Perforator and gas discharge device

Abstract

To provide a technology that inhibits a seal plate from being torn when a cutting edge of a piston rod perforates the seal plate on a perforator for evacuating a gas from a gas bottle.SOLUTION: A perforator includes: a piston rod including a cutting edge disposed while being opposite to a seal plate on a tip side in a state where the perforator is fitted to a gas bottle; and a drive part for launching the piston rod toward the seal plate to perforate the seal plate with the cutting edge when operating. The cutting edge includes: a plurality of ridgelines; and three or more piston blade surfaces sectioned by respective ridgelines mutually.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a perforator and a gas discharge device for discharging gas from a gas bottle.

Background Art

[0002] There is known a perforator that is used by attaching a gas bottle for storing gas therein, and discharges gas from the gas bottle by opening (unsealing) a sealing plate that seals a gas outlet in the gas bottle (see, for example, Patent Document 1).

[0003] This type of perforator has a piston having a cutting edge facing the sealing plate on the tip side in a state of being attached to the gas bottle, a drive unit that fires the piston toward the sealing plate during operation, and the like.

[0004] For example, Patent Document 1 discloses a perforator provided with a piston rod having a cutting edge portion having a V-shaped cross section that is pointed in a V shape in a side view on the tip side.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the conventional perforator, when the sealing plate is perforated by the cutting edge portion of the piston rod, there is a risk that the sealing plate may be torn.

[0007] In view of the above circumstances, the technology of the present disclosure has been made, and an object of the present disclosure is to provide a technology for suppressing the sealing plate from being torn when the sealing plate is perforated by the cutting edge portion of the piston rod in a perforator for discharging gas from a gas bottle.

Means for Solving the Problem

[0008] The present disclosure solves the above problems in the following aspects. That is, the technology according to the present disclosure is a perforator that is used in a state where a gas bottle is attached, and discharges gas from the gas bottle by opening a sealing plate that seals a gas outlet in the gas bottle during operation, a piston rod having a blade tip portion disposed opposite to the sealing plate in a state where the perforator is attached to the gas bottle at a tip side, a drive unit that fires the piston rod toward the sealing plate during operation and perforates the sealing plate with the blade tip portion, and includes the blade tip portion has a plurality of ridge lines and three or more piston blade surfaces mutually divided by each ridge line.

[0009] Further, the blade tip portion includes a tip ridge line that forms a tip of the blade tip portion, and the projection length of the tip ridge line along the axial direction of the piston rod may be smaller than the diameter of the piston rod.

[0010] Also, one end of another ridge line may be connected to both ends of the tip ridge line.

[0011] Also, the other end of the other ridge line may extend to the side surface of the piston rod.

[0012] Also, a plurality of the other ridge lines may be connected to at least one end of the tip ridge line.

[0013] Also, one ends of a plurality of the ridge lines may gather at a vertex formed at the tip of the blade tip portion, and the other end of each ridge line may extend to the side surface of the piston rod.

[0014] Further, the technology of the present disclosure may be a gas discharge device including any one of the perforators described above and a gas bottle attachable to the perforator.

Advantages of the Invention

[0015] According to the present disclosure, in a perforator for discharging gas from a gas bottle, when a sealing plate is perforated by the cutting edge portion of a piston rod, a technique can be provided to suppress the sealing plate from being torn.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0017] Hereinafter, a protection device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that each configuration and their combinations in the embodiment are examples, and within the scope not departing from the gist of the present disclosure, addition, omission, substitution, and other changes of the configuration are possible as appropriate. The present disclosure is not limited by the embodiment, but is limited only by the scope of the claims.

[0018] The perforator according to this embodiment is used in a state where a gas bottle is attached, and is a perforator for discharging gas from the gas bottle by opening a sealing plate that seals the gas outlet in the gas bottle during operation, a piston having a blade tip portion disposed opposite to the sealing plate in a state where the perforator is attached to the gas bottle at the tip side, a drive unit that fires the piston toward the sealing plate during operation and perforates the sealing plate with the blade tip portion, and is provided with the blade tip portion has a plurality of ridge lines and three or more piston blade surfaces mutually divided by each ridge line.

[0019] <Embodiment> FIG. 1 is a diagram showing a configuration example of a perforator 1 according to an embodiment. The perforator 1 is used in a state where a cartridge-type gas bottle 2 (see FIG. 2) is attached, and is a perforator for discharging gas from the gas bottle by opening a sealing plate that seals the gas outlet in the gas bottle 2 during operation. A gas discharge device is configured by a combination of the perforator 1 and the gas bottle 2 attached to the perforator 1. FIG. 1 shows the perforator 1 in a state before operation. Further, FIG. 2 is a diagram showing a configuration example of the gas bottle 2 according to the embodiment.

[0020] The gas bottle 2 is, for example, an iron cartridge container filled with gas at high pressure inside. The gas bottle 2 is formed with a gas outlet 21 for discharging gas. Further, in the gas bottle 2 before use, the gas outlet 21 is sealed (closed) by a sealing plate 22, whereby the inside of the gas bottle 2 is sealed. The sealing plate 22 is, for example, an iron disc that closes the opening related to the gas outlet 21. Of course, the shape of the sealing plate 22 can be appropriately changed according to the opening shape of the gas outlet 21.

[0021] The gas bottle 2 can be attached to the main body side attachment portion 16 formed on the perforator 1 side with the bottle side attachment portion 23 formed on the gas outlet 21 side, whereby the gas bottle 2 can be detachably attached to the gas bottle 2. The main body side attachment portion 16 of the perforator 1 has, for example, a concave shape capable of receiving the bottle side attachment portion 23 of the gas bottle 2. Further, the connection form between the bottle side attachment portion 23 and the main body side attachment portion 16 is not particularly limited, and examples include a screw connection method.

[0022] The perforator 1 has, as a housing, a cylindrical first housing 10 and a second housing 40. In FIG. 1, the central axis extending in the axial direction of the first housing 10 and the second housing 40 is indicated by reference numeral C1. In the present embodiment, the first housing 10 and the second housing 40 are arranged coaxially, for example.

[0023] One end side of the first housing 10 in its axial direction, the first end portion 11, is an open end, and a connection cap member 13 is attached to the open end. The above-described main body side attachment portion 16 is formed by a concave portion formed inside the connection cap member 13. Further, the other end side of the first housing 10 in its axial direction, the second end portion 12, is an open end, and the cylindrical second housing 40 is connected and fixed to the open end.

[0024] The first end portion 41 located on one end side in the axial direction of the second housing 40 is fitted to the second end portion 12 of the first housing 10, and the two members are integrated so as not to fall off from each other. Further, a cylindrical piston guide 18 is disposed inside the first housing 10. The piston guide 18 is fixed to the inner wall surface of the first housing 10.

[0025] An opening 14 is formed at an intermediate position in the axial direction of the first housing 10, and a cylindrical gas discharge member 15 is connected and fixed to the opening 14. The gas discharge member 15 may be, for example, a screwed pipe connection member called a nipple. The reference sign C2 shown in FIG. 1 indicates the central axis of the gas discharge member 15. For example, the central axis C2 of the gas discharge member 15 extends in a direction orthogonal to the central axis C1 of the first housing 10. The first end portion 15A of the gas discharge member 15 is connected to the opening 14 of the first housing 10. Further, in the axial direction of the gas discharge member 15, a gas pipe or the like that leads to a gas supply target (for example, an airbag), which is the target to which the gas discharge device (perforator 1) supplies gas, is connected to the second end portion 15B located on the side opposite to the first end portion 15A. Inside the gas discharge member 15, a hollow gas flow path 17 that penetrates the gas discharge member 15 along the axial direction is formed, and the gas discharged from the gas outlet 21 of the gas bottle 2 is supplied to the gas supply target through the gas flow path 17 of the gas discharge member 15. The above-described airbag is an example of the gas supply target, and the gas supply target is not particularly limited. and the gas supply target is not particularly limited.

[0026] Next, the internal structure of the housing (the first housing 10 and the second housing 40) in the perforator 1 will be described in detail. Hereinafter, in the axial direction of the second housing 40, the first end 41 side will be described as the front end side, and the second end 42 side located on the opposite side will be described as the rear end side. An initiator 50 as a driving unit is fixed to the second end 42 side (rear end side) of the second housing 40. The initiator 50 is, for example, an electric igniter. The initiator 50 has an ignition part 51 arranged so as to face an accommodation space formed in the second housing 40. The ignition part 51 is configured, for example, in the form of a cup container that houses an ignition charge inside. For example, the ignition charge is housed in the cup container of the ignition part 51 in a state of being in contact with a bridge wire (resistor) that is bridged so as to connect the proximal ends of a pair of conductive pins. As the ignition charge, for example, ZPP (zirconium potassium perchlorate), ZWPP ( zirconium tungsten potassium perchlorate), THPP (titanium hydride potassium perchlorate), lead tricinate, etc. may be adopted.

[0027] Reference numeral 52 is a lead wire, and an operating current for operating the initiator 50 is supplied from a power source through the lead wire 52. When an operating current is supplied to the initiator 50, as a result, the bridge wire in the ignition part 51 generates heat, so that the ignition charge in the cup container ignites and burns, and combustion gas is generated. Then, as the ignition charge in the cup container burns, the pressure in the cup container rises, the cleavage surface 51A of the cup container cleaves, and the combustion gas is released into the accommodation space formed in the second housing 40.

[0028] In the accommodation space formed in the housing (the first housing 10 and the second housing 40) of the perforator 1, the first piston 60 and the second piston 70 are arranged from a position close to the initiator 50. The first piston 60 is arranged so as to be movable along the axial direction of the first piston movement space S1 (that is, along the central axis C1) within the first piston movement space S1 formed inside the second housing 40. For example, the first piston 60 is a piston member having a substantially cylindrical shape, and its outer diameter is equal to the inner diameter of the first guide surface 43 formed by the inner peripheral surface of the second housing 40. Further, a recessed portion 61 having a concave rear end surface is provided at the rear end portion of the first piston 60.

[0029] The second piston 70 has a piston head 71 and a piston rod 72 extending forward from the piston head 71. The piston head 71 and the piston rod 72 of the second piston 70 have a cylindrical shape, and the diameter of the piston rod 72 is smaller than that of the piston head 71. The piston rod 72 is coaxially and integrally connected to the piston head 71. Note that the diameter of the first piston 60 is larger than that of the piston head 71 of the second piston 70. Further, the piston rod 72 of the second piston 70 has a blade tip portion 73 on the tip side.

[0030] Inside the piston guide 18, a second piston movement space S2 is formed to enable the second piston 70 to move. The second piston 70 is movable along the axial direction of the second piston movement space S2 (i.e., along the central axis C1). The piston guide 18 has a small-diameter inner peripheral surface 181 with a relatively small inner diameter and a large-diameter inner peripheral surface 182 with an inner diameter larger than that of the small-diameter inner peripheral surface 181. The small-diameter inner peripheral surface 181 is disposed on the front end side of the piston guide 18, and the large-diameter inner peripheral surface 182 is disposed behind the small-diameter inner peripheral surface 181. The inner diameter of the large-diameter inner peripheral surface 182 is equal to the diameter of the piston head 71 of the second piston 70. Also, the inner diameter of the small-diameter inner peripheral surface 181 is equal to the diameter of the piston rod 72 of the second piston 70. The second piston 70 has the piston rod 72 accommodated in the second piston movement space S2 and is accommodated in the first piston movement space S1 such that the piston head 71 faces the front end surface 62 of the first piston 60.

[0031] Further, the front end surface of the piston guide 18 is formed as a first stopper wall 183 that suppresses the first piston 60 from coming out forward when the perforator 1 operates. Also, the wall surface that forms a step between the small-diameter inner peripheral surface 181 and the large-diameter inner peripheral surface 182 is configured as a second stopper wall 184 for suppressing the piston head 71 of the second piston 70 from coming out forward when the perforator 1 operates.

[0032] The perforator 1 configured as described above is used with the bottle-side mounting portion 23 of the gas bottle 2 mounted on the main body-side mounting portion 16. The materials of each part constituting the perforator 1 are not particularly limited. For example, the first housing 10 and the second housing 40 may be made of a metal such as aluminum or iron. Also, the first piston 60 may be formed of a heat-resistant resin. The second piston 70 may be made of a metal such as stainless steel or iron. The connection cap member 13 and the piston guide 18 may be made of resin. Of course, these materials are merely examples.

[0033] Next, the operation of the perforator 1 will be described. FIG. 3 is a diagram for explaining the operation of the perforator 1 according to the embodiment. Reference numeral 3 in the figure is a gas discharge device including the perforator 1 and the gas bottle 2 attached to the perforator 1. In the initial state before the operation of the perforator 1, the arrangement relationship between the first piston 60 and the second piston 70 is as shown in FIG. 1. That is, the first piston 60 is disposed in the first piston movement space S1 formed in the second housing 40 with the recess 61 facing the ignition portion 51 of the initiator 50. And the second piston 70 is disposed in the second piston movement space S2 with the piston head 71 facing the front end surface 62 of the first piston 60 and the cutting edge portion 73 formed on the tip side facing the sealing plate 22 of the gas bottle 2. The piston head 71 of the second piston 70 is disposed, for example, in contact with the front end surface 62 of the first piston 60.

[0034] In FIG. 3, (a) shows the state at the moment when the initiator 50 operates. When the initiator 50 operates, the igniter in the cup container at the ignition portion 51 ignites and burns, the cleavage surface 51A of the cup container cleaves, and the combustion gas is vigorously discharged into the first piston movement space S1. Then, the first piston 60 receiving the pressure of this combustion gas at the recess 61 is launched forward in the axial direction within the first piston movement space S1. And receiving the forward launch (high-speed movement) of the first piston 60 in the axial direction (the first piston 60 collides with the piston head 71 of the second piston 70), the second piston 70 is also launched in the same axial direction as the first piston 60 within the second piston movement space S2.

[0035] In FIG. 3, (b) shows the state in which the first piston 60 and the second piston 70 are launched. The first piston 60 launched as described above stops by colliding with the first stopper wall 183. Also, the second piston 70 stops when the piston head 71 collides with the second stopper wall 184. When the second piston 70 is launched, in the process, the cutting edge portion 73 formed on the tip side of the piston rod 72 of the second piston 70 collides with the sealing plate 22 of the gas bottle 2, and the sealing plate 22 is perforated by the cutting edge portion 73.

[0036] When the tip portion 73 of the piston rod 72 in the second piston 70 pierces the sealing plate 22 that seals the gas outlet 21 of the gas bottle 2, the gas (diagonal hatched arrow in the figure) that was filled under high pressure in the bottle flows out from the gas outlet 21. (c) in Fig. 3 shows the situation where gas is being discharged from the gas outlet 21 of the gas bottle 2. Due to the gas pressure flowing out from the gas outlet 21 of the gas bottle 2, the second piston 70 is pushed back from the inside of the gas outlet 21. Then, the gas that has flowed out from the gas outlet 21 of the gas bottle 2 flows into the gas flow path 17 formed in the gas discharge member 15 through the space S3 formed between the main body side mounting portion 16 of the perforator 1 and the piston guide 18, and is supplied to a gas supply target such as an airbag.

[0037] Next, regarding the details of the second piston 70 in the perforator 1, the structure of the tip portion 73 will be mainly described. Fig. 4 is a diagram for explaining the detailed structure of the second piston 70 according to the embodiment. (a) shows the first side surface of the second piston 70. (b) shows the second side surface of the second piston 70. The reference symbol C3 shown in (a) is the central axis extending in the axial direction of the second piston 70 (piston rod 72). (b) shows the side surface when the second piston 70 is rotated 90° around the central axis C3 with reference to the first side surface shown in (a). (c) shows the front (front face) of the second piston 70. (d) is a perspective view of the second piston 70.

[0038] In the present embodiment, the tip portion 73 formed on the tip side of the second piston 70 has a plurality of ridge lines EL and three or more piston blade surfaces mutually divided by each ridge line EL. In the example shown in Fig. 4, the tip portion 73 is configured to include six (six surfaces) of piston blade surfaces PL1 to PL6 mutually divided by seven ridge lines (EL0, EL11 to EL16). When not distinguishing each piston blade surface PL1 to PL6, it may be denoted as "piston blade surface PL".

[0039] In the figure, reference symbol EL0 is the leading edge ridge line that forms the tip of the cutting edge portion 73. In the example shown in FIG. 4, the leading edge ridge line EL0 extends in a direction orthogonal (perpendicular to the axis direction) to the central axis C3 of the piston rod 72 (cutting edge portion 73). However, the leading edge ridge line EL0 may extend in an oblique direction with respect to the central axis C3 of the piston rod 72 (cutting edge portion 73). The leading edge ridge line EL0 is set to a dimension such that the projection length (hereinafter referred to as the "axial direction projection length") L0 when the leading edge ridge line EL0 is projected along the central axis C3 direction (axis direction) of the piston rod 72 is shorter than the diameter of the piston rod 72. FIG. 5 is a diagram for explaining the axial direction projection length L0 of the leading edge ridge line EL0. In the aspect described with reference to FIG. 4, since the leading edge ridge line EL0 extends in the direction perpendicular to the axis of the piston rod 72, the actual length L1 of the leading edge ridge line EL0 and the axial direction projection length L0 are equal (FIG. 5(a)). On the other hand, when the leading edge ridge line EL0 extends in an oblique direction with respect to the central axis C3 of the piston rod 72 (FIG. 5(b)), the axial direction projection length L0 is smaller than the actual length L1 of the leading edge ridge line EL0.

[0040] Also, in the configuration example of the cutting edge portion 73 shown in FIG. 4, one end of another ridge line is connected to both ends of the leading edge ridge line EL0. The other ridge line referred to here means a ridge line other than the leading edge ridge line EL0. At that time, a plurality of other ridge lines (hereinafter referred to as "oblique ridge lines") may be connected to at least one end of the leading edge ridge line EL0. In the example shown in FIG. 4, one end of the oblique ridge lines EL11, EL13, and EL15 is connected to the first end e1 of the leading edge ridge line EL0. Also, one end of the oblique ridge lines EL12, EL14, and EL16 is connected to the second end e2 of the leading edge ridge line EL0. Further, the other ends of the oblique ridge lines EL11 to EL16 connected to any of the ends e1 and e2 of the leading edge ridge line EL0 extend to the side surface 721 of the piston rod 72. The oblique ridge lines EL11 to EL16 can also be said to be ridge lines that gradually increase the diameter of the cutting edge portion 73 from the tip side (leading edge ridge line EL0 side) to the base end side (opposite side of the leading edge ridge line EL0) in the axial direction of the cutting edge portion 73. Note that the reference symbol θ1 shown in FIG. 4(a) is the inclination angle of the oblique ridge line (EL12 in the illustrated example) with respect to the leading edge ridge line EL0.

[0041] The cutting edge portion 73 of the piston rod 72 configured as described above is configured in a knife edge form including a tip ridge line EL0 disposed at the tip. The cutting edge portion 73 in the present embodiment has three or more piston blade surfaces PL mutually divided by ridge lines (EL0, EL11 to EL16).

[0042] FIG. 6 is a diagram for explaining a piston rod R1 having a cutting edge portion EP1 according to Comparative Example 1. The piston rod R1 according to Comparative Example 1 shown in FIG. 6(a) has a so-called two-sided cut cutting edge portion EP1, and two piston blade surfaces PL'1 and PL'2 are divided by a tip ridge line EL0' disposed at the tip. In such Comparative Example 1, when the axial projection length L0' of the tip ridge line EL0' that divides the two piston blade surfaces PL' is projected in the axial direction of the piston rod R1, it is equal to the diameter of the piston rod R1. Thus, in Comparative Example 1 where the axial projection length L0' is equal to the diameter of the piston rod R1, it is necessary to make the dimension of the axial projection length L0' (the diameter of the piston rod R1) the same as or smaller than the diameter of the sealing plate to be perforated. Therefore, in such Comparative Example 1, stroke management when the piston rod R1 is fired during the operation of the perforator 1 becomes severe, and when the piston rod R1 is inserted too deeply into the gas outlet 21 of the gas bottle 2, there is a risk that the sealing plate perforated by the cutting edge portion EP1 will be torn. FIG. 6(b) schematically shows the situation after perforating the sealing plate 22 that had sealed the gas outlet 21 of the gas bottle 2 with the cutting edge portion EP1 of the piston rod R1 according to Comparative Example 1. Reference numeral OE is the edge of the gas outlet 21. (b) shows the situation after the sealing plate 22 that had closed the opening formed inside the edge OE has been perforated. Reference numeral 22'P1 is the remaining piece remaining after perforating the sealing plate 22. Further, reference numeral 22'P2 is a separated piece separated from the remaining piece 22'P1 of the sealing plate 22. If the separated piece 22'P2 is torn when the sealing plate 22 is perforated, there is a risk that the separated piece 22'P2 will be transferred through the gas flow path 17 in the gas discharge member 15 to, for example, an airbag as a gas supply target, causing problems such as damaging the airbag.

[0043] In contrast, in the piston rod 72 according to the present embodiment, the cutting edge portion 73 includes a plurality of ridge lines EL and three or more piston blade surfaces PL that are mutually divided by each ridge line EL. According to such an aspect, the axial projection length L0 of the tip ridge line EL0 located at the tip of the cutting edge portion 73 is smaller than the diameter of the piston rod 72 (the maximum outer diameter of the cutting edge portion 73). According to this, the inner diameter of the edge OE at the gas outlet 21 of the gas bottle 2, that is, the diameter of the sealing plate 22, can be set to a larger dimension than the diameter of the piston rod 72 (the maximum outer diameter of the cutting edge portion 73), and it becomes possible to pierce the sealing plate 22 by inserting only a part of the cutting edge portion 73 into the inside of the gas outlet 21 (see FIG. 7). That is, the axial projection length L0 of the tip ridge line EL0 in the cutting edge portion 73 can be set to a dimension smaller than the diameter of the sealing plate 22, and the diameter of the piston rod 72 (the maximum outer diameter of the cutting edge portion 73) can be set to a dimension larger than the diameter of the sealing plate 22.

[0044] FIG. 7 is a diagram illustrating a situation where the sealing plate 22 of the gas bottle 2 is pierced by the cutting edge portion 73 of the piston rod 72 according to the present embodiment. The symbol L2 is the insertion depth (hereinafter referred to as "cutting edge insertion depth (length)") when the cutting edge portion 73 is inserted deeper (inside the gas bottle 2 side) than the position of the sealing plate 22 when the piston rod 72 fired during the operation of the perforator 1 pierces the sealing plate 22 with the cutting edge portion 73. For example, in the example shown in FIG. 7, when the diagonal ridge lines EL11 and EL12 of the cutting edge portion 73 collide with the edge OE at the gas outlet 21 during the operation of the perforator 1, the movement of the piston rod 72 fired toward the gas outlet 21 stops. In the present embodiment, the cutting edge insertion depth L2 can be easily adjusted by adjusting the length of the tip ridge line EL0 and the inclination angles of the diagonal ridge lines EL11 to EL16.

[0045] FIG. 8 is a diagram comparing the piercing situations of the sealing plates in the embodiment and Comparative Example 1. Comparative Example 1 is shown in the upper row, and the embodiment is shown in the lower row. Also, the symbol BL in the figure indicates the boundary position between the sealing plate 22 and the edge OE, that is, the outer peripheral position of the sealing plate 22.

[0046] (a) shows the situation when the cracking of the sealing plate 22 starts. (d) shows the situation when the perforation of the sealing plate 22 is completed. (b) and (c) show each situation from (a) to (d), that is, each situation in the process where the perforation of the sealing plate 22 gradually progresses. Note that the hatched portions in each figure schematically show the apertured portions formed in the sealing plate 22. This is the case.

[0047] Here, as the basic performance required for the perforator 1, the opening cross-sectional area (the "required opening cross-sectional area") formed when the sealing plate 22 is perforated can be mentioned. This required opening cross-sectional area can be obtained, for example, from the pressure (MPa / s) of the gas flowing out from the gas outlet 21 of the gas bottle 2 when the sealing plate 22 is perforated. For example, the required value set for the gas pressure at the initial stage of perforation is 4.5 (MPa / s), and an example where the required value set for the required opening cross-sectional area to satisfy this condition is 10 (mm 2 ) can be given. Of course, these respective required values are examples. In both the embodiment and Comparative Example 1, it is the same in that it is necessary to secure the required opening cross-sectional area when the sealing plate 22 is perforated.

[0048] In Fig. 8(a), when the sealing plate 22 cracks, the crack length in Comparative Example 1 corresponds to the length of the tip ridge line EL0' (axial direction projection length L0'), and in the embodiment, it corresponds to the length of the tip ridge line EL0 (axial direction projection length L0). In Comparative Example 1, in the process of transitioning from (b)→(c)→(d), the cracking of the sealing plate 22 proceeds due to the two piston blade surfaces PL'1 and PL'2 formed on both sides of the tip ridge line EL0'. Therefore, the cracking of the sealing plate 22 proceeds along the direction orthogonal to the extending direction of the tip ridge line EL0' (the direction orthogonal to the tip ridge line), and finally reaches the perforation completion state of (d) while gradually increasing the crack width. The broken line part in the figure is the folding line FL of the folding piece where the cracked sealing plate 22 is folded to the inner side of the gas bottle 2. As shown in Fig. 8, in Comparative Example 1, as the perforation process of the sealing plate 22 proceeds from (b)→(c)→(d), the length of the folding line FL gradually decreases. Therefore, as described in Fig. 6, there is a possibility that a part of the sealing plate 22 will be torn off as the separation piece 22'P2 during the perforation process of the sealing plate 22.

[0049] On the other hand, as shown in the lower part of FIG. 8, the cutting edge portion 73 of the piston rod 72 according to the embodiment has a tip ridge line EL0 at the tip that is shorter than the diameter of the piston rod 72 (the maximum outer diameter of the cutting edge portion 73). From the end portions e1 and e2 of the tip ridge line EL0, diagonal ridge lines EL11 to EL16 extend radially toward the side surface 721 of the piston rod 72, and the cross-sectional area of the cutting edge portion 73 gradually increases from the tip side toward the base end side by the piston blade surfaces PL1 to PL6 defined by these diagonal ridge lines EL11 to EL16. According to this, as shown in the lower part of FIG. 8, as the piercing process of the sealing plate 22 progresses from (b) → (c) → (d), the piercing area gradually increases. However, contrary to Comparative Example 1, the length of the folding line FL gradually becomes longer. This cannot be achieved in Comparative Example 1 which has only two piston blade surfaces PL, and is a technical feature peculiar to the cutting edge portion 73 according to the embodiment having three or more piston blade surfaces PL. As a result, in the embodiment, it is possible to preferably suppress the sealing plate 22 from being torn until the piercing completion state of (d) is reached. Therefore, it is possible to preferably suppress the separated piece 22'P2 of the sealing plate 22 from being transferred, for example, to a gas supply target (airbag) through the gas flow path 17 in the gas discharge member 15.

[0050] In particular, according to the cutting edge portion 73 of the piston rod 72 in the embodiment, one ends of a plurality of diagonal ridge lines gather at each of the end portions e1 and e2 of the tip ridge line EL0, and the other ends of the respective diagonal ridge lines are connected to the side surface 721 of the piston rod 72. Therefore, it is easy to form a cutting edge portion 73 with a multi-faceted cut having a large number of piston blade surfaces PL.

[0051] Also, according to the cutting edge portion 73 of the piston rod 72 in the embodiment, since it has three or more piston blade surfaces PL, the piercing force when piercing the sealing plate 22 during the operation of the piercer 1 can be increased compared to Comparative Example 1 which has only two piston blade surfaces PL'. Further, according to the present embodiment, since the length of the tip ridge line EL0 can be made shorter than the diameter of the piston rod 72, the collision energy required for the cracking of the sealing plate 22 can also be made smaller compared to Comparative Example 1. That is, according to the present embodiment, when the piercer 1 operates, the piston rod Even if the firing energy when firing the odd 72 is small, it is possible to suitably punch the sealing plate 22.

[0052] In addition, as Comparative Example 2, a piston rod R2 having a blade tip portion EP2 including a single piston blade surface PL' as shown in FIG. 9 can also be considered. In the blade tip portion EP2 of the one-sided cutting type as in Comparative Example 2, as in the blade tip portion EP1 of the two-sided cutting type as in Comparative Example 1, a part of the sealing plate 22 is likely to be torn during the punching process of the sealing plate 22. Further, as shown in the lower part of FIG. 9, since the blade tip portion EP2 according to Comparative Example 2 pushes through the sealing plate 22 by shearing, there is a possibility that the opening (gas flow path) formed with the sheared sealing plate 22 may be blocked.

[0053] Also, a Comparative Example 3 in which the blade tip portion EP3 has a so-called conical shape like the piston rod R3 shown in FIG. 10 can be considered. In such a Comparative Example 3, there is an advantage that it is easy to adjust the blade tip insertion depth L2 of the blade tip portion EP3 when the perforator 1 operates. However, since the structure is such that no ridge line is formed on the blade surface, it is difficult to sufficiently ensure the punching force of the sealing plate 22 when the perforator 1 operates. Therefore, even if punching of the sealing plate 22 is started from the apex VP of the blade tip portion EP3 when the perforator 1 operates, there is a possibility that the piston rod R3 may be pushed back due to the pressure of the gas flowing out from the inside of the gas bottle 2 and an opening having a predetermined required opening cross-sectional area cannot be formed. However, according to the piston rod 72 according to the present embodiment, inconveniences such as those in Comparative Example 3 can be avoided.

[0054] <Modification Example> Next, a modified example of the piston rod 72 according to the present embodiment will be described. FIG. 11 is a diagram for explaining the tip portion 73A of the piston rod 72A according to the first modified example. (a) is a perspective view of the tip portion 73A side of the piston rod 72A, and (b) is a front view thereof. Different from the tip portion 73 described with reference to FIG. 4, the tip portion 73A according to the first modified example does not have a tip ridge line EL0 formed on the tip side, and the apex VP formed at the tip has a sharpened conical shape. And, a plurality of ridge lines extend from the apex VP in the tip portion 73A. Specifically, one ends of the plurality of ridge lines gather at the apex VP, and the other ends of each ridge line extend to the side surface 721 of the piston rod 72A. The tip portion 73A according to the first modified example shown in FIG. 11 has a quadrangular pyramid shape with a square bottom shape, and four diagonal ridge lines EL21 to EL24 extend from the apex VP. And, four piston blade surfaces PL1 to PL4 are defined by the respective ridge lines EL21 to EL24.

[0055] FIG. 12 is a diagram for explaining the tip portion 73B of the piston rod 72B according to the second modified example. Also for the tip portion 73B according to the second modified example, as in the first modified example, one ends of the plurality of ridge lines gather at the apex VP, and the other ends of each ridge line extend to the side surface 721 of the piston rod 72A. The tip portion 73B according to the second modified example shown in FIG. 12 has a triangular pyramid shape with a triangular bottom shape, and three diagonal ridge lines EL31 to EL33 extend from the apex VP. And, three piston blade surfaces PL1 to PL3 are defined by the respective ridge lines EL31 to EL33.

[0056] Even in the piston rods 72A and 72B having the cutting edges 73A and 73B according to Modification 1 and Modification 2, the same technical effects as those of the piston rod 72 having the cutting edge 73 described above are achieved. That is, in the cutting edges 73A and 73B according to Modification 1 and Modification 2, since they have a conical shape, the cutting edge insertion depth L2 during the operation of the perforator 1 can be easily adjusted. And according to the cutting edges 73A and 73B, similar to the cutting edge 73 described above, they include a plurality of ridge lines and three or more piston blade surfaces PL mutually separated by each ridge line. Therefore, in the process of perforating the sealing plate 22, the length of the folding line FL where the sealing plate 22 is folded inward does not become shorter. As a result, it is possible to preferably suppress the sealing plate 22 from being torn when the sealing plate 22 is perforated. Also, different from Comparative Example 3 described above, since ridge lines are formed at the boundary portions between the respective piston blade surfaces, the perforating force (cracking force) when perforating ( cracking) the sealing plate 22 during the operation of the perforator 1 is excellent.

[0057] As described above, the embodiments according to the present disclosure have been described. However, each aspect disclosed in this specification can be combined with any other features disclosed in this specification.

Explanation of Reference Numerals

[0058] 1 ··· Perforator 2 ··· Gas bottle 3 ··· Gas discharge device 10 ··· First housing 21 ··· Gas outlet 22 ··· Sealing plate 40 ··· Second housing 50 ··· Initiator 60 ··· First piston 70 ··· Second piston 71 ··· Piston head 72 ··· Piston rod 73 ··· Cutting edge

Claims

1. A perforator for discharging gas from a gas bottle by opening a sealing plate that seals the gas outlet in the gas bottle when in use with the gas bottle attached, having a piston rod with a cutting edge portion disposed opposite the sealing plate in a state where the perforator is attached to the gas bottle at a tip side, and a drive unit that fires the piston rod toward the sealing plate during operation to pierce the sealing plate with the cutting edge portion, comprising: The cutting edge portion has a plurality of ridge lines and three or more piston blade surfaces mutually defined by each ridge line. Perforator.

2. The cutting edge portion includes a tip ridge line that forms the tip of the cutting edge portion, and the projection length of the tip ridge line along the axial direction of the piston rod is smaller than the diameter of the piston rod. The perforator according to claim 1.

3. The perforator according to claim 2, wherein one end of another ridge line is connected to both ends of the tip ridge line.

4. The perforator according to claim 2, wherein the other end of the other ridge line extends to the side surface of the piston rod.

5. The perforator according to claim 3, wherein a plurality of the other ridge lines are connected to at least one end of the tip ridge line.

6. One end of a plurality of the ridge lines converges at a vertex formed at the tip of the cutting edge portion, and the other end of each ridge line extends to the side surface of the piston rod. The perforator according to claim 5.

7. The perforator according to any one of claims 1 to 6, and a gas bottle attachable to the perforator. comprising: Gas discharge device.

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