JP6344312B2 - Conduction interruption device - Google Patents

Description

  The present invention relates to a conduction interrupting device that interrupts electrical conduction between devices constituting an electric circuit through cutting of a conductor.

  The electrical circuit is provided with a continuity interrupting device that shuts off electrical continuity between the devices by operating when the devices constituting the electrical circuit are abnormal or when the system in which the electrical circuit is mounted is abnormal. As one aspect thereof, for example, Patent Document 1 discloses a conduction interrupting device including a conductor, a gas generator, and a cutting member. The conductor is interposed between devices constituting the electric circuit. A gas generator is arrange | positioned in the location away from the conductor, and generates gas. The cutting member is disposed between the conductor and the gas generator, and is moved by the gas from the gas generator to cut the conductor. By this cutting, a pair of cut ends that are separated from each other are generated in the conductor, and the conductor is divided between the two cut ends, and conduction between the devices is cut off.

  By the way, when the conduction interrupting device is activated and the conductive material is cut, an electric potential difference is generated between the pair of cut ends generated by the cut, so that an arc is generated, that is, exists between both cut ends. There is a case where a phenomenon occurs in which current flows due to breakdown of gas insulation.

  When the arc is generated, the two cut ends are electrically connected, and there is a possibility that the conductor is maintained in an energized state (conduction is not interrupted) even though the conductor is physically disconnected. In addition, the arc may melt the conductor and the surrounding resin member.

  On the other hand, in the conduction interruption device described in Patent Document 1, in addition to the above configuration, the conductor is cut by the cutting member, and an arc generated between the pair of cut ends generated in the conductor by the cutting is generated. An arc extinguishing chamber for damping is provided. The arc extinguishing chamber is made of a material having electrical insulation. The inner wall surface of the arc extinguishing chamber is provided with a recess at least in a region including at least a portion where one of the two cutting ends approaches and a portion where the other approaches when the conductor is cut.

  For this reason, when the conductor in an energized state is cut by the cutting member, the arc flows from the one cut end toward the other cut end along the wall surface of the recess. Since the arc is along the wall surface of the recess, the length of the path through which the arc flows is longer than when the recess is not provided, and the arc is attenuated. Therefore, the influence of the arc on the conduction breaker is smaller than that in which no measures are taken to attenuate the arc.

JP 2014-49300 A

  As described above, the technique described in Patent Document 1 attempts to attenuate the arc by lengthening the path through which the arc flows. However, this technique is not the only method for attenuating the arc, and there is a need for a conduction breaker that can attenuate the arc in a different manner.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a conduction interrupting device capable of efficiently attenuating an arc generated between cut ends due to cutting of a conductor. It is in.

  A continuity-breaking device that solves the above problems is formed between a conductor that is interposed between devices constituting an electric circuit and has a long plate-shaped part to be cut in one part and a thickness direction of the part to be cut. An arc extinguishing chamber, a gas generator disposed on the opposite side of the arc extinguishing chamber in the thickness direction with the cut portion interposed therebetween, and between the cut portion and the gas generator And a cutting member that is moved toward the arc-extinguishing chamber by the gas generated by the gas generator and cuts the cut portion by the blade portion in the arc-extinguishing chamber. And a cut-off device that generates a pair of cut ends in a state of being separated from each other to cut off the conduction between the devices, and is an outer wall surface of the blade portion. Locations where one of the cutting ends approaches and the other approaches after the cutting portion is cut by the blade portion. A fitting portion is provided in a region between and a fitting portion that is fitted in a state in which at least a part of the fitting portion is in contact with the inner wall surface of the arc extinguishing chamber. Yes.

  According to said structure, if gas is generated from a gas generator in the state with electricity supplied to the conductor, the pressure of the gas will be applied to a cutting member, and the cutting member will be moved to the arc-extinguishing chamber side. The part to be cut is pressed by the blade part of the cutting member and cut in the arc extinguishing chamber. Along with this cutting, a pair of cut ends in a state of being separated from each other are generated in the portion to be cut. A conductor will be in the state divided | segmented between both the cutting ends, and the continuity between apparatuses will be interrupted | blocked.

  At this time, the arc tends to flow from one cutting end toward the other cutting end via the space between the blade portion of the cutting member and the arc extinguishing chamber. However, after cutting the part to be cut, the fitting part of the cutting member is fitted to the fitting part of the arc extinguishing chamber between the two cutting ends, and the gap between the fitting part and the fitting part is between Since the space is narrowed, the arc is difficult to flow through this space.

  And the said fitting is made in the state in which at least one part of the fitting part contacted the to-be-fitted part. The space between the fitting portion and the fitted portion is in a state where it is divided in the length direction of the cut portion with the contact portion as a boundary, and the arc is more difficult to flow through this space.

  In the conduction interrupting device, the fitting portion is provided at a tip portion of the blade portion in a moving direction of the cutting member, and the fitting portion is the fitting of the inner wall surface of the arc extinguishing chamber. It is preferable that it is provided in the back wall surface which opposes the front end surface of a part.

  According to said structure, after the to-be-cut | disconnected part is cut | disconnected by the blade part of a cutting member, the fitting part provided in the front-end | tip part in the moving direction of a cutting member is an inner wall surface of an arc extinguishing chamber among blade parts. Of these, it is fitted to a fitted portion provided on a back wall surface facing the front end surface of the fitting portion. At the time of this fitting, at least a part of the fitting portion is brought into contact with the fitted portion. Thus, fitting with contact with the fitted portion of the fitting portion is performed on the distal end side in the moving direction of the cutting member.

  Therefore, the arc flows from one cut end toward the tip end side in the moving direction of the cutting member, and then flows toward the other cut end after passing through the space between the fitting portion and the fitted portion. It will be. However, since the space between the fitting portion and the fitted portion is narrow on the tip end side and is in a divided state, the arc hardly flows in the same space.

  In the above-described conduction interrupting device, the fitted portion is configured by a recess opening in the inner wall surface of the arc extinguishing chamber, and the fitting portion is inserted into the fitted portion, The cutting member is fitted to the fitted part in a state of being in contact with the inner wall surface of the fitted part at the tip in the moving direction, and at least the back part of the fitted part is the cut object It is preferable that the dimension in the length direction of the part is formed so as to become smaller as the distance from the inner wall surface of the arc extinguishing chamber decreases.

  By forming at least the back part of the fitted part into a shape that satisfies the above conditions, in the process of inserting the fitting part into the fitted part, the tip of the fitted part is in the fitted part. It becomes easy to contact at least one of the inner wall surfaces facing the length direction of the part to be cut. The fitting portion is fitted to the fitted portion in a state where the tip thereof is in contact with the inner wall surface of the fitted portion.

  In the continuity interrupting device, the inner wall surface of the fitting portion that faces the distal end surface of the fitting portion is pressed by the fitting portion that is inserted into the fitting portion. It is preferable to provide a rib that can be deformed in this manner.

  According to said structure, as insertion to the to-be-fitted part of a fitting part progresses, the front end surface of a fitting part approaches the inner back wall surface of a to-be-fitted part. Even after the front end surface of the fitting portion contacts the rib provided on the inner back wall surface of the fitted portion, if the movement of the fitting portion continues, the rib is pressed and deformed by the fitting portion. The space between the front end surface of the fitting portion and the inner back wall surface of the fitted portion is filled with the deformed rib as described above, the space is further reduced, and the arc fills this space more. It becomes more difficult to flow.

  In the conduction interrupting device, the fitting portion is provided on a side wall surface orthogonal to the width direction of the cut portion of the blade portion, and the fitted portion is the width of the arc extinguishing chamber. It is preferable to be provided on the side wall surface orthogonal to the direction.

  According to said structure, after cutting the to-be-cut part by the blade part of a cutting member, the fitting part provided in the side wall surface orthogonal to the width direction of a to-be-cut part is the arc extinguishing chamber among the blade parts. The fitting portion is fitted to the fitting portion provided on the side wall surface orthogonal to the width direction of the to-be-cut portion. At the time of this fitting, at least a part of the fitting portion is brought into contact with the fitted portion. Thus, the fitting with the contact of the fitting portion with the fitted portion is performed on the side along the width direction of the cut portion.

  Therefore, the arc flows from one cut end along the width direction of the cut portion, passes through the space between the fitting portion and the fit portion, and then flows toward the other cut end. Become. However, since the space between the fitting portion and the fitted portion is narrow on the outer end side in the width direction of the cut portion and is in a divided state, it is difficult for the arc to flow in the same space.

  In the conduction interrupting device, the fitted portion is configured by a recess that opens in the side wall surface of the arc-extinguishing chamber and extends along a moving direction of the cutting member, and the fitting portion includes: By being inserted into the fitted portion, the cutting member is fitted into the fitted portion while being in contact with the inner wall surface of the fitted portion at the distal end in the moving direction. Of the fitting parts, at least the tip part in the moving direction of the cutting member is preferably formed such that the depth of the fitted part becomes shallower toward the tip side in the same direction.

  In the process of inserting the fitting part into the fitted part, at least the tip part in the moving direction of the cutting member is formed in a shape that satisfies the above conditions among the fitted parts. The tip is easily brought into contact with at least one of the inner wall surfaces facing the width direction of the cut portion in the fitted portion. The fitting portion is fitted to the fitted portion in a state where the tip thereof is in contact with the inner wall surface of the fitted portion.

  In the above-described conduction interrupting device, the arc-extinguishing chamber has a polygonal opening that opens to face the conductor, and a side of the opening that extends along the width direction of the cut portion is a cutting edge portion. The blade part is for cutting the part to be cut between the cutting edge part by moving the part approaching the cutting edge part in the arc extinguishing chamber, and the cutting member is The fitting portion is formed of a material that can be elastically deformed, and when the fitting portion is inserted into the fitting portion, the cutting member is elastically deformed to the cutting edge portion side, thereby forming the fitting portion. It is preferable that it is contacted.

  According to the above configuration, when gas is generated from the gas generator while the conductor is energized, the gas causes the blade portion of the cutting member to be in the arc extinguishing chamber and to be cut in the opening. The part which approached the cutting edge part comprised by the one side extended along the width direction of this is moved. The conductor is cut between these narrowly cut edge portions and blade portions.

  Here, the cutting member is made of an elastically deformable material. Therefore, when the fitting portion is inserted into the fitted portion, the cutting member is elastically deformed toward the cutting edge portion, so that the fitting portion is fitted while contacting the fitted portion.

  In the continuity interrupting device, a rib that is pressed and deformed by the fitting portion is provided on a surface of the inner wall surface of the fitting portion that faces the tip surface of the fitting portion. Is preferred.

  According to said structure, as insertion to the to-be-fitted part of a fitting part progresses, the front end surface of a fitting part becomes a surface which opposes the front end surface of a fitting part among the inner wall surfaces of a to-be-fitted part. Get closer. Even after the front end surface of the fitting portion contacts the rib provided on the surface of the fitted portion, if the movement of the fitting portion continues, the rib is pressed and deformed by the fitting portion. The space between the front end surface of the fitting portion and the surface of the fitted portion is filled with the deformed rib as described above, the space is further reduced, and the arc further fills this space. It becomes difficult to flow.

  According to the said conduction | electrical_connection interruption | blocking apparatus, the arc which generate | occur | produced between the cutting ends with the cutting | disconnection of a conductor can be attenuate | damped efficiently.

Sectional drawing which shows the internal structure of the conduction | electrical_connection interruption | blocking apparatus in one Embodiment. The schematic diagram which shows schematic structure of the electric circuit to which the conduction | electrical_connection interruption apparatus of FIG. 1 is applied. The fragmentary sectional view which expands and shows the X section in FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. The partial perspective view which shows the blade part and fitting part of a cutting member in the conduction | electrical_connection interruption | blocking apparatus of one Embodiment. (A) is the fragmentary sectional view which shows the state by which the to-be-cut | disconnected part of the conductor was cut | disconnected in the conduction | electrical_connection interruption | blocking apparatus of one Embodiment, (b) is a part which expands and shows a part of FIG. 6 (a) Sectional drawing. 7A is a cross-sectional view taken along line 7-7 in FIG. 6A, and FIG. 7B is a partial cross-sectional view showing a part of FIG. It is a figure corresponding to FIG.6 (b), (a) is a fragmentary sectional view which shows the modification by which the rib was provided in the inner back wall surface of the to-be-fitted part, (b) is a figure of Fig.8 (a). The fragmentary sectional view which shows the state by which the rib was pressed and deform | transformed by the fitting part. It is a figure which shows the modification of a fitting part and a to-be-fitted part, and the state by which the fitting part was made to contact the to-be-fitted part in multiple places is made by elastically deforming a cutting member to the cutting edge part side. FIG. It is a figure corresponding to Drawing 6 (b), and a fragmentary sectional view showing a modification of a to-be-fitted part. It is a figure corresponding to Drawing 6 (b), and a fragmentary sectional view showing a modification of a fitting part and a fitting part. It is a figure corresponding to Fig.6 (a), and the fragmentary sectional view which shows the state by which the to-be-cut | disconnected part of the conductor was cut | disconnected by the conduction | electrical_connection interruption device of the modification.

Hereinafter, an embodiment embodied in a continuity blocking device for a vehicle will be described with reference to FIGS.
FIG. 2 shows an electric circuit 11 to which the conduction interruption device C is applied. The electric circuit 11 includes a storage battery 12 and an electric device 13 as devices constituting the electric circuit 11. In the electric circuit 11, the electric device 13 is operated by supplying power from the storage battery 12. The electrical device 13 boosts the power input from the storage battery 12 and outputs the converter 14; the inverter 15 that converts the DC power input from the converter 14 into AC power suitable for driving the motor; The motor 16 is driven by AC power output from the inverter 15.

  The electric circuit 11 is mounted on the vehicle 10. When an impact due to a collision is applied to the vehicle 10, there is a risk that the electric device 13 may not operate properly or a leakage from the electric circuit 11 may be caused. Therefore, the vehicle 10 is provided with a continuity interrupting device C that interrupts continuity between devices constituting the electric circuit 11, for example, between the storage battery 12 and the electric device 13 in the event of the collision. The vehicle 10 is provided with a collision sensor 17 that detects the presence or absence of the collision and an electronic control unit 18 that is configured around a microcomputer and that receives a signal from the collision sensor 17. When the electronic control unit 18 detects a collision of the vehicle 10 based on the output signal of the collision sensor 17, the electronic control unit 18 activates the conduction cutoff device C. By this operation, the power supply from the storage battery 12 to the electrical device 13 is interrupted.

  Next, the basic structure of the conduction cutoff device C will be described. As shown in FIG. 1, the conduction cutoff device C includes a conductor 20, a case 30, an explosive gas generator 59, and a cutting member 60. Next, each member which comprises the conduction | electrical_connection interruption | blocking apparatus C is demonstrated.

<Conductor 20>
The conductor 20 constitutes a conduction path for conducting between the storage battery 12 and the converter 14, and is also called a bus bar. The conductor 20 is made of a metal material having high electrical conductivity. As such a metal material, copper is representative, but other materials such as brass and aluminum may be used. Both end portions of the conductor 20 constitute external connection portions 20a and 20b. These external connection parts 20 a and 20 b are places connected to the storage battery 12 and the converter 14. That is, a through hole 21 is formed in each external connection portion 20a, 20b. Then, one of the external connection portions 20 a and 20 b is connected to a terminal conducting to the storage battery 12 and the other is connected to a terminal conducting to the converter 14 by a screw or the like using the through hole 21. The In this way, the conductor 20 is connected to the terminal of the electric circuit 11 at the external connection portions 20a and 20b, whereby the storage battery 12 and the converter 14 are electrically connected through the conductor 20.

  In addition to the external connection portions 20a and 20b, the conductor 20 has a cut portion 22 between them. The to-be-cut part 22 is extended in the parallel arrangement direction (left-right direction of FIG. 1) between both the external connection parts 20a and 20b, and has comprised the elongate plate shape. In addition, the extending direction of the part to be cut 22, that is, the juxtaposed direction of the external connection parts 20 a and 20 b may be referred to as the length direction of the part to be cut 22. Further, the thickness direction of the cut portion 22 refers to the thickness direction of the cut portion 22 before cutting.

<Case 30>
The case 30 is made of a material having electrical insulation and high strength, for example, a resin material, and an arrangement portion 31 for arranging the conductor 20 is formed therein. The conductor 20 is disposed in the arrangement portion 31 in a state where the external connection portions 20 a and 20 b are exposed to the outside of the case 30. In the case 30, an arc extinguishing chamber 32 is formed on one side of the cut portion 22 in the thickness direction (upward in FIG. 1). In the case 30, a movable chamber 41 is formed in the thickness direction on the opposite side of the arc extinguishing chamber 32 (lower side in FIG. 1) with the cut portion 22 interposed therebetween.

  The arc extinguishing chamber 32 cuts the cut portion 22 by the cutting member 60 and generates an arc generated between the pair of cut ends 23 and 24 (see FIG. 6A) generated in the cut portion 22 by cutting. It is a room for damping. The depth of the arc extinguishing chamber 32 (dimension in the direction perpendicular to the paper surface of FIG. 1) is set slightly larger than the width of the cut portion 22 (dimension in the direction perpendicular to the paper surface of FIG. 1). The cut portion 22 can enter the arc extinguishing chamber 32.

  As shown in FIG. 3, the arc extinguishing chamber 32 has a polygonal opening 33 that opens to face the cut portion 22 before cutting. In the opening 33, one side (left side in FIG. 3) in the length direction of the cut portion 22 extends in the width direction of the cut portion 22 to form a cut edge portion 34.

  The arc extinguishing chamber 32 has a first side wall surface 35, a second side wall surface 36, a pair of third side wall surfaces 37, and a back wall surface 38. The first side wall surface 35 includes the cutting edge portion 34 and extends in a direction that intersects the cutting target portion 22 before cutting at a right angle or close thereto. The second side wall surface 36 is located at a location separated from the first side wall surface 35 in the length direction of the cut portion 22. The second side wall surface 36 is inclined with respect to the first side wall surface 35 so that the distance from the first side wall surface 35 decreases as the distance from the opening 33 increases (the upper side in FIG. 3). Each third side wall surface 37 is orthogonal to the width direction of the cut portion 22. The back wall surface 38 is located at a location away from the opening 33 and is in a state parallel to or close to the portion 22 to be cut before cutting.

  As shown in FIG. 1, the movable chamber 41 has a substantially cylindrical shape extending along the thickness direction of the cut portion 22. Guide grooves 42 extending along the thickness direction are formed at a plurality of locations on the inner wall surface of the movable chamber 41.

<Gas generator 59>
The gas generator 59 is used as a drive source for the conduction cutoff device C. The gas generator 59 is in the thickness direction of the part to be cut 22, on the opposite side of the arc extinguishing chamber 32 across the part to be cut 22, with a part of itself exposed to the movable chamber 41. It is arranged in the inside. The gas generator 59 is connected to the electronic control unit 18, and generates a gas by igniting and burning the built-in explosive as the operation signal is input from the electronic control unit 18.

  In general, an apparatus driven using the explosive gas generator 59 can be driven more quickly than an apparatus using another system (such as an electromagnetic system) as a drive source. It is inexpensive and has high operational reliability.

<Cutting member 60>
The cutting member 60 protrudes from the main body portion 61 toward the arc extinguishing chamber 32 and extends in the thickness direction of the portion to be cut 22, and cooperates with the cutting edge portion 34 to be cut. And a blade portion 62 for cutting the portion 22. The cutting member 60 is disposed in the movable chamber 41 and between the cut portion 22 and the gas generator 59. Guide protrusions 63 extending along the thickness direction of the cut portion 22 are provided at a plurality of locations on the outer wall surface of the main body 61. The main body 61 is engaged with the guide groove 42 of the movable chamber 41 at the guide protrusion 63 so as to be movable in the thickness direction of the cut portion 22.

  As shown in FIGS. 3, 5, and 6 (a), the blade portion 62 has a first side wall surface 65, a second side wall surface 66, a pair of third side wall surfaces 67, and a tip surface 68. The first side wall surface 65 has a slight amount suitable for cutting (shearing) the cut portion 22 in cooperation with the cut edge portion 34 from the cut edge portion 34 in the length direction of the cut portion 22. The distance D1 (see FIG. 3) extends, for example, at a location about 0.5 mm away from the cut portion 22 before cutting in a direction that intersects perpendicularly or in a state close thereto. The second side wall surface 66 is located at a location separated from the first side wall surface 65 in the length direction of the cut portion 22. The second side wall surface 66 is inclined corresponding to the second side wall surface 36 of the arc extinguishing chamber 32, that is, the farther away from the main body portion 61 (the upper side in FIG. 6A), the more the first side wall surface 65 and Is inclined with respect to the first side wall surface 65 so as to be narrowed. The pair of third side wall surfaces 67 are orthogonal to the width direction of the cut portion 22. The front end surface 68 is located at a position away from the main body 61 in the blade portion 62 and is parallel to or close to the portion to be cut 22 before cutting.

The cutting member 60 is formed using a material having electrical insulation, high strength, and elastic deformation, such as a resin material.
When the cut portion 60 is cut by using the cutting member 60, the pair of cut ends 23 and 24 generated by the cutting are separated in the length direction and the thickness direction of the cut portion 22. One cutting end 23 is located near the cutting edge portion 34. The other cutting end 24 is located on the front end surface 68 of the blade portion 62 and at an intermediate portion between the first side wall surface 65 and the second side wall surface 66.

  The structure described above is the basic structure of the conduction cutoff device C. In the present embodiment, in addition to the basic structure, the blade portion 62 is provided with a fitting portion 70, and the arc extinguishing chamber 32 is provided with a fitted portion 45. Next, each part will be described.

<Fitting part 70>
The fitting portion 70 is an outer wall surface of the blade portion 62, and is between a location where one of the cutting ends 23 and 24 approaches and a location where the other approaches after the cutting portion 22 is cut by the blade portion 62. It is provided in the area. As a place satisfying this condition, the fitting part 70 is provided around the blade part 62 (on the front end face 68 and on both third side wall faces 67) at a place close to the first side wall face 65.

  As shown in FIGS. 5, 6 (a), 6 (b) and 7 (a), 7 (b), the fitting portion 70 includes an upper fitting portion 71, a pair of side fitting portions 72, and a pair of It is comprised by the connection fitting part 73. FIG. The upper fitting portion 71 protrudes upward from a position near the first side wall surface 65 in the tip surface 68 of the blade portion 62, and has an elongated shape in the width direction of the cut portion 22. The surface on the cutting edge portion 34 side of the fitting portion 70 is located on the same plane as the first side wall surface 65 of the blade portion 62. Therefore, the fitting part 70 has a function of cutting the part to be cut 22 in cooperation with the cutting edge part 34, similarly to the blade part 62. Each side fitting part 72 protrudes to the outer side in the width direction of the to-be-cut part 22 from the part near the first side wall face 65 in the third side wall face 67 of the blade part 62, and has an elongated shape in the vertical direction. ing. Each connection fitting part 73 is provided between the both outer end parts in the width direction of the part to be cut 22 in the upper fitting part 71 and the tip part in the moving direction of the cutting member 60 in each side fitting part 72. Connected to each other.

<Fitted part 45>
As shown in FIGS. 4, 6 (a), 6 (b) and 7 (a), 7 (b), the fitted portion 45 is fitted with at least a part of the fitted portion 70 being in contact. It is a place to be done. As a place satisfying this condition, the fitted portion 45 is provided around the back wall surface 38 and both the third side wall surfaces 37 at a location close to the first side wall surface 35.

  The fitted portion 45 includes an upper fitted portion 46, a pair of side fitted portions 47, and a pair of connected fitted portions 48. The upper fitting portion 46 is configured by a recess that opens at a location near the first side wall surface 35 in the back wall surface 38 and is recessed upward. The upper fitted portion 46 extends along the width direction of the cut portion 22.

  Each side fitted portion 47 is recessed from both the third side wall surfaces 37 near the first side wall surface 35 to both outer sides in the width direction of the cut portion 22. Each side fitted portion 47 extends along the moving direction of the cutting member 60. Each connection fitting part 48 is between the both ends in the width direction of the cut part 22 in the upper fitting part 46 and the tip part in the moving direction of the cutting member 60 in each side fitting part 47. Provided to connect them together.

  The upper fitting portion 71 and the both coupling fitting portions 73 in the fitting portion 70 are inserted into the upper fitting portion 46 and the both coupling fitting portions 48 in the fitting portion 45. By this insertion, the upper fitting portion 71 and the both coupling fitting portions 73 are in contact with the inner wall surfaces of the upper fitting portion 46 and the both coupling fitting portions 48 at least in part.

Further, the both side fitting portions 72 in the fitting portion 70 are inserted into the both side fitted portions 47 in the fitted portion 45.
In the upper mated portion 46 and the both coupled mated portions 48, the surface farthest away from the inner wall surface 38 of the arc extinguishing chamber 32 is referred to as an inner inner wall surface 49, and the vicinity of the inner inner wall surface 49 (the inner inner wall surface 49 Including) is referred to as the back part 51.

  In the back part 51, inclined surfaces 53 are respectively formed on a pair of edge parts 52 extending in parallel with each other along the width direction of the cut part 22. The inclined surface 53 for each edge 52 moves the cutting member 60 so that the dimension L1 between both edges 52 in the length direction of the cut portion 22 decreases as the distance from the inner wall 38 of the arc extinguishing chamber 32 increases. Inclined with respect to the direction.

  In the back portion 51, inclined surfaces 55 are respectively formed on a pair of edge portions 54 that extend parallel to each other along the length direction of the cut portion 22. The direction of movement of the cutting member 60 is such that the inclined surface 55 of each edge portion 54 is such that the dimension L2 between the edge portions 54 in the width direction of the cut portion 22 decreases as the distance from the inner wall surface 38 of the arc extinguishing chamber 32 increases. It is inclined to.

  Further, each of the connection fitting portions 48 in the inner portion 51 is different from the both side fitting portions 72 and both connection fitting portions 73 in the fitting portion 70, and both the side fitting portions 47 and the connection covered portions in the fitting portion 45. A tip portion when moving along the fitting portion 48 is formed. At the distal end portion, the depth D2 from the third side wall surface 37 is shallower toward the distal end side in the moving direction of the cutting member 60 due to the formation of the both inclined surfaces 55.

Next, the operation of the conduction cutoff device C of the present embodiment configured as described above will be described.
When the collision of the vehicle 10 is not detected by the collision sensor 17, no operation signal is output from the electronic control unit 18 to the gas generator 59, and no gas is generated from the gas generator 59. As shown in FIGS. 1 and 3, the cutting member 60 is located between the cut portion 22 and the gas generator 59 and is retracted from the arc extinguishing chamber 32. Therefore, the to-be-cut part 22 is not cut | disconnected, but it will be in the state electrically connected between the storage battery 12 and the converter 14 via the conductor 20. FIG.

  On the other hand, when the collision of the vehicle 10 is detected by the collision sensor 17 while the conductor 20 is energized, an operation signal is output from the electronic control unit 18 to the gas generator 59. In response to this activation signal, the gas generator 59 is activated to generate gas. The cutting member 60 receives gas pressure toward the arc extinguishing chamber 32. At this time, the cutting member 60 is guided to the arc extinguishing chamber 32 side by the guide protrusion 63 moving in the guide groove 42 of the movable chamber 41.

  The cutting member 60 moves at a high speed toward the arc extinguishing chamber 32 with the upper fitting portion 71 and the both coupling fitting portions 73 at the top. Along with this movement, the upper fitting portion 71 of the cutting member 60 first hits the cut portion 22 and the cut portion 22 is pressed toward the arc extinguishing chamber 32. By this pressing, stress is concentrated on the portion to be cut 22 in the vicinity of the cutting edge portion 34. The part to be cut 22 is cut between the cutting edge part 34 and the upper fitting part 71. By this cutting, as shown in FIGS. 6A and 6B, a pair of cut ends 23 and 24 that are separated from each other are generated in the cut portion 22. The movement of the cutting member 60 continues after the cutting, so that the fitting portion 70 and the blade portion 62 enter the inner depth of the arc extinguishing chamber 32.

  As shown in FIGS. 4, 6 (a), 6 (b) and 7 (a), 7 (b), the connection fitting portion 73 and the side fitting portion 72 correspond to each other by the movement of the cutting member 60. It is inserted into the side fitted portion 47 in order, and slides along the same side fitted portion 47. This sliding movement is performed between the cutting ends 23 and 24.

  One of the cut ends 23 is not pressed by the blade portion 62 after the occurrence thereof, and thus is located near the cut edge portion 34. On the other hand, a portion including the other cut end 24 in the cut portion 22 is pressed by the blade portion 62 and enters the arc extinguishing chamber 32. The portion of the cut portion 22 is bent at an obtuse angle along the inclined second side wall surface 66 of the blade portion 62 and the inclined second side wall surface 36 of the arc extinguishing chamber 32 by the pressing. The load required for such bending is smaller than the load required for cutting. Therefore, the load required to move the cutting member 60 toward the arc extinguishing chamber 32 can be small.

  The other cut end 24 is located near the tip surface 68 of the blade portion 62. In other words, the cutting end 24 is located between the back wall surface 38 of the arc extinguishing chamber 32 and the tip surface 68 of the blade portion 62 that has entered the arc extinguishing chamber 32.

Here, the conductor 20 made of copper is rich in ductility. When the cut portion 22 extends during cutting, the distance between the cut ends 23 and 24 becomes short, and an arc is likely to occur.
In this regard, in this embodiment, the conductor 20 is constituted by the cutting edge portion 34 and the fitting portion 70 and the blade portion 62 (the first side wall surface 65) that move at a position separated by a slight distance D1. Disconnected. Therefore, the amount of elongation of the portion to be cut 22 is small as compared with the case where the portion to be cut 22 is cut only by pressing of the fitting portion 70 and the blade portion 62 without the cutting edge portion 34. Accordingly, the distance between the cut ends 23 and 24 is increased.

  The to-be-cut part 22 will be in the state divided | segmented between both the cut ends 23 and 24, and the continuity between the storage battery 12 and the converter 14 will be interrupted | blocked. At this time, an arc is generated by generating a potential difference between the two cut ends 23 and 24 generated by the cutting, that is, the gas insulation existing between the two cut ends 23 and 24 may be broken and a current may flow. . At this time, the arc tends to flow from one of the cut ends 23 and 24 toward the other via the space between the fitting portion 70 and the blade portion 62 and the inner wall surface of the arc extinguishing chamber 32.

  However, in the present embodiment, the upper fitting portion 71 is inserted into the upper fitting portion 46 as the cutting member 60 moves. Each connection fitting part 73 slid and moved along each side fitting part 47 is inserted into the corresponding connection fitting part 48.

  Here, in the back part 51 of the upper fitting part 46 and both connection fitting parts 48, the inclined surface 53 is formed in each of a pair of edge part 52, and the back in the length direction of the to-be-cut part 22 is formed. The dimension L <b> 1 of the part 51 becomes smaller as the distance from the inner wall 38 of the arc extinguishing chamber 32 increases. Therefore, the upper fitting portion 71 and the both coupling fitting portions 73 are in contact with the back portion 51 on both inclined surfaces 53 in the process of insertion.

  In addition, a part of the inner portion 51 constitutes a tip portion of the fitted portion 45 in the moving direction of the cutting member 60. An inclined surface 55 is formed in each of the pair of edge portions 54 of the back portion 51 (tip portion), and the depth D2 of each connection fitting portion 48 is shallower toward the tip side. Therefore, each connection fitting part 73 contacts the back part 51 in both the inclined surfaces 55 by slidingly moving along the side fitting part 47 and the connection fitting part 48.

  Then, as described above, the upper fitting portion 46 and the both coupling fitting portions 73 and the both coupling fitting portions 73 are in contact with the inclined surfaces 53 and 55 in at least a part of each. It is fitted to the part 48. Further, the both side fitting portions 72 are fitted to the both side fitted portions 47.

  By such fitting, the space between the upper fitting portion 71 and the upper fitting portion 46 is narrowed, and the space between each coupling fitting portion 73 and each coupling fitting portion 48 is narrowed. The space between the side fitting portion 72 and each side fitted portion 47 is narrowed.

  Therefore, a part of the arc flows from one cut end 23 (24) toward the tip end side in the moving direction of the cutting member 60 as shown by a path R1 in FIG. After going through the space between the fitting portion 46, it tends to flow toward the other cut end 24 (23). However, since the space is narrow, the arc hardly flows along the path R1.

  Further, a part of the arc flows from one cut end 23 (24) to the outer end side in the width direction of the cut portion 22 as shown by a path R2 in FIG. After passing through the space between the mating portion 73 and the side fitted portion 47 and the connected fitted portion 48, it tends to flow toward the other cut end 24 (23). However, since the space is narrow, the arc hardly flows along the path R2.

  In addition, in the above-described fitting, the upper fitting portion 71 and the both coupling fitting portions 73 are in contact with the inner wall surfaces of the upper fitting portion 46 and the both coupling fitting portions 48 in at least a part thereof. Made in These contacts are made between the cut ends 23 and 24. The space between the upper fitting portion 71 and the both connected fitting portions 73 and the upper fitted portion 46 and both connected fitted portions 48 is divided in the length direction of the cut portion 22 with the contact portion as a boundary. It will be like a state. Thus, the arc is more suitably attenuated.

  Furthermore, the arc tends to be attenuated as the path through which the arc flows becomes longer. In this regard, in this embodiment, the space between the outer wall surface of the fitting portion 70 and the inner wall surface of the fitted portion 45 constitutes a part of the path through which the arc flows between the pair of cut ends 23 and 24. . Therefore, the path through which the arc flows becomes longer than in the case where the fitted portion 45 and the fitting portion 70 are not provided, and the arc is more easily attenuated in this respect.

  As a result, the influence of the arc on the conduction breaker C is reduced. For example, it becomes difficult to generate a state in which the cut ends 23 and 24 are electrically connected by an arc. In spite of the fact that the conductor 20 is physically cut, a phenomenon in which it is maintained in an energized state (conduction is not interrupted) is less likely to occur. Further, the phenomenon that the conductor 20 and the surrounding resin members (the case 30, the cutting member 60, etc.) are softened or melted due to exposure to a high-temperature arc is suppressed.

According to the embodiment described in detail above, the following effects can be obtained.
(1) It is an outer wall surface of the blade part 62, and fits in a region between a place where one of the cutting ends 23 and 24 approaches and a place where the other approaches after the cutting part 22 is cut by the blade part 62. A joint 70 is provided. The inner wall surface of the arc extinguishing chamber 32 is provided with a fitted portion 45 to be fitted in a state where at least a part of the fitting portion 70 is brought into contact (FIG. 1).

  Therefore, after cutting the cut portion 22, the space between the fitting portion 70 and the fitted portion 45 is narrowed, and an arc generated between the cut ends 23 and 24 due to the cutting of the cut portion 22 is efficiently performed. Can be attenuated well.

In addition, the arc flow path can be lengthened to further attenuate the arc.
(2) The upper fitting portion 71 and both coupling fitting portions 73 of the fitting portion 70 are provided at the distal end portion of the blade portion 62 in the moving direction of the cutting member 60. The upper mating portion 46 and both coupled mated portions 48 of the mated portion 45 are opposed to the front end surfaces of the upper mating portion 71 and both coupled fitting portions 73 of the inner wall surface of the arc extinguishing chamber 32. The back wall 38 is provided (FIGS. 3 and 4).

  Therefore, the fitting with the contact of the fitting portion 70 with the fitted portion 45 can be performed on the distal end side in the moving direction of the cutting member 60. By making the space between the fitting part 70 and the fitted part 45 narrow and divided, it is possible to suppress the arc from flowing through the distal end side in the moving direction of the cutting member 60, The arc can be attenuated.

  (3) The upper fitted portion 46 and both connected fitted portions 48 of the fitted portion 45 are constituted by recesses opened in the inner wall surface 38 of the arc extinguishing chamber 32. By inserting the upper fitting portion 71 and both coupling fitting portions 73 of the fitting portion 70 into the upper fitting portion 46 and both coupling fitting portions 48, It fits in the state which contacted with respect to the inner wall surface of the to-be-fitted part 46 and both connection to-be-fitted parts 48. FIG. The rear portions 51 of the upper fitted portion 46 and the both connected fitted portions 48 are formed so that the dimension L1 in the length direction of the cut portion 22 decreases as the distance from the deep wall surface 38 of the arc extinguishing chamber 32 increases. (FIG. 4, FIG. 6 (a)).

  For this reason, the fitting portion 70 is covered with the tips of the upper fitting portion 71 and the both coupling fitting portions 73 in contact with the inner wall surfaces of the upper fitting portion 46 and the both coupling fitting portions 48. The fitting part 45 can be fitted.

  (4) The both side fitting portions 72 and the both coupling fitting portions 73 in the fitting portion 70 are provided on the third side wall surface 67 of the blade portion 62 that is orthogonal to the width direction of the cut portion 22. In the arc extinguishing chamber 32, both side fitted portions 47 and both connected fitted portions 48 of the fitted portion 45 are provided on the third side wall surface 37 orthogonal to the width direction (FIGS. 4 and 7). (A)).

  Therefore, the fitting with the contact of the fitting portion 70 with the fitted portion 45 can be performed on both outer end sides in the width direction of the to-be-cut portion 22. By making the space between the fitting portion 70 and the fitted portion 45 narrow and divided, it is possible to suppress the arc from flowing through both outer end sides in the width direction, and Can be attenuated.

  (5) Both side fitted portions 47 and both coupled fitted portions 48 of the fitted portion 45 are opened in the third side wall surface 37 of the arc extinguishing chamber 32 and extend along the moving direction of the cutting member 60. A recess is used. The both-side fitting part 72 and both connection fitting parts 73 of the fitting part 70 are inserted into the both-side fitting part 47 and both connection fitting parts 48 of the fitting part 45 and are slid and moved. The fitting portion 73 is fitted in a state in which the fitting portion 73 is brought into contact with the inner wall surfaces of both the connected fitting portions 48 at the tip in the moving direction of the cutting member 60. At least the distal end portion in the moving direction of the cutting member 60 is formed so that the depth D2 of the coupled fitted portion 48 becomes shallower toward the distal end side in the same direction in each connected fitted portion 48 (see FIG. 4).

  Therefore, the fitting part 70 is fitted to the fitted part 45 in a state in which the tips of the two coupling fitting parts 73 in the fitting part 70 are in contact with the inner wall surfaces of the two coupled fitted parts 48 in the fitted part 45. Can be fitted.

In addition, the said embodiment can also be implemented as a modification which changed this as follows.
<About the arc extinguishing chamber 32>
-The shape of the opening 33 of the arc extinguishing chamber 32 may be changed to a polygonal shape different from the above embodiment.

<About the fitted portion 45>
-As shown to Fig.8 (a), the rib 56 which is pressed and deformed by the fitting part 70 may be provided in the inner back wall surface 49 of the to-be-fitted part 45. FIG.

  If it does in this way, the front end surface of fitting part 70 will approach inner back wall 49 of to-be-fitted part 45 as insertion to fitting part 45 of fitting part 70 advances. If the movement of the fitting part 70 continues even after the front end surface of the fitting part 70 contacts the rib 56, the rib 56 is pressed and deformed by the fitting part 70 as shown in FIG. It is done. When the upper fitting portion 71 comes into contact with the inclined surface 53, the space between the front end surface of the fitting portion 70 and the inner back wall surface 49 of the fitted portion 45 is filled with the rib 56 deformed as described above. The space becomes smaller, and the arc becomes more difficult to flow through the space.

  -In the said embodiment, the fitting part 70 which protrudes from the blade part 62 is omitted, it is an outer wall surface of the blade part 62, Comprising: One of both the cutting ends 23 and 24 after the cut | disconnected part 22 by the blade part 62 is cut | disconnected The area between the place where the two approaches and the place where the other approaches is the fitting portion.

  Moreover, in the said embodiment, the to-be-fitted part 45 dented from the back wall surface 38 of the arc-extinguishing chamber 32 is omitted, and in the state where at least a part of the fitting portion is in contact with the inner wall surface of the arc-extinguishing chamber 32. The part to be fitted is defined as the fitted part. And the rib which is pressed and deform | transformed by a fitting part may be provided in the surface facing the front end surface of a fitting part among the inner wall surfaces of a to-be-fitted part.

  If it does in this way, as insertion to a to-be-fitted part of a fitting part advances, a tip end face of a fitting part will approach a surface which counters a tip end face of a fitting part among inner wall surfaces of a to-be-fitted part. Even after the front end surface of the fitting portion contacts the rib provided on the surface of the fitted portion, if the movement of the fitting portion continues, the rib is pressed and deformed by the fitting portion. The space between the front end surface of the fitting portion and the surface of the fitted portion is filled with the deformed rib as described above, the space is further reduced, and the arc further fills this space. It becomes difficult to flow.

  As shown in FIG. 9, a pair of edge portions extending in parallel along the width direction of the cut portion 22 (direction orthogonal to the paper surface of FIG. 9) at the back portion 51 in the depth direction of the fitted portion 45. The inclined surface 53 may be formed only on one of the 52.

FIG. 9 shows an example in which the inclined surface 53 is formed on the edge portion 52 on the side far from the first side wall surface 35 including the cutting edge portion 34.
In this case, the following effects can also be expected.

  That is, the upper fitting portion 71 and the blade portion 62 are cut between the cutting edge portion 34 by moving a portion slightly separated from the cutting edge portion 34 (distance D1) in the arc extinguishing chamber 32. The part 22 is cut. On the other hand, the cutting member 60 is formed of a material that can be elastically deformed as described above.

  Also in this case, the inclined surface 53 becomes smaller as the dimension L1 between the two edge portions 52 in the length direction (the left-right direction in FIG. 9) of the cut portion 22 becomes farther away from the inner wall surface 38 of the arc extinguishing chamber 32. In this manner, the cutting member 60 is inclined with respect to the moving direction.

  Therefore, the fitting part 70 contacts the inclined surface 53 in the process of being inserted into the fitted part 45. Thereafter, when the insertion into the fitted portion 45 continues, the cutting member 60 is elastically deformed toward the cutting edge portion 34 as shown by a two-dot chain line in FIG. Contact the inner wall. The number of contact points of the fitting portion 70 with respect to the inner wall surface of the fitted portion 45 is increased, and the space between the fitting portion 70 and the fitted portion 45 is more accurately divided, and the arc further divides this space. It becomes difficult to flow.

  In the fitted portion 45, the portion where the dimension L 1 in the length direction of the cut portion 22 is formed to become smaller as the distance from the inner wall surface 38 of the arc extinguishing chamber 32 becomes smaller than the depth of the fitted portion 45. The area may be changed to a region that includes the back part 51 and is wider than the back part 51 in the vertical direction.

  FIG. 10 shows an example in which the portion (the inclined surface 53) is formed over the entire depth direction of the fitted portion 45. In this case, in the process in which the fitting portion 70 is inserted into the fitted portion 45, the inner wall surface (inclined surface 53) of the fitted portion 45 is more easily contacted.

<About the fitting part 70>
-In the blade part 62, the combination of the side fitting part 72 and the connection fitting part 73 may be provided only in the one side in the width direction of the to-be-cut | disconnected part 22. FIG.

-The fitting part 70 may be comprised only by the upper fitting part 71. FIG.
-The fitting part 70 may be comprised only by the side fitting part 72. FIG. In that case, the fitting part 70 may be comprised by the both-side fitting part 72, and may be comprised only by the one side fitting part 72. FIG.

  As shown in FIG. 11, the fitting part 70 has a thickness T <b> 1 of the fitting part 70 in the length direction of the part to be cut 22 (left and right direction in FIG. 11). You may form so that it may become so small (upper side of FIG. 11). Also in this case, in the process in which the fitting portion 70 is inserted into the fitted portion 45, the inner wall surface of the fitted portion 45 is easily contacted.

<Regarding the Concavity and Concavity of the Fitting Part 70 and the Fitting Part 45>
-As shown in FIG. 12, the fitting part 70 and the to-be-fitted part 45 may be formed so that both concavo-convex relation may become contrary to the said embodiment. In this case, on the outer wall surface of the blade portion 62, the region between the location where one of the cutting ends 23, 24 approaches and the location where the other approaches approaches the tip side in the moving direction of the cutting member 60 (upper side in FIG. 12). ) Is provided on the surface, and a fitting portion 70 is formed by the recess. In addition, a protrusion that protrudes from the inner wall 38 of the arc extinguishing chamber 32 toward the blade 62 is provided, and the fitted portion 45 is formed by this protrusion. Then, at least a part of the fitting portion 70 is fitted to the fitted portion 45 in a state where the fitting portion 70 is in contact with the fitted portion 45.

<Others>
In the above embodiment, a resin material can be used as the material for forming the cutting member 60. In addition, the material is strong enough to cut the cut portion 22, and can be elastically deformed. In addition, any material can be adopted on the condition that the material has appropriate electrical insulation.

  In the above embodiment, as a method of forming the case 30 and the cutting member 60, any method such as a method of forming using mold molding or a method of forming by cutting can be employed.

  The continuity cutoff device C is not limited to the one provided between the storage battery 12 and the converter 14, but is applied as long as it is a device that is provided between devices constituting an electric circuit and cuts off continuity between the devices. be able to. As such a device, for example, in a fuel cell vehicle, a continuity cutoff device provided between a fuel cell and a vehicle driving motor, a continuity cutoff device provided between a power source of a stationary system and an electric device, a stationary type Examples thereof include a continuity cutoff device provided between the electrical devices of the system.

  DESCRIPTION OF SYMBOLS 11 ... Electric circuit, 12 ... Storage battery (equipment which comprises an electric circuit), 13 ... Electric equipment (equipment which comprises an electric circuit), 20 ... Conductor, 22 ... Cut part, 23, 24 ... Cut end, 32 ... Arc extinguishing chamber, 33 ... opening, 34 ... cutting edge, 38 ... back wall, 45 ... mated part, 49 ... inner back wall, 51 ... back, 56 ... rib, 59 ... gas generator, 60 ... Cutting member, 62 ... blade part, 68 ... tip surface, 70 ... fitting part, C ... conduction cutoff device, D2 ... depth, L1, L2 ... dimensions.

Claims (8)

A conductor interposed between devices constituting an electric circuit and having a part to be cut in a long plate shape in part;
An arc extinguishing chamber formed on one side in the thickness direction of the cut portion;
A gas generator disposed on the opposite side of the arc-extinguishing chamber in the thickness direction with the cut portion interposed therebetween;
The portion to be cut and the gas generator are disposed and moved toward the arc extinguishing chamber by the gas generated by the gas generator, and the cut portion is moved by the blade portion to the arc extinguishing chamber. And a cutting member that cuts at a position, and the cutting portion generates a pair of cutting ends that are separated from each other by the cutting, and cuts off the conduction between the devices. ,
In the outer wall surface of the blade portion, a fitting portion is provided in a region between a location where one of both cutting ends approaches and a location where the other approaches after the cutting of the cut portion by the blade portion,
A conduction interrupting device, wherein an inner wall surface of the arc extinguishing chamber is provided with a fitted portion to be fitted in a state in which at least a part of the fitting portion is in contact. The fitting portion is provided at a distal end portion in the moving direction of the cutting member among the blade portions,
The conduction interrupting device according to claim 1, wherein the fitted portion is provided on a back wall surface of the inner wall surface of the arc extinguishing chamber that faces the front end surface of the fitting portion. The fitted portion is configured by a recess opening in the inner wall surface of the arc extinguishing chamber,
The fitting part is inserted into the fitted part, so that the fitting part is fitted into the fitted part in a state of being in contact with the inner wall surface of the fitted part at the tip in the moving direction of the cutting member. And
The conduction interruption according to claim 2, wherein at least a back part of the fitted part is formed such that a dimension in a length direction of the cut part decreases as the distance from the back wall surface of the arc extinguishing chamber decreases. apparatus.   Of the inner wall surface of the fitted portion, the inner back wall surface facing the tip surface of the fitted portion has a rib that is pressed and deformed by the fitted portion inserted into the fitted portion. The conduction | electrical_connection interruption | blocking apparatus of Claim 3 provided. The fitting portion is provided on the side wall surface orthogonal to the width direction of the cut portion of the blade portion,
The conduction interrupting device according to any one of claims 1 to 4, wherein the fitted portion is provided on a side wall surface orthogonal to the width direction in the arc extinguishing chamber. The fitted portion is configured by a recess that opens in the side wall surface of the arc extinguishing chamber and extends along the moving direction of the cutting member;
The fitting part is inserted into the fitted part, so that the fitting part is fitted into the fitted part in a state of being in contact with the inner wall surface of the fitted part at the tip in the moving direction of the cutting member. And
The conduction according to claim 5, wherein at least a distal end portion in the moving direction of the cutting member among the fitted portions is formed such that a depth of the fitted portion becomes shallower toward a distal end side in the same direction. Shut-off device. The arc extinguishing chamber has a polygonal opening that opens to face the conductor, and a side that extends along the width direction of the cut portion in the opening serves as a cutting edge.
The blade part is for cutting the part to be cut between the cutting edge part by moving a location approaching the cutting edge part in the arc extinguishing chamber,
The cutting member is made of an elastically deformable material,
The said fitting part contacts the said to-be-fitted part by elastically deforming the said cutting member to the said cutting edge part side, when inserting in the said to-be-fitted part. Continuity cutoff device.   The conduction according to claim 2, wherein a rib that is pressed and deformed by the fitting portion is provided on a surface of the inner wall surface of the fitted portion that faces the distal end surface of the fitting portion. Shut-off device.