Sliding structure, method for operating sliding structure, and electrical circuit shielding device

Abstract

The purpose of the present invention is to provide a technology capable of limiting deterioration of slidability of a projectile in a sliding structure. The sliding structure comprises: a housing that encloses an accommodation space extending in one direction; an igniter that is provided to the housing; a projectile that is disposed in the accommodation space, is fired from one end side of the accommodation space by means of energy received from the igniter, and slides along the extending direction of the accommodation space; and a relief space that is provided in at least a portion of a site where an inner wall defining the accommodation space and the projectile are fitted, and releases an expanding portion when the volume of at least one among the projectile and the housing has expanded with respect to the other among the projectile and the housing.

Description

Sliding structure, operating method of sliding structure, and electrical circuit interrupting device

[0001] The present invention relates to a sliding structure, a method for operating the sliding structure, and an electrical circuit interruption device.

[0002] 2. Description of the Related Art Conventionally, an electric circuit breaker is known as a device that slides a projectile by energy imparted from an igniter or the like (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2022-156302

[0004] In a high-temperature environment, if the volume of the projectile or its surroundings expands, the sliding properties of the projectile may deteriorate, resulting in a decrease in the velocity of the projectile. This decrease in the velocity of the projectile may result in the failure to achieve the required performance.

[0005] The technology of the present disclosure aims to provide a technology that can suppress deterioration of the sliding properties of a projectile.

[0006] (Aspect 1) A sliding structure comprising: a housing containing a storage space extending in one direction; an igniter provided in the housing; a projectile disposed in the storage space, fired from one end of the storage space by energy received from the igniter, and sliding along the extension direction of the storage space; and an escape space provided in at least a portion of a portion where an inner wall defining the storage space and the projectile are fitted, for escaping an expansion portion when at least one of the projectile and the housing expands in volume relative to the other of the projectile or the housing. (Aspect 2) In the sliding structure described in Aspect 1, the escape space may be provided within a range where the projectile slides. (Aspect 3) In the sliding structure described in Aspect 1 or 2, the housing may have a groove provided in the inner wall, the groove being concave radially outward of the housing and having a depth shorter than its width, and the escape space may be formed between a bottom of the groove and the projectile. (Aspect 4) In the sliding structure according to Aspect 3, a central angle formed by an imaginary line connecting one end of the groove in the width direction to the central axis of the accommodation space and an imaginary line connecting the other end of the groove in the width direction to the central axis of the accommodation space may be 90° to 120°. (Aspect 5) In the sliding structure according to Aspect 3 or 4, the groove may be recessed by 0.2 mm to 0.6 mm radially outward from the housing with respect to an outline of the projectile. (Aspect 6) In the sliding structure according to any one of Aspects 1 to 5, the projectile may have a round cross section when cut in a direction perpendicular to the radial direction. (Aspect 7) In the sliding structure according to Aspect 1, the projectile may have a groove provided on its outer periphery, recessed radially inward from the projectile, and having a depth shorter than its width, and the escape space may be formed between a bottom of the groove and the inner wall. (Aspect 8) In the sliding structure according to Aspect 7, a central angle formed by an imaginary line connecting one end of the groove in the width direction and the central axis of the projectile and an imaginary line connecting the other end of the groove in the width direction and the central axis of the projectile may be 90° to 120°.(Aspect 9) In the sliding structure according to Aspect 7 or 8, the groove may have a diameter that narrows by 0.2 mm to 0.6 mm toward the center in the radial direction of the projectile relative to an inner outline of the accommodating space. (Aspect 10) In the sliding structure according to any one of Aspects 7 to 9, the accommodating space may have a circular cross section when cut in a direction perpendicular to the radial direction. (Aspect 11) This may be an electrical circuit breaking device comprising: the sliding structure according to any one of Aspects 1 to 10; and a conductor piece that is provided in the housing and forms part of an electric circuit, the conductor piece having a cut-out portion that is cut off by the projectile, the cut-out portion being arranged to cross the accommodating space.

[0007] The present disclosure can also be understood from the aspect of a method for operating a sliding structure. (Aspect 12) The method may include: activating an igniter to impart energy to a projectile for sliding the projectile inside a housing; and sliding the projectile in a state in which at least one of the projectile and the housing has an escape space for escaping an expansion portion when the volume of the projectile expands relative to the other of the projectile and the housing.

[0008] The contents described in the means for solving the problems can be combined as much as possible within the scope of the problems and technical ideas of this disclosure.

[0009] According to the present disclosure, deterioration of the sliding properties of the projectile can be suppressed.

[0010] FIG. 1 is a diagram illustrating the internal structure of an electrical circuit interrupting device according to an embodiment. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. FIG. 4 is a top view of the upper housing body. FIG. 5 is a longitudinal cross-sectional view of the upper housing body taken along line C-C in FIG. 4. FIG. 6 is a longitudinal cross-sectional view of the upper housing body taken along line D-D in FIG. 4. FIG. 7 is a bottom view of the upper housing body. FIG. 8 is a top view of the lower housing body. FIG. 9 is a longitudinal cross-sectional view of the lower housing body taken along line E-E in FIG. 8. FIG. 10 is a longitudinal cross-sectional view of the lower housing body taken along line F-F in FIG. 8. FIG. 11 is a bottom view of the lower housing body. FIG. 12 is a front view of a projectile. FIG. 13 is a bottom view of a projectile. FIG. 14 is a perspective view of a projectile. FIG. 15 is a diagram illustrating the operation of the circuit interrupting device 1 according to an embodiment. FIG. 16 is a flowchart illustrating an operation method of the circuit interrupting device 1 according to an embodiment. FIG. 17 is a top view of the upper housing body. FIG. 18 is a diagram explaining the test method of the load measurement test. FIG. 19 is a graph showing the results of the load measurement test. FIG. 20 is a top view of the lower housing main body. FIG. 21 is a longitudinal cross-sectional view of the lower housing main body taken along line G-G shown in FIG. 20. FIG. 22 is a longitudinal cross-sectional view of the lower housing main body taken along line H-H shown in FIG. 20. FIG. 23 is a bottom view of the lower housing main body. FIG. 24 is a top view of the lower housing main body. FIG. 25 is a front view of the projectile. FIG. 26 is a bottom view of the projectile.

[0011] <Embodiment 1> An electrical circuit interruption device according to embodiment 1 of the present disclosure will be described below with reference to the drawings. Note that each configuration and their combinations in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications of configurations are possible as appropriate within the scope of the present disclosure. The present disclosure is not limited by the embodiments, but only by the scope of the claims. Furthermore, in this specification, expressions such as "X or more and Y or less" and "X to Y" that represent numerical ranges mean numerical ranges that include the lower and upper limits, which are the endpoints, unless otherwise specified.

[0012] In this embodiment, an electric circuit interrupter will be described as an example of a sliding structure. The electric circuit interrupter is a device that includes a sliding structure that slides a projectile and interrupts an electric circuit by causing the projectile to cut a conductor piece that forms part of the electric circuit. The electric circuit interrupter according to this embodiment causes the projectile to slide at high speed using energy applied from an ignition or the like, forcibly and physically cutting the conductor piece that forms part of the electric circuit. The electric circuit interrupter is a device that prevents major damage by interrupting an electric circuit in the event of an abnormality in an electric circuit included in, for example, an automobile, a home appliance, a solar power generation system, or a system including a battery (e.g., a lithium-ion battery) of the electric circuit.

[0013] <Configuration> Fig. 1 is a diagram illustrating the internal structure of an electric circuit breaking device (hereinafter simply referred to as "breaking device") 1 according to an embodiment, Fig. 2 is a cross-sectional view taken along line A-A shown in Fig. 1, and Fig. 3 is a cross-sectional view taken along line B-B shown in Fig. 1. In this specification, a cross section taken along the height direction (the direction in which a housing space 13, which will be described later, extends) shown in Fig. 1 is referred to as a longitudinal cross section of the breaking 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 breaking device 1. Fig. 1 shows the state of the breaking device 1 before it is activated.

[0014] 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 embodiment. For example, the orientation of the circuit breaker 1 when installed is not limited to the directions shown in the figures.

[0015] [Housing] The housing 10 includes a housing body 100, a top holder 110, and a bottom container 120. The top holder 110 and the bottom container 120 are coupled to the housing body 100, thereby forming the housing 10 as a single unit.

[0016] The housing body 100 is divided vertically at the position where the conductor piece 50 is disposed, and has an upper housing body 130 disposed above the conductor piece 50 and a lower housing body 140 disposed below the conductor piece 50. The housing body 100 is not limited to a divided configuration, and may be formed integrally from the upper end connected to the top holder 110 to the lower end connected to the bottom container 120.

[0017] The housing body 100, with the upper housing body 130 and the lower housing body 140 combined, has, for example, a generally rectangular prism-shaped outer shape. However, the shape of the housing body 100 is not particularly limited. A hollow portion is formed in the housing body 100 so as to extend vertically through the housing body 100, and this hollow portion forms a part of the storage space 13. The housing body 100 also has an upper surface 101 to which the flange portion 111 of the top holder 110 is fixed, and a lower surface 102 to which the flange portion 121 of the bottom container 120 is fixed. In this embodiment, a cylindrical upper cylindrical wall 103 extends upward from the outer periphery of the upper surface 101 of the housing body 100. In this embodiment, the upper cylindrical wall 103 has, for example, a rectangular prism-shaped outer shape, but may have other shapes. A cylindrical lower cylindrical wall 104 extends downward from the outer periphery of the lower surface 102 of the housing body 100. In this embodiment, the lower tube wall 104 has, for example, a rectangular tube shape, but may have other shapes.

[0018] Next, we will explain the upper housing main body 130. Fig. 4 is a top view of the upper housing main body 130, Fig. 5 is a vertical cross-sectional view of the upper housing main body 130 taken along line CC shown in Fig. 4, Fig. 6 is a vertical cross-sectional view of the upper housing main body 130 taken along line DD shown in Fig. 4, and Fig. 7 is a bottom view of the upper housing main body 130.

[0019] 4 and 7, the upper housing main body 130 has a generally rectangular outer shape in a plan view, and has a hollow portion 135 in its center. This hollow portion 135 forms part of the storage space 13 when the upper housing main body 130 is combined with other components that form the housing 10.

[0020] The inner wall 133 defining the cavity 135 of the upper housing main body 130 forms a circular peripheral wall, and a groove 131 is provided in a portion of the wall, expanding in the radial direction of the upper housing main body 130. The groove 131 extends along the extension direction (vertical direction) of the accommodation space 13. Two grooves 131 are formed in the Z-axis direction, symmetrical with respect to the X-axis. Figures 4, 5, and 7 illustrate an imaginary circle IC1 assuming that the inner wall 133 is circular. The groove 131 is recessed outward relative to the imaginary circle IC1, i.e., recessed radially outward from the upper housing main body 130. The depth of the groove 131 is shorter than its width. Here, the width of the groove 131 refers to the length along the X-axis direction in Figures 4 and 7, and the depth of the groove 131 refers to the distance in the Z-axis direction from the imaginary circle IC1 to the bottom 131B of the groove 131. The bottom 131B is formed in an arc shape concentric with the imaginary circle IC3, and the depth of the entire groove 131 is uniform. The grooves 131 are formed on the inner wall 133 within a predetermined inter-edge inner wall area SA located between the first cutting edge portion 511 and the second cutting edge portion 521 of the conductor piece 50, which are cut when the circuit breaker 1 is activated, as described below. The dimensions of each groove 131, such as width, spacing, and depth, are not particularly limited and may be set arbitrarily. The grooves 131 function as escape spaces for escaping the expanded portion when at least one of the projectile 40 and the upper housing main body 130 expands in volume relative to the other of the projectile 40 and the upper housing main body 130. Specifically, the space formed between the bottom 131B of the groove 131 and the projectile 40 serves as the escape space. The imaginary circle IC1 coincides with the outline of the projectile 40 when not expanded. Here, when the imaginary circle IC1 is the outline of the projectile 40, the groove 131 is recessed in the range of 0.2 mm to 0.6 mm radially outward from the outline of the projectile 40 on the upper housing body 130.

[0021] 4 and 7, the upper housing body 130 has four corners provided with bolt holes 132 that penetrate in the vertical direction. A rectangular upper cylindrical wall 103 extends upward from the outer edge of the top surface of the upper housing body 130.

[0022] Next, a description will be given of the lower housing main body 140. Fig. 8 is a top view of the lower housing main body 140, Fig. 9 is a vertical cross-sectional view of the lower housing main body 140 taken along line E-E shown in Fig. 8, Fig. 10 is a vertical cross-sectional view of the lower housing main body 140 taken along line F-F shown in Fig. 8, and Fig. 11 is a bottom view of the lower housing main body 140.

[0023] As shown in FIG. 8 , the lower housing main body 140 has a generally rectangular outer shape in a plan view, with a hollow portion 145 defined by an inner wall 143 at its center. The hollow portion 145 is cylindrical, and the inner wall 143 forms a circular peripheral wall when viewed from the top and bottom. The hollow portion 145 forms part of the accommodation space 13 when the lower housing main body 140 is combined with other components of the housing 10. On the left and right sides of the hollow portion 145 are provided conductor piece holding portions 144, which are recesses into which the conductor pieces 50 are fitted. The conductor piece holding portions 144 are shaped by recessing the upper surface of the lower housing main body 140 downward along the contour of the conductor piece 50. By fitting the end of the conductor piece 50 into these conductor piece holding portions 144, the conductor piece 50 is positioned so as to cross the hollow portion 145 (accommodation space 13).

[0024] 8 and 11, lower housing body 140 has four corners with bolt holes 142 that penetrate vertically. A rectangular cylindrical lower tube wall 104 extends downward from the outer edge of the lower surface of lower housing body 140.

[0025] The upper housing body 130 and the lower housing body 140 configured as described above may be made of an insulating material such as a synthetic resin. For example, the upper housing body 130 and the lower housing body 140 may be made of polycarbonate or nylon, which is a type of polyamide synthetic resin.

[0026] [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 a hollow interior. The top holder 110 includes a small-diameter cylinder portion 112 located on the upper side (first end 11 side), a large-diameter cylinder portion 113 located on the lower side, a connecting portion 114 connecting these, and a flange portion 111 extending outward from the lower end of the large-diameter cylinder portion 113. For example, the small-diameter cylinder portion 112 and the large-diameter cylinder portion 113 are arranged coaxially, and the large-diameter cylinder portion 113 has a diameter slightly larger than that of the small-diameter cylinder portion 112.

[0027] 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.

[0028] The cavity formed inside the small-diameter cylinder portion 112 of the top holder 110 functions as an accommodating space that accommodates a portion of the igniter 20, as shown in FIG. 1 . Furthermore, the cavity formed inside the large-diameter cylinder portion 113 of the top holder 110 communicates with the cavity of the housing main body 100 located below, and forms a portion of the accommodating space 13. The top holder 110 configured as described above can be formed from an appropriate metal member, such as stainless steel or aluminum, which has excellent strength and durability. However, the material from which the top holder 110 is formed is not particularly limited. Furthermore, the above-described embodiment of the shape of the top holder 110 is merely an example, and other shapes may be adopted.

[0029] [Bottom Container] Next, the bottom container 120 will be described. The bottom container 120 has a hollow, generally bottomed cylindrical shape and includes a side wall 122, a bottom wall 123 connected to the lower end of the side wall 122, and a flange 121 connected to the upper end of the side wall 122. The side wall 122 has, for example, a cylindrical shape, and the flange 121 extends outward from the upper end of the side wall 122. The flange 121 of the bottom container 120 has a generally rectangular outline that fits inside the lower cylindrical wall 104 of the housing main body 100. A bolt-through hole (not shown) for passing a fastening bolt is provided vertically through the flange 121.

[0030] The above-described shape of the bottom container 120 is merely 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 may be formed from an appropriate metal member, such as stainless steel or aluminum, that has excellent strength and durability. However, the material from which the bottom container 120 is formed is not particularly limited. The bottom container 120 may also have a multi-layer structure. For example, the exterior portion of the bottom container 120 facing the outside may be formed from an appropriate metal member, such as stainless steel or aluminum, that has excellent strength and durability, and the interior portion facing the storage space 13 may be formed from an insulating material, such as synthetic resin. Of course, the entire bottom container 120 may be formed from an insulating material.

[0031] As described above, the housing 10 in this embodiment is configured by vertically assembling the top holder 110, upper housing main body 130, lower housing main body 140, and bottom container 120 together. During this assembly process, the conductor piece 50 is disposed through the housing main body 100. For example, the conductor piece 50 is fitted into the conductor piece holding portion 144 of the lower housing main body 140, and is disposed so that the conductor piece crosses the cavity portion 145. In this state, the lower surface of the upper housing main body 130 is butted against the upper surface of the lower housing main body 140 so that the bolt through-holes 142 of the lower housing main body 140 and the bolt through-holes 132 of the upper housing are coaxial. Furthermore, the flange portion 111 of the top holder 110 is inserted into the inside of the upper cylindrical wall 103 of the upper housing body 130, thereby placing the top holder 110 on the upper housing body 130, and the flange portion 121 of the bottom container 120 is inserted into the inside of the lower cylindrical wall 104 of the lower housing body 140, thereby placing the bottom container 120 below the lower housing body 140. Then, bolts are passed through the bolt holes of the top holder 110, upper housing body 130, lower housing body 140, and bottom container 120 to fasten each part together. Note that this fastening is not limited to bolts, and other fastening means such as rivets may be used.

[0032] Furthermore, each part may be joined with a sealant applied between the top holder 110 and the upper housing body 130, between the upper housing body 130 and the lower housing body 140 and the conductor piece 50, between the lower housing body 140 and the conductor piece 50, and between the lower housing body 140 and the bottom container 120. This increases the airtightness of the storage space 13 formed within the housing 10. Furthermore, the airtightness of the storage space 13 may be increased by interposing a packing or gasket 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.

[0033] [Igniter] Next, the igniter 20 will be described. The igniter 20 is an electric igniter including an ignition unit 21 containing an ignition charge and an igniter body 22 having a pair of conductive pins (not shown) connected to the ignition unit 21. The igniter body 22 is surrounded by, for example, insulating resin. Furthermore, the tip sides of the pair of conductive pins in the igniter body 22 are exposed to the outside and are connected to a power source when the circuit breaker 1 is in use.

[0034] The igniter main body 22 includes a generally cylindrical main body portion 221 housed inside the small-diameter cylinder portion 112 of the top holder 110, and a connector portion 222 located on top of the main body portion 221. The igniter main body 22 is fixed to the small-diameter cylinder portion 112, for example, by press-fitting the main body portion 221 into the inner circumferential surface of the small-diameter cylinder portion 112. Furthermore, a constricted portion, whose outer circumferential surface is recessed compared to other portions, is formed in an annular shape along the circumferential direction of the main body portion 221 at an axially intermediate portion of the main body portion 221, and an O-ring 223 is fitted into this constricted portion. The O-ring 223 is made of, for example, rubber (e.g., silicone rubber) or synthetic resin, and functions to increase the airtightness between the inner circumferential surface of the small-diameter cylinder portion 112 and the main body portion 221.

[0035] 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.

[0036] As shown in FIG. 1 , the ignition unit 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). The ignition unit 21 is configured, for example, as an igniter cup in which an ignition charge is accommodated. For example, the ignition charge is accommodated in the igniter cup of the ignition unit 21 while in contact with a bridge wire (resistor) that connects the base ends of a pair of conductive pins. Examples of the ignition charge that may be used include ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), THPP (titanium hydride potassium perchlorate), and lead tricinate.

[0037] When the igniter 20 is operated, an operating current for igniting the ignition charge is supplied from the power source to the conductive pin, causing the bridge wire in the ignition portion 21 to heat up, igniting and burning the ignition charge in the igniter cup and generating combustion gas. As the ignition charge in the igniter cup of the ignition portion 21 burns, the pressure in the igniter cup increases, causing the cleavage surface 21A of the igniter cup to cleave, and the 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 the projectile 40 placed in the accommodating space 13.

[0038] [Projectile] Next, the projectile 40 will be described. FIG. 12 is a front view of the projectile 40, FIG. 13 is a bottom view of the projectile 40, and FIG. 14 is a perspective view of the projectile 40. Note that in FIG. 14, the bottom surface of the projectile 40 is shown facing upward in order to illustrate the bottom surface of the projectile 40. The projectile 40 is formed, for example, from an insulating material such as synthetic resin. As shown in FIG. 13, the cross section of the projectile 40 when cut in a direction perpendicular to the radial direction is round. In this embodiment, the cross section of the projectile 40 is approximately a perfect circle. The projectile 40 includes a piston portion 41 and a rod portion 42 connected to the piston portion 41. The piston portion 41 has a roughly cylindrical shape and an outer diameter that roughly corresponds to the inner diameter of the large-diameter cylinder portion 113 of 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.

[0039] Furthermore, a recess 411 having, for example, a cylindrical shape is formed on the upper surface of the piston portion 41, and this recess 411 receives the ignition portion 21. The bottom surface of the recess 411 is formed as a pressure-receiving surface 411A that receives energy from the igniter 20 when the igniter 20 is activated. Furthermore, a constricted portion, whose outer peripheral surface is recessed compared to other portions, is formed in an annular shape along the circumferential direction of the piston portion 41 in the axial middle portion of the piston portion 41, and an O-ring 43 is fitted into this constricted portion. The O-ring 43 is made of, for example, rubber (e.g., silicone rubber) or synthetic resin, and functions to increase the airtightness between the inner peripheral surface of the large-diameter cylinder portion 113 and the piston portion 41.

[0040] 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 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 the cut portion 53 from the conductor piece 50 when the interrupter 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 may be changed depending on the shape and size of the cut portion 53 to be cut from the conductor piece 50 when the interrupter 1 is activated. The rod portion 42 may have a columnar shape, such as a cylindrical column or a rectangular column. Note that, in the initial position of the projectile 40 shown in FIG. 1 , the tip side region of the rod portion 42 of the projectile 40, including the cutting surface 420, is positioned in the hollow portion of the housing main body 100 (forming part of the storage space 13). The diameter of the rod portion 42 is, for example, slightly smaller than the inner diameter of the inner surface of the housing main body 100, and is configured so that the outer surface of the rod portion 42 is guided along the inner surface when the projectile 40 is launched.

[0041] As will be described in detail later, when the igniter 20 is activated, the projectile 40 configured as described above is launched from the initial position shown in FIG. 1 and moves at high speed toward the second end 12 (downward) along the accommodation space 13 due to the energy from the igniter 20 being received by the upper surface of the piston portion 41, including the pressure-receiving surface 411A. 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. In this embodiment, the piston portion 41 of the projectile 40 has a generally cylindrical shape, but the shape is not particularly limited. The outer shape of the piston portion 41 may be an appropriate shape and size depending on the shape and size of the inner wall surface of the large-diameter cylinder portion 113.

[0042] [Conductor Piece] Next, the conductor piece 50 will be described. As shown in FIG. 2 , the conductor piece 50 is fitted into the conductor piece holding portion 144 of the lower housing main body 140 and is arranged to cross the accommodation space 13. The conductor piece 50 extends along the X-axis. The conductor piece 50 constitutes a part of the components of the circuit breaker 1 and is a conductive metal body that forms part of a predetermined electric circuit when the circuit breaker 1 is attached to the electric circuit. The conductor piece 50 is sometimes called a bus bar. The conductor piece 50 may be formed of a metal such as copper (Cu). However, the conductor piece 50 may be formed of a metal other than copper or 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).

[0043] In one embodiment shown in FIG. 2 , the conductor piece 50 is formed as an elongated flat piece overall, including a first connecting end 51 and a second connecting end 52 at both ends, and a cut-off portion 53 located in the middle. 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 for connecting to other conductors (e.g., lead wires) in an electrical 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 severed by the rod portion 42 of the projectile 40 and cut off from the first connecting end 51 and the second connecting end 52 in the event of an abnormality such as an excessive current in the electrical 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 cutting and cutting off the cut-off portion 53.

[0044] The conductor piece 50 is cut at a position overlapping the inner surface (inner wall surface) of the inner wall 143 that defines the cavity 145 of the housing body 100, i.e., at a position overlapping the outer peripheral surface of the rod portion 42, and the excised portion 53 is cut off. At the first connecting end 51 of the conductor piece 50, the boundary portion between the excised portion 53 and the excised portion 53 is designated as a first cutting edge portion 511, and at the second connecting end 52, the boundary portion between the excised portion 53 and the excised portion 53 is designated as a second cutting edge portion 521.

[0045] Here, the conductor piece 50 can have various shapes, 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 limited to this. For example, the cut-out portion 53 of the conductor piece 50 may be connected perpendicular to the first connecting end 51 and the second connecting end 52 or at an angle. Furthermore, 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 of the conductor piece 50 can be omitted as appropriate.

[0046] [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, because a gap is formed on the side of the excised portion 53 disposed across the accommodation space 13, the projectile initial placement region R1 and the arc-extinguishing region R2 are not completely isolated by the excised portion 53, but are instead connected to each other. Of course, depending on the shape and size of the cut-out portion 53, the projectile initial placement region R1 and the arc-extinguishing region R2 may be completely isolated by the cut-out portion 53.

[0047] 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 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.

[0048] The arc-extinguishing region R2 in the circuit breaker 1 is a space for receiving the excision target portion 53 excised 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 excises the excision target portion 53. In order to effectively extinguish the arc generated when the excision target portion 53 is excised from the conductor piece 50, a coolant material 60 is disposed in the arc-extinguishing region R2 as an arc-extinguishing material.

[0049] In one aspect of the embodiment, the coolant material 60 is solid. In another aspect of the embodiment, the coolant material 60 is formed from a shape-retaining material. The shape-retaining material here refers to a material that maintains a certain shape when no external force is applied and that can maintain its integrity (does not fall apart) even if it is deformed when an external force is applied. For example, a fibrous material formed into a desired shape can be used as the shape-retaining material. In this embodiment, the coolant material 60 is formed from metal fibers, which are shape-retaining materials. Here, examples of the metal fibers that form the coolant material 60 include at least one of steel wool and copper wool. However, the above-described aspects of the coolant material 60 are merely examples and are not intended to be limiting.

[0050] The coolant material 60 is formed, for example, in a generally disk shape and is placed at the bottom of the bottom container 120 .

[0051] The circuit breaking device 1 of this embodiment has a sliding structure consisting of a housing 10, an igniter 20 attached to the housing 10, and a projectile 30 that can slide within the housing 10, and is used as a device that cuts a conductor piece 50 using the sliding structure.

[0052] <Operation> Next, a description will be given of the operation performed when the circuit breaker 1 is activated to interrupt an electric circuit. As described above, Fig. 1 shows the state before activation of the circuit breaker 1 (hereinafter also referred to as the "initial state before activation"). In this initial state before activation, the projectile 40 in the circuit breaker 1 is set to an initial position in which the piston portion 41 is positioned on the first end 11 side (upper end side) of the accommodating space 13 and the cut surface 420 formed on the lower end of the rod portion 42 is positioned on the upper surface of the cut portion 53 of the conductor piece 50.

[0053] Furthermore, the circuit breaker 1 according to the embodiment further includes an abnormality detection sensor (not shown) that detects an abnormal state of a device (e.g., a vehicle, a power generation facility, or a power storage facility) connected to the electrical circuit to be interrupted, and a control unit (not shown) that controls the operation of the igniter 20. The abnormality detection sensor may be capable of detecting an abnormal state based on the voltage or temperature of the conductor piece 50 in addition to the current flowing through the conductor piece 50. The abnormality detection sensor may also be, for example, an impact sensor, a temperature sensor, an acceleration sensor, or a vibration sensor, and may detect an abnormal state such as an accident or fire based on impact, temperature, acceleration, or vibration in a device such as a vehicle. The control unit of the circuit breaker 1 is, for example, a computer that can perform a predetermined function by executing a predetermined control program. The predetermined function of the control unit can also be realized by corresponding hardware. When an excessive current flows through the conductor piece 50, which forms part of the electrical circuit to which the circuit breaker 1 is applied, the abnormal current is detected by the abnormality detection sensor. Abnormality information regarding the detected abnormal current is passed from the abnormality detection sensor to the control unit. For example, the control unit receives current from an external power source (not shown) connected to the conductive pin of the igniter 20 based on the current value detected by the abnormality detection sensor, and activates the igniter 20. Here, the abnormal current may be a current value that exceeds a predetermined threshold value set to protect a predetermined electric circuit. Note that the above-mentioned abnormality detection sensor and control unit do not need to be included as components of the circuit breaker 1, and may be included in 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.

[0054] 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.

[0055] 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 through the accommodation space 13 along the extension direction (axial direction) of the accommodation space 13.

[0056] FIG. 15 is a diagram illustrating the operation of the circuit breaker 1 according to the embodiment. The upper part of FIG. 15 illustrates the state during operation of the circuit breaker 1, and the lower part of FIG. 15 illustrates the state after completion of operation of the circuit breaker 1. 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 through 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. 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.

[0057] 15, the projectile 40 moves downward a predetermined stroke in the extension direction (axial direction) of the accommodation space 13 until the lower end surface of the piston portion 41 abuts (collides) against the upper surface 101 of the housing main body 100. In this state, the cut portion 53 cut from the conductor piece 50 by the rod portion 42 of the projectile 40 is received in the arc-extinguishing region R2 in which the coolant material 60 is disposed. As a result, the first connection end 51 and the second connection end 52 located at both ends of the conductor piece 50 are electrically disconnected, and the predetermined electric circuit to which the circuit breaking device 1 is applied is forcibly interrupted.

[0058] Next, with reference to Figure 17, a method of operating the electrical circuit breaker according to this embodiment will be described. In step S101 of the operating method, the igniter 20 is activated. By activating the igniter 20, energy is imparted to the projectile 40 to cause it to slide within the accommodation space 13. In step S101, the sliding of the projectile 40 results in the severing of the conductor piece 50. In step S102, the projectile 40 is slid in a state where at least one of the projectile 40 and the housing 10 provides an escape space for escaping the expansion portion when the volume of the projectile 40 or the housing 10 expands relative to the other of the projectile 40 or the housing 10. The escape space is formed by providing a groove 131.

[0059] <Insulation Resistance After Activation> As described above, when the interrupting device 1 is activated, the first connecting end 51 is cut by the projectile 40 at the first cutting edge 511 ( FIG. 2 ), and the second connecting end 52 is cut by the second cutting edge 521. Furthermore, the first connecting end 51 and the second connecting end 52 come into contact with the housing body 100 and the rod portion 42 of the projectile 40. However, because the housing body 100 and the rod portion 42 are insulators, the first connecting end 51 and the second connecting end 52 are essentially insulated from each other after the interrupting device 1 is activated.

[0060] However, the moment the cut-off portion 53 of the conductor piece 50 is cut, an arc discharge occurs between the separating cut-off portion 53 and the first connecting end 51 and the second connecting end 52, causing the conductor piece 50 to evaporate and adhere to the inner wall of the housing main body 100 and the outer circumferential surface of the rod portion 42. When the conductor piece 50 adheres to the inner wall of the housing main body 100 and the outer circumferential surface of the rod portion 42 in this way and the degree of contamination increases, even if the housing main body 100 and the rod portion 42 themselves are insulators, and the insulation resistance value between the first connecting end 51 and the second connecting end 52 may decrease.

[0061] For this reason, the circuit breaking device 1 of this embodiment is provided with a coolant material 60 in the arc extinguishing region R2 that receives the cut portion 53 after cutting, and quickly extinguishes the arc and reduces the amount of evaporation of the conductor piece 50, thereby suppressing a decrease in the insulation resistance value.

[0062] Furthermore, a small gap is provided between the inner wall of the housing body 100 and the outer peripheral surface of the rod portion 42 so that the projectile 40 can move within the accommodating space 13 of the housing body 100, and the evaporated conductor piece 50 enters this gap and adheres to it, which is one of the causes of a decrease in the insulation resistance value. For this reason, the circuit breaker 1 of this embodiment has grooves 131, 141 on the inner wall of the housing body 100 and ensures a large creepage distance between the first connecting end 51 and the second connecting end 52, thereby suppressing a decrease in the insulation resistance value.

[0063] The circuit breaker may be used in an electric vehicle equipped with a high-voltage power supply. Automotive parts may be subjected to environmental testing that exceeds the actual vehicle operating environment. For example, a circuit breaker may be subjected to testing to determine whether it functions properly after being exposed to a 120°C environment for 12 consecutive days.

[0064] The housing and projectile of the circuit breaker are assumed to be made of resin with high insulating properties. Resin has a higher linear expansion coefficient than metal. In the circuit breaker 1 according to this embodiment, the upper housing body 130 and the lower housing body 140 are made of polycarbonate, and the projectile 40 is made of nylon. Resins such as polycarbonate and nylon exhibit a higher rate of volumetric expansion with increasing temperature compared to metals. Therefore, when the circuit breaker is subjected to the above-mentioned test in an environment of 120°C, the volumetric expansion of the projectile and housing deteriorates the projectile's sliding properties, resulting in a decrease in projectile speed. The decrease in projectile speed requires time for the cut portion of the conductor piece to come into contact with the coolant, which delays arc extinction and prolongs the exposure of resin components such as the housing and projectile to the high temperature of the arc. Exposure of the resin components to high temperatures increases the amount of carbonization of the resin, increasing the amount of carbonization around the cut portion of the conductor piece, which in turn reduces the insulating performance when the circuit breaker cuts the conductor piece. Thus, a decrease in projectile speed leads to a problem of reduced insulating performance when the conductor piece is cut.

[0065] Therefore, in the blocking device 1 according to this embodiment, a groove 131 is provided in the upper housing body 130 at a portion where the projectile 40 is fitted with the upper housing body 130. In the blocking device 1 according to this embodiment, the projectile 40 in the initial position is fitted to the inner wall 133 of the upper housing body 130, and the groove 131 only needs to be provided in at least a portion of the portion where the inner wall 133 and the projectile 40 are fitted together. In other words, the groove 131 is provided so that an escape space is formed between the inner wall 133 within the range of the initial position of the projectile 40 and the projectile 40 facing the inner wall 133. By providing the groove 131, an escape space can be provided between the projectile 40 and the upper housing body 130 during volumetric expansion. For example, in a high-temperature environment of about 120°C, when the projectile 40 expands in volume relative to the upper housing main body 130, the projectile 40 expands toward the escape space, causing the upper housing main body 130 and the projectile 40 to no longer fit together in the escape space, creating a gap between them. This allows the circuit breaker 1 to eliminate frictional resistance between the projectile 40 and the upper housing main body 130 in the escape space, preventing the projectile 40 from sliding smoothly. The circuit breaker 1 can prevent a decrease in insulation performance when the conductor piece 50 is cut, which is caused by a decrease in the speed of the projectile 40.

[0066] Here, the relationship between the groove 131 and the center O of the imaginary circle IC1 will be described. FIG. 17 is a top view of the upper housing main body 130 similar to FIG. 4 . FIG. 17 illustrates the center O of the imaginary circle IC1. The center O coincides with the central axis of the cavity 135 (accommodation space 13). In this embodiment, the central angle CA1 formed by an imaginary line IL1 connecting one widthwise end of the groove 131 to the center O and an imaginary line IL2 connecting the other widthwise end of the groove 131 to the center O is set to be greater than or equal to 90° and less than or equal to 120° (90° to 120°). Note that the central angle CA1 is symmetrical with respect to the Z-axis direction. A central angle CA1 of 90° means that the central angle CA1 is 45° to the right of the Z-axis and 45° to the left of the Z-axis. Similarly, a central angle CA1 of 120° means that the central angle CA1 is 60° to the right of the Z-axis and 60° to the left of the Z-axis. When viewed from the same perspective as the central angle CA1, the conductor piece 50 extends in a direction of a central angle of 180°. The conductor piece 50 extends below the upper housing main body 130. If the central angle CA1 were greater than 120°, the groove 131 and the conductor piece 50 would overlap in the vertical direction. Since it is preferable not to provide the groove 131 in the area overlapping the conductor piece 50, the upper limit of the central angle CA1 is set to 120° in this embodiment. On the other hand, if the central angle CA1 is less than 90°, the width of the groove 131 is insufficient to suppress deterioration of the sliding properties of the projectile 40, and the effect of suppressing deterioration of sliding properties is not fully achieved. For this reason, the lower limit of the central angle CA1 is set to 90°.

[0067] Next, samples of the circuit breaker 1 were prepared when the central angle CA1 was 90° and when the central angle CA1 was 120°, and the insulation resistance value between the first cutting edge portion 511 and the second cutting edge portion 521 of the conductor piece 50, which is cut when the circuit breaker 1 is operated, was measured. The insulation resistance values ​​were measured using an insulation resistance meter (IR4053) manufactured by Hioki E.E. Corporation. Table 1 below shows the insulation resistance values ​​measured when the central angle CA1 was 90°. As shown in Table 1, nine samples of the circuit breaker 1 with a central angle CA1 of 90° were prepared. For Samples No. 1 to 4, the insulation resistance values ​​were measured when the circuit breaker 1 was operated in an environment at 85°C after being subjected to an environmental load at 120°C for 12 days. For Samples No. 5 to 9, the insulation resistance values ​​were measured when the circuit breaker 1 was operated in an environment at -40°C after being subjected to an environmental load at 120°C for 12 days.

[0068]

[0069] Table 2 below shows the insulation resistance values ​​measured when the central angle CA1 was 120°. As shown in Table 2, 10 samples of circuit breaker 1 with a central angle CA1 of 120° were produced. For samples 1 to 5, the insulation resistance values ​​were measured when an environmental load was applied at 120°C for 12 days and then operated in an environment at 85°C, and for samples 6 to 10, the insulation resistance values ​​were measured when an environmental load was applied at 120°C for 12 days and then operated in an environment at -40°C.

[0070]

[0071] As shown in Tables 1 and 2, a relatively high insulation resistance value was obtained for all samples. In the circuit breaker 1 according to this embodiment, by setting the central angle CA1 to 90° to 120°, the insulation resistance value between the first cutting edge 511 and the second cutting edge 521 can be made a relatively high value.

[0072] Next, the extent of the recession of groove 131 was examined when imaginary circle IC1 was the outline of projectile 40. In this embodiment, as described above, groove 131 is recessed from the outline of projectile 40 by 0.2 mm to 0.6 mm radially outward of upper housing main body 130. The recession of groove 131 was measured as a diameter (Φ) from the center of imaginary circle IC1. Samples of blocking device 1 with a diameter of 20.6 mm (expanded 0.2 mm) from imaginary circle IC1, a diameter of 20.8 mm (expanded 0.4 mm) from imaginary circle IC1, and a diameter of 21.0 mm (expanded 0.6 mm) from imaginary circle IC1 were prepared, as well as a comparative sample with no diameter expansion from imaginary circle IC1, i.e., no groove 131 formed, and subjected to a load measurement test. The comparative sample had a hollow portion 135 with a diameter of 20.4 mm, which coincided with imaginary circle IC1.

[0073] Next, in this embodiment, a load measurement test was performed to evaluate the interrupter 1. Fig. 18 is a diagram illustrating the internal structure of the interrupter 1 when a load measurement test is performed. First, the igniter 20 and the O-ring 223 were removed from the interrupter 1, and the jig 500 was placed on the projectile 40. Next, using a tensile tester (manufactured by MinebeaMitsumi (model NMB / TG-250kN)), the zero point was taken at the upper end of the jig 500, and the displacement (mm) and load (kN) of the jig 500 were measured when the jig 500 was pushed downward at a speed of 500 mm / min.

[0074] FIG. 19 is a graph showing the results of the load measurement test. The vertical axis of the graph in FIG. 19 represents load (kN), and the horizontal axis of FIG. 19 represents displacement (mm). The solid line L1 in the graph in FIG. 19 represents the test results for the comparative sample (Φ=20.4 mm, no diameter expansion), the dashed-dotted line L2 in the graph represents the test results for sample 1 (Φ=20.6 mm, 0.2 mm diameter expansion), the dotted line L3 in the graph represents the test results for sample 2 (Φ=20.8 mm, 0.4 mm diameter expansion), and the dashed-two-dot line L4 in the graph represents the test results for sample 3 (Φ=21.0 mm, 0.6 mm diameter expansion). Table 3 below shows the load (kN) at the maximum displacement of each sample.

[0075]

[0076] In the load measurement test, the results were the same for sample 2, which had a diameter (Φ) of 20.8 mm, and sample 3, which had a diameter (Φ) of 21.0 mm, and the maximum load reached its lower limit when the diameter (Φ) was 20.8 mm or greater. Therefore, when the imaginary circle IC1 is the outline of the projectile 40, the groove 131 is recessed in the range of 0.2 mm to 0.6 mm radially outward of the upper housing main body 130 relative to the outline of the projectile 40. In other words, by having the diameter of the groove 131 in the range of 0.2 mm to 0.6 mm, the blocking device 1 can sufficiently suppress frictional resistance and suppress a decrease in the speed of the projectile 40 compared to a comparative example without a groove.

[0077] Additionally, samples of the circuit breaker 1 with diameters (Φ) of 20.6 mm, 20.8 mm, and 21.0 mm were prepared, and the insulation resistance between the first cutting edge 511 and the second cutting edge 521 of the conductor piece 50, which is cut when the circuit breaker 1 is activated, was measured. The insulation resistance was measured using an insulation resistance meter (IR4053) manufactured by Hioki E.E. Corporation. Table 4 below shows the insulation resistance values ​​measured for each sample. For Samples 1-1, 1-2, 2-1, 2-2, 3-1, and 3-2, the insulation resistance was measured when the samples were operated in an environment at 85°C after being subjected to an environmental load at 120°C for 12 days. For Samples 1-3 to 1-5, 2-3 to 2-5, and 3-3 to 3-5, the insulation resistance was measured when the samples were operated in an environment at -40°C after being subjected to an environmental load at 120°C for 12 days.

[0078]

[0079] As shown in Table 4, a relatively high insulation resistance value was obtained for all samples. In the circuit breaker 1 according to this embodiment, the diameter of the groove 131 is in the range of 0.2 to 0.6 mm, and therefore the circuit breaker 1 can achieve a relatively high insulation resistance value between the first cutting edge portion 511 and the second cutting edge portion 521.

[0080] The depth (diameter) of groove 131 is shorter than the width. If groove 131 were too deep, evaporated conductor pieces might get in, reducing the insulation resistance, or the resin might be more likely to crack due to a reduction in the strength of housing 10. Therefore, in this embodiment, groove 131 is formed with a depth (diameter) shorter than the width, and the depth is set in the range of 0.2 mm to 0.6 mm, thereby preventing problems such as a reduction in insulation resistance or a reduction in the strength of housing 10 that makes the resin more likely to crack.

[0081] Next, a description will be given of a shutoff device according to embodiment 2. The shutoff device according to this embodiment has the same configuration as that of embodiment 1, but differs from embodiment 1 in that a groove 141 is formed in the lower housing main body 140.

[0082] Fig. 20 is a top view of lower housing main body 140, Fig. 21 is a vertical cross-sectional view of lower housing main body 140 taken along line G-G shown in Fig. 20, Fig. 22 is a vertical cross-sectional view of lower housing main body 140 taken along line H-H shown in Fig. 20, and Fig. 23 is a bottom view of lower housing main body 140. Note that components corresponding to those in the first embodiment described above are given the same reference numerals, and descriptions thereof will be omitted.

[0083] The inner wall 143 defining the cavity 145 of the lower housing main body 140 forms a circular peripheral wall, and a groove 141 is provided in a portion of the wall, expanding in the radial direction of the lower housing main body 140. The groove 141 extends along the extension direction (up-down direction) of the accommodation space 13. Two grooves 141 are formed in the Z-axis direction, symmetrical with respect to the X-axis. Figures 20, 21, and 23 show an imaginary circle IC2 assuming that the inner wall 143 is circular. The groove 141 is formed concave outward relative to the imaginary circle IC2, i.e., concave outward in the radial direction of the lower housing main body 140. The depth of the groove 141 is shorter than its width. Here, the width of the groove 141 refers to the length along the X-axis direction in Figures 20 and 23, and the depth of the groove 141 refers to the distance in the Z-axis direction from the imaginary circle IC2 to the bottom 141B of the groove 141. The bottom 141B is formed in an arc shape concentric with the imaginary circle IC2, and the depth of the entire groove 141 is uniform. The groove 141 is formed on the inner wall 143 within a predetermined inter-edge inner wall area SA located between the first cutting edge portion 511 and the second cutting edge portion 521 of the conductor piece 50 that is cut when the circuit breaker 1 is activated. The dimensions of the groove 141, such as width, spacing, and depth, are not particularly limited and may be set arbitrarily. The groove 141 functions as a relief space for escaping the expanded portion when at least one of the projectile 40 and the lower housing main body 140 expands in volume relative to the other of the projectile 40 and the lower housing main body 140. Specifically, the space formed between the bottom 141B of the groove 141 and the projectile 40 serves as the relief space. The imaginary circle IC2 coincides with the outline of the projectile 40 when not expanded. As in the above-described first embodiment, when the imaginary circle IC2 is the outline of the projectile 40, the groove 141 is recessed radially outward of the upper housing body 130 by a distance of 0.2 mm to 0.6 mm relative to the outline of the projectile 40.

[0084] In the interrupting device 1 according to this embodiment, a groove 141 is provided at the location where the projectile 40 slides on the lower housing main body 140. Providing the groove 141 allows for a relief space to be provided between the projectile 40 and the upper housing main body 130 during volumetric expansion. For example, in a high-temperature environment of approximately 120°C, if the projectile 40 expands in volume relative to the lower housing main body 140, a relief space can also be provided in the lower housing main body 140. This eliminates frictional resistance between the projectile 40 and the lower housing main body 140 in the relief space, thereby preventing deterioration of the sliding properties of the projectile 40. The interrupting device 1 can prevent a decrease in insulation performance when the conductor piece 50 is cut, which is caused by a decrease in the projectile 40's speed. In this manner, a relief space may be provided within the range where the projectile 40 slides.

[0085] Here, the relationship between the groove 141 and the center O of the imaginary circle IC2 will be described. FIG. 24 is a top view of the lower housing main body 140 similar to FIG. 20 . FIG. 24 illustrates the center O of the imaginary circle IC2. The center O coincides with the central axis of the hollow portion 145 (accommodation space 13). In this embodiment, the central angle CA2 formed by the imaginary line IL3 connecting one widthwise end of the groove 141 to the center O and the imaginary line IL4 connecting the other widthwise end of the groove 141 to the center O is set to be greater than or equal to 90° and less than or equal to 120° (90° to 120°). Note that the central angle CA2 is symmetrical with respect to the Z-axis direction. A central angle CA2 of 90° means that the central angle CA2 is 45° to the right of the Z-axis and 45° to the left of the Z-axis. Similarly, a central angle CA2 of 120° means that the central angle CA2 is 60° to the right of the Z-axis and 60° to the left of the Z-axis. When viewed from the same perspective as the central angle CA2, the conductor piece 50 extends in a direction of a central angle of 180°. The conductor piece 50 extends above the lower housing main body 140. If the central angle CA2 were greater than 120°, the groove 141 and the conductor piece 50 would overlap in the vertical direction. Since it is preferable not to provide the groove 141 in the area overlapping the conductor piece 50, the upper limit of the central angle CA2 is set to 120° in this embodiment. On the other hand, if the central angle CA2 is less than 90°, the width of the groove 141 is insufficient to suppress deterioration of the sliding properties of the projectile 40, and the effect of suppressing deterioration of sliding properties is not fully achieved. For this reason, the lower limit of the central angle CA2 is set to 90°.

[0086] <Embodiment 3> Next, a description will be given of an interrupting device according to embodiment 3. The interrupting device according to this embodiment has the same configuration as that of embodiment 1, and is characterized in that the projectile 40 has a portion whose diameter is reduced relative to the storage space.

[0087] FIG. 25 is a front view of the projectile 40, and FIG. 26 is a bottom view of the projectile 40. In this embodiment, a groove 421 is provided in the rod portion 42 of the projectile 40. The groove 421 is provided on the outer periphery of the rod portion 42 and is concave radially inward of the projectile 40. As shown in FIG. 26, two grooves 421 are formed in the Z-axis direction so as to be symmetrical about the X-axis. FIG. 26 also illustrates an imaginary circle IC3 assuming that the cross section of the rod portion 42 cut along the X-Z plane is circular. The groove 421 is concave inward relative to the imaginary circle IC3, i.e., is concave radially inward of the projectile 40. The depth of the groove 421 is shorter than its width. Here, the width of the groove 421 refers to the length along the X-axis direction in FIGS. 25 and 26, and the depth of the groove 421 refers to the distance in the Z-axis direction from the imaginary circle IC3 to the bottom 421B of the groove 421. The bottom 421B is formed in an arc shape concentric with the imaginary circle IC3, and the depth of the entire groove 421 is uniform. The groove 421 is formed in a position facing the inner wall 143 within a predetermined inter-edge inner wall area SA located between the first cutting edge portion 511 and the second cutting edge portion 521 of the conductor piece 50 that is cut when the circuit breaker 1 is activated. The dimensions of the groove 421, such as width, spacing, and depth, are not particularly limited and may be set as desired. The groove 421 functions as a relief space for escaping expansion when the projectile 40 and at least one of the upper housing body 130 and the lower housing body 140 expand in volume relative to the other of the projectile 40 or the upper housing body 130 and the lower housing body 140. Specifically, the space formed between the bottom 421B of the groove 421 and the inner wall 133 of the upper housing body 130 and the inner wall 143 of the lower housing body 140 serves as the relief space. The imaginary circle IC3 substantially coincides with the inner wall of the accommodating space 13 when the housing 10 is not volumetrically expanded. The accommodating space 13 has a circular cross section when the housing 10 is cut in a direction perpendicular to the radial direction. As in the first embodiment, when the imaginary circle IC3 is the inner outline of the accommodating space 13, the groove 421 is recessed by 0.2 mm to 0.6 mm radially outward from the outer outline of the projectile 40.

[0088] In the blocking device 1 according to this embodiment, a groove 421 is provided in the projectile 40 at a portion where the projectile 40 fits into the upper housing body 130. In the blocking device 1 according to this embodiment, the projectile 40 is fitted to the inner wall 133 of the upper housing body 130 in the initial position, and the groove 421 only needs to be provided in at least a portion of the portion where the inner wall 133 and the projectile 40 fit together. In other words, the groove 421 is provided so that an escape space is formed between the inner wall 133 within the range of the initial position of the projectile 40 and the projectile 40 facing the inner wall 133. By providing the groove 421, an escape space can be provided between the projectile 40 and the upper housing body 130 during volumetric expansion. For example, in a high-temperature environment of about 120°C, when the projectile 40 expands in volume relative to the upper housing main body 130, the projectile 40 expands toward the escape space, causing the upper housing main body 130 and the projectile 40 to no longer fit together in the escape space, creating a gap between them. This allows the circuit breaker 1 to eliminate frictional resistance between the projectile 40 and the upper housing main body 130 in the escape space, preventing the projectile 40 from sliding smoothly. The circuit breaker 1 can prevent a decrease in insulation performance when the conductor piece 50 is cut, which is caused by a decrease in the speed of the projectile 40.

[0089] Here, the relationship between the groove 421 and the center O of the imaginary circle IC3 will be described. FIG. 26 illustrates the center O of the imaginary circle IC3. The center O coincides with the central axis of the projectile 40 and the central axis of the hollow portion 145 (the housing space 13). In this embodiment, the central angle CA3 formed by the imaginary line IL5 connecting one end of the groove 421 in the width direction to the center O and the imaginary line IL6 connecting the other end of the groove 421 in the width direction to the center O is set to be greater than or equal to 90° and less than or equal to 120° (90° to 120°). The central angle CA3 is symmetrical with respect to the Z-axis direction. A central angle CA3 of 90° means that the central angle CA3 is 45° to the right of the Z-axis and 45° to the left of the Z-axis. Similarly, a central angle CA3 of 120° means that the central angle CA3 is 60° to the right of the Z-axis and 60° to the left of the Z-axis. When viewed from the same perspective as the central angle CA3, the conductor piece 50 extends in the direction of a central angle of 180°. The conductor piece 50 extends below the projectile 40 in the initial position. If the central angle CA3 were greater than 120°, the groove 421 and the conductor piece 50 would overlap in the vertical direction. Since it is preferable not to provide the groove 421 in the area overlapping the conductor piece 50, the upper limit of the central angle CA3 is set to 120° in this embodiment. On the other hand, if the central angle CA3 is less than 90°, the width of the groove 421 is insufficient to suppress deterioration of the sliding properties of the projectile 40, and the effect of suppressing deterioration of sliding properties is not fully achieved. For this reason, the lower limit of the central angle CA3 is set to 90°.

[0090] Other Embodiments Although the embodiments of the present disclosure have been described above, the various embodiments described above can be combined as much as possible. For example, the sliding structure of the present disclosure can be used in a needleless syringe that ejects an injection target substance, such as a medicinal solution, from its tip by sliding a piston using energy received from an igniter. The sliding structure of the present disclosure can also be used in a perforator, pin puller, hood lifter, power pollard, or the like that drills a hole in an object by sliding a piston using energy received from an igniter. A power pollard is a device that is buried under the road surface near a vehicle entrance and, when activated, protrudes a cylindrical structure from the road surface to prevent vehicles from passing through.

[0091] 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.

[0092] 1: Breaker device 10: Housing 13: Storage space 20: Igniter 40: Projectile 42: Rod portion 50: Conductor piece 53: Portion to be cut 60: Coolant material 100: Housing body 130: Upper housing body 131: Groove 140: Lower housing body 141: Groove

Claims

1. A sliding structure comprising: a housing containing an accommodating space extending in one direction; an igniter provided in said housing; a projectile disposed within said accommodating space, fired from one end of said accommodating space by energy received from said igniter, and sliding along the extension direction of said accommodating space; and an escape space provided in at least a portion of the area where an inner wall defining said accommodating space and said projectile are fitted together, for allowing an expanded portion to escape when the volume of at least one of said projectile and said housing expands relative to the other of said projectile or said housing.

2. The sliding structure according to claim 1, wherein the escape space is provided within a range in which the projectile slides.

3. The sliding structure according to claim 1, wherein the housing has a groove formed in the inner wall, the groove being concave radially outward of the housing and having a depth shorter than its width, and the escape space is formed between the bottom of the groove and the projectile.

4. The sliding structure according to claim 3, wherein the central angle formed by an imaginary line connecting one end of the groove in the width direction and the central axis of the storage space and an imaginary line connecting the other end of the groove in the width direction and the central axis of the storage space is 90° to 120°.

5. A sliding structure according to claim 3 or 4, wherein the groove is recessed in the range of 0.2 mm to 0.6 mm radially outward from the housing relative to the outer contour of the projectile.

6. A sliding structure according to any one of claims 1 to 3, wherein the cross section of the projectile when cut in a direction perpendicular to the radial direction is round.

7. The sliding structure according to claim 1, wherein the projectile has a groove provided on its outer periphery, which groove is concave radially inward of the projectile and has a depth shorter than its width, and the escape space is formed between the bottom of the groove and the inner wall.

8. The sliding structure according to claim 7, wherein the central angle formed by an imaginary line connecting one end of the groove in the width direction and the central axis of the projectile and an imaginary line connecting the other end of the groove in the width direction and the central axis of the projectile is 90° to 120°.

9. A sliding structure according to claim 7 or 8, wherein the groove has a diameter that narrows in the range of 0.2 mm to 0.6 mm toward the center in the radial direction of the projectile relative to the inner contour of the storage space.

10. The sliding structure according to claim 7 or 8, wherein the housing space has a circular cross section when cut in a direction perpendicular to the radial direction.

11. An electric circuit breaking device comprising: the sliding structure according to claim 1 or 2; and a conductor piece provided in the housing and forming part of an electric circuit, the conductor piece having a cut-out portion that can be cut out by the projectile, the cut-out portion being positioned so as to traverse the accommodation space.

12. A method for operating a sliding structure, comprising: activating an igniter to impart energy to a projectile for sliding the projectile inside a housing; and sliding the projectile in a state where at least one of the projectile and the housing has an escape space for escaping expansion when the volume of the projectile expands relative to the other of the projectile or the housing.

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