JPH0570475U - Sewing device for prone seams for airbags - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a sewing device for sewn seams capable of performing a sewn seam extremely accurately and quickly and capable of producing a highly reliable airbag. [Structure] In a sewing device 100 for bind-off seams, the stitching ends of the fabric are sewn so as to lie along the fabric ground.
A lower holder 21 capable of holding the cloth folded back on the upper surface of the sewing holder 20 while restricting the position of the sewing end portion upstream of the needle drop portion, and pressing the cloth from above the lower holder. An upper holder 10 having a protrusion capable of restricting the position of the folded back portion of the cloth from its side surface, and an upper holder 10 which itself has elasticity in the cloth pressing direction; And a guide member (25, 26) that is pressed against and is pulled in a direction away from both holders.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an airbag that protects an occupant from an impact by expanding when a vehicle such as an automobile collides, and more particularly, to a sewing device for a bottom stitch of an airbag having a complicated shape.

[0002]

[Prior Art]

 In recent years, as a cushioning system that supports a seat belt device for safely holding a vehicle occupant in a seat, in the event of a collision, the occupant's body, especially the head and chest, is received by a balloon-shaped airbag, and then the interior Airbags have been put into practical use, which gradually release the gas of the above to obtain a buffer stroke and to suppress the impact force applied to the human body.

In an airbag of this type, for example, in an emergency such as a vehicle collision, the passenger seat bag has a pressure of a reaction gas released from an inflator fixed to an instrument panel or other vehicle body fixing portion. It instantly expands, and plays an important role in avoiding collision of passengers with the vehicle body. By the way, since the above-mentioned airbag has an extremely important role of protecting the occupant as described above from its original purpose, when it is inflated, not only its strength but also its shape is used. It is required to have a shape suitable for the place to be used. Therefore, in order to satisfy this demand, an airbag is constructed by stitching a plurality of pieces of cloth which are quite durable to obtain a desired shape. Further, since the air bag is rapidly expanded by the gas generated by the inflator, its function is greatly influenced by the relationship between the gas generated and the airbag volume. That is, whether or not the volume of the airbag reaches the set value extremely accurately has a great influence on the impact absorbing action.

For these reasons, when sewing airbags, the positioning and seam allowance of the cloth pieces to be sewn at the time of sewing directly affect the shape and volume of the airbag when it is inflated, and affect the operating effect of the airbag. It had to be very careful because it would have a big impact. Therefore, even if a relatively simple piece of cloth, such as an airbag set in the center of the steering wheel, whose shape is almost a circle, an ellipse, or an ellipse is sewn, it is extremely difficult to perform completely automatic sewing. was difficult.

Furthermore, the airbag on the passenger side is considerably more complicated than the airbag on the driver's side even in the shape of the airbag, and the size is also large, so it was very difficult to sew. That is, it is desirable that the passenger side airbag has a shape that fits to the front side vehicle interior wall surface of the passenger seat when it is inflated, and therefore has an asymmetric shape in the up and down directions. Furthermore, since a large space is formed between the instrument panel and front windshield and the passenger seat, it is necessary to have a size that fills this space, and usually three or more sheets are used. In order to reliably produce the operating effect of the airbag when the airbag is manufactured by sewing the cloth pieces together, extremely accurate sewing is required for the reasons described above.

As shown in FIG. 5 in which the airbag 40 is turned upside down, a pair of lateral side cloth pieces 42, 43 in the left-right direction and a front cloth piece 41 are sewn by a lock stitch (also double chain stitches may be used). It is sewn together to form a bag. Here, in the state where the cloth pieces are connected by the suture thread 45, the suture area is in a state in which the tip end side 50 on the cloth end side of the suture thread 45 is projected from the cloth as shown in FIG. A bag-shaped prototype of the airbag 40 is produced. In this state, since only the suture thread 45 is sewn together, the connecting strength is not sufficient. Therefore, the bottom stitching is performed so that the tip portion 50 is sewn so as to lie along one of the cloths. For example, as shown in FIG. 7, this bind-off stitch is sewn with two bind-off stitch sutures 46 so that the tip end portion 50 is bent. As shown in FIG. 8, the airbag 40 can be turned upside down, and after this sewn-in stitch, the airbag 40 can be mounted at a predetermined position. Here, the number of the suture stitches 46 for sewn-off stitch is two, but of course, this may be one. The bind-up sewing does not necessarily have to be performed after the prototype of the airbag 40 is made, and may be performed each time the front cloth piece 41 and the side cloth piece on one side are sewn together.

In the above-described sewing work, since the side cloth pieces 42, 43 and the front cloth piece 41 are largely different in shape, not only is it extremely difficult to perform automatic sewing in terms of positioning of the sewn portion, etc. , Especially when sewing one side cloth piece after sewing the other side cloth piece, one side cloth piece and the front cloth piece are sewn together, so the cloth shape to be handled has a three-dimensional shape to some extent. Due to the complicated shape, it requires a high level of skill to perform this sewing work accurately, and relied heavily on manual work. Furthermore, in the case of bottom stitching, the already sewn portion is further sewn as described above, and it is very difficult to operate the fabric at the time of sewing, and accurate sewing is required.

[0008]

[Problems to be solved by the device]

 As described above, in the conventional airbag manufacturing, a high precision is required for the sewing work, so that it takes time and a lot of time is required for the manufacturing. In addition, the skill of the operator is required so that the quality does not vary due to the manual work. However, since the sewn-on portion is made to bend the fabric, the thickness of the fabric is thicker than other portions, and in the conventional sewing device, the pressing of the fabric at the needle drop portion is not stable. , Cloth feeding was very difficult. This is because the structure of the cloth feed at the needle drop section is usually determined by the vertical movement and back-and-forth movement of the feed fitting on the sewing machine head, and the feed dog on the sewing table side that operates in accordance with the feed fitting. Since the holding and the releasing are repeated, it is difficult to push and open the cloth in the sewing area in a direction intersecting the cloth feeding direction. In other words, since the state of holding the bind-off stitch part is intermittently opened, the bind-off stitch part is misaligned due to an error in the adjustment of the pushing force, and it is easy for the stitch position shift to occur. In particular, when sewing cloth pieces that differ greatly in shape as described above, the stitching position is adjusted by adjusting the buckling, so the substantial change in the fabric thickness at the sewn section is large and To maintain the accuracy of sewing, passive measures such as slowing down the sewing speed were taken. However, it was not possible to hope for productivity improvement with such passive measures.

For this reason, in the conventional sewing method, at least one worker is required for one sewing device, which is a major factor in the high production cost. Further, if the shape of the airbag becomes complicated, it is difficult to increase productivity because the size and shape of the fabric to be sewn greatly differ, and even if the shape is the same as in the passenger airbag, it is difficult to improve the productivity. The production cost of vehicles that differ greatly depending on the type of vehicle was extremely high due to poor productivity related to the total number of vehicles produced. This high cost created the current situation of limiting the types of vehicles that can be equipped with this airbag to high-end vehicles. Therefore, it has been earnestly desired to solve the problem of high manufacturing cost.

In view of the above-mentioned circumstances, the problem of the present invention is to be able to extremely accurately and quickly perform the bind-off stitching of the part where the cloths having greatly different shapes are sewn together, and to produce a highly reliable airbag. An object of the present invention is to provide a sewing device for face-down sewing.

[0011]

[Means for Solving the Problems]

 The above-mentioned problem of the present invention is to fabricate an airbag, which is sewn with at least a front cloth piece and a pair of side cloth pieces having substantially the same shape, after the cloth pieces are sewn together. In the sewing machine for sewn seams, which sews so as to bend along the cloth ground, position the sewing end on the sewing table side upstream of the needle drop section and hold the cloth folded back on the upper surface. A lower holder that is made possible and an upper portion that has elasticity in the cloth pressing direction and that has a protrusion that can hold the cloth from above the lower holder and regulate the position of the folded portion of the cloth from its side surface. The sewing machine for the bottom stitch of an airbag, comprising: a holder; and a guide member that presses the cloth against the sewing table in the left and right areas of both holders and pulls the cloth in a direction away from the holders. To Ri can be achieved to.

[0012]

[Work]

 According to this invention, the guide members arranged in a direction intersecting the cloth feed direction (direction opening in a V shape) can push the cloth open in the bind-off sewing area, and at the same time, can lower the lower holder and the upper holder. The projections can firmly hold the bind-off stitch in a folded state, so that the shift in the bind-off stitch can be prevented. Further, since the upper holder itself has elasticity in the fabric pressing direction, even when the feeding metal fitting and the feed dog of the sewing portion are separated from each other, the bind-off sewing portion is constantly pressed against the sewing table side. Therefore, it is possible to stabilize the retention of the binding stitch.

[0013]

【Example】

 Hereinafter, one embodiment of the present invention will be described in detail. FIG. 1 is a perspective view of an essential part of a sewing device for sewn-down an airbag according to the present invention. This sewing device is used for sewing an airbag having a shape as shown in FIG. 5, for example. FIG. 2 is a cross-sectional arrow view of a portion of the apparatus shown in FIG. 1 taken along the line C-C, showing a state in which the upper holder is not pressing the cloth. FIG. 3 is a cross-sectional arrow view of the portion of the apparatus shown in FIG. 1 taken along the line C-C, showing a state in which the upper holder holds the cloth.

The sewing device 100 shown in FIG. 1 includes a needle bar 1 having two sewing needles 2 at the tip of a sewing machine head (not shown), a support bar 3 extending in parallel with the needle bar 1 and pressing of the tip thereof. A metal fitting made of gold 4 is attached. An upper holder 10 for pressing the cloth from above is attached to the support rod 3. Further, the sewing machine head is provided with a pair of pressing rollers 25 and 26 so as to be vertically movable at a position sandwiching the stitched portion. On the other hand, the sewing table 20 is provided with a rack-shaped feed dog 6 at a position facing the presser foot 4 as in the conventional case, and the feed tooth 6 cooperates with the presser foot 4 to correspond to sewing. Can be sent out in a predetermined direction. Further, on the front side of the feed dog 6, there is provided a lower holder 21 for pressing the tip end portion 50 of the bind-off stitch portion toward the sewing table 20 side. The lower holder 21 has an overhanging portion 22 formed at its upper end extending substantially parallel to the surface of the sewing table 20. The sewn portion is laid in the gap formed by the overhanging portion 22 and the sewing table 20. It is possible to hold the tip portion 50 of the.

The above-mentioned upper holder 10 has a mounting portion 11 fixed to the supporting column 3 with a screw 5 or the like in a portion parallel to the supporting column 3, and a substantially right angle (substantially horizontal) bending from the mounting portion 11 to the front side. (An upstream side in the cloth feeding direction) and an inclined portion 12 that extends downwardly, a tip portion 13 of the inclined portion 12 that extends horizontally above the lower holder 21, and a holding portion. The lower surface of the lower holder 13 has a protrusion 14 protruding to a position close to the protruding portion 22 of the lower holder 21. Further, the tip 15 of the pressing portion 13 is bent upward so that the cloth can be easily introduced under the pressing portion 13 when the cloth is fed (in the direction of arrow D).

The pressing rollers 25 and 26 are guide members according to the present invention, and are arranged so as to sandwich the sewn portion as described above. The direction of the pressing rollers is the moving direction of the cloth (D direction). With respect to each other, they are oriented so as to open each other, which is a so-called C-shape. The press rollers 25 and 26 are supported by cylinders 25a and 26a so as to be movable up and down. When the cloth is sewn, the press rollers 25 and 26 are lowered to clamp the cloth between the pressing rollers 25 and 26 and the sewing table 20. Therefore, when the pressing rollers 25 and 26 elastically press the cloth at the time of sewing, the rollers 25 and 26 rotate due to the movement of the cloth, and the cloth is moved in the directions inclined (the arrow E direction and the arrow F direction). Pull the fabric. That is, the cloth can be pressed against the sewing table 20 in the left and right regions of the both holders 10 and 21, and the cloth can be guided so as to be pulled away from the holders. It should be noted that other guide means, such as air blows provided before and after the stitching area, may be used as an aid for feeding the cloth.

The stitching by the sewing device 100 having the above configuration will be described. The cloth in the state where the side cloth piece 42 and the front cloth piece 41 shown in FIG. 4 are sewn with the lock stitch suture thread 45 is set on the sewing table 20 as shown in FIG. That is, the end portion 50 of the cloth is placed so as to be inserted below the overhang portion 22. After that, by moving the pressing metal fitting downward (in the direction of arrow G), the vicinity of the folded-back portion 41a of the front cloth piece 41 is elastically moved by the lower holder 21 and the pressing portion 13 of the upper holder 10, as shown in FIG. The folded-back portion 41a and the side surface cloth piece 42 are pressed by the protrusion 14. Further, the pressing rollers 25 and 26 also press the cloths on both sides of the sewn portion by operating the cylinders 25a and 26a and lowering them.

After that, when sewing is started, the fabric is pulled by the presser bar 4 and the feed dog 6 while the tip 50 is held by the holders 10 and 21, and the fabric is fed (in the direction of arrow D). ) Is performed, the suture is performed with the bind-off suture thread 46. At this time, the pressing roller 25, which is a guide member arranged in a direction intersecting the cloth feeding direction, pulls the side cloth piece 42, and the pressing roller 26 pulls the front cloth piece 41 in an oblique direction. Being held by 21, it acts to push open the fabric in its sewn area.

As the cloth is pulled by the pressing rollers 25 and 26 in this manner, the cloth can be sewn in a desired folded state at the needle drop portion without a cloth jam or the like. Therefore, it is possible to prevent the displacement of the bind-off stitch. Further, since the upper holder 10 itself has elasticity (elasticity indicated by arrow H) in the fabric pressing direction, even when the feed fitting of the suture portion and the feed dog 6 are separated from each other, the bottom stitched portion is Since it can be constantly pressed down to the sewing table side, the shape of the bottom seam does not collapse, and accurate seams without variations in the seam allowances and deviations in the seams are possible, enabling high-quality seams to be sewn quickly. ..

The present invention is not limited to the above-mentioned embodiment, but can be variously modified. The shape and size of the lower holder 21 and the upper holder 10 can be appropriately changed according to the thickness of the cloth and the size of the bottom stitch. For example, as shown in FIG. It is possible to make the pressing force of the pressing portion 13 against the fabric uniform and to increase the pressing force by making it into a square shape having a fixing portion. The other members in FIG. 4 are the same as those in the configuration shown in FIG.

Further, the upper holder 10 is detachable, and different upper holders can be attached according to its use, while the lower holder 21 is detachable so that various bottom stitch shapes can be easily achieved. Therefore, the versatility of the sewing device can be improved. In the above embodiment, the pressing rollers 25 and 26 are provided in a pair, but the number is not limited to this, and the number may be further increased, or the pressing rollers may be driven. Although the above embodiment has described the passenger airbag, the present invention is not limited to this and can be applied to various airbags.

[0022]

[Effect of the device]

 As described above, according to the present invention, the lower holder and the protrusions of the upper holder can firmly hold the sewn-up portion in the folded state, and the guide members arranged in the direction intersecting with the cloth feeding direction can be used. Since it can be pushed open in the bind-off area, it is possible to automatically perform sewing without the shape of the bind-off sewing portion and the stitch position deviation. Also, since the upper holder itself has elasticity in the fabric pressing direction, even when the feed metal fitting and the feed dog of the stitching part are separated, the bind-off sewing part should always be pressed against the sewing table side. Since it is possible to securely hold the bind-over stitch part. Therefore, unlike the conventional method, the sewn seam does not need to rely on a skilled worker and can be performed almost automatically, so that the productivity of the airbag can be significantly improved. Since it is possible to perform various sewing operations in an extremely short time, it is possible to improve the quality of the airbag, significantly improve the productivity, and reduce the cost.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of a sewing device for bind-down sewing of an airbag according to the present invention.

FIG. 2 is a cross-sectional arrow view of a portion of the apparatus shown in FIG. 1 taken along the line C-C, showing a state in which the upper holder is not pressing the cloth.

FIG. 3 is a cross-sectional arrow view of a portion of the apparatus shown in FIG. 1 taken along the line C-C, showing a state where the upper holder holds down the cloth.

FIG. 4 is a partial perspective view showing an essential part of another embodiment of the present invention.

FIG. 5 is a perspective view showing a shape of the airbag in an inflated state.

FIG. 6 is a cross-sectional view of a portion taken along the line AA in FIG. 5, showing a state before bind-off sewing.

7 is a sectional view of a portion taken along the line BB in FIG. 8, showing a state after bind-off sewing.

FIG. 8 is a perspective view showing the shape of the airbag after it is sewn up and inflated.

[Explanation of symbols]

 1 Needle bar 2 Sewing needle 3 Support bar 4 Presser foot 5 Screw 6 Feed dog 10 Upper holder 11 Fixed part 12 Inclined part 13 Holding part 14 Protrusion 15 Tip part 20 Sewing table 21 Lower holder 22 Overhanging part 25, 26 Holding roller 25a, 26a Cylinder 42, 43 Side cloth piece 45 Suture thread for lock stitch 46 Suture thread for bind-off stitch 50 Tip part of bind-off stitch portion 100 Sewing device

Claims (1)

[Scope of utility model registration request] 1. When manufacturing an airbag formed by sewing at least a front cloth piece and a pair of side cloth pieces having substantially the same shape, the cloth stitching end portion is made to follow the cloth ground after the seaming of the cloth pieces. In a sewing device for bind-off sewing that sews in a reflexive manner, a lower holder capable of holding the folded cloth on the upper surface of the stitching end portion at the upstream side of the needle drop portion while restricting the position on the sewing table side, An upper holder having a protrusion capable of pressing the cloth from above the lower holder and controlling the position of the folded portion of the cloth from its side surface, and an upper holder having elasticity in the cloth pressing direction, and both left and right sides of the holders. And a guide member that pushes the cloth against the sewing table in the area of 1 and pulls the cloth in a direction away from the holders.