70 has a groove shape that extends along the circumferential direction of the sliding surface 143 (including 143A) in the lower resin housing portion 140 (first cylindrical portion 146). The housing portion 70 may extend over the entire circumference of the sliding surface 143 (including 143A), or it may be provided in a part of the circumferential direction of the sliding surface 143 (including 143A). For example, multiple housing portions 70 may be provided at intervals along the circumferential direction of the sliding surface 143 (including 143A). The position in the height direction (Y-axis direction) in which the housing portion 70 is provided is not particularly limited, but in the examples shown in Figures 1 and 6, the housing portion 70 is located at a position lower than the height of the conductor piece holding portion 144 (i.e., the height of the conductor piece 50 held by the conductor piece holding portion 144) (i.e., the position on the second end portion 12 side).

[0042] [Top Holder] Next, the top holder 110 will be described with reference to Figure 1. The top holder 110 is, for example, a cylinder member having a stepped cylindrical shape, and the inside is hollow. 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 that connects them, and a flange portion 111 that extends 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 diameter of the large-diameter cylinder portion 113 is slightly larger than that of the small-diameter cylinder portion 112.

[0043] Furthermore, the contour of the flange portion 111 in the top holder 110 has a roughly rectangular shape that fits inside the upper cylindrical wall 103 of the resin housing portion 100. The flange portion 111 is provided with bolt holes that pass through in the vertical direction for fastening bolts.

[0044] 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 resin housing portion 100 located below it, 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.

[0045] [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 resin housing portion 100. The flange portion 121 is provided with bolt holes that pass through in the vertical direction for fastening bolts.

[0046] 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 resin housing portion 100 located above it, forming part of the storage space 13. The bottom container 120 configured as described above can be formed from suitable metal members 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 outer casing of the bottom container 120 may be made of stainless steel, which has excellent strength and durability. It may be formed from an appropriate metal component such as aluminum, and the interior part facing the storage space 13 may be formed from an insulating material such as synthetic resin. Of course, the entire bottom container 120 may also be formed from an insulating material.

[0047] As described above, the housing 10 in this embodiment is constructed by integrally assembling the top holder 110, the resin housing portion 100 (upper resin housing portion 130, lower resin housing portion 140), and the bottom container 120 in the vertical direction. During this assembly process, the conductor piece 50 is positioned through the resin housing portion 100. For example, the conductor piece 50 is fitted into the conductor piece holding portion 144 of the lower resin housing portion 140, and the conductor piece is positioned so as to cross the cavity portion 145. In this state, the lower surface of the upper resin housing portion 130 is abutted against the upper surface of the lower resin housing portion 140 so that the bolt holes 142 of the lower resin housing portion 140 and the bolt holes 132 of the upper housing are coaxial. Furthermore, the flange portion 111 of the top holder 110 is fitted inside the upper cylindrical wall 103 of the upper resin housing portion 130, thereby positioning the top holder 110 on the upper resin housing portion 130. At the same time, the flange portion 121 of the bottom container 120 is fitted inside the lower cylindrical wall 104 of the lower resin housing portion 140, thereby positioning the bottom container 120 below the lower resin housing portion 140. Then, bolts are passed through the bolt holes of the top holder 110, the upper resin housing portion 130, the lower resin housing portion 140, and the bottom container 120 to fasten each part together. Note that this fastening is not limited to bolts; other fastening means such as rivets may also be used.

[0048] Furthermore, sealant may be applied between the top holder 110 and the upper resin housing portion 130, between the upper resin housing portion 130 and the lower resin housing portion 140 and the conductor piece 50, between the lower resin housing portion 140 and the conductor piece 50, and between the lower resin housing portion 140 and the bottom container 120 before joining the parts. This can improve the airtightness of the containment space 13 formed inside the housing 10. Alternatively, instead of sealant, or in combination with sealant, packings or gaskets may be interposed between the parts to improve the airtightness of the containment space 13. The containment space 13 houses the igniter 20, piston 40, the cut-off portion 53 of the conductor piece 50, and coolant material 60, which will be described in detail below.

[0049] [Igniter] Next, the igniter 20 will be described. The igniter 20 is an electric igniter comprising an ignition unit 21 containing an ignition charge (explosive) and an igniter body 22 having a pair of conductive pins 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 in use.

[0050] 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.

[0051] 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.

[0052] As shown in Figure 1, the ignition unit 21 of the igniter 20 is positioned to face the housing space 13 of the housing 10 (more specifically, the cavity formed inside the large-diameter cylinder section 113). The ignition unit 21 is configured, for example, to house the igniter charge (explosive) within the igniter cup. For example, the igniter charge is housed within the igniter cup of the igniter unit 21 in contact with a bridge wire (resistor) that is strung together to connect the base ends of a pair of conductive pins. Examples of igniters include ZPP (zirconium-potassium perchlorate), ZWPP (zirconium-tungsten-potassium perchlorate), and THPP (titanium hydride-perchlorate). Potassium, lead tricinate, etc. may be used.

[0053] When the igniter 20 is activated, an operating current for igniting the igniter is supplied from the power source to the conductive pin. As a result, the bridge wire in the ignition unit 21 heats up, causing the igniter in the igniter cup to ignite and burn, generating combustion gas. Then, as the igniter burns in the igniter cup of the igniter unit 21, the pressure inside the igniter cup increases, causing the split surface 21A of the igniter cup to split, and the combustion gas is released from the igniter cup into the containment space 13. More specifically, the combustion gas from the igniter cup is released into the recess 411 of the piston portion 41 of the piston 40, which will be described later, located in the containment space 13.

[0054] [piston] Next, the piston 40 will be described. Figure 7 is a side view of the piston 40 according to Embodiment 1. Figure 8 is a bottom view of the piston 40 according to Embodiment 1. Figure 9 is a perspective view of the piston 40 according to Embodiment 1. In Figure 9, the bottom surface of the piston 40 is shown facing upwards in order to show the bottom surface of the piston 40. The piston 40 is formed of an insulating material such as synthetic resin. As shown in Figure 8, the cross-section of the piston 40 when cut in a direction perpendicular to the radial direction is circular (round). In this embodiment, the cross-section of the piston 40 is approximately a perfect circle. The piston 40 includes a piston portion 41 and a rod portion 42 integrally connected below the piston portion 41. The piston portion 41 has a generally cylindrical shape and an outer diameter that roughly corresponds to the inner diameter of the large-diameter cylinder portion 113 in the top holder 110. For example, the diameter of the piston portion 41 may be slightly smaller than the inner diameter of the large-diameter cylinder portion 113. The shape of the piston 40 can be appropriately changed according to the shape of the housing 10, etc.

[0055] A cylindrical recess 411 is formed on the upper surface of the piston portion 41, and the ignition portion 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 (combustion gas pressure) from the igniter 20 when the igniter 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.

[0056] The rod portion 42 of the piston 40 is, for example, a rod-shaped member having a smaller outer diameter than the piston portion 41. The rod portion 42 has a cylindrical shape extending in one direction and is integrally connected to the lower end side of the piston portion 41. 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 circuit breaker 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 circuit breaker 1 is operated. The rod portion 42 may have a columnar shape such as a cylinder or a rectangular prism. In the initial position of the piston 40 shown in Figure 1, the tip-side region of the rod portion 42 of the piston 40, including the cutting surface 420, is the cavity of the resin housing portion 100. It is positioned in a part of the containment space 13. Reference numeral 421 denotes the outer circumferential surface (side circumferential surface) of the rod portion 42. When the piston 40 is fired during the operation of the shutoff device 1, the outer circumferential surface 421 of the rod portion 42 slides along the sliding surfaces 133 and 143 formed by the inner wall of the resin housing portion 100, while being guided by it.

[0057] As described above, when the igniter 20 is activated, the piston 40 receives energy from the igniter 20, and the upper surface of the piston portion 41, including the pressure receiving surface 411A, receives the pressure, causing the piston 40 to be launched at high speed along the housing space 13 from the initial position shown in Figure 1 toward the second end 12 side (downward). As shown in Figure 1, the piston portion 41 of the piston 40 is housed inside the large-diameter cylinder portion 113 in the top holder 110 and is slidable in the axial direction along the inner wall surface of the large-diameter cylinder portion 113. In this embodiment, the piston portion 41 of the piston 40 is generally cylindrical in shape, but its shape is not particularly limited. The outer shape and size of the piston portion 41 can be appropriately chosen according to the shape and size of the inner wall surface of the large-diameter cylinder portion 113.

[0058] [Conducting piece] Next, the conductor piece 50 will be described. As shown in Figure 2, the conductor piece 50 is held (supported) by being fitted into the conductor piece holding portion 144 of the lower resin housing portion 140 and is installed so as to cross the housing space 13. In the example shown in Figure 2, the conductor piece 50 is formed as an elongated flat plate piece extending in one direction. Reference numeral x1 is the axis along the longitudinal direction of the conductor piece 50. The conductor piece 50 is held in the conductor piece holding portion 144 such that, for example, the axis x1 passes through the center C1 of the housing space 13 and is parallel to the X-axis. The conductor piece 50 is a conductive metal body that constitutes a component of the circuit breaker 1 and also forms a part of the electrical circuit when the circuit breaker 1 is attached to a predetermined electrical circuit, and is sometimes called a bus bar. The 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).

[0059] In one embodiment shown in Figure 2, the conductor piece 50 includes a first connecting end 51 and a second connecting end 52 located at each end in the longitudinal direction, and a cut-off portion 53 located in the intermediate portion between them. The first connecting end 51 and the second connecting end 52 of the conductor piece 50 are provided with connecting holes 51A and 52A, respectively. These connecting 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 connecting holes 51A and 52A of the conductor piece 50 are not shown. The cut-off portion 53 of the conductor piece 50 is a portion that is forcibly and physically cut by the rod portion 42 of the piston 40 and cut off from the first connecting end 51 and the second connecting end 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.

[0060] The conductor piece 50 is cut, for example, at a position that overlaps with the sliding surfaces 133 and 143 that define the housing space 13, that is, at a position that overlaps with the outer circumferential surface 421 of the rod portion 42, and the portion to be cut off 53 is severed. The boundary portion between the first connecting end 51 and the portion to be cut off 53 is called the first cutting edge portion 511. The boundary portion between the second connecting end 52 and the portion to be cut off 53 is called the second cutting edge portion 521.

[0061] 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 conductor piece 50 may have the first connecting end 51 and The portion to be cut 53 may be connected to the second connecting end 52 in a perpendicular or inclined position. Furthermore, the planar shape of the portion to be cut 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. Additionally, the notch 54 on the conductor piece 50 can be omitted as appropriate.

[0062] [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 operation of the shut-off device 1 (igniter 20), the portion to be cut 53 of the conductor piece 50, which is held in the resin housing portion 100, is positioned to cross 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 53 of the conductor piece 50 where the piston 40 is positioned will be called the "piston initial placement area R1," and the area (space) on the opposite side of the piston 40 will be called the "arc extinguishing area R2." As described above, since a gap is formed on the side of the portion to be cut 53 which is positioned to cross the housing space 13, the piston initial placement area R1 and the arc extinguishing area R2 are not completely isolated by the portion to be cut 53, but are in communication with each other. Of course, depending on the shape and size of the portion to be cut 53, the piston initial placement area R1 and the arc extinguishing area R2 may be completely isolated by the portion to be cut 53.

[0063] The arc-extinguishing region R2 of the containment space 13 is a region (space) for receiving the cut-off portion 53 that is cut off by the rod portion 42 of the piston 40 when the shut-off device 1 (igniter 20) is activated. Coolant material 60 is placed in this arc-extinguishing region R2 as an arc-extinguishing material. The coolant material 60 is a coolant that removes the thermal energy of the arc and the cut-off portion 53 generated when the piston 40 cuts off the cut-off portion 53 of the conductor piece 50, thereby suppressing arc generation when the current is interrupted, or extinguishing (eliminating) the generated arc.

[0064] The arc extinguishing region R2 in the circuit breaker 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 piston 40, and at the same time, it has significance as a space for effectively extinguishing the arc generated when the piston 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.

[0065] In one embodiment, the coolant material 60 is in solid form. In another embodiment, the coolant material 60 is formed from metal fibers. Here, the metal fibers forming the coolant material 60 include at least one of steel wool and copper wool. However, the above embodiments of the coolant material 60 are examples and are not limited thereto. The coolant material 60 is, for example, formed into a roughly disc shape and placed at the bottom of the bottom container 120.

[0066] <Operation> Next, we will explain the operation of the circuit breaker 1 when it is activated to interrupt the electrical circuit. As described above, Figure 1 shows the state of the circuit breaker 1 before activation (hereinafter also referred to as the "initial state before activation"). In this initial state before activation, the piston 40 of the circuit breaker 1 is set in an initial position where 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.

[0067] The system including the circuit breaker 1 may also include, for example, an abnormality detection sensor (not shown) that detects an abnormal condition in a device (vehicle, power generation equipment, energy storage equipment, etc.) to which the electrical circuit to be shut off is connected, and a control unit (not shown) that controls the operation of the igniter 20. The sensor may also be able to detect abnormal conditions based on voltage or temperature of the conductor piece 50, in addition to the current flowing through the conductor piece 50. Furthermore, the abnormality detection sensor may be, for example, an impact sensor, temperature sensor, acceleration sensor, or vibration sensor, and may detect abnormal conditions such as accidents or fires based on impact, temperature, acceleration, or vibration in a vehicle or other device. 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 performed by the control unit can also be implemented 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. The abnormality 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 exceeding a predetermined threshold set for the protection of a predetermined electrical circuit. Furthermore, the anomaly detection sensor and control unit described above do not necessarily have to be included as components of the tripping device 1; for example, they may be included in a separate device. Also, the anomaly detection sensor and control unit are not essential components of the tripping device 1.

[0068] For example, when an abnormal current in an electrical circuit is detected by an abnormal current detection sensor that detects abnormal currents in the electrical circuit, 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), resulting in the ignition charge in the ignition unit 21 igniting and burning, and combustion gas being generated. Then, due to the pressure rise inside the ignition unit 21, the crack surface 21A cracks open, and the combustion gas is released from inside the ignition unit 21 into the containment space 13.

[0069] The ignition unit 21 of the igniter 20 is received in a 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 of the piston 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 piston 40 is launched along the extending direction (axial direction) of the housing space 13 and moves at high speed downward (from the first end 11 side to the second end 12 side) within the housing space 13.

[0070] Figure 10 is a diagram illustrating the operation of the shut-off device 1 according to Embodiment 1. The upper part of Figure 10 shows the state of the shut-off device 1 during operation, and the lower part of Figure 10 shows the state of the shut-off device 1 after operation is complete. As described above, when the igniter 20 is activated, the piston 40, which receives pressure (combustion energy) from the combustion gas of the igniter, is forcefully pushed downward, and as a result, the cut 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 from the conductor piece 50. The shape and dimensions of the piston 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 piston 40 may be set to the same dimension as the inner diameter of the large diameter cylinder portion 113 of the top holder 110.

[0071] Then, as shown in the lower part of Figure 10, the piston 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 abuts against (collides with) the upper surface 101 of the resin housing portion 100. In this state, the cut portion 53 that has been cut off from the conductor piece 50 by the rod portion 42 of the piston 40 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 inoperable, and the predetermined electrical circuit to which the circuit breaker 1 is applied is forcibly interrupted.

[0072] <Insulation performance of circuit breakers> The resin housing portion 100 and piston 40 in the circuit breaker 1 are made of insulating resin. Therefore, at the moment the conductor piece 50 is cut by the piston 40 (the moment the portion to be cut 53 is cut), the first connection end 51 and the second connection end 52 are in an insulated state. However, at the moment the conductor piece 50 is cut, an arc discharge may occur between the portion to be cut 53 and the first connection end 51, and between the portion to be cut 53 and the second connection end 52, as they are physically separating. Due to the heat from this arc, some of the metal material forming the conductor piece 50 may evaporate, or some of the resin material forming the resin housing portion 100 and piston 40 may carbonize, resulting in the generation of a sooty conductive substance. Thus, if the sooty conductive substance generated when the circuit breaker 1 is activated adheres between the sliding surfaces 133 and 143 of the resin housing portion 100 and the outer peripheral surface 421 of the rod portion 42 of the piston 40, an electrical circuit may be formed between the first connecting end 51 and the second connecting end 52 immediately after the conductor piece 50 is cut, potentially reducing the insulation resistance between the first connecting end 51 and the second connecting end 52.

[0073] Therefore, the shut-off device according to this disclosure is provided with a concave housing portion that opens to the housing space 13 on at least one of the resin housing portion 100 and the piston 40, so that the sooty conductive substance generated when the shut-off device 1 (igniter 20) is operated is contained in the housing portion. In this embodiment, as shown in Figures 1 and 6, a concave housing portion 70 that opens to the housing space 13 is provided on the sliding surfaces 143, 143A of the first cylindrical portion 146 in the lower resin housing portion 140. This allows the sooty conductive substance generated when the shut-off device 1 (igniter 20) is operated to be contained (captured) in the housing portion 70. As a result, the amount of sooty conductive substance that adheres (deposits) between the sliding surfaces 133, 143 of the resin housing portion 100 and the outer peripheral surface 421 of the rod portion 42 of the piston 40 can be reduced. This makes it difficult for an electrical circuit to form between the first connection end 51 and the second connection end 52 immediately after the conductor piece 50 is cut, thereby suppressing a decrease in the insulation performance of the circuit breaker 1.

[0074] Furthermore, even if, for example, the resin material forming the rod portion 42 and the resin housing portion 100 shrinks in a low-temperature environment, or if the gap between the sliding surfaces 133, 143 of the resin housing portion 100 and the outer peripheral surface 421 of the rod portion 42 widens due to geometric tolerances, the insulation performance of the circuit breaker 1 can be suppressed by capturing the sooty conductive substance generated when the circuit breaker 1 (igniter 20) is activated in the housing portion 70.

[0075] Furthermore, in the shut-off device 1 according to this embodiment, relief grooves 131 and 141 are provided on the sliding surfaces 133 and 143 of the resin housing portion 100. Therefore, even if the resin housing portion 100 and the piston 40, which are formed of resin which has a higher coefficient of thermal expansion compared to metal, expand, deterioration of the sliding performance of the piston 40 can be suppressed.

[0076] Furthermore, in this embodiment, when the piston 40 is launched during the operation of the circuit breaker 1 (igniter 20), the outer circumferential surface 421 of the rod portion 42 slides along the sliding surfaces 133A and 143A while being press-fitted. Therefore, even if a sooty conductive substance is generated when the circuit breaker 1 (igniter 20) is operated, it is difficult for this sooty conductive substance to enter the boundary between the outer circumferential surface 421 of the rod portion 42 and the sliding surfaces 133A and 143A. In other words, the sliding surfaces 133A and 143A into which the rod portion 42 of the piston 40 is press-fitted contribute to suppressing the formation of electrical circuits caused by sooty conductive substances. According to this, it is possible to suppress the formation of electrical circuits caused by sooty conductive material across adjacent relief grooves 131A (131A) and 131B (141B) along the circumferential direction, and between relief grooves 131C (141C) and 131D (141D).

[0077] Furthermore, the housing portion 70 of the shut-off device 1 has a groove shape that extends in the circumferential direction of the sliding surface 143 in the resin housing portion 100. Therefore, over a wide area along the circumferential direction of the sliding surface 143 In this configuration, the formation of soot-like conductive material along the vertical direction (Y-axis direction) can be effectively suppressed.

[0078] Furthermore, in Embodiment 1, the housing portion 70 is located on the second end 12 side relative to the conductor piece holding portion 144 (holding portion). In other words, the housing portion 70 is located at a lower position (on the second end 12 side) than the installation height of the conductor piece 50 held by the conductor piece holding portion 144. This arrangement allows the housing portion 70A to effectively suppress the accumulation of sooty conductive material along the vertical direction (Y-axis direction) of the sliding surface 143 in the resin housing portion 100 toward the first connecting end 51 and the second connecting end 52 of the conductor piece 50 cut by the rod portion 42 of the piston 40, thereby suppressing a decrease in the insulation performance of the circuit breaker 1.

[0079] <Modified form of Embodiment 1> In the first embodiment of the shut-off device 1, a housing portion 70A may be provided on the rod portion 42 of the piston 40 instead of, or in combination with, the housing portion 70 provided on the resin housing portion 100. Figure 11 is a diagram illustrating a modified version of the shut-off device 1A of the first embodiment. The shut-off device 1A shown in Figure 11 is equipped with a housing portion 70A on the rod portion 42 of the piston 40 instead of the housing portion 70 described above. The housing portion 70A is a recess for housing (capturing) sooty conductive material generated when the shut-off device 1A (igniter 20) is operated. When describing the shut-off device 1A according to this modified version, components common to the shut-off device 1 described above will be denoted by the same reference numerals and their explanation will be omitted.

[0080] The housing portion 70A is formed by a recess in the outer circumferential surface 421 of the rod portion 42 of the piston 40, and exhibits a pocket shape that opens into the housing space 13. For example, the housing portion 70A has a groove shape that extends along the circumferential direction of the outer circumferential surface 421 of the rod portion 42. The housing portion 70A may extend over the entire circumference of the outer circumferential surface 421 of the rod portion 42, or it may be provided on a part of the outer circumferential surface 421. For example, multiple housing portions 70A may be provided at intervals along the circumferential direction of the outer circumferential surface 421 of the rod portion 42. In the specific example shown in Figure 11, the housing portion 70A is formed as an annular groove that extends over the entire circumference of the outer circumferential surface 421 of the rod portion 42. Also, in the example shown in Figure 11, the housing portion 70A is provided on the lower end side in the axial direction of the rod portion 42 (i.e., the part proximal to the cut surface 420).

[0081] As shown in this modified example, opening the housing portion 70A provided on the outer peripheral surface 421 of the rod portion 42 into the housing space 13 also produces the same effects as the circuit breaker 1 equipped with the housing portion 70 described above. That is, by housing (capturing) the sooty conductive substance generated in conjunction with the operation of the circuit breaker 1A (igniter 20) in the housing portion 70A, the amount of sooty conductive substance adhering (accumulating) between the sliding surfaces 133, 143 of the resin housing portion 100 and the outer peripheral surface 421 of the rod portion 42 of the piston 40 can be reduced. As a result, it becomes more difficult for an electrical circuit to form between the first connection end 51 and the second connection end 52 immediately after the conductor piece 50 is cut, and a decrease in the insulation performance of the circuit breaker 1A can be suppressed.

[0082] Figure 12 shows the state after the operation of the shut-off device 1A according to a modified embodiment of Embodiment 1 has been completed. The piston 40 is positioned by the lower end portion 412 of the piston portion 41 contacting the upper surface 101 of the resin housing portion 100 (upper resin housing portion 130) (more specifically, the edge portion of the upper surface 101 that surrounds the cavity portion 135). Hereinafter, this position will be referred to as the "piston stop position". As shown in the example in Figure 12, when the piston 40, which has been launched in conjunction with the operation of the igniter 20, is positioned at the piston stop position, it is preferable that the housing portion 70A is provided on the outer peripheral surface 421 of the rod portion 42 such that the housing portion 70A is positioned on the second end portion 12 side (downward side) than the conductor piece holding portion 144 (holding portion). For example, when the piston 40 is positioned at the piston stop position, the housing portion 70A is positioned on the conductor piece holding portion It is positioned below 144 (holding portion) (towards the second end 12) and above the lower end of the sliding surface 143 (towards the first end 11). This effectively prevents soot-like conductive material from accumulating along the vertical direction (Y-axis direction) of the sliding surface 143 in the resin housing portion 100 toward the first connecting end 51 and the second connecting end 52 of the conductor piece 50 cut by the rod portion 42 of the piston 40, thereby preventing a decrease in the insulation performance of the circuit breaker 1. Furthermore, as described above, by making the housing portion 70A a groove shape that extends along the circumferential direction of the outer peripheral surface 421 of the rod portion 42, it is possible to effectively prevent soot-like conductive material from accumulating along the vertical direction (Y-axis direction) over a wide area along the circumferential direction of the sliding surface 143.

[0083] Furthermore, the shut-off device can be provided by combining the housing portion 70A provided on the rod portion 42 of the piston 40 according to this modified example and the housing portion 70 provided on the resin housing portion 100.

[0084] <Embodiment 2> Next, a circuit breaker according to Embodiment 2 will be described. Figure 13 is a diagram illustrating the circuit breaker 1B according to Embodiment 2. Embodiment 2 differs from Embodiment 1 in that a receiving portion, which is a recess for containing (capturing) the sooty conductive substance generated when the circuit breaker is operated, is provided in the second cylindrical portion 149 of the resin housing portion 100 (lower resin housing portion 140). Other aspects are basically the same as the circuit breaker 1 according to Embodiment 1. In the following, the differences from the circuit breaker 1 will be explained in detail, and components common to the circuit breaker 1 will be denoted by the same reference numerals and their explanation will be omitted.

[0085] Figure 14 is a bottom view of the lower resin housing portion 140 of the circuit breaker 1B according to Embodiment 2. Here, the second cylindrical portion 149, which protrudes downward (towards the second end portion 12) from the first cylindrical portion 146 of the lower resin housing portion 140, will be described in detail. In Embodiment 2, the second cylindrical portion 149 is provided with a housing portion 70B, which is a recess for housing (capturing) sooty conductive material generated when the circuit breaker 1B is operated. The second cylindrical portion 149 has a cylindrical shape as described in Figure 6 of Embodiment 1 and has an inner circumferential surface 149A. Reference numeral 149C in Figure 14 is the outer circumferential surface of the second cylindrical portion 149, and reference numeral 149D is the lower end surface of the second cylindrical portion 149. As shown in Figure 13, in the circuit breaker 1B, the outer circumferential side of the second cylindrical portion 149 is fitted with the side wall portion 122 of the bottom container 120, and the outer circumferential side of the second cylindrical portion 149 is covered by the side wall portion 122. Furthermore, in the shut-off device 1B, the housing portion 70B of the second cylindrical portion 149 is provided to open to the housing space 13.

[0086] In the example shown in Figure 14, two housing sections 70B are provided in the second cylindrical section 149. For convenience, hatching is applied to the locations of the housing sections 70B in Figure 14. z1 shown in Figure 14 is a reference line that passes through the center C1 of the housing space 13 and extends parallel to the Z-axis. The reference line z1 is perpendicular to the axis x1 of the conductor piece 50 held by the conductor piece holding section 144 of the lower resin housing section 140. In the example shown in Figure 14, each housing section 70B is positioned at a location offset by 90° around the Y-axis with C1 as the center from the axis x1 of the conductor piece 50. That is, the pair of housing sections 70B are positioned on the reference line z1, and the positional relationship between the housing sections 70B is symmetrical with respect to the XY plane passing through the center C1 of the housing space 13.

[0087] As shown in Figure 14, each housing portion 70B of the second cylindrical portion 149 is positioned to correspond to the sliding surface 143A of the first cylindrical portion 146. Therefore, the pair of sliding surfaces 143A in the first cylindrical portion 146 are positioned at a 90° offset around the Y-axis with C1 as the center, similar to the housing portions 70B. Furthermore, both of the pair of sliding surfaces 143A are positioned on the reference line z1, and the positional relationship between the sliding surfaces 143A is symmetrical with respect to the XY plane passing through the center C1 of the housing space 13.

[0088] Figure 15 is a view of the housing portion 70B of the second cylindrical portion 149 from the direction of arrow D in Figure 14. Figure 15 shows the housing portion 70B of the second cylindrical portion 149 and its surrounding area. In this embodiment, the housing portion 70B is formed as a notch provided at the lower end of the second cylindrical portion 149 and penetrates the second cylindrical portion 149 in the radial direction (plate thickness direction).

[0089] Here, based on Figure 15, the details of the housing section 70B having a notched shape (also called a slit shape) will be described. The housing section 70B is defined by a pair of notched side walls 149E and a notched top wall 149F that connects the upper ends of the notched side walls 149E. The reference numeral P1 shown in Figure 15 indicates the upper end position of the housing section 70B (notch).

[0090] Figure 16 shows the state after the operation of the shut-off device 1B according to Embodiment 2 has been completed. In this embodiment, the shut-off device 1B is provided with a housing section 70B that opens into the housing space 13 in the second cylindrical section 149 of the resin housing section 100 (lower resin housing section 140), so that the sooty conductive substance generated when the shut-off device 1B (igniter 20) is operated can be contained (captured) in the housing section 70B. As described above, the outer circumference of the second cylindrical section 149 is covered by the side wall section 122 of the bottom container 120. Therefore, the portion of the side wall section 122 located on the outer circumference side of the housing section 70B functions as a peripheral wall that covers the outer circumference of the housing section 70B.

[0091] As described above, by capturing the sooty conductive material in the recessed housing portion 70B formed from the housing space 13, the amount of sooty conductive material adhering (accumulating) between the sliding surfaces 133, 143 of the resin housing portion 100 and the outer peripheral surface 421 of the rod portion 42 of the piston 40 can be reduced, similar to Embodiment 1 and its modified form described above. Furthermore, even when considering the possibility that an electrical circuit may be formed by sooty conductive material adhering to the wall surface defining the housing portion 70B (notched side wall 149E, notched top wall 149F, etc.), the path through which the electrical circuit is formed by the sooty conductive material can be extended compared to when the housing portion 70B is not formed in the second cylindrical portion 149. As a result, it becomes more difficult for an electrical circuit to be formed between the first connection end 51 and the second connection end 52 immediately after the conductor piece 50 is cut, and a decrease in the insulation performance of the circuit breaker 1B can be suppressed.

[0092] As shown in Figure 16, the upper end position P1 of the housing portion 70B provided in the second cylindrical portion 149 of the resin housing portion 100 (lower resin housing portion 140) may correspond to the lower end position of the piston 40 (rod portion 42) positioned at the piston stop position. The lower end position of the piston 40 (rod portion 42) is the end on the second end portion 12 side in the axial direction of the piston 40 (rod portion 42), and is the end on which the cut surface 420 is located. By forming the housing portion 70B in this range, it is possible to effectively suppress the entry of sooty conductive material from below into the gap between the sliding surfaces 133, 143 of the resin housing portion 100 and the outer peripheral surface 421 of the rod portion 42 of the piston 40.

[0093] The above-described configuration of the housing portion 70B is merely an example, and various configurations can be adopted. For example, instead of a notched configuration, the housing portion 70B may be formed as a recessed area where the inner circumferential surface 149A of the second cylindrical portion 149 is concave. Furthermore, the number, position, and range of the housing portions 70B described in Figure 14 are also merely examples.

[0094] Furthermore, the circuit breaker 1B according to this embodiment includes, in addition to the housing portion 70B provided in the second cylindrical portion 149 of the resin housing portion 100 (lower resin housing portion 140), a housing portion 70 provided on the sliding surface 143 of the first cylindrical portion 146. By combining the housing portion 70B with other types of housing portions 70 in this way, the deterioration of the insulation performance of the circuit breaker can be suppressed more effectively. Of course, instead of the housing portion 70, a modified housing portion 70A according to Embodiment 1 can be used. The housing section 70B according to Embodiment 2 may be used in combination with the other embodiment, or the housing section 70B may be used alone.

[0095] While embodiments and variations 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]

[0096] 1, 1A, 1B: Circuit breaker 10: Housing 13: Containment Space 20:Igniter 40: Piston 42: Rod section 50: Conductor piece 53: Part to be excised 70, 70A, 70B: Storage section 100: Resin housing part 130: Upper resin housing section 133: Sliding surface 140: Lower resin housing section 143: Sliding surface

Claims

1. A housing containing a containment space extending in one direction, The housing includes an igniter that ignites gunpowder to generate combustion gases, A resin piston is placed within the containment space and is launched by the pressure of the combustion gas from the first end to the second end of the containment space along the extending direction of the containment space, A conductive piece is arranged to cross the aforementioned containment space, forms part of the electrical circuit before the ignition is activated, and is cut by the piston when the ignition is activated. A resin housing portion constituting a part of the housing, having a holding portion for holding the conductive piece and a sliding surface that faces the housing space and on which the outer circumferential surface of the piston slides, A recessed housing portion is provided in at least one of the resin housing portion and the piston so as to open to the housing space, for housing the sooty conductive substance generated when the igniter is in operation, Equipped with, Electrical circuit breaker.

2. The electrical circuit breaker according to claim 1, wherein the housing portion is formed by a recess in which the outer circumferential surface of the piston or the sliding surface of the resin housing portion is concave.

3. The electrical circuit breaker according to claim 2, wherein the recess has a groove shape that extends along the circumferential direction of the outer surface of the piston or the sliding surface of the resin housing portion.

4. The electrical circuit breaker according to claim 2, wherein the housing portion is provided on the sliding surface of the resin housing portion at a position closer to the second end portion than the holding portion.

5. The housing portion is provided on the outer surface of the piston, The electrical circuit interrupter according to claim 2, wherein, when the piston that was fired in conjunction with the operation of the ignition device is positioned at a predetermined piston stop position, the housing portion is positioned on the second end side of the holding portion.

6. The resin housing portion comprises a first cylindrical portion whose inner wall is formed as the sliding surface, and a second cylindrical portion which is connected to the first cylindrical portion toward the second end and has an inner circumferential surface with an inner diameter larger than that of the sliding surface. The aforementioned housing section is provided in the second cylindrical section. The electrical circuit breaker according to claim 1.

7. The housing portion is formed by a recess in which the inner circumferential surface of the second cylindrical portion is concave, or by a notch provided in the second cylindrical portion. The electrical circuit breaker according to claim 6.

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