How to install an inflator

Abstract

To reduce a load at the time of determination of a method of winding a bracket around an inflator insertion part of a curtain airbag and an inflator in the inside of the inflator insertion part.SOLUTION: An inflator attachment method includes the steps of: pressing an inflator against a jig in a state where a reception part to which a part of the inflator is inserted is arranged so as to overlap with a bracket in the jig; winding the bracket around the reception part to which the inflator is inserted such that two through holes of the bracket overlap each other by a tool that performs rotary movement around the inflator; fixing two facing portions in the bracket to each other; and determining a size of a force for pressing the inflator against the jig, a radius of rotary movement, and a direction in which the tool presses the bracket at the end of the rotary movement such that the two through holes overlap each other and a tightening state by the bracket of the reception part to which the inflator is inserted is in a target state, in prior to the pieces of processing described above.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method for attaching an inflator to a bag.

Background Art

[0002] Conventionally, there is a curtain airbag device. The curtain airbag device of Patent Document 1 includes an airbag module and a resin cover that covers the airbag module. The airbag module includes a curtain airbag and an inflator. A part of the inflator is inserted into an inflator insertion part that is a part of the curtain airbag.

[0003] An inflator mounting bracket is arranged at the middle part in the longitudinal direction of the cover. The inflator mounting bracket has a pair of clamps provided at the upper part and a pair of mounting legs provided at the lower part. Each of the pair of clamps is formed in a band shape. The inflator is caulked and fixed to the inflator mounting bracket by the pair of clamps with a part of the inflator inserted into the inflator insertion part of the curtain airbag. The inflator mounting bracket is fixed to the center pillar of the vehicle by bolting the pair of mounting legs.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventors of the present invention have investigated the following curtain airbag device. In this curtain airbag device, the inflator inserted into the inflator insertion section of the curtain airbag is tightened from the outside of the inflator insertion section together with the inflator insertion section by an inflator mounting bracket. As a result, the inflator insertion section and the inflator are fixed to each other. Near both ends of the inflator mounting bracket that tightens the inflator, holes are provided for bolting when attaching the inflator mounting bracket to the vehicle. When manufacturing this curtain airbag device, the ends of the inflator mounting bracket are overlapped and fixed to each other so that the two holes in the inflator mounting bracket, which is bent to sandwich the inflator insertion section and the inflator, overlap. Bolts are then passed through the overlapping holes. The inflator mounting bracket is fixed to the center pillar by these bolts.

[0006] In the above embodiment, it is desirable that the inflator mounting bracket be wrapped around the inflator insertion portion of the curtain airbag and the inflator within the inflator insertion portion in an appropriate shape, such that the positions of the two holes provided by the inflator mounting bracket coincide. On the other hand, it is desirable that the inflator mounting bracket tightens the inflator insertion portion and the inflator with appropriate force so that a large amount of gas does not leak out from the gap between the inflator insertion portion and the inflator when the curtain airbag inflates. However, determining a method for wrapping the inflator mounting bracket around the inflator insertion portion of the curtain airbag and the inflator within the inflator insertion portion in order to satisfy both of these objectives simultaneously required a vast amount of trial and error prior to the manufacture of the curtain airbag device. [Means for solving the problem]

[0007] This disclosure can be implemented in the following forms:

[0008] (1) According to one embodiment of the present disclosure, a method for attaching an inflator to a bag is provided. This method for attaching an inflator to a bag includes the steps of: (a) preparing a cylindrical inflator, a bag to be inflated by the inflator having a receiving portion into which at least a portion of the inflator, including one end of the inflator, is inserted, and a plate-shaped bracket for fixing the inflator to the bag, the bracket having two through holes; (b) placing the bracket on a jig, and pressing the inflator against the jig with the receiving portion into which at least a portion of the inflator is inserted and at least a portion of the inflator overlapping the bracket; and (c) using a tool that rotates around the inflator pressed against the jig to move the bracket through the jig. The process includes: (d) pressing a portion of the bracket that is not pressed by the tool, and wrapping the bracket around the receiving portion into which the inflator is inserted, such that the two through holes of the bracket overlap; (b) fixing two opposing portions of the wrapped bracket together; and (e) determining, prior to steps (b) and (c), the magnitude of the force used to press the inflator against the jig, the radius of the rotational movement, and the direction in which the tool presses the bracket at the end of the rotational movement, such that in step (c) the two through holes overlap and after step (d) the tightening state of the receiving portion into which the inflator is inserted by the bracket becomes the target tightening state. In this configuration, the bracket can be deformed to allow for precise alignment of the two through holes and tightening of the bag and inflator with appropriate force, thereby enabling the inflator to be attached to the bag. Furthermore, processes (b) and (c) can be determined that allow for precise alignment of the two through holes and tightening of the bag and inflator with appropriate force, without requiring extensive trial and error while changing the settings for numerous parameters in the process of attaching the inflator to the bag, other than the magnitude of the force pressing the inflator against the jig, the radius of rotation, and the direction in which the tool presses the bracket at the end of the rotation. (2) In the method for installing the inflator according to the above embodiment, the tool is configured to be able to adjust the position of the center of rotational movement, and step (c) may include the step of pressing the bracket with the tool, whose position of the center of rotational movement has been adjusted, in the orientation determined in step (e) at the end point of the rotational movement. By adopting this configuration, a single tool can be used to set the direction in which the tool presses against the bracket at the end of its rotational movement to various orientations, depending on the target relative positions of the two through holes and the target tightening state of the inflator. (3) In the method for mounting the inflator according to the above embodiment, step (a) further includes the step of preparing an additional bracket having two through holes, and step (b) is the step of (i) the bracket being placed on the jig and the receiving portion into which a part of the inflator is inserted and the part of the inflator being placed on top of the bracket, and further (ii) the additional bracket being placed on an additional jig and the other part of the inflator being placed on top of the additional bracket, the inflator being located between the jig and the additional jig The method comprises the steps of (g) pressing the inflator against the fixture and the additional fixture by pressing another part of the inflator against the additional fixture, and the method may be configured to include (g) using an additional tool that rotates around the inflator which is pressed against the additional fixture, pressing a part of the additional bracket that is not pressed against the additional fixture so that the two through holes of the additional bracket overlap the inflator, and (h) fixing two opposing parts of the wrapped additional bracket to each other. This configuration allows the inflator to be pressed against the jig without interference with the jig and tools. The inflator will be pressed at a point that is different in the direction of the central axis from the point where the inflator is applying force toward the jig. However, with the above configuration, the inflator can be pressed against the jig by linear pressure applied to a point different from the point where the inflator is applying force toward the jig. (4) In the method for mounting the inflator according to the above configuration, the determination of the magnitude of the force used to press the inflator against the jig, the radius of the rotational movement, and the direction in which the tool presses the bracket at the end of the rotational movement in step (e) may be carried out using orthogonal planning. This disclosure can also be implemented in various forms other than the method for mounting an inflator. For example, it can be implemented in the form of a method for mounting a bracket, a method for determining the mounting process, a method for controlling a machine tool that performs the mounting of the bracket, a computer program that implements these methods, or a non-temporary recording medium that stores the computer program. [Brief explanation of the drawing]

[0009] [Figure 1] This is an exploded perspective view of the curtain airbag device 100 in the first embodiment. [Figure 2] This is a magnified perspective view of the area near the inflator 130 of the curtain airbag system 100 installed in the vehicle. [Figure 3] This is a flowchart showing a method for manufacturing a curtain airbag system. [Figure 4] This is an explanatory diagram showing the manufacturing process of curtain airbag devices in a factory. [Figure 5] This is a photograph showing the process in step S220 of Figure 3. [Figure 6] This is a perspective view illustrating the process of attaching the inflator 130 to the bag 110 in steps S210 to S240. [Figure 7] This is an explanatory diagram illustrating the process of step S220 in Figure 3. [Figure 8] This is an explanatory diagram illustrating the process of step S230 in Figure 3. [Figure 9] This is an explanatory diagram schematically showing the processes in steps S230 and S240 of Figure 3. [Figure 10] This is a plan view showing the process in step S240 of Figure 3. [Figure 11] This is an explanatory diagram showing the state of the inflator 130, the receiving section 116 of the bag 110, and the bracket 141 after step S240. [Figure 12] This is a schematic cross-sectional view showing the configuration of the receiving section 116 and the inflator 130. [Figure 13]It is a diagram showing the characteristics of parameters that can affect the deviation of the center position of the through hole and the interval of the arm portion.

Embodiments for Carrying out the Invention

[0010] A. First Embodiment: A1. Configuration of the curtain airbag device: FIG. 1 is an exploded perspective view of a curtain airbag device 100 according to the first embodiment. In FIG. 1, the right curtain airbag device 100 out of a pair of left and right curtain airbag devices 100 attached to a vehicle is shown. The curtain airbag device 100 includes a bag 110, an inflater 130, brackets 141 and 142, and a case 150. In the middle of FIG. 1, the folded bag 110 is shown. In the lower part of FIG. 1, the deployed bag 110 is shown by a broken line.

[0011] The bag 110 expands and deploys by being supplied with inflation gas from the inflater 130. The bag 110 has a bag-like configuration with a substantially rectangular outer shape (see the lower part of FIG. 1). The bag 110 is constituted by two substantially rectangular pieces of cloth being overlapped and sewn together. The two substantially rectangular pieces of cloth constituting the bag 110 are made of polyethylene terephthalate. Each piece of cloth is coated with a resin.

[0012] The bag 110 is wound upward with a part including the lower end and the other part including the upper end is folded in a zigzag manner from the state shown by a broken line in the lower part of FIG. 1 to form a long shape (see arrow Af). In that state, the bag 110 is housed in the case 150 (see the middle of FIG. 1). When the curtain airbag device 100 attached to the vehicle operates, the bag 110 is inflated by the inflater 130. More specifically, the bag 110 is inflated and deployed from the state shown in the middle of FIG. 1 to the state shown in the lower part of FIG. 1 by being supplied with inflation gas from the inflater 130.

[0013] The bag 110 includes a receiving portion 116 (see the middle center part of FIG. 1). The receiving portion 116 functions as an inlet for inflation gas into the bag 110. The receiving portion 116 is a cylindrical portion that protrudes rearward and upward on the upper side of the bag 110 having a substantially rectangular outer shape (see the lower center part of FIG. 1). The receiving portion 116, which is a part of the bag 110, is formed by overlapping and sewing a part of two pieces of cloth that constitute the bag 110. The receiving portion 116 is inserted with a part 131 including one end of the inflator 130. When inflation gas is supplied from the inflator 130 to the receiving portion 116, the bag 110 is deployed.

[0014] The inflator 130 has a function of inflating the bag 110 (see the upper right part of FIG. 1). The inflator 130 has a substantially cylindrical shape. A part 131 including one end of the inflator 130 is inserted into the receiving portion 116 of the bag 110. The inflator 130 receives a signal from a control unit (not shown) and ejects inflation gas from one end. When the inflation gas ejected from the inflator 130 is sent into the bag 110 through the receiving portion 116, the bag 110 inflates and deploys (see the lower part of FIG. 1).

[0015] FIG. 2 is a perspective view showing an enlarged view of the vicinity of the inflator 130 among the curtain airbag devices 100 attached to a vehicle. The bracket 141 fixes the inflator 130 to the bag 110 (see the upper right part of FIG. 1). The bracket 141 is further used to fix the inflator 130 and the bag 110 to the vehicle body CB (see the middle center part of FIG. 2). The bracket 141 is a member having a plate-like shape (see the upper right part of FIG. 1). The bracket 141 is shaped by being bent in advance prior to being wound around the inflator 130 (see the upper right part of FIG. 1). The bracket 141 is made of metal.

[0016] Bracket 141 has two through holes 141h1 and 141h2. The two through holes 141h1 and 141h2 are located near both ends of the bracket 141 in the longitudinal direction. Through hole 141h1 is oval-shaped. Through hole 141h2 is circular. With this configuration, even if the centers of the through holes 141h1 and 141h2 are offset within a certain range in the longitudinal direction of the bracket 141 when the bracket 141 is wrapped around the inflator 130, bolts can still be passed through the overlapping through holes 141h1 and 141h2. In Figures 1 and 2, only through hole 141h1 is shown.

[0017] The inflator 130 is secured to the bag 110 by wrapping the bracket 141 around the receiving portion 116 of the bag 110 into which the inflator 130 is inserted. The bracket 141 is wrapped around the inflator 130 and the receiving portion 116 so that its two through holes 141h1 and 141h2 overlap.

[0018] Bracket 142 has a shape symmetrical to that of bracket 141 (see the middle section of Figure 2). That is, brackets 141 and 142 have shapes that are like a right hand and a left hand. Except for the symmetrical shape, bracket 142 has the same configuration as bracket 141. For example, bracket 142 has two through holes 142h1 and 142h2. The two through holes 142h1 and 142h2 are located near both ends in the longitudinal direction of bracket 142. The inflator 130 is fixed to bracket 142 by wrapping bracket 142 around part 132 of the inflator 130 located outside the bag 110. Bracket 142 is wrapped around the inflator 130 so that the two through holes 141h2 and 142h2 overlap.

[0019] Bolts B1 are passed through the through holes 141h1 and 141h2 of the overlapping brackets 141, respectively (see the middle section of Figure 2). Bolts B2 are passed through the through holes 142h1 and 142h2 of the overlapping brackets 142. The inflator 130 is fixed to the vehicle body CB by screwing these bolts B1 and B2 to the vehicle body CB. In this specification, when brackets 141 and 142 are referred to without distinction, they will be written as bracket 140.

[0020] Case 150 houses a bag 110 folded into a long shape (see upper part of Figure 1). Case 150 includes a first case 151, a second case 152, and a third case 153. The first case 151, the second case 152, and the third case 153 are arranged in that order along the longitudinal direction of the vehicle. The first case 151, the second case 152, and the third case 153 each have a portion with a roughly semicircular cross-sectional shape. The bag 110, folded into a long shape, is housed in the recess with the roughly semicircular cross-sectional shape.

[0021] A2. Manufacturing of curtain airbag systems: Figure 3 is a flowchart illustrating a method for manufacturing a curtain airbag system. In step S100 of Figure 3, the processing details for each step in the manufacturing of the curtain airbag system are determined. Step S200 is executed at the curtain airbag system manufacturing plant according to the parameters of each step determined in step S100. The processing in step S100 will be explained later.

[0022] In step S200 of Figure 3, the specific curtain airbag device is manufactured. Step S200 includes steps S210 to S250. In steps S210 to S240, the method for attaching the inflator 130 to the bag 110 is performed (see the upper center of Figure 1). In step S250, the case 150 is attached to the bag 110 (see the middle of Figure 1).

[0023] Figure 4 is an explanatory diagram showing the manufacturing process of a curtain airbag system in a factory. In step S210 of Figure 3, the inflator 130, the bag 110, and the brackets 141 and 142 are prepared (see the left side of Figure 4). As mentioned above, the brackets 141 and 142 are both plate-shaped members. However, the brackets 141 and 142 are given shape by being bent in advance for wrapping around the inflator 130 (see the upper right side of Figure 1). Operator OP1 temporarily assembles the inflator 130, the bag 110, and the brackets 141 and 142.

[0024] Figure 5 is a photograph showing the process of step S220 in Figure 3. In Figure 5, the left curtain airbag device 100 of a pair of left and right curtain airbag devices 100 to be installed in a vehicle is shown. In step S220 in Figure 3, the bracket 141 is placed on the jig JG1 of the manufacturing device FM1 by operator OP1 (see the right side of Figure 5). The receiving section 116 into which one end 131, which is part of the inflator 130, is inserted, and the one end 131 of the inflator 130 inside the receiving section 116 is placed on the jig JG1 of the manufacturing device FM1, overlapping the bracket 141.

[0025] Furthermore, operator OP1 places the bracket 142 on the jig JG2 of the manufacturing apparatus FM2 (see the left side of Figure 5). The other end 132 of the inflator 130, which is located outside the bag 110, is placed on top of the bracket 142.

[0026] Figure 6 is a perspective view illustrating the process of attaching the inflator 130 to the bag 110 in steps S210 to S240. In Figure 6, the inflator 130 is not shown for the sake of ease of understanding the technology.

[0027] Figure 7 is a schematic diagram illustrating the process of step S220 in Figure 3. Brackets 141 and 142 are pre-bent (see the middle section of Figure 7 and the upper right section of Figure 1). The bent bracket 141 has a curved portion 141s, ends 141f1 and 141f2, and connecting portions 141a1 and 141a2 (see Figures 6 and 7).

[0028] The curved section 141s is the part that receives the inflator 130 and wraps around it (see the middle section of Figure 7). The curved section 141s is pre-curved. The central angle of the curve of the curved section 141s is approximately 300 degrees. The curved section 141s receives the inflator 130.

[0029] End portions 141f1 and 141f2 are parts that overlap each other during the processing in step S220 (see upper part of Figure 7). Both end portions 141f1 and 141f2 are flat plate-shaped portions. Through holes 141h1 and 141h2 are provided in end portions 141f1 and 141f2, respectively.

[0030] The connecting parts 141a1 and 141a2 are the parts that connect the curved part 141s to the ends 141f1 and 141f2 (see the middle section of Figure 7). The curved part 141s and the connecting part 141a1 are connected at an angle of approximately 100 degrees. The curved part 141s and the connecting part 141a2 are connected at an angle of approximately 90 degrees. The connecting part 141a1 and the end 141f1 are connected at an angle of approximately 120 degrees. The connecting part 141a2 and the end 141f2 are connected at an angle of approximately 120 degrees.

[0031] Bracket 142 is pre-bent to have a shape symmetrical to that of bracket 141 (see the left side of Figure 5 and the upper right side of Figure 1).

[0032] With the bracket 141 and one end 131, which is part of the inflator 130 inside the receiving section 116, positioned on fixture JG1, and the bracket 142 and the other end 132 of the inflator 130 outside the bag 110 positioned on fixture JG2, the central portion 133, which is yet another part of the inflator 130 located between fixtures JG1 and JG2, is pressed. The central portion 133 is the part of the inflator 130 located between the one end 131 and the other end 132. The central portion 133 of the inflator 130 is pressed downward toward fixtures JG1 and JG2 by the pressing tool PT (see central portion in Figure 5). As a result, the inflator 130 is pressed toward fixtures JG1 and JG2 (see arrow Ap1 shown in Figures 6 and 7). The process in step S220 is carried out so that the inflator 130 is pressed with a force Pf of the magnitude determined in step S100.

[0033] With this configuration, in step S220, the inflator 130 can be pressed against the jig JG1 without interfering with the jig JG1 and the tool RT1 (see the central part in Figure 5). The inflator 130 is pressed at its central part 133, which is located at a different position in the direction of the central axis Cif from the end 131 to which the inflator 130 is applying force toward the jig JG1 (see Figure 5). With the above configuration, the inflator 130 can be pressed against the jig JG1 by linear pressure on the central part 133, which is different from the end 131 to which the inflator 130 is applying force toward the jig JG1, without applying torque to the inflator 130 (see arrow Ap1 in Figures 6 and 7).

[0034] The manufacturing apparatus FM1 is equipped with a rotating tool RT1 (see arrow Ar21 in Figure 7). The tool RT1 is configured to allow adjustment of the position of the center Crt of the rotating Ar22 (see the lower center of Figure 7). The manufacturing apparatus FM1 is further configured to allow adjustment of the relative distance between the position of the tip of the tool RT1 that contacts part 141p2 of the bracket 141 and the center Crt of the rotating Ar22.

[0035] The manufacturing apparatus FM2 also includes a rotating tool RT2 (see upper left of Figure 5). The tool RT2 is also configured so that the position of the center of rotation can be adjusted. The manufacturing apparatus FM2 is also configured so that the relative distance between the position of the tip of the tool RT2 that contacts the bracket 141 and the center of rotation can be adjusted.

[0036] Figure 8 is a schematic diagram illustrating the process of step S230 in Figure 3. In step S230 of Figure 3, the part of the bracket 141 not pressed by the jig JG1, 141p2, is pressed by the tool RT1, which rotates around the inflator 130 pressed by the jig JG1 (see upper center of Figure 8). Specifically, the tool RT1 rotates due to being pressed by a linearly moving cylinder Srt (see arrows As22 and Ar22 in Figure 8). The rotational movement of the tool RT1 deforms the bracket 141. As a result, the bracket 141 is wrapped around the receiving part 116 into which the inflator 130 is inserted (see arrow Ar22 in Figures 6 and 8). The wrapping of the bracket 141 is performed so that the two through holes 141h1 and 141h2 of the bracket 141 overlap (see upper right of Figure 8).

[0037] The process in step S230 is performed such that, at the end point Pre3 of the rotational movement Ar22, the tool RT1, whose position at the center Ct of the rotational movement Ar22 has been adjusted, presses against the bracket 141 in the orientation Pd determined in step S100.

[0038] With this configuration and processing of the tool RT1, a single tool RT1 can set the direction Pd in ​​which the tool RT1 presses against the bracket 141 at the end point Pre3 of the rotational movement Ar22 to various directions, depending on the target relative positions of the two through holes 141h1 and 141h2, and the target tightening state with respect to the inflator 130 (see Ap3 and Pd in ​​Figure 8).

[0039] The process in step S230 is performed such that the tool RT1 rotates with the swivel radius Pr determined in step S100, by adjusting the relative distance between the position of the tip of the tool RT1 in contact with part 141p2 of the bracket 141 and the center Crt of the rotational movement Ar22.

[0040] With this configuration and processing of tool RT1, the swivel radius Pr of tool RT1 can be set to various values ​​depending on the target relative positions of the two through holes 141h1 and 141h2, as well as the target tightening state relative to the inflator 130, using a single tool RT1.

[0041] Similarly, an additional tool RT2 rotates Ar22 around the inflator 130, which is pressed against the fixture JG2, thereby pressing the portion of the additional bracket 142 that is not pressed against the additional fixture JG2. As a result, the bracket 142 is wrapped around the inflator 130. The wrapping of the bracket 142 is performed so that the two through holes 142h1 and 142h2 of the bracket 142 overlap.

[0042] Figure 9 is a schematic diagram illustrating the processes of steps S230 and S240 in Figure 3. Figure 10 is a plan view showing the process of step S240 in Figure 3. In Figure 10, the left curtain airbag device 100 of a pair of left and right curtain airbag devices 100 installed in the vehicle is shown (see the right side of Figure 5).

[0043] In step S240 of Figure 3, the opposing ends 141f1 and 141f2 of the wrapped bracket 141 are fixed to each other (see arrow Ac3 in Figure 9). Specifically, the bracket 141 is crimped and fixed at both sides 141c1 and 141c2 of the overlapping through holes 141h1 and 141h2 using a crimping tool ST (see upper part of Figure 10).

[0044] Similarly, two opposing portions of the wrapped bracket 142 are fixed to each other. Specifically, the bracket 142 is crimped and fixed at both sides of the overlapping through holes 142h1 and 142h2 using a crimping tool.

[0045] In Figure 10, the displacement of the centers of the overlapping through holes 141h1 and 141h2 is shown as Dh. The displacement of the centers of the overlapping through holes 141h1 and 141h2, Dh, is measured along the direction of the straight line LS obtained by projecting a plane containing the direction of rotational movement of the end portion 141f1 of the bracket 141 (see Ar22 in Figure 8) and the central axis of the through hole 141h1 onto the surface of the end portion 141f1 of the bracket 141.

[0046] Figure 11 is an explanatory diagram showing the state of the inflator 130, the receiving portion 116 of the bag 110, and the bracket 141 after step S240. Figure 11 corresponds to the XI-XI cross section in Figure 10. As a result of the opposing ends 141f1 and 141f2 of the bracket 141 being fixed to each other, the inflator 130 and the receiving portion 116 of the bag 110 are tightened from the outside by the bracket 141. As a result, the inflator 130 is fixed to the bag 110. In Figure 10, the force with which the bracket 141 tightens the inflator 130 and the receiving portion 116 of the bag 110 is indicated by the arrow At.

[0047] In step S250 of Figure 3, operator OP2 attaches the bag 110 to the case 150 (see the middle section of Figure 1 and the right section of Figure 4).

[0048] A3. Determination of the processing steps for each stage in the manufacturing of curtain airbag systems: (1) Requirements for the bracket wrapping result: As a result of the processing in steps S210 to S240 of Figure 3, the bracket 141 wrapped around the inflator 130 and the receiving portion 116 of the bag 110 must satisfy the following requirements. (r1) The displacement Dh of the center positions of the through holes 141h1 and 141h2 is less than or equal to a predetermined standard value (see upper left of Figure 10). (r2) The force At at which the bracket 141 tightens the inflator 130 and the receiving portion 116 of the bag 110 is within a predetermined range (see Figure 11).

[0049] The magnitude of the force At that the bracket 141 exerts on the inflator 130 and the receiving portion 116 of the bag 110 is correlated with the distance Sg between the connection portions 141a1 and 141a2 of the bracket 141 wrapped around the inflator 130 and the receiving portion 116 of the bag 110 (see upper center of Figure 11). Therefore, the above requirement (r2) can be replaced with the following requirement (r2m). The distance Sg is measured at a predetermined position on the connection portion 141a1, along the direction perpendicular to the connection portion 141a1. (r2m) The distance Sg between the connection parts 141a1 and 141a2 of the bracket 141 is within a predetermined range (see Figure 11).

[0050] (2) Parameters that may affect the displacement of the center position of the through hole and the spacing of the arm parts: Figure 12 is a schematic cross-sectional view showing the configuration of the receiving section 116 and the inflator 130. Various parameters can affect the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the spacing Sg between the connection sections 141a1 and 141a2 of the bracket 141, such as the following.

[0051] (i) Product design parameters: (Pp1) The diameter Ri of one end 131 of the inflator 130 located inside the receiving section 116. (Pp2) The thicknesses Ts1 and Ts2 of the two sheets 116c1 and 116c2 that constitute the receiving section 116. (Pp3) Misalignment of the sewing portions 116s1 and 116s2 of the two sheets 116c1 and 116c2 that constitute the receiving section 116 (see arrow Ama in Figure 12). (Pp4) Heights Hs1 and Hs2 of the sewn portions 116s1 and 116s2 of the two sheets 116c1 and 116c2 that constitute the receiving section 116.

[0052] (ii) Parameters of equipment conditions: (Pf1) The magnitude of the force Pf applied to the inflator 130 by the fixtures JG1 and JG2 (see arrow Ap1 in Figure 7). (Pf2) The stroke amount Ps as the distance that cylinder Srt pushes tool RT1 (see arrow As22 in Figure 8).

[0053] (iii) Parameters for jig design: (Pg1) The radius Pr of the rotational movement Ar22 of the tool RT1 (see the middle section of Figure 8). Note that the radius Pr of the rotational movement Ar22 is the distance between the contact point 141p2 between the bracket 141 and the tip of the tool RT1 and the center Crt of the rotational movement Ar21 of the tool RT1. (Pg2) The angle Pd at which the tool RT1 pushes a part 141p2 of the bracket 141 at the end of the rotational movement (see the middle right part of Figure 9). Note that the angle Pd is measured from a direction parallel to the lower surface of the end portion 141f2 toward the inflator 130 placed on the jig JG1.

[0054] The inventors used D-optimal design, a type of experimental design method, to extract the parameters that have the greatest influence from among various parameters that could affect the displacement Dh of the center positions of the through holes 141h1 and 141h2, and the spacing Sg of the connection parts 141a1 and 141a2 of the bracket 141. As a result, the following parameters were extracted. (Pf1) The magnitude of the force Pf applied to the inflator 130 by the fixtures JG1 and JG2 (see arrow Ap1 in Figure 7). (Pg1) The radius Pr of the rotational movement Ar22 of the tool RT1 (see the middle section of Figure 8). (Pg2) The angle Pd at which the tool RT1 presses a part 141p2 of the bracket 141 at the end of the rotational movement (see the middle right part of Figure 9).

[0055] (3) Determination of parameter values ​​that may affect the displacement of the center position of the through hole and the spacing of the arm sections: Figure 13 shows the characteristics of parameters that can affect the displacement of the center position of the through-holes and the spacing of the arm portions. The inventors used an orthogonal design, a type of center composite design, to determine the values ​​of the following parameters that have a significant effect on the displacement Dh of the center positions of the through-holes 141h1 and 141h2 and the spacing Sg of the connection portions 141a1 and 141a2 of the bracket 141. (Pf1) The magnitude of the force Pf applied to the inflator 130 by the fixtures JG1 and JG2 (see arrow Ap1 in Figure 7). (Pg1) The radius Pr of the rotational movement Ar22 of the tool RT1 (see the middle section of Figure 8). (Pg2) The angle Pd at which the tool RT1 presses a part 141p2 of the bracket 141 at the end of the rotational movement (see the middle right part of Figure 9).

[0056] (i) The radius Pr of the rotational movement Ar22 of the tool RT1 is thought to affect the displacement Dh of the center positions of the through holes 141h1 and 141h2, and the distance Sg between the connection parts 141a1 and 141a2 of the bracket 141, in accordance with the following principle.

[0057] The larger the radius Pr, the more the tool RT1 presses on the part of the bracket 141a1 that is closer to the through hole 141h1 (see the middle section of Figure 8). As a result, the larger the radius Pr, the more the through hole 141h1 moves relative to the through hole 141h2 to the right in Figure 9, that is, upward in Figure 10 (see the upper section of Figure 13).

[0058] The larger the radius Pr, the further the tool RT1 will press on the part of the bracket 141 that is farther from the part 141p1 where the bracket 141 is pressed against the jig JG1 and its position is fixed (see the middle section of Figure 9). As a result, the larger the radius Pr, the greater the torque with which the connection part 141a1 of the bracket 141 is wound, and the smaller the distance Sg between the connection parts 141a1 and 141a2 of the bracket 141 becomes (see the middle section of Figure 13).

[0059] (ii) The angle Pd at which the tool RT1 pushes a part 141p2 of the bracket 141 at the end of the rotational movement is thought to affect the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the distance Sg between the connecting parts 141a1 and 141a2 of the bracket 141, in accordance with the following principle.

[0060] The larger the angle Pd, the smaller the component of the force Ap3 applied by the tool RT1 to a part 141p2 of the bracket 141, which is parallel to the surface of the end portion 141f1 at the connection portion 141a1 (see the middle section of Figure 9). As a result, the larger the angle Pd, the greater the movement of the through hole 141h1 relative to the through hole 141h2, to the left in Figure 9, i.e., downward in Figure 10 (see the upper right section of Figure 13).

[0061] The larger the angle Pd, the more the direction of the force Ap3 exerted by the tool RT1 on part 141p2 of the bracket 141 shifts downward from being perpendicular to the end portion 141f1, and the component force that exerts perpendicular to the end portion 141f1 becomes smaller (see the middle section of Figure 9). As a result, the larger the angle Pd, the larger the gap Sg between the connection portions 141a1 and 141a2 of the bracket 141 (see the middle right section of Figure 13).

[0062] (iii) The magnitude of the force Pf applied to the inflator 130 by the fixtures JG1 and JG2 is thought to be affected by the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the distance Sg between the connection parts 141a1 and 141a2 of the bracket 141, according to the following principle.

[0063] When the magnitude of the force Pf is within a first range R1 that is smaller than a certain value, the larger the magnitude of the force Pf, the less likely the inflator 130 is to be lifted upward on the jig JG1 when the bracket 141 is deformed by the tool RT1 (see the lower center of Figure 8). As a result, the larger the magnitude of the force Pf, the more the through hole 141h1 moves to the right in Figure 9, i.e., upward in Figure 10, relative to the through hole 141h2 (see the lower left and upper left of Figure 13). Furthermore, the larger the magnitude of the force Pf, the smaller the distance Sg between the connection parts 141a1 and 141a2 of the bracket 141 becomes (see the lower left and middle left of Figure 13).

[0064] When the magnitude of the force Pf is within the second range R2, which is greater than a certain value mentioned above, the larger the magnitude of the force Pf, the more strongly the inflator 130 is pressed against the jig JG1 while maintaining close contact with part 141p1 of the bracket 141. As a result, the larger the magnitude of the force Pf, the more the part 141p1, which is the fulcrum of the bending of the bracket 141, opens up, and the through hole 141h1 moves to the left in Figure 9, i.e., downward in Figure 10, relative to the through hole 141h2 (see the lower left and upper left parts of Figure 13). Furthermore, the larger the magnitude of the force Pf, the larger the distance Sg between the connection parts 141a1 and 141a2 of the bracket 141 (see the lower left and middle left parts of Figure 13).

[0065] In other words, the magnitude Pf of the force Pf applied to the inflator 130 and bracket 141 by the jig JG has a preferred value with respect to the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the distance Sg between the connecting parts 141a1 and 141a2 of the bracket 141. When the wrapping of the bracket 141 around the inflator 130 by the tool RT1 is completed, it is desirable that the inflator 130 and bracket 141 be pressed against the jig JG with a force such that the center Cif of the inflator 130 and the center of the curved part 141s of the bracket 141, which has been deformed into an arc shape around the inflator 130, are as close as possible.

[0066] Through the above process, step S100 in Figure 3 can be executed. That is, prior to steps S220 and S230, the magnitude Pf of the force pressing the inflator 130 against the jig JG1, the radius Pr of the rotational movement Ar22, and the direction Pd in ​​which the tool RT1 presses the bracket 141 at the endpoint Pre3 of the rotational movement Ar22 are determined. Each parameter is determined such that in step S230 the two through holes 141h1 and 141h2 overlap within the target range of displacement, and after step S240 the tightening state of the bracket 141 of the receiving section 116 into which the inflator 130 is inserted becomes the target tightening state (see Dh in Figure 10 and At in Figure 11).

[0067] According to this embodiment, the bracket 141 can be deformed to allow for precise alignment of the two through holes 141h1 and 141h2, and to tighten the bag 110 and inflator 130 with appropriate force, thereby enabling the inflator 130 to be attached to the bag 110. Furthermore, the processing content of steps S220 and S230 can be determined to obtain a favorable processing result without having to perform extensive trial and error while changing the settings for numerous parameters in the process of attaching the inflator 130 to the bag 110, other than the magnitude Pf of the force pressing the inflator 130 against the jig JG1, the radius Pr of the rotational movement Ar22, and the direction Pd in ​​which the tool RT1 presses the bracket 141 at the endpoint Pre3 of the rotational movement Ar22. As a result, the processing of steps S220 and S230 is performed in such a way that the two through holes 141h1 and 141h2 can be precisely aligned, and the bag 110 and inflator 130 can be tightened with appropriate force.

[0068] In this embodiment, the bracket 142 is also called an "additional bracket." The jig JG2 is also called an "additional jig." One end 131 of the inflator 130 is also called a "part of the inflator." The other end 132 of the inflator 130 is also called another "part of the inflator." The central part 133 of the inflator 130 is also called yet another "part of the inflator."

[0069] B. Other embodiments: B1. Other Embodiments 1: (1) In the above embodiment, only two through holes 141h1 and 141h2 are mentioned as through holes provided in the bracket 141 (see upper part of Figure 6). However, the bracket may have through holes other than those two that are to be overlapped in step S230.

[0070] (2) In the above embodiment, the bracket 141 is a metal member having a plate-like shape (see upper right part of Figure 1). However, the bracket 141 can be made of various materials other than metal that can be plastically deformed by a tool while also possessing elasticity.

[0071] (3) In the above embodiment, the central angle of the curve of the curved portion 141s of the bracket 141 prepared in step S210 of Figure 3 is approximately 300 degrees. However, the central angle of the curve of the curved portion 141s of the bracket 141 prepared in advance may be other angles, such as 280 degrees or 320 degrees.

[0072] (4) In the above embodiment, in the bracket 141 prepared in step S210 of Figure 3, the curved portion 141s and the connecting portion 141a1 are connected at an angle of approximately 100 degrees. The curved portion 141s and the connecting portion 141a2 are connected at an angle of approximately 90 degrees. However, the angle between the curved portion and the connecting portion may be other angles, such as 80 degrees or 110 degrees.

[0073] (5) In the above embodiment, in the bracket 141 prepared in step S210 of Figure 3, the connecting portion 141a1 and the end portion 141f1 are connected at an angle of approximately 120 degrees. The connecting portion 141a2 and the end portion 141f2 are connected at an angle of approximately 120 degrees. However, the angle between the connecting portion and the end portion may be other angles, such as 110 degrees or 130 degrees.

[0074] (6) In the above embodiment, the brackets 141 and 142 are pre-shaped by bending them in advance prior to the process of step S210 in Figure 3 for wrapping around the inflator 130 (see upper right of Figure 1). However, in the process of step S210 in Figure 3, a flat bracket may be prepared, and in the process of step S220, the flat bracket may be deformed and wrapped around the inflator 130 and the receiving portion 116.

[0075] (7) In the above embodiment, one end 131, which is part of the inflator 130, is inserted into the receiving portion 116 of the bag 110 (see the middle right part of Figure 5). However, the entire inflator 130 may be inserted into the receiving portion 116 of the bag 110. In such an embodiment, the bracket 142 is also wrapped around the inflator 130 and the receiving portion 116 from outside the receiving portion 116 of the bag 110.

[0076] (8) In the above embodiment, the inflator 130 is directly pressed by the pressing tool PT at its central portion 133 (see central portion in Figure 5). However, the inflator 130 may be pressed through other components, such as the receiving portion 116 of the bag 110.

[0077] (9) In step S230 of Figure 3, the angle at which the bracket 141 is wrapped around the receiving portion 116 into which the inflator 130 is inserted can be any angle (see arrow Ar22 in Figures 6 and 8). However, the central angle of the bracket 141 wrapping is preferably 300 degrees or more, more preferably 330 degrees or more, and even more preferably 350 degrees or more. The larger the central angle of the bracket 141 wrapping, the greater the possibility of reducing the amount of gas that leaks out from the gap between the inflator insertion portion of the curtain airbag and the inflator when the curtain airbag inflates.

[0078] (10) In the above embodiment, the bracket 141 is crimped and fixed at the parts 141c1 and 141c2 on both sides of the overlapping through holes 141h1 and 141h2 using a crimping tool ST (see upper part of Figure 10). However, in the process of fixing two opposing parts of the bracket to each other, various methods such as bonding and welding can be used for fixing. Also, the number of parts that are specifically crimped, bonded, welded, etc. can be any number, such as one place or three places. In other words, it is sufficient that the two opposing parts do not move relative to each other.

[0079] (11) In the above embodiment, using the D optimal design, parameters that have a significant influence were extracted from among various parameters that may affect the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the spacing Sg of the connection parts 141a1 and 141a2 of the bracket 141. As a result, the following parameters were extracted (see Figure 13). However, parameters that have a significant influence on the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the spacing Sg of the connection parts 141a1 and 141a2 of the bracket 141 can also be determined using other methods of experimental design.

[0080] B2. Another Embodiment 2: (1) In the above embodiment, the manufacturing apparatus FM1 includes a rotating tool RT1 (see arrow Ar21 in Figure 7). The tool RT1 is configured to allow adjustment of the position of the center Crt of the rotating movement Ar21 (see the lower center of Figure 7). However, the process S230 in Figure 3 can also be performed using a tool that does not have such a function. In such an embodiment, for example, multiple types of fixtures and tools may be used alternatively, depending on the orientation Pd in ​​which the tool RT1 presses the bracket 141 at the endpoint Pre3 of the rotating movement Ar22.

[0081] (2) In the above embodiment, the manufacturing apparatus FM1 is configured to adjust the relative distance between the position of the tip of the tool RT1 that contacts the portion 141p2 of the bracket 141 and the center Crt of the rotational movement Ar22 (see Figure 7). However, the process of S230 in Figure 3 can also be performed using a tool that does not have such a function. In such an embodiment, for example, several types of fixtures and tools may be used alternatively depending on the rotational radius Pr when the tool RT1 presses against the bracket 141.

[0082] B3. Other Embodiments 3: In the above embodiment, the bracket 141 and one end 131 of the inflator 130 inside the receiving section 116 are placed on the jig JG1, and the bracket 142 and the other end 132 of the inflator 130 outside the bag 110 are placed on the jig JG2, and the central part 133 of the inflator 130 located between the jig JG1 and the additional jig JG2 is pressed (see Figure 5).

[0083] However, the inflator 130 may be pressed without the provision of jig JG2, with the bracket 141 and one end 131 of the inflator 130, which is part of the inflator 130 inside the receiving section 116, placed on jig JG1, and the bracket 142 and the other end 132 of the inflator 130 outside the bag 110 not placed on jig JG2. In such an embodiment, the inflator 130 can be pressed against jig JG1 while avoiding interference between jig JG1 and the tool by grasping a portion 133 of the inflator 130 that is different from the portion 131 that presses against jig JG1 with a tool, and applying torque to the grasped portion 132 while pressing the grasped portion 132. In this case, it is preferable that the torque is applied in a direction perpendicular to the central axis Cif of the inflator 130 and the direction in which the inflator 130 should be pressed against jig JG1.

[0084] B4. Other Embodiments 4: In the above embodiment, orthogonal design was used to determine the values ​​of parameters that greatly affect the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the spacing Sg of the connection parts 141a1 and 141a2 of the bracket 141 (see Figure 13). However, the values ​​of parameters that greatly affect the displacement Dh of the center positions of the through holes 141h1 and 141h2 and the spacing Sg of the connection parts 141a1 and 141a2 of the bracket 141 can also be determined using other methods, such as D-optimal design.

[0085] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]

[0086] 100...Curtain airbag device, 110...Bag, 116...Receiving part, 116c1...Sheet, 116c2...Sheet, 116s1...Sewing part, 116s2...Sewing part, 130...Inflator, 131...One end, 132...Other end, 133...Center part, 140...Bracket, 141...Bracket, 141a1...Connecting part, 141a2...Connecting part, 141c1...Crimped part, 141c2...Crimped part, 141f1...End, 141f2...End, 141h1...Through hole, 141h2...Through hole, 141p1...Pressing part, 141p2...Pressing part, 141s ...curved section, 142...bracket, 142h1...through hole, 142h2...through hole, 150...case, 151...first case, 152...second case, 153...third case, Ac3...arrow indicating movement of crimping tool ST, Af...arrow indicating folding of bag 110, Ap1...force pressing bracket 141 toward jig JG1, Ap3...force tool RT1 pushing bracket 141, Ar21...arrow indicating rotational movement of tool RT1, Ar22...arrow indicating rotational movement of tool RT1, As22...arrow indicating movement of cylinder Srt, At...bra Force applied by bracket 141 to inflator 130 and receiving section 116, B1...bolt, B2...bolt, CB...body, Cif...central axis of inflator 130, Crt...center of rotation of tool RT1, Dh...shift in the center position of through holes 141h1, 141h2, FM1...manufacturing equipment, FM2...manufacturing equipment, Hs1...height of sewing section 116s1, Hs2...height of sewing section 116s2, JG1...jig, JG2...jig, LS...straight line, OP1...operator, OP2...operator, PT...pressing tool, Pd...angle at which tool RT1 presses bracket 141 Pf…Magnitude of the force applied to the inflator 130 by the fixtures JG1 and JG2, Pr…Radius of rotational movement of tool RT1, Pre3…End point position of rotational movement of tool RT1, Ps…Distance (stroke) that cylinder Srt pushes tool RT1, R1…First range of pressing force, R2…Second range of pressing force, RT1…Tool, RT2…Tool, Ri…Diameter of one end 131 of inflator 130, ST…Crimping tool, Sg…Distance between connecting parts 141a1 and 141a2, Srt…Cylinder, Ts1…Thickness of sheet 116c1, Ts2…Thickness of sheet 116c2

Claims

1. A method for attaching an inflator to a bag, (a) A step of preparing a cylindrical inflator, a bag that is inflated by the inflator and has a receiving portion into which at least a part of the inflator, including one end of the inflator, is inserted, and a plate-shaped bracket for fixing the inflator to the bag, the bracket having two through holes, (b) The step of pressing the inflator against the jig with the bracket positioned on the jig and the receiving portion into which at least a portion of the inflator is inserted and at least a portion of the inflator positioned on top of the bracket, (c) A step of wrapping the bracket around the receiving portion into which the inflator is inserted, such that the two through holes of the bracket overlap, by using a tool that rotates around the inflator which is pressed against the jig to press against the part of the bracket that is not pressed against the jig, (d) The step of fixing two opposing parts of the wrapped bracket to each other, (e) A method for mounting an inflator, comprising the step of determining, prior to steps (b) and (c), the magnitude of the force used to press the inflator against the jig, the radius of the rotational movement, and the direction in which the tool presses the bracket at the end point of the rotational movement, such that in step (c) the two through holes overlap and after step (d) the tightening state by the bracket of the receiving portion into which the inflator is inserted becomes a target tightening state.

2. A method for attaching an inflator according to claim 1, The tool is configured to allow adjustment of the position of the center of rotational movement. A method for mounting an inflator, wherein step (c) includes the step of pressing the bracket with the tool, whose center of rotation has been adjusted, at the endpoint of the rotational movement in the orientation determined in step (e).

3. A method for attaching an inflator according to claim 1, The aforementioned step (a) further includes the step of preparing an additional bracket having two through holes, Step (b) is a step of pressing the inflator against the jig and the additional jig by pressing yet another part of the inflator located between the jig and the additional jig, in a state where (i) the bracket is placed on the jig and the receiving portion into which a part of the inflator is inserted and the part of the inflator is placed on top of the bracket, and (ii) the additional bracket is placed on the additional jig and the other part of the inflator is placed on top of the additional bracket. The aforementioned method, (g) A step of wrapping the additional bracket around the inflator such that the two through holes of the additional bracket overlap, by using an additional tool that rotates around the inflator pressed by the additional jig to press the portion of the additional bracket that is not pressed by the additional jig, (h) A method for mounting an inflator, comprising the step of fixing two opposing portions of the additional bracket that is wrapped around it to each other.

4. A method for attaching an inflator according to any one of claims 1 to 3, An inflator mounting method wherein the determination of the magnitude of the force pressing the inflator against the jig, the radius of the rotational movement, and the direction in which the tool presses the bracket at the end point of the rotational movement in step (e) is performed using orthogonal planning.

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