JP2011218932A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generator wherein a cup body and a holder thereof are surely fixed to each other, and a strength in a gas generating direction (a holding force in a longitudinal direction) is increased with a simple structure in a joint of the cup body and the holder.SOLUTION: The gas generator 1 includes the cup body 3 which is in the shape of a bottomed cylinder with a flange 12 externally provided around its opening, an igniter 4 with an ignition mechanism, a cylindrical holder 5 which fixes the igniter and the cup body with a fitting groove 6 for fitting the flange part of the cup body therein, a swaging guard 7 for swaging and fixing the flange part of the cup body, and an cylindrical igniter supporting part 8 for swaging and fixing the igniter, and a combustion chamber 9 which is surrounded and formed by the cup body, the igniter and the holder, and is filled with a gas generating agent. At least one continuous circumferential groove 10 is formed at the bottom of the fitting groove, and a protrusion 11 is formed in the flange part of the cup body. The circumferential groove and the protrusion are arranged so as to be engaged with each other.

Description

  The present invention relates to a gas generator for operating an automobile seat belt pretensioner and the like. In particular, the present invention relates to a gas generator in which a cup body that partitions a combustion chamber is securely locked to prevent the cup body from coming off and rotating.

  Various vehicle occupant safety devices have been devised and installed in automobiles to protect crew members from impacts caused by automobile collisions. Many of these vehicle occupant safety devices have a gas generator applied as an activation device and are incorporated in a vehicle safety device module. The seat belt pretensioner device is a safety device for winding up the slack of the seat belt at the time of a collision of the automobile and securely restraining the passenger. Such a seat belt pretensioner device includes, for example, a mechanism for pulling a seat belt and a small gas generator for operating the mechanism, as described in Patent Document 1. Such a small gas generator includes a cup body filled with a gas generating agent, an igniter for igniting the gas generating agent, and a holder for holding the igniter. The holder of the small gas generator is a member having a function of caulking and fixing the igniter by the igniter holding portion and caulking and fixing the cup body, and the gas generating agent is loaded by fixing and holding each member. A combustion chamber is defined. The small gas generator generates gas by burning a gas generating agent, breaks the bottom surface of the cup body by the gas pressure, and discharges the gas accompanied by the pressure to the outside of the gas generator. In the seat belt pretensioner device, the small gas generator is installed by inserting the cup body side, which is the gas discharge side, into a module mechanism for pulling the seat belt. When inserting and installing the gas generator into the module mechanism, it is necessary that the gas generator is firmly fixed so that there is no rotational slip between the cup body of the gas generator and the holder.

  The operating mechanism of the safety device including these gas generators will be described below. First, an igniter of a gas generator as an ignition device receives an electrical signal generated from a collision sensor when a collision accident occurs, and the igniter generates heat. Due to the heat generated by the igniter, the gas generating agent is ignited and combusted, and accordingly, a high temperature and high pressure gas is generated. The safety device is activated by the gas pressure of the generated high temperature and high pressure gas. At this time, since the combustion chamber of the gas generator is instantaneously exposed to high temperature and high pressure conditions, the configuration of the combustion chamber of the igniter of the gas generator must be designed to withstand such high temperature and high pressure conditions. That is, the structure must be such that a combustion chamber is ensured even under high temperature and high pressure conditions.

  Furthermore, the gas generating agent loaded in the gas generator is concerned with quality deterioration due to moisture. Therefore, it is essential that the combustion chamber partitioned by the cup body and the holder has a structure in which airtightness is maintained by blocking the entry of outside air. Further, the combustion chamber needs to maintain pressure tightness and airtightness in order to obtain a predetermined generated gas pressure immediately after the gas generator is activated. Therefore, the caulking and fixing of the cup body and the holder that define the combustion chamber is important to have a strong and airtight engagement form.

  In such a gas generator, a structure is known in which a cup body and a holder that partition a combustion chamber are firmly fixed. Patent Document 2 discloses a gas generator in which a convex portion is provided on at least one of a cup body or a holder of a gas generator and a concave portion that is engaged with the other is provided on the other side. A specific form of the convex portion is a plurality of pin-shaped protrusions. Moreover, the installation site | part of this convex part and the opposing recessed part is installed in the inner wall surface of the crimping hook of a holder, and the cup body flange outer wall surface facing this.

  Further, Patent Document 3 discloses a structure in a small gas generator that can prevent slipping (displacement) between the holder and the cup body by causing a caulking hook for fixing the cup body to bite into the side wall of the cup body in the holder. is doing.

Special table 2008-518832 gazette International Publication Number WO02 / 060728 JP 2008-37389 A

The gas generator sends a predetermined gas pressure to the seat belt pretensioner device with directivity to activate the device mechanism. In order to exert its function reliably, it is necessary to fix and hold the cup body loaded with the gas generating agent firmly and hermetically in the holder in which the igniter is contained. In each of the above-described prior art documents, in the mechanism for fixing the caulking hook of the holder to the cup body, a configuration is adopted in which the cup body in which the convex portion is formed or the opposing member is deformed into the concave shape and engaged by the holder member. Is. However, these configurations are accompanied by thinning of the deformed portion of the member, and there is a concern that the mechanical strength of the member is lowered although the joint strength of the engaging portion is increased. That is, although the rotational strength of the joint between the cup body and the holder increases, there is a concern that the longitudinal strength coaxial with the gas generation direction cannot ensure sufficient longitudinal tensile strength due to a decrease in the mechanical strength of the member. there were. In the case of the prior art, in order to compensate for this problem, it is necessary to preliminarily increase the thickness of the member wall of the concave deformable member, resulting in an increase in the weight of the gas generator or an increase in the size of the gas generator. It was.
Furthermore, in the conventional gas generator, the filling amount of the gas generating agent is 400 to 1000 mg, which is a small amount of filling of the gas generating agent. However, when designing a vehicle safety device mechanism that requires a stronger driving force, it is necessary to provide a high-power gas generator with the gas generating agent filling amount increased to 1000 to 2000 mg, which constitutes the gas generator. The improvement of the mechanical strength of the members and the improvement of the assembly strength of each member must be considered. In particular, since a large amount of gas is generated in the high-power gas generator and the possibility that the cup body jumps out of the holder at the time of gas generation is increased, a stronger holding of the cup body is required.
The present invention securely fixes the cup body and the holder of the gas generator, and improves the strength in the same direction as the gas generation direction (longitudinal holding force) in a simple configuration at the joint between the cup body and the holder. The purpose is to provide a generator.

As a result of intensive studies, the present inventors have found that a gas generator including a holder in which a circumferential groove continuous to the bottom of the fitting groove is disposed and a cup body in which a convex portion is disposed in the flange portion has the above problems. The inventors have found that the problem is solved and have reached the present invention. That is, the present invention is as follows.
(1) A gas generator for operating a vehicle occupant restraint device, which is activated by a gas generating agent, a cup body having a bottomed cylindrical shape with a flange extending to an opening, and an electric signal An igniter having an ignition mechanism, a fitting groove for fitting the flange portion of the cup body, a caulking rod for caulking and fixing the flange portion of the cup body, and a cylindrical igniter holding for caulking and fixing the igniter And a combustion chamber that is partitioned and formed by the cup body, the igniter, and the holder. A gas generator containing the gas generating agent, wherein at least one continuous circumferential groove is formed at a bottom portion of the fitting groove, and a convex portion is formed at a flange portion of the cup body. The circumferential groove and the convex part are engaged A gas generator, characterized in that the gas generator is disposed.
A specific example of the vehicle occupant restraint device is a seat belt pretensioner device. According to the said structure, the convex part formed in the flange part by the side of a cup body and the circumferential groove by the side of a holder engage in the junction part of a cup body and a holder, and joint strength improves. Specifically, it is possible to obtain a result that the rotational torque value, which is an index of strength in the rotational direction, is improved, and the longitudinal holding force value, which is an index of a mechanism for preventing the cup body from popping out when gas is generated, is improved. In addition, the airtightness of the combustion chamber is maintained on a satisfactory standard. Therefore, when the gas generator is attached to the seat belt pretensioner device, the desired performance of the small gas generator can be exhibited and the seat belt pretensioner device can be operated reliably. In the gas generator having the above configuration, when the cup body and the holder are caulked and fixed, the flange portion of the cup body is formed with a convex portion by plastic deformation, but the flange portion is not thinned due to the deformation, and the member The mechanical strength of is maintained. In addition, the structure according to the present invention is easier to process than the conventional gas generator with uneven portions, which is advantageous in terms of ensuring the structure of the member and the cost of manufacturing the member. is there. Since high accuracy can be ensured in the member structure, an excellent effect is also exhibited in terms of ensuring the quality of the performance of the assembled gas generator.

(2) In the gas generator according to (1), a ratio (W / L) of a groove width (W) of the circumferential groove and a groove width (L) of the fitting groove is 0.2 to 0.6. It is preferable that
By adopting a configuration in which the design of the circumferential groove follows the relative relationship with the fitting groove, a joint surface with the flange portion of the opposing cup body can be secured, and the convex portion formed on the flange portion and the circumferential groove Can be reliably engaged, and the bonding strength between the cup body and the holder can be ensured.
(3) In the gas generator according to (1) or (2), a ratio of a depth (D) of the circumferential groove to a plate thickness (T) of the cup body flange portion is (D / T) is 0. .3 or more is preferable.
By making the design of the circumferential groove in accordance with the relative relationship with the plate thickness of the flange portion, the engagement of the convex portion formed on the flange portion with the circumferential groove contributes to the improvement of the holding power of the cup body. It can be set as the structure to do.

(4) In the gas generator according to any one of (1) to (3), the circumferential groove has a groove width of 0.2 to 0.8 mm, and the fitting groove has a groove width of 0.8. It is preferable that it is 8-3.2 mm.
(5) In the gas generator according to (1) to (4), the circumferential groove has a depth of 0.1 to 0.8 mm, and the cup body flange portion has a plate thickness of 0. It is preferably 3 to 0.7 mm.
According to the above configuration, by defining the shape of the circumferential groove, the shape of the cup body holding portion of the holder including the fitting groove and the caulking ridge, and the shape of the cup body flange portion, the flange portions of the opposing cup body are convex due to plastic deformation. A portion can be formed, and the convex portion of the formed flange portion can be reliably engaged with the circumferential groove, and the bonding strength between the cup body and the holder can be ensured.

(6) In the gas generator according to any one of (1) to (5), the groove width of the fitting groove is 1.2 to 2.4 mm, and is continuous from the outer wall surface of the cup body. It is preferable that the outer wall surface of the flange and the shape of the surface of the caulking rod on the side in contact with the flange are matched and joined.
By following the above configuration, the holding force between the holder and the cup body is further improved by increasing the contact area between the cup body holding portion and the cup body flange portion of the holder.

(7) In the gas generator according to any one of (1) to (6), the fitting groove is formed along an outer peripheral portion of the holder, and the circumferential groove is formed at a bottom portion of the fitting groove. It is preferable that it is formed in the outermost peripheral part.
(8) In the gas generator according to any one of (1) to (6), the fitting groove is formed along an outer peripheral portion of the holder, and the circumferential groove is formed at a bottom portion of the fitting groove. It is preferable that one is formed on the outermost peripheral part and the innermost peripheral part.
The above configuration specifies the formation position of the circumferential groove arranged at the bottom of the fitting groove of the holder, and gas that improves the holding force in both the rotational direction and the vertical direction holding force of the cup body and the holder. A generator can be provided.
(9) In the gas generator according to (1), it is preferable that the gas generating agent has a filling amount of 1200 mg or more. The gas generator according to the present application is one in which the cup body and the holder are firmly held, and can be applied to a high-power small gas generator having a larger amount of gas generating agent than a conventional small gas generator.
(10) A gas generating agent, a cup body having a low-cylindrical shape and a flange having a convex portion at the opening, an igniter having an ignition mechanism activated by an electric signal, and the flange of the cup body At least one continuous groove at the bottom of the fitting groove, a fitting groove for fitting the fitting portion, a caulking rod for caulking and fixing the flange portion of the cup body, and a cylindrical igniter holding portion for caulking and fixing the igniter A cylindrical holder having a circumferential groove and fixing the cup body and the igniter;
A manufacturing method of a gas generator comprising a combustion chamber that is defined by being surrounded by the cup body, the igniter, and the holder, wherein the gas generating agent is contained in the combustion chamber,
(I) An igniter mounting step of attaching an igniter to the cylindrical holder, deforming the cylindrical igniter holding portion so as to reduce the diameter, and fixing the igniter by caulking, thereby creating a holder with an igniter;
(Ii) a fitting step of fitting the cup body filled with the gas generating agent to the holder with the igniter;
(Iii) The caulking flange of the holder is deformed so as to reduce the diameter, and the flange portion of the cup body is sandwiched between the fitting groove and the caulking rod, and at the same time, the flange portion facing the circumferential groove of the holder is caulked. A caulking process in which a convex portion is formed by plastic deformation via caulking caulking,
The manufacturing method of the gas generator containing is mentioned. By the above manufacturing method, the cup body flange portion can be formed with a convex portion at the same time as the cup body is fixed to the holder, and the convex portion can be arranged to be surely engaged with the circumferential groove of the holder. It is what. Furthermore, the manufacturing process of the conventional gas generator is the same, and there is an advantage that a new manufacturing facility is not required.

  According to the present invention, it is possible to provide a gas generator in which the longitudinal direction holding force and the rotational direction holding force at the joint between the cup body and the holder of the gas generator are significantly improved as compared with the prior art. Along with the reliable joining of the joined portion, the airtightness of the combustion chamber is sufficiently secured, and a highly reliable gas generator can be provided with a simple configuration. Furthermore, the gas generator of the present invention can be manufactured by the same manufacturing process as that of the related art by using a holder member that does not require a complicated shape, and the cost related to the manufacturing process can be suppressed. Further, since the cup body and the holder can be firmly held as compared with the conventional configuration, it is possible to reduce the thickness of the cup body and the members of the holder and to adopt a lightweight material. And weight reduction can be achieved.

It is sectional drawing of the small gas generator which concerns on the 1st Embodiment of this invention. It is an expanded sectional view of the junction part (part enclosed by the dotted line of Drawing 1) of the cup body and a holder of the small gas generator concerning a 1st embodiment of the present invention. It is sectional drawing of the small gas generator which concerns on the 2nd Embodiment of this invention. It is an expanded sectional view of the junction part (part enclosed by the dotted line of Drawing 3) of a cup body and a holder of a small gas generator concerning a 2nd embodiment of the present invention. It is sectional drawing of the small gas generator which concerns on the 3rd Embodiment of this invention. It is an expanded sectional view of the junction part (part enclosed by the dotted line of Drawing 5) of a cup body and a holder of a small gas generator concerning a 3rd embodiment of the present invention. It is sectional drawing of the small gas generator by a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a cross-sectional view showing a first embodiment of a gas generator according to the present invention. The gas generator shown in FIG. 1 is a small gas generator 1 mainly used in a seat belt pretensioner device. The small gas generator 1 includes a metal cup body 3, an igniter 4 for igniting the gas generating agent 2, and a metal cylindrical holder 5 that holds the cup body 3 and the igniter 4. Prepare. And the combustion chamber 9 divided and enclosed by the cup body 3, the igniter 4, and the holder 5 is formed, and the gas generating agent 2 is filled into this division. The igniter 4 is disposed adjacent to the gas generating agent 2 in order to immediately ignite the gas generating agent 2 when a collision accident occurs.

  The igniter 4 is an ignition device that is activated by an electric signal to generate a flame and ignite the gas generating agent 2 to start combustion. The igniter 4 includes an ignition agent (not shown) and a resistor (not shown) for igniting the ignition agent. The resistor is connected to a pair of electrode pins 14 and 15, and each electrode pin is inserted and held in the base portion 19 and penetrates to the outside. Nichrome wire or the like is generally used as the resistor, and ZPP (zirconium / potassium perchlorate), ZWPP (zirconium / tungsten / potassium perchlorate), lead tricinate, or the like is generally used as the igniting agent. The metal cover 18 is installed in order to give directivity to the high-temperature flame generated from the igniter 4 and to burn the gas generating agent 2 reliably.

  The igniter 4 is held by the holder 5 in a form in which the igniter holding portion 8 whose opening end is reduced in diameter and the base portion 19 of the igniter are in contact with each other. The electrode pins 14 and 15 are inserted into the holes 13, and the tip portions of the electrode pins are inserted into the connector insertion portion 16 side. The hole 13 may be a single hole into which the plurality of electrode pins 14 and 15 can be inserted together, or a plurality of holes into which the electrode pins can be individually inserted. An O-ring 17 is interposed between the igniter 4 and the holder 5 in order to improve airtightness. The O-ring 17 is made of a rubber material having heat resistance and moisture resistance.

The cup body 3 is press-molded in two stages: a reduced diameter cylindrical portion with a reduced diameter at the tip of the cup bottom direction side surface and a large diameter cylindrical portion with a large diameter at the side surface in the opening end direction, and the end of the opening end is bent. Thus, a disc-shaped flange portion 12 is formed. A fragile portion 20 is installed on the bottom of the cup body 3. As a specific form of the fragile portion 20, there is an installation of a thin portion in the cup body, and more specifically, a plurality of linear notches are arranged. When the gas generating agent 2 filled in the cup is combusted, the fragile portion 20 is broken, and the generated gas is released with pressure to a seat belt pretensioner mechanism (not shown).
The material used for the cup body 3 is selected from materials such as aluminum, iron, copper, steel, alloys thereof, and resins, and is formed by forging, pressing, drawing, molding, or the like. In the present invention, it is preferable to employ a cup body made of aluminum or aluminum alloy. Note that the cup body 3 and the holder 5 are securely fixed by selecting the material and thickness of the cup body in accordance with the output of the gas generated by the burned gas generating agent 2.

The flange part 12 arrange | positioned at the cup body 3 is a disk shape which has the edge width fitted to the holder fitting groove | channel 6 mentioned later. That is, the flange portion 12 is a continuous disk shape having the same shape as the fitting groove 6 and has an edge width smaller than the fitting groove width. The flange portion 12 is fixed to the holder 5 by caulking, and the plate thickness (T) of the flange portion that is caulked and fixed requires a plate thickness of at least 0.1 mm or more so as to be fixed by caulking force. To do. More preferably, the plate thickness (T) of the flange portion requires 0.3 mm or more.
A sealant (not shown) is applied between the flange portion 12 of the cup body and the holding portion of the holder 5. This sealant is not essential, but is applied as necessary to ensure a hermetic seal between the holder 5 and the cup body 3. As the sealant, it is preferable to use a material having low moisture permeability and excellent durability. For example, a silicone sealant is preferably used. Further, when a sealing agent in which a solid component is dissolved in a solvent is used, the housing is preferably caulked and fixed after application and drying of the sealing agent.

The holder 5 is made of a hollow, substantially cylindrical member, and is formed of a molded product using, for example, an aluminum alloy. The holder 5 has an igniter holding portion 8 that holds the igniter 4 so as to cover the base portion 19. The igniter holding part 8 is clamped and held from the vertical direction of the base part 19 of the igniter by caulking. A cylindrical connector insertion portion 16 is installed in the other end direction, and communicates with the igniter holding portion 8 side through the hole 13.
A cylindrical groove of the holder 5 is provided with a fitting groove 6 for holding the cup body 3 and a caulking rod 7. In the cup body 3, the flange portion 12 is fitted in the fitting groove 6, and the caulking collar 7 is engaged with the flange portion 12 and is fixed to the holder 5 by caulking. Therefore, the caulking rod 7 has a shape in which the end portion is reduced in diameter toward the center side by undergoing plastic deformation on the cylindrical center portion side of the holder 5 by caulking.

  In the gas generator 1 according to the first embodiment of the present invention, a continuous circumferential groove 10 is formed in the center portion of the bottom of the fitting groove 6, and the circular portion 10 is further formed in the flange portion 12. A convex portion 11 that engages with the circumferential groove 10 is formed. Specifically, it has a structure as shown in FIG. 2 in which a portion surrounded by a dotted line in FIG. 1 is enlarged. This will be described below with reference to FIG.

  The flange portion 12 formed in the cup body 3 is inserted into the fitting groove 6 of the holder 5. Further, the caulking rod 7 of the holder 5 is bent and deformed so as to come into contact with the outer wall portion of the flange portion 12, and is reduced in diameter toward the inner side of the holder 5. That is, the caulking ridge 7 has a shape bent in the holder inner direction by the plate thickness (T) of the flange portion 12 of the cup body 3. One continuous circumferential groove 10 is formed at the center of the bottom of the fitting groove 6. The inner wall side of the cup body 3 of the flange portion 12 is disposed in contact with the bottom portion of the fitting groove 6, and the flange portion 12 has a convex portion 11 at a position facing the circumferential groove 10. The circumferential groove 10 and the convex portion 11 are arranged to engage with each other. The gas generator 1 according to the first embodiment of the present application includes a mechanism in which the cup body 3 is caulked and fixed by the caulking rod 7 and the fitting groove 6, and the circumferential groove 10 and the flange convex portion 11 are engaged. Thereby, the firm fixation of the cup body 3 to the holder 5 can be achieved.

  The convex portion 11 formed on the cup body flange portion 12 is formed so that the flange portion 12 is caulked when the cup body flange portion 12 is inserted into the holder fitting groove 6 and the cup body 3 is caulked and fixed to the holder 5. It is formed by being plastically deformed at a portion facing the circumferential groove 10 by caulking. Therefore, the force for deforming the caulking rod 7 needs to apply sufficient force to plastically deform the caulking rod 7 to form the reduced diameter portion and to plastically deform the flange portion 12 to form the convex portion 11. It is. By adopting such a method, the convex portion 11 can be arranged to engage with the circumferential groove 10 without any difference.

The gas generator 1 according to the first embodiment of the present application is such that the cup body 3 is firmly held by the holder 5 by the above-described configuration, but a suitable range in each part configuration of the cup body 3 and the holder 5 is adopted. Therefore, the function is more reliably exhibited.
Specifically, the circumferential groove 10 is disposed so that the groove width (W) thereof is W / L in the range of 0.2 to 0.6 with respect to the groove width (L) of the fitting groove 6. It is preferable. Or it is preferable that the ratio (D / T) of the depth (D) and the plate | board thickness (T) of the cup body flange part 12 is 0.3 or more. More preferred is a gas generator installed in a relative arrangement in which W / L is in the range of 0.2 to 0.6 and D / T is 0.3 or more. The circumferential groove 10 disposed at the bottom of the fitting groove 6 has a flange portion 12 when the groove width (W) is small, that is, when W / L is less than 0.2 relative to the fitting groove. Sufficient engagement with the convex portion 11 cannot be achieved. Further, when the groove width (W) of the circumferential groove 10 is large, that is, W / L is larger than 0.6, the engagement between the convex portion 11 of the flange portion 12 and the circumferential groove 10 is ensured, but the convex portion The strength of the portion 11 is weakened, and the locking strength between the cup body 3 and the holder 5 is lowered. Moreover, when the depth (D) of the circumferential groove 10 is not deep enough with respect to the plate thickness (T) of the cup body flange portion 12, the convex portion 11 disposed in the flange portion 12 is also naturally small. Thus, sufficient locking strength between the cup body 3 and the holder 5 cannot be obtained. Therefore, the relative ratio (D / T) of the depth (D) of the circumferential groove 10 and the plate thickness (T) of the flange portion 12 is preferably 0.3 or more.
More specifically, the fitting groove 6 of the holder 5 is preferably installed with a groove width (L) of 0.8 to 3.2 mm. When the fitting groove width is smaller than 0.8 mm, the portion of the cup body flange portion 12 covered by the caulking rod 7 is small, so that the holding force is not sufficient, and it is difficult to reliably fix the cup body. When the fitting groove width is larger than 3.2 mm, the diameter of the gas generator is increased, which is not preferable. The height of the crimping ridge 7 is set to 0.8 to 3.2 mm. The caulking rod 7 is bent so as to cover and reduce the diameter of the flange portion 12 of the cup body. The height of the caulking rod 7 refers to the length from the bottom of the fitting groove 6 to the reduced diameter end portion. When the height of the caulking rod 7 is out of this set range, the cup body holding force becomes insufficient, or the small gas generator has a large diameter, resulting in inconvenience. It is preferable that the plate thickness (T) of the caulking fixed flange portion 12 is set to 0.3 to 0.7 mm. When the plate thickness of the flange portion 12 is smaller than 0.3 mm, when the convex portion 11 is formed, the mechanical strength of the cup body 3 is significantly reduced due to the thinning of the flange portion 12, resulting in a decrease in cup body holding force. To do. Moreover, when larger than 0.7 mm, since the enlargement of the crimping cage | basket 7 is required, it is not preferable.

Furthermore, the circumferential groove 10 formed at the center of the bottom of the fitting groove has a circumferential groove width (W) of 0.2 to 0.8 mm and a depth (D) of 0.1 to 0.8 mm. It is preferable to form in the range. When the groove width (W) of the circumferential groove 10 is smaller than 0.1 mm, sufficient engagement between the convex portion 11 and the circumferential groove 10 cannot be achieved. Further, the formation of the convex portion 11 due to plastic deformation of the flange portion 12 due to the caulking of the caulking rod 7 cannot be sufficiently achieved. If the groove width (W) of the circumferential groove 10 is larger than 0.8 mm, the flange portion 12 may be thinned. On the other hand, when the depth (D) of the circumferential groove 10 is smaller than 0.2 mm, sufficient engagement between the convex portion 11 and the circumferential groove 10 cannot be achieved. Moreover, the convex part 11 is not fully formed by the plastic deformation of the flange part 12 by caulking of the caulking rod 7. When the depth (D) of the circumferential groove 10 is larger than 0.8 mm, there is a concern that the overall strength of the holder 5 is lowered. Therefore, when it deviates from the suitable design range in each part composition of cup body 3 and holder 5, engagement with circumferential groove 10 and convex part 11, and caulking fixation strength by caulking rod 7 is not achieved, and cup body 3 and holder A sufficient holding force of 5 is not ensured.
In a more preferable design value in the first embodiment, the groove width (L) of the fitting groove 6 is set to 1.2 to 2.4 mm, and the height of the caulking ridge 7 is set to 1.2 to 2.4 mm. is there. The circumferential groove 10 has a groove width (W) of 0.4 to 0.7 mm and a depth (D) of 0.3 to 0.7 mm. And it is preferable that the circumferential groove 10 is arrange | positioned in the range whose groove width (W) is 0.2-0.6 with respect to the groove width (L) of the fitting groove 6. FIG. Or it is preferable that the ratio (D / T) of the depth (D) and the plate | board thickness (T) of the cup body flange part 12 is 0.3 or more.

  FIG. 7 shows a cross-sectional view of a conventional gas generator. In the conventional small gas generator 301, a flange portion 312 is formed at the opening end portion of the cup body 303. In addition, the holder 305 has a cylindrical end portion that fixes the fitting groove 306 into which the flange portion 303 of the cup body is inserted and the flange portion 312 of the cup body in the outermost shell circumferential portion in order to hold the cup body 303. Is provided with a caulking rod 307 that is reduced in diameter toward the inner side of the holder. The cup body 303 has a flange portion 312 inserted into the fitting groove 306 and a caulking rod 307 is caulked so that the end portion is reduced in diameter toward the center and is fixed to the holder 305. With this configuration, a combustion chamber 309 that is surrounded by the cup body 303, the igniter 304, and the holder 305 is formed. However, regarding securing of the cup body and the holder and securing of airtightness in the combustion chamber according to the conventional technology, it cannot be said that the fixing by the clamping mechanism using the fitting groove 306 and the caulking rod 307 is sufficient and reliable. Therefore, establishment of a stronger fixing method for the cup body and the holder is desired. The gas generator according to the present invention can solve the problem.

  Next, a procedure for assembling the gas generator 1 according to the first embodiment of the present invention shown in FIG. 1 will be described with reference to FIG. First, the igniter 4 is inserted into the cylindrical holder 5 from the electrode pins 14 and 15 side, and the igniter 4 is mounted so as to be accommodated in the cylindrical igniter holding portion 8 of the holder 5 via the O-ring 17. . Next, the igniter holding portion 8 is deformed so as to cover the base portion 19 of the igniter, and the igniter 4 is caulked and fixed to the holder 5 and attached integrally. Next, the holder 5 equipped with the igniter is inserted into the cup body 3 filled with the gas generating agent 2 in advance. At this time, the flange portion 12 of the cup body 3 is fitted into the fitting groove 6 of the cylindrical holder 5, and the caulking rod 7 is caulked and fixed. At this time, the flange portion 12 is subjected to plastic deformation by caulking of the caulking rod 7, and the convex portion 11 is formed at a portion facing the circumferential groove 10 arranged at the bottom of the fitting groove 12. The caulking force of the caulking rod 7 needs to be 15 to 35 kN for the plastic deformation of the caulking rod 7 and the formation of the convex portion 11 by the plastic deformation of the flange portion 12.

The principle that the gas generator 1 described above operates and the seat belt pretensioner device functions as a safety device will be described below. First, when the vehicle collides, a collision detection signal is transmitted from the collision sensor, and the igniter 4 receives the signal via an electric control unit (ECU). When a collision is detected, a predetermined amount of current flows through the resistor via the electrode pins 14 and 15. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and an unillustrated igniter starts burning. The high-temperature flame (hot gas and hot particles) generated by the combustion ignites the gas generating agent 2. The time from when the current flows through the resistor until the ignition device is activated is 2 milliseconds or less when a nichrome wire is used as the resistor. A combustion chamber 9 defined by the cup body 3, the cylindrical holder 5 and the igniter 4 is filled with the gas generating agent 2. The gas generating agent 2 is ignited and burned by a high-temperature flame generated when the igniter 4 is started, and a large amount of gas is generated from the gas generating agent 2 with combustion. The generated gas ruptures and opens the fragile portion 20 of the cup body 3 by setting the inside of the combustion chamber 9 to a predetermined internal pressure or higher, and is sent to the pretensioner mechanism. As a result, the pretensioner mechanism is activated by the gas pressure, the seat belt is pulled, and the safety of the occupant is ensured.
In order to operate the seat belt pretensioner mechanism accurately, the gas generator needs to generate a prescribed gas pressure to the pretensioner mechanism with directivity. The small gas generator 1 according to the present invention joins the flange portion 12 of the cup body, the fitting groove 6 of the cylindrical holder, and the caulking rod 7 when a high-temperature gas is generated with combustion of the gas generating agent 2. Since the fixing of the part and the hermetic sealing are achieved, the internal pressure in the combustion chamber 9 can be sufficiently secured. In addition, when the pressure in the combustion chamber is sufficiently increased, there is no disconnection or pressure breakage of the cup body 3 at the joint portion, and the seat belt is passed through the bottom notch portion 20 of the cup body 3 that is a predetermined gas ejection port. High pressure gas can be led to the pretensioner mechanism. The seat belt pretensioner mechanism to which the small gas generator according to the present application is applied can be operated with a predetermined seat belt retracting force during a predetermined operation time because a starting gas is fed in a predetermined direction with a predetermined gas pressure.

  As the gas generating agent 2 for activating the seat belt pretensioner mechanism, a smokeless explosive (nitrocellulose) molded article, a non-azide composition molded article containing a nitrogen-containing organic compound and an oxidizing agent, or the like is used. . In recent years, a non-nitrocellulose-based gas generating agent that generates a very small amount of harmful components such as carbon monoxide has been used as a gas generating agent for a pretensioner of a seat belt device. As the shape of the molded body of the gas generating agent 2, various shapes such as granules, pellets, cylinders, and disks are used. In addition, a porous (for example, macaroni or lotus root) shaped body having holes inside the shaped body is also used. These shapes are preferably selected as appropriate according to the specifications of the unit in which the gas generator is assembled. For example, the optimum shape is selected so that the gas generation rate changes during combustion of the gas generating agent. In addition to the shape of the gas generating agent, the size of the molded body is appropriately selected in consideration of the linear combustion rate of the gas generating agent, the pressure index, and the like.

  The filling amount of the gas generating agent 2 is appropriately changed according to the specifications of the unit to be assembled, but usually about 200 to 2000 mg of the gas generating agent is used and loaded. In the case of general specifications, the filling amount of the gas generating agent is 400 to 1000 mg. However, in order to cope with various uses of the small gas generator, development of a gas generator that exhibits a stronger driving force is being promoted, and an increase in the amount of gas generating agent loaded is being studied. Specifically, development of a high-power gas generator filled with 1000 to 2000 mg of a gas generating agent is underway. In the case of such a high power type gas generating agent, a gas generator having a higher durability standard for the generated gas is required. The gas generator 1 according to the present application has excellent holding power in the cup body 3 and the holder 5 compared to the gas generator 301 having a conventional configuration, and can be suitably used in a high-power gas generator. It is.

Second Embodiment
Next, the gas generator 101 which concerns on 2nd Embodiment of this invention is demonstrated using FIG.3 and FIG.4. FIG. 3 is a cross-sectional view of a second embodiment of the gas generator of the present application, and FIG. 4 is an enlarged cross-sectional view of a portion surrounded by a dotted line in FIG. Note that, in the present embodiment, among the parts to which the reference numerals are attached, those having the same last two digits as the reference numerals in the first embodiment are the same parts, and the description may be omitted.

  In the gas generator 101 of the present embodiment, a fitting groove 106 is formed on the outer periphery of the cylindrical holder 105. One continuous circumferential groove 110 is formed at a position adjacent to the caulking collar 107 on the outermost peripheral side of the fitting groove bottom. A flange portion 112 is formed at the opening end portion of the cup body 103, and this is inserted into the fitting groove 106, and is caulked and fixed by a caulking rod 107 having a reduced diameter inside the holder 105. A convex portion 111 is formed on the flange portion 112 at a position facing the circumferential groove 110, and the convex portion 111 and the circumferential groove 110 are arranged to engage with each other. In the gas generator 101 according to the second embodiment of the present application, the flange portion 112 of the cup body 103 is sandwiched and fixed by the caulking rod 107 and the fitting groove 106 and is formed on the outermost peripheral portion of the fitting groove 106. By combining the mechanism in which the circumferential groove 110 and the convex portion 111 of the flange portion 112 engage with each other, the cup body 103 can be firmly fixed to the holder 105.

  Hereinafter, the gas generator 101 will be described in more detail. The caulking rod 107 is plastically deformed into a shape in which the opening end has a reduced diameter by caulking, and is disposed in contact with the outer wall portion of the flange portion 112. That is, the caulking rod 107 has a shape bent in the holder inner direction by the plate thickness (T) of the flange portion 112 of the cup body 103. The convex portion 111 of the flange portion 112 is formed by plastic deformation at a position facing the circumferential groove 110 of the flange portion 112 by the caulking force of the caulking rod 107. Accordingly, the force for caulking the caulking rod 107 applies sufficient stress so that the caulking rod 107 is plastically deformed to form a reduced diameter portion and the flange portion 112 is plastically deformed to form the convex portion 111. is required. By adopting such a method, the convex portion 111 can be arranged to engage with the circumferential groove 110 without any difference. In the gas generator according to the second embodiment, the flange portion 112 is deformed into a curved shape along the shape extending from the fitting groove 108 to the circumferential groove 110, and the tip portion is dropped into the circumferential groove 110. The convex part 111 is formed in the shape to be inserted. Accordingly, in the second embodiment, the convex portion 111 is formed in a form not accompanied by a change in the plate thickness (T) of the flange portion 112, and the plate thickness (T) of the flange portion 112 is relatively thin. In the gas generator using the member of the cup body 103, it can be suitably applied.

In the gas generator 101 according to the second embodiment of the present application, the cup body 103 is firmly held by the holder 105 by the above-described configuration, but a range of suitable design numerical values in each part configuration of the cup body 103 and the holder 105 is used. By adopting, the function is more reliably exhibited.
Specifically, the circumferential groove 110 is disposed such that the groove width (W) is within a range of W / L from 0.2 to 0.6 with respect to the groove width (L) of the fitting groove 106. It is preferable. Alternatively, the circumferential groove 110 preferably has a ratio (D / T) of the depth (D) and the plate thickness (T) of the cup body flange portion 112 of 0.3 or more. More preferred is a gas generator installed in a relative arrangement in which W / L is in the range of 0.2 to 0.6 and D / T is 0.3 or more. The circumferential groove 110 disposed at the bottom of the fitting groove 106 has a flange portion 112 when the groove width (W) is small, that is, when W / L is less than 0.2 relative to the fitting groove. Sufficient engagement with the convex portion 111 cannot be achieved. Further, when the groove width (W) of the circumferential groove 110 is large, that is, W / L is larger than 0.6, the engagement between the convex portion 111 of the flange portion 112 and the circumferential groove 110 is ensured, but the convex portion The strength of the portion 111 is weakened, and the locking strength between the cup body 103 and the holder 105 is lowered. In addition, when the depth (D) of the circumferential groove 110 is not sufficient with respect to the plate thickness (T) of the cup body flange portion 112, the convex portion 111 disposed in the flange portion 112 is also naturally small. Thus, sufficient locking strength between the cup body 103 and the holder 105 cannot be obtained. Therefore, the relative ratio (D / T) of the depth (D) of the circumferential groove 110 and the plate thickness (T) of the flange portion 112 is preferably 0.3 or more.
Specifically, it is essential that the fitting groove 106 of the holder 105 has a size into which the flange portion 112 is inserted, but the groove width (L) is set to 0.8 to 3.2 mm. preferable. More preferably, the groove width (L) is 1.2 to 2.4 mm. The height of the caulking ridge 107 is set to 0.8 to 3.2 mm. The caulking ridge is bent so as to cover the outer wall portion of the flange portion 112 of the cup body and reduce the diameter. The height of the caulking ridge 107 is the length from the bottom of the fitting groove 6 to the reduced diameter end portion. Point to. More preferably, the height of the caulking rod 107 is designed to be 1.2 to 2.4 mm. The flange edge width of the caulking fixed flange portion 112 is smaller than the groove width (L) of the fitting groove 106. Since the flange portion 112 can be plastically deformed to form the convex portion 111, the plate thickness (T) is an important factor and is preferably set to 0.3 to 0.7 mm.

Further, the circumferential groove 110 formed on the outermost peripheral portion of the bottom of the fitting groove 106 has a groove width (W) of 0.2 to 0.8 mm and a depth (D) of 0.1. It is preferably formed in a range of ˜0.8 mm. When the groove width (W) of the circumferential groove 110 is smaller than 0.2 mm, sufficient engagement between the convex portion 111 and the circumferential groove 110 cannot be achieved. Further, the convex portion 111 is not sufficiently formed by plastic deformation due to the caulking of the caulking ridge 107. When the groove width of the circumferential groove 110 is larger than 0.8 mm, the flange portion 112 may be thinned. Moreover, when the depth (D) of the circumferential groove 110 is smaller than 0.1 mm, sufficient engagement between the convex portion 111 and the circumferential groove 110 cannot be achieved. Further, the convex portion 111 is not sufficiently formed by plastic deformation due to the caulking of the caulking ridge 107. On the other hand, when the depth of the circumferential groove 110 is larger than 0.8 mm, there is a concern that the overall strength of the holder 105 is lowered. Therefore, when it deviates from the suitable design range in each part configuration of the cup body 103 and the holder 105, the engagement between the circumferential groove 110 and the convex portion 111 and the caulking fixing strength by the caulking rod 107 are not achieved, and the cup body 103 and the holder A sufficient holding force of 105 is not ensured.
In a more preferable design value in the second embodiment, the groove width (L) of the fitting groove 106 is set to 1.2 to 2.4 mm, and the height of the crimping collar 107 is set to 1.2 to 2.4 mm. It is. The circumferential groove 110 is more preferably set with a groove width (W) of 0.4 to 0.7 mm and a depth (D) of 0.3 to 0.7 mm. Furthermore, it is preferable that the circumferential groove 110 is disposed in a range where the groove width (W) is 0.2 to 0.6 with respect to the groove width (L) of the fitting groove 106. Alternatively, the circumferential groove 110 preferably has a ratio (D / T) of the depth (D) and the plate thickness (T) of the cup body flange portion 112 of 0.3 or more.
The gas generator 101 according to the second embodiment of the present application achieves secure fixing of the cup body 103 by a configuration in which the convex portion 111 formed on the flange portion 112 is engaged with the circumferential groove 110. In addition, it is possible to provide a gas generator in which the longitudinal holding force is significantly improved as compared with the prior art. Along with the reliable joining of the joining portion, the airtightness of the combustion chamber is sufficiently ensured.

<Third Embodiment>
Next, the gas generator 201 which concerns on 3rd Embodiment of this invention is demonstrated using FIG.5 and FIG.6. FIG. 5 is a cross-sectional view of a third embodiment according to the gas generator of the present application, and FIG. 6 is an enlarged cross-sectional view of a portion surrounded by a dotted line in FIG. Note that, in the present embodiment, among the parts to which the reference numerals are attached, those having the same last two digits as the reference numerals in the first embodiment are the same parts, and the description may be omitted.

  In the gas generator 201 of the present embodiment, a fitting groove 206 is formed in the outer peripheral portion of the cylindrical holder 205. At the bottom of the fitting groove 206, continuous circumferential grooves 210a and 210b are formed at positions adjacent to the caulking rod 207 on the outermost peripheral side and positions adjacent to the igniter holding portion 208 on the innermost peripheral side, respectively. Yes. A flange portion 212 is formed at the opening end portion of the cup body 203, which is inserted into the fitting groove 206, and is fixed by caulking with a caulking rod 207 having a reduced diameter inside the holder 205. On the flange portion 212, convex portions 211a and 211b are formed at positions facing the circumferential grooves 210a and 210b, respectively. The convex portion 211a is formed so that the front end portion of the flange portion 212 is curved along the circumferential groove 210a, and the convex portion 211b is formed so that the inner peripheral portion of the flange portion 212 is dropped into the circumferential groove 210b. . The convex portions 211a and 211b and the circumferential grooves 210a and 210b are arranged to engage with each other. In the gas generator 201 according to the third embodiment of the present application, the flange portion 212 of the cup body 203 is sandwiched and fixed by the caulking rod 207 and the fitting groove 206, and the outermost and innermost portions of the fitting groove 206 are fixed. In addition, by combining the circumferential grooves 210a and 210b respectively formed with the convex portions 211a and 211b of the flange portion, the cup body 203 can be firmly fixed to the holder 205.

  Hereinafter, the gas generator 201 will be described more specifically. The caulking rod 207 is plastically deformed into a shape in which the opening end is reduced in diameter by caulking, and is placed in contact with the outer wall portion of the flange portion 212. That is, the caulking rod 207 has a shape that is bent in the holder inner direction by the plate thickness (T) of the flange portion 212 of the cup body 203. The convex portions 211 a and 211 b of the flange portion 212 are formed by plastic deformation at positions facing the circumferential grooves 210 a and 210 b of the flange portion 212 due to the caulking force of the caulking rod 207. Accordingly, the caulking force of the caulking rod 207 needs to apply sufficient stress so that the caulking rod 207 is plastically deformed to form a reduced diameter portion and the flange portion 212 is plastically deformed to form the convex portions 211a and 211b. It is. By adopting such a method, the convex portions 211a and 211b can definitely be arranged to engage with the circumferential grooves 210a and 210b. In the gas generator according to the third embodiment, two convex portions 211a and 211b are formed on the flange portion 212 in accordance with the arrangement of the two circumferential grooves 210a and 210b. It is the form where a part is installed. Therefore, in the third embodiment, a stronger holding force can be exhibited by engagement of the circumferential groove and the convex portion at two locations.

In the gas generator 201 according to the third embodiment of the present application, the cup body 203 is firmly held by the holder 205 by the above-described configuration, but a range of suitable design numerical values in the configuration of each part of the cup body 203 and the holder 205 is used. By adopting, the function is more reliably exhibited.
Specifically, in the circumferential groove 210a or 210b, Wa (or Wb) / L is 0.2 to 0 with respect to the groove width (L) of the fitting groove 206 in each groove width (Wa or Wb). .6 in the range. Alternatively, the circumferential groove 210a or 210b may have a ratio (Da (or Db) / T) of a depth (Da or Db) and a plate thickness (T) of the cup body flange portion 212 of 0.3 or more. preferable. More preferably, a gas generator installed in a relative arrangement in which Wa (or Wb) / L is in the range of 0.2 to 0.6 and Da (or Db) / T is 0.3 or more. it can. Even if the circumferential grooves 210a and 210b of the book have the same width and the same depth, or different groove widths and depths, there is no particular problem as long as the circumferential grooves are within the above range. The circumferential groove 210a or 210b disposed at the bottom of the fitting groove 206 has a small width (Wa or Wb), that is, relative to the fitting groove, Wa (or Wb) / L is 0. When smaller than 2, sufficient engagement with the convex part 211a or 211b of the flange part 212 cannot be achieved. When the groove width (Wa or Wb) of the circumferential groove 210a or 210b is large, that is, when Wa (or Wb) / L is larger than 0.6, the convex portion 211a or 211b of the flange portion 212 and the circumferential groove 210a or Although the engagement with 210b is ensured, the strength of the convex portion 211a or 211b is weakened, and the locking strength between the cup body 203 and the holder 205 is lowered. Further, when the depth (Da or Db) of the circumferential groove 210a or 210b is not sufficient with respect to the plate thickness (T) of the cup body flange portion 212, the convex portion disposed on the flange portion 212. 211a or 211b is naturally small, and sufficient locking strength between the cup body 203 and the holder 205 cannot be obtained. Therefore, the relative ratio (Da (or Db) / T) of the depth (Da or Db) of the circumferential groove 210a or 210b and the plate thickness (T) of the flange portion 212 is preferably 0.3 or more. .
Specifically, it is essential that the fitting groove 206 of the holder 205 is a size into which the flange portion 212 is inserted, but the groove width (L) is set to 0.8 to 3.2 mm. preferable. More preferably, the groove width (L) is 1.2 to 2.4 mm. The height of the caulking ridge 207 is set to 0.8 to 3.2 mm. The caulking rod 207 is bent in a shape that covers the flange portion of the cup body and has a reduced diameter. The height of the caulking rod 207 indicates the length from the bottom of the fitting groove 206 to the reduced diameter end portion. More preferably, the height of the caulking ridge 207 is designed to be 1.2 to 2.4 mm. The flange portion 212 that is caulked and fixed is smaller than the groove width (L) of the fitting groove 206, but the plate thickness (T) is important in order to be able to plastically deform to form the convex portions 211a and 211b. It is a factor and is preferably set to 0.3 to 0.7 mm.

Further, the circumferential grooves 210a and 210b formed on the outermost periphery of the bottom of the fitting groove 206 have a groove width (W) of 0.2 to 0.8 mm and a depth (D) of the circumferential grooves 210a and 210b, respectively. It is preferably formed in the range of 0.1 to 0.8 mm. Even if the two circumferential grooves 210a and 210b have the same width and the same depth, or different groove widths and depths, there is no particular problem as long as the circumferential grooves are within the above range. When the groove width (W) of the circumferential grooves 210a and 210b is smaller than 0.2 mm, sufficient engagement between the convex portions 211a and 211b and the circumferential grooves 210a and 210b cannot be achieved. Further, the convex portions 211a and 211b are not sufficiently formed by the plastic deformation due to the caulking of the caulking rod 207. When the groove width (W) of the circumferential grooves 210a and 210b is larger than 0.8 mm, the flange portion 212 may be thinned. Further, when the depth (D) of the circumferential grooves 210a and 210b is smaller than 0.1 mm, sufficient engagement between the convex portions 211a and 211b and the circumferential grooves 210a and 210b cannot be achieved. Further, the convex portions 211a and 211b are not sufficiently formed by plastic deformation due to caulking of the caulking ridge 207. On the other hand, when the depth of the circumferential grooves 210a and 210b is larger than 0.8 mm, there is a concern that the overall strength of the holder 205 may be reduced. Therefore, when it deviates from the suitable design range in each part configuration of the cup body 203 and the holder 205, the engagement between the circumferential grooves 210a and 210b and the convex portions 211a and 211b and the caulking fixing strength by the caulking rod 207 are not achieved. A sufficient holding force between the body 203 and the holder 205 is not ensured.
In a more preferable design in the third embodiment, the groove width (L) of the fitting groove 206 is set to 1.2 to 2.4 mm, and the height of the caulking rod 207 is set to 1.2 to 2.4 mm. The circumferential grooves 210a and 210b have a groove width (W) of 0.4 to 0.7 mm and a depth (D) of 0.1 to 0.7 mm.
The gas generator 201 according to the third embodiment of the present application has a cup body configured by forming two engaging portions in the convex portions 211a and 211b and the circumferential grooves 210a and 210b formed in the flange portion 212. The gas generator can achieve reliable fixing of 203, and can provide a gas generator in which the longitudinal holding force and the strength in the rotational direction are significantly improved as compared with the prior art. Along with the reliable joining of the joining portion, the airtightness of the combustion chamber is sufficiently ensured.

  Hereinafter, specific examples of the gas generator according to the present application will be described in detail with reference to examples, and verification of the effects will be described with reference to test examples.

Example 1
The gas generator 1 in which the circumferential groove 10 shown in FIG. 1 was installed at the center of the fitting groove 6 was used. The cup body 3 of the gas generator is made of an aluminum alloy, the holder 5 is made of an aluminum alloy, the groove width (L) of the fitting groove 6 is 1.58 mm, the groove width (W) of the circumferential groove 10 is 0.38 mm, and the groove The depth (D) was 0.5 mm, and the flange 12 plate thickness (T) was 0.55 mm. The gas generator according to Example 1 was manufactured by caulking the caulking rod 7 so as to reduce the diameter at a caulking load of 25 kN.

Example 2
The gas generator 101 in which the circumferential groove 110 shown in FIG. 3 was installed on the outermost periphery of the fitting groove 106 was used. The cup body 103 of the gas generator is made of an aluminum alloy, the holder 105 is made of an aluminum alloy, the groove width (L) of the fitting groove 106 is 1.58 mm, the groove width (W) of the circumferential groove 110 is 0.79 mm, and the groove The depth (D) was 0.5 mm, and the plate thickness (T) of the flange portion 112 was 0.55 mm. The gas generator according to Example 2 was manufactured by caulking the caulking rod 107 so that the diameter thereof was reduced at a caulking load of 25 kN.

Example 3
The gas generator 201 in which the circumferential grooves 210a and 210b shown in FIG. 5 are installed in the outermost periphery and the innermost periphery of the fitting groove 206 was used. The cup body 203 of the gas generator is made of an aluminum alloy, the holder 205 is made of an aluminum alloy, the groove width (L) of the fitting groove 206 is 1.58 mm, and the groove widths (W) of the circumferential grooves 210a and 210b are W (210a). ) = 0.65 mm, W (210b) = 0.65 mm, and the groove depth (D) was D (210a) = 0.15 mm and D (210b) = 0.15 mm. The plate thickness (T) of the flange portion 212 was 0.40 mm. The gas generator according to Example 3 was manufactured by caulking the caulking rod 207 so that the diameter thereof was reduced at a caulking load of 25 kN.

Comparative Example 1
The gas generator 301 shown in FIG. 7 was used. The cup body 303 of the gas generator was made of an aluminum alloy, the holder 305 was made of an aluminum alloy, and the groove width (L) of the fitting groove 306 was 1.58 mm. The plate thickness (T) of the flange portion 312 was 0.55 mm. The gas generator according to Comparative Example 1 was manufactured by caulking the caulking trough 307 so as to reduce the diameter at a caulking load of 25 kN.

Test Example 1: Cup body punching test In the gas generators according to Examples 1 to 3 and Comparative Example 1, the igniter (4, 104, 204, 304) and the gas generating agent (2, 102, 202, 302) Was removed, and epoxy resin was poured into the space generated in the combustion chamber portion (9, 109, 209, 309), and the solidified material was used as a test sample for cup body punching test measurement of each gas generator. A punching jig was inserted into the hole (13, 113, 213, 313) for inserting the electrode pin (14, 15 etc.), and a punching force was gradually applied from the inside of the cup body. The load value at which the cup body dissociated from the holder was read and used as the cup body punching force test value in the gas generator. It shows that the holding force in the vertical direction of a cup body is so high that the numerical value of a punching force value is large in the said cup body punching test. The test results of each test sample are summarized in Table 1.

Test Example 2: Cup Torque Torque Test In the gas generators according to Examples 1 to 3 and Comparative Example 1, the igniter (4, 104, 204, 304) and the gas generating agent (2, 102, 202, 302) ) Was removed, and epoxy resin was poured into the space generated in the combustion chamber portion (9, 109, 209, 309), and the solidified material was used as a test sample for measuring the cup body rotational torque of each gas generator. The sample sample holder (5, 105, 205, 305) is fixed with a fixing jig and set in a torque tester. A rotational load was manually applied to the cup body (3, 103, 203, 303), and the torque value at which the cup body rotated and the positional deviation occurred was defined as the rotational torque value. In the cup body rotational torque test, the larger the rotational torque value, the higher the holding force in the lateral rotation of the cup body. The test results of each test sample are summarized in Table 1.

Test Example 3; Airtightness Test The gas generators according to Examples 1 to 3 and Comparative Example 1 were used as test samples. Each test sample was placed in one tank. Next, from the aluminum alloy lump, a master sample having the same shape as each sample sample and having no internal space is cut out and prepared, and placed in the other tank. The tanks were connected through a differential pressure gauge. Then, both tanks were pressurized with air to 900 kPa, and the differential pressure generated at that time was detected and used as an airtightness test value. In the said airtightness test, it shows that the airtightness in the junction part of the cup body and holder of a sample sample is so high that the numerical value of an airtightness test value is small. The test results of each test sample are summarized in Table 1.

Table 1: List of test results of Test Examples 1 to 3
Test Example 1 Test Example 2 Test Example 3
Test sample Punch test Rotational torque test Airtightness test example 1 Cup body breakage (2300 N) 8.16 N · m 34 Pa
Example 2 Cup body breaking (2100 N) T.A. N. T.A.
Example 3 Cup body breakage (2300 N) 6.32 N · m 36 Pa
Comparative example 1 1280N (cup body missing) 4.89N · m 34Pa
N. T.A. ; Not measured

  Examples 1 to 3 which are gas generators according to the present application are the ones in which the base material of the cup body is broken in any of the test samples in the punching test of the cup body of Test Example 1. The longitudinal holding force by the holder caulking portion could not be measured. The punching load at that time is 2100 to 2300N, and the longitudinal holding force between the cup body (3, 103, 203) and the holder (5, 105, 205) exceeds the mechanical strength of the cup body base material. Met. On the other hand, in Comparative Example 1, which is a gas generator according to the conventional configuration, when the load load value is 1280 N, the cup body 303 slips from the caulking portion formed by the caulking rod 307 and the fitting groove 308 of the holder 305, and the cup body 303 is The phenomenon of detachment was observed. Therefore, it became clear that the vertical direction holding force of the cup body of the gas generator concerning Examples 1-3 is remarkably improved rather than a comparative example. In Test Example 2, when the holding force in the lateral rotation direction of the cup body was verified, Examples 1 and 3 showed rotational torque resistance that was significantly higher than that of Comparative Example 1. Furthermore, in Test Example 3, it was proved that the gas generator according to the present application sufficiently secured the airtightness in the cup body and the holder. From the results of these test examples 1 to 3, the gas generator according to the present application has a higher holding power than the gas generator of the conventional configuration in both the longitudinal direction and the lateral direction of the cup body. It was also revealed that the airtightness was sufficiently maintained. In particular, since the remarkable improvement effect in the longitudinal holding force was confirmed, the gas generator of the present invention has a structure that can be suitably applied to a high-power gas generator that requires a high holding force in the vertical direction. It was shown that.

  The gas generator according to the present application functions as an activation device for a vehicle occupant safety device, and can be suitably employed as a small gas generator for activating an automobile seat belt pretensioner and the like.

1, 101, 201, 301 Small gas generator 2 Gas generating agent 3, 103, 203, 303 Cup body 4, 104, 204, 304 Igniter 5, 105, 205, 305 Holder 6, 106, 206, 306 Fit Groove 7, 107, 207, 307 Caulking cage 8 Igniter holding part 9 Combustion chamber 10, 110, 210a, 210b Circumferential groove 11, 111, 211, 311 Protruding part 12, 112, 212, 312 Flange part 16 Connector insertion part L Fitting groove width W Circumferential groove width D Circumferential groove depth T Flange thickness

Claims (10)

A gas generator for operating a vehicle occupant restraint device comprising: a gas generating agent; a cup body having a bottomed cylindrical shape with a flange extending to an opening; and an ignition mechanism activated by an electric signal. An igniter having a fitting groove for fitting the flange portion of the cup body, a caulking rod for caulking and fixing the flange portion of the cup body, and a cylindrical igniter holding portion for caulking and fixing the igniter. And a cylindrical chamber that fixes the cup body and the igniter, a combustion chamber that is defined by the cup body, the igniter, and the holder. A gas generator containing a generating agent,
At least one continuous circumferential groove is formed at the bottom of the fitting groove, a convex portion is formed on the flange portion of the cup body, and the circumferential groove and the convex portion are arranged to engage with each other. A gas generator characterized by comprising: The gas generator according to claim 1, wherein a ratio (W / L) of a groove width (W) of the circumferential groove and a groove width (L) of the fitting groove is 0.2 to 0.6. The gas generator according to claim 1 or 2, wherein a ratio (D / T) of a depth (D) of the circumferential groove and a plate thickness (T) of the cup body flange portion is 0.3 or more. The groove width of the circumferential groove is a circumferential groove of 0.2 to 0.8 mm, and the groove width of the fitting groove is 0.8 to 3.2 mm. The gas generator described. The depth of the circumferential groove is a circumferential groove of 0.1 to 0.8 mm, and the plate thickness of the cup body flange portion is 0.3 to 0.7 mm. 5. A gas generator according to 1. The groove width of the fitting groove is 1.2 to 2.4 mm, and the outer wall surface of the flange continuous from the outer wall surface of the cup body matches the shape of the surface of the caulking rod on the side in contact with the flange. The gas generator according to claim 1, which is in contact with the gas generator. The gas generator according to any one of claims 1 to 6, wherein the circumferential groove is formed in an outermost peripheral portion of a bottom portion of the fitting groove. The gas generator according to any one of claims 1 to 6, wherein the circumferential groove is formed one by one in an outermost peripheral portion and an innermost peripheral portion of a bottom portion of the fitting groove. The gas generator according to any one of claims 1 to 8, wherein the gas generating agent is a gas generating agent having a total filling amount of 1200 to 2000 mg. Fits a gas generating agent, a cup body having a bottomed cylindrical shape with a flange having a convex portion at the opening, an igniter having an ignition mechanism activated by an electric signal, and a flange portion of the cup body. A fitting groove, a caulking rod for caulking and fixing the flange portion of the cup body, a cylindrical igniter holding portion for caulking and fixing the igniter, and at least one continuous circumferential groove at the bottom of the fitting groove A cylindrical holder that fixes the cup body and the igniter, a combustion chamber that is defined by being surrounded by the cup body, the igniter, and the holder. A method for producing a gas generator containing the gas generating agent,
(I) An igniter mounting step of attaching an igniter to the cylindrical holder, caulking and fixing the igniter so as to reduce the diameter of the cylindrical igniter holding portion, and creating a holder with an igniter;
(Ii) a fitting step of fitting the cup body filled with the gas generating agent to the holder with the igniter;
(Iii) When the caulking collar of the holder is caulked and fixed so as to reduce the diameter, the flange portion of the cup body is sandwiched between the fitting groove and the caulking collar, and at the same time, a flange facing the circumferential groove of the holder A caulking process in which a portion is plastically deformed by caulking force through a caulking ridge to form a convex portion;
A method for manufacturing a gas generator, comprising:

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